bluuebunny/crossref_metadata_2025 huggingface dataset:
A multiyear estimate of methane fluxes in Alaska from CARVE atmospheric observations
Authors: Miller Scot M. , Miller Charles E. , Commane Roisin , Chang Rachel Y.‐W. , Dinardo Steven J. , Henderson John M. , Karion Anna , Lindaas Jakob , Melton Joe R. , Miller John B. , Sweeney Colm , Wofsy Steven C. , Michalak Anna M.
Published: September 2016

Methane (CH4) fluxes from Alaska and other arctic regions may be sensitive to thawing permafrost and future climate change, but estimates of both current and future fluxes from the region are uncertain. This study estimates CH4 fluxes across Alaska for 2012–2014 using aircraft observations from the Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) and a geostatistical inverse model (GIM). We find that a simple flux model based on a daily soil temperature map and a static map of wetland extent reproduces the atmospheric CH4 observations at the statewide, multiyear scale more effectively than global‐scale process‐based models. This result points to a simple and effective way of representing CH4 fluxes across Alaska. It further suggests that process‐based models can improve their representation of key processes and that more complex processes included in these models cannot be evaluated given the information content of available atmospheric CH4 observations. In addition, we find that CH4 emissions from the North Slope of Alaska account for 24% of the total statewide flux of 1.74 ± 0.26 Tg CH4 (for May–October). Global‐scale process models only attribute an average of 3% of the total flux to this region. This mismatch occurs for two reasons: process models likely underestimate wetland extent in regions without visible surface water, and these models prematurely shut down CH4 fluxes at soil temperatures near 0°C. Lastly, we find that the seasonality of CH4 fluxes varied during 2012–2014 but that total emissions did not differ significantly among years, despite substantial differences in soil temperature and precipitation.
Observational evidence of the nonlinear wave growth theory of plasmaspheric hiss
Authors: Nakamura Satoko , Omura Yoshiharu , Summers Danny , Kletzing Craig A.
Published: September 2016

We test the recently developed nonlinear wave growth theory of plasmaspheric hiss against discrete rising tone elements of hiss emissions observed by the Van Allen Probes. From the phase variation of the waveforms processed by bandpass filters, we calculate the instantaneous frequencies and wave amplitudes. We obtain the theoretical relation between the wave amplitude and frequency sweep rates at the observation point by applying the convective growth rates and dispersion factors to the known relation at the equator. By plotting the theoretical relation over scatterplots of the wave amplitudes and the frequency sweep rates for rising tone elements, we find good agreement between the hiss observations and the nonlinear theory. We also find that the duration periods of the hiss elements are in good agreement with the nonlinear transition time necessary for the formation of a resonant current through coherent nonlinear wave‐particle interactions.
A new paradigm for large earthquakes in stable continental plate interiors
Authors: Calais E. , Camelbeeck T. , Stein S. , Liu M. , Craig T. J.
Published: September 2016

Large earthquakes within stable continental regions (SCR) show that significant amounts of elastic strain can be released on geological structures far from plate boundary faults, where the vast majority of the Earth's seismic activity takes place. SCR earthquakes show spatial and temporal patterns that differ from those at plate boundaries and occur in regions where tectonic loading rates are negligible. However, in the absence of a more appropriate model, they are traditionally viewed as analogous to their plate boundary counterparts, occurring when the accrual of tectonic stress localized at long‐lived active faults reaches failure threshold. Here we argue that SCR earthquakes are better explained by transient perturbations of local stress or fault strength that release elastic energy from a prestressed lithosphere. As a result, SCR earthquakes can occur in regions with no previous seismicity and no surface evidence for strain accumulation. They need not repeat, since the tectonic loading rate is close to zero. Therefore, concepts of recurrence time or fault slip rate do not apply. As a consequence, seismic hazard in SCRs is likely more spatially distributed than indicated by paleoearthquakes, current seismicity, or geodetic strain rates.
Off‐great‐circle paths in transequatorial propagation: 2. Nonmagnetic‐field‐aligned reflections
Authors: Tsunoda Roland T. , Maruyama Takashi , Tsugawa Takuya , Yokoyama Tatsuhiro , Ishii Mamoru , Nguyen Trang T. , Ogawa Tadahiko , Nishioka Michi
Published: September 2016

There is considerable evidence that plasma structure in nighttime equatorial F layer develops from large‐scale wave structure (LSWS) in bottomside F layer. However, crucial details of how this process proceeds, from LSWS to equatorial plasma bubbles (EPBs), remain to be sorted out. A major obstacle to success is the paucity of measurements that provide a space‐time description of the bottomside F layer over a broad geographical region. The transequatorial propagation (TEP) experiment is one of few methods that can do so. New findings using a TEP experiment, between Shepparton (SHP), Australia, and Oarai (ORI), Japan, are presented in two companion papers. In Paper 1 (P1), (1) off‐great‐circle (OGC) paths are described in terms of discrete and diffuse types, (2) descriptions of OGC paths are generalized from a single‐reflection to a multiple‐reflection process, and (3) discrete type is shown to be associated with an unstructured but distorted upwelling, whereas the diffuse type is shown to be associated with EPBs. In Paper 2 (P2), attention is placed on differences in east‐west (EW) asymmetry, found between OGC paths from the SHP‐ORI experiment and those from another near‐identical TEP experiment. Differences are reconciled by allowing three distinct sources for the EW asymmetries: (1) reflection properties within an upwelling (see P1), (2) OGC paths that depend on magnetic declination of geomagnetic field (B), and (3) OGC paths supported by non‐B‐aligned reflectors at latitudes where inclination of B is finite.
The effect of losing and gaining flow conditions on hyporheic exchange in heterogeneous streambeds
Authors: Fox A. , Laube G. , Schmidt C. , Fleckenstein J. H. , Arnon S.
Published: September 2016

Bed form‐induced hyporheic exchange flux (qH) is increasingly viewed as a key process controlling water fluxes and biogeochemical processes in river networks. Despite the fact that streambeds are inherently heterogeneous, the majority of bed form flume‐scale studies were done on homogeneous systems. We conducted salt and dye tracer experiments to study the effects of losing and gaining flow conditions on qH using a laboratory recirculating flume system packed with a heterogeneous streambed, and equipped with a drainage system that enabled us to apply losing or gaining fluxes. We found that when either losing or gaining fluxes increased (regardless of whether the flux was upward or downward), qH followed an exponential decline, the volume of the hyporheic flow cell drastically reduced, and the mean residence times declined moderately. A numerical flow model for the heterogeneous streambed was set up and fitted against the experimental data in order to test whether an equivalent homogeneous case exists. The measured qH were accurately predicted with the heterogeneous model, while it was underestimated using a homogeneous model characterized by the geometric mean of the hydraulic conductivity. It was also shown that in order to produce the results of the heterogeneous model with an equivalent hydraulic conductivity, the latter had to be increased as the losing or gaining fluxes increase. The results strongly suggest that it is critical to adequately account for the heterogeneous streambed structure in order to accurately predict the effect of vertical exchange fluxes between the stream and groundwater on hyporheic exchange.
Transposons: Prokaryotic
Authors: Chandler Michael
Published: September 2016

Transposons are DNA (deoxyribonucleic acid) segments found ubiquitously in the genomes of living organisms and capable of moving from place to place within a genome. They are frequently associated with the sequestration and transmission of accessory genes in bacteria and archaea. They carry genes such as resistance to anti‐bacterials, virulence and symbiotic factors and catabolism of xenobiotics. They have a large impact on public health by facilitating the spread of these phenotypic characters. Transposons generate a variety of DNA rearrangements that have profound consequences for cell survival and evolution. These rearrangements are associated with transposition events (catalysed by transposon‐specific enzymes, transposases) but repeated transposon copies can act as portable regions of homology and undergo homologous recombination using the host recombination system. Transposons are diverse in structure, highly regulated by a multitude of mechanisms but only specify a limited number of catalytic chemistries. Transposons can represent a large proportion of prokaryotic genomes.

Key Concepts

Transposable elements are ubiquitous and show a high degree of diversity.

Transposable elements use a limited number of different chemical mechanisms for their transposition.

Transposons are key elements in the short‐term evolution of prokaryotic genomes.

Trasposons are central to driving the spread of antibiotic resistance.
Hydrophobic Interaction Chromatography
Authors: Jennissen Herbert P
Published: September 2016

Hydrophobic interaction chromatography (HIC) – today a key method in the purification of monoclonal antibodies – involves the separation of protein molecules in their native and biologically active state owing to a differential interaction of these molecules with hydrophobic sites on the surface of a solid support. Therefore, an understanding of the principles involved in this method is crucial. In the separation process, hydrophobic patches on the protein surface interact with hydrophobic molecules (e.g. alkyl residues) immobilised on the hydrophilic solid‐phase surface (e.g. agarose). In the article, a historical overview is followed by a consideration of the biochemical and biophysical mechanisms involved in HIC and a discussion of the critical hydrophobicity method and other approaches to hydrophobic interaction chromatographic methods. A detailed protocol for the individual synthesis and screening of gel libraries for specific needs has been published elsewhere. The treatise is concluded with a discussion on the predictability of chromatographic results, new developments and an outlook into the future.

Key Concepts

Hydrophobic interaction chromatography is a biological recognition process corresponding to a two‐dimensional lock‐and‐key model, that is, the dynamic pairing of a 2D key (protein) with its complementary 2D ‘lock’ (alkyl lattice).

Proteins are adsorbed to hydrophobic agaroses as metastable states of adsorption–desorption hysteresis, indicating energetically that a local energy minimum exists (i.e. nonequilibrium state) in distinction to the global energy minimum, that is, true equilibrium.

Critical hydrophobicity is the threshold hydrophobicity under low salt concentrations (e.g. 50 mM Tris, 150 mM NaCl and pH 7.0) and characterises a gel for reversible HIC binding properties.

A homologous gel library consists of gels carrying covalently immobilised hydrocarbons (e.g. alkyl residues) comprising a homologous series.

A quantised hydrophobicity gradient is a hydrophobicity gradient separated into a library of distinct gels of varying hydrophobicity for determining the critical hydrophobicity.

The lattice‐site binding function is a protein adsorption isotherm (often showing positive cooperativity) as a function of the surface concentration of immobilised hydrocarbons (e.g. alkyl residues).

The bulk ligand‐binding function is a protein adsorption isotherm on immobilised hydrocarbons (often showing negative cooperativity) as a function of the bulk protein concentration.

Predicting chromatographic behaviour from sorption isotherms and protein structure are the ultimate aim in understanding and utilising HIC.

The critical hydrophobic patch area hypothesis is a method of predicting the chromatographic behaviour of proteins in HIC from protein structure, utilising the area of hydrophobic patches on the surface of proteins.
Foraging
Authors: Roitberg Bernard D , Roitberg Gabi
Published: September 2016

Foraging theory can be used to explain two important phenomena, how and why organisms choose particular foodstuffs (Optimal Diet Theory) and how long individuals will remain in resource patches before seeking others (marginal value theorem). The theories are analytical and produce explicit, quantitative predictions. In order to test predictions from foraging theory, one must tweak the theory to account for details of an organism's natural history. In general, experimental tests of the theory support its predictions but most often in a qualitative, not quantitative manner. Foraging theory can be applied to a wide range of resources beyond the classic food examples including mates and hosts for parasitoids. The conditions under which a game theoretical approach is best used to explain foraging decisions are, for example when the performance of a focal individual depends on the number and behaviour of other competitors in any given patch.

Key Concepts

Resources (e.g. food) can vary in quality as well as in distribution (e.g. aggregated).

Optimal foraging theory was developed to explain how and why foods of particular quality are chosen by resource‐seeking individuals.

Further, because resources are often patchily distributed, foragers must decide when to give up and seek other patches. Such decisions can be understood by employing the marginal value theorem, a theorem that falls under the foraging theory umbrella.

Foraging theory models are quantitative and explicit. For example, they predict diet breadth (i.e. which resources should be included in the diet of a foraging individual) under a specific set of environmental conditions.

Foraging theory predictions can be tested using wild or domesticated organisms in the laboratory or in nature.

Tests of foraging theory predictions generally support the theory in a qualitative sense (e.g. the diet will expand as highest‐quality resources become rare) but often not quantitatively (e.g. the exact resource value at which diet expansion will occur).

Classic foraging theory ignores the physiological state of foraging organisms (e.g. energy reserves) but the theory can easily be modified to take into account such parameters.
Factor
V
L
eiden
Authors: Dahlbäck Björn
Published: September 2016

Factor V (FV) circulates in plasma as a procofactor with little procoagulant activity. It is activated by thrombin to FVa, which is a highly efficient cofactor to factor Xa in the activation of prothrombin. FVa is regulated by activated protein C (APC) together with its cofactor protein S. A single point mutation in the FV gene (
F5
), FV Leiden, is a common genetic risk factor for venous thrombosis. It results in the replacement of arginine506 with a glutamine. Arginine506 constitutes one of the three APC‐cleavage sites in FVa. The resulting APC resistance causes an imbalance between pro‐ and anticoagulant forces and a lifelong hypercoagulable state that increases the risk of venous thrombosis approximately three‐ to sevenfold. The FV Leiden mutation is the result of a single mutation event that is estimated to have occurred around 20–25 000 years ago in a Caucasian ancestor, which explains why the mutation is highly prevalent (up to 15%) in Caucasian and rare in other ethnic groups.

Key Concepts

Factor V is an important blood coagulation protein, which after its activation by thrombin functions as cofactor to factor Xa in the activation of prothrombin to thrombin.

Blood coagulation is controlled by several anticoagulant pathways.

Protein C, protein S, TFPI (tissue factor pathway inhibitor) and antithrombin are the main anticoagulant proteins in plasma.

Activated protein C (APC) together with its cofactor protein S regulates coagulation by cleaving and inactivating factor Va and factor VIIIa.

Venous thrombosis is a multifactorial disease.

Multiple genetic and circumstantial risk factors contribute to the risk of venous thrombosis.

The APC resistance phenotype is the most common inherited risk factor for venous thrombosis. It is caused by a single factor V gene (
F5
) mutation (Factor V Leiden) that results in the loss of one of the APC cleavage sites as Arg506 is replaced with a Gln.

Factor V Leiden is the result of a single mutation event that took place around 20–25 000 years ago.

Factor V Leiden is mainly present in Caucasians.

Heterozygous carriers of the FV Leiden mutation have a lifelong three‐ to sevenfold increased risk of thrombosis.
Genetics and Genomics Education of Primary Care Health Professionals in
B
ritain
Authors: Kirk Maggie , Tonkin Emma
Published: September 2016

There is long‐standing acknowledgement that primary care has a pivotal role in ensuring patients benefit from the rapid advances in genetic science and technologies and subsequent emergence of genomic medicine as an integral part of mainstream healthcare. However, significant deficits in knowledge and skills in genetics and genomics have been found in primary care professionals, exacerbated by a lack of education guidelines and limited accessible resources. That picture is changing with new strategic initiatives such as England's Genomics Education Programme, built on a strong policy foundation and driving development of curriculum guidelines and learning resources. Although significant challenges remain, there is evidence of an evolution from justification of the incorporation of genetics and genomics into mainstream healthcare and education, to an exploration of the effectiveness of different educational approaches and their impact on practice. More recently, global leaders have been driving a growing interest in strategic, collaborative effort across healthcare.

Key Concepts

The scope and pace of developments in genomics have implications across all areas of healthcare, including primary care.

Governments such as in the United Kingdom and the United States are promoting policies and initiatives to optimise the benefits that genomics can bring to healthcare.

There are significant challenges to address in engaging healthcare staff in genomics, including those in primary care, and in providing relevant, accessible education and training.

Education strategies are shifting in focus from defining content to effective approaches in teaching and learning.

Responses to these challenges have been robust, with international efforts in mobilising resources to support education of primary care health professionals and others.
Chromothripsis and Human Genetic Disease
Authors: Nazaryan‐Petersen Lusine , Tommerup Niels
Published: September 2016

Chromothripsis (CTH) is a newly discovered mutational mechanism, which in a single catastrophic event results in localised complex structural rearrangements confined to one or a few chromosomes. After an initial shattering or clustered fragmentation of a chromosomal region, the fragments join together in random order and orientation. During this process some of the generated fragments may be lost. It is not entirely clear which factors trigger the localised fragmentation; however, several mechanisms have been proposed, such as ionising radiation, aborted apoptosis, isolation of chromosome(s) in micronuclei, LINE1‐endonucleases, etc. CTH may disrupt multiple genes and/or regulatory regions. When it is incompatible with cell survival, the result should be apoptosis. However, if a cell escapes apoptosis, the extensive genomic rearrangements may have different phenotypic outcomes: cancer (somatic), congenital and developmental disorders (germline), neutral or even beneficial effects.

Key Concepts

Chromothripsis is a phenomenon where multiple localised double‐stranded DNA breaks result in complex genomic rearrangements.

Chromothripsis occurs within a single cell cycle.

Ionising radiation, aborted apoptosis, isolation of chromosome(s) in micronuclei and LINE1‐endonucleases are proposed to have a role in chromothripsis.

Chromothripsis in somatic cells may trigger cancer development.

Chromothripsis in the germline may result in congenital and developmental disorders.
Recovery of Gold from Incinerated Sewage Sludge
Authors: Sugawara Katsuyasu
Published: September 2016

In order to develop an efficient and selective recovery process for gold, which eliminates the need for water, the release behavior of gold from an incinerated sewage sludge ash heated to between 100 and 1000 °C under a chlorine gas stream was investigated. A release of gold was observed above 600 °C, with all gold being transferred to the gas phase at 1000 °C. The addition of solid carbon to the incinerated ash reduced this initial release temperature to 400 °C, with all gold being released into both the gas phase and on to the solid carbon at 700 °C. Subsequent optimization of the reaction conditions to maximize the amount of gold reporting to the solid carbon determined that the mixture of incinerated ash and carbon should first be heated to a terminal temperature of 800 °C under a nitrogen gas stream. Upon reaching this temperature, the gas stream should be switched from nitrogen to chlorine, and the mixture held at 800 °C for 1 h. Scanning electron microscopy and X‐ray diffraction measurements confirm that this produces a distribution of fine metallic gold over the carbon surface.
Life Cycle Sustainability Assessments
Authors: Halog Anthony , Manik Yosef
Published: September 2016

Assessing the sustainability of products (e.g., chemicals) and their process technologies is a challenging task, and hence key indicators and tools have to be developed continually to manage the impacts of social and economic threats while operating within ecological limits. The conventional life cycle assessment (LCA) method is one of such systems‐based tools, and standardized for environmental impact evaluation of product systems. However, LCA is pertinent to assessing mainly the “environmental dimension” of systems' sustainability; it was not historically developed to evaluate the other sustainability dimensions: economic and social. Hence, recent challenges in LCA have led to its broadening to encompass these other dimensions, which has resulted in what we call now the life cycle sustainability assessment (LCSA). LCSA needs to be a systemwide, integrated, and interdisciplinary analysis over space and time whereby an integrated modeling tool is needed to simulate and analyze the inter‐relationships among/between social, ecological, and economic systems. This article explains the basics of LCSA, LCA, life cycle costing, and social life cycle assessment and includes an initial LCSA application to palm oil‐based products. We introduced a framework here to provide a systematic basis for LCSA operationalization and identified a set of key economic, environmental, and social indicators at each stage of the palm oil biodiesel life cycle. The LCSA application thus helps to understand the complexity of a palm oil biodiesel life cycle through an integrated sustainability assessment and modeling.
Ionic Liquids: Bacterial Degradation in Wastewater Treatment Plants
Authors: Diaz Elena , Monsalvo Victor , Palomar Jose , Mohedano Angel F.
Published: September 2016

Ionic liquids (ILs) are probably the kind of chemical compounds that have been most intensively investigated in the past 10 years. The potential applications of ILs cover practically all disciplines of chemistry, having received particular attention in separation processes, catalysis, electrochemistry, nanotechnology, and material science. This increasing use promotes the synthesis and application of the new IL compounds at larger scales. As a consequence, a parallel effort has been made by the scientific community to evaluate the potential environmental hazards of ILs. With equal focus, several researches have also made relevant progress in the development of effective treatments to recover or remove ILs from wastewaters and soils. Certainly, the current state of art in the field of ILs results from the cooperative and multidisciplinary work of experts from different scientific fields. In this work, the toxicity and biodegradability of ILs have been revised from the point of view of environmental engineers, centering the analysis on the expected need of managing ILs in a wastewater treatment plant (WWTP). For this purpose, the available standard tests and other methods to evaluate the toxicity of potential xenobiotic compounds are summarized. An overview of the reported toxicities of ILs toward different assays is presented, with particular emphasis in the available guidelines for designing ILs with low toxicity. The standardized tests for determining the biodegradability of xenobiotics are also collected and described. Lastly, the biodegradation behavior of ILs have been summarized, as evidenced in the bibliography, depending on their structural features and the biological systems used in the bioassays. Preliminary analysis, focused on relevant aspects on the toxicity and biodegradability of ILs, was performed in our laboratory using activated sludge. The main aim is to provide useful guidelines for the future development of biological processes for treating wastewater contaminated with ILs in a WWTP.
TiO
2

‐Based Heterogeneous Catalysis for Photocatalytic Hydrogen Generation and Photodegradation
Authors: Wang Jing , Ong Wei Li , Gao Minmin , Zhu Liangliang , Ho Ghim Wei
Published: September 2016

Globalization, industrialization, and manufacturing have expanded at an alarming rate over past decades. This has caused a rapid depletion of natural energy sources (such as oil and gas) and the production of tones of wastes polluting the environment, which in turn has imposed negative impact on human health. A promising way to tackle the energy crisis and environmental issues is to substitute traditional fossil fuels with clean and sustainable sources of energy. Among them, solar energy is an inexhaustible and the most environment‐friendly resource, which can be effectively absorbed and utilized via a photocatalysis process for hydrogen production from water splitting and degradation of organic pollutants. Titanium dioxide (TiO
2
) is one of the most extensively studied photocatalytic materials, by virtue of its compatible band‐edge position, physiochemical stability, nontoxicity and low cost. However, its photoactivity is remarkably restricted due to the inefficient light absorption only in the UV region of the solar spectrum, as well as easy recombination of photogenerated electrons/holes. To mitigate these limitations, synergistic combination of electronic and structural strategies has been developed in recent years. In this chapter, we have highlighted TiO
2
‐based photocatalysts with well‐defined electronic structure control and structural design that contribute to significant improvements in vital processes and attributes, such as light absorption in the visible region, charge‐carrier dynamics, high surface area, and enhanced light harvesting. Electronic structure engineering, namely doping and heterostructuring, plays a critical role in improving the kinetics of the charge carriers, that is, the separation of electrons and holes pairs, and the extension of light absorption to visible light region, thereby enhancing the photoefficiency of TiO
2
. The structural design of TiO
2
involves various dimensions and morphologies, which not only augments the specific surface area, but also provides suitable platforms to incorporate other materials for maximizing the photocatalytic efficiency. Furthermore, fundamental understanding of the kinetics and dynamics of photoreactivity and other physicochemical properties is covered. The goal is to provide a comprehensive background toward rational engineering of semiconducting photocatalysts and also a guide for future structural design of nanoscale catalysts for solar‐to‐fuel conversion purposes in pursuit of an exciting future of clean and renewable fuel and environmental remediation.
Solid Catalysts for Epoxidation with Dilute Hydrogen Peroxide
Authors: Fraile José M.
Published: September 2016

From an environmental point of view, dilute hydrogen peroxide is one of the most attractive oxidants for epoxidation of alkenes, but it requires the use of highly selective catalysts to prevent or minimize the side reactions associated with the homolytic breakdown of the hydrogen peroxide molecule and the presence of water. Heterogeneous catalysts can activate diluted hydrogen peroxide through different mechanisms, but the expected high activity, selectivity, and recoverability require an integral design of the catalyst, both the near environment of the metal (active) center and the surface and textural properties of the whole solid. Titanium‐based heterogeneous catalysts are the most popular ones, with TS‐1 zeolite as a successful example of practical application in the synthesis of propylene oxide, combining the required isolated tetrahedral Ti sites with a hydrophobic microporous structure of the solid. Supported tungstates are also useful catalysts for epoxidation with diluted hydrogen peroxide, whereas other metals, such as Mn, usually require the presence of organic ligands to modulate their activity and selectivity. In all those cases the generated intermediate (metal–peroxy, metal–hydroperoxy, metal–oxo) is electrophilic and the catalysts are more efficient with electron‐rich alkenes. However, it is possible to activate hydrogen peroxide by abstraction of a proton, leading to a nucleophilic hydroperoxide anion able to epoxidize electron‐poor alkenes. Hence solid bases, such as Al–Mg mixed oxides or modified phosphates, can also play the role of epoxidation catalysts.
Sustainable Production of Glycerol
Authors: Ciriminna Rosaria , Pagliaro Mario
Published: September 2016

Following the boom in biodiesel and oleochemical manufacturing that started in 2004, the glycerol market traditionally dominated by oleochemical/soap suppliers and by selected manufacturers of petrochemical glycerol has been completely reshaped. In about a decade, the yearly glycerol output reaching the marketplace has gone up from a few 100 000 tons to 4 million tons in 2014, independently of market demand. This study investigates the sustainability of bioglycerol production and utilization a decade after the beginning of the bioglycerol era.
Trends in Food and Agricultural Waste Valorization
Authors: Burange Anand , Clark James H. , Luque Rafael
Published: September 2016

Food and agricultural waste emerged as a resource with significant potential to be employed as raw material for the production of valuable products in biorefineries. The present contribution has been aimed at providing a general overview of the current trends in food and agricultural waste valorization to a number of chemicals, materials and fuels, providing a range of examples related to various initiatives and types of feedstocks under investigation, worldwide. Particular emphasis will be laid on second generation waste valorization and reuse strategies for the production of higher value and marketable products rather than conventional food waste processing (incineration for energy recovery, feed, or composting) while highlighting the issues linked to the use of food and agricultural waste as a sustainable raw material.
Sustainable Syntheses with Microwave Irradiation
Authors: Vats Tanvi , Mishra Anuradha
Published: September 2016

This article deals with the application of MW in field of sustainable syntheses covering major fields like organic, polymers, inorganic and nano particles. A considerable portion of the article is devoted to the understanding of MW instrumentation and effects from a chemist's point of view. The monomodal and multimodal instruments are described in detail. The utility and limitation of domestic MW oven in laboratory along with hazards and safety measures related to MW in laboratory are described. It also explains the modus operandi of MW heating, the manner in which it differs from conventional heating; various thermal and non thermal MW effects are also covered. Besides these the sustainability in various solvents as well as solvent free synthesis has also been talked about.

In the field of organic synthesis the thrust is upon controlled MW reactions. These reactions find use in several synthetic procedures and commercial exploitation of several such MW aided reactions has taken place. Various kinds of polymerization reactions that involve the use of MW irradiations are also outlined. This segment also includes the MW aided synthesis of commercially important hydrogels and polymer scaffolds used in drug delivery and tissue engineering among others.

The synthesis of inorganic materials under MW irradiations is segmented in various categories, viz., (a) direct reactions, including those involving the use of simple compounds; (b) preparation of solids which involve decompositions and combinations giving rise to solids of complex composition; (c) nitridation reactions; (d) reactions brought about in liquid media; (e) preparation of glasses; (f) selective deoxidation reactions; and (g) plasma‐assisted reactions.

The nanoparticle synthesis is dealt in terms of solvents used. The various solvent systems described are aqueous, alcoholic, ionic liquids and mixed solvent systems.

The article concludes in the various challenges, limitation and scope of MW aided syntheses on commercial platform. It also discusses new opportunities in this field.
Sustainable Water Remediation
Authors: Gupta Anjali , Mishra Anuradha
Published: September 2016

Contamination of water bodies such as rivers, lakes, aquifers, oceans, and groundwater has led to a serious problem of water pollution. The various reasons for this threat constitute both anthropogenic and non‐anthropogenic factors including population explosion, industrialization, and globalization, which lead to the addition of toxic metals, dyes, and organic and inorganic compounds in water. Consumption of these toxic metals for longer time may cause various disorders in the human body including decreased immunological defenses, disabilities associated with malnutrition, and high rate of upper gastrointestinal cancer. Remediation of water includes the elimination of contaminants for a pollution‐free environment. Attention has also been focused on developing green sustainable technologies that must be esthetic, eco‐friendly, socially acceptable, and economical. Water remediation using green technologies has been divided into two groups; bioremediation, that is decontamination using plants, fungi, algae, bacteria, and other microorganisms and second remediation method is through natural products or modified natural products. Bioremediation is the use of plants and microorganisms for the breakdown of contaminants to nontoxic or less harmful products. It is used to purify groundwater, soil, sludge‐carrying pesticides, hydrocarbons, and other organic chemicals for detoxification. Bioremediation consists of phytoremediation through which detoxification is carried out through green plants and their biomass. It helps in the removal of toxic metals by complexation. Periphyton biofilms composed of bacilli and cocci for the treatment of aquatic ecosystem remove COD, UV254 nm matter, and toxic metals; algal biomass is used for the removal of harmful dyes from wastewater. Natural products also emerge as potential compounds to remediate toxic metals from industrial effluents. Some of the natural products used for this purpose are polysaccharides, crab shell, papaya wood, etc.; modified natural products such as zeolites having selectivity for ammonia, transition metals, bacteria, and radioactive elements; functionalized silica gel for removing metals; nanomaterials as potential antimicrobial agents and to remove metals and organic contaminants; ionic liquids as excellent solvent for the extraction of various heavy metals; surfactant modification for removal of oxo ions such as chromate, oxalate, etc.; and inorganic–organic hybrid polymeric materials for water purification. The use of such materials will lead to a better and more sustainable way of treating polluted water.
Renewable Plant‐Based Raw Materials for Industry
Authors: Tripathy Divya Bajpai , Mishra Anuradha
Published: September 2016

Renewable raw materials can be defined as the sum of all substances obtained from living world, from plant and animal kingdom. The total production of biomass on our earth is estimated at about 170 billion tons per annum that roughly consists of 75% carbohydrates, 20% lignins, and 5% of other materials such as oils and fats, proteins, alkaloids, and terpenes, etc. Out of which about 6 billion tons are currently being used for human needs (3.7 billion tons for food purposes, 2 billion for energy fuels, pulp and paper production, 300 million tons for specialty materials, etc.).

Plant‐based renewable raw materials are obtained from agriculture and forestry. There are a number of plants products that have proven potential to be used as a feedstock for many industries. Plant oils, steroids, polysaccharides, terpenoids/terpenes, alkaloids, and flavonoids are the most important plant materials that have been in use in many industrial sectors. Sugar or glucose obtained from sugar cane, sugar beet, potatoes, corn, wheat, cassava, rice, and so on are known to be used as one of the most essential substrate for industrial fermentation processes. Plant oils, for example, palm, soybean, rice bran, and coconut oil, produce various oleo‐chemicals such as triglycerides, fatty acids/alcohols, and glycerol that are utilized to produce specialty products such as tensides, cosmetics, and pharmaceuticals. Cellulose obtained from wood is particularly used in pulp and paper industry. Flavonoids extracted from aromatic plants such as rose, acacia, and many more are the chief raw materials in perfumeries.

The plant‐based raw materials go through many chemical and biotechnological processes to come into a shape of end product. The most common raw materials such as sugars, cellulose, and oils can produce an almost infinite range of products.

Plant‐based raw materials have so many advantages over fossil feedstocks. They are nontoxic and hence assert their suitability for the products, which have direct contact with skin and eyes such as cosmetics, medicines, and surfactants. Their easy biodegradability makes them superior from an environmental point of view.

Despite having many advantages, plant‐based raw materials have some limitations. The seasonal variation in quality and quantity of crops and their noncontinuous supply are the major disadvantages associated with plant‐based raw materials.
Methylethers from Alcohols and Dimethyl Carbonate
Authors: Aricò Fabio , Tundo Pietro
Published: September 2016

Different synthetic approaches to methylethers by reaction of alcohols with dimethyl carbonate (DMC) have been reported. Direct methylation has been achieved in good yields using basic alumina or hydrotalcite KW2000 as catalyst either in batch or continuous‐flow conditions. A two‐step synthetic approach, consisting of carboxymethylation of the parent alcohol followed by decarboxylation, was also reported. In this case the reaction is complicated by the side reactions occurring and required the use of high temperature and appropriate solvent to achieve methylethers in high yield. A high‐yielding methylation of cyclic sugar isosorbide that incorporates secondary hydroxyls groups, by reaction with DMC, has been also reported. It is noteworthy that methylation of secondary alcohols usually required high temperature and it is complicated by the formation of elimination products; however, in this case, dimethyl isosorbide was achieved at low temperature (90 °C) and in quantitative yield.
Zinc‐Transporting
P
‐Type
ATPases
Authors: Sitsel Oleg , Duelli Annette , Gourdon Pontus
Published: September 2016

P‐type ATPases are active transporters that translocate a range of ions and molecules across cellular membranes. While the overall structure and transport cycle are conserved, subclasses have adapted to the transport of specific ions. This article provides a compact guide to zinc‐transporting subclass 1B‐2 P‐type ATPases (Zn(II)‐ATPases), examining their topology, transport cycle, occurrence, and biological function. Focusing on the Zn(II)‐ATPase from the bacterium
Shigella sonnei
, it outlines how the protein can be overproduced, purified, functionally characterized, and crystallized. Finally, functionally crucial aspects of the structure of Zn(II)‐ATPases are examined, including adaptations for ion acquisition, high‐affinity binding, and subsequent release.
Fe4S4‐Quinolinate Synthase (NadA)
Authors: Cherrier Mickaël V , de Choudens Sandrine Ollagnier , Fontecilla‐Camps Juan C
Published: September 2016

Quinolinate synthase is the second enzyme in the nicotinamide adenine dinucleotide (NAD) syntheticde novopathway I. The enzyme reacts iminoaspartate with dihydroxylaceton phosphate to form the universal NAD precursor quinolinic acid. Iminoaspartate is made froml‐aspartate by aspartate oxidase in many prokaryotes such asEscherichia coli, and by aspartate dehydrogenase in Archaea and hyperthermophilic bacteria. Quinolinate synthase is a fascinating multifunctional enzyme capable of catalyzing a TIM‐like isomerization, a dephosphorylation‐coupled condensation, and two dehydrations. All these reactions appear to take place in a relative small cavity facing the Fe4S4cluster at the end of a protein tunnel that gets obstructed by their binding.
Ionic Liquids: Recycling
Authors: Sklavounos Evangelos , Helminen Jussi K.J. , Kyllönen Lasse , Kilpeläinen Ilkka , King Alistair W.T.
Published: September 2016

For ionic liquid processes to be adopted by industry there are two main challenges. First is the enormous capital and running costs when using expensive ionic liquids, compared to molecular solvents. In addition, if ionic liquids are disposed of there is great potential for environmental damage. These factors can be mitigated, by recycling ionic liquids in any process or product life cycle, as far as possible. This chapter reviews the topic of ionic liquid recycling, covering the main methods of recycling in the academic and patent literature. These include the classical methods of recycling compounds such as distillation, phase separation, extraction and crystallization. Adsorption and membrane methods are also covered. The various mechanisms of distillation will be covered, including distillation of ion pairs or dissociation of ionic liquids into volatile neutral species, which vaporize and recondense. The topic of aqueous biphasic systems is also covered, under the general method of phase separation. It is shown how even water miscible ionic liquids can be separated with the use of kosmotropic salts, commonly described in the Hofmeister series. Throughout this discussion the applicability to recycling of ionic liquids on an industrial scale is also considered.
An ERP study on hostile attribution bias in aggressive and nonaggressive individuals
Authors: Gagnon Jean , Aubin Mercédès , Emond Fannie Carrier , Derguy Sophie , Brochu Alex Fernet , Bessette Monique , Jolicoeur Pierre
Published: September 2016

Hostile attribution bias (e.g., tendency to interpret the intention of others as hostile in ambiguous social contexts) has been associated with impulsive aggression in adults, but the results are mixed and the complete sequence of hostile inferential processes leading to aggression has not been investigated yet. The goal of this event‐related brain potentials (ERPs) study was to track the neural activity associated with the violation of expectations about hostile versus nonhostile intentions in aggressive and nonaggressive individuals and examine how this neural activity relates to self‐reported hostile attributional bias and impulsive aggression in real life. To this end, scenarios with a hostile versus nonhostile social context followed by a character's ambiguous aversive behavior were presented to readers, and ERPs to critical words that specified the hostile versus nonhostile intent behind the behavior were analysed. Thirty‐seven aggressive and fifty nonaggressive individuals participated in the study. The presentation of a critical word that violated hostile expectation caused an N400 response that was significantly larger in aggressive than nonaggressive individuals. Results also showed an enhanced late positive potential‐like component in aggressive individuals when hostile intention scenarios took place in a nonhostile context, which is associated with impulsive aggression in real life even after having controlled for the effect of self‐reported hostile attributional bias. The Hostile Expectancy Violation paradigm evaluated in this study represents a promising tool to investigate the relationship between the online processing of hostile intent in others and impulsive aggression. Aggr. Behav. 43:217–229, 2017. © 2016 Wiley Periodicals, Inc.
Chemoselectivity Improvement via Partial Shielding of an Imidazole Active Site in Branched/Dendritic Homogeneous Catalysts of the Baylis–Hillman Reaction
Authors: Karabline‐Kuks Jeny , Ramesh Palakuri , Portnoy Moshe
Published: September 2016

While comparing analogous polystyrene‐supported and homogeneous catalysts for the Baylis–Hillman reaction, we hypothesized that the hydrophobic envelopment of the imidazole catalytic sites of the former is responsible for the significantly better chemoselectivity exhibited by the heterogeneous catalysts compared to their homogeneous counterparts. In order to test this hypothesis, we prepared a series of branched/dendritic homogeneous catalysts, with an imidazole active site near the focal point and flexible tails of various lengths and polarities, capable of providing partial shielding of this site. The design of the catalysts was based on a 5‐hydroxyisophthalate scaffold, and they were prepared through a number of multistep synthetic pathways. The comparison of the catalysts under a variety of conditions in a model Baylis–Hillman reaction demonstrated that long hydrophobic tales enhance the chemoselectivity parameter of the catalysis, while reducing the rate of the consumption of the substrates, and that the chemoselectivity is further improved by the presence of a free phenolic moiety in the vicinity of the catalytic imidazole unit. Moreover, in second‐generation catalysts, the peripheral long tails could be either hydrophobic or polar, since the dendritic inner backbone itself presumably partially provides the necessary isolation of the catalytic site. Thus, experimental results support our hypothesis.

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Supramolecular Activation of Hydrogen Peroxide in the Selective Sulfoxidation of Thioethers by a Self‐Assembled Hexameric Capsule
Authors: La Sorella Giorgio , Sperni Laura , Strukul Giorgio , Scarso Alessandro
Published: September 2016

An efficient metal‐free organocatalytic activation of hydrogen peroxide (H2O2) towards thioethers leading to the corresponding sulfoxides in high yields at room temperature within hours was promoted by the hexameric capsule formed by the self‐assembly of resorcin[4]arene units. The capsule plays a dual role of activating the oxidant through hydrogen bonding and favouring the oxidation reaction inside the cavity. Inactivation of the supramolecular organocatalyst was observed by using competitive ammonium guests, mimicking the inactivation of enzymes by competitive inhibitors.

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