bluuebunny/crossref_metadata_2025 huggingface dataset:
Control of Cardiac Mitochondrial Fuel Selection by Calcium
Authors: Jones Edith , Kandel Sunil M. , Dasika Santosh K. , Nourabadi Neda , Van den Bergh Françoise , Choi Hyo Sub , Haidar Ali , Dash Ranjan K. , Beard Daniel A.
Published: October 2017

Calcium ion concentration modulates the function of pyruvate dehydrogenase, isocitrate dehydrogenase, and α-ketoglutarate dehydrogenase. Previous studies have shown that despite its ability to affect the function of these dehydrogenases, [Ca2+] does not substantially alter mitochondrial ATP synthesis in vitro under physiological sub-strate conditions. We hypothesize that, rather than contributing to respiratory control, [Ca2+] governs fuel selection. Specifically, cardiac mitochondria are able to use different primary carbon substrates to synthesize ATP aerobically. To determine if and how [Ca2+] affects the relative use of carbohydrates versus fatty acids we measured oxygen consumption and tricarboxylic acid cycle intermediate concentrations in suspensions of cardiac mitochondria with different combinations of pyruvate and palmitoyl-L-carnitine in the media at various [Ca2+] and ADP infusion rates. Results reveal that when both fatty acid and carbohydrate substrates are available, fuel selection is sensitive to both calcium and ATP synthesis rate. When no Ca2+is added under low ATP-demand conditions, β-oxidation provides roughly half of acetyl-CoA for the citrate synthase reaction with the rest coming from the pyruvate dehydrogenase reaction. Under low demand conditions with increasing [Ca2+], the fuel utilization ratio shifts to increased fractional consumption of pyruvate, with 83±10% of acetyl-CoA derived from pyruvate at the highest [Ca2+] evaluated. With high ATP demand, the majority of acetyl-CoA is derived from pyruvate, regardless of the Ca2+level. Our results suggest that changes in work rate alone are enough to effect a switch to carbohydrate use while in vivo the rate at which this switch happens may depend on mitochondrial calcium.

Key Points

Despite its effects on activity of mitochondrial dehydrogenases, Ca2+does not substantially alter mitochondrial ATP synthesis in vitro under physiological substrate conditions. Nor does is appear to play an important role in respiratory control in vivo in the myocardium.

We hypothesize that Ca2+plays a role mediating the switch in fuel selection to increasing carbohydrate oxidation and decreasing fatty acid oxidation with increasing work rate.

To determine if and how Ca2+affects the relative use of carbohydrates versus fatty acids in vitro we measured oxygen consumption and TCA cycle intermediate concentrations in suspensions of purified rat ventricular mitochondria with carbohydrate, fatty acid, and mixed substrates at various [Ca2+] and ATP demand rates.

Our results suggest that changes in work rate alone are enough to effect a switch to carbohydrate use in vitro while in vivo the rate at which this switch happens may depend on mitochondrial calcium.
Immuno-phenotypes of Pancreatic Ductal Adenocarcinoma: Metaanalysis of transcriptional subtypes
Authors: Santiago Ines de , Yau Christopher , Middleton Mark , Dustin Michael , Markowetz Florian , Sivakumar Shivan
Published: October 2017

Pancreatic ductal adenocarcinoma (PDAC) is the most common malignancy of the pancreas and has one of the highest mortality rates of any cancer type with a 5-year survival rate of < 5% and median overall survival of typically six months from diagnosis. Recent transcriptional studies of PDAC have provided several competing stratifications of the disease. However, the development of therapeutic strategies will depend on a unique and coherent classification of PDAC. Here, we use an integrative meta-analysis of four different PDAC gene expression studies to derive the consensus PDAC classification. Despite the fact that immunotherapies have yet to have an impact in treatment of PDAC, the gene expression signatures that stratify PDAC across studies are immunologic. We define these as “adaptive”, “innate” and “immune-exclusion” immunologic signatures, which are prognostic across independent cohorts. An appreciation of the immune composition of PDAC with prognostic significance is an opportunity to understand distinct immune escape mechanisms in development of the disease and design novel immune-oncology therapeutic strategies to overcome current barriers.
Bayesian multiple logistic regression for case-control GWAS
Authors: Banerjee Saikat , Zeng Lingyao , Schunkert Heribert , Söding Johannes
Published: October 2017

Genetic variants in genome-wide association studies (GWAS) are tested for disease association mostly using simple regression, one variant at a time. Standard approaches to improve power in detecting disease-associated SNPs use multiple regression with Bayesian variable selection in which a sparsity-enforcing prior on effect sizes is used to avoid overtraining and all effect sizes are integrated out for posterior inference. For binary traits, thelogisticmodel has not yielded clear improvements over the linear model. For multi-SNP analysis, the logistic model required costly and technically challenging MCMC sampling to perform the integration.

Here, we introduce thequasi-Laplaceapproximation to solve the integral and avoid MCMC sampling. We expect the logistic model to perform much better than multiple linear regression except when predicted disease risks are spread closely around 0.5, because only close to its inflection point can the logistic function be well approximated by a linear function. Indeed, in extensive benchmarks with simulated phenotypes and real genotypes, our Bayesian multiple LOgistic REgression method (B-LORE) showed considerable improvements (1) when regressing on many variants in multiple loci at heritabilities ≥ 0.4 and (2) for unbalanced case-control ratios.

B-LORE also enables meta-analysis by approximating the likelihood functions of individual studies by multivariate normal distributions, using their means and covariance matrices as summary statistics. Our work should make sparse multiple logistic regression attractive also for other applications with binary target variables. B-LORE is freely available from:https://github.com/soedinglab/b-lore.
“Cell surface associated LapA ofPseudomonas fluorescensis anchored inside its Type-1 Secretion TolC-like Pore”
Authors: Jarrod Smith T. , Sondermann Holger , A. O’Toole George
Published: October 2017

The type-1 secretion system (T1SS) of gram-negative bacteria enables a one-step translocation strategy known to move functionally diverse proteins from the cytoplasm into the extracellular environment without a periplasmic intermediate. LapA ofPseudomonas fluorescensPf0-1 is a giant type-1 secreted (T1S) adhesin that facilitates biofilm formation only when displayed at the cell surface. A LapA-targeting periplasmic protease, LapG, connects intracellular cyclic diguanylate (c-di-GMP) levels with cell surface-associated LapA by cleaving and absolving LapA from the cell surface under conditions unsuitable for biofilm formation. Here, we demonstrate that LapA contains a novel N-terminal element, called the retention module (RM), which prohibits classical one-step T1S of LapA. We provide evidence that the RM of LapA tethers LapA at the cell surface through its outer membrane TolC-like pore, LapE, where LapA is accessible to the periplasmic protease LapG. We also demonstrate that this unusual retention strategy is likely conserved among LapA-like proteins and represents a new subclass of T1SS ABC transporters exclusively involved in transporting LapA-like adhesins.

Significance Statement

Bacteria have evolved multiple secretion strategies to interact with their environment. For many bacteria, the secretion of cell surface associated adhesins is often key for initiating contact with a preferred substrate to facilitate biofilm formation. Our work demonstrates thatP. fluorescensuses a previously unrecognized secretion strategy to retain the giant adhesin LapA at its cell surface. Further, we identify likely LapA-like adhesins in various pathogenic and commensal Proteobacteria and provide phylogenetic evidence these adhesins are secreted by a new subclass of T1SS ABC transporters.
Hox-logic of body plan innovations for social symbiosis in rove beetles
Authors: Parker Joseph , Taro Eldredge K. , Thomas Isaiah M. , Coleman Rory , Davis Steven R.
Published: October 2017

How symbiotic lifestyles evolve from free-living ecologies is poorly understood. In Metazoa’s largest family, Staphylinidae (rove beetles), numerous lineages have evolved obligate behavioral symbioses with ants or termites. Widespread convergence of this lifestyle is thought to stem from a novel, chemically defended body plan that enables free-living species to infiltrate colonies and undergo extreme evolutionary specialization. Here we show how this innovative body plan evolved, via newHoxfunctions in staphylinids that remodeled the coleopteran groundplan. Using a model staphylinid,Dalotia coriaria, we reveal theHoxbasis for changes in thoracic appendage morphology that shortened the beetle elytron and left the abdomen physically unprotected, selecting for an abdominal defense gland that was likely key to unlocking ant and termite societies. We present evidence that the gland evolved through a novel, combinatorial role of the abdominal Hox proteins AbdA and AbdB. These proteins function together to specify distinct gland cell types in neighboring segmental compartments, each cell type synthesizing a different class of compound—irritant, ester and solvent. Only when secreted together do these compounds constitute a bioactive secretion, providing an example of emergent chemical functionality that arises from synergy between individual gland cell types. Hox-controlled specification of glandular diversity implies a modularity in compound biosynthesis that likely catalyzed the evolvability of rove beetle chemistry, including the capacity of symbiotic taxa to produce potent compounds for host deception. This study reveals how Hox-controlled body axis modifications predispose a major animal to convergently evolve into symbionts.
Testing the role of the Red Queen and Court Jester as drivers of the macroevolution of Apollo butterflies
Authors: Condamine Fabien L. , Rolland Jonathan , Höhna Sebastian , Sperling Felix A. H. , Sanmartín Isabel
Published: October 2017

In macroevolution, the Red Queen (RQ) model posits that biodiversity dynamics depend mainly on species-intrinsic biotic factors such as interactions among species or life-history traits, while the Court Jester (CJ) model states that extrinsic environmental abiotic factors have a stronger role. Until recently, a lack of relevant methodological approaches has prevented the unraveling of contributions from these two types of factors to the evolutionary history of a lineage. Here we take advantage of the rapid development of new macroevolution models that tie diversification rates to changes in paleoenvironmental (extrinsic) and/or biotic (intrinsic) factors. We inferred a robust and fully-sampled species-level phylogeny, as well as divergence times and ancestral geographic ranges, and related these to the radiation of Apollo butterflies (Parnassiinae) using both extant (molecular) and extinct (fossil/morphological) evidence. We tested whether their diversification dynamics are better explained by a RQ or CJ hypothesis, by assessing whether speciation and extinction were mediated by diversity-dependence (niche filling) and clade-dependent host-plant association (RQ) or by large-scale continuous changes in extrinsic factors such as climate or geology (CJ). For the RQ hypothesis, we found significant differences in speciation rates associated with different host-plants but detected no sign of diversity-dependence. For CJ, the role of Himalayan-Tibetan building was substantial for biogeography but not a driver of high speciation, while positive dependence between warm climate and speciation/extinction was supported by continuously varying maximum-likelihood models. We find that rather than a single factor, the joint effect of multiple factors (biogeography, species traits, environmental drivers, and mass extinction) is responsible for current diversity patterns, and that the same factor might act differently across clades, emphasizing the notion of opportunity. This study confirms the importance of the confluence of several factors rather than single explanations in modeling diversification within lineages.
Spatial Control of Draper Receptor Signaling Initiates Apoptotic Cell Engulfment
Authors: Williamson Adam P. , Vale Ronald D.
Published: October 2017

The engulfment of apoptotic cells is essential for tissue homeostasis and responding to damage. Engulfment is mediated by receptors that recognize ligands exposed on apoptotic cells, such as phosphatidylserine (PS). Here, we convert Drosophila S2 cells into proficient phagocytes by transfecting the Draper engulfment receptor and replacing apoptotic cells with PS-coated beads. We show that PS-ligated Draper forms microclusters that exclude a bulky transmembrane phosphatase and recruit phosphotyrosine binding proteins, revealing a triggering mechanism similar to the T cell receptor (TCR). Analogous to the TCR, Draper’s extracellular domain and PS can be replaced with FRB and FKBP respectively, resulting in a rapamycin-inducible engulfment system. However, in contrast to the TCR, we show that localized signaling at Draper microclusters results in time-dependent depolymerization of actin filaments. Collectively, our results reveal mechanistic similarities and differences between the receptors involved in apoptotic corpse clearance and mammalian immunity and demonstrate that engulfment can be reprogrammed towards non-native targets.

Condensed title

Spatial Control of Engulfment Signaling
An epigenetic mechanism for cavefish eye degeneration
Authors: Gore Aniket V. , Tomins Kelly A. , Iben James , Ma Li , Castranova Daniel , Davis Andrew , Parkhurst Amy , Jeffery William R. , Weinstein Brant M.
Published: October 2017

Coding and non-coding mutations in DNA contribute significantly to phenotypic variability during evolution. However, less is known about the role of epigenetics in this process. Although previous studies have identified eye development genes associated with the loss of eyes phenotype in the Pachón blind cave morph of the Mexican tetraAstyanax mexicanus1-6, no inactivating mutations have been found in any of these genes2,3,7-10. Here we show that excess DNA methylation-based epigenetic silencing promotes eye degeneration in blind caveAstyanax mexicanus.By performing parallel analyses inAstyanax mexicanuscave and surface morphs and in the zebrafishDanio rerio,we have discovered that DNA methylation mediates eye-specific gene repression and globally regulates early eye development. The most significantly hypermethylated and down-regulated genes in the cave morph are also linked to human eye disorders, suggesting the function of these genes is conserved across the vertebrates. Our results show that changes in DNA methylation-based gene repression can serve as an important molecular mechanism generating phenotypic diversity during development and evolution.
Brd4-bound enhancers drive cell intrinsic sex differences in glioblastoma
Authors: Kfoury Najla , Qi Zongtai , Prager Briana C , Wilkinson Michael N , Broestl Lauren , Berrett Kristopher C , Moudgil Arnav , Sankararaman Sumithra , Chen Xuhua , Gertz Jay , Rich Jeremy Naftali , Mitra Robi D , Rubin Joshua B
Published: October 2017

Sex can be an important determinant of cancer phenotype, and exploring sex-biased tumor biology holds promise for identifying novel therapeutic targets and new approaches to cancer treatment. In an established isogenic murine model of glioblastoma, we discovered correlated transcriptome-wide sex differences in gene expression, H3K27ac marks, large Brd4-bound enhancer usage, and Brd4 localization to Myc and p53 genomic binding sites. These sex-biased gene expression patterns were also evident in human glioblastoma stem cells (GSCs). These observations led us to hypothesize that Brd4-bound enhancers might underlie sex differences in stem cell function and tumorigenicity in GBM. We found that male and female GBM cells exhibited opposing responses to pharmacological or genetic inhibition of Brd4. Brd4 knockdown or pharmacologic inhibition decreased male GBM cell clonogenicity andin vivotumorigenesis, while increasing both in female GBM cells. These results were validated in male and female patient-derived GBM cell lines. Furthermore, analysis of the Cancer Therapeutic Response Portal of human GBM samples segregated by sex revealed that male GBM cells are significantly more sensitive to BET inhibitors than are female cells. Thus, for the first time, Brd4 activity is revealed to drive a sex differences in stem cell and tumorigenic phenotype, resulting in diametrically opposite responses to BET inhibition in male and female GBM cells. This has important implications for the clinical evaluation and use of BET inhibitors.

Significance

Consistent sex differences in incidence and outcome have been reported in numerous cancers including brain tumors. GBM, the most common and aggressive primary brain tumor, occurs with higher incidence and shorter survival in males compared to females. Brd4 is essential for regulating transcriptome-wide gene expression and specifying cell identity, including that of GBM. We report that sex-biased Brd4 activity drive sex differences in GBM and render male and female tumor cells differentially sensitive to BET inhibitors. The observed sex differences in BETi treatment strongly indicate that sex differences in disease biology translate into sex differences in therapeutic responses. This has critical implications for clinical use of BET inhibitors further affirming the importance of inclusion of sex as a biological variable.
Sleep and the gut microbiome: antibiotic-induced depletion of the gut microbiota reduces nocturnal sleep in mice
Authors: Lendrum Jonathan , Seebach Bradley , Klein Barrett , Liu Sumei
Published: October 2017

Several bacterial cell wall components such as peptidoglycan and muramyl peptide are potent inducers of mammalian slow-wave sleep when exogenously administered to freely behaving animals. It has been proposed that the native gut microflora may serve as a quasi-endogenous pool of somnogenic bacterial cell wall products given their quantity and close proximity to the intestinal portal. This proposal suggests that deliberate manipulation of the host's intestinal flora may elicit changes in host sleep behavior. To test this possibility, we evaluated 24 h of sleep-wake behavior after depleting the gut microbiota with a 14 d broad-spectrum antibiotic regimen containing high doses of ampicillin, metronidazole, neomycin, and vancomycin. High-throughput sequencing of the bacterial 16S rDNA gene was used to confirm depletion of fecal bacteria and sleep-wake vigilance states were determined using videosomnography techniques based on previously established behavioral criteria shown to highly correlate with standard polysomnography-based methods. Additionally, considering that germ-free and antibiotic-treated mice have been earlier shown to display increased locomotor activity, and since locomotor activity has been used as a reliable proxy of sleep, we suspected that the elevated locomotor activity previously reported in these animals may reflect an unreported reduction in sleep behavior. To examine this potential relationship, we also quantified locomotor activity on a representative subsample of the same 24 h of video recordings using the automated video-tracking software ANY-maze. We found that antibiotic-induced depletion of the gut microbiota reduced nocturnal sleep, but not diurnal sleep. Likewise, antibiotic-treated mice showed increased nocturnal locomotor activity, but not diurnal locomotor activity. Taken together, these results support a link between the gut microbiome and nocturnal sleep and locomotor physiology in adult mice. Additionally, our findings indicate that antibiotics may be insomnogenic via their ability to diminish gut-derived bacterial somnogens. Given that antibiotics are among the most commonly prescribed drugs in human medicine, these findings have important implications for clinical practice with respect to prolonged antibiotic therapy, insomnia, and other idiopathic sleep-wake and circadian-rhythm disorders affecting an estimated 50-70 million people in the United States alone.

Highlights

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14 d broad-spectrum antibiotic treatment effectively depletes the gut microbiota.

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Gut microbiota depletion reduces nocturnal sleep, but not diurnal sleep.

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Gut microbiota depletion increases nocturnal locomotion, but not diurnal locomotion.

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Antibiotics may be insomnogenic: implications for idiopathic sleep disorders.
Prediction of human Plasmodium sex specific gene by homology search: a systematic review and meta-synthesis
Authors: Odaka Mitsuhiro , Sassy Amen , Khatab Shymmaa , Tran Linh , Ismaeil Khaled , Elawady Sameh , Abdelkhalek Mariam , Salman Samar , Gad Heba , Elfaituri Muhammed Khaled , Morsy Sara , Huy Nguyen Tien , Hirayama Kenji
Published: October 2017

Human Plasmodium species have a sex specific process in the life cycle namely gametocytogenesis or gametogenesis. Gametocytes production and subsequent gametes zygosis are critical for malaria parasites to link to mosquito stage and to merge to sexual reproduction. Here, we aimed at the identification of genes related to gametocytogenesis or gametogenesis in human malaria using systematic review, meta-synthesis and homology search. Based on our search terms, we conducted a systematic search of published data in nine databases resulting in 96 finally included papers with a total of 255 genes from apicomplexan species. We found more papers involved in Plasmodium than we had expected, which reflects that the extensive amount of research on Plasmodium genes have been examined. Subsequently we searched sequence homology between FASTA sequences of apicomplexan sex specific genes other than human malaria parasites and those of human malaria parasites genome on PlasmoDB. We focused on eight candidate genes of Plasmodium falciparum (PF). Finally we predicted that PRPF6, SMC1 and SMC2 can be the especially promising candidate genes.
Htz1 and Set1 Regulate Ergosterol Levels in Response to Environmental Stress
Authors: Aslan Kubra , Özaydin Bilge
Published: October 2017

Ergosterol is an essential isoprenoid for cellular integrity and proper membrane fluidity of fungi. Proper level of ergosterol is crucial for resistance to various stressful conditions, such as hypoxia, hypothermia, and hyperosmolarity. The isoprenoid building blocks of ergosterol are synthesized via the mevalonate pathway, which relies on the availability of many central metabolites, such as acetyl-coA and S-adenosyl methionine (SAM). The metabolic currencies are also the substrates for epigenetic modifications such as histone acetylation and methylation. To have a better understanding of how isoprenoid synthesis and these epigenetic mechanisms affect each other, we re-analyzed the results of our screen onSaccharomyces cerevisiaegene deletion collection for isoprenoid production and found a group of chromatin regulators with significant effects on isoprenoid production. More specifically, the canonical histone Htz1 (H2A.z), the SWR1 complex that loads Htz1 onto chromatin, and the histone demethylase Jhd2 inhibited, whereas the Htz1 unloading INO80 complex and histone methylase Set1 enhanced isoprenoid production. Further analysis of genome-wide expression data revealed that Htz1 and Set1 differentially regulate stress-response genes which presumably affect isoprenoid synthesis. Conversely, changes in isoprenoid production alters the transcription of the same set of genes. Further analysis of ergosterol levels in these gene deletions showed thathtz1, set1double deletion leads to accumulation of ergosterol beyond homeostatic levels and renders cells vulnerable to environmental stress. Our re-analysis of multiple published data and follow-up experiments revealed an epigenetic crosstalk mechanism between ergosterol levels and stress response genes that is essential for maintaining optimum concentration of ergosterol under various conditions.
Aberration-free aspherical lens shape for shortening the focal distance of an already convergent beam
Authors: Sutter John P. , Alianelli Lucia
Published: October 2017

The shapes of single lens surfaces capable of focusing divergent and collimated beams without aberration have already been calculated. However, nanofocusing compound refractive lenses (CRLs) require many consecutive lens surfaces. Here a theoretical example of an X-ray nanofocusing CRL with 48 consecutive surfaces is studied. The surfaces on the downstream end of this CRL accept X-rays that are already converging toward a focus, and refract them toward a new focal point that is closer to the surface. This case, so far missing from the literature, is treated here. The ideal surface for aberration-free focusing of a convergent incident beam is found by analytical computation and by ray tracing to be one sheet of a Cartesian oval. An `X-ray approximation' of the Cartesian oval is worked out for the case of small change in index of refraction across the lens surface. The paraxial approximation of this surface is described. These results will assist the development of large-aperture CRLs for nanofocusing.
Characterization of X-ray gas attenuator plasmas by optical emission and tunable laser absorption spectroscopies
Authors: Martín Ortega Álvaro , Lacoste Ana , Béchu Stéphane , Bès Alexandre , Sadeghi Nader
Published: October 2017

X-ray gas attenuators are used in high-energy synchrotron beamlines as high-pass filters to reduce the incident power on downstream optical elements. The absorption of the X-ray beam ionizes and heats up the gas, creating plasma around the beam path and hence temperature and density gradients between the center and the walls of the attenuator vessel. The objective of this work is to demonstrate experimentally the generation of plasma by the X-ray beam and to investigate its spatial distribution by measuring some of its parameters, simultaneously with the X-ray power absorption. The gases used in this study were argon and krypton between 13 and 530 mbar. The distribution of the 2pexcited states of both gases was measured using optical emission spectroscopy, and the density of argon metastable atoms in the 1s5state was deduced using tunable laser absorption spectroscopy. The amount of power absorbed was measured using calorimetry and X-ray transmission. The results showed a plasma confined around the X-ray beam path, its size determined mainly by the spatial dimensions of the X-ray beam and not by the absorbed power or the gas pressure. In addition, the X-ray absorption showed a hot central region at a temperature varying between 400 and 1100 K, depending on the incident beam power and on the gas used. The results show that the plasma generated by the X-ray beam plays an essential role in the X-ray absorption. Therefore, plasma processes must be taken into account in the design and modeling of gas attenuators.
A hybrid imidazolylidene/imidazolium nickel NHC complex: an isolated intermediate
Authors: Altmann Philipp J. , Ehrenreich Michael , Pöthig Alexander
Published: October 2017

Macrocyclic ligand systems with a variety of (different) donor sites oftentimes give rise to very exciting and unexpected multinuclear metal complexes. We report herein the structure of a trinuclear mixed imidazolylidene/imidazolium nickel N-heterocyclic carbene (NHC) complex, namely di-μ-chlorido-bis{μ-calix[2]imidazolium[2]imidazolylidene[2]pyrazolate}trinickel(II) tetrakis(hexafluoridophosphate) acetonitrile tetrasolvate, [Ni3(C24H24N12)2Cl2](PF6)4·4CH3CN or [Ni3(L
Me)2Cl2](PF6)4·4CH3CN, that can be understood as a trapped reaction intermediate during the synthesis of the respective [Ni2
L
Me](PF6)2 product. The structure not only contains protonated next to deprotonated imidazole heterocycles, but also Ni2+ ions with fundamentally different coordination modes within one molecule. Two of the three metal atoms are coordinated in a square-pyramidal fashion by half a ligand molecule and one chloride ligand, whereas the third Ni2+ ion is bound octahedrally by four pyrazolate moieties and two chloride anions.
Cation tautomerism, twinning and disorder in the triclinic and monoclinic forms of 4-amino-5-chloro-2,6-dimethylpyrimidinium 5-chloro-2-hydroxybenzoate and a new disordered refinement of 2-amino-4,6-dimethoxypyrimidin-1-ium thiophene-2-carboxylate
Authors: Rajam Ammaiyappan , Muthiah P. Thomas , Butcher Ray J. , Jasinski Jerry P. , Glidewell Christopher
Published: October 2017

Pyrimidines are important compounds in biology and medicine, and the aminopyrimidine fragment can be identified in three of the four bases in DNA. The targeted drug action of pharmaceuticals containing this functionality is likely to depend heavily on molecular recognition processes involving hydrogen bonding. Crystallization of an equimolar mixture of 4-amino-5-chloro-2,6-dimethylpyrimidine and 5-chloro-2-hydroxybenzoic acid yielded two forms of the 1:1 salt, C6H9ClN3
+·C7H4ClO3
−, each containing a different tautomeric form of the cation. 6-Amino-5-chloro-2,4-dimethylpyrimidin-1-ium 5-chloro-2-hydroxybenzoate, (I), crystallizes in the space group P\overline{1}, with Z′ = 2, and all of the component ions are fully ordered. 4-Amino-5-chloro-2,6-dimethylpyrimidin-1-ium 5-chloro-2-hydroxybenzoate, (II), also crystallizes with Z′ = 2, but in the space group P21/c and as a merohedral twin which closely mimics an orthorhombic unit cell. In (II), one of the cations and one of the anions is disordered, each over two sets of atomic sites having occupancies of 0.836 (2) and 0.164 (2), and 0.834 (2) and 0.166 (2). The bond lengths in the cations of (I) and (II) provide evidence for o-quinonoid and p-quinonoid bond fixation, respectively. A combination of six N—H...O hydrogen bonds links the component ions of (I) into two independent four-ion aggregates, but the ions in (II) are linked by a combination of four N—H...O and two N—H...N hydrogen bonds to form a three-dimensional framework structure. The recently reported structure of 2-amino-4,6-dimethoxypyrimidin-1-ium thiophene-2-carboxylate, C6H10N3O2
+·C5H3O2S−, (III), has been rerefined, using the original data set, to show that the anion is disordered over two sets of atomic sites, approximately related by a 180° rotation about the exocyclic C—C bond, and having occupancies of 0.8687 (19) and 0.1313 (19).
Crystal structure of an epoxysterol: 9α,11α-epoxy-5α-cholest-7-ene-3β,5,6α-triol 3,6-diacetate
Authors: Piccialli Vincenzo , Tuzi Angela , Centore Roberto
Published: October 2017

The title compound, C31H48O6, is a polyoxygenated epoxy steroid obtained by a multi-step synthesis involving oxidation of 7-dehydrocholesterol. It crystallizes in theP212121space group; however, the absolute structure of the molecule in the crystal could not be determined by resonant scattering. The configuration at the C5 and C6 positions is in both cases of the α-type, as is that of the C atoms of the epoxy ring. Molecules in the crystal form chains parallel to thebaxis by hydrogen bonding between O—H donors and carbonyl O-atom acceptors. Some atoms of the alkyl chain are disordered over two orientations, with a refined occupancy ratio of 0.511 (10):0.489 (10).
Crystal structure and features of 3′,8-dibenzylidene-4a,5,6,7,8,8a-hexahydro-2′H-spiro[chromene-2,1′-cyclohexan]-2′-one
Authors: Anis'kov Alexander , Grinev Vyacheslav , Klochkova Irina
Published: October 2017

The synthesis and crystal structure of the title compound, C28H28O2, are reported. The C=C—C—C torsion angles in the phenylmethylidene units are 166.6 (3) and −48.0 (4)°. In the crystal, molecules form a three-dimensional network by means of weak C—H...O hydrogen bonds. The most important contributions to the crystal structure are the H...H interactions (68.8%), while the H...O contacts account for 4.5%.
(E)-2,4-Dibromo-6-(hydrazinylidenemethyl)phenol
Authors: Bhat Rayees A. , Kumar D. , Ganaie Javeed A. , Butcher Ray J. , Gupta Sushil K.
Published: October 2017

The title compound, C7H6Br2N2O, was obtained from a condensation reaction of 3,5-dibromo-2-hydroxybenzaldehyde and hydrazine hydrate. The molecule is approximately planar, the largest deviation from the mean plane through all of the non-H atoms being 0.053 (1) Å. The molecular conformation is stabilized by an intramolecular O—H...N hydrogen bond, generating anS(6) ring motif. In the crystal, intermolecular N—H...Br and N—H...O hydrogen bonds link the molecules, forming chains parallel to thebaxis. Molecules are further linked by π–π stacking interactions, with centroid–centroid distances of 3.925 (3)–3.926 (3) Å, forming a three-dimensional network.
[(1,2,5,6-η)-Cycloocta-1,5-diene](1-ethyl-3-isopropyl-1,3-imidazol-2-ylidene-κC2)(triphenylphosphane-κP)iridium(I) tetrafluoridoborate
Authors: Idrees Karam B. , Rutledge William J. , Roberts Sue A. , Rajaseelan Edward
Published: October 2017

In the title compound, [Ir(C8H12)(C8H14N2)(C18H15P)]BF4, the cationic complex has the anticipated square-planar geometry. The asymmetric unit comprises the iridium complex and one tetrafluoridoborate anion. The space group is non-centrosymmetric, with the Flack parameter of 0.007 (3) well determined, and confirms the hand for the complex cation. This compound shows promising catalytic activity in transfer hydrogenation reactions.
catena-Poly[[diaquabis[1,4-bis(pyridin-4-yl)buta-1,3-diyne-κN]iron(II)]-μ-cyanido-κ2N:C-[dicyanido-κ2C-platinum(II)]-μ-cyanido-κ2C:N]
Authors: Piñeiro-López Lucia , Valverde-Muñoz Francisco Javier , Seredyuk Maksym , Znovjyak Kateryna
Published: October 2017

The molecular structure of the title compound, [FePt(CN)4(C14H8N2)2(H2O)2]n, consists of one-dimensional polymeric [–Fe–NC–Pt(CN)2–CN–]∞chains. Two water molecules and two monodentate 1,4-bis(pyridin-4-yl)buta-1,3-diyne (bpb) ligand molecules complete the octahedral coordination sphere of the FeIIatoms. The Fe—N(py) bond length (py is pyridine) is 2.2700 (15) Å, Fe—N(cyanide) is 2.1185 (16) Å and the Fe—O distance is 2.1275 (14) Å. The water molecules are hydrogen bonded to either bpb ligands or cyanide groups of the planar [Pt(CN)4]2−anion of adjacent polymeric chains. These O—H...N hydrogen bonds, in conjunction with offset and tilted π–π stacking interactions between bpb ligands and cyanide groups, extend the one-dimensional chains into a three-dimensional assembly.
tert-Butyl (3-oxocyclopentyl)carbamate
Authors: Lough Alan J. , Tait Katrina , Tam William
Published: October 2017

In the title compound, C10H17NO3, the five-membered ring is in a slightly twisted envelope conformation. The carbonyl group is disordered over two sites on the five-membered ring, with refined occupancies of 0.906 (4) and 0.094 (4). In the crystal, molecules are linkedviaN—H...O hydrogen bonds formingC(4) chains along [001].
2-{3-[2-(2-Chlorophenyl)ethyl]-2-oxo-1,2-dihydroquinoxalin-1-yl}acetohydrazide
Authors: Ramli Youssef , Missioui Mohcine , El Fal Mohammed , Ouhcine Mohammed , Essassi El Mokhtar , Mague Joel T
Published: October 2017

In the title compound, C18H17ClN4O2, the dihydroquinoxaline moiety deviates slightly from planarity. The benzene ring and its chloro and methylene substituents are disordered over two sets of sites, with an occupancy ratio of 0.675 (3):0.325 (3). In the crystal, corrugated sheets parallel to (100) are formed by N—H...O, N—H...Cl and N—H...N hydrogen bonds. The structure was refined as a two-component inversion twin.
Symbolic consumption and Generation Y consumers: evidence from Thailand
Authors: Tangsupwattana Wanrudee , Liu Xiaobing
Published: October 2017

Purpose

The purpose of this paper is to investigate Generation Y consumers’ symbolic consumption on brand attitude and purchase intention toward global brands.

Design/methodology/approach

A conceptual model has been developed to illustrate the proposed relationships among the related variables. Data from a total of 300 usable surveys were collected from Thai Generation Y consumers. The proposed hypotheses were tested using structural equation modeling analyses.

Findings

The study found that Generation Y consumers’ symbolic consumption has a significant and positive effect on brand attitude and purchase intention.

Research limitations/implications

Time and resources limitation did not allow to study the larger sample. Future research should include more product categories and more global brands. Sample can be extended to consumers in ASEAN countries to provide more comprehensive insights into consumer perceptions and brand behaviors toward global brands.

Practical implications

The findings suggest that symbolic consumption is a key motivation to increase purchase intention when developing marketing strategies for the Generation Y consumer.

Originality/value

This study has contributions to symbolic consumption and Generation Y literature combining several important dimensions into a structural model, and examines the relationships among these dimensions.
From resentment to excitement – Australasian students’ perception towards a sales career
Authors: Handley Brian , Shanka Tekle , Rabbanee Fazlul K.
Published: October 2017

Purpose

The purpose of this paper is to explore Australasian students’ current perception towards a sales career.

Design/methodology/approach

Data were collected through a self-administered survey from 431 students enrolled in a Sales Management unit in a large Australian university and its Asian campuses.

Findings

The study reveals a four-factor solution with factors labeled as “exciting,” “deceptive,” “taxing,” and “challenging,” with “exciting” being the only factor to significantly predict likelihood of pursuing a sales career. Although no differences of perception were found between males and females, Asian students were found to perceive sales career as more exciting, innovative and fun than Australian students.

Research limitations/implications

Although significant difference was noted between Australian and Asian students’ perceptions towards sales as an exciting career, it is prudent to interpret and generalize the finding with caution as Asia is the largest continent with different cultures, religions and races.

Practical implications

The four factors that were found to influence students’ perception towards a sales career are novel, psychometrically sound, and are pertinent for businesses conducting graduate recruitment. This study indicates how sales education at university level assist in changing students’ views towards a sales career from negative to positive.

Originality/value

While previous research has reported negative perceptions about sales as a career, this study reveals that students consider sales to be an “exciting” career.
The effects of consumer perception of volume discount benefits on intention to purchase grocery products
Authors: Iranmanesh Mohammad , Jayaraman KrishnaSwamy , Zailani Suhaiza , Ghadiri Seyed Mohammadreza
Published: October 2017

Purpose

The purpose of this paper is to investigate the effects of consumers’ perceptions towards volume discount (VD) benefits on their intention to purchase grocery products under this scheme using deal proneness as a moderator.

Design/methodology/approach

Data were gathered through a survey of 583 Malaysian consumers, and were analysed using the partial least squares technique.

Findings

The results showed that perceived savings, self-expression value, and convenience positively affected consumers’ intention to purchase grocery products under VDs. Deal proneness negatively moderated the relationship between perceived quality, innovation, and consumers’ intention to purchase under VDs.

Practical implications

The findings of the study will help retailers to understand the effects of consumers’ perceptions of VD benefits on their intention to purchase products under VDs, thereby allowing retailers to promote products under VDs more effectively.

Originality/value

Although the VD is a common type of sales promotion, this topic is rarely explored. This study thus contributes to the advancement of knowledge by determining the effects of the potential benefits of VDs on consumers’ intention to purchase.
The Big Bazaar: an examination of Indian shopping mall behaviour and demographic differences
Authors: Pare Vipul , Pourazad Naser
Published: October 2017

Purpose

The purpose of this paper is to examine the extent to which Indian consumers of different demographic groups vary in terms of shopping mall visits (frequency of visit, hours spent in the mall, and number of shops visited) and purchase behaviour (total money spent, number of shops purchased from and number of items purchased).

Design/methodology/approach

The study used a self-administered survey of 400 Indian mall shoppers to examine Indian shoppers’ behaviour with respect to visiting and buying behaviour. Descriptive analyses and χ2 tests were conducted to identify patterns and capture the significant relationships in shopping behaviour across different demographic segments.

Findings

The results show that shoppers of different age cohorts and from different household sizes behave differently from one another in a significant manner. In terms of gender, however, men and women tend to behave in a similar manner in terms of visit frequency, time and money spent per visit. The study also provides insight into where the differences occur and between which specific groups.

Research limitations/implications

Data comes from one major city of India which limits the generalizability of the results.

Practical implications

For mall managers and retailers, the study findings indicate that the stores that serve recreational needs should focus more on younger segments, where men and women share similar buying patterns. Findings from this study could also be used for segmentation exercises and to build strategies to convert footfall into actual purchase, especially within the rapidly growing Indian mall market.

Originality/value

The study adds value to the body of retail literature and provides empirical evidence from the rapidly developing Indian market. The study also provides insight into where differences occur and between which specific groups. By highlighting the differences in greater detail, the study benefits retailers in general and specifically, mall managers.
Why do good people do bad things? The effect of ethical ideology, guilt proneness, and self-control on consumer ethics
Authors: Arli Denni , Leo Cheryl
Published: October 2017

Purpose

Various studies showed that unethical behaviours committed by consumers occur more frequently than may be expected. People have stolen from a shop at some time in their life and remained silent, people walk out of a grocery store have stolen something from the store and employees have stolen from their workplace. Why seemingly good people do bad things and vice versa? What factors contribute to this discrepancy? Hence, the purpose of this paper is threefold: first, to examine the impact of ethical ideology on self-control and guilt proneness; second, to examine the roles of self-control and guilt proneness in consumer ethical decision making; and finally, to explore the mediating effects of self-control and guilt proneness on the relationship between consumer ideology and ethical decision making.

Design/methodology/approach

The authors collected a non-probability sample using a cross-sectional online survey of adult consumers across Australia wide. The sampling frame was from a pre-recruited online panel company Permissioncorp. Consumers were introduced to the study in relation to their beliefs in general consumer ethics behaviours. The response rate for the survey invite was 17.9 per cent, with a final sample size of 311 consumers out of 3,246 that were invited to participate based on the these screening criteria, i.e. their country of birth (Australia only), gender, age group, and state in which they reside to ensure representation across these groups.

Findings

The results showed that idealism was a positive determinant of guilt proneness and self-control, whereas relativistic individuals were less prone to guilt and less able to control their behaviour. In addition, there was a significant negative correlation between self-control and unethical consumer behaviour. Finally, both self-control and guilt proneness had an indirect mediating effect on the relationship between ethical ideology and consumer behaviour.

Originality/value

This is one of the first studies to explore the interactions between ethical ideology, self-control, guilt proneness, and consumer ethics.
Systematic approach for asset management of urban water pipeline infrastructure systems
Authors: Zamenian Hamed , Choi Juyeong , Sadeghi Seyed Amir , Naderpajouh Nader
Published: October 2017

Purpose

The purpose of this paper is to develop a systemic approach to evaluate physical condition of water pipeline infrastructure with limited condition assessment data that can help asset managers prioritize capital investments in maintenance projects for urban water pipeline systems.

Design/methodology/approach

Spatial pattern analyses are conducted in this research to find the spatial pattern of the service life of pipelines. Based on the spatial relationship, the critical areas where groups of pipelines with short service life are likely to be found were located using spatial statistical analyses. A visualized platform was also developed and used to validate the implementation of the proposed approach with the case study of urban water pipeline infrastructure in a city in the Midwest region of the USA.

Findings

The results of the spatial pattern analyses reveal that water pipelines are spatially clustered based on their service life. Further, it was found that on average the pipelines in the center of a city have longer service life while the average expected service life of the pipelines in the marginal areas is shorter. The interpolation method produced raster data with continuous information about the service years of pipelines that are useful for asset maintenance planning.

Originality/value

With the limited data, the proposed approach enables identification of the critical area of water pipelines with the likelihood of shorter service life. This result can be used as a priority rule for a rehabilitation plan and contributes to shifting from a responsive to a preventive approach in underground asset management.
LiVE approach: Lean integrated Value Engineering for construction industry
Authors: Ekanayake E.M.A.C. , Sandanayake Y.G.
Published: October 2017

Purpose

Increasing demand for the best value for client’s money necessitates waste reduction while enhancing the project functionality in construction industry. The purpose of this paper is to propose Lean integrated Value Engineering (LiVE) approach by establishing the synergy between Lean and Value Engineering (VE) concepts for construction industry.

Design/methodology/approach

A literature survey and in-depth un-structured interviews with six subject matter experts in three steps were used to investigate the synergy between Lean principles and VE job plan to develop LiVE approach for the construction industry. The gathered data were analysed using code-based content analysis and the LiVE approach was finally validated using interviews by two additional subject matter experts representing industry and academia.

Findings

Research findings established that there is a synergy between Lean principles and VE job plan. Accordingly, the study developed a LiVE approach, which specify client’s value, identify the value stream, make value flow without interruption, let the client pull functional requirements and pursue perfection during “value establishment”, “value analysis of functional requirements”, “value creativity”, “value evaluation”, “value development”, “value verification” and “value achievement” phases.

Originality/value

The novel LiVE approach will guide construction industry practitioners on how to integrate Lean concept with VE in order to reduce unnecessary costs and wastes, to enhance project functionality and ultimately to achieve value for client’s money.