bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of an RNA interference (RNAi) gene knockdown protocol in the anaerobic gut fungusPecoramyces ruminantiumstrain C1A
Authors: Calkins Shelby S. , Elledge Nicole C. , Mueller Katherine E. , Marek Stephen M. , Couger MB , Elshahed Mostafa S. , Youssef Noha H.
Published: January 2018

Members of the anaerobic gut fungi (AGF) reside in rumen, hindgut, and feces of ruminant and non-ruminant herbivorous mammals and reptilian herbivores. No protocols for gene insertion, deletion, silencing, or mutation are currently available for the AGF, rendering gene-targeted molecular biological manipulations unfeasible. Here, we developed and optimized an RNA interference (RNAi)-based protocol for targeted gene silencing in the anaerobic gut fungusPecoramyces ruminantiumstrain C1A. Analysis of the C1A genome identified genes encoding enzymes required for RNA silencing in fungi (Dicer, Argonaute,Neurospora crassaQDE-3 homolog DNA helicase, Argonaute-interacting protein, andNeurospora crassaQIP homolog exonuclease); and the competency of C1A germinating spores for RNA uptake was confirmed using fluorescently labeled small interfering RNAs (siRNA). Addition of chemically-synthesized siRNAs targeting D-lactate dehydrogenase (ldhD) gene to C1A germinating spores resulted in marked target gene silencing; as evident by significantly lowerldhDtranscriptional levels, a marked reduction in the D-LDH specific enzymatic activity in intracellular protein extracts, and a reduction in D-lactate levels accumulating in the culture supernatant. Comparative transcriptomic analysis of untreated versus siRNA-treated cultures identified a few off-target siRNA-mediated gene silencing effects. As well, significant differential up-regulation of the gene encoding NAD-dependent 2-hydroxyacid dehydrogenase (Pfam00389) in siRNA-treated C1A cultures was observed, which could possibly compensate for loss of D-LDH as an electron sink mechanism in C1A. The results demonstrate the feasibility of RNAi in anaerobic fungi, and opens the door for gene silencing-based studies in this fungal clade.
Biogeochemical Role of Subsurface Coherent Eddies in the Ocean: Tracer Cannonballs, Hypoxic Storms, and Microbial Stewpots?
Authors: Frenger Ivy , Bianchi Daniele , Stührenberg Carolin , Oschlies Andreas , Dunne John , Deutsch Curtis , Galbraith Eric , Schütte Florian
Published: January 2018

Subsurface eddies are known features of ocean circulation, but the sparsity of observations prevents an assessment of their importance for biogeochemistry. Here we use a global eddying (0.1°) ocean‐biogeochemical model to carry out a census of subsurface coherent eddies originating from eastern boundary upwelling systems (EBUS) and quantify their biogeochemical effects as they propagate westward into the subtropical gyres. While most eddies exist for a few months, moving over distances of hundreds of kilometers, a small fraction (<5%) of long‐lived eddies propagates over distances greater than 1,000 km, carrying the oxygen‐poor and nutrient‐rich signature of EBUS into the gyre interiors. In the Pacific, transport by subsurface coherent eddies accounts for roughly 10% of the offshore transport of oxygen and nutrients in pycnocline waters. This “leakage” of subsurface waters can be a significant fraction of the transport by nutrient‐rich poleward undercurrents and may contribute to the well‐known reduction of productivity by eddies in EBUS. Furthermore, at the density layer of their cores, eddies decrease climatological oxygen locally by close to 10%, thereby expanding oxygen minimum zones. Finally, eddies represent low‐oxygen extreme events in otherwise oxygenated waters, increasing the area of hypoxic waters by several percent and producing dramatic short‐term changes that may play an important ecological role. Capturing these nonlocal effects in global climate models, which typically include noneddying oceans, would require dedicated parameterizations.
Addressing Pollution‐Related Global Environmental Health Burdens
Authors: Filippelli Gabriel M. , Taylor Mark P.
Published: January 2018

New analyses are revealing the scale of pollution on global health, with a disproportionate share of the impact borne by lower‐income nations, minority and marginalized individuals. Common themes emerge on the drivers of this pollution impact, including a lack of regulation and its enforcement, research and expertise development, and innovative funding mechanisms for mitigation. Creative approaches need to be developed and applied to address and overcome these obstacles. The existing “business as usual” modus operandi continues to externalize human health costs related to pollution, which exerts a negative influence on global environmental health.
An Argo‐Derived Background Diffusivity Parameterization for Improved Ocean Simulations in the Tropical Pacific
Authors: Zhu Yuchao , Zhang Rong‐Hua
Published: January 2018

Model biases are substantial in ocean and coupled ocean‐atmosphere simulations in the tropical Pacific Ocean, including a too cold tongue and too diffuse thermocline. These biases can be partly attributed to vertical mixing parameterizations in which the background diffusivity depiction has great uncertainties. Here based on the fine‐scale parameterization, the Argo data are used to derive the spatially varying background diffusivity, with a magnitude of O(10−6 m2 s−1) in the most area of tropical Pacific. This new scheme is then employed into the version 5.1 of the Modular Ocean Model‐based ocean‐only and coupled models, resulting in substantial improvements in ocean simulations, including a more realistic cold tongue and equatorial thermocline. The improved simulations can be attributed to the reduced cooling effects induced by weakened equatorial upwelling. Additionally, the subsurface cooling effect is attributed to the reduced heat transfer from the upper layer to the subsurface layer and the convergence of the colder water from off the equator.
The North Atlantic Ocean Is in a State of Reduced Overturning
Authors: Smeed D. A. , Josey S. A. , Beaulieu C. , Johns W. E. , Moat B. I. , Frajka‐Williams E. , Rayner D. , Meinen C. S. , Baringer M. O. , Bryden H. L. , McCarthy G. D.
Published: January 2018

The Atlantic Meridional Overturning Circulation (AMOC) is responsible for a variable and climatically important northward transport of heat. Using data from an array of instruments that span the Atlantic at 26°N, we show that the AMOC has been in a state of reduced overturning since 2008 as compared to 2004–2008. This change of AMOC state is concurrent with other changes in the North Atlantic such as a northward shift and broadening of the Gulf Stream and altered patterns of heat content and sea surface temperature. These changes resemble the response to a declining AMOC predicted by coupled climate models. Concurrent changes in air‐sea fluxes close to the western boundary reveal that the changes in ocean heat transport and sea surface temperature have altered the pattern of ocean‐atmosphere heat exchange over the North Atlantic. These results provide strong observational evidence that the AMOC is a major factor in decadal‐scale variability of North Atlantic climate.
Top‐Down CO Emissions Based On IASI Observations and Hemispheric Constraints on OH Levels
Authors: Müller J.‐F. , Stavrakou T. , Bauwens M. , George M. , Hurtmans D. , Coheur P.‐F. , Clerbaux C. , Sweeney C.
Published: January 2018

Assessments of carbon monoxide emissions through inverse modeling are dependent on the modeled abundance of the hydroxyl radical (OH) which controls both the primary sink of CO and its photochemical source through hydrocarbon oxidation. However, most chemistry transport models (CTMs) fall short of reproducing constraints on hemispherically averaged OH levels derived from methylchloroform (MCF) observations. Here we construct five different OH fields compatible with MCF‐based analyses, and we prescribe those fields in a global CTM to infer CO fluxes based on Infrared Atmospheric Sounding Interferometer (IASI) CO columns. Each OH field leads to a different set of optimized emissions. Comparisons with independent data (surface, ground‐based remotely sensed, aircraft) indicate that the inversion adopting the lowest average OH level in the Northern Hemisphere (7.8 × 105 molec cm−3, ∼18% lower than the best estimate based on MCF measurements) provides the best overall agreement with all tested observation data sets.
Ultrasonic Acoustic Velocities During Partial Melting of a Mantle Peridotite KLB‐1
Authors: Weidner Donald J. , Li Li , Whitaker Matthew L. , Triplett Richard
Published: January 2018

Knowledge of the elastic properties of partially molten rocks is crucial for understanding low‐velocity regions in the interior of the Earth. Models of fluid and solid mixtures have demonstrated that significant decreases in seismic velocity are possible with small amounts of melt, but there is very little available data for testing these models, particularly with both P and S waves for mantle compositions. We report ultrasonic measurements of P and S velocities on a partially molten KLB‐1 sample at mantle conditions using a multi‐anvil device at a synchrotron facility. The P, S, and bulk sound velocities decrease as melting occurs. We find that the quantity, ∂lnVS/∂lnVB (where VB is the bulk sound velocity) is lower than mechanical models estimate. Instead, our data, as well as previous data in the literature, are consistent with a dynamic melting model in which melting and solidification interact with the stress field of the acoustic wave.
The Spectral Nature of Titan's Major Geomorphological Units: Constraints on Surface Composition
Authors: Solomonidou A. , Coustenis A. , Lopes R. M. C. , Malaska M. J. , Rodriguez S. , Drossart P. , Elachi C. , Schmitt B. , Philippe S. , Janssen M. , Hirtzig M. , Wall S. , Sotin C. , Lawrence K. , Altobelli N. , Bratsolis E. , Radebaugh J. , Stephan K. , Brown R. H. , Le Mouélic S. , Le Gall A. , Villanueva E. V. , Brossier J. F. , Bloom A. A. , Witasse O. , Matsoukas C. , Schoenfeld A.
Published: January 2018

We investigate Titan's low‐latitude and midlatitude surface using spectro‐imaging near‐infrared data from Cassini/Visual and Infrared Mapping Spectrometer. We use a radiative transfer code to first evaluate atmospheric contributions and then extract the haze and the surface albedo values of major geomorphological units identified in Cassini Synthetic Aperture Radar data, which exhibit quite similar spectral response to the Visual and Infrared Mapping Spectrometer data. We have identified three main categories of albedo values and spectral shapes, indicating significant differences in the composition among the various areas. We compare with linear mixtures of three components (water ice, tholin‐like, and a dark material) at different grain sizes. Due to the limited spectral information available, we use a simplified model, with which we find that each albedo category of regions of interest can be approximately fitted with simulations composed essentially by one of the three surface candidates. Our fits of the data are overall successful, except in some cases at 0.94, 2.03, and 2.79 μm, indicative of the limitations of our simplistic compositional model and the need for additional components to reproduce Titan's complex surface. Our results show a latitudinal dependence of Titan's surface composition, with water ice being the major constituent at latitudes beyond 30°N and 30°S, while Titan's equatorial region appears to be dominated partly by a tholin‐like or by a very dark unknown material. The albedo differences and similarities among the various geomorphological units give insights on the geological processes affecting Titan's surface and, by implication, its interior. We discuss our results in terms of origin and evolution theories.
A Combined (U‐Th)/He and Cosmogenic 3He Record of Landscape Armoring by Biogeochemical Iron Cycling
Authors: Monteiro H. S. , Vasconcelos P. M. P. , Farley K. A.
Published: January 2018

(U‐Th)/He geochronology and cosmogenic 3He in iron oxides reveal mineral precipitation ages as old as 55 Ma and exposure ages greater than 5 Ma for canga‐cemented plateaus in the Quadrilátero Ferrífero, Brazil, showing that lateritic profiles overlying banded iron‐formation (BIF) landscapes in tropical regions have a long history of surface exposure. The long‐term erosion history obtained from cosmogenic 3He on BIF plateaus confirms that relic surfaces persist in the landscape for millions of years. Combined 3He and (U‐Th)/He dating shows that cangas are preferentially goethite cemented by biogeochemical reactions in the subsurface. Importantly, pebbles of hematite‐magnetite in colluvia or shallow creeks draining the canga‐cemented plateaus record a much longer exposure history than in situ canga blocks, showing that even older duricrusts, now eroded, once blanketed these plateaus. Physically stable but biogeochemically dynamic, cangas armor the landscape by pervasive and recurrent iron cycling and cementation, slowing down the delivery of weathered BIF or friable hematite–magnetite ore to erosion.
The Influence of Shallow Taliks on Permafrost Thaw and Active Layer Dynamics in Subarctic Canada
Authors: Connon Ryan , Devoie Élise , Hayashi Masaki , Veness Tyler , Quinton William
Published: January 2018

Measurements of active layer thickness (ALT) are typically taken at the end of summer, a time synonymous with maximum thaw depth. By definition, the active layer is the layer above permafrost that freezes and thaws annually. This study, conducted in peatlands of subarctic Canada, in the zone of thawing discontinuous permafrost, demonstrates that the entire thickness of ground atop permafrost does not always refreeze over winter. In these instances, a talik exists between the permafrost and active layer, and ALT must therefore be measured by the depth of refreeze at the end of winter. As talik thickness increases at the expense of the underlying permafrost, ALT is shown to simultaneously decrease. This suggests that the active layer has a maximum thickness that is controlled by the amount of energy lost from the ground to the atmosphere during winter. The taliks documented in this study are relatively thin (<2 m) and exist on forested peat plateaus. The presence of taliks greatly affects the stability of the underlying permafrost. Vertical permafrost thaw was found to be significantly greater in areas with taliks (0.07 m year−1) than without (0.01 m year−1). Furthermore, the spatial distribution of areas with taliks increased between 2011 and 2015 from 20% to 48%, a phenomenon likely caused by an anomalously large ground heat flux input in 2012. Rapid talik development and accelerated permafrost thaw indicates that permafrost loss may exhibit a nonlinear response to warming temperatures. Documentation of refreeze depths and talik development is needed across the circumpolar north.
Vertical Stratification of Peat Pore Water Dissolved Organic Matter Composition in a Peat Bog in Northern Minnesota
Authors: Tfaily Malak M. , Wilson Rachel M. , Cooper William T. , Kostka Joel E. , Hanson Paul , Chanton Jeffrey P.
Published: January 2018

We characterized dissolved organic matter (DOM) composition throughout the peat column at the Marcell S1 forested bog in northern Minnesota and tested the hypothesis that redox oscillations associated with cycles of wetting and drying at the surface of the fluctuating water table correlate with increased carbon, sulfur, and nitrogen turn over. We found significant vertical stratification of DOM molecular composition and excitation‐emission matrix parallel factor analysis components within the peat column. In particular, the intermediate depth zone (~ 50 cm) was identified as a zone where maximum decomposition and turnover is taking place. Surface DOM was dominated by inputs from surface vegetation. The intermediate depth zone was an area of high organic matter reactivity and increased microbial activity with diagenetic formation of many unique compounds, among them polycyclic aromatic compounds that contain both nitrogen and sulfur heteroatoms. These compounds have been previously observed in coal‐derived compounds and were assumed to be responsible for coal's biological activity. Biological processes triggered by redox oscillations taking place at the intermediate depth zone of the peat profile at the S1 bog are assumed to be responsible for the formation of these heteroatomic PACs in this system. Alternatively, these compounds could stem from black carbon and nitrogen derived from fires that have occurred at the site in the past. Surface and deep DOM exhibited more similar characteristics, compared to the intermediate depth zone, with the deep layer exhibiting greater input of microbially degraded organic matter than the surface suggesting that the entire peat profile consists of similar parent material at different degrees of decomposition and that lateral and vertical advection of pore water from the surface to the deeper horizons is responsible for such similarities. Our findings suggest that molecular composition of DOM in peatland pore water is dynamic and is a function of ecosystem activity, water table, redox oscillation, and pore water advection.
On Lack of Robustness in Hydrological Model Development Due to Absence of Guidelines for Selecting Calibration and Evaluation Data: Demonstration for Data‐Driven Models
Authors: Zheng Feifei , Maier Holger R. , Wu Wenyan , Dandy Graeme C. , Gupta Hoshin V. , Zhang Tuqiao
Published: January 2018

Hydrological models are used for a wide variety of engineering purposes, including streamflow forecasting and flood‐risk estimation. To develop such models, it is common to allocate the available data to calibration and evaluation data subsets. Surprisingly, the issue of how this allocation can affect model evaluation performance has been largely ignored in the research literature. This paper discusses the evaluation performance bias that can arise from how available data are allocated to calibration and evaluation subsets. As a first step to assessing this issue in a statistically rigorous fashion, we present a comprehensive investigation of the influence of data allocation on the development of data‐driven artificial neural network (ANN) models of streamflow. Four well‐known formal data splitting methods are applied to 754 catchments from Australia and the U.S. to develop 902,483 ANN models. Results clearly show that the choice of the method used for data allocation has a significant impact on model performance, particularly for runoff data that are more highly skewed, highlighting the importance of considering the impact of data splitting when developing hydrological models. The statistical behavior of the data splitting methods investigated is discussed and guidance is offered on the selection of the most appropriate data splitting methods to achieve representative evaluation performance for streamflow data with different statistical properties. Although our results are obtained for data‐driven models, they highlight the fact that this issue is likely to have a significant impact on all types of hydrological models, especially conceptual rainfall‐runoff models.
Impact of stroke mechanism in acute basilar occlusion with reperfusion therapy
Authors: Lee Woo‐Jin , Jung Keun‐Hwa , Ryu Young Jin , Kim Jeong‐Min , Lee Soon‐Tae , Chu Kon , Kim Manho , Lee Sang Kun , Sohn Chul‐Ho , Roh Jae‐Kyu
Published: January 2018

Objective

We aimed to evaluate the impact of underlying mechanism of basilar artery (BA) occlusion on the outcomes after endovascular therapy (EVT) for reperfusion and the outcome factors associated with each mechanism, and to identify radiologic parameters enabling to distinguish the underlying mechanism.

Methods

From a registry database, 194 consecutive patients with acute BA occlusion who underwent EVT were analyzed. Stroke mechanism, classified into in situ atherosclerotic thrombosis (ISAT) and embolism, clot sign location profiles in pre‐angiography magnetic resonance image (MRI), parameters of angiography and EVT, and reperfusion were assessed. Poor outcome was defined as a modified Rankin‐Scale score at 90 days of 3–6.

Results

The mean age was 68.8±11.8 years (range 21–92 years) and seventy‐eight (40.2%) were female patients. 102 (52.6%) patients were classified into an embolism mechanism and 92 (47.4%) into an ISAT mechanism. Overall, ISAT mechanism compared with embolism was significantly associated with poor outcomes (P = 0.002), along with the NIHSS scores, reperfusion status, and collateral status. In the embolism group, reperfusion (P = 0.001), NIHSS scores (P < 0.001), and onset‐to‐treatment time (P = 0.030) were significant outcome factors. However, in the ISAT group, baseline collateral status (P = 0.001) and NIHSS scores (P < 0.001) were significant outcome factors. A clot sign at the distal BA segment on pre‐angiography MRI was strongly associated with embolism mechanism (P < 0.001).

Interpretation

Stroke mechanism has a major influence on outcomes, and outcome predictors differ according to the underlying mechanism in acute BA occlusion with EVT. Clot sign profile on pre‐angiography MRI might be useful to determine the underlying mechanism.
Hydrolytic Stability of Boronate Ester‐Linked Covalent Organic Frameworks
Authors: Li Huifang , Li Haoyuan , Dai Qingqing , Li Hong , Brédas Jean‐Luc
Published: January 2018

The stability of covalent organic frameworks (COFs) is essential to their applications. However, the common boronate ester‐linked COFs are susceptible to attack by nucleophiles (such as water molecules) at the electron‐deficient boron sites. To provide an understanding of the hydrolytic stability of the representative boronate ester‐linked COF‐5 and of the associated hydrolysis mechanisms, density functional theory (DFT) calculations were performed to characterize the hydrolysis reactions of the molecule formed by the condensation of 1,4‐phenylenebis(boronic acid) (PBBA) and 2,3,6,7,10,11‐hexahydroxytriphenylene (HHTP) monomers; two cases were considered, one dealing with the freestanding molecule and the other with the molecule interacting with COF layers. It was found that the boronate ester (B–O) bond dissociation, which requires one H2O molecule, has a relatively high energy barrier of 22.3 kcal mol−1. However, the presence of an additional H2O molecule significantly accelerates hydrolysis by reducing the energy barrier by a factor of 3. Importantly, the hydrolysis of boronate ester bonds situated in a COF environment follows reaction pathways that are different and have increased energy barriers. These results point to an enhanced hydrolytic stability of COF‐5 crystals.
Anion–Cation Double Substitution in Transition Metal Dichalcogenide to Accelerate Water Dissociation Kinetic for Electrocatalysis
Authors: Tran Ngoc Quang , Bui Viet Q. , Le Hung M. , Kawazoe Yoshiyuki , Lee Hyoyoung
Published: January 2018

Until now, many works have shown that the hydrogen evolution reaction (HER) performance can be improved by anion or cation substitution into the crystal lattice of pyrite‐structure materials. However, the synergistic effects of anion–cation double substitution for overall enhancement of the catalytic activity remains questionable. Here, the simultaneous incorporation of vanadium and phosphorus into the CoS2 moiety for preparing 3D mesoporous cubic pyrite‐metal Co1‐xVxSP is presented. It is demonstrated that the higher catalytic activity of CoS2 after V incorporation can be primarily attributed to abundance active sites, whereas P substitution is responsible for improving HER kinetics and intrinsic catalyst. Interestingly, due to the synergistic effect of P–V double substitution, the 3D Co1‐xVxSP shows superior electrocatalysis toward the HER with a very small overpotential of 55 mV at 10 mA cm−2, a small Tafel slope of 50 mV dec−1, and a high turnover frequency of 0.45 H2 s−1 at 10 mA cm−2, which is very close to commercial 20% Pt/C. Density functional theory calculation reveals that the superior catalytic activity of the 3D Co1‐xVxSP is contributed by the reduced kinetic energy barrier of rate‐determining HER step as well as the promotion of the desorption H2 gas process.
Efficient Perovskite Solar Cells Fabricated by Co Partially Substituted Hybrid Perovskite
Authors: Xu Wenzhan , Zheng Luyao , Zhang Xiaotao , Cao Yu , Meng Tianyu , Wu Dezhen , Liu Lei , Hu Wenping , Gong Xiong
Published: January 2018

In the past years, hybrid perovskite materials have attracted great attention due to their superior optoelectronic properties. In this study, the authors report the utilization of cobalt (Co2+) to partially substitute lead (Pb2+) for developing novel hybrid perovskite materials, CH3NH3Pb1‐xCoxI3 (where x is nominal ratio, x = 0, 0.1, 0.2 and 0.4). It is found that the novel perovskite thin films possess a cubic crystal structure with superior thin film morphology and larger grain size, which is significantly different from pristine thin film, which possesses the tetragonal crystal structure, with smaller grain size. Moreover, it is found that the 3d orbital of Co2+ ensures higher electron mobilities and electrical conductivities of the CH3NH3Pb1‐xCoxI3 thin films than those of pristine CH3NH3Pb4 thin film. As a result, a power conversion efficiency of 21.43% is observed from perovskite solar cells fabricated by the CH3NH3Pb0.9Co0.1I3 thin film. Thus, the utilization of Co, partially substituting for Pb to tune physical properties of hybrid perovskite materials provides a facile way to boost device performance of perovskite solar cells.
Identification of an Ene Reductase from Yeast Kluyveromyces Marxianus and Application in the Asymmetric Synthesis of (R)‐Profen Esters
Authors: Li Zhining , Wang Zexu , Meng Ge , Lu Hong , Huang Zedu , Chen Fener
Published: January 2018

Given their ability to reduce activated alkenes thereby generating up to two stereogenic centers, ene reductases from the old yellow enzyme (OYE) family have received much attention as effective biocatalysts. Through genome mining, a “classical” OYE, KYE2, was identified from Kluyveromyces marxianus CBS4857 and fully characterized in vitro. This NADPH‐dependent enzyme displayed a broad substrate spectrum for the bioreduction of activated alkenes. The highly stereoselective synthesis (>95 % ee) of various (R)‐profen methyl esters, including the synthesis of (R)‐flurbiprofen methyl ester on a semi‐preparative scale further demonstrates the potential of KYE2 to be developed as a general biocatalyst for chemical synthesis.
What have we been looking at? A call for consistency in studies of primate vigilance
Authors: Allan Andrew T.L. , Hill Russell A.
Published: January 2018

Vigilance functions to detect threats. In primates, these threats emerge from both predators and conspecifics, but a host of other social, demographic, and ecological factors have been shown to influence primate vigilance patterns. The primate vigilance literature is thus characterized by considerable variation in findings, with inconsistent or contradictory results reported not only across different species but also within species and populations across studies. Some of this variation could emerge from fundamental differences in the methods employed, making comparisons across species and groups challenging. Furthermore, identifying consistent behavioral markers for the state of vigilance appears to have proved challenging in primates, leading to a range of definitions being developed. Deviation at this level leads directly into concomitant variation at the level of sampling methodologies. As a result, the primate vigilance literature currently presents a diverse series of approaches to exploring subtly different behaviors and phenomena. This review calls for a greater consistency in studying vigilance, with the aim of encouraging future research to follow similar principles leading to more comparable results. Identifying whether an animal is in a vigilant state is challenging for most field researchers; identifying and recording a more general behavior of “looking” should though be more achievable. Experimental approaches could then be employed to understand the compatibility “looking” has with predator detection (and other threats) in individual study systems. The outcome of this approach will allow researchers to understand the key determinants of looking in their study groups and explore threat detection probabilities given an individual or group's relative level of looking.
Ossification Pattern in Forelimbs of the Siamese Crocodile (Crocodylus siamensis): Similarity in Ontogeny of Carpus Among Crocodylian Species
Authors: Gregorovičová Martina , Kvasilová Alena , Sedmera David
Published: January 2018

Crocodylians have highly derived elongated carpus, which is related to their use of forelimbs in many types of gaits as well as in burrowing. The objective of present study was to describe the ossification of the forelimb in five stages of Siamese crocodile (Crocodylus siamensis). The ossification begins approximately at stage 20 in arm and forearm bones moving sequentially to the metacarpal elements. The first carpal elements with ossification centers are radiale + intermedium and ulnare (stage 22–23), and their ossification mode is typical of long bones. Between stages 22 and 24 distal carpals 3, 4, and 5 fuse together to a single formation. In the stage 25, the ossification proceeds to the pisiform, which starts ossifying late during the embryogenesis. The phalangeal formula of the digits is 2,3,4,5,3. Although there are some interspecific differences, it appears that all crocodylians have similarly uniform skeletal pattern, the process of ossification, number of carpal elements and phalangeal formulas probably due to their similar lifestyles. Anat Rec, 301:1159–1168, 2018. © 2018 Wiley Periodicals, Inc.
Cardiac repolarization during fingolimod treatment in patients with relapsing–remitting multiple sclerosis
Authors: Laiho Aapo , Laitinen Tiina M. , Hartikainen Päivi , Hartikainen Juha E. K. , Laitinen Tomi P. , Simula Sakari
Published: January 2018

Background

Fingolimod is a sphingosine‐1‐phosphate receptor modulator for the treatment of relapsing–remitting multiple sclerosis (RRMS). Despite an established effect on heart rate, the effect of fingolimod on cardiac repolarization is not completely known.

Methods

Twenty‐seven patients with RRMS underwent 24‐hr ambulatory ECG before fingolimod (baseline), at the day of fingolimod initiation (1D) and after three‐month treatment (3M). The mean values of RR‐interval as well as QT‐interval corrected by Bazzet's (QTcBaz) and Fridericia's (QTcFri) formula were compared between baseline, 1D, and 3M over 24‐hr period as well as at daytime and nighttime.

Results

QTcBaz over 24‐hr was shorter at 1D (414 ± 20 ms, p < .001) and at 3M (414 ± 20 ms, p < .001) than at baseline (418 ± 20 ms). In contrast, QTcFri over 24‐hr was longer at 1D (410 ± 19 ms, p < .001) but similar at 3M (406 ± 19 ms, p = .355) compared to baseline (407 ± 19 ms). Daytime QTcBaz was shorter at 1D (p < .001) and at 3M (p = .007), whereas daytime QTcFri was longer at 1D (p < .05) but similar at 3M (p = ns) compared to baseline. During the night, changes were observed neither in QTcBaz nor in QTcFri between baseline, 1D, and 3M.

Conclusions

Changes in cardiac repolarization after fingolimod initiation were mild and occurred at daytime. Ambiguously, QTcBaz demonstrated shortening, whereas QTcFri showed prolongation in cardiac repolarization after fingolimod initiation. The formula applied for QT‐interval correction needs to be taken carefully into account as evaluating pharmacovigilance issues related to fingolimod.
The dilemma of environmental sustainability in a developing country: Environmental crimes in southern Brazil
Authors: Roque Patrícia Gonçalves , Severo Eliana Andréa , Dorion Eric Charles Henri , Roque Eliel de Souza , de Guimarães Julio Cesar Ferro
Published: January 2018

In a contemporary society, awareness of the importance of environmental causes is eminent; however, crimes against the Brazilian environment do occur at an unacceptable rate, because it concerns a developing country situation. This study aims to analyze the most incident environmental crimes that occurred in the State of Rio Grande do Sul, a meridional region of Brazil, in a territory that covers 239 municipalities. The study analyzes the environmental management dilemmas that occurred in the inspection carried out by the Third Environmental Battalion of the Military Brigade in the period of 2011 to 2016. The method was qualitative and exploratory considering that the research is the first of its kind in the region. The results highlight a lack of commitment with the Brazilian environmental legislation, from offenders acting in the criminal, administrative, and civil spheres. The 5 most serious environmental crimes refer to deforestation, unlicensed activities, captive animals, solid waste pollution, and effluents pollution. Furthermore, environmental sustainability is still not present as a strategic area in the Brazilian organizations, and the ones that do have some internal practices do it more in reaction to legal penalties than for awareness of the environmental causes. The research brings important environmental information on decision making related to actions and public policies that promote environmental sustainability in developing countries.
The differences on efficacy of oxaliplatin in locally advanced colon cancer between mucinous and nonmucinous adenocarcinoma
Authors: Yu Dehao , Gao Peng , Song Yongxi , Yang Yuchong , Chen Xiaowan , Sun Yu , Li Ailin , Wang Zhenning
Published: January 2018

Until now, it remains unclear how to best use the histological subtype in clinical practice. This study aimed to compare differences in the efficacy of postoperative chemotherapy among different histological subtypes of colon adenocarcinomas. Using the Surveillance, Epidemiology, and End Results‐Medicare database, 51,200 patients with stage II or III primary colon carcinomas who underwent resection for curative intent between 1992 and 2008 were included. The survival benefit was evaluated using a Cox proportional hazards model, interaction analyses, and propensity score‐matched techniques. There was no significant difference in survival for low‐risk stage II mucinous adenocarcinoma (MA) or nonmucinous adenocarcinoma (NMA) between 5‐FU and oxaliplatin‐treated groups (P = 0.387 for MA, P = 0.629 for NMA). Patients with high‐risk stage II NMA who received the oxaliplatin chemotherapy regimen had significantly improved cancer‐specific survival (CSS) compared with the 5‐FU group (P = 0.004), while those with MA saw no improvement (P = 0.690). For stage III tumors, patients with NMA who received the oxaliplatin chemotherapy regimen had significantly improved CSS compared with the 5‐FU group (P < 0.001), while those with MA saw no improvement (P = 0.300). There were significant interactions between chemotherapy regimen and histological subtype. For patients with resected colon cancer who received 5‐FU‐based postoperative chemotherapy, oxaliplatin chemotherapy prolongs CSS for stage III and high‐risk stage II NMA. Conversely, there was no similar improvement with addition of oxaliplatin for patients with stage III or stage II MA.
Selective Oxidative Carbonylation of Aniline to Diphenylurea with Ionic Liquids
Authors: Zahrtmann Nanette , Claver Carmen , Godard Cyril , Riisager Anders , Garcia‐Suarez Eduardo J.
Published: January 2018

A catalytic system for the selective oxidative carbonylation of aniline to diphenylurea based on Pd complexes in combination with imidazolium ionic liquids is presented. Both oxidants, Pd complexes, and ionic liquids affect the activity of the reaction, and the choice of oxidant determines the selectivity of the reaction. Together they allow the reaction to proceed under comparatively mild conditions without a loss of activity. Examination of the reaction by use of in situ NMR spectroscopy allowed us to observe an intermediate suggested only previously, which supported the proposed mechanism.
Was noch zu sagen bliebe
Authors: Machhammer Otto
Published: January 2018

No abstract.
Icosahedral Pt–Ni Nanocrystalline Electrocatalyst: Growth Mechanism and Oxygen Reduction Activity
Authors: Tian Renxiu , Shen Shuiyun , Zhu Fengjuan , Luo Liuxuan , Yan Xiaohui , Wei Guanghua , Zhang Junliang
Published: January 2018

Engineering the structure of Pt alloy offers an effective way to the design of high performance electrocatalysts. Herein, we synthesize a sandwich‐structured, icosahedral Pt2.1Ni catalyst through a hot injection method. Its growth involves three steps: 1) burst nucleation of Pt atoms to form a Pt‐enriched core, 2) heterogeneous nucleation of Ni atoms onto the Pt core to form a Ni‐enriched interlayer, and 3) kinetic controlled growth of a Pt‐enriched shell. The Pt‐enriched core protects the nanostructure from collapse and mitigates the strain change caused by lattice mismatch, and thus enhances the stability of the structure. The Ni‐enriched interlayer induces the electronic modification of the outermost Pt shell, and in turn tunes the activity. The Pt‐enriched shell provides more active sites through the exposure of (1 1 1) facets and retards the dissolution of Ni atoms. As a result, this sandwich‐structure enables impressive electrocatalytic activity (0.91 mA cm−2 and 0.32 A
@ 0.9 V) and duability.
Ursolic acid derivatives as potential antidiabetic agents: In vitro, in vivo, and in silico studies
Authors: Guzmán‐Ávila Ricardo , Flores‐Morales Virginia , Paoli Paolo , Camici Guido , Ramírez‐Espinosa Juan José , Cerón‐Romero Litzia , Navarrete‐Vázquez Gabriel , Hidalgo‐Figueroa Sergio , Yolanda Rios Maria , Villalobos‐Molina Rafael , Estrada‐Soto Samuel
Published: January 2018

Hit, Lead & Candidate Discovery

Protein tyrosine phosphatase 1B (PTP‐1B) has attracted interest as a novel target for the treatment of type 2 diabetes, this because its role in the insulin‐signaling pathway as a negative regulator. Thus, the aim of current work was to obtain seven ursolic acid derivatives as potential antidiabetic agents with PTP‐1B inhibition as main mechanism of action. Furthermore, derivatives 1–7 were submitted in vitro to enzymatic PTP‐1B inhibition being 3, 5, and 7 the most active compounds (IC50 = 5.6, 4.7, and 4.6 μM, respectively). In addition, results were corroborated with in silico docking studies with PTP‐1B orthosteric site A and extended binding site B, showed that 3 had polar and Van der Waals interactions in both sites with Lys120, Tyr46, Ser216, Ala217, Ile219, Asp181, Phe182, Gln262, Val49, Met258, and Gly259, showing a docking score value of −7.48 Kcal/mol, being more specific for site A. Moreover, compound 7 showed polar interaction with Gln262 and Van der Waals interactions with Ala217, Phe182, Ile219, Arg45, Tyr46, Arg47, Asp48, and Val49 with a predictive docking score of −6.43 kcal/mol, suggesting that the potential binding site could be localized in the site B adjacent to the catalytic site A. Finally, derivatives 2 and 7 (50 mg/kg) were selected to establish their in vivo antidiabetic effect using a noninsulin‐dependent diabetes mice model, showing significant blood glucose lowering compared with control group (p < .05).
The potential of radiolabeled chemotherapeutics in tumor diagnosis: Preliminary investigations with 68Ga‐gemcitabine
Authors: Ghosh Subhajit , Das Tapas , D. Sarma Haladhar , Dash Ashutosh
Published: January 2018

Preclinical Research & Development

Gemcitabine, a nucleoside analog, is a well‐known chemotherapeutic drug that is used either alone or with other agents to treat a wide variety of cancers. The aim of the present work was to evaluate the potential of 68Ga‐labeled gemcitabine for its application in positron emission tomography (PET) imaging of tumorous lesions. Gemcitabine was coupled with p‐NCS‐benzyl‐DOTA in order to facilitate radiolabeling with 68Ga. The gemcitabine‐p‐NCS‐benzyl‐DOTA was radiolabeled with 68Ga, obtained from a 68Ge/68Ga radionuclide generator. The radiolabeled product was characterized by high performance liquid chromatography (HPLC) and its tumor specificity was evaluated by biodistribution studies in Swiss mice bearing fibrosarcoma tumors. Preliminary bioevaluation study showed good tumor uptake within 1 hr post‐administration [2.5% Injected Activity (IA) per g of tumor] with rapid renal clearance (>90% IA) and a high tumor to muscle ratio. 68Ga‐gemcitabine may have potential as a PET agent for tumor imaging.
A novel sperm adaptation to evolutionary constraints on reproduction: Pre‐ejaculatory sperm activation in the beach spawning capelin (Osmeridae)
Authors: Beirão José , Lewis Jason A. , Wringe Brendan F. , Purchase Craig F.
Published: January 2018

Reproduction of external fertilizing vertebrates is typically constrained to either fresh or salt water, not both. For all studied amphibians and fishes, this constraint includes immotile sperm that are activated after ejaculation only by the specific chemistry of the fertilizing medium in which the species evolved (fresh, brackish, or salt water). No amphibians can reproduce in the sea. Although diadromous fishes may migrate between salt and fresh water, they are shackled to their natal environment for spawning in part because of sperm activation. Here, we report for the first time among all documented external fertilizing vertebrates, that in the absence of any external media, sperm are motile at ejaculation in a marine spawning fish (Osmeridae, capelin, Mallotus villosus). To illuminate why, we evaluated sperm behavior at different salinities in M. villosus as well as the related freshwater spawning anadromous rainbow smelt (Osmerus mordax). Surprisingly, sperm performance was superior in fresh water for both species. M. villosus spend their entire life at sea but our results show that their sperm are deactivated by sea water, suggesting a freshwater ancestry. By circumventing constraining water chemistry, we interpret the unique pre‐ejaculatory sperm activation in this species as a novel adaptation that enables fertilization in the marine environment. These findings also contribute to understanding the persistence of anadromy, despite great energetic costs to adult fishes.
Sea ice meiofauna distribution on local to pan‐Arctic scales
Authors: Bluhm Bodil A. , Hop Haakon , Vihtakari Mikko , Gradinger Rolf , Iken Katrin , Melnikov Igor A. , Søreide Janne E.
Published: January 2018

Arctic sea ice provides microhabitats for biota that inhabit the liquid‐filled network of brine channels and the ice–water interface. We used meta‐analysis of 23 published and unpublished datasets comprising 721 ice cores to synthesize the variability in composition and abundance of sea ice meiofauna at spatial scales ranging from within a single ice core to pan‐Arctic and seasonal scales. Two‐thirds of meiofauna individuals occurred in the bottom 10 cm of the ice. Locally, replicate cores taken within meters of each other were broadly similar in meiofauna composition and abundance, while those a few km apart varied more; 75% of variation was explained by station. At the regional scale (Bering Sea first‐year ice), meiofauna abundance varied over two orders of magnitude. At the pan‐Arctic scale, the same phyla were found across the region, with taxa that have resting stages or tolerance to extreme conditions (e.g., nematodes and rotifers) dominating abundances. Meroplankton, however, was restricted to nearshore locations and landfast sea ice. Light availability, ice thickness, and distance from land were significant predictor variables for community composition on different scales. On a seasonal scale, abundances varied broadly for all taxa and in relation to the annual ice algal bloom cycle in both landfast and pack ice. Documentation of ice biota composition, abundance, and natural variability is critical for evaluating responses to decline in Arctic sea ice. Consistent methodology and protocols must be established for comparability of meiofauna monitoring across the Arctic. We recommend to (1) increase taxonomic resolution of sea ice meiofauna, (2) focus sampling on times of peak abundance when seasonal sampling is impossible, (3) include the bottom 30 cm of ice cores rather than only bottom 10 cm, (4) preserve specimens for molecular analysis to improve taxonomic resolution, and (5) formulate a trait‐based framework that relates to ecosystem functioning.
Mate choice decision rules: Trait synergisms and preference shifts
Authors: Burley Nancy Tyler , Hamedani Elnaz , Symanski Cole
Published: January 2018

An important and understudied question in sexual selection is how females evaluate information from multiple secondary sexual traits (SSTs), particularly when expression of traits is phenotypically uncorrelated. We performed mate choice experiments on zebra finches (Taeniopygia guttata castanotisGould) to evaluate two hypotheses: preference shifts (obstacles to choice using one trait increase chooser reliance on others) and trait synergisms (choice based on the sum/product of two or more independently varying traits). The first experiment, which employed males raised on diets that impactSSTexpression, supported the trait synergism hypothesis: overall, male pairing success was best predicted by synergisms involving beak color and cheek patch size. Results did not support the preference shift hypothesis. Results of a follow‐up experiment that included males reared on a single diet, and in which male beak color and cheek patch size were manipulated, were also consistent with the trait synergism hypothesis. Results have implications for understanding the long‐term persistence of multipleSSTs in populations and for the measurement of repeatability and heritability of mate preferences.
Multiple surveys employing a new sample‐processing protocol reveal the genetic diversity of placozoans in Japan
Authors: Miyazawa Hideyuki , Nakano Hiroaki
Published: January 2018

Placozoans, flat free‐living marine invertebrates, possess an extremely simple bauplan lacking neurons and muscle cells and represent one of the earliest‐branching metazoan phyla. They are widely distributed from temperate to tropical oceans. Based on mitochondrial 16S rRNA sequences, 19 haplotypes forming seven distinct clades have been reported in placozoans to date. In Japan, placozoans have been found at nine locations, but 16S genotyping has been performed at only two of these locations. Here, we propose a new processing protocol, “ethanol‐treated substrate sampling,” for collecting placozoans from natural environments. We also report the collection of placozoans from three new locations, the islands of Shikine‐jima, Chichi‐jima, and Haha‐jima, and we present the distribution of the 16S haplotypes of placozoans in Japan. Multiple surveys conducted at multiple locations yielded five haplotypes that were not reported previously, revealing high genetic diversity in Japan, especially at Shimoda and Shikine‐jima Island. The observed geographic distribution patterns were different among haplotypes; some were widely distributed, while others were sampled only from a single location. However, samplings conducted on different dates at the same sites yielded different haplotypes, suggesting that placozoans of a given haplotype do not inhabit the same site constantly throughout the year. Continued sampling efforts conducted during all seasons at multiple locations worldwide and the development of molecular markers within the haplotypes are needed to reveal the geographic distribution pattern and dispersal history of placozoans in greater detail.