bluuebunny/crossref_metadata_2025 huggingface dataset:
Addressing Control Implementation Issues in Robotic Systems Using Adaptive Control
Authors: Hayat Rameez , Leibold Marion , Buss Martin
Published: May 2019

This paper addresses three control implementation issues for trajectory tracking of robotic manipulators: unmodeled dynamics, unknown input saturation and peaking effects during the transient phase. A model-free first-order robust-adaptive control method is used to deal with the unmodeled dynamics. Robust optimality and stability of the controller are proved using the 𝓗∞ technique and the game-algebraic Riccati equation. An intuitive approach is devised to incorporate the unknown input saturation by modifying the speed of the desired trajectory. The trajectory scaling is performed by using only the state errors. Furthermore, two different techniques are utilized to suppress peaking during the transient response of the trajectory tracking. The first method adds an extra term in the input while the second method uses variable gain to improve the transient response. A systematic procedure for finding the controller parameters is formulated using features, such as rise time and settling time. A three-degree-of-freedom robot manipulator is used for the validation of the proposed controller in simulations and experiments.
From Design to Evaluation: Applications of Health Technology Assessment in Myanmar and Lessons for Low or Lower Middle-Income Countries
Authors: Dabak Saudamini Vishwanath , Teerawattananon Yot , Win Thiri
Published: May 2019

Objectives

Health technology assessment (HTA) has been widely used to inform coverage decisions in high-income countries over the past few decades and has been getting increasing attention in middle-income countries as a tool for healthcare decision making in recent years. This study aims to use the case of the Maternal and Child Health Voucher Scheme (MCHVS) in Myanmar to understand how HTA can have a policy impact in a low or lower middle-income country.

Methods

The stages heuristic framework was used to describe the policy-making process. A document review was conducted and tacit knowledge of researchers involved was recorded.

Results

The opportunity for a grant propelled maternal and child health to the policy agenda. An ex-ante HTA, which included a model-based health economic evaluation, informed the design of the scheme. The framework and key parameters from the ex-ante HTA were used for a mid-term review, which provided feedback to the policy implementation process. An ex-post HTA involved fielding a household survey to assess the impact of the scheme.

Conclusions

HTA can be a useful method for informing resource allocation throughout the policy process in low and lower middle-income settings where no formal mechanism for making coverage decisions exists.
Biotechnology and plant breeding: relevance of cell genetics in potato improvement
Authors: Meyer R. , Salamini F. , Uhrig H.
Published: May 2019

Synopsis

The adoption of emerging biotechnological methods in plant breeding is presented discussing specifically the relevance of cell genetics to potato improvement. The finding and use of efficient anther plant producing strains of potato (EAPP clones) is first discussed. This is followed by the presentation of recent progress toward the obtaining of diploid potato strains producing a high percentage of monohaploids from anthers. The selection of homozygous diploid regenerants (potato ‘pure lines’) by using an RFLP approach is also presented. A summary chart is presented, containing the description of an integrated breeding procedure that may be considered for future breeding of this species.
Computer-aided drug discovery
Authors: Richards W. Graham
Published: May 2019

Synopsis:

The role of computers in drug discovery depends on just how much is known about the target macromolecule. If atomic detail of the receptor is known, binding free energy differences between drug variants may be computed. Major effort is being expended in extending the area of applicability of such studies by predicting protein structure based on homologies with known protein crystal data. Where no target structure is available, computational methods can provide leads by defining transition state structures and then using the approach of molecular similarity to define stable mimics to act as blockers.
Arteriovenous Malformations of the Brain in Children: A Forty Year Experience
Authors: Kondziolka Douglas , Humphreys Robin P. , Hoffman Harold J. , Hendrick E. Bruce , Drake James M.
Published: May 2019

Despite the great capacity for the pediatric brain to recover from stroke, the morbidity and mortality in children who harbor an arteriovenous malformation (AVM) remains high. This study examines the clinical data and management experience with 132 patients with brain AVM from 1949 to 1989. Although the high tendency for a childhood AVM to present with hemorrhage (79%) remained constant for the forty year study period, the associated morbidity and mortality of hemorrhage changed. The mortality rate from hemorrhage for the entire series was 25%, which was reduced from 39% to 16% after the introduction of computed tomography. The mortality from AVM hemorrhage since 1975 was dependent on location; 8 of 14 patients (57%) with a cerebellar AVM died from hemorrhage while only 2 of 44 patients (4.5%) with a cerebral hemisphere AVM died (p < 0.0001). Sixteen children (12%) presented with a chronic seizure disorder. Surgical excision of the malformation resulted in complete seizure control off anti-convulsant medication in 73% of patients. Although 21% of patients were treated non-operatively (many with terminal poor-grade hemorrhage), 79% had a surgical procedure with total AVM excision achieved in 70 patients (53.1%). Complete AVM resection was followed by a normal neurological outcome in 47 children (67%). Most partial excisions (n=9) and clipping of feeding arteries (n=7) were performed in the early years of this study, and did not provide protection from rehe-morrhage. Although conservative management has been advocated for selected non-hemorrhagic AVMs, we conclude that essentially all children with an AVM should be treated in order to eliminate the risk of hemorrhage. Long-term conservative management in pediatric patients is warranted only in patients with large AVMs not amenable to treatment using current multimodality techniques.
Predator-Prey Systems in Pest Management
Authors: Harper Carolyn R.
Published: May 2019

The use of chemical pesticides frequently causes minor pests to become serious problems by disturbing the natural controls that keep them in check. As a result, it is possible to suffer heavier crop losses after pesticides are introduced than before their introduction. Efficient use of pesticides requires complete biological modeling that takes the appropriate predator-prey relationships into account. A bioeconomic model is introduced involving three key species: a primary target pest, a secondary pest, and a natural enemy of the secondary pest. Optimal decision rules are derived and contrasted with myopic decision making, which treats the predator-prey system as an externality. The issue of resistance in the secondary pest is examined briefly.
Economic Modeling of Farm Production and Conservation Decisions in Response to Alternative Resource and Environmental Policies
Authors: Ellis John R. , Hughes David W. , Butcher Walter R.
Published: May 2019

Growing concern over resource use and protection of the environment has prompted greater demand for agricultural policy analysis at the local, regional, and national levels. Faced with declining surface-water quality, silting of reservoirs, and contaminated groundwater supplies, the public has demanded greater protection of the environment. With the call for more regulation of agriculture comes the need for policy analysis. What policy is best? Should a national standard apply, or do local conditions warrant local standards? Who will benefit, and who will lose, and by how much?
Commercial Agriculture and the Environment: An Evolutionary Perspective
Authors: Phipps Tim T.
Published: May 2019

The decade of the 1980s saw a resurgence of concern over the environmental and health effects of agricultural production that exceeded even the concern in the sixties generated by the publication of Rachel Carson's book, Silent Spring. Consumers worried about the health effects of pesticide residues on foods; conversion of wetlands to crop production was blamed for the decreased population of migratory waterfowl; rural residents worried about the effects of nitrates and pesticides found in their groundwater supplies; and sediment, nutrients, and pesticides in surface waters were blamed for the decline of estuaries such as the Chesapeake Bay and contributed to problems in freshwater and coastal fisheries.
Processes and patterns of glacier-influenced sedimentation and recent tidewater glacier dynamics in Darbel Bay, western Antarctic Peninsula
Authors: Batchelor C.L. , Dowdeswell J.A. , Hogan K.A. , Larter R.D. , Parsons E. , West O.
Published: May 2019

Bathymetric data of unprecedented resolution are used to provide insights into former ice dynamics and glacial processes in a western Antarctic Peninsula embayment. An assemblage of submarine glacial landforms, which includes subglacially produced streamlined features and ice-marginal ridges, reveals the former pattern of ice flow and retreat. A group of more than 250 small (< 1–3 m high, 10–20 m wide) and relatively evenly spaced recessional moraines was identified beyond the margin of Philippa Glacier. The small recessional moraines are interpreted to have been produced during short-lived, possibly annual re-advances of a grounded ice margin during overall retreat. This is the first time that these features have been shown to be part of the assemblage of landforms produced by tidewater glaciers on the Antarctic Peninsula. Glacier-terminus changes during the last four decades, mapped from LANDSAT satellite images, were analysed to determine whether the moraines were produced during recent still-stands or re-advances of Philippa Glacier and to further investigate the short-term (annual to decadal) variability in ice-marginal position in tidewater glacier systems. The asynchronous response of individual tidewater glaciers in Darbel Bay is interpreted to be controlled mainly by local topography rather than by glacier catchment-area size.
Emotion regulation processes linking peer victimization to anxiety and depression symptoms in adolescence
Authors: Adrian Molly , Jenness Jessica L. , Kuehn Kevin S. , Smith Michele R. , McLaughlin Katie A.
Published: May 2019

Difficulties with emotion regulation can take many forms, including increased sensitivity to emotional cues and habitual use of maladaptive cognitive or behavioral regulation strategies. Despite extensive research on emotion regulation and youth adjustment, few studies integrate multiple measures of emotion regulation. The present study evaluated the underlying structure of emotion regulation processes in adolescence using both task- and survey-based measures and determined whether differences in these emotion regulation latent factors mediated the association between peer victimization and internalizing psychopathology. Adolescents aged 16–17 years (n= 287; 55% female; 42% White) recruited in three urban centers in the United States completed baseline and follow-up assessments 4 months apart. Three models of emotion regulation were evaluated with confirmatory factor analysis. A three-factor model fit the data best, including cognitive regulation, behavioral regulation, and emotional reactivity latent factors. Task-based measures did not load onto these latent factors. Difficulties with behavioral regulation mediated the association between peer victimization and depression symptoms, whereas cognitive regulation difficulties mediated the association with anxiety symptoms. Findings point to potential targets for intervention efforts to reduce risk for internalizing problems in adolescents following experiences of peer victimization.
FAMINE FOODS AND FOOD SECURITY IN THE NORTHERN MAYA LOWLANDS: MODERN LESSONS FOR ANCIENT RECONSTRUCTIONS
Authors: Dine Harper , Ardren Traci , Bascopé Grace , Báez Celso Gutiérrez
Published: May 2019

Inequality and changing responses to food scarcity may create a stigmatization complex around certain foods. Here, we conduct a literature search to develop a working definition of “famine foods” in the Maya lowlands, centering qualities such as hardiness, productivity, nutrition, preparation, and stigmatization complexes. An analysis of the nutritional characteristics that might make up such a food yields the idea that famine foods are likely members of a time- and place-specific arsenal of plant resources. We compare the results of the literature search to botanical data from arejolladasurvey from Xuenkal and asolar(house garden) survey conducted in Yaxunah. Examining the data through the lens of a history of manipulation of food access, shifting relations of power, and modern responses to food insecurity illuminates cultural plasticity and resilience in diet and agricultural strategies in the Maya lowlands. We conceptualizesolaresandrejolladasas food-related resilience strategies.
ETHNOECOLOGY IN PRE-HISPANIC CENTRAL AMERICA: FOODWAYS AND HUMAN-PLANT INTERFACES
Authors: Morell-Hart Shanti , Joyce Rosemary A. , Henderson John S. , Cane Rachel
Published: May 2019

In recent years, researchers in pre-Hispanic Central America have used new approaches that greatly amplify and enhance evidence of plants and their uses. This paper presents a case study from Puerto Escondido, located in the lower Ulúa River valley of Caribbean coastal Honduras. We demonstrate the effectiveness of using multiple methods in concert to interpret ethnobotanical practice in the past. By examining chipped-stone tools, ceramics, sediments from artifact contexts, and macrobotanical remains, we advance complementary inquiries. Here, we address botanical practices “in the home,” such as foodways, medicinal practices, fiber crafting, and ritual activities, and those “close to home,” such as agricultural and horticultural practices, forest management, and other engagements with local and distant ecologies. This presents an opportunity to begin to develop an understanding of ethnoecology at Puerto Escondido, here defined as the dynamic relationship between affordances provided in a botanical landscape and the impacts of human activities on that botanical landscape.
Consensus and the Constitution
Authors: Watkin Thomas Glyn
Published: May 2019

Church in Wales voted by secret ballot – the first such ballot in the seventy-four year history of that Body – on the motion that the Bill to Enable Women to be Ordained as Priests be passed. The result of the vote was as follows:
Providing Services to Special Needs Students in a Decentralised Education System: An Australian Perspective
Authors: Dimmock Clive , Bain Alan
Published: May 2019

The purpose of this paper is to examine the implications of decentralisation for Australian special education service delivery. Initiatives to decentralise educational service have become afocus of education policy both in Australia and overseas in recent years, although there has been little discussion of its effect on special education. This trend is examined from an Australian perspective. Problems associated with the provision of special education services are discussed in conjunction with an overview of the school based management of special education services.
A Comparison of Regular and Resource Teacher Instructional Plans for Academically Handicapped Children: An Assessment of the Efficacy of Withdrawal Model Remedial Teaching
Authors: Fields Barry A.
Published: May 2019

Pull-out or withdrawal remedial instruction is the dominant service delivery model for regular class children with learning problems. The efficacy of this model has been in question for a number of years with claims that remedial instruction as delivered in such settings is neither special nor exemplary. The findings of the study reported here suggest these claims may be accurate, and they raise questions about both the training and deployment of resource/ remedial teachers.
A Systematic Review and Meta-Analysis on the Association Between Driving Ability and Neuropsychological Test Performances after Moderate to Severe Traumatic Brain Injury
Authors: Egeto Peter , Badovinac Shaylea D. , Hutchison Michael G. , Ornstein Tisha J. , Schweizer Tom A.
Published: May 2019

Objectives: Guidelines on return-to-driving after traumatic brain injury (TBI) are scarce. Since driving requires the coordination of multiple cognitive, perceptual, and psychomotor functions, neuropsychological testing may offer an estimate of driving ability. To examine this, a meta-analysis of the relationship between neuropsychological testing and driving ability after TBI was performed. Methods: Hedge’s g and 95% confidence intervals were calculated using a random effects model. Analyses were performed on cognitive domains and individual tests. Meta-regressions examined the influence of study design, demographic, and clinical factors on effect sizes. Results: Eleven studies were included in the meta-analysis. Executive functions had the largest effect size (g = 0.60 [0.39–0.80]), followed by verbal memory (g = 0.49 [0.27–0.71]), processing speed/attention (g = 0.48 [0.29–0.67]), and visual memory (g = 0.43 [0.14–0.71]). Of the individual tests, Useful Field of Vision (UFOV) divided attention (g = 1.12 [0.52–1.72]), Trail Making Test B (g = 0.75 [0.42–1.08]), and UFOV selective attention (g = 0.67 [0.22–1.12]) had the largest effects. The effect sizes for Choice Reaction Time test and Trail Making Test A were g = 0.63 (0.09–1.16) and g = 0.58 (0.10–1.06), respectively. Years post injury (β = 0.11 [0.02–0.21] and age (β = 0.05 [0.009–0.09]) emerged as significant predictors of effect sizes (both p < .05). Conclusions: These results provide preliminary evidence of associations between neuropsychological test performance and driving ability after moderate to severe TBI and highlight moderating effects of demographic and clinical factors.
A nutrition education programme improves quality of life but not anthropometric status of adults living with HIV in Abeokuta, Nigeria
Authors: Bello Temitope K , Gericke Gerda J , Maclntyre Una E , Becker Piet
Published: May 2019

Objective:

The focus of interventions for adults living with HIV (ALH) in Nigeria has been mostly on prevention and provision of antiretroviral therapy (ART) with little consideration to nutrition-related matters. Therefore, the present study aimed to improve the quality of life (QoL) and anthropometric status of ALH in Abeokuta, Nigeria.

Design:

A quasi-experimental design where 200 conveniently selected participants were stratified by gender and duration on ART. The intervention group (n100) received the nutrition education programme (NEP) for 12 weeks. The control group received a brochure on nutrition guidelines for ALH. Socio-biographical information, QoL and anthropometric status were assessed using previously validated questionnaires and standard techniques at baseline, week 12 and week 24. Generalised least squares (GLS) regression analysis was used for group comparisons. Anthropometric status was summarised by gender.

Setting:

Two tertiary hospitals in Abeokuta, Nigeria.

Participants:

ALH.

Results:

The NEP led to significant improvement in the physical functioning (week 12 and 24:P< 0·01), role limitation due to physical health (week 12:P= 0·01; week 24:P= 0·002) and pain (week 12:P= 0·01) constructs of the QoL of the intervention group compared with the control group. There was no significant difference (P= 0·07) between the mean weights of the two groups at baseline.

Conclusions:

There was a significant improvement at week 12 and week 24 in the QoL of the intervention participants. The results indicated that a tailored NEP could make a positive contribution to the management of ALH.
The association between iron and vitamin D status in Arab adolescents
Authors: Masoud Mohammad S , Yakout Sobhy M , Al-Attas Omar S , Alokail Majed S , Al-Daghri Nasser M
Published: May 2019

Objective:

Both vitamin D and Fe micronutrient deficiencies are common in Saudi Arabia but the association between them is unclear. The present study aimed to determine whether Fe indices are associated with vitamin D status and other metabolic markers in Arab adolescents.

Design:

Single-centre, cross-sectional study gathering anthropometrics, glucose and lipid profile. Serum 25-hydroxyvitamin D (25(OH)D), Fe, total iron-binding capacity (TIBC), transferrin saturation (%) and other parameters were measured.

Setting:

Vitamin D School Project Database, King Saud University (2014–2016).

Participants:

Arab adolescents aged 10–17 years randomly selected from the Vitamin D School Project Database (170 Saudi students; 100 girls, seventy boys).

Results:

Among Fe indices, only TIBC was found to be significantly and inversely associated with 25(OH)D (r = −0·20; P < 0·01) and only in girls (r = −0·20; P < 0·05). Among cardiometabolic parameters, serum Fe was associated with TAG in boys (r = 0·36; P < 0·01) and inversely associated with HDL-cholesterol in girls (r = −0·29; P < 0·05). Age was the most significant predictor of serum Fe for all participants, accounting for 5 % (R2 = 0·05; P = 0·004) of variance perceived. Serum 25(OH)D and age, on the other hand, were the most significant predictors for TIBC, accounting for 10·1 % (R2 = 0·10; P < 0·001) of variance perceived.

Conclusions:

Among healthy Arab adolescents, the association between vitamin D and Fe indices, particularly TIBC, is modest, inverse and sex-dependent. Larger studies with inclusion of markers such as hepcidin and ferritin, vitamin D metabolites and endogenous sex hormones may provide a clearer view of this complex association.
Four-Dimensional Scanning Transmission Electron Microscopy (4D-STEM): From Scanning Nanodiffraction to Ptychography and Beyond
Authors: Ophus Colin
Published: May 2019

Scanning transmission electron microscopy (STEM) is widely used for imaging, diffraction, and spectroscopy of materials down to atomic resolution. Recent advances in detector technology and computational methods have enabled many experiments that record a full image of the STEM probe for many probe positions, either in diffraction space or real space. In this paper, we review the use of these four-dimensional STEM experiments for virtual diffraction imaging, phase, orientation and strain mapping, measurements of medium-range order, thickness and tilt of samples, and phase contrast imaging methods, including differential phase contrast, ptychography, and others.
THE AGE OF CONCERTED CULTIVATION
Authors: Manning Alex
Published: May 2019

In this paper I develop a race-centered, intersectional critique of concerted cultivation. First developed by Annette Lareau inUnequal Childhoodsto describe the dominant middle-class cultural style of parenting, this powerful concept continues to shape scholarship on parenting and the social reproduction of social inequality through culture and class. I critique and reconstruct this concept based upon: 1) Existing research on racial identity and racial socialization, and racialized parenting techniques, and 2) Alternative readings of selected ethnographic material presented inUnequal Childhoods. First, I argue that concerted cultivation is a racialized parenting practice and that families negotiate and navigate a complex race- and-class-based social context of childrearing. Second, I present a re-reading of excerpts fromUnequal Childhoodsto show how families of color, and in particular Black families, cultivate racial knowledge and skills in their children. Third, I make a case for the larger sociological usefulness of a layered race and class analysis of parenting culture, and argue that such a framework adds more depth to core arguments made by Lareau. In the last section, I discuss the social tensions that exist within concerted cultivation and intensive parenting culture. I reflect on possible implications for normative parenting culture that matches well with neoliberal market rationality, exists within racial capitalism, but at the same time connects to anti-racist socialization and rejection of hegemonic cultural ideologies.
Survival and development of Chilo partellus (Swinhoe) on sorghum cultivars
Authors: Duale A. H. , Reddy K. V. Seshu
Published: May 2019

Survival and development of Chilo partellus were studied on five sorghum cultivars (IS-18363, IS-18520, ICS-1, ICS-2 and IS-4660) in the laboratory at Mbita Point Field Station, Kenya, at 26 ± 2°C and 65 ± 5% RH. Larval developmental period differed significantly on different cultivars. Number of instars was numerically greater for the females than for the males on all cultivars. Average pupal weight varied with sex; females were twice as heavy as males. The pupal period was longer for males than for females on all cultivars, with the exception of ICS-1, where the pupal period of males was equal to that of females. Ovipositional period was significantly longer on IS-18520 (5.18 ± 0.30 days) than on other cultivars. The shortest ovipositional period (3.70 ± 0.27 days) was recorded on IS-4660. There were no statistically significant differences in adult longevity. Sex ratio of the moths also did not affect the adult longevity of C. partellus reared on the five sorghum cultivars. The variations found in the development of C. partellus on different cultivars were attributed to the nutritional value of the food source.
Field evaluation of four synthetic pyrethroids for their termiticidal efficacy
Authors: Prasad R. , Rao K. M.
Published: May 2019

Permethrin, deltamethrin, fenvalerate and cypermethrin were evaluated for their termiticidal efficacy in a graveyard test. Semul wood, Salmalia malabaricum veneers (size 15.00 × 6.00 × 0.06 cm) were impregnated with concentrations of 0.25, 0.50 and 0.75% aqueous solution of these chemicals. Fenvalerate provided 100% protection for 44 months at all three concentrations. Cypermethrin provided 100% protection at 0.50 and 0.75% concentrations, while permethrin and deltamethrin provided 100% protection at 0.75% concentration for 7 and 10 months, respectively.
Screening of Florida mango fruits from germplasm for resistance to immature stages of Caribbean fruit fly
Authors: Hennessey Michael K. , Schnell Raymond J.
Published: May 2019

Mature fruits from 21 mango, Mangifera indica L., cultivare grown in the Miami National Clonal Germplasm Repository were examined for resistance under laboratory conditions to identify those resistant (antibiotic or antixenotic) to the eggs and larvae of the Caribbean fruit fly, Anastrepha suspensa (Leow). The bioassay consisted of artificially infesting a slice of fruit with eggs obtained from a laboratory colony and counting the adults that emerged. Emergence ranged from 26.6% (on Tobago Small Red) to 119.0% (on Sabre) of controls (on artifical diet). Tobago Small Red, Becky, Saigon Seedling, Zilate, Sandersha, 13–1, Keitt, Turpentine, Rumani, Tommy Atkins, Irwin and Peach had the highest level of resistance observed with less than 80% emergence. The most resistant cultivars are promoted to breeders and growers for production in areas under quarantine for Caribbean fruit fly.
Die Perspektive Gesundheit in der Arbeitsgemeinschaft für Sportpsychologie (asp)
Authors: Sudeck Gorden , Seelig Harald
Published: May 2019

Zusammenfassung. Seit nunmehr etwa 30 Jahren ist die Perspektive Gesundheit ein ausgewiesener Bestandteil des Spektrums sportpsychologischer Forschung und Anwendung in der Arbeitsgemeinschaft für Sportpsychologie (asp) der Bundesrepublik Deutschland. Anlässlich des 50-jährigen Jubiläums der Arbeitsgemeinschaft für Sportpsychologie widmen wir uns mit diesem Beitrag einigen Entwicklungslinien, die sich für die Sportpsychologie mit Perspektive Gesundheit darbieten. Aufbauend auf einer einführenden Gegenstandsbestimmung wird eine kurze Charakterisierung von Forschungsthemen und Aktivitäten in der Arbeitsgemeinschaft für Sportpsychologie gegeben. Es wird der Versuch unternommen, Potenziale und Herausforderungen zu skizzieren, die für den gegenwärtigen und zukünftigen Bedarf an sportpsychologischer Forschung und der Anwendung in Gesundheitsförderung, Prävention, Therapie und Rehabilitation von Bedeutung sein können.
Extracting Auroral Key Local Structures From All‐Sky Auroral Images by Artificial Intelligence Technique
Authors: Yang Qiuju , Tao Dacheng , Han Desheng , Liang Jimin
Published: May 2019

Extracting auroral key local structures (KLS) containing both morphological information and spatial location from large amount of auroral images is the key for automatic auroral classification and event recognition and thus is very important for improving the efficiency of aurora study. However, it is labor‐intensive for human experts and challenging for computer execution because of the blurry boundary and inhomogeneous luminosity of aurora. In this work, we formulate the automatic KLS extraction to learn a mapping from an all‐sky auroral image to a KLS mask style with artificial intelligence technique. We explore the Cycle‐consistent Generative Adversarial Network to generate the KLS masks based on the unpaired training data set consisting of 2508 all‐sky auroral images observed between years 2003–2009 at the Arctic Yellow River Station, of which only 200 images were manually annotated as the ground truth of KLS masks. The extracted KLS are consistent with human visual perception, and the intersection‐over‐union metric is significantly improved by at least 17% than previous method by Niu et al. (2018) (https://doi.org/10.1109/TGRS.2018.2848725). Classification accuracy has been improved when combining the KLS masks further indicates the effectiveness and value of this work.
A Comparison of Cross‐Track Ion Drift Measured by the Swarm Satellites and Plasma Convection Velocity Measured by SuperDARN
Authors: Koustov A. V. , Lavoie D. B. , Kouznetsov A. F. , Burchill J. K. , Knudsen D. J. , Fiori R.A.D.
Published: May 2019

Cross‐track ion drifts measured by the Swarm A satellite are compared with colocated line‐of‐sight Super Dual Auroral Radar Network (SuperDARN) velocities in approximately the same directions. More than 200 Swarm A passes over four polar cap SuperDARN radars in the Northern and Southern Hemispheres are considered. Overall, the Swarm‐based velocities are larger than the SuperDARN velocities; the slope of the best fit line to the data is ~0.67. Somewhat stronger differences are found when Swarm A measurements for the entire year 2016 are compared with SuperDARN vector data from global‐scale convection maps. Swarm ion drift data demonstrate known features of the high‐latitude convection patterns, for example, reverse convection cells at interplanetary magnetic field Βz > 0. The latitudes of the convection reversal boundary inferred from SuperDARN are found to be in reasonable agreement with those determined from Swarm A and Swarm B, with Swarm‐based latitudes occurring roughly 1° more equatorward, typically.
Salish Sea Response to Global Climate Change, Sea Level Rise, and Future Nutrient Loads
Authors: Khangaonkar Tarang , Nugraha Adi , Xu Wenwei , Balaguru Karthik
Published: May 2019

Given annual occurrences of hypoxia, harmful algal blooms, and evidence of coastal acidification, the potential impacts of climate change on water quality are of increasing concern in the U.S. Pacific Northwest estuaries such as the Salish Sea. While large‐scale global climate projections are well documented, our understanding of the nearshore estuarine‐scale response is not as well developed. In this study, the future response within the Salish Sea fjord‐like environment was examined using the Salish Sea Model driven by downscaled outputs from the National Center for Atmospheric Research climate model Community Earth System Model. We simulated a single projection of 95‐year change under the representative concentration pathway 8.5 greenhouse gas emissions scenario. Results indicate that higher temperatures, lower pH, and decreased dissolved oxygen levels in the upwelled shelf waters in the future would propagate into the Salish Sea. Results point to potential changes in average Salish Sea temperature (≈+1.51 °C), dissolved oxygen (≈−0.77 mg/L), and pH (acidification −0.18 units) in the Y2095 relative to historical Y2000. The algal biomass in the Salish Sea could increase by ≈23% with a potential species shift from diatoms toward dinoflagellates. The region of annually recurring hypoxia could increase from <1% today to ≈16% in the future. The results suggest that the future response in the Salish Sea is less severe relative to the change predicted near the continental shelf boundary. This resilience of the Salish Sea may be attributed to the existence of strong vertical circulation cells that provide mitigation and serve as a physical buffer, thus keeping waters cooler, more oxygenated, and less acidic.
Modeling the 1783–1784 Laki Eruption in Iceland: 1. Aerosol Evolution and Global Stratospheric Circulation Impacts
Authors: Zambri Brian , Robock Alan , Mills Michael J. , Schmidt Anja
Published: May 2019

The 1783–1784 CE Laki flood lava eruption began on 8 June 1783. Over the course of 8 months, the eruption released approximately 122 Tg of sulfur dioxide gas into the upper troposphere and lower stratosphere above Iceland. Previous studies that have examined the impact of the Laki eruption on sulfate aerosol and climate have either used an aerosol model coupled off‐line to a general circulation model (GCM) or used a GCM with incomplete aerosol microphysics. Here, we study the impact on stratospheric aerosol evolution and stratospheric and tropospheric circulation using a fully coupled GCM with complete aerosol microphysics, the Community Earth System Model version 1, with the Whole Atmosphere Chemistry Climate Model high‐top atmosphere component. Simulations indicate that the Laki aerosols had peak average effective radii of approximately 0.4 μm in Northern Hemisphere (NH) middle and high latitudes, with peak average effective radii of 0.25 μm in NH tropics and 0.2 μm in the Southern Hemisphere. We find that the Laki aerosols are transported globally and have significant impacts on the circulation in both hemispheres, strengthening the Southern Hemisphere polar vortex and shifting the tropospheric NH subtropical jet equatorward.
The Long‐Term Trends of Nocturnal Mesopause Temperature and Altitude Revealed by Na Lidar Observations Between 1990 and 2018 at Midlatitude
Authors: Yuan Tao , Solomon S. C. , She C.‐Y. , Krueger D. A. , Liu H.‐L.
Published: May 2019

The mesopause, a boundary between mesosphere and thermosphere with the coldest atmospheric temperature, is formed mainly by the combining effects of radiative cooling of CO2, and the vertical adiabatic flow in the upper atmosphere. A continuous multidecade (1990‐2018) nocturnal temperature data base of an advanced Na lidar, obtained at Fort Collins, CO (41°N, 105°W), and at Logan, UT (42°N, 112°W), provides an unprecedented opportunity to study the long‐term variations of this important atmospheric boundary. In this study, we categorize the lidar‐observed mesopause into two categories: the “high mesopause” (HM) above 97 km during nonsummer months, mainly formed through the radiative cooling, and the “low mesopause” (LM) below 92 km during nonwinter months, generated mostly by the adiabatic cooling. These lidar observations reveal a cooling trend of more than 2 K/decade in absolute mesopause temperature since 1990, along with a decreasing trend in mesopause height: The HM is moving downward at a speed of ~ 450 ± 90 m/decade, while the LM has a slower downward trend of ~ 130 ± 160 m/decade. However, since 2000, while the height trend (‐ 470 ± 160 m/decade for the HM and 150 ± 290 m/decade for the LM) is consistent, the temperature trend becomes statistically insignificant (‐ 0.2 ± 0.7 K/decade and ‐1 ± 0.9 K/decade for the HM and the LM, respectively). A long‐term study by Whole Atmosphere Community Climate Model with thermosphere and ionosphere extension (WACCM‐X) also indicated the similar mesopause changes, mostly caused by stratosphere‐lower mesosphere cooling and contraction.
Thirty Years of Regional Climate Modeling: Where Are We and Where Are We Going next?
Authors: Giorgi Filippo
Published: May 2019

The year 2019 marks the thirtieth anniversary of the development of the first regional climate model (RCM), and here an overview is provided of the progress in regional modeling research and of the main challenges lying ahead. RCMs were primarily developed to provide fine‐scale climate information for impact studies, but they have evolved into general and multipurpose modeling tools. Among the main achievements in RCM research the focus is on: the development of community RCMs applicable to a wide variety of studies and regional contexts; the increase of model simulation length up to centennial scales and spatial resolutions up to convection‐permitting scales (few kilometers), leading to a better understanding of regional to local climate change signals; the development of fully coupled Regional Earth System Models; the inception of intercomparison projects culminating in the international Coordinated Regional Climate Downscaling Experiment; the extensive use of RCM simulations for impact assessments; and the involvement of the scientific community from developing countries in climate modeling research. Among the outstanding issues in need of more attention are the Added Value of using this downscaling technique; various technical aspects concerning RCM simulations; and uncertainties in RCM‐based climate projections. Future directions in RCM research are discussed, with highlight on: transition to convection‐permitting modeling systems; further development of Regional Earth System Models including the human component; next phase of the Coordinated Regional Climate Downscaling Experiment project; and use of RCMs in the distillation of actionable information for contribution to climate service activities. A brief historical overview of regional climate modeling is also presented.
Electron‐Driven Dissipation in a Tailward Flow Burst
Authors: Chen Z. Z. , Fu H. S. , Liu C. M. , Wang T. Y. , Ergun R. E. , Cozzani G. , Huang S. Y. , Khotyaintsev Y. V. , Le Contel O. , Giles B. L. , Burch J. L.
Published: May 2019

Traditionally, the magnetotail flow burst outside the diffusion region is known to carry ions and electrons together (Vi = Ve), with the frozen‐in condition well satisfied (E + Ve × B = 0). Such picture, however, may not be true, based on our analyses of the high‐resolution MMS (Magnetospheric Multiscale mission) data. We find that inside the flow burst the electrons and ions can be decoupled (Ve ≠ Vi), with the electron speed 5 times larger than the ion speed. Such super‐Alfvenic electron jet, having scale of 10 di (ion inertial length) in XGSM direction, is associated with electron demagnetization (E + Ve × B ≠ 0), electron agyrotropy (crescent distribution), and O‐line magnetic topology but not associated with the flow reversal and X‐line topology; it can cause strong energy dissipation and electron heating. We quantitatively analyze the dissipation and find that it is primarily attributed to lower hybrid drift waves. These results emphasize the non‐MHD (magnetohydrodynamics) behaviors of magnetotail flow bursts and the role of lower hybrid drift waves in dissipating energies.
Whistler Waves Driven by Field‐Aligned Streaming Electrons in the Near‐Earth Magnetotail Reconnection
Authors: Ren Y. , Dai L. , Li W. , Tao X. , Wang C. , Tang B. , Lavraud B. , Wu Y. , Burch J. L. , Giles B. L. , Le Contel O. , Torbert R. B. , Russell C. T. , Strangeway R. J. , Ergun R. E. , Lindqvist P.‐A.
Published: May 2019

We analyze Magnetospheric Multiscale Mission observations of whistler waves and associated electron field‐aligned crescent distribution in the vicinity of the magnetotail near‐Earth X‐line. The whistler waves propagate outward from the X‐line in the neutral sheet. The associated field‐aligned streaming electrons exhibit a crescent‐like shape, with an inverse slope (df/d|v|||>0) at 1–5 keV. The parallel phase velocity of the waves is in the range (1–5 keV) of the inverse slope of the field‐aligned crescents in the velocity space. We demonstrate that the observed whistler waves are driven by the electron field‐aligned crescents through Landau resonance. The cyclotron resonance is at the high‐energy tail with negligible free energy of pitch angle anisotropy in these events.
Net Community Production in a Productive Coastal Ocean From an Autonomous Buoyancy‐Driven Glider
Authors: Haskell W. Z. , Hammond D. E. , Prokopenko M. G. , Teel E. N. , Seegers B. N. , Ragan M. A. , Rollins N. , Jones B. H.
Published: May 2019

Net community production (NCP), an analog of carbon export out of the surface ocean, is often estimated using budgets of dissolved oxygen. Accurate estimates of oxygen‐based NCP, especially in dynamic coastal regions, require constraints on vertical transport of water with O2 out of equilibrium with the atmosphere, nonsteady state change in the oxygen inventory, heating/cooling‐driven O2 disequilibrium, and the rate of bubble injection from wave activity. The latter two are typically evaluated by using discrete measurements of the O2/Ar ratio in lieu of O2 only. Because sophisticated sampling and measurement techniques are required to make these measurements, they are often limited in spatiotemporal resolution. However, high‐resolution estimates of NCP may be useful in determining small‐scale patchiness in export. In this study, we calculated high‐resolution NCP in coastal Southern California using dissolved oxygen measurements made by an autonomous buoyancy‐driven Slocum glider and an empirical relationship derived using discrete measurements of O2/Ar in the surface mixed layer to remove the influence of bubble injection, which accounted for approximately one fourth of the O2 supersaturation observed. Using estimates of vertical transport from wind speed‐based parameterizations, previously validated using a 7Be budget, we were able to correct for the physical biases to the signal, which are known to significantly influence dissolved oxygen budgets in this region. Our results agree well with previously published NCP estimates for the study area but also reveal higher‐frequency variability that discrete sampling was unable to resolve, suggesting that this approach may be useful in other regions with well‐constrained vertical transport rates.
Observation and Attribution of Temperature Trends Near the Stratopause From HALOE
Authors: Remsberg Ellis
Published: May 2019

This study considers time series of temperature versus pressure, T(p), from the Halogen Occultation Experiment (HALOE) across the stratopause region, where the effects of radiative forcings from the greenhouse gases (CO2 and H2O) and from ozone are most pronounced. Trend analyses of HALOE T(p) values for 1993–2005 are for six levels from 2.0 to 0.3 hPa with a vertical resolution of about 4 km and for eight latitude zones from 65°S to 65°N. The analyses account for the forcing effects from the 11‐yr solar cycle. HALOE trends at 2.0 hPa are of the order of −1.0 K/decade across the tropics and subtropics but then become smaller (−0.5 K/decade) at the middle latitudes. Near‐global T(p) trends are of order −0.5 K/decade but have a minimum of −0.2 K/decade at 1.0 hPa; they are clearly negative in the southern but slightly positive in the northern hemisphere. The combined radiative forcings from CO2, H2O, and ozone vary between −0.4 and −0.7 K/decade for 1993–2005 and are hemispherically symmetric. The HALOE temperature trend and total radiative cooling profiles differ from those reported from observations and calculations for 1980–2000, mainly because the ozone trends changed from clearly negative in the 1980s through mid‐1990s to slightly positive during the time of HALOE. Trends at low latitudes for the tracer, methane (CH4), increase from 2% to 4%/decade from 50 to 10 hPa and then to ~6%/decade by 5 hPa. Analyses of time series of CH4 across the stratopause reveal subseasonal scale variability within the northern hemisphere that reduces the significance of the T(p) trends.
Cul4a promotes zebrafish primitive erythropoiesis via upregulating scl and gata1 expression
Authors: Yang Fan , Hu Huili , Liu Yuanyuan , Shao Ming , Shao Changshun , Gong Yaoqin
Published: May 2019

CUL4A and CUL4B are closely related members in Cullin family and can each assemble a Cullin-RING E3 ligase complex (Cullin-RING Ligase 4A or 4B, CRL4A, or CRL4B) and participate in a variety of biological processes. Previously we showed that zebrafish cul4a, but not cul4b, is essential for cardiac and pectoral fin development. Here, we have identified cul4a as a crucial regulator of primitive erythropoiesis in zebrafish embryonic development. Depletion of cul4a resulted in a striking reduction of erythroid cells due to the inhibition of erythroid differentiation. Transcript levels for early hematopoietic regulatory genes including scl, lmo2, and gata1 are significantly reduced in cul4a-deficient embryos. Mechanistically, we demonstrated that scl and gata1, the central regulators of primitive hematopoiesis for erythroid determination, are transcriptionally upregulated by cul4a. These findings demonstrate an important role for cul4a in primitive erythropoiesis and may bear implications in regeneration medicine of anemia and related diseases.
Experimental demonstration of quantum walks with initial superposition states
Authors: Su Qi-Ping , Zhang Yu , Yu Li , Zhou Jia-Qi , Jin Jin-Shuang , Xu Xiao-Qiang , Xiong Shao-Jie , Xu QingJun , Sun Zhe , Chen Kefei , Nori Franco , Yang Chui-Ping
Published: May 2019

The preparation of initial superposition states of discrete-time quantum walks (DTQWs) is necessary for the study and applications of DTQWs. Based on an encoding method, here, we propose a DTQW protocol in linear optics, which enables the preparation of arbitrary initial superposition states of the walker and the coin and enables to obtain the states of the DTQW in addition to the probability distribution of the walker. With this protocol, we experimentally demonstrate the DTQW in the polarization space with both the walker and the coin initially in superposition states, by using only passive linear-optical elements. The effects of the walker’s different initial superposition states on the spread speed of the DTQW and on the entanglement between the coin and the walker are also experimentally investigated, which have not been reported before. When the walker starts with superposition states, we show that the properties of DTQWs are very different from those of DTQWs starting with a single position. Our findings reveal different properties of DTQWs and pave an avenue to study DTQWs with arbitrary initial states. Moreover, this encoding method enables one to encode an arbitrary high-dimensional quantum state, using a single physical qubit, and may be adopted to implement other quantum information tasks.
Detecting dynamic spatial correlation patterns with generalized wavelet coherence and non-stationary surrogate data
Authors: Chavez Mario , Cazelles Bernard
Published: May 2019

Time series measured from real-world systems are generally noisy, complex and display statistical properties that evolve continuously over time. Here, we present a method that combines wavelet analysis and non-stationary surrogates to detect short-lived spatial coherent patterns from multivariate time-series. In contrast with standard methods, the surrogate data proposed here are realisations of a non-stationary stochastic process, preserving both the amplitude and time-frequency distributions of original data. We evaluate this framework on synthetic and real-world time series, and we show that it can provide useful insights into the time-resolved structure of spatially extended systems.