By N. Thorek. Webb Institute. 2018.
It may be tempting but is inadvisable to attribute symptoms to normal aging phenomena erythromycin 500 mg line. In my experience cheap erythromycin 500mg with visa, disc degeneration is no more pathological than graying hair or wrinkling skin. In recent years there have been numerous reports in the medical literature of herniated discs in patients with no history of back pain. They were discovered inadvertently on CT or MRI studies done to investigate other parts of the body. In fairness to an objective evaluation of the problem, it should be noted that in one statistical study there was a higher incidence of back pain historically in people with evidence of disc abnormalities. I have tried to reconcile this with the clear observation that it is TMS and not disc pathology that causes the pain and can only conclude that in the mysterious process by which the brain chooses a site for TMS it selects an area of abnormality (like disc herniation) even though the anatomical aberration may not be pathological. One hundred and nine patients were interviewed by telephone by a research assistant. Their names were selected randomly from a large population of patients who were seen and treated from one to three years previously. In each case pain was attributed to a herniated disc that could be seen on CT scan. Based on history and physical examination, the diagnosis was TMS; all went through the usual treatment program. The results were as follows: Free, or nearly free of pain, unrestricted physical activity................................... Yet each of these patients had been told that this was the reason for the pain; thirty-nine had been advised to have surgery; three had already had such surgery; and most of the rest had been told that surgery might be necessary if conservative measures failed. The patient was a twenty-five- year-old man with a history of low back and right leg pain; he had had a lumbar myelogram showing a herniated disc two months before I saw him in consultation. He was advised to stop all physical activity and surgery was recommended, both appropriate recommendations if the disc was the cause of the pain. A dedicated athlete (basketball and squash were his favorites), he was devastated by the diagnosis.
Prepare prompt cards What do you take in with you in the form of notes to your presentation? If all you do is read directly from a prepared script cheap 250 mg erythromycin amex, there will be no effective communication with your audience buy erythromycin 250mg amex. You might as well have distributed a photocopy of your talk and asked the audience to sit and read it. Reading also removes any opportunity for eye contact, for judging how the presentation is being received, or for spontaneity. They serve partly as an aide memoire and partly as a means of reducing the anxiety of drying up. Check out the venue and equipment Arrive at the venue early enough to check out the room size and layout, the location of light switches and the equipment you are intending to use. If you have opted for a PowerPoint presentation, check that the system is compatible with your computer/floppy. Be sure you know how to operate the equipment – slide projector/OHP controls, laser pointers, lectern layout, video recorders, etc. The audience will be irritated if you are apparently experimenting with your equipment at the start of your presentation. Content Say what you’re going to say; say it; then say what you’ve said All presentations should have a beginning, a middle, and an end. First, you describe the purpose of the talk and the key areas you will be considering. This should cover: • why the work was done • how it was done • what was found • what it means. Put your talk in context It is often erroneously assumed that an audience understands the context of a presentation. Although this example may seem a little unusual, there is much documented evidence in educational research showing that learners are often not able to relate new knowledge to whatever they already know about a certain subject.
Metaphors Metaphor is the projection of a conceptual structure from a source domain discount erythromycin 500 mg without a prescription, relatively literally understood generic 500mg erythromycin otc, onto a target domain which is then partly understood in terms familiar from the source domain. Basic categories and their central prototypes as well as image schemas for organizing our primary and central existential situation and affects are pyramided into higher level, more abstract concepts and metaphors. For example, the position image schemas Front/Back and Ahead/Behind were outlined earlier. Numerous metaphors facilitating our understanding in varied realms of experience such as time, attitude and success or failure map them onto the position schemas of Front/Back and Ahead/Behind. Each of these examples uses the literal and concrete cognitive structure of position to enable comprehension of something else. The word comprehension itself illustrates the historic pervasiveness of cognitive metaphor, cognizing understanding in terms of getting a grip. The informal reasoning used for construing and solving means/ends problems is based on several alternative metaphorical understandings of causation. The metaphorical comprehension of event structure, however, precedes the attribution and structuring of causation. Lakoff and Johnson include "events, causes, changes, states, actions and purposes" in the group of event structure concepts. The "state" is simply the status quo ante of whatever affairs are considered affected. An example is "Her memory" as in "Her memory worsened after the coronary artery bypass. What is selected to be referred to as the initial state depends entirely on what slice of the entire space-time COGNITIVE SEMANTIC STRUCTURES 23 continuum is to be highlighted, in a particular instance, as an "event. So an initial "state" is selected to be considered, certain changes for a certain duration are considered, and an outcome is identified as the final "state. Multiple possible states are amalgamated into two, and multiple, conceivably separable events are treated as one in this example. However, the metaphors are not arbitrary or radically relative to history and culture. They have latitude, but it is limited by their grounding in universal bodily experience.
Because mortality rate increases species that have been studied purchase erythromycin 250mg otc, including ﬂies purchase erythromycin 250 mg mastercard, nematodes, exponentially with age, these effects are more easily and rodents, increases exponentially with time, ﬁrst understood by subjecting the rate data to a logarithmic observed in humans by Benjamin Gompertz after observ- transform. After such a transform, log (mortality rate) ing actuarial statistics and reported in 1825. Normal and enhanced envi- pertz equation can be stated succinctly as Rm(t) =-(1/n) ronment groups have similar slopes. If anything, the dn/dt = R e(at), where Rm(t) is the mortality rate at time enhanced environment group may exhibit a slightly * 0 or age t, n = the number of survivors at time t, R0 is the higher slope because the intercept is lower, whereas mortality rate at time t = 0, interpreted as a vulnerability genotype and dietary restriction can actually decrease the factor depending on the hostility of the environment, slope of this transform. This When the rate of mortality becomes high enough, an equation can be linearized by log transform into arbitrarily small number of individuals will be left alive lnRm(t) = ln(R0) + at. In practice, maximum The intercept of this line is generally dependent on the life span is determined empirically, and in humans is gen- hostility of the environment, whereas the slope is depend- erally assumed to be around 125 years (for women; some- ent on the genetic background of the population, for what lower for men). Normal, standard population dynamics; enhanced environment, dynamic pattern as might be observed by idealized optimization of environ- ment, leading to "rectangularization" of the survival curve; enhanced genotype or dietary restriction, dynamic pattern observed by single gene mutations that extend maximum life span (such as AGE-1) or by dietary restriction regimens that extend maximum life span. Depicted in this way, rate of mortal- ity increases exponentially with age (Gompertz function). Note that rectangularization of the mor- tality curve may decrease initial rate of mortality but does not necessarily increase maximum life span and may indeed lead to increased mortality rate during the late period of life, whereas genetic or dietary enhancement of maximal life span is expected to entail decreased rate of mortality but not necessarily a decreased initial mortality rate. In humans, the generally population of heterologous individuals in this phenome- accepted range of applicability is between ages 20 and 80 non has yet to be determined. A particularly interesting recent development is evidence in both humans and other species29,30 that the Pathology Versus Senescence slope of the linearized Gompertz equation (that is, the increase in the rate of mortality, or the second derivative The Gompertz equation applies not only to mortality but of survival) begins to decrease at very old ages, and also to diseases and may be used to resolve a major and possibly the rate of mortality becomes constant (e. These remarkable results have profound ogy, or disease, and what is commonly (although, as we implications for our view of the process of senescence, have seen, unrigorously) called normal aging? This dis- because senescence necessarily entails an increased rate tinction is not merely semantic but addresses fundamen- of mortality with age. The role of selection from within a cases in a population of that age; rate equations such as 20 C. Mobbs 35 the Gompertz curve only describe incidence, and thus the population as a whole peaks around age 70. Because incidence is the most informative from a mechanistic twin studies have indicated that genotype makes little point of view.