37 research outputs found
Comment on Martinez-Garcia et al. 'Heavy metals in human bones in different historical epochs'.
MartĂnez-GarcĂa et al. (Sci. Tot Env. 348:51–72) have examined heavy metal exposure of humans in the Cartagena region using analysis of archaeological bones. An analysis of the lead and iron levels they report shows that they are physiologically implausible and must therefore result from diagenesis. This, and analogy with the known diagenetic origin of certain other elements, suggests that the other metal analyses they report are also unlikely to be in vivo concentrations. Lifetime heavy metal exposure cannot be deduced from diagenetically altered concentrations
A Culturally Competent Phenotypic Evaluation / Obesity Assessment in African and African American Populations: Pilot Study
BMI, a ratio of weight over height, is a culturally-biased tool imposed upon the scientific, academic and medical communities as an errant measure of obesity across ethnic - ity. Body Mass Index (BMI) relates mass (g) to a relative fat distribution with regards to height. Its genesis is from the actuarially derived and ethnically exclusive height and weight tables that promote the fictional notion of inter-eth - nic ideal weights that would be later adopted by the Na - tional Institutes of Health (NIH) as a competent measure of adiposity. Best practice, movement towards individualized medicine and deployment of effective models that impact the diabetes epidemic and its related precursors like insulin resistance and the metabolic syndrome, requires terminal use of BMI, a biologically meaningless and crude indicator of obesity, in favor of effective and culturally competent non-relative body composition evaluation of genetically determined adiposity that untenably compares values among groups. African Americans are among the increasingly affected groups for diabetes and posses unique composition variation requiring proper intra-cultural evaluation independent of inter-ethnic Eurocentric assumptions that over assesses obesity risk. Incorporating use of 4C models to evaluate adiposity and assess risk for diabetic predisposition and onset provides an effective unbiased assessment of the cultural components inherent within body composition variation among ethnicity, age, gender. Obesity and type II diabetes onset and pre-disposition is assessed phenotypically, in creation of a body mass profile among African and African American groups, using 4C model, photography, anthropometry, somatotype and genetic evaluation. Environmental obeseogenic cultural factors are also explored
Strong Coupling Corrections to the Ginzburg-Landau Theory of Superfluid ^{3}He
In the Ginzburg-Landau theory of superfluid He, the free energy is
expressed as an expansion of invariants of a complex order parameter. Strong
coupling effects, which increase with increasing pressure, are embodied in the
set of coefficients of these order parameter invariants\cite{Leg75,Thu87}.
Experiments can be used to determine four independent combinations of the
coefficients of the five fourth order invariants. This leaves the
phenomenological description of the thermodynamics near incomplete.
Theoretical understanding of these coefficients is also quite limited. We
analyze our measurements of the magnetic susceptibility and the NMR frequency
shift in the -phase which refine the four experimental inputs to the
phenomenological theory. We propose a model based on existing experiments,
combined with calculations by Sauls and Serene\cite{Sau81} of the pressure
dependence of these coefficients, in order to determine all five fourth order
terms. This model leads us to a better understanding of the thermodynamics of
superfluid He in its various states. We discuss the surface tension of
bulk superfluid He and predictions for novel states of the superfluid
such as those that are stabilized by elastic scattering of quasiparticles from
a highly porous silica aerogel.Comment: 9 pages, 7 figures, 2 table