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By W. Lisk. Gardner-Webb University. 2018.

The circular cylinder shown in the figure is in neutral equilib- rium because disturbance from equilibrium position in the horizontal plane does not bring out new forces generic cialis black 800 mg online. If on the other hand the elliptical cylinder is tilted a little generic 800 mg cialis black amex, the new contact force that arises will rotate it back to its equilibrium configuration buy cheap cialis black 800 mg on line. The top row (a) pre- sents examples of unstable (U) buy cialis black 800 mg cheap, neutral (N) cheap 800 mg cialis black overnight delivery, and stable (S) equilibrium of rigid ob- jects. The middle row (b) classifies the various configurations of a rod under sta- tic equilibrium. The bottom row (c) illustrates that for nonrigid structures static equilibrium does not neccessarily correspond to the configuration where the cen- ter of gravity is at a minimum height. The height d of the center of mass of the rod for the configurations from left to right are given by the equations: d 5 L sin 30° cos 30° d 5 (L/2) sin 60° d 5 (L/2) sin 30° The configuration on the far right corresponds to the smallest value of d and is, therefore, in stable equilibrium. For structures other than a rigid body, stable equilibrium does not necessarily correspond to the configu- ration that brings the center of gravity to minimum height. Consider, for example, the structure composed of two flat plates and a spring (Fig. The plates are hinged at one edge and are also connected by a spring at midlength. The free ends of the plates are free to slide on the flat surface shown in the figure. If the gravitational force and the react- ing contact force were the only external loads acting on the structure, sta- ble equilibrium would have corresponded to the configuration where the two plates lay flat on the horizontal plane. In that configuration, how- ever, the spring would have been stretched drastically and therefore could snap with the smallest of the disturbance. How do we determine which configuration corresponds to static equilibrium in this case? The answer to the question is that the potential energy of the structure is minimum at stable equilibrium. The potential energy V for this structure is given by the relation: V 5 mg (L/2) sin u 1 mg (L/2) sin u 1 (k/2) d2 (5. The last term is the energy stored into the spring as a result of its stretch, with d denoting the extension of the length of the spring. It is a measure of the strength of the spring force relative to the force of gravity. Solution of this algebraic equation corresponds to minimum potential energy when the second derivative of V with respect to u (d 2 V/d2u) is positive. Note that for very stiff springs the angle u that corresponds to stable equilibrium will be slightly less than 60°. Statics the spring stiffness is decreased toward zero, the structure will flatten at static equilibrium, with u reducing toward zero. Although the structure discussed here does not look anything like the human body or any part of the body, there are resemblances. Muscle–tendon complexes of the hu- man body store energy like the spring of the two-rod structure. When a calf muscle goes into contraction, the stable equilibrium of the leg will be much different than when the muscle is relaxed and therefore has much less stiffness. The reader might have experienced a muscle spasm and how it can distort the resting configuration of a leg. In the human shoulder, the glenoid fossa region of the scapula supports the humerus of the up- per arm much like the nose of a seal balancing a ball (Fig. Be- cause the humerus is not uniform, it is much more difficult to keep it balanced. Solution: Consider a uniform rod of length L and mass m that is in un- stable equilibrium (Fig. Let us apply a small perturbation to the bar in the form of a horizontal force df. Because the rod will tend to move in the direction of the unbalanced force, the rough substrate on which the rod is resting will exert a frictional force in the direction opposite to df. Both the perturbation force df and the frictional force f will produce coun- terclockwise moment with respect to the center of the rod.

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When this form of power remains invisible to couples cialis black 800 mg fast delivery, its effects can be insidious (Foucault cheap 800mg cialis black with visa, 1979; White discount 800mg cialis black amex, 1991) buy 800mg cialis black visa. Narrative therapists listen for oppressive (often invisible) discourses that influence a couple’s relationship proven cialis black 800mg. Once identified, therapeutic inquiry de- constructs the assumptions and beliefs that support the taken-for-granted Narrative Therapy with Couples: Promoting Liberation 173 status of the discourse. When an oppressive discourse is made visible, cou- ples are invited to renegotiate their position within that discourse or to choose an alternate discourse that is less restrictive. By refusing to comply with a marginalizing discourse, couples are challenging the status quo and promoting social justice in the larger community. Anorexia had successfully recruited Suzanne into self-subjugating practices of self-starvation, excessive exercise, rigid rules regarding eating, and continual practices of measuring up. The meaning she has constructed of the events in her life is that she is a "mess," unable to handle the stres- sors in her life and "codependent. By unveiling the tricks Anorexia uses and the cultural discourses that keep it alive, Suzanne and Pete are able to join forces in reclaiming their relationship from the problem’s grip. Suzanne enlists Pete’s support in resisting Anorexia’s attempts to under- mine her efforts, and as a result, she is no longer silenced by Secrecy and Shame. In the following, Pete and Suzanne are invited to consider the socio- cultural influences that have supported Anorexia: "Suzanne, how do you think Anorexia gets women to participate in self- shrinkage and diminishment? How do we challenge practices that position us as "agents of social control" (Foucault, 1979)? Narrative thera- pists turn a critical eye on practices that might inadvertently maintain dominant ideologies by supporting certain groups over others (Freed- man & Combs, 1996; Madigan, 1993). Although it is not possible to com- pletely flatten the hierarchy inherent in the therapeutic relationship, we remain vigilant about using our power in support of client agency and empowerment. Whether we are talking about a couple, two religious groups, or two nations, narrative practice is inter- ested in how people handle the process of differing. Do conversations around difference create space for many perspectives, or do they quiet the voices that stand outside the dominant view? How do cultural discourses influence the ways in which a couple handles day-to-day dilemmas? Western society privileges productivity and gives power to individuals and groups based on binary positions; educated/uneducated, rich/poor, white/person of color, heterosexual/gay, thin/large, young/old, able- bodied/disabled (Cushman, 1995). Dominant and privileged groups de- velop exaggerated entitlements that lead to abuses of power and the ongo- ing oppression of less-dominant groups (Winslade & Monk, 2001). Narrative therapists challenge discourses related to race, class, gender, sexual orientation, age, and mental and physical ability. The following ex- amples illustrate the deconstruction of any oppressive discourse. GENDER A culture that gives men resources to succeed in a capitalist society may have the effect of objectifying women in relationships. Through this lens, questions would aim to make the effects of this structure visible for cou- ples to evaluate: "I am wondering what society has taught you about ‘being a man’ in re- lationship to women. Narrative therapists Narrative Therapy with Couples: Promoting Liberation 175 also explore the effects of power relations between themselves and the cou- ple, and may reflect on the following questions: "Does the therapy room create enough room for women’s voices? As far back as the Elizabethan Poor Laws, one’s status in society was commensurate with one’s ability to work and produce. Not only do ideas of Productivity and Worth continue to impact modern day couple re- lationships, but they also impact the therapist’s relationship with the cou- ple. Are couples that are marginalized by discourses of class able to choose a direction for themselves, or is the path largely being chosen for them? The following question invites the couple to consider the impact of class on the therapeutic relationship: "I’m wondering how I might be alerted to the possibility that our class differences could be affecting our therapy conversations? For example, bell hooks (2000) examines cultural discourses re- lated to the concept of love. Media and culture support notions of romantic love and the as- sumption that love is a feeling. When lived experiences don’t fit the result- ing norms and expectations, couples conclude (or are told) that something in them, or in their relationship, is "dysfunctional": "Instead of defining Love as a feeling, what difference would it make if Love were something that was demonstrated through acts of Care, Re- sponsibility, Respect, and Commitment? It is less interested in supporting the rightness of any theory and more interested in remaining open to new ideas and possibilities that can lead to more meaningful change in the lives of couples.

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Prostate- specific antigen: a surrogate endpoint for screening new agents against prostate cancer? Only three of them actually com m itted a m urder; the other seven are innocent of any crim e cheap cialis black 800mg. These five features constitute discount 800 mg cialis black visa, respectively discount cialis black 800mg on-line, the sensitivity purchase cialis black 800mg fast delivery, specificity discount 800 mg cialis black with mastercard, positive predictive value, negative predictive value, and accuracy of this jury’s perform ance. The rest of this chapter considers these five features applied to diagnostic (or screening) tests when com pared with a "true" diagnosis or gold standard. By then, you should be able to work out that the likelihood ratio of a positive jury verdict in the above exam ple is 1. If you can’t, don’t worry – m any em inent clinicians have no idea what a likelihood ratio is. The nurse in his general practitioner’s surgery had asked him to produce a urine specim en and dipped a special stick in it. The stick stayed green, which m eant, apparently, that there was no sugar (glucose) in his urine. I had trouble explaining to the window-cleaner that the test result did not necessarily m ean this at all, any m ore than a guilty verdict necessarily m akes som eone a m urderer. The definition of diabetes, according to the W orld H ealth Organisation, is a blood glucose level above 7 m m ol/l in the fasting state, or above 11. These values m ust be achieved on two separate 106 PAPERS TH AT REPORT D IAG N OSTIC OR SCREEN IN G TESTS occasions if the person has no sym ptom s, but on only one occasion if they have typical sym ptom s of diabetes (thirst, passing large am ounts of urine, and so on). These stringent criteria can be term ed the gold standard for diagnosing diabetes. In other words, if you fulfil the W H O criteria you can call yourself diabetic and if you don’t, you can’t (although note that experts rightly challenge categorical statem ents such as this and indeed, since the first edition of this book was published the cutoff values in the gold standard test for diabetes using blood glucose levels have all changed1). For one thing, you m ight be a true diabetic but have a high renal threshold; that is, your kidneys conserve glucose m uch better than m ost people’s, so your blood glucose level would have to be m uch higher than m ost people’s for any glucose to appear in your urine. Alternatively, you m ay be an otherwise norm al individual with a low renal threshold, so glucose leaks into your urine even when there isn’t any excess in your blood. In fact, as anyone with diabetes will tell you, diabetes is very often associated with a negative test for urine glucose. There are, however, m any advantages in using a urine dipstick rather than the full blown glucose tolerance test to "screen" people for diabetes. The test is cheap, convenient, easy to perform and interpret, acceptable to patients, and gives an instant yes/no result. In real life, people like m y window-cleaner m ay decline to take an oral glucose tolerance test. Even if he was prepared to go ahead with it, his general practitioner m ight decide that the window-cleaner’s sym ptom s did not m erit the expense of this relatively sophisticated investigation. I hope you can see that even though the urine test cannot say for sure if som eone is diabetic, it has a definite practical edge over the gold standard. Specificity True negative rate H ow good is this d/b+d (negative in health) test at correctly excluding people without the condition? Positive predictive Post-test probability If a person tests a/a+b value of a positive test positive, what is the probability that (s)he has the condition? N egative predictive Indicates the post- If a person tests d/c+d value test probability of a negative, what is the negative test* probability that (s)he does not have the condition? Accuracy W hat proportion of (a+d)/(a+b+c+d) all tests have given the correct result (i. Likelihood ratio H ow m uch m ore Sensitivity/ of a positive test likely is a positive (1- specificity) test to be found in a person with, as opposed to without, the condition? W e could then see, for each person, whether the result of the screening test m atched the gold standard. W e could express the results of the validation study in a 2 x 2 table (also known as a 2 x 2 m atrix) as in Table 7. If the values for the various features of a test (such as sensitivity and specificity) fell within reasonable lim its, we would be able to say that the test was valid (see question 7 below). The validity of urine testing for glucose in diagnosing diabetes has been looked at by Andersson and colleagues,2 whose data I have used in the exam ple in Table 7. In fact, the original study was perform ed on 3268 subjects, of whom 67 either refused to produce a specim en or, for som e other reason, were not adequately tested. For sim plicity’s sake, I have ignored these irregularities and expressed the results in term s of a denom inator (total num ber tested) of 1000 subjects. If the validation had been the m ain aim of the study, the subjects selected would have included far m ore diabetic individuals, as question 2 in section 7.

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The Lie/Bet questionnaire81 may be a useful more cheap 800 mg cialis black with mastercard, alcoholism increases the older patient’s risk of screening tool purchase cialis black 800mg on-line. Problem Screening measure Positive screen Vision Two parts: Yes to question and inability to read greater Ask: "Do you have difficulty driving or watching television cheap 800mg cialis black mastercard, or than 20/40 on Snellen chart reading buy 800mg cialis black free shipping, or doing any of your daily activities because of your eyesight? If yes discount 800 mg cialis black, then: Test each eye with Snellen chart while patient wears corrective lenses (if applicable) Hearing Use audioscope set at 40 dB Inability to hear 1000 or 2000 Hz in both ears or Test hearing using 1000 and 2000 Hz either of these frequencies in one ear Leg mobility Time the patient after asking: "Rise from the chair; walk 20 feet Unable to complete task in 15 s briskly, turn, walk back to the chair, and sit down" Urinary incontinence Two parts: Yes to both questions Ask: "In the last year, have you ever lost your urine and gotten wet? Nutrition/weight loss Two parts: Yes to the question or weight <100 lb Ask: "Have you lost 10 lb over the past 6 months without trying to do so? Preferences for Care Functional Status Although not classically part of the history, before dis- cussing end-of-life decision making and advance direc- Data support the validity of self-reported physical func- tives, it is wise to take a values history: the patient’s tional status. The patient should be asked screening ques- beliefs about technologic interventions to prolong life, tions about independence and self-care—ability to get 82,83 what defines life quality for the patient as an individual, out of bed, dress, shop, and cook. Any reported or and with what decrements the patient would still think observed difficulty should provoke more elaborate ques- life were worth living. Documenting discussions, execut- tions concerning dependence in activities of daily liv- ing a living will, and designating a proxy decision maker ing (ADLs: mobility, bathing, transferring, toileting, 84 and durable power of attorney for health care are part continence, dressing, hygiene, and feeding ) and in of this process of helping the patient have a voice in instrumental activities of daily living (IADLs: shopping, decisions that may need to be made when the patient, cooking, cleaning, managing money, telephoning, laundry, 86 28 by reason of illness, cannot participate. Questions should also be asked about vision, hearing, continence, and depression; deficits should be followed up. A brief screening instrument 85 Physical Examination for common impairments, administered by trained non- medical personnel, was found to be inexpensive and General appearance of the older patient should include clinically useful (i. Beyond age 60, these signs do not identify neglect, or poverty; hygiene and grooming) deserve increased risk. Merely observing how long it takes for the Visual acuity and hearing screening are necessary, patient to get ready for examination and the extent and given the high prevalence of impaired vision and audi- nature of help that may be required remains a useful and tory acuity among older persons. Hypothermia is visual impairment was found predictive of mortality in 10 more common, and reliable low-reading thermometers years, whereas combined impairment confers the highest are essential, especially for emergency room and winter- risk of 10-year functional dependence. Blood pressure should be taken in the supine situations, a pocket Snellen chart, held 14 in. Orthostatic hypotension, defined as pered voice is as sensitive as an audioscope for detection either 20 mmHg drop in systolic pressure or any drop of hearing loss,95,96 but the latter is, to date, the best objec- accompanied by typical symptoms, occurs in 11% to 28% tive measurement of hearing and more accurate at fol- of individuals older than 65 years. Inspecting the ear canals and blood loss, postural hypotension is a fairly specific but drums using an otoscope is especially necessary if hear- poorly sensitive sign of hypovolemia. Al- widely recommended in the past, is not reliable in older though on the decline, oral cancers are most common people. Specific assessment of general or local- than for ipsilateral stroke, and may cease unpredictably. Fat diminished, making breast tissue and the Skin undergoes many changes with age, including tumors that arise from it more easily palpable. Wrinkl- screening mammograms annually or every other year ing is more powerfully predicted by sun exposure and should be continued lifelong or until a decision is reached cigarette smoking than by age. Most proliferative le- that a discovered cancer would not be treated100; age- sions, benign and malignant, are related to sun ex- specific breast cancer incidence increases at least until posure; accordingly, basal and squamous cell cancers and age 85, and no evidence indicates that treatment is not melanomas should be most aggressively hunted on effective in older women. Because of skin aging, turgor is not a for breast cancer screening suggest yearly mammography reliable sign of hydration status. All skin should be until age 69, but there has been much discussion about examined, exposed to sun or not, for evidence of estab- revising the age to 74, 79, or removing an upper age limit lished or incipient (nonblanching redness) pressure entirely. Ecchymoses should also be noted, whether due to part of the Medicare benefit, and age cutoffs or stopping purpura of thin old skin or trauma; the possibility of screening on the basis of age alone is controversial (see abuse should be considered. Routine screening mammo- Head and neck examination begins with careful obser- grams should be continued with the understanding vation of sun-exposed areas for premalignant and malig- that the patient and/or family are aware that an abnor- nant lesions (as above). Palpation of temporal arteries for mal result will provoke more aggressive evaluation. Musculoskeletal examination, often a source of abun- Cardiac examination has several special features in dant complaints and pathology in older adults, begins aged patients. In the absence of complaints or common at baseline without symptoms or ominous prog- loss of function, brief tests of function are adequate to nosis. For upper extremity, 4 free of cardiac disease, S3 is associated with congestive "Touch the back of your head with your hands" and "Pick heart failure. The ubiquitous systolic ejection murmur is up the spoon" are sensitive and specific.

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