435 research outputs found
A Survey of Some Relict Areas of The Great Plains
A study was made of nineteen relict grassland areas scattered throughout the Great Plains. The study was made to determine basal cover, percentage composition and per cent frequency of the grass and sedge species, and also the soil texture present on these areas. Areas were scattered from Miami, Texas to Shelly, Montana . The study was conducted during the summer of 1956. Vegetation was sampled by the square root method as described by Voigt and Weaver (1941). The hydrometer method was used to determine the soil texture. Texture was sampled at depths of six and 24 inches
Food Security in the Caribbean - A Policy Perspective
Among the several development issues facing Caribbean SIDS, food and nutrition security has emerged as a particularly important challenge given its role in affecting the health and well-being of all of its peoples. According to the Food and Agriculture Organization (FAO), (2021), as much as 67.5 per cent of the subregion’s population
is currently living in moderate to severe food insecurity. This is related mainly to the cost of accessing food, as well as the quality of food accessed. This compares to a global average of 27.6 per cent
Tenofovir disoproxil fumarate for prevention of HIV infection in women: a phase 2, double-blind, randomized, placebo-controlled trial.
ObjectivesThe objective of this trial was to investigate the safety and preliminary effectiveness of a daily dose of 300 mg of tenofovir disoproxil fumarate (TDF) versus placebo in preventing HIV infection in women.DesignThis was a phase 2, randomized, double-blind, placebo-controlled trial.SettingThe study was conducted between June 2004 and March 2006 in Tema, Ghana; Douala, Cameroon; and Ibadan, Nigeria.ParticipantsWe enrolled 936 HIV-negative women at high risk of HIV infection into this study.InterventionParticipants were randomized 1:1 to once daily use of 300 mg of TDF or placebo.Outcome measuresThe primary safety endpoints were grade 2 or higher serum creatinine elevations (>2.0 mg/dl) for renal function, grade 3 or 4 aspartate aminotransferase or alanine aminotransferase elevations (>170 U/l) for hepatic function, and grade 3 or 4 phosphorus abnormalities (<1.5 mg/dl). The effectiveness endpoint was infection with HIV-1 or HIV-2.ResultsStudy participants contributed 428 person-years of laboratory testing to the primary safety analysis. No significant differences emerged between treatment groups in clinical or laboratory safety outcomes. Study participants contributed 476 person-years of HIV testing to the primary effectiveness analysis, during which time eight seroconversions occurred. Two were diagnosed in participants randomized to TDF (0.86 per 100 person-years) and six in participants receiving placebo (2.48 per 100 person-years), yielding a rate ratio of 0.35 (95% confidence interval = 0.03-1.93), which did not achieve statistical significance. Owing to premature closures of the Cameroon and Nigeria study sites, the planned person-years of follow-up and study power could not be achieved.ConclusionDaily oral use of TDF in HIV-uninfected women was not associated with increased clinical or laboratory adverse events. Effectiveness could not be conclusively evaluated because of the small number of HIV infections observed during the study
Effectiveness and effects of attempts to regulate the UK petrol industry
This paper evaluates the impact that investigation and regulation of the UK petrol industry has had on the profitability of the companies. Using a gross margin for petrol, we estimate a series of variable parameter autoregressive processes. The results demonstrate that the 1979 Monopolies and Mergers Commission investigation into the industry, caused a long term decline in profit margins in the industry, despite the fact that no recommendations or undertakings were made. This cannot however be said for subsequent investigations
Preliminary overview of the economies of the Caribbean 2012-2013
Includes bibliographyIn the face of weak global growth in major export markets the Caribbean economies have underperformed. The situation is much more severe among service producers1 which have suffered the decline in tourist arrivals and offshore banking services. The goods producers have benefited from the commodity boom and have tended to show more robust growth. The expectations for 2013 are that growth will be positive in the region with the service producers growing at 1.5per cent and the goods producers at 3.6per cent. This performance will depend heavily on improved performances in the major export markets. The fiscal policy stance in most countries in the region in 2012 tended to be expansionary with the average deficit increasing from 3.1 per cent of GDP to 3.4 per cent. The economic structure was an indicator of fiscal health as the service producers had greater deficits. The central challenge on the fiscal side in the region is the large debt problem. Between 2011 and 2012 the average debt burden increased marginally from 64.2per cent of GDP to 65.5per cent of GDP and in a few cases the debt burden was in excess of 100 per cent of GDP. This situation calls for a consistent attempt at fiscal consolidation over the medium term. With respect to monetary policy, the stance was mostly neutral given sluggish demand and stable prices. In a few cases, lending rates trended down slightly but deposit rates also declined and money supply remained practically constant. At the same time, domestic credit to both the private and public sector remained unchanged and the private sector remained risk averse. Inflation trends in 2012 were mixed but overall inflation remained relatively low. The current account balance which is a source of growing concern, increased due to rising imports and sluggish exports. Elevated commodity prices helped to keep the cost of imports high .In terms of the financial and capital accounts, there was an increase in FDI inflows to the subregion but much of this was outside of the tourism sector
Recommended from our members
Questionnaire study to gain an insight into the manufacturing and fitting process of artificial eyes in children: an ocularist perspective
Purpose
To gain an insight into the manufacturing and fitting of artificial eyes in children and potential improvements to the process.
Method
An online qualitative survey was distributed to 39 ocularists/prosthetists in Europe and Canada. Participants were recruited through purposive sampling, specifically maximum variation sampling from the researcher’s contacts and an online search.
Results
The findings highlighted the current impression technique as being the most difficult yet most important part of the current process for both the ocularist and child patient. Negatively affecting obtaining a good impression, the child patients distress can be reduced by their parents by providing encouragement, reassurance, practicing the insertion and removal of the artificial eye and being matter of fact. Whilst improvements to the current process provided mixed views, the incorporation of current technology was perceived as not being able to meet the requirements to produce aesthetically pleasing artificial eyes.
Conclusion
The current artificial eye process can be seen as an interaction with its success being dependent on the child patient’s acceptance and adjustment which is dependent on the factors associated to the process. Investigation into the needs of the patient and whether technology can improve the process are the next steps in its advancement
Climate and vegetational regime shifts in the late Paleozoic ice age earth
The late Paleozoic earth experienced alternation between glacial and non-glacial climates at multiple temporal scales, accompanied by atmospheric CO 2 fluctuations and global warming intervals, often attended by significant vegetational changes in equatorial latitudes of Pangaea. We assess the nature of climate–vegetation interaction during two time intervals: middle–late Pennsylvanian transition and Pennsylvanian–Permian transition, each marked by tropical warming and drying. In case study 1, there is a catastrophic intra-biomic reorganization of dominance and diversity in wetland, evergreen vegetation growing under humid climates. This represents a threshold-type change, possibly a regime shift to an alternative stable state. Case study 2 is an inter-biome dominance change in western and central Pangaea from humid wetland and seasonally dry to semi-arid vegetation. Shifts between these vegetation types had been occurring in Euramerican portions of the equatorial region throughout the late middle and late Pennsylvanian, the drier vegetation reaching persistent dominance by Early Permian. The oscillatory transition between humid and seasonally dry vegetation appears to demonstrate a threshold-like behavior but probably not repeated transitions between alternative stable states. Rather, changes in dominance in lowland equatorial regions were driven by long-term, repetitive climatic oscillations, occurring with increasing intensity, within overall shift to seasonal dryness through time. In neither case study are there clear biotic or abiotic warning signs of looming changes in vegetational composition or geographic distribution, nor is it clear that there are specific, absolute values or rates of environmental change in temperature, rainfall distribution and amount, or atmospheric composition, approach to which might indicate proximity to a terrestrial biotic-change threshold.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73033/1/j.1472-4669.2009.00192.x.pd
Climate change impacts on critical international transportation assets of Caribbean Small Island Developing States (SIDS): the case of Jamaica and Saint Lucia
This contribution presents an assessment of the potential vulnerabilities to climate variability and change (CV & C) of the critical transportation infrastructure of Caribbean Small Island Developing States (SIDS). It focuses on potential operational disruptions and coastal inundation forced by CV & C on four coastal international airports and four seaports in Jamaica and Saint Lucia which are critical facilitators of international connectivity and socioeconomic development. Impact assessments have been carried out under climatic conditions forced by a 1.5 °C specific warming level (SWL) above pre-industrial levels, as well as for different emission scenarios and time periods in the twenty-first century. Disruptions and increasing costs due to, e.g., more frequent exceedance of high temperature thresholds that could impede transport operations are predicted, even under the 1.5 °C SWL, advocated by the Alliance of Small Island States (AOSIS) and reflected as an aspirational goal in the Paris Climate Agreement. Dynamic modeling of the coastal inundation under different return periods of projected extreme sea levels (ESLs) indicates that the examined airports and seaports will face increasing coastal inundation during the century. Inundation is projected for the airport runways of some of the examined international airports and most of the seaports, even from the 100-year extreme sea level under 1.5 °C SWL. In the absence of effective technical adaptation measures, both operational disruptions and coastal inundation are projected to increasingly affect all examined assets over the course of the century
The Exact Discretisation of CARMA Models with Applications in Finance
The problem of estimating a continuous time model using discretely observed data is common in empirical finance. This paper uses recently developed methods of deriving the exact discrete representation for a continuous time ARMA (autoregressive moving average) system of order p, q to consider three popular models in finance. Our results for two benchmark term structure models show that higher order ARMA processes provide a significantly better fit than standard Ornstein-Uhlenbeck processes. We then explore present value models linking stock prices and dividends in the presence of cointegration. Our methods enable us to take account of the fact that the two variables are observed in fundamentally different ways by explicitly modelling the data as mixed stock-flow type, which we then compare with the (more common, but incorrect) treatment of dividends as a stock variable
Paleoecology of the Springfield Coal Member (Desmoinesian, Illinois Basin) near the Leslie Cemetery paleochannel, southwestern Indiana
- …