Winter time inversions

Winter HH (1997) Analysis of dynamic mechanical data inversion into a relaxation time spectrum and consistency check. J Non-Newtonian Fluid Mech 68 225-39. 

The phenomenon known as the quantum Zeno effect takes place in a system which is subject to frequent measurements projecting it onto its (necessarily known) initial state if the time interval between two projections is small enough the evolution of the system is nearly "frozen". This effect, and its inverse (the anti-Zeno effect), have been widely investigated theoretically [Khalhn 1957-58 Winter 1961 Misra 1977 Fonda 1978 Kofman 1996 Kof-man 2000 Lewenstein 2000 Kofman 2001 (a) Schmidt 2003 / 2004] as well as experimentally [Cook 1988 Itano 1990 Wilkinson 1997 Fischer 2001], Generalizations have been proposed which employ incomplete measurements [Facchi 2002] in this setting, the Hilbert space is split into "Zeno subspaces" (degenerate multidimensional eigenspaces of the measured observable), and the state vector of the system is compelled by frequent measurements of the physical observable to remain in its initial Zeno subspace. The dynamics of the system in the Zeno subspaces has also been studied in different specific situations [Facchi 2001 (b)]. 

The inversion effect is difficult to assess accurately as the frequency and height of inversions varies over Europe. As a result relatively few people have attempted to quantify the effect of inversions. One French paper concluded that on account of the frequency of inversions and of stable and unstable conditions, emission height was important 50% of the time in summer and 80% of the time in winter. 

H. H. Winter, Analysis of Dynamic Mechanical Data-Inversion into a Relaxation-Time Spectrum and Consistency Check J. Non-Newt. FI. Mech. 68,225—239 (1997). 

A definite seasonal variation in cholesterol levels (usually higher in winter months) has been seen in a number of studies. Scientists from the National Institutes of Health in the US carried out one of the finest studies in this area. They examined carefully the data from the 10 American Lipid Research Climes. They observed that the etiology of their findings was unknown but they found the total and LDL cholesterol levels varied inversely with length of day. The level of HDL cholesterol varied much less, but its variation was correlated directly with ambient temperature. The foregoing does not reduce the importance of measuring cholesterol levels but makes it important to take into consideration the subjects physical and mental state as well as time of year. 

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