bluuebunny/crossref_metadata_2025 huggingface dataset:
Constraining the Shape Distribution of Near-Earth Objects from Partial Light Curves
Authors: McNeill A. , Hora J. L. , Gustafsson A. , Trilling D. E. , Mommert M.
Published: April 2019

In the absence of dense photometry for a large population of near-Earth objects (NEOs), the best method of obtaining a shape distribution comes from sparse photometry and partial light curves. We have used 867 partial light curves obtained by Spitzer to determine a shape distribution for subkilometer NEOs. From this data we find a best-fit average elongation of

. We compare this result with a shape distribution obtained from 1869 NEOs in the same size range observed by Pan-STARRS 1 (PS1) and find the Spitzer-obtained elongation to be in excellent agreement with this PS1 value of

. These values are also in agreement with literature values for 1 < D < 10 km objects in the main asteroid belt, however, there is a size discrepancy between the two data sets. Using a smaller sample of NEOs in the size range of 1 < D < 5 km from PS1 data, we obtain an average axis ratio of b/a = 0.70 ± 0.12. This is more elongated than the shape distribution for main belt objects in the same size regime, although the current uncertainties are sizeable and this should be verified using a larger data set. As future large surveys come online it will be possible to observe smaller main belt asteroids to allow for better comparisons of different subkilometer populations.
Interpreting the Relation between the Gamma-Ray and Infrared Luminosities of Star-forming Galaxies
Authors: Zhang Yi , Peng Fang-Kun , Wang Xiang-Yu
Published: April 2019

It has been found that there is a quasi-linear scaling relationship between the gamma-ray luminosity in GeV energies and the total infrared luminosity of star-forming galaxies, i.e.,

with α ≃ 1. However, the origin of this linear slope is not well understood. Although extreme starburst galaxies can be regarded as calorimeters for hadronic cosmic-ray interaction and thus a quasi-linear scaling may hold, it may not be the case for low star formation rate (SFR) galaxies, as the majority of cosmic rays in these galaxies are expected to escape. We calculate the gamma-ray production efficiency in star-forming galaxies by considering realistic galaxy properties, such as the gas density and galactic wind velocity in star-forming galaxies. We find that the slope for the relation between gamma-ray luminosity and the infrared luminosity gets steeper for low infrared luminosity galaxies, i.e.,

, due to increasingly lower efficiency for the production of gamma-ray emission. We further find that the measured data of the gamma-ray luminosity is compatible with such a steepening. The steepening in the slope suggests that cosmic-ray escape is very important in low-SFR galaxies.
The Physical Nature of Neutral Hydrogen Intensity Structure
Authors: Clark S. E. , Peek J. E. G. , Miville-Deschênes M.-A.
Published: April 2019

We investigate the physical properties of structures seen in channel map observations of 21 cm neutral hydrogen (H i) emission. H i intensity maps display prominent linear structures that are well aligned with the ambient magnetic field in the diffuse interstellar medium (ISM). Some literature hold that these structures are “velocity caustics,” fluctuations imprinted by the turbulent velocity field, and are not three-dimensional density structures in the ISM. We test this hypothesis by stacking probes of the density field—broadband far-infrared (FIR) emission and the integrated H i column density (

)—at the locations of linear H i intensity structures. We find that the H i intensity features are real density structures and not velocity caustics. We generalize the investigation to all small-scale structure in H i channel maps and analyze this correlation as a function of velocity channel width, finding no measurable contribution from velocity caustics to the H i channel map emission. Further, we find that small-scale H i channel map structures have elevated FIR/

, implying that this emission originates from a colder, denser phase of the ISM than the surrounding material. The data are consistent with a multiphase diffuse ISM in which small-scale structures in narrow H i channel maps are preferentially cold neutral medium (CNM) that is anisotropically distributed and aligned with the local magnetic field. The shallow spatial power spectrum (SPS) of narrow H i channels is often attributed to velocity caustics. We conjecture instead that the small-scale structure and narrow line widths typical of CNM explain the observed relationship between the SPS and channel width.
Size Scaling of Clump Instabilities in Turbulent, Feedback-regulated Disks
Authors: Ali Kamran , Obreschkow Danail , Wang Liang , Fisher Deanne B. , Glazebrook Karl , Damjanov Ivana , Abraham Roberto G. , Wisnioski Emily
Published: April 2019

We explore the scaling between the size of star-forming clumps and rotational support in massively star-forming galactic disks. The analysis relies on simulations of a clumpy galaxy at z = 2 and the observed DYnamics of Newly Assembled Massive Objects (DYNAMO) sample of rare clumpy analogs at z ≈ 0.1 to test a predictive clump size scaling proposed by Fisher et al. in the context of the violent disk instability (VDI) theory. We here determine the clump sizes using a recently presented two-point estimator, which is robust against resolution/noise effects, hierarchical clump substructure, clump–clump overlap and other galactic substructure. After verifying Fisher’s clump scaling relation for the DYNAMO observations, we explore whether this relation remains characteristic of the VDI theory, even if realistic physical processes, such as local asymmetries and stellar feedback, are included in the model. To this end, we rely on hydrodynamic zoom-simulations of a Milky Way-mass galaxy with four different feedback prescriptions. We find that, during its marginally stable epoch at z = 2, this mock galaxy falls on the clump scaling relation, although its position on this relation depends on the feedback model. This finding implies that Toomre-like stability considerations approximately apply to large (∼kpc) instabilities in marginally stable turbulent disks, irrespective of the feedback model, but also emphasizes that the global clump distribution of a turbulent disk depends strongly on feedback.
Modeling Gamma-Ray Light Curves with More Realistic Pulsar Magnetospheres
Authors: Cao Gang , Yang Xiongbang
Published: April 2019

We study the gamma-ray emission patterns and light curves in dissipative pulsar magnetospheres. We produce the gamma-ray light curves by using the geometric method and the particle trajectory method. For the geometric method, assuming the gamma-ray emission originates in a finite-width layer along the last closed lines, we generate the gamma-ray light curves based on the uniform emissivity along the magnetic field lines in the comoving frame. For the particle trajectory method, we consider the spatial distribution of conductivity σ by assuming a very high conductivity within the light cylinder (LC) and a finite conductivity outside the LC. Assuming that all the γ-ray emission originates in the outer magnetosphere outside the LC, we generate the gamma-ray light curves by computing realistic particle trajectories and Lorentz factors, taking into account both the accelerating electric field and curvature radiation loss. Further, we compare the modeling light curves to the observed light curves at >0.1 GeV energies for the Vela pulsar. Our results show that the magnetosphere with the low σ value is preferred for the geometric method. However, the magnetosphere with a near force-free regime within the LC and a high σ value outside the LC is favored for the particle trajectory method. It is noted that the particle trajectory method uses the parallel electric fields that are self-consistent with the magnetic fields of the magnetosphere. We suggest that the results from the particle trajectory method are better supported on the physical ground.
Research on an Improved Coordinating Method Based on Genetic Algorithms and Particle Swarm Optimization
Authors: Li Rongrong , Qiu Linrun , Zhang Dongbo
Published: April 2019

In this article, a hierarchical cooperative algorithm based on the genetic algorithm and the particle swarm optimization is proposed that the paper should utilize the global searching ability of genetic algorithm and the fast convergence speed of particle swarm optimization. The proposed algorithm starts from Individual organizational structure of subgroups and takes full advantage of the merits of the particle swarm optimization algorithm and the genetic algorithm (HCGA-PSO). The algorithm uses a layered structure with two layers. The bottom layer is composed of a series of genetic algorithm by subgroup that contributes to the global searching ability of the algorithm. The upper layer is an elite group consisting of the best individuals of each subgroup and the particle swarm algorithm is used to perform precise local search. The experimental results demonstrate that the HCGA-PSO algorithm has better convergence and stronger continuous search capability, which makes it suitable for solving complex optimization problems.
Concentration Areas of Sentiment Lexica in the Word Embedding Space
Authors: Razova Elena , Kotelnikov Evgeny
Published: April 2019

Sentiment lexicons play an important role in opinion mining systems and cognitive linguistics. Previous work aimed mostly at creating sentiment lexicons, but not thorough research into their fundamental properties. In this paper the arrangement of sentiment lexica in the multidimensional space of distributed word representations is studied. A hypothesis on the existence of sentiment lexica concentration areas is introduced and it is tested on the basis of the joint analysis of the distribution of sentiment words and general lexica. The results of the test allow to confirm the proposed hypothesis and discover the words which more than 80% of the sentiment lexica is concentrated around.
Analysis and Text Classification of Privacy Policies From Rogue and Top-100 Fortune Global Companies
Authors: Boldt Martin , Rekanar Kaavya
Published: April 2019

In the present article, the authors investigate to what extent supervised binary classification can be used to distinguish between legitimate and rogue privacy policies posted on web pages. 15 classification algorithms are evaluated using a data set that consists of 100 privacy policies from legitimate websites (belonging to companies that top the Fortune Global 500 list) as well as 67 policies from rogue websites. A manual analysis of all policy content was performed and clear statistical differences in terms of both length and adherence to seven general privacy principles are found. Privacy policies from legitimate companies have a 98% adherence to the seven privacy principles, which is significantly higher than the 45% associated with rogue companies. Out of the 15 evaluated classification algorithms, Naïve Bayes Multinomial is the most suitable candidate to solve the problem at hand. Its models show the best performance, with an AUC measure of 0.90 (0.08), which outperforms most of the other candidates in the statistical tests used.
Regional centroid moment tensor solutions for eastern Canadian earthquakes: 2016
Authors: Bent A L
Published: April 2019

Regional centroid moment tensor solutions have been determined for five moderate-sized earthquakes in eastern Canada during 2016. Four additional earthquakes were also evaluated but their solutions did not meet the minimum quality standards for acceptance. The
moment tensor inversion method is used to determine the focal mechanism, depth and seismic moment of the earthquakes. These parameters, in turn, provide information about the seismotectonic environment in which the earthquakes occur and may help improve seismic hazard estimates. Focal mechanisms
determined from first motions for four small earthquakes in New Brunswick are also included. The purpose of this report is not to provide an in-depth analysis of any specific earthquake but to catalog the solutions and data used to obtain them to make them available for future research
projects.
Informações contábeis tempestivas: uma análise dos mecanismos isomórficos do processo de fechamento contábil
Authors: Salvador Gisele Fernanda , Parisi Claudio , Peleias Ivam Ricardo , Guerreiro Reinaldo
Published: April 2019

Organizações preocupadas com sua continuidade e crescimento despendem considerável esforço para obter eficácia e conferir eficiência aos sistemas de controle gerencial. Esta pesquisa teve como objetivo conhecer a influência dos mecanismos isomórficos no processo de fechamento contábil tempestivo. É um estudo de caso acerca dos processos de uma organização multinacional representativa no segmento em que atua. Foram realizadas entrevistas, aplicados questionários e analisados filmes institucionais, para identificar e avaliar a ação das contribuições por meio de exames dos três mecanismos do isomorfismo em relação ao fechamento contábil tempestivo. Constatou-se que não há relação entre os três mecanismos do isomorfismo. Foi identificada uma influência relativa do isomorfismo mimético, por conta do Sistema Toyota de Produção, uma forte influência do mecanismo coercitivo por influência da matriz em relação à tempestividade do fechamento contábil, não tendo sido identificada evidência relativa à influência do isomorfismo normativo.
Linking first lactation survival to milk yield and components and lactation persistency in Tunisian Holstein cows
Authors: Grayaa Marwa , Vanderick Sylvie , Rekik Boulbaba , Ben Gara Abderrahman , Hanzen Christian , Grayaa Siwar , Reis Mota Rodrigo , Hammami Hedi , Gengler Nicolas
Published: April 2019

Abstract. Genetic parameters were estimated for first lactation survival defined as a binary trait (alive or dead to second calving) and the curve shape traits of milk yield, fat and protein percentages using information from 25 981 primiparous Tunisian Holsteins. For each trait, shape curves (i.e. peak lactation, persistency), level of production adjusted to 305 days in milk (DIMs) for total milk yield (TMY), and average fat (TF %) and protein (TP %) percentages were defined. Variance components were estimated with a linear random regression model under three bivariate animal models. Production traits were modelled by fixed herd × test-day (TD) interaction effects, fixed classes of 25 DIMs × age of calving × season of calving interaction effects, fixed classes of pregnancy, random environment effects and random additive genetic effects. Survival was modelled by fixed herd × year of calving interaction effects and age of calving × season of calving interaction effects, random permanent environment effects, and random additive genetic effects. Heritability (h2) estimates were 0.03 (±0.01) for survival and 0.23 (±0.01), 0.31 (±0.01) and 0.31 (±0.01) for TMY, TF % and TP %, respectively. Genetic correlations between survival and TMY, TF % and TP % were 0.26 (±0.08), −0.24 (±0.06) and −0.13 (±0.06), respectively. Genetic correlations between survival and persistency for fat and protein percentages were −0.35 (±0.09) and −0.19 (±0.09), respectively. Cows that had higher persistencies for fat and protein percentages were more likely not to survive.
Evolution of Anthropogenic Air Pollutant Emissions in
Guangdong Province, China, from 2006 to 2015
Authors: Bian Yahui , Ou Jiamin , Huang Zhijiong , Zhong Zhuangmin , Xu Yuanqian , Zhang Zhiwei , Xiao Xiao , Ye Xiao , Wu Yuqi , Yin Xiaohong , Chen Liangfu , Shao Min , Zheng Junyu
Published: April 2019

Abstract. Guangdong province (GD), one of the most prosperous and populous regions in China, still experiences haze events and growing ozone pollution, although it has seen substantial air quality improvement in recent years. Co-control of fine particulate matter (PM2.5) and ozone in GD calls for a systematic review of historical emission patterns. In this study, emission trends, spatial variations, source-contribution variations, and reduction potentials of sulfur dioxide (SO2), nitrogen oxides (NOx), PM2.5, inhalable particles (PM10), carbon monoxide (CO), ammonia (NH3), and volatile organic compounds (VOCs) in GD from 2006 to 2015 are revealed using a dynamic methodology, taking into account economic development, technology penetration, and emission controls. The relative change rates of anthropogenic emissions in GD during 2006–2015 were −48% for SO2, −0.5 % for NOx, −16 % for PM2.5, −22 % for PM10, 13 % for CO, 3 % for NH3, and 13 % for VOCs. The declines of SO2, NOx, PM2.5, and PM10 emissions are mainly attributed to the control-driven emission reductions in the Pearl River Delta (PRD) region, especially from power plants, industrial combustion, on-road mobile sources, and fugitive dust, and partly to the shift of industries from the PRD to the non-PRD (NPRD) region in GD. NPRD also contributed to part of the emission decline, but it was only effective until 2011 when GD’s Clean Air Action of 12th Five-Year was implemented. Due to the growth of solvent use and the absence of effective control measures, VOC emissions in PRD and NPRD both steadily increased, and this might be one of the reasons that led to the slight upward trends of ozone concentrations in GD. To further reduce emissions, future work should focus on power plants and industrial combustion in GD and industrial process source in NPRD for emissions of SO2, NOx, and particulate matter, and on solvent use and on-road mobile sources for VOC emissions. This study provides solid scientific support for further air quality improvement in GD. In addition, it provides robust data to quantify the impact of emission and meteorology variations on air quality and unveil the primary cause of significant air quality change in the PRD region in recent decade.
Emission of trace gases and aerosols from biomass burning –
An updated assessment
Authors: Andreae Meinrat O.
Published: April 2019

Abstract. Since the publication of the compilation of biomass burning emission factors by Andreae and Merlet (2001), a large number of studies has greatly expanded the amount of available data on emissions from various types of biomass burning. Using essentially the same methodology as Andreae and Merlet (2001), this paper presents an updated compilation of emission factors. The data from over 350 published studies were critically evaluated and integrated into a consistent format. Several new categories of biomass burning have been added, and the number of species for which emission data are presented has been increased from 93 to 121. Where field data are still insufficient, estimates based on appropriate extrapolation techniques are proposed. Based on these emission factors and published global activity estimates, I have derived estimates of pyrogenic emissions for important species emitted by the various types of biomass burning.
OMI total bromine monoxide (OMBRO) data product: algorithm, retrieval and measurement comparisons
Authors: Suleiman Raid M. , Chance Kelly , Liu Xiong , González Abad Gonzalo , Kurosu Thomas P. , Hendrick Francois , Theys Nicolas
Published: April 2019

Abstract. This paper presents the retrieval algorithm for the
operational Ozone Monitoring Instrument (OMI) total bromine monoxide (BrO)
data product (OMBRO) developed at the Smithsonian Astrophysical Observatory
(SAO) and shows comparisons with correlative measurements and retrieval
results. The algorithm is based on direct nonlinear least squares fitting of
radiances from the spectral range 319.0–347.5 nm. Radiances are modeled from
the solar irradiance, attenuated by contributions from BrO and interfering
gases, and including rotational Raman scattering, additive and
multiplicative closure polynomials, correction for Nyquist undersampling
and the average fitting residual spectrum. The retrieval uses albedo- and
wavelength-dependent air mass factors (AMFs), which have been pre-computed
using a single mostly stratospheric BrO profile. The BrO cross sections are
multiplied by the wavelength-dependent AMFs before fitting so that the
vertical column densities (VCDs) are retrieved directly. The fitting
uncertainties of BrO VCDs typically vary between 4 and 7×1012 molecules cm−2
(∼10 %–20 % of the measured BrO VCDs).
Additional fitting uncertainties can be caused by the interferences from
O2-O2 and H2CO and their correlation with BrO. AMF
uncertainties are estimated to be around 10 % when the single
stratospheric-only BrO profile is used. However, under conditions of high
tropospheric concentrations, AMF errors due to this assumption of profile
can be as high as 50 %. The retrievals agree well with GOME-2 observations at simultaneous nadir
overpasses and with ground-based zenith-sky measurements at Harestua,
Norway, with mean biases less than -0.22±1.13×1013
and 0.12±0.76×1013 molecules cm−2, respectively. Global distribution and seasonal variation of OMI
BrO are generally consistent with previous satellite observations. Finally,
we confirm the capacity of OMBRO retrievals to observe enhancements of BrO
over the US Great Salt Lake despite the current retrieval setup
considering a stratospheric profile in the AMF calculations. OMBRO
retrievals also show significant BrO enhancements from the eruption of the
Eyjafjallajökull volcano, although the BrO retrievals are affected under
high SO2 loading conditions by the sub-optimum choice of SO2 cross
sections.
Using the tracer flux ratio method with flight measurements to estimate dairy farm CH4 emissions in central California
Authors: Daube Conner , Conley Stephen , Faloona Ian C. , Arndt Claudia , Yacovitch Tara I. , Roscioli Joseph R. , Herndon Scott C.
Published: April 2019

Abstract. Tracer flux ratio methodology was applied to airborne
measurements to quantify methane (CH4) emissions from two dairy farms
in central California during the summer. An aircraft flew around the
perimeter of each farm measuring downwind enhancements of CH4 and a
tracer species released from the ground at a known rate. Estimates of
CH4 emission rates from this analysis were determined for whole sites
and major sources within a site (animal housing and liquid manure lagoons).
Whole-site CH4 flux rates for each farm, Dairy 1 (6108±821 kg CH4 d−1,
95 % confidence interval) and Dairy 2 (4018±456 kg CH4 d−1,
95 % confidence interval), closely resembled
findings by established methods: ground-based tracer flux ratio and mass
balance. Individual source emission rates indicate a greater fraction of the
whole-site emissions come from liquid manure management than animal housing
activity, similar to bottom-up estimates. Despite differences in altitude,
we observed that the tracer release method gave consistent results when
using ground or air platforms.
Optimal estimation method retrievals of stratospheric ozone profiles from a DIAL
Authors: Farhani Ghazal , Sica Robert J. , Godin-Beekmann Sophie , Haefele Alexander
Published: April 2019

Abstract. This paper provides a detailed description of a first-principle
optimal estimation method (OEM) applied to ozone retrieval analysis
using differential absorption lidar (DIAL) measurements. The air density,
detector dead times, background coefficients, and lidar constants are
simultaneously retrieved along with ozone density profiles. Using an
averaging kernel, the OEM provides the vertical resolution of the retrieval
as a function of altitude. A maximum acceptable height at which the a
priori has a small contribution to the retrieval is calculated for each
profile as well. Moreover, a complete uncertainty budget including both
systematic and statistical uncertainties is given for each individual
retrieved profile. Long-term stratospheric DIAL ozone measurements have been
carried out at the Observatoire de Haute-Provence (OHP) since 1985. The OEM
is applied to three nights of measurements at OHP during an intensive ozone
campaign in July 2017 for which coincident lidar–ozonesonde measurements are
available. The retrieved ozone density profiles are in good agreement with
both traditional analysis and the ozonesonde measurements. For the three
nights of measurements, below 15 km the difference between the OEM and the
sonde profiles is less than 25 %, and at altitudes between 15 and 25 km the
difference is less than 10 %; the OEM can successfully catch many
variations in ozone, which are detected in the sonde profiles due to its
ability to adjust its vertical resolution as the signal varies. Above 25 km
the difference between the OEM and the sonde profiles does not exceed 20 %.
Harmonization and comparison of vertically resolved atmospheric state observations: Methods, effects, and uncertainty budget
Authors: Keppens Arno , Compernolle Steven , Verhoelst Tijl , Hubert Daan , Lambert Jean-Christopher
Published: April 2019

Abstract. Many applications of atmospheric composition and climate data involve the comparison or combination of vertically resolved atmospheric state variables. Calculating differences and combining data require harmonization of data representations in terms of physical quantities and vertical sampling at least. If one or both datasets result from a retrieval process, knowledge of prior information and averaging kernel matrices in principle allows accounting for retrieval differences as well. Spatiotemporal mismatch of the sensed air masses and its contribution to the data discrepancies can be estimated with chemistry-transport modelling support. In this work an overview of harmonization or matching operations for atmospheric profile observations is provided. The effect of these manipulations on the information content of the original data and on the uncertainty budget of data comparisons is examined and discussed.
Surface-circulation change in the Southern Ocean across the Middle Eocene Climatic Optimum: inferences from dinoflagellate cysts and biomarker paleothermometry
Authors: Cramwinckel Marlow J. , Woelders Lineke , Huurdeman Emiel P. , Peterse Francien , Gallagher Stephen J. , Pross Jörg , Burgess Catherine , Reichart Gert-Jan , Sluijs Appy , Bijl Peter K.
Published: April 2019

Abstract. Global climate cooled from the early Eocene hothouse (~ 52–50 Ma) to the latest Eocene (~ 34 Ma). At the same time, the tectonic evolution of the Southern Ocean was characterized by the opening and deepening of circum-Antarctic gateways, which affected both surface- and deep-ocean circulation. The Tasman Gateway played a key role in regulating ocean throughflow between Australia and Antarctica. Southern Ocean surface currents through and around the Tasman Gateway have left recognizable tracers in the spatiotemporal distribution of plankton fossils, including organic-walled dinoflagellate cysts. This spatiotemporal distribution depends on physico-chemical properties of the water masses in which these organisms thrived. The degree to which the geographic path of surface currents (primarily controlled by tectonism) or their physico-chemical properties (significantly impacted by climate) have controlled the composition of the fossil assemblages has, however, remained unclear. In fact, it is yet poorly understood to what extent oceanographic response as a whole was dictated by climate change, independent of tectonics-induced oceanographic changes that operate on longer time scales. To disentangle the effects of tectonism and climate in the southwest Pacific Ocean, we target a climatic deviation from the long-term Eocene cooling trend, a 500 thousand year long global warming phase termed the Middle Eocene Climatic Optimum (MECO; ~ 40 Ma). The MECO warming is unrelated to regional tectonism, and thus provides a test case to investigate the oceans physiochemical response to climate change only. We reconstruct changes in surface-water circulation and temperature in and around the Tasman Gateway during the MECO through new palynological and organic geochemical records from the central Tasman Gateway (Ocean Drilling Program Site 1170), the Otway Basin (southeastern Australia) and the Hampden Section (New Zealand). Our results confirm that dinocyst communities track tectonically driven circulation patterns, yet the variability within these communities can be driven by superimposed temperature change. Together with published results from the east of the Tasman Gateway, our results suggest that as surface-ocean temperatures rose, the East Australian Current extended further southward during the peak of MECO warmth. Simultaneous with high sea-surface temperatures in the Tasman Gateway area, pollen assemblages indicate warm temperate rainforests with paratropical elements along the southeastern margin of Australia. Finally, based on new age constraints we suggest that a regional southeast Australian transgression might have been caused by sea-level rise during MECO.
Greenhouse gas flux studies: An automated online system for gas emission measurements in aquatic environments
Authors: Thanh Duc Nguyen , Silverstein Samuel , Wik Martin , Crill Patrick , Bastviken David , Varner Ruth K.
Published: April 2019

Abstract. Aquatic ecosystems are major sources of greenhouse gases (GHG). Robust measurements of natural GHG emissions are vital for evaluating regional to global carbon budgets and for assessing climate feedbacks on natural emissions to improve climate models. Diffusive and ebullitive (bubble) transport are two major pathways of gas release from surface waters. To capture the high temporal variability of these fluxes in a well-defined footprint, we designed and built an inexpensive device that includes an easily mobile diffusive flux chamber and a bubble counter, all in one. In addition to automatically collecting gas samples for subsequent various analyses in the laboratory, this device also utilizes a low cost carbon dioxide (CO2) sensor (SenseAir, Sweden) and methane (CH4) sensor (Figaro, Japan) to measure GHG fluxes. Each of the devices were equipped with an XBee module to enable a local radio communication (DigiMesh network) for time synchronization, and data readout at a server-controller station on the lakeshore. Software of this server-controller is operated on a low-cost computer (Raspberry Pi) which has a 3G connection for remote control and monitor functions from anywhere in the world. This study shows the potential of a low cost automatic sensor network system to study GHG fluxes on lakes in remote locations.
Generation of Rossby waves off the Cape Verde peninsula; role of
the coastline
Authors: Sirven Jérôme , Mignot Juliette , Crépon Michel
Published: April 2019

Abstract. In December 2002 and January 2003 satellite observations of Chlorophyll showed a strong coastal signal along the west african coast between 10° and 22° N. In addition, a wavelike pattern with a wavelength of about 750 kms was observed from December 20th 2002 and was detectable for one month in the open sea, south west to the Cape Verde peninsula. Such a pattern suggests the existence of a locally generated Rossby wave which slowly propagated westward during this period. To verify this hypothesis a numerical study based on a reduced gravity shallow water model has been conducted. A wind burst, broadly extending over the region where the offshore oceanic signal is observed, is applied during 5 days. A Kelvin wave quickly develops along the northern edge of the cape, then propagates and leaves the area in a few days. Simultaneoulsly, a Rossby wave whose characterisics seem similar to the observed pattern forms and slowly propagates westward. The existence of the peninsula limits the extent of the wave to the north. The spatial extent of the wind burst determines the extent of the response and correspondingly the time scale of the phenomenon (about 100 days in the present case). When the wind burst has a large zonal and small meridional extent, the behaviour of a wave to the north of the peninsula differs from that to the south. These results are corroborated and completed by an analytical study of a linear reduced gravity model using a non-Cartesian coordinate system. This system is introduced to evaluate the potential impact of the coastline shape. The analytical computations confirm that, considering the value of the wavelength, a time scale around 100 days can be associated with the observed wave. They also show that the role of the coastline remains moderate at such time scales. On the contrary, when the period becomes shorter (smaller than 20–30 days), the behaviour of the waves is modified because of the shape of the coast. South of the peninsula, a narrow band of sea isolated from the rest of the ocean by two critical lines appears. Its meridional extent is about 100 km and Rossby waves could propagate there towards the coast.
Seasonal and regional variations of sinking in the subpolar North Atlantic from a high-resolution ocean model
Authors: Sayol Juan-Manuel , Dijkstra Henk , Katsman Caroline
Published: April 2019

Abstract. Previous studies have indicated that most of the net sinking associated with the downward branch of the Atlantic Meridional Overturning Circulation (AMOC) must occur near the subpolar North Atlantic boundaries. In this work we have used monthly mean fields of a high-resolution ocean model (0.1 deg at the equator) to quantify this sinking. To this end we have calculated the Eulerian net vertical transport (WΣ) from the modelled vertical velocities, its seasonal variability and its spatial distribution under repeated climatological atmospheric forcing conditions. Based on this simulation, we find that for the whole subpolar North Atlantic WΣ peaks at about −14 Sv at a depth of 1139 m, matching both the mean depth and the magnitude of the meridional transport of the AMOC at 45° N. It displays a seasonal variability of around 10 Sv. Three sinking regimes are identified according to the characteristics of the accumulated W with respect to the distance to the coast: one within the first 110 km and onto the bathymetric slope at around the peak of the boundary current speed (regime I), the second between 110 km and 290 km covering the remainder of the shelf where mesoscale eddies exchange properties (momentum, heat, mass) between the interior and the boundary (regime II), and the third sinking regime at larger distances from the coast where WΣ is mostly driven by the ocean's interior eddies (regime III). Regimes I and II accumulate ∼ 90 % of the total sinking and display smaller seasonal changes and spatial variability than regime III. We find that such a distinction in regimes is also useful to describe the characteristics of WΣ in marginal seas located far from the overflow areas, although the regime boundaries can shift a few tens of km inshore or offshore depending on the bathymetric slope and shelf width of each marginal sea. The largest contributions to the sinking come from the Labrador Sea, the Newfoundland region and the overflow regions. The magnitude, the seasonal variability and the depth at which WΣ peaks vary for each region, thus revealing a complex picture of sinking in the subpolar North Atlantic.
Can anaerobic oxidation of methane prevent seafloor gas escape in a warming climate?
Authors: Stranne Christian , O'Regan Matt , Jakobsson Martin , Brüchert Volker , Ketzer Marcelo
Published: April 2019

Abstract. Assessments of future climate warming-induced seafloor methane (CH4) release rarely include anaerobic oxidation of methane (AOM) within the sediments. Considering that more than 90 % of the CH4 produced in ocean sediments today is consumed by AOM, this may result in substantial overestimations of future seafloor CH4 release. Here we integrate a fully coupled AOM module with a numerical hydrate model to investigate under what conditions rapid release of CH4 can bypass AOM and result in significant fluxes to the ocean and atmosphere. The results presented in this study should be seen as a first step towards understanding AOM dynamics in relation to climate change and hydrate dissociation. Although the model is somewhat poorly constrained, our results indicate that vertical CH4 migration through hydraulic fractures can result in low AOM efficiencies. Fracture flow is the predicted mode of methane transport under warming-induced dissociation of hydrates on upper continental slopes. Therefore, in a future climate-warming scenario, AOM might not significantly reduce methane release from marine sediments.
Structural Breaks and Volatility Spillovers: The Case of the US and Canadian Stock Markets
Authors: Tsuji Chikashi
Published: April 2019

This paper investigates the relations of structural breaks and volatility spillovers by using the US and Canadian stock return data. Specifically, applying spillover MGARCH models without and with structural break dummy variables to the two stock returns, this study derives the following interesting evidence. (1) First, we reveal that for both the US and Canadian stock returns, the volatility persistence parameter values in our spillover MGARCH models decline when structural break dummy variables are incorporated. (2) Second, we further clarify that when we do not take structural breaks into account, the spillover effect was unidirectional from Canada to the US. However, when we take structural breaks into consideration, the results from our spillover MGARCH model with structural break dummies demonstrate that the volatility spillover effects between the US and Canada become bidirectional. (3) Third, we furthermore reveal that around the Lehman Brothers bankruptcy in 2008, the time-varying volatilities derived from our spillover MGARCH model with structural break dummy variables show slightly higher values than those volatilities from our spillover MGARCH model with no structural break dummy variable.
Comparison of electrocatalytic activity for glucose electrooxidation of gold nanoparticles fabricated by different methods
Authors: Upskuvienė Daina , Balčiūnaitė Aldona , Vaičiūnienė Jūratė , Selskis Algirdas , Vaitkus Rimantas , Tamašauskaitė-Tamašiūnaitė Loreta , Norkus Eugenijus
Published: April 2019

In this study, the gold nanoparticles (AuNPs) without carbon support were prepared using the well-known citrate reduction method. The carbon supported AuNPs nanocomposites were fabricated by two different approaches: chemical adsorption of AuNPs from the prepared citrate stabilized AuNP colloidal solution on the carbon powder surface and one-pot microwave-assisted synthesis. The nanocomposites were characterized using scanning electron microscopy (SEM) and inductively coupled plasma optical emission spectroscopy (ICP-OES). The electrocatalytic activity of the prepared catalysts was evaluated for the electrooxidation of glucose in an alkaline media using cyclic voltammetry.
The highest electrocatalytic activity was observed for the catalyst of carbon supported Au nanoparticles prepared by microwave-assisted synthesis, followed by the catalyst of carbon supported Au nanoparticles prepared by means of the adsorption method, whereas the pure Au nanoparticles without carbon support exhibited the lowest electrocatalytic properties for glucose electrooxidation.
The Perspective of Overcoming Nihilism in Heidegger’s Dialogue with Jünger
Authors: Vėželis Tautvydas
Published: April 2019

This article examines the problem of overcoming nihilism in Heidegger’s dialogue with Jünger. It is suggested that nihilism is manifested in various forms and is the deep logic of the whole history of European civilization. One of the main aims of this paper is to outline the relationship of nihilism and Nothing in Heidegger’s dispute with Jünger, viewing how Heidegger distinguishes his approach from Jünger’s point of view. Heidegger, on the one hand, treats nihilism as consummation of the Western metaphysical tradition, on the other hand, identifies Nothing itself as the shadow of Being, which cannot be overcome in the traditional dialectical thinking manner.
Alternatives to the Culture of Consumerism, or the Charm of Skeptical Solitude
Authors: Vidauskytė Lina
Published: April 2019

The paper focuses on the elaboration of an opposition to the consumer commodity market which is recognised as a sovereign by British sociologist Zygmunt Bauman. For Bauman, consumerism is an archetype of loneliness, and besides the question of alternative to consumerism, there shows up the question of communication. Odo Marquard insists that a modern man experiences inauthentic loneliness and, in fact, he lost an ability to be alone in a positive sense. Loneliness gives us a perfect distance for a sober evaluation of reality and ourselves. In this article skeptical loneliness, among other forms of positive loneliness, is considered as freedom from all dogmas and the wishes of consumers, and as an opposition to a sovereign in the form of the consumer commodity market.
Educación Física Bilingüe en Inglés. Opinión y Formación de los Maestros de Educación Física
Authors: López Sánchez G. F. , Gris Roca J. , Sánchez Mompeán S. , Zauder R. , Smith L.
Published: April 2019

El objetivo de esta investigación fue conocer las opiniones de los maestros de Educación Física (EF) acerca de la EF bilingüe y saber si se sentían cualificados para impartir EF en inglés. Participaron 30 individuos con la titulación de Maestro de Educación Primaria (especialidad EF). Se utilizó el 'Cuestionario sobre la formación bilingüe del profesorado de Educación Física'. Se llevó a cabo un análisis estadístico mediante SPSS-22: estadísticos descriptivos, test de Shapiro-Wilk, prueba U de Mann-Whitney, y prueba de Kruskal-Wallis. La mayoría de los maestros de la muestra presentaban opiniones positivas hacia la EF bilingüe, aunque no tenían mucha experiencia enseñando de forma bilingüe y no estaban suficientemente preparados para impartir enseñanza bilingüe. Sería recomendable diseñar y llevar a cabo programas educativos para mejorar la cualificación de los maestros de educación física para impartir enseñanza bilingüe, verificando la efectividad de estos programas.
Nivel de actividad física, equilibrio energético y exceso de peso en jóvenes universitarios
Authors: Gómez Infante E. A. , Ceballos Gurrola O. , Enríquez Reyna M. C.
Published: April 2019

La asociación entre la nutrición, actividad física y exceso de peso han sido estudiadas como determinantes del sobrepeso y enfermedades crónicas durante la adultez. Poco se sabe de la población universitaria en lugares donde convergen circunstancias climáticas, nutricionales y culturales adversas para la salud. Se analizaron las diferencias entre el nivel de actividad física, el equilibrio energético y la grasa corporal considerando la prevalencia de exceso de peso. Se aplicaron el International Physical Activity Questionnaire, el Recordatorio de 24 horas de pasos múltiples, análisis de bioimpedancia y mediciones antropométricas. De los 369 participantes, el 44.2% de los hombres y 23.2% de las mujeres presentó exceso de peso de acuerdo al IMC (>25 kg/m2). Se encontraron diferencias entre grupos al respecto del nivel de actividad y la grasa corporal (p<.01). El nivel de actividad se asoció de forma inversa con el equilibrio energético y la grasa corporal.
Evolución de la capacidad de cambio de dirección en función de la edad en niños y niñas en edad escolar
Authors: Rodríguez-Negro J. , Romaratezabala E. , Yanci J.
Published: April 2019

Los objetivos de este estudio fueron describir la capacidad de cambio de dirección (CODA) en estudiantes de educación primaria (EP, n = 394) y analizar las diferencias atendiendo a su edad.Se han encontrado diferencias significativas en la CODA entre todos los cursos, excepto entre G1-G2 (p > 0,05, TE = -0,3, bajo), G1-G3 (p > 0,05, TE = -0,3, bajo), G2-G3 (p > 0,05, TE = 0,1, trivial), G4-G6 (p > 0,05, TE = -0,5, moderado) y G5-G6 (p > 0,05, TE = 0,1, trivial). En el presente estudio no se han observado diferencias significativas en la CODA entre estudiantes de primero, segundo y tercero de educación primaria (6-8 años), pero si a partir de esa edad (9-12 años). Estas diferencias han sido especialmente relevantes entre G3 y G5. Estos hallazgos nos llevan a pensar que la edad de los 8-9 años puede ser una etapa crítica diferenciadora en la CODA de los estudiantes de EP.
Adaptación de la multidimensional sportspersonship orientations scale al contexto español de la educación física
Authors: Burgueño R. , Sánchez-Gallardo I. , Medina-Casaubón J.
Published: April 2019

El objetivo fue analizar la estructura factorial de las diferentes versiones propuestas para la Multidimensional Sportspersonship Orientations Scale (MSOS) en el contexto español de la educación física. Los participantes fueron 652 estudiantes de educación secundaria y bachillerato (353 hombres y 299 mujeres; Medad = 14.98, DTedad = 1.59). El análisis factorial confirmatorio no apoyó psicométricamente ninguna de las versiones planteadas por los trabajos previos para la MSOS. Sin embargo, los hallazgos sustentaron psicométricamente un modelo de cuatro factores correlacionados y 17 ítems (i.e., respecto por las convenciones sociales, respeto por las reglas, compromiso y respeto por el compañero) para la educación física. Esta estructura fue invariante por género. Las correlaciones sustentaron la validez discriminante del instrumento. El análisis de fiabilidad reflejó valores adecuados para cada factor. Como conclusión, se recomienda la utilización de una nueva estructural factorial para la MSOS en el contexto español de la educación física.
Redistribución económica y precariedad. El caso de los anfitriones de Airbnb. / Economic redistribution and precariousness. The case of Airbnb hosts
Authors: Gil García Javier
Published: April 2019

Todos los particulares pueden obtener ingresos extra y recuperar el poder adquisitivo perdido en el contexto de la crisis, anuncia Airbnb. Este estudio analiza la forma que adquiere el trabajo de los anfitriones -las personas que alquilan su vivienda o habitación- en Airbnb. Se plantea que la actividad de los anfitriones adquiere la forma de trabajo abstracto, pero que es un trabajo que se articula y se desarrolla sobre la propia vida y cotidianidad de los anfitriones: sobre la esfera reproductiva de la persona y sobre actividades no económicas. Para que los anfitriones pueden maximizar los beneficios que obtienen, adoptan la forma de empresarios de sí mismos. Como resultado, los anfitriones reducen su precariedad económica pero la actividad de hospedar en Airbnb les genera nuevas formas de precariedad vital.Everyone can earn extra income and recover the lost consumption power due to the crisis, adevertises Airbnb. This study analyzes the form that the work of Airbnb hosts - people who rent their home or room on the platforma- acquires. It is stated that the activity of the hosts is a type of abstract labour, but that develops over the life of the hosts: over the reproductive sphere of the person and over non-economic activities. In order for hosts to maximize the benefits they can obtain on Airbnb, they become entrepreneurs of themselves. As a result, hosts reduce their economic precariousness but the activity of hosting on Airbnb generates new ways of vital precariousness.
Bullshit jobs: Graeber y la alienación en el capitalismo financiarizado
Authors: Ramos Colás Álvaro
Published: April 2019

En el presente ensayo intentaremos exponer algunos aspectos de la crítica de Graeber al capitalismo financiarizado. En el primer apartado introduciremos su concepto de alienación, clave para entender el sentido de su obra. En los apartados posteriores presentaremos las ideas principales que se pueden encontrar en Bullshit Jobs, su último libro. En él expone una teoría de los trabajos basura o inútiles, que considera uno de los pilares fundamentales de la ideología neoliberal, junto con la omnipresencia de la burocracia y la moralidad de la deuda. El fenómeno social de los trabajos basura es estudiado desde diversos niveles: qué son, cómo afectan a los que los realizan, cuáles son las causas económicas y por qué nadie hace nada para acabar con ellos.In the present paper I try to delve into some of Graeber’s critiques of the financialised capitalism. In the first section, I will introduce his idea of alienation, key to understand the sense of his work. In the rest of the paper I will present the main ideas of his last book, Bullshit Jobs. There Graeber presents a theory of bullshit jobs, which he believes to be an important base of the neoliberal system, along with the bureaucracy and the debt. He analyses the social phenomenon of bullshit jobs from different perspectives: what they are, how they affect the people doing them, which are the economic causes and why nothing is done.