bluuebunny/crossref_metadata_2025_split huggingface dataset:
The (Un)Constitutional Appropriation and Expenditure of Public Funds in Nigeria: Analysing the “Security Vote” Paradigm through the Law
Authors: Ezeilo Joy Ngozi , Nwoke Uchechukwu , Anya Sylvester Ndubuisi 
Published: May 2018

AbstractSecurity challenges have continued to trouble governments internationally. From the Islamic State terrorists in the Gulf region, to the murderous activities of Boko Haram and “herdsmen” in Nigeria in recent times, it has become imperative for those entrusted with maintaining security to redefine the conditions of national security. In this context, it is now conventional for various governments in Nigeria to appropriate enormous amounts of money in their budgets for “national security” (“tagged security vote”). This article explores the emergence, configuration, constitutionality and abuses of security votes in Nigeria. It also explores the appropriation and expenditure of security funds in the USA and attempts to draw lessons from this jurisdiction. It argues that there is a robust connection between security votes and corruption and, thus, attempts to identify legal structures for preventing the misspending and embezzlement of public funds (security votes) in the country's monetary appropriation and expenditure.
Childhood trauma- and cannabis-associated microstructural white matter changes in patients with psychotic disorder: a longitudinal family-based diffusion imaging study
Authors: Domen Patrick , Michielse Stijn , Peeters Sanne , Viechtbauer Wolfgang , van Os Jim , Marcelis Machteld ,   for Genetic Risk and Outcome of Psychosis (G.R.O.U.P.)
Published: May 2018

AbstractBackgroundDecreased white matter (WM) integrity in patients with psychotic disorder has been a consistent finding in diffusion tensor imaging (DTI) studies. However, the contribution of environmental risk factors to these WM alterations is rarely investigated. The current study examines whether individuals with (increased risk for) psychotic disorder will show increased WM integrity change over time with increasing levels of childhood trauma and cannabis exposure.MethodsDTI scans were obtained from 85 patients with a psychotic disorder, 93 non-psychotic siblings and 80 healthy controls, of which 60% were rescanned 3 years later. In a whole-brain voxel-based analysis, associations between change in fractional anisotropy (ΔFA) and environmental exposures as well as interactions between group and environmental exposure in the model of FA and ΔFA were investigated. Analyses were adjusted for a priori hypothesized confounding variables: age, sex, and level of education.ResultsAt baseline, no significant associations were found between FA and both environmental risk factors. At follow-up as well as over a 3-year interval, significant interactions between group and, respectively, cannabis exposure and childhood trauma exposure in the model of FA and ΔFA were found. Patients showed more FA decrease over time compared with both controls and siblings when exposed to higher levels of cannabis or childhood trauma.ConclusionsHigher levels of cannabis or childhood trauma may compromise connectivity over the course of the illness in patients, but not in individuals at low or higher than average genetic risk for psychotic disorder, suggesting interactions between the environment and illness-related factors.
Chemical composition of Rosmarinus officinalis (Lamiaceae) essential oils and evaluation of their toxicity against Bruchus rufimanus (Coleoptera: Chrysomelidae: Bruchinae) in Morocco
Authors: Hannour Karima , Boughdad Ahmed , Maataoui Abdelwahed , Bouchelta Aziz 
Published: May 2018

AbstractControl methods used to limit field losses caused byBruchus rufimanusBoheman, 1833 consist of synthetic insecticides that pose health risks to farmers, consumers and the environment. In an attempt to find safer alternatives, we screened essential oils from the leaves ofRosmarinus officinaliscollected in the Middle Atlas and Loukkos regions of Morocco in the laboratory as natural fumigants againstB. rufimanus.These essential oils were extracted by steam distillation using a Clevenger distiller, characterised chemically by coupled gas chromatography–mass spectrometry (GC/MS) and tested at five concentrations (0, 10, 20, 40, 80 µl/l air). The essential oils ofR. officinalismainly comprised oxygenated monoterpenes (Middle Atlas: 79.4%; Loukkos: 48.78%) and terpenes (Middle Atlas: 14.71%; Loukkos: 32.33%). The lethal concentrations (LC50) of Middle Atlas and Loukkos essential oils against male beetles ranged from, respectively, 46.53 to 1.19 µl/l air and 58.85 to 11.57 µl/l air. Similarly, doses ofR. officinalisessential oils from Middle Atlas and Loukkos lethal to females, ranged from 44.6 to 2.08 µl/l air and from 53.00 to 5.38 µl/l air, respectively. Additionally, the lethal time (LT50and LT99) of exposed adults ranged from 1–8 and from 2–13 days for different concentrations ofR. officinalisessential oils from Middle Atlas and Loukkos, respectively. With no mortality recorded in the control groups, these findings demonstrate the fumigant potential of these oils against this bruchid under the storage conditions.
A Finite Difference Time Domain Investigation of Electric Field Enhancements Along Ocean‐Continent Boundaries During Space Weather Events
Authors: Pokhrel Santosh , Nguyen Bach , Rodriguez Miguel , Bernabeu Emanuel , Simpson Jamesina J. 
Published: May 2018

AbstractGeomagnetic disturbances caused by solar storms have the potential to create large‐scale geomagnetically induced currents in long conductors at the Earth's surface. These may disrupt the operation of electric power grids and cause blackouts. Ocean‐continent boundary regions are of particular concern because of the sharp contrast between the higher ocean electrical conductivity compared to the lower continental conductivity. This contrast may generate high‐amplitude geoelectric fields and cause power grids in coastal regions to be more vulnerable to space weather hazards. Previously, analytical calculations were used to estimate geomagnetically induced currents at ocean‐continent boundaries. However, for the analytical equations to be solvable, the physics and geometries of the problem were simplified. As a result of these simplifications and due to a lack of published measurements examining this issue in coastal regions, it is difficult to know for sure whether there are unique hazards to electric power grids at ocean‐continent boundaries. In this paper, a grid‐based, time domain modeling approach is used to solve the complete Maxwell's equations, which permits accommodation of (1) the complete physics of the propagating electromagnetic fields from disturbed ionospheric currents through the air and into the lithosphere and even into the ocean via the skin effect and (2) more realistic coastal geometries. Using this more robust approach, in the variety of scenarios studied in this paper, only a local enhancement of the electric fields was observed, which are expected to only pose potential hazards to power grids only a local scale near ocean‐continent boundaries.
Spacecraft‐Charging Mitigation of a High‐Power Electron Beam Emitted by a Magnetospheric Spacecraft: Simple Theoretical Model for the Transient of the Spacecraft Potential
Authors: Lucco Castello F. , Delzanno G. L. , Borovsky J. E. , Miars G. , Leon O. , Gilchrist B. E. 
Published: May 2018

AbstractA spacecraft‐charging mitigation scheme necessary for the operation of a high‐power electron beam in the low‐density magnetosphere is analyzed. The scheme is based on a plasma contactor, that is, a high‐density charge‐neutral plasma emitted prior to and during beam emission and its ability to emit high ion currents without strong space‐charge limitations. A simple theoretical model for the transient of the spacecraft potential and contactor expansion during beam emission is presented. The model focuses on the contactor ion dynamics and is valid in the limit when the ion contactor current is equal to the beam current. The model is found in very good agreement with particle‐in‐cell simulations over a large parametric study that varies the initial expansion time of the contactor, the contactor current, and the ion mass. The model highlights the physics of the spacecraft‐charging mitigation scheme, indicating that the most important part of the dynamics is the evolution of the outermost ion front, which is pushed away by the charge accumulated in the system by the beam. The model can be also used to estimate the long‐time evolution of the spacecraft potential. For a short contactor expansion (0.3‐ or 0.6‐ms helium plasma or 0.8‐ms argon plasma, both with 1‐mA current) it yields a peak spacecraft potential of the order of 1–3 kV. This implies that a 1‐mA relativistic electron beam would be easily emitted by the spacecraft.
Frontal Dynamics of a Buoyancy‐Driven Coastal Current: Quantifying Buoyancy, Wind, and Isopycnal Tilting Influence on the Nova Scotia Current
Authors: Dever Mathieu , Skagseth Øystein , Drinkwater Ken , Hebert David 
Published: May 2018

AbstractThe focus of this study is on the relative roles of winds and buoyancy in driving the Nova Scotia Current (NSC) utilizing detailed hydrographic glider transects along the Halifax Line. We define a Hydrographic Wind Index (HWI) using a simplistic two‐layer model to represent the NSC and its frontal system. The HWI is based on local characteristics of the density front extracted from the glider data (e.g., frontal slope). The impact of wind‐driven isopycnal tilting on the frontal slope is estimated and corrected for to accurately scale the buoyancy‐driven component of the NSC. Observations from independent current profilers deployed across the NSC confirm that the HWI captures the low‐frequency variability of the NSC. The monthly wind‐driven flow is estimated to represent between 1.0% (±0.1%) and 48% (±1%) of the total alongshore currents, with a yearly mean of about 36% (±1%). We demonstrate that using local conditions is more appropriate to the study of buoyancy‐driven currents ranging over distances on the order of
(100 km), compared to the traditional approach based on upstream conditions. Contrary to the traditional approach, the HWI is not affected by the advective time lag associated with the downshelf propagation of the buoyant water coming from the upstream source. However, the HWI approach requires high‐resolution data sets, as errors on the estimates of the buoyancy‐ and wind‐driven flows become large as the sampling resolution decreases. Despite being data intensive, we argue that the HWI is also applicable to multisource currents, where upstream conditions are difficult to define.
Seasonal Variability and Generation Mechanisms of Nonlinear Internal Waves in the Strait of Georgia
Authors: Li Lan , Pawlowicz Richard , Wang Caixia 
Published: May 2018

AbstractSeasonal variability and generation mechanisms of large nonlinear internal waves are reported, based on an analysis of 9 years of continuous observational data collected at nodes of the Ocean Networks Canada coastal observatory in the Strait of Georgia, Canada. About one thousand large nonlinear internal wave packets were identified. The timing of these packets suggests a very strong correlation with daily tides and fortnightly cycles. More waves are seen during the stronger tides of the fortnightly cycle but overall waves are seen in less than 40% of all days. Other wave characteristics show seasonal variations. In winter, when the pycnocline is weaker, both the spatial and temporal scales of internal waves are several times larger than summertime waves and wave amplitudes can approach 30 m. These waves are large enough vertically but small enough horizontally that standard acoustic Doppler current profiler (ADCP) processing algorithms present a strongly distorted view of wave shape and features. A specialized reprocessing of the beam velocities is used to correctly measure the wave velocity field and to determine wave propagation speed and direction. In addition to the previously known northward‐propagating waves in the Strait, we also found waves propagating in other directions and a noticeable correlation with winds, which may be a proxy for spatial variations in density and/or velocity shear. By considering wave propagation direction, relationship with tidal phase, and relationship with wind, three generation mechanisms were found. Two particularly interesting generation mechanisms involve waves radiating from the Sand Heads area.
Upper Ocean Cooling in a Coupled Climate Model Due to Light Attenuation by Yellowing Materials
Authors: Kim Grace E. , Gnanadesikan Anand , Del Castillo Carlos E. , Pradal Marie‐Aude 
Published: May 2018

AbstractColored detrital matter consists of dissolved organic molecules and detrital materials that impart a yellow shift to the ocean's color. These materials reduce light penetration, concentrating heating by sunlight closer to the surface. We ran two climate model simulations: one of an ocean including colored detrital matter (Yellow Ocean) and one without (Green Ocean). Due to the decreased water clarity in the Yellow Ocean, upper ocean heat content was lower and temperatures were colder compared to the Green Ocean. The difference between these simulations is opposite to the ocean warming that has been observed in recent decades. Increasing precipitation in high‐latitude regions has also been observed, with greater inputs of terrestrial organic materials to the ocean. We suggest that an increase in these yellowing materials behaves as a buffer that mitigates some effects of a warming climate. Future studies should investigate this link between the atmosphere, land, and ocean systems.
What Causes Radiation Belt Enhancements: A Survey of the Van Allen Probes Era
Authors: Boyd A. J. , Turner D. L. , Reeves G. D. , Spence H. E. , Baker D. N. , Blake J. B. 
Published: May 2018

AbstractWe survey radiation belt enhancement events during the Van Allen Probes era to determine what mechanism is the dominant cause of enhancements and where it is most effective. Two primary mechanisms have been proposed: (1) betatron/Fermi acceleration due to the Earthward radial transport of electrons, which produces monotonic gradients in phase space density (PSD), and (2) “local acceleration” due to gyro/Landau resonant interaction with electromagnetic waves, which produces radially localized growing peaks in PSD. To differentiate between these processes, we examine radial profiles of PSD in adiabatic coordinates using data from the Van Allen Probes and Time History of Events and Macroscale Interactions during Substorms satellites for 80 outer belt enhancement events from October 2012 to April 2017 This study shows that local acceleration is the dominant acceleration mechanism for MeV electrons in the outer belt, with 87% of the enhancement events exhibiting growing peaks. The strong correlation of the location of these with geomagnetic activity further supports this conclusion.
Global Aurora on Mars During the September 2017 Space Weather Event
Authors: Schneider N. M. , Jain S. K. , Deighan J. , Nasr C. R. , Brain D. A. , Larson D. , Lillis R. , Rahmati Ali , Halekas J. S. , Lee C. O. , Chaffin M. S. , Stiepen A. , Crismani M. , Evans J. S. , Stevens M. H. , Lo D. Y. , McClintock W. E. , Stewart A. I. F. , Yelle R. V. , Clarke J. T. , Holsclaw G. M. , Lefevre F. , Montmessin F. , Jakosky B. M. 
Published: May 2018

AbstractWe report the detection of bright aurora spanning Mars' nightside during the space weather event occurring in September 2017. The phenomenon was similar to diffuse aurora detected previously at Mars, but 25 times brighter and detectable over the entire visible nightside. The observations were made with the Imaging UltraViolet Spectrograph, a remote sensing instrument on the Mars Atmosphere and Volatile EvolutioN spacecraft orbiting Mars. Images show that the emission was brightest around the limb of the planet, with a fairly uniform faint glow against the disk itself. Spectra identified four molecular emissions associated with aurora, and limb scans show the emission originated from an altitude of ~60 km in the atmosphere. Both are consistent with very high energy particle precipitation. The auroral brightening peaked around 13 September, when the flux of solar energetic electrons and protons both peaked. During the declining phase of the event, faint but statistically significant auroral emissions briefly appeared against the disk of the planet in the form of narrow wisps and small patches. These features are approximately aligned with predicted open field lines in the region of strong crustal magnetic fields in Mars' southern hemisphere.
Effects of Iron Spin Transition on the Structure and Stability of Large Primordial Reservoirs in Earth's Lower Mantle
Authors: Li Yang , Vilella Kenny , Deschamps Frédéric , Zhao Liang , J. Tackley Paul 
Published: May 2018

AbstractExperimental and theoretical studies have shown that the iron spin transition alters the properties of lower mantle minerals. This may have important implications for mantle dynamics. In particular, the vigor of convection is enhanced, which in turn may impact the stability of large primordial reservoirs at the base of the lower mantle. Here we performed numerical experiments of thermochemical convection in 2‐D annulus geometry including the change of density induced by iron spin transition. Our results show that this density change only slightly affects mantle dynamics by increasing the convection vigor. This, in turn, slightly increases the entrainment of primordial dense materials by plumes and leads to smaller reservoirs with sharper edges. However, this effect is small compared to those of the intrinsic density contrast between the dense primordial and regular mantle materials, which is the dominant parameter controlling the long‐term stability of the large primordial reservoirs.
Control of ITCZ Width by Low‐Level Radiative Heating From Upper‐Level Clouds in Aquaplanet Simulations
Authors: Dixit Vishal , Geoffroy Olivier , Sherwood Steven C. 
Published: May 2018

AbstractAtmospheric cloud radiative effects (ACRE) narrow the Intertropical Convergence Zones (ITCZs) in climate models. Some studies have attributed this to the upper tropospheric heating by deep clouds. We report two types of idealized aquaplanet experiments, one where ACRE in specific altitude ranges is removed and another where the ACRE associated with clouds in specific altitude ranges is removed. Lower tropospheric heating due to upper tropospheric clouds in the deep tropics exerts the greatest impact on the ITCZ width and meridional overturning, even though the heating is weaker than in the upper troposphere. It is argued that this is because radiatively driven changes in the shallow circulation drive a feedback via net import of MSE and make the ITCZ more unstable in its core, thereby forcing the ITCZ to contract. The radiative effects of clouds in the subsiding subtropics are found to be of secondary importance in driving the necessary circulation changes.
An Explanation of Episodic Tremor and Slow Slip Constrained by Crack‐Seal Veins and Viscous Shear in Subduction Mélange
Authors: Ujiie Kohtaro , Saishu Hanae , Fagereng Åke , Nishiyama Naoki , Otsubo Makoto , Masuyama Haruna , Kagi Hiroyuki 
Published: May 2018

AbstractEpisodic tremor and slow slip (ETS) occurs in the transition zone between the locked seismogenic zone and the deeper, stably sliding zone. Actual mechanisms of ETS are enigmatic, caused by lack of geological observations and limited spatial resolution of geophysical information from the ETS source. We report that quartz‐filled, crack‐seal shear and extension veins in subduction mélange record repeated low‐angle thrust‐sense frictional sliding and tensile fracturing at near‐lithostatic fluid pressures. Crack‐seal veins were coeval with viscous shear zones that accommodated deformation by pressure solution creep. The minimum time interval between thrusting events, determined from a kinetic model of quartz precipitation in shear veins, was less than a few years. This short recurrence time of low‐angle brittle thrusting at near‐lithostatic fluid overpressures within viscous shear zones may be explained by frequent release of accumulated strain by ETS.
Injection‐Induced Moment Release Can Also Be Aseismic
Authors: McGarr A. , Barbour Andrew J. 
Published: May 2018

AbstractThe cumulative seismic moment is a robust measure of the earthquake response to fluid injection for injection volumes ranging from 3,100 to about 12 million m3. Over this range, the moment release is limited to twice the product of the shear modulus and the volume of injected fluid. This relation also applies at the much smaller injection volumes of the field experiment in France reported by Guglielmi et al. (2015, https://doi.org/10.1126/science.aab0476) and laboratory experiments to simulate hydraulic fracturing described by Goodfellow et al. (2015, https://doi.org/10.1002/2015GL063093). In both of these studies, the relevant moment release for comparison with the fluid injection was aseismic and consistent with the scaling that applies to the much larger volumes associated with injection‐induced earthquakes with magnitudes extending up to 5.8. Neither the microearthquakes, at the site in France, nor the acoustic emission in the laboratory samples contributed significantly to the deformation due to fluid injection.
From Slab Coupling to Slab Pull: Stress Segmentation in the Subducting Nazca Plate
Authors: Bloch Wasja , Schurr Bernd , Kummerow Jörn , Salazar Pablo , Shapiro Serge A. 
Published: May 2018

AbstractWe investigate the stress field that the Nazca slab experiences during subduction beneath the South American plate by determining the focal mechanisms of moderate subduction‐related earthquakes continuously from 20‐ to 120‐km depth and inverting for the stress directions of four slab regions. Our results show the sharp termination of the coupling zone, which is characterized by compressional stresses, uplift of the overlying mountain range, and likely the activation of preexisting slab structures. Beyond and below this zone slab pull is the dominant stress. Near the slab surface, we also find signatures of the activation of inherited structures. Deeper in the slab, fault orientations are more likely controlled by the stress field alone. Along the subduction pathway, we find indication for an increase of the absolute slab pull component of the stress field that correlates with an increase in event rate and the occurrence possibility of M > 7 intermediate depth earthquakes.