bluuebunny/crossref_metadata_2025 huggingface dataset:
CEDAR‐GEM Challenge for Systematic Assessment of Ionosphere/Thermosphere Models in Predicting TEC During the 2006 December Storm Event
Authors: Shim J. S. , Rastätter L. , Kuznetsova M. , Bilitza D. , Codrescu M. , Coster A. J. , Emery B. A. , Fedrizzi M. , Förster M. , Fuller‐Rowell T. J. , Gardner L. C. , Goncharenko L. , Huba J. , McDonald S. E. , Mannucci A. J. , Namgaladze A. A. , Pi X. , Prokhorov B. E. , Ridley A. J. , Scherliess L. , Schunk R. W. , Sojka J. J. , Zhu L.
Published: September 2017

In order to assess current modeling capability of reproducing storm impacts on total electron content (TEC), we considered quantities such as TEC, TEC changes compared to quiet time values, and the maximum value of the TEC and TEC changes during a storm. We compared the quantities obtained from ionospheric models against ground‐based GPS TEC measurements during the 2006 AGU storm event (14–15 December 2006) in the selected eight longitude sectors. We used 15 simulations obtained from eight ionospheric models, including empirical, physics‐based, coupled ionosphere‐thermosphere, and data assimilation models. To quantitatively evaluate performance of the models in TEC prediction during the storm, we calculated skill scores such as RMS error, Normalized RMS error (NRMSE), ratio of the modeled to observed maximum increase (Yield), and the difference between the modeled peak time and observed peak time. Furthermore, to investigate latitudinal dependence of the performance of the models, the skill scores were calculated for five latitude regions. Our study shows that RMSE of TEC and TEC changes of the model simulations range from about 3 TECU (total electron content unit, 1 TECU = 1016el m−2) (in high latitudes) to about 13 TECU (in low latitudes), which is larger than latitudinal average GPS TEC error of about 2 TECU. Most model simulations predict TEC better than TEC changes in terms of NRMSE and the difference in peak time, while the opposite holds true in terms of Yield. Model performance strongly depends on the quantities considered, the type of metrics used, and the latitude considered.
FeS
Cluster Assembly:
NIF
System in Nitrogen‐Fixing Bacteria
Authors: Santos Patricia C. Dos , Dean Dennis R.
Published: September 2017

Biological nitrogen fixation is restricted to a specialized group of microorganisms, called diazotrophs, and is catalyzed by the complex metalloenzyme nitrogenase. All diazotrophs recognized so far produce a molybdenum‐containing nitrogenase. However, some diazotrophs also produce paralogous nitrogenases that utilize a transition metal other than Mo as a constituent of the active site cofactor called FeMo‐cofactor. Early genetic studies established that proteins required to produce, activate, and sustain nitrogenase are not limited to the catalytic components but also include other proteins involved in the assembly of nitrogenase‐associated metal‐containing cofactors, protein folding, electron transfer, and regulation. The number of genes associated with nitrogen fixation varies among different species, and the involvement of accessory proteins depends on the metabolic and environmental conditions encountered during growth. To date, nearly all nitrogen‐fixing species having sequenced genomes contain a minimum of six genes dedicated to nitrogen fixation. These include genes encoding the nitrogenase catalytic components,
nifH
,
nifD
,
nifK
, and three genes,
nifE
,
nifN
, and
nifB
, whose products are required for FeMo‐cofactor formation. In some instances, genes associated with nitrogen fixation encode proteins that mirror other related cellular process. For example, the products of
nifU
and
nifS
are specifically involved in the assembly of [Fe–S] clusters dedicated to nitrogenase activation, whereas the structurally and functionally related housekeeping genes
iscU
and
iscS
are involved in [Fe–S] cluster formation that supports other Fe–S proteins.

The best‐studied diazotrophic organism is the strict aerobic microbe
Azotobacter vinelandii
. This organism is capable of producing three genetically distinct, but mechanistically similar, nitrogenases: Mo‐, V‐, and Fe‐only‐dependent enzymes. Under conditions of diazotrophy,
A
.
vinelandii
specifically elevates the expression of more than 60 genes. Among those, NifU and NifS are known to affect the synthesis and accumulation of active nitrogenase catalytic components in all three systems. In this chapter, we describe the initial assembly of [Fe–S] clusters necessary for the formation of both simple and complex [Fe–S] clusters associated with nitrogen fixation. This minimal toolkit for [Fe–S] cluster assembly includes a cysteine desulfurase, encoded by
nifS
, and an [Fe–S] cluster assembly scaffold, encoded by
nifU
. Studies on the nitrogenase specific system have also indicated that electron transfer reactions are required for effective [Fe–S] cluster formation and that preformed [Fe–S] clusters are likely trafficked to client proteins by specific carrier proteins. All of these features have provided a framework for studies on the general process of [Fe–S] cluster assembly that appears to be conserved throughout nature.
FeSCluster Assembly:SUFSystem in Bacteria, Plastids and Archaea
Authors: Dong Guangchao , Witcher Savannah , Outten F. Wayne , Pilon Marinus
Published: September 2017

Iron–sulfur (Fe–S) clusters are essential cofactors in biology due to their use in critical pathways such as nitrogen fixation, photosynthesis, and respiration. Fe–S cluster biogenesis requires complex systems to mobilize iron and sulfide, assemble the nascent cluster, and target Fe–S clusters to downstream target proteins. All of these steps must be coordinated to protect Fe–S cluster biogenesis intermediates from reactive oxygen species and other stressors. Multiple Fe–S cluster biogenesis pathways exist in different organisms and organelles. The Suf (sulfurformation) pathway is phylogenetically the most ancient of the cluster biogenesis systems and is distributed across all domains of life. It can be found as the primary Fe–S cluster biogenesis pathway or as an auxiliary pathway adapted to maintain Fe–S cluster metabolism under stress conditions. Here we describe the biochemical, genetic, and physiological characterization of the Suf system, in all of its iterations.
Assembly of Nitrogenase
FeMoco
and
P
Cluster
Authors: Sickerman Nathaniel S. , Rettberg Lee A. , Hu Yilin , Ribbe Markus W.
Published: September 2017

The catalytic reduction of dinitrogen by nitrogenase metalloenzymes to form ammonia is a critically important process in the global nitrogen cycle. Accomplishing this difficult reduction reaction under ambient conditions requires the cooperation of a series of nitrogenase proteins. The three main nitrogenase variants known are the iron/molybdenum‐containing Mo‐nitrogenase, the iron/vanadium‐containing V‐nitrogenase, and the iron‐only nitrogenase. All three variants utilize a MgATP‐dependent reductase component and perform substrate reduction within a larger catalytic component. In the case of Mo‐nitrogenase (encoded by
nif
genes), the reductase component, NifH, contains a canonical [Fe
4
S
4
] cluster; the catalytic component, NifDK, contains two unique metal‐containing clusters that are necessary for N
2
reduction: the site of catalytic substrate reduction, the [MoFe
7
S
9
C(
R
‐homocitrate)] FeMo cofactor, also called M cluster, and a capacitor‐like [Fe
8
S
7
]‐core unit called the P cluster. Biosynthesis of these two sophisticated metalloclusters involves the concerted effort of several nitrogenase assembly proteins. For both clusters, simple 2Fe units are first converted to [Fe
4
S
4
] clusters on the scaffold protein NifU with assistance by the cysteine desulfurase enzyme NifS. For M‐cluster biosynthesis, the 4Fe building blocks are supplied to the scaffold protein NifB to equip this radical
S
‐adenosylmethionine (SAM) enzyme with a SAM‐responsive cluster and a pair of 4Fe units called the “K cluster”. One equivalent of SAM donates a methyl group to the K cluster on NifB, while a second equivalent of SAM abstracts a hydrogen atom from the transferred methyl group. The
S
–CH
2
⋅ species formed by the second SAM equivalent facilitates cluster fusion, and following concomitant addition of a “9th sulfur” atom and deprotonation of the methylene unit, the [Fe
8
S
9
C]‐core L cluster is generated. The L cluster is handed off from NifB to another scaffold protein NifEN for further processing. On NifEN, the precursor cluster is matured to the M cluster through the actions of NifH, inserting homocitrate and a reduced form of Mo to produce completed M cluster. Following a conformational rearrangement, NifEN directly transfers the M cluster to a high‐affinity site on NifDK, which embeds the cofactor within the catalytic active site. P cluster biosynthesis begins on NifDK with a pair of protein subunit‐bridging 4Fe clusters termed the P* cluster. Through the actions of NifH and assistance by the chaperone‐like protein NifZ, reductive coupling of the clusters occurs to form functional P cluster. Genetic deletion mutants of NifDK suggest that P‐cluster maturation occurs in a stepwise manner and that M‐cluster insertion is only possible after P‐cluster assembly. This chapter outlines the complex facets of Mo‐nitrogenase metallocluster biosynthesis.
FeFe
‐Hydrogenase Assembly
Authors: Caserta Giorgio , Pecqueur Ludovic , Papini Cecilia , Fontecave Marc
Published: September 2017

Hydrogenases are a class of enzymes involved in the conversion of dihydrogen into protons and electrons and the reverse reaction, reduction of protons into hydrogen. The reaction takes place at a unique 6Fe‐metallocenter, named the H cluster. It consists of a classical [4Fe–4S] cluster and a unique [2Fe] subcluster linked to each other via a cysteine bridge. Maturation of [FeFe]‐hydrogenases involves the synthesis of the ligands of the [2Fe] subcluster, namely CO, CN
−
, and azapropanedithiolate (adt
2−
), and the assembly of the [2Fe] subcluster, depending on the concerted action of three metalloproteins, HydE, HydF, and HydG. HydE and HydG are “radical SAM” enzymes involved in the synthesis of the ligands. HydF functions as a scaffold protein in which a precursor of the [2Fe] subcluster is assembled before being transferred to the hydrogenase. An original chemical approach for the maturation of [FeFe]‐hydrogenases has been recently developed: a small synthetic complex, [Fe
2
(adt)(CO)
4
(CN)
2
]
2−
, mimicking the hydrogenase active site, can transform an inactive hydrogenase, lacking the [2Fe] subcluster, into a fully active enzyme, with no need for the HydEFG maturation machinery. Here, we review the current knowledge regarding the structure and the function of the three maturases and the assembly of the [2Fe] subcluster of [FeFe]‐hydrogenases via natural and chemical maturation.
CODehydrogenase and Acetyl‐CoASynthase Assembly
Authors: Dobbek Holger
Published: September 2017

Ni,Fe‐containing carbon monoxide dehydrogenases (CODHs) and acetyl‐CoA synthases (ACSs) are ubiquitous among anaerobic bacteria and archaea. CODHs catalyze the reversible reduction of CO2with two electrons and two protons to CO and water. ACSs catalyze the reversible condensation of CO, coenzyme A, and a methyl cation to acetyl‐CoA, and both enzymes can occur in a monofunctional or as a stable bifunctional complex. Compared to what is known about the maturation of other Ni‐containing enzymes, how CODH and ACS mature is just beginning to emerge. Despite differences in active‐site metal content (CODH: 1xNi, 4xFe; ACS: 2xNi, 4xFe), architecture (CODH: Ni integrated in a NiFe3S4cubanoidal subcluster; ACS: two Ni next to a [4Fe4S] cluster), active‐site accessibility, and protein fold, both Ni,Fe‐clusters are matured by homologous ATPases of the MinD/Mrp‐family called CooC (CODH maturation) and AcsF (ACS maturation).

CooC sustains the ATP‐dependent Ni insertion into the active‐site cluster of CODHs in the presence of physiological nickel concentrations. CooC can bind nickel at a GCXC motif in the dimer interface and ADP/ATP binding changes the coordination of nickel. AcsF forms a tight complex with Ni‐free ACS, together creating a binding platform for two nickel ions. The Ni‐loaded ACS–AcsF complex remains inactive until MgATP is added to it, resulting in fully active ACS. Details of the mechanisms and structures known to date are discussed in the chapter.
MoCu CO Dehydrogenase Assembly
Authors: Mickoleit Frank
Published: September 2017

Aerobic chemolithoautotrophic bacteria likeOligotropha carboxidovoransbiosynthesize CO (carbon monoxide) dehydrogenases to utilize CO as energy and carbon source. The enzyme comprises an (LMS)2heterohexameric structure with each heterotrimer building up an electron transport chain. CO oxidation proceeds at a unique bimetallic [CuSMoO2] cluster within the CoxL subunit. Released electrons are subsequently transferred to the [2Fe–2S] clusters of the iron–sulfur protein CoxS. Finally, the electrons are transmitted to the FAD (flavin‐adenine‐dinucleotide) cofactor in CoxM and released to the electron transport system of the cytoplasmic membrane, generating a proton‐motive force. Using substrate analogues and performing quantum chemical modeling, different schemes for the CO oxidation reaction cycle were developed. In the first case, a thiocarbonate transition state was proposed, whereas in the second case it was assumed that binding of CO via its carbon atom to the Cu1+ion is the first step in the catalytic cycle, followed by the transfer of the equatorial oxygen‐derived ligand on the molybdenum. The metal cluster matures post‐translationally with the molybdenum cofactor already being integrated into the completely folded and fully assembled apo‐CO dehydrogenase. Furthermore, the accessory proteins CoxD, CoxE, and CoxF are required. It was suggested that biosynthesis starts with the MgATP‐dependent, reductive sulfuration of [MoVIO3] to [MoVO2SH], which involves the function of the AAA+‐ATPase chaperone CoxD. After reoxidation of the molybdenum, Cu1+is inserted. The latter is supplied by soluble CoxF, which forms a complex with the membrane‐bound von Willebrand protein CoxE. Within this complex, Cu2+is reduced to Cu1+by electrons from respiration. Copper appears as Cu2+‐phytate, is mobilized through the phosphatase/phytase activity of CoxF, and is subsequently transferred to the CoxF copper‐binding site. Knowledge of the molybdenum and copper oxidation states during active‐site cluster assembly also enables the chemical reconstitution of the active site. CoxD, CoxE, and CoxF combine motifs of a DEAD‐box RNA helicase, which leads to a mutual translation of the polypeptides. The presence of a pleckstrin homology (PH) domain on CoxG suggests a role in recruiting CO dehydrogenase to the cytoplasmic membrane enabling electron transfer from the enzyme to the respiratory chain.
Photoassembly of the

CaMn
5
O
5

Catalytic Core and Its Inorganic Mutants in Photosystem
II
Authors: Gates Colin , Ananyev Gennady , Dismukes G. Charles
Published: September 2017

“What I cannot create (build), I do not understand”—Richard Feynman

The ability to take apart and reassemble atom by atom the elements of the water‐oxidizing complex (WOC) of photosynthetic enzymes and substitute each cofactor, while monitoring the consequences on photolytic charge separation and catalytic activity, has given deep insights into how photosynthetic water oxidation works, equal to any other method or technique. Here we summarize the literature covering the reconstitution of the inorganic core (Mn
4
CaO
5
) of photosystem II water‐oxidizing complexes (PSII‐WOCs), called photoassembly, and the consequences of substitution of the inorganic cofactors with nonnative cofactors. We give the evidence that explains the universal utilization of manganese as the sole redox‐active element for O
2
evolution by all native PSII‐WOCs. The selection of Mn
2+
over other more abundant transition metals during uptake and photooxidation by apo‐WOC‐PSII is shown to be achieved by a combination of thermodynamic advantage (bicarbonate stabilization of Mn
3+
photoproduct) and kinetic advantage favoring slow charge recombination from its intermediates. Manganese is shown to be favored over other transition metals because it can operate over a wider range of turnover rates produced by solar fluxes from morning to midday to dusk. The speciation of aqueous manganese in cells in equilibrium with air and bicarbonate is described from thermodynamic data and used to explain how (bi)carbonate stabilizes Mn
2+
→ Mn
3+
photooxidation and provides the core oxo bridges that build the Mn
4
CaO
5
cluster. The oxidation states of manganese obtained from photoassembly experiments are described and compared to spectroscopic results. The functional role of Ca
2+
in photoassembly and catalysis is revealed by substitution with Sr
2+
and Cd
2+
. These properties are advanced in order to understand how it is that evolution of only a single enzymatic blueprint for photosynthetic water oxidation has emerged, despite the access to every ecological niche on Earth and over 3 billion years of evolutionary history.
Urease Activation
Authors: Hausinger Robert P.
Published: September 2017

Synthesis of the urease dinuclear nickel active site requires the apoprotein (Apo), nickel ions, bicarbonate/CO
2
, Mg·GTP, and the participation of several accessory proteins beyond those that transport this metal ion into the cell. Bacteria and archaea typically require UreD (alternatively named UreH in some microorganisms), UreE, UreF, and UreG maturation proteins, whereas fungi and plants possess homologues of UreD, UreF, and UreG but lack proteins comparable to UreE. Unique to the bacterium
Helicobacter pylori
, the hydrogenase activation proteins HypA and HypB are also required for urease maturation. The various components have been shown to form specific protein–protein complexes: Apo·UreD, Apo·UreD·UreF, Apo·UreD·UreF·UreG, UreH·UreF, UreD/H·UreF·UreG, HypA·HypB, HypA·UreE, and UreE·UreG under defined conditions. In the current model for urease activation, (i) a lysine residue at the nascent active site of urease is carbamylated by CO
2
to form a metal‐bridging ligand, (ii) the metallochaperone UreE donates nickel to UreG, (iii) nickel‐bound UreG forms the Apo·UreD·UreF·UreG·Ni preactivation complex, (iv) nickel transfer from UreG to Apo is driven by the GTPase activity of UreG, (v) nickel ions pass through a molecular tunnel within the UreF and UreD/H scaffold proteins, (vi) metallocenter assembly is followed by dissociation of the accessory proteins from the urease holoenzyme. In
H. pylori
, HypA and HypB are thought to provide nickel to UreE. Here, evidence supporting the current model for urease maturation is summarized and the remaining open questions related to this process are discussed.
Topaquinone Biogenesis in Cu Amine Oxidases
Authors: Dooley David M. , Brown Doreen E. , Shepard Eric M.
Published: September 2017

Copper‐containing amine and lysyl oxidase (LOX) enzymes are responsible for catalyzing the oxidative deamination of biogenic primary amines or lysine residues in connective tissue precursor proteins. These two enzyme classes each undergo remarkable posttranslational, self‐processing reactions that are dependent solely on copper and molecular oxygen. The formation of the mature enzymes involves oxidation of an absolutely conserved tyrosine residue within the polypeptide sequence of the protein and results in formation of a quinone species. The autocatalytic process generates trihydroxyphenylalanine quinone (TPQ) in copper‐containing amine oxidases (CuAO) and lysyl tyrosine quinone (LTQ) in LOXs. The discovery of TPQ was the first of its kind and helped establish a new paradigm in biology for the modification and synthesis of amino acid derivatives that in turn exhibit unique chemical functionality. For copper‐containing amine and LOX enzymes, the quinone cofactors themselves are responsible for the coordination of amine substrates in Schiff base complexes, which then can be hydrolyzed to yield aldehyde product and a reduced aminoquinol that must then be reoxidized to afford the resting state of the enzyme. In terms of the biogenesis mechanisms, the tyrosine residue that undergoes oxidation is bound in close proximity to a type II copper center. Initial steps in TPQ and LTQ biosynthesis are proposed to be identical, and one possibility invokes coordination of tyrosine to copper(II) to introduce some radical or charge‐transfer character into the ring that could increase susceptibility to attack by molecular oxygen to yield a copper(II)‐peroxoquinone species; this moiety is then converted into 3,4‐dihydroxyphenylalanine quinone or dopaquinone. At this stage, TPQ biogenesis proceeds through attack of solvent water or hydroxide to the O2 position of the ring, whereas LTQ biogenesis proceeds through attack of a conserved polypeptide‐derived lysine residue to the O2 position of the ring. This chapter summarizes the discoveries of TPQ and LTQ and the large repertoire of experimental work that has gone into understanding the biogenesis mechanisms for these two extraordinary biological cofactors.
A patient safety education program in a medical physics residency
Authors: Ford Eric C. , Nyflot Matthew , Spraker Matthew B. , Kane Gabrielle , Hendrickson Kristi R. G.
Published: September 2017

Education in patient safety and quality of care is a requirement for radiation oncology residency programs according to accrediting agencies. However, recent surveys indicate that most programs lack a formal program to support this learning. The aim of this report was to address this gap and share experiences with a structured educational program on quality and safety designed specifically for medical physics therapy residencies. Five key topic areas were identified, drawn from published recommendations on safety and quality. A didactic component was developed, which includes an extensive reading list supported by a series of lectures. This was coupled with practice‐based learning which includes one project, for example, failure modes and effect analysis exercise, and also continued participation in the departmental incident learning system including a root‐cause analysis exercise. Performance was evaluated through quizzes, presentations, and reports. Over the period of 2014–2016, five medical physics residents successfully completed the program. Evaluations indicated that the residents had a positive experience. In addition to educating physics residents this program may be adapted for medical physics graduate programs or certificate programs, radiation oncology residencies, or as a self‐directed educational project for practicing physicists. Future directions might include a system that coordinates between medical training centers such as a resident exchange program.
Projected Burden of Osteoarthritis and Rheumatoid Arthritis in Australia: A Population‐Level Analysis
Authors: Ackerman Ilana N. , Pratt Clare , Gorelik Alexandra , Liew Danny
Published: September 2017

Objective

To forecast the prevalence and direct health care costs of osteoarthritis (OA) and rheumatoid arthritis (RA) in Australia to the year 2030.

Methods

An epidemiologic model of the Australian population was developed. Data on the national prevalence of OA and RA were obtained from the Australian Bureau of Statistics (ABS) 2014–2015 National Health Survey. Future prevalence was estimated using ABS population projections for 2020, 2025, and 2030. Available government data on direct health care expenditure for OA and RA were modeled to forecast costs (in Australian $) for the years 2020, 2025, and 2030, from the perspective of the Australian public health care system.

Results

The number of people with OA is expected to increase nationally from almost 2.2 million in 2015 to almost 3.1 million Australians in 2030. The number of people with RA is projected to increase from 422,309 in 2015 to 579,915 in 2030. Health care costs for OA were estimated to be over $2.1 billion in 2015; by the year 2030, these are forecast to exceed $2.9 billion ($970 for every person with the condition). Health care costs for RA were estimated to be over $550 million in 2015, including $273 million spent on biologic disease‐modifying antirheumatic drugs. Health care costs for RA are projected to rise to over $755 million by the year 2030.

Conclusion

OA and RA are costly conditions that will impose an increasing health care burden at the population level. These projections provide tangible data that can be used to map future health service provision to expected need.
Fused Deposition Modeling for Unmanned Aerial Vehicles (UAVs): A Review
Authors: Klippstein Helge , Diaz De Cerio Sanchez Alejandro , Hassanin Hany , Zweiri Yahya , Seneviratne Lakmal
Published: September 2017

Additive Manufacturing (AM) is a game changing production technology for aerospace applications. Fused deposition modeling is one of the most widely used AM technologies and recently has gained much attention in the advancement of many products. This paper introduces an extensive review of fused deposition modeling and its application in the development of high performance unmanned aerial vehicles. The process methodology, materials, post processing, and properties of its products are discussed in details. Successful examples of using this technology for making functional, lightweight, and high endurance unmanned aerial vehicles are also highlighted. In addition, major opportunities, limitations, and outlook of fused deposition modeling are also explored. The paper shows that the emerge of fused deposition modeling as a robust technique for unmanned aerial vehicles represents a good opportunity to produce compact, strong, lightweight structures, and functional parts with embedded electronic.
Sub‐Micrometer Structure Formation during Spin Coating Revealed by Time‐Resolved In Situ Laser and X‐Ray Scattering
Authors: van Franeker Jacobus J. , Hermida‐Merino Daniel , Gommes Cedric , Arapov Kirill , Michels Jasper J. , Janssen René A. J. , Portale Giuseppe
Published: September 2017

Solution‐processed thin polymer films have many applications, such as organic electronics and block‐copolymer nanofabrication. These films are often made by spin coating a solution that contains one or more solids and can show different phase‐separated structures. The formation mechanism of the droplet‐like morphology is studied here by processing polystyrene (PS) and a fullerene derivative ([6,6]‐phenyl‐C71‐butyric acid methyl ester, [70]PCBM) from o‐xylene. The final structure consists of [70]PCBM droplets partially embedded in a PS‐rich matrix showing interdomain distance of 100–1000 nm as determined from transmission electron microscopy and grazing incidence small angle X‐ray scattering (GISAXS). To elucidate the formation of these morphologies in real time, ultrafast in situ GISAXS coupled with laser interferometry and laser scattering is performed during spin coating. In situ thickness measurements and laser scattering show that liquid–liquid phase separation occurs at ≈70 vol% solvent. Subsequently, in only 100–400 ms, almost dry [70]PCBM domains start to protrude from the swollen PS‐rich matrix. These results are used to verify the ternary phase diagram calculated using Flory–Huggins theory. The discussed multitechnique approach can be applied to study fundamental aspects in soft matter such as phase separation in thin films occurring at very short time scales.
Atomic Layer Deposition of Zinc Glutarate Thin Films
Authors: Salmi Leo D. , Mattinen Miika , Niemi Teemu , Heikkilä Mikko J. , Mizohata Kenichiro , Korhonen Sanna , Hirvonen Sami‐Pekka , Räisänen Jyrki , Ritala Mikko
Published: September 2017

Deposition of zinc glutarate thin films by atomic layer deposition is studied at 200–250 °C using zinc acetate and glutaric acid as the precursors. The films are characterized by UV–vis spectrophotometry, X‐ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, atomic force microscopy, and time‐of‐flight elastic recoil detection analysis. According to X‐ray diffraction, the films deposited at 200 °C are crystalline with a crystal structure matching to zinc glutarate. The elastic recoil detection analysis shows that the composition of the films is a close match to zinc glutarate. Catalytic activity of the films is demonstrated using the copolymerization reaction of propylene oxide and CO2.
Compound heterozygous TRPV4 mutations in two siblings with a complex phenotype including severe intellectual disability and neuropathy
Authors: Thibodeau My Linh , Peters Colin H. , Townsend Katelin N. , Shen Yaoqing , Hendson Glenda , Adam Shelin , Selby Kathryn , Macleod Patrick M. , Gershome Cynthia , Ruben Peter , Jones Steven J. M. ,   the FORGE Canada Consortium, Friedman Jan M. , Gibson William T. , Horvath Gabriella A.
Published: September 2017

TRPV4 encodes a polymodal calcium‐permeable plasma membrane channel. Dominant pathogenic mutations in TRPV4 lead to a wide spectrum of abnormal phenotypes. This is the first report of biallelic TRPV4 mutations and we describe two compound heterozygous siblings presenting with a complex phenotype including severe neuromuscular involvement. In light of previously well described dominant inheritance for TRPV4‐related neuromuscular disease, our study suggests a role for compound heterozygosity and loss‐of‐function as a potential novel disease mechanism for this group of disorders. Profound intellectual disability was also noted in both affected children, suggesting that TRPV4 may be necessary for normal brain development.
Reduced range of the endangered crested capuchin monkey (Sapajus robustus) and a possible hybrid zone withSapajus nigritus
Authors: Martins Waldney Pereira , Lynch Alfaro Jessica , Rylands Anthony B.
Published: September 2017

The crested capuchin monkey (Sapajus robustus) is an endangered species endemic to the highly fragmented Atlantic Forest of Brazil. Surveys forS. robustuswere carried out over a 25‐month period (2003–2005) to obtain more precise geographical limits for the western range of the species. Previously published localities forS. robustuswere mapped, and each point was given a 25‐km radius “buffer zone.” The largest forest remnants in the buffer zones (>300 ha) in Minas Gerais were visited in order to interview the local people and/or survey the forests directly using playback recordings ofS. robustus. Camera traps were used in key localities if interviews suggested the presence of capuchins but no animals were sighted during the surveys. Of 127 valid interviews, only 39 people reported the presence ofSapajusin nearby forest fragments. We confirmed the presence ofSapajusin only 19 of these.S. robustusoccurred in four, andS. libidinosus,S. nigritus,S. xanthosternos, orS. robustus × S. nigritus(hybrids?) occurred in the remaining 15. Based on our study, the estimated geographical distribution ofS. robustusis 119,654 km2, which represents a reduction of more than 70,000 km2when compared to its formerly described range. The geographical limits as defined in this study are: northeast—the Jequitinhonha River; northwest and west—the Jequitinhonha River; southwest—the Suaçuí Grande River and the Espinhaço mountains; southeast—the Doce River; east—the Atlantic Ocean. A probable hybrid zone where capuchin monkeys have morphological features of bothS. nigritusandS. robustuswas found between the Santo Antônio and the Suaçuí Grande rivers. The elucidation of the geographical distribution ofS. robustusis important for its conservation, facilitating the delineation of priority areas for the creation of reserves and the initiation of studies of the species’ ecology and behavior.
Age at reproductive debut: Developmental predictors and consequences for lactation, infant mass, and subsequent reproduction in rhesus macaques (Macaca mulatta)
Authors: Pittet Florent , Johnson Crystal , Hinde Katie
Published: September 2017

Objectives

The age at which females initiate their reproductive career is a critical life‐history parameter with potential consequences on their residual reproductive value and lifetime fitness. The age at reproductive debut may be intimately tied to the somatic capacity of the mother to rear her young, but relatively little is known about the influence of age of first birth on milk synthesis within a broader framework of reproductive scheduling, infant outcomes, and other life‐history tradeoffs.

Material and Methods

Our study investigated the predictors of age at first reproduction among 108 captive rhesus macaque (Macaca mulatta) females, and associations with their milk synthesis at peak lactation, infant mass, and ability to subsequently conceive and reproduce.

Results

The majority of females reproduced in their fourth year (typical breeders); far fewer initiated their reproductive career one year earlier or one year later (respectively early and late breeders). Early breeders (3‐year‐old) benefited from highly favorable early life development (better juvenile growth, high dominance rank) to accelerate reproduction, but were impaired in milk synthesis due to lower somatic resources and their own continued growth. Comparatively, late breeders suffered from poor developmental conditions, only partially compensated by their delayed reproduction, and evinced compromised milk synthesis. Typical breeders not only produced higher available milk energy but also had best reproductive performance during the breeding and birth seasons following primiparity.

Discussion

Here, we refine and extend our understanding of how life‐history tradeoffs manifest in the magnitude, sources, and consequences of variation in age of reproductive debut. These findings provide insight into primate reproductive flexibility in the context of constraints and opportunities.
New primate locality from the early Miocene of Patagonia, Argentina
Authors: Novo Nelson M. , Tejedor Marcelo F. , Pérez María E. , Krause J. Marcelo
Published: September 2017

Objectives

The purpose of this work is to present a new primate locality with evidence that increases the knowledge on the radiation of the extinct platyrrhine primates.

Materials and methods

We studied the new specimen and compared it to specimens identified as Mazzonicebus almendrae.

Results

The new first and second molars were comparable to Mazzonicebus almendrae in all morphological details, allowing us to allocate the new specimen to M. almendrae and add comments on morphological variation in this species regarding the orientation of the labial cristae and development of the anterolingual cingulum. This new maxilla also present the first known M3 for the species.

Discussion

The new specimen increases our knowledge of the extinct platyrrhines from Patagonia. Their age and geographical distribution ranges from early to middle Miocene in an area between 40° to 47° of southern latitude.
Graphene Oxide Facilitates Solvent‐Free Synthesis of Well‐Dispersed, Faceted Zeolite Crystals
Authors: Li Hui , Liu Xing , Qi Siqi , Xu Linli , Shi Guosheng , Ding Yihong , Yan Xiaoying , Huang Yong , Geng Jianxin
Published: September 2017

Zeolites with molecular dimension pores are widely used in petrochemical and fine‐chemical industries. While traditional solvothermal syntheses suffer from environmental, safety, and efficiency issues, the newly developed solvent‐free synthesis is limited by zeolite crystal aggregation. Herein, we report well‐dispersed and faceted silicalite ZSM‐5 zeolite crystals obtained using a solvent‐free synthesis facilitated by graphene oxide (GO). The selective interactions between the GO sheets and different facets, which are confirmed by molecular dynamics simulations, result in oriented growth of the ZSM‐5 crystals along the c‐axis. More importantly, the incorporation of GO sheets into the ZSM‐5 crystals leads to the formation of mesopores. Consequently, the faceted ZSM‐5 crystals exhibit hierarchical pore structures. This synthetic method is superior to conventional approaches because of the features of the ZSM‐5 zeolite.
Fabrication of polypropylene blends with excellent low‐temperature toughness and balanced toughness‐rigidity by a combination of EPR and SEEPS
Authors: Jia Erwen , Shangguan Yonggang , Xiong Junwen , Chen Feng , Zheng Qiang
Published: September 2017

To overcome serious rigidity depression of rubber‐toughened plastics and fabricate a rigidity‐toughness balanced thermoplastic, a combination of styrene‐[ethylene‐(ethylene‐propylene)]‐styrene block copolymer (SEEPS) and ethylene‐propylene rubber (EPR) was used to toughen polypropylene. The dynamic mechanical properties, crystallization and melting behavior, and mechanical properties of polypropylene (PP)/EPR/SEEPS blends were studied in detail. The results show that the combination of SEEPS and EPR can achieve the tremendous improvement of low‐temperature toughness without significant strength and rigidity loss. Dynamic mechanical properties and phase morphology results demonstrate that there is a good interfacial strength and increased loss of compound rubber phase comprised of EPR component and EP domain of SEEPS. Compared with PP/EPR binary blends, although neither glass transition temperature (Tg) of the rubber phase nor Tg of PP matrix in PP/EPR/SEEPS blends decreases, the brittle‐tough transition temperature (Tbd) of PP/EPR/SEEPS blends decreases, indicating that the increased interfacial interaction between PP matrix and compound rubber phase is also an effective approach to decrease Tbd of the blends so as to improve low‐temperature toughness. The balance between rigidity and toughness of PP/EPR/SEEPS blends is ascribed to the synergistic effect of EPR and SEEPS on toughening PP. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45714.
Swelling behavior of polymeric membranes to metalworking fluids
Authors: Nguyen‐Tri Phuong , Tuduri Ludovic , Gauvin Chantal , Triki Ennouri , Vu‐Khanh Toan
Published: September 2017

In some working places, such as metal manufacturing or automotive services, mechanical hazards commonly occur along with chemical hazards, particularly metalworking fluids (MWFs). The presence of these chemicals could modify the properties of gloves made from polymeric materials and thus reduce their protective properties against chemical contamination (solvent, MWFs) and mechanical risks (puncture and cutting). This work focused on determining the swelling characteristics and the resistance of six polymeric membranes which were exposed to seven industrial MWFs. We found that the swelling tests can be used to classify the potential of coating polymers in descending order of their resistance to MWFs: nitrile, polyurethane > poly(vinyl chloride), neoprene > butyl, latex. The analysis by multiple linear regression showed, for the first time, that the density or the viscosity‐gravity constant of the fluid and Hansen's solubility parameters of the polymers have a significant impact on the swelling of polymer. For the first time, two new multiple regression models have been proposed, to predict the swelling phenomena of polymers under various MWFs with an accuracy of ≈80%. The effect of temperature on mechanical properties and morphology of material was also examined. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45717.
Mitigating thermal runaway of lithium‐ion battery by using thermally sensitive polymer blend as cathode binder
Authors: Le Anh V. , Wang Meng , Noelle Daniel J. , Shi Yang , Qiao Yu
Published: September 2017

Thermally sensitive binder (TSB) is developed as an internal safety mechanism of lithium‐ion battery (LIB). The TSB is a polymer blend of poly(vinylidene fluoride) (PVDF) and poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVDF‐HFP). Compared with regular PVDF binder, the softening and swelling of TSB are more pronounced when temperature is above 110 °C. With the TSB, the cycling performance of LIB cell is not affected; upon nail penetration, the heat generation rate is significantly reduced. The crystallinity of TSB is an important factor. This technology may lead to the development of thermal‐runaway‐mitigating LIB cells. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45737.
Biodegradable polypropylene/thermoplastic starch nanocomposites incorporating halloysite nanotubes
Authors: Raee Ehsan , Kaffashi Babak
Published: September 2017

In this work, polypropylene/thermoplastic starch (PP/TPS) with and without halloysite nanotubes (HNTs) was prepared via melt mixing in order to obtain environmentally friendly plastics. PP‐grafted maleic anhydride (PP‐g‐MA) was used to improve the compatibility among the highly incompatible polymers. The mechanical characterization showed a reduction in the tensile properties of the polymer when TPS increased; however, HNT successfully compensated for some of the observed losses. The results from the thermogravimetric analysis (TGA) indicated that HNT is an efficient reinforcement for the thermal stability improvement. TPS caused an increase in the storage modulus (G′) and the complex viscosity (η*) which marks a change in the viscoelastic properties of the system. The scanning electron microscope (SEM) images showed the effective plasticization of starch and better dispersion of TPS in the presence of HNT. Some samples were also buried in the soil to measure their sustainability after their lifetime lapse. The results indicated that TPS improves the biodegradability of the PP/TPS system. PP considerably lowered the moisture uptake of TPS; nevertheless, HNT caused a slight increase in the moisture absorption. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45740.
Preparation of hybrid silicon materials microcapsulated ammonium polyphosphate and its application in thermoplastic polyurethane
Authors: Gao Weiying , Qian Xiaodong , Wang Shujun
Published: September 2017

Silica‐gel microencapsulated ammonium polyphosphate (SiOAPP), prepared by traditional sol–gel method, is still incompatible with polymer and easily attacked by moisture due to the presence of lots of hydroxyl group, so the traditional sol–gel method was optimized with polydimethyl siloxane (PDMS) to improve the related properties of microcapsules in this study. The results showed that the SiOAPP process and shell shape had changed significantly, and the APP microcapsules with silica/silicone carbon composite shell (SiOCAPP) was successfully prepared. The hydrophobicity of SiOCAPP was much better than that of the SiOAPP, the water contact angle of SiOAPP was 54°, while the water contact angle of SiOCAPP could reach 111°. The property reinforcements of the SiOCAPP in thermoplastic polyurethane (TPU) were studied and compared with the TPU/SiOAPP composites. The time to ignition reduced by 2 s and the maximal peak of heat release rate (pk‐HRR) increased by 4.4%, but the average heat release rate and total heat release, respectively, reduced by 15.5% and 31.4%, which was a great improvement on the flame retardancy of TPU, and the char residue rate, which is related to the condensed flame retardant effect, increased by 10%. Besides, the tensile strength and elongation at break increased by 11.8% and 5.84%, respectively. Generally, the sol–gel method modified by PDMS provided an novel method to improve the comprehensive properties of APP. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45742.
Instrumentierte Bauwerksüberwachung im Kontext historischer Bauten
Authors: Lehmann Frank , Schreiner Michael , Reinhardt Hans‐Wolf
Published: September 2017

Die instrumentierte Bauwerksüberwachung erweitert die Möglichkeiten eines Ingenieurs hinsichtlich der Beurteilung von Tragwerken. Dabei ist dieses Werkzeug als Ergänzung zu anderen Prüfungen zu sehen, nicht als Alternative, da der Fokus der Messungen auf kurz‐ und langfristigen Veränderungen am Bauwerk liegt und nicht auf der Erfassung des Ist‐Zustands. Besonders bei historischen Bauten bieten sich entsprechende Überwachungen an, da zweifelsohne eine langfristige Erhaltung angestrebt ist. Die Autoren beschreiben in dem Artikel zuerst allgemein die Einbettung der Bauwerksüberwachung in die Bauwerksprüfung, gefolgt von einigen Überlegungen zu Monitoring an historischen Bauten. Zur Illustration wird dieses am Beispiel der instrumentierten Dauerüberwachung des Sommerrefektoriums im Kloster Bebenhausen gezeigt.
Bacterial Translocation Ratchets: Shared Physical Principles with Different Molecular Implementations
Authors: Hepp Christof , Maier Berenike
Published: September 2017

Secretion systems enable bacteria to import and secrete large macromolecules including DNA and proteins. While most components of these systems have been identified, the molecular mechanisms of macromolecular transport remain poorly understood. Recent findings suggest that various bacterial secretion systems make use of the translocation ratchet mechanism for transporting polymers across the cell envelope. Translocation ratchets are powered by chemical potential differences generated by concentration gradients of ions or molecules that are specific to the respective secretion systems. Bacteria employ these potential differences for biasing Brownian motion of the macromolecules within the conduits of the secretion systems. Candidates for this mechanism include DNA import by the type II secretion/type IV pilus system, DNA export by the type IV secretion system, and protein export by the type I secretion system. Here, we propose that these three secretion systems employ different molecular implementations of the translocation ratchet mechanism.
A sequential test for assessing observed agreement between raters
Authors: Bersimis Sotiris , Sachlas Athanasios , Chakraborti Subha
Published: September 2017

Assessing the agreement between two or more raters is an important topic in medical practice. Existing techniques, which deal with categorical data, are based on contingency tables. This is often an obstacle in practice as we have to wait for a long time to collect the appropriate sample size of subjects to construct the contingency table. In this paper, we introduce a nonparametric sequential test for assessing agreement, which can be applied as data accrues, does not require a contingency table, facilitating a rapid assessment of the agreement. The proposed test is based on the cumulative sum of the number of disagreements between the two raters and a suitable statistic representing the waiting time until the cumulative sum exceeds a predefined threshold. We treat the cases of testing two raters' agreement with respect to one or more characteristics and using two or more classification categories, the case where the two raters extremely disagree, and finally the case of testing more than two raters' agreement. The numerical investigation shows that the proposed test has excellent performance. Compared to the existing methods, the proposed method appears to require significantly smaller sample size with equivalent power. Moreover, the proposed method is easily generalizable and brings the problem of assessing the agreement between two or more raters and one or more characteristics under a unified framework, thus providing an easy to use tool to medical practitioners.
Recoding of synonymous genes to expand evolutionary landscapes requires control of secondary structure affecting translation
Authors: Escudero Jose A. , Nivina Aleksandra , Cambray Guillaume , López‐Igual Rocío , Loot Celine , Mazel Didier
Published: September 2017

Synthetic DNA design needs to harness the many information layers embedded in a DNA string. We previously developed the Evolutionary Landscape Painter (ELP), an algorithm that exploits the degeneracy of the code to increase protein evolvability. Here, we have used ELP to recode the integron integrase gene (intI1) in two alternative alleles. Although synonymous, both alleles yielded less IntI1 protein and were less active in recombination assays than intI1. We spliced the three alleles and mapped the activity decrease to the beginning of alternative sequences. Mfold predicted the presence of more stable secondary structures in the alternative genes. Using synonymous mutations, we decreased their stability and recovered full activity. Following a design‐build‐test approach, we have now updated ELP to consider such structures and provide streamlined alternative sequences. Our results support the possibility of modulating gene activity through the ad hoc design of 5′ secondary structures in synthetic genes.