bluuebunny/crossref_metadata_2025 huggingface dataset:
TTL proteins scaffold brassinosteroid signaling components at the plasma membrane to optimize signal transduction in plant cells
Authors: Amorim-Silva Vítor , García-Moreno Álvaro , Castillo Araceli G. , Lakhssassi Naoufal , Pérez-Sancho Jessica , Li Yansha , del Valle Alicia Esteban , Posé David , Pérez-Rodriguez Josefa , Lin Jinxing , Valpuesta Victoriano , Borsani Omar , Zipfel Cyril , Macho Alberto P. , Botella Miguel A.
Published: June 2018

Brassinosteroids (BRs) form a group of steroidal hormones essential for plant growth, development and stress responses. Here, we report that plant-specific TETRATRICOPEPTIDE THIOREDOXIN-LIKE (TTL) proteins are positive regulators of BR signaling functioning as scaffold for BR signaling components in Arabidopsis. TTL3 forms a complex with all core components involved in BR signaling, including the receptor kinase BRASSINOSTEROID INSENSITIVE1 (BRI1), the transcription factor BRASSINAZOLE RESISTANT1 (BZR1) and the phosphatase BRI1-SUPPRESSOR1 (BSU1), but excluding the co-receptor BAK1. TTL3 is mainly localized in the cytoplasm, but BR treatment increases its localization at the plasma membrane, where it strengthens the association with BR signaling components. Consistent with a role in BR signaling, mutations inTTL3and relatedTTL1andTTL4genes cause reduced BR responsiveness. We propose a mechanistic model for BR signaling, in which cytoplasmic/nuclear BR components bound to TTL proteins are recruited to the plasma membrane upon BR perception, which in turn allows the assembly of a BR signaling complex, leading to the de-phosphorylation and nuclear accumulation of the transcription factors BZR1 and BES1.
An atlas of protein-protein interactions across mammalian tissues
Authors: Skinnider Michael A. , Scott Nichollas E. , Prudova Anna , Stoynov Nikolay , Stacey R. Greg , Gsponer Joerg , Foster Leonard J.
Published: June 2018

Cellular processes arise from the dynamic organization of proteins in networks of physical interactions. Mapping the complete network of biologically relevant protein-protein interactions, the interactome, has therefore been a central objective of high-throughput biology. Yet, because widely used methods for high-throughput interaction discovery rely on heterologous expression or genetically manipulated cell lines, the dynamics of protein interactions across physiological contexts are poorly understood. Here, we use a quantitative proteomic approach combining protein correlation profiling with stable isotope labelling of mammals (PCP SILAM) to map the interactomes of seven mouse tissues. The resulting maps provide the first proteome-scale survey of interactome dynamics across mammalian tissues, revealing over 27,000 unique interactions with an accuracy comparable to the highest-quality human screens. We identify systematic suppression of cross-talk between the evolutionarily ancient housekeeping interactome and younger, tissue-specific modules. Rewiring of protein interactions across tissues is widespread, and is poorly predicted by gene expression or coexpression. Rewired proteins are tightly regulated by multiple cellular mechanisms and implicated in disease. Our study opens up new avenues to uncover regulatory mechanisms that shape in vivo interactome responses to physiological and pathophysiological stimuli in mammalian systems.
The quiescent X, the replicative Y and the Autosomes
Authors: Achaz Guillaume , Gangloff Serge , Arcangioli Benoit
Published: June 2018

From the analysis of the mutation spectrum in the 2,504 sequenced human genomes from the 1000 genomes project (phase 3), we show that sexual chromosomes (X and Y) exhibit a different proportion of indel mutations than autosomes (A), ranking them X>A>Y. We further show that X chromosomes exhibit a higher ratio of deletion/insertion when compared to autosomes. This simple pattern shows that the recent report that non-dividing quiescent yeast cells accumulate relatively more indels (and particularly deletions) than replicating ones also applies to metazoan cells, including humans. Indeed, the X chromosomes display more indels than the autosomes, having spent more time in quiescent oocytes, whereas the Y chromosomes are solely present in the replicating spermatocytes. From the proportion of indels, we have inferred that de novo mutations arising in the maternal lineage are twice more likely to be indels than mutations from the paternal lineage. Our observation, consistent with a recent trio analysis of the spectrum of mutations inherited from the maternal lineage, is likely a major component in our understanding of the origin of anisogamy.
Bilateral asymmetry favours the left hemimandibular side in companion rabbits
Authors: Parés-Casanova Pere M. , Cabello Maria , Gambo Baba Gana , Samuel Michael Oluwale , Olopade James Olukayode
Published: June 2018

Directional asymmetry (DA) appears when the left and right body sides differ consistently from each other. This asymmetry is characterized as a type of natural asymmetry typical of the population’s biology, which can be derived both from genetic inheritance, as of the functional importance acquired by certain features with respect to the environment in which they develop. We report here preliminary findings that for the first time to quantify size asymmetry mandibles of companion rabbits. A total sample of 64 companion rabbits from the same farm were studied by means of geometric morphometric techniques. The mandible morphology was described by a set of 18 landmarks and semilandmarks on the lateral aspect. Tests showed paired differences with variations in distributions, demonstrating a DA in favour of left mandibular side. The detected unilaterality could be interpreted as a manifestation of lateralized masticatory activity. This is a first time report to quantify size asymmetry in this species.
Haplotypes spanning centromeric regions reveal persistence of large blocks of archaic DNA
Authors: Langley Sasha A. , Miga Karen , Karpen Gary , Langley Charles H.
Published: June 2018

Despite critical roles in chromosome segregation and disease, the repetitive structure and vast size of centromeres and their surrounding heterochromatic regions impede studies of genomic variation. We report here large-scale haplotypes (cenhaps) in humans that span the centromere-proximal regions of all metacentric chromosomes, including the arrays of highly repeated α-satellites on which centromeres form.Cenhapsreveal surprisingly deep diversity, including entire introgressed Neanderthal centromeres and equally ancient lineages among Africans. These centromere-spanning haplotypes contain variants, including large differences in α-satellite DNA content, which may influence the fidelity and bias of chromosome transmission. The discovery ofcenhapscreates new opportunities to investigate their contribution to phenotypic variation, especially in meiosis and mitosis, as well as to more incisively model the unexpectedly rich evolution of these challenging genomic regions.

One Sentence Summary

Genomic polymorphism across centromeric regions of humans is organized into large-scale haplotypes with great diversity, including entire Neanderthal centromeres.
Endoplasmic reticulum stress may activate NLRP3 inflammasomes via TXNIP in preeclampsia
Authors: Yang Yong , Li Jianxin , Han Ting-Li , Zhou Xiaobo , Qi Hongbo , Baker Philip N. , Zhou Wei , Zhang Hua
Published: June 2018

Preeclampsia (PE) development is often associated with placental immune and inflammatory dysregulation, as well as endoplasmic reticulum (ER) stress. However, the mechanisms linking ER stress and inflammatory dysregulation to PE have not been clarified. It has been reported that thioredoxin-interacting protein (TXNIP), which can bind with and activate the NLR family pyrin domain containing 3 (NLRP3) inflammasome, plays a critical role in immune regulation. Recent experimental evidence suggests that activated NLRP3 inflammasomes can activate interleukin-1β (IL-1β) production in the placenta of patients with PE. The objective of the current study was to explore if TXNIP plays a critical signaling role linking ER stress with NLRP3 inflammasome activation in PE. We hypothesised that ER stress would induce TXNIP production, which would bind with NLRP3 inflammasomes to activate IL-1β production. HTR8/SVneo cells were subjected to six hours hypoxia followed by six hours reoxygenation (H/R). These cells showed a higher protein level of NLRP3 and IL-1β, as well as a higher enzymatic activity of caspase-1, indicating enhanced inflammatory dysregulation and ER stress. Cells transfected with TXNIP siRNA showed reduced NLRP3 inflammasome activation. Cells treated with 4-phenylbutyric acid, an inhibitor of ER stress, showed a similar result. In addition, the outgrowth of explant with TXNIP lentivirus in H/R or Tunicamycin (inducers of ER stress) was also measured to verify our hypothesis. These findings demonstrated that TXNIP could influence inflammatory dysregulation by mediating ER stress and NLRP3 inflammasome activation in PE. This novel mechanism may further explain the inflammation observed at the maternal-fetal interface, which leads to placental dysfunction in a patient with PE.
Population dynamics and transcriptomic responses ofPseudomonas aeruginosain a complex laboratory microbial community
Authors: Cheng Yingying , Yam Joey Kuok Hoong , Cai Zhao , Ding Yichen , Zhang Lian-Hui , Deng Yinyue , Yang Liang
Published: June 2018

Pseudomonas aeruginosais one of the dominant species when it co-exists with many other bacterial species in diverse environments. To understand its physiology and interactions with co-existing bacterial species in different conditions, we established physiologically reproducible eighteen-species communities, and found thatP. aeruginosabecame the dominant species in mixed-species biofilm community but not in the planktonic community.P. aeruginosaH1 type VI secretion system was highly induced in the mixed-species biofilm community compare to its mono-species biofilm, which was further demonstrated to play a key role forP. aeruginosato gain fitness over other bacterial species. In addition, the type IV pili and Psl exopolysaccharide were shown to be required forP. aeruginosato compete with other bacterial species in the biofilm community. Our study showed that the physiology ofP. aeruginosais strongly affected by interspecies interactions, and both biofilm determinants and H1 type VI secretion system contribute toP. aeruginosafitness over other species in complex biofilm communities.

Importance

Pseudomonas aeruginosausually coexists with different bacterial species in natural environment. However, systematic comparative characterization ofP. aeruginosain complex microbial communities with its mono-species communities is lacking. We constructed mixed-species planktonic and biofilm communities consistingP. aeruginosaand seventeen other bacterial species to study the physiology and interaction ofP. aeruginosain complex multiple-species community. A single molecule detection platform, NanoString nCounter®16S rRNA array, was used to shown thatP. aeruginosacan become the dominant species in the biofilm communities while not in the planktonic communities. Comparative transcriptomic analysis and fluorescence-based quantification further revealed thatP. aeruginosaH1 type VI secretion system and biofilm determinants are both required for its fitness in mixed-species biofilm communities.
Transcriptome analysis of Culter alburnus gonad tissues for discovery of sex-related genes
Authors: Zheng Jianbo , Jia Yongyi , Liu Shili , Jiang Wenping , Chi Meili , Cheng Shun , Gu Zhimin
Published: June 2018

Culter alburnus is an important commercially fish species for freshwater breeding in China, and the females grow faster than the males. However, the molecular genetic mechanism of sex determination in C.alburnus is still poorly characterized. Here, we performed de novo assembly of a transcriptome from adult fish tissues of different gender using short read sequencing technology (Illumina). Our results showed that a total of 364,650 unigenes using Trinity software were obtained, giving rise to an average of 561.92 bp per read. Among them, 70,215 sequences matched known genes, including 5,892 male-biased unigenes and 942 female-biased unigenes. Many sex-related genes and pathways were identified based on annotation information. These results would provide new insights into the genetic mechanism of C.alburnus sex determination and also establish an important foundation for further research on aquaculture breeding.
In vitrotoxicity and efficacy of verdinexor, an exportin 1 inhibitor, on opportunistic viruses affecting immunocompromised individuals
Authors: Widman Douglas G. , Gornisiewicz Savanna , Shacham Sharon , Tamir Sharon
Published: June 2018

Infection of immunocompromised individuals with normally benign opportunistic viruses is a major health burden globally. Infections with viruses such as Epstein-Barr virus (EBV), human cytomegalovirus (HCMV), Kaposi’s sarcoma virus (KSHV), adenoviruses (AdV), BK virus (BKPyV), John Cunningham virus (JCPyV), and human papillomavirus (HPV) are significant concerns for the immunocompromised, including when these viruses exist as a co-infection with human immunodeficiency virus (HIV). These viral infections are more complicated in patients with a weakened immune system, and often manifest as malignancies resulting in significant morbidity and mortality. Vaccination is not an attractive option for these immune compromised individuals due to defects in their adaptive immune response. Verdinexor is part of a novel class of small molecules known as SINE (Selective Inhibitor of Nuclear Export) compounds. These small molecules demonstrate specificity for the nuclear export protein XPO1, to which they bind and block function, resulting in sequestration of XPO1-dependent proteins in the nucleus of the cell. In antiviral screening, verdinexor demonstrated varying levels of efficacy against all of the aforementioned viruses including previously with HIV. Studies by other labs have discussed likely mechanisms of action for verdinexor (ie. XPO-1-dependence) against each virus. GLP toxicology studies suggest that anti-viral activity can be achieved at a tolerable dose range, based on the safety profile of a previous phase 1 clinical trial of verdinexor in healthy human volunteers. Taken together, these results indicate verdinexor has the potential to be a broad spectrum antiviral for immunocompromised subjects for which vaccination is a poor option.
Attenuation of obesity and related metabolic disorders by the individual or combination treatment with IL-2/anti-IL-2 complex and hyperbaric oxygen
Authors: Choi Eun-Jeong , Kim Hyung-Ran , Jeong-Hae Kie , Moon Byung-In , Seoh Ju-Young
Published: June 2018

Obesity is the disease accumulating excessive fat in the body. The prevalence of obesity and related metabolic disorders is increasing every year worldwide. Immunologically, obesity is a chronic low-grade inflammatory state with the increase of M1 macrophages and decrease of regulatory T cells (Tregs). IL-2/anti-IL-2 complex (IL-2C) and hyperbaric oxygen (HBO) are known to expand Tregsin vivoand suppress inflammation. Therefore, in this study, IL-2C and HBO were investigated for the preventive effect of obesity and related metabolic disorders. Male C57BL/6 mice were fed with a high-fat diet (HFD) for 16 weeks, and counterparts were fed with a low-fat diet (LFD). At the end of the experiment, the body weight gain and impaired glucose metabolism, elevated levels of insulin and total cholesterol induced by HFD were improved by the individual or combination treatment with Il-2C and HBO. Histological examination of the epididymal white adipose tissue showed adipocyte hypertrophy and many crown-like structures in the HFD control groups. In addition, the liver showed the progression of non-alcoholic fatty liver disease (NAFLD) in the HFD control groups, but it was significantly improved by the individual or combination treatment with IL-2C and HBO.

As for the underlying mechanism, inflammation induced by obesity was decreased, and HIF-1α expression by adipocyte hypertrophy was also reduced by the individual or combination treatment with IL-2C and HBO. In addition, adipose tissue browning was activated in brown and inguinal adipose tissue, and the expression of UCP-1 involved in the thermogenesis was increased by the individual or combination treatment with IL-2C and HBO. Overall, these results suggested that IL-2C and HBO might be a new promising immunotherapy for the treatment of obesity and related metabolic disorders by regulation of inflammation and activation of adipose tissue browning.
High-performance biodegradable membrane for point of need paper-based micro-scale microbial fuel cell analytical devices
Authors: González-Pabón María Jesús , Figueredo Federico , Martínez-Casillas Diana C. , Cortón Eduardo
Published: June 2018

One limiting aspect to make microbial fuel cells (MFCs) a viable technology is to obtain low cost and environmentally sound materials for their components. In this work we synthesized membranes by a simple procedure involving low price and biodegradable materials such as poly (vinyl alcohol) (PVA), chitosan (CS) and PVA:CS, all cross-linked with sulfuric acid; they were compared to Nafion®, as our reference/control membrane. PVA:CS show lower oxygen permeability in comparison to Nafion®membranes, a strong advantage in order to maintain anaerobic conditions in the anodic compartment of MFCs. Membranes were characterized in typical H-Type MFCs, and results show that PVA:CS membranes outperform Nafion®4 times (power production) while being 75 times more economic. Moreover, we design a paper-based micro-scale MFC, which was assayed as a toxicity biosensor; we obtained results in less than 20 min using 16 μL volume samples containing formaldehyde as a model toxicant. The PVA:CS membrane presented here can offer low environmental impact (materials, fabrication and disposal) and become a very interesting option for point of need single use disposable analytical devices.
Learned predictiveness acquired through experience prevails over the influence of conflicting verbal instructions in rapid selective attention
Authors: Cobos Pedro L. , Vadillo Miguel A. , Luque David , Le Pelley Mike E.
Published: June 2018

Previous studies have provided evidence that selective attention tends to prioritize the processing of stimuli that are good predictors of upcoming events over nonpredictive stimuli. In the present study we explored whether the mechanism responsible for this effect critically reflects the influence of prior experience of predictiveness (history of attentional selection of predictive stimuli), or whether it reflects a more flexible process that can be adapted to new verbally acquired knowledge. Our experiment manipulated participants’ experience of the predictiveness of different stimuli over the course of trial-by-trial training; we then provided explicit verbal instructions regarding stimulus predictiveness that were designed to be either consistent or inconsistent with the previously established learned predictiveness. The effects of training and instruction on attention to stimuli were measured using a dot probe task. Results revealed a rapid attentional bias towards stimuli experienced as predictive (versus those experienced as nonpredictive), that was completely unaffected by verbal instructions. This was not due to participants’ failure to recall or use instructions appropriately, as revealed by analyses of their learning about stimuli, and their memory for instructions. Overall, these findings suggest that stimuli experienced as predictive through trial-by-trial training produce a relatively inflexible attentional bias based on prior selection history, which is not (always) easily altered through instructions.
Potential PGPR properties of cellulolytic, nitrogen-fixing, and phosphate-solubilizing bacteria of a rehabilitated tropical forest soil
Authors: Tang Amelia , Haruna Ahmed Osumanu , Majid Nik Muhamad Ab.
Published: June 2018

In the midst of major soil degradation and erosion faced by tropical ecosystems, rehabilitated forests are established to avoid further deterioration of forest land. In this context, cellulolytic, nitrogen-fixing (N-fixing), and phosphate-solubilizing bacteria are very important functional groups in regulating the elemental cycle and plant nutrition, hence replenishing the nutrient content in forest soil. As other potential plant growth-promoting (PGP) rhizobacteria, these functional bacteria could have cross-functional abilities or beneficial traits that are essential for plants and improve their growths. This study was conducted to isolate, identify, and characterize selected PGP properties of these 3 functional groups of bacteria from tropical rehabilitated forest soils at Universiti Putra Malaysia Bintulu Sarawak Campus, Malaysia. Isolated cellulolytic, N-fixing and phosphate-solubilizing bacteria were characterized for respective functional activities, biochemical properties, molecularly identified, and assessed for PGP assays based on seed germination and indole-3-acetic acid (IAA) production. Out of 15 identified bacterial isolates exhibiting beneficial phenotypic traits, a third belong to genusBurkholderiaand a fifth toStenotrophomonassp. with both genera consisting of members from two different functional groups. Among the tested bacterial strains, isolateSerratia nematodiphilaC46d,Burkholderia nodosaNB1, andBurkholderia cepaciaPC8 showed outstanding cellulase, N-fixing, and phosphate-solubilizing activities, respectively. The results of the experiments confirmed the multiple PGP traits of selected bacterial isolates based on respective high functional activities, root, shoot lengths, and seedling vigour improvements when bacterized on mung bean seeds, as well as presented some significant IAA productions. The results of this study indicated that these functional bacterial strains could potentially be included in future biotechnological screenings to produce beneficial synergistic effectsviatheir versatile properties on improving soil fertility and possible crop growth stimulation.
Antibiotic-driven Escape of Host in a Parasite-induced Red Queen Dynamics
Authors: Anzia Elizabeth L. , Rabajante Jomar F.
Published: June 2018

Winnerless coevolution of hosts and parasites could exhibit Red Queen dynamics, which is characterized by parasite-driven cyclic switching of expressed host phenotypes. We hypothesize that the application of antibiotics to suppress the reproduction of parasites can provide opportunity for the hosts to escape such winnerless coevolution. Here, we formulate a minimal mathematical model of host-parasite interaction involving multiple host phenotypes that are targeted by adapting parasites. Our model predicts the levels of antibiotic effectiveness that can steer the parasite-driven cyclic switching of host phenotypes (heteroclinic oscillations) to a stable equilibrium of host survival. Our simulations show that uninterrupted application of antibiotic with high-level effectiveness (> 85%) is needed to escape the Red Queen dynamics. Intermittent and low level of antibiotic effectiveness are indeed useless to stop host-parasite coevolution. This study can be a guide in designing good practices and protocols to minimize risk of further progression of parasitic infections.
No evidence that predictions and attention modulate the first feedforward sweep of cortical information processing
Authors: Alilović Josipa , Timmermans Bart , Reteig Leon C. , van Gaal Simon , Slagter Heleen A.
Published: June 2018

Predictive coding models propose that predictions (stimulus likelihood) reduce sensory signals as early as primary visual cortex (V1), and that attention (stimulus relevance) can modulate these effects. Indeed, both prediction and attention have been shown to modulate V1 activity, albeit with fMRI, which has low temporal resolution. This leaves it unclear whether these effects reflect a modulation of the first feedforward sweep of visual information processing and/or later, feedback-related activity. In two experiments, we used EEG and orthogonally manipulated spatial predictions and attention to address this issue. Although clear top-down biases were found, as reflected in pre-stimulus alpha-band activity, we found no evidence for top-down effects on the earliest visual cortical processing stage (<80ms post-stimulus), as indexed by the amplitude of the C1 ERP component and multivariate pattern analyses. These findings indicate that initial visual afferent activity may be impenetrable to top-down influences by spatial prediction and attention.
Biased signaling downstream of epidermal growth factor receptor regulates proliferative versus apoptotic response to ligand
Authors: Ali Remah , Brown Wells , Purdy Stephen Conner , Davisson V. Jo , Wendt Michael K.
Published: June 2018

Inhibition of EGFR signaling by small molecule kinase inhibitors and monocloncal antibodies has proven effective in the treatment of multiple cancers. In contrast, metastatic breast cancers (BC) derived from EGFR-expressing mammary tumors are inherently resistant to EGFR-targeted therapies. Mechanisms that contribute to this inherent resistance remain poorly defined. Here we show that in contrast to primary tumors, ligand-mediated activation of EGFR in metastatic BC is dominated by STAT1 signaling. This change in downstream signaling leads to apoptosis and growth inhibition in response to EGF in metastatic BC cells. Mechanistically, these changes in downstream signaling result from an increase in the internalized pool of EGFR in metastatic cells, increasing physical access to the nuclear pool of STAT1. Along these lines, an EGFR mutant that is defective in endocytosis is unable to elicit STAT1 phosphorylation and apoptosis. Additionally, inhibition of endosomal signaling using an EGFR inhibitor linked to a nuclear localization signal specifically prevents EGF-induced STAT1 phosphorylation and cell death, without affecting EGFR:ERK1/2 signaling. Pharmacologic blockade of ERK1/2 signaling through the use of the allosteric MEK1/2 inhibitor, trametinib, dramatically biases downstream EGFR signaling toward a STAT1 dominated event, resulting in enhanced EGF-induced apoptosis in metastatic BC cells. Importantly, combined administration of trametinib and EGF also facilitated an apoptotic switch in EGFR-transformed primary tumor cells, but not normal mammary epithelial cells. These studies reveal a fundamental distinction for EGFR function in metastatic BC. Furthermore, the data demonstrate that pharmacological biasing of EGFR signaling toward STAT1 activation is capable of revealing the apoptotic function of this critical pathway.
Role of clathrin-mediated endocytosis in the use of heme and hemoglobin by the fungal pathogen Cryptococcus neoformans
Authors: Bairwa Gaurav , Caza Mélissa , Horianopoulos Linda , Hu Guanggan , Kronstad James
Published: June 2018

Heme is a major source of iron for pathogens of humans, and its use is critical in determining the outcome of infection and disease. Cryptococcus neoformans is an encapsulated fungal pathogen that causes life-threatening infections in immunocompromised individuals. C. neoformans effectively uses heme as an iron source but the underlying mechanisms are poorly defined. Non-iron metalloporphyrins (MPPs) are toxic analogues of heme and are thought to enter microbial cells via endogenous heme acquisition systems. We therefore carried out a mutant screen for susceptibility against manganese metalloporphyrin (Mn MPP) to identify new components for heme uptake in C. neoformans. We identified several genes involved in signaling, DNA repair, sugar metabolism and trafficking that play important roles in susceptibility to Mn MPP and in the use of heme as an iron source. We focused on investigating the role of clathrin-mediated endocytosis (CME) and found that several components of CME including Chc1, Las17, Rvs161 and Rvs167 are required for growth on heme and hemoglobin, and for endocytosis and intracellular trafficking of these molecules. We show that the hemoglobin uptake process in C. neoformans involves clathrin heavy chain, Chc1, which appears to co-localize with hemoglobin containing-vesicles and to potentially assist in proper delivery of hemoglobin to the vacuole. Additionally, C. neoformans strains lacking Chc1, Las17, Rvs161, or Rvs167 were defective in the elaboration of several key virulence factors and a las17 mutant was avirulent in a mouse model of cryptococcosis. Overall, this study unveils crucial functions of CME in the use of heme iron by C. neoformans and reveals a role for CME in fungal pathogenesis.
Uncovering Natural Longevity Alleles from Intercrossed Pools of Aging Fission Yeast Cells
Authors: Ellis David A. , Mustonen Ville , Rodríguez-López María , Rallis Charalampos , Malecki Michał , Jeffares Daniel C. , Bähler Jürg
Published: June 2018

Quantitative traits often show large variation caused by multiple genetic factors. One such trait is the chronological lifespan of non-dividing yeast cells, serving as a model for cellular aging. Screens for genetic factors involved in ageing typically assay mutants of protein-coding genes. To identify natural genetic variants contributing to cellular aging, we exploited two strains of the fission yeast,Schizosaccharomyces pombe, that differ in chronological lifespan. We generated segregant pools from these strains and subjected them to advanced intercrossing over multiple generations to break up linkage groups. We chronologically aged the intercrossed segregant pool, followed by genome sequencing at different times to detect genetic variants that became reproducibly enriched as a function of age. A region on Chromosome II showed strong positive selection during ageing. Based on expected functions, two candidate variants from this region in the long-lived strain were most promising to be causal: small insertions and deletions in the 5’-untranslated regions ofppk31andSPBC409.08. Ppk31 is an orthologue of Rim15, a conserved kinase controlling cell proliferation in response to nutrients, while SPBC409.08 is a predicted spermine transmembrane transporter. Both Rim15 and the spermine-precursor, spermidine, are implicated in ageing as they are involved in autophagy-dependent lifespan extension. Single and double allele replacement suggests that both variants, alone or combined, have subtle effects on cellular longevity. Furthermore, deletion mutants of bothppk31andSPBC409.08rescued growth defects caused by spermidine. We propose that Ppk31 and SPBC409.08 may function together to modulate lifespan, thus linking Rim15/Ppk31 with spermidine metabolism.
Supramolecular architectures of succinates of 1-hydroxypropan-2-aminium derivatives
Authors: Żesławska Ewa , Nitek Wojciech , Marona Henryk , Waszkielewicz Anna M.
Published: June 2018

Aminoalkanol and aroxyalkyl derivatives are known as potential anticonvulsants. Two new salts, namely bis{(R,S)-N-[2-(2,6-dimethylphenoxy)ethyl]-1-hydroxypropan-2-aminium} succinate (1s), C13H22NO2
+·0.5C4H4O4
2−, and bis{(S)-(+)-N-[2-(2,6-dimethylphenoxy)ethyl]-1-hydroxypropan-2-aminium} succinate (2s), C13H22NO2
+·0.5C4H4O4
2−, have been prepared and characterized by single-crystal X-ray diffraction. The N atoms are protonated by proton transfer from succinic acid. Salt 1s crystallizes in the space group P21/n with one cation and half an anion in the asymmetric unit across an inversion centre, while (2s) crystallizes in the space group P21 with four cations and two anions in the asymmetric unit. The hydroxy group of the cation of 1s is observed in two R/S disorder positions. The crystals of these two salts display similar supramolecular architectures (i.e. two-dimensional networks), built mainly by intermolecular N+—H...Oδ− and O—H...Oδ− hydrogen bonds, where `δ−' represents a partial charge. The succinate anions are engaged in hydrogen bonds, not only with protonated N atoms, but also with hydroxy groups.
Structure of copper(II) complexes grown from ionic liquids – 1-ethyl-3-methylimidazolium acetate or chloride
Authors: Serov Nikita Yu. , Shtyrlin Valery G. , Islamov Daut R. , Kataeva Olga N. , Krivolapov Dmitry B.
Published: June 2018

Crystals of four new copper(II) complexes have been grown from copper(II) acetate/chloride–1-ethyl-3-methylimidazolium acetate/chloride–water systems and characterized by X-ray analysis. The first complex, bis(1-ethyl-3-methylimidazolium) tetra-μ-acetato-bis[chloridocuprate(II)], [Emim]2[Cu2(C2H3O2)4Cl2] (1) (Emim is 1-ethyl-3-methylimidazolium, C6H11N2), contains [Cu2(C2H3O2)4Cl2]2− coordination anions with a paddle-wheel structure and ionic liquid cations. Two of the synthesized complexes are one-dimensional polymers, namely catena-poly[1-ethyl-3-methylimidazolium [[tetra-μ-acetato-dicuprate(II)]-μ-chlorido] monohydrate], {[Emim][Cu2(C2H3O2)4Cl]·H2O}
n
(2), and catena-poly[1-ethyl-3-methylimidazolium [[tetra-μ-acetato-dicuprate(II)]-μ-acetato]], {[Emim][Cu2(C2H3O2)5]}
n
(3). In these compounds, the Cu2(C2H3O2)4 units with a paddle-wheel structure are connected to each other through chloride (in 2) or acetate (in 3) anions to form parallel chains, between which cations of ionic liquid are situated. The last compound, bis(1-ethyl-3-methylimidazolium) tetra-μ-acetato-bis[aquacopper(II)] tetra-μ-acetato-bis[acetatocuprate(II)] dihydrate, [Emim]2[Cu2(C2H3O2)4(H2O)2][Cu2(C2H3O2)6]·2H2O (4), contains two different binuclear coordination units (neutral and anionic), connected through hydrogen bonds between water molecules and acetate ions.
How is process mining technology used by organizations? A systematic literature review of empirical studies
Authors: Thiede Malte , Fuerstenau Daniel , Bezerra Barquet Ana Paula
Published: June 2018

Purpose

The purpose of this paper is to review empirical studies on process mining in order to understand its use by organizations. The paper further aims to outline future research opportunities.

Design/methodology/approach

The authors propose a classification model that combines core conceptual elements of process mining with prior models from technology classification from the enterprise resource planning and business intelligence field. The model incorporates an organizational usage, a system-orientation and service nature, adding a focus on physical services. The application is based on a systematic literature review of 144 research papers.

Findings

The results show that, thus far, the literature has been chiefly concerned with realization of single business process management systems in single organizations. The authors conclude that cross-system or cross-organizational process mining is underrepresented in the ISR, as is the analysis of physical services.

Practical implications

Process mining researchers have paid little attention to utilizing complex use cases and mining mixed physical-digital services. Practitioners should work closely with academics to overcome these knowledge gaps. Only then will process mining be on the cusp of becoming a technology that allows new insights into customer processes by supplying business operations with valuable and detailed information.

Originality/value

Despite the scientific interest in process mining, particularly scant attention has been given by researchers to investigating its use in relatively complex scenarios, e.g., cross-system and cross-organizational process mining. Furthermore, coverage on the use of process mining from a service perspective is limited, which fails to reflect the marketing and business context of most contemporary organizations, wherein the importance of such scenarios is widely acknowledged. The small number of studies encountered may be due to a lack of knowledge about the potential of such scenarios as well as successful examples, a situation the authors seek to remedy with this study.
Determination of an additive time- and space-dependent coefficient in the heat equation
Authors: Huntul Mousa , Lesnic Daniel , Johansson Tomas
Published: June 2018

Purpose

The purpose of this study is to provide an insight and to solve numerically the identification of an unknown coefficient of radiation/absorption/perfusion appearing in the heat equation from additional temperature measurements.

Design/methodology/approach

First, the uniqueness of solution of the inverse coefficient problem is briefly discussed in a particular case. However, the problem is still ill-posed as small errors in the input data cause large errors in the output solution. For numerical discretization, the finite difference method combined with a regularized nonlinear minimization is performed using the MATLAB toolbox routine lsqnonlin.

Findings

Numerical results presented for three examples show the efficiency of the computational method and the accuracy and stability of the numerical solution even in the presence of noise in the input data.

Research limitations/implications

The mathematical formulation is restricted to identify coefficients which separate additively in unknown components dependent individually on time and space, and this may be considered as a research limitation. However, there is no research implication to overcome this, as the known input data are also limited to single measurements of temperature at a particular time and space location.

Practical implications

As noisy data are inverted, the study models real situations in which practical measurements are inherently contaminated with noise.

Social implications

The identification of the additive time- and space-dependent perfusion coefficient will be of great interest to the bio-heat transfer community and applications.

Originality/value

The current investigation advances previous studies which assumed that the coefficient multiplying the lower-order temperature term depends on time or space separately. The knowledge of this physical property coefficient is very important in biomedical engineering for understanding the heat transfer in biological tissues. The originality lies in the insight gained by performing for the first time numerical simulations of inversion to find the coefficient additively dependent on time and space in the heat equation from noisy measurements.
Convective–radiative heat transfer in a cavity filled with a nanofluid under the effect of a nonuniformly heated plate
Authors: Sheremet Mikhail , Chinnasamy Sivaraj
Published: June 2018

Purpose

The purpose of this study is to examine the radiation effect on the natural convective heat transfer of an alumina–water nanofluid in a square cavity in the presence of centered nonuniformly heated plate.

Design/methodology/approach

The square cavity filled with alumina–water nanofluid has a nonuniformly heated plate placed horizontally or vertically at its center. The plate is heated isothermally with linearly varying temperature. The vertical walls are cooled isothermally with a constant temperature, while the horizontal walls are insulated. The governing equations have been discretized using finite volume method on a uniformly staggered grid system. Simulations were carried out for different values of the heated plate nonuniformity parameter (λ = –1, 0 and 1), the nanoparticles solid volume fraction (Φ = 0.01 − 0.04) and the radiation parameter (Rd = 0 – 2) at the Rayleigh number of Ra = 1e+07.

Findings

It is found that the total heat transfer rate is enhanced with an increase in the radiation parameter for both the horizontal and vertical plates. The role of nanoparticles addition to the base fluid can have dual effects on the heat transfer rate by augmenting and dampening for the absence of radiation while it dampens the heat transfer rate for the presence of radiation.

Originality/value

The originality of this work is to analyze steady natural convection in a square cavity filled with a water-based nanofluid in the presence of centered nonuniformly heated plate. The results would benefit scientists and engineers to become familiar with the analysis of convective heat and mass transfer in nanofluids, and the way to predict the properties of nanofluid convective flow in advanced technical systems, in industrial sectors including transportation, power generation, chemical sectors, electronics, etc.
Brand management in mergers and acquisitions
Authors: Liu Yipeng , Öberg Christina , Tarba Shlomo Yedidia , Xing Yijun
Published: June 2018

Purpose

The purpose of this paper is to focus on emerging market companies that internationalize into advanced economies by means of acquisitions and to investigate brand management during post-acquisition integration from a multi-level perspective and to identify how a brand management strategy can be constructed. It takes into account the influences of country-of-origin image, corporate brand and brand portfolio to obtain a granular view of post-acquisition brand management.

Design/methodology/approach

A multiple case study approach was adopted. By using case studies and storytelling qualitative research methods, the empirical setting was related to the acquisitions undertaken by Chinese companies in Germany.

Findings

The authors identified three mechanisms for brand management in the post-acquisition integration of emerging market companies – namely, transferring, dynamically redeploying and categorizing – that underpin the interconnection and combined influence of country-of-origin image at the national level, corporate brand at the organizational level and brand portfolio at the product level.

Practical implications

Brand has been viewed as a strategic asset in Chinese cross-border mergers and acquisitions (M&As). Brand management is a dynamic process that involves learning and interaction between the acquirer and target. The research offers a practical guideline for both acquirers and targets in managing brand in the context of acquisitions undertaken by emerging market companies in advanced economies.

Originality/value

The findings provide important insights into the brand management strategies adopted in Chinese cross-border M&As in particular, and emerging market companies venturing into advanced economies in general. The interlinking of country, company and product levels introduces new ideas to the brand literature related to acquisitions, and the setting of Chinese companies acquiring German ones constitutes an important contribution to the understanding of the different ways in which companies from emerging economies may pursue branding strategies in the context of cross-border M&As.
Stewardship behaviour and perceived goal congruence in local governments in Uganda
Authors: Lubogoyi Bumaali , Kasekende Francis , Kagaari James , Ngoma Muhammed , Munene John C. , Bakunda Geofrey
Published: June 2018

Purpose

The purpose of this paper is to investigate the relationship between stewardship behaviour and perceived goal congruence. Using local governments, the paper introduces collectivism as a moderating variable to ascertain whether the mixed views in the stewardship behaviour-perceived goal congruence nexus is due to variations in collectivism.

Design/methodology/approach

The paper espouses a cross-sectional descriptive and analytical design. The authors use structural equation modelling to investigate hypotheses. Using proportionate and simple random sampling procedures, a sample of 310 respondents were drawn from local governments in Uganda of which a response rate of 72.6 per cent was obtained.

Findings

The findings show that stewardship behaviour and collectivism are significant predictors of perceived goal congruence. Furthermore, the magnitude effect of stewardship behaviour on perceived goal congruence depends on collectivism; implying that the assumption of non-additivity is met.

Research limitations/implications

Only a single research methodological approach was employed and future research through interviews could be undertaken to triangulate.

Practical implications

Variations that occur in stewardship behaviour create variations in goal congruence in local governments. It is confirmed that collectivism technically strengthens the link between stewardship behaviour and perceived goal congruence: suggesting that indeed collectivism could establish a maximal impact on the stewardship behaviour—perceived goal congruence link.

Originality/value

This is one of the few studies that focus on testing the interactive effects of collectivism on the relationship between stewardship behaviour and perceived goal congruence in local governments in Uganda.
Taxation of the Bitcoin: initial insights through a correspondence analysis
Authors: Ram Asheer Jaywant
Published: June 2018

Purpose

The Bitcoin has experienced wide popularity in academic and commercial spheres during the years following 2012. Research has been conducted in respect of information technology, finance and reporting paradigms, but there has been little research into the taxation of the Bitcoin. The purpose of this paper is to present a conceptual approach for developing a taxation policy for the Bitcoin, using a multi-jurisdictional analysis.

Design/methodology/approach

An interpretive mixed-method approach is followed. The traits of the Bitcoin are determined through a review of the literature, followed by the determination of key taxation themes using a multi-jurisdictional view where the jurisdictions were determined using the largest Bitcoin exchanges. These form the row and column headings of the correspondence table research instrument, respectively. The correspondence table was completed by 40 tax experts. Correspondence analysis (a multivariate statistical technique) was then used to determine correlations between the Bitcoin traits and taxation themes, further used to present initial insights into developing a taxation policy for the Bitcoin.

Findings

The correspondence analysis reveals that, contrary to current tax laws, the manner of acquisition as opposed to the reason (intention) for acquisition is key in determining how the Bitcoin is to be taxed. For taxing purposes, Bitcoin is seen as being distinct from currency, given that transactions with the Bitcoin are seen as barter transactions. Finally, because of the unique characteristics of the Bitcoin, it is shown that exchanges and the Bitcoin need to be regulated in the same manner as a currency.

Research limitations/implications

This research focuses on income tax including capital gains tax and consumption taxes and was conducted with a sample of purposefully selected South African tax experts, given that the Bitcoin is experiencing enhanced popularity in South Africa. As a result, this research does not provide generalisable positivist conclusions and does not purport to represent the views of all tax practitioners. This paper does, however, provide an initial mechanism to develop taxation treatments for transactions not covered by existing legislation.

Originality/value

This paper is the first to provide normative recommendations on the taxation of the Bitcoin. Using correspondence analysis, this paper offers an innovative approach for developing taxation policies when a transaction is not specifically included in the extant legislation. Further value is added through the use of a third dimension in the correspondence analysis which enhances the exploratory potential of the research.