Follow Loads, Forces, Stresses

Follow the loads, forces and stresses.
Notches are stress-raisers but not much problem on a compression-only stressed surface or where stresses are low.
A hole in the web of an I beam similarly sees little stress. Look at the large lightening holes in the aircraft wing ribs. Holes drilled in the horizontal neutral plane web of aluminum dog sled runners, the same. A small notch, however, in the stressed flange is a serious weakness.
This aluminum brake bar has a large notch on the bottom side where the claw is clamped, preventing the claw from sliding back on the bar. The nature and direction of the loads/forces prevents it from weakening the bar.

More Is Not Necessarily Better

…with the immune system.

False proxies and endpoints, straw man logic are often misleading in the evaluation of medicine, vaccines, and overall health.
>Peter Aaby’s research showed
that even though the levels of antibodies went down, the death rate of children
following measles infection was four times lower than the death rate for
children who didn’t contract measles. Here is the quote from Aaby’s paper:
“Exposed children developing clinical measles had lower age-adjusted mortality
over the next four years than exposed children who did not develop clinical
measles.”

Letters, Winter 2019

https://www.frontiersin.org/articles/10.3389/fpubh.2018.00079/full

UAF Sled Study

The Winner is Kuzmin!sledsliding5

Test parameters were combinations of heavy/light loading and slow/fast speed.

Note that by the time the UAF Engineering students had instrumentation and equipment ready the snow season was almost over so the trials were in temperatures near zero C and many other variables were not explored. I am surprised that HDPE was not comparable to UHMW, not as fast. I do expect HDPE to be best in extreme cold. I think most knowledgeable mushers use UHMW over cheaper HDPE in warmer conditions because of the much better wear/abrasion resistance in case of exposed dirt, rocks etc.

I think that boundary layer lubrication theory fits the limited relevant data best for all conditions. According to that, with a thicker film/boundary layer of water and adsorbed vapor, in warm temps the primary variable factor for most materials is corresponding surface tension/contact angle of a water droplet. Years ago I made a little hinged table with different plastics and measured not contact angle directly but angle at which a drop of water began to roll off. That would be static friction/drag vs. dynamic.

The prelimary report from UAF study below:

Authors Danny Eagan, Ian McKee    5/1/18

Test Parameters

Test Samples

1: Prairie Bilt, Fast Trax™ Proprietary Blend, yellow, shiny (1.75” wide)

2: Prairie Bilt, Fast Trax™ Proprietary Blend “White Lightning”, contains lubricating additives, white, shiny (1.75” wide)

3: Tim White HDPE

4: Tim White UHMWPE

5: Tim White, HDPE “XH”, white, very waxy (1.375” wide)

Weight: Approximate loaded weight based on 50 lb sandbags

  • Light: 150 lb
  • Heavy: 250 lb

Speed: approximate speed throughout duration of test (0.5 miles for Test 1, 200m for Test 2)

  • Slow: ~5 mph = 8.04 km/h
  • Fast: ~ 12.4 mph = 20 km/h (Test 1)
  • Fast: ~9.3 mph = 15 km/h (Test 2)

Test 1 (3/29/18): Runner Samples 3 and 4

Raw Data:

Table 1: Test results for runner sets 3 and 4

Runner Set 3: Tim White HDPE

Load Weight

Speed

Average Pulling Force (lb)

Heavy

Slow

42.9

Heavy

Fast

47.2

Light

Slow

22.7

Light

Fast

32.9

Runner Set 4: Tim White UHMWPE

Load Weight

Speed

Average Pulling Force (lb)

Heavy

Slow

20.9

Heavy

Fast

22.6

Light

Slow

11.9

Light

Fast

16.5

Figure 1: Raw data collected during testing of runner samples 3 and 4

Processed Data:

Figure 2: Preliminary results for all testing configurations of samples 3 and 4

Test 2 (4/213/18): Runner Samples 1, 2 and 5

Raw Data:

Table 2: Test results for runner samples 1, 2, and 5

Runner Set 1: Prairie Bilt, Fast Trax™ Proprietary Blend

Load Weight

Speed

Average Pulling Force (lb)

Heavy

Slow

23.56

Heavy

Fast

44.96

Light

Slow

35.91

Light

Fast

35.44

Runner Set 2: Prairie Bilt, Fast Trax™ Proprietary Blend “White Lightning”

Load Weight

Speed

Average Pulling Force (lb)

Heavy

Slow

56.46

Heavy

Fast

64.81

Light

Slow

52.01

Light

Fast

44.07

Runner Set 5: Tim White, HDPE “XH”

Load Weight

Speed

Average Pulling Force (lb)

Heavy

Slow

22.29

Heavy

Fast

26.83

Light

Slow

29.55

Light

Fast

28.14

Figure 3: Raw data collected during testing of runner samples 1, 2, and 5

Processed Data:

sledsliding4

Figure 4: Preliminary results for all testing configurations of samples 1, 2, and 5

Combined Results (Both Tests)

sledsliding5

Figure 5: Preliminary results for all testing configurations of all runner samples

Lubrication in sliding is also the subject of research in medicine. For example:

>It is becoming clear that, whether the gliding is cartilage on cartilage or tendon on tendon sheath, the basic biologic strategies are very similar. Specifically, the gliding surface in both cases contains a fixed lubricating glycoprotein, called lubricin,8,9 in addition to the high-molecular-weight glycoprotein, aggrecan, which tends to disperse the collagen fibrils and makes the surface structure more resistant to compression10,11 This type of lubrication, called boundary lubrication, is fundamentally different from the lubrication provided by an intervening fluid film, which is called hydrodynamic lubrication9,12-14 Indeed, it may be that the synovial fluid, comprised chiefly of hyaluronan, is more of a high viscosity nutrient delivery vehicle than a lubricant.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1370263/

Fireweed

Who does not like Fireweed?
So many names for the same plant. No wonder I did not connect the info from various sources in the past.
Rosebay, Willowherb, Bombweed and many more. Epilobium is the former Genus/name, Chamerion the newer Genus.

Fireweed Russ

Ivan-Chai/Tea (https://medicomo.ru/et/herbs/tea-with-ivan-tea-is-good-recipe-for-leek-with-lemon-juice-for-weight-loss/)

Fireweed (Chamerion angustifolium) is an often-overlooked herb with amazing medicinal properties. Traditional First Nations usage and modern pharmacology as well as clinical studies suggest its beneficial effects in a number of health concerns. Fireweed has been known to possess anti-inflammatory effects in addition to the recent evidence on its therapeutic effects for both benign prostatic hyperplasia (BPH), and prevention of prostate cancers.

This mini review provides some additional information obtained from First Nations healers, the empirical knowledge associated with clinical practice and aims to stimulate additional interest in the genus, and especially in the circumpolar species of Chamerion angustifolium.

The Cree call it Ihkapaskwa, and noted it
flowered when the moose were fattening and mating.
Other names include Askapask, Athkapask, and
Akapuskwah. The root was macerated and applied to
boils or infections. The leaves were plastered on
bruises. The raw roots were a popular native food
source. Even the summer stem was split open with the
thumbnail or between the teeth, to extract the inner
edible “pith”. It tastes a bit like cucumber but is very
sweet and can give a sugar buzz when needed. The
Kamtschadalis of eastern Russia boiled the plant with
fish and used the leaves as tea. The pith was scraped
out with shells, tied in bundles and sun-dried known
as Kipri, it was boiled into thick, sweet wort and used
to make Quaffe, a fermented drink of malted rye, flour
and wild mint. Six pounds of Kipri was mixed with
one pound of cow parsnip stalks and fermented for
vinegar.
The Woods Cree of Saskatchewan made a tea
of the whole plant for intestinal parasites. The root
can be crushed and applied to boils or abscesses, or to
draw out infection from open wounds.
The Ojibwa call it Zhoshkidjeebik or
Oja’cid’bik meaning slippery root, or soap root. They
would moisten and pound the root until it lathered up
and applied it as a poultice to bruises, boils, furuncles
and sores. An alternate name is Kegi’nano’kuk
meaning sharp pointed weed. The northern
Chipewyan call fireweed, Gon Dhi’ele meaning Fire
New Branch. Natives of Nunavut ate the tops of
Paunnait as summer food. The young stems are full of
sweet water and can be sucked out. Sophie Thomas, a
Sai’Kuz elder and herbalist, suggests drying the root
and then cooking it to treat asthma.   (https://phytomedicine.ejournals.ca/index.php/phytomedicine/article/viewFile/16/pdf_4)

A Growing Problem

What is the secret to the luxuriant growth of nursery plants despite such small pot with minimal soil and root ball?

It seems in most cases that nitrogen is otherwise a limiting factor. But not just any nitrogen. Proteins and their decomposition products, peptides and amino acids. The fungi and bacteria that decompose have probiotic and prebiotic effects for plants the same was with human and animal diets.

Commercial nurseries often use fish emulsion but perhaps for reasons of convenience and availability.

>Plants can’t make use of large molecules such as oils and proteins; see Organic Fertilizer – What is it’s Real Value? for more details. When these molecules are added to soil, microbes digest them and turn them into small molecules like nitrate, and phosphate. It is only then that plants can make use of these molecules.

Since the large molecules need to be degraded before plants can use them, there is little difference – to the plant – between proteins and oils from fish, cows (manure), or even plants. I have found no support for the claim that fish fertilizer is better than any other organic fertilizer.

The main thing plants need from fertilizer is a source of nitrogen. Garden soils usually have enough P and K and the other minor nutrients. Nitrogen is the thing that is missing in soils. Given this fact, fish fertilizer is no better or worse than other types of fertilizer. (https://www.gardenmyths.com/fish-fertilizer-worth-buying/)

A factoid worth investigating and testing among the comments section of the article: that adding lactic acid bacteria fermentation to the fish or othe stinky emulsions will degrade the noxious smell.

 

You Can’t Always Buy What You Want

“But if you try real hard you just might get what you need.”

You don’t always get what you pay for. USA health and health care indices are far behind Cuba despite spending far more per capita.
Adversity and necessity are the mothers of invention and imagination.
>Beginning in 1990, Raul Castro, brother of Fidel Castro, wanted to rescue the Cuban tradition of herbal medicine to provide natural medicines for its healthcare system. The immaculately maintained farm has grown from a modest four crops in its first year to a spectacular 45 crops in 2003; it has continued to grow with a small staff of only 45 workers and with no machinery. (By government mandate, only oxen are permitted for use in the fields.)
The major herbs grown for use by the ministry this season include oregano, calendula, Japanese mint, German chamomile, aloe vera, eucalyptus, banana leaves and turmeric.

The children were proud to show us their medicinal herbal garden.

The local school, Republica Oriental Del Uraguay, at Las Terrazas was vibrant and noisy as children poured out at the end of the day. Daniel Perez, the school principal, explained that his students are taught how to use plants for common problems as part of the school curriculum. The children were proud to show us their medicinal herbal garden. As part of the prevention theme, at-risk children, with problems such as obesity, receive counselling and encouragement from the school’s therapist to change cooking and eating habits at home.

http://www.positivehealth.com/article/herbal-medicine/cuba-s-green-revolution-natural-medicine-advances

From Birchbark to Chaga

chaga

Western red cedar’s known active principal compound, β-thujaplicin, has been studied in atopic dermatitis. White spruce’s known active principal compound, 7-hydroxymatairesinol, has anti-inflammatory activity, while phase II clinical trials have been completed on a birch bark emulsion for the treatment of actinic keratoses, epidermolysis bullosa, and the healing of split thickness graft donor sites. Balsam poplar has been used clinically as an anti-aging remedy. Black spruce bark contains higher amounts of the anti-oxidant trans-resveratrol than red wine. (https://www.ncbi.nlm.nih.gov/pubmed/28300445)

 

In summary our results contribute to the understanding of the molecular mechanism of the clinically proven wound healing effect of birch bark. Our results, together with the proven efficacy, identify birch bark as the first medical plant with a high potential to improve wound healing, a field which urgently needs effective remedies. Moreover, birch bark is a successful example that traditional medicinal plants can become rational drugs. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3899119/)

 

The Queen of Herbs

And herb of the Queen, Catherine de Medici.

Nice video (with music!) of growing then flowering Woodland Tobacco. The two species with fine jasmine smell are Nicotiana sylvestris and Nicotiana alata. Sylvestris/Woodland tobacco has many decorative garden cultivars/varieties with fancy colors. The white flowers variety are the original primitive plant ancestor to the smoking tobaccos and some others such as Nicotiana rustica, probably the species first introduced to Iberia where Jean Nicot, French ambassador to Portugal, encountered the plant ca. 450 years ago then popularized it as a medicinal poultice cure to treat skin cancer and ringworm and as snuff or chew for migraine headaches, sending some to Catherine de Medici, Queen of France, for her own headaches and/or those of Dauphin Francois II. With so much associated buzz Linnaeus named the genus Nicotiana.

Nicot tobacco

Image of Nicot presenting tobacco to Catherine de  Medici

http://tobaccopipeartistory.blogspot.com/2013/04/nicot-or-not-nicot-that-is-question.html

Macular Degeneration and BDNF

Alva2 eye

A new study from LSU Health Sciences Center found that one of the omega-3 fatty acids protects your retina from lethal injuries as they happen. But it does much more… Researchers found that docosahexaenoic acid (DHA) also protects your eyes from damage that may occur in the future. They said that DHA “preconditions” photoreceptor cells — special neurons in the retina — to survive future injuries.

It does the same thing for your retinal pigment epithelium (RPE) cells. The RPE nourishes your retina. It’s also the first line of defense against age-related macular degeneration (AMD), a major cause of blindness. In other words, DHA acts like a vaccine. It provides protection against a future injury to the retina or other parts of the eye. When rats were given DHA before oxidative stress struck, the DHA protected against the damage that usually would occur in the eye.

If you have ever been diagnosed with an eye condition such as macular degeneration or cataracts, the doctor might have told you: “All we can do is watch and track the disease’s progress. It will inevitably get worse, and there is no way to reverse or regenerate the deterioration.
> Researchers found that cells in the eyes—specifically retinal ganglion cells (RGCs), which are responsible for transmitting information from the eyes to the brain—are capable of regeneration, too. This is groundbreaking.

BDNF crucial to healing and regeneration of eyes.

We can reverse and heal damage due to traumatic injuries or degenerative diseases by boosting our BDNF levels. This is powerful information! Here’s how to do it:

Do aerobic exercise for at least 20 minutes per day.
Get 30 minutes of sunlight per day.
Try intermittent fasting. Fasting rests your digestive system and stimulates healing.
Consume omega-3 fatty acids.
Add pre-probiotic fiber to your diet. Gut bacteria converts prebiotics into butyrate, a substance that has been shown to increase BDNF.
Eat curcumin to enhance mood and cognition and improve BDNF production.
Eliminate sugar and processed foods.
Drink antioxidant-rich green tea.
Maintain a healthy weight.
Cultivate positive relationships.
Add resveratrol and other polyphenols to your diet for their neuroprotective properties.
Get good-quality sleep.
Reduce your stress levels. Irregular cortisol levels can disrupt BDNF production.
Add magnesium to your diet. It’s estimated more than 50 percent of Americans are deficient in this mineral.
Add zinc to your diet. This trace mineral has antidepressant qualities and can increase BDNF levels in the brain.

Add these foods with eye-healthy nutrients to your diet.

>Asparagus. It contains glutathione, known as the ‘master antioxidant’ of the body, which is especially important in the lens and macula of the eye. Asparagus also contains folic acid which has been shown to prevent or reduce age-related macular degeneration.
Avocados. I eat one avocado a day. It has Omega-9 oils which prevent optic nerve problems and support a healthy brain, eye, and body.
Carrots. The beta-carotene is really great for all the eye tissues.
Coconut oil. This is a great fat that protects the optic nerve and the macula. It also helps reduce inflammation in the body.
Cordyceps. This is a medicinal mushroom that helps improve the respiratory system and the kidneys
Corn. Of course, I’m talking about non-GMO corn. But the yellow and the orange parts of the corn contain lutein, which is an important carotenoid that helps protect our retinas.
Blueberries. These are high in antioxidants that protect microcapillaries of the retina. It also helps our night vision.
Goji berries. This is a superfood which contains amino acids that help protect the macula and overall retina.
Lime. This is another very important fruit that has high levels of flavonoids, which balance the pH level in the body. Limes are also loaded with antioxidants.
Pumpkin seeds. These seeds contain high amounts of zinc and are a good source of protein and trace minerals. This is one of my go-tos in terms of getting plant-based protein.
Strawberries. Last but not least, strawberries are excellent for the health of your macula and retina.    (https://www.mindbodygreen.com/articles/resorting-your-vision-with-diet-and-lifestyle-change)

(Note that the preceding recommendations are based on proxies such as BDNF and others listed, antioxidants, lutein, glutathione, etc.