bluuebunny/crossref_metadata_2025 huggingface dataset:
Doppler lidar at Observatoire de Haute Provence for wind profiling up to 75 km altitude: performance evaluation and observations
Authors: Khaykin Sergey M. , Hauchecorne Alain , Wing Robin , Keckhut Philippe , Godin-Beekmann Sophie , Porteneuve Jacques , Mariscal Jean-Francois , Schmitt Jerome
Published: November 2019

Abstract. A direct-detection Rayleigh-Mie Doppler lidar for measuring horizontal wind speed in the middle atmosphere has been deployed at Observatoire de Haute Provence (OHP) in southern France since 1993. After a recent upgrade, the instrument gained the capacity of wind profiling between 5 and 75 km altitude with high vertical and temporal resolution. The lidar comprises a monomode Nd:Yag laser emitting at 532 nm, three telescope assemblies, and a double-edge Fabry-Perot interferometer for detection of the Doppler shift in the backscattered light. In this article, we describe the instrument design, recap retrieval methodology and provide an updated error estimate for horizontal wind. The evaluation of the wind lidar performance is done using a series of twelve time-coordinated radiosoundings conducted at OHP. A point-by-point intercomparison shows a remarkably small average bias of 0.1 m/s between the lidar and the radiosonde wind profiles with a standard deviation of 2.2 m/s. We report examples of a weekly and an hourly observation series, reflecting various dynamical events in the middle atmosphere, such as a Sudden Stratospheric Warming event in January 2019 and an occurrence of a stationary gravity wave, generated by the flow over the Alps. A qualitative comparison between the wind profiles from the lidar and the ECMWF Integrated Forecast System is also discussed. Finally, we present an example of early validation of the ESA Aeolus space-borne wind lidar using its ground-based predecessor.
The 2018 fire season in North America as seen by TROPOMI: aerosol layer height validation and evaluation of model-derived plume heights
Authors: Griffin Debora , Sioris Christopher , Chen Jack , Dickson Nolan , Kovachik Andrew , de Graaf Martin , Nanda Swadhin , Veefkind Pepijn , Dammers Enrico , McLinden Chris A. , Makar Paul , Akingunola Ayodeji
Published: November 2019

Abstract. Before the launch of TROPOMI, only two other satellite instruments were able to observe aerosol plume heights globally, MISR and CALIOP. The TROPOMI aerosol layer height is a potential game changer, since it has daily global coverage and the aerosol layer height retrieval is available in near-real time. The aerosol layer height can be useful for aviation and air quality alerts, as well as for improving air quality forecasting related to wildfires. Here, TROPOMI's aerosol layer height product is evaluated with MISR and CALIOP observations for wildfire plumes in North America for the 2018 fire season (June to August). Further, observing system simulation experiments were performed to interpret the fundamental differences between the different products. The results show that MISR and TROPOMI are, in theory, very close for aerosol profiles with single plumes. For more complex profiles with multiple plumes, however, different plume heights are retrieved: the MISR plume height represents the top layer, and the plume height retrieved with TROPOMI tends to be an average altitude of several plume layers. The comparison between TROPOMI and MISR plume heights shows, that on average, the TROPOMI aerosol layer heights are lower, by approximately 600 m, compared to MISR which is likely due to the different measurement techniques. From the comparison to CALIOP, our results show that the TROPOMI aerosol layer height is more accurate for thicker plumes and plumes below approximately 4.5 km. MISR and TROPOMI are further used to evaluate the plume height of Environment and Climate Change Canada's operational forecasting system FireWork with fire plume injection height estimates from the Canadian Forest Fire Emissions Prediction System (CFFEPS). The modelled plume heights are similar compared to the satellite observations, but tend to be slightly higher with average differences of 270–580 m and 60–320 m compared to TROPOMI and MISR, respectively.
Climatology of intermediate descending layers (or 150 km echoes) over the equatorial and low-latitude regions of Brazil during the deep solar minimum of 2009
Authors: dos Santos Ângela Machado , Batista Inez Staciarini , Abdu Mangalathayil Ali , Sobral José Humberto Andrade , de Souza Jonas Rodrigues , Brum Christiano Garnett Marques
Published: November 2019

Abstract. In this work, we have performed a study for the first time on the
climatology of the intermediate descending layers (ILs) over Brazilian
equatorial and low-latitude regions during the extreme solar minimum period
of 2009. The result of this study shows that the occurrence frequency of the
ILs is very high, being > 60 % over São Luís
(2∘ S, 44∘ W; inclination: −3.8∘) and > 90 % in Cachoeira Paulista (22.42∘ S, 45∘ W; inclination:
−33.5∘). In most cases the ILs occur during the day at altitudes
varying from 130 to 180 km and they may descend to lower altitudes
(∼100 km) in a time interval of a few minutes to hours. The
main driving force for the ILs at the low-latitude region, may be considered
to be the diurnal tide (24 h) followed in smaller dominance by the
semidiurnal (12 h), terdiurnal (8 h) and quarter-diurnal (6 h) components. In
the magnetic equatorial sector, similar behavior was seen, with the exception of
the semidiurnal tide, which in general does not appear to have influenced the
IL's dynamics (except in summer). Additionally, the IL mean descent
velocity over São Luís and Cachoeira Paulista shows a day-to-day
variability that may be associated with a wave-like perturbation with a
periodicity of some days. Some peculiarities in the IL dynamics were noted,
such as the presence of the ILs during the night hours. Ascending and
descending ILs appeared to have been formed from some connection with the
ionospheric F layer. Quite often, these characteristics are observed in the
presence of strong signatures of the gravity wave propagation as suggested
by the F layer traces in the ionogram. The descending intermediate layer
over Brazil appears to have been formed through a process of F1 layer base
detachment. An interesting case study showed that an ascending ILs,
initially detected at ∼130 km, reached the base of the F2
layer, due probably to the gravity wave propagation and/or the effect of a
prompt penetration electric field.
Regulation of carbon dioxide and methane in small agricultural reservoirs: optimizing potential for greenhouse gas uptake
Authors: Webb Jackie R. , Leavitt Peter R. , Simpson Gavin L. , Baulch Helen M. , Haig Heather A. , Hodder Kyle R. , Finlay Kerri
Published: November 2019

Abstract. Small farm reservoirs are abundant in many agricultural
regions across the globe and have the potential to be large contributing
sources of carbon dioxide (CO2) and methane (CH4) to agricultural
landscapes. Compared to natural ponds, these artificial waterbodies remain
overlooked in both agricultural greenhouse gas (GHG) inventories and inland
water global carbon (C) budgets. Improved understanding of the environmental
controls of C emissions from farm reservoirs is required to address and
manage their potential importance in agricultural GHG budgets. Here, we
conducted a regional-scale survey (∼ 235 000 km2) to
measure CO2 and CH4 surface concentrations and diffusive fluxes
across 101 small farm reservoirs in Canada's largest agricultural area. A
combination of abiotic, biotic, hydromorphologic, and landscape variables
were modelled using generalized additive models (GAMs) to identify
regulatory mechanisms. We found that CO2 concentration was estimated by
a combination of internal metabolism and groundwater-derived alkalinity
(66.5 % deviance explained), while multiple lines of evidence support a
positive association between eutrophication and CH4 production
(74.1 % deviance explained). Fluxes ranged from −21 to 466 and 0.14 to 92 mmol m−2 d−1 for CO2 and CH4, respectively, with
CH4 contributing an average of 74 % of CO2-equivalent
(CO2-e) emissions based on a 100-year radiative forcing. Approximately
8 % of farm reservoirs were found to be net CO2-e sinks. From our
models, we show that the GHG impact of farm reservoirs can be greatly
minimized with overall improvements in water quality and consideration to
position and hydrology within the landscape.
Identifying the core bacterial microbiome of hydrocarbon degradation and a shift of dominant methanogenesis pathways in the oil and aqueous phases of petroleum reservoirs of different temperatures from China
Authors: Zhou Zhichao , Liang Bo , Wang Li-Ying , Liu Jin-Feng , Mu Bo-Zhong , Shim Hojae , Gu Ji-Dong
Published: November 2019

Abstract. Microorganisms in petroleum reservoirs play significant roles in hydrocarbon
degradation, and through the terminal electron-accepting process of
methanogenesis, they also contribute to microbially enhanced oil recovery
(MEOR) worldwide, with great economic and environmental benefits. Here, a
molecular investigation, using the 16S rRNA and mcrA gene profiles based on
MiSeq sequencing and clone library construction methods, was conducted on
oil and water (aqueous) phases of samples of high (82–88 ∘C),
moderate (45–63 ∘C), and low temperatures (21–32 ∘C) from
seven petroleum reservoirs in China. A core bacterial microbiome with a
small proportion of shared operational taxonomic unit (OTU) values, but a high
proportion of sequences among all reservoirs was discovered, including
aerobic degraders, sulfate- and nitrate-reducing bacteria, fermentative bacteria,
and sulfur-oxidizing bacteria distributed mainly in Proteobacteria, Bacteroidetes, Deferribacteres,
Deinococcus–Thermus, Firmicutes, Spirochaetes, and Thermotogae. Their prevalence in the previously reported petroleum reservoirs
and successive enrichment cultures suggests their common roles and functions
involved in aliphatic and aromatic hydrocarbon degradation. The methanogenic
process generally shifts from the dominant hydrogenotrophic pathway in the
aqueous phase to the acetoclastic pathway in the oil phase in high-temperature
reservoirs, but the opposite was true for low-temperature reservoirs. No
difference was detected between the two phases in moderate temperature
reservoirs. Physicochemical factors, including pH; temperature; phase
conditions; and nitrate, Mn2+, and Mg2+ concentrations were the
main factors correlated to the microbial compositional and functional profiles
significantly. Linear discriminant analysis (LDA) effect size (LEfSe) analysis shows distribution
differences of microbial groups towards pH, temperature, and the oil and aqueous
phases. Using the software Tax4Fun for functional profiling indicated
functional metabolism differences between the two phases, including amino
acids, hydrocarbons in the oil phase, and carbohydrates in the aqueous phase.
Biogeographical distribution of microbial communities along the Rajang River–South China Sea continuum
Authors: Sia Edwin Sien Aun , Zhu Zhuoyi , Zhang Jing , Cheah Wee , Jiang Shan , Holt Jang Faddrine , Mujahid Aazani , Shiah Fuh-Kwo , Müller Moritz
Published: November 2019

Abstract. The Rajang River is the main drainage system for central Sarawak in
Malaysian Borneo and passes through peat domes through which peat-rich material
is being fed into the system and eventually into the southern South China
Sea. Microbial communities found within peat-rich systems are important
biogeochemical cyclers in terms of methane and carbon dioxide sequestration.
To address the critical lack of knowledge about microbial communities in
tropical (peat-draining) rivers, this study represents the first seasonal
assessment targeted at establishing a foundational understanding of the
microbial communities of the Rajang River–South China Sea continuum. This
was carried out utilising 16S rRNA gene amplicon sequencing via Illumina
MiSeq in size-fractionated samples (0.2 and 3.0 µm GF/C filter
membranes) covering different biogeographical features and sources from
headwaters to coastal waters. The microbial communities found along the
Rajang River exhibited taxa common to rivers (i.e. predominance of β-Proteobacteria) while estuarine and marine regions exhibited taxa that were common to the
aforementioned regions as well (i.e. predominance of α− and γ-Proteobacteria). This is in agreement with studies from other rivers which observed
similar changes along salinity gradients. In terms of particulate versus
free-living bacteria, nonmetric multi-dimensional scaling (NMDS) results
showed similarly distributed microbial communities with varying separation
between seasons. Distinct patterns were observed based on linear models as a
result of the changes in salinity along with variation of other
biogeochemical parameters. Alpha diversity indices indicated that microbial
communities were higher in diversity upstream compared to the marine and
estuarine regions, whereas anthropogenic perturbations led to increased
richness but less diversity. Despite the observed changes in bacterial
community composition and diversity that occur along the continuum of the Rajang River to the sea, the PICRUSt predictions showed minor variations. The results
provide essential context for future studies such as further analyses on the
ecosystem response to anthropogenic land-use practices and probable
development of biomarkers to improve the monitoring of water quality in this
region.
Geo-locate project: a novel approach to resolving meteorological station location issues with the assistance of undergraduate students
Authors: Noone Simon , Brody Alison , Brown Sasha , Cantwell Niamh , Coleman Martha , Sarsfield Collins Louise , Darcy Caoilfhionn , Dee Dick , Donegan Seán , Fealy Rowan , Flattery Padraig , McGovern Rhonda , Menkman Caspar , Murphy Michael , Phillips Christopher , Roche Martina , Thorne Peter
Published: November 2019

Abstract. The Global Land and Marine Observations Database aims to produce a
comprehensive land-based meteorological data archive and inventory. This
requires the compilation of available information on data from land-based
meteorological stations from all known available in situ meteorological data
repositories/sources at multiple timescales (e.g. sub-daily, daily, and
monthly). During this process the service team members have identified that
many of the data sources contain stations with incorrect location
coordinates. These stations cannot be included in the processing to be
served via the Copernicus Climate Change Service until the issues are
satisfactorily resolved. Many of these stations are in regions of the world
where a sparsity of climate data currently exists, such as Southeast Asia
and South America. As such, resolving these issues would provide important
additional climate data, but this is a very labour-intensive task.
Therefore, we have developed the Geo-locate project – that enrols the help of
undergraduate geography students at Maynooth University, Ireland – to resolve
some of the land-based station geolocation issues. To date, we have run two
Geo-locate projects: the first in the 2017/2018 academic year and the second
in the 2018/2019 academic year. Both iterations have been very successful with
1926 of the 2168 total candidate stations ostensibly resolved, which equates
to an 88 % success rate. At the same time, students have gained critical skills that
helped to meet the expected pedagogical outcomes of the second-year
curriculum, while producing a lasting scientific legacy. We asked the class
of 2018/2019 to reflect critically upon the outcomes, and we present the results
herein; these results provide important feedback on what students felt that they
gained from their participation and how we may improve the experience and
learning outcomes in future. We will be continuing to run Geo-locate
projects over the next few years. We encourage other organizations to
investigate the potential for engaging university students to help resolve
similar data issues while enriching the student experience and aiding in the delivery of learning outcomes. This paper provides details of the project,
and all supporting information such as project guidelines and templates to
enable other organizations to instigate similar programmes.
Modelling biomass burning emissions and the effect of spatial resolution: a case study for Africa based on the Global Fire Emissions Database (GFED)
Authors: van Wees Dave , van der Werf Guido R.
Published: November 2019

Abstract. Large-scale fire emission estimates may be influenced by
the spatial resolution of the model and input datasets used. Especially in
areas with relatively heterogeneous land cover, a coarse model resolution
might lead to substantial errors in estimates. We developed a
model using MODerate resolution Imaging Spectroradiometer (MODIS) satellite
observations of burned area and vegetation characteristics to study the
impact of spatial resolution on modelled fire emission estimates. We
estimated fire emissions for sub-Saharan Africa at 500 m spatial
resolution (native MODIS burned area) for the 2002–2017 period, using a
simplified version of the Global Fire Emissions Database (GFED) modelling
framework, and compared this to model runs at a range of coarser resolutions
(0.050, 0.125, 0.250∘). We estimated fire
emissions of 0.68 Pg C yr−1 at 500 m resolution and 0.82 Pg C yr−1 at 0.25∘ resolution; a difference of 24 %. At
0.25∘ resolution, our model results were relatively similar to
GFED4, which also runs at 0.25∘ resolution, whereas our 500 m
estimates were substantially lower. We found that lower emissions at finer
resolutions are mainly the result of reduced representation errors when
comparing modelled estimates of fuel load and consumption to field
measurements, as part of the model calibration. Additional errors stem from
the model simulation at coarse resolution and lead to an additional 0.02 Pg C yr−1 difference in estimates. These errors exist due to the aggregation of quantitative and qualitative model input data; the average-
or majority- aggregated values are propagated in the coarse-resolution
simulation and affect the model parameterization and the final result. We
identified at least three error mechanisms responsible for the differences
in estimates between 500 m and 0.25∘ resolution simulations,
besides those stemming from representation errors in the calibration
process, namely (1) biome misclassification leading to errors in
parameterization, (2) errors due to the averaging of input data and the
associated reduction in variability, and (3) a temporal mechanism related to
the aggregation of burned area in particular. Even though these mechanisms
largely neutralized each other and only modestly affect estimates at a
continental scale, they lead to substantial error at regional scales with
deviations of up to a factor 4 and may affect large-scale estimates
differently for other continents. These findings could prove valuable in
improving coarse-resolution models and suggest the need for increased
spatial resolution in global fire emission models.
Wave energy attenuation in fields of colliding ice floes – Part 1: Discrete-element modelling of dissipation due to ice–water drag
Authors: Herman Agnieszka , Cheng Sukun , Shen Hayley H.
Published: November 2019

Abstract. The energy of water waves propagating through sea ice is attenuated due to non-dissipative (scattering) and dissipative processes. The nature of those processes and their contribution to attenuation depends on wave characteristics and ice properties and is usually difficult (or impossible) to determine from limited observations available. Therefore, many aspects of relevant dissipation mechanisms remain poorly understood. In this work, a discrete-element model (DEM) is used to study one of those mechanisms: dissipation due to ice–water drag. The model consists of two coupled parts, a DEM simulating the surge motion and collisions of ice floes driven by waves and a wave module solving the wave energy transport equation with source terms computed based on phase-averaged DEM results. The wave energy attenuation is analysed analytically for a limiting case of a compact, horizontally confined ice cover. It is shown that the usage of a quadratic drag law leads to non-exponential attenuation of wave amplitude a with distance x, of the form a(x)=1/(αx+1/a0), with the attenuation rate α linearly proportional to the drag coefficient. The dependence of α on wave frequency ω varies with the dispersion relation used. For the open-water (OW) dispersion relation, α∼ω4. For the mass loading dispersion relation, suitable for ice covers composed of small floes, the increase in α with ω is much faster than in the OW case, leading to very fast elimination of high-frequency components from the wave energy spectrum. For elastic-plate dispersion relation, suitable for large floes or continuous ice, α∼ωm within the high-frequency tail, with m close to 2.0–2.5; i.e. dissipation is much slower than in the OW case. The coupled DEM–wave model predicts the existence of two zones: a relatively narrow area of very strong attenuation close to the ice edge, with energetic floe collisions and therefore high instantaneous ice–water velocities, and an inner zone where ice floes are in permanent or semi-permanent contact with each other, with attenuation rates close to those analysed theoretically. Dissipation in the collisional zone increases with an increasing restitution coefficient of the ice and with decreasing floe size. In effect, two factors contribute to strong attenuation in fields of small ice floes: lower wave energy propagation speeds and higher relative ice–water velocities due to larger accelerations of floes with smaller mass and more collisions per unit surface area.
Wave energy attenuation in fields of colliding ice floes – Part 2: A laboratory case study
Authors: Herman Agnieszka , Cheng Sukun , Shen Hayley H.
Published: November 2019

Abstract. This work analyses laboratory observations of wave energy attenuation in fragmented sea ice cover composed of interacting, colliding floes. The experiment, performed in a large (72 m long) ice tank, includes several groups of tests in which regular, unidirectional, small-amplitude waves of different periods were run through floating ice with different floe sizes. The vertical deflection of the ice was measured at several locations along the tank, and video recording was used to document the overall ice behaviour, including the presence of collisions and overwash of the ice surface. The observational data are analysed in combination with the results of two types of models: a model of wave scattering by a series of floating elastic plates, based on the matched eigenfunction expansion method (MEEM), and a coupled wave–ice model, based on discrete-element model (DEM) of sea ice and a wave model solving the stationary energy transport equation with two source terms, describing dissipation due to ice–water drag and due to overwash. The observed attenuation rates are significantly larger than those predicted by the MEEM model, indicating substantial contribution from dissipative processes. Moreover, the dissipation is frequency dependent, although, as we demonstrate in the example of two alternative theoretical attenuation curves, the quantitative nature of that dependence is difficult to determine and very sensitive to assumptions underlying the analysis. Similarly, more than one combination of the parameters of the coupled DEM–wave model (restitution coefficient, drag coefficient and overwash criteria) produce spatial attenuation patterns in good agreement with observed ones over a range of wave periods and floe sizes, making selection of “optimal” model settings difficult. The results demonstrate that experiments aimed at identifying dissipative processes accompanying wave propagation in sea ice and quantifying the contribution of those processes to the overall attenuation require simultaneous measurements of many processes over possibly large spatial domains.
Estimating early-winter Antarctic sea ice thickness from deformed ice morphology
Authors: Mei M. Jeffrey , Maksym Ted , Weissling Blake , Singh Hanumant
Published: November 2019

Abstract. Satellites have documented variability in sea ice areal extent for decades, but there are significant challenges in obtaining analogous measurements for sea ice thickness data in the Antarctic, primarily due to difficulties in estimating snow cover on sea ice. Sea ice thickness (SIT) can be estimated from snow freeboard measurements, such as those from airborne/satellite lidar, by assuming some snow depth distribution or empirically fitting with limited data from drilled transects from various field studies. Current estimates for large-scale Antarctic SIT have errors as high as ∼50 %, and simple statistical models of small-scale mean thickness have similarly high errors. Averaging measurements over hundreds of meters can improve the model fits to existing data, though these results do not necessarily generalize to other floes. At present, we do not have algorithms that accurately estimate SIT at high resolutions. We use a convolutional neural network with laser altimetry profiles of sea ice surfaces at 0.2 m resolution to show that it is possible to estimate SIT at 20 m resolution with better accuracy and generalization than current methods (mean relative errors ∼15 %). Moreover, the neural network does not require specification of snow depth or density, which increases its potential applications to other lidar datasets. The learned features appear to correspond to basic morphological features, and these features appear to be common to other floes with the same climatology. This suggests that there is a relationship between the surface morphology and the ice thickness. The model has a mean relative error of 20 % when applied to a new floe from the region and season. This method may be extended to lower-resolution, larger-footprint data such as such as Operation IceBridge, and it suggests a possible avenue to reduce errors in satellite estimates of Antarctic SIT from ICESat-2 over current methods, especially at smaller scales.
New Last Glacial Maximum ice thickness constraints for the Weddell Sea Embayment, Antarctica
Authors: Nichols Keir A. , Goehring Brent M. , Balco Greg , Johnson Joanne S. , Hein Andrew S. , Todd Claire
Published: November 2019

Abstract. We describe new Last Glacial Maximum (LGM) ice
thickness constraints for three locations spanning the Weddell Sea Embayment
(WSE) of Antarctica. Samples collected from the Shackleton Range, Pensacola
Mountains, and the Lassiter Coast constrain the LGM thickness of the Slessor
Glacier, Foundation Ice Stream, and grounded ice proximal to the modern
Ronne Ice Shelf edge on the Antarctic Peninsula, respectively. Previous
attempts to reconstruct LGM-to-present ice thickness changes around the WSE
used measurements of long-lived cosmogenic nuclides, primarily 10Be. An
absence of post-LGM apparent exposure ages at many sites led to LGM
thickness reconstructions that were spatially highly variable and
inconsistent with flow line modelling. Estimates for the contribution of the
ice sheet occupying the WSE at the LGM to global sea level since
deglaciation vary by an order of magnitude, from 1.4 to 14.1 m of sea level
equivalent. Here we use a short-lived cosmogenic nuclide, in situ-produced
14C, which is less susceptible to inheritance problems than 10Be
and other long-lived nuclides. We use in situ 14C to evaluate the
possibility that sites with no post-LGM exposure ages are biased by
cosmogenic nuclide inheritance due to surface preservation by cold-based ice
and non-deposition of LGM-aged drift. Our measurements show that the Slessor
Glacier was between 310 and up to 655 m thicker than present at the LGM. The
Foundation Ice Stream was at least 800 m thicker, and ice on the Lassiter
Coast was at least 385 m thicker than present at the LGM. With evidence for
LGM thickening at all of our study sites, our in situ 14C measurements
indicate that the long-lived nuclide measurements of previous studies were
influenced by cosmogenic nuclide inheritance. Our inferred LGM
configuration, which is primarily based on minimum ice thickness constraints
and thus does not constrain an upper limit, indicates a relatively modest
contribution to sea level rise since the LGM of < 4.6 m, and
possibly as little as < 1.5 m.
Las ordenanzas de arraeces y pescadores de las ciudades de Vera (Almería, siglo XVIII) y Cartagena (Murcia, siglos XVI-XVII) y las reales ordenanzas de la pesca con pareja de 'bous' de 1786
Authors: Porras Arboledas Pedro Andrés
Published: November 2019

Se recogen en este estudio tres conjuntos de ordenanzas, dos de carácter local, aprobadas por concejos y pescadores y confirmadas en Consejo, relativas a los enclaves mediterráneos de Vera y Cartagena, donde viene reflejada la práctica moderna existente en la pesquería de bajura y en la posterior comercialización del pescado. La tercera pieza, ya de finales de la Edad Moderna, pretendía prohibir y regular, allí donde se permitía, la pesca de arrastre, llamada de parejas de bueyes o bous, según la experiencia de Sáñez Reguart.
Cyanide in Cassava Varieties and People’s Perception on Cyanide Poisoning in Selected Regions of Tanzania
Authors: Mushumbusi Cornelius B. , Max Robert A. , Bakari Gaymary G. , Mushi James R. , Balthazary Sakurani T.
Published: November 2019

Cassava, an important food crop in the tropical regions of the world, is known to carry varying levels of cyanogenic glucosides that are potential poison to humans. In Tanzania, cases of cyanide poisoning have been reported in many cassava producing areas. This study was launched to quantify cyanide in fresh tubers of so called “sweet” cassava varieties and to gauge peoples’ perception on cyanide poisoning in Kagera and Morogoro regions. The study employed a questionnaire survey and a cross-sectional research design to identify different cassava varieties and their cyanide content using alkaline titration method. Findings showed that cyanide content in all of the analyzed tubers were above the internationally accepted levels in human consumables. Some sweet varieties were found to be wrongly classified as sweet because their cyanide content was above acceptable limits. For the same variety tubers sampled from a lowland area had significantly higher (P < 0.01) cyanide content than those from a highland point. It was also found that the upper (slippery) parenchymal tissue had more cyanide content (P < 0.05) than the inner tissue. Nearly 80% of the studied population was unaware of cyanide poisoning, its health effects and how to reduce cyanide content prior to consumption. It is concluded that consumption of raw cassava tubers can lead to undesirable health effects despite of some of them being categorized as sweet. The public should be sensitized on the issues of cyanide in cassava and should avoid consuming raw cassava tubers as preventive measures against cyanide poisoning.
Black Power and the Mills Girl: Gender and the Black Campus Movement at Mills College, 1967–69
Authors: Araiza Lauren
Published: November 2019

This article examines the rise and impact of the Black campus movement at Mills College, a women’s college in Oakland, California. Founded in 1852 for the daughters of western industrialists, Mills actively promoted an image of its elite students as refined, intelligent, and ladylike—“the Mills girl.” Administrators historically had discouraged the students from political engagement and activism because they considered these activities to be unfeminine and believed that they would jeopardize students’ prospects for marriage and motherhood. These ideals were challenged in 1968–69 when the newly formed Black Student Union (BSU) employed direct-action protest strategies that led to the hiring of Black faculty and staff, the increased recruitment of students of color, increased financial aid, and the establishment of one of the first departments of ethnic studies in the country and the first and only at a women’s college. Although successful, the Mills BSU’s actions were met with resentment and resistance from the college administration and derision from much of the public. While the Black campus movement challenged Eurocentric curricula and racially homogenous student bodies and faculty at numerous universities, at Mills the movement also challenged gendered expectations of acceptable behavior for female students. I argue that, in critics’ views, what was most disturbing about the BSU’s actions was not its desire to make Mills inclusive and its curriculum relevant to Black students, but that, by protesting, the BSU upended the carefully crafted and protected image of “the Mills girl.”
Investigating the Efficiency of GCC Banking Sector: An Empirical Comparison of Islamic and Conventional Banks
Authors: Khokhar Imran , Hassan Mehboob Ul , Khan Muhammad Nauman , Amin Md Fouad Bin
Published: November 2019

We examine and compare the performance of 63 (21 Islamic and 42 conventional) GCC banks at two tiers, covering the period of 2010–2016. In the first tier, an industry-level analysis is conducted of each country, followed by an individual bank-level analysis in the second tier. Deposits, assets, and capital are taken as inputs to measure the outputs using data envelopment analysis techniques. At the industry level, we find that Islamic banking is at par with-if not better than-conventional banking in all terms of efficiency. Particularly, banking in Bahrain and KSA is among the best, whereas there is no scope for improvement in the UAE’s banking industry. This low performance could be attributed to a lack of standardization in products and schemes as well as the level of prudence in decision-making, governance, and operations. At the bank level, many Islamic banks perform even better than conventional banks. Most studies on GCC and MENA focus on the determinants and indicators of development and the banking industry growth in general. Uniquely, we further examine GCC banking performance at the individual bank level by incorporating the latest available data.
The Internationalization of Business and Their Approach to New Markets: A Focus on US Wine Consumer
Authors: Mastroberardino Piero , Calabrese Giuseppe , Cortese Flora , Petracca Miriam
Published: November 2019

The paper develops an exploratory research. It aims to understand the elements considered by a wine company to enter the US market and the characteristics considered to be important for US wine consumers when choosing a wine. For this purpose, the paper conducts two different steps of study: (1) it analyzes the US wine market, through a secondary data set; and (2) it studies a random sample of 4,560 reviews of US wines consumers found on CellarTracker. After a reflection on cultural issues related to the internationalization of companies, the paper presents briefly the theme of cross-cultural management, which is fundamental for the approach to new markets, and then it focuses on the wine industry. The focus will be on the peculiarity of the production of Italian wine companies and their choices of internationalization, particularly in the US market. The analyses show that (1) the US market ranks first in terms of consumption and represents, among other things, the first destination area for Italian sales and (2) the US consumer is strongly focused on the organoleptic properties of the wine.
Using Mobile Applications: A Model of Technology Adoption in the Grocery Setting
Authors: Aiolfi Simone , Bellini Silvia
Published: November 2019

One of the most discussed topics in the academic literature is the adoption of new technologies by consumers. However, researchers conducted few studies on the adoption of mobile apps for grocery shopping. Particularly, the few researches carried out focused on the adoption of mobile commerce by consumers, while no study was concerned with the use of mobile applications out-of-store, as means for shopping preparation or in-store, as tools for self-regulation. Since individuals are becoming increasingly reliant on mobile technologies, understanding the role of mobile devices in influencing the attitude of consumers towards the app’s adoption in the grocery retail setting is extremely important for retailers and manufacturers who should develop mobile apps to exploit consumers’ mobile dependence in order to influence consumer and buying behavior during the path-to-purchase. The study we proposed led to the development of a new version of the technology adoption model of a smart mobile application for grocery shopping, in the Italian retail context, which could help researchers and managers better understand the shoppers’ behaviour in the new retail landscape. Our model includes variables related to the use of the mobile both out-of-store, as a means of shopping preparation, and in-store, as a tool for self-regulation.
Seeing like a Circle: Perspectives on the Field from a Dialogue on Urban Aboriginal Economic Development
Authors: Horn Charles L , Halseth Greg
Published: November 2019

Since the early 1970s, Aboriginal communities, policy analysts, and researchers have constructed “urban Aboriginal economic development” as both a domain of strategic intervention and a field of tactical contestation. An integral part of this project has been the creation of a body of academic knowledge about urban Aboriginal peoples and their relationship to the economy. This article surveys the current state of knowledge about urban Aboriginal economic development, identifying strengths and gaps in our understanding of this topic, arguing that unlike the policy and program domains, academic knowledge is characterized by its refracted, indirect nature. The analysis is informed by the results of a multi-year dialogue process on urban economic development between Aboriginal peoples, researchers, and policy analysts. In response to the limitations identified in the existing literature, we suggest two supplemental approaches: place-based economics, and new regionalism.
Effect of Sintering Temperature on Property of Low-Density Ceramic Proppant Adding Coal Gangue
Authors: HAO Jianying , HAO Huilan , GAO Yunfeng , LI Xianjun , QIN Mei , WANG Kaiyue
Published: November 2019

Calcined flint clay (45.6 wt.% Al2O3) and solid waste coal gangue were used to prepare low-density ceramic proppant by solid state sintering method. The density and breakage ratio of the ceramic proppant were systematically investigated as a function of sintering temperature. The morphology and phase composition of the ceramic proppant were examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results show that the ceramic proppant is composed of rod-like mullite and granular cristobalite. Bulk density and apparent density of the proppant first rise and then slightly decrease with increasing the sintering temperature, while breakage ratios under 35 MPa and 52 MPa pressure gradually decrease and then increase. As the sintering temperature increases up to 1400 °C, the ceramic proppant shows denser microstructure. The proppant sintered at 1400 °C have the best performance with 1.27 g/cm3 of bulk density, 2.79 g/cm3 of apparent density, 3.27 % of breakage ratio under 35 MPa closed pressure and 8.36 % of breakage ratio under 52 MPa closed pressure, which conform to the requirement of low-density ceramic proppant. The addition of solid waste can greatly reduce the preparation cost of the ceramic proppant.
Adolescent Coping: In-Person and Cyber-Victimization
Authors: Armstrong Stacey B. , Dubow Eric F. , Domoff Sarah E.
Published: November 2019

Cyber-victimization has become a serious concern facing adolescents in the digital age. Given the differences and similarities between cyber-victimization and in-person victimization, research needs to examine whether prior understanding of coping with in-person victimization applies to coping with cyber-victimization. The purpose of this study was to compare the use and effectiveness of coping strategies in both in-person and cyber-victimization contexts in a sample of adolescents (N = 321; 11-15 years old) in the United States. Results indicated that adolescents tend to use more strategies overall to cope with in-person victimization than cyber-victimization, and female adolescents used more distraction and social support from friends than male adolescents. Adolescents also used problem solving, social support from friends and family/adults, and distraction more frequently than distancing and retaliation; when problem solving was used, adolescents felt positive about the outcome, regardless of victimization type. The use of retaliation was negatively associated with coping efficacy for both situations. Further, social support from friends and social support from family/adults were associated with coping efficacy for cyber-victimization. Our findings can be used to inform interventionists about which strategies adolescents perceive work best to cope with cyber-victimization.
Can "slacktivism" work? Perceived power differences moderate the relationship between social media activism and collective action intentions through positive affect
Authors: Foster Mindi D. , Hennessey Eden , Blankenship Benjamin T. , Stewart Abigail
Published: November 2019

We argue that the often-used critique of social media activism as merely a ‘feel-good’ mechanism can be countered by conceptualizing social media activism as a necessary type of collective action (i.e., consensus mobilization), incorporating theory on the benefits of positive feelings for activism, and by examining how power may affect these relationships. Women from two different samples (MTurk and university) were randomly assigned to recall a high- versus low-power experience, view real-world events of sexism, and then complete questionnaires assessing endorsement of social media activism, positive affect, and collective action intentions. A dual moderated mediation analyses at the second stage of mediation showed equivalency across two samples, at which point the single moderated mediation model was tested on the combined sample. The model was significant, such that among those in the high-power condition, endorsing social media activism was associated with greater positive affect, which in turn predicted greater collective action intentions. Among those in the low-power condition, however, this indirect effect was not significant. This study provides counter-evidence to the ‘slacktivism’ critique, contributes to theories of collective action, power and their integration, and identifies a possible intervention to enhance the effectiveness of social media activism.
Trajetórias através de um prisma: Caribe, raça e consciência oposicional em C. L. R. James e Oliver C. Cox
Authors: Borda Erik Wellington Barbosa
Published: November 2019

Este trabalho tem dois objetivos fundamentais. O primeiro é lançar uma interpretação sobre os diferentes rumos que tomam dois autores negros do Caribe, Oliver C. Cox e C. L. R. James. Para esta tarefa, realiza-se um contraste entre as trajetórias iniciais dos autores, cujo periodo é marcado pelo nascimento de ambos na colônia britânica de Trinidad, no Caribe, em 1901 até a publicação de suas magnum opi; 1948 para Cox e 1938 para James. O segundo objetivo é, em debate com tendências sociológicas voltadas ao estudo de trajetórias intelectuais, argumentar em pró da utilidade de se trabalhar com categorias que colocam os deslocamentos derivados da experiência racial – e as disfunções decorrentes – no princípio da explicação sociológica, e não ao final como resíduos ou eventos. Por fim, é levando isso em consideração que se buscou nos nexos entre as experiências sociais dos autores e os tipos de intervenções propostas por eles, explicações acerca da disparidade entre os destinos sociais de ambos.
Un erudito ignorado, José Martínez Rives. Epigrafía romana procedente de Clunia en un manuscrito olvidado = An Ignored Scholar, José Martínez Rives. Roman Epigraphy from Clunia in a Forgotten Manuscript
Authors: Del Hoyo Calleja Javier , Rodríguez Ceballos Mariano
Published: November 2019

Los autores rescatan del olvido a José Martínez Rives, polifacético escritor del siglo XIX, que elaboró en 1846 un informe sobre la arqueología de la provincia de Burgos, en el que incluyó nueve inscripciones latinas procedentes de la colonia romana de Clunia, de las que una —hoy desaparecida— ha permanecido inédita.AbstractThe authors present José Martínez Rives, a nineteenth-century multifaceted writer, who undertook a report in 1846 about the archeology of the province of Burgos, which includes nine Latin inscriptions from the Roman colony of Clunia, one of which —now gone— has remained unpublished.
A population-based study on the treatment and outcome of enterococcal prosthetic joint infections. A consecutive series of 55 cases
Authors: Thompson Olof , Rasmussen Magnus , Stefánsdóttir Anna , Christensson Bertil , Åkesson Per
Published: November 2019

Abstract. AIM: Enterococci cause 2-11% of all prosthetic joint infections (PJI) and are generally considered difficult to treat. However, study-results are not consistent. In this study we present a population-based case series of 55 cases with enterococcal PJI, investigating treatment and outcome, as well as describing the affected patient population regarding demography and co-morbidities.METHODS: We identified all enterococcal PJIs in the Region of Skåne, Sweden, during a five-year period (2011-2015) and reviewed the patients' medical records.RESULTS: Fifty-five enterococcal PJIs were found. Enterococcus faecalis was the most frequently isolated species (84%), and poly-microbial infections were common (64%). Treatment with intention to cure was given to 43 (78%) cases. Debridement with retention of the implant and antibiotics (DAIR) was the most common surgical treatment strategy (71%), with a cure-rate of 72%. Overall cure-rate was 67%, and in cases where cure was intended, this was achieved in 80%.CONCLUSIONS: When cure is aimed for, the prognosis for enterococcal PJI is not so poor, and DAIR treatment can provide adequate results in many cases.
An image-computable model for the stimulus selectivity of gamma oscillations
Authors: Hermes Dora , Petridou Natalia , Kay Kendrick N , Winawer Jonathan
Published: November 2019

Gamma oscillations in visual cortex have been hypothesized to be critical for perception, cognition, and information transfer. However, observations of these oscillations in visual cortex vary widely; some studies report little to no stimulus-induced narrowband gamma oscillations, others report oscillations for only some stimuli, and yet others report large oscillations for most stimuli. To better understand this signal, we developed a model that predicts gamma responses for arbitrary images and validated this model on electrocorticography (ECoG) data from human visual cortex. The model computes variance across the outputs of spatially pooled orientation channels, and accurately predicts gamma amplitude across 86 images. Gamma responses were large for a small subset of stimuli, differing dramatically from fMRI and ECoG broadband (non-oscillatory) responses. We propose that gamma oscillations in visual cortex serve as a biomarker of gain control rather than being a fundamental mechanism for communicating visual information.