Hansen studies

OTA found two principal threats to validity of the methods used to estimate cash outlays per success 1) the small number of NCEs in the samples, especially in the Hansen study and 2) the reliance on unverifiable cost data that responding companies supplied. Although most companies were capable of estimating the costs associated with discovery and development of particular NCEs with reasonable accuracy, inherent differences in the structure of cost-accounting systems across companies introduce potential inconsistency and bias. More importantly, any company that understood the study methods and the potential policy uses of the study s conclusions could overestimate costs without any potential for discovery. Thus, the motivation to overestimate costs cannot be discounted. 

Although the time periods covered in the clinical trial survey do not correspond exactly to the Hansen and DiMasi research periods,11 the survey results do show that the number of subjects in clinical trials increased in the period between the later years of the Hansen study and the later years of the DiMasi study, even within reasonably homogeneous therapeutic categories. 

The adequacy of the sample size to reliably predict costs is determined by the underlying variation in the costs to be measured. The sample size in the Hansen study was 65 to 70 NCEs. The precise NCE sample size was not reported. DiMasi examined 93 NCEs. The higher the... 

The combined impact on total capitalized costs of potential changes in the NDA review times in the Hansen study and a longer preclinical period is shown in table 3-5. The estimated capitalized costs increase modestly—by about 4 to 6 percent in both studies-as a result of these potential errors in timing. 

Hansen estimated a mean 4.5-year lag between ind and NDA submission and a 2-year period from NDA submission to approval. Therefore, the Hansen study period for NCEs first entering human trials in 1963-75 would correspond roughly to NCEs reaching approval between 1969 and 1982. 

Stell G 1999 New results on some ionic fluid problems, new approaches to problems in liquid state theory Proc. NATO Advanced Study Institute (Patte Marina, Messina, Italy 1998) ed C Caccamo, J P Hansen and G Stell (Dordrecht Kluwer)... 

Hansen, D. A., Puckett, K. ]., Jansen, ]. ]., Lusis, M., and Vickery, J. S., The Eulerian Model Evaluation Field Study (EMEFS). Paper 5.1, pp 58-62, in "Preprints, Seventh Joint Conference on Applications of Air Pollution Meteorology with AWMA," Jan. 14-18, 1991, New Orleans. American Meteorological Society, Boston, 1991. 

Paine et al. [85] extensively studied the effect of solvent in the dispersion polymerization of styrene in the polar media. In their study, the dispersion polymerization of styrene was carried out by changing the dispersion medium. They used hydroxypropyl cellulose (HPC) as the stabilizer and its concentration was fixed to 1.5% within a series of -alcohols tried as the dispersion media. The particle size increased from only 2.0 /itm in methanol to about 8.3 /itm in pentanol, and then decreased back to 1 ixm in octadecanol. The particle size values plotted against the Hansen solubility parameters... 

Continuous emulsion polymerization systems are studied to elucidate reaction mechanisms and to generate the knowledge necessary for the development of commercial continuous processes. Problems encountered with the development of continuous reactor systems and some of the ways of dealing with these problems will be discussed in this paper. Those interested in more detailed information on chemical mechanisms and theoretical models should consult the review papers by Ugelstad and Hansen (1), (kinetics and mechanisms) and by Poehlein and Dougherty (2, (continuous emulsion polymerization). 

Additional contributions to 5 from, for instance, hydrogen-bonding forces, well studied by Hansen, C.M. J. Paint TechnoL, 39(505), 105, 1967), have not been relevant to MERL s general usage of this parameter. 

A relatively new arrangement for the study of the interfacial region is achieved by so-called emersed electrodes. This experimental technique developed by Hansen et al. consists of fully or partially removing the electrode from the solution at a constant electrical potential. This ex situ experiment (Fig. 9), usually called an emersion process, makes possible an analysis of an electrode in an ambient atmosphere or an ultrahigh vacuum (UHV). Research using modem surface analysis such as electron spectroscopy for chemical analysis (ESCA), electroreflectance, as well as surface resistance, electrical current, and in particular Volta potential measurements, have shown that the essential features (e.g., the charge on... 

In contrast, initial studies of neostriatal unit activity in unanesthetized, behaving animals suggested that neostriatal units were excited by even small doses of amphetamine (Hansen and McKenzie 1979 Rebec and Gardiner 1985 Trulson and Jaeobs 1979 Warenycia and McKenzie 1984a ... 

Distribution of U-Th-Ra in weathering profiles. The first U-Th studies (Pliler and Adams 1962 Rosholt et al. 1966 Hansen and Stout 1968) generally showed a U loss relative to Th at the base of the profiles, and an enrichment in the uppermost horizons and/or in some accumulation layers. The development of weathering studies, however, point out that this situation is not to be generalized and that reverse trends can be observed even at the scale of a single toposequence (Fig. 11). 

Hansen A. and Zeiske E. (1998). The peripheral olfactory organ of the zebrafish, Danio rerio an ultrastructural study. Chem Senses 23, 39-48. 

Defusing the Global Warming Time Bomb, 2004. James Hansen—Director of NASA Goddard Institute for Space Studies, Scientific American, Vol. 290, Number 3, March. 

Larsen, F.K. and Hansen, N.K. (1984) Diffraction studies of the electron density distribution in beryllium metal, Acta Cryst., B40, 169-179. 

Hansen ON, Trillingsgaard A, Beese I, et al. 1989. A neuropsychological study of children with elevated dentine lead level Assessment of the effect of lead in different socioeconomic groups. Neurotoxicol Teratol 11 205-213. 

Lyngbye T, Hansen ON, Grandjean P. 1987. The influence of environmental factors on physical growth in school age A study of low level lead exposure. In Lindberg SE, Hutchinson TC, eds. International Conference on Heavy Metals in the Environment, Vol. 2, New Orleans, LA, September. Edinburgh, UK CEP Consultants, Ltd. 210-212. 

Lyngbye T, Hansen ON, Grandjean P. 1988a. Bias from non-participation A study of low-level lead exposure in children. Scand J Soc Med 16 209-216. 

Almenningen, A., O. Bastiansen u. L. Hansen Electron diffraction studies... 

Field electron emission coupled with flash-filament studies have been employed by Condon and Hansen to study benzene chemisorption on tungsten (21). Evidence was obtained for the chemisorption of benzene by a single bond (probably of -character) to the surface. This form of asso-ciatively adsorbed benzene [(I), Scheme 1] appeared to exist in equilibrium with cr-adsorbed-CeHs (II) and adsorbed atomic hydrogen. 

Agerholm-Larsen B, Nordestgaard BG, Tybjaerg-Hansen A. ACE Gene Polymorphism in Cardiovascular Disease. Meta-Analyses of Small and Large Studies in Whites. Arterioscler Thromb Vase Biol 2000 20 484 192. 

Sethi AA, Nordestgaard BG, Ager-holm-Larsen B, Frandsen E, Jensen G, Tybjaerg-Hansen A. Angiotensinogen polymorphisms and elevated blood pressure in the general population - the Copenhagen City Heart study. Hypertension 2001 37 875-881. 

Gerdes LU, Gerdes C, Kervinen K, Sa-volainen M, Klausen IC, Hansen PS, et al. The apolipoprotein epsilon4 allele determines prognosis and the effect on prognosis of simvastatin in survivors of myocardial infarction a substudy of the Scandinavian simvastatin survival study. Circulation 2000 101 1366-1371. 

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