bluuebunny/crossref_metadata_2025 huggingface dataset:
Dry season diet composition of four-horned antelopeTetracerus quadricornisin tropical dry deciduous forests, Nepal
Authors: Oli Chet Bahadur , Panthi Saroj , Subedi Naresh , Ale Gagan , Pant Ganesh , Khanal Gopal , Bhattarai Suman
Published: June 2018

It is essential to assess the feeding strategies of threatened species during resource-scarce seasons to understand their dietary niche breadth and inform appropriate habitat management measures. In this study, we examined the diet composition of four-horned antelope (FHA)Tetracerusandquadricornis, one of the least studied ungulate species, in Banke National Park, Nepal. A total of 53 fresh pellet groups were collected between December 2015 and January 2016 and analyzed using micro-histological fecal analysis technique. First, we prepared 133 micro-histological photographs of different parts of 64 reference plant species. Then we compared 1,590 fragments of 53 fecal samples with photographs of reference plants to assess the percentage of occurrence of different plant species in FHA diet. A total of 30 plant species belonging to 18 different families were identified in fecal samples. Chi-square goodness of fit tests showed that FHA appeared not to feed all plant uniformly. Out of 1,520 identified fragments in fecal samples, 1,300 were browse species and 220 were grass species. Browse represented 85.5% of the identified plant fragments, suggesting that FHA might be adopting a browser strategy at least during winter when grasses are low in abundance and their nutritive quality is poor. Tree species had the highest contribution in the diet (46.55%) followed by shrubs (24.52%). The family Gramineae was consumed in the highest proportion (27.68%) followed by Euphorbiaceae (11.95%). Overall, our results suggest that FHA has the feeding plasticity to adapt to resource fluctuation. Based on the findings of this study, we recommend that dicot plant species—particularly fruit trees and shrubs, which are the major source of nutrients for FHA during resource-lean, dry season—be conserved and natural regeneration of these taxa be promoted.
Forecasting influenza epidemics by integrating internet search queries and traditional surveillance data with the support vector machine regression model in Liaoning, from 2011 to 2015
Authors: Liang Feng , Guan Peng , Wu Wei , Huang Desheng
Published: June 2018

Background

Influenza epidemics pose significant social and economic challenges in China. Internet search query data have been identified as a valuable source for the detection of emerging influenza epidemics. However, the selection of the search queries and the adoption of prediction methods are crucial challenges when it comes to improving predictions. The purpose of this study was to explore the application of the Support Vector Machine (SVM) regression model in merging search engine query data and traditional influenza data.

Methods

The official monthly reported number of influenza cases in Liaoning province in China was acquired from the China National Scientific Data Center for Public Health from January 2011 to December 2015. Based on Baidu Index, a publicly available search engine database, search queries potentially related to influenza over the corresponding period were identified. An SVM regression model was built to be used for predictions, and the choice of three parameters (C, γ, ε) in the SVM regression model was determined by leave-one-out cross-validation (LOOCV) during the model construction process. The model’s performance was evaluated by the evaluation metrics including Root Mean Square Error, Root Mean Square Percentage Error and Mean Absolute Percentage Error.

Results

In total, 17 search queries related to influenza were generated through the initial query selection approach and were adopted to construct the SVM regression model, including nine queries in the same month, three queries at a lag of one month, one query at a lag of two months and four queries at a lag of three months. The SVM model performed well when with the parameters (C = 2, γ = 0.005, ɛ = 0.0001), based on the ensemble data integrating the influenza surveillance data and Baidu search query data.

Conclusions

The results demonstrated the feasibility of using internet search engine query data as the complementary data source for influenza surveillance and the efficiency of SVM regression model in tracking the influenza epidemics in Liaoning.
Hi-MC: a novel method for high-throughput mitochondrial haplogroup classification
Authors: Smieszek Sandra , Mitchell Sabrina L. , Farber-Eger Eric H. , Veatch Olivia J. , Wheeler Nicholas R. , Goodloe Robert J. , Wells Quinn S. , Murdock Deborah G. , Crawford Dana C.
Published: June 2018

Effective approaches for assessing mitochondrial DNA (mtDNA) variation are important to multiple scientific disciplines. Mitochondrial haplogroups characterize branch points in the phylogeny of mtDNA. Several tools exist for mitochondrial haplogroup classification. However, most require full or partial mtDNA sequence which is often cost prohibitive for studies with large sample sizes. The purpose of this study was to develop Hi-MC, a high-throughput method for mitochondrial haplogroup classification that is cost effective and applicable to large sample sizes making mitochondrial analysis more accessible in genetic studies. Using rigorous selection criteria, we defined and validated a custom panel of mtDNA single nucleotide polymorphisms that allows for accurate classification of European, African, and Native American mitochondrial haplogroups at broad resolution with minimal genotyping and cost. We demonstrate that Hi-MC performs well in samples of European, African, and Native American ancestries, and that Hi-MC performs comparably to a commonly used classifier. Implementation as a software package in R enables users to download and run the program locally, grants greater flexibility in the number of samples that can be run, and allows for easy expansion in future revisions. Hi-MC is available in the CRAN repository and the source code is freely available at https://github.com/vserch/himc.
Revealing the Mechanics of Helicoidal Composites through Additive Manufacturing and Beetle Developmental Stage Analysis
Authors: Zaheri Alireza , Fenner Joel S. , Russell Benjamin P. , Restrepo David , Daly Matthew , Wang Di , Hayashi Cheryl , Meyers Marc A. , Zavattieri Pablo D. , Espinosa Horacio D.
Published: June 2018

Investigation into the microstructure of high performance natural materials has revealed common patterns that are pervasive across animal species. For example, the helicoid motif has gained significant interest in the biomaterials community, where recent studies have highlighted its role in enabling damage tolerance in a diverse set of animals. Moreover, the helicoid motif corresponds to a highly adaptable architecture where the control of the pitch rotation angle between fibrous structures produces large changes in its mechanical response. Nature, takes advantage of this special feature enabling an active response to particular biological needs occurring during an animal's ontogeny. In this work, we demonstrate this adaptive behavior in helicoidal architectures by performing a mechanistic analysis of the changes occurring in the cuticle of the figeater beetle (Cotinis mutabilis) during its life cycle. We complement our investigation of the beetle with the testing of 3D printing samples and a systematic analysis of the effect of pitch angle in the inherent mechanics of helicoidal architectures. Experimentation and analysis reveal improved isotropy and enhanced toughness at lower pitch angles, highlighting the flexibility of the helicoidal architecture. Moreover, trends in stiffness measurements were found to be well‐predicted by laminate theory, suggesting facile mechanics laws for use in biomimicry.
Bioinspired Mineral–Organic Bioresorbable Bone Adhesive
Authors: Kirillova Alina , Kelly Cambre , von Windheim Natalia , Gall Ken
Published: June 2018

Bioresorbable bone adhesives have potential to revolutionize the clinical treatment of the human skeletal system, ranging from the fixation and osteointegration of permanent implants to the direct healing and fusion of bones without permanent fixation hardware. Despite an unmet need, there are currently no bone adhesives in clinical use that provide a strong enough bond to wet bone while possessing good osteointegration and bioresorbability. Inspired by the sandcastle worm that creates a protective tubular shell around its body using a proteinaceous adhesive, a novel bone adhesive is introduced, based on tetracalcium phosphate and phosphoserine, that cures in minutes in an aqueous environment and provides high bone‐to‐bone adhesive strength. The new material is measured to be 10 times more adhesive than bioresorbable calcium phosphate cement and 7.5 times more adhesive than non‐resorbable poly(methyl methacrylate) bone cement, both of which are standard of care in the clinic today. The bone adhesive also demonstrates chemical adhesion to titanium approximately twice that of its adhesion to bone, unlocking the potential for adherence to metallic implants during surrounding bony incorporation. Finally, the bone adhesive is shown to demonstrate osteointegration and bioresorbability over a 52‐week period in a critically sized distal femur defect in rabbits.
Topography Tuning for Plasmonic Color Enhancement via Picosecond Laser Bursts
Authors: Guay Jean‐Michel , Calà Lesina Antonino , Baxter Joshua , Killaire Graham , Ramunno Lora , Berini Pierre , Weck Arnaud
Published: June 2018

The tuning of 3D topographical features on silver for the production of plasmonic colors is reported. The topography is produced by applying closely time‐spaced laser bursts. Using laser bursts increases the Chroma of the colors produced by up to 100% compared to the nonburst coloring method. By adjusting the energy distribution of the laser pulses in a burst, while maintaining the total burst energy constant, significantly different color palettes and topographical structures are produced. Scanning electron microscope analysis of the surfaces produced reveals the creation of three distinct sets of laser‐induced periodic‐like surface structures (LIPSS): low spatial frequency LIPSS (LSFL), high spatial frequency LIPSS (HSFL), and large LIPSS that have a period about 7× that of the laser wavelength. Two‐temperature model simulations of silver irradiated by a laser burst show a significant increase in the electron–phonon coupling which is mainly responsible for the creation of LIPSS. Finite‐difference time‐domain simulations of a model of the surface, consisting of nanoparticles arranged on a sinusoidal‐modulated surface of varying amplitude (0 to 150 nm) and period (200 and 1000 nm), elucidate the importance of the HSFL and LSFL structures for color formation, including the increase in Chroma (saturation) observed experimentally.
Ultrafast Multilevel Optical Tuning with CSb2Te3 Thin Films
Authors: Meng Yun , Behera Jitendra K. , Wen Shuai , Simpson Robert E. , Shi Jianjun , Wu Liangcai , Song Zhitang , Wei Jingsong , Wang Yang
Published: June 2018

Tunable and reconfigurable functionalities are crucial for advanced photonic devices. In this study, CSb2Te3 is proposed as a new optical tuning material. Single‐shot picosecond laser pulses are used to transform the CSb2Te3 into six different optical states; each optical state can be achieved from any other state. The dielectric function for each optical state is unique and the switching is achieved on a picosecond time scale. The impact of the crystal structure on the optical tuning mechanism is studied using transmission electron microscopy and density functional theory. Second harmonic generation in the CSb2Te3 films indicates that the crystal orientation for the switched layer is influenced by the pump laser polarization. Thus electric field may provide a further degree of freedom to design phase change materials.
Bright Polariton Coumarin‐Based OLEDs Operating in the Ultrastrong Coupling Regime
Authors: Genco Armando , Ridolfo Alessandro , Savasta Salvatore , Patanè Salvatore , Gigli Giuseppe , Mazzeo Marco
Published: June 2018

Organic microcavities in strong and ultrastrong light–matter coupling regimes allow the exploration of intriguing quantum phenomena, such as Bose–Einstein condensation of exciton‐polaritons, even at room temperature. Nevertheless, electrically driven organic polariton devices have shown so far poor performances, insufficient for practical applications, mainly due to the lack of an effective approach to exploit the molecular properties in order to optimize the population mechanism of polariton states. Here, novel bright polariton organic light‐emitting diodes (OLED) are reported based on a coumarin dye, which showed coupling strengths up to 37%, entering in the ultrastrong coupling regime. Owing to a high molecular emission efficiency, a large Stokes shift, and a fine cavity‐exciton tuning, the radiative pumping mechanism of polariton states has been fully optimized, leading a large portion of excitons to be converted in polariton emission. The resulting polariton OLEDs showed external quantum efficiencies up to 0.2% and maximum luminance of 700 cd m−2, which are, to the best of our knowledge, the highest values reported so far for this class of devices. Furthermore, the findings give clear indications for an effective exploitation of organic polariton dynamics toward the development of novel optoelectronic devices.
Efficient Synthesis of Phthalimides via Cobalt‐Catalyzed C(sp2)−H Carbonylation of Benzoyl Hydrazides with Carbon Monoxide
Authors: Qiu Shuxian , Zhai Shengxian , Wang Huifei , Tao Cheng , Zhao Hua , Zhai Hongbin
Published: June 2018

A cobalt‐catalyzed C−H carbonylation of benzoyl hydrazides has been developed by using 2‐(1‐methylhydrazinyl)pyridine as the bidentate directing group. This transformation is mild, efficient, operationally simple, and highly functional‐group‐tolerant. The protocol has generated a broad range of phthalimide derivatives in good to excellent yields. The ligand moiety can be readily removed through hydrogenolysis.

magnified image
Novel 2D Sb2S3 Nanosheet/CNT Coupling Layer for Exceptional Polysulfide Recycling Performance
Authors: Yao Shanshan , Cui Jiang , Huang Jian‐Qiu , Lu Ziheng , Deng Yang , Chong Woon Gie , Wu Junxiong , Ihsan Ul Haq Muhammad , Ciucci Francesco , Kim Jang‐Kyo
Published: June 2018

2D layer‐structured materials are considered a promising candidate as a coupling material in lithium sulfur batteries (LSBs) due to their high surface‐volume ratio and abundant active binding sites, which can efficiently mitigate shuttling of soluble polysulfides. Herein, an electrochemical Li intercalation and exfoliation strategy is used to prepare 2D Sb2S3 nanosheets (SSNSs), which are incorporated onto a separator in LSBs as a new 2D coupling material for the first time. The cells containing a rationally designed separator which is coated with an SSNS/carbon nanotube (CNT) coupling layer deliver a much improved specific capacity with a remarkable 0.05% decay rate for over 200 cycles at a current density of 2 C. The capability of the SSNSs to entrap polysulfides through their favorable interfacial functionality and the high electrical conductivity of the CNT network facilitates recycling of active materials. The first‐principle calculations verify the important roles of SSNSs, which demonstrate ideal binding strengths (1.33–2.14 eV) to entrap Li2Sx as well as a low‐energy barrier (189 meV) for Li diffusion. These findings offer new insights into discovering novel coupling layers for high‐performance LSBs and shed new light on the application of 2D layer‐structured materials in energy storage systems.
Rational Architecture Design Enables Superior Na Storage in Greener NASICON‐Na4MnV(PO4)3 Cathode
Authors: Li Huangxu , Jin Ting , Chen Xiaobin , Lai Yanqing , Zhang Zhian , Bao Weizhai , Jiao Lifang
Published: June 2018

Na3V2(PO4)3 has attracted great attention due to its high energy density and stable structure. However, in order to boost its application, the discharge potential of 3.3–3.4 V (vs Na+/Na) still needs to be improved and substitution of vanadium with other lower cost and earth‐abundant active redox elements is imperative. Therefore, the Na superionic conductor (NASICON)‐structured Na4MnV(PO4)3 seems to be more attractive due to its lower toxicity and higher voltage platform resulting from the partial substitution of V with Mn. However, Na4MnV(PO4)3 still suffers from poor electronic conductivity, leading to unsatisfactory capacity delivering and poor high‐rate capability. In this work, a graphene aerogel–supported in situ carbon–coated Na4MnV(PO4)3 material is synthesized through a feasible solution‐route method. The elaborately designed Na4MnV(PO4)3 can reach ≈380 Wh kg−1 at 0.5 C (1 C = 110 mAh g−1) and realize superior high‐rate capability evenat 50 C (60.1 mAh g−1) with a long cycle‐life of 4000 cycles at 20 C. This impressive progress should be ascribed to the multifunctional 3D carbon framework and the distinctive structure of trigonal Na4MnV(PO4)3, which are deeply investigated by both experiments and calculations.
A novel evaluation of density differences in subcutaneous abdominal adipose tissue layers in pregnancy using elastography
Authors: Kennedy Narelle , Quinton Ann , Peek Michael John , Robledo Kristy , Benzie Ron , Nanan Ralph
Published: June 2018

Introduction

Chronic inflammation leads to adipose tissue (AT) fibrosis through excessive accumulation of extracellular matrix proteins. An increasing degree of fibrosis in AT is associated with increasing body mass index (BMI) and insulin resistance. Anecdotally AT has been observed to vary with ease of ultrasound penetration on medical examinations. Ultrasound strain elastography (SE) is a useful tool in assessing fibrosis in liver disease but has not previously been used to assess AT fibrosis. This study assesses the variance in density of the two anatomical layers of subcutaneous AT, superficial subcutaneous adipose tissue (SSAT) and deep subcutaneous adipose tissue (DSAT) in pregnancy using SE.

Method

Women (n = 210) recruited in early pregnancy. Density of SSAT and DSAT were assessed using SE at five‐time points throughout pregnancy and post‐partum. Semi‐quantitative density measures were achieved using two methods, strain values (SV) of the two layers and ImageJ software to calculate the percentage colour pixels in the elastography image and correlated with the SSAT/DSAT thickness and BMI.

Results

Adipose tissue demonstrated a difference in density with the SSAT layer being denser than DSAT. Correlation of tissue density measures with BMI was poor. There was slight change of AT density during pregnancy with a tendency towards harder SSAT and softer DSAT in the third trimester. Post‐partum SSAT became softer associated with an increase in SSAT thickness.

Conclusion

Elastography demonstrated density differences in adipose tissue. SE is a new method of assessing the AT demonstrating density differences in adipose tissue. Information on AT density may determine AT fibrosis and be valuable for metabolic disease risk.
Thinking Outside the Box—Novel Antibacterials To Tackle the Resistance Crisis
Authors: Lakemeyer Markus , Zhao Weining , Mandl Franziska A. , Hammann Peter , Sieber Stephan A.
Published: June 2018

The public view on antibiotics as reliable medicines changed when reports about “resistant superbugs” appeared in the news. While reasons for this resistance development are easily spotted, solutions for re‐establishing effective antibiotics are still in their infancy. This Review encompasses several aspects of the antibiotic development pipeline from very early strategies to mature drugs. An interdisciplinary overview is given of methods suitable for mining novel antibiotics and strategies discussed to unravel their modes of action. Select examples of antibiotics recently identified by using these platforms not only illustrate the efficiency of these measures, but also highlight promising clinical candidates with therapeutic potential. Furthermore, the concept of molecules that disarm pathogens by addressing gatekeepers of virulence will be covered. The Review concludes with an evaluation of antibacterials currently in clinical development. Overall, this Review aims to connect select innovative antimicrobial approaches to stimulate interdisciplinary partnerships between chemists from academia and industry.
Self‐Assembly of Functional Discrete Three‐Dimensional Architectures in Water
Authors: Taylor Lauren L. K. , Riddell Imogen A. , Smulders Maarten M. J.
Published: June 2018

Construction of discrete, self‐assembled architectures in water has gained significant interest in recent years as a wide range of applications arises from their defined 3D structure. In this review we jointly discuss the efforts of supramolecular chemists and biotechnologists who previously worked independently, to tackle discipline‐specific challenges associated with construction of assemblies from synthetic and bio‐derived components, respectively. Going forward, a more interdisciplinary research approach will expedite development of complexes with real‐world applications that exploit the benefits of compartmentalisation. In support of this, we summarise advances made in the development of discrete, water‐soluble assemblies, with particular focus on their current and prospective applications. Areas where understanding and methodologies can be transferred from one sector to the adjacent field are highlighted in anticipation this will yield advances not possible from either field alone.
Untangling the mechanism of 3‐methyladenine in enhancing the specific productivity: Transcriptome analysis of recombinant Chinese hamster ovary cells treated with 3‐methyladenine
Authors: Baek Eric , Lee Jae Seong , Lee Gyun Min
Published: June 2018

3‐Methyladenine (3‐MA) is a chemical additive that enhances the specific productivity (q
p) in recombinant Chinese hamster ovary (rCHO) cell lines. Different from its widely known function of inhibiting autophagy, 3‐MA has instead shown to increase autophagic flux in various rCHO cell lines. Thus, the mechanism by which 3‐MA enhances the qp requires investigation. To evaluate the effect of 3‐MA on transcriptome dynamics in rCHO cells, RNA‐seq was performed with Fc‐fusion protein–producing rCHO cells treated with 3‐MA. By analyzing genes that were differentially expressed following the addition of 3‐MA during culture, the role of 3‐MA in the biological processes of rCHO cells was identified. One pathway markedly influenced by the addition of 3‐MA was the unfolded protein response (UPR). Having a close relationship with autophagy, the UPR reestablishes protein‐folding homeostasis under endoplasmic reticulum (ER) stress. The addition of 3‐MA increased the expression of key regulators of the UPR, such as Atf4, Ddit3, and Creb3l3, further supporting the idea that the enhancement of ER capacity acts as a key in increasing the qp. Consequently, the downstream effectors of UPR, which include autophagy‐promoting genes, were upregulated as well. Hence, the role of 3‐MA in increasing UPR pathway could have made a salient contribution to the increased autophagic flux in rCHO cells. Taken together, transcriptome analysis improved the understanding of the role of 3‐MA in gene expression dynamics in rCHO cells and its mechanism in enhancing the qp.
Topographical study of the connections of the rami communicantes from the first to the fifth thoracic sympathetic ganglia
Authors: Won Hyung‐Jin , Lee Jong Eun , Lee Won‐Taek , Won Hyung‐Sun
Published: June 2018

This study investigated the morphological variations and histological patterns of the rami communicantes (RCs) arising from the first to the fifth thoracic sympathetic ganglia, and considered the clinical significance of these variations. Fifty upper thoracic portions from 26 adult Korean cadavers were used in this study. There were 731 RCs arising from the first to the fifth thoracic sympathetic ganglia. They were classified into three types depending on the connection between the sympathetic ganglion and the intercostal nerves: in type I, the RCs connected the ganglion to the corresponding intercostal nerve, and in types II and III, respectively, they connected it to the nerve one level above or below the corresponding intercostal nerve. Some RCs of types I and II could not be observed without additional preliminary surgical procedures. Diverse combinations of RC types arose from the first to the fifth thoracic sympathetic ganglia, combinations of types I and III being the most common (70%) in the first sympathetic ganglion and those comprising only type I being most frequent in the other ganglia. The RCs could not be identified by the naked eye in either fresh or fixed cadavers, so they were confirmed on the basis of their histological appearance. These results are expected to improve knowledge of morphological variations of the RCs in the upper five thoracic sympathetic ganglia, and to provide helpful information for clinical management in this region. Clin. Anat. 31:1151–1157, 2018. © 2018 Wiley Periodicals, Inc.
Sb Nanoparticles Embedded in a Nitrogen‐Doped Carbon Matrix with Tuned Voids and Interfacial Bonds for High‐Rate Lithium Storage
Authors: Wang Zhen‐Zhen , Qu Jin , Hao Shu‐Meng , Zhang Yu‐Jiao , Kong Fan‐Qiang , Yang Dongzhi , Yu Zhong‐Zhen
Published: June 2018

Though metal based electrodes have good resistivity, their huge volume changes upon lithiation and interparticle contact resistance should be carefully stressed to achieve high rate lithium storage performances. A yolk‐hollow structure with a continuous conductive framework would solve above problems. Inspired by the yolk‐hollow structure and functions of watermelon‐flesh, we fabricated Sb/amorphous carbon/graphene nanocomposites, in which Sb nanoparticles are formed in‐situ inside the carbon nanocages that are homogeneously decorated on graphene and distributed in a continuous N‐doped amorphous carbon matrix. The generated Sb−O−C bonds improve the electron transfer rate; the carbon nanocages as mini‐electrochemical nanoreactors sustain the volume change; the conductive matrix reduces the contact resistance. The optimized nanocomposite delivers a remarkable reversible capacity of 592 mA h g−1 at 500 mA g−1 with a good cyclability for 400 cycles. A high capacity of 413 mA h g−1 is retained even after 700 cycles at 1000 mA g−1. Such a long cycle life at the high current density has rarely been reported so far for Sb‐based lithium‐ion battery anodes.
A comparative study of full‐duplex relaying schemes for low latency applications
Authors: Airod Fatima Ezzahra , Chafnaji Houda , Tamtaoui Ahmed
Published: June 2018

Various sectors are likely to carry a set of emerging applications while targeting a reliable communication with low latency transmission. To address this issue, upon a spectrally‐efficient transmission, this paper investigates the performance of a 1 full‐dulpex relay system and considers for that purpose, 2 basic relaying schemes, namely, the symbol‐by‐symbol transmission, i.e., amplify‐and‐forward and the block‐by‐block transmission, i.e., selective decode‐and‐forward. The conducted analysis presents an exhaustive comparison, covering both schemes, over 2 different transmission modes, i.e., the noncombining mode where the best link, direct, or relay link is decoded and the signals combining mode, where direct and relay links are combined at the receiver side. While targeting latency purpose as a necessity, simulations show a refined results of performed comparisons and reveal that amplify‐and‐forward relaying scheme is more adapted to combining mode, whereas the selective decode‐and‐forward relaying scheme is more suitable for noncombining mode.
Energy‐spectrum‐efficient three‐tier heterogeneous networks with D2D harvesting energy and uplink coverage analysis
Authors: Ji Shanshan , Jia Xiangdong , Fan Qiaoling , Xie Mangang , Zhou Meng
Published: June 2018

To guard the communication quality of cell edge users (CEUs) and simultaneously improve the energy‐spectrum efficiency, a novel 3‐tier heterogeneous network (HetNet) model is proposed, which consists of macro cells, femtocells, and device‐to‐device (D2D) networks. Specially, with a predefined cell split factor R, the macro cell users are split into as cell center users (CCUs) and CEUs, respectively. Correspondingly, the total available spectrum band consisting of N channels is divided into CCU band and CEU band with a given coefficient pm. The CCU band containing pmN subchannels is shared by CCUs and femtocell users (FUs), and the CEU band containing (1 − pm) N subchannels is shared by D2D users and CEUs. The perfect network synchronization is assumed, and a communication round consists of downlink transmission and uplink transmission phases. The battery‐free D2D terminals harvest energy from the ambient radio frequency interference in the downlink transmission phase based on inverse power control scheme and communicate in the uplink transmission phase only when they harvest enough energy to perform channel inversion toward the receiver. For such 3‐tier HetNets, by modeling the network elements as independent Poisson point processes (PPPs) and using stochastic geometry method, we first investigate the sufficiency probability that a D2D transmitter harvests enough energy to establish a communication link. Then, by combining sufficiency probability and channel access probability, the thinned independent PPPs for the locations of CCUs, CEUs, FUs, and D2D users are modeled. Based on these thinned PPP models, we perform a comprehensive investigation on the coverage probabilities of CCU, CEU, and FU uplinks as well as the D2D transmission. The simulated and numerical results show that using the presented cell split strategy enhances the performance of CCUs and CEUs because of the decrease of interference. The presented comparison analysis displays that the effect of D2D networks on the macro cell or the whole HetNets is limited and can be omitted. Therefore, the energy and spectrum efficiencies of networks are enhanced, simultaneously. At the same time, our results indicate that by using our derivations, we can perform the optimal design of the HetNets.
Learning is what it is all about
Authors: Hodges Dawn Z.
Published: June 2018

Jason Allaire, an enrollment counselor with ­Cornerstone University Professional and Graduate Studies, writes, “Students are now much more interested in interactive and self‐guided approaches [to learning]. With so much information online and available for free, universities and colleges are restructuring curricula to stay current and equip students to work with emerging technologies,” in the blog post “Five Issues Facing Higher Education in 2018.”
Understand your institution's responsibilities under the General Data Protection Regulations
Authors: Sutton Halley
Published: June 2018

If international students from the European Union interact with any part of your website, your institution is subject to the E.U.'s comprehensive privacy rules, the General Data Protection Regulations, which went into effect May 25, 2018. The American Association of Collegiate Registrars and Admissions Officers, along with partners including the Council for Advancement and Support of Education and Educause, has released a guide to help navigate GDPR compliance.
Personalize online learning for a high‐quality learning experience
Authors: Hope Joan
Published: June 2018

“We have a stong belief that online learning can be impactful,” said Paul Krause, chief executive officer of eCornell and associate vice provost of online learning at Cornell University. He was describing eCornell's focus on providing personalized, high‐touch online education.
Influence of drought on plant performance through changes in belowground tritrophic interactions
Authors: Guyer Anouk , Hibbard Bruce E. , Holzkämper Annelie , Erb Matthias , Robert Christelle A. M.
Published: June 2018

Climate change is predicted to increase the risk of drought in many temperate agroecosystems. While the impact of drought on aboveground plant‐herbivore‐natural enemy interactions has been studied, little is known about its effects on belowground tritrophic interactions and root defense chemistry. We investigated the effects of low soil moisture on the interaction between maize, the western corn rootworm (WCR,Diabrotica virgifera), and soil‐borne natural enemies ofWCR. In a manipulative field experiment, reduced soil moisture andWCRattack reduced plant performance and increased benzoxazinoid levels. The negative effects ofWCRon cob dry weight and silk emergence were strongest at low moisture levels. Inoculation with entomopathogenic nematodes (EPNs,Heterorhabditis bacteriophora) was ineffective in controllingWCR, and theEPNs died rapidly in the warm and dry soil. However, ants of the speciesSolenopsis molestainvaded the experiment, were more abundant inWCR‐infested pots and predatedWCRindependently of soil moisture. Ant presence increased root and shoot biomass and was associated with attenuated moisture‐dependent effects ofWCRon maize cob weight. Our study suggests that apart from directly reducing plant performance, drought can also increase the negative effects of root herbivores such asWCR. It furthermore identifiesS. molestaas a natural enemy ofWCRthat can protect maize plants from the negative impact of herbivory under drought stress. Robust herbivore natural enemies may play an important role in buffering the impact of climate change on plant‐herbivore interactions.
Plastic responses to competition: Does bacteriocin production increase in the presence of nonself competitors?
Authors: Bhattacharya Amrita , Pak Hannah Tae‐Young , Bashey Farrah
Published: June 2018

Anticompetitor traits such as the production of allelopathic toxins can confer significant competitive benefits but are often costly to produce. Evolution of these traits may be facilitated by environment‐specific induction; however, the extent to which costly anticompetitor traits are induced by competitors is not well explored. Here, we addressed this question using bacteriocins, which are highly specific, proteinaceous anticompetitor toxins, produced by most lineages of bacteria and archaea. We tested the prediction that bacteriocin production is phenotypically plastic and induced by the presence of competitors by examining bacteriocin production in the presence and absence of nonself competitors over the course of growth of a producing strain. Our results show that bacteriocin production is detectable only at high cell densities, when competition for resources is high. However, the amount of bacteriocin activity was not significantly different in the presence vs. the absence of nonself competitors. These results suggest that bacteriocin production is either (a) canalized, constitutively produced by a fixed frequency of cells in the population or (b) induced by generic cues of competition, rather than specific self/nonself discrimination. Such a nonspecific response to competition could be favored in the natural environment where competition is ubiquitous.
Scaling marine fish movement behavior from individuals to populations
Authors: Griffiths Christopher A. , Patterson Toby A. , Blanchard Julia L. , Righton David A. , Wright Serena R. , Pitchford Jon W. , Blackwell Paul G.
Published: June 2018

Understanding how, where, and when animals move is a central problem in marine ecology and conservation. Key to improving our knowledge about what drives animal movement is the rising deployment of telemetry devices on a range of free‐roaming species. An increasingly popular way of gaining meaningful inference from an animal's recorded movements is the application of hidden Markov models (HMMs), which allow for the identification of latent behavioral states in the movement paths of individuals. However, the use of HMMs to explore the population‐level consequences of movement is often limited by model complexity and insufficient sample sizes. Here, we introduce an alternative approach to current practices and provide evidence of how the inclusion of prior information in model structure can simplify the application of HMMs to multiple animal movement paths with two clear benefits: (a) consistent state allocation and (b) increases in effective sample size. To demonstrate the utility of our approach, we apply HMMs and adapted HMMs to over 100 multivariate movement paths consisting of conditionally dependent daily horizontal and vertical movements in two species of demersal fish: Atlantic cod (Gadus morhua; n = 46) and European plaice (Pleuronectes platessa; n = 61). We identify latent states corresponding to two main underlying behaviors: resident and migrating. As our analysis considers a relatively large sample size and states are allocated consistently, we use collective model output to investigate state‐dependent spatiotemporal trends at the individual and population levels. In particular, we show how both species shift their movement behaviors on a seasonal basis and demonstrate population space use patterns that are consistent with previous individual‐level studies. Tagging studies are increasingly being used to inform stock assessment models, spatial management strategies, and monitoring of marine fish populations. Our approach provides a promising way of adding value to tagging studies because inferences about movement behavior can be gained from a larger proportion of datasets, making tagging studies more relevant to management and more cost‐effective.
Best hyperspectral indices for assessing leaf chlorophyll content in a degraded temperate vegetation
Authors: Peng Yu , Fan Min , Wang Qinghui , Lan Wenjuan , Long Yating
Published: June 2018

Extensive studies have focused on assessing leaf chlorophyll content through spectral indices; however, the accuracy is weakened by limited wavebands and coarse resolution. With hundreds of wavebands, hyperspectral data can substantially capture the essential absorption features of leaf chlorophyll; however, few such studies have been conducted on same species in various degraded vegetations. In this investigation, complete combinations of either original reflectance or first‐order derivative spectra we conducted a complete combination on either original reflectance or its first‐order derivative value from 350 to 1000 nm to quantify leaf total chlorophyll (Chll), chlorophyll‐a (Chla), and chlorophyll‐b (Chlb) contents. This was performed using three hyperspectral datasets collected in situ from lightly, moderately, and severely degraded vegetations in temperate Helin County, China. Suitable combinations were selected by comparing the numbers of significant correlation coefficients with leaf Chll, Chla, and Chlb contents. The combinations of reflectance difference (Dij), normalized differences (ND), first‐order derivative (FD), and first‐order derivative difference (FD(D)) were found to be the most effective. These sensitive band‐based combinations were further optimized by means of a stepwise linear regression analysis and were compared with 43 empirical spectral indices, frequently used in the literature. These sensitive band‐based combinations on hyperspectral data proved to be the most effective indices for quantifying leaf chlorophyll content (R2 > 0.7, p < 0.01), demonstrating great potential for the use of hyperspectral data in monitoring degraded vegetation at a fine scale.
Discovery of a multispecies shark aggregation and parturition area in the Ba Estuary, Fiji Islands
Authors: Vierus Tom , Gehrig Stefan , Brunnschweiler Juerg M. , Glaus Kerstin , Zimmer Martin , Marie Amandine D. , Rico Ciro
Published: June 2018

Population declines in shark species have been reported on local and global scales, with overfishing, habitat destruction and climate change posing severe threats. The lack of species‐specific baseline data on ecology and distribution of many sharks, however, makes conservation measures challenging. Here, we present a fisheries‐independent shark survey from the Fiji Islands, where scientific knowledge on locally occurring elasmobranchs is largely still lacking despite the location's role as a shark hotspot in the Pacific. Juvenile shark abundance in the fishing grounds of the Ba Estuary (north‐western Viti Levu) was assessed with a gillnet‐ and longline‐based survey from December 2015 to April 2016. A total of 103 juvenile sharks identified as blacktip Carcharhinus limbatus (n = 57), scalloped hammerhead Sphyrna lewini (n = 35), and great hammerhead Sphyrna mokarran (n = 11) sharks were captured, tagged, and released. The condition of umbilical scars (68% open or semihealed), mean sizes of individuals (±SD) (C. limbatus: 66.5 ± 3.8 cm, S. lewini: 51.8 ± 4.8 cm, S. mokarran 77.4 ± 2.8 cm), and the presence of these species over recent years (based on fishermen interviews), suggest that the Ba Estuary area is a critical habitat for multiple species that are classified as “Near Threatened” or “Endangered.” Specifically, the area likely acts as a parturition ground over the studied period, and potentially as a subsequent nursery area. We identified subareas of high abundance and found that temperature, salinity and depth acted as small‐scale environmental drivers of shark abundance. The data suggests a tendency for species‐specific spatial use, both horizontally (i.e., between sampling areas) and vertically (i.e., across the water column). These results enhance the understanding of shark ecology in Fiji and provide a scientific basis for the implementation of local conservation strategies that contribute to the protection of these threatened species.
Gene flow and Andean uplift shape the diversification of Gasteracantha cancriformis (Araneae: Araneidae) in Northern South America
Authors: Salgado‐Roa Fabian C. , Pardo‐Diaz Carolina , Lasso Eloisa , Arias Carlos F. , Solferini Vera Nisaka , Salazar Camilo
Published: June 2018

The Andean uplift has played a major role in shaping the current Neotropical biodiversity. However, in arthropods other than butterflies, little is known about how this geographic barrier has impacted species historical diversification. Here, we examined the phylogeography of the widespread color polymorphic spider Gasteracantha cancriformis to evaluate the effect of the northern Andean uplift on its divergence and assess whether its diversification occurred in the presence of gene flow. We inferred phylogenetic relationships and divergence times in G. cancriformis using mitochondrial and nuclear data from 105 individuals in northern South America. Genetic diversity, divergence, and population structure were quantified. We also compared multiple demographic scenarios for this species using a model‐based approach (Phrapl) to determine divergence with or without gene flow. At last, we evaluated the association between genetic variation and color polymorphism. Both nuclear and mitochondrial data supported two well‐differentiated clades, which correspond to populations occurring on opposite sides of the Eastern cordillera of the Colombian Andes. The final uplift of this cordillera was identified as the most likely force that shaped the diversification of G. cancriformis in northern South America, resulting in a cis‐ and trans‐Andean phylogeographic structure for the species. We also found shared genetic variation between the cis‐ and trans‐Andean clades, which is better explained by a scenario of historical divergence in the face of gene flow. This has been likely facilitated by the presence of low‐elevation passes across the Eastern Colombian cordillera. Our work constitutes the first example in which the Andean uplift coupled with gene flow influenced the evolutionary history of an arachnid lineage.
The future of cold‐adapted plants in changing climates: Micranthes (Saxifragaceae) as a case study
Authors: Stubbs Rebecca L. , Soltis Douglas E. , Cellinese Nico
Published: June 2018

Research has shown species undergoing range contractions and/or northward and higher elevational movements as a result of changing climates. Here, we evaluate how the distribution of a group of cold‐adapted plant species with similar evolutionary histories changes in response to warming climates. We selected 29 species of Micranthes (Saxifragaceae) representing the mountain and Arctic biomes of the Northern Hemisphere. For this analysis, 24,755 data points were input into ecological niche models to assess both present fundamental niches and predicted future ranges under climate change scenarios. Comparisons were made across the Northern Hemisphere between all cold‐adapted Micranthes, including Arctic species, montane species, and species defined as narrow endemics. Under future climate change models, 72% of the species would occupy smaller geographical areas than at present. This loss of habitat is most pronounced in Arctic species in general, but is also prevalent in species restricted to higher elevations in mountains. Additionally, narrowly endemic species restricted to high elevations were more susceptible to habitat loss than those species found at lower elevations. Using a large dataset and modeling habitat suitability at a global scale, our results empirically model the threats to cold‐adapted species as a result of warming climates. Although Arctic and alpine biomes share many underlying climate similarities, such as cold and short growing seasons, our results confirm that species in these climates have varied responses to climate change and that key abiotic variables differ between these two habitats.
A genetic analysis of dragonfly population structure
Authors: Phillips Payton , Swanson Bradley J.
Published: June 2018

Dragonflies reside in both aquatic and terrestrial environments, depending on their life stage, necessitating the conservation of drastically different habitats; however, little is understood about how nymph and adult dragonflies function as metapopulations within connected habitat. We used genetic techniques to examine nymphs and adults within a single metapopulation both spatially and temporally to better understand metapopulation structure and the processes that might influence said structure. We sampled 97 nymphs and 149 adult Sympetrum obtrusum from eight locations, four aquatic, and four terrestrial, at the Pierce Cedar Creek Institute in Southwest Michigan over two summers. We performed AFLP genetic analysis and used the Bayesian analysis program STRUCTURE to detect genetic clusters from sampled individuals. STRUCTURE detected k = u4 populations, in which nymphs and adults from the same locations collected in different years did not necessarily fall into the same clusters. We also evaluated grouping using the statistical clustering analyses NMDS and MRPP. The results of these confirmed findings from STRUCTURE and emphasized differences between adults collected in 2012 and all other generations. These results suggest that both dispersal and a temporal cycle of emergence of nymphs from unique clusters every other year could be influential in structuring dragonfly populations, although our methods were not able to fully distinguish the influences of either force. This study provides a better understanding of local dragonfly metapopulation structure and provides a starting point for future studies to investigate the spatial and temporal mechanisms controlling metapopulation structure. The results of the study should prove informative for managers working to preserve genetic diversity in connected dragonfly metapopulations, especially in the face of increasing anthropogenic landscape changes.