bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cloud Heterogeneity in the Marine Midlatitudes: Dependence on Large‐Scale Meteorology and Implications for General Circulation Models
Authors: Loveridge Jesse , Davies Roger 
Published: March 2019

AbstractWe examine the sensitivity of cloud heterogeneity to large‐scale meteorology in the marine midlatitudes using satellite observations from the Multiangle Imaging Spectroradiometer and Moderate Resolution Imaging Spectroradiometer instruments aboard the Terra satellite and nudged simulations from the UK Met Office's Global Atmosphere 7.0 (GA7) for the year 2007. Using Multiangle Imaging Spectroradiometer observations, we quantify several sources of observational uncertainty due to cloud heterogeneity such as finite‐resolution cloud fraction biases and subpixel heterogeneity. With a simple measure of cloud geometry, we show that these sources of observational uncertainty are maximized in post–cold‐frontal conditions, where scattered subpixel clouds are frequent, and are minimized in the warm sector, where subpixel clouds are infrequent. These results demonstrate the greater difficulty in interpreting remote sensing measurements in post–cold‐frontal conditions compared to quiescent or warm‐sector conditions. We show that the neglect of this observational uncertainty can qualitatively alter the interpretation of how cloud properties respond to large‐scale meteorology in GA7 and general circulation models in general. However, conservative application of the satellite data still allows robust evaluation of the simulated clouds. For overcast domains, Moderate Resolution Imaging Spectroradiometer observations show that overcast cloud heterogeneity is independent of large‐scale meteorology. However, heterogeneity increases when moving from warm sector to post‐cold‐frontal conditions in GA7. GA7 overestimates the heterogeneity of the low‐topped clouds that populate these regimes. For overcast domains, this bias is equivalent to a 15% underestimation in the mean cloud optical depth. These results suggest a systematic error in the subgrid‐scale variability parameterization, which, when corrected, will improve the simulation of the midlatitudes in GA7.
Polarisation independent dual‐band conformal metamaterial absorber for X‐band microwave application
Authors: Kalraiya S. , Chaudhary R.K. , Abdalla M.A. , Gangwar R.K. 
Published: March 2019

A polarisation independent conformal absorber has been proposed for X‐band microwave application. The absorber unit cell consists of three resonators, which generate three absorption bands at 9.1, 11.04 and 11.44 GHz with more than 90% absorption. The full wave at half maximum bandwidth of the absorber is 320 and 720 MHz at lower and upper‐frequency bands. The absorber is conformal as it has a low‐profile flexible substrate with an ultrathin thickness of 0.01λo, where λo is the wavelength at 9.1 GHz. The proposed absorber unit cell has a fourfold symmetry, which makes the absorber polarisation independent and possesses a wide angle stability under oblique incident angle up to 50°. The absorption performance of the absorber on various radii of cylindrically curved surface has been confirmed through the simulated and measured results.
Biosynthesis, characterisation and antibacterial activity of Mikania micrantha leaf extract‐mediated AgNPs
Authors: Biswas Aayushi , Vanlalveni Chhangte , Adhikari Partha Pradip , Lalfakzuala Ralte , Rokhum Lalthazuala 
Published: March 2019

In the present years, nanobiotechnology has to turn out to be an important division of research. Here, this work reported a novel Mikania micrantha leaf extract‐mediated silver nanoparticle (AgNP) under room temperature condition. The biosynthesised AgNPs were further characterised by various analysis techniques such as ultraviolet–visible spectrophotometer, Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD) and transmission electron microscope (TEM) energy‐dispersive X‐ray spectroscopy. The formation of AgNPs was confirmed by XRD spectrum which displayed intense peaks corresponding to the (1 1 1), (2 0 0), (2 2 0) and (3 1 1) lattice planes of Ag. The plant extracts stirred with Ag nitrate solution gradually changes its colour from light yellow to dark brown. The biogenic AgNPs were mostly spherical in shape with varying sizes ranging from 5 to 20 nm, as evident by TEM analysis. FT‐IR spectra of the extract revealed the presence of amide I and amide II bonds of the proteins. The synthesised AgNPs showed excellent activity results against various Gram‐positive and Gram‐negative bacterial strains.
Building protoplanetary disks from the molecular cloud: redefining the disk timeline
Authors: Baillié K. , Marques J. , Piau L. 
Published: March 2019

Context. Planetary formation models are necessary to understand the characteristics of the planets that are the most likely to survive. Their dynamics, their composition and even the probability of their survival depend on the environment in which they form. We therefore investigate the most favorable locations for planetary embryos to accumulate in the protoplanetary disk: the planet traps.
Aims. We study the formation of the protoplanetary disk by the collapse of a primordial molecular cloud, and how its evolution leads to the selection of specific types of planets.
Methods. We use a hydrodynamical code that accounts for the dynamics, thermodynamics, geometry and composition of the disk to numerically model its evolution as it is fed by the infalling cloud material. As the mass accretion rate of the disk onto the star determines its growth, we can calculate the stellar characteristics by interpolating its radius, luminosity and temperature over the stellar mass from pre-calculated stellar evolution models. The density and midplane temperature of the disk then allow us to model the interactions between the disk and potential planets and determine their migration.
Results. At the end of the collapse phase, when the disk reaches its maximum mass, it pursues its viscous spreading, similarly to the evolution from a minimum mass solar nebula (MMSN). In addition, we establish a timeline equivalence between the MMSN and a “collapse-formed disk” that would be older by about 2 Myr.
Conclusions. We can save various types of planets from a fatal type-I inward migration: in particular, planetary embryos can avoid falling on the star by becoming trapped at the heat transition barriers and at most sublimation lines (except the silicates one). One of the novelties concerns the possible trapping of putative giant planets around a few astronomical units from the star around the end of the infall. Moreover, trapped planets may still follow the traps outward during the collapse phase and inward after it. Finally, this protoplanetary disk formation model shows the early possibilities of trapping planetary embryos at disk stages that are anterior by a few million years to the initial state of the MMSN approximation.
Astrophysical detections and databases for the mono deuterated species of acetaldehyde CH2DCOH and CH3COD
Authors: Coudert L. H. , Margulès L. , Vastel C. , Motiyenko R. , Caux E. , Guillemin J.-C. 
Published: March 2019

Context. Detection of deuterated species may provide information on the evolving chemistry in the earliest phases of star-forming regions. For molecules with two isomeric forms of the same isotopic variant, gas-phase and solid-state formation pathways can be differentiated using their abundance ratio.
Aims. Spectroscopic databases for astrophysical purposes are built for the two mono deuterated isomeric species CH2DCOH and CH3COD of the complex organic molecule acetaldehyde. These databases can be used to search and detect these two species in astrophysical surveys, retrieving their column density and therefore abundances.
Methods. Submillimeter wave and terahertz transitions were measured for mono deuterated acetaldehyde CH2DCOH which is a non-rigid species displaying internal rotation of its asymmetrical CH2D methyl group. An analysis of a dataset consisting of previously measured microwave data and the newly measured transition was carried out with a model accounting for the large amplitude torsion.
Results. The frequencies of 2556 transitions are reproduced with a unitless standard deviation of 2.3 yielding various spectroscopic constants. Spectroscopic databases for astrophysical purposes were built for CH2DCOH using the results of the present analysis and for CH3COD using the results of a previous spectroscopic investigation. These two species were both searched for and are detected toward a low-mass star-forming region.
Conclusions. We report the first detection of CH2DCOH (93 transitions) and the detection of CH3COD (43 transitions) species in source B of the IRAS 16293−2422 young stellar binary system located in the ρ Ophiuchus cloud region, using the publicly available ALMA Protostellar Interferometric Line Survey.
Management of Pathologic Fractures Around the Hip: Part 2–Acetabulum
Authors: Auran Richard L. , Duran Michael D. , de Comas Amalia M. , Jacofsky David J. 
Published: March 2019

AbstractMetastatic disease to the periacetabular region of the pelvis is a complex and challenging problem to treat. Similar to the proximal femur, this area of the skeleton has a high proportion of involvement when primary tumors metastasize to bone. Surgical intervention to treat this patient population is significantly more difficult than treating lesions of the proximal femur. There tends to be higher rates of intraoperative blood loss and postoperative complications, as well as poorer prognoses. It is important for the operating surgeon to evaluate the patient's medical status using a multidisciplinary approach and fully understand their prognosis before planning and performing surgical intervention. Given the complex nature of these surgeries, they are best performed by orthopaedic oncologists or experienced revision arthroplasty specialists. The clinical evaluation, workup, and perioperative adjuncts to treatment for periacetabular metastatic disease are similar to those for disease of the proximal femur as discussed in part 1 of this article series. This review focuses on aspects specific to acetabular disease and surgical intervention in these patients.
An Unusual Case of Infantile Spasms Due to a Pathogenic Variant in the MECP2 Gene
Authors: Charkhand Behshad , Liu Natarie , Barrett Karlene T. , Al-Hertani Walla , Scantlebury Morris H. 
Published: March 2019

AbstractThe infantile spasms (IS) syndrome is a developmental epileptic encephalopathy disorder characterized by epileptic spasms occurring in infancy, hypsarrhythmia on the electroencephalography (EEG) and developmental arrest or regression. The etiologies include structural, metabolic, and genetic causes. We report an unusual case of IS due to a de novo variant in the MECP2 gene. The patient also had variants of uncertain significance in the SCN9A and SCN5A genes inherited from the father and mother, respectively. This report highlights the need for broad genetic testing in MECP2-related disorders with atypical presentations to better understand the disease etiology.
Mechanisms for achieving high speed and efficiency in biomolecular machines
Authors: Wagoner Jason A. , Dill Ken A. 
Published: March 2019

Significance
Molecular machines are cellular proteins that transduce energy. They can convert energy to motion, recharge ATP stores by harnessing ion flows, and pump ions energetically uphill. Molecular machines are able to be both fast and efficient at the same time. How do they achieve high speeds at high efficiency? Here we explore mechanisms of evolution or synthetic design that can optimize these properties, such as a conformationally driven mechanical step, which varies the conformational free-energy landscape to mitigate large kinetic barriers, and mechanical substeps, which split one large kinetic barrier into multiple smaller ones.
Regulation of T cell expansion by antigen presentation dynamics
Authors: Mayer Andreas , Zhang Yaojun , Perelson Alan S. , Wingreen Ned S. 
Published: March 2019

SignificanceAntigen-specific T cells proliferate multiple times during an immune reaction to fight against disease. This expansion of T cells must be carefully regulated to ensure an effective defense while avoiding autoimmunity. One challenge to regulation is that the initial size of antigen-specific T cell clones can be quite variable. Intriguingly, a recent study in mice found that the fold expansion of a T cell clone depends as an inverse power law on its initial size. We propose a simple mathematical model that naturally yields the observed power law relation. Our model accounts for multiple experiments on T cell proliferation, suggests optimal vaccination protocols, and highlights dynamics of presented antigen as a key regulator of the size of an immune response.
Array atomic force microscopy for real-time multiparametric analysis
Authors: Yang Qingqing , Ma Qian , Herum Kate M. , Wang Chonghe , Patel Nirav , Lee Joon , Wang Shanshan , Yen Tony M. , Wang Jun , Tang Hanmei , Lo Yu-Hwa , Head Brian P. , Azam Farooq , Xu Sheng , Cauwenberghs Gert , McCulloch Andrew D. , John Scott , Liu Zhaowei , Lal Ratnesh 
Published: March 2019

Significance
High-resolution multipoint simultaneous structure–function analysis is becoming of great interest in a broad spectrum of fields for deciphering multiscale dynamics, especially in biophysics and materials science. However, current techniques are limited in terms of versatility, resolution, throughput, and biocompatibility. Here, a multifunctional imaging platform is introduced that shows high sensitivity, minimum cross-talk, and a variety of probe-based sensing. This is demonstrated by parallel multiparametric studies in air and liquid, including mechanical wave propagation in a soft polymer film, imaging of live neurons, and cooperative activities of living coupled cardiac muscle cells. As an experimental demonstration of array atomic force microscopy for multiparametric analysis in dynamic systems this work sheds light on the study of emergent properties in wide-ranging fields.
Antibiotic treatment affects the expression levels of copper transporters and the isotopic composition of copper in the colon of mice
Authors: Miller Kerri A. , Vicentini Fernando A. , Hirota Simon A. , Sharkey Keith A. , Wieser Michael E. 
Published: March 2019

SignificanceIsotopic analysis has the ability to detect changes in metal homeostasis in vivo. Using this advanced technique to investigate metal metabolism, we identified a significant change in copper processing in the gut of mice with depleted gut microbiota. In addition, we observed changes in the expression of copper transporters in the colon. The role of intestinal microbiota in copper processing in the gastrointestinal tract was previously unknown. Using the unique ability of isotopic analyses to detect changes in metal processing has enabled the identification of the intestinal microbiota as a significant influence on copper metabolism in the gut.
Discovery of novel carbohydrate-active enzymes through the rational exploration of the protein sequences space
Authors: Helbert William , Poulet Laurent , Drouillard Sophie , Mathieu Sophie , Loiodice Mélanie , Couturier Marie , Lombard Vincent , Terrapon Nicolas , Turchetto Jeremy , Vincentelli Renaud , Henrissat Bernard 
Published: March 2019

Significance
In the context of genome and metagenome sequencing, the assignment of function to sequences is a serious issue. In the case of enzymes of strong substrate specificity, such as those involved in the breakdown of polysaccharides (e.g., glycoside hydrolases and polysaccharide lyases), assignments become unreliable when sequence similarity to experimentally studied enzymes is low. To better explore the sequence-to-function relationships of these enzymes, we successfully applied a strategy based on a rational bioinformatic selection of enzyme targets, synthetic gene synthesis, and screening of recombinant proteins on a wide diversity of carbohydrate substrates. Seventy-nine of our 564 targets exhibited enzymatic activity, including three activities that have not been described previously, and 13 novel enzyme families could be defined.
Human pregnancy zone protein stabilizes misfolded proteins including preeclampsia- and Alzheimer’s-associated amyloid beta peptide
Authors: Cater Jordan H. , Kumita Janet R. , Zeineddine Abdallah Rafaa , Zhao Guomao , Bernardo-Gancedo Ana , Henry Amanda , Winata Wendy , Chi Mengna , Grenyer Brin S. F. , Townsend Michelle L. , Ranson Marie , Buhimschi Catalin S. , Charnock-Jones D. Stephen , Dobson Christopher M. , Wilson Mark R. , Buhimschi Irina A. , Wyatt Amy R. 
Published: March 2019

SignificancePregnancy is a unique physiological state involving biological stresses that promote protein damage (misfolding) within the maternal body. Currently, little is known regarding how the maternal body copes with elevated protein misfolding in pregnancy. This is important, because the accumulation of misfolded proteins underlies many human disorders, including preeclampsia, a serious complication of pregnancy. In this study, we show that pregnancy zone protein (PZP) efficiently inhibits the aggregation of misfolded proteins, including the amyloid beta peptide, which forms plaques in preeclampsia and in Alzheimer’s disease. We propose that up-regulation of PZP is a major maternal adaptation that helps to maintain protein homeostasis during pregnancy. Moreover, pregnancy-independent up-regulation of PZP indicates that its chaperone function could be broadly important in humans.
Intracellular cargo transport by single-headed kinesin motors
Authors: Schimert Kristin I. , Budaitis Breane G. , Reinemann Dana N. , Lang Matthew J. , Verhey Kristen J. 
Published: March 2019

Significance
Intracellular transport is driven by molecular motors that carry cargoes along cytoskeletal tracks. Molecular motors, such as kinesin-1, contain two motor domains so they can walk processively (take many steps per encounter) along a microtubule track. The two motor domains alternate their catalytic activities so that one of them is always attached to the track. Here we show that kinesins with one motor domain are not processive as individuals but can work collectively to drive continuous transport in cells. However, their transport is most efficient when the motor-to-cargo distance is short and the cargo imposes little load on the motor. These results lend insight into the minimal requirements for kinesin transport and the synergies gained through teamwork and coordination.
Energy conservation by a hydrogenase-dependent chemiosmotic mechanism in an ancient metabolic pathway
Authors: Schoelmerich Marie Charlotte , Müller Volker 
Published: March 2019

Significance
Acetogenic bacteria are the most primordial living organisms. They can live solely on inorganic compounds by using carbon monoxide or molecular hydrogen as energy sources to fix carbon dioxide to acetate and rely on a chemiosmotic mechanism for energy conservation. Most microorganisms possess a complex respiratory chain that is composed of many different components to establish the chemiosmotic gradient. Here, we dissect the bioenergetics in a chemolithoautotrophic thermophilic acetogenic bacterium. This living fossil uses a simple respiration comprising only a hydrogenase and an ATP synthase for energy conservation. This two-module respiration system is sufficient to sustain primordial microbial life.
Interplay between DNA sequence and negative superhelicity drives R-loop structures
Authors: Stolz Robert , Sulthana Shaheen , Hartono Stella R. , Malig Maika , Benham Craig J. , Chedin Frederic 
Published: March 2019

Significance
Three-stranded R-loop structures form during transcription when the nascent RNA transcript rehybridizes to the template DNA strand. This creates an RNA:DNA hybrid and forces the nontemplate DNA strand into a single-stranded, looped-out state. R-loops form universally over conserved hotspot regions. To date, the physicochemical bases underlying R-loop formation remain unclear. Using a “first-principle” mathematical approach backed by experimental validation, we elucidated the relative contributions of DNA sequence and DNA topology to R-loop formation. Our work provides a quantitative assessment of the energies underlying R-loop formation and of their interplay. It further reveals these structures as important regulators of the DNA topological state.
GSAP modulates γ-secretase specificity by inducing conformational change in PS1
Authors: Wong Eitan , Liao George P. , Chang Jerry C. , Xu Peng , Li Yue-Ming , Greengard Paul 
Published: March 2019

Significance
γ-Secretase cleaves multiple transmembrane proteins, but little is known about how it controls its substrate specificity. γ-Secretase activating protein (GSAP) has been reported to differentially activate γ-secretase for APP and Notch cleavages. The mechanism by which GSAP regulates γ-secretase specificity is elusive. Here, we demonstrate that GSAP directly regulates γ-secretase activity and specificity. Furthermore, GSAP functions as a switch between two forms of γ-secretase that have different activities for APP and Notch substrates, leading to different specificities. These findings open a new avenue for drug development through targeting the specificity of modifying proteins. This work also suggests that the association of GSAP with aging, Alzheimer’s disease, and Down syndrome could be attributed to the function of GSAP in the regulation of γ-secretase.
Stretchable materials of high toughness and low hysteresis
Authors: Wang Zhengjin , Xiang Chunping , Yao Xi , Le Floch Paul , Mendez Julien , Suo Zhigang 
Published: March 2019

Significance
Many applications in engineering require stretchable materials that dissipate little energy during normal operation of cyclic loads (low hysteresis), but dissipate much energy to resist rupture (high toughness), and survive prolonged cyclic loads (fatigue resistant). However, existing stretchable materials cannot meet these requirements simultaneously. Here we present a principle to achieve this goal, and demonstrate the principle by a composite of two stretchable materials of low hysteresis, with large modulus contrast and strong adhesion. The composite retains the low hysteresis, but is much tougher and more fatigue resistant than the constituents. The same principle applies to elastomers, gels, and elastomer–gel hybrids. This class of materials provides opportunities to create high-cycle and low-dissipation soft robots and soft human–machine interfaces.
Lipoprotein lipase is active as a monomer
Authors: Beigneux Anne P. , Allan Christopher M. , Sandoval Norma P. , Cho Geoffrey W. , Heizer Patrick J. , Jung Rachel S. , Stanhope Kimber L. , Havel Peter J. , Birrane Gabriel , Meiyappan Muthuraman , Gill John E. , Murakami Masami , Miyashita Kazuya , Nakajima Katsuyuki , Ploug Michael , Fong Loren G. , Young Stephen G. 
Published: March 2019

Significance
Lipoprotein lipase (LPL) plays a central role in plasma lipid metabolism, hydrolyzing the triglycerides in lipoproteins and releasing fatty acid nutrients for vital tissues. LPL is synthesized by adipocytes and myocytes and secreted into the interstitial spaces, whereupon it is captured by an endothelial cell protein, GPIHBP1, and transported to its site of action within the capillary lumen. For decades, LPL has been assumed to be a homodimer, with dimerization thought to be required for both secretion and catalytic activity. In the present study, we revisited the notion that LPL is a homodimer. Our findings indicate that LPL and GPIHBP1-bound LPL are active in a monomeric state.