Wood Anatomy of Sabiaceae (S.L.)

Quantitative and qualitative data were offered for 30 taxa of Meliosma and one species each of Ophiocaryon and Sabia; qualitative data were available for additional species of Meliosma and Sabia. For a small family restricted to mesic sites, Sabiaceae had a wide range of wood anatomical expressions (e.g., long scalariform to simple perforation plates; heterocellular to homocellular multiseriate rays; tracheids, fiber-tracheids, or libriform fibers as imperforate tracheary elements; presence or absence of silica bodies and calcium oxalate crystals in rays). Growth ring type, vessel diameter, vessel density, and vessel element length were sensitively related to ecology, but to degree of winter cold rather than to aridity. Ophiocaryon differed somewhat from all or most species of Meliosma in quantitative features, but the genera agreed in qualitative features. Some authors segregate these arborescent or arboreal genera in Meliosmaceae because of distinctive features of Sabia, a liana genus; wood of lianas differs in anatomy from that of trees, and these features account for the wood differences between Sabia and Meliosma. All wood features of Sabiaceae are widespread in the genera of Rutales (Sapindales), even scalariform perforation plates. Sabiaceae are therefore best placed in Rutales, although wood of Sabiaceae is modally more primitive than that of other Rutales. Characters restricted to particular species were cited, but designation of them as diagnostic criteria was not advocated because the sampling of the family was rather incomplete

Representations of Time Coordinates in FITS

In a series of three previous papers, formulation and specifics of the representation of World Coordinate Transformations in FITS data have been presented. This fourth paper deals with encoding time. Time on all scales and precisions known in astronomical datasets is to be described in an unambiguous, complete, and self-consistent manner. Employing the well--established World Coordinate System (WCS) framework, and maintaining compatibility with the FITS conventions that are currently in use to specify time, the standard is extended to describe rigorously the time coordinate. World coordinate functions are defined for temporal axes sampled linearly and as specified by a lookup table. The resulting standard is consistent with the existing FITS WCS standards and specifies a metadata set that achieves the aims enunciated above.Comment: FITS WCS Paper IV: Time. 27 pages, 11 table

Ctenis Clarnoensis Sp. N., an Unusual Cycadalean Foliage from the Eocene Clarno Formation, Oregon

Premise of research. Leaves of an extinct kind of cycad are recognized from the middle and late Eocene Clarno Formation of Oregon. Although the pinnately compound leaf is similar in gross form and organization to some other extant and Cenozoic cycads such as Dioon Lindl., Encephalartos Lehm., and Dioonopsis Horiuchi et Kimura, it is readily distinguished from them by its venation, consisting of a closed reticulum of a single order of veins with a frequent dichotomizing and anastomosing pattern. Methodology. Fossils stored in the Museum of Paleontology (University of California), Florida Museum of Natural History (University of Florida), and Condon Museum of Natural History (University of Oregon) were studied applying conventional macromorphological and micromorphological methods including transmitted light and epifluorescence microscopy. Pivotal results. The leaves conform in their peculiar venation and epidermal anatomy to the extinct genus Ctenis Lindley et Hutton, which previously was known only from Mesozoic occurrences. Ctenis clarnoensis Erdei et Manchester sp. n. adds to the diversity of cycads known from the Paleogene of western North America. Conclusions. The record of the reticulate-veined C. clarnoensis and other fossil cycad genera with anastomosing venation patterns from the Paleogene implies that an extinct lineage or lineages of cycads sharing the character of reticulate venation, previously considered to be restricted to the Mesozoic, may have persisted into the Paleogene. Some physiognomic features of leaflets including the involute margin and pointed apex may suggest periodically dry conditions. By the present record the stratigraphic range of Ctenis is significantly extended from its previously known latest records in the Early Cretaceous up to as late as the Eocene

Evolution of the intercontinental disjunctions in six continents in the Ampelopsis clade of the grape family (Vitaceae)

<p>Abstract</p> <p>Background</p> <p>The <it>Ampelopsis </it>clade (<it>Ampelopsis </it>and its close allies) of the grape family Vitaceae contains ca. 43 species disjunctly distributed in Asia, Europe, North America, South America, Africa, and Australia, and is a rare example to study both the Northern and the Southern Hemisphere intercontinental disjunctions. We reconstruct the temporal and spatial diversification of the <it>Ampelopsis </it>clade to explore the evolutionary processes that have resulted in their intercontinental disjunctions in six continents.</p> <p>Results</p> <p>The Bayesian molecular clock dating and the likelihood ancestral area analyses suggest that the <it>Ampelopsis </it>clade most likely originated in North America with its crown group dated at 41.2 Ma (95% HPD 23.4 - 61.0 Ma) in the middle Eocene. Two independent Laurasian migrations into Eurasia are inferred to have occurred in the early Miocene via the North Atlantic land bridges. The ancestor of the Southern Hemisphere lineage migrated from North America to South America in the early Oligocene. The Gondwanan-like pattern of intercontinental disjunction is best explained by two long-distance dispersals: once from South America to Africa estimated at 30.5 Ma (95% HPD 16.9 - 45.9 Ma), and the other from South America to Australia dated to 19.2 Ma (95% HPD 6.7 - 22.3 Ma).</p> <p>Conclusions</p> <p>The global disjunctions in the <it>Ampelopsis </it>clade are best explained by a diversification model of North American origin, two Laurasian migrations, one migration into South America, and two post-Gondwanan long-distance dispersals. These findings highlight the importance of both vicariance and long distance dispersal in shaping intercontinental disjunctions of flowering plants.</p

Plasma Turbulence in the Local Bubble

Turbulence in the Local Bubble could play an important role in the thermodynamics of the gas that is there. The best astronomical technique for measuring turbulence in astrophysical plasmas is radio scintillation. Measurements of the level of scattering to the nearby pulsar B0950+08 by Philips and Clegg in 1992 showed a markedly lower value for the line-of-sight averaged turbulent intensity parameter $$than is observed for other pulsars, consistent with radio wave propagation through a highly rarefied plasma. In this paper, we discuss the observational progress that has been made since that time. At present, there are four pulsars (B0950+08, B1133+16, J0437-4715, and B0809+74) whose lines of sight seem to lie mainly within the local bubble. The mean densities and line of sight components of the interstellar magnetic field along these lines of sight are smaller than nominal values for pulsars, but not by as much expected. Three of the four pulsars also have measurements of interstellar scintillation. The value of the parameter$$ is smaller than normal for two of them, but is completely nominal for the third. This inconclusive status of affairs could be improved by measurements and analysis of ``arcs'' in ``secondary spectra'' of pulsars.Comment: Submitted to Space Science Reviews as contribution to Proceedings of ISSI (International Space Science Institute) workshop "From the Heliosphere to the Local Bubble". Refereed version accepted for publicatio

A machine learning classifier for fast radio burst detection at the VLBA

Time domain radio astronomy observing campaigns frequently generate large volumes of data. Our goal is to develop automated methods that can identify events of interest buried within the larger data stream. The V-FASTR fast transient system was designed to detect rare fast radio bursts within data collected by the Very Long Baseline Array. The resulting event candidates constitute a significant burden in terms of subsequent human reviewing time. We have trained and deployed a machine learning classifier that marks each candidate detection as a pulse from a known pulsar, an artifact due to radio frequency interference, or a potential new discovery. The classifier maintains high reliability by restricting its predictions to those with at least 90% confidence. We have also implemented several efficiency and usability improvements to the V-FASTR web-based candidate review system. Overall, we found that time spent reviewing decreased and the fraction of interesting candidates increased. The classifier now classifies (and therefore filters) 80%–90% of the candidates, with an accuracy greater than 98%, leaving only the 10%–20% most promising candidates to be reviewed by humans

Evolutionary dynamics and biogeography of Musaceae reveal a correlation between the diversification of the banana family and the geological and climatic history of Southeast Asia

Article PurchasedTropical Southeast Asia, which harbors most of the Musaceae biodiversity, is one of the most species-rich regions in the world. Its high degree of endemism is shaped by the region's tectonic and climatic history, with large differences between northern Indo-Burma and the Malayan Archipelago. Here, we aim to find a link between the diversification and biogeography of Musaceae and geological history of the Southeast Asian subcontinent. The Musaceae family (including five Ensete, 45 Musa and one Musella species) was dated using a large phylogenetic framework encompassing 163 species from all Zingiberales families. Evolutionary patterns within Musaceae were inferred using ancestral area reconstruction and diversification rate analyses. All three Musaceae genera - Ensete, Musa and Musella - originated in northern Indo-Burma during the early Eocene. Musa species dispersed from 'northwest to southeast' into Southeast Asia with only few back-dispersals towards northern Indo-Burma. Musaceae colonization events of the Malayan Archipelago subcontinent are clearly linked to the geological and climatic history of the region. Musa species were only able to colonize the region east of Wallace's line after the availability of emergent land from the late Miocene onwards

Measuring factors that influence the utilisation of preventive care services provided by general practitioners in Australia

Background: Relatively little research attention has been given to the development of standardised and psychometrically sound scales for measuring influences relevant to the utilisation of health services. This study aims to describe the development, validation and internal reliability of some existing and new scales to measure factors that are likely to influence utilisation of preventive care services provided by general practitioners in Australia.----- Methods: Relevant domains of influence were first identified from a literature review and formative research. Items were then generated by using and adapting previously developed scales and published findings from these. The new items and scales were pre-tested and qualitative feedback was obtained from a convenience sample of citizens from the community and a panel of experts. Principal Components Analyses (PCA) and internal reliability testing (Cronbach's alpha) were then conducted for all of the newly adapted or developed scales utilising data collected from a self-administered mailed survey sent to a randomly selected population-based sample of 381 individuals (response rate 65.6 per cent).----- Results: The PCA identified five scales with acceptable levels of internal consistency were: (1) social support (ten items), alpha 0.86; (2) perceived interpersonal care (five items), alpha 0.87, (3) concerns about availability of health care and accessibility to health care (eight items), alpha 0.80, (4) value of good health (five items), alpha 0.79, and (5) attitudes towards health care (three items), alpha 0.75.----- Conclusion The five scales are suitable for further development and more widespread use in research aimed at understanding the determinants of preventive health services utilisation among adults in the general population

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research