5,793 research outputs found
Microlensing of circumstellar envelopes: II. emission lines from radial and azimuthal flow during fold caustic crossings
This paper examines the line profile evolution due to bulk motion in circumstellar envelopes during microlensing fold caustic crossing events. These events have recently been shown to be a sensitive probe of stellar surface brightness profiles, thus providing a means - through both photometric and spectroscopic observations - to constrain and test stellar atmosphere models. Here it is demonstrated, through the examination of simplified line profiles, that spectroscopic studies of fold caustic crossings could also prove to be a powerful diagnostic of bulk motion in circumstellar envelopes
The Efficiency of Canadian Capital Markets: Some Bank of Canada Research
Capital markets and their related financial instruments make an important contribution to the welfare of Canadians. The Bank of Canada is interested in the efficient functioning of capital markets through each of its responsibilities for monetary policy, the financial system, and funds management. Hendry and King highlight the key findings of Bank research published over the past year that addresses capital market efficiency and summarize lessons that have been learned. The research conducted thus far suggests that Canadian capital markets are efficient for a capital market of Canada's size but are less diverse than the U.S. capital markets, indicating that there is room for improvement in certain areas.capital market efficiency; Canada; bond; equity; foreign exchange; derivatives; securitization.
The Efficiency of Canadian Capital Markets: Some Bank of Canada Research
Capital markets and their related financial instruments make an important contribution to the welfare of Canadians. The Bank of Canada is interested in the efficient functioning of capital markets through each of its responsibilities for monetary policy, the financial system, and funds management. Hendry and King highlight the key findings of Bank research published over the past year that addresses capital market efficiency and summarize lessons that have been learned. The research conducted thus far suggests that Canadian capital markets are efficient for a capital market of Canada's size but are less diverse than the U.S. capital markets, indicating that there is room for improvement in certain areas.
Evaluating three models of school–university partnership at the University of York : learning lessons and planning for the future
On the structure of the deep Gulf Stream
Tlk zonal and temporal structure of the mean and low-frequency flow beneath the Gulf Stream at 55W is explored in an analysis of 17 months of current and temperature measurements at 4000 m depth…
The Corralitos Observatory program for the detection of lunar transient phenomena
This is a final report on the establishment, observing procedures, and observational results of a survey program for the detection of lunar transient phenomena (LTP's) by electro-optical image conversion means. For survey, a unique detection system with an image orthicon was used as the primary element in conjunction with a 24-in. f/20 Cassegrainian telescope. Observations in three spectral ranges, with 6,466 man-hours of observing, were actually performed during the period from October 27, 1965, to April 26, 1972. Within this entire period, no color or feature change within the detection capabilities of the instrumentation was observed, either independently or in follow up of amateur LTP reports, with the exception of one general bluing and several localized bluings (probably ascribable to the effects of the terrestrial atmosphere) that were observed solely by the Corralitos system. A table is presented indicating amateur and professional reports of LTP's and the results of efforts to confirm these reports through the Corralitos system
Silicon isotopes in Antarctic sponges : an interlaboratory comparison
Cycling of deepwater silicon (Si) within the Southern Ocean, and its transport into other ocean basins, may be an important player in the uptake of atmospheric carbon, and global climate. Recent work has shown that the Si isotope (denoted by δ29Si or δ30Si) composition of deep sea sponges reflects the availability of dissolved Si during growth, and is a potential proxy for past deep and intermediate water silicic acid concentrations. As with any geochemical tool, it is essential to ensure analytical precision and accuracy, and consistency between methodologies and laboratories. Analytical bias may exist between laboratories, and sponge material may have matrix effects leading to offsets between samples and standards. Here, we report an interlaboratory evaluation of Si isotopes in Antarctic and sub-Antarctic sponges. We review independent methods for measuring Si isotopes in sponge spicules. Our results show that separate subsamples of non-homogenized sponges measured by three methods yield isotopic values within analytical error for over 80% of specimens. The relationship between δ29Si and δ30Si in sponges is consistent with kinetic fractionation during biomineralization. Sponge Si isotope analyses show potential as palaeoceaongraphic archives, and we suggest Southern Ocean sponge material would form a useful additional reference standard for future spicule analyses
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Non-traumatic chest pain in patients presenting to an urban emergency Department in sub Saharan Africa: a prospective cohort study in Tanzania.
BACKGROUND:Non-traumatic chest pain (NTCP) is a common reason for emergency department (ED) attendance in high-income countries, with the primary concern focused on life threatening cardiovascular diseases. There is general lack of data on aetiologies, diagnosis and management of NTPC in Sub Sahara African (SSA) countries. We aimed to describe evaluation, diagnosis and outcomes of adult patients presenting with NTCP to an urban ED in Tanzania. METHOD:This was a prospective observational cohort study of consecutive adult (≥18 years) patients presenting with non-traumatic chest pain to the Emergency Medicine Department (EMD) of Muhimbili National Hospital (MNH) in Dar es salaam from September 2017 to April 2018. Structured case report form was used to collected demographics, clinical presentation, investigations, diagnosis, and EMD disposition and in hospital mortality. We determined frequency of NTCP among our patients, aetiologies, 24-h and 7-day in-hospital mortality, and predictors for mortality. RESULTS:We screened 29,495 adults attending EMD-MNH during the study and 389 (1.3%) presented with NTCP of these, 349 (90%) were enrolled. The median age was 45 (IQR 29-60) years and 177 (50.7%) were female. Overall, 69.1% patients received electrocardiography (ECG) in the EMD and 34.1% had a troponin test. Heart failure and pulmonary tuberculosis (PTB) were the leading hospital diagnoses (12.6% each), followed by chronic kidney disease (10%) and acute coronary syndrome (ACS) (9.6%). Total of 167 (48%) patients were admitted, and the 24-h and 7-day in-hospital mortality were 5 (3%) and 16 (9.6%) respectively. Univariate risk factors for mortality were a Glasgow Coma Scale of < 15 [RR = 3.4 (95%CI 3.2-23)], Acute Coronary Syndrome [RR = 5.7 (95% CI 1.7-11.8) and Troponin > 0.04 ng/ml [RR 2.9 (95%CI 1.2-7.3)]. Features distinguishing cardiovascular from other causes were: bradycardia [RR = 2.6 (95%CI 2.1-3.2)], heart beat awareness [RR = 2.3 (95%CI 1.7-3.2)] and history of diabetic mellitus [RR = 2.2 (95% CI 1.6-3.0)]. CONCLUSION:In this ED of SSA country, heart failure and pulmonary tuberculosis were the leading causes of NCTP, and ACS was present in 9.6%. NTCP in this setting carries high mortality, and ACS was the leading risk factor for death. ED providers in SSA must increasingly consider cardiovascular causes of NTCP
Analisis Perbandingan Akurasi Model Prediksi Pasang Surut: Studi Kasus Di Selat Larantuka, Flores Timur, Nusa Tenggara Timur
Sebagai negara maritim, informasi hidro-oseanografi sangatlah penting dalam mendukung segala aktivitas kelautan dan perikanan di Indonesia. Salah satu data dan informasi yang sangat penting adalah parameter pasang surut. Ketersediaan data pasang surut hasil pengukuran di lapangan yang baik sangat minim jika dibandingkan dengan luas wilayah lautan Indonesia. Model numerik pasang surut menjadi salah satu solusi untuk memberi gambaran Perubahan elevasi muka air suatu perairan. Saat ini telah banyak modul prediksi pasang surut yang mampu memberikan informasi fluktuasi muka air laut suatu perairan dengan tingkat keakurasian dan error yang berbeda. Penelitian ini bertujuan untuk membandingkan tingkat keakurasian model pasut dari NAOTIDE, LePROVOST, TMDTPXO 7.1 dan MIKE21. Pasang surut perairan Selat Larantuka, Nusa Tenggara Timur digunakan sebagai lokasi percontohan untuk uji akurasi model tipe perairan selat di Indonesia. Hasil analisis menunjukkan bahwa untuk tipe perairan selat, model prediksi pasang surut NaoTide memberikan keakuratan lebih baik dengan persentase error sebesar 1,79 % dibandingkan dengan model pasut lainnya
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