bluuebunny/crossref_metadata_2025_split huggingface dataset:
Demographic and ecogeographic factors limit wild grapevine spread at the southern edge of its distribution range
Authors: Rahimi Oshrit , Ohana‐Levi Noa , Brauner Hodaya , Inbar Nimrod , Hübner Sariel , Drori Elyashiv 
Published: May 2021

AbstractThe spatial distribution of plants is constrained by demographic and ecogeographic factors that determine the range and abundance of the species. Wild grapevine (Vitis vinifera ssp. sylvestris) is distributed from Switzerland in the north to Israel in the south. However, little is known about the ecogeographic constraints of this species and its genetic and phenotypic characteristics, especially at the southern edge of its distribution range in the Levant region. In this study, we explore the population structure of southern Levantine wild grapevines and the correlation between demographic and ecogeographic characteristics. Based on our genetic analysis, the wild grapevine populations in this region can be divided into two major subgroups in accordance with a multivariate spatial and ecogeographical clustering model. The identified subpopulations also differ in morphological traits, mainly leaf hairiness which may imply adaptation to environmental stress. The findings suggest that the Upper Jordan River population was spread to the Sea of Galilee area and that a third smaller subpopulation at the south of the Golan Heights may represent a distinguished gene pool or a recent establishment of a new population. A spatial distribution model indicated that distance to water sources, Normalized difference vegetation index, and precipitation are the main environmental factors constraining V. v. sylvestris distribution at its southern distribution range. These factors in addition to limited gene flow between populations prevent further spread of wild grapevines southwards to semi‐arid regions.
Challenges and opportunities for comparative studies of survival rates: An example with male pinnipeds
Authors: Brusa Jamie L. , Rotella Jay J. , Banner Katharine M. , Hutchins Patrick R. 
Published: May 2021

AbstractSurvival rates are a central component of life‐history strategies of large vertebrate species. However, comparative studies seldom investigate interspecific variation in survival rates with respect to other life‐history traits, especially for males. The lack of such studies could be due to the challenges associated with obtaining reliable datasets, incorporating information on the 0–1 probability scale, or dealing with several types of measurement error in life‐history traits, which can be a computationally intensive process that is often absent in comparative studies. We present a quantitative approach using a Bayesian phylogenetically controlled regression with the flexibility to incorporate uncertainty in estimated survival rates and quantitative life‐history traits while considering genetic similarity among species and uncertainty in relatedness. As with any comparative analysis, our approach makes several assumptions regarding the generalizability and comparability of empirical data from separate studies. Our model is versatile in that it can be applied to any species group of interest and include any life‐history traits as covariates. We used an unbiased simulation framework to provide “proof of concept” for our model and applied a slightly richer model to a real data example for pinnipeds. Pinnipeds are an excellent taxonomic group for comparative analysis, but survival rate data are scarce. Our work elucidates the challenges associated with addressing important questions related to broader ecological life‐history patterns and how survival–reproduction trade‐offs might shape evolutionary histories of extant taxa. Specifically, we underscore the importance of having high‐quality estimates of age‐specific survival rates and information on other life‐history traits that reasonably characterize a species for accurately comparing across species.
Microhabitat distribution of aquatic oligochaete communities in the Western Balkans peat bog
Authors: Brigić Andreja , Alegro Antun , Gottstein Sanja , Kerovec Mladen 
Published: May 2021

AbstractPeat bog pools are rare and fragmented in the Western Balkans. Thus, aquatic macroinvertebrate diversity and the implications for microhabitat loss in these ecosystems are poorly known. Aquatic oligochaetes, widely used as indicators, were sampled using a benthos net in the largest and oldest Croatian bog, in four main water body types: a pond, a deep pool, a shallow pool and a ditch. As these microhabitats lack spatial replication both in the studied bog and in the region, we applied a nested study design with replicates sampled over time. We found a species‐rich aquatic oligochaete fauna, with 11 taxa recorded. Oligochaete communities were strongly affected by vegetation complexity and the morphology of bog water bodies, namely, their size and depth. As revealed by generalised linear mixed models (GLMMs), taxon richness and abundance were significantly higher in the ditch than in other water body types. This could be attributed to the vegetation complexity, supporting many different niches and providing allochthonous food supplies for oligochaetes. The various bog pools contribute to regional biodiversity and promote distinct patterns in the spatial distribution of oligochaetes. However, the predominance of ubiquitous oligochaetes, with high taxon richness, might indicate the degradation of the studied peat bog. This was further confirmed by the spread of vascular plants to the bog area and higher pH water values. All these warning signals suggest that hydro‐ecological conditions should be urgently improved in order to preserve communities in the bog studied.
Non‐additive effects of foundation species determine the response of aquatic ecosystems to nutrient perturbation
Authors: Lürig Moritz D. , Narwani Anita , Penson Hannele , Wehrli Bernhard , Spaak Piet , Matthews Blake 
Published: May 2021

AbstractEutrophication is a persistent threat to aquatic ecosystems worldwide. Foundation species, namely those that play a central role in the structuring of communities and functioning of ecosystems, are likely important for the resilience of aquatic ecosystems in the face of disturbance. However, little is known about how interactions among such species influence ecosystem responses to nutrient perturbation. Here, using an array (N = 20) of outdoor experimental pond ecosystems (15,000 L), we manipulated the presence of two foundation species, the macrophyte Myriophyllum spicatum and the mussel Dreissena polymorpha, and quantified ecosystem responses to multiple nutrient disturbances, spread over two years. In the first year, we added five nutrient pulses, ramping up from 10 to 50 μg P/L over a 10‐week period from mid‐July to mid‐October, and in the second year, we added a single large pulse of 50 μg P/L in mid‐October. We used automated sondes to measure multiple ecosystems properties at high frequency (15‐minute intervals), including phytoplankton and dissolved organic matter fluorescence, and to model whole‐ecosystem metabolism. Overall, both foundation species strongly affected the ecosystem responses to nutrient perturbation, and, as expected, initially suppressed the increase in phytoplankton abundance following nutrient additions. However, when both species were present, phytoplankton biomass increased substantially relative to other treatment combinations: non‐additivity was evident for multiple ecosystem metrics following the nutrient perturbations in both years but was diminished in the intervening months between our perturbations. Overall, these results demonstrate how interactions between foundation species can cause surprisingly strong deviations from the expected responses of aquatic ecosystems to perturbations such as nutrient additions.
Environmental DNA detection of the giant freshwater crayfish (Astacopsis gouldi)
Authors: Trujillo‐Gonzalez Alejandro , Hinlo Rheyda , Godwin Sam , Barmuta Leon A. , Watson Anne , Turner Perpetua , Koch Amy , Gleeson Dianne 
Published: May 2021

AbstractThe giant freshwater crayfish, Astacopsis gouldi Clark, 1936, is an endangered endemic freshwater species native to Northern Tasmania. Habitat loss, fishing pressure, and climate change have been identified as threatening processes. The Australian government approved a recovery plan for A. gouldi in 2017 that requires routine population surveys to assess the impact of ongoing threats and recovery actions. We developed a novel species‐specific probe‐based assay targeting a 219 bp fragment in the Cytochrome Oxidase 1 gene region to detect traces of A. gouldi DNA in environmental samples as a cost‐effective, sensitive, and non‐invasive surveillance method to assess the presence of this endangered species. We tested assay specificity against ten crayfish species commonly found in Tasmania within the Astacopsis, Cherax, Geocharax, Engaeus, and Ombrastacoides genera and determined assay sensitivity using tissue‐derived genomic DNA and synthetic oligo standards designed for A. gouldi. We then tested water samples collected from aquaria and natural freshwater streams in Northern Tasmania with known occurrence of A. gouldi, as well as one site with no known A. gouldi occurrence. The probe‐based assay designed in this study successfully detected A. gouldi DNA and eDNA with a 10 copies/µl limit of detection and showed no amplification of non‐targeted co‐existing crayfish species. We successfully detected the presence of A. gouldi eDNA in water samples from six sites with known occurrences of the species. There was no detection from the negative site. This study validates the use of eDNA‐based detection of A. gouldi by real‐time PCR as a non‐invasive monitoring tool to assist field monitoring, assessment, and complement ongoing recovery actions to protect habitable ecosystems of A. gouldi.
Immunogenicity of the BNT162b2 mRNA vaccine in heart transplant recipients – a prospective cohort study
Authors: Itzhaki Ben Zadok Osnat , Shaul Aviv A. , Ben‐Avraham Binyamin , Yaari Vicky , Ben Zvi Haim , Shostak Yael , Pertzov Barak , Eliakim‐Raz Noa , Abed Galia , Abuhazira Miriam , Barac Yaron D. , Mats Israel , Kramer Mordechai R. , Aravot Dan , Kornowski Ran , Ben‐Gal Tuvia 
Published: May 2021

AbstractAimsTo assess the short‐term immunogenicity to severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) mRNA vaccine in a population of heart transplant (HTx) recipients. A prospective single‐centre cohort study of HTx recipients who received a two‐dose SARS‐CoV‐2 mRNA vaccine (BNT162b2, Pfizer‐BioNTech).Methods and resultsWhole blood for anti‐spike IgG (S‐IgG) antibodies was drawn at days 21–26 and at days 35–40 after the first vaccine dose. Geometric mean titres (GMT) ≥50 AU/mL were interpreted positive. Included were 42 HTx recipients at a median age of 61 [interquartile range (IQR) 44–69] years. Median time from HTx to the first vaccine dose was 9.1 (IQR 2.6–14) years. Only 15% of HTx recipients demonstrated the presence of positive S‐IgG antibody titres in response to the first vaccine dose [GMT 90 (IQR 54–229) AU/mL]. Overall, 49% of HTx recipients induced S‐IgG antibodies in response to either the first or the full two‐dose vaccine schedule [GMT 426 (IQR 106–884) AU/mL]. Older age [68 (IQR 59–70) years vs. 46 (IQR 34–63) years, P = 0.034] and anti‐metabolite‐based immunosuppression protocols (89% vs. 44%, P = 0.011) were associated with low immunogenicity. Importantly, 36% of HTx recipients who were non‐responders to the first vaccine dose became S‐IgG seropositive in response to the second vaccine dose. Approximately a half of HTx recipients did not generate S‐IgG antibodies following SARS‐CoV‐2 two‐dose vaccine.ConclusionsThe generally achieved protection from SARS‐CoV‐2 mRNA vaccination should be regarded with caution in the population of HTx recipients. The possible benefit of additive vaccine should be further studied.
CXCR3 and CXCR5 are highly expressed in HIV‐1‐specific CD8 central memory T cells from infected patients
Authors: Olivo Anaëlle , Lécuroux Camille , Bitu Marie , Avettand‐Fenoel Véronique , Boufassa Faroudy , Essat Asma , Meyer Laurence , Doisne Jean‐Marc , Favier Benoit , Vaslin Bruno , Schlecht‐Louf Géraldine , Noël Nicolas , Goujard Cécile , Lambotte Olivier , Bourgeois Christine 
Published: May 2021

AbstractNew ways of characterizing CD8+ memory T cell responses in chronic infections are based on the measurement of chemokine receptor expression (CXCR3, CXCR5, and CX3CR1). We applied these novel phenotyping strategies to chronic HIV infection by comparing healthy donors (HDs), HIV‐infected patients receiving antiretroviral therapy (ART), and spontaneous HIV controllers (HICs). In all groups, the memory cells exhibited high proportion of CXCR3+ cells. Proportions of CXCR5+ and CX3CR1+ cells were preferentially observed among central memory cells (Tcm) and effector memory cells (Tem) respectively.Chronic controlled HIV infection impacted the chemokine receptor profile of both HIV‐specific and nonspecific CD8+ T cells. In total CD8+ T cells, the proportions of CXCR3–CXCR5–CX3CR1–Tcm and Tem were lower in HIV‐infected patients than in HDs with subtle differences between ART and HICs. Such phenotyping strategy also revealed differences in exhaustion and senescence phenotypes, the CXCR3+CXCR5+CX3CR1– being more exhausted and senescent than the CXCR3+CXCR5–CX3CR1– Tcm fraction. Among HIV‐specific CD8+ T cells, the vast majority of Tcm cells were CXCR3+ and CXCR5+ cells in contrast with their nonspecific counterparts.In conclusion, the addition of migration markers contributes to better characterize Tcm/Tem compartment.
Epigenetic regulation in antiviral innate immunity
Authors: Wang Xiao , Xia Huawei , Liu Shengde , Cao Lili , You Fuping 
Published: May 2021

AbstractEmerging life‐threatening viruses have posed great challenges to public health. It is now increasingly clear that epigenetics plays a role in shaping host‐virus interactions and there is a great need for a more thorough understanding of these intricate interactions through the epigenetic lens, which may represent potential therapeutic opportunities in the clinic. In this review, we highlight the current understanding of the roles of key epigenetic regulators — chromatin remodeling and histone modification — in modulating chromatin openness during host defense against virus. We also discuss how the RNA modification m6A (N6‐methyladenosine) affects fundamental aspects of host‐virus interactions. We conclude with future directions for uncovering more detailed functions that epigenetic regulation exerts on both host cells and viruses during infection.
Coordination Features of the 1,3,5‐Triazapentadienyl Ligand in Alkyl Complexes of Rare‐Earth Metals
Authors: Rad'kova Natalia Yu. , Kovylina Tatyana A. , Cherkasov Anton V. , Lyssenko Konstantin A. , Ob'edkov Anatoly M. , Trifonov Alexander A. 
Published: May 2021

AbstractThe reactions of 1,3,5‐triazapentadiene 2,6‐iPr2C6H3NC(Ph)NC(Ph)NHC6H3iPr2‐2,6 (1) with Ln(CH2SiMe3)3(THF)2 (Ln=Y, Lu) in hexane afford bis(alkyl) complexes [2,6‐iPr2C6H3NC(Ph)NC(Ph)NC6H3iPr2‐2,6]Ln(CH2SiMe3)2(THF) (Ln=Y (2), Lu (3)) in 58 (2) and 62 (3) % yields. The X‐ray diffraction study revealed that in 3 the triazapentadienyl ligand coordinates with the Lu3+ ion in “amidinate” fashion resulting in the formation of a four‐membered metallocycle. In contrast, the reaction of 1 with the scandium analogue Sc(CH2SiMe3)3(THF)2 in toluene proceeds with the cleavage of C−N bond of 1,3,5‐triazapentadiene and leads to the formation of a dinuclear monoalkyl complex [{μ2‐2,6‐iPr2C6H3NC(Ph)N}Sc(CH2SiMe3)(THF)]2 (4) in 43 % yield. Complex 4 features κ2‐N,N‐coordination of the residual dianionic {μ2‐2,6‐iPr2C6H3NC(Ph)N}2− ligand μ‐bridging two Sc3+ centers. Alkyl complexes 2–4 were evaluated as pre‐catalysts for isoprene polymerization and hydrosilylation of unsaturated substrates with PhSiH3.
A Tea Saponin‐Carbohydrate‐Protein Complex Could Be One Key Emulsifiable Compound in the Emulsion Formed during Aqueous Extraction of Camellia Oil
Authors: Yang Jian‐Yuan , Li Jing , Wang Mei , Zheng Liu‐Feng , Peng Bin , Zou Xian‐Guo , Yin Yu‐Long , Deng Ze‐Yuan 
Published: May 2021

AbstractThe oil/water (O/W) emulsions are spontaneously formed during the process of aqueous extraction of camellia oil which indicates that there are natural emulsifiers with excellent emulsifying capacity exist in Camellia oleifera Abel. seeds. To explore the formation mechanism of these emulsions, a strongly emulsifiable component, a tea saponin‐carbohydrate‐protein complex (TCPC), is separated and purified by means of chromatography. Its physicochemical properties are characterized by the fourier transform infrared, thermogravimetric analysis, and scanning electron microscopy. The emulsifying properties of O/W emulsions prepared with TCPC (pH 7.0) are investigated systematically. The results show that the emulsions are remarkably stable over a wide range of pH values (5–11), ionic strength (0–200 mm NaCl), thermal treatment (60–90 °C; 30 min), and even after 14 days storage at room temperature (10–25 °C). Moreover, the rheological properties reveal that all determined emulsions show typical pseudoplastic fluid characteristics and shear‐thinning flow behavior. However, the emulsions are unstable during freeze‐thaw cycle. These results imply that TCPC may be one key emulsifiable compound during aqueous extraction of camellia oil.Practical Applications: Aqueous extraction is a promising technique for edible oil extraction from Camellia oleifera Abel. seeds because of its nutrition, safety and economy. However, the oil/water emulsions formed during the process of aqueous extraction of camellia oil, which makes oil hard to be separated. TCPC with excellent emulsifying activity and emulsion stability was separated and characterized, which could be regarded as a potential target to obtain free oil by frozen/thawed method. Thus, it could be contributing to the industrial application of aqueous extraction of camellia oil.
Design and Characteristics of Novel Sensory and Nutritionally Oriented Olive, Seed, and Nut Virgin Oils’ Blendings
Authors: González‐Gamallo Sergio , Salvador María Desamparados , Fregapane Giuseppe 
Published: May 2021

AbstractVirgin olive oil is considered a key component of the Mediterranean Diet, while nut and seed “cold‐pressed” oils stand out as an interesting ingredient due to the growing consumer demand toward so‐called gourmet and healthy oils. The main objective of this work is the development and characterization of novel virgin vegetal oils based on blendings of virgin olive oil with virgin oils obtained from seeds (sesame and flaxseed) and nuts (hazelnut and pistachio) of interest due to their peculiar nutritional and organoleptic characteristics. Oil formulations elaborated with 5% of sesame oils achieve a high content in vitamin E (842 mg kg−1, 11.8 mg per standard 14 g oil dose, corresponding to an 80% of the recommended daily intake) and with 10% of flaxseed a high level in essential α‐linolenic acid (6.4%, 0.90 mg per dose corresponding to a 66% of the recommended daily intake). In addition, sensory analysis shows that blends enriched with both 50% hazelnut oil and 75% pistachio oil not only maintain the typical aroma of virgin olive oil, but incorporate the characteristic nutty, roasty, seed‐like, and sweet sensory attributes of nuts, providing an added value to the consumers.
Ruthenium(II)‐Catalyzed Cross‐Coupling of Benzoyl Formic Acids with Toluenes: Synthesis of 2‐Phenylacetophenones
Authors: Yang Shan , Dai Chenyang , Chen Yujie , Jiang Yaqiqi , Shu Sai , Huang Zhibin , Zhao Yingsheng 
Published: May 2021

AbstractHerein, we report a direct method to synthesize 2‐phenylacetophenone through a ruthenium(II)‐catalyzed cross‐coupling reaction between acyl and benzyl radical. The various derivatives of 2‐phenylacetophenone were prepared easily in moderate to good yields. These reactions provide a straightforward pathway to synthesize a variety of ketones bearing various functional groups.
Efficient Synthesis of Polysubstituted Furans through a Base‐Promoted Oxacyclization of (Z)‐2‐En‐4‐yn‐1‐ols
Authors: Hrizi Asma , Thiery Emilie , Romdhani‐Younes Moufida , Jacquemin Johan , Thibonnet Jérôme 
Published: May 2021

AbstractAn efficient base catalyzed oxacyclization of Z‐enynols has been developed under transition metal‐free reaction conditions, thus resulting in a variety of new di‐, tri‐, and tetra‐substituted furans. This approach allowed us to obtain 32 new compounds. Furthermore, DFT calculations were realized to depict a relationship between the natural population analysis and experimental results with alkyl or aryl groups for the synthesis of 2‐benzylfuran. A one‐pot Sonogashira/oxacyclization approach offers a flexible, robust and efficient alternative to base catalyzed cyclization is also carried out.
Ring Expansion to 8‐Membered Silacycles through Formal Cross‐Dimerization of 5‐Membered Palladacycles with Silacyclobutanes
Authors: Wang Xi–Chao , Wang Hao‐Ran , Xu Xiufang , Zhao Dongbing 
Published: May 2021

AbstractInvestigations of the sila‐8‐membered ring fused biaryls are of high significance for the discovery of new drug lead compounds. However, such compounds are still unknown due to the synthetic challenge. Herein, we describe the chemo‐ and regio‐selective cross‐dimerization of 5‐membered palladacycles with silacyclobutanes enabled by Pd‐catalytic conditions, which constitutes an expedient ring expansion route to the sila‐8‐membered ring fused biaryl skeletons.
MWCNT‐Organoimido Polyoxomolybdate Hybrid Material: Analytical Applications for Amperometric Sensing of Hydrogen Peroxide
Authors: Mujica Michael López , Sotomayor‐Santander Ilania , Hermosilla‐Ibáñez Patricio , Oyarzun‐Ampuero Felipe , Rodríguez Marcela C. , Rivas Gustavo A. , Venegas‐Yazigi Diego , Bollo Soledad 
Published: May 2021

AbstractWe report a hybrid material obtained by dispersing the polyoxometalate n‐[Bu4‐N]2[Mo6O18NC13H9] functionalized with 2‐aminofluorene (POMAF) and multi‐walled carbon nanotubes (MWCNTs) in 1,3‐dioxolane (MWCNT‐ POMAF). We demonstrate the peroxidase‐like activity of the hybrid material and its application for the amperometric quantification of hydrogen peroxide at −0.450 V previous drop‐coating at glassy carbon electrodes, with a linear range between 1.0 μM and 6.0 μM and a detection limit of 330 nM. The reproducibility was 2.2 % using one MWCNTs‐POMAF dispersion, and 3.9 % using 4 different dispersions. The sensor was successfully used for the quantification of hydrogen peroxide in enriched milk samples.
Purification and characterization of the receptor‐binding domain of SARS‐CoV‐2 spike protein from Escherichia coli
Authors: He Yunxia , Qi Jinming , Xiao Lucheng , Shen Lijuan , Yu Weili , Hu Tao 
Published: May 2021

AbstractSARS‐CoV‐2 is responsible for a disruptive worldwide viral pandemic, and renders a severe respiratory disease known as COVID‐19. Spike protein of SARS‐CoV‐2 mediates viral entry into host cells by binding ACE2 through the receptor‐binding domain (RBD). RBD is an important target for development of virus inhibitors, neutralizing antibodies, and vaccines. RBD expressed in mammalian cells suffers from low expression yield and high cost. E. coli is a popular host for protein expression, which has the advantage of easy scalability with low cost. However, RBD expressed by E. coli (RBD‐1) lacks the glycosylation, and its antigenic epitopes may not be sufficiently exposed. In the present study, RBD‐1 was expressed by E. coli and purified by a Ni Sepharose Fast Flow column. RBD‐1 was structurally characterized and compared with RBD expressed by the HEK293 cells (RBD‐2). The secondary structure and tertiary structure of RBD‐1 were largely maintained without glycosylation. In particular, the major β‐sheet content of RBD‐1 was almost unaltered. RBD‐1 could strongly bind ACE2 with a dissociation constant (KD) of 2.98 × 10–8 M. Thus, RBD‐1 was expected to apply in the vaccine development, screening drugs and virus test kit.