12 research outputs found

    Hiding in plain sight, Ficus desertorum (Moraceae), a new species of rock fig for Central Australia

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    A new species of lithophytic fig, Ficus desertorum B.C.Wilde & R.L.Barrett, endemic to arid Central Australia, is described and illustrated. It is distinguished from other species in Ficus section Malvanthera Corner by having stiff lanceolate, dark green, discolorous leaves; many parallel, often obscure lateral veins; petioles that are continuous with the midrib; with minute, usually white hairs and non- or slightly sunken intercostal regions on the lower surface. Previously included under broad concepts of either Ficus platypoda (Miq.) Miq. or Ficus brachypoda (Miq.) Miq., this species has a scattered distribution throughout Central Australia on rocky outcrops, jump-ups (mesas) and around waterholes. This culturally significant plant, colloquially referred to as the desert fig, grows on elevated landscapes in central Australia, including Uluru (Ayers Rock), Kata Tjuta (The Olgas) and Karlu Karlu (Devils Marbles), three of Central Australia’s best-known natural landmarks. Evidence is provided to show these plants are geographically and morphologically distinct from Ficus brachypoda, justifying the recognition of F. desertorum as a new species. Taxonomic issues with F. brachypoda and F. atricha D.J.Dixon are also discussed. Lectotypes are selected for Urostigma platypodum forma glabrior Miq. and Ficus platypoda var. minor Benth

    Genome-wide association study identifies six new loci influencing pulse pressure and mean arterial pressure.

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    Numerous genetic loci have been associated with systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Europeans. We now report genome-wide association studies of pulse pressure (PP) and mean arterial pressure (MAP). In discovery (N = 74,064) and follow-up studies (N = 48,607), we identified at genome-wide significance (P = 2.7 × 10(-8) to P = 2.3 × 10(-13)) four new PP loci (at 4q12 near CHIC2, 7q22.3 near PIK3CG, 8q24.12 in NOV and 11q24.3 near ADAMTS8), two new MAP loci (3p21.31 in MAP4 and 10q25.3 near ADRB1) and one locus associated with both of these traits (2q24.3 near FIGN) that has also recently been associated with SBP in east Asians. For three of the new PP loci, the estimated effect for SBP was opposite of that for DBP, in contrast to the majority of common SBP- and DBP-associated variants, which show concordant effects on both traits. These findings suggest new genetic pathways underlying blood pressure variation, some of which may differentially influence SBP and DBP

    Allele Surfing and Holocene Expansion of an Australian Fig (Ficus—Moraceae)

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    The creek sandpaper fig of southeastern Australia, Ficus coronata Spin, is culturally significant to Australian traditional owners who made use of the leaves to smooth timber and ate the fruit. The species is thought to have a long history on the continent, with some suggesting a Gondwanan origin. However, distributional patterns and overall ecology suggest a recent expansion across suitable habitats. We used landscape genomic techniques and environmental niche modelling to reconstruct its history and explore whether the species underwent a recent and rapid expansion along the east coast of New South Wales. Genomic analysis of 178 specimens collected from 32 populations throughout the species’ New South Wales distribution revealed a lack of genetic diversity and population structure. Some populations at the species’ southern and western range limits displayed unexpected diversity, which appears to be the result of allele surfing. Field work and genetic evidence suggest a Holocene expansion which may have increased since European colonisation. We also present a novel method for detecting allele surfing—MAHF (minor allele at highest frequency)

    Device orientation of a leadless pacemaker and subcutaneous implantable cardioverter-defibrillator in canine and human subjects and the effect on intrabody communication

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    Aims: The development of communicating modular cardiac rhythm management systems relies on effective intrabody communication between a subcutaneous implantable cardioverter-defibrillator (S-ICD) and a leadless pacemaker (LP), using conducted communication. Communication success is affected by the LP and S-ICD orientation. This study is designed to evaluate the orientation of the LP and S-ICD in canine subjects and measure success and threshold of intrabody communication. To gain more human insights, we will explore device orientation in LP and S-ICD patients. Methods and results: Canine subjects implanted with a prototype S-ICD and LP (both Boston Scientific, MA, USA) with anterior-posterior fluoroscopy images were included in this analysis. For comparison, a retrospective analysis of human S-ICD and LP patients was performed. The angle of the long axis of the LP towards the vertical axis of 0°, and distance between the coil and LP were measured. Twenty-three canine subjects were analysed. Median angle of the LP was 29° and median distance of the S-ICD coil to LP was 0.8 cm. All canine subjects had successful communication. The median communicating threshold was 2.5 V. In the human retrospective analysis, 72 LP patients and 100 S-ICD patients were included. The mean angle of the LP was 56° and the median distance between the S-ICD coil and LP was 4.6 cm. Conclusion: Despite the less favourable LP orientation in canine subjects, all communication attempts were successful. In the human subjects, we observed a greater and in theory more favourable LP angle towards the communication vector. These data suggests suitability of human anatomy for conductive intrabody communication

    Acute and 3-Month Performance of a Communicating Leadless Antitachycardia Pacemaker and Subcutaneous Implantable Defibrillator

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    Objectives The primary objective was to assess the acute and 3-month performance of the modular antitachycardia pacing (ATP)-enabled leadless pacemaker (LP) and subcutaneous implantable cardioverter-defibrillator (S-ICD) system, particularly device–device communication and ATP delivery. Background Transvenous pacemakers and implantable cardioverter-defibrillators (ICDs) have considerable rates of lead complications. We examined the next step in multicomponent leadless cardiac rhythm management: feasibility of pacing (including ATP) by a LP, commanded by an implanted S-ICD through wireless, intrabody, device–device communication. Methods The combined modular cardiac rhythm management therapy system of the LP and S-ICD prototypes was evaluated in 3 animal models (ovine, porcine, and canine) both in acute and chronic (90 days) experiments. LP performance, S-ICD to LP communication, S-ICD and LP rhythm discrimination, and ATP delivery triggered by the S-ICD were tested. Results The LP and S-ICD were successfully implanted in 98% of the animals (39 of 40). Of the 39 animals, 23 were followed up for 90 days post-implant. LP performance was adequate and exhibited appropriate VVI behavior during the 90 days of follow-up in all tested animals. Unidirectional communication between the S-ICD and LP was successful in 99% (398 of 401) of attempts, resulting in 100% ATP delivery by the LP (10 beats at 81% of the coupling interval). Adequate S-ICD sensing was observed during normal sinus rhythm, LP pacing, and ventricular tachycardia/ventricular fibrillation. Conclusions This study presents the preclinical acute and chronic performance of the combined function of an ATP-enabled LP and S-ICD. Appropriate VVI functionality, successful wireless device–device communication, and ATP delivery were demonstrated by the LP. Clinical studies on safety and performance are needed

    Long-term performance of a novel communicating antitachycardia pacing–enabled leadless pacemaker and subcutaneous implantable cardioverter-defibrillator system: A comprehensive preclinical study

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    Background: Subcutaneous implantable cardioverter-defibrillators (S-ICDs) and leadless pacemakers (LPs) are intended to diminish transvenous lead–related complications. However, S-ICDs do not deliver antibradycardia pacing or antitachycardia pacing, and currently, there is no commercially available coordinated leadless option for patients with defibrillator and (expected) pacing needs. Objective: We evaluated the performance, safety, and potential replacement strategies of a novel modular cardiac rhythm management (mCRM) system, a wirelessly communicating antitachycardia pacing–enabled LP and S-ICD in a preclinical model. Methods: LP implantation was attempted in 68 canine subjects, and in 38 an S-ICD was implanted as well. Animals were evaluated serially up to 18 months. At all evaluations, communication thresholds (CTs) between the devices, LP electrical parameters, and system-related complications were assessed. Different replacement strategies were tested. Results: The LP was successfully implanted in 67 of 68 (98.5%) and the concomitant S-ICD in 38 of 38 (100%). mCRM communication was successful in 1022 of 1024 evaluations (99.8%). The mean CT was 2.2 ± 0.7 V at implantation and stable afterward (18 months: 1.8 ± 0.7 V). In multivariable analysis, larger LP-to-S-ICD angle and dorsal posture were associated with higher CTs. At implantation, the mean pacing capture threshold, impedance, and R-wave amplitude were 0.3 ± 0.1 V, 898.4 ± 198.9 Ω, and 26.4 ± 8.2 mV. The mean pacing capture threshold remained stable and impedance and R-wave amplitudes were within acceptable ranges throughout (0.7 ± 0.4 V, 619.1 ± 90.6 Ω, and 20.1 ± 8.4 mV at 18 months). Different replacement strategies seem feasible. Conclusion: This first mCRM system demonstrated excellent performance up to 18 months in a preclinical model

    Large-Scale Gene-Centric Analysis Identifies Novel Variants for Coronary Artery Disease

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    Coronary artery disease (CAD) has a significant genetic contribution that is incompletely characterized. To complement genome-wide association (GWA) studies, we conducted a large and systematic candidate gene study of CAD susceptibility, including analysis of many uncommon and functional variants. We examined 49,094 genetic variants in ~2,100 genes of cardiovascular relevance, using a customised gene array in 15,596 CAD cases and 34,992 controls (11,202 cases and 30,733 controls of European descent; 4,394 cases and 4,259 controls of South Asian origin). We attempted to replicate putative novel associations in an additional 17,121 CAD cases and 40,473 controls. Potential mechanisms through which the novel variants could affect CAD risk were explored through association tests with vascular risk factors and gene expression. We confirmed associations of several previously known CAD susceptibility loci (eg, 9p21.3:p<10−33; LPA:p<10−19; 1p13.3:p<10−17) as well as three recently discovered loci (COL4A1/COL4A2, ZC3HC1, CYP17A1:p<5×10−7). However, we found essentially null results for most previously suggested CAD candidate genes. In our replication study of 24 promising common variants, we identified novel associations of variants in or near LIPA, IL5, TRIB1, and ABCG5/ABCG8, with per-allele odds ratios for CAD risk with each of the novel variants ranging from 1.06–1.09. Associations with variants at LIPA, TRIB1, and ABCG5/ABCG8 were supported by gene expression data or effects on lipid levels. Apart from the previously reported variants in LPA, none of the other ~4,500 low frequency and functional variants showed a strong effect. Associations in South Asians did not differ appreciably from those in Europeans, except for 9p21.3 (per-allele odds ratio: 1.14 versus 1.27 respectively; P for heterogeneity = 0.003). This large-scale gene-centric analysis has identified several novel genes for CAD that relate to diverse biochemical and cellular functions and clarified the literature with regard to many previously suggested genes
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