Saturday, April 28, 2018

POLAR ICE

Global Warming

Environmental changes caused by global warming seem to be more widely accepted by most, even those living in area with colder than usual weather caused by shifting oceanic currents and the anomalies of air currents and shifts in polar air masses.  A recent increase in melting of shelf ice and discharge of cold water was viewed with alarm as something that might be detrimental to life in the surrounding Southern Ocean.

Krill

The crustaceans known as krill serve as intermediates in the food chain  by feeding on algae and then being eaten by others in the food chain; even being directly consumed by the largest whales at the top of the food chain, as well as by fish and others.  Some think the biomass of krill is greater than the biomass of any other animal.

Krill have a life cycle of at least two years beginning with eggs released from adults near the surface of water close to the Antarctic ice-covered water.  The eggs sink and hatch as they are carried by currents of near freezing sea water north from their point of origin.  The eggs hatch and the larvae make their way toward somewhat warmer water near the surface that is moving toward Antarctica replacing and then becoming the cold, northward streaming deeper water.  By then, two or more years later, the larvae have grown into adults that lay eggs beginning another generation that repeats the journey north in cold deep water, and back to the southern point of origin.

Ice shelves

The reduction of ice shelves and increasing flows of melt water from the continental margin may cause some reduction in salinity with increase in temperature.  Over the centuries marine life may have experienced similar changes and developed the ability to survive such changes.  Animals dependent on krill may have to adapt to new locations of krill abundance due their changing environment.

Sea level changes

Shelf ice floating on sea water will not change the level when it melts.  If it has built up after resting on the shallow sea bottom it could raise the ocean level.  If ground ice interface on land warms and contributes to glacial flow into the sea more rise would result.  Since the vast amount of ice in Antarctica is under high elevations of ice it is not likely to be rapidly melted.

Greenland

The general consensus years ago was that the ice cover was immune to major melting.  It now seems that it is a real danger, but of much less magnitude than melting Antarctic ice would represent.

Joe Engemann     Kalamazoo, Michigan    April 28, 2018


Wednesday, April 11, 2018

EVOLUTION, AGE, AND ALZHEIMER'S

The Role of Evolution

Evolution may not contribute much to solving the Alzheimer's problems although it must have been involved in the selection of genes and functional aspects responsible.  Whether knowing more about the biochemistry of amyloid and tau proteins involved in the plaques and tangles diagnostic for Alzheimer's will lead to successful treatments is uncertain.

Clues about the disease may come from more primitive animals with smaller and less complicated brains.  Finding such clues may require greater knowledge of the process in our own brains.  The pogonophorans live to extreme ages under very adverse conditions of limited food and are presumably much like the ancestors of the animal line leading to vertebrates.  More recent ancestors are more likely to be of value.  I personally think study of diverse human populations for their diet and health parameters may give the best clues to further research.

AGE

Because Alzheimer's and/or senile dementia increase in severity and frequency with advancing age, typically beyond the fertile years, the hereditary component thought to be about 40 percent is only indirectly subject to natural selection.  Selection may differ if societies with multi-generational families are compared with societies of smaller two or three generation families.  Such a comparison is not likely to be informative since the shift has been quite recent.  The stress of dealing with the afflicted versus the wisdom of elders without the disease may contribute to a shift in the gene pool of such groups.

Increasing age seems to enable the disease process to advance, whether by increased deposits in the brain or increased neuron death or impaired function.  Life-style changes may help avert disease progress.  Maintaining a social life, physical and mental activity, getting adequate rest, and good nutrition (moderation in quantities, more fruits and vegetables, and reduced animal fats).  An article by Paula Spencer Scott in the April 8 (2018) edition of Parade is accompanied by a list of suggestions including the value of music.

I'm not very good at doing the suggested changes even though I suspect several deceased relatives had the disease at death 80 or fewer years ago.  I thank my spouse for my being alive with some mental function as a result of her efforts to limit my animal fat intake and increase the vegetarian portion of my diet.

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DIETER'S CAUTION

Toxic substances such as DDT and other halogenated hydrocarbons polluting the food chain accumulate in animal fat deposits because they are fat soluble and poorly eliminated in urine,  They may enter the blood stream in greater amounts when fats diminish due to dieting or illness.  At such times the high concentration may cause or increase behavioral aberrations such as depression.  Even people with little fat could experience such problems compounding illness if the little fat they had released its toxic store.
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It may be too early to determine if Facebook and Twitter are adequate for the social component of a healthy lifestyle.  I have minimal exposure to both, but maybe if I increase my blogging it will help.

An afterthought on music.  The article referred to above noted singing is supposed to be a good form of music.  Years ago it was common to gather around someone's piano (or other instrument) and sing together.  When my father was doing physical work in his printshop he was typically whistling the same tune over and over.  He was still fairly alert mentally the year he died when he was 96 years old,  Maybe I will whistle more frequently.  Do you think it will help?


Joe Engemann    Kalamazoo, Michigan       April 11, 2018