bluuebunny/crossref_metadata_2025 huggingface dataset:
Incidence and Prevalence of Major Adverse Cardiovascular Events in Rheumatoid Arthritis, Psoriatic Arthritis, and Axial Spondyloarthritis
Authors: Lauper Kim , Courvoisier Delphine S. , Chevallier Paola , Finckh Axel , Gabay Cem
Published: April 2018

Objective

To compare the risk of major adverse cardiovascular events (MACE) in a large observational cohort of patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA), or axial spondyloarthritis (SpA) patients.

Methods

We conducted a mixed retrospective and prospective cohort study using data from patients with RA, PsA, or axial SpA included in the Swiss Clinical Quality Management registry. The primary outcome of interest was a composite of myocardial infarction, transient or permanent cerebrovascular event, or cardiovascular‐associated death.

Results

A total of 5,315 patients were eligible for the analysis of incidence, with a total follow‐up time of 37,495 patient‐years for RA, 19,837 patient‐years for axial SpA, and 9,171 patient‐years for PsA. The unadjusted incidence rate of MACE per 1,000 patient‐years was 2.67 for RA, 1.41 for axial SpA, and 1.42 for PsA. Compared to the unadjusted incidence rate ratios (IRRs) in patients with RA, those in patients with axial SpA were 0.53 (95% confidence interval [95% CI] 0.34–0.80; P = 0.003) and in patients with PsA were 0.53 (95% CI 0.30–0.95; P = 0.03). After adjustment for traditional cardiovascular risk factors, age at disease onset, sex, and disease duration, the difference was not significant between RA and axial SpA (adjusted IRR 0.93 [95% CI 0.51–1.69]; P = 0.80) or between RA and PsA (adjusted IRR 0.56 [95% CI 0.27–1.14]; P = 0.11). We found a similar result with the analysis of prevalence.

Conclusion

There was no significant difference in the incidence and prevalence of MACE between RA and axial SpA or PsA, suggesting that inflammation, rather than a particular disease, drives the increased risk of cardiovascular disease.
Fuzzy adaptive leader‐following consensus of second‐order multiagent systems with imprecise communication topology structure
Authors: Chen Jiaxi , Li Junmin , Wu Hui
Published: April 2018

The consensus problem of second‐order nonlinear multiagent systems (MAS) with imprecise communication topology structure is addressed in this paper. Takagi‐Sugeno fuzzy models are presented to describe the leader‐following MAS with imprecise communication topology structure. By designing the distributed adaptive controller, an efficient framework is proposed for the consensus control of the MAS with both uncertain parameters and input disturbances. Under the conditions that the communication topology is fuzzy union connected and the dynamics of the leader agent is unknown to any agent of followers, the proposed protocol can guarantee that the consensus errors asymptotically approach zeros. Furthermore, the proposed algorithm is extended to solve the formation control problem. Sufficient conditions are given for the consensus and formation problems of the MAS based on the Lyapunov stability theory. Finally, a numerical example and multiple pendulum systems are given to illustrate the effectiveness of the proposed control protocols.
Copper‐Catalyzed Successive C−C bond formations on Indoles or Pyrrole: A Convergent Synthesis of Symmetric and Unsymmetric Hydroxyl Substituted N‐H Carbazoles
Authors: Qiao Yu , Wu Xin‐Xing , Zhao Yupeng , Sun Yongqing , Li Baoguo , Chen Shufeng
Published: April 2018

A novel copper‐catalyzed successive C−Cbond formations on indoles and pyrrole approach for the direct synthesis of hydroxyl substituted N‐H carbazoles is described. The current process represents an atom‐economical method for the preparation of both symmetric and unsymmetric densely substituted and hydroxyl containing N‐H carbazoles from easily accessible starting materials without the need for expensive metals and harsh reaction conditions.

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Morphology characterization and the phase separation behavior of UHMWPE/recycled‐PA6 blends using FTIR imaging and thermomechanical analysis
Authors: Yang Xiuying , Yuan Zhihua , Cheng Junye , Yan Eryun , Wang Wenbo , Zhang Deqing
Published: April 2018

Phase morphology and phase separation behavior are always important factors affecting polymer blends’ properties. Here, we employed FTIR imaging technique and thermomechanical analysis (TMA) to characterize the phase morphology and phase separation behavior of ultra‐high molecular weight polyethylene (UHMWPE)/recycled‐polyamide 6 (R‐PA6) blends, which were prepared via extrusion using high‐density polyethylene‐graft‐maleic anhydride (HDPE‐g‐MAH) as the compatibilizer. The crystallization and thermal properties of UHMWPE/R‐PA6/HDPE‐g‐MAH were discussed from the viewpoint of phase behavior of the blend. Morphology characterization and TMA analysis indicated that UHMWPE and R‐PA6 were thermodynamically incompatible phases, and R‐PA6 phase was continuous and UHMWPE phase was dispersed phased, respectively. X‐ray diffraction results showed that the interaction between the blending components adversely affected the crystal growth of the components, resulting in reduced crystallization in the blends. It was demonstrated that the morphology and phase separation behavior of the components affected the thermal properties of the blends.
Ecological niche modeling of the genus Papio
Authors: Fuchs Amanda J. , Gilbert Christopher C. , Kamilar Jason M.
Published: April 2018

Objective

Ecological niche modeling (ENM) has been used to assess how abiotic variables influence species distributions and diversity. Baboons are broadly distributed throughout Africa, yet the degree of climatic specialization is largely unexplored for individual taxa. Also, the influence of climate on baboon phylogenetic divergence is unknown. In this study, we constructed ENMs to investigate how niches vary across Papio species to understand how climatic variables have influenced their biogeography and mode of speciation.

Materials and Methods

We used Maxent to generate ENMs by collating locality data for six Papio species and climate information from WorldClim. In addition, we examined the degree of niche overlap among all possible pairs of taxa, which can provide insight into patterns of species diversity. Lastly, we conducted a Mantel test to assess the relationship between niche overlap and estimated time since divergence.

Results

Our models performed moderately to extremely well, with a mean area under the curve value of 0.868. The species with the best models include P. papio and P. kindae, whereas P. hamadryas had the poorest models. We found that most species pairs exhibited significantly different niches. Lastly, we found no significant correlation between niche overlap and divergence times.

Discussion

Niche models had good predictive power, which indicates Papio species distributions are correlated with climatic variables to varying degrees. Significantly little niche overlap and incomplete geographic boundaries suggests these models generally support a parapatric speciation scenario for the genus Papio.
Effect of Acid Modification of Soy Glycinin on Its Interfacial and Emulsifying Properties
Authors: Abirached Cecilia , Medrano Alejandra , Añón María C. , Panizzolo Luis A.
Published: April 2018

Soybean glycinin [11S] was modified by an acidic pH treatment to improve its emulsifying properties. Glycinin was obtained by isoelectric precipitation (11Sn) and then treated with acid (11St). The oil–water interfacial tension and rheology were measured. The rate constants of adsorption (ka) and rearrangement (kr) of proteins at the interface and the dilational (E), elastic (Ed), and viscous modulus (Ev) of the protein interfacial film were determined. Particle size distribution (PSD), interfacial protein concentration (Γ), and the creaming destabilization rate constants ks (for the smaller droplets) and kl (for the larger droplets) were analyzed in oil‐in‐water emulsions (25% v/v of oil and 75% v/v of 1 mg/mL protein solution in 10 mM sodium phosphate buffers, pH 7.0 and 2.5, respectively).

Compared to the native protein, the acid treatment caused irreversible denaturation of 11S and significantly increased Г, ka, E, Ed, and Ev (P ≤ 0.05), resulting in a greater rate of protein adsorption to the interface and a stronger interfacial film. PSD showed a bimodal distribution with peaks above and below 4 μm. Smaller droplets moved toward smaller diameters for 11St. It also showed lower values of creaming destabilization constants ks (d ≤ 4 μm) and kl (d ≥ 4 μm) than 11Sn. In conclusion, acid treatment of 11S enhances the creaming stability of its emulsions by improving the interfacial properties and reducing the droplet size.
Blended films containing polybutyrolactam and chitosan for potential wound dressing applications
Authors: Wu De , Wei Wu , Li Hong , Wang Xuehong , Wang Tinglan , Tang Songchao , Li Quan , Yao Yuan , Pan Yongkang , Wei Jie
Published: April 2018

In this study, polybutyrolactam (PBA) was synthesized, and the PBA/chitosan (CS) blended films were fabricated for wound dressings. The results showed that the surface roughness of the blended films decreased with the increasing ratios of CS. In addition, the tensile strength of the film with 50 wt % CS (NC50) was about 33.6 MPa and the highest compared with other films. The hydrophilicity of the blended films gradually decreased while the water vapor transmission rates (WVTRs) increased with the increase of CS content. Moreover, the blended films could be biodegradable in phosphate buffer saline. Both PBA and blended films were non‐toxic and good for L929 cells growth, showing good cytocompatibility. Furthermore, the NC50 was found to promote the cell proliferation better than other groups. It can be suggested that the NC50 combined the advantages of both PBA and CS well. Therefore, the NC50 with good cytocompatibility, mechanical properties, and WVTRs might be suitable for wound dressing applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46511.
A protocol for high‐throughput, untargeted forest community metabolomics using mass spectrometry molecular networks
Authors: Sedio Brian E. , Boya P. Cristopher A. , Rojas Echeverri Juan Camilo
Published: April 2018

Premise of the Study

We describe a field collection, sample processing, and ultra‐high‐performance liquid chromatography–tandem mass spectrometry (UHPLC‐MS/MS) instrumental and bioinformatics method developed for untargeted metabolomics of plant tissue and suitable for molecular networking applications.

Methods and Results

A total of 613 leaf samples from 204 tree species was collected in the field and analyzed using UHPLC‐MS/MS. Matching of molecular fragmentation spectra generated over 125,000 consensus spectra representing unique molecular structures, 26,410 of which were linked to at least one structurally similar compound.

Conclusions

Our workflow is able to generate molecular networks of hundreds of thousands of compounds representing broad classes of plant secondary chemistry and a wide range of molecular masses, from 100 to 2500 daltons, making possible large‐scale comparative metabolomics, as well as studies of chemical community ecology and macroevolution in plants.
IL1RN Variation Influences Both Disease Susceptibility and Response to Recombinant Human Interleukin‐1 Receptor Antagonist Therapy in Systemic Juvenile Idiopathic Arthritis
Authors: Arthur Victoria L. , Shuldiner Emily , Remmers Elaine F. , Hinks Anne , Grom Alexei A. , Foell Dirk , Martini Alberto , Gattorno Marco , Özen Seza , Prahalad Sampath , Zeft Andrew S. , Bohnsack John F. , Ilowite Norman T. , Mellins Elizabeth D. , Russo Ricardo , Len Claudio , Oliveira Sheila , Yeung Rae S. M. , Rosenberg Alan M. , Wedderburn Lucy R. , Anton Jordi , Haas Johannes‐Peter , Rösen‐Wolff Angela , Minden Kirsten , Szymanski Ann Marie ,   INCHARGE Consortium, Thomson Wendy , Kastner Daniel L. , Woo Patricia , Ombrello Michael J.
Published: April 2018

Objective

To determine whether systemic juvenile idiopathic arthritis (JIA) susceptibility loci that were identified by candidate gene studies demonstrate association with systemic JIA in the largest study population assembled to date.

Methods

Single‐nucleotide polymorphisms (SNPs) from 11 previously reported systemic JIA risk loci were examined for association in 9 populations, including 770 patients with systemic JIA and 6,947 controls. The effect of systemic JIA–associated SNPs on gene expression was evaluated in silico in paired whole genome and RNA sequencing data from the lymphoblastoid cell lines (LCLs) of 373 European subjects from the 1000 Genomes Project. Responses of systemic JIA–associated SNPs to anakinra treatment were evaluated in 38 US patients for whom treatment response data were available.

Results

We found no association between the previously reported 26 SNPs and systemic JIA. Expanded analysis of the regions containing the 26 SNPs revealed only 1 significant association: the promoter region of IL1RN (P < 1 × 10–4). Systemic JIA–associated SNPs correlated with IL1RN expression in LCLs, with an inverse correlation between systemic JIA risk and IL1RN expression. The presence of homozygous IL1RN high expression alleles correlated strongly with a lack of response to anakinra therapy (odds ratio 28.7 [95% confidence interval 3.2–255.8]).

Conclusion

In our study, IL1RN was the only candidate locus associated with systemic JIA. The implicated SNPs are among the strongest known determinants of IL1RN and interleukin‐1 receptor antagonist levels, linking low expression with increased systemic JIA risk. Homozygous high expression alleles predicted nonresponsiveness to anakinra therapy, making them ideal candidate biomarkers to guide systemic JIA treatment. This study is an important first step toward the personalized treatment of systemic JIA.
A real‐time fluorescence assay for protease activity and inhibitor screening based on the aggregation‐caused quenching of a perylene probe
Authors: Wang Yan , Zhang Zhifang , Zhang Ya , Yu Cong
Published: April 2018

We have established a real‐time and label‐free fluorescence turn‐on strategy for protease activity detection and inhibitor screening via peptide‐induced aggregation‐caused quenching of a perylene probe. Because of electrostatic interactions and high hydrophilicity, poly‐l‐glutamic acid sodium salt (PGA; a negatively charged peptide) could induce aggregation of a positively charged perylene probe (probe 1) and the monomer fluorescence of probe 1 was effectively quenched. After a protease was added, PGA was enzymatically hydrolyzed into small fragments and probe 1 disaggregated. The fluorescence recovery of probe 1 was found to be proportional to the concentration of protease in the range from 0 to 1 mU/ml. The detection limit was down to 0.1 mU/ml. In the presence of a protease inhibitor, protease activity was inhibited and fluorescence recovery reduced. Moreover, we demonstrated the potential application of our method in a complex mixture sample including 1% human serum. Our method is simple, fast and cost effective.
Pretreatment subcutaneous adipose tissue predicts the outcomes of patients with head and neck cancer receiving definitive radiation and chemoradiation in Taiwan
Authors: Pai Ping Ching , Chuang Chi Cheng , Chuang Wen Ching , Tsang Ngan Ming , Tseng Chen Kan , Chen Kuan Hung , Yen Tzu Chen , Lin Chien Yu , Chang Kai Ping , Lei Kin Fong
Published: April 2018

We aimed to determine whether body composition assessment before treatment can predict outcomes in patients with head and neck cancer (HNC). All 881 patients with locoregional head and neck cancer treated with curative intent radiotherapy (RT) between 2005 and 2012 were retrospectively investigated. Body composition was analyzed via pre‐RT planning computed tomography (CT) images. Subcutaneous adipose tissue (SAT) and skeletal muscle (SM) indices were measured cross‐sectionally at the level of the third thoracic vertebra. Overall survival (OS), locoregional control (LRC), and distant metastasis‐free survival (MFS) were analyzed by body composition index and body mass index (BMI). Survivors were followed up for a median of 4.68 years. The SAT indices in female patients were significantly higher than those in males (P < 0.001). The median SAT and muscle indices were 18.6 and 34.3 cm2/m2 for women and 6.19 and 51.74 cm2/m2 for men, respectively. The 5‐ and 10‐year MFS, LRC, and OS rates were 83% and 82.1%, 73.4% and 71.4%, and 66.4 and 57.6%, respectively. Higher pretreatment SAT index was associated with MFS (hazard ratio [HR]: 0.65; P = 0.015), LRC (HR: 0.758; P = 0.047), and OS (HR: 0.604; P < 0.001). Higher pretreatment BMI was associated with MFS (HR: 0.642; P = 0.031) and OS (HR: 0.615; P < 0.001). The pretreatment SM index had no significant effect on MFS, LRC, and OS. Multivariate analysis revealed that T‐stage, N‐stage, lesion sites, age, and RT treatment days are independent factors associated with OS; T‐stage, N‐stage, and lesion sites are independent factors associated with MFS; and N‐stage, smoking history, and betel quid chewing history are independent factors associated with LRC. A higher CT‐assessed SAT index predicts superior MSF, LCR, and OS in patients with curative HNC, whereas SM does not predict survival or locoregional control.
Aging‐related prognosis analysis of definitive radiotherapy for very elderly esophageal cancer
Authors: Zhou Yong‐Chun , Chen Li‐Li , Xu Hong‐Bo , Sun Qian , Zhang Qi , Cai Han‐Fei , Jiang Hao
Published: April 2018

Because of the exclusion for the patients more than 75 years (very elderly patients) in many clinical trials of esophageal cancer (EC), there is no consensus on prognosis and treatment for this population. We aim to evaluate the outcomes and aging‐related prognostic factors of definitive radiotherapy (RT) for very elderly EC patients. We retrospectively analyzed 149 very elderly EC patients consecutively treated between January 2015 and June 2016 by definitive intensity‐modulated radiotherapy (IMRT) with or without chemotherapy. The clinical outcome and toxicities were assessed, and the potential prognostic factors, such as nutritional risk index (NRI) and neutrophil–lymphocyte ratio (NLR), were analyzed statistically. The median follow‐up time for survivors was 22.5 months. The 2‐year overall survival (OS), local–regional failure‐free survival (LRFFS), and distant metastasis‐free survival (DMFS) were 51.6%, 54.7%, and 85.2%, respectively. Independent predictors for poorer OS were higher American Joint Committee on Cancer (AJCC) stage, lower NRI, and higher NLR value before RT. Meanwhile, the total dose (cutoff value 60 Gy) of planning gross tumor volume (PGTV) and chemotherapy was also identified as independent prognostic indicator for LRFFS and DMFS, respectively. 72 patients had treatment failure and 58 (80.6%), 6 (8.3%), and 18 (25.0%) patients had experienced local, regional, and distant failure, respectively. Few severe toxicities were observed. The conservative definitive RT with modern technique was effective for very elderly EC patients in short term with low rate and tolerable toxicities. Local residue or recurrence was the most common failure pattern. The aging‐related prognostic factors concerned nutrition and immune, such as NRI and NLR before RT, should be considered for use in future clinical practice.
Cervical lymph node carcinoma metastasis from unknown primary site: a retrospective analysis of 154 patients
Authors: Wang Yan , He Sha‐Sha , Bao Yong , Cai Xiu‐Yu , Chen Hai‐Yang , Yang Xing‐Li , Chen Dan‐Ming , Lu Li‐Xia , Chen Yong
Published: April 2018

Despite advances in diagnosis and treatment, the existence of cervical lymph node carcinoma of unknown primary site (CCUP) has always been an urgent problem worldwide. There is still no consensus on the optimal management for CCUP. In this retrospective review, we analyze the clinical characteristics of CCUP patients treated at our institution and examine how these characteristics and treatments were associated with survival. Clinicopathologic features, treatments, and survival outcomes of 154 CCUP patients were collected from the hospital records and analyzed. Survival was estimated by Kaplan–Meier methods and compared by the log‐rank test. Cox proportional hazards regression analysis was used to assess the factors independently associated with overall survival (OS) and progression‐free survival (PFS). Median follow‐up period was 26.44 months (range, 0.53–146.53 months). Multivariate analysis showed N stage, pathologic type, and lymph node extranodal extension (ENE) to be independent prognostic factors for OS in CCUP patients, but not PFS. Subgroup analysis of patients who received radiotherapy showed that radiotherapy to the pharyngeal mucosa was associated with better OS (P = 0.045), but not with better PFS. Advanced N stage, nonsquamous cell carcinoma, and lymph node ENE predict poor prognosis in patients with CCUP. In addition, radiotherapy to suspicious mucosa is accompanied by better OS. These study findings should be useful to clinicians when selecting the treatment approach.
The direct and indirect association of cervical microbiota with the risk of cervical intraepithelial neoplasia
Authors: Zhang Chaoting , Liu Ying , Gao Weijiao , Pan Yaqi , Gao Yunong , Shen Jing , Xiong Hongchao
Published: April 2018

Cervical microbiota composition is associated with cervical HPV infection and CIN severity. Previous studies only assessed the total association between cervical microbiota and HPV infections or CINs, and yet no study reported the direct and indirect associations between cervical microbiota and CINs mediated by HPV infection, respectively. The aim of this study was to investigate the direct and indirect associations between microbiotas and CIN severity. Cervical microbiota of 126 women with CIN 1− (normal cytology and CIN 1) and 40 with CIN 2+ (CIN 2 and CIN 3) were analyzed using Illumina sequencing based on the 16S rRNA gene. HPV was detected using a highly sensitive PCR primer set (SPF1/GP6+). Indirect effects of Pseudomonas stutzeri, Bacteroides fragilis, Lactobacillus delbrueckii, Atopobium vaginae, and Streptococcus agalactiae mediated by HPV infection on CIN status were observed. The directions of the direct and the indirect associations between CIN status and Ps. stutzeri were opposite. The directions of the direct and the indirect associations between CIN status and A. vaginae were the same. B. fragilis, L. delbrueckii, and S. agalactiae only had indirect association with CIN status. In summary, our study provided suggestive evidence that some microbial populations could have direct or indirect effects mediated by affecting HPV infection on CIN progression. Besides HPV infection, microbial community composition possibly plays a role in cervical carcinogenesis.
Alkynylnicotinamide‐Based Compounds as ABL1 Inhibitors with Potent Activities against Drug‐Resistant CML Harboring ABL1(T315I) Mutant Kinase
Authors: Larocque Elizabeth A. , Naganna N. , Opoku‐Temeng Clement , Lambrecht Alyssa M. , Sintim Herman O.
Published: April 2018

The introduction of imatinib into the clinical scene revolutionized the treatment of chronic myelogenous leukemia (CML). The overall eight‐year survival rate for CML has increased from about 6 % in the 1970s to over 90 % in the imatinib era. However, about 20 % of CML patients harbor primary or acquired resistance to tyrosine kinase inhibitors. ABL1 point mutations in the BCR‐ABL1 fusion protein, such as ABL1(T315I), typically emerge after prolonged kinase inhibitor treatment. Ponatinib (AP24534) is currently the only approved CML drug that is active against the ABL1(T315I) mutation. However, ponatinib has severe cardiovascular toxicities; hence, there have been efforts to find safer CML drugs that work against ABL1 secondary mutations. We reveal that isoquinoline‐ or naphthyridine‐based compounds, such as HSN431, HSN576, HSN459, and HSN608 potently inhibit the enzymatic activities of ABL1, ABL1(T315I), and ABL1(E255K). These compounds inhibit the proliferation of ABL1‐driven CML cell lines, K652 and KCL22 as well as the drug‐resistant cell line, KCL22‐IR, which harbors the secondary mutated ABL1(T315I) kinase.
Convergence of the Allen‐Cahn Equation to Multiphase Mean Curvature Flow
Authors: Laux Tim , Simon Theresa M.
Published: April 2018

We present a convergence result for solutions of the vector‐valued Allen‐Cahn equation. In the spirit of the work of Luckhaus and Sturzenhecker we establish convergence towards a distributional formulation of multiphase mean~curvature flow using sets of finite perimeter. Like their result, ours relies on the assumption that the time‐integrated energies of the approximations converge to those of the limit. Furthermore, we apply our proof to two variants of the equation, incorporating external forces and volume constraints.© 2018 Wiley Periodicals, Inc.
Message‐Passing Algorithms for Synchronization Problems over Compact Groups
Authors: Perry Amelia , Wein Alexander S. , Bandeira Afonso S. , Moitra Ankur
Published: April 2018

Various alignment problems arising in cryo‐electron microscopy, community detection, time synchronization, computer vision, and other fields fall into a common framework of synchronization problems over compact groups such as ℤ/L, U(1), or SO(3). The goal in such problems is to estimate an unknown vector of group elements given noisy relative observations. We present an efficient iterative algorithm to solve a large class of these problems, allowing for any compact group, with measurements on multiple “frequency channels” (Fourier modes, or more generally, irreducible representations of the group). Our algorithm is a highly efficient iterative method following the blueprint of approximate message passing (AMP), which has recently arisen as a central technique for inference problems such as structured low‐rank estimation and compressed sensing. We augment the standard ideas of AMP with ideas from representation theory so that the algorithm can work with distributions over general compact groups. Using standard but nonrigorous methods from statistical physics, we analyze the behavior of our algorithm on a Gaussian noise model, identifying phases where we believe the problem is easy, (computationally) hard, and (statistically) impossible. In particular, such evidence predicts that our algorithm is information‐theoretically optimal in many cases, and that the remaining cases exhibit statistical‐to‐computational gaps. © 2018 Wiley Periodicals, Inc.
A Liouville Theorem for the Complex Monge‐Ampère Equation on Product Manifolds
Authors: Hein Hans‐Joachim
Published: April 2018

Let Y be a closed Calabi‐Yau manifold. Let ω be the Kähler form of a Ricci‐flat Kähler metric on . We prove that if ω is uniformly bounded above and below by constant multiples of , where is the standard flat Kähler form on and ωY is any Kähler form on Y, then ω is a product Kähler form up to a certain automorphism of . © 2018 Wiley Periodicals, Inc.
Our use, misuse, and abandonment of a concept: Whither habitat?
Authors: Kirk David Anthony , Park Allysia C. , Smith Adam C. , Howes Briar J. , Prouse Brigid K. , Kyssa Naschelly G. , Fairhurst Elizabeth N. , Prior Kent A.
Published: April 2018

The foundational concept of habitat lies at the very root of the entire science of ecology, but inaccurate use of the term compromises scientific rigor and communication among scientists and nonscientists. In 1997, Hall, Krausman & Morrison showed that ‘habitat’ was used correctly in only 55% of articles. We ask whether use of the term has been more accurate since their plea for standardization and whether use varies across the broader range of journals and taxa in the contemporary literature (1998–2012). We searched contemporary literature for ‘habitat’ and habitat‐related terms, ranking usage as either correct or incorrect, following a simplified version of Hall et al.'s definitions. We used generalized linear models to compare use of the term in contemporary literature with the papers reviewed by Hall et al. and to test the effects of taxa, journal impact in the contemporary articles and effects due to authors that cited Hall et al. Use of the term ‘habitat’ has not improved; it was still only used correctly about 55% of the time in the contemporary data. Proportionately more correct uses occurred in articles that focused on animals compared to ones that included plants, and papers that cited Hall et al. did use the term correctly more often. However, journal impact had no effect. Some habitat terms are more likely to be misused than others, notably ‘habitat type’, usually used to refer to vegetation type, and ‘suitable habitat’ or ‘unsuitable habitat’, which are either redundant or nonsensical by definition. Inaccurate and inconsistent use of the term can lead to (1) misinterpretation of scientific findings; (2) inefficient use of conservation resources; (3) ineffective identification and prioritization of protected areas; (4) limited comparability among studies; and (5) miscommunication of science‐based findings. Correct usage would improve communication with scientists and nonscientists, thereby benefiting conservation efforts, and ecology as a science.
Tree seed rain and seed removal, but not the seed bank, impede forest recovery in bracken (Pteridium aquilinum (L.) Kuhn)‐dominated clearings in the African highlands
Authors: Ssali Fredrick , Moe Stein R. , Sheil Douglas
Published: April 2018

Considerable areas dominated by bracken Pteridium aquilinum (L.) Kuhn occur worldwide and are associated with arrested forest recovery. How forest recovery is impeded in these areas remains poorly understood, especially in the African highlands. The component processes that can lead to recruitment limitation—including low seed arrival, availability and persistence—are important determinants of plant communities and offer a potential explanation for bracken persistence. We investigated key processes that can contribute to recruitment limitation in bracken‐dominated clearings in the Bwindi Impenetrable National Park, Uganda. We examined if differences in seed rain (dispersal limitation), soil seed bank, or seed removal (seed viability and persistence) can, individually or in combination, explain the differences in tree regeneration found between bracken‐dominated areas and the neighboring forest. These processes were assessed along ten 50‐m transects crossing the forest–bracken boundary. When compared to the neighboring forest, bracken clearings had fewer seedlings (bracken 11,557 ± 5482 vs. forest 34,515 ± 6066 seedlings/ha), lower seed rain (949 ± 582 vs. 1605 ± 335 tree seeds m−2 year−1), comparable but sparse soil seed bank (304 ± 236 vs. 264 ± 99 viable tree seeds/m2), higher seed removal (70.1% ± 2.4% vs. 40.6% ± 2.4% over a 3‐day interval), and markedly higher rodent densities (25.7 ± 5.4 vs. 5.0 ± 1.6 rodents per 100 trapping sessions). Camera traps revealed that rodents were the dominant animals visiting the seeds in our seed removal study. Synthesis: Recruitment limitation contributes to both the slow recovery of forest in bracken‐dominated areas, and to the composition of the tree species that occur. Low seed arrival and low persistence of unburied seeds can both explain the reduced density of seedlings found in bracken versus neighboring forest. Seed removal, likely due to rodents, in particular appears sufficient to constrain forest recovery and impacts some species more severely than others.
An evaluation of government‐recommended stocking systems for sustaining pastoral businesses and ecosystems of the Alpine Meadows of the Qinghai‐Tibetan Plateau
Authors: Wang Yingxin , Hodgkinson Kenneth C. , Hou Fujiang , Wang Zhaofeng , Chang Shenghua
Published: April 2018

China introduced the “Retire Livestock and Restore Grassland” policy in 2003. It was strengthened in 2011 by additional funding for on‐farm structures. On the Qinghai‐Tibetan Plateau (QTP), fences were erected, livestock excluded from degraded areas, rotational stocking introduced, nighttime shelters were built, forages grown, and seed sown. However, the effectiveness of these actions and their value to Tibetan herders has been questioned. We conducted a sheep stocking experiment for 5 years in an Alpine Meadow region of the QTP to evaluate stocking options recommended by Government. Cold and warm season stocking each at three rates (0, 8, and 16 sheep/ha) and continuous stocking at 0 and 4 sheep/ha were compared. We measured live weights of sheep, plant species richness and evenness, root biomass and carbon (C), nitrogen (N) and phosphorus (P) contents of the 0–10 cm of soil. We found that resting grassland from stocking during the warm season for later cold season stocking significantly reduced plant species richness and evenness and root biomass but not soil C, N, and P. During cold season stocking, live weights of sheep declined whether at a stocking rate of 8 or 16 per ha. In contrast, sheep continuously stocked on grassland at 4 per ha gained weight throughout both the warm and cold seasons and plant species richness and evenness were maintained. Warm season stocking at 8 and 16 sheep/ha increased plant species richness and root biomass but reduced plant species evenness. Resting these alpine grasslands from stocking in the warm season has adverse consequences for plant conservation. Fencing from stocking in the warm season is not justified by this study; all grassland should be judiciously stocked during the warm season to maintain plant species richness. Neither resting nor stocking during the cold season appears to have any adverse consequences but sheltering and in‐door feeding of sheep during the cold season may be more profitable than cold season stocking with use of open nighttime yards.
Identifying important conservation areas for the clouded leopard Neofelis nebulosa in a mountainous landscape: Inference from spatial modeling techniques
Authors: Penjor Ugyen , Macdonald David W. , Wangchuk Sonam , Tandin Tandin , Tan Cedric Kai Wei
Published: April 2018

The survival of large carnivores is increasingly precarious due to extensive human development that causes the habitat loss and fragmentation. Habitat selection is influenced by anthropogenic as well as environmental factors, and understanding these relationships is important for conservation management. We assessed the environmental and anthropogenic variables that influence site use of clouded leopard Neofelis nebulosa in Bhutan, estimated their population density, and used the results to predict the species’ site use across Bhutan. We used a large camera‐trap dataset from the national tiger survey to estimate for clouded leopards, for the first time in Bhutan, (1) population density using spatially explicit capture–recapture models and (2) site‐use probability using occupancy models accounting for spatial autocorrelation. Population density was estimated at (0.10 SD) and (0.12 SE) per 100 km2. Clouded leopard site use was positively associated with forest cover and distance to river while negatively associated with elevation. Mean site‐use probability (from the Bayesian spatial model) was (0.076 SD). When spatial autocorrelation was ignored, the probability of site use was overestimated, (0.066 SD). Predictive mapping allowed us to identify important conservation areas and priority habitats to sustain the future of these elusive, ambassador felids and associated guilds. Multiple sites in the south, many of them outside of protected areas, were identified as habitats suitable for this species, adding evidence to conservation planning for clouded leopards in continental South Asia.
The energetic consequences of behavioral variation in a marine carnivore
Authors: McHuron Elizabeth A. , Peterson Sarah H. , Hückstädt Luis A. , Melin Sharon R. , Harris Jeffrey D. , Costa Daniel P.
Published: April 2018

Intraspecific variability in foraging behavior has been documented across a range of taxonomic groups, yet the energetic consequences of this variation are not well understood for many species. Understanding the effect of behavioral variation on energy expenditure and acquisition is particularly crucial for mammalian carnivores because they have high energy requirements that place considerable pressure on prey populations. To determine the influence of behavior on energy expenditure and balance, we combined simultaneous measurements of at‐sea field metabolic rate (FMR) and foraging behavior in a marine carnivore that exhibits intraspecific behavioral variation, the California sea lion (Zalophus californianus). Sea lions exhibited variability in at‐sea FMR, with some individuals expending energy at a maximum of twice the rate of others. This variation was in part attributable to differences in diving behavior that may have been reflective of diet; however, this was only true for sea lions using a foraging strategy consisting of epipelagic (<200 m within the water column) and benthic dives. In contrast, sea lions that used a deep‐diving foraging strategy all had similar values of at‐sea FMR that were unrelated to diving behavior. Energy intake did not differ between foraging strategies and was unrelated to energy expenditure. Our findings suggest that energy expenditure in California sea lions may be influenced by interactions between diet and oxygen conservation strategies. There were no apparent energetic trade‐offs between foraging strategies, although there was preliminary evidence that foraging strategies may differ in their variability in energy balance. The energetic consequences of behavioral variation may influence the reproductive success of female sea lions and result in differential impacts of individuals on prey populations. These findings highlight the importance of quantifying the relationships between energy expenditure and foraging behavior in other carnivores for studies addressing fundamental and applied physiological and ecological questions.
Smell the change: On the potential of gas‐chromatographic ion mobility spectrometry in ecosystem monitoring
Authors: Vautz Wolfgang , Hariharan Chandrasekhara , Weigend Maximilian
Published: April 2018

Plant volatile organic compounds (pVOCs) are being recognized as an important factor in plant–environment interactions. Both the type and amount of the emissions appear to be heavily affected by climate change. A range of studies therefore has been directed toward understanding pVOC emissions, mostly under laboratory conditions (branch/leaf enclosure). However, there is a lack of rapid, sensitive, and selective analytical methods, and therefore, only little is known about VOC emissions under natural, outdoor conditions. An increased sensitivity and the identification of taxon‐specific patterns could turn VOC analysis into a powerful tool for the monitoring of atmospheric chemistry, ecosystems, and biodiversity, with far‐reaching relevance to the impact of climate change on pVOCs and vice versa. This study for the first time investigates the potential of ion mobility spectrometry coupled to gas‐chromatographic preseparation (GC‐IMS) to dramatically increase sensitivity and selectivity for continuous monitoring of pVOCs and to discriminate contributing plant taxa and their phenology. Leaf volatiles were analyzed for nine different common herbaceous plants from Germany. Each plant turned out to have a characteristic metabolite pattern. pVOC patterns in the field would thus reflect the composition of the vegetation, but also phenology (with herbaceous and deciduous plants contributing according to season). The technique investigated here simultaneously enables the identification and quantification of substances characteristic for environmental pollution such as industrial and traffic emissions or pesticides. GC‐IMS thus has an enormous potential to provide a broad range of data on ecosystem function. This approach with near‐continues measurements in the real plant communities could provide crucial insights on pVOC‐level emissions and their relation to climate and phenology and thus provide a sound basis for modeling climate change scenarios including pVOC emissions.
Diversity and distribution of parasitic angiosperms in China
Authors: Zhang Guangfu , Li Qian , Sun Shucun
Published: April 2018

Parasitic plants are an important component of vegetation worldwide, but their diversity and distribution in China have not been systematically reported. This study aimed to (1) explore floral characteristics of China's parasitic plants, (2) map spatial distribution of diversity of these species, and (3) explore factors influencing the distribution pattern. We compiled a nationwide species list of parasitic plants in China, and for each species, we recorded its phylogeny, endemism, and life form (e.g., herb vs. shrub; hemiparasite vs. holoparasite). Species richness and area‐corrected species richness were calculated for 28 provinces, covering 98.89% of China's terrestrial area. Regression analyses were performed to determine relationships between provincial area‐corrected species richness of parasitic plants and provincial total species richness (including nonparasitic plants) and physical settings (altitude, midlongitude, and midlatitude). A total of 678 species of parasitic angiosperms are recorded in China, 63.13% of which are endemic. Of the total, 59.73% (405 species) are perennials, followed by shrubs/subshrubs (14.75%) and vines (1.47%). About 76.11% (516 species) are of root hemiparasites, higher than that of stem parasites (100, 14.75%), root holoparasites (9.00%), and endophytic parasites (0.15%). A significant positive relationship is found between the area‐corrected species richness and the total species richness, which has been previously demonstrated to increase with decreasing longitude and latitude. Moreover, more parasitic species are found in the southwest high‐altitude areas than low areas. Consistently, the area‐corrected species richness increases with increasing altitude, decreasing latitude, and decreasing longitude, as indicated by regression analyses. China is rich in parasitic flora with a high proportion of endemic species. Perennials and root hemiparasites are the dominant types. The spatial distribution of parasitic plants is largely heterogeneous, with more species living in southwest China, similar to the distribution pattern of Chinese angiosperms. The positive relationship between parasitic and nonparasitic plant species richness should be addressed in the future.
Upwelling and eddies affect connectivity among local populations of the goldeye rockfish,Sebastes thompsoni(Pisces, Scorpaenoidei)
Authors: Yu Hyo Jae , Kim Jin‐Koo
Published: April 2018

Abstrat

The goldeye rockfish,Sebastes thompsoni, commercial rockfish catch in the Northwest Pacific Ocean, may influence its population structure. To clarify the population genetic structure of KoreanS. thompsoniand its degree of hybridization with the most close species,Sebastes joyneri, we analyzed a mitochondrial (mt)DNAcontrol region and eleven polymorphic microsatellite (ms) loci.S. joyneriindividuals were clearly distinguished fromS. thompsoniby the mtDNAcontrol region and ms loci results, with single interspecific hybridization between two species suggesting no impact on genetic structure ofS. thompsoni. Analysis of mtDNArevealed no population structure withinS. thompsoni, suggesting the survival of a single population in southern refugia during the glacial period. The ms loci results, in contrast, showed two genetically distinct clusters withinS. thompsoni: One was predominant throughout Korean coasts (from the Yellow Sea, via the Korea Strait to the East Sea); the other was predominant at Dokdo Island in the East Sea; and both occurred in similar ratios at Wangdolcho Reef in the East Sea. A possible factor that restricts gene flow between Korean coastal and offshore populations in the East Sea may be related to the complex oceanic current patterns such as eddies and upwelling, which represent impermeable barriers to population connectivity for this species. Our findings highlight that these two populations might be representative of two separate stock within Korean waters and maintain their geographically related genetic structure.
Resource diversity and provenance underpin spatial patterns in functional diversity across native and exotic species
Authors: Méndez Verónica , Wood Jamie R. , Butler Simon J.
Published: April 2018

Functional diversity metrics are increasingly used to augment or replace taxonomic diversity metrics to deliver more mechanistic insights into community structure and function. Metrics used to describe landscape structure and characteristics share many of the same limitations as taxonomy‐based metrics, particularly their reliance on anthropogenically defined typologies with little consideration of structure, management, or function. However, the development of alternative metrics to describe landscape characteristics has been limited. Here, we extend the functional diversity framework to characterize landscapes based on the diversity of resources available across habitats present. We then examine the influence of resource diversity and provenance on the functional diversities of native and exotic avian communities in New Zealand. Invasive species are increasingly prevalent and considered a global threat to ecosystem function, but the characteristics of and interactions between sympatric native and exotic communities remain unresolved. Understanding their comparative responses to environmental change and the mechanisms underpinning them is of growing importance in predicting community dynamics and changing ecosystem function. We use (i) matrices of resource use (species) and resource availability (habitats) and (ii) occurrence data for 62 native and 25 exotic species and 19 native and 13 exotic habitats in 2015 10 × 10 km quadrats to examine the relationship between native and exotic avian and landscape functional diversity. The numbers of species in, and functional diversities of, native and exotic communities were positively related. Each community displayed evidence of environmental filtering, but it was significantly stronger for exotic species. Less environmental filtering occurred in landscapes providing a more diverse combination of resources, with resource provenance also an influential factor. Landscape functional diversity explained a greater proportion of variance in native and exotic community characteristics than the number of habitat types present. Resource diversity and provenance should be explicitly accounted for when characterizing landscape structure and change as they offer additional mechanistic understanding of the links between environmental filtering and community structure. Manipulating resource diversity through the design and implementation of management actions could prove a powerful tool for the delivery of conservation objectives, be they to protect native species, control exotic species, or maintain ecosystem service provision.