66 research outputs found

    Complete Sequences of Organelle Genomes from the Medicinal Plant Rhazya Stricta (Apocynaceae) and Contrasting Patterns of Mitochondrial Genome Evolution Across Asterids

    Get PDF
    Rhazya stricta is native to arid regions in South Asia and the Middle East and is used extensively in folk medicine to treat a wide range of diseases. In addition to generating genomic resources for this medicinally important plant, analyses of the complete plastid and mitochondrial genomes and a nuclear transcriptome from Rhazya provide insights into inter-compartmental transfers between genomes and the patterns of evolution among eight asterid mitochondrial genomes. Results: The 154,841 bp plastid genome is highly conserved with gene content and order identical to the ancestral organization of angiosperms. The 548,608 bp mitochondrial genome exhibits a number of phenomena including the presence of recombinogenic repeats that generate a multipartite organization, transferred DNA from the plastid and nuclear genomes, and bidirectional DNA transfers between the mitochondrion and the nucleus. The mitochondrial genes sdh3 and rps14 have been transferred to the nucleus and have acquired targeting presequences. In the case of rps14, two copies are present in the nucleus; only one has a mitochondrial targeting presequence and may be functional. Phylogenetic analyses of both nuclear and mitochondrial copies of rps14 across angiosperms suggests Rhazya has experienced a single transfer of this gene to the nucleus, followed by a duplication event. Furthermore, the phylogenetic distribution of gene losses and the high level of sequence divergence in targeting presequences suggest multiple, independent transfers of both sdh3 and rps14 across asterids. Comparative analyses of mitochondrial genomes of eight sequenced asterids indicates a complicated evolutionary history in this large angiosperm clade with considerable diversity in genome organization and size, repeat, gene and intron content, and amount of foreign DNA from the plastid and nuclear genomes. Conclusions: Organelle genomes of Rhazya stricta provide valuable information for improving the understanding of mitochondrial genome evolution among angiosperms. The genomic data have enabled a rigorous examination of the gene transfer events. Rhazya is unique among the eight sequenced asterids in the types of events that have shaped the evolution of its mitochondrial genome. Furthermore, the organelle genomes of R. stricta provide valuable genomic resources for utilizing this important medicinal plant in biotechnology applications.King Abdulaziz UniversityIntegrative Biolog

    Electronic word of mouth in social media: The common characteristics of retweeted and favourited marketer-generated content posted on Twitter

    Get PDF
    Marketers desire to utilise electronic word of mouth (eWOM) marketing on social media sites. However, not all online content generated by marketers has the same effect on consumers; some of them are effective while others are not. This paper aims to examine different characteristics of marketer-generated content (MGC) that of which one lead users to eWOM. Twitter was chosen as one of the leading social media sites and a content analysis approach was employed to identify the common characteristics of retweeted and favourited tweets. 2,780 tweets from six companies (Booking, Hostelworld, Hotels, Lastminute, Laterooms and Priceline) operating in the tourism sector are analysed. Results indicate that the posts which contain pictures, hyperlinks, product or service information, direct answers to customers and brand centrality are more likely to be retweeted and favourited by users. The findings present the main eWOM drivers for MGC in social media.Abdulaziz Elwalda and Mohammed Alsagga

    Antecedents and outcomes of psychological contract breach: Coping behaviour as a mediator of the effects of feelings of violation related to service outcomes

    Get PDF
    Psychological contract is “an individual’s relational schema regarding the rules and conditions of the resource exchange between the organization and the person” (Guo et al., 2015, p.4). When people think they are not getting what they expect from a contractual agreement, psychological contract breach occurs (Morrison and Robinson, 1997). Driven by lack of research investigating the antecedents and outcomes of psychological contract breach within service encounters, this study extends existing research on psychological contract theory (Rousseau, 1995) and service marketing literature using the cognitive appraisal theory to investigate antecedents and outcomes of psychological contract breach within a service setting. The study examines a comprehensive model that analyses cognitive appraisal and emotional elicitation to further contribute to service marketing literature. An examination of the direct effects of feelings of violation on service outcomes precludes an understanding of people’s responses to violation-inducing service incidents. Building upon stress-and-coping theory (Folkman and Lazarus, 1984), this study also examines three consumer coping strategies as mediators of violation on consumer’s affective states and behavioural outcomes. Therefore, this study aims to build on prior marketing literature research, which has focused narrowly on psychological contract fulfilment and violation, to expand service failure literature by examining antecedents and outcomes of perceived psychological contract breach in a more holistic view. Using a survey-based approach, 779 usable responses were collected using an online panel by targeting mobile phone users in the USA. Subsequently, structural equation modelling procedures were followed using AMOS23 to analyse the data. The findings reveal that psychological contract breach can be a source of service failure during service encounters and the perception of contract breach within service encounter failures lead to negative outcomes. Service managers should ask customers to provide feedback that tailored to capture psychological contract issues. Customer active and expressive coping strategies mediate effects of violation on service outcomes. Hence, when customers perceive a contract breach, service managers should encourage customers to use active coping to fix the problem. Otherwise, customers may cope by expressing their feelings of violation to others or deny the failure episode, both of which lead to unfavourable service outcomes for the firm

    Role of salivary transcriptomics as potential biomarkers in oral cancer: A systematic review

    Get PDF
    Introduction: Transcriptomes in saliva can be used as potential biomarkers for both diagnostic and response to treatment in oral squamous cell carcinoma (OSCC). In this review, we explored their application in this increasingly common disease. Materials and methods: PubMed, EMBASE, Scopus, Web of Science and grey literature from January 1990 to May 2017 were searched. Two independent reviewers performed the study selection according to eligibility criteria. Results: A total of nine studies were included. Three studies showed increased expression of DUSP1, IL8, IL1B, OAZ1, SAT1, S100P and two showed increased expression of miRNA‐31 among study groups compared to normal healthy controls. The sensitivity ranged from 14% to 100%, while the specificity ranged from 38% to 100%. miRNA‐27b had the highest AUC (write in full) of 0.9643 and DUSP1 had the minimum AUC of 0.41. Conclusion: Salivary transcriptomics may play an effective role as a robust and non‐invasive biomarker sighting tool for the diagnosis and management of OSCC

    Composición química, estabilidad oxidativa y propiedades sensoriales de las mezclas de aceites de semillas de Boerhavia elegana Choisy (alhydwan)/aceite de maní

    Get PDF
    This study investigated the effects of blending alhydwan seed oil and peanut oil as a way of enhancing the stability and chemical characteristics of plant seed oils and to discover more innovative foods of high nutraceutical value which can be used in other food production systems. Alhydwan seed oil and peanut oil blended at proportions of 10:90, 20:80, 30:70, 40:60 and 50:50 (v/v) were evaluated according to their physi­cochemical properties, including refractive index, relative density, saponification value, peroxide value, iodine value, free fatty acids, oxidative stability index, and tocopherol contents using various standard and published methods. At room temperature, all of the oil blends were in the liquid state. The physicochemical profiles of the blended oils showed significant decreases (p < 0.05) in peroxide value (6.97–6.02 meq O2/kg oil), refractive index at 25 °C (1.462–1.446), free fatty acids (2.29–1.71%), and saponification value (186.44–183.77 mg KOH/g), and increases in iodine value and relative density at 25 °C (98.10–102.89 and 0.89–0.91, respectively), especially with an analhydwan seed oil to peanut oil ratio of 10:90. Among the fatty acids, oleic and linoleic acids were most abundant in the 50:50 and 10:90 alhydwan seed oil to peanut oil blends, respectively. Oxidative stability increased as the proportion of alhydwan oil increased. In terms of tocopherol contents (γ, δ, and α), γ-tocopherol had the highest values across all of the blended proportions, followed by δ-tocopherol. The overall acceptability was good for all blends. The incorporation of alhydwan seed oil into peanut oil resulted in inexpensive, high-quality blended oil that may be useful in health food products and pharmaceuticals without compromising sensory characteristics.Este estudio investigó los efectos de mezclar aceites de semillas de alhidwan y aceites de maní como una forma de mejorar la estabilidad y las características químicas de los aceites de semillas de plantas y descubrir alimentos más innovadores de alto valor nutracéutico que pueden usarse en otros sistemas de producción de alimentos. El aceite de semilla de Alhydwan y el aceite de maní se mezclaron en proporciones: 10:90, 20:80, 30:70, 40:60 y 50:50 (v/v), respectivamente, y se evaluaron sus propiedades fisicoquímicas, incluido el índice de refracción, densidad, índice de saponificación, índice de peróxido, índice de yodo, ácidos grasos libres, estabilidad oxidativa y contenido de tocoferoles, utilizando métodos estandarizados publicados. A temperatura ambiente, todas las mezclas de aceite estaban en estado líquido. Los perfiles fisicoquímicos de los aceites mezclados mostraron disminuciones significativas (p < 0.05) en el valor de peróxido (6,97–6,02 meqO2/kg de aceite), índice de refracción a 25 °C (1,462–1,446), ácidos grasos libres (2,29–1,71%) e índice de saponificación (186,44–183,77 mg KOH/g), y aumentos en el índice de yodo y la densi­dad relativa a 25 °C (98,10–102,89 y 0,89–0,91, respectivamente), especialmente en una relación de aceite de semilla de analhidwan a aceite de maní de 10:90. Entre los ácidos grasos, los ácidos oleico y linoleico fueron los más abundantes en las mezclas de aceite de semilla de alhydwan/aceite de maní 50:50 y 10:90, respectivamente. La estabilidad oxidativa aumentó a medida que aumentó la proporción de aceite de alhidwan. En términos de contenido de tocoferoles (γ, δ y α), el γ-tocoferol tuvo los valores más altos en todas las proporciones de las mezclas, seguido por el δ-tocoferol. La aceptabilidad general fue buena para todas las mezclas. La incorpora­ción del aceite de semilla de alhydwan al aceite de maní da como resultado mezclas económicas y de alta cali­dad que pueden ser útiles en productos alimenticios saludables y productos farmacéuticos sin comprometer las características sensoriales

    A split-mouth randomized controlled trial to compare the rate of canine retraction after a soft tissue procedure compared against a corticotomy procedure for accelerated tooth movement

    Get PDF
    Background and Aim: Various methods to accelerate the orthodontic tooth movement have been used, among which corticotomy is considered to be the most common one. The suggested reasoning for such acceleration was the regional acceleratory phenomenon (RAP). Since the RAP is a property of both the hard and soft tissues, we designed a soft tissue flap procedure to compare the effects with the conventional corticotomy procedure. A split-mouth study was conducted where the two procedures were assessed in a single participant. Patients and Methods: The total sample size was calculated to be 40 with 20 participants in each group. The rate of tooth movement was the primary outcome measure, and the secondary outcomes were dentoalveolar changes, which were studied in both the conventional corticotomy and the flap-only procedure based on a cone-beam computed tomography (CBCT) wherein the alveolar bone density (BD) around canines, tipping, and rotational changes in canines, premolars, and molars were assessed. Results: Corticotomy resulted in greater canine angulation, lesser canine rotation and premolar rotation, and greater molar rotation compared with flap elevation, but these differences were statistically insignificant. Conclusion: Though the corticotomy resulted in higher BD, the differences were statistically insignificant. There was no significant difference in the rate of space closure assessed by the two techniques compared
    corecore