bluuebunny/crossref_metadata_2025 huggingface dataset:
The Classification and Explanation of Depression
Authors: Clack Samuel , Ward Tony
Published: February 2019

In the field of psychopathology there is still a lack of consensus on how mental disorders, such as depression, should be classified and explained. Many of our current classifications suffer from disorder heterogeneity and are conceptually vague. While some researchers have argued that mental disorders are better explained from a biological perspective, others have made the case for pluralistic and integrative explanations. Using depression as an extended example, we explore the challenges in classifying and explaining psychopathology. We begin by evaluating the current approaches to classification, including frameworks for what we consider a mental disorder. This is followed by a detailed summary of current explanatory perspectives in psychiatry. The relationship between classification and explanation presents unique theoretical challenges in understanding mental disorders. We suggest that by adjusting our focus from understanding syndromes to clinical phenomena we can advance our understanding of mental disorders.
An Uncontrolled Open Trial of a Brief Behavioural Activation Treatment for Depression in Patients with Chronic Spontaneous Urticaria
Authors: Tull Matthew T. , Rosenblatt Claire B. , Berghoff Christopher R. , Dixon Laura J. , Ciarloni Evan , Montgomery Denise D. , Wheeless Linnie E. , Marshall Gailen D.
Published: February 2019

Chronic spontaneous urticaria (CSU) has been associated with depression and can have an impact on quality of life. Therefore, researchers have suggested the potential utility of psychological interventions for targeting depression among CSU patients. Psychological interventions that may hold the most promise are those that are brief and easily transportable, such as brief behavioural activation treatment for depression. We report results of a preliminary investigation of an uncontrolled open trial of a one-session behavioural activation treatment for depression designed for patients with CSU (BATD-CSU) at a university-based allergy and immunology clinic. Participants were 11 females with chronic, poorly controlled urticaria and symptoms of depression. Following the completion of pretreatment questionnaires, participants were administered BATD-CSU primarily by non-mental health professionals trained and supervised in its delivery. One month post-BATD-CSU, participants completed follow-up questionnaires. Participants exhibited significant reductions in depression severity, avoidance/rumination, and work/school impairment. BATD-CSU was also associated with improvements in urticaria control one month post-treatment. Moreover, five of nine patients reported reliable and clinically significant improvement on at least one outcome. Results demonstrate that BATD-CSU may have benefits for CSU patients even when consisting of one session and delivered by professionals with limited background in psychological interventions, thus speaking to its feasibility and transportability.
An Overview of the Health Services Provision in the 2017 Kermanshah Earthquake
Authors: Ghanjal Ali , Bahadori Mohammadkarim , Ravangard Ramin
Published: February 2019

Objective

Iran, in terms of disasters, is among the top 10 countries in the world. Therefore, timely coordination and provision of rescue, transport, and treatment services after disasters are of particular importance. This study aimed to investigate and provide a short report on the provision of rescue, transport, and treatment services after the 2017 earthquake in Kermanshah.

Methods

This was a review and a descriptive study conducted using the analysis of documents and news published on valid Iranian sites and reports of some service providers in 2017 after the earthquake in Kermanshah.

Results

The most important strengths of post-earthquake services were the military force’s cooperation, people’s support, sending the popular aid and donations to earthquake areas, and the tremendous national support and religious sympathy among the people. Sending the popular aid and donations was such that they resulted in the blockage of communication routes, heavy traffic on the roads, and disrupted the relief and rescue efforts process. However, the most important weaknesses in the provision of services after this earthquake were the lack of preparedness of the government systems and the lack of orderly management for appropriate assistance and relief and, therefore, there was an inappropriate distribution of popular aid and donations among the earthquake victims.

Conclusion

Proper coordination and service delivery after unexpected events in Iran have a considerable distance to reaching the desired point. Unfortunately, similar problems had also occurred in other earthquakes such as the Bam and Rudbar earthquakes. The repetition of these problems indicates the authorities’ lack of readiness and commitment to troubleshoot weaknesses in their emergency response plan. Therefore, it is necessary for government officials to have more preparedness in all related affairs and aspects. (Disaster Med Public Health Preparedness. 2019;13:691–694)
BELIEFS OVER AVOWALS: SETTING UP THE DISCOURSE ON SELF-KNOWLEDGE
Authors: Schwengerer Lukas
Published: February 2019

Wright (1998) and Bar-On (2004) put pressure on the idea that self-knowledge as an explanandum should be identified with privileged belief formation. They argue that setting up the discourse on the level of belief and belief formation rules out promising approaches to explain self-knowledge. Hence, they propose that we should characterize self-knowledge on the level of linguistic practice instead. I argue against them that self-knowledge cannot be fully characterized by features of our linguistic practice. I propose that in some circumstances – disagreements about one's mental states – self-knowledge plays a role, but this role cannot be described in virtue of features of our linguistic practice. I consider three objections to the argument and conclude that we should not conceive self-knowledge solely in terms of linguistic practice.
Rates in almost sure invariance principle for slowly mixing dynamical systems
Authors: CUNY C. , DEDECKER J. , KOREPANOV A. , MERLEVÈDE F.
Published: February 2019

We prove the one-dimensional almost sure invariance principle with essentially optimal rates for slowly (polynomially) mixing deterministic dynamical systems, such as Pomeau–Manneville intermittent maps, with Hölder continuous observables. Our rates have form $o(n^{\unicode[STIX]{x1D6FE}}L(n))$, where $L(n)$ is a slowly varying function and $\unicode[STIX]{x1D6FE}$ is determined by the speed of mixing. We strongly improve previous results where the best available rates did not exceed $O(n^{1/4})$. To break the $O(n^{1/4})$ barrier, we represent the dynamics as a Young-tower-like Markov chain and adapt the methods of Berkes–Liu–Wu and Cuny–Dedecker–Merlevède on the Komlós–Major–Tusnády approximation for dependent processes.
Deviations in the Franks–Misiurewicz conjecture
Authors: PASSEGGI ALEJANDRO , SAMBARINO MARTÍN
Published: February 2019

We show that if there exists a counter example for the rational case of the Franks–Misiurewicz conjecture, then it must exhibit unbounded deviations in the complementary direction of its rotation set.
Revisiting the linear stability analysis and absolute–convective transition of two fluid core annular flow
Authors: Salin D. , Talon L.
Published: February 2019

Numerous experimental, numerical and theoretical studies have shown that core annular flows can be unstable. This instability can be convective or absolute in different situations: miscible fluids with matched density but different viscosities, creeping flow of two immiscible fluids or buoyant flow along a fibre. The analysis of the linear stability of the flow equation of two fluids injected in a co-current and concentric manner into a cylindrical tube leads to a rather complex eigenvalue problem. Until now, all analytical solution to this problem has involved strong assumptions (e.g. lack of inertia) or approximations (e.g. developments at long or short wavelengths) even for axisymmetric disturbances. However, in this latter case, following C. Pekeris, who obtained, almost seventy years ago, an elegant explicit solution for the dispersion relationship of the flow of a single fluid, we derive an explicit solution for the more general case of two immiscible fluids of different viscosity, density and inertia separated by a straight interface. This formulation is well adapted to commercial software. First, we review the creeping flow limit (zero Reynolds number) of two immiscible fluids as it is used in microfluidics. Secondly, we consider the case of two fluids of different viscosities but of the same density in the absence of surface tension and also without diffusion (i.e. miscible fluids with infinite Schmidt number). In both cases, we study the transition from convective to absolute instability according to the different control parameters.
Phylogenetic analysis of the genusRetrotapesdel Río, 1997 (Bivalvia, Veneridae) and systematic analysis of its taxa from Chile
Authors: Alvarez Maximiliano Jorge
Published: February 2019

Since the genusRetrotapeswas erected, some authors have favored or opposed its validity, or argued about the assignment of the extant speciesR.exalbidusandR.lenticularistoRetrotapes. Some authors synonymizedRetrotapeswith the Miocene genusFrigichione, and others with the extant genusEurhomaleato which most of the species that belong toRetrotapeswere previously assigned. In the present contribution, a phylogenetic analysis of the genus is performed to test these controversies. In addition, a systematic revision of the Chilean species of the genus is performed to complete the analysis ofRetrotapestaxa from Patagonia and Antarctica started by previous authors. This study demonstrates thatRetrotapesis a monophyletic genus, which is not closely related toFrigichioneorEurhomalea. Instead,Retrotapesis closely related to some Austral taxa from Kerguelen Island (Paleomarcia), New Zealand (Atamarcia), and Australia (Katelysia), a relationship previously unknown. Besides, the extant speciesR.lenticularisandR.exalbidusbelong toRetrotapesand were recovered as part of a clade closely related to the type species of the genus,R.ninfasiensis(Miocene, Patagonia).Retrotapesis reported in Chile beginning in the late Eocene, where it was represented byR.difficilisn. comb., which is a taxon that resembles some Eocene species of the same genus from Antarctica. In the late Oligocene–early Miocene, it was represented byR.navidadisand later in the Pliocene by three species: the fossilR.fuenzalidaeand the two extant ones.
Late Pleistocene to present lake-level fluctuations at Pyramid and Winnemucca lakes, Nevada, USA
Authors: Adams Kenneth D. , Rhodes Edward J.
Published: February 2019

A new lake-level curve for Pyramid and Winnemucca lakes, Nevada, is presented that indicates that after the ~15,500 cal yr BP Lake Lahontan high stand (1338 m), lake level fell to an elevation below 1200 m, before rising to 1230 m at the 12,000 cal yr BP Younger Dryas high stand. Lake level then fell to 1155 m by ~10,500 cal yr BP followed by a rise to 1200 m around 8000 cal yr BP. During the mid-Holocene, levels were relatively low (~1155 m) before rising to moderate levels (1190–1195 m) during the Neopluvial period (~4800–3400 cal yr BP). Lake level again plunged to about 1155 m during the late Holocene dry period (~2800–1900 cal yr BP) before rising to about 1190 m by ~1200 cal yr BP. Levels have since fluctuated within the elevation range of about 1170–1182 m except for the last 100 yr of managed river discharge when they dropped to as low as 1153 m. Late Holocene lake-level changes correspond to volume changes between 25 and 55 km3 and surface area changes between 450 and 900 km2. These lake state changes probably encompass the hydrologic variability possible under current climate boundary conditions.
The symbiotic complex of Dendroctonus simplex: implications in the beetle attack and its life cycle
Authors: Durand A.-A. , Constant P. , Déziel E. , Guertin C.
Published: February 2019

The eastern larch beetle (Dendroctonus simplex Le Conte) is recognized as a serious destructive forest pest in the upper part of North America. Under epidemic conditions, this beetle can attack healthy trees, causing severe damages to larch stands. Dendroctonus species are considered as holobionts, as they engage in multipartite interactions with microorganisms, such as bacteria, filamentous fungi, and yeasts, which are implicated in physiological processes of the insect, such as nutrition. They also play a key role in the beetle's attack, as they are responsible for the detoxification of the subcortical environment and weaken the tree's defense mechanisms. The eastern larch beetle is associated with bacteria and fungi, but their implication in the success of the beetle remains unknown. Here, we investigated the bacterial and fungal microbiota of this beetle pest throughout its ontogeny (pioneer adults, larvae and pupae) by high-throughput sequencing. A successional microbial assemblage was identified throughout the beetle developmental stages, reflecting the beetle's requirements. These results indicate that a symbiotic association between the eastern larch beetle and some of these microorganisms takes place and that this D. simplex symbiotic complex is helping the insect to colonize its host tree and survive the conditions encountered.
Net nutrition on the late 19thand early 20thcentury American Great Plains: a robust biological response to the challenges to the Turner Hypothesis
Authors: Carson Scott Alan
Published: February 2019

In 1893, Frederick Jackson Turner proposed that America’s Western frontier was an economic ‘safety-valve’ – a place where settlers could migrate when conditions in eastern states and Europe crystallized against their upward economic mobility. However, recent studies suggest the Western frontier’s material conditions may not have been as advantageous as Jackson proposed because settlers lacked the knowledge and human capital to succeed on the Plains and Far Western frontier. Using stature, BMI and weight from five late 19thand early 20thcentury prisons, this study uses 61,276 observations for men between ages 15 and 79 to illustrate that current and cumulative net nutrition on the Great Plains did not deteriorate during the late 19thand early 20thcenturies, indicating that recent challenges to the Turner Hypothesis are not well supported by net nutrition studies.
Onset of magnetic reconnection in a collisionless, high- plasma
Authors: Alt Andrew , Kunz Matthew W.
Published: February 2019

In a magnetized, collisionless plasma, the magnetic moment of the constituent particles is an adiabatic invariant. An increase in the magnetic-field strength in such a plasma thus leads to an increase in the thermal pressure perpendicular to the field lines. Above a$\unicode[STIX]{x1D6FD}$-dependent threshold (where$\unicode[STIX]{x1D6FD}$is the ratio of thermal to magnetic pressure), this pressure anisotropy drives the mirror instability, producing strong distortions in the field lines on ion-Larmor scales. The impact of this instability on magnetic reconnection is investigated using a simple analytical model for the formation of a current sheet (CS) and the associated production of pressure anisotropy. The difficulty in maintaining an isotropic, Maxwellian particle distribution during the formation and subsequent thinning of a CS in a collisionless plasma, coupled with the low threshold for the mirror instability in a high-$\unicode[STIX]{x1D6FD}$plasma, imply that the geometry of reconnecting magnetic fields can differ radically from the standard Harris-sheet profile often used in simulations of collisionless reconnection. As a result, depending on the rate of CS formation and the initial CS thickness, tearing modes whose growth rates and wavenumbers are boosted by this difference may disrupt the mirror-infested CS before standard tearing modes can develop. A quantitative theory is developed to illustrate this process, which may find application in the tearing-mediated disruption of kinetic magnetorotational ‘channel’ modes.
Wave modes in a cold pair plasma: the complete phase and group diagram point of view
Authors: Keppens Rony , Goedbloed Hans
Published: February 2019

We present a complete analysis of all wave modes in a cold pair plasma, significantly extending standard textbook treatments. Instead of identifying the maximal number of two propagating waves at fixed frequency $\unicode[STIX]{x1D714}$, we introduce a unique labelling of all 5 mode pairs described by the general dispersion relation $\unicode[STIX]{x1D714}(k)$, starting from their natural ordering at small wavenumber $k$. There, the 5 pairs start off as Alfvén (A), fast magnetosonic (F), modified electrostatic (M) and electromagnetic O and X branches, and each $\unicode[STIX]{x1D714}(k)$ branch smoothly connects to large wavenumber resonances or limits. For cold pair plasmas, these 5 branches show avoided crossings, which become true crossings at exactly parallel or perpendicular orientation. Only for those orientations, we find a changed connectivity between small and large wavenumber behaviour. Analysing phase and group diagrams for all 5 wave modes, distinctly different from the Clemmow–Mullaly–Allis representation, reveals the true anisotropy of the A, M and O branches.
Updated distribution and first description of Scyllarus subarctus (Crustacea: Scyllaridae) decapodid stage
Authors: Genis-Armero Rebeca , Landeira José , Capaccioni-Azzati Romana , Palero Ferran
Published: February 2019

The phyllosoma larva of spiny and slipper lobsters (Palinuridae and Scyllaridae respectively) can disperse during several months before metamorphosing into a decapodid stage, which is the key phase for a successful settlement. The largest Scyllarus decapodid known to date was recently collected near the Canary Islands and identified by DNA analysis as Scyllarus subarctus. This species had never been previously reported from the area, and the decapodid stage is described here for the first time. The examination of further museum specimens has now significantly expanded the current distribution of S. subarctus, including much of the NW African coast, St Helena and Canary Islands. These results highlight the importance of combining molecular analysis of recently collected specimens with historical collections.
The Ebola virus disease outbreak in Tonkolili district, Sierra Leone: a retrospective analysis of the Viral Haemorrhagic Fever surveillance system, July 2014–June 2015
Authors: Miglietta Alessandro , Solimini Angelo , Djeunang Dongho Ghyslaine Bruna , Montesano Carla , Rezza Giovanni , Vullo Vincenzo , Colizzi Vittorio , Russo Gianluca
Published: February 2019

In Sierra Leone, the Ebola virus disease (EVD) outbreak occurred with substantial differences between districts with someone even not affected. To monitor the epidemic, a community event-based surveillance system was set up, collecting data into the Viral Haemorrhagic Fever (VHF) database. We analysed the VHF database of Tonkolili district to describe the epidemiology of the EVD outbreak during July 2014–June 2015 (data availability). Multivariable analysis was used to identify risk factors for EVD, fatal EVD and barriers to healthcare access, by comparing EVD-positive vs. EVD-negative cases. Key-performance indicators for EVD response were also measured. Overall, 454 EVD-positive cases were reported. At multivariable analysis, the odds of EVD was higher among those reporting contacts with an EVD-positive/suspected case (odds ratio (OR) 2.47; 95% confidence interval (CI) 2.44–2.50; P < 0.01) and those attending funeral (OR 1.02; 95% CI 1.01–1.04; P < 0.01). EVD cases from Kunike chiefdom had a lower odds of death (OR 0.22; 95% CI 0.08–0.44; P < 0.01) and were also more likely to be hospitalised (OR 2.34; 95% CI 1.23–4.57; P < 0.05). Only 25.1% of alerts were generated within 1 day from symptom onset. EVD preparedness and response plans for Tonkolili should include social-mobilisation activities targeting Ebola/knowledge-attitudes-practice during funeral attendance, to avoid contact with suspected cases and to increase awareness on EVD symptoms, in order to reduce delays between symptom onset to alert generation and consequently improve the outbreak-response promptness.
Identifying best practices in interstage care: using a positive deviance approach within the National Pediatric Cardiology Quality Improvement Collaborative
Authors: Bates Katherine E. , Yu Sunkyung , Mangeot Colleen , Shea Judy A. , Brown David W. , Uzark Karen
Published: February 2019

Introduction

To identify interstage best practices associated with lower mortality, we studied National Pediatric Cardiology Quality Improvement Collaborative centres registry using a positive deviance approach.

Methods

Positive deviant and control centre team members were interviewed to identify potential interstage best practices. Subsequently, all collaborative centres were surveyed on the use of these practices to test their associations with centre mortality. Questionnaires were scored using Likert scales; the overall score was linearly transformed to a 0–100-point scale with higher scores indicating increased use of practices. Mortality was based on patients enrolled after a centre’s first year in the collaborative. Centre mortality rates were divided into tertiles. Survey scores for the low mortality tertile were compared with the other tertiles.

Results

For this study, seven positive deviant and four control teams were interviewed. A total of 20 potential best practices were identified, including team composition, improvement practices, and parent involvement. Questionnaires were completed by 36/43 eligible centres, providing 1504 patients for analysis. Average survey score was 50.2 (SD 13.4). Average mortality was 6.1% (SD 4.1). There was no correlation between survey scores and mortality (r=0.14, p=0.41). The one practice associated with the low mortality tertile was frequency of discussion of interstage results: 58.3% of low mortality teams discussed results at least monthly versus 8.4% of the middle and high tertile centres (p=0.02).

Conclusions

Low-mortality centres more frequently discuss interstage results than high-mortality centres. Heightened awareness of outcomes may influence practice; however, further study is needed to understand the variation in outcomes across centres.
Do I Have to Take the GRE? Standardized Testing in MPA Admissions
Authors: Cooper Christopher A. , Knotts H. Gibbs
Published: February 2019

Graduate-program decision makers face a similar challenge: how to design an admissions process that screens out applicants who are unlikely to succeed but does not provide too high an entry barrier for students who can be successful. This study catalogs the use of standardized testing in Master of Public Administration admissions and finds that less than one third of programs require standardized tests for all applicants. Moreover, program prestige, program diversity, and program size do not affect the likelihood that a program requires the Graduate Record Examination. This study also reviews the various standards that universities use to provide test waivers and also discusses other common application materials. The results should be of interest to undergraduate academic advisers and graduate-program directors as well as scholars and practitioners of higher-education administration more generally.
Sociodemographic predictors of exclusive breast-feeding among low-income women attending a Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) programme
Authors: Rethy Janine A , Gallo Sina , Doig Amara Channell , Brady Jennifer , Goodfriend David
Published: February 2019

Objective

To describe infant feeding practices and predictors of exclusive breast-feeding among women attending a local Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) programme.

Design

Cross-sectional survey. Outcomes included reported infant feeding practices at 3 and 6 months, timing and reasons for introduction of formula. Descriptive statistics, χ
2 tests and logistic regression were used describe the sample and explore relationships between variables.

Setting

Loudoun County, VA, USA.

Subjects

A sample of 190 predominantly Hispanic women attending local WIC clinics.

Results

Overall, 84 % of women reported ever breast-feeding and 61 % of infants received formula in the first few days of life. Mothers who reported on infant feeding practices were less likely to exclusively breast-feed (34 v. 45 %) and more likely to provide mixed feeding (50 v. 20 %) at 3 months compared with 6 months, respectively. Significant (P<0·05) predictors of exclusive breast-feeding at 3 months included setting an exclusive breast-feeding goal and completing some high school (compared with completing high school or more). Only education remained a significant predictor of exclusive breast-feeding at 6 months.

Conclusions

A high proportion of women reported giving formula in the first few days of life and many changed from mixed to exclusive breast-feeding or formula by 6 months, suggesting possibly modifiable factors. Further investigation can help drive direct service- as well as policy and systems-based interventions to improve exclusive breast-feeding.
DE MORGAN INTERPRETATION OF THE LAMBEK–GRISHIN CALCULUS
Authors: KAMINSKI MICHAEL , FRANCEZ NISSIM
Published: February 2019

We present an embedding of the Lambek–Grishin calculus into an extension of the nonassociative Lambek calculus with negation. The embedding is based on the De Morgan interpretation of the dual Grishin connectives.
Compact planar ultra-wideband antenna with dual notched band for WiMAX and WLAN
Authors: Siddique A. K. M. Ariful H. , Azim Rezaul , Islam Mohammad T.
Published: February 2019

A compact planar ultra-wideband (UWB) antenna with WiMAX and WLAN notched band is presented in this paper. The presented antenna consists of a rectangular patch and slotted partial ground plane and fed by a microstrip feed line. The volumetric size of the antenna is 30 mm × 22 mm × 1.6 mm. Method of moment-based simulation technology is used to simulate and analyze the characteristics of the antenna. To generate two notch bands at WiMAX and WLAN, a pair of parasitic resonator is placed beneath the radiating patch. The presented antenna achieves an operating band (VSWR ≤2) ranging from 2.98 to 12 GHz with an average gain of 3.95 dBi along with considerable efficiency and symmetric radiation patterns. Moreover, the antenna exhibits two notch bands at 3.5 and 5.45 GHz and is able to avoid possible interference with pre-existing narrow band services. The proposed antenna is low cost and low profile and is modeled to be used as a transceiver in UWB communication applications.
Can YKL-40 be an Inflammatory Biomarker in Vitamin D Deficiency?
Authors: Can Ummugulsum , Uysal Saliha , Ruveyda Ugur Ayse , Toker Aysun , Aslan Uysaler , Taha Hidayetoglu Bahauddin
Published: February 2019

Abstract. Vitamin D deficiency is associated with several non-homeostatic conditions and/or diseases like inflammation, atherosclerosis, cardiovascular disease and mortality. YKL-40 is a glycoprotein, secreted by macrophages, neutrophils and different cell types and it is also associated with inflammation and pathological tissue remodeling. In this study, we aimed to evaluate relationship between the proinflammatory biomarkers YKL-40 and hs-CRP levels and vitamin D deficiency. Our study group includes 45 subjects with vitamin D deficiency (Group 1) (20 M, 25 F; mean age 37.72 ± 7.70 years) and 40 age and sex-matched healthy subjects with normal serum levels of vitamin D (Group 2) (19 M, 21 F; mean age 39.26 ± 7.41 years). Plasma 25 (OH) vitamin D levels were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Plasma YKL-40 analysis was performed by ELISA. Serum hs-CRP levels were measured by nephelometric method. Plasma vitamin D levels below 20 ng/mL were accepted as vitamin D deficiency. Although we could not find any significant differences by means of serum hs-CRP levels between Group 1 and Group 2 (2.21 (0.27–11.70); 1.79 (0.16–9.85) mg/L, p = 0.247), plasma YKL-40 levels were significantly higher in group 1 than group2 (70.47 (17.84–198.50); 47.14 (4.80–135.48) ng/mL, p = 0.047). In literature, vitamin D deficiency is associated with inflammation. In our study, we found similar hs-CRP levels between groups and higher YKL-40 levels in group 1. Vitamin D deficiency may be related to high YKL-40 levels in terms of causing chronic inflammation.
Large Contribution of Pteropods to Shallow CaCO3 Export
Authors: Buitenhuis Erik T. , Le Quéré Corinne , Bednaršek Nina , Schiebel Ralf
Published: February 2019

The literature on the relative contributions of pelagic calcifying taxa to the global ocean export of CaCO3 is divided. Studies based on deep sediment trap data tend to argue that either foraminifers or coccolithophores, both calcite producers, dominate export. However, the compilations of biomass observations for pteropods, coccolithophores, and foraminifers instead show that pteropods dominate the global ocean calcifier biomass and therefore likely also carbonate export. Here we present a new global ocean biogeochemical model that explicitly represents these three groups of pelagic calcifiers. We synthesize databases of the physiology of the three groups to parameterize the model and then tune the unconstrained parameters to reproduce the observations of calcifier biomass and CaCO3 export. The model can reproduce both these observational databases; however, substantial dissolution of aragonite above the aragonite saturation horizon is required to do so. We estimate a contribution of pteropods to shallow (100 m) export of CaCO3 of at least 33% and to pelagic calcification of up to 89%. The high production‐high dissolution configuration that shows closest agreement with all the observations has a CaCO3 production of 4.7 Pg C/year but CaCO3 export at 100 m of only 0.6 Pg C/year.
Impact of Deadly Dust Storms (May 2018) on Air Quality, Meteorological, and Atmospheric Parameters Over the Northern Parts of India
Authors: Sarkar Sudipta , Chauhan Akshansha , Kumar Rajesh , Singh Ramesh P.
Published: February 2019

The northern part of India, adjoining the Himalaya, is considered as one of the global hot spots of pollution because of various natural and anthropogenic factors. Throughout the year, the region is affected by pollution from various sources like dust, biomass burning, industrial and vehicular pollution, and myriad other anthropogenic emissions. These sources affect the air quality and health of millions of people who live in the Indo‐Gangetic Plains. The dust storms that occur during the premonsoon months of March–June every year are one of the principal sources of pollution and originate from the source region of Arabian Peninsula and the Thar desert located in north‐western India. In the year 2018, month of May, three back‐to‐back major dust storms occurred that caused massive damage, loss of human lives, and loss to property and had an impact on air quality and human health. In this paper, we combine observations from ground stations, satellites, and radiosonde networks to assess the impact of dust events in the month of May 2018, on meteorological parameters, aerosol properties, and air quality. We observed widespread changes associated with aerosol loadings, humidity, and vertical advection patterns with displacements of major trace and greenhouse gasses. We also notice drastic changes in suspended particulate matter concentrations, all of which can have significant ramifications in terms of human health and changes in weather pattern.
Deep Learning Models Augment Analyst Decisions for Event Discrimination
Authors: Linville Lisa , Pankow Kristine , Draelos Timothy
Published: February 2019

Long‐term seismic monitoring networks are well positioned to leverage advances in machine learning because of the abundance of labeled training data that curated event catalogs provide. We explore the use of convolutional and recurrent neural networks to accomplish discrimination of explosive and tectonic sources for local distances. Using a 5‐year event catalog generated by the University of Utah Seismograph Stations, we train models to produce automated event labels using 90‐s event spectrograms from three‐component and single‐channel sensors. Both network architectures are able to replicate analyst labels above 98%. Most commonly, model error is the result of label error (70% of cases). Accounting for mislabeled events (~1% of the catalog) model accuracy for both models increases to above 99%. Classification accuracy remains above 98% for shallow tectonic events, indicating that spectral characteristics controlled by event depth do not play a dominant role in event discrimination.
Rough Subducting Seafloor Reduces Interseismic Coupling and Mega‐Earthquake Occurrence: Insights From Analogue Models
Authors: van Rijsingen Elenora , Funiciello Francesca , Corbi Fabio , Lallemand Serge
Published: February 2019

The roughness of the subduction interface is thought to influence seismogenic behavior in subduction zones, but a detailed understanding of how such roughness affects the state of stress along the subduction megathrust is still debated. Here, we use seismotectonic analogue models to investigate the effect of subduction interface roughness on seismicity in subduction zones. We compared analogue earthquake source parameters and slip distributions for two roughness endmembers. Models characterized by a very rough interface have lower integrated fault strength and lower interseismic coupling than models with a smooth interface. Overall, ruptures in the rough models have smaller rupture area, duration, and mean displacement. Individual slip distributions indicate a segmentation of the subduction interface by the rough geometry. We propose that flexure of the overriding plate is one of the mechanisms that contribute to a heterogeneous stress distribution, responsible for the observed seismic behavior.
InSAR Meteorology: High‐Resolution Geodetic Data Can Increase Atmospheric Predictability
Authors: Miranda P. M. A. , Mateus P. , Nico G. , Catalão J. , Tomé R. , Nogueira M.
Published: February 2019

The present study assesses the added value of high‐resolution maps of precipitable water vapor, computed from synthetic aperture radar interferograms , in short‐range atmospheric predictability. A large set of images, in different weather conditions, produced by Sentinel‐1A in a very well monitored region near the Appalachian Mountains, are assimilated by the Weather Research and Forecast (WRF) model. Results covering more than 2 years of operation indicate a consistent improvement of the water vapor predictability up to a range comparable with the transit time of the air mass in the synthetic aperture radar interferograms footprint, an overall improvement in the forecast of different precipitation events, and better representation of the spatial distribution of precipitation. This result highlights the significant potential for increasing short‐range atmospheric predictability from improved high‐resolution precipitable water vapor initial data, which can be obtained from new high‐resolution all‐weather microwave sensors.
Contrasting Air Mass Advection Explains Significant Differences in Boundary Layer Depth Seasonal Cycles Under Onshore Versus Offshore Flows
Authors: Pal Sandip , Lee Temple R.
Published: February 2019

The complexities in the atmospheric boundary layer depth (BLD) features over coastal regions pose challenges for meteorological forecasts, air quality, greenhouse gas mixing and transport, and wind energy production. Here, for the first time, we investigated afternoon BLD variability over 18 coastal sites in the contiguous United States located along the Gulf of Mexico, Atlantic Ocean, and Pacific Ocean using 25 years of rawinsonde launches. Due to influence of shallow marine layer air via onshore flow, substantially large BLD contrasts (∆BLD, BLD under offshore minus onshore) were found. ∆BLDs over the sites varied both seasonally and spatially among the coastal regions and within a region. For the sites along the Gulf of Mexico and Atlantic Ocean, ∆BLDs were found to be higher in spring and summer (500–1,500 m) than in winter and fall (100–450 m). Results underscore the importance of advection on BLD footprints and provide observational constraints for model evaluation.
Alfvén Wave Generation by a Compact Source Moving on the Magnetopause: Asymptotic Solution
Authors: Klimushkin Dmitri Yu. , Mager Pavel N. , Zong Qiugang , Glassmeier Karl‐Heinz
Published: February 2019

The spatiotemporal structure of Alfvén waves excited by a moving pressure pulse on the magnetopause is analytically explored. These waves are supposed to be responsible for field‐aligned currents generating traveling convection vortices in the ionosphere. It is found that a moving source generates two wave modes, a primary and a secondary mode, having different azimuthal wave vectors and frequencies. Both modes represent surface waves with amplitudes exponentially decreasing from the magnetopause. At a given azimuthal location, they also decrease with time as the source passes away. For the primary mode, the wave frequency equals the Alfvén resonant frequency on the surface of the source, while for the secondary mode the frequency equals the local resonant frequency. The dependence of the frequency of the secondary mode on the radial coordinate results in phase mixing, which leads to a change of the wave polarization from mixed into toroidal polarization. For both primary and secondary modes, the azimuthal component of the wave vector equals the corresponding wave frequency divided by the speed of the source. Superposition of the primary and secondary modes produces plasma vortices behind the source.
Localized Structures and Turbulent Spectra in the Magnetopause
Authors: Pathak Neha , Uma R. , Sharma R. P.
Published: February 2019

Kinetic Alfvén wave (KAW) and whistler wave play a key role in the framework of turbulence and reconnection. There are lot of observations of these wave in the magnetopause region. The present paper deals with the nonlinear evolution of KAW and a weak whistler wave through the preexisting magnetic reconnection site. For this study the dynamical evolution equations are derived by taking into account the ponderomotive force driven density modification and magnetic field fluctuations due to shear field modeled by the Harris sheet. Furthermore, these equations have been solved numerically as well as semianalytically. For numerical integrations we have used the pseudospectral method and finite difference method and for semianalytically Runge Kutta method. Simulated results have shown the evolution of coherent structures or current sheets, which are capable to energy transfer efficiently. These structures have scale size around ion gyroradius as well as electron inertial length as calculated analytically. At a later time the chaotic structures arise in this reconnection site. This gives the signature of turbulence generation. Therefore, the magnetic power spectrum with scaling is also presented in this manuscript and their relevance with the observed spectrum (calculated from the Cluster data (Chaston, 2008, https://doi.org/10.1029/2008GL033601)) is also pointed out.
Simultaneous Trapping of Electromagnetic Ion Cyclotron and Magnetosonic Waves by Background Plasmas
Authors: Yuan Zhigang , Yu Xiongdong , Ouyang Zhihai , Yao Fei , Huang Shiyong , Funsten H. O.
Published: February 2019

Electromagnetic ion cyclotron waves and fast magnetosonic waves are found to be simultaneously modulated by background plasma density: both kinds of waves were observed in high plasma density regions but vanished in low‐density regions. Theoretical analysis based on Snell's law and linear growth theory has been utilized to investigate the physical mechanisms driving such modulation. It is suggested that the modulation of fast magnetosonic waves might be due to trapping by plasma density structures, which results from the conservation of the parameter Q during their propagation. Here Q = nrsinψ, with n as the refractive index, r as the radial distance, and ψ as the wave azimuthal angle. As for electromagnetic ion cyclotron waves, the modulation might be owed to the ion composition difference between different plasma density regions. Our results indicate the alternative mechanism for the simultaneous appearance of electromagnetic ion cyclotron waves and fast magnetosonic waves (rather than wave excitations of both two wave emissions), which might take combined effects on the evolution of radiation belt electrons.
Contribution of ULF Wave Activity to the Global Recovery of the Outer Radiation Belt During the Passage of a High‐Speed Solar Wind Stream Observed in September 2014
Authors: Da Silva L. A. , Sibeck D. , Alves L. R. , Souza V. M. , Jauer P. R. , Claudepierre S. G. , Marchezi J. P. , Agapitov O. , Medeiros C. , Vieira L. E. A. , Wang C. , Jiankui S. , Liu Z. , Gonzalez W. , Dal Lago A. , Rockenbach M. , Padua M. B. , Alves M. V. , Barbosa M. V. G. , Fok M.‐C. , Baker D. , Kletzing C. , Kanekal S. G. , Georgiou M.
Published: February 2019

Energy coupling between the solar wind and the Earth's magnetosphere can affect the electron population in the outer radiation belt. However, the precise role of different internal and external mechanisms that leads to changes of the relativistic electron population is not entirely known. This paper describes how ultralow frequency (ULF) wave activity during the passage of Alfvénic solar wind streams contributes to the global recovery of the relativistic electron population in the outer radiation belt. To investigate the contribution of the ULF waves, we searched the Van Allen Probes data for a period in which we can clearly distinguish the enhancement of electron fluxes from the background. We found that the global recovery that started on 22 September 2014, which coincides with the corotating interaction region preceding a high‐speed stream and the occurrence of persistent substorm activity, provides an excellent scenario to explore the contribution of ULF waves. To support our analyses, we employed ground‐ and space‐based observational data and global magnetohydrodynamic simulations and calculated the ULF wave radial diffusion coefficients employing an empirical model. Observations show a gradual increase of electron fluxes in the outer radiation belt and a concomitant enhancement of ULF activity that spreads from higher to lower L‐shells. Magnetohydrodynamic simulation results agree with observed ULF wave activity in the magnetotail, which leads to both fast and Alfvén modes in the magnetospheric nightside sector. The observations agree with the empirical model and are confirmed by phase space density calculations for this global recovery period.
Dynamics of Megaelectron Volt Electrons Observed in the Inner Belt by PROBA‐V/EPT
Authors: Pierrard V. , Lopez Rosson G. , Botek E.
Published: February 2019

Using the observations of the EPT (Energetic Particle Telescope) onboard the satellite PROBA‐V, we study the dynamics of inner and outer belt electrons from 500 keV to 8 MeV during quiet periods and geomagnetic storms. This high time‐resolution (2‐s) spectrometer operating at the altitude of 820 km on a low polar orbit is providing continuously valuable electrons fluxes for already 5 years. We emphasize especially that some megaeleactron volt electrons are observed in low quantities in the inner belt, even during periods when they are not observed by Van Allen Probes. We show that they are not due to proton contamination but to clear injections of particles from the outer belt during strong geomagnetic storms of March and June 2015, and September 2017. Electrons with lower energy are injected also during less strong storms and the L shell of the electron flux peak in the outer belt shifts inward with a high dependence on the electron energy. With the new high‐resolution EPT instrument, we can study the dynamics of relativistic electrons, including megaelectron volt electrons in the inner radiation belt, revealing how and when such electrons are injected into the inner belt and how long they reside there before being scattered into the Earth's atmosphere or lost by other mechanisms.
Multi‐Instrumental Observation of Storm‐Induced Ionospheric Plasma Bubbles at Equatorial and Middle Latitudes
Authors: Cherniak Iurii , Zakharenkova Irina , Sokolovsky Sergey
Published: February 2019

June solstice is considered as a period with the lowest probability to observe typical equatorial plasma bubbles (EPBs) in the postsunset period. The severe geomagnetic storm on 22–23 June 2015 has drastically changed the situation. Penetrating electric fields associated with a long‐lasting southward IMF support favorable conditions for postsunset EPBs generation in the dusk equatorial ionosphere for several hours. As a result, the storm‐induced EPBs were progressively developed over a great longitudinal range following the sunset terminator. The affected area has a large longitudinal range of ~100° in the American sector and a rather localized zone of ~20° in longitude in the African sector. Plasma depletions of equatorial origin were registered at midlatitudes (30°–40° magnetic latitude) of both hemispheres in the African and American longitudinal sectors. We examine global features of the large‐scale plasma depletion by using a combination of ground‐based and space‐borne measurements—ground‐based Global Positioning System/Global Navigation Satellite System (GPS/GNSS) networks, Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) GPS Radio Occultation (RO), Swarm upward looking GPS data, and in situ plasma density observations provided by Swarm, Communications/Navigation Outage Forecasting System (C/NOFS), and Defense Meteorological Satellite Program (DMSP) missions. Joint analysis of the satellite observations revealed that these storm‐induced EPBs structures had extended over 500 km in altitude, at least from ~350 to ~850 km. These irregularities caused strong amplitude and phase scintillations of GPS/GNSS signals for ground‐based and space‐borne (COSMIC RO) measurements and seriously affected performance of navigation‐based services.
Solar Rotation Period Driven Modulations of Plasmaspheric Density and Convective Electric Field in the Inner Magnetosphere
Authors: Thaller S. A. , Wygant J. R. , Cattell C. A. , Breneman A. W. , Tyler E. , Tian S. , Engel A. , De Pascuale S. , Kurth W. S. , Kletzing C. A. , Tears J. , Malaspina David M.
Published: February 2019

This paper presents the first analysis of Van Allen Probes measurements of the cold plasma density and electric field in the inner magnetosphere to show that intervals of strong modulation at the solar rotation period occur in the locations of the outer plasmasphere and plasmapause (~0.7 RE peak‐to‐peak), in the large‐scale electric field (~0.24 mV/m peak‐to‐peak), and in the cold plasma density (~250 to ~70 cm−3 peak‐to‐peak). Solar rotation modulation of the inner magnetosphere is more apparent in the declining phase of the solar cycle than near solar maximum. The periodicities in these parameters are compared to solar extreme ultraviolet irradiance, solar wind dawn‐dusk electric field, and Kp. The variations in the plasmapause location at the solar rotation period anticorrelate with solar wind electric field, magnetospheric electric field, and Kp, but not with extreme ultraviolet irradiance, indicating that convective erosion is the dominant physical process controlling the plasmapause at these timescales.