Y. Jose. Kansas Newman College.
This makes the mean the best score to use when predicting any individual score order prednisolone 20 mg online, because the total error across all such estimates will equal zero purchase 5 mg prednisolone with visa. In graphing the results of an experiment cheap prednisolone 10mg with visa, the independent variable is plotted on the X axis and the dependent variable on the Y axis cheap 40 mg prednisolone mastercard. A line graph is created when the in- dependent variable is measured using a ratio or an interval scale. A bar graph is cre- ated when the independent variable is measured using a nominal or an ordinal scale. On a graph, if the summary data points form a line that is not horizontal, then the individual Y scores change as a function of changes in the X scores, and a relation- ship is present. If the data points form a horizontal line, then the Y scores do not change as a function of changes in the X scores, and a relationship is not present. A random sample mean 1X2 is the best estimate of the corresponding population’s mean 1 2. The X in each condition of an experiment is the best estimate of the that would be found if the population was tested under that condition. We conclude that a relationship in the population is present when we infer different values of , implying different distributions of dependent scores, for two or more conditions of the independent variable. What two pieces of information about the location of a score does a deviation score convey? Why do we use the mean of a sample to predict any score that might be found in that sample? You misplaced two of the scores in a sample, but you have the data indicated be- low. On a normal distribution of scores, four participants obtained the following deviation scores: 25, 0, 13, and 11. In a normal distribution of scores, five participants obtained the following devi- ation scores: 11, 22, 15, and 210. You hear that a line graph of data from the Grumpy Emotionality Test slants downward as a function of increases in the amount of sunlight present on the day participants were tested. You conduct a study to determine the impact that varying the amount of noise in an office has on worker productivity. Condition 1: Condition 2: Condition 3: Low Noise Medium Noise Loud Noise 15 13 12 19 11 9 13 14 7 13 10 8 (a) Assuming that productivity scores are normally distributed ratio scores, com- pute the summaries of this experiment. When graphing the results of an experiment: (a) Which variable is plotted on the X axis? Foofy conducts an experiment in which participants are given 1, 2, 3, 4, 5, or 6 hours of training on a new computer statistics program. She summarizes her results by computing that the mean number of training hours per participant is 3. For each of the experiments below, determine (1) which variable should be plotted on the Y axis and which on the X axis, (2) whether the researcher should use a line graph or a bar graph to present the data, and (3) how she should summarize scores on the dependent variable: (a) a study of income as a function of age; (b) a study of politicians’ positive votes on environmental issues as a function of the presence or absence of a wildlife refuge in their political district; (c) a study of running speed as a function of carbohydrates consumed; (d) a study of rates of alcohol abuse as a function of ethnic group. Using independent and dependent: In an experiment, the characteristics of the ___________ variable determine the measure of central tendency to compute, and the characteristics of the ___________ variable determine the type of graph to produce. If N is an odd number, the score in ΣX X 5 the middle position is roughly the median. The formula for a score’s deviation is X 2 X the middle positions is roughly the median. So far you’ve learned that applying descriptive statistics involves considering the shape of the frequency distribution formed by the scores and then computing the appropriate measure of central tendency. This information simplifies the distribution and allows you to envision its general properties. But not everyone will behave in the same way, and so there may be many, very dif- ferent scores. Therefore, to have a complete description of any set of data, you must also answer the question “Are there large differences or small differences among the scores? The following sections discuss (1) the concept of variability, (2) how to compute statistics that describe variability, and (3) how to use these statistics in research. Thus, to find ΣX2 for the scores 2, 2, and 3, we have 22 1 22 1 32, which becomes 4 1 4 1 9, which equals 17. We have a similar looking operation called the squared sum of X that is symbolized by 1ΣX22.
The unique affinities of various antipsychotics result in their unique activities and their unique side effects purchase prednisolone 10mg with visa. Phenytoin and carbamazepine can be used in partial seizures or in tonic-clonic seizures order prednisolone 20 mg online. Gingival hyperplasia is a unique side effect of phenytoin discount 40mg prednisolone free shipping, which can be partially avoided by meticulous oral hygiene cheap 40mg prednisolone with visa. Aplastic anemia is a rare, but a potential complication of carbamaze- pine, ethosuximide. Ethosuximide has been associated with a severe form of erythema multiforme, the Steven-Johnson syndrome. Tiagabine is an anticonvulsant used in conjunction with drugs such as pheny- toin. Gabapentin is approved for the treatment of diabetic nephropathy, an unfortunate consequence in this patient’s presentation. Acetazolamide, sometimes used as a treat- ment for absence seizure control, is used in the treatment of glaucoma. Salicylate toxicity initially increases the medullary response to carbon dioxide, with resulting hyperventilation and respiratory alkalosis. Increases in lactic acid and ketone body formation result in a metabolic acidosis. Treatment includes correction of acid–base disturbances, replacement of electrolytes and fluids, cooling, alkalinization of urine, and forced diuresis. From the presented list, only methotrexate is known to be an antineoplastic agent. This medication has been used successfully in rheumatoid arthritis and other rheumato- logic conditions. Probenecid and sulfin- pyrazone reduce urate levels by preventing reabsorption of uric acid. Allopurinol is a xanthine oxidase inhibitor; it is also used for treatment of chronic gout. Cyclophosphamide has been successfully used for treatment of lupus nephri- tis; however, it does carry significant morbidity associated with its use. Deferoxamine is an iron-chelating agent and as such can be given in cases of iron supplement overdose. Diazepam and lorazepam are very effective at treating the vertigo associated with Meniere disease. Loop diuretics, such as furosemide, can precipitate vertigo secondary to volume depletion and resultant orthostatic hypotension. Both omeprazole and lansoprazole are proton inhibitors that would not increase the protective mucus and bicarbonate. Nizatidine is an H2-blocker that would also do nothing to increase the production of protective prostaglandins. Pepto Bismol, clarithromycin and amoxicillin, and omeprazole can be used for 7 days to eradicate Helicobacter pylori associated with peptic ulcer disease (metronidazole and tetracycline are additional choices for antibiotics). Regimens containing clarithromycin are used for cases of resistance to metronidazole. Psyllium and methylcellulose are bulk-forming agents good for chronic constipation. Salt-containing osmotic agents such as magnesium sulfate are good for acute evacuation of the bowels. Loperamide would be a good choice in this patient as it effectively controls diarrhea. Both codeine and diphenoxylate are opioids with abuse potential, especially in patients with abusive histories. Diphenoxylate is available in combination with atropine to reduce the potential for abuse. Anticholinergic agents such as propantheline prevent cramping but have little effect on diarrhea. Octreotide is used for diarrhea secondary to increased release of gastrointesti- nal hormones. Bismuth subsalicylate and loperamide can be used in the treatment of uncompli- cated diarrhea.
Care must also be taken in choosing the inspired tidal volume in volume-cycled ventilatory modes as high inspired tidal volumes can contrib- ute to development of acute lung injury due to overdistention of alveoli cheap prednisolone 20mg amex. Because these conditions are characterized by expiratory ﬂow limitation discount prednisolone 20 mg amex, a long expiratory time is re- quired to allow a full exhalation 10 mg prednisolone visa. However buy discount prednisolone 20mg on-line, because breath sounds are heard bilaterally, pneumo- thorax is less likely, and tube thoracostomy is not indicated at this time. A ﬂuid bolus may temporarily increase the blood pressure but would not eliminate the underlying cause of the hypotension. Sedation can be accomplished with a combination of benzodiazepines and narcotics or propofol. Initiation of vasopressor support is not indi- cated, unless other measures fail to treat the hypotension and it is suspected that sepsis is the cause of hypotension. It should be stressed that there are two compo- nents to diagnosis: symptoms of daytime sleepiness combined with obstructive breathing while asleep. The central pathogenesis of sleep apnea is pharyngeal narrowing that leads to airway obstruction when somnolent. Insulin resistance has been shown to be related to increasing frequency of apneas and hypopneas. These patients are in a hyperadrenergic state characterized by hypertension, tachycardia, tonic-clonic seizures, dyspnea and ventricular arrhythmias. There is concern with giving beta-blockers in patients with cocaine-induced chest pain or myocar- dial ischemia because of the potential for unopposed alpha activity provoking coronary vasospasm. Calcium channel blockers are often used in patients with cocaine intoxication and potential coronary ischemia to avoid this effect. Hy- dralazine may manage the hypertension but would have no effect on the ventricular arrhythmia and might cause a reﬂex tachycardia. Cardioversion is not indicated for this patient who is in nonsustained ventricular tachycardia. Norepinephrine would be contraindicated as it would exacerbate the hyperadrenergic state. In addition, 67 to 75% of patients with idiopathic pulmonary ﬁbrosis also have a history of ciga- rette use. The clinical presentation and radiogram are consistent with farmer’s lung, a hypersensitivity pneumonitis caused by Actinomyces. In this disorder moldy hay with spores of actinomycetes are inhaled and produce a hypersensitivity pneumonitis. Patients present generally 4 to 8 h after exposure with fever, cough, and shortness of breath with- out wheezing. The exposure history will differentiate this disorder from other types of pneumonia. Pathology shows the presence of granulation tissue plugging airways, alveolar ducts, and alveoli. Azathioprine is an immunosuppressive therapy that is commonly used in interstitial lung disease due to usual interstitial pneumonitis. Hydroxychloroquine is frequently useful for joint symptoms in autoim- mune disorders. In this setting, the alveolar-arterial (A – a) oxygen gradient will be normal but the minute ventilation is low, producing a respiratory acidosis. Diaphragmatic dysfunction and maximal inspiratory or expiratory pressures are commonly impaired with respiratory neuromuscular dysfunction but may be normal in other disorders of central hypoventilation such as stroke. The physical abnormalities caused by the forward and lateral curvature of the spine result in abnormal pulmonary mechanics. This is man- ifested primarily as restrictive lung disease with chronic alveolar hypoventilation. This in turn leads to ventilation-perfusion imbalances that result in hypoxic vasoconstriction and may cause the eventual development of pulmonary hypertension.
The spatial kernel described above with all positive weighting factors reduces noise but degrades spatial resolution of the image cheap prednisolone 40 mg free shipping. Sharp edges in the original image become blurred in the smoothed image as a result of averaging the counts of the edge pixels with those of the neighboring pixels buy prednisolone 40mg on-line. Another ﬁlter kernel commonly used in the spatial domain consists of a narrow central peak with both positive and negative values on both sides of the peak buy prednisolone 10 mg low price, as shown in Figure 12 buy prednisolone 40 mg overnight delivery. When this so-called edge-sharpening ﬁlter is applied centrally to a pixel for correction, the negative values in effect cancel or erase all neighboring pixel count densities, thus creating a corrected central pixel value. This is repeated for all pixels in each projec- tion and the corrected projections are then backprojected. This technique reproduces the original image with better spatial resolution but with increasing noise. Note that blurring due to simple backprojection is removed by this technique but the noise inherent in the data acquisition due to the limitations of the spatial resolution of the imaging device is not removed but rather enhanced. The negative side-lobes in the spatial domain cancel out the unwanted contributions that lead to blurring in the recon- structed image. Thus, the data for each row and column of the acquisition matrix can be considered as composed of sinusoidal waves of varying amplitudes and frequencies in the frequency domain. The process of determining the amplitudes of sinusoidal waves is called the Fourier transformation (Fig. A proﬁle in the spatial domain can be expressed as an inﬁnite sum of sinusoidal func- tions (the Fourier series). For example, the activity distribution as a function of dis- tance in an organ (A) can be composed by the sum of the four sine functions (B). The Fourier transform of this activity distribution is represented in (C), in which the amplitude of each sine wave is plotted at the corresponding frequency of the sine wave. Single Photon Emission Computed Tomography The Fourier method of reconstruction can be applied in two ways: either directly or by using ﬁlters. In the direct Fourier method, the Fourier trans- forms of individual acquisition projections are taken in polar coordinates in the frequency domain, which are then used to calculate the values in rec- tangular coordinates. The method is not a true backprojection and is rarely used in reconstruction of images in nuclear medicine because of the time- consuming computation. In this method, ﬁlters are used to eliminate the blurring function l/r that arises from simple backprojection of the projection data. In image reconstruction, ﬁlters do the same thing, modulating the amplitudes of different frequencies, preserving the broad structures (the image) represented by low frequencies and removing the ﬁne structures (noise) represented by high frequencies. The Fourier method of ﬁltering the projection data is based on the initial transformation of these data from the spatial domain to the frequency domain, which is symbolically expressed as F′( x, y) = Ff(x, y) (12. Next a Fourier ﬁlter, H( ) is applied in the frequency domain; that is, F′( ) = H( ) · F( ) (12. Finally, the inverse Fourier transformation is performed to obtain the ﬁltered projections, which are then backprojected. The results obtained by the Fourier method are identical to those obtained by the convolution method. Although the Fourier method appears to be somewhat cumbersome and difﬁcult to understand, the use of modern computers has made it much easier and faster to compute the reconstruction of images than the convolution method. Types of Filters A number of Fourier ﬁlters have been designed and used in the recon- struction of images in nuclear medicine. All of them are characterized by a maximum frequency, called the Nyquist frequency, that gives an upper limit to the number of frequencies necessary to describe the sine or cosine curves Single Photon Emission Computed Tomography 163 representing an image projection. Because the acquisition data are discrete, the maximum number of peaks possible in a projection would be in a situ- ation in which peaks and valleys occur in every alternate pixel (i. If the pixel size is known for a given matrix, then the Nyquist frequency can be determined.
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