4,076 research outputs found
Regulating Innovative Medicine: Fitting Square Pegs in Round Holes
Increasingly, innovative medical products are creating a quandary for the Food and Drug Administration ( FDA ) because they often transcend the FDA\u27s traditional categorical approach to regulating medical products. In a recent attempt to simplify this process, the FDA has proposed a new rule for regulating combination products. This iBrief discusses the FDA\u27s current approach and analyzes the possible affects of the proposed regulation. Because of the many shortcomings of both systems, this iBrief concludes that the FDA should instead stop assigning center jurisdiction based on a product\u27s primary mode of action, and give the Office of Combination Products internal agency jurisdiction over combination products. This alternative approach would increase consistency and efficiency while maintaining the FDA\u27s high standards for medical product safety and efficacy
Independent doubly truncated gamma variables
Density and distribution functions of the sum of independent variables, each having a truncated gamma density function, were derived for use in the measurement of complex physical phenomena
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FESTER - An elasto-viscoplastic finite-element program for geotechnical applications
Primigravid Women's Views of Being Approached to Participate in a Hypothetical Term Cephalic Trial of Planned Vaginal Birth versus Planned Cesarean Birth
Background: Several papers have called for a trial of planned cesarean section versus planned vaginal birth for low-risk women—a recommendation that is fiercely debated. Although proponents of a trial have voiced their support, evidence suggests that in the United Kingdom few midwives and obstetricians believe such a trial to be feasible, and no studies reporting women's views on the prospect of such a trial have been published. The purpose of this study is to explore women's views of participation in a trial of planned cesarean birth versus planned vaginal birth.
Methods: A qualitative study was conducted using in-depth interviews in a large maternity hospital in the United Kingdom. Sixty-four women were interviewed 12 months after giving birth. Women were asked “How do you think you would have felt if you had been approached to take part in such a trial during your first pregnancy?” Data were analyzed thematically.
Results: Only 3 of the 64 women stated that they would have participated in a trial of planned vaginal birth versus planned cesarean section, had they been asked. However, five other women said that they would have consented to participate if they had been asked during pregnancy, but with hindsight, would have regretted that decision. The remainder of women would not have participated, unless a preference arm was offered. Three main themes were identified: “feeling cheated,”“let nature take its course, ” and “just another trauma that you don't need.”
Conclusions: Few women supported a trial and most suggested that it was intuitively wrong. Given the strong views voiced by women, it is unlikely that a trial of planned vaginal delivery versus planned cesarean delivery would be feasible
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Physical oceanography
The main objective of the physical oceanography program was to describe the upper ocean water structure around the Elephant Island area in relationship to the observed distribution of biological organisms. This was accomplished by measuring the vertical density profile of the waters to a depth of 750m (where possible) over (1) a coarse grid of 50 stations (Surveys A and D, Figure 3.1.1) around Elephant Island, (2) a finer-scale grid to the north of Elephant Island (Surveys Band C, Figures 3.1.2 and 3.1.3), (3) closely spaced stations along two sections extending across the shelf-break, also to the north of Elephant Island, and ( 4) by continuously monitoring the meteorological conditions along the ship's track to study mechanisms maintaining the upper mixed layer and pycnocline. The grids and transects were repeated on Leg II of the cruise.Marine Scienc
Small, low cost, artificial kidney
Disposable hemodialyzer is described that can be used at home by non-medically trained personnel. Short lengths of semipermeable membrane tubes are arranged in parallel, supported by plastic mesh and encased in epoxy at ends. Tubes are connected to input and output blood manifolds which are separated by dialysate chamber. Daily dialysis requires only two hours or less
Interim report on the progress of an inventory of artesian wells in Florida: leading to the enforcement of sections 370.051 - 370.54, Florida statues
One of the causes of lower artesian pressure, water
waste and aquifer contamination is the misuse and insufficient
care of artesian wells. In 1953, Senate Bill No. 57, entitled
"An Act to Protect and Control the Artesian Waters of the
State" (see Appendix) became a law. This law was passed
through the efforts exerted by leading members of the Senate
and the House of Representatives, who understood the need
for a wise and controlled expenditure of our most valuable
natural resource.
The State Geologist and his authorized representatives
were designated by this law to enforce this conservation
measure; however, no financial provision was included for
the 1953-55 biennium. The proposed program of the Florida
Geological Survey for this biennium did not include the funds
nor provide any full-time personnel for the enforcement of
this statute. As a result, little actual work was accomplished during these two years, although much time was given to
planning and discussion of the problem.
Realizing that this program could provide additional basic
data needed in the analysis of the water-supply problem, the
State Geologist sought and was granted by the 1955 Legislature
adequate funds with which to activate the first phase of the
enforcement of Florida Statute No. 370.051-054.
Enumerated below is a summary of the progress made
on this investigation as outlined previously:
1. Data have been collected on 967 wildly flowing wells
in 22 counties.
2. Chloride determinations have been run on 850 of the
967 wells.
3. Of the 967 wells, 554 have chlorides in excess of the
250 ppm, the upper limit assigned by the State Board
of Health for public consumption.
4. Water escapes at the rate of 37, 762 gallons per minute
from these 967 wells. This amounts to 54, 377, 280
gallons per day.
The investigation is incomplete at this time; therefore,
no final conclusions can be reached. However, from data
already collected, the following recommendations are proposed:
1. That the present inventory of wildly flowing wells be
completed for the entire State.
2. That the current inventory of wildly flowing wells be
expanded at the conclusion of the present inventory
to include all flowing wells.
3. That a complete statewide inventory program be
established and conducted in cooperation with the
Ground Water Branchof the U.S. Geological Survey.
4. That the enforcement functions as set down in Sections
370.051/.054, Florida Statutes, be separated from
the program to collect water-resource data and that
these functions be given to the Water Resources
Department, if such is created (to be recommended
by the Water Resources Study Commission in a water
policy law presented to the 1957 Legislature).
5. That the research phase (well inventory) of the program
remain under the direction of the Florida Geological
Survey. (PDF contains 204 pages.
Response of the West African Monsoon to the Madden–Julian Oscillation
Observations show that rainfall over West Africa is influenced by the Madden-Julian Oscillation (MJO). A number of mechanisms have been suggested: 1) forcing by equatorial waves; 2) enhanced monsoon moisture supply; and 3) increased African easterly wave (AEW) activity. However, previous observational studies are not able to unambiguously distinguish between cause and effect. Carefully designed model experiments are used to assess these mechanisms. Intraseasonal convective anomalies over West Africa during the summer monsoon season are simulated in an atmosphere-only global circulation model as a response to imposed sea surface temperature (SST) anomalies associated with the MJO over the equatorial warm pool region. 1) Negative SST anomalies stabilize the atmosphere leading to locally reduced convection. The reduced convection leads to negative midtropospheric latent heating anomalies that force dry equatorial waves. These waves propagate eastward (Kelvin wave) and westward (Rossby wave), reaching Africa approximately 10 days later. The associated negative temperature anomalies act to destabilize the atmosphere, resulting in enhanced monsoon convection over West and central Africa. The Rossby waves are found to be the most important component, with associated westward-propagating convective anomalies over West Africa. The eastward-propagating equatorial Kelvin wave also efficiently triggers convection over the eastern Pacific and Central America, consistent with observations. 2) An increase in boundary layer moisture is found to occur as a result of the forced convective anomalies over West Africa rather than a cause. 3) Increased shear on the African easterly jet, leading to increased AEW activity, is also found to occur as a result of the forced convective anomalies in the model
Knob linkage permits one-hand control of several operations
Electromechanical device with single knob provides one-hand control of numerous electrical or mechanical functions. The principle of this design may have application to remote-control switching devices
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