bluuebunny/crossref_metadata_2025 huggingface dataset:
Major flowering time genes of barley: allelic diversity, effects, and comparison with wheat
Authors: Fernández-Calleja Miriam , Casas Ana M. , Igartua Ernesto
Published: May 2021

Key message

This review summarizes the allelic series, effects, interactions between genes and with the environment, for the major flowering time genes that drive phenological adaptation of barley.

The optimization of phenology is a major goal of plant breeding addressing the production of high-yielding varieties adapted to changing climatic conditions. Flowering time in cereals is regulated by genetic networks that respond predominately to day length and temperature. Allelic diversity at these genes is at the basis of barley wide adaptation. Detailed knowledge of their effects, and genetic and environmental interactions will facilitate plant breeders manipulating flowering time in cereal germplasm enhancement, by exploiting appropriate gene combinations. This review describes a catalogue of alleles found in QTL studies by barley geneticists, corresponding to the genetic diversity at major flowering time genes, the main drivers of barley phenological adaptation: VRN-H1 (HvBM5A), VRN-H2 (HvZCCTa-c), VRN-H3 (HvFT1), PPD-H1 (HvPRR37), PPD-H2 (HvFT3), and eam6/eps2 (HvCEN). For each gene, allelic series, size and direction of QTL effects, interactions between genes and with the environment are presented. Pleiotropic effects on agronomically important traits such as grain yield are also discussed. The review includes brief comments on additional genes with large effects on phenology that became relevant in modern barley breeding. The parallelisms between flowering time allelic variation between the two most cultivated Triticeae species (barley and wheat) are also outlined. This work is mostly based on previously published data, although we added some new data and hypothesis supported by a number of studies. This review shows the wide variety of allelic effects that provide enormous plasticity in barley flowering behavior, which opens new avenues to breeders for fine-tuning phenology of the barley crop.
Vestibulo-perceptual influences upon the vestibulo-spinal reflex
Authors: Bonsu Angela N. , Nousi Sofia , Lobo Rhannon , Strutton Paul H. , Arshad Qadeer , Bronstein Adolfo M.
Published: May 2021

The vestibular system facilitates gaze and postural stability via the vestibulo-ocular (VOR) and vestibulo-spinal reflexes, respectively. Cortical and perceptual mechanisms can modulate long-duration VOR responses, but little is known about whether high-order neural phenomena can modulate short-latency vestibulo-spinal responses. Here, we investigate this by assessing click-evoked cervical vestibular myogenic-evoked potentials (VEMPS) during visual roll motion that elicited an illusionary sensation of self-motion (i.e. vection). We observed that during vection, the amplitude of the VEMPs was enhanced when compared to baseline measures. This modulation in VEMP amplitude was positively correlated with the subjective reports of vection strength. That is, those subjects reporting greater subjective vection scores exhibited a greater increase in VEMP amplitude. Control experiments showed that simple arousal (cold-induced discomfort) also increased VEMP amplitude but that, unlike vection, it did not modulate VEMP amplitude linearly. In agreement, small-field visual roll motion that did not induce vection failed to increase VEMP amplitude. Taken together, our results demonstrate that vection can modify the response of vestibulo-collic reflexes. Even short-latency brainstem vestibulo-spinal reflexes are influenced by high-order mechanisms, illustrating the functional importance of perceptual mechanisms in human postural control. As VEMPs are inhibitory responses, we argue that the findings may represent a mechanism whereby high-order CNS mechanisms reduce activity levels in vestibulo-collic reflexes, necessary for instance when voluntary head movements need to be performed.
New proof to Somos’s Dedekind eta-function identities of level 10
Authors: Kumar B. R. Srivatsa , Shruthi
Published: May 2021

Michael Somos used PARI/GP script to generate several Dedekind eta-function identities by using computer. In the present work, we prove two new Dedekind eta-function identities of level 10 discovered by Somos in two different methods. Also during this process, we give an alternate method to Somos’s Dedekind eta-function identities of level 10 proved by B. R. Srivatsa Kumar and D. Anu Radha. As an application of this, we establish colored partition identities.
Rapid amelioration of anorexia nervosa in a male adolescent during metreleptin treatment including recovery from hypogonadotropic hypogonadism
Authors: Antel Jochen , Tan Susanne , Grabler Marvin , Ludwig Christine , Lohkemper Dominik , Brandenburg Tim , Barth Nikolaus , Hinney Anke , Libuda Lars , Remy Miriam , Milos Gabriella , Hebebrand Johannes
Published: May 2021

With this case report we support our medical hypothesis that metreleptin treatment ameliorates starvation related emotional, cognitive and behavioral symptomatology of anorexia nervosa (AN) and show for the first time strong effects in a male patient with AN. A 15.9 year old adolescent with severe AN of eight-month duration was treated off-label with metreleptin. Hyperactivity was assessed with accelerometry. Visual analogue scales (VAS), validated self- and clinician rating scales and lab results tracked changes from baseline to end of the 24-day dosing period and a five-month follow-up. Substantial improvements of mood and eating disorder related cognitions and hyperactivity set in after two days of treatment. During dosing, sub-physiological testosterone and TT3 levels normalized; clinically libido reemerged. Weight did not increase substantially during the dosing period. During follow-up target weight was attained; mood did not deteriorate; hyperactivity ceased. The results substantiate the strong effects seen in female cases and underscore the need for a double-blind placebo-controlled trial to confirm the observed strong, multiple and rapid onset beneficial effects of metreleptin in AN.
Choroidal thickness changes in children with chronic heart failure due to dilated cardiomyopathy
Authors: Rakusiewicz Klaudia , Kanigowska Krystyna , Hautz Wojciech , Ziółkowska Lidia
Published: May 2021

Purpose

To evaluate choroidal thickness (CTh) in children with chronic heart failure (CHF) secondary to dilated cardiomyopathy (DCM) using spectral domain optical coherence tomography (SD-OCT) and to compare their values to those of healthy children.

Methods

Sixty eyes of thirty children (mean age 9.9 ± 3.57 years) with chronic heart failure (left ventricular ejection fraction, LVEF ≤ 55%) due to DCM lasting for over 6 months were prospectively enrolled. The control group consisted of 30 age- (mean age 10.16 ± 3.42 years) and sex-matched healthy children. All participants underwent transthoracic echocardiography with LVEF measured using the Simpson method and had the blood serum level of N-terminal-pro-brain natriuretic peptide marker (NT-proBNP) determined. All children underwent SD-OCT and had subfoveal choroidal thickness (SFCTh) and CTh measured at 1500 µm (μm) nasally, temporally, superiorly and inferiorly from the fovea in both eyes by two investigators.

Results

CTh at all locations was statistically significantly lower in children with DCM compared to the control group. Mean CTh in the group with CHF compared to the control group were (304.03 vs. 369.72 μm, p < 0.05) at the subfoveal location, (245.87 vs. 284 μm, p < 0.05) 1500 μm nasally from the fovea, (291.5 vs. 355.95 μm, p < 0.05) 1500 μm temporally from the fovea, (303.98 vs. 357.58 μm, p < 0.05) 1500 μm superiorly from the fovea and (290.92 vs. 344.96 μm, p < 0.05) 1500 μm inferiorly from the fovea. The average difference CTh between the study groups ranged from 38.13 to 65.69 μm at individual locations. In both groups, CTh was the thickest at subfoveal location (304.03 vs. 369.72 μm, p < 0.05) and the thinnest was 1500 μm nasally from the fovea (262.37 vs. 336.87 μm, p < 0.05). There was no correlation between CTh and age, gender, biometry and refractive error. No correlation was found between CTh and LVEF and NT-proBNP.

Conclusion

Patients with CHF due to DCM had a thinner CTh at all measured locations. The results of our research indicate that CHF affects CTh and this parameter may be very helpful in monitoring the clinical course of the disease in children with DCM.
Analysis of stochastic gradient descent in continuous time
Authors: Latz Jonas
Published: May 2021

Stochastic gradient descent is an optimisation method that combines classical gradient descent with random subsampling within the target functional. In this work, we introduce the stochastic gradient process as a continuous-time representation of stochastic gradient descent. The stochastic gradient process is a dynamical system that is coupled with a continuous-time Markov process living on a finite state space. The dynamical system—a gradient flow—represents the gradient descent part, the process on the finite state space represents the random subsampling. Processes of this type are, for instance, used to model clonal populations in fluctuating environments. After introducing it, we study theoretical properties of the stochastic gradient process: We show that it converges weakly to the gradient flow with respect to the full target function, as the learning rate approaches zero. We give conditions under which the stochastic gradient process with constant learning rate is exponentially ergodic in the Wasserstein sense. Then we study the case, where the learning rate goes to zero sufficiently slowly and the single target functions are strongly convex. In this case, the process converges weakly to the point mass concentrated in the global minimum of the full target function; indicating consistency of the method. We conclude after a discussion of discretisation strategies for the stochastic gradient process and numerical experiments.
Static balance adaptations after neuromuscular electrical stimulation on quadriceps and lumbar paraspinal muscles in healthy elderly
Authors: Bondi Danilo , Jandova Tereza , Verratti Vittore , D’Amico Moreno , Kinel Edyta , D’Attilio Michele , Di Filippo Ester Sara , Fulle Stefania , Pietrangelo Tiziana
Published: May 2021

Background

Strength training as neuromuscular electrical stimulation (NMES) is effective in counteracting age-related postural impairments in elderly. However, it remains unknown whether training different muscle groups would entail in different adaptations.

Aim

To evaluate the effect of NMES training on balance function in healthy inactive elderly, targeting paravertebral muscles, in addition to thigh muscles.

Methods

Eleven healthy elderly were trained with NMES for 8 week allocated to combined training (CT: quadriceps and lumbar paraspinal muscles) or to quadriceps training (QT), after completing lifestyle questionnaire and spine morphology measurements. Functional balance, static stabilometry, and isometric strength tests were assessed before and after the training period.

Results and conclusion

The CT group showed a greater improve in static balance control, i.e., reducing the CEA of the CoP displacement from 99 ± 38 to 76 ± 42 mm2 (Cohen’s d = 0.947). Benefits for improving static balance through CT might be due to NMES training, which increases spinal stabilization.
Emission of typical pollutants (NOX, SO2) in the oxygen combustion process with air in-leakages
Authors: Moroń Wojciech , Ferens Wiesław , Wach Janusz
Published: May 2021

Oxygen combustion, being an alternative to air combustion, is distinguished in a variety of modern coal management technologies by quick and easy removal of CO2 from the combustion process, which is the key merit of this oxy-fuel technology. The laboratory work conducted so far has not directly addressed the issue of air in-leakages in the oxy-fuel system. The previous studies showed that air in-leakages in the combustion system (both under the air and oxygen regime) occur and affect the combustion process. However, there are no direct research studies on the volume of air in-leakages and their impact on the individual stages of combustion, including the emission of gaseous pollutants. This article focuses on the assessment of the impact of air in-leakages on NOx and SO2 emissions for a single-stage coal-dust combustion system. Moreover, these studies were supplemented with measurements on the rate of devolatilisation of volatile matters and, in particular, on the rate of nitrogen compounds released from fuel. The obtained results of combustion in the oxy-fuel atmosphere with the following air in-leakage levels: 10, 15 and 20% were compared to combustion conditions in the air. Air in-leakages in the oxygen combustion system create an additional flow of oxygen and nitrogen appearing in the combustion area, which affects the course of pollutants and their emission. The conducted studies have shown that when adequate tightness of the combustion system is provided, it contributes to the reduced emission of nitrogen compounds.
Resilience mechanisms at work: The psychological immunity-psychological elasticity (PI-PE) model of psychological resilience
Authors: IJntema Richta C. , Schaufeli Wilmar B. , Burger Yvonne D.
Published: May 2021

Recently, scientists have shifted their focus from studying psychological resilience as a single, isolated construct (e.g. attribute or outcome) to studying it as a dynamic process encompassing a number of temporally related elements. Models depicting this process explain why some people adapt to stressor exposure, whereas others do not. To date, these process models did not sufficiently explain how people adapt differently to a stressor. To address this issue, we developed a new model of psychological resilience, called the Psychological Immunity-Psychological Elasticity (PI-PE) model. The aim of this article is to clarify this model and to discuss its added value. First, we explain how we derived the PI-PE model from the literature regarding both the crucial elements in any resilience process model and the (mal)adaptive outcomes following stressful events. Secondly, we describe the different elements that make up the model. Characteristic of the PI-PE model is that it distinguishes between two pathways of psychological resilience – psychological immunity and psychological elasticity – with four adaptive outcomes, namely sustainability, recovery, transformation and thriving. To explain how people arrive at these different outcomes, we argue that two consecutive mechanisms are critical in these pathways: tolerance and narrative construction. Taken as a whole, the PI-PE model presents a comprehensive framework to inspire both research and practice. It explains how the process of psychological resilience works differently for different people and how to support individuals in their process towards successfully and differently adapting to stressors.
Bayesian Optimization Approaches for Identifying the Best Genotype from a Candidate Population
Authors: Tsai Shin-Fu , Shen Chih-Chien , Liao Chen-Tuo
Published: May 2021

Bayesian optimization is incorporated into genomic prediction to identify the best genotype from a candidate population. Several expected improvement (EI) criteria are proposed for the Bayesian optimization. The iterative search process of the optimization consists of two main steps. First, a genomic BLUP (GBLUP) prediction model is constructed using the phenotype and genotype data of a training set. Second, an EI criterion, estimated from the resulting GBLUP model, is employed to select the individuals that are phenotyped and added to the current training set to update the GBLUP model until the sequential observed EI values are less than a stopping tolerance. Three real datasets are analyzed to illustrate the proposed approach. Furthermore, a detailed simulation study is conducted to compare the performance of the EI criteria. The simulation results show that one augmented version derived from the distribution of predicted genotypic values is able to identify the best genotype from a large candidate population with an economical training set, and it can therefore be recommended for practical use. Supplementary materials accompanying this paper appear on-line.
Assessing perceptions and priorities for health impacts of climate change within local Michigan health departments
Authors: Carter Julie M. , Koman Patricia D. , Cameron Lorraine , Ferguson Aaron , Jacuzzo Patrick , Duvall Jason
Published: May 2021

Climate change affects Michigan’s public health in several primary ways, including increased incidences of vector-borne, waterborne, heat-related, and respiratory illness. Because local health departments (LHDs) play a central role in surveillance and preventative health services, they are among the first institutions to contend with the local impacts of climate change. To assess current perceptions among Michigan public health officials, an online survey was conducted in partnership with the Michigan Association for Local Public Health (MALPH). Most of the Michigan respondents (62%, n = 34) agreed that their jurisdictions have experienced climate change in the last 20 years, and 77% agreed that climate change will impact their jurisdictions in the coming 20 years. However, only 35% (n = 34) of Michigan officials agreed that climate change is a priority in their departments. About one quarter (25%, n = 34) of Michigan LHD respondents did not know about the level of expertise of either the state and federal agencies, responsible for assisting them with information and programs related to climate change and health. Uncertainty regarding the resources available to them may hinder LHDs from developing necessary preparedness, so meeting this need could bolster the public health response to climate change.
Simulation of methane adsorption in diverse organic pores in shale reservoirs with multi-period geological evolution
Authors: Chen Shangbin , Zhang Chu , Li Xueyuan , Zhang Yingkun , Wang Xiaoqi
Published: May 2021

In shale reservoirs, the organic pores with various structures formed during the thermal evolution of organic matter are the main storage site for adsorbed methane. However, in the process of thermal evolution, the adsorption characteristics of methane in multi type and multi-scale organic matter pores have not been sufficiently studied. In this study, the molecular simulation method was used to study the adsorption characteristics of methane based on the geological conditions of Longmaxi Formation shale reservoir in Sichuan Basin, China. The results show that the characteristics of pore structure will affect the methane adsorption characteristics. The adsorption capacity of slit-pores for methane is much higher than that of cylindrical pores. The groove space inside the pore will change the density distribution of methane molecules in the pore, greatly improve the adsorption capacity of the pore, and increase the pressure sensitivity of the adsorption process. Although the variation of methane adsorption characteristics of different shapes is not consistent with pore size, all pores have the strongest methane adsorption capacity when the pore size is about 2 nm. In addition, the changes of temperature and pressure during the thermal evolution are also important factors to control the methane adsorption characteristics. The pore adsorption capacity first increases and then decreases with the increase of pressure, and increases with the increase of temperature. In the early stage of thermal evolution, pore adsorption capacity is strong and pressure sensitivity is weak; while in the late stage, it is on the contrary.
Subjective sleep quality, quantitative sleep features, and their associations dependent on demographic characteristics, habitual sleep–wake patterns, and distinction of weekdays/weekends
Authors: Choilek Siwalee , Karashima Akihiro , Motoike Ikuko , Katayama Norihiro , Kinoshita Kengo , Nakao Mitsuyuki
Published: May 2021

Generally applicable qualifications of sleep and principles for achieving better sleep are difficult to design, because sleep quality can depend on individual demographic characteristics and lifestyles. In this study, the static and dynamic features of sleep–wake patterns were analyzed in association with quantitative sleep-related parameters and self-rated sleep quality to serve as a practical selection of sleep–wake patterns fitted to individual conditions. Data obtained over a 2-week period by actigraphy from university students and information technology workers were measured to obtain a daily subjective rating of sleep quality using the Oguri–Shirakawa–Azumi (OSA) sleep inventory. Qualitative sleep quality in terms of OSA score and quantitative sleep-related and chronobiological features were analyzed with regard to their dependency on the demographic characteristics, habitual sleep–wake patterns (HSWP), and distinction of weekdays/weekends. Multi-factor ANOVA was used to further investigate their dependencies regarding multiple ways of interactions between the demographic characteristics, HSWP, and distinction of weekdays/weekends. Subjective sleep quality and quantitative sleep-related parameters depended on the demographic characteristics, and so did their associations. The classification of day-to-day variations in HSWP showed four clusters that were effective factors for understanding their dependencies. Multi-factor analysis revealed demographic characteristics, HSWP, distinction of weekdays/weekends, and their multi-way interactions up to 3rd order as significant effectors of qualitative and quantitative quality of sleep. This study clarified how quantitative sleep-related parameters, subjective sleep quality, and their associations depended on demographic characteristics. Furthermore, their dependency was understood as a combination of multi-way interactions between the demographic characteristics, HSWP, and the distinction of weekdays/weekends. Our findings could provide a basis for the design of individually matched sleep–wake patterns.
Mapping Young NEETs Across Europe: Exploring the Institutional Configurations Promoting Youth Disengagement from Education and Employment
Authors: Assmann Marie-Luise , Broschinski Sven
Published: May 2021

Over the past decade, the number of young people neither in employment, education, or training (NEET) has reached a seriously high level in many European countries. Previous studies have illustrated the heterogeneity of this group and that they differ considerably across Europe. However, the reasons of these cross-country differences have hardly been investigated so far. This study explores how the rates of different NEET subgroups are conditioned by various institutional configurations by applying fuzzy-set Quantitative Comparative Analysis for 26 European countries using aggregated EU Labour Force Survey data from 2018. The analysis reveals that institutional causes of being NEET are as diverse as the group itself. Thus, high levels of young NEETs with care responsibilities are found in countries with a lack of family-related services in conjunction with weak formalised long-term care as it is true in mostly Central Eastern European countries. In contrast, high rates of NEETs with a disability are prevalent mainly in Northern European countries where generous and inefficient disability benefit schemes exist that create false incentives to stay away from the labour market. Finally, high proportions of unemployed and discouraged young NEETs are found in those countries hit hardest by the crisis and with high labour market rigidities, low vocational specificity, and a lack of active labour market policies like in the Southern and some Central Eastern European countries. The results illustrate that young people face very different barriers across Europe and that country-specific measures must be taken to reduce the number of NEETs in Europe.
Tuberculous and non‐tuberculous cervical lymphadenopathy incidence and distribution in Somalia from 2016 to 2020: A review of 241 cases
Authors: Tahtabasi Mehmet , Sahiner Fatih
Published: May 2021

Objective

To determine the incidence of tuberculous lymphadenitis (TBL) and other pathologies in cervical lymphadenopathies in Somalia and accompanying radiological findings.

Methods

In this hospital‐based retrospective study, the demographic characteristics, pathology results and radiological findings of 263 patients who underwent ultrasound (US)‐guided cervical lymph node biopsy between January 2016 and February 2020 were analyzed.

Results

Of 241 patients 118 men and 123 women (mean age 27.9 ± 18.1 years) included in the study, 46.1% (n = 111) were diagnosed as necrotizing granulomatous lymphadenitis (caseified, consistent with TBL) and 21.6% (n = 12, atypical lymphoid cells and n = 40, metastases) as malignancy. The most common type of metastasis was squamous cell cancer (n = 31), and the primary source of most of them was esophageal cancer (16/31, 51.6%). The age of patients with TBL was significantly lower than that of non‐TBL (21.9 ± 14.6 vs. 41.9 ± 24.6, P = 0.003) and the incidence of TBL in pediatric patients was statistically higher (58.0% vs. 21.5%, P = 0.019). The rate of patients with TBL being localized at level 4 and level 5 was significantly more than non‐TBL patients (18.0% vs. 10.0% and 23.4% vs. 10.8%, respectively, P = 0.01). Half of patients with TBL who have chest radiography had pathological findings; consolidation and bronchopneumonia were present in 52.6% of them. There were 2 patients with paravertebral abscess and one patient with gastrointestinal tuberculosis.

Conclusion

In Somalia, in the presence of cervical lymphadenopathy, after diagnosis by using US‐guided biopsy; primarily considering of TBL and malignancy, thoracic involvement should be investigated, and esophageal carcinoma must be excluded in terms of metastatic lymph node.
US Surveillance of Foreign Currency Exchange and Macroeconomic Practices
Authors: Qureshi Asif H.
Published: May 2021

This article focuses on the manner in which the US identifies the exchange rate and macroeconomic policies of its key trading partners and the policy advice it gives to them, when according to the US set criteria the trading partner's exchange rate and macroeconomic policies contribute to the US trade deficit. The article focuses on the US apparatus that is set in two different pieces of US legislation concerned essentially with currency manipulation mainly from the perspective of the WTO and IMF legal regimes. The paper concludes that although the US regime concerns currency manipulation, and is implemented to address a compliance void under the IMF and WTO procedures, it is flawed and that the Reports prepared under the US legislation are not qualitatively enlightening.
VGF Expression by Monocytes in Patients with Alzheimer’s Disease and Vascular Dementia
Authors: Busse Stefan , Meyer Eva , Dobrowolny Henrik , Mawrin Christian , Hartig Roland , Bogerts Bernhard , Busse Mandy
Published: May 2021

Abstract. Because its secretion is changed in cerebrospinal fluid and peripheral blood, the neuronal polypeptide VGF (nonacronymic) has been discussed as a biomarker for neuropsychiatric disorders. We have shown an enhanced VGF expression by T-cells from Alzheimer’s disease (AD) patients. In this study, we investigated the VGF expression by peripheral monocytes in 38 AD patients, 5 patients with vascular dementia (VD), and 20 neuropsychiatrically healthy individuals using flow cytometry. We determined an enhanced number of VGF-expressing monocytes in VD patients compared to AD patients. VGF+CD14+ monocytes were not correlated with age, body mass index, Mini-Mental State Examination (MMSE), or Q albumin. These preliminary data support findings indicating that VGF might play a role as a peripheral biomarker in VD.
New Drought Projections Over East Asia Using Evapotranspiration Deficits From the CMIP6 Warming Scenarios
Authors: Kim Daeha , Ha Kyung‐Ja , Yeo Ji‐Hye
Published: May 2021

In this work, we projected future drought risks over East Asia from the perspective of evapotranspiration (ET) deficit using the new climate projections of the Coupled Model Intercomparison Project Phase 6 (CMIP6). For the regional drought projections, we employed a state‐of‐the‐art complementary relationship (CR) method to estimate ET and atmospheric evaporative demand (Ep) that quantify the combined impact of water deficiency and vapor pressure deficit stress. The performance of the CR method was validated using the reanalysis climate data and independent water‐balance ET estimates. The same CR method was again applied to hindcasts and projections of seven global climate models (GCM) in the CMIP6 archive. Results showed that the CR ET estimates and the GCM‐driven ET products were both able to approximately close the basin‐scale water balance and tightly correlated with each other. The application with the CMIP6 GCM hindcasts provided the same indication that the CR ET and the GCM‐driven ET are consistent. The drought assessments using the ET deficit (ET − Ep) from the CMIP6 projections implicates that future drought risks over East Asia would be much higher than indicated by precipitation or soil moisture projections. Rising trends of Ep are expected to outpace those of ET even under the medium‐level greenhouse gas emission scenario. Our new drought projections suggest that Ep amplified by soil water deficiency could raise agricultural and wildfire risks substantially by the end of the 21st century.
Reduced Complexity Model Intercomparison Project Phase 2: Synthesizing Earth System Knowledge for Probabilistic Climate Projections
Authors: Nicholls Z. , Meinshausen M. , Lewis J. , Corradi M. Rojas , Dorheim K. , Gasser T. , Gieseke R. , Hope A. P. , Leach N. J. , McBride L. A. , Quilcaille Y. , Rogelj J. , Salawitch R. J. , Samset B. H. , Sandstad M. , Shiklomanov A. , Skeie R. B. , Smith C. J. , Smith S. J. , Su X. , Tsutsui J. , Vega‐Westhoff B. , Woodard D. L.
Published: May 2021

Over the last decades, climate science has evolved rapidly across multiple expert domains. Our best tools to capture state‐of‐the‐art knowledge in an internally self‐consistent modeling framework are the increasingly complex fully coupled Earth System Models (ESMs). However, computational limitations and the structural rigidity of ESMs mean that the full range of uncertainties across multiple domains are difficult to capture with ESMs alone. The tools of choice are instead more computationally efficient reduced complexity models (RCMs), which are structurally flexible and can span the response dynamics across a range of domain‐specific models and ESM experiments. Here we present Phase 2 of the Reduced Complexity Model Intercomparison Project (RCMIP Phase 2), the first comprehensive intercomparison of RCMs that are probabilistically calibrated with key benchmark ranges from specialized research communities. Unsurprisingly, but crucially, we find that models which have been constrained to reflect the key benchmarks better reflect the key benchmarks. Under the low‐emissions SSP1‐1.9 scenario, across the RCMs, median peak warming projections range from 1.3 to 1.7°C (relative to 1850–1900, using an observationally based historical warming estimate of 0.8°C between 1850–1900 and 1995–2014). Further developing methodologies to constrain these projection uncertainties seems paramount given the international community's goal to contain warming to below 1.5°C above preindustrial in the long‐term. Our findings suggest that users of RCMs should carefully evaluate their RCM, specifically its skill against key benchmarks and consider the need to include projections benchmarks either from ESM results or other assessments to reduce divergence in future projections.
The Importance of Water Mass Transport and Dissolved‐Particle Interactions on the Aluminum Cycle in the Subtropical North Atlantic
Authors: Artigue Lise , Wyatt Neil J. , Lacan François , Mahaffey Claire , Lohan Maeve C.
Published: May 2021

New dissolved aluminum (dAl) data from the 2017 GEOTRACES process study GApr08 along 22°N in the subtropical North Atlantic are presented. They show an east to west increase in dAl concentration in the surface waters. Simulation of these data with a 1D advection‐dust deposition revealed that, (a) advection and dust dissolution are equally important dAl sources, (b) scavenging plays a minor role compared to advection in dAl removal, and (c) in addition to dust dissolution, another dAl source is required at the westernmost stations to fully explain our observations. We attribute this additional source to the dissolution of erosion products delivered to the western subtropical North Atlantic by the Lesser Antilles. For waters deeper than ∼200–300 m, an optimum multi‐parameter analysis allowed to separate the component of the dAl signal derived from water mass transport from its biogeochemical component. This revealed, (a) a major role played by water mass transport, (b) a net dAl removal between 200 and 800 m, attributed to scavenging at the subtropical North Atlantic scale, and (c) internal dAl inputs between 800 m and the seafloor, attributed to reversible scavenging. While the dAl oceanic distribution is usually considered to be dominated by the atmospheric dust input and removal by particle scavenging, this study highlights the important role played by advection, and the need to explicitly take this into account in order to quantitatively reveal the impact of external sources and dissolved‐particulate interactions on the Al cycle in the North Atlantic Ocean.
Global Simulation and Evaluation of Soil Organic Matter and Microbial Carbon and Nitrogen Stocks Using the Microbial Decomposition Model ORCHIMIC v2.0
Authors: Huang Y. , Guenet B. , Wang Y. L. , Ciais P.
Published: May 2021

Soils contain the largest amount of land carbon, even a small change of this pool can significantly affect atmospheric CO2 and climate change. A good representation of soil organic carbon (SOC) dynamics in Earth system models is therefore crucial to predict future climate change. The dynamics of SOC is largely driven by microbial activities and modulated by N cycles. Nevertheless, very few models have explicitly represented soil microorganisms and N cycles integrated at global scale. Here, we present an update of the microbial‐mediated ORCHIMIC model and its application to simulate global gridded SOC stocks, microbial biomass, soil C/N ratio, microbial C/N ratio, and heterotrophic respiration. This is a new attempt to model SOC dynamics with an explicit microbial representation with N dynamics applied at global scale. The model shows relatively good performance in reproducing global SOC and microbial biomass C. The spatial distributions of soil and microbial C/N ratios were not well reproduced because they are sensitive to mineral nitrogen availability controlled by plant uptake, which is not explicitly represented in the model. However, similar relationship between C/N ratios of microbes and soil as observation demonstrated the potential of the model to reproduce global C/N ratios for both microbe and soil pools. Dynamic carbon use efficiency modulated by substrate C/N ratio, consistent with observation, were well represented by mechanistic including microbial dynamics. Modeled suppressed microbial biomass growth under warming climate indicating a weaker positive feedback between soil C pool and climate compared to that predicted by traditional Earth system models.
Comparative Rhyolite Systems: Inferences From Vent Patterns and Eruptive Episodicities: Eastern California and Laguna del Maule
Authors: Hildreth Wes
Published: May 2021

Distilling my experience in having field mapped in detail the volcanic fields at Laguna del Maule and Long Valley and having worked out their time‐volume‐composition magmatic histories, I compare and contrast the postglacial rhyolites of the former with six multi‐vent eruptive sequences of rhyolite in California. Compilations and discussions are made of volcanic‐field areas and longevities, their compositions, vent distributions, individual batch and total volumes, eruptive episodicities, and tectonic influences. Growth of long‐lived pluton‐scale reservoirs of granitic crystal mush, from which the rhyolite melts separated, are interpreted in terms of conceptual models I published previously—(1) fundamentally basaltic transcrustal magmatism, 1981; (2) the deep‐crustal MASH zone model, 1988; and (3) the rhyolite‐melt crystal‐mush model, 2001. Inferences and speculations are advanced concerning processes and timescales of rhyolite‐melt separation from granitic mush and of prompt or long‐delayed subsequent eruption.
Insight Into the Dynamics of the Radiating Internal Tide Associated With the Kuroshio Current
Authors: Xu Zhenhua , Wang Yang , Liu Zhiqiang , McWilliams James C. , Gan Jianping
Published: May 2021

Ocean circulation strongly influences how internal tides radiate and break and stimulates the spatial inhomogeneity and temporal variation of internal tidal mixing. Qualitative and quantitative characterizations of interactions between internal tides and general circulation are critical to multi‐scale circulation dynamics. Based on significant progress in regional circulation simulation, we obtain an observation‐supported internal tide energy field around Luzon Strait by deterministically resolving the dynamics of the radiating paths of the internal tide energy. These paths are created when the known most powerful internal tide of Luzon Strait interacts with the Kuroshio Current. We found that the radiating tidal pattern, local dissipation efficiency, and energy field respond differently to the leaping, looping, and leaking Kuroshio paths within Luzon Strait. Our new insights into the dynamics and our clarifying the controlling refraction mechanism within the general circulation create the potential for internal tides to be represented better in climate models.
Emissions of Trace Organic Gases From Western U.S. Wildfires Based on WE‐CAN Aircraft Measurements
Authors: Permar Wade , Wang Qian , Selimovic Vanessa , Wielgasz Catherine , Yokelson Robert J. , Hornbrook Rebecca S. , Hills Alan J. , Apel Eric C. , Ku I‐Ting , Zhou Yong , Sive Barkley C. , Sullivan Amy P. , Collett Jeffrey L. , Campos Teresa L. , Palm Brett B. , Peng Qiaoyun , Thornton Joel A. , Garofalo Lauren A. , Farmer Delphine K. , Kreidenweis Sonia M. , Levin Ezra J. T. , DeMott Paul J. , Flocke Frank , Fischer Emily V. , Hu Lu
Published: May 2021

We present emission measurements of volatile organic compounds (VOCs) for western U.S. wildland fires made on the NSF/NCAR C‐130 research aircraft during the Western Wildfire Experiment for Cloud Chemistry, Aerosol Absorption, and Nitrogen (WE‐CAN) field campaign in summer 2018. VOCs were measured with complementary instruments onboard the C‐130, including a proton‐transfer‐reaction time‐of‐flight mass spectrometer (PTR‐ToF‐MS) and two gas chromatography (GC)‐based methods. Agreement within combined instrument uncertainties (<60%) was observed for most co‐measured VOCs. GC‐based measurements speciated the isomeric contributions to selected PTR‐ToF‐MS ion masses and generally showed little fire‐to‐fire variation. We report emission ratios (ERs) and emission factors (EFs) for 161 VOCs measured in 31 near‐fire smoke plume transects of 24 specific individual fires sampled in the afternoon when burning conditions are typically most active. Modified combustion efficiency (MCE) ranged from 0.85 to 0.94. The measured campaign‐average total VOC EF was 26.1 ± 6.9 g kg−1, approximately 67% of which is accounted for by oxygenated VOCs. The 10 most abundantly emitted species contributed more than half of the total measured VOC mass. We found that MCE alone explained nearly 70% of the observed variance for total measured VOC emissions (r2 = 0.67) and >50% for 57 individual VOC EFs representing more than half the organic carbon mass. Finally, we found little fire‐to‐fire variability for the mass fraction contributions of individual species to the total measured VOC emissions, suggesting that a single speciation profile can describe VOC emissions for the wildfires in coniferous ecosystems sampled during WE‐CAN.
The Mechanism of Increasing Summer Water Vapor Over the Tibetan Plateau
Authors: He Yongli , Tian Wenlong , Huang Jianping , Wang Guodong , Ren Yu , Yan Hongru , Yu Haipeng , Guan Xiaodan , Hu Huancui
Published: May 2021

Rapid warming over the Tibetan Plateau (TP) has been associated with an increasing trend in atmospheric water vapor content, which is critical for recharging the Asian water tower. However, the mechanism associated with the wetting phenomenon remains unclear. Long‐term changes in moisture balance and precipitation (PRE) recycling processes are investigated using the ERA5 reanalysis from 1979 to 2019. The increasing trend over TP is mainly due to the summer water vapor trend with signiﬁcantly increases over the western TP. Based on the moisture balance analysis, it is found that PRE, evaporation, and the convergence of moisture are all increasing over the western TP but decreasing over the eastern TP. Based on the dynamical PRE recycling model, the results suggest that both internal and external cycles contributes to the wetting over TP, with 63.87% and 36.13% contributions respectively. Further analysis found that the atmospheric heating source is also increasing over the western TP, which could shift the moisture transportation from east to west at the southern boundary of TP. The increasing moisture convergence could enhance PRE, and the enhanced latent heating in the mid‐atmosphere can further induced moisture convergence, which forms a positive feedback. However, an opposite situation occurred over the eastern TP. The internal and external cycle of the water cycle can stimulate (suppress) each other through PRE over the western (eastern) TP. This mechanism linked the changes in the PRE recycling and atmospheric circulation, and induced the increasing trend over TP in summer.
Pre‐Thrusting Stratigraphic Control on the Transition From a Thin‐Skinned to Thick‐Skinned Structural Style: An Example From the Double‐Decker Idaho‐Montana Fold‐Thrust Belt
Authors: Parker S. D. , Pearson D. M.
Published: May 2021

Continental fold‐thrust belts display a variety of structural styles, ranging from thin‐skinned thrusts following weak lithologic contacts to thick‐skinned thrusts that deform mechanical basement. The common practice of splitting fold‐thrust belts into thin‐skinned and thick‐skinned map domains has not yielded a predictive model of the primary controls on structural style. Within the Mesozoic‐Paleogene Idaho‐Montana fold‐thrust belt (44°N‐45°N, 112°W‐114°W), we identify crosscutting thin‐skinned and thick‐skinned thrusts within an otherwise thin‐skinned map domain. This transition occurs within a thin (∼2.5 km) portion of the western Laurentian passive margin, where lower strata pinch out over a prominent basement high (Lemhi arch). Early fold‐thrust belt shortening of sedimentary cover rocks was accommodated through detachment folding, followed by east‐directed, thin‐skinned thrusting along regional‐scale faults (Thompson Gulch and Railroad Canyon thrusts). Later, basement and cover rocks were tilted toward the southeast and a basement‐involved normal fault was reactivated during thick‐skinned thrusting (Radio Tower‐Baby Joe Gulch‐Italian Gulch thrusts), which accommodated shortening at an oblique angle to and truncated the basal detachment of the older thin‐skinned thrusts. This progression from thin‐skinned to thick‐skinned thrusting occurred >50 km from the foreland, coincident with a regional basement high. Thus, the Idaho‐Montana fold‐thrust belt is a double‐decker system, with upper thin‐skinned and lower thick‐skinned domains. This double‐decker model is applicable to other fold‐thrust belts and predicts that the transition from thin‐skinned to thick‐skinned thrusting occurs where the growing critically tapered wedge can no longer fit within the sedimentary cover rocks and the basal detachment steps down into the structurally lower mechanical basement.
Chemical Weather and Chemical Climate
Authors: Brasseur Guy P. , Kumar Rajesh
Published: May 2021

Progress in fundamental understanding of atmospheric chemistry in the past decades has enabled the development of advanced environmental predictive capability. Accurate chemical weather forecasts and source attribution information can play a decisive role in mitigating the short‐term exposure of the public to acute air pollution episodes. Chemical climate projections will allow investigation of the long‐term consequences of human choices and their impact on the future evolution of the Earth system. This commentary stresses the importance of integrating atmospheric chemistry in operational environmental prediction and projection systems.
Climate Change and Changes in Compound Coastal‐Riverine Flooding Hazard Along the U.S. Coasts
Authors: Ghanbari Mahshid , Arabi Mazdak , Kao Shih‐Chieh , Obeysekera Jayantha , Sweet William
Published: May 2021

The cooccurrence of coastal and riverine flooding leads to compound events with substantial impacts on people and property in low‐lying coastal areas. Climate change could increase the level of compound flood hazard through higher extreme sea levels and river flows. Here, a bivariate flood hazard assessment method is proposed to estimate compound coastal‐riverine frequency under current and future climate conditions. A copula‐based approach is used to estimate the joint return period (JRP) of compound floods by incorporating sea‐level rise (SLR) and changes in peak river flows into the marginal distributions of flood drivers. Specifically, the changes in JRP of compound major coastal‐riverine flooding defined based on simultaneous exceedances above major coastal and riverine thresholds, are explored by midcentury. Subsequently, the increase in the probability of occurrence of at least one compound major coastal‐riverine flooding for a given period of time is quantified. The proposed compound flood hazard assessment is conducted at 26 paired tidal‐riverine stations along the Contiguous United States coast with long‐term data and defined flood thresholds. We show that the northeast Atlantic and the western part of the Gulf coasts are experiencing the highest compound major coastal‐riverine flood probability under current conditions. However, future SLR scenarios show the highest frequency amplification along the southeast Atlantic coast. The impact of changes in peak river flows is found to be considerably less than that of SLR. Climate change impacts, especially SLR, may lead to more frequent compound events, which cannot be ignored for future adaptation responses in estuary regions.
Acceleration of Oxygen Ions In Dipolarization Events: 2. PSBL Distributions
Authors: Birn J. , Hesse M. , Bingham S. T. , Turner D. L. , Nakamura R.
Published: May 2021

This paper represents the second part of an investigation of the acceleration of energetic oxygen ions from encounters with a dipolarization front (DF), based on test particle tracing in the fields of an MHD simulation. In this paper, we focus on distributions in the plasma sheet boundary layer (PSBL). O+ beams close to the plasma sheet boundary are found to be less pronounced and/or delayed against the H+ beams. The reason is that these particles are accelerated by nonadiabatic motion in the duskward electric field such that O+ ions gain the same amount of energy, but only 1/4 of the speed of protons. This causes a delay and larger equatorward displacement by the E × B drift. In contrast, the O+ beams somewhat deeper inside the plasma sheet, where previously multiple proton beams were found, are accelerated at an earthward propagating DF just like H+, forming a field‐aligned beam at a similar speed as the lowest‐energy H+ beam. We found that the source location depends on the adiabaticity of the orbit. For larger adiabaticity, the beam ions originate initially from the outer plasma sheet, but later from the opposite PSBL or lobe, but for low adiabaticity, sources are well inside the plasma sheet. The energy gained from a single encounter of a DF is comparable to the kinetic energy associated with the front speed. Assuming maximum speeds of 500–1,000 km/s, this yields a mass dependent acceleration of about 1–5 keV for protons and 20–80 keV for oxygen ions, independent of their charge state.