bluuebunny/crossref_metadata_2025 huggingface dataset:
Interactions between plant genome size, nutrients and herbivory by rabbits, molluscs and insects on a temperate grassland
Authors: Guignard Maïté S. , Crawley Michael J. , Kovalenko Dasha , Nichols Richard A. , Trimmer Mark , Leitch Andrew R. , Leitch Ilia J.
Published: March 2019

Angiosperm genome sizes (GS) varyca2400-fold. Recent research has shown that GS influences plant abundance, and plant competition. There are also tantalizing reports that herbivores may select plants as food dependent on their GS. To test the hypothesis that GS plays a role in shaping plant communities under herbivore pressure, we exploit a grassland experiment that has experimentally excluded herbivores and applied nutrient over 8 years. Using phylogenetically informed statistical models and path analyses, we show that under rabbit grazing, plant species with small GS generated the most biomass. By contrast, on mollusc and insect-grazed plots, it was the plant species with larger GS that increased in biomass. GS was also shown to influence plant community properties (e.g. competitive strategy, total biomass) although the impact varied between different herbivore guilds (i.e. rabbits versus invertebrates) and nutrient inputs. Overall, we demonstrate that GS plays a role in influencing plant–herbivore interactions, and suggest potential reasons for this response, which include the impact of GS on a plant's response to different herbivore guilds, and on a plant's nutrient quality. The inclusion of GS in ecological models has the potential to expand our understanding of plant productivity and community ecology under nutrient and herbivore stress.
Genomic evidence for MHC disassortative mating in humans
Authors: Dandine-Roulland Claire , Laurent Romain , Dall'Ara Irene , Toupance Bruno , Chaix Raphaëlle
Published: March 2019

Although pervasive in many animal species, the evidence for major histocompatibility complex (MHC) disassortative mating in humans remains inconsistent across studies. Here, to revisit this issue, we analyse dense genotype data for 883 European and Middle Eastern couples. To distinguish MHC-specific effects from socio-cultural confounders, the pattern of relatedness between spouses in the MHC region is compared to the rest of the genome. Couples from Israel exhibit no significant pattern of relatedness across the MHC region, whereas across the genome, they are more similar than random pairs of individuals, which may reflect social homogamy and/or cousin marriages. On the other hand, couples from The Netherlands and more generally from Northern Europe are significantly more MHC-dissimilar than random pairs of individuals, and this pattern of dissimilarity is extreme when compared with the rest of the genome. Our findings support the hypothesis that the MHC influences mate choice in humans in a context-dependent way: MHC-driven preferences may exist in all populations but, in some populations, social constraints over mate choice may reduce the ability of individuals to rely on such biological cues when choosing their mates.
Evidence for non-colligative function of small cryoprotectants in a freeze-tolerant insect
Authors: Toxopeus Jantina , Koštál Vladimír , Sinclair Brent J.
Published: March 2019

Freeze tolerance, the ability to survive internal ice formation, facilitates survival of some insects in cold habitats. Low-molecular-weight cryoprotectants such as sugars, polyols and amino acids are hypothesized to facilitate freeze tolerance, but theirin vivofunction is poorly understood. Here, we use a combination of metabolomics and manipulative experimentsin vivoandex vivoto examine the function of multiple cryoprotectants in the spring field cricketGryllus veletis. Cold-acclimatedG. veletisare freeze-tolerant and accumulatemyo-inositol, proline and trehalose in their haemolymph and fat body. Injecting freeze-tolerant crickets with proline and trehalose increases survival of freezing to lower temperatures or for longer times. Similarly, exogenousmyo-inositol and trehalose increaseex vivofreezing survival of fat body cells from freeze-tolerant crickets. No cryoprotectant (alone or in combination) is sufficient to confer freeze tolerance on non-acclimated, freeze-intolerantG. veletis. Given that each cryoprotectant differentially impacts survival in the frozen state, we conclude that small cryoprotectants are not interchangeable and likely function non-colligatively in insect freeze tolerance. Our study is the first to experimentally demonstrate the importance of non-colligative cryoprotectant function for insect freeze tolerance bothin vivoandex vivo, with implications for choosing new molecules for cryopreservation.
Cell wall inhibitors increase the accumulation of rifampicin in Mycobacterium tuberculosis
Authors: McNeil Matthew B. , Chettiar Somsundaram , Awasthi Divya , Parish Tanya
Published: March 2019

There is a need for new combination regimens for tuberculosis. Identifying synergistic drug combinations can avoid toxic side effects and reduce treatment times. Using a fluorescent rifampicin conjugate, we demonstrated that synergy between cell wall inhibitors and rifampicin was associated with increased accumulation of rifampicin. Increased accumulation was also associated with increased cellular permeability.
A genomic analysis and transcriptomic atlas of gene expression inPsoroptes ovisreveals feeding- and stage-specific patterns of allergen expression
Authors: Burgess Stewart TG , Marr Edward J , Bartley Kathryn , Nunn Francesca G , Down Rachel E , Weaver Robert J , Prickett Jessica C , Dunn Jackie , Rombauts Stephane , Van Leeuwen Thomas , Van de Peer Yves , Nisbet Alasdair J
Published: March 2019

Psoroptic mange, caused by infestation with the ectoparasitic mite,Psoroptes ovis, is highly contagious, resulting in intense pruritus and represents a major welfare and economic concern for the livestock industry Worldwide. Control relies on injectable endectocides and organophosphate dips, but concerns over residues, environmental contamination, and the development of resistance threaten the sustainability of this approach, highlighting interest in alternative control methods. However, development of vaccines and identification of chemotherapeutic targets is hampered by the lack ofP. ovistranscriptomic and genomic resources. Building on the recent publication of theP. ovisdraft genome, here we present a genomic analysis and transcriptomic atlas of gene expression inP. ovisrevealing feeding- and stage-specific patterns of gene expression, including novel multigene families and allergens. Network-based clustering revealed 14 gene clusters demonstrating either single- or multi-stage specific gene expression patterns, with 3,075 female-specific, 890 male-specific and 112, 217 and 526 transcripts showing larval, protonymph and tritonymph specific-expression, respectively. Detailed analysis ofP. ovisallergens revealed stage-specific patterns of allergen gene expression, many of which were also enriched in “fed” mites and tritonymphs, highlighting an important feeding-related allergenicity in this developmental stage. Pair-wise analysis of differential expression between life-cycle stages identified patterns of sex-biased gene expression and also identified novelP. ovismultigene families including known allergens and novel genes with high levels of stage-specific expression. The genomic and transcriptomic atlas described here represents a unique resource for the acarid-research community, whilst the OrcAE platform makes this freely available, facilitating further community-led curation of the draftP. ovisgenome.
Protein fold prediction using simulated DEER distance distributions and decay traces
Authors: Alamo Diego del , Tessmer Maxx , Stein Richard , Feix Jimmy B. , Mchaourab Hassane S. , Meiler Jens
Published: March 2019

Despite advances in sampling and scoring strategies, Monte Carlo modeling methods still struggle to accurately predict de novo the structures of large proteins, membrane proteins, or proteins of complex topologies. Previous approaches have addressed these shortcomings by leveraging sparse distance data gathered using site-directed spin labeling and electron paramagnetic resonance spectroscopy (SDSL-EPR) to improve protein structure prediction and refinement outcomes. However, existing computational implementations must choose between coarse-grained models of the spin label that lower the resolution and explicit models that lead to resource-intense simulations. Existing methods are further limited by their reliance on distance distributions, which are calculated from a primary refocused echo decay signal and may contain artifacts introduced during this processing step. Here, we addressed these challenges by developing RosettaDEER, a scoring method within the Rosetta software suite capable of simulating distance distributions and echo decay traces between spin labels fast enough to fold proteins de novo. We demonstrate that the accuracy of resulting distance distributions match or exceed those generated by more computationally intensive methods. Moreover, decay traces generated from these distributions recapitulate intermolecular background coupling parameters, allowing RosettaDEER to discriminate between poorly-folded and native-like models even when the time window of EPR data collection is truncated, rendering them unsuitable for accurate transformation into distance distributions. Finally, we demonstrate that one decay trace per nine residues is sufficient to predict the folds of Bax and the C-terminus of ExoU, two soluble proteins with surface-exposed amphipathic structural features that prevent the Rosetta energy function from correctly identifying native-like models in the absence of experimental data. These benchmarking results confirm that RosettaDEER can effectively leverage sparse experimental data for a wide array of modeling applications built into the Rosetta software suite.
Allelopathic effect of Anogeissus pendula Edgew. and Grewia flavescens A.Juss on Desmodium species in Alwar district of Rajasthan
Authors: Prasad Rajendra , Yadav A S
Published: March 2019

The effect of leaf leachates of Anogeissus pendula Edgew. and Grewia flavescens A.Juss was evaluated on growth of the three species of Desmodium in Alwar district of Rajasthan (27°4’ to 28°4’ N and 76°7’ to 77°13’ E). Anogeissus pendula reduced the seed germination of Desmodium repandum from 85% in control to 43% at 2% concentration, Desmodium gangeticum from 80% in control to 50% at 6% concentration and Desmodium triflorum from 78% in control to 28% at 0.1% concentration of leaf leachates. Similarly, the leaf leachates of Grewia flavescens reduced the seed germination of Desmodium repandum from 85% in control to 40% at 2% concentration, Desmodium gangeticum from 80% in control to 50% even at 0.1% concentration and Desmodium triflorum from 78% in control to 21% at 0.5% concentration. The leaf leachates of both the species also reduced the elongation of radicle and plumule of three Desmodium species; however, the adverse effect of leaf leachate of Grewia flavescens was more severe than that of the other species. Among the three Desmodium species, the allelopathic effect of Grewia flavescens and Anogeissus pendula was more severe on Desmodium triflorum as compared to the other two species. It may be suggested that the population of three species of Desmodium is partly regualated by the allelopathic effect of Anogeissus pendula and Grewia flavescens in this tropical dry deciduous forest.
A type III CRISPR ancillary ribonuclease degrades its cyclic oligoadenylate activator
Authors: Athukoralage Januka S. , Graham Shirley , Grüschow Sabine , Rouillon Christophe , White Malcolm F.
Published: March 2019

Cyclic oligoadenylate (cOA) secondary messengers are generated by type III CRISPR systems in response to viral infection. cOA allosterically activates the CRISPR ancillary ribonucleases Csx1/Csm6, which degrade RNA non-specifically using a HEPN (Higher Eukaryotes and Prokaryotes, Nucleotide binding) active site. This provides effective immunity, but can also lead to growth arrest in infected cells, necessitating a means to deactivate the ribonuclease once viral infection has been cleared. In the crenarchaea, dedicated ring nucleases degrade cA4(cOA consisting of 4 AMP units), but the equivalent enzyme has not been identified in bacteria. We demonstrate that, inThermus thermophilusHB8, the uncharacterised protein TTHB144 is a cA4-activated HEPN ribonuclease that also degrades its activator. TTHB144 binds and degrades cA4at an N-terminal CARF (CRISPR Associated Rossman Fold) domain. The two activities can be separated by site-directed mutagenesis. TTHB144 is thus the first example of a self-limiting CRISPR ribonuclease.

Graphical abstract
Effect of partial selfing and polygenic selection on establishment in a new habitat
Authors: Sachdeva Himani
Published: March 2019

This paper analyzes how partial selfing in a large source population influences its ability to colonize a new habitat via the introduction of a few founder individuals. Founders experience inbreeding depression due to partially recessive deleterious alleles as well as maladaptation to the new environment due to selection on a large number of additive loci. I first introduce a simplified version of the Inbreeding History Model (Kelly, 2007) in order to characterize mutation-selection balance in a large, partially selfing source population under selection involving multiple non-identical loci. I then use individual-based simulations to study the eco-evolutionary dynamics of founders establishing in the new habitat under a model of hard selection. The study explores how selfing rate shapes establishment probabilities of founders via effects on both inbreeding depression and adaptability to the new environment, and also distinguishes the effects of selfing on the initial fitness of founders from its effects on the long-term adaptive response of the populations they found. A high rate of (but not complete) selfing is found to aid establishment over a wide range of parameters, even in the absence of mate limitation. The sensitivity of the results to assumptions about the nature of polygenic selection are discussed.
Dynamic ubiquitination determines transcriptional activity of the plant immune coactivator NPR1
Authors: Skelly Michael J. , Furniss James J. , Grey Heather L. , Wong Ka-Wing , Spoel Steven H.
Published: March 2019

Activation of systemic acquired resistance in plants is associated with transcriptome reprogramming induced by the unstable coactivator NPR1. Immune-induced ubiquitination and proteasomal degradation of NPR1 are thought to facilitate continuous delivery of active NPR1 to target promoters, thereby maximising gene expression. Because of this potentially costly sacrificial process, we investigated if ubiquitination of NPR1 plays transcriptional roles prior to its proteasomal turnover. Here we show ubiquitination of NPR1 is a processive event in which initial modification by a Cullin-RING E3 ligase promotes its chromatin association and expression of target genes. Only when polyubiquitination of NPR1 is enhanced by the E4 ligase, UBE4, it is targeted for proteasomal degradation. Conversely, ubiquitin ligase activities are opposed by UBP6/7, two proteasome-associated deubiquitinases that enhance NPR1 longevity. Thus, immune-induced transcriptome reprogramming requires sequential actions of E3 and E4 ligases balanced by opposing deubiquitinases that fine-tune activity of NPR1 without strict requirement for its sacrificial turnover.
The dynamics of centromere motion through the metaphase-to-anaphase transition reveal a centromere separation order
Authors: Armond Jonathan W. , Dale Katie L. , Burroughs Nigel J. , McAinsh Andrew D. , Vladimirou Elina
Published: March 2019

During cell division, chromosomes align at the equator of the cell before sister chromatids separate to move to each daughter cell during anaphase. We use high-speed imaging, Bayesian modelling and quantitative analysis to examine the regulation of centromere dynamics through the metaphase-to-anaphase transition. We find that, contrary to the apparent instantaneous separation seen in low-frequency imaging, centromeres separate asynchronously over 1-2 minutes. The timing of separations negatively correlates with the centromere intersister distance during metaphase, which could potentially be explained by variable amounts of cohesion at centromeres. Depletion of condensin I increases this asynchrony. Depletion of condensin II, on the other hand, abolishes centromere metaphase oscillations and impairs centromere speed in anaphase. These results suggest that condensin complexes have broader direct roles in mitotic chromosome dynamics than previously believed and may be crucial for the regulation of chromosome segregation.
Sex Solves Haldane’s Dilemma
Authors: Hickey Donal A. , Golding G. Brian
Published: March 2019

The cumulative reproductive cost of multi-locus selection has been seen as a potentially limiting factor on the rate of adaptive evolution. In this paper, we show that Haldane’s arguments for the accumulation of reproductive costs over multiple loci are valid only for a clonally reproducing population of asexual genotypes. We show that a sexually reproducing population avoids this accumulation of costs. Thus, sex removes a perceived reproductive constraint on the rate of adaptive evolution. The significance of our results is twofold. First, the results demonstrate that adaptation based on multiple genes – such as selection acting on the standing genetic variation - does not entail a huge reproductive cost as suggested by Haldane, provided of course that the population is reproducing sexually. Secondly, this reduction in the cost of natural selection provides a simple biological explanation for the advantage of sex. Specifically, Haldane’s calculations illustrate the evolutionary disadvantage of asexuality; sexual reproduction frees the population from this disadvantage.
Identifying the neural representation of fast and slow states in force field adaptation via fMRI
Authors: Farrens Andria J. , Sergi Fabrizio
Published: March 2019

Neurorehabilitation is centered on motor learning and control processes, however our understanding of how the brain learns to control movements is still limited. Motor adaptation is a rapid form of motor learning that is amenable to study in the laboratory setting. Behavioral studies of motor adaptation have coupled clever task design with computational modeling to study the control processes that underlie motor adaptation. These studies provide evidence of fast and slow learning states in the brain that combine to control neuromotor adaptation.

Currently, the neural representation of these states remains unclear, especially for adaptation to changes in task dynamics, commonly studied using force fields imposed by a robotic device. Our group has developed the MR-Softwrist, a robot capable of executing dynamic adaptation tasks during functional magnetic resonance imaging (fMRI) that can be used to localize these networks in the brain.

We simulated an fMRI experiment to determine if signal arising from a switching force field adaptation task can localize the neural representations of fast and slow learning states in the brain. Our results show that our task produces reliable behavioral estimates of fast and slow learning states, and distinctly measurable fMRI activations associated with each state under realistic levels of behavioral and measurement noise. Execution of this protocol with the MR-Softwrist will extend our knowledge of how the brain learns to control movement.
Cardiac remodeling after six weeks of high-intensity interval training to exhaustion in endurance-trained males
Authors: Mahjoub Haïfa , Le Blanc Olivier , Paquette Myriam , Imhoff Sarah , Labrecque Lawrence , Drapeau Audrey , Poirier Paul , Bédard Élisabeth , Pibarot Philippe , Brassard Patrice
Published: March 2019

High-intensity interval training (HIIT) improves physical performance of endurance athletes, although studies examining its cardiovascular effects are sparse. We evaluated the impact of HIIT on blood pressure, heart rate and cardiac cavities size and function in endurance-trained adults. Seventeen endurance-trained males underwent 24-hour ambulatory blood pressure monitoring (ABPM) and Doppler echocardiography at baseline and after 6 weeks of HIIT. Participants were divided in 2 groups (85% maximal aerobic power (MP); HIIT85, n=8 and 115% MP; HIIT115, n = 9) in order to compare the impact of different HIIT intensities. ABPM and cardiac chambers size and function were similar between groups at baseline. HIIT reduced heart rate (55 ± 8 vs. 51 ± 7 bpm; p= 0.003), systolic blood pressure (SBP; 121 ± 11 vs 118 ± 9 mmHg; p = 0.01), mean arterial pressure (MAP; 90 ± 8 vs 89 ± 6 mmHg; p = 0.03) and pulse pressure (52 ± 6 vs 49 ± 5 mmHg; p = 0.01), irrespective of training intensity. Left atrium (LA) volumes increased after HIIT (maximal: 50 ± 14 vs 54 ±14 ml; p= 0.02; minimal: 15 ± 5 vs 20 ± 8 ml; p = 0.01) in both groups. Right ventricle (RV) global longitudinal strain lowered after training in the HIIT85 group only (20 ± 4 vs. 17 ± 3%, p = 0.04). In endurance-trained males, six weeks of HIIT reduce SBP and MAP and increase LA volumes irrespective of training intensity, whereas submaximal HIIT deteriorates RV systolic function.

Key points

High-intensity interval training improves physical performance of endurance athletes, although studies examining its cardiovascular effects are sparse.

We evaluated the impact of submaximal (85% maximal aerobic power) and supramaximal (115% maximal aerobic power) high-intensity interval training on ambulatory blood pressure, heart rate and cardiac cavities size and function in endurance-trained adults.

Irrespective of training intensity, six weeks of high-intensity interval training increase left atrial volumes in endurance-trained adults, whereas the submaximal training decreases right ventricular systolic function.

These results may help identify the exercise threshold for potential toxicity of intense exercise training for at-risk individuals and ideal exercise training regimens conferring optimal cardiovascular protection and adapted endurance training for athletes.
A stochastic hybrid model of DNA replication incorporating 3D protein mobility dynamics
Authors: Windhager Jonas , Paine Amelia , Nathanailidou Patroula , Tasiudi Eve , Rodríguez Martínez María , Lygeros John , Lygerou Zoi , Rapsomaniki Maria Anna
Published: March 2019

DNA replication, the basis of genetic information maintenance, is a remarkably robust yet highly stochastic process. We present a computational model that incorporates experimental genome structures and protein mobility dynamics to mechanistically describe the stochastic foundations of DNA replication. Analysis of about 300,000in silicoprofiles for fission yeast indicates that the number of firing factors is rate-limiting and dominates completion time. Incorporating probabilistic activation and binding, a full-genome duplication was achieved with at least 300 firing factors, with the only assumption that factors get recycled upon replication fork collision. Spatial patterns of replication timing were reproduced only when firing factors were explicitly activated proximally to the spindle pole body. Independentin vivoexperiments corroborate that the spindle pole body acts as a replication activator, driving origin firing. Our model provides a framework to realistically simulate full-genome DNA replication and investigate the effects of nuclear architecture.
Air mass source determines airborne microbial diversity at the ocean-atmosphere interface of the Great Barrier Reef marine ecosystem
Authors: Archer Stephen D.J. , Lee Kevin C , Caruso Tancredi , King-Miaow Katie , Harvey Mike , Huang Danwei , Wainwright Benjamin J , Pointing Stephen B
Published: March 2019

The atmosphere is the least understood biome on Earth despite its critical role as a microbial transport medium. The influence of surface cover on composition of airborne microbial communities above marine systems is unclear. Here we report evidence for a dynamic microbial presence at the ocean-atmosphere interface of a major marine ecosystem, the Great Barrier Reef, and identify that recent air mass trajectory over an oceanic or continental surface associated with observed shifts in airborne bacterial and fungal diversity. Relative abundance of shared taxa between air and coral microbiomes varied between 2.2-8.8% and included those identified as part of the core coral microbiome. We propose that this variable source of atmospheric inputs may in part contribute to the diverse and transient nature of the coral microbiome.
The signaling mechanism of Hcy-induced atrial fibrosis mediated by TRPC3
Authors: Han Lu , Tang Yanhua , Wu Yanqing , Chen Xiaoshu , Hong Kui , Li Juxiang
Published: March 2019

Background

High plasma levels of homocysteine (Hcy) are regarded as a risk factor for atrial fibrillation (AF), which is closely associated with the pathological consequence of atrial fibrosis and can lead to heart failure with a high mortality rate; Currently, there is no effective therapy for preventing atrial fibrosis, owing to a lack in fundamental understanding of the underlying mechanism. Here, we show that atrial fibrosis is mediated by the relationship between canonical transient receptor potential 3 (TRPC3) channels and sirtuin type 1 (SIRT1) under the stimulation of Hcy.

Methods

The left atrial appendage was obtained from patients with either sinus rhythm (SR) or AF, who underwent cardiothoracic surgery, and used to evaluate the relationship between the concentration of Hcy and a potential mechanism of cardiac fibrosis mediated by TRPC3 and SIRT1. We next performed transverse aortic constriction (TAC) in mouse to investigate the relationship. The mechanisms underlying atrial fibrosis involving TRPC3 and SIRT1 proteins were explored by co-immunoprecipitation (co-IP), bio-layer interferometry (BLI) and lentivirus transfection experiments. Quantitative polymerase chain reaction (qPCR) and western blotting (WB) were performed to analyse gene and protein expression, respectively.

Results

The majority of AF patients displayed atrial fibrosis, as demonstrated by Masson staining and immunohistochemistry. In the mouse model of TAC, more severe fibrosis was detected in the high-Hcy diet (HH) group, compared to NH mice; and the duration of induced AF was longer in the HH groups than in the normal diet (NH) group. Moreover, the HH group exhibited higher expression levels of TRPC3 and related fibrosis proteins, such as TGF-ß and Col-I, than the NH group, despite also showing a higher level of SIRT1 was observed. The activator of SIRT1 (Resveratrol, Res) attenuated the enhancement of TRPC3 and decrease in SIRT1 observed in the HH group. Further cell culture experiments confirmed that Hcy could promote the proliferation and differentiation of fibroblasts, the up-regulation of TRPC3, and the decrease in the protein level of SIRT1. Ultimately, the results of Co-IP and BLI indicated a direct interaction between TRPC3-C terminal domain (569-863) and SIRT1 proteins, in which the two proteins are antagonistic and in combination regulate the pathogenesis of atrial fibrosis.

Conclusions

The higher level of atrial fibrosis were observed in the HH mouse group, compared with the NH mice group, Such results suggest that AF patients may be more susceptible to atrial fibrosis and possess a high probability of progressing to hyperhomocysteinemia. Moreover, our findings are consistent with the hypothesis that TRPC3 channel up-regulation leads to abnormal accumulation of collagen, with the down-regulation of SIRT1 as an aetiological factor of high Hcy, which in turn predisposes to atrial fibrosis and strongly enhances the possibility of AF.
Evaluation of PicoGreen variants for use in microscopy and flow cytometry
Authors: Khatoo Muznah , Yang Jongtae , Gee Kyle R. , Gasser Stephan
Published: March 2019

PicoGreen is a fluorescent probe that binds dsDNA and forms a highly luminescent complex when compared to the free dye in solution. This unique probe is widely used in DNA quantitation assays but has limited application in flow cytometry and microscopy. Here we have investigated various PicoGreen variants for the ability to stain low amounts of cytosolic DNA present in many tumor cells. Analysis of stained cells by flow cytometry and fluorescent microscopy showed that certain variants improved the ability to stain low levels of cytosolic DNA when compared to the commercially available PicoGreen molecule.
The formation of the salt and neutral molecule cocrystal from equimolar solution of heliamine and bicyclo[2.2.1]hept-5-ene-endo-2,3-dicarboxylic acid
Authors: Shishkina Svitlana V. , Isaiev Ivan A. , Urzhuntseva Viktoriya V. , Palchykov Vitalii A.
Published: March 2019

The possible interaction of 6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline (heliamine) with bicyclo[2.2.1]hept-5-ene-endo-2,3-dicarboxylic acid anhydride has been studied. Instead of the reaction with heliamine, the acid anhydride was hydrolyzed into the appropriate dicarboxylic acid. An equimolar mixture of unreacted heliamine and in-situ-generated dicarboxylic acid crystallized in space group P21/c. The comprehensive study of the obtained crystals shows that the peculiarities of the crystallization process lead to the formation of the salt-cocrystal structure where the dianion interacts simultaneously with two cations forming a chain as the primary structural motif. The neutral molecules of dicarboxylic acid link the dianions of the neighbouring chains, forming a layer as the secondary structural motif. As a result, the stronger hydrogen bonds formed by the neutral molecules play a secondary role in the crystal structure formation.
4-(Benzofuran-2-yl)-2-[3-(4-chlorophenyl)-5-(4-fluorophenyl)-4,5-dihydro-1H-pyrazol-1-yl]thiazole
Authors: El-Hiti Gamal A. , Abdel-Wahab Bakr F. , Alqahtani Alaa , Hegazy Amany S. , Kariuki Benson M.
Published: March 2019

The molecule of the title compound, C26H17ClFN3OS, comprises benzofuranyl (A), thiazolyl (B), pyrazolyl (C), chlorophenyl (D) and fluorophenyl (E) ring systems. Rings A–D are almost coplanar, as indicated by the twist angles between the ring pairs A/B, B/C and C/D of 7.6 (1), 4.7 (1) and 6.9 (2)°, respectively. Ring E is twisted by 73.2 (1)° from the plane through ring C. In the crystal, pairwise C—H...F interactions link the molecules into inversion dimers. Aromatic π–π interactions are also observed between rings A and E and between rings B and C for neighbouring pairs of molecules related by inversion symmetry. Taken together, the weak interactions generate [010] chains.
Understanding credibility judgements for web search snippets
Authors: Kattenbeck Markus , Elsweiler David
Published: March 2019

Purpose

It is well known that information behaviour can be biased in countless ways and that users of web search engines have difficulty in assessing the credibility of results. Yet, little is known about how search engine result page (SERP) listings are used to judge credibility and in which if any way such judgements are biased. The paper aims to discuss these issues.

Design/methodology/approach

Two studies are presented. The first collects data by means of a controlled, web-based user study (N=105). Studying judgements for three controversial topics, the paper examines the extent to which users agree on credibility, the extent to which judgements relate to those applied by objective assessors and to what extent judgements can be predicted by the users’ position on and prior knowledge of the topic. A second, qualitative study (N=9) utilises the same setup; however, transcribed think-aloud protocols provide an understanding of the cues participants use to estimate credibility.

Findings

The first study reveals that users are very uncertain when assessing credibility and their impressions often diverge from objective judges who have fact checked the sources. Little evidence is found indicating that judgements are biased by prior beliefs or knowledge, but differences are observed in the accuracy of judgements across topics. Qualitatively analysing think-aloud transcripts from participants think-aloud reveals ten categories of cues, which participants used to determine the credibility of results. Despite short listings, participants utilised diverse cues for the same listings. Even when the same cues were identified and utilised, different participants often interpreted these differently. Example transcripts show how participants reach varying conclusions, illustrate common mistakes made and highlight problems with existing SERP listings.

Originality/value

This study offers a novel perspective on how the credibility of SERP listings is interpreted when assessing search results. Especially striking is how the same short snippets provide diverse informational cues and how these cues can be interpreted differently depending on the user and his or her background. This finding is significant in terms of how search engine results should be presented and opens up the new challenge of discovering technological solutions, which allow users to better judge the credibility of information sources on the web.
Accruals quality and the cost of debt: the European evidence
Authors: Eliwa Yasser , Gregoriou Andros , Paterson Audrey
Published: March 2019

Purpose

This paper aims to investigate the empirical relationship between the cost of debt (CoD) and accruals quality (AQ) of European listed firms during the period of 2005 to 2014. Also, it aims to test the impact of the interrelationship between the financial crisis (2008-2009) and AQ on CoD. Finally, we decompose AQ into two components; the innate (InnateAQ) and discretionary components (DiscAQ); and test their relationships with CoD.

Design/methodology/approach

To empirically examine the relationship between AQ and CoD, a sample including 15 member states of the EU is constructed. AQ proxy is based on the McNichols (2002) modification of Dechow and Dichev (2002) model. A univariate analysis and a multivariate analysis are conducted to examine the relationship between AQ and CoD after controlling for firm characteristics and institutional variables.

Findings

We find a significant negative association between AQ and CoD in a vast proportion of the 15 countries under review. Also, the results indicate that during the crisis period, creditors pay relatively more attention to the quality of accounting information than during the pre-crisis period when they determine CoD of firms. Moreover, we report a link between the magnitude of this relationship and national characteristics and provide evidence of the significant effects of national characteristics and market forces on CoD. Finally, we find that InnateAQ drives the relationship with CoD.

Practical implications

This paper provides up-to-date evidence on the economic consequences of AQ and IFRS in the capital market. The results should, therefore, be of interest to managers, creditors, regulators and standard-setters.

Originality/value

To the best of the authors’ knowledge, this is the first paper to investigate the effects of AQ on CoD for European listed firms. Also, it examines the impact of financial crisis on the association between AQ and CoD.
Empirical analysis of HPO framework in public sector organizations of Pakistan
Authors: Kalimullah Kalimullah , Arshad Mohd Anuar , Khan Qaiser , Khan Shahid
Published: March 2019

Purpose

Building on high-performance organizations (HPO) framework, the purpose of this paper is to hypothesize the direct impact of five factors of HPO framework on public organizations’ performance in Pakistan. This is first research to employ the partial least squares (PLS) method to provide empirical evidence of the predictive power of the framework in public organizations.

Design/methodology/approach

This is a cross-sectional study conducted in non-contrived settings thereby keeping researcher interference to a minimum. Data collection was carried out by distributing online questionnaires to 513 employees from three different service-based public organizations in Pakistan. PLS is used to examine the statistical and substantive significance of five factors by employing SmartPLS 3.2.6.

Findings

This study concludes that the HPO framework has predictive relevance for public organizations’ performance surveyed in this study. Furthermore, three out of the five factors of HPO framework, namely, management quality, workforce quality and long-term orientation have positive relationships, while openness and action orientation (OAO), and continuous improvement process and renewal have a negative relationship with the performance of public sector organizations (PSOs) surveyed in Pakistan.

Research limitations/implications

The study’s small sample size limits this research, and only quantitative methodology is applied. A significant limitation of this research is that this study relied on a subset of respondents of surveyed organizations and may not representative of the population. Therefore, result should be carefully interpreted as some degree of biasness may be present. Furthermore, findings of the study cannot be generalized to all PSOs of Pakistan.

Practical implications

The implication for public managers is that the HPO framework has predictive relevance and substantive significance. However, the ideal value of HPO framework will occur when leadership considers HPO factors and struggles persistently to improve performance. The useful implication is that public managers should focus on continuous improvement process and renewal and OAO to meet stakeholders’ satisfaction.

Originality/value

This study answer two questions, first “is there any significant relationship of five factors of HPO framework with public organizations’ Performance in Pakistan?” and second “what is the predictive relevance level of HPO framework in the Public organizations in Pakistan?” The answers to these research questions will fill the gaps in the literature by providing empirical evidence to the existing knowledge on improvement methods, especially the public sector (PS), and contributing insights on the real world working of the five factors of HPO framework in a PS.
Upwelling as the major source of nitrogen for shallow and deep reef‐building corals across an oceanic atoll system
Authors: Radice Veronica Z. , Hoegh‐Guldberg Ove , Fry Brian , Fox Michael D. , Dove Sophie G.
Published: March 2019

Oceanographic processes shape coral reefs worldwide by redistributing inorganic nutrients and particulate resources over depth. Deep‐water upwelling occurs frequently in coral reef ecosystems, but its impact on coral nutrition remains unclear.

This study investigated the influence of upwelling on the trophic ecology of three common reef‐building corals (Galaxea fascicularis,Pachyseris speciosaandPocillopora verrucosa) from different reef depths (shallow reef, 10 m, vs. deep reef, 30 m) and reef exposures (oceanic rim vs. Inner Sea) across > 250 km of the Maldives archipelago, Indian Ocean. Carbon and nitrogen stable isotope ratios (δ13C and δ15N) of coral hosts, their symbionts and particulate organic matter (POM) were used to characterize coral trophic strategies.

Across the Maldives, consistent mean δ15N values were recorded in hosts (5.5‰) and symbionts (5.2‰) of the three coral species from shallow and deep reefs of oceanic and Inner Sea reef exposures. Coral hosts, symbionts and POM from both depths had δ15N values that were consistent with the isotopic signature of a deep‐water nitrate source transported to surface waters via upwelling.

In contrast, a wide range of δ13C values (~10‰) revealed different trophic strategies and isotopic niches among the coral species. Different mean δ13C values ofG. fascicularisindicated greater symbiont autotrophy in corals from shallow (‐15.5‰) compared to deep reefs (‐17.6‰). Conversely, the mean δ13C values ofP. speciosa(‐15.1‰) andP. verrucosa(‐17.7‰) were not affected by reef depth. These corals maintained consistent trophic strategies over depth, withP. speciosarelying more on autotrophy compared toP. verrucosa.

Despite different reef exposure to oceanic waters, coral host and POM δ15N and δ13C values did not differ between oceanic and Inner Sea reef exposures. Nutritional resources appear to be homogenous in the central Maldives due to atoll‐wide water circulation. However, species‐specific trophic strategies resulted in diverse patterns of δ13C values over depth. Because heterotrophic feeding has been linked to coral host survival through coral bleaching events, understanding the trophic ecology of corals within the reef assemblage can provide insight into species resilience under ocean warming conditions. As a member of the typically competitive Pocilloporidae family, the dependence ofP. verrucosaon heterotrophy may help this coral be a future “winner” under sustained ocean warming.

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Water‐soluble bioactive natural compounds in Trapa japonica leaves: Temporal changes in chemical composition and effects on cladocerans
Authors: Ishimota Makoto , Nakajima Daisuke , Sakamoto Masaki , Miyabara Yuichi
Published: March 2019

Littoral macrophyte vegetation provides a refuge for zooplankton from fish under certain circumstances. However, some chemicals produced by macrophytes harm zooplankton. Trapa japonica, a common annual floating‐leaved macrophyte, commonly occurs in Asian shallow and eutrophic lakes. In this study, we conducted preliminary evaluation of the adverse effects of T. japonica leaf extracts on Daphnia magna survival. Specifically, we investigated the effects of lake water to D. magna in relation to T. japonica abundance. The effect of littoral water samples peaked when the density of the macrophyte leaves began to decline. These findings coincided with those of acute immobilization tests of leaf extracts that had substances from leaves in the early yellowing stage showed strongest effect to the cladocerans, D. magna and Scapholeberis kingi. Moreover, the ion composition and amount of each ion varied depending on the leaf stage. Additionally, the multimodel inference approach showed that leaf extract effects depend on the total amount of the chemicals. Our findings indicate that the littoral macrophytes have unintended effects on zooplankton due to those differential decomposition.
The genera of bacteriophages and their receptors are the major determinants of host range
Authors: Gencay Yilmaz Emre , Gambino Michela , Prüssing Tessa From , Brøndsted Lone
Published: March 2019

The host range of phages is a key to understand their impact on bacterial ecology and evolution. Because of the complexity of phage–host interactions, the variables that determine the breadth of a phage host range remain poorly understood. Here, we propose a novel holistic approach to identify the host range determinants of a new collection of phages infecting Salmonella, isolated from animal, environmental and wastewater samples that were able to infect 58 of the 71 Salmonella strains in our collection. By using a set of statistic approaches (non‐metric dimensional scaling, Bray–Curtis distance, PERMANOVA), we analysed phenotypic (host range on wild‐type and receptor mutants) and genetic data (taxonomic assignment and receptor binding proteins) to evaluate the impact of isolation strain and niche, phage receptor and genus on the host range. Statistical analysis revealed that two phage characteristics influence the host range by explaining the most variance: the receptor by 45% and the genus by 51%. Interestingly, phage genus and receptor in combination explained 79% of the variance, establishing these characteristics as the major determinants of the host range. This study demonstrates the power and the novelty of applying statistical approaches to phenotypic and genetic data to investigate the ecology of phage–host interactions.
An investigation of change: elementary students with an individual education program participating in a school‐based mental health counselling intervention
Authors: Kelchner Viki P. , Perleoni Mary K. , Lambie Glenn W.
Published: March 2019

There is a high prevalence of mental health concerns among youth in the United States. School‐based mental health counselling interventions maybe one way of addressing the mental health concerns of youth. This study investigated changes in students’ behavioural and emotional problems scores and discipline referrals for those who participated in a 5‐week school‐based mental health counselling intervention (SBMHCI) at three Title I elementary schools, located in Southeastern United States. The participants (N = 35) to participate had an active Individual Education Program (IEP). They then received the SBMHCI grounded in a Humanistic counselling approach. A single‐group, pre‐test‐post‐test design was used to examine change in participants’ scores (internalizing and externalizing). There was no control group in place for this study therefore there was no comparisons made between participants and non‐participants’ outcomes. The researchers identified significant improvement over time on the parents’ ratings of the students’ internalizing problem scores and the teachers’ ratings of the students’ externalizing problem scores, and total problems scores per both parents and teachers’ report. Furthermore, the number of office discipline referrals decreased significantly over time.
Radiotherapy is an independent prognostic marker of favorable prognosis in non‐small cell lung cancer patients after treatment with the immune checkpoint inhibitor, nivolumab
Authors: Yamaguchi Ou , Kaira Kyoichi , Hashimoto Kosuke , Mouri Atsuto , Miura Yu , Shiono Ayako , Nishihara Fuyumi , Murayama Yoshitake , Noda Shin‐ei , Kato Shingo , Kobayashi Kunihiko , Kagamu Hiroshi
Published: March 2019

Background

It remains unclear why radiation clinically provides a synergistic effect when combined with immune checkpoint inhibitors such as nivolumab. The purpose of our study was to retrospectively evaluate whether the therapeutic efficacy of nivolumab is improved as a result of a history of radiotherapy (RT) in patients with previously treated advanced non‐small cell lung cancer (NSCLC).

Methods

From February 2016 to December 2017, 124 consecutive patients were administered nivolumab for pretreated advanced NSCLC. The patients were divided into RT and non‐RT groups.

Results

Sixty‐six (53%) of the 124 patients had been administered RT before the initiation of nivolumab, 52 (42%) received extracranial RT, and 40 (32%) were treated with thoracic RT. The median number of nivolumab cycles was 4 (range: 1–43). The overall response rate (ORR) and disease control rate (DCR) of nivolumab in all patients were 28.0% and 58.4%, respectively. The ORR (36.4%) was significantly higher in patients who had received previous RT than in patients who had not received any RT (19%). The therapeutic efficacy of nivolumab was particularly noteworthy in patients with non‐adenocarcinoma and squamous cell carcinoma histology administered extracranial RT, with ORRs of 48.3% and 52.6%, and DCRs of 87.1% and 84.2%, respectively.

Conclusion

Previous RT was an independent prognostic marker of favorable prognosis after nivolumab administration and improved the response rate to nivolumab treatment. Previous RT was clinically identified to have a synergistic effect with nivolumab treatment, increasing the response rate and improving the outcome of patients with advanced NSCLC.