bluuebunny/crossref_metadata_2025 huggingface dataset:
Crop Analysis Using Image Processing
Authors: V Srujana , P Chaithanya , B Ramesh , S Manoranjan , V Mahesh
Published: June 2020

To detect the uniqueness and quantities of agriculture product images a new method is proposed using MATLAB software .In this paper we propose a method to increase the contrast level of a image with exponential low pass filter and histogram equalization technique. Next by using region props function we extract the binary features of the image, and then we calculated the number of targets in gray level image. This method can be easily applied in modern agriculture.
La historiografía sobre las izquierdas en Chile: un campo en expansión
Authors: Álvarez Vallejo Rolando
Published: June 2020

El presente artículo examina la evolución de la historiografía sobre las izquierdas en Chile desde el retorno a la democracia en 1990 hasta el presente. Plantea que a partir de cambios político-sociales relacionados con el contexto nacional del país, así como por otros producidos en los cuerpos docentes de las principales universidades chilenas, el campo historiográfico sobre las izquierdas ha experimentado un marcado proceso de expansión. Se examinan los principales autores y corrientes que dieron origen a las nuevas orientaciones de la historiografía de las izquierdas, surgidas durante la década de 1980 en Chile a partir de las reflexiones académicas y políticas de los cientistas sociales de la época. A partir de esto, el artículo ofrece una visión panorámica de la producción historiográfica sobre las izquierdas chilenas en las últimas tres décadas.
Presentación del dossier
Authors: Visacovsky Nerina
Published: June 2020

Presentación del dossier
La reproducción social en disputa: un debate entre autonomistas y marxistas
Authors: Varela Paula
Published: June 2020

Este texto aborda el debate, teórico-político, entre la visión autonomista y la visión marxista de la reproducción social. Para hacerlo, nos basamos en el reciente dossier publicado por la revista Radical Philosophy “Social Reproduction Theory”, cuya presentación está escrita por Silvia Federici y su artículo teórico por Alessandra Mezzadri. El núcleo duro del dossier está dirigido a polemizar con las posiciones sostenidas en el libro de Tithi Bhattacharya Social Reproduction Theory: Remapping Class, Recentering Opression. Presentamos aquí una “crítica de la crítica” para proponer una lectura de la Teoría de la Reproducción Social en tanto teoría de la relación entre producción y reproducción en la sociedad capitalista.
Las visiones del trabajo en la teoría feminista
Authors: Ferguson Susan
Published: June 2020

Este artículo recorre las diversas formas en que el trabajo ha sido objeto de análisis en la teoría feminista. Identifica dos enfoques analíticos generales que, si bien comparten la idea de que la devaluación social del trabajo que realizan las mujeres es una característica definitoria de la desigualdad y laopresión que sufren, difieren en sus conceptualizaciones sobre el poder social y, por ende, en sus proyectos políticos para la emancipación de las mujeres. El primero, “feminismo de la igualdad”, se centra en la división sexual del trabajo; el segundo, “feminismo de la reproducción social”, se central en el trabajo reproductivo como elemento clave para la reproducción continua de la sociedad capitalista. El artículo analiza ambas perspectivas y da los argumentos de por qué el segundo enfoque logra superar las debilidades del primero.
“¡Los comunistas no somos subversivos!”. El PC y la dictadura militar argentina (1976-1983)
Authors: Casola Natalia
Published: June 2020

El presente artículo examina la actuación del PC durante la última dictadura militar. En primer lugar, el trabajo busca vincular la orientación oficial de los comunistas, el apoyo “táctico” al gobierno de J. R. Videla y el llamado a la “convergencia cívico militar”, con la política histórica del partido sustentada en la idea de revolución por etapas. En segunda instancia el artículo se detiene en la materialización práctica de esas definiciones, en el papel de la legalidad y en la relación con las Fuerzas Armadas. Finalmente, la investigación analiza el lugar de la disciplina partidaria como factor que permite explicar, al menos en parte, la persistencia de la línea oficial, sostenida contra la propia realidad: la extensión del sistema de terror por encima de las rivalidades existentes al interior de las Fuerzas Armadas.
El período formativo de un intelectual: Milcíades Peña y el trotskismo en las décadas de 1940-1950
Authors: Camarero Hernán
Published: June 2020

Milcíades Peña fue uno de los más importantes intelectuales de la izquierda argentina durante el siglo XX. Propuso una visión marxista original y crítica sobre el pasado nacional, la estructura socioeconómica del país, la clase dominante y el peronismo. En este artículo, a partir del análisis de fuentes primarias, se examinan asuntos poco explorados: el modo en que Peña se insertó en una de las tendencias del trotskismo argentino; las características teóricas, políticas, programáticas y organizativas de dicha corriente; y la incidencia que esta experiencia militante tuvo en la formación intelectual de Peña. La hipótesis propuesta es que, si bien la producción teórica de Peña luego fue cobrando una extraordinaria lucidez y autonomía creativa, apenas puede comprenderse sin sus contextos militantes previos.
La crítica del sindicalismo revolucionario argentino al parlamentarismo (1905-1912)
Authors: Belkin Alejandro
Published: June 2020

En este artículo nos proponemos desarrollar la crítica a la democracia burguesa que elaboraron los sindicalistas revolucionarios. Se plantea que sus apreciaciones sobre el parlamentarismo tuvieron como punto de inflexión los debates suscitados en torno a la Ley Sáenz Peña. La reforma electoral, especialmente la sanción del voto obligatorio, incentivó sus reflexiones. Su sistema de ideas se enriqueció, presentando una explicación más compleja de los modernos mecanismos de dominación en la sociedad capitalista. Algunos de los tópicos que encontramos en sus argumentaciones fueron retomados posteriormente por las ciencias sociales y en los debate políticos. En comparación con sus rivales en el movimiento obrero, los sindicalistas revolucionarios habrían desarrollado un análisis más sofisticado sobre los cambios que se estaban produciendo en el sistema de dominación.
Criminalizar al rojo. La represión al movimiento obrero en los informes de 1934 sobre la Sección Especial
Authors: López Cantera Mercedes F.
Published: June 2020

El presente artículo toma como centro al debate de 1934 sobre la Sección Especial de Represión al Comunismo. Con el fin de analizar la existencia de una “cuestión comunista” en el Estado argentino de ese entonces se abordan dos documentos clave: el informe del Ministerio del Interior sobre la actividad de la Sección Especial, y el documento-denuncia del Socorro Rojo Internacional acerca de la represión política del gobierno de Agustín P. Justo. En base a ello, nos proponemos comprender cómo el aparato estatal empleó la criminalización de las actividades políticas de una parte del movimiento obrero y de otros actores con el fin de ampliar el control sobre la clase trabajadora en el escenario de los años 30.
El periódico Palabra Socialista (1912-1914) y los comienzos de la disidencia marxista en el PS
Authors: Díaz Hernán M.
Published: June 2020

El texto aborda el análisis del periódico Palabra Socialista, primer órgano del ala izquierda del Partido Socialista que desembocará en 1918 en la creación del Partido Socialista Internacional (luego Partido Comunista). Se relevan aspectos técnicos, las principales ideas programáticas, se traza un cuadro de los principales miembros del grupo y se realiza un balance de su participación en el ámbito de la política argentina entre 1912 y 1914.
El socialismo argentino frente a Enrico Ferri
Authors: Herrera Carlos Miguel
Published: June 2020

Las visitas del socialista italiano Enrico Ferri fueron la ocasión de fuertes debates en el socialismo argentino. Pero contrariamente a lo que se cree habitualmente, estos no se resumieron a la célebre respuesta de Juan B. Justo. No sólo otras voces participan de la discusión: estas dejan aparecer un conjunto de tensiones que terminarán traduciéndose en rupturas a partir de la Primera Guerra Mundial. Las posiciones de Ferri sobre el socialismo argentino, pero también su propia evolución dentro del socialismo italiano, aparecen como los síntomas de la crisis del socialismo parlamentario.
A supressão dos meios de vida dos pescadores profissionais impactados pela usina Hidrelétrica Foz do Chapecó
Authors: Winckler Silvana , Renk Arlene
Published: June 2020

O texto tem como objetivo analisar impactos socioambientais da instalação da Usina Hidrelétrica Foz do Chapecó no rio Uruguai, região sul do Brasil, na pesca artesanal e as alterações produzidas nos meios de vida dos profissionais da Colônias de Pescadores Z 35. Na Colônia, verificou-se que houve redução de um terço no número de pescadores após o enchimento do lago. Metodologicamente, a pesquisa caracteriza-se como qualitativa. Compreende revisão de literatura, levantamento documental de diagnósticos, planos e programas ambientais e entrevistas com pescadores afetados. Adota-se como estratégia a pesquisa narrativa. Constatamos que, ante a inviabilidade da atividade, os pescadores recorrem à previdência social e ao empreendedor a fim de obter os meios de vida na forma de seguro defeso, aposentadoria e indenização. Concluímos que operam, neste caso, a lógica do encolhimento dos benefícios sociais do Estado e a liberdade de atuação empresarial no contexto neoliberal. Evidenciamos a desproteção das vítimas do desenvolvimento, condenadas a conviver com as consequências nefastas do empreendimento desenvolvimentista. Planos e programas ambientais do empreendedor, que visam transformar o pescador em aquicultor, não foram implementados.
Community Development in the Southeast: Regional Economic Indicators
Authors: McCall Jamie
Published: June 2020

Community development is inherently place-based: the geographic contours of a locale have a strong effect on the socioeconomic destiny of its residents. Economic growth is not equal across all communities. Many lower-income and minority communities never fully recovered from the Great Recession. We assess several data indicators related to sustainable development, socioeconomic mobility, health outcomes, and racial disparities in the Southeast. Though the region saw much growth over the past decade, the data show a mixed picture of progress. In many cases it seems the COVID-19 pandemic caused the most economic destruction in places still not fully recovered from the 2008 recession.
Severe Coronary Artery Disease and Metabolic Syndrome in Patients with Acute Coronary Syndrome in South Punjab Region of Pakistan
Authors: Niazi GZK , Adnan F , Saleemi MS , Akhtar A , Ahmed N , Shehzad ST
Published: June 2020

Background:
Hypertension, dyslipidemia, and disturbed glucose metabolism associated with central obesity are often referred to as Metabolic Syndrome (MetS) and patients of MetS have a two- to three-fold increased risk for the development of cardiovascular diseases.
Objective: Objectives were to determine the frequency of MetS in patients presenting with acute coronary syndromes and to compare the frequencies of severe coronary artery disease in patients with and without MetS.

Methods:
This descriptive cross-sectional study included 200 patients with acute coronary syndromes over a period of six months. Frequency of MetS was calculated. The frequencies of severe coronary artery disease were compared between patients having MetS and not having MetS using chi-square chart.

Results:
Total 200 patients with the mean age of 54.24 ± 9.41 years were included. 131 (65.5%) patients with acute coronary syndrome had MetS. Total 112 patients (56%) had severe coronary artery disease. 63.35% with MetS and 42.03% without MetS had severe coronary artery disease (p=0.003).

Conclusion:
The frequency of metabolic syndrome was high (65.5%) in patients with acute coronary syndromes and severe coronary artery disease was found to be associated with the presence of metabolic syndrome in these patients.
A capacidade do Estado frente a gestão de riscos e desastres após a Política Nacional de Proteção e Defesa Civil (Lei 12.608/2012)
Authors: Ferentz Larissa Maria da Silva , Garcias Carlos Mello
Published: June 2020

A frequência elevada de eventos extremos nas cidades tem voltado o olhar para a necessidade da adoção de medidas que auxiliassem os gestores na redução de riscos no mundo todo. No Brasil, após a instituição da Política Nacional de Proteção e Defesa Civil em 2012, destacou-se a importância da implementação da política de forma multissetorial, sendo necessário a revisão dos diversos planos e leis. Além disto, a necessidade de integração entre os setores da sociedade é um dos pontos chave da política, pois a minimização dos riscos de desastres nos municípios se dá a partir da colaboração de todos. A metodologia da presente pesquisa se baseou em três análises principais: (1) a integração da Política Nacional perante às legislações setoriais; (2) apresentação das capacidades e incapacidades dos Estados e Municípios perante às competências da Política Nacional; e (3) avaliação de medidas e instrumentos para monitorar a Política Nacional. Ainda será necessário percorrer um caminho longo no país considerando todos os desafios encontrados nas análises. No primeiro momento, foi possível observar que embora as legislações setoriais tenham de forma clara seu papel perante os desastres, a falta de integração ainda é perceptível. As medidas adotadas para distribuição de recursos, além da falta de capacitação de gestores e da população, são os principais pontos de incapacidade dos Estados e Municípios. Além disso, a falta de instrumentos que ajudem a monitorar e acompanhar as ações tomadas no enfrentamento dos riscos, continua a prejudicar o atingimento das metas para alcançar cidades mais resilientes.
Refuncionalização da pena de prisão: abordagem acerca da alienação do trabalho desde uma criminologia materialista
Authors: Da Silva Leal Jackson
Published: June 2020

O presente trabalho volta-se para um estudo de criminologia da dependência que se pretende voltado para a questão do processo de alienação do trabalho, da força e do corpo do povo latino-americano, permitindo um processo histórico de acumulação capitalista com base da extração de mais-valia relativa e absoluta. E como esse processo se apresenta continuamente e sóciometabolicamente nos diferentes momentos históricos na região. Centrando-se esse estudo sobretudo no momento contemporâneo neoliberal e de encarceramento em massa, e como a prisão se apresenta como foco de produção e extração de mais-valia absoluta e relativa no atual paradigma e modelo societário e de controle social. Esse trabalho se apresenta como momento de aprofundamento teórico de categorias da teoria marxista e da criminologia latino-americana desde a teoria da dependência. O objetivo desse trabalho é contribuir como elementos e aportar categorias que permitam uma aprimorada compreensão da realidade atual com base na produção de capital desde o trabalho prisional.
Comparison of south-east Atlantic aerosol direct radiative effect over clouds from SCIAMACHY, POLDER and OMI–MODIS
Authors: de Graaf Martin , Schulte Ruben , Peers Fanny , Waquet Fabien , Tilstra L. Gijsbert , Stammes Piet
Published: June 2020

Abstract. The direct radiative effect (DRE) of aerosols above
clouds has been found to be significant over the south-east Atlantic
Ocean during the African biomass burning season due to elevated smoke
layers absorbing radiation above the cloud deck. So far, global
climate models have been unsuccessful in reproducing the high DRE
values measured by various satellite instruments. Meanwhile, the
radiative effects by aerosols have been identified as the largest
source of uncertainty in global climate models. In this paper, three
independent satellite datasets of DRE during the biomass burning
season in 2006 are compared to constrain the south-east Atlantic
radiation budget. The DRE of aerosols above clouds is derived from the
spectrometer SCanning Imaging Absorption spectroMeter for
Atmospheric CHartographY (SCIAMACHY), the polarimeter Polarization and
Directionality of the Earth's Reflectances (POLDER), and
collocated measurements by the spectrometer Ozone Monitoring
Instrument (OMI) and the imager Moderate Resolution Imaging
Spectroradiometer (MODIS). All three datasets confirm the high DRE
values during the biomass season, underlining the relevance of local
aerosol effects. Differences between the instruments can be attributed
mainly to sampling issues. When these are accounted for, the
remaining differences can be explained by a higher cloud optical
thickness (COT) derived from POLDER compared to the other instruments
and a neglect of aerosol optical thickness (AOT) at shortwave infrared
(SWIR) wavelengths in the method used for SCIAMACHY and OMI–MODIS. The
higher COT from POLDER by itself can explain the difference found in
DRE between POLDER and the other instruments. The AOT underestimation
is mainly evident at high values of the aerosol DRE and accounts for
about a third of the difference between POLDER and OMI–MODIS DRE. The
datasets from POLDER and OMI–MODIS effectively provide lower and upper
bounds for the aerosol DRE over clouds over the south-east Atlantic,
which can be used to challenge global circulation models (GCMs). Comparisons
of model and satellite datasets should also account for sampling
issues. The complementary DRE retrievals from OMI–MODIS and POLDER may
benefit from upcoming satellite missions that combine spectrometer
and polarimeter measurements.
Sensitivity of mixed-phase moderately deep convective clouds to parameterisations of ice formation – An ensemble perspective
Authors: Miltenberger Annette K. , Field Paul R.
Published: June 2020

Abstract. The formation of ice in clouds is an important processes in mixed-phase and ice-phase clouds. Yet, the representation of ice formation in numerical models is highly uncertain. In the last decade several new parameterisations for heterogeneous freezing have been proposed. It is so far unclear what the effect of choosing one parameterisation over another is in the context of numerical weather prediction. We conducted high-resolution simulations (Δx = 250 m) of moderately deep convective clouds (cloud to about ~ −18 °C over the southwestern UK using several formulations of ice formation and compare the resulting changes in cloud field properties to the spread of a initial condition ensemble for the same case. The strongest impact of altering the ice formation representation is found in the hydrometeor number concentration and mass mixing ratio profiles. While change in accumulated precipitation are around 10 %, high precipitation rates (95th percentile) vary by 20. Using different ice formation representations changes the outgoing short-wave radiation by about 2.9 W m−2 averaged over daylight hours. The choice of a particular representation for ice formation has always a smaller impact then omitting heterogeneous ice formation completely. Excluding the representation of the Hallett–Mossop process or altering the heterogeneous freezing parameterisation has an impact of similar magnitude on most cloud macro- and microphysical variables with the exception of the frozen hydrometeor mass mixing ratios and number concentrations. A comparison to the spread of cloud properties in a 10-member high-resolution initial condition ensemble shows that the sensitivity of hydrometeor profiles to the formulation of ice formation processes is larger than sensitivity to initial conditions. In particular, excluding the Hallet–Mossop representation results in profiles clearly different from any in the ensemble. In contrast, the ensemble spread clearly exceeds the changes introduced by using different ice formation representations in accumulated precipitation, precipitation rates, condensed water path, cloud fraction and outgoing radiation fluxes.
Radiative effects of long-range-transported Saharan air layers as determined from airborne lidar measurements
Authors: Gutleben Manuel , Groß Silke , Wirth Martin , Mayer Bernhard
Published: June 2020

Abstract. The radiative effect of long-range-transported Saharan air layers is investigated on the basis of simultaneous airborne high spectral resolution and differential absorption lidar measurements in the vicinity of Barbados. Within the observed Saharan air layers increased water vapor concentrations compared to the dry trade wind atmosphere are found. The measured profiles of aerosol optical properties and water vapor mixing ratios are used to characterize the atmospheric composition in radiative transfer calculations, to calculate radiative effects of moist Saharan air layers and to determine radiative heating rate profiles. An analysis based on three case studies reveals that the observed enhanced amounts of water vapor within Saharan air layers have a much stronger impact on heating rate calculations than mineral dust aerosol. Maximum mineral dust short-wave heating and long-wave cooling rates are found in altitudes of highest dust concentration (short-wave: +0.5 Kd−1, long-wave: −0.2 Kd−1, net: +0.3 Kd−1). However, when considering both aerosol concentrations and measured water vapor mixing ratios in radiative transfer calculations the maximum heating/cooling rates shift to the top of the dust layer (short-wave: +2.2 Kd Kd−1, long-wave: −6.0 to −7.0 Kd−1, net: −5.0 to −4.0 Kd−1). Additionally, the net-heating rates decrease with height – indicating a destabilizing effect in the dust layers. Long-wave counter radiation of Saharan air layers is found to reduce cooling at the top of the subjacent marine boundary layers and might lead to less convective mixing in these layers. The overall short-wave radiative effect of mineral dust particles in Saharan air layers indicates a maximum magnitude of −40 Wm−2 at surface level and a maximum of −25 Wm−2 at the top of the atmosphere.
Impact of organic acids on chloride depletion of inland transported sea spray aerosols
Authors: Su Bojiang , Zhuo Zeming , Fu Yuzhen , Sun Wei , Chen Ying , Du Xubing , Yang Yuxiang , Wu Si , Huang Fugui , Chen Duohong , Li Lei , Zhang Guohua , Bi Xinhui , Zhou Zhen
Published: June 2020

Abstract. Heterogeneous reactions on sea spray aerosols (SSA) are the main pathway to drive the circulation of chlorine, nitrogen, and sulfur in the atmosphere. The release of Cl will significantly affect the physicochemical properties of SSA. However, the impact of organic acids and mixing state on chloride depletion of SSA is still unclear. Hence, the size and chemical composition of individual SSA particles during the East Asian summer monsoon were investigated by a single particle aerosol mass spectrometer (SPAMS). According to the chemical composition, SSA particles were classified into SSA-Aged, SSA-Bio and SSA-Ca. In comparison to the aged Na-rich SSA particles (SSA-Aged), some additional organic species related to biological origin were observed in SSA-Bio, and each of two types accounts for approximately 50 % of total SSA particles. SSA-Ca may associated with organic shell of Na-rich SSA particles, which only accounts for ~ 3 %. Strongly positive correlations between Na and organic acids (including formate, acetate, propionate, pyruvate, oxalate, malonate, succinate, and glutarate) were observed for the SSA-Aged (r2 = 0.52, p
Source apportionment of black carbon aerosols from light absorption observation and source-oriented modeling: An implication in a coastal city in China
Authors: Deng Junjun , Guo Hao , Zhang Hongliang , Zhu Jialei , Wang Xin , Fu Pingqing
Published: June 2020

Abstract. Black carbon (BC) is the most important light absorbing aerosol in the atmosphere. However, sources of atmospheric BC aerosols are largely uncertain, making it difficult to assess its influence on radiative forcing and climate change. In this study, year-round light-absorption observations were conducted during 2014 using an aethalometer in Xiamen, a coastal city in southeast China. Source apportionment of BC was performed and temporal variations in BC sources were characterized based on both light absorption measurements and a source-oriented air quality model. The annual average concentrations of BC from fossil fuel (BCff) and biomass burning (BCbb) were 2932 ± 1444 ng m−3 and 1340 ± 542 ng m−3, contributing 66.7 % and 33.3 % to total BC, respectively. BCbb contribution exhibited clear diurnal cycle with the highest level (37.9 %) in the evening rush hour and seasonal pattern with the maximum (39.9 %) in winter. Conditional probability function (CPF) analysis revealed the large biomass burning contributions were accompanied by east-northeasterly and northerly winds. Backward trajectory indicated that air masses from north and east-central China were associated with larger biomass burning contributions. Potential source contribution function (PSCF) and concentration-weighted trajectory (CWT) suggested that north and east-central China and Southeast Asia were potential sources for both BCff and BCbb. The source-oriented modeling results showed that transportation, residential and open biomass burning accounting for 45.3 %, 30.1 % and 17.6 % were the major BC sources. Among the three fuel catalogs, liquid fossil fuel (46.5 %) was the largest source, followed by biomass burning (32.6 %) and coal combustion (20.9 %). Source contributions of biomass burning and fossil fuel combustion identified by the source-oriented model and observation-based method were in good agreement. The source-oriented model also captured the majority of seasonal variations in source contributions. The findings provide solid supports for controlling fossil fuel sources to limit the impacts of BC on climate change and environmental degradation in the relatively clean region in China.
A comparative and experimental study of the reactivity with nitrate radical of two terpenes: α-terpinene and γ-terpinene
Authors: Fouqueau Axel , Cirtog Manuela , Cazaunau Mathieu , Pangui Edouard , Doussin Jean-François , Picquet-Varrault Bénédicte
Published: June 2020

Abstract. Biogenic volatile organic compounds (BVOCs) are intensely emitted by forests and crops into the atmosphere. During the night, they react very rapidly with the nitrate radical (NO3), leading to the formation of a variety of functionalized products including organic nitrates and to large amounts of secondary organic aerosols (SOA). Organic nitrates (ONs) have been shown to play a key role in the transport of reactive nitrogen and consequently in the ozone budget, but also to be important components of the total organic aerosol while SOA are known to play a direct and indirect role on the climate. However, the reactivity of BVOCs with NO3 remains poorly studied. The aim of this work is to provide new kinetic and mechanistic data for two monoterpenes (C10H16), α- and γ-terpinene, through experiments in simulation chambers. These two compounds, which have very similar chemical structures, have been chosen in order to fill the lack of experimental data but also to highlight the influence of the chemical structure on the reactivity. Rate constants have been measured using both relative and absolute methods. They were found to be (1.2 ± 0.5) x 10-10 and (2.9 ± 1.1) x 10-11 cm3 molecule-1 s-1 for α- and γ-terpinene respectively. Mechanistic studies have also been conducted in order to identify and quantify the main reaction products. Total organic nitrate and SOA yields have been determined. While organic nitrate formation yields appear to be similar, SOA yields exhibit large differences with γ-terpinene being a much more efficient precursor of aerosols. In order to provide explanations for this difference, chemical analysis of the gas phase products were performed at the molecular scale. Detected products allowed proposing chemical mechanisms and providing explanations through peroxy and alkoxy reaction pathways.
Box canyon erosion along the Canterbury coast (New Zealand): A rapid and episodic process controlled by rainfall intensity and substrate variability
Authors: Micallef Aaron , Marchis Remus , Saadatkhah Nader , Clavera-Gispert Roger , Pondthai Potpreecha , Everett Mark E. , Avram Anca , Timar-Gabor Alida , Cohen Denis , Preca Trapani Rachel , Weymer Bradley A.
Published: June 2020

Abstract. Box canyon formation has been associated to groundwater seepage in unconsolidated sand to gravel sized sediments. Our understanding of box canyon evolution mostly relies on experiments and numerical simulations, and these rarely take into consideration contrasts in lithology and permeability. In addition, process-based observations and detailed instrumental analyses are rare. As a result, we have a poor understanding of the temporal scale of box canyon formation and the influence of geological heterogeneity on their formation. We address these issues along the Canterbury coast of the South Island (New Zealand) by integrating field observations, optically stimulated luminescence dating, multi-temporal Unmanned Aerial Vehicle and satellite data, time-domain electromagnetic data, and slope stability and landscape evolution modelling. We show that box canyon formation is a key process shaping the sandy gravel cliffs of the Canterbury coastline. It is an episodic process associated to groundwater flow that occurs once every 227 days on average, when rainfall intensities exceed 40 mm per day. The majority of the box canyons in a study area SE of Ashburton has undergone erosion, predominantly by elongation, during the last 11 years, with the most recent episode occurring 3 years ago. The two largest box canyons have not been eroded in the last 2 ka, however. Canyons can form at rates of up to 30 m per day via two processes: the formation of alcoves and tunnels by groundwater seepage, followed by retrogressive slope failure due to undermining and a decrease in shear strength driven by excess pore pressure development. The location of box canyons is determined by the occurrence of hydraulically-conductive zones, such as relict braided river channels and possibly tunnels, and of sand lenses exposed across sandy gravel cliff. We also show that box canyon formation is best represented by a linear diffusive model and geometrical scaling.
QuickSampling v1.0: a robust and simplified pixel-based multiple-point simulation approach
Authors: Gravey Mathieu , Mariethoz Grégoire
Published: June 2020

Abstract. Multiple-point geostatistics enable the realistic simulation of complex
spatial structures by inferring statistics from a training image. These
methods are typically computationally expensive and require complex
algorithmic parametrizations. The approach that is presented in this paper
is easier to use than existing algorithms, as it requires few independent
algorithmic parameters. It is natively designed for handling continuous
variables and quickly implemented by capitalizing on standard libraries.
The algorithm can handle incomplete training images of any dimensionality,
with categorical and/or continuous variables, and stationarity is not
explicitly required. It is possible to perform unconditional or conditional
simulations, even with exhaustively informed covariates. The method provides
new degrees of freedom by allowing kernel weighting for pattern matching.
Computationally, it is adapted to modern architectures and runs in constant
time. The approach is benchmarked against a state-of-the-art method. An
efficient open-source implementation of the algorithm is released and can be
found here (https://github.com/GAIA-UNIL/G2S, last access: 19 May 2020) to promote reuse
and further evolution. The highlights are the following:
A new approach is proposed for pixel-based multiple-point geostatistics
simulation. The method is flexible and straightforward to parametrize. It natively handles continuous and multivariate simulations. It has high computational performance with predictable simulation times. A free and open-source implementation is provided.
Impacts of climate change on groundwater flooding and ecohydrology in lowland karst
Authors: Morrissey Patrick , Nolan Paul , McCormack Ted , Johnston Paul , Naughton Owen , Gill Laurence
Published: June 2020

Abstract. Lowland karst aquifers can generate unique wetland habitats which are caused by groundwater fluctuations that result in extensive groundwater-surface water interactions (i.e. flooding). However, the complex hydrogeological attributes of these systems often present difficulty in predicting how they will respond to changing climatological conditions. Extremely fast aquifer recharge processes and flow through well-connected conduit networks in such karst systems make them very susceptible to surcharge conditions – i.e. groundwater-surface water interaction (flooding) – and therefore vulnerable to changes in the sequence and intensity of precipitation patterns. This study investigates the predicted impacts of climate change on a lowland karst catchment by employing a semi-distributed karst model populated with output from high-resolution regional climate models for Ireland. The lowland karst catchment is located on the west coast of Ireland and is characterised by a well-developed karstified limestone aquifer which discharges to the sea via intertidal and submarine springs. Annual above ground flooding associated with this complex karst system has led to the development of unique wetland habitats in the form of ephemeral lakes known as turloughs, however extreme flooding of these features causes widespread damage and disruption in the catchment. This analysis has shown that mean, 95th and 99th percentile flood levels are expected to increase by significant proportions for all future emission scenarios. The frequency of events currently considered to be extreme is predicted to increase, indicating that more significant groundwater flooding events seem likely to become far more common. The seasonality of annual flooding is also predicted to shift later in the flooding season which could have far reaching consequences in terms of ecology and land use in the catchment. The impacts of increasing mean sea levels were also investigated, however it was found that anticipated rises had very little impact on groundwater flooding due to the marginal impact on ebb tide outflow volumes. Overall, this study highlights the vulnerability of lowland karst systems to future changing climate conditions mainly due to the extremely fast recharge which can occur in such systems. The study presents a novel and highly effective methodology for quantifying the potential impact of climate change in lowland karst systems by coupling karst hydrogeological models with the output from high resolution climate simulations.
Uncertainty of simulated groundwater recharge at different global warming levels: A global-scale multi-model ensemble study
Authors: Reinecke Robert , Müller Schmied Hannes , Trautmann Tim , Burek Peter , Flörke Martina , Gosling Simon N. , Grillakis Manolis , Hanasaki Naota , Koutroulis Aristeidis , Pokhrel Yadu , Seaby Lauren , Thiery Wim , Wada Yoshihide , Yusuke Satoh , Döll Petra
Published: June 2020

Abstract. Billions of people rely on groundwater as an accessible source for drinking water and irrigation, especially in times of drought. Its importance will likely increase with a changing climate. It is still unclear, however, how climate change will impact groundwater systems globally and thus the availability of this vital resource. This study investigates uncertainties in groundwater recharge projections using a multi-model ensemble of eight global hydrological models (GHMs) that are driven by the bias-adjusted output of four global circulation models (GCMs). Preindustrial and current groundwater recharge values are compared with recharge for different global warming (GW) levels as a result of three representative concentration pathways (RCPs). Results suggest that the uncertainty range is extensive, and projections with confidence can only be made for specific regions of the world. In some regions, reversals of groundwater recharge trends can be observed with global warming. On average, a consistent median increase of groundwater recharge in northern Europe of 19 % and a decrease of 10 % in the Amazon at 3 °C GW compared to preindustrial levels are simulated. In the Mediterranean, a 2 °C GW leads to a reduction of GWR of 38 %. Because most GHMs do not include CO2 driven vegetation processes, we investigate how, including the effect of evolving CO2 concentrations into the calculation of future groundwater recharge impacts the results. In some regions, the inclusion of these processes leads to differences in groundwater recharge changes of up to 100 mm year−1. Overall, models that include CO2 driven vegetation processes simulate less severe decreases of groundwater recharge and in some regions even increases instead of decreases. In regions where GCMs predict decreases in precipitation, and groundwater availability is most important, the model agreement among GHMs with dynamic vegetation is lowest in contrast to GHMs without, which show a high agreement.
Bias in dynamically downscaled rainfall characteristics for hydroclimatic projections
Authors: Potter Nicholas J. , Chiew Francis H. S. , Charles Stephen P. , Fu Guobin , Zheng Hongxing , Zhang Lu
Published: June 2020

Abstract. Dynamical downscaling of future projections of global
climate model outputs can provide useful information about plausible and
possible changes to water resource availability, for which there is
increasing demand in regional water resource planning processes. By
explicitly modelling climate processes within and across global climate
model grid cells for a region, dynamical downscaling can provide higher-resolution hydroclimate projections and independent (from historical time series), physically
plausible future rainfall time series for hydrological modelling
applications. However, since rainfall is not typically constrained to
observations by these methods, there is often a need for bias correction
before use in hydrological modelling. Many bias-correction methods (such as
scaling, empirical and distributional mapping) have been proposed in the
literature, but methods that treat daily amounts only (and not sequencing)
can result in residual biases in certain rainfall characteristics, which
flow through to biases and problems with subsequently modelled runoff. We
apply quantile–quantile mapping to rainfall dynamically downscaled by
the NSW and ACT Regional Climate Modelling (NARCliM) Project in the state of Victoria, Australia, and examine the effect of this
on (i) biases both before and after bias correction in different rainfall
metrics, (ii) change signals in metrics in comparison to the bias and (iii) the effect of bias correction on wet–wet and dry–dry transition
probabilities. After bias correction, persistence of wet states is
under-correlated (i.e. more random than observations), and this results in a
significant bias (underestimation) of runoff using hydrological models
calibrated on historical data. A novel representation of quantile–quantile
mapping is developed based on lag-one transition probabilities of dry and
wet states, and we use this to explain residual biases in transition
probabilities. Representing quantile–quantile mapping in this way
demonstrates that any quantile mapping bias-correction method is unable to
correct the underestimation of autocorrelation of rainfall sequencing, which
suggests that new methods are needed to properly bias-correct dynamical
downscaling rainfall outputs.
Monitoring crustal CO2 flow: methods and their applications to the mofettes in West Bohemia
Authors: Fischer Tomáš , Vlček Josef , Lanzendörfer Martin
Published: June 2020

Abstract. Monitoring of CO2 degassing in seismoactive areas allows the
study of correlations of gas release and seismic activity. Reliable
continuous monitoring of the gas flow rate in rough field conditions
requires robust methods capable of measuring gas flow at different types of
gas outlets such as wet mofettes, mineral springs, and boreholes. In this
paper we focus on the methods and results of the long-term monitoring of
CO2 degassing in the West Bohemia/Vogtland region in central Europe,
which is typified by the occurrence of earthquake swarms and discharge of
carbon dioxide of magmatic origin. Besides direct flow measurement using
flowmeters, we introduce a novel indirect technique based on quantifying the
gas bubble contents in a water column, which is capable of functioning in
severe environmental conditions. The method calculates the mean bubble
fraction in a water–gas mixture from the pressure difference along a fixed
depth interval in a water column. Laboratory tests indicate the nonlinear
dependence of the bubble fraction on the flow rate, which is confirmed by
empirical models found in the chemical and nuclear engineering literature.
Application of the method in a pilot borehole shows a high correlation
between the bubble fraction and measured gas flow rate. This was
specifically the case for two coseismic anomalies in 2008 and 2014, when the
flow rate rose during a seismic swarm to a multitude of the preseismic
level for several months and was followed by a long-term flow rate decline.
However, three more seismic swarms occurring in the same fault zone were not
associated with any significant CO2 flow anomaly. We surmise that this
could be related to the slightly farther distance of the hypocenters of
these swarms compared to the two ones which caused the coseismic CO2 flow
rise. Further long-term CO2-flow monitoring is required to verify the
mutual influence of CO2 degassing and seismic activity in the area.
The physics of fault friction: Insights from experiments on simulated gouges at low shearing velocities
Authors: Verberne Berend A. , van den Ende Martijn P. A. , Chen Jianye , Niemeijer André R. , Spiers Christopher J.
Published: June 2020

Abstract. The strength properties of fault rocks at shearing rates spanning the transition from crystal-plastic flow to frictional slip play a central role in determining the distribution of crustal stress, strain and seismicity in tectonically-active regions. We review experimental and microphysical modelling work aimed at elucidating the processes that control the transition from pervasive ductile flow of fault rock to rate-and-state dependent frictional (RSF) slip and to runaway rupture, carried out at Utrecht University in the past two or so decades. We address shear experiments on simulated gouges composed of calcite, halite-phyllosilicate mixtures, and phyllosilicate-quartz mixtures, performed under laboratory conditions spanning the brittle-ductile transition. With increasing shear rate (or decreasing temperature), the results consistently show transitions from (1) stable, velocity(v)-strengthening to potentially unstable, v-weakening behavior, and (2) back to v-strengthening. Sample microstructures show that the first transition, seen at low shear rates and/or high temperatures, represents a switch from pervasive, fully ductile deformation to frictional sliding, involving dilatant granular flow in localized shear bands, where intergranular slip is incompletely accommodated by creep of individual mineral grains. A recent microphysical model, treating fault rock deformation as controlled by a competition between rate-sensitive (diffusional or crystal-plastic) deformation of individual grains and rate-insensitive sliding interactions between grains (granular flow), predicts both transitions well. Unlike classical RSF approaches, this model quantitatively reproduces a wide range of (transient) frictional behaviors using input parameters with direct physical meaning. When implemented in numerical codes for crustal fault-slip, it offers a single, unified framework for understanding slip patch nucleation and growth to critical (seismogenic) dimensions, and for simulating the entire seismic cycle.
Os Surui-Aikewara e a guerrilha do Araguaia: um caso de reparação pendente
Authors: Ferraz Iara
Published: June 2020

Ao tratar do caso dos Surui-Aikewara - povo tupi-guarani que habita a Terra Indígena Sororó, localizada entre os municípios de Brejo Grande do Araguaia, São Domingos do Araguaia, São Geraldo do Araguaia e Marabá, no sudeste do estado do Pará, gostaríamos de apresentar aqui algumas observações acerca da reparação e seus desdobramentos no âmbito da justiça de transição, a título de contribuição para o entendimento de processos recentes, ainda pouco conhecidos e analisados.
“Meu avô foi o primeiro a encontrar os soldados na floresta”
Authors: Surui (Aikewara) Murue
Published: June 2020

Recupera a experiência dos Aikewara com os marehai (soldados), no contexto da repressão militar à guerrilha do Araguaia, explora alguns aspectos do processo de anistia política pela Comissão de Anistia e apresenta os atuais vetores de pressões e ameaças à comunidade indígena e à Terra Indígena Sororó. Fala realizada na Mesa “Perspectivas e iniciativas indígenas em torno da história e da justiça”, no Seminário Povos Indígenas: Memória, Verdade, Justiça, realizado no Centro de Pesquisa e Formação do Sesc-SP, em abril de 2019.
The Impact of Digital Marketing on Consumer Buying Decision Process in the Egyptian Market
Authors: Omar Amira M. , Atteya Nermine
Published: June 2020

This research examines digital marketing channels (E-mail Marketing, Mobile Marketing, and Retargeting) for marketers. It analyzes the effect of these channels on the consumer buying decision process in the Egyptian market.

The author researched an online questionnaire. The questionnaires were administered based on a simple sampling method and obtained in the Egyptian market. 285 questionnaires were distributed, and 213 available samples were collected, except incomplete questionnaires, resulted in a response rate of 74.7% to all those who chose to participate. Findings indicate that e-mail has a profoundly positive influence on consumer buying decisions in two phases (post-purchase) and information research). In the purchase, the decision phase has a negative effect on customer decisions. The mobile, as a digital marketing channel, has a negative impact on consumer decisions through all the stages of the consumer buying decision process in the Egyptian market. Also, re-targeting has a high effect on consumer decisions in the evaluation stage; then, information research needs recognition, purchase decision, and post-purchase.

Targeting is the most influential variable in the consumer buying decision process. We can notice that the most significant effect on the consumer decision is in the evaluation stage, and this can be due to that the re-targeting channel directed to the consumer who has already been searching for the product.