Dose latitude

In the face of so much variability in dosing, one naturally asks about how much latitude each drug may allow without either degradation of its beneficial effects or increase in its hazards. A few agents have been so characterized. 

The mechanical and electrical properties of selected high strength alloys in cast and wrought forms are provided in Table 5. A similar compilation for the high conductivity alloys is given in Table 6. The mechanical properties shown in the tables correspond to standard hardening times and temperatures and therefore are dose to peak conditions. Considerable latitude exists for achieving a wide variety of special mechanical and electrical property combinations. 

We are all exposed to radiation on a daily basis from both natural and man-made sources. Background radiation levels vary widely depending on altitude, local geology, and latitude, but average background radiation dose in the United States and Canada is about 360 milli-rem (mrem) annually. Of this, nearly 300 mrem is due... 

A missed oral dose allows even less latitude than the combined pill. If a dose is more than 3 hours late it should be taken at once and a barrier method used for 7 days. Act similarly where there has been vomiting, severe diarrhoea, or if an enzyme-inducing drug has been taken. 

Particularly now that the lowest effective doses are in use there is little latitude between success and failure if the absorption, distribution and metabolism are distrubed. Any additional drug-taking must be looked at critically lest it reduces efficacy. 

Toxic doses of the plant extract are difficult to determine due to differing concentrations of eight pip-eridinic alkaloids in the plant. The concentrations of alkaloids vary with the age of the plant. Plants up to 1-year-old have very low alkaloid content in roots, 0.15% in stems and 0.3-0.6% in the leaves. Plants in their second year have an alkaloid content of 1% in all parts of the plant. Geographic latitude and drying will also affect the coniine content of the plant. A toxic dose of coniine is estimated to be... 

Exposure to natural sources of external ionizing radiation results from the levels of cosmic and terrestrial X and gamma radiation present in the environment. Cosmic radiation at the earth s surface is affected by altitude, geomagnetic latitude, and solar modulation. For example, the dose rate at... 

R. McKenzie, G. Seckmeyer, A.F. Bais, J.B. Kerr, S. Madronich (2001). Satellite-retrievals of erythemal UV dose compared with ground-based measurements at Northern and Southern mid-latitudes. J. Geophys. Res., 106, 24051-24062. 

E. C. DeFabo, F.P. Noonan, J.E. Frederick (1990). Biologically effective doses of sunlight for immune suppression at various latitudes and their relationship to changes in stratospheric ozone. Photochem. Photobiol, 52, 811-817. 

Changes in the optical properties of the skin, such as those caused by a drug vehicle, can result in a greater UV dose to the viable layers of the skin. Data on correlation of latitude, UV exposure, and cancer risk in humans indicate that an increase in UV exposure as small as 20% could result in a fourfold increase in basal-cell carcinoma.16... 

The sea level cosmic ray dose is 300 millirad-yr and the sea level ionization is 2.2 x 10 ion pairs m s l The sea level flux has a soft component, which can be absorbed in about 100 mm of lead (about 100 g-cm of absorber) and a more penetrating (largely muon) hard component. The sea level radiation is Icirgely produced in the atmosphere and is a secondary component from interactions of the primary particles. The steep primary energy spectrum means that most secondaries at sea level are from rather low energy primaries. Thus the secondary flux is dependent on the solar cycle and the geomagnetic latitude of the observer. 

Figure 9.2 Process latitude (in terms of overlap depth of focus for 0.5- jLm lines patterned with Mine lithography) of UCB-JSR 1x500 resist with and without AZ Aquatar top antireflection coatings. Shown are the contour plots for the O.S-fjim line as a function of focus and exposure dose. ...

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