bluuebunny/crossref_metadata_2025 huggingface dataset:
La afectación prioritaria de los trabajadores de mayor edad en el despido colectivo
Authors: Solà Monells Xavier
Published: November 2016

Aunque la prohibición de discriminación por razón de edad se extrae con claridad del  art. 14 de la CE, el art. 17.1 del TRLET y de la normativa internacional, en la práctica la selección de las personas que verán extinguida su relación laboral en los procedimientos de despido colectivo se basa a menudo en ese factor.La jurisprudencia ordinaria ha admitido tradicionalmente la afectación prioritaria de los trabajadores de edad como una opción lícita y no discriminatoria, al considerar que permite configurar una estructura de plantilla más estable, siendo razonable concentrar las extinciones en aquellas personas que tengan una expectativa laboral más corta.La reciente STC 66/2015, de 13 de abril y la toma en consideración de los criterios establecidos por el TJUE en relación al art. 6.1 de la Directiva 2000/78/CE, donde se determina en qué supuestos pueden estar justificadas las diferencias de trato por motivos de edad, obligan a adoptar un planteamiento bastante más exigente y requerir la concurrencia de dos elementos para excluir la discriminación: primero, que la medida en la que se materializa el trato diferenciado persiga un objetivo legítimo de política social; y segundo, que sea adecuado y necesario para la consecución de dicho objetivo.
De racionalización a extensión: los incentivos al empleo en la crisis económica en España
Authors: Molina Romo Oscar
Published: November 2016

Este artículo aborda el análisis de la transformación, diseño e impacto en los últimos años del instrumento que dentro de las políticas de empleo consiste en proveer incentivos a la contratación (nueva o mantenimiento), por ser este el más significativo en términos de recursos. Del análisis efectuado se desprende un desarrollo poco coherente en las políticas de incentivos a la contratación, permaneciendo en cualquier caso importantes deficiencias sobre todo en lo que se refiere a la vinculación con formación y la condicionalidad al empresario que se beneficia de estos incentivos. Por otra parte, el creciente uso de reducciones (en lugar de bonificaciones) a las cuotas de la Seguridad Social, dificulta el diagnóstico de la política de incentivos e introduce problemas de sostenibilidad del sistema.
A Translational and Narratological Approach to Audio Describing Narrative Characters
Authors: Vercauteren Gert
Published: November 2016

The present article examines two issues in the field of audio description (AD) that so far have received little attention. Research in AD is highly multi- and interdisciplinary, and while semiotics, discourse analysis, narratology and film studies are some of the frameworks that are regularly used to study audio description, few attempts have been made to frame AD within the field of translation studies (TS). The first part of this article, therefore, describes a functionalist approach to audio description, both to strengthen the position of AD within TS and to contribute to a systematization of AD research. In the second part, such a systematic approach is applied to one question deemed “vital” in many national AD guidelines: the audio description of characters. Based on principles from formal narratology, a strategy is developed that allows describers to analyze characters in a structured, general way and to select relevant character information to be included in their descriptions.
Towards an integrated primary and secondary HIV prevention continuum for the United States: a cyclical process model
Authors: Horn Tim , Sherwood Jennifer , Remien Robert H , Nash Denis , Auerbach Judith D. ,   for the Treatment Action Group and Foundation for Aids Research HIV Prevention Continuum Working Group
Published: November 2016

Introduction

Every new HIV infection is preventable and every HIV‐related death is avoidable. As many jurisdictions around the world endeavour to end HIV as an epidemic, missed HIV prevention and treatment opportunities must be regarded as public health emergencies, and efforts to quickly fill gaps in service provision for all people living with and vulnerable to HIV infection must be prioritized.

Discussion

We present a novel, comprehensive, primary and secondary HIV prevention continuum model for the United States as a conceptual framework to identify key steps in reducing HIV incidence and improving health outcomes among those vulnerable to, as well as those living with, HIV infection. We further discuss potential approaches to address gaps in data required for programme planning, implementation and evaluation across the elements of the HIV prevention continuum.

Conclusions

Our model conceptualizes opportunities to monitor and quantify primary HIV prevention efforts and, importantly, illustrates the interplay between an outcomes‐oriented primary HIV prevention process and the HIV care continuum to move aggressively forward in reaching ambitious reductions in HIV incidence. To optimize the utility of this outcomes‐oriented HIV prevention continuum, a key gap to be addressed includes the creation and increased coordination of data relevant to HIV prevention across sectors.
Functional dichotomy and distinct nanoscale assemblies of a cell cycle-controlled bipolar zinc-finger regulator
Authors: Mignolet Johann , Holden Seamus , Bergé Matthieu , Panis Gaël , Eroglu Ezgi , Théraulaz Laurence , Manley Suliana , Viollier Patrick H
Published: November 2016

Protein polarization underlies differentiation in metazoans and in bacteria. How symmetric polarization can instate functional asymmetry remains elusive. Here, we show by super-resolution photo-activated localization microscopy and edgetic mutations that the bitopic zinc-finger protein ZitP implements specialized developmental functions – pilus biogenesis and multifactorial swarming motility – while shaping distinct nanoscale (bi)polar architectures in the asymmetric model bacterium Caulobacter crescentus. Polar assemblage and accumulation of ZitP and its effector protein CpaM are orchestrated in time and space by conserved components of the cell cycle circuitry that coordinate polar morphogenesis with cell cycle progression, and also act on the master cell cycle regulator CtrA. Thus, this novel class of potentially widespread multifunctional polarity regulators is deeply embedded in the cell cycle circuitry.
PDIA3 gene induces visceral hypersensitivity in rats with irritable bowel syndrome through the dendritic cell-mediated activation of T cells
Authors: Zhuang Zhaomeng , Zhang Lu , Wang Xiaoteng , Tao Liyuan , Lv Bin
Published: November 2016

This study investigated the mechanism of protein disulfide-isomerase A3 (PDIA3)-induced visceral hypersensitivity in irritable bowel syndrome (IBS). Rats were treated with saline (control), acetic acid and restraint stress (IBS model), empty vector (RNAi control) and PDIA3-RNAi vector (PDIA3-RNAi). Mesenteric lymph node DCs (MLNDCs) and splenic CD4+/CD8+ T cells were isolated for co-cultivation. Compared with control, MLNDCs co-cultured with CD4+ or CD8+ T cells showed an increased ability to promote T cell proliferation and produced more IL-4 or IL-9 secretion. Compared with the RNAi control, MLNDCs from the PDIA3 knockdown models were less effective in promoting the proliferation of CD4+/CD8+ T cells. It is concluded that PDIA3 plays an important role in the development of IBS through the DC-mediated activation of T cells, resulting in degranulation of MCs and visceral hypersensitivity.
Ceratopogonidae (Diptera: Nematocera) of the piedmont of the Yungas forests of Tucumán: ecology and distribution
Authors: Direni Mancini José Manuel , Veggiani-Aybar Cecilia Adriana , Fuenzalida Ana Denise , Lizarralde de Grosso Mercedes Sara , Quintana María Gabriela
Published: November 2016

Within the Ceratopogonidae family, many genera transmit numerous diseases to humans and animals, while others are important pollinators of tropical crops. In the Yungas ecoregion of Argentina, previous systematic and ecological research on Ceratopogonidae focused on Culicoides, since they are the main transmitters of mansonelliasis in northwestern Argentina; however, few studies included the genera Forcipomyia, Dasyhelea, Atrichopogon, Alluaudomyia, Echinohelea, and Bezzia. Therefore, the objective of this study was to determine the presence and abundance of Ceratopogonidae in this region, their association with meteorological variables, and their variation in areas disturbed by human activity. Monthly collection of specimens was performed from July 2008 to July 2009 using CDC miniature light traps deployed for two consecutive days. A total of 360 specimens were collected, being the most abundant Dasyhelea genus (48.06%) followed by Forcipomyia (26.94%) and Atrichopogon (13.61%). Bivariate analyses showed significant differences in the abundance of the genera at different sampling sites and climatic conditions, with the summer season and El Corralito site showing the greatest abundance of specimens. Accumulated rainfall was the variable that related the most to the abundance of Culicoides (10.56%), while temperature was the most closely related variable to the abundance of Forcipomyia, Dasyhelea, and Atrichopogon.
Salinity modulates thermotolerance, energy metabolism and stress response in amphipodsGammarus lacustris
Authors: Vereshchagina Kseniya P. , Lubyaga Yulia A. , Shatilina Zhanna , Bedulina Daria , Gurkov Anton , Axenov-Gribanov Denis V. , Baduev Boris , Kondrateva Elizaveta S. , Gubanov Mikhail , Zadereev Egor , Sokolova Inna , Timofeyev Maxim
Published: November 2016

Temperature and salinity are important abiotic factors for aquatic invertebrates. We investigated the influence of different salinity regimes on thermotolerance, energy metabolism and cellular stress defense mechanisms in amphipodsGammarus lacustrisSars from two populations. We exposed amphipods to different thermal scenarios and determined their survival as well as activity of major antioxidant enzymes (peroxidase, catalase, glutathione S-transferase) and parameters of energy metabolism (content of glucose, glycogen, ATP, ADP, AMP and lactate). Amphipods from a freshwater population were more sensitive to the thermal challenge, showing higher mortality during acute and gradual temperature change compared to their counterparts from a saline lake. A more thermotolerant population from a saline lake had high activity of antioxidant enzymes. The energy limitations of the freshwater population (indicated by low baseline glucose levels, downward shift of the critical temperature of aerobic metabolism and inability to maintain steady-state ATP levels during warming) was observed, possibly reflecting a trade-off between the energy demands for osmoregulation under the hypo-osmotic condition of a freshwater environment and protection against temperature stress.
Managing essential inputs: the case of methanol supply in biodiesel industry
Authors: Goulart Daniel Franco
Published: November 2016

This paper aims to discuss the ways that biodiesel producers manage the supply chain of methanol, an indispensable input obtained almost exclusively through importation. To build this discussion, it was firstly drawn the main features of the Brazilian biodiesel industry and, after that, it was described the main methanol’s origins, applications and market. It was identified two ways on which biodiesel companies acquire methanol: a) via long-term contracts or b) in the spot market. If the first option means supply safety, the second one means more competitive prices. This qualitative study was built from two different data collection steps: a) participant observation and b) semi-structured interviews.
Aperture Antennas
Authors: Kozakoff Dennis
Published: November 2016

Aperture antennas include those having large planar areas such as parabolic reflectors. The classic technique used in the calculation of aperture antenna radiation patterns is applying the equivalence principle followed by physical optics approximations. The equivalence principle is based on replacing the physical antenna aperture with a virtual antenna aperture consisting of an ensemble of Huygens' sources, each of which is a source of spherical wavelets. The total pattern is taken as a construction of these Huygens' secondary waves. It can be further shown that a simple Fourier transform relation exists between the amplitude distribution of these sources and the radiation pattern in angle space. For many aperture antenna problems, the distribution can be assumed from theoretical considerations or determined empirically from near‐field probes of the aperture fields. But there are many other antennas such as horn antennas, where a virtual aperture can also be constructed in front of the physical aperture in order to model and analyze the antenna. Thus, an aperture antenna has more to do with the method used to model the antenna than its actual form.

For most aperture antenna problems, these classical techniques are adequate and give reasonably accurate results. However, other analysis techniques such as the method of moments (MoM), the finite‐element method (FEM), and the finite‐difference time‐domain (FDTD) method are applicable. These methods are more robust, but the complexity and large amount of computer resources required must be traded off with the accuracy desired compared to the relatively simple techniques discussed.
Electromagnetic Wave Scattering
Authors: Musselman Randall L.
Published: November 2016

Electromagnetic wave scattering is the reradiation of electromagnetic energy that results when an electromagnetic field encounters an abrupt change in electrical or magnetic properties. Typically, this occurs when an electromagnetic field is incident on a structure or scattering object. When the original electromagnetic field crosses the boundary between two regions, each with different electrical or magnetic parameters, the field will change as it enters the second region. This abruptly changing propagation medium induces sources of scattering at the boundary between the two media, including conduction and displacement currents. These currents act as sources of electromagnetic reradiation, much like the sources that created the original incident electromagnetic field, such as from an antenna. This reradiation is called electromagnetic wave scattering, because it scatters the incident electromagnetic field from its original propagation path. The three mechanisms for electromagnetic wave scattering are reflection, refraction, and diffraction, and can be specular or diffuse. Snell's law and the fundamental electromagnetic theorems of uniqueness, induction, and equivalence are useful for solving electromagnetic wave scattering problems. Diffraction around obstructions is analyzed using ray‐tracing techniques, such as geometrical theory of diffraction (
GTD
), or full‐wave analysis, such as physical optics. Babinet's principle allows the solution for electromagnetic wave scattering through apertures to be used to analyze scattering around conductive plates, by treating these two distinct cases as complements of each other. Electromagnetic wave scattering forms the basis for radar cross section, integral to both monostatic and bistatic radar systems. Rayleigh and Mie scattering are special cases of electromagnetic wave scattering.
Radar Antennas
Authors: Niu Tiaoming , Mei Zhonglei , Cui Tie Jun
Published: November 2016

Radar is an object‐detection system that transmits/receives and processes reflected electromagnetic waves to determine the location, angle, and velocity of targets such as aircraft, spacecraft, guided missiles, motor vehicles, and ships. In the radar system, the antenna is an essential component and plays an important role in detecting objects. There are various antenna candidates that can be adopted into radar systems. In this article, definitions of fundamental antenna parameters are given, and then various possible antenna candidates for radar systems are demonstrated and analyzed. Various reflectors with corresponding feeding source have been widely used as radar antennas with high gain and low cost, while phased‐arrays provide the radar system with the ability of dynamic scanning with a flat profile. Combing the advantages of the reflector and the phased array, the concept of reflectarray is introduced and the corresponding design principles and characteristics are discussed. Different types of radiation elements with corresponding characteristics for constructing reflectarrays are presented. Due to the innovative enhancement that novel metamaterials can provide to antenna engineering, radar antennas based on (or incorporating) metamaterials are also presented. In addition, for each antenna type representative examples are demonstrated for a more comprehensive understanding.
Propagation of Extremely Low‐Frequency Radio Waves
Authors: Nickolaneko Alexander P. , Shvets Alexander V. , Hayakawa Masashi
Published: November 2016

We address the subionospheric extremely low‐frequency (ELF) radio propagation with an emphasis put on the global and transverse electromagnetic resonance and on geophysical information deduced from resonance parameters. The expected spectra are demonstrated for the global electromagnetic (Schumann resonance,SR) and the waveforms are given for theELFtransients orQ‐bursts. Models ofELFpropagation constant are presented together with efficient models of the lower ionosphere conductivity that provide realisticSRdata in the direct field computations such asFDTD(finite‐difference time‐domain) method. Observational aspects are also addressed, including a brief description of the field sources, instrumentation, and typical signal processing with illustrations of actual data.
Superconducting Quantum Interference Devices (SQUIDs)
Authors: Fagaly Robert L.
Published: November 2016

Superconducting Quantum Interference Device (SQUID)‐based instruments have proven to be the most sensitive measurement techniques for not only magnetization measurements but also for a number of other electrical measurements. Their device noise (well below 1 mK), flat frequency and phase response that extends from DC to above 10 GHz, and low drift permit electromagnetic measurements at levels far superior to conventional techniques. SQUID instruments consist of a SQUID amplifier or sensor and a detection circuit that transforms the signal of interest into a magnetic flux that is detected by the SQUID sensor. Associated control electronics transform this signal into a room temperature voltage that is available for additional signal processing if needed. The SQUID amplifier and the detection coils are superconducting devices that are kept at cryogenic temperatures. Various types of SQUID sensors and materials (low‐temperature and high‐temperature superconductors) are discussed along with a wide variety of applications, including laboratory, geophysical, nondestructive test and evaluation along with specific examples of medical applications.
Artificial Hearts and Cardiac Assist Devices: Performance, Control, and Power Delivery
Authors: Trumble Dennis R.
Published: November 2016

Organ transplantation is a medical therapy that poses persistent risks of tissue rejection that are managed on a continual basis by immunosuppressive drugs such as cyclosporine, prednisone, and azathioprine. However, despite the effectiveness of these antirejection medications widespread application of this technology has been, and continues to be, severely limited by the shortage of suitable donor organs. Artificial organ systems constructed by man‐made materials have an advantage over tissue‐based therapies insofar as they are not subject to rejection problems or limited by organ availability. Still, the development and use of these synthetic devices present its own unique set of challenges that have yet to be completely overcome. The reason is simple. The heart, liver, kidney, and other internal organs perform functions that are not fully understood by modern science. Artificial organs for implant therefore provide, at best, an incomplete solution to a complex medical problem. While the use of artificial organs can be satisfactory in many cases, these interventions generally involve the implantation of nonbiological elements within the body, raising issues of biocompatibility, and requiring stringent sterilization protocols. Moreover, the use of implanted man‐made structures that contact with circulating blood (e.g., heart valves) has been associated with an increased incidence of thromboembolic events. This article considers the energy requirements and sensor/control aspects of artificial hearts and ventricular assist devices designed to augment blood flow and tissue perfusion levels provided by the failing heart.
Simultaneous Localization and Mapping (SLAM)
Authors: Birk Andreas , Pfingsthorn Max
Published: November 2016

This article gives an overview of simultaneous localization and mapping (SLAM), that is, probabilistic methods to generate a 2D or 3D map of unknown areas under imperfect localization. The article provides a survey of the theoretical basis of SLAM as well as the core background information about the underlying techniques for implementing actual SLAM systems.
Phase Change Memories: Principles and Applications
Authors: Pirovano Agostino
Published: November 2016

The phase‐change memory (PCM) is a nonvolatile semiconductor technology based on thermally induced phase transitions of a thin‐film material, typically a chalcogenide. PCM relies on a resistance change to store data permanently. Although the historical origin of the PCM concept dates back to the 1970s, nowadays it is considered one of the most promising candidates for the next‐generation nonvolatile memories (NVM). In comparison with flash, PCM has the potential to improve the random access time, read throughput (versus NOR flash), write throughput (versus NAND flash), direct write, bit granularity, and endurance, as well as to be scalable beyond flash technology. The interest of the semiconductor industries for the PCM technology has led to several research programs that culminated in the mass production in 2012 of a 1 GB PCM chip for mobile applications.
Substrate Integrated Multibeam Antennas
Authors: Cheng Yu J.
Published: November 2016

There is an increasing need for antennas with multiple beam capability to satisfy the growing demand for communication systems and multiple target radars. In the millimeter‐wave frequency band, the power budget is usually costly and difficult to satisfy the requirement for long‐distance and wide‐coverage applications. Therefore, high‐gain, high‐efficient multibeam antennas are necessary for millimeter‐wave systems to improve their performances. An antenna array scheme based on the passive beamforming network (BFN) is an efficient way to form multiple beams in different directions from the same aperture. Depending on simple circuitry and cheap cost, this type of multibeam antenna can be a substitution of passive, active, and digital phased arrays.

The currently popular substrate integrated waveguide (SIW) techniques, also called as postwall waveguide or laminated waveguide, combine the best and complementary features of both planar transmission lines and nonplanar waveguides. Thus, it is found very appropriate to construct different high‐frequency circuits and antennas that have been validated by several successful examples.

This article presents recent achievements in the development of microwave and millimeter‐wave substrate integrated beamforming networks (BFNs) incorporating both lens‐ and circuit‐based types. They include SIW Butler matrix, Blass matrix, Nolen matrix, Rotman lens, R‐KR lens, reflector lens, and multimode lens. Integrated with proper antennas, compact and on‐substrate multibeam antenna arrays are achieved with good performance. Such a series of SIW BFNs and multibeam antennas present excellent candidates for low‐cost and mass‐reproducible applications in space‐ and ground‐based integrated systems with multiple beam capability.
Tissue Engineering Biomaterials
Authors: Ma Peter X. , Eyster Thomas W. , Doleyres Yasmine
Published: November 2016

Tissue engineering has shown great promise in developing novel therapies for treating injured tissue and organ failure. Scaffolds play a pivotal role in tissue engineering. Biodegradable polymers are the primary choice of material for tissue engineering scaffolds, due to their numerous advantageous properties. In this article, the principles of tissue engineering are discussed in relation to polymer science and engineering. The most frequently used polymers in tissue engineering are briefly reviewed. These include synthetic and natural polymers commonly used in constructing both porous and hydrogel scaffolds. Their structure and critical properties in relation to scaffold function are discussed in depth, along with a detailed review of the important roles functionalized materials and controlled release play in tissue engineering. Important polymer processing techniques in the context of scaffold fabrication are also reviewed. These include the textile technologies, electrospinning, particulate‐leaching techniques, phase‐separation techniques, rapid prototyping, and other novel three‐dimensional (3D) fabrication techniques. In this update, the impact of pluripotent stem cells, conductive polymers, controlled drug release, 3D printing, and nanofibrous topology on tissue engineering are also discussed.
Combining snow, streamflow, and precipitation gauge observations to infer basin‐mean precipitation
Authors: Henn Brian , Clark Martyn P. , Kavetski Dmitri , McGurk Bruce , Painter Thomas H. , Lundquist Jessica D.
Published: November 2016

Precipitation data in mountain basins are typically sparse and subject to uncertainty due to difficulties in measurement and capturing spatial variability. Streamflow provides indirect information about basin‐mean precipitation, but inferring precipitation from streamflow requires assumptions about hydrologic model structure that influence precipitation amounts. In this study, we test the extent to which using both snow and streamflow observations reduces differences in inferred annual total precipitation, compared to inference from streamflow alone. The case study area is the upper Tuolumne River basin in the Sierra Nevada of California, where distributed and basin‐mean snow water equivalent (SWE) estimates have been made using LiDAR as part of the NASA Airborne Snow Observatory (ASO). To reconstruct basin‐mean SWE for years prior to the ASO campaign, we test for a robust relationship between SWE estimates from ASO and from snow courses and pillows, which have a longer record. Relative to ASO's distributed SWE observations, point SWE measurements in this part of the Sierra Nevada tend to overestimate SWE at a given elevation, but undersample high‐elevation areas. We then infer precipitation from snow and streamflow, obtained from multiple hydrologic model structures. When included in precipitation inference, snow data reduce by up to one third the standard deviations of the water year total precipitation between model structures and improve the consistency between structures in terms of the yearly variability in precipitation. We reiterate previous findings that multiple types of hydrologic data improve the consistency of modeled physical processes and help identify the most appropriate model structures.
Two black carbon pools transported by the Changjiang and Huanghe Rivers in China
Authors: Wang Xuchen , Xu Caili , Druffel Ellen M. , Xue Yuejun , Qi Yuanzhi
Published: November 2016

Major rivers play important roles in transporting large amounts of terrestrial organic matter from land to the ocean each year, and the organic matter carried by rivers contains a significant fraction of black carbon (BC). A recent study estimated that 0.027 Gt of BC is transported in the dissolved phase by rivers each year, which accounts for ~10% of the global flux of dissolved organic carbon. The relative sources of this large amount of riverine dissolved black carbon (DBC) from biomass burning (young, modern 14C) and fossil fuel (old, 14C free) combustion are not known. We present radiocarbon measurements of BC in both dissolved and particulate phases transported by the Changjiang and Huanghe Rivers, the two largest rivers in China, during 2015. We show that two, distinct BC pools (young and old) were carried by the rivers. The DBC pool was much younger than the particulate BC (PBC) pool. Mass balance calculations indicate that most (78–85%) of the DBC in the Changjiang and Huanghe Rivers was derived from biomass burning, and only 15–22% was from fossil fuel combustion. In contrast, PBC from biomass burning and fossil fuel combustion were approximately equal in these two rivers. Export of PBC and DBC by the rivers are decoupled, and fluxes of PBC were 4.1 and 6.7 times higher than DBC in the Changjiang and Huanghe Rivers, respectively. The 14C age differences of the two BC pools suggest that BC derived from biomass burning and fossil fuel combustion are mobilized in different phases and on different time scales in these rivers.
A practical tool for examining paleoerosion rates from sedimentary deposits using cosmogenic radionuclides: Examples from hypothetical scenarios and data
Authors: Val Pedro , Hoke Gregory D.
Published: November 2016

We provide a MatlabTM‐based algorithm that calculates paleoerosion rates based on measured Cosmogenic Radionuclide (CRN) concentrations from sedimentary deposits and additional geological constraints provided by the user. Based on the input data, the algorithm models CRN concentrations accumulated due to sediment burial and the subsequent exhumation of these deposits. Description of the methods and applications of the algorithm are provided, which includes single or coupled CRNs (i.e., 10Be or 10Be + 26Al). Results from the literature are reproduced. Further applicability of this algorithm is demonstrated with hypothetical scenarios of paleoerosion rates. The tool can be used toward the exploration of necessary assumptions, feasibility of case‐studies, and method limits. This contribution accompanies an overview of the paleoerosion rate method, its applications, and necessary assumptions.
Cryogenic flow features on Ceres: Implications for crater‐related cryovolcanism
Authors: Krohn K. , Jaumann R. , Stephan K. , Otto K. A. , Schmedemann N. , Wagner R. J. , Matz K.‐D. , Tosi F. , Zambon F. , von der Gathen I. , Schulzeck F. , Schröder S. E. , Buczkowski D. L. , Hiesinger H. , McSween H. Y. , Pieters C. M. , Preusker F. , Roatsch T. , Raymond C. A. , Russell C. T. , Williams D. A.
Published: November 2016

Craters on Ceres, such as Haulani, Kupalo, Ikapati, and Occator show postimpact modification by the deposition of extended plains material with pits, multiple lobate flows, and widely dispersed deposits that form a diffuse veneer on the preexisting surface. Bright material units in these features have a negative spectral slope in the visible range, making it appear bluish with respect to the grey‐toned overall surface of Ceres. We calculate the drop height‐to‐runout length ratio of several flow features and obtain a coefficient of friction of < 0.1: The results imply higher flow efficiency for flow features on Ceres than for similar features on other planetary bodies with similar gravity, suggesting low‐viscosity material. The special association of flow features with impact craters could either point to an impact melt origin or to an exogenic triggering of cryovolcanic processes.
Work done by atmospheric winds on mesoscale ocean eddies
Authors: Xu Chi , Zhai Xiaoming , Shang Xiao‐Dong
Published: November 2016

Mesoscale eddies are ubiquitous in the ocean and dominate the ocean's kinetic energy. However, physical processes influencing ocean eddy energy remain poorly understood. Mesoscale ocean eddy‐wind interaction potentially provides an energy flux into or out of the eddy field, but its effect on ocean eddies has not yet been determined. Here we examine work done by atmospheric winds on more than 1,200,000 mesoscale eddies identified from satellite altimetry data and show that atmospheric winds significantly damp mesoscale ocean eddies, particularly in the energetic western boundary current regions and the Southern Ocean. Furthermore, the large‐scale wind stress curl is found to on average systematically inject kinetic energy into anticyclonic (cyclonic) eddies in the subtropical (subpolar) gyres while mechanically damps anticyclonic (cyclonic) eddies in the subpolar (subtropical) gyres.
First performance results of a new field‐widened spatial heterodyne spectrometer for geocoronal Hα research
Authors: Gardner D. D. , Mierkiewicz E. J. , Roesler F. L. , Harlander J. M. , Jaehnig K. P. , Nossal S. M. , Haffner L. M.
Published: November 2016

A new, high‐resolution field‐widened spatial heterodyne spectrometer (FW‐SHS) designed to observe geocoronal Balmer α (Hα, 6563 Å) emission was installed at Pine Bluff Observatory (PBO) near Madison, Wisconsin. FW‐SHS observations were compared with an already well‐characterized dual‐etalon Fabry‐Perot Interferometer (PBO FPI) optimized for Hα, also at PBO. The FW‐SHS is a robust Fourier transform instrument that combines a large throughput advantage with high spectral resolution and a relatively long spectral baseline (~10 times that of the PBO FPI) in a compact, versatile instrument with no moving parts. Coincident Hα observations by FW‐SHS and PBO FPI were obtained over similar integration times, resolving powers (~67,000 and 80,000 at Hα) and fields of view (1.8° and 1.4°, respectively). First light FW‐SHS observations of Hα intensity and temperature (Doppler width) versus viewing geometry (shadow altitude) show excellent relative agreement with the geocoronal observations previously obtained at PBO by FPI. The FW‐SHS has a 640 km/s (14 Å) spectral band pass and is capable of determining geocoronal Hα Doppler shifts on the order of 100 m/s with a temporal resolution on the order of minutes. These characteristics make the FW‐SHS well suited for spectroscopic studies of relatively faint (~12–2 R), diffuse‐source geocoronal Hα emission from Earth's upper thermosphere and exosphere and the interstellar medium in our Galaxy. Current and future FW‐SHS observations extend long‐term geocoronal hydrogen observation data sets already spanning three solar minima. This paper describes the FW‐SHS first light performance and Hα observational results collected from observing nights across 2013 and 2014.
Identification of scintillation signatures on GPS signals originating from plasma structures detected with EISCAT incoherent scatter radar along the same line of sight
Authors: Forte Biagio , Coleman Chris , Skone Susan , Häggström Ingemar , Mitchell Cathryn , Da Dalt Federico , Panicciari Tommaso , Kinrade Joe , Bust Gary
Published: November 2016

Ionospheric scintillation originates from the scattering of electromagnetic waves through spatial gradients in the plasma density distribution, drifting across a given propagation direction. Ionospheric scintillation represents a disruptive manifestation of adverse space weather conditions through degradation of the reliability and continuity of satellite telecommunication and navigation systems and services (e.g., European Geostationary Navigation Overlay Service, EGNOS). The purpose of the experiment presented here was to determine the contribution of auroral ionization structures to GPS scintillation. European Incoherent Scatter (EISCAT) measurements were obtained along the same line of sight of a given GPS satellite observed from Tromso and followed by means of the EISCAT UHF radar to causally identify plasma structures that give rise to scintillation on the co‐aligned GPS radio link. Large‐scale structures associated with the poleward edge of the ionospheric trough, with auroral arcs in the nightside auroral oval and with particle precipitation at the onset of a substorm were indeed identified as responsible for enhanced phase scintillation at L band. For the first time it was observed that the observed large‐scale structures did not cascade into smaller‐scale structures, leading to enhanced phase scintillation without amplitude scintillation. More measurements and theory are necessary to understand the mechanism responsible for the inhibition of large‐scale to small‐scale energy cascade and to reproduce the observations. This aspect is fundamental to model the scattering of radio waves propagating through these ionization structures. New insights from this experiment allow a better characterization of the impact that space weather can have on satellite telecommunications and navigation services.
Partitioning of integrated energy fluxes in four tail reconnection events observed by Cluster
Authors: Tyler Evan , Cattell Cynthia , Thaller Scott , Wygant John , Gurgiolo Chris , Goldstein Melvyn , Mouikis Christopher
Published: November 2016

We present the partitioning of integrated energy flux from four tail reconnection events observed by Cluster, focusing on the relative contributions of Poynting flux, electron, H+ and O+ enthalpy, and kinetic energy flux in the tailward and earthward directions in order to study temporal and spatial features of each event. We further subdivide the Poynting flux into three frequency bands to examine the possible structures and waves that contribute most significantly to the total Poynting flux from the reconnection region. Our results indicate that H+ enthalpy flux is often dominant, but O+ enthalpy, electron enthalpy, Poynting flux, and H+ kinetic energy flux can contribute significant or greater total energy flux depending on spacecraft location with respect the current sheet, flow direction, temporal scale, and local conditions. We observe integrated H+ enthalpy fluxes that differ by factors of 3–4 between satellites, even over ion inertial length scales. We observe strong differences in behavior between H+ and O+ enthalpy fluxes in all events, highlighting the importance of species‐specific energization mechanisms. We find tailward‐earthward asymmetry in H+ enthalpy flux, possibly indicative of the influence of the closed earthward boundary of the magnetotail system. Frequency filtering of the Poynting flux shows that current sheet surface waves and structures on the timescale of current sheet flapping contribute significantly, while large‐scale structure contributions are relatively small. We observe that the direction and behavior of the Poynting flux differs between bands, indicating that the observed flux originates from multiple distinct sources or processes.
Three‐dimensional ionospheric tomography reconstruction using the model function approach in Tikhonov regularization
Authors: Wang Sicheng , Huang Sixun , Xiang Jie , Fang Hanxian , Feng Jian , Wang Yu
Published: November 2016

Ionospheric tomography is based on the observed slant total electron content (sTEC) along different satellite‐receiver rays to reconstruct the three‐dimensional electron density distributions. Due to incomplete measurements provided by the satellite‐receiver geometry, it is a typical ill‐posed problem, and how to overcome the ill‐posedness is still a crucial content of research. In this paper, Tikhonov regularization method is used and the model function approach is applied to determine the optimal regularization parameter. This algorithm not only balances the weights between sTEC observations and background electron density field but also converges globally and rapidly. The background error covariance is given by multiplying background model variance and location‐dependent spatial correlation, and the correlation model is developed by using sample statistics from an ensemble of the International Reference Ionosphere 2012 (IRI2012) model outputs. The Global Navigation Satellite System (GNSS) observations in China are used to present the reconstruction results, and measurements from two ionosondes are used to make independent validations. Both the test cases using artificial sTEC observations and actual GNSS sTEC measurements show that the regularization method can effectively improve the background model outputs.
Controlling factors of rainwater and water vapor isotopes at Bangalore, India: Constraints from observations in 2013 Indian monsoon
Authors: Rahul P. , Ghosh Prosenjit , Bhattacharya S. K. , Yoshimura Kei
Published: November 2016

Isotopic ratios of rainwaters are believed to decrease with the amount of rainfall. However, analyses of the isotopic composition of rainwater and water vapor samples collected from Bangalore during the monsoon period of 2013 fail to show any simple relationship with the local meteorological parameters whereas show good correlation with the regional integrated convective activity. The correlation is particularly high when the averaging is done over the preceding 8 to 15 days, showing the influence of mixing or residence time scale of atmospheric moisture. This observation emphasizes the role of regional atmospheric circulation driving the isotopic values. A comparison between observed isotope ratios in water vapor and rainwater with Isotope‐enabled Global Spectral Model shows discrepancies between the two. The observed values are relatively enriched, indicating a systematic bias in the model values. The higher observed values suggest underestimation of the evaporation in the model, which we estimate to be about 28 ± 15% on average. Simultaneous analyses of rainwater and water vapor isotopic composition again show definitive presence of raindrop evaporation (31 ± 14%). We also documented a distinct pattern of isotopic variation in six samples collected at Bangalore due to mixing of vapor from a cyclonic system in close proximity that originated from the Bay of Bengal. It seems that large‐scale isotopic depletion occurs during cyclones caused by Rayleigh fractionation due to massive rainout. These results demonstrate the power of rainwater and water vapor isotope monitoring to elucidate the genesis and dynamics of water recycling within synoptic‐scale monsoon systems.
Reply to Comment by Xu et al. on “Sr‐Nd isotope composition and clay mineral assemblages in eolian dust from the central Philippine Sea over the last 600 kyr: Implications for the transport mechanism of Asian dust” by Seo et al.
Authors: Seo Inah , Lee Yong Il , Yoo Chan Min , Kim Hyung Jeek , Hyeong Kiseong
Published: November 2016

Against Xu et al. (2016), who argued that East Asian Desert (EAD) dust that traveled on East Asian Winter Monsoon winds dominates over Central Asian Desert (CAD) dust in the Philippine Sea with presentation of additional data, we reconfirm Seo et al.'s (2014) conclusion that CAD dust carried on the Prevailing Westerlies and Trade Winds dominates over EAD dust in overall dust budget of the central Philippine Sea. The relative contribution of dust from EADs and CADs using clay mineral composition should be evaluated with elimination of mineralogical contribution from the volcanic end‐member which is enriched in kaolinite and overestimate the contribution of EAD dust.
Geodetic mass balance of surge‐type Black Rapids Glacier, Alaska, 1980–2001–2010, including role of rockslide deposition and earthquake displacement
Authors: Kienholz C. , Hock R. , Truffer M. , Arendt A. A. , Arko S.
Published: November 2016

We determine the geodetic mass balance of surge‐type Black Rapids Glacier, Alaska, for the time periods 1980–2001 and 2001–2010 by combining modern interferometric synthetic aperture radar (InSAR)‐derived digital elevation models (DEMs), DEMs derived from archival aerial imagery, laser altimetry data, and in situ surface elevation measurements. Our analysis accounts for both the large rockslides and terrain displacements caused by the 2002 M7.9 earthquake on the Denali fault, which runs through Black Rapids Glacier. To estimate uncertainties, we apply Monte Carlo simulations. For the earthquake‐triggered rockslides we find a volume of 56.62 ± 2.86 × 106 m3, equivalent to an average debris thickness of 4.44 ± 0.24 m across the 11.7 km2 deposit area on the glacier. Terrain displacement due to the earthquake corresponds to an apparent glacier volume change of −53.1 × 106 m3, which would cause an apparent specific mass balance of −0.19 meter water equivalent (mwe) if not taken into account. The geodetic mass balance of Black Rapids Glacier is −0.48 ± 0.07 mwe a−1 for the entire 30 year period, but more negative for the period 2001–2010 (−0.64 ± 0.11 mwe a−1) than the period 1980–2001 (−0.42 ± 0.11 mwe a−1), in agreement with trends indicated by in situ mass balance measurements. Elevation data indicate no net thickening of the surge reservoir between 1980 and 2010, in contrast to what is expected during the quiescent phase. A surge of Black Rapids Glacier in the near future is thus considered unlikely.
Debris flow runup on vertical barriers and adverse slopes
Authors: Iverson Richard M. , George David L. , Logan Matthew
Published: November 2016

Runup of debris flows against obstacles in their paths is a complex process that involves profound flow deceleration and redirection. We investigate the dynamics and predictability of runup by comparing results from large‐scale laboratory experiments, four simple analytical models, and a depth‐integrated numerical model (D‐Claw). The experiments and numerical simulations reveal the important influence of unsteady, multidimensional flow on runup, and the analytical models highlight key aspects of the underlying physics. Runup against a vertical barrier normal to the flow path is dominated by rapid development of a shock, or jump in flow height, associated with abrupt deceleration of the flow front. By contrast, runup on sloping obstacles is initially dominated by a smooth flux of mass and momentum from the flow body to the flow front, which precedes shock development and commonly increases the runup height. D‐Claw simulations that account for the emergence of shocks show that predicted runup heights vary systematically with the adverse slope angle and also with the Froude number and degree of liquefaction (or effective basal friction) of incoming flows. They additionally clarify the strengths and limitations of simplified analytical models. Numerical simulations based on a priori knowledge of the evolving dynamics of incoming flows yield quite accurate runup predictions. Less predictive accuracy is attained in ab initio simulations that compute runup based solely on knowledge of static debris properties in a distant debris flow source area. Nevertheless, the paucity of inputs required in ab initio simulations enhances their prospective value in runup forecasting.