bluuebunny/crossref_metadata_2025_split huggingface dataset:
Morphology‐Dependent Stability of Complex Metal Hydrides and Their Intermediates Using First‐Principles Calculations
Authors: Kang ShinYoung , Heo Tae Wook , Allendorf Mark D. , Wood Brandon C. 
Published: March 2019

AbstractComplex light metal hydrides are promising candidates for efficient, compact solid‐state hydrogen storage. (De)hydrogenation of these materials often proceeds via multiple reaction intermediates, the energetics of which determine reversibility and kinetics. At the solid‐state reaction front, molecular‐level chemistry eventually drives the formation of bulk product phases. Therefore, a better understanding of realistic (de)hydrogenation behavior requires considering possible reaction products along all stages of morphological evolution, from molecular to bulk crystalline. Here, we use first‐principles calculations to explore the interplay between intermediate morphology and reaction pathways. Employing representative complex metal hydride systems, we investigate the relative energetics of three distinct morphological stages that can be expressed by intermediates during solid‐state reactions: i) dispersed molecules; ii) clustered molecular chains; and iii) condensed‐phase crystals. Our results verify that the effective reaction energy landscape strongly depends on the morphological features and associated chemical environment, offering a possible explanation for observed discrepancies between X‐ray diffraction and nuclear magnetic resonance measurements. Our theoretical understanding also provides physical and chemical insight into phase nucleation kinetics upon (de)hydrogenation of complex metal hydrides.
Hydrogen in Palladium and Storage Properties of Related Nanomaterials: Size, Shape, Alloying, and Metal‐Organic Framework Coating Effects
Authors: Dekura Shun , Kobayashi Hirokazu , Kusada Kohei , Kitagawa Hiroshi 
Published: March 2019

AbstractOne of the key issues for an upcoming hydrogen energy‐based society is to develop highly efficient hydrogen‐storage materials. Among the many hydrogen‐storage materials reported, transition‐metal hydrides can reversibly absorb and desorb hydrogen, and have thus attracted much interest from fundamental science to applications. In particular, the Pd−H system is a simple and classical metal‐hydrogen system, providing a platform suitable for a thorough understanding of ways of controlling the hydrogen‐storage properties of materials. By contrast, metal nanoparticles have been recently studied for hydrogen storage because of their unique properties and the degrees of freedom which cannot be observed in bulk, i. e., the size, shape, alloying, and surface coating. In this review, we overview the effects of such degrees of freedom on the hydrogen‐storage properties of Pd‐related nanomaterials, based on the fundamental science of bulk Pd−H. We shall show that sufficiently understanding the nature of the interaction between hydrogen and host materials enables us to control the hydrogen‐storage properties though the electronic‐structure control of materials.
Ligand Effect on the Stability of Water‐Soluble Iridium Catalysts for High‐Pressure Hydrogen Gas Production by Dehydrogenation of Formic Acid
Authors: Iguchi Masayuki , Onishi Naoya , Himeda Yuichiro , Kawanami Hajime 
Published: March 2019

AbstractAiming to develop a highly effective and durable catalyst for high‐pressure H2 production from dehydrogenation of formic acid (DFA), the ligand effect on the catalytic activity and stability of Cp*Ir (Cp*:pentamethylcyclopentadienyl anion) complexes were investigated using 5 different kinds of N,N’‐bidentate ligands (bipyridine, biimidazoline, pyridyl‐imidazoline, pyridyl‐pyrazole and picolinamide). The Ir complex with biimidazoline ligand exhibited the highest catalytic activity, but deactivation occurred readily at high pressure. The pyridine moiety in the ligand can enhance the stability of Ir complex catalysts for the high‐pressure reaction. The Ir complex catalyst containing pyridyl‐imidazoline ligand showed the high activity and best stability under the high‐pressure conditions.
Evaluation of changes in the upper airway after Twin Block treatment in patients with Class II malocclusion
Authors: Entrenas Inmaculada , González‐Chamorro Elena , Álvarez‐Abad Covadonga , Muriel Juan , Menéndez‐Díaz Iván , Cobo Teresa 
Published: March 2019

AbstractThe purpose of this prospective case control study is to describe in growing patients with mandibular hypoplasia, treatment outcomes following functional therapy in terms of volumetric changes in nasopharynx and oropharynx, that is, upper and lower pharynx. We recruited 60 study participants aged between 8 and 12 years having mandibular Class II malocclusion and a reduced upper airway (UA) size, as determined by McNamara cephalometric analyses. Forty patients received Twin Block treatment, whereas the remaining 20 patients did not receive treatment, thus constituting the control group. The control group included patients who did not start treatment after their first visit but returned for a consultation one or 2 years later. All patients underwent an initial teleradiography examination of the skull and a final teleradiography examination to measure changes using McNamara cephalometric analysis of the UA. Pretreatment and posttreatment changes were assessed using Student's t test for independent samples with a significance level of 0.05. Both anatomical structures analyzed—the upper pharynx (nasopharynx) and lower pharynx (oropharynx)—showed significant increases after treatment regardless of whether the patients were boys or girls. The controls showed a decrease in UA size on average after approximately 2 years of growth. A clear relationship exists between the mandibular advancement achieved with TB treatment and an increased UA size. Therefore, the appliance is considered suitable for improving the respiratory quality of growing patients with a decreased UA size.
A Chemical Blowing Strategy to Fabricate Biomass‐Derived Carbon‐Aerogels with Graphene‐Like Nanosheet Structures for High‐Performance Supercapacitors
Authors: Zhang Hai , Zhang Ze , Luo Jin‐Di , Qi Xing‐Tao , Yu Ji , Cai Jian‐Xin , Wei Jun‐chao , Yang Zhen‐Yu 
Published: March 2019

AbstractThe efficient exploitation and utilization of low‐cost and biomass‐derived carbon materials will play an active role in developing sustainable energy storage systems. However, the difficult morphology control and incomplete activation limits their pervasive application in electrochemical energy storage. Inspired by the famous Chinese folk handicraft of sugar‐figure blowing, biomass‐derived carbon aerogels (GCA) with 2 D graphene‐like thin nanosheets were fabricated by a simple chemical blowing strategy from a viscous agaric solution obtained through hydrothermal treatment of agaric. A chemical blowing agent (NH4Cl) was used to effectively exfoliate the bulk biomass‐derived carbon flake into 2 D graphene‐like nanosheets, which resulted in a highly porous structure and high specific area (2200 m2 g−1) after the activation process. As a result, a high specific capacitance of 340 F g−1 at 3 A g−1 and a high specific energy of 25.5 Wh kg−1 at a power density of 2 kW kg−1 was obtained for the GCA electrode, which can be attributed to the abundant electrochemically active surfaces, short ion transport paths, and effective electrolyte infiltration.. This work demonstrates an effective and low‐cost strategy to prepare hierarchical and well‐organized porous biomass carbon materials with graphene‐like nanosheets for high‐performance supercapacitors.
Automated sensing of daily activity: A new lens into development
Authors: de Barbaro Kaya 
Published: March 2019

AbstractRapidly maturing technologies for sensing and activity recognition can provide unprecedented access to the complex structure daily activity and interaction, promising new insight into the mechanisms by which experience shapes developmental outcomes. Motion data, autonomic activity, and “snippets” of audio and video recordings can be conveniently logged by wearable sensors (Lazer et al., 2009). Machine learning algorithms can process these signals into meaningful markers, from child and parent behavior to outcomes such as depression or teenage drinking. Theoretically motivated aspects of daily activity can be combined and synchronized to examine reciprocal effects between children’s behaviors and their environments or internal processes. Captured over longitudinal time, such data provide a new opportunity to study the processes by which individual differences emerge and stabilize. This paper introduces the reader to developments in sensing and activity recognition with implications for developmental phenomena across the lifespan, sketching a framework for leveraging mobile sensors for transactional analyses that bridge micro‐ and longitudinal‐ timescales of development. It finishes by detailing resources and best practices to facilitate the next generation of developmentalists to contribute to this emerging area.
The classification of eating disorders in China: A categorical model or a dimensional model
Authors: Zheng Yuchen , Kang Qing , Huang Jiabin , Jiang Wenhui , Liu Qiang , Chen Han , Fan Qing , Wang Zhen , Xiao Zeping , Chen Jue 
Published: March 2019

AbstractObjectiveAccording to the ICD‐10 and DSM‐5, eating disorders (EDs) are classified using a categorical model that assumes the subtypes are qualitatively different from one another. However, it is still intensely debated that a dimensional model is more suitable. The aim of this study is to examine whether EDs have a categorical or dimensional latent structure using a sample of Chinese ED patients.MethodThe sample included 322 patients, diagnosed with an ED from 2010 to 2017 in the Shanghai Mental Health Center, and comparison participants (N = 850), recruited from undergraduate students in one university in Shanghai. Participants were evaluated with the Eating Disorder Inventory‐2 (EDI‐2) questionnaire and another questionnaire developed by the researchers. Three taxometric procedures (MAXimum EIGenvalue [MAXEIG], latent‐mode factor analysis [L‐Mode], and Mean Above Minus Below A Cut [MAMBAC]) were applied, respectively, to analyze the patients' clinical symptoms data.ResultsPatients were divided into three groups according to their clinical diagnosis. The plots of the three taxometric analysis procedures supported the categorical construct in anorexia nervosa, binge‐eating/purging group, and bulimia nervosa group. The Comparison Curve Fit Indices of the MAXEIG, L‐Mode, and MAMBAC procedures were 0.694, 0.709, 0.704 in the AN‐BP group and 0.727, 0.67, 0.62 in the BN group, respectively, which also support the categorical construct.DiscussionThe results support two distinct classes of ED subtypes among Chinese sample. Further work on applying hybrid model in analysis has been discussed.
The effects of management on long‐term carbon stability in a southeastern U.S. forest matrix under extreme fire weather
Authors: Krofcheck D. J. , Loudermilk E. L. , Hiers J. K. , Scheller R. M. , Hurteau M. D. 
Published: March 2019

AbstractHow fire interacts with an ecosystem is driven by forest structure, fuel bed heterogeneity, topography, and weather. The juxtaposition of two distinct vegetation types with divergent properties can further influence the effects of fire on an ecosystem. In the southeastern United States, pine flatwoods and hardwood–cypress swamps are distinct ecosystems that can be geographically intermixed as a function of elevation, affecting how fires move across the landscape. We sought to understand the consequence of extreme fire weather on landscape wildfire severity and biomass accumulation taking into consideration the spatial configuration of the two ecosystems and fuels reduction management strategies. We used a spatially explicit growth and succession model at the landscape scale to simulate a suite of management activities employed at the Osceola National Forest (Florida, USA), which are aimed at mitigating severe wildfire, maintaining ecosystem function, and producing wood fiber. We found that with extreme fire weather, hardwood–cypress swamps were more available to burn because of drier and hotter conditions, increasing the risk of high‐severity fire in the adjacent pine flatwoods. This reduced landscape aboveground biomass stability relative to contemporary fire weather, with an end‐of‐simulation range from 59.2 to 69.2 Mg C/ha. When we incorporated targeted mechanical thinning and prescribed burning into the simulations under extreme fire weather, the landscape showed higher aboveground biomass stability, with an end‐of‐simulation range of 70.9–72.8 Mg C/ha. We found that targeting mechanical thinning treatments to the interface of the hardwood–cypress swamps and maintaining the pine flatwoods with prescribed burning constrained the spread of high‐severity wildfire at the landscape scale. These results highlight the importance of understanding how changes to fire weather severity may alter fire regimes and consequently carbon stability of these highly interspersed yet functionally dissimilar ecosystems.
Tidal regime influences the spatial variation in trait‐based responses of Suaeda salsa and edaphic conditions
Authors: Wang Fangfang , Yan Jiaguo , Ma Xu , Qiu Dongdong , Xie Tian , Cui Baoshan 
Published: March 2019

AbstractTidal regime is recognized as a vital hydrological process in the restructuring of saltmarsh vegetation communities, resulting in differing edaphic conditions and ecosystem functions. Ample studies have focused on the context‐dependent effects of tidal disturbance on saltmarsh vegetation worldwide, particularly trait‐based responses to physical factors; however, to our knowledge, there are few insights into the edaphic conditions and responses of saltmarsh plants as well as plant–soil systems to tidal disturbance gradients in the Yellow River Delta (YRD), a temperate estuary in northern China. Here, we conducted field surveys and experimental fieldwork at four distinct sites that varied with tidal regime. Site‐specific effects of tidal disturbance on the annual saltmarsh foundation plant Suaeda salsa, as well as their edaphic surroundings, were analyzed. Our results showed that trait‐based responses largely explained the tidal disturbance impacts on S. salsa; moreover, the edaphic environment differed significantly among sites. We found that flooding frequency had a significantly negative relation to S. salsa total biomass, which consisted of above‐ and belowground biomass, and a significantly positive relation to height. In general, total organic carbon, total nitrogen, and total phosphorus differed among sites, and these differences changed with the soil layers. In addition, there were some correlations between the soil environment and plant traits. Total organic carbon was linearly positively linked to the biomass of S. salsa at each soil depth. The carbon, nitrogen, and phosphorus stoichiometry of the soil had a low correlation with that of the belowground biomass of S. salsa but had a significant correlation with that of the aboveground biomass of S. salsa. Our study suggests that spatial patterns of S. salsa and edaphic conditions in the YRD vary with tidal regime, therefore providing a basis for the context‐dependent conservation and restoration of coastal saltmarsh ecosystems, especially in areas with irregular, semidiurnal tides. Moreover, our findings highlight the importance of potential interactive effects between plant traits and tidal disturbances in regulating biogeochemical cycles, especially carbon sequestration, in coastal saltmarsh systems.
Uneven global distribution of food web studies under climate change
Authors: Cameron Erin K. , Sundqvist Maja K. , Keith Sally A. , CaraDonna Paul J. , Mousing Erik A. , Nilsson Karin A. , Metcalfe Daniel B. , Classen Aimée T. 
Published: March 2019

AbstractTrophic interactions within food webs affect species distributions, coexistence, and provision of ecosystem services but can be strongly impacted by climatic changes. Understanding these impacts is therefore essential for managing ecosystems and sustaining human well‐being. Here, we conducted a global synthesis of terrestrial, marine, and freshwater studies to identify key gaps in our knowledge of climate change impacts on food webs and determine whether the areas currently studied are those most likely to be impacted by climate change. We found research suffers from a strong geographic bias, with only 3.5% of studies occurring in the tropics. Importantly, the distribution of sites sampled under projected climate changes was biased—areas with decreases or large increases in precipitation and areas with low magnitudes of temperature change were under‐represented. Our results suggest that understanding of climate change impacts on food webs could be broadened by considering more than two trophic levels, responses in addition to species abundance and biomass, impacts of a wider suite of climatic variables, and tropical ecosystems. Most importantly, to enable better forecasts of biodiversity responses to climate change, we identify critically under‐represented geographic regions and climatic conditions which should be prioritized in future research.
Wind erosion and dust from US drylands: a review of causes, consequences, and solutions in a changing world
Authors: Duniway Michael C. , Pfennigwerth Alix A. , Fick Stephen E. , Nauman Travis W. , Belnap Jayne , Barger Nichole N. 
Published: March 2019

AbstractErosion by wind is one of the principal processes associated with land degradation in drylands and is a significant concern to land managers and policymakers globally. In the drylands of North America, millions of tons of soil are lost to wind erosion annually. Of the 60 million ha in the United States identified as most vulnerable to wind erosion (arid and dominated by fine sandy soils), 64% are managed by federal agencies (37 million ha). Here we review the drivers and consequences of wind erosion and dust emissions on drylands in the United States, with an emphasis on actionable responses available to policymakers and practitioners. We find that while dryland soils are often relatively stable when intact, disturbances including fire, domestic livestock grazing, and off‐highway vehicles can increase horizontal eolian flux by an order of magnitude, in some cases as much as 40‐fold. A growing body of literature documents the large‐scale impacts of deposited dust changing the albedo of mountain snow cover and in some cases reducing regional water supplies by ~5%. Predicted future increases in aridity and extreme weather events, including drought, will likely increase wind erosion and consequent dust generation. Under a drier and more variable future climate, new and existing soil‐ and vegetation‐disturbing practices may interact in synergistic ways, with dire consequences for environments and society that are unforeseen to many but fairly predictable given current scientific understanding. Conventional restoration and reclamation approaches, which often entail surface disturbance and rely on adequate moisture to prevent erosion, also carry considerable erosion risk especially under drought conditions. Innovative approaches to dryland restoration that minimize surface disturbance may accomplish restoration or reclamation goals while limiting wind erosion risk. Finally, multidisciplinary and multijurisdictional approaches and perspectives are necessary to understand the complex processes driving dust emissions and provide timely, context‐specific information for mitigating the drivers and impacts of wind erosion and dust.
Coarse particulate organic matter dynamics in ephemeral tributaries of a Central Appalachian stream network
Authors: Fritz Ken M. , Pond Gregory J. , Johnson Brent R. , Barton Chris D. 
Published: March 2019

AbstractHeadwater ephemeral tributaries are interfaces between uplands and downstream waters. Terrestrial coarse particulate organic matter (CPOM) is important in fueling aquatic ecosystems; however, the extent to which ephemeral tributaries are functionally connected to downstream waters through fluvial transport of CPOM has been little studied. Hydrology and deposition of leaf and wood, and surrogate transport (Ginkgo biloba leaves and wood dowels) were measured over month‐long intervals through the winter and spring seasons (6 months) in 10 ephemeral tributaries (1.3–5.4 ha) in eastern Kentucky. Leaf deposition and surrogate transport varied over time, reflecting the seasonality of litterfall and runoff. Leaf deposition was higher in December than February and May but did not differ from January, March, and April. Mean percent of surrogate leaf transport from the ephemeral tributaries was highest in April (3.6% per day) and lowest in February (2.5%) and May (2%). Wood deposition and transport had similar patterns. No CPOM measures were related to flow frequency. Ephemeral tributaries were estimated to annually contribute 110.6 kg AFDM·km−1·yr−1 of leaves to the downstream mainstem. Ephemeral tributaries are functionally connected to downstream waters through CPOM storage and subsequent release that is timed when CPOM is often limited in downstream waters.
Comparison of the non‐native herbAlliaria petiolatawith dominant native herbs in microhabitats of a Midwestern forest
Authors: Anderson Michael D. , Davis Mark A. , Burke Craig , Dalrymple Cody , Ensley‐Field Mira , Lewanski Alex , Manning Paul , Moore Zach , Morisawa Rina , Nguyen Phuong , Pillar Allison , Dosch Jerald J. 
Published: March 2019

AbstractA mechanistic understanding of the causes of naturalization in terrestrial plant communities, and the consequences for associated ecosystems, relies on understanding whether and how native and non‐native plant traits differ. Traits of non‐native plants may either help them compete or avoid competition with natives, and depending on their interaction with the native community, the non‐native may act as more or less of an active driver vs. a passive passenger of change in the native ecosystem. Trait comparisons between native and non‐native plants are often laboratory‐based, providing insights that can be difficult to apply to natural communities. Studies of the impacts of non‐native plants, by contrast, are generally performed in natural communities, but usually do not compare observed impacts of the non‐natives with those exerted by dominant natives on each other and the community. Thus, the likely relative disruption of the non‐native to the community is unclear. In a four‐year observational study conducted at the microhabitat scale in the herbaceous layer of a Midwestern oak forest, we compared the non‐native herbAlliaria petiolata(garlic mustard) with dominant native herbaceous species in terms of correlational patterns related to three broad categories of traits: (1) environmental correlates (light, topography, soil nutrients) with presence and cover, (2) inter‐annual regeneration and phenology, and (3) associations with other species (competition and herbivory). We found thatAlliariadiffered strongly from dominant native herbs in all three categories. Compared with native herbs,Alliariawas more strongly associated with south‐facing slopes and high nutrient levels, displayed earlier phenology and enhanced dispersal ability, and was strongly avoided by the generalist native herbivore,Odocoileus virginianus(white‐tailed deer). Despite well‐described allelopathic effects ofAlliariaon mycorrhizae and mycorrhizal plants, we found little evidence to suggest thatAlliariahad negative interactions with native plants that were stronger than those of native community members. Overall, our data suggest that naturalization ofAlliariain this site is primarily due to differences from native plants in phenology, dispersal capability, and avoidance of herbivory, and thatAlliariais therefore more likely to be acting as a passenger than as a driver of change in our site.