on 16-Aug-2018 (Thu)

Osmotic diarrhoea The gut mucosa acts as a semipermeable membrane and fluid enters the bowel if there are large quantities of non- absorbed hypertonic substances in the lumen.

The volume of diarrhoea produced by these mechanisms is reduced by the absorption of fluid by the ileum and colon.

Cholera toxin binds to its receptor (monosialoganglioside G i ) via fimbria (toxin co-regulated pilus) on its β-subunit. This activates the a s subunit (of the Gs protein), which in turn dissociates and activates cyclic AMP (cAMP).

The increase in cAMP activates intermediates (e.g. protein kinase and Ca 2+ ) which then act on the apical membrane causing Cl − secretion (with water) and inhibition of Na + and Cl − absorption

Diaabetic, post-vagotomy and hyperthyroid diarrhoea are all due to abnormal motility of the upper gut. Symptoms may be exacerbated by small bowel bacterial overgrowth.

diarrhoea due to viral agents may also last 24–48 hours

Bile acid malabsorption is an underdiagnosed cause of chronic diarrhoea and many patients with this disorder are assumed to have irritable bowel syndrome.

Bile acid diarrhoea occurs when the terminal ileum fails to reabsorb bile acids. Bile acids (particularly the dihydroxy bile acids: deoxy- cholate and chenodeoxycholate) when present in increased concentrations in the colon lead to diarrhoea by reducing absorption of water and electrolytes and, at higher concen- trations, inducing secretion as well as increasing colonic motility

The Posterior Analytics is a text from Aristotle's Organon that deals with demonstration, definition, and scientific knowledge

De acordo com Aristóteles:
When the premises are certain, true, and primary, and the conclusion formally follows from them, this is demonstration, and produces scientific knowledge of a thing. Such syllogisms are called apodeictical. When the premises are not certain, such a syllogism is called dialectical. A syllogism which seems to be perfect both in matter and form, but which is not, is called sophistical.

Note: the structure is symmetrical in geometry not in mass.

Purgative abuse This is most commonly seen in females who surreptitiously take high-dose purgatives and are often extensively investi- gated for chronic diarrhoea. The diarrhoea is usually of high volume (> 1 L daily) and patients may have a low serum potassium. Biochemical analysis of the stool may help diag- nose laxative abuse. Management is difficult as most patients deny purgative ingestion. Purgative abuse often occurs in association with eating disorders and patients may need psychiatric help.

Chronic diarrhoea is a common symptom in HIV infection, but HIV’s role in the pathogenesis of diarrhoea is unclear. Cryptosporidium is the pathogen most commonly isolated. Isospora belli and microsporidia have also been found.

When we do Save As... , Gmsh saves a copy but does not switch to this newly created file, it keeps work- ing on the current file,

We can notice some instructions about what can be done in the context displayed at the top center of the main window.

The symmetry is defined by a vector, A, B, C being the 3 components (in X, Y, Z) of the vector normal to the plane and D the distance in space from the plane to the origin of the global axis, in short the 4 parameters of the plane equation in space

In Gmsh groups are called Physical

Code_Aster we must not use group names longer than 24 characters 1 .

To select multiple items at once, we push ctrl and draw a bound- ing box with the mouse, any entity having a bit of itself within the bounding box is selected.

Leave unchecked the box Save all (ignore physical groups) so as to save the groups created in the mesh

To finish with, pushing ctrl + L displays the ’Message Console’ which is a log, and appears at the bottom of the main window, and can be re-sized.

Code_Aster command files do not require any mandatory indent at all as long as we do not use conventional Python inside them, however a command must start at the beginning of a line without any indent. 2 Code_Aster is case sensitive: ’TRUE’, ’true’ and ’truE’ point to 3 different objects while ’True’ is a Python reserved word. And a concept can be named ’modele’, while ’MODELE’ is a Code_Aster reserved word. 3 More generally the .comm file follows the Python syntax. 4 The names created on the left hand side on the “=” sign.

In Code_Aster the MAILLAGE contains only the topology of the mesh and nothing else

the discrete element, ’massN’, is not assigned a material, this is not necessary, but Code_Aster does not complain if we assign one.

I strongly advise not to mix fixations and loads in a boundary condition set and to split the loads in as many elementary AFFE_CHAR_MECA as is logical.

Code_Aster cannot yet calculate with more than one distributed load on beam elements!

Viral and bacterial infective diarrhoeas do not last more than two weeks

This is a very annoying limitation. The work around is to replace it with an equivalent nodal force applied to the GROUP_NO=(’topbeam’,) which we have created earlier with DEFI_GROUP and which contains all the nodes of GROUP_MA=(’topbeam’,). This equivalent nodal force is the distributed load multiplied by the length of the beam elements 2 .

liste=DEFI_LIST_REEL ( DEBUT =2.0 , INTERVALLE=_F (JUSQU_A=6 ,PAS = 1 . 0 , ) , ) ; We must understand what is done just above. We perform the calcula- tion at five steps or instants, INST in the Code_Aster jargon, from 2 to 6, for every integer: • at INST 2, we have no load at all 2 ; 1 The word instant must be taken here with some restriction, it just only means step, it is not related to time (in time unit, seconds) but the same word, INST, is used by Code_Aster to specify the step in static analysis and a real instant, in seconds, in a dynamic analysis. 2 We start at 2 but we might have started at 0, -5 or 1.342! In linear static the choice is completely arbitrary and left to the user.

For now the concept stat contains only the displacement at nodes, as well as the forces at Gauss points, we must enhance it with some useful results on elements. Enhance! that’s why we use the keyword reuse, which is curiously written in lower case.

FORMAT_R=’1PE12.3’ prints the numbers with twelve characters, 3 digits after the decimal point and one digit to the left of the decimal point, for example −2.762E + 03 while FORMAT_R=’E12.3’ would print −0.276E + 04.

I reckon that checking the calculated mass with the estimates made oth- erwise is the prime test of the model validity. In structures made of beams this calls for an increased mass density of the materials so as to cope with all the unmodeled bits and pieces which contribute nonetheless to the loading of the structure by their own weight.

People with functional gastrointestinal disorders (FGID) are characterized by having a greater gastrointestinal motility response to life events than normal subjects.

Patients with Functional Gastro Intestinal Disorders have been shown to have abnormalities in visceral sensation and have a lower pain threshold when tested with balloon distension (visceral hyperalgesia).

A systematic review of published studies suggest that 10% of patients who experience an acute infective gastro- enteritis develop a degree of FGID

IBS co-exists with chronic fatigue syndrome, fibromyalgia and temperomandibular joint dysfunction.