bluuebunny/crossref_metadata_2025 huggingface dataset:
APOGEE KINEMATICS. I. OVERVIEW OF THE KINEMATICS OF THE GALACTIC BULGE AS MAPPED BY APOGEE
Authors: Ness M. , Zasowski G. , Johnson J. A. , Athanassoula E. , Majewski S. R. , Pérez A. E. García , Bird J. , Nidever D. , Schneider Donald P. , Sobeck J. , Frinchaboy P. , Pan Kaike , Bizyaev Dmitry , Oravetz Daniel , Simmons Audrey
Published: February 2016

We present the stellar kinematics across the Galactic bulge and into the disk at positive longitudes from the SDSS-III APOGEE spectroscopic survey of the Milky Way. APOGEE includes extensive coverage of the stellar populations of the bulge along the midplane and near-plane regions. From these data, we have produced kinematic maps of 10,000 stars across longitudes of 0° < l < 65°, and primarily across latitudes of

< 5° in the bulge region. The APOGEE data reveal that the bulge is cylindrically rotating across all latitudes and is kinematically hottest at the very center of the bulge, with the smallest gradients in both kinematic and chemical space inside the innermost region

 < (5°, 5°). The results from APOGEE show good agreement with data from other surveys at higher latitudes and a remarkable similarity to the rotation and dispersion maps of barred galaxies viewed edge-on. The thin bar that is reported to be present in the inner disk within a narrow latitude range of

< 2° appears to have a corresponding signature in

and

. Stars with

> −0.5 have dispersion and rotation profiles that are similar to that of N-body models of boxy/peanut bulges. There is a smooth kinematic transition from the thin bar and boxy bulge

< (15°, 12°) out to the disk for stars with

> −1.0, and the chemodynamics across (l, b) suggests that the stars in the inner Galaxy with

> −1.0 originate in the disk.
NuSTAR UNVEILS A HEAVILY OBSCURED LOW-LUMINOSITY ACTIVE GALACTIC NUCLEUS IN THE LUMINOUS INFRARED GALAXY NGC 6286
Authors: Ricci C. , Bauer F. E. , Treister E. , Romero-Cañizales C. , Arevalo P. , Iwasawa K. , Privon G. C. , Sanders D. B. , Schawinski K. , Stern D. , Imanishi M.
Published: February 2016

We report the detection of a heavily obscured active galactic nucleus (AGN) in the luminous infrared galaxy (LIRG) NGC 6286 identified in a 17.5 ks Nuclear Spectroscopic Telescope Array observation. The source is in an early merging stage and was targeted as part of our ongoing NuSTAR campaign observing local luminous and ultra-luminous infrared galaxies in different merger stages. NGC 6286 is clearly detected above 10 keV and by including the quasi-simultaneous Swift/XRT and archival XMM-Newton and Chandra data, we find that the source is heavily obscured (N
H ≃(0.95−1.32) × 1024 cm−2) with a column density consistent with being Compton-thick (CT,

). The AGN in NGC 6286 has a low absorption-corrected luminosity (L
2−10 keV ∼ 3−20 × 1041 erg s−1) and contributes ≲1% to the energetics of the system. Because of its low luminosity, previous observations carried out in the soft X-ray band (<10 keV) and in the infrared did not notice the presence of a buried AGN. NGC 6286 has multiwavelength characteristics typical of objects with the same infrared luminosity and in the same merger stage, which might imply that there is a significant population of obscured low-luminosity AGNs in LIRGs that can only be detected by sensitive hard X-ray observations.
EVOLUTIONARY TRACKS FOR BETELGEUSE
Authors: Dolan Michelle M. , Mathews Grant J. , Lam Doan Duc , Lan Nguyen Quynh , Herczeg Gregory J. , Dearborn David S. P.
Published: February 2016

We have constructed a series of nonrotating quasi-hydrostatic evolutionary models for the M2 Iab supergiant Betelgeuse (α Orionis). Our models are constrained by multiple observed values for the temperature, luminosity, surface composition, and mass loss for this star, along with the parallax distance and high-resolution imagery that determines its radius. We have then applied our best-fit models to analyze the observed variations in surface luminosity and the size of detected surface bright spots as the result of up-flowing convective material from regions of high temperature in the surface convective zone. We also attempt to explain the intermittently observed periodic variability in a simple radial linear adiabatic pulsation model. Based on the best fit to all observed data, we suggest a best progenitor mass estimate of

and a current age from the start of the zero-age main sequence of 8.0–8.5 Myr based on the observed ejected mass while on the giant branch.
ARE WE THERE YET? TIME TO DETECTION OF NANOHERTZ GRAVITATIONAL WAVES BASED ON PULSAR-TIMING ARRAY LIMITS
Authors: Taylor S. R. , Vallisneri M. , Ellis J. A. , Mingarelli C. M. F. , Lazio T. J. W. , Haasteren R. van
Published: February 2016

Decade-long timing observations of arrays of millisecond pulsars have placed highly constraining upper limits on the amplitude of the nanohertz gravitational-wave stochastic signal from the mergers of supermassive black hole binaries (∼10−15 strain at f = 1 yr−1). These limits suggest that binary merger rates have been overestimated, or that environmental influences from nuclear gas or stars accelerate orbital decay, reducing the gravitational-wave signal at the lowest, most sensitive frequencies. This prompts the question whether nanohertz gravitational waves (GWs) are likely to be detected in the near future. In this Letter, we answer this question quantitatively using simple statistical estimates, deriving the range of true signal amplitudes that are compatible with current upper limits, and computing expected detection probabilities as a function of observation time. We conclude that small arrays consisting of the pulsars with the least timing noise, which yield the tightest upper limits, have discouraging prospects of making a detection in the next two decades. By contrast, we find large arrays are crucial to detection because the quadrupolar spatial correlations induced by GWs can be well sampled by many pulsar pairs. Indeed, timing programs that monitor a large and expanding set of pulsars have an ∼80% probability of detecting GWs within the next 10 years, under assumptions on merger rates and environmental influences ranging from optimistic to conservative. Even in the extreme case where 90% of binaries stall before merger and environmental coupling effects diminish low-frequency gravitational-wave power, detection is delayed by at most a few years.
ALMA OBSERVATIONS OF A GAP AND A RING IN THE PROTOPLANETARY DISK AROUND TW HYA
Authors: Nomura Hideko , Tsukagoshi Takashi , Kawabe Ryohei , Ishimoto Daiki , Okuzumi Satoshi , Muto Takayuki , Kanagawa Kazuhiro D. , Ida Shigeru , Walsh Catherine , Millar T. J. , Bai Xue-Ning
Published: February 2016

We report the first detection of a gap and a ring in 336 GHz dust continuum emission from the protoplanetary disk around TW Hya, using the Atacama Large Millimeter/Submillimeter Array (ALMA). The gap and ring are located at around 25 and 41 au from the central star, respectively, and are associated with the CO snow line at ∼30 au. The gap has a radial width of less than 15 au and a mass deficit of more than 23%, taking into account that the observations are limited to an angular resolution of ∼15 au. In addition, the 13CO and C18O

lines show a decrement in CO line emission throughout the disk, down to ∼10 au, indicating a freeze-out of gas-phase CO onto grain surfaces and possible subsequent surface reactions to form larger molecules. The observed gap could be caused by gravitational interaction between the disk gas and a planet with a mass less than super-Neptune (2

), or could be the result of the destruction of large dust aggregates due to the sintering of CO ice.
La luz y el color en la pintura de El Greco
Authors: Company Ximo
Published: February 2016

El presente trabajo reconsidera el extraordinario valor estético de la luz y el color en la pintura de El Greco, entendidas ambas categorías como el resultado de un extenso y meditado proceso mental y creativo del gran maestro cretense. Ahonda, además, en la urgente necesidad de practicar una historia del arte en España que equilibre la excesiva hipertrofia del dato literario en beneficio de un conocimiento de la pintura más en directo y a pie de obra.
Nuevos campos abiertos a la investigación a partir de algunas exposiciones dedicadas a la obra de El Greco
Authors: Mateo Gómez Isabel
Published: February 2016

Antes de que en 1579 El Greco pintara El Expolio, un pintor toledano, Juan Correa de Vivar, había interpretado este tema cuatro veces, en las décadas de los cuarenta, cincuenta y sesenta. Las anomalías iconográficas del tema respecto a los Evangelios Canónicos, que aparecen ya en las composiciones de Correa, están inspiradas en la literatura mística medieval, ligada a la Orden Cisterciense.
Otro enigma de El Greco: ¿un pintor escéptico que realiza pintura religiosa?
Authors: Rodríguez G. de Ceballos Alfonso
Published: February 2016

Frente a la opinión reciente, El Greco no solo fue pintor de amplísima obra religiosa, sino personalmente de arraigadas convicciones religiosas, tanto como miembro de una familia de fe ortodoxa como también después de su paso al catolicismo romano, como lo demuestran muchos episodios y acontecimientos de su vida y muerte. Avalan esta suposición tanto la correcta y tradicional iconografía de su pintura sacra, cuanto muchas de las características ideológicas, técnicas y expresivas de su obra.
IPad in Elementary School Math Learning Setting
Authors: Al-Mashaqbeh Ibtesam Fares
Published: February 2016

The aim of this study was to investigate the difference between the effect of using traditional teaching instruction and using iPad to teach math for first grade students. This study was conducted in one private elementary school in Jordan. The study used a quasi-experimental control design. Students have access to a few math software and websites that was downloaded to improve their math skills. Every student in the experimental group will have a personal iPad to be used during their math class period. Both groups will be given a pre-test and a post-test to measure their achievements in math. The motive for this research was encouraging teachers and students to use iPad for educational purpose instead of use it most of the time for fun and games. it a helpful tool to be used as part of the mathematic learning process. Also, there are many software and internet sites that can be downloading in the iPadt to improve students’ math skills. Index Terms — math, tablet, e-textbook, e-learning, education, educational technology.
Dyslexia and ICTs, Assessment and Early Intervention in Kindergarten
Authors: Drigas Athanasios , Batziaka Elektra
Published: February 2016

This article is a review of how Information and Communication Technologies (ICTs) help in the assessment and early intervention of reading disabilities (RD) and especially of dyslexia. Phonological awareness is highlighted as a main ability that predicts later reading skills. Here are presented several studies that display computer games, programs and applications by which teachers can intervene to boost phonological awareness and help preventing RD or dyslexia from an early age. Most studies focus in preschool age, although dyslexia in kindergarten is a field that has not been investigated thoroughly, and are certainly a precursor for studies to follow.
Optimization of Chemical Composition and Heat Treatment of High-Carbon Iron Alloys with 14% Chromium and 3% Vanadium
Authors: Koryagin Yu.D. , Okishev K.Yu. , Sozykina A.S.
Published: February 2016

A series of iron alloys for wear applications containing 14 %Cr, 3 %V and 1.5 to 4.2 %C is investigated in as-cast and quenched condition. In almost all alloys carbide phases were hexagonal M7C3 and cubic VC carbides. Critical points of the alloys were determined dilatometrically; cooling from 1000 °C at a rate of 0.4 K/s results in diffusional decomposition of austenite, and at the rate of 15 K/s (air) - in martensitic transformation. The experiments on modifying the alloys with 0.1–0.5 %Ce showed that cerium refines the structure at the concentrations not exceeding 0.3 %Ce. Strength and wear resistance reach maximum at ~ 0.2–0.3 %Ce, and alloy hardness is not significantly affected. Heat treated (quench hardened) alloys show typical behaviour of high-carbon ledeburitic alloys, viz. hardness as a function of quenching temperature reaches maximum when the amount of retained austenite is increased. The greatest hardness of 68.5 HRC is achieved in the 3.5 %C alloy, which also has the highest wear resistance. A method of phase composition and hardness calculation for high-carbon alloys based on thermodynamic description of ternary system Fe–Cr–C is presented; the calculation results align with the experimental data.
Calculation of Adsorption Parameters for Lithium on Carbon Nanotube (7,7) with a Double Vacancy
Authors: Sozykin Sergey Anatolevich , Beskachko Valeriy Petrovich , Vyatkin G.P.
Published: February 2016

The adsorption of lithium atoms on carbon nanotubes with double vacancy structural defects (2V-defect) is being studied with first-principle modeling. The structure of defective tubes in ground state is considered, the role of effects related to finite sizes of a model is evaluated. It is demonstrated that the location of a carbon 8-ring formed by 2V-defect above the center is the most preferable for a lithium atom.
Magnetic Properties of Mn Substituted Barium Hexaferrite Single Crystals
Authors: Vinnik D.A. , Zakharchuk I.A. , Lähderanta Erkki
Published: February 2016

This paper presents magnetic properties of manganese substituted barium hexaferrite BaFe12-xMnxO19 single crystals. Crystals of BaFe12–xMnxO19 with x up to 1.5 and sizes up to 8 mm were observed. The influence of Fe substitution by Mn on the magnetic properties was investigated. For the BaFe10.5Mn1.5O19 single crystal samples saturation magnetization reduced from 72 to 63.5 emu/g at room temperature, and Curie temperature decreased from 455 to 380 °C.
The Influence of the Current Density in the Open Welding Arc Active Spots on Cathode and Anode Voltage Breakdowns
Authors: Osipov A.M. , Bezgans Yuriy Viktorovich , Bezgans T.V.
Published: February 2016

Surfacing in gas-shielded as well as by the open arc burning between consumable electrodes, is usually made in reverse polarity. It is connected with the stable burning of arc and the minimum spatter of electrode metal. In this case, the cathode spot of the welding arc is on the plate, and the anode spot is on the wire end. These conditions of the arc spots existence affect the processes proceeding in the cathode and anode areas of the arc. The article considers the influence of the arc active spots formation conditions and its modes on the cathode and anode voltage breakdowns.
Intercritical Quench Hardening of Structural Pipeline Steels
Authors: Mirzaev D.A. , Makovetskii A.N.
Published: February 2016

The paper considers the effect of low-carbon pipeline steels initial condition on their mechanical properties and structure after quench hardening at different temperatures in the intercritical temperature range Ac1–Ac3 (ITR) followed by tempering at 600 °C. If the prior heat treatment is annealing or normalizing , which produces the ferrite-pearlite structure, then quenching from temperatures just above Ac1 causes very strong embrittlement due to the formation of a high-carbon austenite film at ferrite/pearlite boundaries. Increasing quenching temperature in the intercritical range increases impact toughness and ductile fracture fraction for both types of prior treatment, though normalizing provides higher impact toughness than annealing. On the contrary, if the prior heat treatment is quench hardening, then the highest impact toughness is observed when the second quenching temperature lies a little above Ac1. Impact toughness and ductile fraction for preliminarily quenched samples gradually decreases along with the increase in austenitization temperature in the intercritical range.
Pilot Testing of the Waste Metalworking Fluids Biosorption Treatment
Authors: Shulaev M.V. , Khramova I.A. , Emelyanov V.M.
Published: February 2016

Metalworking fluids are liquid wastes of the machines cutting, cooling, and lubrication operations coming in the form of emulsified oil. Waste metalworking fluids in the emulsified form are liberated into the environment through machining wastewater which becomes contaminated with microorganisms and results in a drastic problem of water pollution. To reduce its polluting biosorption the method of treating waste metalworking fluids was employed. An investigation into the anaerobic biological wastewater treatment was conducted for 50 days with the initial sludge dose 2.8 g/l in a horizontal tank with a drum-type mixing device. The results of this study indicate that the existing industrial-activated sludge plant could be used to treat waste MWFs under anaerobic conditions after the additional treatment by fermentation at a temperature of 32-37 оС with nutritional elements input at certain days. The efficiency of biosorption treatment using the granular diatomite as an adsorbent is insignificantly inferior to the system with granular activated carbon SKT-3. So it would be more reasonable to use the diatomite in industrial plants because it is significantly cheaper than the granular activated carbon and there are large quantities available. The COD reduction was significant but to achieve optimum performance further investigation is needed.
Development of the Technology of Eco-Friendly Single-Layer Vitreous Art Enamels for Copper
Authors: Yatsenko E.A. , Karandashova N.S. , Goltsman B.M.
Published: February 2016

The main types of enamel coatings for decorative arts were described. The best type of enamel - «hot» single-layer vitreous enamel - was established. The composition of the initial colorless enamel was designed; its basic properties were set. Wide palette of colored enamels based on the original enamel was developed. The manufacturing technology for the products based on the developed enamels was described.
Atomic Structure and Mechanical Properties of Defective Carbon Nanotube (7,7)
Authors: Sozykin Sergey Anatolevich , Beskachko Valeriy Petrovich , Vyatkin G.P.
Published: February 2016

The article presents the results of first-principle modeling of a defectless (7,7) carbon nanotube and (7,7) nanotubes containing single and double vacancy defects, as well as Stone–Wales defects. These types of defects are often found in real nanotubes and affect their properties. We have established that reliable results can be obtained by using models of more than 1.5 nm in length. It turned out that a single vacancy defect has the least influence on Young modulus, and double n type vacancy defect in the most influential. The elongation at break also depends on the defect type and is 30-60% less than for perfect tubes.
Practical Nutrition Management of Children with Chronic Kidney Disease
Authors: Nguyen Lieuko , Levitt Rayna , Mak Robert H.
Published: February 2016

Chronic kidney disease (CKD) introduces a unique set of nutritional challenges for the growing and developing child. This article addresses initial evaluation and ongoing assessment of a child with CKD. It aims to provide an overview of nutritional challenges unique to a pediatric patient with CKD and practical management guidelines. Caloric assessment in children with CKD is critical as many factors contribute to poor caloric intake. Tube feeding is a practical option to provide the required calories and fluid in children who have difficulty with adequate oral intake. Protein intake should not be limited and should be further adjusted for protein loss with dialysis. Supplementation or restriction of sodium is patient specific. Urine output, fluid status, and modality of dialysis are factors that influence sodium balance. Hyperkalemia poses a significant cardiac risk, and potassium is closely monitored. In addition to a low potassium diet, potassium binders may be prescribed to reduce potassium load from oral intake. Phosphorus and calcium play a significant role in cardiovascular and bone health. Phosphorus binders have helped children and families manage phosphorus levels in conjunction with a phosphorus-restricted diet. Nutritional management of children with CKD is a challenge that requires continuous reassessment and readjustment as the child ages, CKD progresses, and urine output decreases.
Using UNIFORMAT and GENE[RATE] to Analyze Data with Ambiguities in Population Genetics
Authors: Nunes José Manuel
Published: February 2016

Some genetic systems frequently present ambiguous data that cannot be straightforwardly analyzed with common methods of population genetics. Two possibilities arise to analyze such data: one is the arbitrary simplification of the data and the other is the development of methods adapted to such ambiguous data. In this article, we present an attempt at such a development, the UNIFORMAT grammar and the GENEE[RATE] tools, highlighting the specific aspects and the adaptations required to analyze ambiguous nominal data in population genetics.
Identifying Flood-Related Infectious Diseases in Anhui Province, China: A Spatial and Temporal Analysis
Authors: Gao Lu , Zhang Ying , Ding Guoyong , Liu Qiyong , Jiang Baofa
Published: February 2016

The aim of this study was to explore infectious diseases related to the 2007 Huai River flood in Anhui Province, China. The study was based on the notified incidences of infectious diseases between June 29 and July 25 from 2004 to 2011. Daily incidences of notified diseases in 2007 were compared with the corresponding daily incidences during the same period in the other years (from 2004 to 2011, except 2007) by Poisson regression analysis. Spatial autocorrelation analysis was used to test the distribution pattern of the diseases. Spatial regression models were then performed to examine the association between the incidence of each disease and flood, considering lag effects and other confounders. After controlling the other meteorological and socioeconomic factors, malaria (odds ratio [OR] = 3.67, 95% confidence interval [CI] = 1.77–7.61), diarrhea (OR = 2.16, 95% CI = 1.24–3.78), and hepatitis A virus (HAV) infection (OR = 6.11, 95% CI = 1.04–35.84) were significantly related to the 2007 Huai River flood both from the spatial and temporal analyses. Special attention should be given to develop public health preparation and interventions with a focus on malaria, diarrhea, and HAV infection, in the study region.
The Spectrum of Chromobacterium violaceum Infections from a Single Geographic Location
Authors: Lin Yi dan , Majumdar Suman S. , Hennessy Jann , Baird Robert W.
Published: February 2016

Chromobacterium violaceum is a bacterium associated with soil and water exposure in tropical regions and causes rare and serious clinical infections that are often fatal. We reviewed the demographic and clinical details of 28 patients with C. violaceum detected over 15 years from 2000 to 2015, from the Top End of the Northern Territory. Of these patients, 18 had infections attributable to C. violaceum. Patients with infections were more commonly male (55.6%), and in the 16- to 60-year (61.1%) age group. Skin and soft tissue infections (50%), predominantly involving the limbs, were the major clinical manifestation. Water, mud exposure, and trauma were all noted as precipitating circumstances and comorbidities were present in 61.1% of the patients with infections. Of the 28 patients, 10 (35.8%) had C. violaceum isolated as an incidental finding or as asymptomatic colonization; these 10 patients did not require or receive therapy for C. violaceum bacterial infections. There were no relapsing infections in this group. Chromobacterium violaceum remains a serious infection, with seven patients (25%) in our series requiring intensive care management. However, the mortality rate (7.1%) in our series was far lower than previously described. This case series of C. violaceum infections from a single geographic area provides additional information of the characteristics of infection with this pathogen.
Humour and Irony in Dutch Post-War Fiction Film
Authors: Verstraten Peter
Published: February 2016

Dutch cinema, when discussed, is typically treated only in terms of pre-war films or documentaries, leaving post-war fictional film largely understudied. At the same time, a "Hollandse school," a term first coined in the 1980s, has developed through deadpan, ironic films like those of director and actor Alex van Warmerdam. Using seminal theories on humour and comedy, this book explores a number of Dutch films using the notion of categories, such as low-class comedies, neurotic romances, deliberate camp, and grotesque satire. With its original approach, this study makes surprising connections between Dutch films from various decades.
The Cynical Public: Claims about Science in the Discourse on Hydrofracking
Authors: Seale Elizabeth , Fulkerson Gregory
Published: February 2016

This content analysis of newspaper articles and online social media from English-speaking sources on the topic of ‘fracking’ interrogates the use of scientific legitimacy in claims-makings and how public understandings of science develop through these media. In both forms of media, science is invoked in one sense as rational and objective to either neutralize or support emotionally-charged accounts and fears of hydraulic fracturing dangers. In another sense, however, science is viewed as a bureaucratic tool used at the will of government and business interests and easily corrupted to support ideological or interest-based positions. Claims regarding science typically follow ideological positions rather than the reverse - the ‘science’ that supports fracking as safe is called into question by those skeptical of fracking, while the anti-fracking position is designated as ‘anti-science’ by those who favor fracking. These strategies as they play out in the media serve to spread uncertainty, heighten cynicism, and undermine public confidence in science. An understanding of science as incomplete and cumulative, however, lends itself to the precautionary principle.
Building a Research Partnership in a Prison Context: From Collaboration to Co-Construction
Authors: Brosens Dorien , De Donder Liesbeth , Dury Sarah , Verté Dominique
Published: February 2016

This research paper describes a framework for building a collaborative research partnership in a prison context. There is an increasing awareness of the added value of partnerships for prison research, but most academics and correctional institutions are not familiar with this methodology. Besides, this paper demonstrates that participatory research in a prison has the potential to increase the response rate and realize a better research design. The establishment of a steering group of professionals provided an important participation forum. The steering group was responsible for the design, planning, implementation, coordination and evaluation of the research project. Prisoners were central figures in providing information, giving feedback, etc. during the whole research process. This article evaluates the different methodological and practical steps in building the partnership and conducting the research. Furthermore, the ethical and emotional challenges associated with prison research as well as the challenges related to participatory research are considered. Conclusively, key factors are discussed that contributed to the success of the research project.
Risk, Choice and Social Disadvantage: Young People's Decision-Making in a Marketised Higher Education System
Authors: Clark Sheryl , Mountford-Zimdars Anna , Francis Becky
Published: February 2016

Rising tuition fees in England have been accompanied by a policy mandate for universities to widen participation by attracting students from socio-economically disadvantaged backgrounds. This article focuses on one such group of high achieving students and their responses to rising tuition fees within the context of their participation in an outreach scheme at a research-intensive university in the UK. Our findings suggest that rather than being deterred from attending university as a result of fee increases, these young people demonstrated a detailed and fairly sophisticated understanding of higher education provision as a stratified and marketised system and justified fees within a discourse of ‘private good.’ Our analysis situates their ‘risk’ responses within the discursive tensions of the fees/widening participation mandate. We suggest that this tension highlights an intensified commodification of the relationship between higher education institutions and potential students from disadvantaged backgrounds in which widening participation agendas have shifted towards recruitment exercises. We argue that an ongoing effect of this shift has resulted in increased instrumentalism and a narrowing of choices for young people faced with the task of seeking out ‘value for money’ in their degrees whilst concurrently engaging in a number of personalised strategies aimed at compensating for social disadvantage in a system beset by structural inequalities.
Charlie Hebdo, Free Speech and Counter-Speech
Authors: Dawes Simon
Published: February 2016

This brief rapid response article considers the French media framing of the Charlie Hebdo attack in terms of ‘Republican values’ such as free speech, and critiques the post-political and moralistic reduction of debate to ‘right and wrong’ arguments, as well as the fetishisation of the right to offend and the depoliticisation of the right to be offended.
Does imperfect information always disturb the evolution of reciprocity?
Authors: Kurokawa Shun
Published: February 2016

Reciprocity has long been regarded as a potential explanatory mechanism for the maintenance of cooperation. However, a possible problematic case relevant to the theory of reciprocity evolution arises when the information about an opponent’s behavior is imperfect. Although it has been confirmed that imperfect information disturbs the evolution of reciprocity, this argument is based on the assumption that those who attempt to cooperate always succeed in doing so. In reality, mistakes can occur, and previous studies have demonstrated that this can sway the evolution of reciprocity. In this study, removing the assumption that mistakes do not occur, we examine whether imperfect information disturbs the evolution of reciprocity in the iterated prisoner’s dilemma game with errors in behavior. It might be expected that when mistakes occur, reciprocity can evolve more in the case of imperfect information than in the case of perfect information. This is because in the former case, reciprocators can miss defections incurred by other reciprocators’ mistakes owing to imperfect information, which allows cooperation to persist. Contrary to this expectation, however, our analysis reveals that imperfect information still disturbs the evolution of reciprocity when mistakes occur. Additionally, we have determined that the condition under which reciprocity evolves remains unaffected, whatever reciprocators subsequently do when the opponent's last behavior was missed.
Pre-activation of ice-nucleating particles by the pore condensation and freezing mechanism
Authors: Wagner Robert , Kiselev Alexei , Möhler Ottmar , Saathoff Harald , Steinke Isabelle
Published: February 2016

Abstract. In spite of the resurgence in ice nucleation research a comparatively small number of studies deal with the phenomenon of pre-activation in heterogeneous ice nucleation. Fifty years ago, it was shown that various mineral dust and volcanic ash particles can be pre-activated to become nuclei for ice crystal formation even at temperatures as high as 270–271 K. Pre-activation was achieved under ice-subsaturated conditions without any preceding macroscopic ice growth by just temporarily cooling the particles to temperatures below 228 K. A two-step mechanism involving capillary condensation of supercooled water and subsequent homogeneous freezing was proposed to account for the particles' enhanced ice nucleation ability at high temperatures. This work reinvestigates the efficiency of the proposed pre-activation mechanism in temperature-cycling experiments performed in a large cloud chamber with suspended particles. We find the efficiency to be highest for the clay mineral illite as well as for highly porous materials like zeolite and diatomaceous earth, whereas most aerosols generated from desert dust surface samples did not reveal a measurable pre-activation ability. The pre-activation efficiency is linked to particle pores in a certain size range. As estimated by model calculations, only pores with diameters between about 5 and 8 nm contribute to pre-activation under ice-subsaturated conditions. This range is set by a combination of requirements from the negative Kelvin effect for condensation and a critical size of ice embryos for ice nucleation and melting. In contrast to the early study, pre-activation is only observed for temperatures below 260 K. Above that threshold, the particles' improved ice nucleation ability disappears due to the melting of ice in the pores.
Ground Based Lidar and Microwave Radiometry Synergy for High Vertical Resolution Absolute Humidity Profiling
Authors: Barrera-Verdejo María , Crewell Susanne , Löhnert Ulrich , Orlandi Emiliano , Di Girolamo Paolo
Published: February 2016

Abstract. Continuous monitoring of atmospheric humidity profiles is important for many applications, e.g. assessment of atmospheric stability and cloud formation. Nowadays there is a wide variety of ground-based sensors for atmospheric humidity profiling. Unfortunately there is no single instrument able to provide a measurement with complete vertical coverage, high vertical and temporal resolution, and good performance under all weather conditions, simultaneously. For example, Raman lidar (RL) measurements can provide water vapor with a high vertical resolution albeit with limited vertical coverage, due to sunlight contamination and the presence of clouds. Microwave radiometers (MWR) receive water vapor information throughout the troposphere though their vertical resolution is poor. In this work, we present a MWR and RL system synergy, which aims to overcome the specific sensor limitations. The retrieval algorithm combining these two instruments is an Optimal Estimation Method (OEM), which allows for an uncertainty analysis of the retrieved profiles. The OEM combines measurements and a priori information taking the uncertainty of both into account. The measurement vector consists of a set of MWR brightness temperatures and RL water vapor profiles. The method is applied to a two month field campaign around Jülich (Germany), focusing on clear sky periods. Different experiments are performed to analyse the improvements achieved via the synergy compared to the individual retrievals. When applying the combined retrieval, on average the theoretically determined absolute humidity uncertainty can be reduced by 60 % (38 %) with respect to the retrieval using only-MWR (only-RL) data. The analysis in terms of degrees of freedom per signal reveals that most information is gained above the usable lidar range, especially important during daytime when the lidar vertical coverage is limited. The retrieved profiles are further evaluated using radiosounding and GPS water vapor measurements. In general, the benefit of the sensor combination is especially strong in regions where Raman lidar data is not available (i.e. blind region, regions characterized by low signal to noise ratio), whereas if both instruments are available, RL dominates the retrieval. In the future, the method will be extended to cloudy conditions, when the impact of the MWR becomes stronger.
Twin-cuvette measurement technique for investigation of dry deposition of O3 and PAN to plant leaves under controlled humidity conditions
Authors: Sun Shang , Moravek Alexander , von der Heyden Lisa , Held Andreas , Sörgel Matthias , Kesselmeier Jürgen
Published: February 2016

Abstract. We present a dynamic twin-cuvette system for quantifying the trace-gas exchange fluxes between plants and the atmosphere under controlled temperature, light, and humidity conditions. Compared with a single-cuvette system, the twin-cuvette system is insensitive to disturbing background effects such as wall deposition. In combination with a climate chamber, we can perform flux measurements under constant and controllable environmental conditions. With an Automatic Temperature Regulated Air Humidification System (ATRAHS), we are able to regulate the relative humidity inside both cuvettes between 40 and 90 % with a high precision of 0.3 %. Thus, we could demonstrate that for a cuvette system operated with a high flow rate (> 20 L min−1), a temperature-regulated humidification system such as ATRAHS is an accurate method for air humidification of the flushing air. Furthermore, the fully automatic progressive fill-up of ATRAHS based on a floating valve improved the performance of the entire measurement system and prevented data gaps. Two reactive gas species, ozone (O3) and peroxyacetyl nitrate (PAN), were used to demonstrate the quality and performance of the twin-cuvette system. O3 and PAN exchange with Quercus ilex was investigated over a 14 day measurement period under controlled climate chamber conditions. By using O3 mixing ratios between 32 and 105 ppb and PAN mixing ratios between 100 and 350 ppt, a linear dependency of the O3 flux as well as the PAN flux in relation to its ambient mixing ratio could be observed. At relative humidity (RH) of 40 %, the deposition velocity ratio of O3 and PAN was determined to be 0.45. At that humidity, the deposition of O3 to the plant leaves was found to be only controlled by the leaf stomata. For PAN, an additional resistance inhibited the uptake of PAN by the leaves. Furthermore, the formation of water films on the leaf surface of plants inside the chamber could be continuously tracked with our custom built leaf wetness sensors. Using this modified leaf wetness sensor measuring the electrical surface conductance on the leaves, an exponential relationship between the ambient humidity and the electrical surface conductance could be determined.
Diurnal variation in the coupling of photosynthetic electron transport and carbon fixation in iron-limited phytoplankton in the NE subarctic Pacific
Authors: Schuback Nina , Flecken Mirkko , Maldonado Maria T. , Tortell Philippe D.
Published: February 2016

Abstract. Active chlorophyll a fluorescence approaches, including fast repetition rate fluorometry (FRRF), have the potential to provide estimates of phytoplankton primary productivity at an unprecedented spatial and temporal resolution. FRRF-derived productivity rates are based on estimates of charge separation in reaction center II (ETRRCII), which must be converted into ecologically relevant units of carbon fixation. Understanding sources of variability in the coupling of ETRRCII and carbon fixation provides physiological insight into phytoplankton photosynthesis and is critical for the application of FRRF as a primary productivity measurement tool. In the present study, we simultaneously measured phytoplankton carbon fixation and ETRRCII in the iron-limited NE subarctic Pacific over the course of a diurnal cycle. We show that rates of ETRRCII are closely tied to the diurnal cycle in light availability, whereas rates of carbon fixation appear to be influenced by endogenous changes in metabolic energy allocation under iron-limited conditions. Unsynchronized diurnal oscillations of the two rates led to 3.5-fold changes in the conversion factor between ETRRCII and carbon fixation (Kc / nPSII). Consequently, diurnal variability in phytoplankton carbon fixation cannot be adequately captured with FRRF approaches if a constant conversion factor is applied. Utilizing several auxiliary photophysiological measurements, we observed that a high conversion factor is associated with conditions of excess light and correlates with the increased expression of non-photochemical quenching (NPQ) in the pigment antenna, as derived from FRRF measurements. The observed correlation between NPQ and Kc / nPSII requires further validation but has the potential to improve estimates of phytoplankton carbon fixation rates from FRRF measurements alone.
Negligible effects of ocean acidification on Eurytemora affinis (Copepoda) offspring production
Authors: Almén Anna-Karin , Vehmaa Anu , Brutemark Andreas , Bach Lennart , Lischka Silke , Stuhr Annegret , Furuhagen Sara , Paul Allanah , Bermúdez J. Rafael , Riebesell Ulf , Engström-Öst Jonna
Published: February 2016

Abstract. Ocean acidification is caused by increasing amounts of carbon dioxide dissolving in the oceans leading to lower seawater pH. We studied the effects of lowered pH on the calanoid copepod Eurytemora affinis during a mesocosm experiment conducted in a coastal area of the Baltic Sea. We measured copepod reproductive success as a function of pH, chlorophyll a concentration, diatom and dinoflagellate biomass, carbon to nitrogen (C : N) ratio of suspended particulate organic matter, as well as copepod fatty acid composition. The laboratory-based experiment was repeated four times during 4 consecutive weeks, with water and copepods sampled from pelagic mesocosms enriched with different CO2 concentrations. In addition, oxygen radical absorbance capacity (ORAC) of animals from the mesocosms was measured weekly to test whether the copepod's defence against oxidative stress was affected by pH. We found no effect of pH on offspring production. Phytoplankton biomass, as indicated by chlorophyll a concentration and dinoflagellate biomass, had a positive effect. The concentration of polyunsaturated fatty acids in the females was reflected in the eggs and had a positive effect on offspring production, whereas monounsaturated fatty acids of the females were reflected in their eggs but had no significant effect. ORAC was not affected by pH. From these experiments we conclude that E. affinis seems robust against direct exposure to ocean acidification on a physiological level, for the variables covered in the study. E. affinis may not have faced acute pH stress in the treatments as the species naturally face large pH fluctuations.
Influence of mesoscale eddies on the distribution of nitrous oxide in the eastern tropical South Pacific
Authors: Arévalo-Martínez Damian L. , Kock Annette , Löscher Carolin R. , Schmitz Ruth A. , Stramma Lothar , Bange Hermann W.
Published: February 2016

Abstract. Recent observations in the eastern tropical South Pacific (ETSP) have shown the key role of meso- and submesoscale processes (e.g. eddies) in shaping its hydrographic and biogeochemical properties. Off Peru, elevated primary production from coastal upwelling in combination with sluggish ventilation of subsurface waters fuels a prominent oxygen minimum zone (OMZ). Given that nitrous oxide (N2O) production–consumption processes in the water column are sensitive to oxygen (O2) concentrations, the ETSP is a region of particular interest to investigate its source–sink dynamics. To date, no detailed surveys linking mesoscale processes and N2O distributions as well as their relevance to nitrogen (N) cycling are available. In this study, we present the first measurements of N2O across three mesoscale eddies (two mode water or anticyclonic and one cyclonic) which were identified, tracked, and sampled during two surveys carried out in the ETSP in November–December 2012. A two-peak structure was observed for N2O, wherein the two maxima coincide with the upper and lower boundaries of the OMZ, indicating active nitrification and partial denitrification. This was further supported by the abundances of the key gene for nitrification, ammonium monooxygenase (amoA), and the gene marker for N2O production during denitrification, nitrite reductase (nirS). Conversely, we found strong N2O depletion in the core of the OMZ (O2 < 5 µmol L−1) to be consistent with nitrite (NO2−) accumulation and low levels of nitrate (NO3−), thus suggesting active denitrification. N2O depletion within the OMZ's core was substantially higher in the centre of mode water eddies, supporting the view that eddy activity enhances N-loss processes off Peru, in particular near the shelf break where nutrient-rich, productive waters from upwelling are trapped before being transported offshore. Analysis of eddies during their propagation towards the open ocean showed that, in general, “ageing” of mesoscale eddies tends to decrease N2O concentrations through the water column in response to the reduced supply of material to fuel N loss, although hydrographic variability might also significantly impact the pace of the production–consumption pathways for N2O. Our results evidence the relevance of mode water eddies for N2O distribution, thereby improving our understanding of the N-cycling processes, which are of crucial importance in times of climate change and ocean deoxygenation.
Interactions between climate change and human activities during the Early to Mid Holocene in the East Mediterranean basins
Authors: Berger J. F. , Lespez L. , Kuzucuoğlu C. , Glais A. , Hourani F. , Barra A. , Guilaine J.
Published: February 2016

Abstract. This paper focuses on Early Holocene Rapid Climate Changes (RCC) records in the Mediterranean zone, which are under-represented in continental archives (9.2 to 8.2 ka events) and on their impact on prehistoric societies. This lack of data handicaps indeed assumptions about climate impact on human societies which flourished in recent years. Key questions remain about the impact of Early Holocene cooling events on the Mediterranean climate, ecosystems and human societies. In this paper, we discuss some examples from river and lake systems from the eastern to central Mediterranean area (Central Anatolia, Cyprus, NE and NW Greece,) that illustrate some paleohydrological and erosion variations that modified the sustainability of the first Neolithic populations in this region. Results allow us to present direct land-sea correlations, and to reconstruct regional long-term trends as well as millennial to centennial-scaled climatic changes. In this context, we question the socio-economic and geographical adaptation capacities of these societies (mobility, technology, economic practices, social organisation) during the "Early Holocene" interval (11.7 to 8.2 ka) which corresponds partly to the Sapropele 1 deposition in the Eastern Mediterranean sea.
Scaling regimes and linear/nonlinear responses of last millennium climate to volcanic and solar forcings
Authors: Lovejoy Shaun , Varotsos Costas
Published: February 2016

Abstract. At scales much longer than the deterministic predictability limits (about 10 days), the statistics of the atmosphere undergoes a drastic transition, the high-frequency weather acts as a random forcing on the lower-frequency macroweather. In addition, up to decadal and centennial scales the equivalent radiative forcings of solar, volcanic and anthropogenic perturbations are small compared to the mean incoming solar flux. This justifies the common practice of reducing forcings to radiative equivalents (which are assumed to combine linearly), as well as the development of linear stochastic models, including for forecasting at monthly to decadal scales. In order to clarify the validity of the linearity assumption and determine its scale range, we use last millennium simulations, with both the simplified Zebiak–Cane (ZC) model and the NASA GISS E2-R fully coupled GCM. We systematically compare the statistical properties of solar-only, volcanic-only and combined solar and volcanic forcings over the range of timescales from 1 to 1000 years. We also compare the statistics to multiproxy temperature reconstructions. The main findings are (a) that the variability in the ZC and GCM models is too weak at centennial and longer scales; (b) for longer than  ≈  50 years, the solar and volcanic forcings combine subadditively (nonlinearly) compounding the weakness of the response; and (c) the models display another nonlinear effect at shorter timescales: their sensitivities are much higher for weak forcing than for strong forcing (their intermittencies are different) and we quantify this with statistical scaling exponents.