bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantification of nitrate content with FT-NIR technique in lettuce (Lactuca sativa L.) variety types: a statistical approach
Authors: Boros Ildikó Fruzsina , Sipos László , Kappel Noémi , Csambalik László , Fodor Marietta 
Published: April 2020

AbstractAccording to the Commission Regulation (EC) No. 1258/2011, the maximum allowed nitrate content of lettuce is defined within a broad range (2000–5000 mg NO3/kg), depending on harvest season and technology. This study focuses on the identification of the differences in nitrate accumulation between lettuce types and varieties, depending on production technology and on the investigation of the application of non-destructive FT-NIR spectroscopy for nitrate quantification, towards widely used UV–Vis spectroscopy.In the present study, combinations of seasons and technologies (spring × greenhouse, autumn × open field) were employed for the production of types (batavia, butterhead, lollo and oak leaf; both red and green colored); a total of 266 lettuce heads were analyzed. It was found that with standardized technology and conditions, autumn harvested green oak leaf lettuce types accumulated significantly less nitrate, than red oak or lollo leaf types. With spring harvested lettuces, batavia types generally accumulated generally more nitrates than butterhead types. Based on the linear discriminant analysis (LDA) of FT-NIR measurements the four distinct variety types diverge; the lollo type explicitly diverges from batavia and butterhead types. The LDA further revealed, that within lollo and oak leaf variety types, red and green leaved varieties diverge as well. A model was successfully built for the FT-NIR quantification of the nitrate content of lettuce samples (R2 = 0.95; RMSEE = 74.4 mg/kg fresh weight; Q2 = 0.90; RMSECV = 99.4 mg/kg fresh weight). The developed model is capable of the execution of a fast and non-invasive measurement; the method is suitable for the routine measurement of nitrate content in lettuce.
Modeling for anthracnose development in mango in relation to weather parameters
Authors: Singh Rajender , Deepankar  
Published: April 2020

AbstractMango anthracnose severity on leaves was recorded at 14 day intervals throughout the year 2013, 2014, 2015, 2017 and 2018 on mango cultivar Dashaheri. Logistic model was best for the year 2013, 2014, 2015, 2018 and pooled data of these years had lower mean square error (MSE) 37.67, 91.29, 100.84, 65.80 and 72.32 along with high coefficient of determination (R(Dodd et al. 1991)) 0.753, 0.532, 0.534, 0.656 and 0.606, respectively. Maximum anthracnose development i.e. periodical disease progression (6.9%) was highest from 31st to 33th Standard Meteorological Weeks (SMW) because of cumulative effect of minimum temperature (27 °C) and morning relative humidity (≥ 90%) along with the rainfall (56 mm). Mango anthracnose severity was positively and significantly correlated with the minimum temperature (0.62) followed by rainfall (0.46) on all year pooled data basis, whereas the highest correlation 0.65 was observed for the years 2014 and 2015. The regression model based on pooled data has performed better an alternative regression model of each individual year with the highest adjusted R2 value i.e. 0.747, explaining the effects of minimum temperature, morning relative humidity and rainfall on the anthracnose severity.
Use of laser-induced break spectroscopy for the determination of major and trace elements in Zanthoxylum armatum
Authors: Shahida Shabnam , Khan Muhammad Imran , Azad Sadaf , Ahmed Nasar , Lashari Mushtaq Hussain , Khraisheh Majeda , Almomani Fares , Zafar Shagufta 
Published: April 2020

AbstractZanthoxylum armatum (ZA) is a medicinal plant (MP) that is widely distributed in hilly and moist areas and has a different medical effect on human curative functions. Laser-induced breakdown spectroscopy (LIBS) was employed as a simple, easy, and accurate method to analyze the elemental profile of Zanthoxylum armatum (ZA) (timur). Various elements present in different parts of ZA were identified including sodium, magnesium, calcium, potassium, titanium, iron, barium, aluminum, lithium, and silicon. The proposed method accuracy was found to be comparable with high technical complicated lab equipment The concentrations of these elements were determined and were found to be below the toxic level.
African Solutions to African Challenges: The Role of Legitimacy in Mediating Civil Wars in Africa
Authors: Duursma Allard 
Published: April 2020

AbstractThe current scholarly literature on the international mediation of civil wars draws predominantly on a rationalist-materialist perspective. This perspective suggests that the ticket to mediation success is the material manipulation of the bargaining environment by third parties with a high degree of economic and military resources. I argue that legitimacy also determines outcomes of mediation because if a mediator has legitimacy, it can continue to look for a mutually satisfactory outcome and try to pull the conflict parties toward compliance. I show that legitimacy matters by systematically comparing the effectiveness of African and non-African third parties. African third parties are typically considered ineffective because of a low degree of economic and military capacity. However, they effectively mediate civil wars in Africa because of a high degree of legitimacy, which is a result of a strong conviction within the African society of states that African mediation is the most desirable type in conflicts there. Drawing on data from the Uppsala Conflict Data Program supplemented with unique data, which together cover all mediation efforts in Africa between 1960 and 2017, I find quantitative evidence supporting the effectiveness of African third parties. Compared to non-African ones, African third parties are far more likely to conclude negotiated settlements that are more likely to be durable. African third parties are especially effective if the conflict parties are highly committed to the African solutions norm. Theoretically, this study deviates from much of the literature that puts forward solely rationalist-materialist explanations of mediation success. By bringing legitimacy to the forefront, this article supplements the current mediation literature that emphasizes material sources of power and ignores social structures.
Fast collisional electron heating and relaxation in thin foils driven by a circularly polarized ultraintense short-pulse laser
Authors: Sundström Andréas , Gremillet Laurent , Siminos Evangelos , Pusztai István 
Published: April 2020

The creation of well-thermalized, hot and dense plasmas is attractive for warm dense matter studies. We investigate collisionally induced energy absorption of an ultraintense and ultrashort laser pulse in a solid copper target using particle-in-cell simulations. We find that, upon irradiation by a$2\times 10^{20}~\text{W}\,\text{cm}^{-2}$intensity, 60 fs duration, circularly polarized laser pulse, the electrons in the collisional simulation rapidly reach a well-thermalized distribution with${\sim}3.5~\text{keV}$temperature, while in the collisionless simulation the absorption is several orders of magnitude weaker. Circular polarization inhibits the generation of suprathermal electrons, while ensuring efficient bulk heating through inverse bremsstrahlung, a mechanism usually overlooked at relativistic laser intensity. An additional simulation, taking account of both collisional and field ionization, yields similar results: the bulk electrons are heated to${\sim}2.5~\text{keV}$, but with a somewhat lower degree of thermalization than in the pre-set, fixed-ionization case. The collisional absorption mechanism is found to be robust against variations in the laser parameters. At fixed laser pulse energy, increasing the pulse duration rather than the intensity leads to a higher electron temperature.
Kinetic Alfvén wave generation by velocity shear in collisionless plasmas
Authors: Maiorano Teresa , Settino Adriana , Malara Francesco , Pezzi Oreste , Pucci Francesco , Valentini Francesco 
Published: April 2020

The evolution of a linearly polarized, long-wavelength Alfvén wave propagating in a collisionless magnetized plasma with a sheared parallel-directed velocity flow is here studied by means of two-dimensional hybrid Vlasov–Maxwell (HVM) simulations. The unperturbed sheared flow has been represented by an exact solution of the HVM set of equations of (Malara et al., Phys. Rev. E, vol. 97, 2018, 053212), thus avoiding spurious oscillations that would arise from the non-stationary initial state and inevitably affect the dynamics of the system. We have considered the evolution of both a small and a moderate amplitude Alfvén wave, in order to separate linear wave–shear flow couplings from kinetic effects, the latter being more relevant for larger wave amplitudes. The phase mixing generated by the shear flow modifies the initial perturbation, leading to the formation of small-scale transverse fluctuations at scales comparable with the proton inertial length/Larmor radius. By analysing both the polarization and group velocity of perturbations in the shear regions, we identify them as kinetic Alfvén waves (KAWs). In the moderate amplitude run, kinetic effects distort the proton distribution function in the shear region. This leads to the formation of a proton beam, at the Alfvén speed and parallel to the magnetic field. Such a feature, due to the parallel electric field associated with KAWs, positively compares with solar wind observations of suprathermal ion populations, suggesting that it may be related to the presence of ion-scale KAW-like fluctuations.
FISCAL CRISES, FORCED LOANS AND UNINTENDED INSTITUTIONAL CONSEQUENCES IN WARTIME BUENOS AIRES, 1800-1820
Authors: Moutoukias Zacarias , ’T Hart Marjolein 
Published: April 2020

ABSTRACTBetween 1800 and 1820, Buenos Aires and the former colonial Viceroyalty of Rio de la Plata faced an unprecedented fiscal crisis caused by the revolutionary wars, eventually solved by levying forced loans. This paper considers the unintended institutional consequences of these loans. The novel devices allowed (1) the holders of forced-loan coupons to use these bonds to pay off debts incurred in customs duties and (2) the holders of bills of exchange involved in the provisioning of the military to use these bills to pay part of their forced loans. Starting with the conceptualisation of the institutional order as a complex system, this paper examines the interactions among the circulation of financial paper bills, the financing of war and changes in the position of the merchants' guild and the legal framework for Atlantic trade. It thereby contributes to renewing institutional change approaches in the Spanish-American context.
Marked increase in community-associated methicillin-resistant Staphylococcus aureus infections, Western Australia, 2004–2018
Authors: Bloomfield L. E. , Coombs G. W. , Tempone S. , Armstrong P. K. 
Published: April 2020

Abstract
This study presents enhanced surveillance data from 2004 to 2018 for all community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) specimens collected in Western Australia (WA), and describes the changing epidemiology over this period. A total of 57 557 cases were reviewed. Annual incidence rates increased from 86.2 cases per 100 000 population to 245.6 per 100 000 population (IRR = 2.9, CI95 2.7–3.0). The proportion of isolates carrying Panton–Valentine leucocidin (PVL)-associated genes increased from 3.4% to 59.8% (χ2 test for trend 7021.9, P < 0.001). The emergence of PVL-positive, ‘Queensland CA-MRSA’ (ST93-IV) and ‘WA 121’ (ST5-IV) accounted for the majority of increases in CA-MRSA across the study period. It is unclear why some clones are more prolific in certain regions. In WA, CA-MRSA rates increase as indices of temperature and humidity increase after controlling for socioeconomic disadvantage. We suggest climatic conditions may contribute to transmission, along with other socio-behavioural factors. A better understanding of the ability for certain clones to form ecological niches and cause outbreaks is required.
Evolution of the number of communicative civilizations in the Galaxy: implications on Fermi paradox
Authors: Spada Giorgio , Melini Daniele 
Published: April 2020

AbstractIt has been recently proposed DeVito [(2019) On the meaning of Fermi's paradox.Futures, 389–414] that aminimalnumber of contacts with alien radio-communicative civilizations could be justified by their logarithmically slow rate of growth in the Galaxy. Here we further develop this approach to the Fermi paradox, with the purpose of expanding the ensemble of the possible styles of growth that are consistent with the hypothesis of a minimal number of contacts. Generalizing the approach in DeVito (2019), we show that a logarithmic style of growth is still found. We also find that a style of growth following a power law would be admissible, however characterized by an exponent less than one, hence describing a sublinear increase in the number of communicative civilizations, still qualitatively in agreement with DeVito (2019). No solutions are found indicating a superlinear increase in the number of communicative civilizations, following for example an exponentially diverging law, which would cause, in the long run, an unsustainable proliferation. Although largely speculative, our findings corroborate the idea that a sublinear rate of increase in the number of communicative civilizations in the Galaxy could constitute a further resolution of Fermi paradox, implying a constant and minimal – but not zero – number of contacts.
The Pace of Fluvial Meanders on Mars and Implications for the Western Delta Deposits of Jezero Crater
Authors: Lapôtre Mathieu G. A. , Ielpi Alessandro 
Published: April 2020

AbstractAlthough there is little doubt that rivers once flowed on Mars' surface, how sustained and frequent their flows were remains enigmatic. Understanding the hydrology of early Mars, nonetheless, is a prerequisite to resolving the planet's climate history and the astrobiological potential of various ancient putative ecosystems. In 2021, NASA's Perseverance rover will attempt to land near ancient fluviodeltaic deposits in Jezero crater. Deltas offer enhanced organic‐matter burial and preservation on Earth but translating this notion to early Martian environments remains speculative in the absence of information on flow intermittency and sedimentation rates. Here we develop a new model to infer the lateral migration rate of Martian river meanders, which, combined with orbiter‐based observations of the fluviodeltaic deposits at Jezero crater, allows us to determine a minimum timescale for the formation of its delta. We then independently constrain the total duration of delta formation, including dry spells. Our best estimates suggest that delta formation spanned ~19–37 years over a total duration of ~380,000 years, i.e., that rivers flowed for a minimum ~1 sol/15–30 Martian years and conceivably more frequently, but uncertainties on total duration are large. Despite a possibly arid climate, predicted sedimentation rates are high, suggesting a rapid burial of putative organics in distal deposits. Altogether, our results support Jezero crater's potential as a prime target to look for ancient Martian life and acquire samples to return to Earth. Any discrepancies between our predictions of the deposits' grain‐to‐bedform‐scale architecture and future rover observations will shed critical light onto Mars' early surface environments.
Stress Drop Variation of Deep‐Focus Earthquakes Based on Empirical Green's Functions
Authors: Liu Meichen , Huang Yihe , Ritsema Jeroen 
Published: April 2020

AbstractWe analyze source characteristics of global, deep‐focus (>350 km) earthquakes with moment magnitudes (Mw) larger than 6.0–8.2 using teleseismic P‐wave and S‐wave spectra and an empirical Green's functions approach. We estimate the corner frequency assuming Brune's source model and calculate stress drops assuming a circular crack model. Based on P‐wave and S‐wave spectra, the one standard deviation ranges are 3.5–369.8 and 8.2–328.9 MPa, respectively. Based on the P‐wave analysis, the median of our stress drop estimates is about a factor of 10 higher than the median stress drop of shallow earthquakes with the same magnitude estimated by Allmann and Shearer (2009, https://doi.org/10.1029/2008JB005821). This suggests that, on average, the shear stress of deep faults in the mantle transition zone is an order of magnitude higher than the shear stress of faults in the crust. The wide range of stress drops implies coexistence of multiple physical mechanisms.
Amagmatic Subduction Produced by Mantle Serpentinization and Oceanic Crust Delamination
Authors: Yang Jianfeng , Lu Gang , Liu Tong , Li Yang , Wang Kun , Wang Xinxin , Sun Baolu , Faccenda Manuele , Zhao Liang 
Published: April 2020

AbstractRecycling of oceanic lithosphere and serpentinized peridotites into the mantle leads to dehydration melting and volcanic arcs. However, the mechanism of the occurrence of long‐term volcanic gap in subduction zones remains poorly understood. Two‐dimensional thermomechanical numerical models focusing on resisting the transport of the major hosts of hydrous minerals to mantle depths, show that thin oceanic crust together with rheologically weak and buoyant serpentinized mantle could result in hydrated lithologies piling up in the accretionary wedge and no or sparse occurrence of arc magmatism. This scenario may occur during subduction of oceanic lithosphere formed at (ultra)slow‐spreading margins characterized by thin crust and extensive mantle serpentinization, which is a plausible explanation for the “arc gaps” in the Alps and southern Tibet.
Healing Behavior of Simulated Fault Gouges From the Groningen Gas Field and Implications for Induced Fault Reactivation
Authors: Hunfeld Luuk B. , Chen Jianye , Hol Sander , Niemeijer André R. , Spiers Christopher J. 
Published: April 2020

AbstractWe investigated the frictional strength recovery (healing) and subsequent reactivation and slip‐weakening behavior of simulated fault gouges derived from key stratigraphic units in the seismogenic Groningen gas field (N. E. Netherlands). Direct‐shear, slide‐hold‐slide (SHS) experiments were performed at in situ conditions of 100 °C, 40 MPa effective normal stress and 10–15 MPa pore fluid pressure (synthetic formation brine). Sheared gouges were allowed to heal for periods up to 100 days before subsequent reshearing. The initial coefficient of (steady) sliding friction μ was highest in the Basal Zechstein caprock (μ = 0.65 ± 0.02) and Slochteren sandstone reservoir (μ = 0.61 ± 0.02) gouges, and the lowest in the Ten Boer claystone at the reservoir top (μ = 0.38 ± 0.01) and in the Carboniferous shale substrate (μ ≈ 0.45). Healing and subsequent reactivation led to a marked increase (∆μ) in (static) friction coefficient of up to ~0.16 in Basal Zechstein and ~0.07 in Slochteren sandstone gouges for the longest hold periods investigated, followed by a sharp strength drop (up to ~25%) and slip‐weakening trajectory. By contrast, the Ten Boer and Carboniferous gouges showed virtually no healing or strength drop. Healing rates in the Basal Zechstein and Slochteren sandstone gouges were significantly affected by the stiffness of different machines used, in line with the Ruina slip law, and with a microphysical model for gouge healing. Our results point to marked stratigraphic variation in healed frictional strength and healing rate of faults in the Groningen system, and high seismogenic potential of healed faults cutting the reservoir and Basal Zechstein caprock units, upon reactivation.
Efficient Carbon Recycling at the Central‐Northern Lesser Antilles Arc: Implications to Deep Carbon Recycling in Global Subduction Zones
Authors: Li Kan , Li Long , Aubaud Cyril , Muehlenbachs Karlis 
Published: April 2020

AbstractCarbon recycling efficiency of arc (CREA) is an important parameter to assess the recycling of slab carbon into Earth's deep interior. Although previous studies observed variable degrees of recycled slab carbon at global arcs, the CREA value of any individual subduction zone has not been obtained due to the loose constraints on carbon budget in altered oceanic crust (AOC). Here, through estimates of carbon input by both sediments and AOC at DSDP Site 543 and recycled carbon output from major volcanoes in the Central‐Northern Lesser Antilles, we show an extremely efficient carbon recycling case, with the CREA value reaching 100±27%. Nearly complete slab carbon release at sub‐arc depth implies little carbon has been lost in the forearc region or subducted into the deep mantle in this subduction zone. Our results highlight strongly variable CREA on a global scale, which must be considered in the modeling of global deep carbon cycle.
Methane, Monsoons, and Modulation of Millennial‐Scale Climate
Authors: Thirumalai Kaustubh , Clemens Steven C. , Partin Judson W. 
Published: April 2020

AbstractEarth's orbital geometry exerts a profound influence on climate by regulating changes in incoming solar radiation. Superimposed on orbitally paced climate change, Pleistocene records reveal substantial millennial‐scale variability characterized by abrupt changes and rapid swings. However, the extent to which orbital forcing modulates the amplitude and timing of these millennial variations is unclear. Here we isolate the magnitude of millennial‐scale variability (MMV) in two well‐dated records, both linked to precession cycles (19,000‐ and 23,000‐year periodicity): composite Chinese speleothem δ18O, commonly interpreted as a proxy for Asian monsoon intensity, and atmospheric methane. At the millennial timescale (1,000–10,000 years), we find a fundamental decoupling wherein precession directly modulates the MMV of methane but not that of speleothem δ18O, which is shown to be strikingly similar to the MMV of Antarctic ice core δ2H. One explanation is that the MMV of methane responds to changes in midlatitude to high‐latitude insolation, whereas speleothem δ18O is modulated by internal climate feedbacks.
Impaired expression of the COSMOC/MOCOS gene unit in ASD patient stem cells
Authors: Rontani Pauline , Perche Olivier , Greetham Louise , Jullien Nicolas , Gepner Bruno , Féron François , Nivet Emmanuel , Erard-Garcia Madeleine 
Published: April 2020

AbstractAutism spectrum disorders (ASD) are complex neurodevelopmental disorders with a very large number of risk loci detected in the genome. However, at best, each of them explains rare cases, the majority being idiopathic. Genomic data on ASD derive mostly from post-mortem brain analyses or cell lines derived from blood or patient-specific induced pluripotent stem cells (iPSCS). Therefore, the transcriptional and regulatory architecture of the nervous system, particularly during early developmental periods, remains highly incomplete. To access the critical disturbances that may have occurred during pregnancy or early childhood, we recently isolated stem cells from the nasal cavity of anesthetized patients diagnosed for ASD and compared them to stem cells from gender-matched control individuals without neuropsychiatric disorders. This allowed us to discover MOCOS, a non-mutated molybdenum cofactor sulfurase-coding gene that was under-expressed in the stem cells of most ASD patients of our cohort, disturbing redox homeostasis and synaptogenesis. We now report that a divergent transcription upstream of MOCOS generates an antisense long noncoding RNA, to which we coined the name COSMOC. Surprisingly, COSMOC is strongly under-expressed in all ASD patients of our cohort with the exception of a patient affected by Asperger syndrome. Knockdown studies indicate that loss of COSMOC reduces MOCOS expression, destabilizes lipid and energy metabolisms of stem cells, but also affects neuronal maturation and splicing of synaptic genes. Impaired expression of the COSMOC/MOCOS bidirectional unit might shed new lights on the origins of ASD that could be of importance for future translational studies.