225 research outputs found

    The Phosphorus Puzzle: Why Metal Phosphites Could Be the Missing Piece

    Get PDF
    It is well understood that phosphorylation of organic molecules is a keystone mechanism toward developing early cell function. However, the source of phosphorous in prebiotic chemistry is under debate. Phosphate minerals were abundant on the early Earth, but they are highly insoluble. In comparison, metal phosphites are significantly more soluble. While they may not have been preserved in the geological record, there are several plausible pathways for their formation under prebiotic conditions. We hypothesize that metal phosphites were a major source of phosphorus. To test our hypothesis, we synthesized and characterized metal phosphites, containing the most abundant cations on the early Earth (Mg2+, Ca2+, Fe2+, Fe3+). Then we reacted the metal phosphites with glycerol or propanol and looked for phosphonylated organic molecules. (n.b., Phosphonylated molecules contain a phosphite (PO33-), and phosphorylated molecules contain a phosphate (PO43-).) In nuclear magnetic resonance (NMR) experiments, we observe the formation of glycerol-a-phosphite and glycerol-b-phosphite when CaHPO3 and glycerol react at 60oC. Experiments investigating the reactivity of iron (II or III) phosphite and magnesium phosphite are ongoing

    Breeding site attendance and breeding success in Phyllomedusa trinitatis (Anura: Phyllomedusidae)

    Get PDF
    Using a natural marker, we documented breeding site attendance patterns by males and females of the Trinidad Leaf Frog, Phyllomedusa trinitatis. We followed attendance at a cluster of three isolated ponds over 53 and 56 consecutive nights in 2016 and 2019 respectively. Most females attended only once, but for those that attended more than once we calculated an inter-nesting interval (mean 27.6 days, N = 7). Males showed high pond fidelity, but some did attend at two of the ponds, always with a strong preference for one of them. Males showed three attendance patterns. A few attended on multiple consecutive nights (maximum, 19 nights); more were sporadic (one attended seven times over 46 nights with gaps of 15 and 19 days in the sequence); some attended only once (2016: 12, 2019: 15), but most were found to be present on multiple nights (2016: 38, 2019: 32). Our analysis suggested that these latter frogs were either newly recruited individuals or had been predated during the study. Our data show that rainfall has some influence on attendance. We found no relationship between male body condition and attendance pattern. In addition, there was no evidence that a particular male attendance pattern was optimal for breeding success

    Are routinely collected NHS administrative records suitable for endpoint identification in clinical trials? Evidence from the West of Scotland coronary prevention study

    Get PDF
    Background: Routinely collected electronic patient records are already widely used in epidemiological research. In this work we investigated the potential for using them to identify endpoints in clinical trials.<p></p> Methods: The events recorded in the West of Scotland Coronary Prevention Study (WOSCOPS), a large clinical trial of pravastatin in middle-aged hypercholesterolaemic men in the 1990s, were compared with those in the record-linked deaths and hospitalisations records routinely collected in Scotland.<p></p> Results: We matched 99% of fatal study events by date. We showed excellent matching (97%) of the causes of fatal endpoint events and good matching (.80% for first events) of the causes of nonfatal endpoint events with a slightly lower rate of mismatching of record linkage than study events (19% of first study myocardial infarctions (MI) and 4% of first record linkage MIs not matched as MI). We also investigated the matching of non-endpoint events and showed a good level of matching, with .78% of first stroke/TIA events being matched as stroke/TIA. The primary reasons for mismatches were record linkage data recording readmissions for procedures or previous events, differences between the diagnoses in the routinely collected data and the conclusions of the clinical trial expert adjudication committee, events occurring outside Scotland and therefore being missed by record linkage data, miscoding of cardiac events in hospitalisations data as ‘unspecified chest pain’, some general miscoding in the record linkage data and some record linkage errors.<p></p> Conclusions: We conclude that routinely collected data could be used for recording cardiovascular endpoints in clinical trials and would give very similar results to rigorously collected clinical trial data, in countries with unified health systems such as Scotland. The endpoint types would need to be carefully thought through and an expert endpoint adjudication committee should be involved.<p></p&gt

    Self-Reported Measures Have a Stronger Association With Dizziness-Related Handicap Compared With Physical Tests in Persons With Persistent Dizziness

    Get PDF
    Background: Associations between dizziness-related handicap and a variety of self-reported measures have been reported. However, research regarding associations between dizziness-related handicap and aspects of functioning that includes both physical tests and self-reported measures is scarce. Objective: The purpose of the study was to describe the variations in signs and symptoms in people with persistent dizziness using physical tests and self-reported outcomes across three severity levels of the Dizziness Handicap Inventory (DHI) and investigate their associations with the DHI. Method: Participants with persistent dizziness (n = 107) were included in this cross-sectional study. The participants underwent (1) physical tests (gait tests, grip strength, body flexibility, and movement-induced dizziness) and completed questionnaires regarding (2) psychological measures (Mobility Inventory of Agoraphobia, Body Sensation Questionnaire, Agoraphobic Cognitions Questionnaire, and Hospital Depression and Anxiety Questionnaire), and (3) fatigue, dizziness severity, and quality of life (Chalders Fatigue Scale, Vertigo Symptom Scale-Short Form, and EQ visual analog scale), in addition to the DHI. Data were presented by descriptive statistics for three DHI severity levels (mild, moderate, and severe). A multiple linear backward regression analysis was conducted for each group of measures in relation to the DHI total score, with additional analyses adjusting for age and sex. Based on these results, significant associations were tested in a final regression model. Results: With increasing severity levels of DHI, the participants demonstrated worse performance on most of the physical tests (preferred and fast gait velocity, dizziness intensity after head movements), presented with worse scores on the self-reported measures (avoidance behavior, fear of bodily sensation, fear of fear itself, psychological distress, fatigue, dizziness severity, quality of life). After adjusting for age and sex, significant associations were found between total DHI and avoidance behavior, psychological distress, dizziness severity, and quality of life, but not with any of the physical tests, explaining almost 56% of the variance of the DHI total score. Conclusion: There was a trend toward worse scores on physical tests and self-reported measurements with increasing DHI severity level. The DHI seems to be a valuable tool in relation to several self-reported outcomes; however, several signs and symptoms may not be detected by the DHI, and thus, a combination of outcomes should be utilized when examining patients with persistent dizziness.publishedVersio

    The British economy [December 1988]

    Get PDF
    The growth of the UK economy continues at a brisk rate. Manufacturing output is especially buoyant. The absence of evidence suggesting a moderation in output growth reflects the continuing strong rate of growth in domestic demand. There is little hard evidence to date of a slow-down in consumer demand. Domestic demand growth continues to outstrip both output growth and the supply capacity of the economy. This is despite the current 'boom' in investment. The deficit on current account therefore continues to deteriorate. The underlying trade position is precarious and is symptomatic of high domestic demand and inflationary pressure. With many indicators pointing in an upward direction, the prospects for inflation are therefore the most immediate cause for concern

    The world economy [December 1988]

    Get PDF
    The buoyancy of the main economies continues. Investment now appears to be the principal driving force behind the current robust performance of the world economy. Growth of GNP is generally expected to be around 4% this year, a full one percentage point, and more, higher than expectations at the beginning of the year. Nevertheless, growth should decline next year due to a tightening by key governments of both fiscal and monetary policies in response to increasing inflationary pressure

    The Scottish economy [December 1988]

    Get PDF
    Between them the Scottish Chambers' Business Survey (SCBS) and the CBI's Industrial Trends Survey provide a reasonable guide to current and recent trends in the Scottish economy. Both surveys are carried out on a quarterly basis with results being derived from the responses of Chambers of Commerce and CBI members, respectively. While the two sources are complementary in nature there do exist important differences between them
    • …
    corecore