3,631 research outputs found

    Advection and eddy mixing in the Mediterranean salt tongue

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    Lagrangian trajectories from the SOFAR float Mediterranean outflow experiment are used to estimate the low frequency variability and mixing in the vicinity of the Mediterranean salt tongue. Two dominant patterns of Lagrangian variability are observed, (1) nearly zonal low frequency motions and (2) wave-like oscillations with northwest to southeast orientation. The zonal motions are found near the core of the salt tongue in the Canary Basin while the oscillations are generally found to the south and east. It is suggested that the zonal motions are the result of baroclinic instability of the large-scale flow. They have zonally enhanced low frequency variability (periods greater than 200 days) and nearly isotropic mesoscale variability (periods 50 to 200 days). The wave motions are believed to be the signature of radiating baroclinic Rossby waves generated to the south at the Cape Verde Frontal Zone. They are strongly peaked at the mesoscale band and have an essentially isotropic low frequency component. Integral time scales for the zonal motions are relatively long (23 and 13 days for the zonal and meridional directions) while for the wave motions they are short (7.7 and 5.0 days). The resulting eddy diffusivities are found to be non-isotropic and non-homogeneous with (Kxx, Kyy) = (21 and 8.4 Ɨ 106 cm2 sāˆ’1) in the core of the salt tongue (mainly zonal motions) and (Kxx, Kyy) = (4.3 and 3.5 Ɨ 106 cm2 sāˆ’1) to the south of the core (mainly wave-like motions). A simple scale analysis indicates that these time dependent motions play the dominant role in the spread of the Mediterranean salt tongue in both the zonal and meridional directions

    Heavy ion induced Single Event Phenomena (SEP) data for semiconductor devices from engineering testing

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    The accumulation of JPL data on Single Event Phenomena (SEP), from 1979 to August 1986, is presented in full report format. It is expected that every two years a supplement report will be issued for the follow-on period. This data for 135 devices expands on the abbreviated test data presented as part of Refs. (1) and (3) by including figures of Single Event Upset (SEU) cross sections as a function of beam Linear Energy Transfer (LET) when available. It also includes some of the data complied in the JPL computer in RADATA and the SPACERAD data bank. This volume encompasses bipolar and MOS (CMOS and MHNOS) device data as two broad categories for both upsets (bit-flips) and latchup. It also includes comments on less well known phenomena, such as transient upsets and permanent damage modes

    SOFAR float Mediterranean outflow experiment : summary and data from 1986-88

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    In October, 1984, the Woods Hole Oceanographic Institution SOFAR float group began a three and a half year field program to measure the velocity field of the Mediterranean water in the eastern North Atlantic. The principal scientific goal was to learn how the Mediterranean salt tongue is produced by the general circulation and the eddy diffusion of the Canary Basin. Thirty-two floats were launched at depths near 1100 m: 14 in a cluster centered on 32Ā°N, 24Ā°W, with nearest neighbors at 20 km spacing, 10 at much wider spacing to explore regional variations of first order flow statistics, and 8 in three different Meddies (Mediterranean water eddies) in collaboration with investigators from Scripps Institution of Oceanography and the University of Rhode Island. The floats were launched in 1984 and 1985, and tracked with U.S. and French ALSs (moored listening stations) from October 1984 to June 1988. This report includes a summary of the whole three and a half year experiment, the final year and a half of data processed from the third ALS setting (October 1986-June 1988), and the first deep sea test of Bobber EB014 in the eastern subtropical North Atlantic (May 1986-May 1988). Approximately 60 years of float trajectories were produced during the three and a half years of the experiment.Funding was provided by the National Science Foundation through Grant Nos. OCE 82-14066, OCE 85-17375, OCE 86-00055, OCE 88-22826

    Cryptic variation in an ecological indicator organism: mitochondrial and nuclear DNA sequence data confirm distinct lineages of Baetis harrisoni Barnard (Ephemeroptera: Baetidae) in southern Africa

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    Baetis harrisoni Barnard is a mayfly frequently encountered in river studies across Africa, but the external morphological features used for identifying nymphs have been observed to vary subtly between different geographic locations. It has been associated with a wide range of ecological conditions, including pH extremes of pH 2.9ā€“10.0 in polluted waters. We present a molecular study of the genetic variation within B. harrisoni across 21 rivers in its distribution range in southern Africa

    Isomorphous template induced crystallisation : a robust method for the targeted crystallisation of computationally predicted metastable polymorphs

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    A new method of inducing the crystallisation of metastable polymorphs by isomorphous templating has been developed and used to reproduce the crystallisation of CBZ-V on the surface of DHC-II. Studies of the growth of CBZ-V on DHC-II single crystals show crystals growing laterally and vertically on DHC-II surfaces without any significant face selectivity. The generality of this computationally inspired crystallisation approach is demonstrated by producing the first crystals of an entirely new polymorph of cyheptamide, which is isomorphous to both DHC-II and CBZ-V

    SOFAR float Mediterranean outflow experiment data from the second year, 1985-86

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    In October, 1984, the Woods Hole Oceanographic Institution SOFAR float group began a three-year-long field program to observe the low frequency currents in the Canary Basin. The principal scientific goal was to learn how advection and diffusion by these currents determine the shape and amplitude of the Mediterranean salt tongue. Fourteen floats were launched at a depth of 1100 min a cluster centered on 32Ā°N, 24Ā°W, and seven other floats were launched incoherently along a north/south line from 24Ā°N to 37Ā°N. At the same time investigators from Scripps Institution of Oceanography and the University of Rhode Island used four other SOFAR floats to tag a Meddy, a submesoscale lens of Mediterranean water. In October, 1985, seven additional floats were launched, four in three different Meddies, one of which was tracked during year 1. This report describes the second year of the floats launched in 1984 and the first year of the ones launched in 1985. Approximately 41 years of float trajectories were produced during the first two years of the experiment. One of the striking accomplishments is the successful tracking of one Meddy over two full years plus the tracking of two other Meddies during the second year.Funding was provided by the National Science Foundation under grant Numbers OCE 82-14066 and OCE 86-00055

    Recent moored current meter and SOFAR float observations in the eastern Atlantic near 32N

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    Basic flow statistics from the two-year deployment of a mooring in the vicinity of 32N and 24W are presented, along with intercomparisons between SOFAR float results concurrent with the first year of moored instrument data. Current-temperature meters were deployed in the main thermocline (āˆ¼500 m depth), in Mediterranean Water (1000ā€“1100 m depth) along with the SOFAR floats, and at an abyssal (āˆ¼3000 m) level. The float and current meter averages over a common time interval are at least roughly the same, with eddy field intercomparisons being better than those for mean flow. Strong year-to-year variability in the time-averaged flow and eddy statistics at thermocline depths is observed. The two-year based eddy kinetic energies (KE) are about the same as found using a variety of data taken nearby, whereas zonal mean speeds exhibit strong, comparatively short horizontal scale variability. It is pointed out that all measurements available exhibit a significant (perhaps dominant) but relatively unexplored interannual variability, not yet explicitly connected to variations in the gyre-scale circulation. Frequency distributions of KE are peaked at the (temporal) mesoscale at abyssal depth, and KE increases with increasing period in the thermocline. The distribution of KE with frequency at thermocline depths is also temporally inhomogeneous, although not at mesoscale and shorter periods. Meridonal frequency distributions of KE are peaked at the mesoscale and zonal distributions are more ā€œred.ā€ The eddy field characteristics at this site are shown to be similar to those from other low energy regions in the North Atlantic and the North Pacific

    Elder Financial Exploitation: Implications for Future Policy and Research in Elder Mistreatment

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    Recent advances in the understanding of elder mistreatment have demonstrated that financial exploitation tends to be one of the most common forms of mistreatment affecting older populations. Agencies such as the World Bank and World Health Organization show significant concern regarding financial exploitation and its connection to physical and emotional injury to victims. The World Bank uses the term ā€œfinancial violenceā€ as a means of generally describing the harm caused to an individual as a result of financial exploitation or abuse. The proportion of financial exploitation in relation to other forms of elder mistreatment is defined in our research. We discuss the potential impact of elder financial exploitation on victims as well as explore the implications for future research and policy development focused on financial aspects of elder mistreatment and call for further study in the concept of financial exploitation as a violent act

    Testing the Infection Prevalence of \u3cem\u3eSchistosoma mansoni\u3c/em\u3e after Mass Drug Administration by Comparing Sensitivity and Specificity of Species- Specific Repeat Fragment Amplification by PCR and Loop-Mediated Isothermal Amplification

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    Schistosomiasis is a blood parasitic disease caused by trematode parasites of the genus Schistosoma. Schistosoma mansoni is one of the main contributors of the disease and 90% of the global burden of schistosomiasis is in Africa. Mass drug administration (MDA) has been implemented to reduce the disease burden in endemic areas. Because of MDA, the diagnostic sensitivity and specificity for classical diagnostic tests are reduced. In any disease situation, diagnosis is vital in determining asymptomatic, concurrent, current, new, and reinfection cases to evaluate the efficacy of any control program. We have evaluated the positive infection for S. mansoni from filtered urine samples collected from Zambian school children after MDA using loop-mediated isothermal amplification (LAMP) and compared its sensitivity and specificity with polymerase chain reaction (PCR). One hundred eleven urine samples collected from school children aged between 7 and 15 years from Siavonga district in southern Zambia were evaluated by PCR and LAMP for DNA extracted by two different protocols (filter-based versus crude extraction). The infection prevalence was 77% with PCR and almost 94% with mansoni-LAMP. Also, LAMP detected 16% (Qiagen extraction) and 10% (LAMP- Procedure for Ultra Rapid Extraction) more positive S. mansoni infection than PCR. We have demonstrated the efficacy of LAMP in a laboratory setup after MDA. The possible inclusion of LAMP as a field-based point-of-care test for surveillance can provide reliable prevalence of schistosomiasis after MDA and help in determining the efficacy of a control program
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