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| == '''[[Diabesity]]''' ==
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| ''by [[User:Gareth Leng|Gareth Leng]], [[User:Hannah Frost|Hannah Frost]], [[User:Luke Kennedy Burke|Luke Kennedy Burke]], [[User:Charlie Player|Charlie Player]] and [[User:Katie Rowland|Katie Rowland]]
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| | | ==Footnotes== |
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| The term '''diabesity''' was coined by [https://vpn.ucsf.edu/oby/journal/v19/n3/full/,DanaInfo=www.nature.com+oby2010334a.html Ethan Sims] in 1973, to describe the close relationship between [[diabetes mellitus type 2]] (T2DM) and [[obesity]]. Their findings suggested that by overfeeding young men, with no previous family history of diabetes, the initial signs of diabetes were induced. This excess consuption led to increases in [[insulin]] production, plasma [[glucose]], [[triglycerides]] and eventually impaired glucose tolerance; all signs predisposing one to T2DM and obesity<ref>
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| Sims EAH ''et al.'' (1973) Endocrine and metabolic effects of experimental obesity in man, ''Recent Prog Horm Res'' 29:457–96</ref><ref>Haslam DW, James WP (2005) Obesity''Lancet'' 366:1197–209</ref>
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| T2DM is a disorder where cells fail to take up glucose from the blood. Glucose is the fuel for respiration which produces energy for our cells to function properly. Diabetes mellitus is the foremost cause of kidney failure ([[diabetic nephropathy]]), blindness ([[diabetic retinopathy]]), and amputation in adults ([[diabetic neuropathy]]). People with this disease lack the ability to utilize the hormone [[insulin]]. Insulin is produced by the [[pancreas]] after a meal inresponse to increased concentrations of glucose in the blood. The insulin signal attaches to specific receptors on the surface of target cells, causing them to switch on their glucose-transporting machinery. People with T2DM have normal or even elevated levels of insulin in their blood, and normal insulin receptors, but the binding of insulin to its receptors does not turn on the glucose-transporting machinery.
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| Proteins called [[IRS proteins]] (insulin receptor substrate) bind with the insulin receptor inside the cell. The receptor responds by adding a phosphate group onto the IRS molecules. This rouses the IRS molecules into action, and they activate a variety of processes, including an enzyme that turns on the glucose transporter machinery. When the IRS genes are deliberately inactivated in [[transgenic]] “knockout” mice, T2DM results. However, there are no IRS gene mutations in inherited T2DM; the IRS genes are normal. This suggests that in T2DM something is impeding with the action of the IRS proteins. An estimated 80% of those who develop T2DM are obese.
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| ==Visceral fat accumulation and type 2 diabetes== | |
| Excess visceral adipose tissue increases the risk for T2DM. Excess fat within the [[abdomen]], known as [[visceral adiposity]], creates a serious health risk of metabolic complications independent from accumulation of adipose tissue in other regions: visceral adiposity is related with an increase in ''[[insulin resistance]]'', whereas abdominal subcutaneous fat is not. (''Insulin resistance'' describes the impaired ability of insulin to suppress hepatic glucose output and promote glucose disposal in the periphery.) As T2DM gets worse, patients have higher blood sugar levels ([[hyperglycaemia]]) because the [[pancreatic beta cells]] are unable to make enough insulin. In insulin resistance, normal amounts of insulin are unable to produce a normal response from adipose, muscle and liver cells. Cnop ''et al.'' showed that visceral fat is the best predictor of insulin sensitivity whilst subcutaneous fat establishes leptin levels <ref>Cnop''et al.'' (2002) The concurrent accumalation of intra-adominal and subcutaneous fat explains the association between insulin resistance and plasma leptin concentrations. ''Diabetes'' 51:1005-15</ref>
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| In 1994, a new hormone was found, called [[leptin]], that provides feedback to the brain of the level of fat in the body. Leptin suppresses appetite, but most obese people have very high leptin levels, as leptin is secreted by adipose cells. Therefore, obesity is not generally caused by a deficiency in leptin; instead there seems to be a defect in leptin signalling. Adipocytes also produce an array of other peptides including [[adiponectin]], [[resistin]] and [[TNF alpha]]. They act on peripheral tissues and thereby affect insulin sensitivity and the processes involved in substrate metabolism.
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| ''[[Diabesity|.... (read more)]]''
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| ! style="text-align: center;" | [[Diabesity#References|notes]]
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After decades of failure to slow the rising global consumption of coal, oil and gas,[1] many countries have proceeded as of 2024 to reconsider nuclear power in order to lower the demand for fossil fuels.[2] Wind and solar power alone, without large-scale storage for these intermittent sources, are unlikely to meet the world's needs for reliable energy.[3][4][5] See Figures 1 and 2 on the magnitude of the world energy challenge.
Nuclear power plants that use nuclear reactors to create electricity could provide the abundant, zero-carbon, dispatchable[6] energy needed for a low-carbon future, but not by simply building more of what we already have. New innovative designs for nuclear reactors are needed to avoid the problems of the past.
(CC) Image: Geoff Russell Fig.1 Electricity consumption may soon double, mostly from coal-fired power plants in the developing world.
[7] Issues Confronting the Nuclear Industry
New reactor designers have sought to address issues that have prevented the acceptance of nuclear power, including safety, waste management, weapons proliferation, and cost. This article will summarize the questions that have been raised and the criteria that have been established for evaluating these designs. Answers to these questions will be provided by the designers of these reactors in the articles on their designs. Further debate will be provided in the Discussion and the Debate Guide pages of those articles.
- ↑ Global Energy Growth by Our World In Data
- ↑ Public figures who have reconsidered their stance on nuclear power are listed on the External Links tab of this article.
- ↑ Pumped storage is currently the most economical way to store electricity, but it requires a large reservoir on a nearby hill or in an abandoned mine. Li-ion battery systems at $500 per KWh are not practical for utility-scale storage. See Energy Storage for a summary of other alternatives.
- ↑ Utilities that include wind and solar power in their grid must have non-intermittent generating capacity (typically fossil fuels) to handle maximum demand for several days. They can save on fuel, but the cost of the plant is the same with or without intermittent sources.
- ↑ Mark Jacobson believes that long-distance transmission lines can provide an alternative to costly storage. See the bibliography for more on this proposal and the critique by Christopher Clack.
- ↑ "Load following" is the term used by utilities, and is important when there is a lot of wind and solar on the grid. Some reactors are not able to do this.
- ↑ Fig.1.3 in Devanney "Why Nuclear Power has been a Flop"
