bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of rapid thermal annealing on the structural and local atomic properties of ZnO: Ge nanocomposite thin films
Authors: Ceylan Abdullah , Rumaiz Abdul K. , Caliskan Deniz , Ozcan Sadan , Ozbay Ekmel , Woicik J. C.
Published: March 2015

We have investigated the structural and local atomic properties of Ge nanocrystals (Ge-ncs) embedded ZnO (ZnO: Ge) thin films. The films were deposited by sequential sputtering of ZnO and Ge thin film layers on z-cut quartz substrates followed by an ex-situ rapid thermal annealing (RTA) at 600 °C for 30, 60, and 90 s under forming gas atmosphere. Effects of RTA time on the evolution of Ge-ncs were investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM), hard x-ray photoelectron spectroscopy (HAXPES), and extended x-ray absorption fine structure (EXAFS). XRD patterns have clearly shown that fcc diamond phase Ge-ncs of sizes ranging between 18 and 27 nm are formed upon RTA and no Ge-oxide peak has been detected. However, cross-section SEM images have clearly revealed that after RTA process, Ge layers form varying size nanoclusters composed of Ge-ncs regions. EXAFS performed at the Ge K-edge to probe the local atomic structure of the Ge-ncs has revealed that as prepared ZnO:Ge possesses Ge-oxide but subsequent RTA leads to crystalline Ge structure without the oxide layer. In order to study the occupied electronic structure, HAXPES has been utilized. The peak separation between the Zn 2p and Ge 3d shows no significant change due to RTA. This implies little change in the valence band offset due to RTA.
Molecular dynamics simulations of field emission from a planar nanodiode
Authors: Torfason Kristinn , Valfells Agust , Manolescu Andrei
Published: March 2015

High resolution molecular dynamics simulations with full Coulomb interactions of electrons are used to investigate field emission in planar nanodiodes. The effects of space-charge and emitter radius are examined and compared to previous results concerning transition from Fowler-Nordheim to Child-Langmuir current [Y. Y. Lau, Y. Liu, and R. K. Parker, Phys. Plasmas 1, 2082 (1994) and Y. Feng and J. P. Verboncoeur, Phys. Plasmas 13, 073105 (2006)]. The Fowler-Nordheim law is used to determine the current density injected into the system and the Metropolis-Hastings algorithm to find a favourable point of emission on the emitter surface. A simple fluid like model is also developed and its results are in qualitative agreement with the simulations.
Initial growth process of Co (Pd) layers on a Pd (Co) surface
Authors: Nishizawa N. , Porquez J. G. , Kitamoto Y. , Munekata H.
Published: March 2015

The deposition process of ultra-thin Co and Pd layers is studied using DC magnetron sputtering and ex situ atomic force microscopy (AFM). It is found that observation with AFM in the air atmosphere is reliable to discuss nucleation of Co and Pd crystallites. It is discussed that a Co ultra-thin layer is formed primarily through the process of two-dimensional island formation, whereas a Pd ultra-thin layer is formed through the process of mixed two- and three-dimensional island formation. On the basis of those results, Co/Pd multilayers having a flat top surface are prepared successfully.
Ferroelectric domain structures in <001>-oriented K0.15Na0.85NbO3 lead-free single crystal
Authors: Chen Yan , Wong Chi-Man , Deng Hao , Yau Hei-Man , Wang Danyang , Yan Zhibo , Luo Haosu , Chan Helen L. W. , Dai Jiyan
Published: March 2015

In this work, ferroelectric domain structures of <001 >-oriented K0.15Na0.85NbO3 single crystal are characterized. Transmission electron microscopy (TEM) observation revealed high-density of laminate domain structures in the crystal and the lattices of the neighboring domains are found to be twisted in a small angle. Superlattice diffraction spots of 12{eeo} and 12{ooe} in electron diffraction patterns are observed in the crystal, revealing the a+a+c− tilting of oxygen octahedral in the perovskite structure. The piezoresponse of domains and in-situ poling responses of K0.15Na0.85NbO3 crystal are observed by piezoresponse force microscopy (PFM), and the results assure its good ferroelectric properties.
Mesozooplankton community in a seasonally hypoxic and highly eutrophic bay
Authors: Jang Min-Chul , Shin Kyoungsoon , Jang Pung-Guk , Lee Woo-Jin , Choi Keun-Hyung
Published: March 2015

A 2-year survey of seawater chemistry and mesozooplankton abundance was carried out in Masan Bay, South Korea, one of the most eutrophic coastal ecosystems known. The study aimed to identify the major factors contributing to the seasonally persistent hypoxia in the bay, to characterise the Bay’s mesozooplankton community and to examine the effects of low oxygen on the distribution of mesozooplankton. Hypoxia (<2mgO2L–1) was present only in summer, with ultrahypoxia (<0.2mg O2 L–1) in the bottom waters of the inner bay in both years. Low summer oxygen can be attributed to high summer phytoplankton stocks, together with reduced oxygen solubility at high temperature and stratification of the water column that limits downward diffusion of oxygen. A seasonally and spatially distinct mesozooplankton community was identified in summer when there was greater influence of freshwater discharge in the inner bay. Marine cladocerans were very abundant, with a population outburst of Penilia avirostris in the inner bay (>4000 individuals m–3) during summer. During hypoxic events, the abundance of Penilia avirostris was positively related to oxygen levels in the bottom water, suggesting that hypoxic conditions may cause mortality or have sublethal negative effects on population growth of this filter-feeding cladoceran.
Water level decrease and increased water stability promotes phytoplankton growth in a mesotrophic subtropical lake
Authors: Fuentes Eduardo V. , Petrucio Mauricio M.
Published: March 2015

Global warming and climate variability can promote changes in freshwater ecosystems that may result in increased frequency of algal blooms. These effects, however, depend strongly on local factors. Peri Lake is a cyanobacteria-dominated shallow lake that has experienced a strong reduction in water level, as well as increased occurrence of algal blooms. The goal of this study was to determine the influence of water level on phytoplankton biomass in Peri Lake. We hypothesise that increased algal blooms are associated with reduction in water level, possibly in response to changes in rainfall patterns. We measured meteorological, physical, and chemical variables over 5 years, as well as chlorophyll-a levels. We observed a strong reduction in total rainfall in the last year of the study, in which the flow of lake water nearly ceased. Phytoplankton biomass increased despite a lack of evidence of water heating or eutrophication. Our results suggest that changes in rainfall regime alter lake characteristics such as retention time and water stability (i.e. increased occurrence of diurnal stratification events), producing favourable conditions for growth of cyanobacterial biomass. These effects perhaps better explain increases in algal biomass in this system than do temperature or nutrient availability alone.
Sierra Nevada fire severity conclusions are robust to further analysis: a reply to Safford et al.
Authors: Hanson Chad T. , Odion Dennis C.
Published: March 2015

Safford et al. (this issue) question our earlier findings that fire severity has not increased in Sierra Nevada conifer forests 1984–2010, hypothesising that an increasing trend might have appeared had we restricted our analysis to wildland fire in frequent-fire forest types on US Forest Service lands. Here, we tested that hypothesis and again found no trend of increasing severity.
Sponge grade body fossil with cellular resolution dating 60 Myr before the Cambrian
Authors: Yin Zongjun , Zhu Maoyan , Davidson Eric H. , Bottjer David J. , Zhao Fangchen , Tafforeau Paul
Published: March 2015

Significance

Phylogenomic extrapolations indicate the last common ancestor of sponges and eumetazoans existed deep in the Cryogenian, perhaps 200 million years (Myr) before the Cambrian (541 Ma). This inference implies a long Precambrian history of animals phylogenetically allied with sponges. However, there is yet little unequivocal paleontological evidence of Precambrian sponges. Here, we present a newly discovered 600-Myr-old fossil preserved at cellular resolution, displaying multiple poriferan features. The animal was covered with a dense layer of flattened cells resembling sponge pinacocytes, displaying a hollow tubular structure with apparent water inflow and outflow orifices. Although requiring additional specimens of similar form for confirmation, this finding is consistent with phylogenomic inference, and implies the presence of eumetazoan ancestors by 60 Myr before the Cambrian.
The effects of reputational and social knowledge on cooperation
Authors: Gallo Edoardo , Yan Chang
Published: March 2015

Significance

Cooperation is essential for societies to prosper. Recent experiments show that cooperation emerges in dynamic networks in which subjects can select their connections. However, these studies fixed the amount of reputation information available and did not display the network to subjects. Here, we systematically vary the knowledge available to subjects about reputation and the network to investigate experimentally their roles in determining cooperation in dynamic networks. Common knowledge about everyone’s reputation is the main driver of cooperation leading to dense and clustered networks. The addition of common knowledge about the network affects the distribution of cooperative activity: cooperators form a separate community and achieve a higher payoff from within-community interactions than members of the less cooperative community.
MiR-2 family regulates insect metamorphosis by controlling the juvenile hormone signaling pathway
Authors: Lozano Jesus , Montañez Raúl , Belles Xavier
Published: March 2015

Significance

MicroRNAs are short, single-stranded RNAs that bind to target mRNAs and block their translation. Five years ago we observed in the cockroachBlattella germanicathat general depletion of microRNAs prevents metamorphosis. This observation led to two key questions: Which microRNAs are involved in this action, and which target do they act on? The results reported herein show that the microRNAs involved are those of an miR-2 family (miR-2, miR-13a, and miR-13b), and the target is the transcription factor Krüppel homolog 1, a master repressor of insect metamorphosis. The data presented indicate that miR-2 microRNAs rapidly clear Krüppel homolog 1 transcripts in the last nymphal instar, a process that is crucial for proper metamorphosis. This reveals the elegant mechanism of an miRNA family leading metamorphosis to its correct conclusion.
Transmembrane tethering of synaptotagmin to synaptic vesicles controls multiple modes of neurotransmitter release
Authors: Lee Jihye , Littleton J. Troy
Published: March 2015

Significance

Synaptotagmin 1 (Syt1) is widely considered to act as the fast Ca
2+
sensor for synchronous synaptic vesicle fusion through its tandem Ca
2+
-binding C2 domains. Here we demonstrate that Syt1’s C2 domains activate rapid synchronous fusion only if they are in the proper orientation and specifically tethered to the synaptic vesicle with an appropriate linker distance. Although expression of the cytoplasmic C2 domains of Syt1 alone did not support fast synchronous release, it did enhance the asynchronous component of exocytosis. These findings demonstrate that synaptic vesicle tethering of Syt1 positions the protein to allow its C2 domains to regulate the kinetics of vesicle fusion.
Genome-wide ancestry of 17th-century enslaved Africans from the Caribbean
Authors: Schroeder Hannes , Ávila-Arcos María C. , Malaspinas Anna-Sapfo , Poznik G. David , Sandoval-Velasco Marcela , Carpenter Meredith L. , Moreno-Mayar José Víctor , Sikora Martin , Johnson Philip L. F. , Allentoft Morten Erik , Samaniego José Alfredo , Haviser Jay B. , Dee Michael W. , Stafford Thomas W. , Salas Antonio , Orlando Ludovic , Willerslev Eske , Bustamante Carlos D. , Gilbert M. Thomas P.
Published: March 2015

Significance

The transatlantic slave trade resulted in the forced movement of over 12 million Africans to the Americas. Although many coastal shipping points are known, they do not necessarily reflect the slaves’ actual ethnic or geographic origins. We obtained genome-wide data from 17th-century remains of three enslaved individuals who died on the Caribbean island of Saint Martin and use them to identify their genetic origins in Africa, with far greater precision than previously thought possible. The study demonstrates that genomic data can be used to trace the genetic ancestry of long-dead individuals, a finding that has important implications for archeology, especially in cases where historical information is missing.
Quantitative modeling of transcription factor binding specificities using DNA shape
Authors: Zhou Tianyin , Shen Ning , Yang Lin , Abe Namiko , Horton John , Mann Richard S. , Bussemaker Harmen J. , Gordân Raluca , Rohs Remo
Published: March 2015

Significance

Genomes provide an abundance of putative binding sites for each transcription factor (TF). However, only small subsets of these potential targets are functional. TFs of the same protein family bind to target sites that are very similar but not identical. This distinction allows closely related TFs to regulate different genes and thus execute distinct functions. Because the nucleotide sequence of the core motif is often not sufficient for identifying a genomic target, we refined the description of TF binding sites by introducing a combination of DNA sequence and shape features, which consistently improved the modeling of in vitro TF−DNA binding specificities. Although additional factors affect TF binding in vivo, shape-augmented models reveal binding specificity mechanisms that are not apparent from sequence alone.
Reduced fitness in progeny from old parents in a natural population
Authors: Schroeder Julia , Nakagawa Shinichi , Rees Mark , Mannarelli Maria-Elena , Burke Terry
Published: March 2015

Significance

As parents age, gamete quality declines. If this decline affects the next generation, it could influence the evolution of longevity. Older parents often produce offspring of low fitness in the laboratory. Our long-term data from a natural bird population shows, for the first time to our knowledge, a transgenerational reduction in fitness of the next generation associated with parental age. We use a 10-year cross-fostering experiment to exclude environmental explanations. Our results challenge the currently favored hypothesis in evolutionary biology and behavioral ecology that old age signals high quality in mating partners. Our results imply a substantial cost of reproducing with older, rather than younger, partners. The results inform increasing concern about delayed reproduction in medicine, sociology, and conservation biology.
Computational protein design enables a novel one-carbon assimilation pathway
Authors: Siegel Justin B. , Smith Amanda Lee , Poust Sean , Wargacki Adam J. , Bar-Even Arren , Louw Catherine , Shen Betty W. , Eiben Christopher B. , Tran Huu M. , Noor Elad , Gallaher Jasmine L. , Bale Jacob , Yoshikuni Yasuo , Gelb Michael H. , Keasling Jay D. , Stoddard Barry L. , Lidstrom Mary E. , Baker David
Published: March 2015

Significance

This paper describes the development of a computationally designed enzyme that is the cornerstone of a novel metabolic pathway. This enzyme, formolase, performs a carboligation reaction, directly fixing one-carbon units into three-carbon units that feed into central metabolism. By combining formolase with several naturally occurring enzymes, we created a new carbon fixation pathway, the formolase pathway, which assimilates one-carbon units via formate. Unlike native carbon fixation pathways, this pathway is linear, not oxygen sensitive, and consists of a small number of thermodynamically favorable steps. We demonstrate in vitro pathway function as a proof of principle of how protein design in a pathway context can lead to new efficient metabolic pathways.
Facilitation of fear extinction by novelty depends on dopamine acting on D1-subtype dopamine receptors in hippocampus
Authors: Menezes Jefferson , Alves Niége , Borges Sidnei , Roehrs Rafael , de Carvalho Myskiw Jociane , Furini Cristiane Regina Guerino , Izquierdo Ivan , Mello-Carpes Pâmela B.
Published: March 2015

Significance

A brief exposure to a novel environment was recently shown to enhance the extinction of contextual fear probably through a protein synthesis-dependent process of synaptic tagging and capture in the hippocampus. Here we report that this finding can be generalized to the extinction of another fear-motivated task, one-trial inhibitory avoidance. This generalization is important because extinction is used in exposure therapy to treat posttraumatic stress disorder in humans, and this may derive from various forms of fear-related stress. In addition, here we show that the effect of novelty on fear extinction is dependent on dopamine D1 but not D5 receptors in the hippocampus. These findings could be applicable to the exposure therapy of fear memory disorders.
Human Ebola virus infection results in substantial immune activation
Authors: McElroy Anita K. , Akondy Rama S. , Davis Carl W. , Ellebedy Ali H. , Mehta Aneesh K. , Kraft Colleen S. , Lyon G. Marshall , Ribner Bruce S. , Varkey Jay , Sidney John , Sette Alessandro , Campbell Shelley , Ströher Ute , Damon Inger , Nichol Stuart T. , Spiropoulou Christina F. , Ahmed Rafi
Published: March 2015

Significance

In 2014, Ebola virus became a household term. The ongoing outbreak in West Africa is the largest Ebola virus outbreak ever recorded, with over 20,000 cases and over 8,000 deaths to date. Very little is known about the human cellular immune response to Ebola virus infection, and this lack of knowledge has hindered development of effective therapies and vaccines. In this study, we characterize the human immune response to Ebola virus infection in four patients. We define the kinetics of T- and B-cell activation, and determine which viral proteins are targets of the Ebola virus-specific T-cell response in humans.
Chromatin proteomic profiling reveals novel proteins associated with histone-marked genomic regions
Authors: Ji Xiong , Dadon Daniel B. , Abraham Brian J. , Lee Tong Ihn , Jaenisch Rudolf , Bradner James E. , Young Richard A.
Published: March 2015

Significance

More than a thousand proteins are thought to contribute to mammalian chromatin and its regulation, but our understanding of the genomic occupancy and function of most of these proteins is limited. We have used a chromatin proteomic profiling approach to produce a catalogue of proteins associated with genomic regions whose chromatin is marked by specific modified histones. A substantial number of the newly identified proteins are associated with human disease. Future chromatin proteomic profiling studies should prove valuable for identifying additional chromatin-associated proteins in a broad spectrum of cell types.
Engagement in Sámi language revitalization
Authors: Hiss Florian
Published: March 2015

In the context of the endangered situation and revitalization of Sámi in a Northern Norwegian local community, this study discusses various aspects of responsibility that are construed and involved in the encounter of a local informant and the researcher in a research interview. The informant uses storytelling as an artful and elaborate means to position himself, to assess his own and other community members’ responsibility for their endangered heritage language, and to involve the researcher in his account. The analysis shows how storytelling operationalizes different social role relations, and how the informant uses the meaning potential of the interview situation as a resource to communicate his view on who are accountable and who should acknowledge their respective responsibilities for Sámi language use and revitalization.
Closing the gap in customer service encounters
Authors: Kevoe-Feldman Heidi
Published: March 2015

Within the context of service inquiries, and the specialized inferential logic associated with the particularized activities (Levinson 1992) there is a gap in the orientations of customers and service representatives. Specifically, one problem that arises in customer service encounters is that customers and service representatives appear to arrive at different understandings of what constitutes a relevant response to a service inquiry. By examining one type of customer service context, calls to an electronic repair facility, this article offers a conversation analytic account of how customers use formulations to collaboratively achieve a mutually agreed upon answer to their service inquiry and close the gap in the underlying logics that emerge in these calls.
Identification and characterization of the diuretic hormone 31 receptor in the silkwormBombyx mori
Authors: Iga Masatoshi , Kataoka Hiroshi
Published: March 2015

The receptor for diuretic hormone 31 (DH31R) was identified in the silkworm Bombyx mori. A heterologous expression system revealed that an orphan G-protein coupled receptor, BNGR-B1, responded to DH31 and upregulated the intracellular cAMP level. DH31R (BNGR-B1) was predominantly expressed in the anterior silk gland, midgut, and ovary, whereas DH31 was predominantly expressed in the central nervous system and midgut.
Lin28b promotes fetal B lymphopoiesis through the transcription factor Arid3a
Authors: Zhou Yan , Li Yue-Sheng , Bandi Srinivasa Rao , Tang Lingjuan , Shinton Susan A. , Hayakawa Kyoko , Hardy Richard R.
Published: March 2015

Mouse B cell precursors from fetal liver and adult bone marrow (BM) generate distinctive B cell progeny when transplanted into immunodeficient recipients, supporting a two-pathway model for B lymphopoiesis, fetal “B-1” and adult “B-2.” Recently, Lin28b was shown to be important for the switch between fetal and adult pathways; however, neither the mechanism of Lin28b action nor the importance of B cell antigen receptor (BCR) signaling in this process was addressed. Here, we report key advances in our understanding of the regulation of B-1/B-2 development. First, modulation of Let-7 in fetal pro-B cells is sufficient to alter fetal B-1 development to produce B cells resembling the progeny of adult B-2 development. Second, intact BCR signaling is required for the generation of B1a B cells from Lin28b-transduced BM progenitors, supporting a requirement for ligand-dependent selection, as is the case for normal B1a B cells. Third, the VH repertoire of Lin28b-induced BM B1a B cells differs from that of normal B1a, suggesting persisting differences from fetal progenitors. Finally, we identify the Arid3a transcription factor as a key target of Let-7, whose ectopic expression is sufficient to induce B-1 development in adult pro-B cells and whose silencing by knockdown blocks B-1 development in fetal pro-B cells.
Deligne-Lusztig theoretic derivation for Weyl groups of the number of reflection factorizations of a Coxeter element
Authors: Michel Jean
Published: March 2015

Chapuy and Stump have given a nice generating series for the number of factorizations of a Coxeter element as a product of reflections. Their method is to evaluate case by case a character-theoretic expression. The goal of this note is to give a uniform evaluation of their character-theoretic expression in the case of Weyl groups, by using combinatorial properties of Deligne-Lusztig representations.
Livšic measurable rigidity for 𝒞¹ generic volume-preserving Anosov systems
Authors: Yang Yun
Published: March 2015

In this paper, we prove that for

C

1

\mathcal {C}^1

generic volume-preserving Anosov diffeomorphisms of a compact connected Riemannian manifold, the Livšic measurable rigidity theorem holds. We also give a parallel result for

C

1

\mathcal {C}^1

generic volume-preserving Anosov flows.
Compact embedding derivatives of Hardy spaces into Lebesgue spaces
Authors: Peláez José
Published: March 2015

We characterize the positive Borel measures such that the differentiation operator of order

n
∈

N

∪
{
0
}

n\in \mathbb {N}\cup \{0\}

is compact from the Hardy space

H
p

H^p

into

L
q

(
μ
)

L^q(\mu )

,

0
>
p
,
q
>
∞

0>p,q>\infty

.
Reducing the search space for causal genetic variants with VASP
Authors: Field Matthew A. , Cho Vicky , Cook Matthew C. , Enders Anselm , Vinuesa Carola G. , Whittle Belinda , Andrews T. Daniel , Goodnow Chris C.
Published: March 2015

Motivation: Increasingly, cost-effective high-throughput DNA sequencing technologies are being utilized to sequence human pedigrees to elucidate the genetic cause of a wide variety of human diseases. While numerous tools exist for variant prioritization within a single genome, the ability to concurrently analyze variants within pedigrees remains a challenge, especially should there be no prior indication of the underlying genetic cause of the disease. Here, we present a tool, variant analysis of sequenced pedigrees (VASP), a flexible data integration environment capable of producing a summary of pedigree variation, providing relevant information such as compound heterozygosity, genome phasing and disease inheritance patterns. Designed to aggregate data across a sequenced pedigree, VASP allows both powerful filtering and custom prioritization of both single nucleotide variants (SNVs) and small indels. Hence, clinical and research users with prior knowledge of a disease are able to dramatically reduce the variant search space based on a wide variety of custom prioritization criteria.

Availability and implementation: Source code available for academic non-commercial research purposes at https://github.com/mattmattmattmatt/VASP.

Contact: matt.field@anu.edu.au

Supplementary information: Supplementary data are available at Bioinformatics online.
A novel chimeric phage lysin with high in vitro and in vivo bactericidal activity against Streptococcus pneumoniae
Authors: Díez-Martínez Roberto , De Paz Héctor D. , García-Fernández Esther , Bustamante Noemí , Euler Chad W. , Fischetti Vincent A. , Menendez Margarita , García Pedro
Published: March 2015

Objectives

Streptococcus pneumoniae is becoming increasingly antibiotic resistant worldwide and new antimicrobials are urgently needed. Our aim was new chimeric phage endolysins, or lysins, with improved bactericidal activity by swapping the structural components of two pneumococcal phage lysozymes: Cpl-1 (the best lysin tested to date) and Cpl-7S.

Methods

The bactericidal effects of four new chimeric lysins were checked against several bacteria. The purified enzymes were added at different concentrations to resuspended bacteria and viable cells were measured after 1 h. Killing capacity of the most active lysin, Cpl-711, was tested in a mouse bacteraemia model, following mouse survival after injecting different amounts (25–500 μg) of enzyme. The capacity of Cpl-711 to reduce pneumococcal biofilm formation was also studied.

Results

The chimera Cpl-711 substantially improved the killing activity of the parental phage lysozymes, Cpl-1 and Cpl-7S, against pneumococcal bacteria, including multiresistant strains. Specifically, 5 μg/mL Cpl-711 killed ≥7.5 log of pneumococcal R6 strain. Cpl-711 also reduced pneumococcal biofilm formation and killed 4 log of the bacterial population at 1 μg/mL. Mice challenged intraperitoneally with D39_IU pneumococcal strain were protected by treatment with a single intraperitoneal injection of Cpl-711 1 h later, resulting in about 50% greater protection than with Cpl-1.

Conclusions

Domain swapping among phage lysins allows the construction of new chimeric enzymes with high bactericidal activity and a different substrate range. Cpl-711, the most powerful endolysin against pneumococci, offers a promising therapeutic perspective for the treatment of multiresistant pneumococcal infections.
Systematic analysis of the role of bacterial Hfq-interacting sRNAs in the response to antibiotics
Authors: Kim Taeyeon , Bak Geunu , Lee Juyeon , Kim Kwang-sun
Published: March 2015

Objectives

To systematically analyse the interplay between the expression of Hfq-associated small non-coding RNAs (sRNAs) and antibiotic susceptibility in Gram-negative bacteria.

Methods

To identify the roles of sRNAs in the antibiotic susceptibility of Escherichia coli and Salmonella species, susceptibility tests, growth analyses and viability assays were performed using E. coli Hfq-associated sRNAs from overexpression libraries. Prediction, susceptibility testing of gene knockouts and expression analysis of target genes under conditions of sRNA overexpression or knockout were performed to identify candidate targets for modulating antibiotic susceptibility.

Results

The susceptibilities of E. coli strains overexpressing each of the 26 known Hfq-dependent sRNAs to major classes of antibiotics were determined. Induced expression of 17 sRNAs modulated the susceptibility of E. coli to antibiotics. Among them, four sRNA knockout strains partially or completely reversed susceptibility phenotypes of sRNA overexpression. The phenotype of OxyS, RseX or MicF was not entirely dependent on the presence of Hfq protein, in contrast to the dependency of previously characterized roles. The function of eight of nine sRNAs was found to be conserved in the response to antibiotics in Salmonella. Some MicF- or RyeB-mediated cellular target genes and pathways that may be important for the regulation of antibiotic susceptibility were identified. Finally, the overexpression of RyeB potentiated the efficacy of levofloxacin against MDR strains.

Conclusions

Our data indicate that Hfq-associated sRNAs potentially enable bacteria to adapt to antibiotic challenges via multifaceted approaches. Therefore, sRNA-based applications will form a new antibiotic arsenal for combating the rise in antibiotic resistance.
Marmoricola solisilvae sp. nov. and Marmoricola terrae sp. nov., isolated from soil and emended description of the genus Marmoricola
Authors: Kim Soo-Jin , Lim Jun-Muk , Hamada Moriyuki , Ahn Jae-Hyung , Weon Hang-Yeon , Suzuki Ken-ichiro , Ahn Tae-Young , Kwon Soon-Wo
Published: March 2015

Two strains of species of the genus

Marmoricola

, designated KIS18-7T and JOS5-1T, were isolated from soil samples in Korea. The 16S rRNA gene sequence of strain KIS18-7T showed highest similarities with

Marmoricola scoriae

Sco-D01T (97.8 %),

Marmoricola aequoreus

SST-45T (97.6 %) and

Marmoricola aurantiacus

BC 361T (97.3 %), and strain JOS5-1T had highest sequence similarities with

M. aequoreus

SST-45T (97.5 %) and

Marmoricola bigeumensis

MSL-05T (97.3 %). The sequence similarity between KIS18-7T and JOS5-1T was 98.1 %. Phylogenetic analysis showed that these strains grouped with species of the genus

Marmoricola

. The major fatty acids of strain KIS18-7T were iso-C16 : 0 and C17 : 1ω8c, and C17 : 1ω8c, C18 : 0 10-methyl (TBSA), C18 : 1ω9c, C17 : 0 10-methyl and C16 : 0 2-OH for strain JOS5-1T. Strain KIS18-7T contained the polar lipids, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylcholine, while strain JOS5-1T contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, one unknown aminolipid and two unknown phospholipids. The peptidoglycan of both strains contained ll-diaminopimelic acid as the diagnostic diamino acid and a single glycine residue as the interpeptide bridge (type A3γ). The major menaquinone of both strains was MK-8(H4). The G+C contents of the DNA of strains KIS18-7T and JOS5-1T were 68.0 mol% and 62.9 mol%, respectively. These data demonstrate that strains KIS18-7T and JOS5-1T are representatives of two novel species of the genus

Marmoricola

, for which the names Marmoricola solisilvae sp. nov. (type strain KIS18-7T = KACC 17307T = DSM 27140T = NBRC 109601T) and Marmoricola terrae sp. nov. (type strain JOS5-1T = KACC 17308T = DSM 27141T = NBRC 109602T) are proposed.
Revisiting the Structure/Function Relationships of H/ACA(-like) RNAs: A Unified Model for Euryarchaea and Crenarchaea
Authors: Toffano-Nioche Claire , Gautheret Daniel , Leclerc Fabrice
Published: March 2015

A structural and functional classification of H/ACA and H/ACA-like motifs is proposed from the analysis of the H/ACA guide RNAs which have been identified previously in the genomes of Euryarchaea (Pyrococcus) and Crenarchaea (Pyrobaculum). A unified structure/function model is proposed based on the common structural determinants shared by H/ACA and H/ACA-like motifs in both Euryarchaea and Crenarchaea. Using a computational approach, structural and energetic rules for the guide-target RNA-RNA interactions are derived from structural and functional data on the H/ACA RNP particles. H/ACA(-like) motifs found in Pyrococcus are evaluated through the classification and their biological relevance is discussed. Extra-ribosomal targets found in both Pyrococcus and Pyrobaculum are presented as testable gene candidates which might support the hypothesis of a gene regulation mediated by H/ACA(-like) guide RNAs.
“Care from the heart”: older minoritised women's perceptions of dignity in care
Authors: Saltus Roiyah , Pithara Christalla
Published: March 2015

Purpose

– Drawing findings from a large mixed-method study on perceptions of dignity, care expectations, and support in relation to older women from Black and minority-ethnic backgrounds, the purpose of this paper is to explore the interrelationships between life course events and the multiple roles adopted by women at different points in time that have shaped their perceptions of care and their care expectations in old age.

Design/methodology/approach

– In total, 32 semi-structured interviews were undertaken, allowing for the collection of data on the participants’ understanding of growing old, and the meaning and attributes of care and what care with dignity “looked and felt like”. The theoretical framework is guided by a life-course approach and grounded within an intersectionality perspective. The majority of the participants were migrants.

Findings

– Social markers such as ethnicity and cultural identity were found to influence the participants’ understanding and expectations of care with factors such as gender identity and integration in the local community also of importance. How women felt they were perceived and “recognised” by others in their everyday lives with particular focus at the time of old age with the increased potential of loss of dignity due to declining capabilities, raised the importance of the family involvement in care provision, and perceived differences in the attributes of paid and non-paid care. The notion of “care from the heart” emerged as a key attribute of care with dignity. Care with dignity was understood as a purposeful activity, undertaken with intent to show respect and to acknowledge the participants’ sense of worth and value.

Practical implications

– The implications of this study are relevant in the current debate taking place at the EU level about the lived experiences of ageing migrant groups and care expectations.

Originality/value

– The study highlights the importance of the social nature of dignity, how wider societal structures can impact and shape how care is understood for older women of migrant and minoritised backgrounds, and the need to explore migration and care across the life course.
Bridging the social divides: a school-based model from India
Authors: Chattopadhay Tamo
Published: March 2015

Purpose

– The purpose of this paper is to examine the transformative potential of a school-based model in India that makes middle class students active stakeholders in the well-being of underprivileged children.

Design/methodology/approach

– Employing a qualitative case study method, data were collected through a survey – containing close-ended and open-ended questions – that was administered to all students in grades 6 through 10.

Findings

– Overall, the data suggest that socialization with underprivileged children had a profound impact on the views of middle class children about social inequalities and their own agency in addressing them. While younger children observed more manifest differences between them and the poor children they engaged; the older children articulated those differences in terms of inequalities of opportunity and violations of rights.

Research limitations/implications

– The research was based on a single school where the intervention was conceived and implement by its visionary leader. It would be important to examine the robustness of the model in a broader sample of schools.

Social implications

– The study demonstrates that with purposive strategies and intentional organizational culture, schools for privileged can promote social inclusion of all children.

Originality/value

– This paper makes the counter-intuitive case – analytically and empirically – that for social policies designed for poor children to be a force for social transformation, they should be purposively conceived in conjunction with the educational and developmental imperatives of children from more privileged backgrounds.
Smart for whom? Cost ambiguity as corporate strategy in the 21st century telco sector
Authors: Gould Anthony Morven , Desjardins Guillaume
Published: March 2015

Purpose

– This paper aims to expose techniques that telco vendors use for maximising revenue from their clients. Although the five-point strategy unearthed was based on the Canadian telco industry, it is interpreted as generic to the digital-age.

Design/methodology/approach

– Findings are based on focus groups with telco vendors and client perception data. Inductive reasoning is used to generalise findings to other distinctively digital-age industries.

Findings

– This paper finds five generic techniques that are used within the Canadian telecommunications (telco) industry to ensure that customers cannot control the cost of a smartphone. These techniques are described as an array of telco hybrid offerings, each with its own cost-structure and pricing strategy; the underestimation problem; devices are not geostationary; third-party agreements; and death-by-a-thousand-qualifications.

Research limitations/implications

– The research develops theory about modularity and platform technologies.

Practical implications

– Findings and insights have implications for strengthening consumer protection arrangements in the teleco industry, as well as other distinctively digital-age industries.

Originality/value

– This paper elaborates theory (particularly with respect to platform technologies and modularity). It interprets the flexibility that comes with modern technology as having a specific downside for consumers, namely, the removal of their capacity to control cost. As far as the authors have been able to ascertain, such an interpretation has not hitherto been presented. It is hoped that the classification of findings will become something of a public policy template for ensuring consumer protection.
Multidimensionality: redefining the digital divide in the smartphone era
Authors: Park Eun-A , Lee Sangwon
Published: March 2015

Purpose

– In a converged and smart media environment, it no longer makes sense to talk only of a digital divide based on access to a platform – instead, a new “smartphone divide” is created based on a user’s ability to access and use an array of different services. Although there is an extensive literature on the digital divide in broadband access and use, zero research efforts have addressed the digital divide in mobile phone usage. Therefore, this research study aims to fill the gap in the literature by looking into new dimensions of the smartphone divide.

Design/methodology/approach

– Data were collected from a college student sample through an online survey and some hypotheses were framed and tested for intergroup (smartphone users vs non-users) and intragroup (active smartphone users vs inactive users) differences based on access, experience and persistence of usage.

Findings

– Findings are: first, smartphone users were more active online as expected. Although no significant difference was detected in the amount of time spent on social networking sites (SNSs) between smartphone users and non-users, smartphone users had more friends online and more “online-only” friends than non-users. Second, smartphone users seem to participate more actively in social and political issues than non-users do. Third, active users were adopting digital technologies faster than less active users, and active users were inclined to spend longer time on SNSs than less active users. Also, active users used more free and paid applications on their smartphones compared to less active users.

Originality/value

– This research study aims to fill the gap in the literature by looking into new dimensions of the smartphone divide and exploring the differential usage of smartphone users in terms of usage level, awareness and usability levels, usage scope and consequential uses controlling for demographics and socioeconomic status. The ensuing pilot study validates some of speculations suggested in the previous literature.
The politics of margin squeeze in telecommunications: diverging paths of the US and EU
Authors: Oğuz Fuat
Published: March 2015

Purpose

– This paper aims to study the historical origins of margin squeeze cases in the USA and Europe.

Design/methodology/approach

– The author compares and contrasts major margin squeeze investigations in the USA and the European Union (EU) in terms of the role of efficiency and fairness and shows their roots in the socialist calculation debate of the 1940s.

Findings

– It was found that the USA and EU diverge in their approaches towards margin squeeze claims. While the USA case law focuses more on efficiency, the European Commission makes decisions based more on fairness and “protection of rivals”. This shows that political and ideological preferences influence legal decision-making.

Research limitations/implications

– The paper is limited to major cases in telecommunications. It leaves aside cases in other areas. Thus, the author cautions that the generalization of the findings of the paper to all margin squeeze cases, or competition policy in general, may be difficult.

Originality/value

– While there is extensive literature on margin squeeze cases in the USA and EU, there is little work on the historical and ideological connections. The paper contributes to the literature by drawing attention to political influences over technical decisions.
Bribery and corruption in telecommunications – the Kingdom of Morocco
Authors: Sutherland Ewan
Published: March 2015

Purpose

– This paper aims to analyse telecommunications in Morocco and the control exercised by the absolute monarch who also owns one of three mobile operators.

Design/methodology/approach

– The single country case study provides a detailed picture of legislative, market and policy developments over a period of 15 years.

Findings

– Severe conflicts of interests with the king as absolute monarch, head of the judiciary, chairman of the cabinet of ministers and owner of one of the largest operators exist. Market entry has only been possible with his sanction and only by acquiring in a stake in one of the existing operators. Investment is predominantly by domestic and Gulf Arabs. No attention has been given to competition and market bottlenecks. Expansion of the royal operator was observed.

Research limitations/implications

– This is a single-country case study of an absolute monarchy.

Practical implications

– Short of ending the monarchy, it is difficult to see a means to remove the conflicts of interest.

Social implications

– The interests of the citizens take second place to royal profit-seeking.

Originality/value

– This is the first critical assessment of telecommunications in Morocco. It adds to the small stock of case studies about bribery, corruption and patrimonialism in telecommunications.
Service role and outcome as moderators in intercultural service encounters
Authors: Sharma Piyush , Tam Jackie L.M. , Kim Namwoon
Published: March 2015

Purpose

– The purpose of this paper is to introduce a comprehensive framework incorporating service roles (customer vs employee) and outcomes (failure vs success) as moderators in the process by which perceived cultural distance (PCD) affects customers and employees in intercultural service encounters (ICSEs).

Design/methodology/approach

– The authors used a 2×2×3 between-subjects experimental design with Chinese undergraduate students, manipulating service role (customer and employee), outcome (failure and success) and PCD (low, medium and high).

Findings

– Compared to service employees, customers perceive higher cultural distance and lower interaction comfort (IC), service quality and satisfaction; and stronger negative moderating effect of PCD in ICSEs. Compared to service success, failure results in lower IC; perceived service quality and satisfaction, and these effects are stronger for customers (vs employees).

Research limitations/implications

– The authors used shorter versions of all the scales to minimize participant fatigue and to increase their involvement along with an experimental design with imaginary service scenario, both of which may restrict the generalizability of the findings.

Practical implications

– Service managers should focus on customer education and employee training to reduce the negative impact of PCD and prevent service failure rather than try to improve service quality and satisfaction beyond customers’ expectations.

Originality/value

– The authors extend prior research by exploring the moderating effects of service role (customer vs employee) and outcome (success vs failure) on the direct and indirect effects of PCD on IC, service quality and satisfaction.
Perceptions are relative
Authors: Keiningham Timothy Lee , Cooil Bruce , Malthouse Edward C , Lariviere Bart , Buoye Alexander , Aksoy Lerzan , De Keyser Arne
Published: March 2015

Purpose

– There is general agreement among researchers and practitioners that satisfaction is relative to competitive alternatives. Nonetheless, researchers and managers have not treated satisfaction as a relative construct. The result has been weak relationships between satisfaction and share of wallet in the literature, and challenges by managers as to whether satisfaction is a useful predictor of customer behavior and business outcomes. The purpose of this paper is to explore the best approach for linking satisfaction to share of wallet.

Design/methodology/approach

– Using data from 79,543 consumers who provided 258,743 observations regarding the brands that they use (over 650 brands) covering 20 industries from 15 countries, various models such as the Wallet Allocation Rule (WAR), Zipf-AE, and Zipf-PM, truncated geometric model, generalization of the WAR and hierarchical regression models are compared to each other.

Findings

– The results indicate that the relationship between satisfaction and share of wallet is primarily driven by the relative fulfillment customers perceive from the various brands that they use (as gauged by their relative ranked satisfaction level), and not the absolute level of satisfaction.

Practical implications

– The findings provide practical insight into several easy-to-use approaches that researchers and managers can apply to improve the strength of the relationship between satisfaction and share of wallet.

Originality/value

– This research provides support to the small number of studies that point to the superiority of using relative metrics, and encourages the adoption of relative satisfaction metrics by the academic community.