bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hypergeometric rational approximations to ζ(4)
Authors: Marcovecchio Raffaele , Zudilin Wadim 
Published: February 2020

AbstractWe give a new hypergeometric construction of rational approximations to ζ(4), which absorbs the earlier one from 2003 based on Bailey's 9F8 hypergeometric integrals. With the novel ingredients we are able to gain better control of the arithmetic and produce a record irrationality measure for ζ(4).
ACAA2 and FASN polymorphisms affect the fatty acid profile of Chios sheep milk
Authors: Symeou Simoni , Tzamaloukas Ouranios , Banos Georgios , Miltiadou Despoina 
Published: February 2020

AbstractThe objective of the research reported in this research communication was the identification and association of single nucleotide polymorphisms (SNP) in the ovine DGAT1, FASN, SCD1 and ACAA2 genes with milk fat percentage and fatty acid (FA) content. Three consecutive monthly milk samplings were obtained from a total of 429 purebred Chios ewes during mid-lactation. Genotypic data were jointly analyzed with 1184 fat content and 37 718 FA percentage records using mixed models. The 3′ untranslated region (UTR) of the DGAT1 gene and the 5′ and 3′UTRs of the SCD1 gene appeared to be monomorphic. The FASN g.14777C>T SNP on exon 31 was associated with C13:0 and the ACAA2 g.2982T>C SNP on the 3′UTR was associated with C9:0, C11:0, C12:1 cis-9, C13:0 and the ω6/ω3 index, while fat percentage was not affected by the identified SNPs. The results could be useful for breeding programs aiming to improve the quality and nutritional value of ovine milk.
Gender, Family, and the Policing of the ‘Criminal Tribes’ in Nineteenth-Century North India
Authors: HINCHY JESSICA 
Published: February 2020

AbstractIn the South Asian setting, the fields of gender history and family history are still predominantly concerned with relatively elite social groups. Few studies have examined issues of gender and the family in the history of Dalit, low-caste, and socially marginalized communities, especially those that were labelled ‘criminal tribes’ from the mid-nineteenth century on. This article explores the ways in which gender patterned criminalized communities’ experiences of everyday colonial governance under Part I of the 1871 Criminal Tribes Act (CTA) in the first two decades that it was enforced in northern India. In this early period, the colonial government did not closely regulate marriage practices, domestic arrangements, or the gendered organization of labour within communities categorized as ‘criminal tribes’. Nevertheless, notions of sexuality and gender underlay colonial knowledge of the ‘criminal tribes’, which emerged in dialogue with middle-class Indian gender and caste politics. Moreover, the family unit was the central target of the CTA surveillance and policing regime, which aimed to produce ‘industrious’ families. Officially endorsed forms of labour had complex implications for criminalized communities in the context of North Indian gender norms and strategies of social mobility. Gender power dynamics also shaped criminalized peoples’ interpersonal, embodied interactions with British and Indian colonial officials on an everyday basis. Meanwhile, different forms of leverage and evasion were open to men and women to cope with their criminalization and so the colonial state was experienced in highly gendered ways.
Arthrobotrys cladodes and Pochonia chlamydosporia in the biological control of nematodiosis in extensive bovine production system
Authors: Vieira Ítalo Stoupa , Oliveira Isabela de Castro , Freitas Samuel Galvão , Campos Artur Kanadani , Araújo Jackson Victor de 
Published: February 2020

AbstractCattle production in extensive systems favours the occurrence of gastrointestinal nematodes, and the use of nematophagous fungi complements the control strategies for these nematodes. The aim of this study was to evaluate the effectiveness of the fungi Arthrobotrys cladodes and Pochonia chlamydosporia in the biological control of gastrointestinal parasitic nematodes in grazing cattle. Twenty-four calves were randomly divided into four groups and allocated to independent paddocks from February 2018 to January 2019. In the first group, the animals received pellets containing P. chlamydosporia. In the second group, the animals received pellets containing A. cladodes. In the third group, the animals received pellets containing a combination of the fungi A. cladodes and P. chlamydosporia. In the control group, the animals received pellets without fungus. The combined use of A. cladodes and P. chlamydosporia showed greater efficacy in the biological control of bovine gastrointestinal parasitic nematodes than the same fungi used separately. The parasite load was lower and weight gain was greater (P ⩽ 0.05) in the groups of cattle treated with nematophagous fungi. Therefore, the use of A. cladodes and P. chlamydosporia is promising in the biological control of nematodiosis in cattle.
The contours of the development of non-living resources in Greenland
Authors: Takahashi Minori 
Published: February 2020

Abstract
In past discussions regarding development (of non-living resources) and indigenous people, a strong tendency existed to understand the act of development as a one-way impact from an outside society. This was often labelled as “environmental racism” and interpreted as a form of ethnic discrimination deeply intertwined with environmental issues. However, this view contained an element of confirmation bias regarding development and indigenous people. For example, it has been reported that in Alaska and elsewhere, indigenous people have taken initiative in developing non-living resources, making it clear that indigenous people are not necessarily passive subjects on whom development is unilaterally imposed. In this paper, after examining recent trends in the development of non-living resources, I shall take up the development of such resources in Greenland with the goal of sorting out and extrapolating the main arguments in the debate, especially within the self-rule government, regarding how the wealth obtained through the development of non-living resources should be enjoyed, while focusing on the notion of sustainable development and taking into consideration previous studies from the field of political science.
A note on the Brown–Erdős–Sós conjecture in groups
Authors: Long Jason 
Published: February 2020

AbstractWe show that a dense subset of a sufficiently large group multiplication table contains either a large part of the addition table of the integers modulo some k, or the entire multiplication table of a certain large abelian group, as a subgrid. As a consequence, we show that triples systems coming from a finite group contain configurations with t triples spanning
$ O(\sqrt t )$
vertices, which is the best possible up to the implied constant. We confirm that for all t we can find a collection of t triples spanning at most t + 3 vertices, resolving the Brown–Erdős–Sós conjecture in this context. The proof applies well-known arithmetic results including the multidimensional versions of Szemerédi’s theorem and the density Hales–Jewett theorem.This result was discovered simultaneously and independently by Nenadov, Sudakov and Tyomkyn [5], and a weaker result avoiding the arithmetic machinery was obtained independently by Wong [11].
Water spreading weirs altering flood, nutrient distribution and crop productivity in upstream–downstream settings in dry lowlands of Afar, Ethiopia
Authors: Getnet Mezegebu , Amede Tilahun , Tilahun Gebeyaw , Legesse Gizachew , Gumma Murali Krishna , Abebe Hunegnaw , Gashaw Tadesse , Ketter Christina , Akker Elisabeth V. 
Published: February 2020

AbstractAfar in Ethiopia is a drought prone area characterized by low rainfall, high temperature and suffering from flash flood emerging from adjacent mountains. We introduced a flood barrier, water spreading weirs (WSWs) in 2015 to convert floods to a productive use and assessed its effect in 2016 and 2017. WSWs resulted in deposition of sediments where sand deposition was higher in the upside of upstream weir whereas silt and clay deposition was prominent at the central location between the two weirs. There was a moisture gradient across farming fields with volumetric water content (VWC) at 20 cm depth varying between 10 and 22% depending on the relative position/distance of fields from the WSWs, consequently, effecting significant difference in yield between fields. There was a positive relationship between VWC made available by WSWs at planting and the yield (P < 0.001, r = 0.76) and biomass productivity (P < 0.005, r = 0.46). WSWs created differing farming zone following soil moisture regime, affecting grain and biomass yield. In good potential zones with high moisture content, the WSW-based farming enabled to produce up to 5 and 15 t ha−1 yr−1 of maize grain and biomass, respectively, while in low potential zones there was a complete crop grain failure. The system enabled pastoralists to produce huge amount of biomass and grain during Belg (short) and Meher (long) growing seasons that was stored and utilized during succeeding dry periods. Furthermore, the practice ensured a visible recovery of degraded rangelands. This was evident from the filling up of the riverbed as well as the two WSW wings with 1 m high and about 450 m length each with fertile sediment from Belg and Meher seasons of 2016 and 2017. Hence, future studies should analyze the sustainability and the potential of flood-based development at large scale.
An Investigation Into the Origin of Nitrate in Arctic Sea Ice
Authors: Clark S. C. , Granger J. , Mastorakis A. , Aguilar‐Islas A. , Hastings M. G. 
Published: February 2020

AbstractAtmospheric deposition has been suggested to be an important source of reactive nitrogen stored in Northern Hemisphere land‐fast ice, in contrast to Antarctic sea ice, where bulk nutrients originate predominantly from underlying seawater. A paucity of sea ice studies in the open Arctic Ocean limits our understanding of the potential for melting ice to contribute to primary production in N‐deplete waters of the Arctic. As part of the U.S. western Arctic GEOTRACES 2015 expedition, samples of pack ice, overlying snow, atmospheric aerosols, and underlying seawater were collected between 82°N and 89°N. To identify the provenance of N in sea ice, we measured a suite of tracers including the isotopic composition of nitrate, ammonium, water, and particulate N. Relatively low concentrations of nitrate and ammonium were detected in sea ice (0.1–8.2 and 0.6–1.2 μmol L−1, respectively), and in atmospheric samples (1.1–3.7 and 0.8–1.2 μmol L−1, respectively). Atmospheric nitrate in snow had characteristically high Δ17O and δ18O (Δ17ONO3 = δ17O − 0.52 × δ18O = 27.1–33.5‰ versus Vienna Standard Mean Ocean Water (VSMOW); δ18ONO3 = 70.8–87.8‰), and low δ15NNO3 (−5.9–2‰ versus N2). In contrast to the atmospheric samples, the sea ice δ15NNO3 was typically higher (−0.3–15.0‰) and the δ17ONO3 and δ18ONO3 much lower (Δ17ONO3 = 0–12.4‰; δ18ONO3 = 23.3–67.5‰). The presence of Δ17ONO3 in the sea ice indicated that 0–40% of the nitrate is sourced from the atmosphere, while the majority of the nitrate is non‐atmospheric (Δ17ONO3 = 0‰). Based upon concentration, isotopic observations, and dynamic box modeling with atmospheric deposition and biological processes, we find that the majority of nitrate can be explained by in‐situ biological nitrate production.
Wavenumber Spectra of Atmospheric Gravity Waves and Medium‐Scale Traveling Ionospheric Disturbances Based on More Than 10‐Year Airglow Images in Japan, Russia, and Canada
Authors: Tsuchiya Satoshi , Shiokawa Kazuo , Otsuka Yuichi , Nakamura Takuji , Yamamoto Mamoru , Connors Martin , Schofield Ian , Shevtsov Boris , Poddelsky Igor 
Published: February 2020

AbstractWe have studied atmospheric gravity waves (AGWs) and nighttime medium‐scale traveling ionospheric disturbances (MSTIDs) by applying three‐dimensional spectral analysis technique to 557.7‐ and 630.0‐nm airglow images at Shigaraki (SGK) (35°N, 136°E, 1999–2017) and Rikubetsu (RIK) (44°N, 144°E, 1999–2017), Japan, Athabasca (ATH), Canada, (55°N, 247°E, 2005–2017), and Magadan (MGD), Russia (60°N, 151°E, 2008–2017), focusing on their horizontal wavenumber spectra. For the AGWs in 557.7‐nm images, the power spectra in summer are stronger than in other seasons, probably due to stronger tropospheric convection. The highest energy content of the waves are mostly at wavelengths between 20 and 300 km at MGD, ATH, and RIK, while it is above 200 km at SGK. The largest power spectral density is obtained at RIK at wavelengths of 30–100 km and then ATH. The slopes of the horizontal wavenumber spectra varies from −2.77 to −3.22. From the MSTIDs in 630.0‐nm images, the power spectra in summer at RIK and SGK are stronger than those in other seasons regardless of solar activity. The power spectra in solar quiet time are stronger than those in solar active time at all four stations. These features can be explained by the Perkins instability with coupling between sporadic E and F layers. The spectral slope decreases with increasing latitudes. Weak positive correlations were obtained between the daily wave power of AGWs in 557.7‐nm images and MSTIDs in 630.0‐nm images, suggesting that the MSTIDs in the thermosphere may be partially generated by the AGWs from the mesopause region.
Dependence of Dayside Electron Densities at Venus on Solar Irradiance
Authors: Hensley K. , Withers P. , Girazian Z. , Pätzold M. , Tellmann S. , Häusler B. 
Published: February 2020

AbstractThe ionosphere of Venus is a weakly ionized plasma layer embedded in the planet's upper atmosphere. Planetary ionospheres provide an excellent opportunity to study how our variable Sun affects the planets in our solar system. Because ionospheres are reservoirs from which atmospheric species can be lost to space, studying how ionospheres respond to changes in solar activity can help us understand how planetary atmospheres have evolved since their formation. While variations of the main and lower ionospheric peaks of Venus have been well studied, the behavior of the ionosphere above the altitude of the greatest electron density has not been fully constrained. To investigate the behavior of this region, we use electron density profiles obtained by the Venus Radio Science experiment aboard Venus Express. An increase in the response of the electron density to increasing solar irradiance with increasing altitude above the peak is readily apparent in these data. By using a one‐dimensional photochemical equilibrium model to investigate the factors that drive the variations of the ionosphere of Venus, we find that changes in the composition of the underlying neutral atmosphere are responsible for the observed increase in ionospheric response with altitude.
ULF Waves Generated Near the Plasmapause by the Magnetosphere‐Ionosphere Interactions
Authors: Streltsov Anatoly V. , Mishin Evgeny V. 
Published: February 2020

AbstractUltralow frequency (ULF) electromagnetic waves are regularly detected by satellites near the plasmapause during substorms. Usually, the small‐scale waves are observed embedded in the large‐scale, quasi‐stationary electric field. We suggest that the small‐scale waves are generated in the ionosphere by the interactions between the large‐scale field and irregularities in the ionospheric density/conductivity. Under certain conditions, these waves can be trapped in the global magnetospheric resonator and amplified by the positive feedback interactions with the ionosphere. To verify this hypothesis, we model with a two‐fluid magnetohydrodynamics code structure and amplitude of the ULF waves simultaneously observed near the plasmapause by the Defense Meteorological Satellite Program satellite at low altitudes and the Combined Release and Radiation Effects satellite at high altitudes. Simulations reproduce in good, quantitative detail the structure and amplitude of the observed waves. In particular, simulations reproduce a “spiky” character of the electric field observed by the Defense Meteorological Satellite Program satellite at low altitude, which is a characteristic feature of ULF waves produced by the ionospheric feedback instability.
Fast and Slow Water Ion Populations in the Enceladus Plume
Authors: Haythornthwaite R. P. , Coates A. J. , Jones G. H. , Waite J. H. 
Published: February 2020

AbstractIon velocities have been measured during the Enceladus E3 and E5 flybys using the Cassini Plasma Spectrometer (CAPS) instrument on the Cassini spacecraft. Data from three sensors in the CAPS instrument have been examined from two flybys that occurred during 2008. Positive ion measurements from the CAPS Ion Beam Spectrometer and Ion Mass Spectrometer have been used to measure positive ion velocities. The CAPS Electron Spectrometer has been used to complement the positive ion findings with measurements of negative ion velocities. Two velocities for the positive ions are found, with the fast ions (2.3–5.8 km/s) originating from the high‐speed neutral gas emission and slow ions (0.2–2.2 km/s) associated with the low‐speed thermal gas emission from Enceladus. Negative ions were found to be near stationary or northerly traveling, implying a deceleration mechanism within the plume. A tentative detection of fast negative ions was also recorded for one of the flybys. These findings will aid in future modeling of plume dynamics.
Suprathermal Fe in the Earth's Plasma Environment: Cluster RAPID Observations
Authors: Haaland S. , Daly P. W. , Vilenius E. , Krcelic P. , Dandouras I. 
Published: February 2020

AbstractBaryonic matter in geospace is almost exclusively in a plasma state, with protons (H
) and to some extent ionized helium (He) and oxygen (O) being the dominant ion species. But also other heavier ion species and even molecular ions are present in geospace. The Research with Adaptive Particle Imaging Detectors (RAPID) on board the Cluster satellites can identify and characterize some of these ions by utilizing their measured time of flight and energy. Usually, the measurements are then assigned into three discrete species channels; protons (H
), helium (He), and a common channel for carbon, nitrogen, and oxygen (CNO), each with flux, energy, and angular information. But RAPID also has a Direct Event (DE) diagnostic mode in which the full time of flight and energy information for a limited number of incident particles are stored. With knowledge about energy losses in the various detector parts, it is then possible to derive the atomic mass of the incident particle. In this paper we report on results from a study of Cluster DE events during the years 2001–2018, with a particular emphasis of iron (Fe) ions. We show that suprathermal Fe ions can be found all over geospace covered by Cluster, and that the time variation is consistent with modulation by geomagnetic disturbances and solar activity. We do not find any clear correlations between detection of suprathermal Fe and meteor showers or sputtering off the moon.
Interhemispheric Asymmetry of Large‐Scale Electron Density Gradients in the Polar Cap Ionosphere: UT and Seasonal Variations
Authors: Jin Yaqi , Xiong Chao 
Published: February 2020

AbstractThe high‐latitude ionosphere is highly dynamical with significant irregularities and density gradients. However, the spatial and temporal distributions of density gradients and irregularities are very different between the Arctic and Antarctic. In this report, we study the interhemispheric asymmetry of the large‐scale (100 km) density gradients in both polar caps. Our results show that density gradients in the Arctic are enhanced during local winter (December solstice) with a peak around 19 UT. The UT and spatial distributions in the Antarctic local winter (June solstice) are similar to the Arctic except that they are reversed by 12 hr, which indicates a mirror symmetry between hemispheres. The 12‐hr difference in the peak density gradients can be explained by the displacements between the geographic and geomagnetic poles. The only asymmetry (anomaly) is the persistence of strong density gradients in the southern polar cap during local summer (December solstice).
The Climatological Horizontal Pattern of Energy Flux in the Tropical Atlantic as Identified by a Unified Diagnosis for Rossby and Kelvin Waves
Authors: Song Qingyang , Aiki Hidenori 
Published: February 2020

AbstractThis study investigates the horizontal distribution of wave energy flux in the tropical Atlantic Ocean using shallow‐water model experiments for three gravest baroclinic modes forced by climatological winds. This is the first attempt to apply a unified diagnostic scheme to the analysis of energy fluxes associated with both Rossby waves (RWs) and Kelvin waves (KWs) in the tropical Atlantic Ocean. Those analyses were difficult in previous studies owing to the difference of equatorial and quasigeostrophic dynamics. The scheme yields the transfer route (i.e., trajectories by group velocity vector) of wave energy originating from both local wind forcing and boundary reflection. The meridional flux of wave energy crossing two zonal sections (at 3°N and at 2°S) is examined for understanding where the equatorial and off‐equatorial regions interconnect. Equatorward energy fluxes into the basin interior are found mainly on the zonal section in the Northern Hemisphere (at 3°N), indicating the radiation of RWs from the Guinea coast. At the equator, seasonal transition in May from eastward wind anomaly to westward anomaly yields a significant energy input at the central basin that radiates both RWs and KWs. The energy flux of these RWs arrives at the western boundary in September, followed by reflection of KWs to yield eastward transbasin energy fluxes in October‐December. The analysis also identifies an unexpected wind input in May at 4°S which induces both RWs and inertial gravity waves.
Intense and Small Freshwater Pools From Rainfall Investigated During Spurs‐2 on 9 November 2017 in the Eastern Tropical Pacific
Authors: Reverdin G. , Supply A. , Drushka K. , Thompson E. J. , Asher W. E. , Lourenço A. 
Published: February 2020

AbstractDuring the second Salinity Processes in the Upper Ocean Regional Study (SPURS‐2) 2017 tropical Pacific cruise, two drifters were deployed on 9 November. The drifters measured temperature and salinity in the top 36 cm, wave spectra, and the noise of rain drops. During a short nearly circular survey with a 1.8‐km radius around the drifters, the R/V Revelle measured air‐sea fluxes, as well as temperature and salinity stratification in the top 1 m from a towed surface salinity profiler (SSP). A C‐band weather radar measuring rain rate within 1‐ to 100‐km range of the ship observed discrete rain cells organized in a system moving from the southeast to the northwest. Some of the intense rain cells were small scale (1 km in diameter or less) with short lifetimes yet dropped more than 5 cm of water in half an hour near the drifters, whereas the ship measured short rain episodes totaling 1.3 cm of rainfall mostly accompanied by very low wind. The data indicate a large spatial heterogeneity in temperature and salinity, with near‐surface freshening of up to 9 psu measured at different times by the two drifters (separated by less than 500 m) and by the SSP. The drifters indicate deepening of the fresh and cool surface layer during the rain which then thinned during the following 40 min with very low wind speed (<2 m/s). Patchy surface‐trapped cold and fresh layers were also observed by the SSP east of the drifters. The high spatial and temporal variability of rainfall and surface‐trapped fresh pools is discussed.