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“Eating Dirt Benefits Kids” is Basically Made Up

I am surprised this writeup didn't mention physical aspects of geophagy. I always thought that tooth-wear was the main hazard of eating dirt. There's plenty of research on geophagy and tooth-wear, both direct like kaolin, and indirect like stone-milled grains which has a big impact in dental specimens in archeology.

Covid 8/26: Full Vaccine Approval

40% of whitetail deer had a SARS-CoV2 infection by March 2021. https://www.biorxiv.org/content/10.1101/2021.07.29.454326v1 I'd expect it to be predominantly Delta in them too by now. Given the population and reproduction rate of deer, I'd expect the virus to keep circulating in deer indefinitely.

Discontinuous progress in history: an update

Interested to see a historical analysis of luminous efficacy. Spans 3 orders of magnitude, similar timeframe to other topics covered, and also like other topics here includes many sequential innovations as opposed to mere iteration on a particular technology.

Open thread, 18-24 March 2014

Consider helminthic therapy. Hookworm infection down-regulates bowel inflammation and my parasitology professor thinks it is a very promising approach. NPR has a reasonably good popularization. Depending on the species chosen, one treatment can control symptoms for up to 5 years at a time. It is commercially available despite lack of regulatory approval. Not quite a magic bullet, but an active area of research with good preliminary results.

Open thread, July 29-August 4, 2013

Activity in many niches could credibly signal high status in some circles by making available many insights with short inferential distance to the general public (outside any of your niches). Allowing one to seem very experienced/intelligent.

Moreover, the benefits to being medium status in several hobby groups and the associated large number of otherwise unrelated social connections may be greater than readily apparent. https://en.wikipedia.org/wiki/Social_network#Structural_holes

Open Thread, July 1-15, 2013

If the commute is mostly flat, consider Freeline skates. They take up much less space than any of the mentioned wheels; the technique is different from skateboarding but the learning curve isn't any worse.

Open Thread, June 16-30, 2013

Adipocyte count is essential to maintaining weight.

It is unclear to what extent weight is genetic rather than environmentally set at a later stage in development.

Given that in adulthood adipocyte number stays constant, and weight changes are predominantly accompanied by changes in adipocyte volume, one may conclude that at some critical point in development the final fat cell number is attained and after this point no fat cell turnover occurs. Analysis of adipocyte turnover using carbon-14 dating (for a detailed methodological description, see Ref. [5]), however, has recently shown that this is not the case, but rather that adipocytes are a dynamic and highly regulated population of cells. New adipocytes form constantly to replace lost adipocytes, such that approximately every 8 years 50% of adipocytes (...) are replaced (emphasis added).

I am unable to find whether fat cell count can be changed over this 8 year time scale, though my biochemistry professor was inclined to that hypothesis.

Obesity can be characterised into two main types, hyperplastic (increase in adipocyte number) and hypertrophic (increase in adipocyte volume). Obese and overweight individuals may exist anywhere along the cellularity scale, however on average certain trends appear. Hypertrophy, to a degree, is characteristic of all overweight and obese individuals. Hyperplasia, however, is correlated more strongly with obesity severity.

Heredity and weight:

at present, it is impossible to conclude whether the average increase in adipocyte number seen in obese and severely obese individuals is the result of adult adipocyte recruitment or rather a reflection of a population of people predisposed (by their pre-adulthood fat cell number) to be become obese/severely obese.

The long-term weight loss cited in this review used a 1-2 year followup, during which time only <16% of adipocytes could have turned over.

it is clear that fat cell number does not decrease in adulthood, even following long-term weight loss. (emphasis added) In line with this, hyperplastic obese individuals have a poorer treatment outcome following diet-induced weight loss than hypertrophic individuals (when controlled for fat mass). Often for hyperplastic obese individuals, treatments other than diet and exercise are necessary if substantial and permanent weight loss is to be achieved. Successful, but invasive therapies include surgery to reduce the amount of calories ingested (e.g. gastric bypass) and/or surgical removal of fat tissue (e.g. reconstructive surgery or liposuction). The recent discovery of a high turnover of adipocytes in adult human white adipose tissue (approximately 10% annually) now establishes an additional therapeutic target for the pharmacological intervention of obesity [1].

Open Thread, January 16-31, 2013

What was bad about the Saxon program for you? I liked its spaced repetition; though being taught in a private school by a retired engineer probably masked any shortcomings in the textbooks. Should I stop recommending Saxon math?

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