bluuebunny/crossref_metadata_2025 huggingface dataset:
Environmental Degradation
Authors: Mauro Salvatore Engel‐Di
Published: March 2017

Environmental degradation refers to a specifically human‐induced decline in the quality of biophysical processes that directly or indirectly enable and sustain human life. Because it encompasses a highly diverse set of inter‐related outcomes, environmental degradation is studied through a great variety of approaches and methods, involving quantitative as well as qualitative data and techniques. There are numerous challenges faced by those studying environmental degradation, aside from integrating the many areas of expertise involved. Among the difficulties are the complex inter‐relations and mutually transforming processes among environmental components as well as the difficulties presented by the relative nature of environmental degradation with respect to what is included as part of the biophysical environment (e.g., cities have tended to be excluded until recently) and the often tacit socially specific criteria used to determine whether an environment is degraded (e.g., what is degraded to some is not necessarily so to others).
Environmental Assessment Techniques
Authors: Fleskens Luuk
Published: March 2017

Environmental assessment techniques comprise a range of analytical and practical tools of varying level of complexity to assess, monitor, or interpret environmental changes: expert judgment, checklist matrices, environmental risk assessment, mapping and spatial analysis, impact prediction, impact evaluation, remote sensing, natural resource accounting, participatory techniques, and crowdsourcing. Such techniques may rely on a combination of judgment, observations, measurements and modeling, and may either be applied autonomously as a stand‐alone tool or embedded within an institutionalized process such as environmental impact assessment requiring a combination of techniques and prescribing certain procedures to be followed. The aim of environmental assessment is to understand better the consequences of environmental change for human societies and the impact of human interference on the quality of the environment. Environmental assessment techniques are typically geared toward informing governments to design regulations or projects and companies to monitor compliance with regulations.
Environmental Science
Authors: Eden Sally
Published: March 2017

Environmental science is a wide field of research that examines all aspects of how environments develop, change, and are impacted by human activity. This includes work on the basic principles of environmental processes and change, but also applied research into policy‐relevant issues, such as climate change and pollution, as well as human–environment research into how human activity impacts on the environment and how this impact might be ameliorated. Environmental science has developed alongside the environmental movement in recent decades and, like all scientific work, it is shaped by this sociopolitical context. Drawing on different disciplines such as geology, ecology, chemistry, geography, and meteorology, it is sometimes considered multidisciplinary or interdisciplinary, although some argue it must become transdisciplinary to fully tackle the challenges of sustainability.
Gated Communities
Authors: Wilson David
Published: March 2017

Gated communities across the world are isolated enclaves designed to be exclusive, exclusionary, and physically detached from the immediate city or community. To achieve this, gated communities typically contain controlled entrances, central open courts or streets, and architectural class‐based meanings. These are designed to enable tenants to perform a maximum amount of traffic surveillance and to communicate who should and who should not be at these microsites. While economic segregation is not new, this form of segregating spills over into public space and intensifies the growing privatization phenomenon.
Human Geography
Authors: Kobayashi Audrey
Published: March 2017

Human geography has ancient roots in many parts of the world. It became a formal discipline in Europe during the mid‐eighteenth century, and has since been dominated by anglophone scholarship. Major debates in the discipline can be understood in the context of the geopolitics of the times, including imperialism and colonialism, capitalism, globalization, and recently neoliberalism, that have written the script of global development. In the twentieth century the discipline moved from an emphasis on region and landscape to develop as a science of space, and during the latter part of the century as a critical subdiscipline influenced both by the radical theories of the 1960s and by poststructuralism. In the twenty‐first century, geographers have taken advantage of rapid technological change to increase analytical power, and continue to address methodological issues around the ontology of subject matter. Geography as a discipline is more and more concerned with geopolitics and ethics around such issues as climate change, human migration, and the diversification of populations.
Networks, Social Capital, and Development
Authors: Hess Martin
Published: March 2017

This entry provides an overview of the role of networks and social capital for development. Networks have become an almost universal organizing principle for societies and economies, and have increasingly been at the center of analysis in human geography and cognate disciplines. At the same time, the concept of social capital has gained prominence in development studies and policy, following in particular Robert Putnam's influential writings in the 1990s. This has led to substantive academic debate about the value of theorizing networks and social capital as conceptual frame for development studies and policy. It is argued that a renewed engagement with more critical readings of networks and social capital can still provide a useful analytical lens for the study of development in today's global network society and economy.
Political Ecology
Authors: McCarthy James
Published: March 2017

Political ecology grew out of efforts to theorize how agrarian production systems and social relations in the Global South were being transformed by capitalist transitions and associated state strategies and interventions. Early political ecology both critiqued and built upon cultural ecology, the natural hazards tradition, and the Berkeley School. It used mixed methods, especially ethnographic ones, to investigate how access to and control over rural lands and resources in the Global South were changing due to various environmental, developmental and conservation interventions. Overtly critical and political, it emphasized how such changes displaced and dispossessed many people. As the field developed, it paid increasing attention to how gender, race, ethnicity, indigeneity, and other aspects of identity intersect with class in the realm of environmental governance. It has also turned to the study of nature–society relations in industrialized countries, cities, and other contexts, providing a critical lens for the analysis of climate change and other contemporary nature–society issues worldwide.
Poststructuralism/Poststructural Geographies
Authors: Woodward Keith
Published: March 2017

Emerging in the late 1960s, poststructuralism initiated multiple political, epistemological, and ontological critiques of Western thought. Growing out of and away from the structuralist movement, it developed concepts such as difference and power to challenge systems that naturalize unevenness, prejudice, oppression, and exploitation. Many of its interventions have since been widely absorbed by the humanities and social sciences. Poststructuralist geographies direct these critiques at foundational ideas and essentialist biases, including racist, sexist, and colonialist history, and lingering structural binaries (nature−culture, emotion−reason, practice−theory, nonhuman−human). It has also given rise to a period of rich creativity, particularly in geographical studies of representation and nonrepresentation, multiple epistemologies and performativity, new spatial ontologies, spaces of affect, new natures, among many others.
Social Movements
Authors: Miller Byron
Published: March 2017

Social movements are an important form of collective political expression that typically address the pressing concerns of oppressed and marginalized social groups. Social movement mobilization requires the building of strong social bonds based in shared identities and values. These processes are rooted in the geographies of lifeworlds, as are the processes of alliance‐building and political resistance. However, because oppression and deprivation often stem from systemic processes with differing geographies, social movement strategies must often confront and attempt to reconcile diverse geographies of experience, grievance, and systemic process.
Urban Political Ecology
Authors: Heynen Nik
Published: March 2017

Urban political ecology (UPE) is a geographic approach geared toward understanding the ways in which political, economic, and ecological processes work together to transform cities and the lives of the people who live in them. Part of the challenge taken up in UPE is how to use critical social theory, especially theories associated with political economy, to better frame the problems faced by people living in cities. While UPE has a cohesive foundation of literature, it is quickly growing as the role of urbanization and the global environment becomes more profound.
Urban Politics
Authors: Miller Byron
Published: March 2017

Urban politics have been defined in a variety of ways. Castells's “classic” definition of urban politics, grounded in collective consumption issues, gave way to a new urban politics of economic growth, and more recently to a diverse range of notions. Urban politics are highly complex and cannot be reduced to processes making and operating within a specific areal unit, such as a city.
Geomorphic Systems
Authors: Oguchi Takashi , Butler David R.
Published: March 2017

General system(s) theory was introduced to geomorphology in the middle of the twentieth century. Since then, geomorphologists have regarded assemblages of landforms as geomorphic systems, with structural hierarchy, interactions between units and subunits, exchange of mass and energy with the surrounding environment, and change toward a steady state or equilibrium. Although the concept of geomorphic systems is established as a general background of research, criticism and re‐evaluation of the concept have increased since the 1990s. Understanding the history of the system approach in geomorphology, introducing newer relevant ideas, and developing more applications of the approach to cases in the real world are important for the future progress of geomorphology.
Snow and Ice Avalanches
Authors: Corona Christophe , Stoffel Markus
Published: March 2017

Avalanches are defined as large masses of snow or ice moving rapidly down a mountainside or over a precipice. Throughout history, avalanches have played an important role and have also shaped mountain societies – nowadays, they remain a threat to human lives and repeatedly damage or destroy infrastructure in mountain regions. Substantial progress has been achieved over the past few decades in the field of snow avalanche research, thereby contributing to the increasing demand for safety. This entry describes the formation and motion of snow (ice) avalanches and the hazards associated with these processes. It also summarizes recent findings on the triggering factors of avalanches, with an emphasis on meteorological factors. The entry concludes with a look at the possible impacts of climatic change on avalanche activity.
Cryosphere: Remote Sensing
Authors: Nolin Anne W.
Published: March 2017

The frozen realm of the cryosphere consists of snow, ice sheets and glaciers, sea ice, and permafrost and frozen ground. Snow and ice have bright reflectance characteristics in the visible spectrum, enabling space‐borne measurements of their spatial extent since the 1960s. Passive microwave sensors have measured sea ice and snow extent for several decades. They also map melt on the ice sheets and detect soil freeze–thaw status. Multispectral and hyperspectral sensors detect snow grain size/specific surface area and retrieve snow albedo from mountains to ice sheets. Space‐borne radars offer information on sea ice type, ice sheet surface roughness, glacier velocity, and frozen soils. Gravity measurements provide estimates of the changing mass of ice sheets and glaciated regions. In recent years, airborne and ground‐basedLiDARand radar remote sensing technologies have advanced and can now measure snow depth, internal snowpack characteristics, ice thickness, sea ice properties, soil freeze–thaw state, and more.
Mountain Hydrology
Authors: Marston Richard A. , Marston Bryce K.
Published: March 2017

Mountains generate a disproportionate share of runoff on Earth, with significant differences in processes and overall flow regime between mountains situated in various eco‐regions. Water on steepland slopes is affected by interception loss and evapotranspiration, which are strongly controlled by vegetation cover. Soil moisture varies strongly by topographic position and soil characteristics in mountains. Water moves by vertical percolation and also laterally through subsurface zones and may eventually reach mountain streams. Runoff in mountains is generated by Hortonian overland flow, saturation return flow, permafrost melt, and effluent seepage. Human activities affect mountain hydrology in indirect ways through timber harvest and road building, grazing and cropland agriculture, urbanization, lode mining, climate change, and altered fire regime. Human activities directly affect mountain hydrology through removing or introducing beaver, dams, and off‐channel diversions. Close links exist between mountain hydrology and the climatology, biogeography, soils, permafrost, glaciers, and geomorphology of mountain areas.
Soil Water
Authors: Beach Tim , M. Flood Jonathan
Published: March 2017

Soil water is perhaps the most important yet most overlooked component of the hydrologic cycle. Humans go to great lengths to acquire and apply it to agricultural fields but readily forget its existence once it is incorporated into crops. Soil water stores and distributes nutrients and flows into plants and aquifers. The largest use of water on Earth is augmenting soil water through irrigation, accounting for 70% of global freshwater use annually. This entry describes types of soil water, its movement in the hydrologic cycle and through the landscape, and its relationship to ecosystems and societies. It concludes with a discussion of trends and short‐term projections for the future of soil water.
Wetland Hydrology
Authors: Beach Tim , Flood Jonathan M.
Published: March 2017

Hydrology is an essential ingredient in wetlands, which are essential for the health and survival of numerous species, including our own. These systems are famous for their biodiversity, soils, and ecosystem services but hydrology is the primary control on their existence, morphology, and character. Described and discussed in this entry are the role of hydrology in wetlands and its connection to important ecosystem functions and services. The dynamic history of human–wetland interaction is then explored and the future hydrologic impacts likely to occur in wetlands over the next several decades are considered.
Environmental Ethics
Authors: Roe Emma
Published: March 2017

Environmental ethics is interested in probing how humans rationalize the relationship they have with the nonhuman world of plants, animal, rivers, geological landforms, and so on, and the morally right or wrong thing to do. Both anthropocentric and nonanthropocentric approaches to studying environmental ethics are discussed. Illustrative examples are drawn primarily from the rise in concern for the welfare of animals in UK society and globally. Considerable attention is given to how relational ontological approaches to ethics are reconfiguring ethical connectivities between humans and nonhumans, through emphasizing the role of the body in how the body is theorized and a praxis of care.
Geotargeted Alerts and Warnings
Authors: Wood Michele M.
Published: March 2017

Recent technological advances have made it possible to deliver geotargeted alert and warning messages to mobile devices. In the context of risk communication alerts and warnings, geotargeting refers to efforts to transmit risk communication messages only to those individuals physically located within the geographic area at risk. How this new technology may influence the manner in which people receive and respond to public warnings bears on the further development of risk communication theory and also on emerging warning practice.
Modeling Uncertainty in Digital Elevation Models
Authors: Shortridge Ashton M. , Fayne Jessica V. , Rice Matthew T.
Published: March 2017

While digital elevation models (DEMs) are widely used to represent the earth's terrain, they are not free from error. Data errors in DEMs are likely to affect any application that uses them: a critical question is, by how much? This entry considers the nature and sources of error in digital elevation data. It describes statistical models that have been used to characterize elevation error distributions as random fields. These error models are coupled with uncertainty propagation to characterize how error in DEMs can impact applications that rely on terrain data input. A general Monte Carlo modeling framework based on stochastic simulation is discussed and illustrated showing how uncertainty can be propagated to any spatial application.
Geospatial Semantic Web
Authors: Janowicz Krzysztof , Hitzler Pascal
Published: March 2017

The Semantic Web is a highly interdisciplinary research field that aims at fostering the publication, retrieval, reuse, and integration of data in a distributed, web‐scale environment in which multithematic and multiperspective information has to be handled by humans and machines alike. This raises many interesting challenges that attract researchers from disciplines such as computer science, cognitive science, geographic information science, bioinformatics, digital humanities, and the life sciences. Over the years this led to a multitude of subcommunities that drive today's Semantic Web research. As one of these communities, the Geospatial Semantic Web is concerned with the semantics of geospatial data, next‐generation cyberinfrastructures, formal vocabularies for the geodomain, and geographic information retrieval, as well as new methods that foster semantic interoperability without restricting heterogeneity.
Geography Education: Community Colleges
Authors: Lyste Kerry
Published: March 2017

Community colleges play an important role in American higher education by providing vocational, technical, and further education colleges for students who have finished their secondary education and are seeking additional training or qualifications for professional advancement or are intending to transfer into a four‐year bachelor's programs. Similar institutions exist in other countries but, in the United States, geography is part of many
US
community college curricula and enrolls many students. Given the importance of community colleges to higher education, more attention is needed to consider how to improve and innovate, particularly given foreseeable budget constraints. As demand for geospatial and
GIS
education increases, community colleges may also be able to expand and grow in these areas, though budgetary and staffing issues present some obstacles.
GeoHumanities
Authors: Cresswell Tim , P. Dixon Deborah
Published: March 2017

The recent emergence of geohumanities signals a cross‐disciplinary and a transdisciplinary engagement with themes of space and place. As a loosely structured field of inquiry, geohumanities combines a long‐standing humanities interest in the Earth, dating back to the Renaissance, with much more recent developments in the digital humanities and creative uses of geographic information science (
GIScience
). This entry explores these varying genealogies of the geohumanities and points toward future prospects for the new field.
Modernization Theory
Authors: Bordoloi Sudarshana , Das Raju J.
Published: March 2017

Modernization theory (MT) developed in the context of de‐colonization and Cold War in which there were threats to the economic‐geopolitical security of the US from a poverty‐stricken Global South attracted to communism. Out of the consequent need to promote socioeconomic development in the Global South, MT emerged as an intellectual project in which many disciplines, including geography, participated. It elaborates the differences between “traditional” and “modern” societies and explains these basically by the absence of modern sociocultural values. MT has numerous problems, including its ethnocentrism and stagist thinking and its neglect of the materiality of culture and of imperialism. MT has lost some of its original popularity but continues to inform development thinking and practice. However, whether it is the traditional version of MT or any of its modern refinements or indeed the postmodernist ideas appearing to be critical of MT as a Western grand theory, the point common to all is that they fail to mount a fundamental intellectual‐political challenge to the dominance of the capitalist and imperialist economic system.
Popular Geographics
Authors: Dobson Jerome E.
Published: March 2017

Geographers have worked to communicate with broader audiences and the general public for centuries. Ongoing efforts through literature, news media, and popular geographics remain a key challenge for geography today as research frontiers expand and outlets multiply. Historical precedents dating back as far as classical antiquity help to inform current debate, but the opportunities and challenges of reaching and engaging contemporary audiences are changing as print publications give way to digital and social media.
Albuminuria in Rheumatoid Arthritis: Associations With Rheumatoid Arthritis Characteristics and Subclinical Atherosclerosis
Authors: Sammut Amanda , Shea Steven , Blumenthal Roger S. , Szklo Moyses , Bathon Joan M. , Polak Joseph F. , Tracy Russell , Giles Jon T.
Published: March 2017

Objective

Albuminuria is a marker for subclinical cardiovascular disease (CVD) in the general population. It is uncertain whether this association is present in patients with rheumatoid arthritis (RA), a population with increased atherosclerosis and CVD events.

Methods

Urine albumin from a spot morning collection was measured, and the urine albumin‐to‐creatinine ratio (uACR) was calculated for RA patients and a population‐based sample of demographically matched non‐RA controls. Associations of elevated uACR (≥25 mg/gm for women and ≥17 mg/gm for men) with CVD risk factors and measures of atherosclerosis (coronary artery calcification, ultrasound‐determined maximal intima‐media thickness of the common carotid artery and internal carotid artery [ICA], and the presence of focal plaque in the ICA) were compared cross‐sectionally according to RA status.

Results

We compared 196 RA patients with 271 non‐RA controls. Elevated uACR was found in 18% of the RA patients compared with 17% of the controls (P = 0.89). After adjustment, RA was associated with 57% lower odds of elevated uACR (P = 0.016). Higher serum creatinine levels and hypertension were both strongly and significantly associated with elevated uACR in the control group but not in the RA group (both P for interaction < 0.05). Among RA characteristics, the adjusted prevalence of elevated uACR among those treated with tumor necrosis factor inhibitors was less than half that among those not so treated (9% versus 20%, respectively; P = 0.047).

Conclusion

There was no association in the RA group of elevated uACR with measures of atherosclerosis or with several key cardiometabolic risk factors, which suggests a lower usefulness of elevated uACR as an indicator of subclinical CVD in RA.
Recursive Bayesian estimation of autoregressive model with uniform noise using approximation by parallelotopes
Authors: Pavelková Lenka , Jirsa Ladislav
Published: March 2017

This paper proposes a recursive algorithm for the estimation of a stochastic autoregressive model with an external input. The noise of the involved model is described by a uniform distribution. The model parameters are estimated using the Bayesian approach. Without an approximation, the support of the posterior distribution is a complex multidimensional polytope whose number of faces increases with time. We propose an approximation of this polytope in each time step by a parallelotope with a constant number of faces. The behaviour of the proposed algorithm is illustrated by simulations and compared with other methods.
Fractional adaptive systems in the presence of bounded disturbances and parameter variations
Authors: Duarte‐Mermoud Manuel Armando , Aguila‐Camacho Norelys
Published: March 2017

This paper presents the analysis of fractional adaptive systems in the presence of bounded disturbances and parameter variations. Fractional adaptive systems are analyzed using the error model approach, to give generality to the results. Modified fractional adaptive laws are proposed to make the adaptive systems robust against bounded disturbances and parameter variations. The boundedness of the signals is analytically proved using Lyapunov functions. A simulation example is included to show the effectiveness of the proposed solutions.
Acoustic Separation of Nanoparticles in Continuous Flow
Authors: Wu Mengxi , Mao Zhangming , Chen Kejie , Bachman Hunter , Chen Yuchao , Rufo Joseph , Ren Liqiang , Li Peng , Wang Lin , Huang Tony Jun
Published: March 2017

The separation of nanoscale particles based on their differences in size is an essential technique to the nanoscience and nanotechnology community. Here, nanoparticles are successfully separated in a continuous flow by using tilted‐angle standing surface acoustic waves. The acoustic field deflects nanoparticles based on volume, and the fractionation of nanoparticles is optimized by tuning the cutoff parameters. The continuous separation of nanoparticlesis demonstrated with a ≈90% recovery rate. The acoustic nanoparticle separation method is versatile, non‐invasive, and simple.
Low‐Temperature‐Processed Printed Metal Oxide Transistors Based on Pure Aqueous Inks
Authors: Scheideler William J. , Kumar Rajan , Zeumault Andre R. , Subramanian Vivek
Published: March 2017

Additive patterning of transparent conducting metal oxides at low temperatures is a critical step in realizing low‐cost transparent electronics for display technology and photovoltaics. In this work, inkjet‐printed metal oxide transistors based on pure aqueous chemistries are presented. These inks readily convert to functional thin films at lower processing temperatures (T ≤ 250 °C) relative to organic solvent‐based oxide inks, facilitating the fabrication of high‐performance transistors with both inkjet‐printed transparent electrodes of aluminum‐doped cadmium oxide (ACO) and semiconductor (InOx). The intrinsic fluid properties of these water‐based solutions enable the printing of fine features with coffee‐ring free line profiles and smoother line edges than those formed from organic solvent‐based inks. The influence of low‐temperature annealing on the optical, electrical, and crystallographic properties of the ACO electrodes is investigated, as well as the role of aluminum doping in improving these properties. Finally, the all‐aqueous‐printed thin film transistors (TFTs) with inkjet‐patterned semiconductor (InOx) and source/drain (ACO) layers are characterized, which show ideal low contact resistance (Rc < 160 Ω cm) and competitive transistor performance (µlin up to 19 cm2 V−1 s−1, Subthreshold Slope (SS) ≤150 mV dec−1) with only low‐temperature processing (T ≤ 250 °C).
Metal‐Organic Framework Nanoparticles in Photodynamic Therapy: Current Status and Perspectives
Authors: Lismont Marjorie , Dreesen Laurent , Wuttke Stefan
Published: March 2017

This feature article covers the recent applications of metal‐organic framework nanoparticles (MOF NPs) in photodynamic therapy (PDT) of cancer. It aims at giving the reader an overview about these two current research fields, i.e., MOF and PDT, and at highlighting the potential synergistic effect that could result from their association. After describing the general photophysics and photochemistry that underlie PDT, the relationship between photosensitizer (PS) properties and PDT requirements is discussed throughout the PSs historical development. This development reveals the advantages of using nanotechnology platforms for the creation of the ideal PS and leads us to define the fourth generation of PSs, which includes NPs built from the PS itself as porphysomes or PS‐based MOF NPs. Especially, the precise spatial control over the PS assembly into well‐defined MOF NPs, which keeps the PS in its monomeric form and prevents PS self‐quenching, appears as a notable feature to solve PS solubility and aggregation issues and therefore improves the PDT efficiency. Finally, we discuss the future perspectives of MOF NPs in PDT and shed light on how promising these nanomaterials are.
Efficient Nonfullerene Polymer Solar Cells Enabled by a Novel Wide Bandgap Small Molecular Acceptor
Authors: Zhang Guangjun , Yang Guofang , Yan He , Kim Joo‐Hyun , Ade Harald , Wu Wenlin , Xu Xiaopeng , Duan Yuwei , Peng Qiang
Published: March 2017

A wide bandgap small molecular acceptor, SFBRCN, containing a 3D spirobifluorene core flaked with a 2,1,3‐benzothiadiazole (BT) and end‐capped with highly electron‐deficient (3‐ethylhexyl‐4‐oxothiazolidine‐2‐yl)dimalononitrile (RCN) units, has been successfully synthesized as a small molecular acceptor (SMA) for nonfullerene polymer solar cells (PSCs). This SMA exhibits a relatively wide optical bandgap of 2.03 eV, which provides a complementary absorption to commonly used low bandgap donor polymers, such as PTB7‐Th. The strong electron‐deficient BT and RCN units afford SFBRCN with a low‐lying LUMO (lowest unoccupied molecular orbital) level, while the 3D structured spirobifluorene core can effectively suppress the self‐aggregation tendency of the SMA, thus yielding a polymer:SMA blend with reasonably small domain size. As the results of such molecular design, SFBRCN enables nonfullerene PSCs with a high efficiency of 10.26%, which is the highest performance reported to date for a large bandgap nonfullerene SMA.
Assessment of First‐Principles and Semiempirical Methodologies for Absorption and Emission Energies of Ce3+‐Doped Luminescent Materials
Authors: Jia Yongchao , Poncé Samuel , Miglio Anna , Mikami Masayoshi , Gonze Xavier
Published: March 2017

In search of a reliable methodology for the prediction of light absorption and emission of Ce3+‐doped luminescent materials, 13 representative materials are studied with first‐principles and semiempirical approaches. In the first‐principles approach, that combines constrained density‐functional theory and ∆SCF, the atomic positions are obtained for both ground and excited states of the Ce3+ ion. The structural information is fed into Dorenbos' semiempirical model. Absorption and emission energies are calculated with both methods and compared with experiment. The first‐principles approach matches experiment within 0.3 eV, with two exceptions at 0.5 eV. In contrast, the semiempirical approach does not perform as well (usually more than 0.5 eV error). The general applicability of the present first‐principles scheme, with an encouraging predictive power, opens a novel avenue for crystal site engineering and high‐throughput search for new phosphors and scintillators.
Chiral and Luminescent TiO2 Nanoparticles
Authors: Cleary Olan , Purcell‐Milton Finn , Vandekerckhove Aurélien , Gun'ko Yurii K.
Published: March 2017

In this work, new chiral and luminescent TiO2 nanomaterials are prepared by a single step nonaqueous synthesis. Using circular dichroism spectroscopy it is shown that TiO2 nanoparticles are optically active with almost identical mirror images of one another in the band‐edge region of titanium dioxide. Investigations of the photoluminescence properties reveal a broad shallow trap state emission centered at 440 nm, with a photoluminescence quantum yield of ≈3.5%, which is among the highest reported for TiO2. Electron microscopy reveals the TiO2 nanostructures to be dendritic aggregates measuring 30–50 nm in size composed of smaller nanorods of 3–4 nm in diameter.
Strong Quantum Confinement and Fast Photoemission Activation in CH3NH3PbI3 Perovskite Nanocrystals Grown within Periodically Mesostructured Films
Authors: Anaya Miguel , Rubino Andrea , Rojas Teresa Cristina , Galisteo‐López Juan Francisco , Calvo Mauricio Ernesto , Míguez Hernán
Published: March 2017

In this Communication, a synthetic route is demonstrated to obtain stabilized MAPbI3 nanocrystals embedded in thin metal oxide films that display well‐defined and adjustable quantum confinement effects over a wide range of 0.34 eV. Mesostructured TiO2 and SiO2 films displaying an ordered 3D pore network are prepared by evaporation‐induced self‐assembly of a series of organic supramolecular templates in the presence of metal oxide precursors. The pores in the inorganic films obtained after thermal annealing are then used as nanoreactors to synthesize MAPbI3 crystallites with narrow size distribution and average radius comprised between 1 and 4 nm, depending on the template of choice. Both the static and dynamic photoemission properties of the ensemble display features distinctive of the regime of strong quantum confinement. Photoemission maps demonstrate that the spectral and intensity properties of the luminescence extracted from the perovskite quantum dot loaded films are homogeneous over squared centimeters areas. At variance with their bulk counterparts, constant emission intensity is reached in time scales at least four orders of magnitude shorter.
Ultrasensitive Iron‐Triggered Nanosized Fe–CoOOH Integrated with Graphene for Highly Efficient Oxygen Evolution
Authors: Han Xiaotong , Yu Chang , Zhou Si , Zhao Changtai , Huang Huawei , Yang Juan , Liu Zhibin , Zhao Jijun , Qiu Jieshan
Published: March 2017

Effectively active oxygen evolution reaction (OER) electrocatalysts are highly desired for water splitting. Herein, the design and fabrication of nanometer‐sized Fe‐modulated CoOOH nanoparticles by a novel conversion tailoring strategy is reported for the first time and these nanoparticles are assembled on graphene matrix to construct 2D nanohybrids (FeCoOOH/G) with ultrasmall particles and finely modulated local electronic structure of Co cations. The Fe components are capable of tailoring and converting the micrometer‐sized sheets into nanometer‐sized particles, indicative of ultrasensitive Fe‐triggered behavior. The as‐made FeCoOOH/G features highly exposed edge active sites, well‐defined porous structure, and finely modulated electron structure, together with effectively interconnected conducting networks endowed by graphene. Density functional theory calculations have revealed that the Fe dopants in the FeCoOOH nanoparticles have an enhanced adsorption capability toward the oxygenated intermediates involved in OER process, thus facilitating the whole catalytic reactions. Benefiting from these integrated characteristics, the as‐made FeCoOOH/G nanohybrids as an oxygen evolution electrocatalyst can deliver a low overpotential of 330 mV at 10 mA cm−2 and excellent electrochemical durability in alkaline medium. This strategy provides an effective, durable, and nonprecious‐metal electrocatalyst for water splitting.
Elucidating the Irreversible Mechanism and Voltage Hysteresis in Conversion Reaction for High‐Energy Sodium–Metal Sulfide Batteries
Authors: Wang Jiajun , Wang Liguang , Eng Christopher , Wang Jun
Published: March 2017

Irreversible electrochemical behavior and large voltage hysteresis are commonly observed in battery materials, in particular for materials reacting through conversion reaction, resulting in undesirable round‐trip energy loss and low coulombic efficiency. Seeking solutions to these challenges relies on the understanding of the underlying mechanism and physical origins. Here, this study combines in operando 2D transmission X‐ray microscopy with X‐ray absorption near edge structure, 3D tomography, and galvanostatic intermittent titration techniques to uncover the conversion reaction in sodium–metal sulfide batteries, a promising high‐energy battery system. This study shows a high irreversible electrochemistry process predominately occurs at first cycle, which can be largely linked to Na ion trapping during the first desodiation process and large interfacial ion mobility resistance. Subsequently, phase transformation evolution and electrochemical reaction show good reversibility at multiple discharge/charge cycles due to materials' microstructural change and equilibrium. The origin of large hysteresis between discharge and charge is investigated and it can be attributed to multiple factors including ion mobility resistance at the two‐phase interface, intrinsic slow sodium ion diffusion kinetics, and irreversibility as well as ohmic voltage drop and overpotential. This study expects that such understandings will help pave the way for engineering design and optimization of materials microstructure for future‐generation batteries.
Efficient removal of organic dye pollutants using covalent organic frameworks
Authors: Zhu Xiang , An Shuhao , Liu Yu , Hu Jun , Liu Honglai , Tian Chengcheng , Dai Sheng , Yang Xuejing , Wang Hualin , Abney Carter W. , Dai Sheng
Published: March 2017

A rational design and synthesis of covalent organic frameworks (COFs) displaying efficient adsorption of surrogates for common organic pollutants is demonstrated herein. Significantly, the top performing mesoporous triazine‐functionalized polyimide COF exhibits superior adsorption of the small dye molecule methylene blue, achieving a maximum adsorption capacity of ∼1691 mg g−1 (∼169 wt %), surpassing the performance of all previously reported nanoporous adsorbents. The experimental results and accompanying in silico simulations suggest that both the size of the organic dye molecules and the intrinsic pore‐size effect of the COF material should be taken into account simultaneously for the construction of COF‐based adsorbents with efficient dyes adsorption capacities. The structural diversity of COF materials along with the understanding of the encapsulation of organic dyes on COFs holds great promise for developing novel COF adsorbents for the efficient removal of organic pollutants from wastewater. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3470–3478, 2017
Pubertal testis volume, age at pubertal onset, and adolescent blood pressure: Evidence from Hong Kong's “Children of 1997” birth cohort
Authors: Kwok Man Ki , Leung Gabriel M. , Schooling C. Mary
Published: March 2017

Objectives

A warning from Health Canada suggests that testosterone increases blood pressure (BP). No evidence from large randomized controlled trials is available, and observational studies are confounded by ill‐health lowering serum testosterone. To address the evidence gap, we assessed the association of pubertal testicular volume, as a reflection of testosterone production, with BP.

Methods

We examined whether testicular volume was associated with sex‐, age‐, and height‐standardized BP z‐score at ∼13 years in a population‐representative Chinese birth cohort (n = 5195, 63% follow‐up). We used age at pubertal onset, determined as the earliest age when Tanner stage II for genitalia, breast, or pubic hair, or testicular volume of 4 mL occurred, as control exposures. These exposures were expected to produce findings different from testicular volume because they are not direct measures of testosterone. They were used to ascertain specificity of exposure and to detect residual confounding.

Results

Greater testicular volume was associated with higher systolic BP by 0.03 z‐score, which is equivalent to 1.40 mm Hg per standard deviation of testicular volume (95% CI 0.02–0.04), adjusted for infant characteristics, socioeconomic position, and childhood body mass index. Similarly adjusted, earlier pubertal onset was not associated with higher systolic BP z‐score in boys or girls.

Conclusions

Greater pubertal testicular volume is related to higher BP, consistent with a potential role of androgens in the higher BP in boys than girls that emerges during puberty. Our finding provides preliminary evidence supportive of more definitive studies to clarify the warning on testosterone from Health Canada.
Interrupted/bipartite clavicle as a diagnostic clue in Kabuki syndrome
Authors: Haanpää Maria , Schlecht Helena , Batra Gauri , Clayton‐Smith Jill , Douzgou Sofia
Published: March 2017

Kabuki syndrome is a rare developmental disorder characterized by typical facial features, postnatal growth deficiency, mild to moderate intellectual disability, and minor skeletal anomalies. It is caused by mutations of the KMT2D and KDM6A genes while recently RAP1A and RAP1B mutations have been shown to rarely contribute to the pathogenesis. We report two patients’ presentation of Kabuki syndrome caused by different KMT2D mutations, both including an interrupted/bipartite clavicle. The clinical diagnosis of Kabuki syndrome may be challenging, especially in younger patients and we suggest that the observation of a bipartite clavicle may be an additional diagnostic clue to prompt investigation for Kabuki syndrome. We also hypothesize that bipartite/pseudofractured clavicles or other skeletal defects may be under‐recognized features of the clinical presentation of the chromatin remodeling disorders.
Two cases of Legg–Perthes and intellectual disability in Tricho–Rhino–Phalangeal syndrome type 1 associated with novel TRPS1 mutations
Authors: Gilman Jordana L. , Newman Heather A. , Freeman Rebecca , Singh Kathryn E. , Puckett Rebecca L. , Morohashi David K. , Stein Constance , Palomino Kathryn , Lebel Robert Roger , Kimonis Virginia E.
Published: March 2017

Tricho–Rhino–Phalangeal syndrome is a rare autosomal dominant genetic disorder caused by mutations in the TRPS1 gene. This malformation syndrome is characterized by distinctive craniofacial features including sparse scalp hair, bulbous tip of the nose, long flat philtrum, thin upper vermilion border, and protruding ears. Skeletal abnormalities include cone‐shaped epiphyses at the phalanges, hip malformations, and short stature. In this report, we describe two patients with the physical manifestations and genotype of TRPS type I but with learning/intellectual disability not typically described as part of the syndrome. The first patient has a novel heterozygous two‐base‐pair deletion of nucleotides at 3198‐3199 (c.3198‐3199delAT) in the TRPS1 gene causing a translational frameshift and subsequent alternate stop codon. The second patient has a 3.08 million base‐pair interstitial deletion at 8q23.3 (113,735,487–116,818,578), which includes the TRPS1 gene and CSMD3. Our patients have characteristic craniofacial features, Legg–Perthes syndrome, various skeletal abnormalities including cone shaped epiphyses, anxiety (first patient), and intellectual disability, presenting unusual phenotypes that add to the clinical spectrum of the disease.
Activity patterns in seven captive lemur species: Evidence of cathemerality in Varecia and Lemur catta?
Authors: Bray Joel , Samson David R. , Nunn Charles L.
Published: March 2017

Cathemerality, or activity throughout the 24‐hr cycle, is rare in primates yet relatively common among lemurs. However, the diverse ecological conditions under which cathemerality is expressed complicates attempts to identify species‐typical behavior. For example, Lemur catta and Varecia have historically been described as diurnal, yet recent studies suggest that they might exhibit cathemeral behavior under some conditions. To investigate this variation, we monitored activity patterns among lemurs that are exposed to similar captive environments. Using MotionWatch 8 ® actigraphy data loggers, we studied 88 lemurs across seven species at the Duke Lemur Center (DLC). Six species were members of the family Lemuridae (Eulemur coronatus, E. flavifrons, E. mongoz, L. catta, V. rubra, V. variegata), while a seventh was strictly diurnal and included as an out‐group (Propithecus coquereli). For each 24‐hr cycle (N = 503), we generated two estimates of cathemerality: mean night (MN) activity and day/night (DN) activity ratio (day and night cutoffs were based on astronomical twilights). As expected, P. coquereli engaged in the least amount of nocturnal activity according to both measures; their activity was also outside the 95% confidence intervals of all three cathemeral Eulemur species, which exhibited the greatest evidence of cathemerality. By these estimates, Varecia activity was most similar to Eulemur and exhibited substantial deviations from P. coquereli (β (MN) = 0.22 ± SE 0.12; β (DN) = −0.21 ± SE 0.12). L. catta activity patterns also deviated from P. coquereli (β (MN) = 0.12 ± SE 0.11; β (DN) = −0.15 ± SE 0.12) but to a lesser degree than either Varecia or Eulemur. Overall, L. catta displayed an intermediate activity pattern between Eulemur and P. coquereli, which is somewhat consistent with wild studies. Regarding Varecia, although additional observations in more diverse wild habitats are needed, our findings support the existence of cathemeral behavior in this genus.
Polydimethylsiloxane/postmodified MIL‐53 composite layer coated on asymmetric hollow fiber membrane for improving gas separation performance
Authors: Zhu Haitao , Jie Xingming , Wang Lina , Liu Dandan , Cao Yiming
Published: March 2017

Composite layer containing postmodified MIL‐53 (P‐MIL‐53) was exploited to be coated on as‐fabricated asymmetric hollow fiber membrane for improving gas separation performance. The morphology and pore size distribution of P‐MIL‐53 particles were characterized by SEM and N2 adsorption isotherm. The EDX mapping and FTIR spectra were performed to confirm the presence of P‐MIL‐53 deposited on the outer surface of hollow fiber membranes. The results of pure gas permeation measurement indicated that incorporation of P‐MIL‐53 particles in coating layer could improve permeation properties of hollow fiber membranes. By varying coating times and P‐MIL‐53 content, the membrane coated with PDMS/15%P‐MIL‐53 composite by three times achieved best performance. Compared to pure PDMS coated membrane, CO2 permeance was enhanced from 29.96 GPU to 40.24 GPU and ideal selectivity of CO2/N2 and CO2/CH4 also increased from 23.28 and 26.95 to 28.08 and 32.03, respectively. The gas transport through composite membrane was governed by solution‐diffusion mechanism and CO2 preferential adsorption of P‐MIL‐53 contributed to considerable increase of CO2 solubility resulting in accelerated permeation rate. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44999.