bluuebunny/crossref_metadata_2025 huggingface dataset:
Vertical Distributions of Coccolithophores, PIC, POC, Biogenic Silica, and Chlorophyll a Throughout the Global Ocean
Authors: Balch William M. , Bowler Bruce C. , Drapeau David T. , Lubelczyk Laura C. , Lyczkowski Emily
Published: December 2017

Coccolithophores are a critical component of global biogeochemistry, export fluxes, and seawater optical properties. We derive globally significant relationships to estimate integrated coccolithophore and coccolith concentrations as well as integrated concentrations of particulate inorganic carbon (PIC) from their respective surface concentration. We also examine surface versus integral relationships for other biogeochemical variables contributed by all phytoplankton (e.g., chlorophyll a and particulate organic carbon) or diatoms (biogenic silica). Integrals are calculated using both 100 m integrals and euphotic zone integrals (depth of 1% surface photosynthetically available radiation). Surface concentrations are parameterized in either volumetric units (e.g., m−3) or values integrated over the top optical depth. Various relationships between surface concentrations and integrated values demonstrate that when surface concentrations are above a specific threshold, the vertical distribution of the property is biased to the surface layer, and when surface concentrations are below a specific threshold, the vertical distributions of the properties are biased to subsurface maxima. Results also show a highly predictable decrease in explained‐variance as vertical distributions become more vertically heterogeneous. These relationships have fundamental utility for extrapolating surface ocean color remote sensing measurements to 100 m depth or to the base of the euphotic zone, well beyond the depths of detection for passive ocean color remote sensors. Greatest integrated concentrations of PIC, coccoliths, and coccolithophores are found when there is moderate stratification at the base of the euphotic zone.
Coccidioidomycosis Dynamics in Relation to Climate in the Southwestern United States
Authors: Gorris M. E. , Cat L. A. , Zender C. S. , Treseder K. K. , Randerson J. T.
Published: December 2017

Valley fever is endemic to the southwestern United States. Humans contract this fungal disease by inhaling spores of Coccidioides spp. Changes in the environment can influence the abundance and dispersal of Coccidioides spp., causing fluctuations in valley fever incidence. We combined county‐level case records from state health agencies to create a regional valley fever database for the southwestern United States, including Arizona, California, Nevada, New Mexico, and Utah. We used this data set to explore how environmental factors influenced the spatial pattern and temporal dynamics of valley fever incidence during 2000–2015. We compiled climate and environmental geospatial data sets from multiple sources to compare with valley fever incidence. These variables included air temperature, precipitation, soil moisture, surface dust concentration, normalized difference vegetation index, and cropland area. We found that valley fever incidence was greater in areas with warmer air temperatures and drier soils. The mean annual cycle of incidence varied throughout the southwestern United States and peaked following periods of low precipitation and soil moisture. From year‐to‐year, however, autumn incidence was higher following cooler, wetter, and productive springs in the San Joaquin Valley of California. In southcentral Arizona, incidence increased significantly through time. By 2015, incidence in this region was more than double the rate in the San Joaquin Valley. Our analysis provides a framework for interpreting the influence of climate change on valley fever incidence dynamics. Our results may allow the U.S. Centers for Disease Control and Prevention to improve their estimates of the spatial pattern and intensity of valley fever endemicity.
Back‐Arc Opening in the Western End of the Okinawa Trough Revealed From GNSS/Acoustic Measurements
Authors: Chen Horng‐Yue , Ikuta Ryoya , Lin Cheng‐Horng , Hsu Ya‐Ju , Kohmi Takeru , Wang Chau‐Chang , Yu Shui‐Beih , Tu Yoko , Tsujii Toshiaki , Ando Masataka
Published: December 2017

We measured seafloor movement using a Global Navigation Satellite Systems (GNSS)/Acoustic technique at the south of the rifting valley in the western end of the Okinawa Trough back‐arc basin, 60 km east of northeastern corner of Taiwan. The horizontal position of the seafloor benchmark, measured eight times between July 2012 and May 2016, showed a southeastward movement suggesting a back‐arc opening of the Okinawa Trough. The average velocity of the seafloor benchmark shows a block motion together with Yonaguni Island. The westernmost part of the Ryukyu Arc rotates clockwise and is pulled apart from the Taiwan Island, which should cause the expansion of the Yilan Plain, Taiwan. Comparing the motion of the seafloor benchmark with adjacent seismicity, we suggest a gentle episodic opening of the rifting valley accompanying a moderate seismic activation, which differs from the case in the segment north off‐Yonaguni Island where a rapid dyke intrusion occurs with a significant seismic activity.
Observations and Modeling of Coseismic and Postseismic Deformation Due To the 2015 Mw 7.8 Gorkha (Nepal) Earthquake
Authors: Wang Kang , Fialko Yuri
Published: December 2017

We use space geodetic data to investigate coseismic and postseismic deformation due to the 2015 Mw 7.8 Gorkha earthquake that occurred along the central Himalayan arc. Because the earthquake area is characterized by strong variations in surface relief and material properties, we developed finite element models that explicitly account for topography and 3‐D elastic structure. We computed the line‐of‐sight displacement histories from three tracks of the Sentinel‐1A/B Interferometric Synthetic Aperture Radar (InSAR) satellites, using persistent scatter method. InSAR observations reveal an uplift of up to ∼70 mm over ∼20 months after the main shock, concentrated primarily at the downdip edge of the ruptured asperity. GPS observations also show uplift, as well as southward movement in the epicentral area, qualitatively similar to the coseismic deformation pattern. Kinematic inversions of GPS and InSAR data and forward models of stress‐driven creep suggest that the observed postseismic transient is dominated by afterslip on a downdip extension of the seismic rupture. A poroelastic rebound may have contributed to the observed uplift and southward motion, but the predicted surface displacements are small. We also tested a wide range of viscoelastic relaxation models, including 1‐D and 3‐D variations in the viscosity structure. Models of a low‐viscosity channel previously invoked to explain the long‐term uplift and variations in topography at the plateau margins predict opposite signs of horizontal and vertical displacements compared to those observed. Our results do not preclude a possibility of deep‐seated viscoelastic response beneath southern Tibet with a characteristic relaxation time greater than the observation period (2 years).
Stochastic Inversion of Geomagnetic Observatory Data Including Rigorous Treatment of the Ocean Induction Effect With Implications for Transition Zone Water Content and Thermal Structure
Authors: Munch F. D. , Grayver A. V. , Kuvshinov A. , Khan A.
Published: December 2017

In this paper we estimate and invert local electromagnetic (EM) sounding data for 1‐D conductivity profiles in the presence of nonuniform oceans and continents to most rigorously account for the ocean induction effect that is known to strongly influence coastal observatories. We consider a new set of high‐quality time series of geomagnetic observatory data, including hitherto unused data from island observatories installed over the last decade. The EM sounding data are inverted in the period range 3–85 days using stochastic optimization and model exploration techniques to provide estimates of model range and uncertainty. The inverted conductivity profiles are best constrained in the depth range 400–1,400 km and reveal significant lateral variations between 400 km and 1,000 km depth. To interpret the inverted conductivity anomalies in terms of water content and temperature, we combine laboratory‐measured electrical conductivity of mantle minerals with phase equilibrium computations. Based on this procedure, relatively low temperatures (1200–1350°C) are observed in the transition zone (TZ) underneath stations located in Southern Australia, Southern Europe, Northern Africa, and North America. In contrast, higher temperatures (1400–1500°C) are inferred beneath observatories on islands, Northeast Asia, and central Australia. TZ water content beneath European and African stations is ∼0.05–0.1 wt %, whereas higher water contents (∼0.5–1 wt %) are inferred underneath North America, Asia, and Southern Australia. Comparison of the inverted water contents with laboratory‐constrained water storage capacities suggests the presence of melt in or around the TZ underneath four geomagnetic observatories in North America and Northeast Asia.
Software‐Defined Radio Decoding of DCF77: Time and Frequency Dissemination with a Sound Card
Authors: Friedt Jean‐Michel , Eustache Clément , Carry Émile , Rubiola Enrico
Published: December 2017

We investigate time and frequency dissemination using software‐defined radio processing of signals acquired from a low‐frequency emitter using a sound card. We use the resulting propagation time measurements for investigating some ionosphere physics and its interaction with cosmic ray flux. Rather than using the amplitude of the transmitted signal as classically considered, we here focus on a precise time of flight measurement by demodulating the spectrum spreading phase modulation added to the DCF77 amplitude modulation.
Trade Openness and Domestic Water Use
Authors: Dang Qian , Konar Megan
Published: December 2017

We contribute to the debate over globalization and the environment by asking, what is the impact of trade on national water use? To address this question, we employ econometric methods to quantify the causal relationship between trade openness and water use. Specifically, we use the instrumental variables methodology to evaluate the impact of trade openness on domestic water withdrawals in agriculture and industry. We find that trade openness does not have a significant impact on total or industrial water withdrawals. However, we show that one percentage point increase in trade openness leads to a 5.21% decrease in agricultural water withdrawals. We find that trade openness reduces water use in agriculture primarily through the intensive margin effect, by leading farmers to produce more with less water, such as through the adoption of technology. We do not find evidence for extensive margin or crop mix impacts on agricultural water withdrawals. Significantly, these results demonstrate that trade openness leads to less water use in agriculture. This finding has broad scientific and policy relevance as we endeavor to untangle causal relationships in the complex global food system and develop policies to achieve water and food security.
Identification of key miRNAs and genes associated with stomach adenocarcinoma from The Cancer Genome Atlas database
Authors: Liu Jixi , Liu Fang , Shi Yanfen , Tan Huangying , Zhou Lei
Published: December 2017

Stomach adenocarcinoma (STAD) is the second leading cause of cancer death and a fuller understanding of its molecular basis is needed to develop new therapeutic targets. miRNA and mRNA data were downloaded from The Cancer Genome Atlas database, and the differentially expressed miRNAs and genes were identified. The target genes of differentially expressed miRNAs were screened by prediction tools. Furthermore, the biological function of these target genes was investigated. Several key miRNAs and their target genes were selected for validation using quantitative real‐time polymerase chain reaction (qRT‐PCR). The Gene Expression Omnibus (GEO) dataset was used to verify the expression of selected miRNAs and target genes. The diagnostic value of identified miRNAs and genes was accessed by receiver operating characteristic analysis. A total of 1248 differentially expressed genes were identified in STAD. Additionally, nine differentially expressed miRNAs were identified and 160 target genes of these nine miRNAs were identified via target gene detection. Interestingly, they were remarkably enriched in the calcium signaling pathway and bile secretion. qRT‐PCR confirmed the expression of several key miRNAs and their target genes. The expression levels of hsa‐miR‐145‐3p, hsa‐miR‐145‐5p, ADAM12, ACAN, HOXC11 and MMP11 in the GEO database were compatible with the bioinformatics results. hsa‐miR‐139‐5p, hsa‐miR‐145‐3p and MMP11 have a potential diagnostic value for STAD. Differential expression of the mature form of miRNAs (hsa‐miR‐139‐5p, hsa‐miR‐145‐3p, hsa‐miR‐145‐5p and hsa‐miR‐490‐3p) and genes including ADAM12, ACAN, HOXC11 and MMP11 and calcium and bile secretion signaling pathways may play important roles in the development of STAD.
Fiber Lasers and Amplifiers: High‐Power Operation
Authors: Liu Anping
Published: December 2017

An overview on high‐power fiber lasers and amplifiers is presented. The article includes a brief review of the fiber laser history, followed by the design rules of double‐cladding fibers for power scaling of the fiber lasers. Typical fiber laser systems, including pump configurations, resonator structures, and system layouts, are explained. Detailed information on key components and wavelength ranges are discussed. It covers high‐power fiber lasers operating at both continuous wave and pulsed modes, including a variety of pulsed systems ranging from actively mode‐locked lasers to passively mode‐locked lasers with pulse durations from femtoseconds to nanoseconds.
Optical Coherence
Authors: Visser Taco D.
Published: December 2017

The coherence properties of an optical source determine how the emitted field propagates, scatters, and behaves on focusing. Because the state of coherence can be actively controlled, this provides an additional tool for field shaping. We show that the observation that two sources with an identical spectrum can produce fields whose spectra are different can be explained by realizing that this field property is in fact a secondary quantity. The primary or fundamental property from which the spectrum is derived is the coherence function of the source. The propagation of this function is governed by wave equations. By calculating the propagated correlation function, the local spectrum can be determined. We illustrate how the manipulation of spatial coherence can give rise to novel physical effects in focusing and scattering.
Optical Mirrors
Authors: Lemaitre Gerard R. , Grange Robert
Published: December 2017

An optical mirror is a sufficiently smooth surface that reflects light – in some wavelength range – to provide an image from given original object. From early plane mirrors, as quiet water, polished obsidian stone, or brass substrates, subsequent mirror fabrication mainly evolved towards use of glass substrates coated with high a reflectivity metal that may receive a protective layer deposit to prevent from tarnishing. Plane and curved – concave or convex – mirrors are commonly used as domestic devices, safety devices and decorative panels. Mirrors are key components of many scientific instruments, such as telescopes, microscopes, lasers, and cameras. Present state of the art of making and testing a mirror optical surface allows reaching the ultimate theoretical limit of diffraction – then called a diffraction‐limited mirror – where the reflected wavefront does not deviate more than a visible quarter‐wave length from a required shape.
Lifelong behavioral and neuropathological consequences of repetitive mild traumatic brain injury
Authors: Mouzon Benoit C. , Bachmeier Corbin , Ojo Joseph O. , Acker Christopher M. , Ferguson Scott , Paris Daniel , Ait‐Ghezala Ghania , Crynen Gogce , Davies Peter , Mullan Michael , Stewart William , Crawford Fiona
Published: December 2017

Objective

Exposure to repetitive concussion, or mild traumatic brain injury (mTBI), has been linked with increased risk of long‐term neurodegenerative changes, specifically chronic traumatic encephalopathy (CTE). To date, preclinical studies largely have focused on the immediate aftermath of mTBI, with no literature on the lifelong consequences of mTBI in these models. This study provides the first account of lifelong neurobehavioral and histological consequences of repetitive mTBI providing unique insight into the constellation of evolving and ongoing pathologies with late survival.

Methods

Male C57BL/6J mice (aged 2–3 months) were exposed to either single or repetitive mild TBI or sham procedure. Thereafter, animals were monitored and assessed at 24 months post last injury for measures of motor coordination, learning deficits, cognitive function, and anxiety‐like behavior prior to euthanasia and preparation of the brains for detailed neuropathological and protein biochemical studies.

Results

At 24 months survival animals exposed to r‐mTBI showed clear evidence of learning and working memory impairment with a lack of spatial memory and vestibule‐motor vestibulomotor deficits compared to sham animals. Associated with these late behavioral deficits there was evidence of ongoing axonal degeneration and neuroinflammation in subcortical white matter tracts. Notably, these changes were also observed after a single mTBI, albeit to a lesser degree than repetitive mTBI.

Interpretation

In this context, our current data demonstrate, for the first time, that rather than an acute, time limited event, mild TBI can precipitate a lifelong degenerative process. These data therefore suggest that successful treatment strategies should consider both the acute and chronic nature of mTBI.
Metabolic Engineering of Microorganisms for the Production of Natural Compounds
Authors: Park Seon Young , Yang Dongsoo , Ha Shin Hee , Lee Sang Yup
Published: December 2017

Natural products have been attracting much interest around the world for their diverse applications, especially in drug and food industries. Plants have been a major source of many different natural products. However, plants are affected by weather and environmental conditions and their successful extraction is rather limited. Chemical synthesis is inefficient due to the complexity of their chemical structures involving enantioselectivity and regioselectivity. For these reasons, an alternative means of overproducing valuable natural products using microorganisms has emerged. In recent years, various metabolic engineering strategies have been developed for the production of natural products by microorganisms. Here, the strategies taken to produce natural products are reviewed. For convenience, natural products are classified into four main categories: terpenoids, phenylpropanoids, polyketides, and alkaloids. For each product category, the strategies for establishing and rewiring the metabolic network for heterologous natural product biosynthesis, systems approaches undertaken to optimize production hosts, and the strategies for fermentation optimization are reviewed. Taken together, metabolic engineering has enabled microorganisms to serve as a prominent platform for natural compounds production. This article examines both the conventional and novel strategies of metabolic engineering, providing general strategies for complex natural compound production through the development of robust microbial‐cell factories.
Modulation of Agglomeration of Vertical Porous Silicon Nanowires and the Effect on Gas‐Sensing Response
Authors: Qin Yuxiang , Jiang Yunqing , Zhao Liming
Published: December 2017

Porous silicon nanowires (PSiNWs) array is a promising material for development of integrated gas sensors operating at room temperature. This work reports the fabrication of PSiNWs assembly with different structural features and its effect on gas‐sensing performance. Bundling and well separating PSiNWs arrays are fabricated by MACE method, respectively, based on the effective modulation of surface wettability of the initial Si substrate. The HF pretreatment creates a hydrophobic surface favorable for deposition of irregular Ag nanoflakes and then for the formation of bundling PSiNWs array. In contrast, the PSiNWs with well lateral separation are formed based on the predeposited uniform Ag nanoparticles on a hydrophilic Si surface. The PSiNWs array featured by tip‐clusters is proved to be highly effective in achieving highly sensitive and rapid response to NO2 gas at room temperature. Satisfying dynamic characteristic and selectivity are meanwhile observed for the bundling array. The formation of the bundling or separating of PSiNWs is discussed in terms of the force balance of individual nanowire, which is further correlated with non‐uniform distribution of Ag nanoclusters caused by H‐termination. Meanwhile, high sensing performance of bundling nanowires is analyzed based on the structural promotion of the unique configuration of tip‐cluster to sensing response.
Physical growth and diets of school children: Trends from 2001 to 2015 in rural West Java, Indonesia
Authors: Sekiyama Makiko , Roosita Katrin , Ohtsuka Ryutaro
Published: December 2017

Objectives

This study aimed to assess changes in physical growth and diets of school children in rural West Java, Indonesia, between 2001 and 2015, a period of rapid socioeconomic change.

Methods

In 2001 and 2015, anthropometric measurements (height, weight, mid‐upper arm circumference, skin‐fold thickness), food consumption surveys, and questionnaires on socioeconomic status were completed by fourth‐grade school children in a rural village in West Java.

Results

Height increments of 5.9 cm for boys and 4.7 cm for girls during this 14‐year period were calculated as 4.21 cm per decade for boys and 3.36 cm per decade for girls, which is equivalent to height increments observed during rapid economic development periods in other countries. Weights also increased by 3.8 kg for boys and 2.0 kg for girls during this period. Variations in weight status significantly increased in 2015; while 98% of the children were within the ‘normal’ range in 2001, the prevalence of overweight increased from 2.4% in 2001 to 13.7% in 2015 and that of thinness was 4.3% in 2015. Energy, protein, and fat intakes significantly increased in 2015. In 2015, a significant correlation between nutritional intake and weight status was observed, especially among boys.

Conclusions

Socioeconomic changes between 2001 and 2015 caused increased heights and weights and greater variation in weight status, especially among boys.
Deconvolution of images from 3D printed cells in layers on a chip
Authors: Yu Sean , Joshi Pranav , Park Yi Ju , Yu Kyeong‐Nam , Lee Moo‐Yeal
Published: December 2017

Layer‐by‐layer cell printing is useful in mimicking layered tissue structures inside the human body and has great potential for being a promising tool in the field of tissue engineering, regenerative medicine, and drug discovery. However, imaging human cells cultured in multiple hydrogel layers in 3D‐printed tissue constructs is challenging as the cells are not in a single focal plane. Although confocal microscopy could be a potential solution for this issue, it compromises the throughput which is a key factor in rapidly screening drug efficacy and toxicity in pharmaceutical industries. With epifluorescence microscopy, the throughput can be maintained at a cost of blurred cell images from printed tissue constructs. To rapidly acquire in‐focus cell images from bioprinted tissues using an epifluorescence microscope, we created two layers of Hep3B human hepatoma cells by printing green and red fluorescently labeled Hep3B cells encapsulated in two alginate layers in a microwell chip. In‐focus fluorescent cell images were obtained in high throughput using an automated epifluorescence microscopy coupled with image analysis algorithms, including three deconvolution methods in combination with three kernel estimation methods, generating a total of nine deconvolution paths. As a result, a combination of Inter‐Level Intra‐Level Deconvolution (ILILD) algorithm and Richardson‐Lucy (RL) kernel estimation proved to be highly useful in bringing out‐of‐focus cell images into focus, thus rapidly yielding more sensitive and accurate fluorescence reading from the cells in different layers. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 34:445–454, 2018
Photothermally Enhanced Plasmon‐Driven Catalysis on Fe5C2@Au Core–Shell Nanostructures
Authors: Miao Peng , Huang Wei , Gao Mansha , Chu Jiayu , Song Bo , Xu Ping
Published: December 2017

Plasmon‐driven catalysis has attracted great attention in recent years, but the reaction efficiency remains to be improved. Photothermal Fe5C2@Au core–shell nanostructures are fabricated through a self‐assembly process of Fe5C2 and Au nanoparticles (NPs) with the assistance of hexanethiol, which can be highly efficient surface enhanced Raman spectroscopy (SERS) platforms for the study of plasmon‐driven dimerization of 4‐aminothiophenol (4‐ATP) and 4‐nitrothiophenol (4‐NTP). As compared to bare Au NPs, much accelerated reaction kinetics can be achieved on the Fe5C2@Au core–shell nanostructures by quantitatively determining the Raman intensity of the ν(N=N) band in the generated 4,4′‐dimercaptobenzene (DMAB). The photothermal effect from the Fe5C2 NPs may lower the energy barrier and generate more hot electrons for the plasmon‐driven catalysis. This photothermal route may open up new avenues for enhancing the reaction rate and broadening the research area of the plasmon‐driven catalysis.
Revisiting the Ullman's Radical Chemistry for Phthalocyanine Derivatives
Authors: Fidan Ismail , Luneau Dominique , Ahsen Vefa , Hirel Catherine
Published: December 2017

Phthalocyanine derivatives do not cease to gain attention due to their numerous properties and applications (e.g., sensor, PDT). This makes them a unique scaffold for the design of new material. In this context, we were interested to develop the synthesis of an imino nitroxide‐substituted phthalocyanine by Ullman's procedure; a challenge due to the intrinsic low solubility of most phthalocyanine derivative in much solvents. To overcome this solubility problem, we designed a phthalocyanine with bulky neopentyl substituents in peripheral positions as counterpart to the imino nitroxide moieties. The imino nitroxide‐substituted phthalocyanine was obtained by condensation of a monoformyl‐substituted phthalocyanine with 2,3‐bis(hydroxylamino)‐2,3‐dimethylbutane in refluxing THF–MeOH (2:1) mixture in the presence of p‐toluenesulfonic acid monohydrate, follow by oxidation with PbO2. Characterization was performed by electrochemistry, UV/Vis and EPR spectroscopy in solution as well as SQUID in solid state.
Stereoselective Palladium‐Catalyzed Approach to Vitamin D3 Derivatives in Protic Medium
Authors: Carballa Diego , Sigüeiro Rita , Rodríguez‐Docampo Zaida , Zacconi Flavia , Maestro Miguel A. , Mouriño Antonio
Published: December 2017

We describe an efficient convergent synthesis of vitamin D3 metabolites and analogues. The synthetic strategy relies on a tandem Pd‐catalyzed A‐ring closure and Suzuki–Miyaura coupling to the CD‐side chain component to set directly the vitamin D triene system under protic conditions. This strategy enables rapid access to vitamin D3 and 3‐epi‐vitamin D3 metabolites and analogues modified at the side chain for biological evaluation and structural and metabolic studies.
Well‐Defined Heterobimetallic Reactivity at Unsupported Ruthenium–Indium Bonds
Authors: Riddlestone Ian M. , Rajabi Nasir A. , Macgregor Stuart A. , Mahon Mary F. , Whittlesey Michael K.
Published: December 2017

The hydride complex [Ru(IPr)2(CO)H][BArF4], 1, reacts with InMe3 with loss of CH4 to form [Ru(IPr)2(CO)(InMe)(Me)][BArF4], 4, featuring an unsupported Ru−In bond with unsaturated Ru and In centres. 4 reacts with H2 to give [Ru(IPr)2(CO)(η2‐H2)(InMe)(H)][BArF4], 5, while CO induces formation of the indyl complex [Ru(IPr)2(CO)3(InMe2)][BArF4], 7. These observations highlight the ability of Me to shuttle between Ru and In centres and are supported by DFT calculations on the mechanism of formation of 4 and its reactions with H2 and CO. An analysis of Ru‐In bonding in these species is also presented. Reaction of 1 with GaMe3 also involves CH4 loss but, in contrast to its In congener, sees IPr transfer from Ru to Ga to give a gallyl complex featuring an η6 interaction of one aryl substituent with Ru.
Distribution and diversity of intrinsically photosensitive retinal ganglion cells in tree shrew
Authors: Johnson Elizabeth N. , Westbrook Teleza , Shayesteh Rod , Chen Emily L. , Schumacher Joseph W. , Fitzpatrick David , Field Greg D.
Published: December 2017

Intrinsically photosensitive retinal ganglion cells (ipRGCs) mediate the pupillary light reflex, circadian entrainment, and may contribute to luminance and color perception. The diversity of ipRGCs varies from rodents to primates, suggesting differences in their contributions to retinal output. To further understand the variability in their organization and diversity across species, we used immunohistochemical methods to examine ipRGCs in tree shrew (Tupaia belangeri). Tree shrews share membership in the same clade, or evolutionary branch, as rodents and primates. They are highly visual, diurnal animals with a cone‐dominated retina and a geniculo‐cortical organization resembling that of primates. We identified cells with morphological similarities to M1 and M2 cells described previously in rodents and primates. M1‐like cells typically had somas in the ganglion cell layer, with 23% displaced to the inner nuclear layer (INL). However, unlike M1 cells, they had bistratified dendritic fields ramifying in S1 and S5 that collectively tiled space. M2‐like cells had dendritic fields restricted to S5 that were smaller and more densely branching. A novel third type of melanopsin immunopositive cell was identified. These cells had somata exclusively in the INL and monostratified dendritic fields restricted to S1 that tiled space. Surprisingly, these cells immunolabeled for tyrosine hydroxylase, a key component in dopamine synthesis. These cells immunolabeled for an RGC marker, not amacrine cell markers, suggesting that they are dopaminergic ipRGCs. We found no evidence for M4 or M5 ipRGCs, described previously in rodents. These results identify some organizational features of the ipRGC system that are canonical versus species‐specific.
Understanding Brønsted‐Acid Catalyzed Monomolecular Reactions of Alkanes in Zeolite Pores by Combining Insights from Experiment and Theory
Authors: Van der Mynsbrugge Jeroen , Janda Amber , Lin Li‐Chiang , Van Speybroeck Veronique , Head‐Gordon Martin , Bell Alexis T.
Published: December 2017

Acidic zeolites are effective catalysts for the cracking of large hydrocarbon molecules into lower molecular weight products required for transportation fuels. However, the ways in which the zeolite structure affects the catalytic activity at Brønsted protons are not fully understood. One way to characterize the influence of the zeolite structure on the catalysis is to study alkane cracking and dehydrogenation at very low conversion, conditions for which the kinetics are well defined. To understand the effects of zeolite structure on the measured rate coefficient (kapp), it is necessary to identify the equilibrium constant for adsorption into the reactant state (Kads‐H+) and the intrinsic rate coefficient of the reaction (kint) at reaction temperatures, since kapp is proportional to the product of Kads‐H+ and kint. We show that Kads‐H+ cannot be calculated from experimental adsorption data collected near ambient temperature, but can, however, be estimated accurately from configurational‐bias Monte Carlo (CBMC) simulations. Using monomolecular cracking and dehydrogenation of C3–C6 alkanes as an example, we review recent efforts aimed at elucidating the influence of the acid site location and the zeolite framework structure on the observed values of kapp and its components, Kads‐H+ and kint.
Population Pharmacokinetics of Polymyxin B
Authors: Manchandani Pooja , Thamlikitkul Visanu , Dubrovskaya Yanina , Babic Jessica T. , Lye David C. , Lee Lawrence S. , Tam Vincent H.
Published: December 2017

Polymyxin B is used as a last treatment resort for multidrug‐resistant Gram‐negative bacterial infections. The objectives of this study were to examine the population pharmacokinetics of polymyxin B and investigate factor(s) influencing pharmacokinetic variability. Four serial blood samples each were collected from 35 adult patients at steady state. The concentrations of individual polymyxin B components were analyzed using a validated liquid chromatography / tandem mass spectrometry assay and combined to derive total concentrations. A maximum likelihood expectation maximization approach was used to fit the data. Various demographic variables were investigated as potential covariates for clearance and volume of distribution (Vd) using linear regression analysis. A one‐compartment model fit to the data satisfactorily (r2 = 0.96). The best‐fit mean ± SD for clearance and Vd were 2.5 ± 1.1 L/h and 34.3 ± 16.4 L, respectively. Creatinine clearance was found to be a statistically significant covariate of clearance, but the magnitude was deemed clinically insignificant.
Small‐cell planning in LTE HetNet to improve energy efficiency
Authors: Wang You‐Chiun , Lee Shih
Published: December 2017

Cell planning is one essential operation in wireless networks, and it significantly affects system performance and cost. Many research efforts consider the cell planning problem with identical base stations (BSs) or to construct a new network on the region without any infrastructure. However, long‐term evolution (LTE) adopts heterogeneous network, which allows operators to tactically deploy small cells to enhance signal coverage and improve performance. It thus motivates us to propose a small‐cell planning problem by adaptively adding low‐powered BSs with the limitation of budget to an existing network to increase its energy efficiency, which is defined by the ratio of network throughput to the amount of energy consumption of BSs. We consider 2 types of LTE small cells, namely, microcells and picocells, and develop different clustering strategies to deploy these cells. Based on the available resource and traffic demand in each cell, we then adjust the transmitted power of the deployed BS with energy concern. Experimental results demonstrate that our small‐cell planning solution can achieve high‐energy efficiency of LTE networks, which means that BSs can better use their transmitted energy to satisfy the traffic demands of user devices. This paper contributes in proposing a practical problem for cell planning with heterogeneous network consideration and developing an efficient solution to provide green communications.
Effect of Polar and Non‐Polar Compounds from Oxidized Oils on Oxidative Stability in Corn Oil
Authors: Choi HyungSeok , Kim Mi‐Ja , Lee JaeHwan
Published: December 2017

The effects of polar and non‐polar compounds recovered from oxidized corn oils on oxidative stability in bulk oils are evaluated in the presence or absence of an antioxidant, tert‐butylhydroquinone (TBHQ). The balance of antioxidant and prooxidant compounds in oils is confirmed using the 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) spectroscopic method. Polar compounds accelerated the depletion of headspace oxygen content and increased the conjugated dienoic acid value and p‐anisidine value in oils with or without 200 ppm TBHQ, which implies that polar compounds from oxidized lipids are prooxidants. However, added non‐polar compounds showed no prooxidative properties in oils, irrespective of the presence of TBHQ. The antioxidant‐prooxidant balance (APB) value, which is calculated as the ratio of the loss of DPPH in isooctane to that in methanol, may reflect the content balance between antioxidant and prooxidative oxidized lipid products in oils. Low APB values indicate that oils are in a highly oxidized state.

Practical Applications: Polar compounds from oxidized oils act as prooxidants. Therefore, it is necessary to determine the polar content in frying oils accurately. Using modified DPPH methods, not only the content of antioxidants but also prooxidative polar compounds in oils can be determined simultaneously. Modified DPPH methods can predict the oxidative stability of frying oil and help to extend the shelf‐life of fried foods in the food industry.

Polar compounds from oxidized oils function as prooxidants. Non‐polar compounds do not act as prooxidants nor antioxidants. Modified 2,2‐diphenyl‐1‐picrylhydrazyl methods can predict the oxidative stability of frying oil.
Sidewall effects and sand trap efficiency in a large wind tunnel
Authors: Hong Cheng , Yi Fang , Sherman Douglas J. , Chenchen Liu , Xueyong Zou , Kaidi Zhang , Liqiang Kang
Published: December 2017

Aeolian sand transport is a widespread physical phenomenon on the surface of Earth, as well as on Mars and Titan. Accurate measurements of the components of the transport system are necessary if we are to understand the nature of the physical processes. Sand traps are typically used to measure sediment transport rates, and issues associated with the sampling efficiency of traps and the development of reliable traps have received considerable attention in recent decades. In this study, we measured aeolian transport rate at five distances from a wind tunnel sidewall using a vertically‐segmented sand trap. Total transport rates were determined by weighing the bed sediment before and after each experiment, and with and without a trap installed. The following results were obtained: (1) sand transport increased linearly with the distance away from the sidewall, and the appropriate location to measure maximum transport is within the central 20% of the wind tunnel; (2) current methods overestimate the sampling efficiency of sand traps when comparing trap data to transport rate data obtained by weighing sand moved through the entire tunnel because the effects of the sidewalls in decreasing total transport are neglected; (3) the efficiency of the vertically‐segmented trap that we tested ranged from 11.57% to 31.68% using our revised methods, whereas standard methods caused efficiency to be overestimated by 32–72% of the efficiency; (4) using either method, the efficiency of the trap increased exponentially with shear velocity for the range we used. Copyright © 2017 John Wiley & Sons, Ltd.
Distinguishing between debris flows and hyperconcentrated flows: an example from the eastern Swiss Alps
Authors: Calhoun Nancy C. , Clague John J.
Published: December 2017

Much research has been done on water‐rich mass flows, but the distinction between hyperconcentrated flows and debris flows, and whether the two are indeed different processes, continue to be debated. Here, we contribute to the ongoing discussion of these phenomena by describing and interpreting the deposit of a large landslide‐induced mass flow in the eastern Swiss Alps. About 9400 years ago, 10‐12 km3 of limestone detached from the wall of the Vorderrhein River valley and rapidly fragmented while sliding towards the valley bottom. The rock mass struck the valley floor with enormous force and liquefied at least 1 km3 of valley‐fill sediments. A slurry of liquefied sediment – the ‘Bonaduz gravel’ – traveled tens of kilometres down the Vorderrhein valley from the impact site, carrying huge fragments of rockslide debris that became stranded on the valley floor, forming hills termed ‘tomas’. Part of the flow was deflected by a cross‐valley barrier and traveled 14 km up a tributary of the Vorderrhein valley. The Bonaduz gravel is >65 m thick and fines upward from massive sandy cobble gravel at its base to silty sand at its top. Sedimentologic and geomorphic evidence indicates that Bonaduz gravel was transported as a hyperconcentated flow, likely above a basal carpet of coarse diamictic sediment that behaved as a debris flow. The large amount of water involved in the flow indicates that at least part of the Flims rockslide entered a lake. The Bonaduz deposit shares many properties with sediments left by hyperconcentrated flows generated in flumes, including normal grading and elutriation pipes produced by the rapid escape of fluids when the flow comes to rest. These properties are characteristic of non‐Newtonian laminar flows with high sediment concentrations. Our study reinforces laboratory and theoretical studies showing that debris flows and hyperconcentrated flows are different processes. © 2017 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd.
Multi‐scale relief model (MSRM): a new algorithm for the visualization of subtle topographic change of variable size in digital elevation models
Authors: Orengo Hector A. , Petrie Cameron A.
Published: December 2017

Morphological analysis of landforms has traditionally relied on the interpretation of imagery. Although imagery provides a natural view of an area of interest (AOI) images are largely hindered by the environmental conditions at the time of image acquisition, the quality of the image and, mainly, the lack of topographical information, which is an essential factor for a correct understanding of the AOI's geomorphology.

More recently digital surface models (DSMs) have been incorporated into the analytical toolbox of geomorphologists. These are usually high‐resolution models derived from digital photogrammetric processes or LiDAR data. However, these are restricted to relatively small areas and are expensive or complex to acquire, which limits widespread implementation.

In this paper, we present the multi‐scale relief model (MSRM), which is a new algorithm for the visual interpretation of landforms using DSMs. The significance of this new method lies in its capacity to extract landform morphology from both high‐ and low‐resolution DSMs independently of the shape or scale of the landform under study. This method thus provides important advantages compared to previous approaches as it: (1) allows the use of worldwide medium resolution models, such as SRTM, ASTER GDEM, ALOS, and TanDEM‐X; (2) offers an alternative to traditional photograph interpretation that does not rely on the quality of the imagery employed nor on the environmental conditions and time of its acquisition; and (3) can be easily implemented for large areas using traditional GIS/RS software.

The algorithm is tested in the Sutlej‐Yamuna interfluve, which is a very large low‐relief alluvial plain in northwest India where 10 000 km of palaeoriver channels have been mapped using MSRM. The code, written in Google Earth Engine's implementation of JavaScript, is provided as Supporting Information for its use in any other AOI without particular technical knowledge or access to topographical data. © 2017 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd.
Dissipative particle dynamic simulation and experimental assessment of the impacts of humic substances on aqueous aggregation and dispersion of engineered nanoparticles
Authors: Wang Zhuang , Quik Joris T.K. , Song Lan , Wouterse Marja , Peijnenburg Willie J.G.M.
Published: December 2017

Comprehensive experimental quantification and mapping of the aggregation and dispersion state of engineered nanoparticles (NPs) in the presence of humic substances is a great challenge. Dissipative particle dynamic (DPD) simulation was adopted to investigate the aggregation and dispersion mechanisms of NPs in the presence of a humic substance analog. Twelve different types of NPs including 2 metal-based NPs, 7 metal oxide-based NPs, and 3 carbon-based NPs in pure water (pH 3.0) and algae medium (pH 8.0) in the presence of a humic substance analogy were selected for experimental verification of the DPD simulation results. In agreement with results obtained with dynamic light scattering and phase analysis light scattering techniques, the simulations demonstrated that the presence of humic substances reduced the aggregation extent of the NPs. The DPD simulations showed that the stability and dispersity of the NPs increased first, and then decreased with increasing concentrations of humic substances. Moreover, there existed a concentration of humic substances where the NPs became more stable and more dispersed, which was experimentally verified in the case of all the NPs in the pure water and in the algae medium. Furthermore, theory and simulation indicate that both hydrophobic and hydrogen interaction play an important role in controlling the formation of NP aggregates in the presence of humic substances. Electrostatic interaction and steric repulsion are the main mechanisms underlying the effects of humic substances on the aqueous dispersion stability of NPs. Environ Toxicol Chem 2018;37:1024–1031. © 2017 SETAC
Two‐phase designs for joint quantitative‐trait‐dependent and genotype‐dependent sampling in post‐GWAS regional sequencing
Authors: Espin‐Garcia Osvaldo , Craiu Radu V. , Bull Shelley B.
Published: December 2017

We evaluate two‐phase designs to follow‐up findings from genome‐wide association study (GWAS) when the cost of regional sequencing in the entire cohort is prohibitive. We develop novel expectation‐maximization‐based inference under a semiparametric maximum likelihood formulation tailored for post‐GWAS inference. A GWAS‐SNP (where SNP is single nucleotide polymorphism) serves as a surrogate covariate in inferring association between a sequence variant and a normally distributed quantitative trait (QT). We assess test validity and quantify efficiency and power of joint QT‐SNP‐dependent sampling and analysis under alternative sample allocations by simulations. Joint allocation balanced on SNP genotype and extreme‐QT strata yields significant power improvements compared to marginal QT‐ or SNP‐based allocations. We illustrate the proposed method and evaluate the sensitivity of sample allocation to sampling variation using data from a sequencing study of systolic blood pressure.
The effect of parental education on child health: Quasi‐experimental evidence from a reduction in the length of primary schooling in Egypt
Authors: Ali Fatma Romeh M. , Elsayed Mahmoud A. A.
Published: December 2017

This paper examines the impact of parental education on child health using a reduction in the length of primary schooling in Egypt. We use a fuzzy regression discontinuity design to compare the health outcomes of children whose parents were exposed to different schooling requirements because they were born either side of a threshold date. Using data from the Demographic and Health Survey (1992–2014), we find no effect of maternal education on child mortality or nutritional status. There is some evidence, although not entirely robust, that father's education reduces the likelihood of child stunting. We find, however, that father's education has no impact on child mortality or other measures of nutritional status. We provide suggestive evidence that, given the low levels of parental education in Egypt accompanied with the inferior quality of primary schooling, education has little effect on intermediate outcomes—literacy and utilization of antenatal care—that may improve the health of offspring.