bluuebunny/crossref_metadata_2025 huggingface dataset:
Semi-automated application for estimating subthalamic nucleus boundaries and optimal target selection for deep brain stimulation implantation surgery
Authors: Thompson John A. , Oukal Salam , Bergman Hagai , Ojemann Steven , Hebb Adam O. , Hanrahan Sara , Israel Zvi , Abosch Aviva
Published: May 2018

OBJECTIVE

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) has become standard care for the surgical treatment of Parkinson’s disease (PD). Reliable interpretation of microelectrode recording (MER) data, used to guide DBS implantation surgery, requires expert electrophysiological evaluation. Recent efforts have endeavored to use electrophysiological signals for automatic detection of relevant brain structures and optimal implant target location.

The authors conducted an observational case-control study to evaluate a software package implemented on an electrophysiological recording system to provide online objective estimates for entry into and exit from the STN. In addition, they evaluated the accuracy of the software in selecting electrode track and depth for DBS implantation into STN, which relied on detecting changes in spectrum activity.

METHODS

Data were retrospectively collected from 105 MER-guided STN-DBS surgeries (4 experienced neurosurgeons; 3 sites), in which estimates for entry into and exit from the STN, DBS track selection, and implant depth were compared post hoc between those determined by the software and those determined by the implanting neurosurgeon/neurophysiologist during surgery.

RESULTS

This multicenter study revealed submillimetric agreement between surgeon/neurophysiologist and software for entry into and exit out of the STN as well as optimal DBS implant depth.

CONCLUSIONS

The results of this study demonstrate that the software can reliably and accurately estimate entry into and exit from the STN and select the track corresponding to ultimate DBS implantation.
Aspirin for primary prevention of stroke in traumatic cerebrovascular injury: association with increased risk of transfusion
Authors: Griffin Russell L. , Falatko Stephanie R. , Aslibekyan Stella , Strickland Virginia , Harrigan Mark R.
Published: May 2018

OBJECTIVE

Blunt traumatic extracranial carotid or vertebral artery injury (i.e., traumatic cerebrovascular injury [TCVI]) occurs in 1%–2% of all blunt trauma admissions, carries a 10% risk of thromboembolic ischemic stroke, and accounts for up to 9600 strokes annually in the US. Screening CT angiograms (CTAs) of patients with trauma has become ubiquitous in recent years, and patients with initially asymptomatic TCVI are commonly treated with antiplatelet agents to prevent stroke. Prophylaxis with antiplatelets is thought to be safer than anticoagulation, which carries a significant risk of hemorrhage in patients with trauma. However, the risk of hemorrhagic complications due to antiplatelets has not been assessed in this population.

METHODS

This is a retrospective cohort study of patients in whom a screening CTA was obtained after admission for blunt trauma at a Level 1 trauma center. Patients with CTAs indicating TCVI were treated routinely with 325 mg aspirin daily. The risk of transfusion > 24 hours after admission was compared according to CTA findings (CTA+ or CTA− for positive or negative findings, respectively) and aspirin treatment (ASA+ or ASA− for treatment or no treatment, respectively).

RESULTS

The mean overall transfusion amount (number of units of packed red blood cells [PRBCs]) was 0.9 ± 2.1 for CTA+/ASA+ patients (n = 196) and 0.3 ± 1.60 for CTA−/ASA− patients (n = 2290) (p < 0.0001). In adjusted models, the overall relative risk (RR) of PRBC transfusion was 1.70 (1.32–2.20) for CTA+/ASA+ patients compared with CTA−/ASA− patients. Among age groups, participants whose ages were 50–69 years had the greatest significantly elevated RR (1.71, 95% CI 1.08–2.72) for CTA+/ASA+ patients compared with CTA−/ASA− patients.

CONCLUSIONS

Treatment with aspirin for the prevention of stroke in patients with initially asymptomatic TCVI carries a significantly increased risk of PRBC transfusion. Future studies are needed to determine if this risk is offset by a reduced risk of ischemic stroke.
The economic consequences of neurosurgical disease in low- and middle-income countries
Authors: Rudolfson Niclas , Dewan Michael C. , Park Kee B. , Shrime Mark G. , Meara John G. , Alkire Blake C.
Published: May 2018

OBJECTIVE

The objective of this study was to estimate the economic consequences of neurosurgical disease in low- and middle-income countries (LMICs).

METHODS

The authors estimated gross domestic product (GDP) losses and the broader welfare losses attributable to 5 neurosurgical disease categories in LMICs using two distinct economic models. The value of lost output (VLO) model projects annual GDP losses due to neurosurgical disease during 2015–2030, and is based on the WHO’s “Projecting the Economic Cost of Ill-health” tool. The value of lost economic welfare (VLW) model estimates total welfare losses, which is based on the value of a statistical life and includes nonmarket losses such as the inherent value placed on good health, resulting from neurosurgical disease in 2015 alone.

RESULTS

The VLO model estimates the selected neurosurgical diseases will result in $4.4 trillion (2013 US dollars, purchasing power parity) in GDP losses during 2015–2030 in the 90 included LMICs. Economic losses are projected to disproportionately affect low- and lower-middle-income countries, risking up to a 0.6% and 0.54% loss of GDP, respectively, in 2030. The VLW model evaluated 127 LMICs, and estimates that these countries experienced $3 trillion (2013 US dollars, purchasing power parity) in economic welfare losses in 2015. Regardless of the model used, the majority of the losses can be attributed to stroke and traumatic brain injury.

CONCLUSIONS

The economic impact of neurosurgical diseases in LMICs is significant. The magnitude of economic losses due to neurosurgical diseases in LMICs provides further motivation beyond already compelling humanitarian reasons for action.
Surgical treatment of middle cluneal nerve entrapment neuropathy: technical note
Authors: Matsumoto Juntaro , Isu Toyohiko , Kim Kyongsong , Iwamoto Naotaka , Morimoto Daijiro , Isobe Masanori
Published: May 2018

OBJECTIVE

The etiology of low-back pain (LBP) is heterogeneous and is unknown in some patients with chronic pain. Superior cluneal nerve entrapment has been proposed as a causative factor, and some patients suffer severe symptoms. The middle cluneal nerve (MCN) is also implicated in the elicitation of LBP, and its clinical course and etiology remain unclear. The authors report the preliminary outcomes of a less invasive microsurgical release procedure to address MCN entrapment (MCN-E).

METHODS

The authors enrolled 11 patients (13 sites) with intractable LBP judged to be due to MCN-E. The group included 3 men and 8 women ranging in age from 52 to 86 years. Microscopic MCN neurolysis was performed under local anesthesia with the patient in the prone position. Postoperatively, all patients were allowed to walk freely with no restrictions. The mean follow-up period was 10.5 months. LBP severity was evaluated on the numerical rating scale (NRS) and by the Japanese Orthopaedic Association (JOA) and the Roland-Morris Disability Questionnaire (RDQ) scores.

RESULTS

All patients suffered buttock pain, and 9 also had leg symptoms. The symptoms were aggravated by standing, lumbar flexion, rolling over, prolonged sitting, and especially by walking. The numbers of nerve branches addressed during MCN neurolysis were 1 in 9 patients, 2 in 1 patient, and 3 in 1 patient. One patient required reoperation due to insufficient decompression originally. There were no local or systemic complications during or after surgery. Postoperatively, the symptoms of all patients improved statistically significantly; the mean NRS score fell from 7.0 to 1.4, the mean RDQ from 10.8 to 1.4, and the mean JOA score rose from 13.7 to 23.6.

CONCLUSIONS

Less invasive MCN neurolysis performed under local anesthesia is useful for LBP caused by MCN-E. In patients with intractable LBP, MCN-E should be considered.
Pyk2 is a Novel Tau Tyrosine Kinase that is Regulated by the Tyrosine Kinase Fyn
Authors: Li Chuanzhou , Götz Jürgen
Published: May 2018

The protein tyrosine kinase Pyk2 is encoded by PTK2B, a novel Alzheimer’s disease (AD) susceptibility variant, with the PTK2B risk allele being associated with increased mRNA levels, suggestive of increased Pyk2 levels. However, the role of Pyk2, a member of the focal adhesion kinase (FAK) family, in AD pathology and its regulation are largely unknown. To address this, we generated mice with neuronal expression of human Pyk2. Because we had previously reported an association of Pyk2 and hyperphosphorylated tau (a hallmark feature of AD) in human tau transgenic pR5 mice, we also generated Pyk2/tau double-transgenic mice, which exhibit increased tyrosine phosphorylation and accumulation of tau. We further demonstrated that Pyk2 colocalizes, interacts with, and phosphorylates tau in vivo and in vitro. Importantly, although Pyk2 interacts with the established tyrosine-directed tau kinase Fyn, we identified an increased Pyk2 activity in mice which constitutively overexpress Fyn (FynCA), and a decreased activity in mice lacking Fyn (FynKO). Together, our study reveals a novel role for Pyk2 as a direct tyrosine kinase of tau that is active downstream of Fyn. Our analysis may enhance the understanding of how the PTK2B risk allele contributes to tauopathy.
Cathodoluminescence as a probe of the optical properties of resonant apertures in a metallic film
Authors: Singh Kalpana , Panchenko Evgeniy , Nasr Babak , Liu Amelia , Wesemann Lukas , Davis Timothy J , Roberts Ann
Published: May 2018

Here we present the results of an investigation of resonances of azimuthal trimer arrangements of rectangular slots in a gold film on a glass substrate using cathodoluminescence (CL) as a probe. The variation in the CL signal collected from specific locations on the sample as a function of wavelength and the spatial dependence of emission into different wavelength bands provides considerable insight into the resonant modes, particularly sub-radiant modes, of these apertures. By comparing our experimental results with electromagnetic simulations we are able to identify a Fabry–Pérot mode of these cavities as well as resonances associated with the excitation of surface plasmon polaritons on the air–gold boundary. We obtain evidence for the excitation of dark (also known as sub-radiant) modes of apertures and aperture ensembles.
DOES REVERSE CAUSALITY EXPLAINS THE RELATIONSHIP BETWEEN ECONOMIC PERFORMANCE AND TECHNOLOGICAL DIVERSITY?
Authors: MOANIBA Igam M. , SU Hsin-Ning , LEE Pei-Chun
Published: May 2018

Previous studies have highlighted technological innovation as a key instrument for economic development. However, although the relationship between innovation and economic growth has been extensively explored, few studies have investigated the impacts of crucial dimensions of innovation on economic growth. This paper presents one of the first empirical attempts to analyze how the “diversity” aspect of technological progress (or innovation) influences economic performance by considering the possible bidirectional causal effects between these two factors. A series of econometric techniques, including a two-stage-least-squares instrumental variable and dynamic autoregressive distributed lag model, are applied on a dataset of 55 countries. The dataset includes patent data from the United States Patent and Trademark Office and combined macroeconomic data from the World Bank’s development indicators and International Monetary Fund’s economic outlook databases. The results show that generally, technological diversity does not directly affect economic growth. By contrast, a negative effect of diversity on GDP per capita is observed in non-high-income countries. This study contributes to the macroeconomics and innovation management literature by providing an integrated empirical application of various popular firm management theories and a well-known endogenous economic growth theory.
The Origin of the Milky Way's Halo Age Distribution
Authors: Carollo Daniela , Tissera Patricia B. , Beers Timothy C. , Gudin Dmitrii , Gibson Brad K. , Freeman Ken C. , Monachesi Antonela
Published: May 2018

We present an analysis of the radial age gradients for the stellar halos of five Milky Way (MW) mass-sized systems simulated as part of the Aquarius Project. The halos show a diversity of age trends, reflecting their different assembly histories. Four of the simulated halos possess clear negative age gradients, ranging from approximately −7 to −19 Myr kpc−1, shallower than those determined by recent observational studies of the Milky Way’s stellar halo. However, when restricting the analysis to the accreted component alone, all of the stellar halos exhibit a steeper negative age gradient with values ranging from −8 to −32 Myr kpc−1, closer to those observed in the Galaxy. Two of the accretion-dominated simulated halos show a large concentration of old stars in the center, in agreement with the Ancient Chronographic Sphere reported observationally. The stellar halo that best reproduces the current observed characteristics of the age distributions of the Galaxy is that formed principally by the accretion of small satellite galaxies. Our findings suggest that the hierarchical clustering scenario can reproduce the MW’s halo age distribution if the stellar halo was assembled from accretion and the disruption of satellite galaxies with dynamical masses less than ∼109.5
M
☉, and a minimal in situ contribution.
A Globular Cluster Luminosity Function Distance to NGC 4993 Hosting a Binary Neutron Star Merger GW170817/GRB 170817A
Authors: Lee Myung Gyoon , Kang Jisu , Im Myungshin
Published: May 2018

NGC 4993 hosts a binary neutron star merger, GW170817/GRB 170817A, emitting gravitational waves and electromagnetic waves. The distance to this galaxy is not well established. We select the globular cluster candidates from the Hubble Space Telescope (HST)/ACS F606W images of NGC 4993 in the archive, using the structural parameters of the detected sources. The radial number density distribution of these candidates shows a significant central concentration around the galaxy center at the galactocentric distance r < 50″, showing that they are mostly the members of NGC 4993. Also, the luminosity function of these candidates is fit well by a Gaussian function. Therefore, the selected candidates at r < 50″ are mostly considered to be globular clusters in NGC 4993. We derive an extinction-corrected turnover Vega magnitude in the luminosity function of the globular clusters at 20″ < r < 50″, F606W (max)0 = 25.36 ± 0.08 (V
0 = 25.52 ± 0.11) mag. Adopting the calibration of the turnover magnitudes of the globular clusters, M

V
(max) = −7.58 ± 0.11, we derive a distance to NGC 4993, d = 41.65 ± 3.00 Mpc (

). The systematic error of this method can be as large as ±0.3 mag. This value is consistent with the previous distance estimates based on the fundamental plane relation and the gravitational wave method in the literature. The distance in this study can be used to constrain the values of the parameters including the inclination angle of the binary system in the models of gravitational wave analysis.
Rester vivant à l’aube de la mort. Clinique du quotidien en ehpad
Authors: Fourques Catherine
Published: May 2018

L’ ehpad , à mi-chemin entre le soin et le domicile, provoque immanquablement une inquiétante étrangeté pour tout visiteur qui en franchit le seuil. La confrontation à la grande vieillesse, à la maladie, à la mort bouleverse et dérange. Comment reconnaître son père, son épouse dans ce corps vulnérable où la subjectivité s’estompe sous le poids de la maladie démentielle ? En référence aux travaux de P. Fédida sur l’humain et le non-humain, l’auteure tente de montrer en quoi le quotidien participe d’un travail de ré-humanisation auprès des résidants et de leurs proches. Mêlé à un savoir être soignant créatif, le quotidien, tel un espace transitionnel, délimité par les gestes anodins et familiers, joue alors un rôle de catalyseur de liens, soutenu par le regard contenant du psychologue.
Éloge de l’ordinaire et du quotidien
Authors: Coblence Françoise
Published: May 2018

Le psychanalyste ne peut que s’intéresser à l’ordinaire et au quotidien, qui est à la fois le banal et ce qui est commun aux hommes. Ce fut le cas de S. Freud avec la psychopathologie de la vie quotidienne. Et depuis le xix e  siècle, la littérature et les sciences humaines ont procédé à une réévaluation de l’ordinaire, voire de l’infra-­ordinaire (Perec), dont la description minutieuse a à la fois une valeur anthropologique et poétique.
Legal vs. economic explanations of the rise in bankruptcies in 19th century France
Authors: Hautcoeur Pierre-Cyrille , Levratto Nadine
Published: May 2018

Ce texte cherche à expliquer l’évolution du nombre de faillites au cours de la seconde partie du XIXe siècle et le début du XXe. Il propose une explication qui reprend les évolutions de la loi mais introduit également une dimension spatiale. On constate en effet que le tribunal de commerce de la Seine est moins « sévère » que les tribunaux de province et que ses pratiques se diffusent vers les autres régions jusqu’à la réforme de 1889 qui introduit la liquidation judiciaire. Au total, il apparaît que l’évolution des textes légaux est loin d’expliquer l’évolution des faillites. Les pratiques locales, les usages de la loi par les acteurs de la justice et les transformations des entreprises constituent également des déterminants importants.
Le financement des entreprises industrielles par leurs actionnaires : étude empirique d’un corpus de sociétés lyonnaises (1921-1953)
Authors: Joly Hervé
Published: May 2018

Qu’apportent les actionnaires au financement d’une entreprise ? Quel ratio s’établit entre les dividendes versés et les souscriptions d’actions en numéraires ? Que change le fait qu’une entreprise fasse appel au public, que ses actions soient cotées en bourse ? Une étude systématique des déclarations de souscription des sociétés par actions exploitant 150 entreprises industrielles ayant eu leur siège dans l’arrondissement de Lyon dans la période 1921-1953 apporte des réponses inédites. Les résultats présentent un fort caractère conjoncturel : ce n’est que dans les périodes de prospérité que les émissions publiques sont possibles, et peuvent alors, comme dans les années 1920, contribuer à la croissance spectaculaire de certaines entreprises. L’introduction en bourse qui suit sert souvent moins à apporter de nouveaux capitaux qu’à rendre le capital plus liquide pour les nouveaux actionnaires.
T Cell Proliferation and Colitis Are Initiated by Defined Intestinal Microbes
Authors: Chiaranunt Pailin , Tometich Justin T. , Ji Junyi , Hand Timothy W.
Published: May 2018

Inflammatory bowel disease has been associated with the dysregulation of T cells specific to Ags derived from the intestinal microbiota. How microbiota-specific T cells are regulated is not completely clear but is believed to be mediated by a combination of IgA, regulatory T cells, and type 3 innate lymphoid cells. To test the role of these regulatory components on microbiota-specific T cells, we bred CBir1 TCR transgenic (CBir1Tg) mice (specific to flagellin from common intestinal bacteria) onto a lymphopenic Rag1−/− background. Surprisingly, T cells from CBir1Tg mice bred onto a Rag1−/− background could not induce colitis and did not differentiate to become effectors under lymphopenic conditions, despite deficits in immunoregulatory factors, such as IgA, regulatory T cells, and type 3 innate lymphoid cells. In fact, upon transfer of conventional CBir1Tg T cells into lymphopenic mice, the vast majority of proliferating T cells responded to Ags other than CBir1 flagellin, including those found on other bacteria, such as Helicobacter spp. Thus, we discovered a caveat in the CBir1Tg model within our animal facility that illustrates the limitations of using TCR transgenics at mucosal surfaces, where multiple TCR specificities can respond to the plethora of foreign Ags. Our findings also indicate that T cell specificity to the microbiota alone is not sufficient to induce T cell activation and colitis. Instead, other interrelated factors, such as the composition and ecology of the intestinal microbiota and host access to Ag, are paramount in controlling the activation of microbiota–specific T cell clones.
A variational level set method image segmentation model with application to intensity inhomogene magnetic resonance imaging
Authors: Li Chun , Su Jinhe , Yu Longlong , Wang Le , Ze Luo
Published: May 2018

ABSTRACT

Background and Objectives:

In this article, we propose an image segmentation model based on Chan-Vese (CV) for image segmentation. By taking into account the local features of the image, the new proposed model can successfully segment images with intensity nonuniformity.

Materials and Methods:

We quantitatively compare our method with other two state-of-the-art algorithms, namely, CV model and local binary fitting (LBF) model in segmenting synthetic MR images with the ground truth from BrainWeb; the data can be available at: https://www.mni/mcgill.ca/brainweb/. For segmenting the missing and weak boundaries, to deal with the intensity inhomogeneity, based on the LBF model, we introduced the convex total variation regularization term, for explicit smoothing of the level set function ø. The evolution equation will be solved through the level set method of calculus of variations.

Results:

In the experimental processing, we use some real images and magnetic resonance imaging brain images as the experimental images, to validate the stabilization of algorithm. The experimental results on comprehensive and sincerity images show the outstanding of our proposed model with reference to stabilization and availability.

Conclusions:

We propose a new segmentation local information of an image and introduce a new regularization functional is to keep the level set function smooth. Finally, various experimental results on real and low-contrast image, showing which is a powerful type of images, including some that would be difficult to segment with gradient-based methods. In addition, the advantages of the proposed model are better than CV model and the LBF model. Our new model can effectively segment a real image.
Digital medicine: Emergence, definition, scope, and future
Authors: Zhang Shaoxiang , Liao Rongxia , Alpert Joseph S. , Kong Jiming , Spetzger Uwe , Milia Paolo , Thiriet Marc , Wortley David John
Published: May 2018

Shaoxiang Zhang, Ph.D., M.D., designed and founded the journal of Digital Medicine as editor-in chief. At Digital Medicine, Dr. Zhang's responsibilities include oversight of all editorial content and policies. His editorial background includes service as an editor-in-chief or associate editor or editorial board member for 15 academic journals including Clinical Anatomy, PLoS ONE, Chinese Journal of Regional Anatomy, Chinese Journal of Anatomy and Clinical Anatomy. A famous specialist in digital medicine and human anatomy, Dr. Zhang maintains an active research program. He is the principal investigator of the Chinese Visible Human Project, and more than 20 scientific projects else supported by National Science Foundation of China, including several key grant projects. He is a recipient of the National Science Fund for Distinguished Young Scholars of China, and the “National Excellent Talent”. Dr. Zhang has published more than 400 articles (over 60 are published in worldwide reputed SCI journals) and 21 books on topics such as human anatomy and digital medicine. His publications have received more than 2800 citations. In 2005, he was invited to deliver the keynote speech on the Chinese Visible Human Project at the 4th Joint Meeting of the American Association of Clinical Anatomists and the British Association of Clinical Anatomists. He won the second prize of National Science and Technology Progress Award twice (in 2001 and 2007) for his contributions to the study of hand surgery and to the study of digital human dataset and its application, respectively. Dr. Zhang is the Distinguished Professor of digital medicine at the Institute of Digital Medicine and professor of human anatomy at the College of Basic Medicine of the Third Military Medical University. He took the lead to establish a digital-human-based anatomy teaching system and promote Digital Medicine to emerge as a new interdiscipline in China. Dr. Zhang has served as a leading scientist in numerous academic societies and committees, including the Chinese Society for Anatomical Sciences, Chinese Society of Digital Medicine, Discipline Appraisal Group of the Academic Degree Committee of the State Council, Expert Committee of Human Anatomy and Digital Anatomy in China, Chongqing Association of Digital Medicine and Chongqing Institute of Artificial Intelligence. Dr. Zhang received his medical degree from the Third Medical Military University. He had been the former Vice President of the Third Military Medical University (2006-2013). He has been the chairman of the Chinese Society for Anatomical Sciences since 2014 and the chairman of the Chinese Society of Digital Medicine since its foundation in 2011.
Power Cylinder Friction: Mechanisms
Authors:   Piston and Ring Standards Committee
Published: May 2018

This document covers the mechanisms from the power cylinder which contribute to the mechanical friction of an internal combustion engine. It will not discuss in detail the influence of other engine components or engine driven accessories on friction.
Brake Rotor Thermal Cracking Procedure for Vehicles Below 4 540 kg GVWR
Authors:   Brake Dynamometer Standards Committee
Published: May 2018

This recommended practice is derived from common test sequences used within the industry. This procedure applies to all on-road passenger cars and light trucks up to 4 540 kg of GVWR. This recommended practice does not address other aspects such as performance, NVH, and durability. Test results from this recommended practice should be combined with other measurements and dynamometer tests (or vehicle-level tests), and acceptance criteria to validate a given design or configuration.
Comparison of accelerometer data calibration methods used in thermospheric neutral density estimation
Authors: Vielberg Kristin , Forootan Ehsan , Lück Christina , Löcher Anno , Kusche Jürgen , Börger Klaus
Published: May 2018

Abstract. Ultra-sensitive space-borne accelerometers on board of low Earth orbit (LEO) satellites are used to measure non-gravitational forces acting on the surface of these satellites. These forces consist of the Earth radiation pressure, the solar radiation pressure and the atmospheric drag, where the first two are caused by the radiation emitted from the Earth and the Sun, respectively, and the latter is related to the thermospheric density. On-board accelerometer measurements contain systematic errors, which need to be mitigated by applying a calibration before their use in gravity recovery or thermospheric neutral density estimations. Therefore, we improve, apply and compare three calibration procedures: (1) a multi-step numerical estimation approach, which is based on the numerical differentiation of the kinematic orbits of LEO satellites; (2) a calibration of accelerometer observations within the dynamic precise orbit determination procedure and (3) a comparison of observed to modeled forces acting on the surface of LEO satellites. Here, accelerometer measurements obtained by the Gravity Recovery And Climate Experiment (GRACE) are used. Time series of bias and scale factor derived from the three calibration procedures are found to be different in timescales of a few days to months. Results are more similar (statistically significant) when considering longer timescales, from which the results of approach (1) and (2) show better agreement to those of approach (3) during medium and high solar activity. Calibrated accelerometer observations are then applied to estimate thermospheric neutral densities. Differences between accelerometer-based density estimations and those from empirical neutral density models, e.g., NRLMSISE-00, are observed to be significant during quiet periods, on average 22 % of the simulated densities (during low solar activity), and up to 28 % during high solar activity. Therefore, daily corrections are estimated for neutral densities derived from NRLMSISE-00. Our results indicate that these corrections improve model-based density simulations in order to provide density estimates at locations outside the vicinity of the GRACE satellites, in particular during the period of high solar/magnetic activity, e.g., during the St. Patrick's Day storm on 17 March 2015.
Teleconnection between the climates of the Polar Regions during the
last ice age
Authors: Yang Xiao , Rial Jose A.
Published: May 2018

Abstract. Understanding the well-documented differences between Greenland and Antarctica's paleoclimate proxy time series in terms of the dynamic processes connecting the two Polar Regions would help develop a quantitative theory of polar climate teleconnections. Multiple conceptual models have been proposed to explain the polar climate time series relationship, and to extend Greenland climate records based on the much longer records from Antarctica. Here we compare the most relevant conceptual models proposed to characterize inter-polar teleconnections associated with these time series. We show that the polar synchronization model, which proposes that the climates of the Polar Regions were phase synchronized over most of the last ice age, shows better overall skill across the range of parameter space under test and provides a physical explanation of the polar teleconnection as the mutual synchronization of two nonlinear, coupled oscillators. Phase synchronization results when two or more nonlinear oscillators couple (in this case the two polar climates coupled through the ocean and atmosphere) and therein adjust their (initially different) natural rhythms to a common frequency and constant relative phase. Detailed analyses presented here show that the polar synchronization is a reliable framework to support further studies of polar climate teleconnections.
Biogeochemical climatology for the Southern Benguela Upwelling System, constructed from in situ monitoring data
Authors: de Villiers Stephanie
Published: May 2018

Abstract. An annual and a seasonal biogeochemical climatology had been constructed for the Southern Benguela Upwelling System, from in situ data collected along a 12 station monitoring line, sampled at monthly intervals from 2001 to 2012. The monitoring line reaches a maximum offshore distance of almost 190 km, with monitoring station depths ranging from 27 to 1465 m. In addition to temperature, salinity and oxygen CTD profile data, archived monitoring data for the macro-nutrients (phosphate, nitrate + nitrite, silicate) and chlorophyll-a was evaluated. The climatologies exhibit clear spatial and seasonal variability patterns for all parameters, that yield important insight into the SBUS upwelling cycle. These data sets comprise valuable additions to our knowledge base, and will aid both future modelling efforts and studies of biogeochemical processes in upwelling systems. Data for the constructed climatologies have been made available via the PANGAEA Data Archiving and Publication database at http://doi.pangaea.de/10.1594/PANGAEA.882218.
Environmental conditions of a salt-marsh biodiversity experiment on the island of Spiekeroog (Germany)
Authors: Zielinski Oliver , Meier Daniela , Löhmus Kertu , Balke Thorsten , Kleyer Michael , Hillebrand Helmut
Published: May 2018

Abstract. Field experiments investigating biodiversity and ecosystem functioning require observation of abiotic parameters, especially when carried out in the intertidal zone. An experiment for biodiversity-ecosystem functioning at the intersection of land and sea was set up in the intertidal zone of the back-barrier salt marsh of Spiekeroog Island in the German Bight. Here we report the accompanying instrumentation, maintenance, data acquisition, data handling and data quality control as well as monitoring results observed over a continuous period from September 2014 through April 2017. Time series of abiotic conditions were measured at several sites in the vicinity of newly built experimental "salt-marsh islands" on the tidal flat. Meteorological measurements were conducted from a weather station (WS, doi:10.1594/PANGAEA.870988), oceanographic conditions were sampled through a bottom mounted recording current meter (RCM, doi:10.1594/PANGAEA.877265) and a bottom mounted tide and wave recorder (TWR, doi:10.1594/PANGAEA.877258). Tide data are essential to calculate flooding duration and flooding frequency with respect to different salt marsh elevation zones. Data loggers (DL) for measuring water level (DL-W, doi:10.1594/PANGAEA.877267), temperature (DL-T, doi:10.1594/PANGAEA.877257), light intensity (DL-L, doi:10.1594/PANGAEA.877256) and conductivity (DL-C, doi:10.1594/PANGAEA.877266) were deployed at different elevational zones within the experimental islands and the investigated salt marsh plots.
Building bridges between experts and the public: a comparison
of two-way communication formats for flooding and air pollution risk
Authors: Loroño-Leturiondo Maria , O'Hare Paul , Cook Simon J. , Hoon Stephen R. , Illingworth Sam
Published: May 2018

Abstract. Urban centres worldwide are adversely affected by flooding and air pollution. Better prepared citizens are crucial to limiting the impacts of these hazards, and both lay knowledge and personal experiences are important in complementing and challenging expert opinion. For the first time, this study offers a critical comparison of how different two-way communication formats have been used worldwide between experts and the public in relation to flooding and air pollution risk. Through a systematic review, we analyse social media, educational programmes, serious games, citizen science, and forums in terms of their effectiveness in respect of communicating short-term incidents, long-term awareness, and long-term knowledge in the context of flooding and air pollution risk. We find that there is neither a one-size-fits-all, nor superior, format of communication. No single format is effective in fulfilling all three communication purposes. All five formats analysed appear to be successful under different circumstances and are never representative of all segments of the population. Communication between experts and the public is difficult and full of tensions, information alone is not enough. Our study shows different ways of incorporating strategies to build trust between experts and the public and make communication more fun and accessible, breaking down hierarchies and creating safe spaces for co-creation where everyone feels empowered to participate and benefits.
Representing the majority and not the minority: the
importance of the individual in communicating climate change
Authors: Illingworth Sam , Bell Alice , Capstick Stuart , Corner Adam , Forster Piers , Leigh Rosie , Loroño Leturiondo Maria , Muller Catherine , Richardson Harriett , Shuckburgh Emily
Published: May 2018

Abstract. This research presents three case studies, through which a creative approach to developing dialogue around climate change is outlined. By working with three distinct communities and encouraging them to discuss and write poetry about how climate change affects them, we demonstrate how such an approach might be adopted at this level. By analysing the discussions and poetry that arose out of these workshops we show how this community-level approach to communicating climate change is an essential counterpart to wider-scale quantitative research. The engagement of each community with climate change is dependent on the lived experiences of their members; a failure to recognise this results in less effective communications and can also cause communities to feel isolated and helpless. By considering the individual needs and aspirations of these communities we can support effective dialogue around the topic of climate change, and in doing so can better engender positive action against the negative effects of anthropogenic climate change.
Advances in representing interactive methane in ModelE2-YIBs
(version 1.1)
Authors: Harper Kandice L. , Zheng Yiqi , Unger Nadine
Published: May 2018

Abstract. Methane (CH4) is both a greenhouse gas and a precursor of tropospheric ozone, making it an important focus of chemistry–climate interactions. Methane has both anthropogenic and natural emission sources, and reaction with the atmosphere's principal oxidizing agent, the hydroxyl radical (OH), is the dominant tropospheric loss process of methane. The tight coupling between methane and OH abundances drives indirect linkages between methane and other short-lived air pollutants and prompts the use of interactive methane chemistry in global chemistry–climate modeling. In this study, an updated contemporary inventory of natural methane emissions and the soil sink is developed using an optimization procedure that applies published emissions data to the NASA GISS ModelE2-Yale Interactive terrestrial Biosphere (ModelE2-YIBs) global chemistry–climate model. Methane observations from the global surface air-sampling network of the Earth System Research Laboratory (ESRL) of the U.S. National Oceanic and Atmospheric Administration (NOAA) are used to guide refinement of the natural methane inventory. The optimization process indicates global annual wetland methane emissions of 140 Tg CH4 y−1. The updated inventory includes total global annual methane emissions from natural sources of 181 Tg CH4 y−1 and a global annual methane soil sink of 60 Tg CH4 y−1. An interactive-methane simulation is run using ModelE2-YIBs, applying dynamic methane emissions and the updated natural methane emissions inventory that results from the optimization process. The simulated methane chemical lifetime of 10.4 ± 0.1 years corresponds well to observed lifetimes. The simulated year 2005 global-mean surface methane concentration is 1.1 % higher than the observed value from the NOAA ESRL measurements. Comparison of the simulated atmospheric methane distribution with the NOAA ESRL surface observations at 50 measurement locations finds that the simulated annual methane mixing ratio is within 1 % (i.e., +1 % to −1 %) of the observed value at 76 % of locations. Considering the 50 stations, the mean relative difference between the simulated and observed annual methane mixing ratio is a model overestimate of only 0.5 %. Comparison of simulated annual column-averaged methane concentrations with SCIAMACHY satellite retrievals provides an independent post-optimization evaluation of modeled methane. The comparison finds a slight model underestimate in 95 % of grid cells, suggesting that the applied methane source in the model is slightly underestimated or the model's methane sink strength is slightly too strong outside of the surface layer. Overall, the strong agreement between simulated and observed methane lifetimes and concentrations indicates that the ModelE2-YIBs chemistry–climate model is able to capture the principal processes that control atmospheric methane.
Assessing water supply capacity in a complex river basin under climate change
using the logistic eco-engineering decision scaling framework
Authors: Kim Daeha , Chun Jong Ahn , Choi Si-Jung
Published: May 2018

Abstract. Climate change is a global stressor that can undermine water management policies developed under the assumption of stationary climate, necessitating robust solutions to reducing the risk of system failures for uncertain future climates. While the response-surface-based assessments have provided convenience to explore responsive behaviours of expected system performance to climatic stresses, they were unable to predict the risk of system failures from individual climate projections. In this study, we proposed to use the logistic regressions for evaluating the probability of non-successive outcomes against pre-defined thresholds directly from climate projections, which may be more informative for decision making processes than the expected performances. As a case study, water supply and ecological reliabilities within a large river basin were assessed by combining the eco-engineering decision scaling framework and the logistic regressions. The impact assessment for the South Korean river basin showed that optimal water supply performance at the sub-basins were expected to be satisfactory for the upcoming 20 years of 2020–2039, while the human-demand-only operations could lower the ecological reliabilities. When considering ecological demands in water operations to reduce the ecological vulnerabilities, the stakeholders should accept increasing risks of unsatisfactory supply at the sub-basins with low demands. This study highlights that binary conversions of the performance metrics from the stress tests allow users to measure the risks of system failures varying across sub-components and standpoints with minimal computational costs.
The development and evaluation of a hydrological seasonal forecast system prototype for predicting spring flood volumes in Swedish rivers
Authors: Foster Kean , Bertacchi Uvo Cintia , Olsson Jonas
Published: May 2018

Abstract. Hydropower makes up nearly half of Sweden's electrical
energy production. However, the distribution of the water resources is not
aligned with demand, as most of the inflows to the reservoirs occur during the
spring flood period. This means that carefully planned reservoir management
is required to help redistribute water resources to ensure optimal
production and accurate forecasts of the spring flood volume (SFV) is
essential for this. The current operational SFV forecasts use a historical
ensemble approach where the HBV
model is forced with historical observations
of precipitation and temperature. In this work we develop and test a
multi-model prototype, building on previous work, and evaluate its ability
to forecast the SFV in 84 sub-basins in northern Sweden. The hypothesis
explored in this work is that a multi-model seasonal forecast system
incorporating different modelling approaches is generally more skilful at
forecasting the SFV in snow dominated regions than a forecast system that
utilises only one approach. The testing is done using cross-validated
hindcasts for the period 1981–2015 and the results are evaluated against
both climatology and the current system to determine skill. Both the
multi-model methods considered showed skill over the reference forecasts.
The version that combined the historical modelling chain, dynamical
modelling chain, and statistical modelling chain performed better than the
other and was chosen for the prototype. The prototype was able to outperform
the current operational system 57 % of the time on average and reduce the
error in the SFV by ∼ 6 % across all sub-basins and forecast
dates.
Tidal bending of ice shelves as a mechanism for large-scale temporal variations in ice flow
Authors: Rosier Sebastian H. R. , Gudmundsson G. Hilmar
Published: May 2018

Abstract. GPS measurements reveal strong modulation of horizontal
ice shelf and ice stream flow at a variety of tidal frequencies, most notably
a fortnightly (Msf) frequency not present in the vertical tides
themselves. Current theories largely fail to explain the strength and
prevalence of this signal over floating ice shelves. We show how well-known
non-linear aspects of ice rheology can give rise to widespread, long-periodic
tidal modulation in ice shelf flow, generated within ice shelves themselves
through tidal flexure acting at diurnal and semidiurnal frequencies. Using
full-Stokes viscoelastic modelling, we show that inclusion of tidal bending
within the model accounts for much of the observed tidal modulation of
ice shelf flow. Furthermore, our model shows that, in the absence of vertical
tidal forcing, the mean flow of the ice shelf is reduced by almost 30 % for
the geometry that we consider.
A Systematic Approach to Offshore Wind Turbine Jacket
Pre-Design and Optimization: Geometry, Cost, and Surrogate
Structural Code Check Models
Authors: Häfele Jan , Damiani Rick , King Ryan , Gebhardt Cristian G. , Rolfes Raimund
Published: May 2018

Abstract. The main obstacles in preliminary design studies or optimization of jacket substructures for offshore wind turbines are high numerical expenses for structural code checks and simplistic cost assumptions. In order to create a basis for fast design evaluations, this work provides the following: firstly, a jacket model is proposed that covers topology and tube sizing with a limited set of design variables. Secondly, a cost model is proposed that goes beyond the simple and common mass-dependent approach. And thirdly, the issue of numerical efficiency is addressed by surrogate models both for fatigue and ultimate limit state code checks. In addition, this work shows an example utilizing all models. The outcome can be utilized for preliminary design studies and jacket optimization schemes and is suitable for scientific and industrial applications.
Role of Employee Engagement on Compensation System and Employee Performance Relationship among Telecommunication Service Providers in Bangladesh
Authors: Hoque Abu Shams Mohammad Mahmudul , Awang Zainudin Bin , Siddiqui Benazir Ahmed , Sabiu Malam Salihu
Published: May 2018

Past studies endorsed that there is a quite number of factors have been considered as the influencing factors of employee performance in an organization. Some of these are selection, training and development, performance appraisal, promotion, job design, security, and satisfaction, compensation system, employee commitment, personality, emotional intelligence, organizational citizenship behavior among others. While several studies considered investigating the influence of human resource management practices on employee performance in different context such as America, Africa and Europe, but very little attention have given in South-Asian countries like Bangladesh.  Hence, this manuscript attempted to investigate the impact of compensation system on employee performance using quantitative analysis. To do so, survey was conducted as well as perceptions of 200 employees working in telecommunication service providers in Bangladesh were obtained to analyze the relationships. The data is analyzed and hypotheses were tested by using IBM-SPSS-AMOS package 25.0. The study found that employee engagement partially mediates the relationship between compensation system and employee performance by the data of this study. This research indorsed that there is a candid need to implement better compensation system by the entrepreneurs which will ensure better employee performance in line with consistent growth of firms as well as Bangladeshi GDP.