bluuebunny/crossref_metadata_2025 huggingface dataset:
Making sense of intralocus and interlocus sexual conflict
Authors: Schenkel Martijn A. , Pen Ido , Beukeboom Leo W. , Billeter Jean‐Christophe
Published: December 2018

Sexual conflict occurs because males and females are exposed to different selection pressures. This can affect many aspects of female and male biology, such as physiology, behavior, genetics, and even population ecology. Its broad impact has caused widespread interest in sexual conflict. However, a key aspect of sexual conflict is often confused; it comprises two distinct forms: intralocus and interlocus sexual conflict (IASC and IRSC). Although both are caused by sex differences in selection, they operate via different proximate and ultimate mechanisms. Intralocus sexual conflict and IRSC are often not clearly defined as separate processes in the scientific literature, which impedes a proper understanding of each form as well as of their relative impact on sexual conflict. Furthermore, our current knowledge of the genetics of these phenomena is severely limited. This prevents us from empirically testing numerous theories regarding the role of these two forms of sexual conflict in evolution. Here, we clarify the distinction between IASC and IRSC, by discussing how male and female interests differ, how and when sex‐specific adaptation occurs, and how this may lead to evolutionary change. We then describe a framework for their study, focusing on how future experiments may help identify the genetics underlying these phenomena. Through this, we hope to promote a more critical reflection on IASC and IRSC as well as underline the necessity of genetic and mechanistic studies of these two phenomena.
Testing the predictive capabilities of ecological niche models: a case study examining Red‐bellied Woodpeckers
Authors: FitzGerald Alyssa M. , Starkloff Naima C. , Kirchman Jeremy J.
Published: December 2018

As humans continue to alter natural habitats indirectly and directly, species’ geographic ranges may change as they track shifting climate regimes or changing landscapes. Ecological niche models (ENMs) are frequently used to show modern ranges and forecast future range changes. These models, however, assume that a species will exhibit niche conservatism, though this is rarely tested. Here, we examine a woodpecker species with a well‐documented recent range expansion to assess the effectiveness of predictive models by comparing the pre‐ and post‐expansion climate/habitat niche using ENMs and multivariate principal components analysis. Occurrence data for the Red‐bellied Woodpecker (Melanerpes carolinus) were obtained from the pre‐expansion (1910–1939; n = 299) and post‐expansion (1980–2009; n = 868) time periods. Ecological niche models were constructed using GIS layers describing climate data and crop cover for the pre‐ and post‐expansion time periods. We then used the pre‐expansion ENM to forecast the distribution of Red‐bellied Woodpeckers into the post‐expansion time period, and vice versa, and calculated the niche overlap of the projected distributions and the actual distributions in those time periods to determine whether pre‐ and post‐expansion niches were similar. Predictive ENMs did not closely match the actual distributions in the pre‐ and post‐expansion time periods, respectively, and the pre‐expansion and post‐expansion niches were significantly different from each other (Schoener's D = 0.745, P < 0.001). Multivariate analyses revealed that the present‐day niche encompasses the past niche and that Red‐bellied Woodpeckers today have broader temperature and precipitation tolerances and are found in both more‐ and less‐forested areas than they were in the pre‐expansion era. Our analyses reveal that Red‐bellied Woodpeckers are not exhibiting climate or habitat niche conservatism, explaining why predictive ENMs for this species could not effectively track their range shift. This study emphasizes that predictive models may not be effective for species undergoing niche changes.
Patterns of mercury and selenium exposure in minnesota common loons
Authors: Kenow Kevin P. , Houdek Steven C. , Fara Luke J. , Erickson Richard A. , Gray Brian R. , Harrison Travis J. , Monson Bruce A. , Henderson Carrol L.
Published: December 2018

Common loons (Gavia immer) are at risk of elevated dietary mercury (Hg) exposure in portions of their breeding range. To assess the level of risk among loons in Minnesota (USA), we investigated loon blood Hg concentrations in breeding lakes across Minnesota. Loon blood Hg concentrations were regressed on predicted Hg concentrations in standardized 12-cm whole-organism yellow perch (Perca flavescens), based on fish Hg records from Minnesota lakes, using the US Geological Survey National Descriptive Model for Mercury in Fish. A linear model, incorporating common loon sex, age, body mass, and log-transformed standardized perch Hg concentration representative of each study lake, was associated with 83% of the variability in observed common loon blood Hg concentrations. Loon blood Hg concentration was positively related to standardized perch Hg concentrations; juvenile loons had lower blood Hg concentrations than adult females, and blood Hg concentrations of juveniles increased with body mass. Blood Hg concentrations of all adult common loons and associated standardized prey Hg for all loon capture lakes included in the study were well below proposed thresholds for adverse effects on loon behavior, physiology, survival, and reproductive success. The fish Hg modeling approach provided insights into spatial patterns of dietary Hg exposure risk to common loons across Minnesota. We also determined that loon blood selenium (Se) concentrations were positively correlated with Hg concentration. Average common loon blood Se concentrations exceeded the published provisional threshold. Environ Toxicol Chem 2019;38:524–532. Published 2018 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.
Physiological responses of Chlorella sorokiniana to copper nanoparticles
Authors: Barreto Daniela Mariano , Tonietto Alessandra Emanuele , Amaral Clarice Dias Britto , Pulgrossi Rafael Catoia , Polpo Adriano , Nóbrega Joaquim Araújo , Lombardi Ana Teresa
Published: December 2018

Copper (Cu) nanomaterials have been increasingly researched and produced for many different consumer products. They have high reactivity and bactericidal properties, making them important in antifouling paints, which are thus directly introduced into aquatic ecosystems. However, studies are scarce on the behavior of Cu nanoparticles (Cu-NPs) in natural aquatic systems and their interactions with primary producers such as microalgae. We investigated the effects of NPs on some physiological responses of the freshwater phytoplankton Chlorella sorokiniana. The cells were exposed to nominal concentrations ranging from 2.50 to 635.00 μg L−1 Cu-NPs for 96 h under laboratory-controlled conditions. The cultures were monitored daily for population growth and maximum photosynthetic quantum yield. Total lipids, proteins, and carbohydrates were quantified at 72 h of Cu-NP exposure. The results showed a positive correlation between nominal Cu-NPs and Cu in the biomass (0.97 correlation coefficient) and that this was inversely proportional to total carbohydrates, with a –0.64 correlation coefficient. At the higher end of the Cu-NP concentrations tested, higher total proteins and reduced growth rates were obtained in comparison with controls; we suggest that metal-binding proteins/antioxidants and nonstructural proteins were preferentially produced under these conditions. Our results contribute to an understanding of the interaction between Cu-NPs and a cosmopolitan phytoplankton, C. sorokiniana, and we emphasize that the disposal and use of Cu-NPs requires monitoring because even at environmentally relevant concentrations, the composition of the algae was affected. Environ Toxicol Chem 2019;38:387–395. © 2018 SETAC
Environmental conditions affecting re-release from particulate matter of 4-Nonylphenol into an aqueous medium
Authors: Lyons Rebecca , Togashi Trevor , Bowyer Chad
Published: December 2018

4-nonylphenol is a persistent organic pollutant with endocrine-disrupting properties. A nonpolar product of microbial degradation derived from the surfactant nonylphenol polyethoxylate, 4-nonylphenol is capable of long-range transport attached to particulates. Bioactive concentrations of 4-nonylphenol have been found in the surface water, soils, snow, and particulate matter of the Eastern Sierra Nevada Mountains (USA) hundreds of miles from their origins. As a result of particulate deposition, seasonal and glacial snow pack concentrations measured 20 to 100 times higher than in surface waters. Batch desorption assays were run on particulate matter dosed with 4-nonylphenol. Desorption was measured in 63 to 500 μm particles under 2 different temperature conditions with varying fractions of organic carbon in turbulent or undisturbed states. Lower temperatures (4 °C) decreased the mean percentage of 4-nonylphenol released from particulates in disturbed and undisturbed conditions, whereas the mean percentage of 4-nonylphenol released at 20 °C was reduced by agitation. The effect of agitation at 4 °C was not practically or statistically significant. Particulates with a higher percentage of organic carbon (75%) released very little of the bound 4-nonylphenol (0.53%) compared with particulates containing 4 to 5% of organic carbon that released up to 13%. Larger particles released the least amount of 4-nonylphenol, whereas smaller particles released the most amount. Water and sediment samples taken from below the Palisades Glacier in the Sierra Nevada Mountains showed the greatest 4-nonylphenol concentrations directly below the glacier, implying that glacial particulates will release adsorbed 4-nonylphenol. Environ Toxicol Chem 2019;38:350–360. © 2018 SETAC
TREM2 triggers microglial density and age‐related neuronal loss
Authors: Linnartz‐Gerlach Bettina , Bodea Liviu‐Gabriel , Klaus Christine , Ginolhac Aurélien , Halder Rashi , Sinkkonen Lasse , Walter Jochen , Colonna Marco , Neumann Harald
Published: December 2018

The microglial triggering receptor expressed on myeloid cells 2 (TREM2) signals via the activatory membrane adaptor molecule TYROBP. Genetic variants or mutations of TREM2 or TYROBP have been linked to inflammatory neurodegenerative diseases associated with aging. The typical aging process goes along with microglial changes and mild neuronal loss, but the exact contribution of TREM2 is still unclear. Aged TREM2 knock‐out mice showed decreased age‐related neuronal loss in the substantia nigra and the hippocampus. Transcriptomic analysis of the brains of 24 months old TREM2 knock‐out mice revealed 211 differentially expressed genes mostly downregulated and associated with complement activation and oxidative stress response pathways. Consistently, 24 months old TREM2 knock‐out mice showed lower transcription of microglial (Aif1 and Tmem119), oxidative stress markers (Inos, Cyba, and Cybb) and complement components (C1qa, C1qb, C1qc, C3, C4b, Itgam, and Itgb2), decreased microglial numbers and expression of the microglial activation marker Cd68, as well as accumulation of oxidized lipids. Cultured microglia of TREM2 knock‐out mice showed reduced phagocytosis and oxidative burst. Thus, microglial TREM2 contributes to age‐related microglial changes, phagocytic oxidative burst, and loss of neurons with possible detrimental effects during physiological aging.
Hydrologic functioning of the deep critical zone and contributions to streamflow in a high‐elevation catchment: Testing of multiple conceptual models
Authors: Dwivedi Ravindra , Meixner Thomas , McIntosh Jennifer C. , Ferré P.A. Ty , Eastoe Christopher J. , Niu Guo‐Yue , Minor Rebecca L. , Barron‐Gafford Greg A. , Chorover Jon
Published: December 2018

High‐elevation mountain catchments are often subject to large climatic and topographic gradients. Therefore, high‐density hydrogeochemical observations are needed to understand water sources to streamflow and the temporal and spatial behaviour of flow paths. These sources and flow paths vary seasonally, which dictates short‐term storage and the flux of water in the critical zone (CZ) and affect long‐term CZ evolution. This study utilizes multiyear observations of chemical compositions and water residence times from the Santa Catalina Mountains Critical Zone Observatory, Tucson, Arizona to develop and evaluate competing conceptual models of seasonal streamflow generation. These models were tested using endmember mixing analysis, baseflow recession analysis, and tritium model “ages” of various catchment water sources. A conceptual model involving four endmembers (precipitation, soil water, shallow, and deep groundwater) provided the best match to observations. On average, precipitation contributes 39–69% (55 ± 16%), soil water contributes 25–56% (41 ± 16%), shallow groundwater contributes 1–5% (3 ± 2%), and deep groundwater contributes ~0–3% (1 ± 1%) towards annual streamflow. The mixing space comprised two principal planes formed by (a) precipitation‐soil water‐deep groundwater (dry and summer monsoon season samples) and (b) precipitation‐soil water‐shallow groundwater (winter season samples). Groundwater contribution was most important during the wet winter season. During periods of high dynamic groundwater storage and increased hydrologic connectivity (i.e., spring snowmelt), stream water was more geochemically heterogeneous, that is, geochemical heterogeneity of stream water is storage‐dependent. Endmember mixing analysis and 3H model age results indicate that only 1.4 ± 0.3% of the long‐term annual precipitation becomes deep CZ groundwater flux that influences long‐term deep CZ development through both intercatchment and intracatchment deep groundwater flows.
Children's psychological adjustment in dual‐ and single‐ethnic families: Coregulation, socialization values, and emotion regulation in a 7‐year follow‐up study
Authors: Lundén Maija , Punamäki Raija‐Leena , Silvén Maarit
Published: December 2018

The study examines how dual‐ethnic and single‐ethnic families differ in terms of children's psychological adjustment and its correlates. Among 48 Finnish–Russian and Finnish families, mothers and fathers reported on children's emotional and conduct problems at ages 4 years and 7 years and children's emotion regulation, emotionality, and their own socialization values at 7 years. Mother–infant and father–infant coregulation was assessed at 7 months. The results show that children had more emotional problems among Finnish–Russian families than among Finnish families at 4 years but not at 7 years. Russian mothers reported more hierarchical and authoritarian values than did Finnish mothers, but the values did not moderate between ethnic context and children's adjustment. Equally many Finnish and Finnish–Russian families had balanced early coregulation, which was linked with fewer attention‐related problems at age 4. In both ethnic contexts, children's emotion regulation was concurrently associated with better psychological adjustment, and high emotionality was associated with more problems. Parental values were not associated with children's adjustment.

Highlights

This study from infancy to school age analyses psychological adjustment and its correlates among children growing up in single‐ and dual‐ethnic families.

Parent‐infant unbalanced co‐regulation related with parent‐reported ADHD problems in preschool children who had more emotional problems in dual‐ethnic than single‐ethnic families.

Found differences in parental values and emotion socialization did not expose children in dual‐ethnic families to enduring risk for problems in emotion regulation or adjustment.
Successful traction‐assisted endoscopic submucosal dissection using dental floss and a clip for a huge superficial nonampullary duodenal epithelial tumor with severe fibrosis (with video)
Authors: Tashima Tomoaki , Nonaka Kouichi , Kurumi Hiroki , Fujii Yuko , Tanisaka Yuki , Ryozawa Shomei
Published: December 2018

Recently, traction‐assisted endoscopic submucosal dissection (ESD) using a clip and thread was reported as useful for treating lesions in the esophagus, stomach, and colorectum in terms of shortening the duration of the procedures and reducing the risk of intraoperative perforation. However, no traction method using the thread and clip for duodenal ESD as described in this article has been reported to date. We report a case in which traction‐assisted ESD using dental floss and a clip was successfully performed on a huge superficial nonampullary duodenal epithelial tumor accompanied by severe fibrosis caused by preoperative biopsies. A 65‐year‐old woman had a 55‐mm flat‐elevated tumor in the second part of the duodenum. Severe fibrosis of the submucosal layer was expected due to repeated biopsies at the same site by the patient’s previous endoscopist. We selected ESD for this lesion, and the initial incision was started from the side proximal to the lesion, but it was difficult to insert the scope under the submucosal layer directly beneath the biopsy scar. Therefore, traction with an endoclip and dental floss was performed to lift the lesion. Excellent traction allowed safe resection of the fibrotic part under accurate visual observation. Finally, the lesion was resected en bloc without adverse events. Traction‐assisted ESD using dental floss and a clip is likely to be an effective adjunctive technique for quick, safe, and successful resection of lesions in the duodenum on which it is difficult to perform ordinary ESD and that have a high probability of intraoperative perforation and massive bleeding.
Synthesis of 13C‐labelled sulfated N‐acetyl‐d‐lactosamines to aid in the diagnosis of mucopolysaccharidosis diseases
Authors: Cameron Scott A. , Zubkova Olga V. , Toms Steven , Furneaux Richard H. , Rendle Phillip M.
Published: December 2018

Morquio A syndrome is an autosomal mucopolysaccharide storage disorder that leads to accumulation of keratan sulfate. Diagnosis of this disease can be aided by measuring the levels of keratan sulfate in the urine. This requires the liquid chromatography tandem mass spectrometry (LCMS/MS) measurement of sulfated N‐acetyl‐d‐lactosamines in the urine after cleavage of the keratan sulfate with keratanase II. Quantification requires isotopically‐labelled internal standards. The synthesis of these 13C6‐labelled standards from 13C6‐galactose and N‐acetylglucosamine is described. The required protected disaccharide is prepared utilising a regioselective, high yielding β‐galactosylation of a partially protected glucosamine acceptor and an inverse addition protocol. Subsequent synthesis of the 13C6‐labelled mono and disulfated N‐acetyllactosamines was achieved in five and eight steps, respectively, from this intermediate to provide internal standards for the LCMS/MS quantification of keratan sulfate in urine.
3T chemical shift‐encoded MRI: Detection of altered proximal femur marrow adipose tissue composition in glucocorticoid users and validation with magnetic resonance spectroscopy
Authors: Martel Dimitri , Leporq Benjamin , Saxena Amit , Belmont H. Michael , Turyan Gabrielle , Honig Stephen , Regatte Ravinder R. , Chang Gregory
Published: December 2018

Background

Osteoporosis (OP) results in weak bone and can ultimately lead to fracture. Drugs such as glucocorticoids can also induce OP (glucocorticoid‐induced osteoporosis [GIO]). Bone marrow adipose tissue composition and quantity may play a role in OP pathophysiology, but has not been thoroughly studied in GIO compared to primary OP.

Purpose/Hypothesis

Chemical shift‐encoded (CSE) MRI allows detection of subregional differences in bone marrow adipose tissue composition and quantity in the proximal femur of GIO compared to OP subjects and has high agreement with the reference standard of magnetic resonance spectroscopy (MRS).

Study Type

Prospective.

Subjects

In all, 18 OP and 13 GIO subjects.

Fields Strength

3T.

Sequence

Multiple gradient‐echo, stimulated echo acquisition mode (STEAM).

Assessment

Subjects underwent CSE‐MRI in the proximal femurs, and for each parametric map regions of interest (ROIs) were assessed in the femoral head (fHEAD), femoral neck (fNECK), Ward's triangle (fTRIANGLE), and the greater trochanter (GTROCH). In addition, we compared CSE‐MRI against the reference standard of MRS performed in the femoral neck and Ward's triangle.

Statistical Tests

Differences between OP/GIO were investigated using the Mann–Whitney nonparametric test. Bland–Altman methodology was used to assess measurement agreement between CSE‐MRI and MRS.

Results

GIO compared with OP subjects demonstrated: decreased monounsaturated fat fraction (MUFA) (–2.1%, P < 0.05) in fHEAD; decreased MUFA (–3.8%, P < 0.05), increased saturated fat fraction (SFA) (5.5%, P < 0.05), and decreased (–3.8 msec, P < 0.05) in fNECK; decreased proton density fat fraction (PDFF) (–15.1%, P < 0.05), MUFA (–9.8%, P < 0.05), polyunsaturated fat fraction (PUFA) (–1.8%, P < 0.01), increased SFA (11.6%, P < 0.05), and decreased (–5.4 msec, P < 0.05) in fTRIANGLE; and decreased (–1.5 msec, P < 0.05) in GTROCH. There was high measurement agreement between MRI and MRS using the Bland–Altman test.

Data Conclusion

3T CSE‐MRI may allow reliable assessment of subregional bone marrow adipose tissue (bMAT) quantity and composition in the proximal femur in a clinically reasonable scan time. Glucocorticoids may alter the lipid profile of bMAT and potentially result in reduced bone quality.

Level of Evidence: 2

Technical Efficacy: Stage 2

J. Magn. Reson. Imaging 2019;50:490–496.
Estimation of soil texture from permanent wilting point measured with a chilled‐mirror dewpoint technique
Authors: Farrick Kegan K. , Wuddivira Mark N. , Martin Osei
Published: December 2018

Soil texture is an important factor governing a range of physical properties and processes in soil. The clay and fine fractions of soil are particularly important in controlling soil water retention, hydraulic properties, water flow and transport. Modern soil texture analysis techniques (x‐ray attenuation, laser diffraction and particle counting) are very laborious with expensive instrumentation. Chilled‐mirror dewpoint potentiameters allows for the rapid measurement of the permanent wilting point (PWP) of soil. As the PWP is strongly dictated by soil texture, we tested the applicability of PWP measured by a dewpoint potentiameter in predicting the clay, silt and sand content of humid tropical soils. The clay, silt, and sand content, organic matter and PWP were determined for 21 soils. Three regression models were developed to estimate the fine fractions and validated using independent soil data. While the first model showed reasonable accuracy (RMSE 16.4%; MAE 13.5%) in estimating the clay, incorporating the organic matter into the equation improved the predictions of the second model (RMSE 17.3%; MAE 10.9%). When used on all soil data, the accuracy of the third model in predicting the fine fraction was poor (RMSE 31.9%; MAE 24.5%). However, for soils with silt content greater than 30%, the model prediction was quite accurate (RMSE 7–12%; MAE 7–9%). The models were used to estimate the sand content and soil textures of soils, which proved relatively accurate. The dewpoint potentiometer can serve a dual purpose of rapidly estimating the PWP and the clay, fine fraction, and soil texture of soils in a cost efficient way.
Does It Help? The Contribution of Wives' Ways of Giving Support to Their Veteran Husbands’ Posttraumatic Stress Symptoms and Functional Impairment
Authors: Dekel Rachel , Siegel Alana , Fridkin Shimon , Svetlitzky Vlad
Published: December 2018

In this study, we aimed to understand female partners' ways of giving support to their male military veteran partners’ adjustment. Specifically, we examined the direct and moderating contributions female partners’ ways of giving support—active engagement, protective buffering, or overprotection—make on their male partners’ posttraumatic stress symptoms (PTSS) and functional impairment. Our hypotheses were that (a) female partners’ active engagement would be negatively correlated with male veterans' PTSS and positively associated with veterans' functioning, (b) female partners’ protective buffering and overprotection would be positively correlated with veterans' PTSS and negatively associated with veterans' functioning, and (c) female partners’ ways of giving support would moderate the association between their secondary PTSS and male partners’ adjustment. Participants were 300 male Israeli veterans of the 2006 Israel–Lebanon War and their female partners, all of whom completed self‐report questionnaires. Active engagement did not contribute to female partners’ or veterans’ adjustment. In addition, whereas the correlations showed both female partners’ protective buffering and overprotection were associated with male veterans’ adjustment, the regression analysis showed only protective buffering made a direct, η2 = .040 and .053, and moderating contribution to veterans’ adjustment, η2 = .019 and .016. Results revealed that when the level of protective buffering was high, female partners' secondary PTSS was associated more positively and strongly with veterans' PTSS than when protective buffering was low. The discussion reviews the complexity of giving support in couples when the veteran has PTSS.
Summability factor relations between absolute weighted and Cesàro means
Authors: Hazar Güleç Güllü Canan
Published: December 2018

By
, we denote the set of all sequences
such that Σϵnan is summable V whenever Σan is summable U, where U and V are two summability methods. Recently, Sarıgöl has characterized the set
for k  >  1,α  >  −1 and arbitrary positive sequences
Now, in the present paper, we characterize the sets
, k  >  1 and
, k  ≥  1 for arbitrary positive sequences
Hence we extend these results to the range α≥ − 1. In this way, some open problems in this topic are also completed.
An efficient semi‐implicit temporal scheme for boundary‐layer vertical diffusion
Authors: Rokhzadi Arman , Mohammadian Abdolmajid
Published: December 2018

Time integration of the boundary‐layer vertical diffusion equation has been investigated. The nonlinearity associated with the diffusion coefficient makes the implicit approach impractical, while the use of an explicit scheme limits the stable time‐step sizes and consequently would be inefficient. By using a diagonally implicit Runge–Kutta scheme, a new approach has been proposed in which the diffusion coefficients at each internal stage are calculated by a weight‐averaged combination of solutions. Using the weight coefficient α offers more robust calculations due to involving implicit solutions and, as shown, it could improve the accuracy due to more engaging the explicit solutions. It has been found that the proposed semi‐implicit method is more accurate and computationally less expensive than the implicit scheme. Moreover, in terms of stability and accuracy improvement, the advantage of the proposed DIRK scheme, compared to the scheme proposed by Diamantakis et al. (), has been revealed, particularly for a highly nonlinear diffusion term.
Tunneling time in driven double‐well system using entangled molecular dynamics method
Authors: Xu Feng
Published: December 2018

We calculate quantum tunneling time in the double‐well system without perturbation and with symmetry‐breaking driven force using the entangled trajectory molecular dynamics method in the present article. Without perturbation, quantum tunneling time decreased with the increase of the energy, and the different contributions of the barrier traversal time and the intrinsic decay time have been shown. The tunneling time dependence on the amplitude and frequency of the symmetry‐breaking driven force are present. In the case of weak driven force, tunneling time has a minimum value in the resonant frequency. For strong driven force, chaos brings a huge change to quantum dynamics, tunneling time significantly becomes short. Finally, we directly show the enhancement of quantum tunneling process by chaotic behavior of entangled trajectories and indicate that it was caused by quantum effect.
Residual behavior of reinforced steel fiber‐reinforced concrete beams damaged by impact
Authors: Zanuy Carlos , Ulzurrun Gonzalo S. D.
Published: December 2018

The awareness of damage caused by impacts in civil structures has increased during the last decades. Existing research has shown that impact strength of concrete structures can be improved with the addition of steel fibers, but little attention has been paid at the assessment of the structural condition after the impact. In fact, the residual capacity of reinforced steel fiber‐reinforced concrete (SFRC) can be considered as one of the main advantages of the employ of SFRC in structures expected to suffer impact damage. The understanding of the residual capacity of impact‐damaged structures, in terms of strength and energy absorption, might be decisive to safely perform evacuation and recovery operations, as well as evaluate rehabilitation tasks. This paper presents a research on the residual capacity of preimpacted reinforced SFRC beams. Seven mixtures of SFRC are evaluated, including three types of steel fibers and two values of fiber amount (as well as companion unreinforced plain concrete mixture). The research includes an experimental campaign as well as a model to understand the contribution of the SFRC to the strength and ductility of undamaged and damaged specimens. Among the conclusions, it has been found out that the failure mode (i.e., shear‐ or flexure‐governed) of damaged specimens depends on the crack pattern caused by the impact, and it can be different from the failure mode of undamaged specimens.
Structure and function of Rnt1p: An alternative to RNAi for targeted RNA degradation
Authors: Abou Elela Sherif , Ji Xinhua
Published: December 2018

The double‐stranded RNA‐binding protein (dsRBP) family controls RNA editing, stability, and function in all eukaryotes. The central feature of this family is the recognition of a generic RNA duplex using highly conserved double‐stranded RNA‐binding domain (dsRBD) that recognizes the characteristic distance between the minor grooves created by the RNA helix. Variations on this theme that confer species and functional specificities have been reported but most dsRBPs retain their capacity to bind generic dsRNA. The ribonuclease III (RNase III) family members fall into four classes, represented by bacterial RNase III, yeast Rnt1p, human Drosha, and human Dicer, respectively. Like all dsRBPs and most members of the RNase III family, Rnt1p has a dsRBD, but unlike most of its kin, it poorly binds to generic RNA helices. Instead, Rnt1p, the only known RNase III expressed in Saccharomyces cerevisiae that lacks the RNAi (RNA interference) machinery, recognizes a specific class of stem‐loop structures. To recognize the specific substrates, the dsRBD of Rnt1p is specialized, featuring a αβββααα topology and a sequence‐specific RNA‐binding motif at the C‐terminus. Since the discovery of Rnt1p in 1996, significant progress has been made in studies of its genetics, function, structure, and mechanism of action, explaining the reasons and mechanisms for the increased specificity of this enzyme and its impact on the mechanism of RNA degradation.

This article is categorized under:

RNA Turnover and Surveillance > Turnover/Surveillance Mechanisms

RNA Interactions with Proteins and Other Molecules > Protein–RNA Recognition

RNA Processing > Processing of Small RNAs

RNA Interactions with Proteins and Other Molecules > RNA–Protein Complexes
Effect of flow on ATP/ADP concentration at the endothelial cell surface: interplay between shear stress and mass transport
Authors: Di Costanzo Ezio , Barakat Abdul I. , Pontrelli Giuseppe
Published: December 2018

The article from this special issue was previously published in ZAMM ‐ Journal of Applied Mathematics and Mechanics / Zeitschrift für Angewandte Mathematik und Mechanik, Volume 98, Issue 8, 2018. For completeness we are including the title page of the article. The full text of the article can be read in Issue 98:8 on Wiley Online Library: https://onlinelibrary.wiley.com/doi/full/10.1002/zamm.201700372
The source of platinum group elements in basalts of the ophiolite complex of the Kamchatsky Mys Peninsula (Eastern Kamchatka)
Authors: Savelyev D.P. , Palesskii S.V. , Portnyagin M.V.
Published: December 2018

Contents of platinum group elements (PGE—Os, Ir, Ru, Rh, Pt, and Pd) and rhenium in basalts of different geochemical types from the ophiolite complex of the Kamchatsky Mys Peninsula have been determined by the isotope dilution–mass spectrometry method. The total contents of PGE in different basalts are commensurate (1.4–3.6 ppb), but the element ratios vary considerably. A specific feature of the rocks is the low degree of PGE fractionation (Pd/Ir = 0.9–6.6, Pt/Pd = 1.0–7.3), which makes them similar to the Hawaiian tholeiitic basalts and picrites. The most fractionated PGE pattern is observed for alkali basalt (Pd/Ir = 6.6), and the least fractionated one, for E-MORB (Pd/Ir = 1.7). The similarity of the PGE patterns of basalts of different geochemical types suggests their similar mantle sources. We propose a model explaining the geochemical features of the basalts of the Kamchatsky Mys ophiolite complex by an impurity of the Earth’s core material in the plume source. The Ir/Pd–Ru/Pd and Pd/10–Ir–Ru discrimination diagrams can be used to identify enriched (plume) basalts based on their PGE content.
Geodynamic setting, structure, and composition of continuous trachybasalt–trachyandesite–rhyolite series in the north of Altai–Sayan area: the role of crust–mantle interaction in continental magma formation
Authors: Vorontsov A.A. , Perfilova O.Yu. , Kruk N.N.
Published: December 2018

The geologic positions and geochemical and isotope parameters of the Ordovician–early Silurian and Early–Middle Devonian continuous volcanic series of the Minusa basin and its mountainous framing are compared. Both series are composed mostly of moderately alkaline rocks with variations in SiO2 contents from 45 to 77 wt.%. The Ordovician–early Silurian series differs from the Early–Middle Devonian one in lower contents of TiO2 (<1.7 wt.%) and Fe2O3tot and higher contents of Al2O3 in all rock varieties and in the more fractionated REE patterns of trachybasalts. The compositions of both series reflect two simultaneous mechanisms of magma evolution. The main process was fractional crystallization leading to the formation of rocks from trachybasalts to trachyrhyodacites. The accessory mechanism was the contamination of fractionated melts by crustal material, anatectic melting of crust, and mixing of deep-seated magmas with crustal melts. These processes had specifics at each stage and were controlled by the composition of the sources of parental melts. Their geochemical and isotopic parameters (high alkalinity, high contents of lithophile elements, negative anomalies of Nb, Ta, and Ti, and enrichment in radiogenic Sr) point to the interaction of mantle plumes with the lithospheric mantle that was metasomatically transformed during the preceding Vendian–early Cambrian subduction processes.
God and Time
Authors: Deng Natalja
Published: December 2018

The God of Western religion is said to be eternal. But what does that mean? Is God somehow beyond time, living a life that does not involve one thing after another? Or is God's relationship to time much more like ours, so that God's eternality just consists in there being no time at which God doesn't exist? Even for non-believers, these issues have interesting implications for the relation between historical and scientific findings on the one hand, and religion on the other. This Element introduces the reader to the requisite metaphysical background, and then examines reasons for and against thinking of God as timeless.
Extinct Megatoothed Shark May Have Been Warm-Blooded
Authors: Cartier Kimberly
Published: December 2018

Preliminary results from a recent study may begin to shed light on why megalodons died out before the most recent ice age.
Inspiring the Next Generation of Earth and Space Scientists
Authors: Dengo Carlos
Published: December 2018

Join AGU’s growing community of philanthropists who are helping to shape the future of our Earth and space sciences by supporting the Austin Endowment for Student Travel.
Penguin Poop Keeps a Record of Antarctic Glaciation
Authors: Bedford Bailey
Published: December 2018

Scientists are digging up Ad�lie penguin guano to study millennia of Antarctica’s history.
Freshwater Export in the East Greenland Current Freshens the North Atlantic
Authors: de Steur L. , Peralta‐Ferriz C. , Pavlova O.
Published: December 2018

Arctic Ocean freshwater content increased in the 2000s. Since variations in freshwater input into the North Atlantic Ocean can modify its properties, monitoring the freshwater export from the Arctic Ocean to southern latitudes is critical. The Arctic Outflow Observatory in Fram Strait has collected continuous ocean measurements from moored platforms since 1997. Here new and improved records of freshwater transport from the mooring array are presented until 2015, showing that, since the last documented record in 2009, the freshwater export was substantially larger from 2010 to 2013. The increase was mostly due to increased southward flow, and secondly due to low salinities. While sea level pressure gradient across the strait explains seasonal variability, it does not explain the observed freshwater anomaly. The cumulative freshwater anomaly between 2010 and 2015 amounted to 3,106 km3, representing a significant external source of freshwater to the North Atlantic.
Hidden heterogeneity and circadian-controlled cell fate inferred from single cell lineages
Authors: Chakrabarti Shaon , Paek Andrew L. , Reyes Jose , Lasick Kathleen A. , Lahav Galit , Michor Franziska
Published: December 2018

The origin of lineage correlations among single cells and the extent of heterogeneity in their intermitotic times (IMT) and apoptosis times (AT) remain incompletely understood. Here we developed single cell lineage-tracking experiments and computational algorithms to uncover correlations and heterogeneity in the IMT and AT of a colon cancer cell line before and during cisplatin treatment. These correlations could not be explained using simple protein production/degradation models. Sister cell fates were similar regardless of whether they divided before or after cisplatin administration and did not arise from proximity-related factors, suggesting fate determination early in a cell’s lifetime. Based on these findings, we developed a theoretical model explaining how the observed correlation structure can arise from oscillatory mechanisms underlying cell fate control. Our model recapitulated the data only with very specific oscillation periods that fit measured circadian rhythms, thereby suggesting an important role of the circadian clock in controlling cellular fates.
Characterizing early drug resistance-related events using geometric ensembles from HIV protease dynamics
Authors: Sheik Amamuddy Olivier , Bishop Nigel T. , Tastan Bishop Özlem
Published: December 2018

The use of antiretrovirals (ARVs) has drastically improved the life quality and expectancy of HIV patients since their introduction in health care. Several millions are still afflicted worldwide by HIV and ARV resistance is a constant concern for both healthcare practitioners and patients, as while treatment options are finite, the virus constantly adapts via complex mutation patterns to select for resistant strains under the pressure of drug treatment. The HIV protease is a crucial enzyme for viral maturation and has been a game changing drug target since the first application. Due to similarities in protease inhibitor designs, drug cross-resistance is not uncommon across ARVs of the same class. It is known that resistance against protease inhibitors is associated with a wider active site, but results from our large scale molecular dynamics simulations combined with statistical tests and network analysis further show, for the first time, that there are regions of local expansions and compactions associated with high levels of resistance conserved across eight different protease inhibitors visible in their complexed form within closed receptor conformations. The observed conserved expansion sites may provide an alternative drug-targeting site. Further, the method developed here is novel, supplementary to methods of variation analysis at sequence level, and should be applicable in analysing the structural consequences of mutations in other contexts using molecular ensembles.
Transcriptome analysis of the anhydrobiotic cell line Pv11 infers the mechanism of desiccation tolerance and recovery
Authors: Yamada Takahiro G. , Suetsugu Yoshitaka , Deviatiiarov Ruslan , Gusev Oleg , Cornette Richard , Nesmelov Alexander , Hiroi Noriko , Kikawada Takahiro , Funahashi Akira
Published: December 2018

The larvae of the African midge,Polypedilum vanderplanki, can enter an ametabolic state called anhydrobiosis to overcome fatal desiccation stress. The Pv11 cell line, derived fromP. vanderplankiembryo, shows desiccation tolerance when treated with trehalose before desiccation and resumes proliferation after rehydration. However, the molecular mechanisms of this desiccation tolerance remain unknown. Here, we performed high-throughput CAGE-seq of mRNA and a differentially expressed gene analysis in trehalose-treated, desiccated, and rehydrated Pv11 cells, followed by gene ontology analysis of the identified differentially expressed genes. We detected differentially expressed genes after trehalose treatment involved in various stress responses, detoxification of harmful chemicals, and regulation of oxidoreduction that were upregulated. In the desiccation phase, L-isoaspartyl methyltransferase and heat shock proteins were upregulated and ribosomal proteins were downregulated. Analysis of differentially expressed genes during rehydration supported the notion that homologous recombination, nucleotide excision repair, and non-homologous recombination were involved in the recovery process. This study provides initial insights into the molecular mechanisms underlying the extreme desiccation tolerance of Pv11 cells.
Identification and quantification of macro- and microplastics on an agricultural farmland
Authors: Piehl Sarah , Leibner Anna , Löder Martin G. J. , Dris Rachid , Bogner Christina , Laforsch Christian
Published: December 2018

Microplastic contamination of aquatic ecosystems is a high priority research topic, whereas the issue on terrestrial ecosystems has been widely neglected. At the same time, terrestrial ecosystems under human influence, such as agroecosystems, are likely to be contaminated by plastic debris. However, the extent of this contamination has not been determined at present. Via Fourier transform infrared (FTIR) analysis, we quantified for the first time the macro- and microplastic contamination on an agricultural farmland in southeast Germany. We found 206 macroplastic pieces per hectare and 0.34 ± 0.36 microplastic particles per kilogram dry weight of soil. In general, polyethylene was the most common polymer type, followed by polystyrene and polypropylene. Films and fragments were the dominating categories found for microplastics, whereas predominantly films were found for macroplastics. Since we intentionally chose a study site where microplastic-containing fertilizers and agricultural plastic applications were never used, our findings report on plastic contamination on a site which only receives conventional agricultural treatment. However, the contamination is probably higher in areas where agricultural plastic applications, like greenhouses, mulch, or silage films, or plastic-containing fertilizers (sewage sludge, biowaste composts) are applied. Hence, further research on the extent of this contamination is needed with special regard to different cultivation practices.
High-resolution deconstruction of evolution induced by chemotherapy treatments in breast cancer xenografts
Authors: Kim Hyunsoo , Kumar Pooja , Menghi Francesca , Noorbakhsh Javad , Cerveira Eliza , Ryan Mallory , Zhu Qihui , Ananda Guruprasad , George Joshy , Chen Henry C. , Mockus Susan , Zhang Chengsheng , Yang Yan , Keck James , Karuturi R. Krishna Murthy , Bult Carol J. , Lee Charles , Liu Edison T. , Chuang Jeffrey H.
Published: December 2018

The processes by which tumors evolve are essential to the efficacy of treatment, but quantitative understanding of intratumoral dynamics has been limited. Although intratumoral heterogeneity is common, quantification of evolution is difficult from clinical samples because treatment replicates cannot be performed and because matched serial samples are infrequently available. To circumvent these problems we derived and assayed large sets of human triple-negative breast cancer xenografts and cell cultures from two patients, including 86 xenografts from cyclophosphamide, doxorubicin, cisplatin, docetaxel, or vehicle treatment cohorts as well as 45 related cell cultures. We assayed these samples via exome-seq and/or high-resolution droplet digital PCR, allowing us to distinguish complex therapy-induced selection and drift processes among endogenous cancer subclones with cellularity uncertainty <3%. For one patient, we discovered two predominant subclones that were granularly intermixed in all 48 co-derived xenograft samples. These two subclones exhibited differential chemotherapy sensitivity–when xenografts were treated with cisplatin for 3 weeks, the post-treatment volume change was proportional to the post-treatment ratio of subclones on a xenograft-to-xenograft basis. A subsequent cohort in which xenografts were treated with cisplatin, allowed a drug holiday, then treated a second time continued to exhibit this proportionality. In contrast, xenografts from other treatment cohorts, spatially dissected xenograft fragments, and cell cultures evolved in diverse ways but with substantial population bottlenecks. These results show that ecosystems susceptible to successive retreatment can arise spontaneously in breast cancer in spite of a background of irregular subclonal bottlenecks, and our work provides to our knowledge the first quantification of the population genetics of such a system. Intriguingly, in such an ecosystem the ratio of common subclones is predictive of the state of treatment susceptibility, showing how measurements of subclonal heterogeneity could guide treatment for some patients.
Comparison of diffusion-weighted MRI and anti-Stokes Raman scattering (CARS) measurements of the inter-compartmental exchange-time of water in expression-controlled aquaporin-4 cells
Authors: Obata Takayuki , Kershaw Jeff , Tachibana Yasuhiko , Miyauchi Takayuki , Abe Yoichiro , Shibata Sayaka , Kawaguchi Hiroshi , Ikoma Yoko , Takuwa Hiroyuki , Aoki Ichio , Yasui Masato
Published: December 2018

We performed multi-b and multi-diffusion-time diffusion-weighted magnetic resonance imaging on aquaporin-4-expressing (AQ) and -non-expressing (noAQ) cells, and demonstrated a clear difference between the signals from the two cell types. The data were interpreted using a two-compartment (intra and extracellular spaces) model including inter-compartmental exchange. It was also assumed that restricted diffusion of water molecules inside the cells leads to the intracellular diffusion coefficient being inversely proportional to the diffusion-time. Estimates of the water-exchange-times obtained with this model are compared to those measured using an independent optical imaging technique (coherent anti-Stokes Raman scattering imaging, CARS). For both techniques it was found that the exchange-time estimated for the noAQ cells was significantly longer than that for the AQ cells.