17 research outputs found

    Hydnora arabica (Aristolochiaceae), a New Species from the Arabian Peninsula and a Key to Hydnora

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    The plant parasite Hydnora arabica (Aristolochiaceae) is described from the Arabian Peninsula. This species was previously identified as Hydnora africana in Oman. It can be separated from other Hydnora taxa primarily by its terete rhizome, red to orange inner perianth tube color, and tepal lobe margins entirely covered with dense strigose setae. In Oman, Hydnora arabica is known to parasitize two leguminous trees: Acacia tortilis and the introduced Pithocellobium dulce, but may parasitize additional Fabaceae. At least eleven synonyms or subspecific varieties of H. abyssinica are described in the literature, all from east or southern Africa. These synonyms are discussed in light of new observations of morphology including tepal margin ornamentation. A new key for Hydnora is proposed

    A New Species of Diploid Quillwort (Isoetes, Isoetaceae, Lycophyta) from Lebanon

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    A new species, Isoetes libanotica Musselman, Bolin & B. D. Bray (Isoetaceae, Lycophyta), is described from Akkar District of northern Lebanon. It is a seasonal terrestrial species of basaltic soils, diploid (2n = 22), with complete velum coverage. Megaspore diameter ranges from 338 to 477 mu m with remote, low tuberculate ornamentation and a low to obsolete equatorial girdle; microspore length ranges from 25 to 30 mu m, with echinate ornamentation. At the type locality of I. libanotica, two other Isoetes L. species occur sympatrically. These superficially similar Isoetes species can be differentiated from I. libanotica using megaspore characters; I. duriei Bory has larger alveolate megaspores and I. olympica A. Braun has a prominent equatorial girdle

    A New Species of Diploid Quillwort (Isoetes, Isoetaceae, Lycophyta) from Lebanon

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    A new species, Isoetes libanotica Musselman, Bolin & B. D. Bray (Isoetaceae, Lycophyta), is described from Akkar District of northern Lebanon. It is a seasonal terrestrial species of basaltic soils, diploid (2n = 22), with complete velum coverage. Megaspore diameter ranges from 338 to 477 mu m with remote, low tuberculate ornamentation and a low to obsolete equatorial girdle; microspore length ranges from 25 to 30 mu m, with echinate ornamentation. At the type locality of I. libanotica, two other Isoetes L. species occur sympatrically. These superficially similar Isoetes species can be differentiated from I. libanotica using megaspore characters; I. duriei Bory has larger alveolate megaspores and I. olympica A. Braun has a prominent equatorial girdle

    Structural Attributes of the Hypogeous Holoparasite Hydnora Triceps Drège & Meyer (Hydnoraceae)

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    The morphology of the hypogeous root holoparasite Hydnora triceps is highly reduced, and as with many holoparasites, the vegetative body is difficult to interpret. The vegetative body of H. triceps has been historically considered a pilot root studded with lateral appendages known as haustorial roots. We found the vegetative body of H. triceps to consist of a rhizome with a thickened root-cap-like structure that covered a vegetative shoot apical meristem. From the apical meristem, procambial strands originated and developed into endarch collateral vascular bundles arranged radially around a pith without an interfascicular cambium. Xylem vessels had scalariform pitting and simple perforation plates. A continuous periderm without root hairs was observed. Increase in girth was attributed to cork and fascicular cambia. Haustorial roots or bumps on the surface of the vegetative body were exogenous, contained meristems and were the origins of vegetative branching, budding, and haustoria. The haustoria of H. triceps were cylindrical and penetrated the host root stele. Phloem and xylem elements were observed within the endophyte, and direct xylem to host-xylem contacts were observed. The arrangement of vascular tissues and xylem anatomy of H. triceps are likely plesiomorphic features in light of Hydnoraceae\u27s placement in the Piperales

    Na+, K+-ATPase Subunit Composition in a Human Chondrocyte Cell Line; Evidence for the Presence of α1, α3, β1, β2 and β3 Isoforms

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    Membrane transport systems participate in fundamental activities such as cell cycle control, proliferation, survival, volume regulation, pH maintenance and regulation of extracellular matrix synthesis. Multiple isoforms of Na+, K+-ATPase are expressed in primary chondrocytes. Some of these isoforms have previously been reported to be expressed exclusively in electrically excitable cells (i.e., cardiomyocytes and neurons). Studying the distribution of Na+, K+-ATPase isoforms in chondrocytes makes it possible to document the diversity of isozyme pairing and to clarify issues concerning Na+, K+-ATPase isoform abundance and the physiological relevance of their expression. In this study, we investigated the expression of Na+, K+-ATPase in a human chondrocyte cell line (C-20/A4) using a combination of immunological and biochemical techniques. A panel of well-characterized antibodies revealed abundant expression of the α1, β1 and β2 isoforms. Western blot analysis of plasma membranes confirmed the above findings. Na+, K+-ATPase consists of multiple isozyme variants that endow chondrocytes with additional homeostatic control capabilities. In terms of Na+, K+-ATPase expression, the C-20/A4 cell line is phenotypically similar to primary and in situ chondrocytes. However, unlike freshly isolated chondrocytes, C-20/A4 cells are an easily accessible and convenient in vitro model for the study of Na+, K+-ATPase expression and regulation in chondrocytes

    Ambivalence: A Key to Clinical Trial Participation?

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    Trust exerts a multidimensional influence at the interpersonal level in the clinical trials setting. Trust and distrust are dynamic states that are impacted, either positively or negatively, with each participant-clinical trials team interaction. Currently, accepted models of trust posit that trust and distrust coexist and their effects on engagement and retention in clinical trials are mediated by ambivalence. While understanding of trust has been informed by a robust body of work, the role of distrust and ambivalence in the trust building process are less well understood. Furthermore, the role of ambivalence and its relationship to trust and distrust in the clinical trials and oncology settings are not known. Ambivalence is a normal and uncomfortable state in the complex decision making process that characterizes the recruitment and active treatment phases of the clinical trials experience. The current review was conducted to understand the constructs of ambivalence as a mediator of trust and distrust among vulnerable, minority participants through different stages of the oncology clinical trials continuum, its triggers and the contextual factors that might influence it in the setting of minority participation in oncology clinical trials. In addition, the researchers have sought to link theory to clinical intervention by investigating the feasibility and role of Motivational Interviewing in different stages of the clinical trials continuum. Findings suggest that ambivalence can be processed and managed to enable a participant to generate a response to their ambivalence. Thus, recognizing and managing triggers of ambivalence, which include, contradictory goals, role conflicts, membership dualities, and supporting participants through the process of reducing ambivalence is critical to successfully managing trust. Contextual factors related to the totality of one's previous health-care experience, specifically among the marginalized or vulnerable, can contribute to interpersonal ambivalence. In addition, changes in information gathering as a moderator of interpersonal ambivalence may have enormous implications for gathering, assessing, and accepting health information. Finally, motivational Interviewing has widespread applications in healthcare settings, which includes enabling participants to navigate ambivalence in shared-decision making with their clinician, as well as executing changes in participant behavior. Ultimately, the Integrated Model of Trust can incorporate the role of therapeutic techniques like Motivational Interviewing in different stages of the clinical trials continuum. Ambivalence is a key component of clinical trial participation; like trust, ambivalence can be managed and plays a major role in the management of trust in interpersonal relationships over time. The management of ambivalence may play a major role in increasing clinical trial participation particularly among the marginalized or the vulnerable, who may be more susceptible to feelings of ambivalence

    A New Species of Hydnora

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    A New Species of Diploid Quillwort ( Isoetes

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    The Genus \u3ci\u3eIsoetes\u3c/i\u3e L. (Isoetaceae, Lycophyta) in South-Western Asia

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    Quillworts or Çim Eğreltisi, species of the genus Isoetes L. in Turkey and the Levant, are poorly studied despite extensive floristic studies in the region. The Flora of Turkey lists 4 taxa: Isoetes olympica A.Braun (2n = 22), I. histrix Bory var. histrix (2n = 20), I. subinermis (Bory) Cesca & Peruzzi [=I. histrix Bory var. subinermis Durieu (2n = 22)] and I. duriei Bory (2n = ca. 121). An additional species, I. anatolica Prada & Rolleri, was described in 2005 from Bolu province, and we report the first count for this species, 2n = 22. In Syria and Lebanon 2 species are known: I. olympica from a site in Syria and a known but undescribed plant from Akkar province (Lebanon) and adjacent Syria (2n = 22, first count). A preliminary molecular phylogeny for these species is presented; their distribution and cytology are discussed. The taxonomy and nomenclature of the I. histrix and I. duriei groups need considerable further study. The first hybrids for the region are documented

    Ambivalence: A key to clinical trial participation?

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    Trust exerts a multidimensional influence at the interpersonal level in the clinical trials setting. Trust and distrust are dynamic states that are impacted, either positively or negatively, with each participant-clinical trials team interaction. Currently, accepted models of trust posit that trust and distrust coexist and their effects on engagement and retention in clinical trials are mediated by ambivalence. While understanding of trust has been informed by a robust body of work, the role of distrust and ambivalence in the trust building process are less well understood. Furthermore, the role of ambivalence and its relationship to trust and distrust in the clinical trials and oncology settings are not known. Ambivalence is a normal and uncomfortable state in the complex decision making process that characterizes the recruitment and active treatment phases of the clinical trials experience. The current review was conducted to understand the constructs of ambivalence as a mediator of trust and distrust among vulnerable, minority participants through different stages of the oncology clinical trials continuum, its triggers and the contextual factors that might influence it in the setting of minority participation in oncology clinical trials. In addition, the researchers have sought to link theory to clinical intervention by investigating the feasibility and role of Motivational Interviewing in different stages of the clinical trials continuum. Findings suggest that ambivalence can be processed and managed to enable a participant to generate a response to their ambivalence. Thus, recognizing and managing triggers of ambivalence, which include, contradictory goals, role conflicts, membership dualities, and supporting participants through the process of reducing ambivalence is critical to successfully managing trust. Contextual factors related to the totality of one\u27s previous health-care experience, specifically among the marginalized or vulnerable, can contribute to interpersonal ambivalence. In addition, changes in information gathering as a moderator of interpersonal ambivalence may have enormous implications for gathering, assessing, and accepting health information. Finally, motivational Interviewing has widespread applications in healthcare settings, which includes enabling participants to navigate ambivalence in shared-decision making with their clinician, as well as executing changes in participant behavior. Ultimately, the Integrated Model of Trust can incorporate the role of therapeutic techniques like Motivational Interviewing in different stages of the clinical trials continuum. Ambivalence is a key component of clinical trial participation; like trust, ambivalence can be managed and plays a major role in the management of trust in interpersonal relationships over time. The management of ambivalence may play a major role in increasing clinical trial participation particularly among the marginalized or the vulnerable, who may be more susceptible to feelings of ambivalence
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