bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regional context and dispersal mode drive the impact of landscape structure on seed dispersal
Authors: San‐José Miriam , Arroyo‐Rodríguez Víctor , Meave Jorge A. 
Published: November 2019

AbstractLand‐use change modifies the spatial structure of tropical landscapes, shaping global biodiversity patterns. Yet, it remains unknown how key ecological processes, such as seed dispersal, can be affected by changes in landscape patterns, and whether such effects differ among regions with different climate and disturbance intensity. We assessed the effect of five landscape metrics (forest cover, matrix openness, forest edge density, forest fragmentation, and interpatch distance) on the seed rain recorded in two Mexican fragmented regions (20 forest sites per region): the more deforested, defaunated, and windy Los Tuxtlas rainforest (LTX), and the better‐preserved Lacandona rainforest (LAC). We quantified the proportions of dispersed tree species and their seeds, separately evaluating wind‐ and animal‐dispersed species. Our findings support the hypothesis that forest loss is more important than fragmentation per se, negatively impacting the seed rain in both regions. As expected, landscape patterns were comparatively more important for wind‐dispersed seeds in LTX, probably because of stronger wind events in this region. Specifically, proportions of wind‐dispersed seeds and species decreased with increasing edge density, suggesting that forest edges prevent dispersal of wind‐dispersed species, which may occur if edges create physical barriers that limit wind flow. This pattern can also be caused by source limitation in landscapes with more forest edges, as tree mortality rates usually increase at forest edges. The wind‐dispersed seed rain was also positively related to matrix openness, especially in LTX, where wind flow can be favored by the dominance of treeless anthropogenic matrices. Surprisingly, the proportion of animal‐dispersed seeds in LTX was positively related to matrix openness and patch isolation, suggesting that seed dispersers in more deforested regions may be forced to concentrate in isolated patches and use the available habitat more intensively. Yet, as expected, patch isolation limited wind‐dispersed seeds in LAC. Therefore, dispersal (and potentially regeneration) of wind‐dispersed trees is favored in regions exposed to stronger wind events, especially in landscapes dominated by regularly shaped patches surrounded by open areas. Conversely, animal‐dispersed seeds are primarily favored by increasing forest cover. Preventing forest loss is therefore critical to promote animal seed dispersal and forest recovery in human‐modified rainforests.
Effects of invasive plants on fire regimes and postfire vegetation diversity in an arid ecosystem
Authors: Underwood Emma C. , Klinger Robert C. , Brooks Matthew L. 
Published: November 2019

AbstractWe assessed the impacts of co‐occurring invasive plant species on fire regimes and postfire native communities in the Mojave Desert, western USA. We analyzed the distribution and co‐occurrence patterns of three invasive annual grasses (Bromus rubens, Bromus tectorum, and Schismus spp.) known to alter fuel conditions and community structure, and an invasive forb (Erodium cicutarium) which dominates postfire sites. We developed species distribution models (SDMs) for each of the four taxa and analyzed field plot data to assess the relationship between invasives and fire frequency, years postfire, and the impacts on postfire native herbaceous diversity. Most of the Mojave Desert is highly suitable for at least one of the four invasive species, and 76% of the ecoregion is predicted to have high or very high suitability for the joint occurrence of B. rubens and B. tectorum and 42% high or very high suitability for the joint occurrence of the two Bromus species and E. cicutarium. Analysis of cover from plot data indicated two or more of the species occurred in 77% of the plots, with their cover doubling with each additional species. We found invasive cover in burned plots increased for the first 20 years postfire and recorded two to five times more cover in burned than unburned plots. Analysis also indicated that native species diversity and evenness as negatively associated with higher levels of relative cover of the four invasive taxa. Our findings revealed overlapping distributions of the four invasives; a strong relationship between the invasives and fire frequency; and significant negative impacts of invasives on native herbaceous diversity in the Mojave. This suggests predicting the distributions of co‐occurring invasive species, especially transformer species, will provide a better understanding of where native‐dominated communities are most vulnerable to transformations following fire or other disturbances.
Novel tri‐isotope ellipsoid approach reveals dietary variation in sympatric predators
Authors: Skinner Christina , Mill Aileen C. , Newman Steven P. , Newton Jason , Cobain Matthew R. D. , Polunin Nicholas V. C. 
Published: November 2019

AbstractSympatric species may partition resources to reduce competition and facilitate co‐existence. While spatial variation and specialization in feeding strategies may be prevalent among large marine predators, studies have focussed on sharks, birds, and marine mammals. We consider for the first time the isotopic niche partitioning of co‐occurring, teleost reef predators spanning multiple families. Using a novel tri‐isotope ellipsoid approach, we investigate the feeding strategies of seven of these species across an atoll seascape in the Maldives. We demonstrate substantial spatial variation in resource use of all predator populations. Furthermore, within each area, there was evidence of intraspecific variation in feeding behaviors that could not wholly be attributed to individual body size. Assessing species at the population level will mask these intraspecific differences in resource use. Knowledge of resource use is important for predicting how species will respond to environmental change and spatial variation should be considered when investigating trophic diversity.
Climate structures bison dietary quality and composition at the continental scale
Authors: Jorns Tami , Craine Joseph , Towne E. Gene , Knox Margaret 
Published: November 2019

AbstractBackgroundNutrition is a key determinant of North American plains bison (Bison bison) weight gain and reproduction, yet little is known about what bison eat and the pattern of nutritional stress across their distribution.AimsIn order to better understand patterns of bison nutrition across broad climatic gradients, bison fecal material was sampled from 50 sites across the United States in June and September of 2018.Materials and MethodsFor each sample, dietary composition and microbial composition were assessed with DNA metabarcoding, along with dietary quality via near‐infrared spectroscopy and elemental composition.ResultsHerds in cool, wet sites typically had diets with high crude protein but not necessarily higher or lower digestible organic matter than in hot, dry sites. Independent of climate and season, on average, 57% and 48% of protein intake was derived from non‐graminoids in June and September, respectively. Cool‐season grass abundance in the diet was greater in cooler climates in June and September, while N2‐fixing plant abundance in the diet was greater in warmer climates in June. Among multivariate patterns, bison eating a high‐quality diet had fecal material with higher concentrations of P, Mg, Mn, and Ca, and a higher relative abundances of cellulose‐digestingRuminococcus.DiscussionBy sampling across broad geographic gradients and across seasons, the drivers of different components of bison diet are becoming clear. Our results show that climate is integral to structuring bison diet quality, diet composition, elemental intake, and their gut microbiomes.ConclusionsAlthough future work remains to better understand seasonal patterns and inter‐annual variation in diet, North American plains bison should no longer be considered strict grazers. Also, given current geographic dietary patterns, bison in a warmer climate are likely to suffer increased nutritional stress unless actions are taken to increase protein availability.
Performance of extraction methods for extracellular DNA from sediments across marine habitats
Authors: Geraldi Nathan R. , Díaz‐Rúa Rubén , Shea Lauren A. , Duarte Carlos M. 
Published: November 2019

AbstractBackgroundUsing environmental DNA (eDNA) to detect taxa is quickly becoming an important technique to determine the distribution and diversity of macroorganisms. Assessing differences in communities based on eDNA extracted from sediment could enhance our understanding of marine communities among the many different marine habitats both from the present and from the past using sediment cores. Although the effect of extraction methods on metabarcoding results has been tested for both water and sediment samples, less is known about how sediment types may affect the extraction and sequencing of eDNA.Methods and ResultsWe used two extraction methods to assess if the amount of extracted DNA was different among three marine habitats: coral reefs, mangrove forests, and seagrass meadows. First, an equal amount of DNA was added to sterilized sediment and there was no difference in the DNA extracted from the different habitats. Second, an equal amount of DNA from a species that did not occur naturally was added to the sediment and the number of sequenced reads of this species was not different among habitats. A concomitant test found that a commercial extraction kit, the MO BIO PowerSoil DNA isolation kit, and published extraction protocol from Lever et al. (2015, Frontiers in Microbiology, 6, 476) had similar results.ConclusionsAlthough different environmental conditions within the habitats will likely affect the degradation of eDNA, these findings suggest that diverse characteristic of the sediments from different habitats does not affect the extraction of DNA. This is an important step in determining whether eDNA within sediment can be utilized to compare the communities from different marine habitats.
Novel Sensing Assembly Comprising Engineered Gold Dendrites and MWCNT‐AuNPs Nanohybrid for Acetaminophen Detection in Human Urine
Authors: Purohit Buddhadev , Kumar Ashutosh , Mahato Kuldeep , Chandra Pranjal 
Published: November 2019

AbstractA layered nanohybrid comprising of multi walled carbon nanotubes(MWCNT)‐gold nanoparticles (AuNPs) has been designed as a matrix for the development of Au dendritic nanostructures (AuDN) with enhanced catalytic activity. The developed sensor matrix was thoroughly characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), and energy dispersive X‐ray spectroscopy (EDX). The developed sensor probe MWCNT‐AuNPs/AuDN over glassy carbon electrode (GCE) was used for the label free detection of acetaminophen (AP), a commonly used drug associated with hepatotoxicity when overdosed, as a model molecule. The final sensor probe was characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), linear sweep voltammetry (LSV), and differential pulse voltammetry (DPV). The sensor shows excellent analytical performances with a linear dynamic range (LDR) of 100 to 7500 nM, and a low limit of detection (LOD) of 2.12 (±0.03) nM, which is better than recently reported AP sensors. The practical application / clinical possibilities of the final sensor were evaluated by real sample analysis in human urine by spike and recovery method, where the AP recoveries were found in between 92 % to 96 %. The sensor probe shows negligible response towards co‐existing interfering molecules like glucose, urea, uric acid and various amino acids, which are commonly found in real samples (p<0.001, n=3). The shelf life of the sensor probe was evaluated and found to be stable for 8 weeks. The fabricated sensor probe using MWCNT‐AuNPs/AuDN is easy to fabricate, simple, robust, and able to detect AP in urine with high recoveries shows its possibilities to be used in clinical settings.
Scaling law analysis of electrohydrodynamics and dielectrophoresis for isomotive dielectrophoresis microfluidic devices
Authors: Rashed Mohamed Z. , Green Nicolas G. , Williams Stuart J. 
Published: November 2019

AbstractIsomotive dielectrophoresis (isoDEP) is a unique DEP geometrical configuration where the gradient of the field‐squared () is constant. IsoDEP analyzes polarizable particles based on their magnitude and direction of translation. Particle translation is a function of the polarizability of both the particles and suspending medium, the particles’ size and shape, and the frequency of the electric field. However, other electrokinetics act on the particles simultaneously, including electrothermal hydrodynamics. Hence, to maximize the DEP force relative to over electrokinetic forces, design parameters such as microchannel geometry, fabrication materials, and applied electric field must be properly tuned. In this work, scaling law analyses were developed to derive design rules, relative to particle diameter, to reduce unwanted electrothermal hydrodynamics relative to DEP‐induced particle translation. For a particle suspended in 10 mS/m media, if the channel width and height are below ten particle diameters, the electrothermal‐driven flow is reduced by ∼500 times compared to a channel that is 250 particles diameters in width and height. Replacing glass with silicon as the device's underlying substrate for an insulative‐based isoDEP reduces the electrothermal induced flow approximately 20 times less.
Quantifying long‐term post‐fire sediment delivery and erosion mitigation effectiveness
Authors: Robichaud Peter R. , Lewis Sarah A. , Wagenbrenner Joseph W. , Brown Robert E. , Pierson Fredrick B. 
Published: November 2019

AbstractLarge wildfires can have profound and lasting impacts not only from direct consumption of vegetation but also longer‐term effects such as persistent soil erosion. The 2002 Hayman Fire burned in one of the watersheds supplying water to the Denver metropolitan area; thus there was concern regarding hillslope erosion and sedimentation in the reservoirs. The efficacy of various treatments for reducing erosion was tested, including hand scarification on contour, agricultural straw mulch, wood mulch, burned controls and unburned reference plots. Simulated rill erosion experiments were used both immediately after the fire and again 10 years post fire. To better understand untreated recovery, the same experiments were applied to control plots in post‐fire years 1, 2, 3 and 4, and in unburned reference plots in years 4 and 10. Results indicate that control and scarified plots produced significantly greater sediment flux rates – 1.9 and 2.8 g s−1 respectively – than the straw and wood mulch treatments – 0.9 and 1.1 g s−1 – immediately after the fire. Mulch treatments reduced runoff rate, runoff velocity, and sediment concentration and flux rate. The straw mulch cover was no longer present, whereas the wood mulch was still there in year 10. Vegetation regrowth was slow and mulch treatments provided effective cover to reduce sediment right after the fire. In post‐fire year 10, there were no significant differences in sediment flux rates across treatments; it is notable, however, that the wood mulch treatment (0.09 g s−1) most closely approached the unburned condition (0.07 g s−1). The burned control plots had high sediment flux rates until post‐fire year 3, when flux rates significantly decreased and were statistically no longer higher than the unburned levels from year 4 and 10. These results will inform managers of the longer‐term post‐fire sediment delivery rates and of the ability of post‐fire emergency hillslope treatments to mitigate erosion rates. Published 2019. This article is a U.S. Government work and is in the public domain in the USA.
Investigation of fractal market hypothesis and forecasting time series stock returns for Tehran Stock Exchange and London Stock Exchange
Authors: Moradi Mahdi , Jabbari Nooghabi Mehdi , Rounaghi Mohammad Mahdi 
Published: November 2019

AbstractAn alternative investment theory to the widely utilized efficient market hypothesis, fractal market hypothesis analyses the daily randomness of the market and the turbulence witnessed during crashes and crises. The framework of the fractal market hypothesis proposes a clear explanation of investor behaviour throughout a market cycle, including booms and busts. Nowadays, the importance and advantages of forecasting in decision and policy making from different dimensions are undeniably accepted. Naturally, the techniques that face the lowest forecasting errors are capable of survival and proper function. Successful structural models have not been recently employed in the field of forecasting; therefore, other tests have been proposed among which L‐Co‐R algorithm is the most notably known for time series analysis. The present study applies L‐Co‐R coevolutionary algorithm for forecasting and analysis of time series stock returns. The current study examines daily, monthly, and yearly time series stock returns on Tehran Stock Exchange and London Stock Exchange over a period from 2007 to 2013. The statistical analysis in London Stock Exchange shows that the L‐Co‐R algorithm outperforms to the other methods, regardless of the horizon, and is capable of predicting short, medium, or long horizons using real known values. The statistical analysis in Tehran Stock Exchange shows that the L‐Co‐R algorithm outperforms to the other methods and is capable of predicting only short and medium terms. Thus, fractal market hypothesis was accepted for Tehran Stock Exchange and rejected for London Stock Exchange.
“Surface,” “satellite” or “simulation”: Mapping intra‐urban microclimate variability in a desert city
Authors: Zhou Bin , Kaplan Shai , Peeters Aviva , Kloog Itai , Erell Evyatar 
Published: November 2019

AbstractMapping spatial and temporal variability of urban microclimate is pivotal for an accurate estimation of the ever‐increasing exposure of urbanized humanity to global warming. This particularly concerns cities in arid/semi‐arid regions which cover two fifths of the global land area and are home to more than one third of the world's population. Focusing on the desert city of Be'er Sheva Israel, we investigate the spatial and temporal patterns of urban–rural and intra‐urban temperature variability by means of satellite observation, vehicular traverse measurement, and computer simulation. Our study reveals a well‐developed nocturnal canopy layer urban heat island in Be'er Sheva, particularly in the winter, but a weak diurnal cool island in the mid‐morning. Near surface air temperature exhibits weak urban–rural and intra‐urban differences during the daytime (<1°C), despite pronounced urban surface cool islands observed in satellite images. This phenomenon, also recorded in some other desert cities, is explained by the rapid increase in surface skin temperature of exposed desert soils (in the absence of vegetation or moisture) after sunrise, while urban surfaces are heated more slowly. The study highlights differences among the three methods used for describing urban temperature variability, each of which may have different applications in fields such as urban planning, climate change mitigation, and epidemiological research.
Validation of the Liver Imaging Reporting and Data System Treatment Response Criteria After Thermal Ablation for Hepatocellular Carcinoma
Authors: Cools Katherine S. , Moon Andrew M. , Burke Lauren M. B. , McGinty Katrina A. , Strassle Paula D. , Gerber David A. 
Published: November 2019

Single hepatocellular carcinoma (HCC) tumors can be successfully eradicated with thermal ablation (TA). We assessed the validity of the Liver Imaging Reporting and Data System Treatment Response (LR‐TR) criteria with a retrospective analysis of a single‐center database of patients with small HCC tumors (<3 cm in diameter) who underwent both laparoscopic TA and liver transplantation (LT) from 2004 to 2018. Postablation MRIs were assigned LR‐TR categories (nonviable, equivocal, and viable) for ablated lesions and Liver Imaging Reporting and Data System (LI‐RADS) categories (probable or definite HCC) for untreated lesions. Interpretations were compared with the histopathology of the post‐LT explanted liver. There were 45 patients with 81 tumors (59 ablated and 22 untreated; mean size, 2.2 cm), and 23 (39%) of the ablated tumors had viable HCC on histopathology. The sensitivity/specificity of LR‐TR categories (nonviable/equivocal versus viable) of ablated tumors was 30%/99%, with a positive predictive value (PPV)/negative predictive value (NPV) of 93%/69%. The sensitivity varied with residual tumor size. The sensitivity/specificity of LI‐RADS 4 and 5 diagnostic criteria at detecting new HCC was 65%/94%, respectively, with a PPV/NPV of 85%/84%. The interrater reliability (IRR) was high for LR‐TR categories (90% agreement, Cohen’s ĸ = 0.75) and for LI‐RADS LR‐4 and LR‐5 diagnostic categories (91% agreement, Cohen’s ĸ = 0.80). In patients with HCC <3 cm in diameter, LR‐TR criteria after TA had high IRR but low sensitivity, suggesting that the LR‐TR categories are precise but inaccurate. The low sensitivity may be secondary to TA’s disruption in the local blood flow of the tissue, which could affect the arterial enhancement phase on MRI. Additional investigation and new technologies may be necessary to improve imaging after ablation.
Pseudodominant inheritance of autosomal recessive congenital stationary night blindness in one family with three co‐segregating deleterious GRM6 variants identified by next‐generation sequencing
Authors: Liu Hong‐Yan , Huang Jia , Xiao Hai , Zhang Ming‐Jie , Shi Fei‐Fei , Jiang Ying‐Hai , Du Han , He Qingzhong , Wang Zheng‐Yuan 
Published: November 2019

AbstractBackgroundThe congenital stationary night blindness (CSNB) affects the patients' dim light vision or dark adaption by impairing the normal function of retina. It is a clinically and genetically heterogeneous disorder and can be inherited in an X‐linked, autosomal dominant or autosomal recessive pattern. Several genetic alterations to the genes involved in visual signal transduction of photoreceptors and/or bipolar cells underlie its pathogenesis.MethodsIn this study, we used Sanger sequencing and next‐generation sequencing (NGS)‐based gene panel screening to investigate a family of three patients with CSNB inherited in an apparent autosomal dominant pattern. We expected to find out the disease‐causing gene defects carried by this family.ResultsWe found that the patients in this family did not carry the RHO, GNAT1, or PDE6B mutation, but carried compound heterozygotes mutations of GRM6. Three deleterious GRM6 variants, p.Arg621Ter, p.Gly51Val, and p.Gly464Arg, were found to be co‐segregating with the disease, causing a pseudodominant inheritance of GRM6‐related autosomal recessive complete CSNB.ConclusionThis study presents a rare case of autosomal recessive CSNB (arCSNB) pseudodominant inheritance, which potentially leads us to expand our gene candidate list in future genetic testing for apparent dominant pedigrees. The discovery of the two novel likely pathogenic variants p.Gly51Val and p.Gly464Arg could broaden our knowledge about the genetics of CSNB and provide insights into the structure and function of the GRM6 protein.