bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessing Potential Impacts of Sea Level Rise on Public Health and Vulnerable Populations in Southeast Florida and Providing a Framework to Improve Outcomes
Authors: Bloetscher Frederick , Polsky Colin , Bolter Keren , Mitsova Diana , Garces Kristin , King Roderick , Carballo Isabel , Hamilton Karen
Published: March 2016

In recent years, ongoing efforts by a multitude of universities, local governments, federal agencies, and non-governmental organizations (NGOs) have been focused on sea-level rise (SLR) adaptation in Florida. However, within these efforts, there has been very little attention given to the potential impacts of sea-level rise on human health. The intent of this project is to identify populations in Southeast Florida that are most vulnerable to sea-level rise from a topographic perspective, determine how vulnerable these population are from a socio-economic perspective, identify potential health impacts, develop adaptation strategies designed to assist these communities, and produce an outreach effort that can be shared with other coastal communities. The location of socially-vulnerable and health-vulnerable populations are correlated, but at present they are not generally in the geographically-vulnerable areas. Projections indicate that they will become at risk in the future but the lack of data on emerging diseases makes public health assessments difficult. We propose a redefinition of “who is vulnerable?” to include health indicators and hard infrastructure solutions for flood and property protection. These tools can be used to help protect water resources from the impacts of climate change, which would, in turn, protect public health via drinking water supplies, and efforts to address social issues.
Making the Most of World Natural Heritage—Linking Conservation and Sustainable Regional Development?
Authors: Conradin Katharina , Hammer Thomas
Published: March 2016

Today, more than 1000 World Heritage (WH) sites are inscribed on UNESCO’s list, 228 of which are natural and mixed heritage sites. Once focused primarily on conservation, World Natural Heritage (WNH) sites are increasingly seen as promoters of sustainable regional development. Sustainability-oriented regions, it is assumed, are safeguards for conservation and positively influence local conservation goals. Within UNESCO, discussions regarding the integration of sustainable development in official policies have recently gained momentum. In this article, we investigate the extent to which WNH sites trigger sustainability-oriented approaches in surrounding regions, and how such approaches in turn influence the WNH site and its protection. The results of the study are on the one hand based on a global survey with more than 60% of the WNH sites listed in 2011, and on the other hand on a complementary literature research. Furthermore, we analyze the policy framework necessary to support WNH sites in this endeavor. We conclude that a regional approach to WNH management is necessary to ensure that WNH sites support sustainable regional development effectively, but that the core focus of WNH status must remain environmental conservation.
Recherches archéologiques à Dungo (Angola)
Authors: Gutierrez Manuel , Guérin Claude , Karlin Claudine , Jesus Maria da Piedade de , Benjamim Maria Helena , Lebatard Anne-Élisabeth , Bourlès Didier L. , Braucher Régis , Leanni Laetitia
Published: March 2016

Les sites de Dungo IV et V, au sud de Baia Farta, province de Benguela, en Angola, apportent des connaissances nouvelles sur le Paléolithique ancien de cette partie du pays. Si les modes de vie ne peuvent être évoqués à Dungo IV qu’à travers l’étude du matériel lithique, à Dungo V, de nombreuses pièces taillées ont été trouvées intimement mêlées au squelette d’une baleine. Cette association démontre, de manière indubitable, la pratique du charognage de mammifère marin à cette période ancienne du Paléolithique. Dans un contexte dépourvu de volcanisme, l’approche de la chronologie ne pouvait se faire qu’en s’appuyant sur des méthodes utilisant de nouveaux critères de datation. La méthode, présentée ici, est basée sur l’âge d’enfouissement des pièces lithiques de Dungo IV. Elle a permis de déterminer que ces pièces ont été enfouies il y a un à deux millions d’années. Il s’agit donc d’un Paléolithique très ancien.
Managing Integrated Brand Communication Strategies in the Online Era
Authors: Mosca Fabrizio , Casalegno Cecilia
Published: March 2016

Since the spread of digital environments has certainly helped to broaden the spectrum of possibilities for managing channels, while opening new areas of competitive confrontation, is to assume that new technologies have contributed to the definition of a hybrid environment in which pre- and post-digital-revolution habits coexist. The aim of the present chapter is to show how this kind of hybrid channels, want to meet the two requirements to communicate and sell - through the use of media platforms that appeal to each other, meet and complement each other – is nowadays managed and how it can be used in the future to reach business and awareness goals in luxury markets. The analysis has been based on ways through which global luxury goods firms integrate their communication and selling tools each other, by focusing the attention on web and social strategies.
Students' Perceptions of the Online Instructors' Roles in a Massive Open Online Course
Authors: Tang Hengtao , Wang Shuyan , Qian Yingxiao , Peck Kyle L.
Published: March 2016

Scholars prefer applying metaphors to interpret the instructor's role in online education, such as facilitators, mentors, e-moderators, and “leading the band”, but the rise of Massive Open Online Courses (MOOCs) has reshaped the online teaching and learning practices. Accordingly, the role of instructors in MOOCs is expected to be redefined based on the precedent framework. This research inquiry thus explores students' perceptions of the instructor's role in a MOOC, Technology Applications in Education, regarding four dimensions of Berge's classifications: pedagogical, managerial, social, and technical. An emerging framework of instructor's role in a MOOC is construed to benefit professionals and academics investing in MOOC teaching and learning. Besides, designing a cohesive, structured course is evident in the roles of MOOC instructors, and instructors' timely interaction as a “real person” also influences students' learning experience.
Diffuse Spinal Leptomeningeal Spread of a Pilocytic Astrocytoma in a 3-Year-Old Child
Authors: Alyeldien Ameer , Teuber-Hanselmann Sarah , Cheko Azad , Höll Tanja , Scholz Martin , Petridis Athanasios K.
Published: March 2016

Pilocytic astrocytomas correspond to lowgrade gliomas and therefore metastasize exceedingly rare. However, pilocytic astrocytomas are able to and leptomeningeal dissemination may be seen. What are the treatment options of these cases? We present a case report of a 3-year-old child with a pilocytic astrocytoma of the optic chiasm with leptomeningeal dissemination of the spinal meninges. Partial resection of the cerebral tumor has been performed. Since the leptomeningeal dissemination was seen all over the spinal meninges, the child did not undergo further surgical treatment. A wait and watch strategy were followed. Chemotherapy was initiated, if a 25% tumor growth was seen. Leptomeningeal dissemination of a pilocytic astrocytoma is seen so infrequently that no standard therapy is established. Since these metastases may occur even up to 2 decades after primary tumor resection, long-term follow- up is indicated. In case of spinal metastases, surgical treatment should be performed if feasible. Otherwise observation should be possessed and/or chemotherapy should be initiated.
Бесконечные детерминантные меры и эргодическое разложение бесконечных мер Пикрелла. II. Сходимость бесконечных детерминантных мер
Authors: Bufetov Aleksandr Igorevich
Published: March 2016

Вторая часть настоящей работы посвящена сходимости последовательностей бесконечных детерминантных мер, понимаемой как сходимость последовательностей отвечающих им конечных детерминантных мер. Кроме слабой
топологии в пространстве вероятностных мер на пространстве конфигураций рассматривается также естественное почти наверно (по бесконечному бесселеву процессу) определенное погружение пространства
конфигураций в пространство конечных мер на полупрямой и отвечающая ей слабая топология в пространстве конечных мер на пространстве конечных мер на полупрямой. Главные результаты второй части - достаточные условия плотности семейств и сходимости последовательностей индуцированных детерминантных процессов, а также сходимости процессов, отвечающих конечномерным возмущениям операторов.
Библиография: 25 наименований.
Метрически и топологически проективные идеалы банаховых алгебр
Authors: Nemesh Norbert Tiborovich
Published: March 2016

В данной статье даются необходимые условия
метрической и топологической проективности
замкнутых идеалов банаховых алгебр. В случае
коммутативных банаховых алгебр получен критерий
метрической и топологической проективности идеалов,
обладающих ограниченной аппроксимативной единицей.
Основной результат работы: замкнутый идеал произвольной
$C^*$-алгебры метрически или топологически проективен
тогда и только тогда, когда он обладает самосопряженной
правой единицей.
Библиография: 13 названий.
The immersion freezing behavior of ash particles from wood and brown coal burning
Authors: Grawe Sarah , Augustin-Bauditz Stefanie , Hartmann Susan , Hellner Lisa , Pettersson Jan B. C. , Prager Andrea , Stratmann Frank , Wex Heike
Published: March 2016

Abstract. It is generally known that ash particles from coal combustion can trigger ice nucleation. However, data on the ice nucleation of ash particles from different sources, including both anthropogenic and natural combustion processes, is still scarce. As coal combustion still fuels the biggest proportion of electric power production worldwide and biomass burning contributes significantly to the global aerosol loading, further data is needed to better assess the ice nucleating efficiency of ash particles. In the framework of this study, we found that ash particles from brown coal (i.e., lignite) burning are more ice active than those from wood burning, with fly ash from a coal-fired power-plant being the most efficient at nucleating ice. Furthermore the effect of particle generation on the freezing behavior was studied. For this, particles were generated either by dispersion of dry sample material, or by atomization of ash-water suspensions, and then led into the Leipzig Aerosol Cloud Interaction Simulator (LACIS) where the immersion freezing behavior was examined. Whereas the immersion freezing behavior of ashes from wood burning was not affected by the particle generation method, it depended on the type of particle generation for ash from brown coal. It was also found that the common practice of treating prepared suspensions in an ultrasonic bath to avoid aggregation of particles led to an enhanced ice nucleation activity. The findings of this study suggest a) that ash from brown coal burning may influence heterogeneous ice nucleation on at least a regional scale and b) that the freezing behavior of ash particles may be altered by a change in sample preparation and/or particle generation.
Physical and biogeochemical spatial scales of variability in the East Australian Current separation from shelf glider measurements
Authors: Schaeffer Amandine , Roughan Moninya , Jones Emlyn M. , White Dana
Published: March 2016

Abstract. In contrast to physical processes, biogeochemical processes are inherently patchy in the ocean, which affects both the observational sampling strategy and the representativeness of sparse measurements in data assimilating models. In situ observations from multiple glider deployments are analysed to characterize spatial scales of variability in both physical and biogeochemical properties, using an empirical statistical model. We find that decorrelation ranges are strongly dependent on the balance between local dynamics and mesoscale forcing. The shortest horizontal (5–10 km) and vertical (45 m) decorrelation ranges are for chlorophyll a fluorescence, whereas those variables that are a function of regional ocean and atmosphere dynamics (temperature and dissolved oxygen) result in anisotropic patterns with longer ranges along (28–37 km) than across the shelf (8–19 km). Variables affected by coastal processes (salinity and coloured dissolved organic matter) have an isotropic range similar to the baroclinic Rossby radius (10–15 km).
Late Quaternary temperature variability described as abrupt transitions on a 1/f noise background
Authors: Rypdal Martin , Rypdal Kristoffer
Published: March 2016

Abstract. In order to have a scaling description of the climate system that is not inherently non-stationary, the rapid shifts between stadials and interstadials during the last glaciation (the Dansgaard-Oeschger events) cannot be included in the scaling law. The same is true for the shifts between the glacial and interglacial states in the Quaternary climate. When these events are omitted from a scaling analysis the climate noise is consistent with a 1/f law on timescales from months to 105 years. If the shift events are included, the effect is a break in the scaling with an apparent 1/fβ law, with β > 1, for the low frequencies. No evidence of multifractal intermittency has been found in any of the temperature records investigated, and the events are not a natural consequence of multifractal scaling.
Delineation of homogenous regions using hydrological variables predicted by projection pursuit regression
Authors: Durocher Martin , Chebana Fateh , Ouarda Taha B. M. J.
Published: March 2016

Abstract. This study investigates the utilization of hydrological information in Regional Frequency Analysis (RFA) to enforce properties for a group of gauged stations. Neighborhoods are a particular type of regions that are centered on target locations. A challenge for using neighborhoods in RFA is that hydrological information is not available at target locations. Instead of using known site characteristics (not hydrological) to define the center of a target location, this study proposes to introduce estimates of (hydrological) reference variables to ensure better homogeneity. These reference variables represent nonlinear relations with the site characteristics obtained by projection pursuit regression; a nonparametric regression method. The resulting neighborhoods are investigated in combination with common regional models: the index-flood model and the regression-based models. The complete approach is illustrated on a real-world case study with gauged sites located in Southern Quebec, Canada, and is compared with the traditional approaches "Region of Influence" and "Canonical Correlation Analysis". The evaluation focuses on the neighborhood properties as well as prediction performances, with special attention to problematic stations. Results show clear improvements in neighborhood definitions and quantile estimates.
Comparing Subject of Assignment of Contract with Similar Concepts of Other Countries' Domestic Laws and International Documents
Authors: Alidousti Naser , Taghizadeh Ebrahim , Ashouri Mehdi , Farsani Ali Khosravi
Published: March 2016

In concluding a contract, the thing being concluded and assigned is a contract which is a credit existence considered as object of assignment. However in assigning liabilities and debts, the thing being assigned is a debt, which is called debt for the debtor and right for the creditor, whether this liability or debt is due to a contract or due to a crime or civil liability and tortious liability. In novation, what is important is fall of the previous obligation and establishment of the new one. Hence in novation you cannot only rely on assigning obligation with the previous status, since the previous obligation does not remain anymore. This is while making an contract has this advantage that without any necessity to fall of the previous obligation, position of the obligor and obligee can be replaced. Each contract, from viewpoint of each of the parties to the contract, bears two parts including rights and obligations. According to the aforementioned issues, rights and obligations can be assigned separately. Now, when one party to the contract assigns both rights and obligations caused by a contract in a legal action, actually an assignment of contract has occurred. In other words, assignment of contract is total assignment of rights and assignment of obligations. Therefore, in comparing these subjects, assignment of contract is general and the other two are specific.
Reviewer Acknowledgements for Journal of Sustainable Development, Vol. 9, No. 2
Authors: Sun Sherry
Published: March 2016

Reviewer Acknowledgements for Journal of Sustainable Development, Vol. 9, No. 2, 2016
Electricity Supply Interruptions: Sectoral Interdependencies and the Cost of Energy Not Served for the Scottish Economy
Authors: Poudineh Rahmatallah , Jamasb Tooraj
Published: March 2016

Modern economies and infrastructure sectors rely upon secure electricity supplies. Due to sectoral interdependencies, major interruptions cause cascading effects in the economy. This paper investigates the economic effects of major power supply disruptions taking such interdependencies into account. We apply a dynamic inoperability input-output model (DIIM) to 101 sectors, including households, of the Scottish economy in 2009 to explore the direct, indirect, and induced effects of supply interruptions. We estimate the societal cost of energy not supplied (SCENS) due to an interruption. The results show that the most economically affected industries, following an outage, are different from the most inoperable ones. The results also indicate that SCENS varies with the duration of a power cut, ranging from ਴,300/MWh for a one-minute outage to \xA38,100/MWh for a three-hour (and higher) interruption. The results can be used to design policies for contingencies and preventive investments in the power sector.
The Interdisciplinary Spiritual Care Model – A holistic Approach to Patient Care
Authors: Hefti René , Esperandio Mary Rute Gomes
Published: March 2016

Nas duas últimas décadas, os estudos sobre a relação entre espiritualidade e saúde tem crescido significativamente no cenário internacional. No Brasil, as pesquisas nesse campo ganharam maior visibilidade a partir de 2009, sobretudo nas Ciências da Saúde, onde começou a aparecer o termo “cuidado espiritual”.  Na Teologia, estudos sobre cuidado espiritual dentro do contexto da saúde são escassos. Este artigo pretende contribuir com a ampliação desta reflexão. Primeiramente, o cuidado espiritual é abordado a partir da produção científica em língua portuguesa. Em seguida, o modelo interdisciplinar de cuidado espiritual é apresentado como uma abordagem holística de cuidado ao paciente e também são delineadas as consequências da aplicação de um modelo de cuidado espiritual. Discute-se ainda, o papel novo e recém definido dos capelães hospitalares, conselheiros pastorais e cuidadores espirituais. O texto conclui mencionando os principais desafios que acompanham o cuidado espiritual interdisciplinar, especialmente aqueles que dizem respeito  ao treinamento dos profissionais do cuidado em saúde.
Automated Extraction of Formalin-Fixed, Paraffin-Embedded Tissue for High-Risk Human Papillomavirus Testing of Head and Neck Squamous Cell Carcinomas Using the Roche Cobas 4800 System
Authors: Kerr Darcy A. , Sweeney Brenda , Arpin Ronald N. , Ring Melissa , Pitman Martha B. , Wilbur David C. , Faquin William C.
Published: March 2016

Context.—Testing for high-risk human papillomavirus (HR-HPV) in head and neck squamous cell carcinomas (HNSCCs) is important for both prognostication and clinical management. Several testing platforms are available for HR-HPV; however, effective alternative automated approaches are needed.

Objective.—To assess the performance of the automated Roche cobas 4800 HPV real-time polymerase chain reaction-based system on formalin-fixed, paraffin-embedded HNSCC specimens and compare results with standard methods of in situ hybridization (ISH) and p16 immunohistochemistry.

Design.—Formalin-fixed, paraffin-embedded samples of HNSCC were collected from archival specimens in the Department of Pathology, Massachusetts General Hospital (Boston), and prepared using the automated system by deparaffinization and dehydration followed by tissue lysis. Samples were integrated into routine cervical cytology testing runs by cobas. Corresponding formalin-fixed, paraffin-embedded samples were evaluated for HR-HPV by ISH and p16 by immunohistochemistry. Discrepant cases were adjudicated by polymerase chain reaction.

Results.—Sixty-two HNSCC samples were analyzed using the automated cobas system, ISH, and immunohistochemistry. Fifty-two percent (n = 32 of 62) of formalin-fixed, paraffin-embedded tumors were positive for HR-HPV by cobas. Eighty-eight percent (n = 28 of 32) of cases were the HPV 16 subtype and 12% (n = 4 of 32) were other HR-HPV subtypes. Corresponding testing with ISH was concordant in 92% (n = 57 of 62) of cases. Compared with the adjudication polymerase chain reaction standard, there were 3 false-positive cases by cobas.

Conclusions.—Concordance in HNSCC HR-HPV status between cobas and ISH was more than 90%. The cobas demonstrated a sensitivity of 100% and a specificity of 91% for detection of HR-HPV. Advantages favoring cobas include its automation, cost efficiency, objective results, and ease of performance.
Actors and Their Use of Avatars as Personal Mediators: An empirical study of avatar-based sense-makings and communication practices in the virtual worlds of EverQuest and Second Life
Authors: Jensen Sisse Siggaard
Published: March 2016

Over the past five years, millions of actors have found it meaningful to move in and settle down in the Metaverse, for example, as an adventurous shaman in an advanced role-playing game such as EverQuest or as a businesswoman in the social world of Second Life. In this article, the main question therefore is: how do the actors and gamers of the two types of virtual worlds make sense of their avatars and the worlds when they act and communicate using their avatars as personal mediators? Participatory observations inspired by virtual ethnography and in-depth video-interviews were conducted to answer this question. The analysis of the substantial amount of empirical data draws on the concepts of intermediaries and mediators from actor-network theory (Latour, 1991, 1998, 2005), Sense-Making methodology (Dervin et al., 2003), social psychology (Yee, 2006), and experimental economics (Bloomfield & Rennekamp, 2008). It is shown how the actors create a personal story and history of their avatar that transforms them into the mediators of being in the virtual world, and also how the avatars act as the mediators that transform the actors themselves. To identify, understand, and keep track of the many transformations of meaning, Nick Yee’s motivation factors (relationships, immersion, achievement, escapism and manipulation) have proven helpful also to the analysis of a social world like Second Life. In future studies, it is recommended that we study further the sense-makings of motivation factors such as creativity and experimentation.
Perniosis
Authors: Baker Joseph S. , Miranpuri Sarnarendra
Published: March 2016

Perniosis, or chilblain, is an uncommon condition of the acral skin. Presented herein is a case report of a 65-year-old otherwise healthy construction worker with perniosis. He had a 3-year history of lesions on the fingers and toes brought on by cold, damp weather. On initial presentation, a biopsy sample was taken of a hallux lesion, and the patient was given a trial course of nifedipine therapy. Follow-up at 3 weeks showed complete relief of symptoms with nifedipine use, and the biopsy results confirmed the diagnosis. The etiology and pathogenesis of perniosis are reviewed. Differential diagnoses and treatment options are reviewed and discussed. Nifedipine therapy has been shown to be effective and should be considered the standard of care in the treatment of perniosis along with avoidance of cold, damp environments, with protection using gloves and warm socks.
Structural and kinetic analysis of the COP9-Signalosome activation and the cullin-RING ubiquitin ligase deneddylation cycle
Authors: Mosadeghi Ruzbeh , Reichermeier Kurt M , Winkler Martin , Schreiber Anne , Reitsma Justin M , Zhang Yaru , Stengel Florian , Cao Junyue , Kim Minsoo , Sweredoski Michael J , Hess Sonja , Leitner Alexander , Aebersold Ruedi , Peter Matthias , Deshaies Raymond J , Enchev Radoslav I
Published: March 2016

The COP9-Signalosome (CSN) regulates cullin–RING ubiquitin ligase (CRL) activity and assembly by cleaving Nedd8 from cullins. Free CSN is autoinhibited, and it remains unclear how it becomes activated. We combine structural and kinetic analyses to identify mechanisms that contribute to CSN activation and Nedd8 deconjugation. Both CSN and neddylated substrate undergo large conformational changes upon binding, with important roles played by the N-terminal domains of Csn2 and Csn4 and the RING domain of Rbx1 in enabling formation of a high affinity, fully active complex. The RING domain is crucial for deneddylation, and works in part through conformational changes involving insert-2 of Csn6. Nedd8 deconjugation and re-engagement of the active site zinc by the autoinhibitory Csn5 glutamate-104 diminish affinity for Cul1/Rbx1 by ~100-fold, resulting in its rapid ejection from the active site. Together, these mechanisms enable a dynamic deneddylation-disassembly cycle that promotes rapid remodeling of the cellular CRL network.
How scientists can reduce their carbon footprint
Authors: Nathans Jeremy , Sterling Peter
Published: March 2016

Cutting down on long-distance air travel is the best way to reduce the emission of greenhouse gases by the scientific community.
Soft tissue artifact evaluation of the cervical spine in motion patterns of flexion and lateral bending: a preliminary study
Authors: Wang Jiajia , Lui Zhongwen , Qian Zhihui , Ren Luquan
Published: March 2016

Background.Soft tissue artifact (STA) is increasingly becoming a focus of research as the skin marker method is widely employed in motion capture technique. At present, medical imaging methods provide reliable ways to investigate the cervical STA. Among these approaches, magnetic resonance imaging (MRI) is a highly preferred tool because of its low radiation.

Methods.In the study, the 3D spatial location of vertebral landmarks and corresponding skin markers of the spinous processes of the second (C2), fifth (C5), and sixth (C6) cervical levels during flexion and lateral bending were investigated. A series of static postures were scanned using MRI. Skin deformation was obtained by the Mimics software.

Results.Results shows that during flexion, the maximum skin deformation occurs at C6, in the superior–inferior (Z) direction. Upon lateral bending, the maximum skin displacement occurs at C2 level, in the left–right (Y) direction. The result presents variability of soft tissue in the terms of direction and magnitude, which is consistent with the prevailing opinion.

Discussion.The results testified variability of cervical STA. Future studies involving large ranges of subject classification, such as age, sex, height, gravity, and etc. should be performed to completely verify the existing hypothesis on human cervical skin deformation.
Hypoxia‐induced endothelial–mesenchymal transition is associated with RASAL1 promoter hypermethylation in human coronary endothelial cells
Authors: Xu Xingbo , Tan Xiaoying , Hulshoff Melanie S. , Wilhelmi Tim , Zeisberg Michael , Zeisberg Elisabeth M.
Published: March 2016

Cardiac fibrosis is integral in chronic heart disease, and one of the cellular processes contributing to cardiac fibrosis is endothelial‐to‐mesenchymal transition (EndMT). We recently found that hypoxia efficiently induces human coronary artery endothelial cells (HCAEC) to undergo EndMT through a hypoxia inducible factor‐1α (HIF1α)‐dependent pathway. Promoter hypermethylation of Ras‐Gap‐like protein 1 (RASAL1) has also been recently associated with EndMT progression and cardiac fibrosis. Our findings suggest that HIF1α and transforming growth factor (TGF)/SMAD signalling pathways synergistically regulate hypoxia‐induced EndMT through both DNMT3a‐mediated hypermethylation of RASAL1 promoter and direct SNAIL induction. The findings indicate that multiple cascades may be activated simultaneously to mediate hypoxia‐induced EndMT.
Crustal structure and fluid distribution beneath the southern part of the Hidaka collision zone revealed by 3‐D electrical resistivity modeling
Authors: Ichihara Hiroshi , Mogi Toru , Tanimoto Kengo , Yamaya Yusuke , Hashimoto Takeshi , Uyeshima Makoto , Ogawa Yasuo
Published: March 2016

The Hidaka collision zone, where the Kurile and northeastern (NE) Japan arcs collide, provides a useful study area for elucidating the processes of arc‐continent evolution and inland earthquakes. To produce an image of the collision structure and elucidate the mechanisms of anomalously deep inland earthquakes such as the 1970 Hidaka earthquake (M6.7), we conducted magnetotelluric observations and generated a three‐dimensional resistivity distribution in the southern part of the Hidaka collision zone. The modeled resistivity was characterized by a high resistivity area in the upper crust of the Kurile arc corresponding to metamorphic rocks. The model also showed conductive zones beneath the center of the collision zone. The boundary between the resistive and conductive areas corresponds geometrically to the Hidaka main thrust, which is regarded as the arc‐arc boundary. The correspondence supports the collision model that the upper‐middle part of crust in the Kurile arc is obducting over the NE Japan arc. The conductive areas were interpreted as fluid‐filled zones associated with collision processes and upwelling of dehydrated fluid from the subducting Pacific slab. The fluid flow possibly contributes to over‐pressurized conduction that produces deep inland earthquakes. We also observed a significant conductive anomaly beneath the area of Horoman peridotite, which may be related to the uplift of mantle materials to the surface.
Swell dissipation from 10 years of Envisat advanced synthetic aperture radar in wave mode
Authors: Stopa Justin E. , Ardhuin Fabrice , Husson Romain , Jiang Haoyu , Chapron Bertrand , Collard Fabrice
Published: March 2016

Swells are found in all oceans and strongly influence the wave climate and air‐sea processes. The poorly known swell dissipation is the largest source of error in wave forecasts and hindcasts. We use synthetic aperture radar data to identify swell sources and trajectories, allowing a statistically significant estimation of swell dissipation. We mined the entire Envisat mission 2003–2012 to find suitable storms with swells (13 < T < 18 s) that are observed several times along their propagation. This database of swell events provides a comprehensive view of swell extending previous efforts. The analysis reveals that swell dissipation weakly correlates with the wave steepness, wind speed, orbital wave velocity, and the relative direction of wind and waves. Although several negative dissipation rates are found, there are uncertainties in the synthetic aperture radar‐derived swell heights and dissipation rates. An acceptable range of the swell dissipation rate is −0.1 to 6 × 10−7 m−1 with a median of 1 × 10−7 m−1.
Thermospheric hydrogen response to increases in greenhouse gases
Authors: Nossal S. M. , Qian L. , Solomon S. C. , Burns A. G. , Wang W.
Published: March 2016

We investigated thermospheric hydrogen response to increase in greenhouse gases and the dependence of this response to solar activity, using a global mean version of the National Center for Atmospheric Research Thermosphere‐Ionosphere‐Mesosphere‐Electrodynamics General Circulation Model. We separately doubled carbon dioxide (CO2) and methane (CH4) to study the influence of temperature and changes to source species for hydrogen. Our results indicate that both CO2 cooling and CH4 changes to the source species for hydrogen lead to predicted increases in the upper thermospheric hydrogen density. At 400 km, hydrogen increases ~30% under solar maximum and ~25% under solar minimum responding to doubling of CH4, indicating that hydrogen response to the source variation due to CH4 increase is relatively independent of solar activity. On the other hand, hydrogen response to doubling of CO2 highly depends on solar activity. At 400 km, doubling of CO2 results in an ~7% hydrogen increase at solar maximum, whereas it is ~25% at solar minimum. Consequently, at solar maximum, the predicted ~40% increase in atomic hydrogen in the upper thermosphere is primarily due to the source variation as a result of doubling of CH4, whereas at solar minimum, both cooling due to doubling of CO2 and the source variation due to doubling of CH4 have commensurate effects, resulting in an approximate 50% increase in the modeled upper thermospheric hydrogen.
The Harang reversal and the interchange stability of the magnetotail
Authors: Ohtani Shinichi , Gkioulidou Matina , Wang Chih‐Ping , Wolf Richard A.
Published: March 2016

The present study addresses steady convection in the plasma sheet in terms of the interchange stability with special attention to the Harang reversal. The closure of the tail current with a field‐aligned current (FAC) results from the divergence/convergence of the pressure gradient current. If the magnetotail is in a steady state, the associated change of local plasma pressure p has to balance with its advective change. Accordingly, for adiabatic transport, the flux tube entropy parameter pVγ increases and decreases along the convection path in regions corresponding to downward and upward FACs, respectively. This requirement, along with the condition for the interchange stability imposes an important constraint on the direction of convection especially in the regions of downward FACs. It is deduced that for the dusk cell, the convection in the downward R2 current has to be directed azimuthally duskward, which follows the sunward, possibly dawnward deflected, convection in the region of the premidnight upward R1 current. This duskward turn of convection takes place in the vicinity of the R1‐R2 demarcation, and it presumably corresponds to the Harang reversal. For the dawn cell the convection in the postmidnight downward R1 current has to deflect dawnward, and then it proceeds sunward in the upward R2 current. The continuity of the associated ionospheric currents consistently reproduces the assumed FAC distribution. The proposed interrelationships between the convection and FACs are also verified with a quasi‐steady plasma sheet configuration and convection reproduced by a modified Rice Convection Model with force balance.
Parallel and oblique firehose instability thresholds for bi‐kappa distributed protons
Authors: Astfalk Patrick , Jenko Frank
Published: March 2016

The parallel and the oblique firehose instability are generally accepted as the leading mechanisms shaping the boundaries of the protons' pressure anisotropies observed in the solar wind forp∥>p⊥. However, it is still an open question which instability dominates this process. Only recently, first attempts were made to study the linear growth of the parallel firehose assuming more realistic bi‐kappa velocity distributions instead of traditionally used bi‐Maxwellians. We apply a newly developed, fully kinetic dispersion solver to numerically derive the instability thresholds for both firehose instabilities. In contrast to former findings, we observe that the presence of suprathermal populations yields a growth amplification which lowers the instability threshold of the parallel firehose. This is due to enhanced cyclotron resonance. For the first time, we also look at the oblique firehose threshold and find a contrary picture. Here the presence of suprathermal particles leads to an increase of the instability threshold. The enhancement of the parallel firehose and the suppression of the oblique firehose are expected to be of relevance in the solar wind and may alter the competition between both instabilities. Based on our findings, we propose a method how solar wind data could be used to identify the instability mechanism dominating this competition and shaping the observed anisotropy boundary.
Coupling between mineral reactions, chemical changes in groundwater, and earthquakes in Iceland
Authors: Andrén Margareta , Stockmann Gabrielle , Skelton Alasdair , Sturkell Erik , Mörth Carl‐Magnus , Guðrúnardóttir Helga Rakel , Keller Nicole Simone , Odling Nic , Dahrén Börje , Broman Curt , Balic‐Zunic Tonci , Hjartarson Hreinn , Siegmund Heike , Freund Friedemann , Kockum Ingrid
Published: March 2016

Chemical analysis of groundwater samples collected from a borehole at Hafralækur, northern Iceland, from October 2008 to June 2015 revealed (1) a long‐term decrease in concentration of Si and Na and (2) an abrupt increase in concentration of Na before each of two consecutive M > 5 earthquakes which occurred in 2012 and 2013, both 76 km from Hafralækur. Based on a geochemical (major elements and stable isotopes), petrological, and mineralogical study of drill cuttings taken from an adjacent borehole, we are able to show that (1) the long‐term decrease in concentration of Si and Na was caused by constant volume replacement of labradorite by analcime coupled with precipitation of zeolites in vesicles and along fractures and (2) the abrupt increase of Na concentration before the first earthquake records a switchover to nonstoichiometric dissolution of analcime with preferential release of Na into groundwater. We attribute decay of the Na peaks, which followed and coincided with each earthquake to uptake of Na along fractured or porous boundaries between labradorite and analcime crystals. Possible causes of these Na peaks are an increase of reactive surface area caused by fracturing or a shift from chemical equilibrium caused by mixing between groundwater components. Both could have been triggered by preseismic dilation, which was also inferred in a previous study by Skelton et al. (2014). The mechanism behind preseismic dilation so far from the focus of an earthquake remains unknown.
Spectral analysis of dike‐induced earthquakes in Afar, Ethiopia
Authors: Tepp Gabrielle , Ebinger Cynthia J. , Yun Sang‐Ho
Published: March 2016

Shallow dike intrusions may be accompanied by fault slip above the dikes, a superposition which complicates seismic and geodetic data analyses. The diverse volcano‐tectonic and low‐frequency local earthquakes accompanying the 2005–2010 large‐volume dike intrusions in the Dabbahu‐Manda Hararo rift (Afar), some with fault displacements of up to 3 m at the surface, provide an opportunity to examine the relations among the earthquakes, dike intrusions, and surface ruptures. We apply the frequency index (FI) method to characterize the spectra of swarm earthquakes from six of the dikes. These earthquakes often have broad spectra with multiple peaks, making the usual peak frequency classification method unreliable. Our results show a general bimodal character with high FI earthquakes associated with deeper dikes (top > 3 km subsurface) and low FI earthquakes associated with shallow dikes, indicating that shallow dikes result in earthquakes with more low‐frequency content and larger‐amplitude surface waves. Low FI earthquakes are more common during dike emplacement, suggesting that interactions between the dike and faults may lead to lower FI. Taken together, likely source processes for low FI earthquakes are shallow hypocenters (<3 km) possibly with surface rupture, slow rupture velocities, and interactions with dike fluids. Strong site effects also heavily influence the earthquake spectral content. Additionally, our results suggest a continuum of spectral responses, implying either that impulsive volcano‐tectonic earthquakes and the unusual, emergent earthquakes have similar source processes or that simple spectral analyses, such as FI, cannot distinguish different source processes.
Seismic tomography and anisotropy of the Helan‐Liupan tectonic belt: Insight into lower crustal flow and seismotectonics
Authors: Cheng Bin , Zhao Dapeng , Cheng Shunyou , Ding Ziteng , Zhang Guowei
Published: March 2016

We determined detailed 3‐D P and S wave velocities (Vp and Vs) and Poisson's ratio (σ) images as well as P wave azimuthal anisotropy in the crust and uppermost mantle beneath the Helan‐Liupan tectonic belt (HLTB) and adjacent regions. The data set used in this study consists of 38,880 P wave and 35,117 S wave arrival times from 5028 local earthquakes recorded by 66 seismic stations in the study area during 1980 to 2014. Obvious low‐Vp and low‐σ anomalies are revealed in the lower crust beneath the Qilian Orogenic Belt and Western Qinling, which we interpret as a weakened zone mainly caused by water and capable of ductile flow on a geological timescale. Our P wave anisotropy results suggest that the flow direction in the lower crust is nearly parallel to the direction of the geodetic crustal motion and that of the upper mantle flow beneath the study region. Most of the 26 large historical earthquakes (1125–1954) in the study region occurred in the boundary zones where Vp, Vs, and σ change drastically over a short distance. Beneath the source areas of the large historical earthquakes, fluid‐related low‐velocity zones exist widely in the lower crust. The fluids result from dehydration of hydrous minerals in the deeper crust and uppermost mantle beneath the northeastern Tibetan Plateau. When the fluids migrate upward to the active faults, the fault zone friction is reduced and so large crustal earthquakes can be triggered. Our present results shed new light on the seismogenesis and geodynamics of the northeastern Tibetan Plateau and adjacent areas.
A novel band‐pass filter based on a periodically drilled SIW structure
Authors: Coves A. , Torregrosa‐Penalva G. , San‐Blas A. A. , Sánchez‐Soriano M. A. , Martellosio A. , Bronchalo E. , Bozzi M.
Published: March 2016

The design and fabrication of a band‐pass step impedance filter based on high and low dielectric constant sections has been realized on substrate integrated waveguide (SIW) technology. The overall process includes the design of the ideal band‐pass prototype filter, where the implementation of the impedance inverters has been carried out by means of waveguide sections of lower permittivity. This can be practically achieved by implementing arrays of air holes along the waveguide. Several SIW structures with and without arrays of air holes have been simulated and fabricated in order to experimentally evaluate their relative permittivity. Additionally, the equivalent filter in SIW technology has been designed and optimized. Finally, a prototype of the designed filter has been fabricated and measured, showing a good agreement between measurements and simulations, which demonstrates the validity of the proposed design approach.
Transcurrent reactivation of Australia's western passive margin: An example of intraplate deformation from the central Indo‐Australian plate
Authors: Hengesh J. V. , Whitney B. B.
Published: March 2016

Australia's northwestern passive margin intersects the eastern termination of the Java trench segment of the Sunda arc subduction zone and the western termination of Timor trough along the Banda arc tectonic collision zone. Differential relative motion between the Sunda arc subduction zone and the Banda arc collision zone has reactivated the former rifted margin of northwestern Australia evidenced by Pliocene to Quaternary age deformation along a 1400 km long offshore fault system. The fault system has higher rates of seismicity than the adjacent nonextended crustal terranes, has produced the largest historical earthquake in Australia (1941ML 7.3 Meeberrie event), and is dominated by focal mechanism solutions consistent with dextral motion along northeast trending fault planes. The faults crosscut late Miocene unconformities that are eroded across middle Miocene inversion structures suggesting multiple phases of Neogene and younger fault reactivation. Onset of deformation is consistent with the timing of the collision of the Scott Plateau part of the passive continental margin with the former Banda trench between 3.0 Ma and present. The range of estimated maximum horizontal slip rates across the zone is ~1.4 to 2.6 mm yr−1, at the threshold of geodetically detectable motion, yet significant with respect to an intraplate tectonic setting. The folding and faulting along this part of the continental margin provides an example of intraplate deformation resulting from kinematic transitions along a distant plate boundary and demonstrates the presence of a youthful evolving intraplate fault system within the Indo‐Australian plate.
Riverine dissolved lithium isotopic signatures in low‐relief central Africa and their link to weathering regimes
Authors: Henchiri Soufian , Gaillardet Jérôme , Dellinger Mathieu , Bouchez Julien , Spencer Robert G. M.
Published: March 2016

The isotopic composition of dissolved lithium (δ7Li) near the Congo River mouth varied from 14‰ to 22‰ in 2010 and was negatively correlated to discharge. From the relationship between dissolved δ7Li and strontium isotopes, we suggest that this large variation is due to mixing of waters from two contrasting continental weathering regimes. One end‐member (high δ7Li ≈ 25‰) represents waters sourced from active lateritic soils covering the periphery of the basin (Li highly sequestered into secondary mineral products) and another representing blackwater rivers (low δ7Li ≈ 5.7‰) derived from the swampy central depression where high organic matter content in water leads to congruent dissolution of the Tertiary sedimentary bedrock. This suggests that the lithium isotopic signature of tropical low‐relief surfaces is not unique and traces the long‐term, large‐scale vertical motions of the continental crust that control geomorphological settings. This evolution should be recorded in the oceanic secular δ7Li curve.
An empirically based steady state friction law and implications for fault stability
Authors: Spagnuolo E. , Nielsen S. , Violay M. , Di Toro G.
Published: March 2016

Empirically based rate‐and‐state friction laws (RSFLs) have been proposed to model the dependence of friction forces with slip and time. The relevance of the RSFL for earthquake mechanics is that few constitutive parameters define critical conditions for fault stability (i.e., critical stiffness and frictional fault behavior). However, the RSFLs were determined from experiments conducted at subseismic slip rates (V < 1 cm/s), and their extrapolation to earthquake deformation conditions (V > 0.1 m/s) remains questionable on the basis of the experimental evidence of (1) large dynamic weakening and (2) activation of particular fault lubrication processes at seismic slip rates. Here we propose a modified RSFL (MFL) based on the review of a large published and unpublished data set of rock friction experiments performed with different testing machines. The MFL, valid at steady state conditions from subseismic to seismic slip rates (0.1 µm/s < V < 3 m/s), describes the initiation of a substantial velocity weakening in the 1–20 cm/s range resulting in a critical stiffness increase that creates a peak of potential instability in that velocity regime. The MFL leads to a new definition of fault frictional stability with implications for slip event styles and relevance for models of seismic rupture nucleation, propagation, and arrest.