Kendler K.S.,Virginia Commonwealth University |
Zachar P.,Auburn University at Montgomery |
Craver C.,Washington University in St. Louis
Psychological Medicine | Year: 2011
This essay explores four answers to the question What kinds of things are psychiatric disorders? Essentialist kinds are classes whose members share an essence from which their defining features arise. Although elegant and appropriate for some physical (e.g. atomic elements) and medical (e.g. Mendelian disorders) phenomena, this model is inappropriate for psychiatric disorders, which are multi-factorial and fuzzy. Socially constructed kinds are classes whose members are defined by the cultural context in which they arise. This model excludes the importance of shared physiological mechanisms by which the same disorder could be identified across different cultures. Advocates of practical kinds put off metaphysical questions about reality and focus on defining classes that are useful. Practical kinds models for psychiatric disorders, implicit in the DSM nosologies, do not require that diagnoses be grounded in shared causal processes. If psychiatry seeks to tie disorders to etiology and underlying mechanisms, a model first proposed for biological species, mechanistic property cluster (MPC) kinds, can provide a useful framework. MPC kinds are defined not in terms of essences but in terms of complex, mutually reinforcing networks of causal mechanisms. We argue that psychiatric disorders are objectively grounded features of the causal structure of the mind/brain. MPC kinds are fuzzy sets defined by mechanisms at multiple levels that act and interact to produce the key features of the kind. Like species, psychiatric disorders are populations with central paradigmatic and more marginal members. The MPC view is the best current answer to What kinds of things are psychiatric disorders? © Cambridge University Press 2010.
Johnson B.E.,Auburn University at Montgomery
Journal of Transport Geography | Year: 2012
The High-Speed Intercity Passenger Rail (HSIPR) Program succeeds in proposing a truly high-speed rail route in California that will offer travelers significantly faster trips than driving on a route that is too short to conveniently fly instead. Unfortunately, the proposed routes in the Northeast, Midwest, and Northwest will continue to chug along at medium-speeds and attract few new riders from among those who currently travel those areas via highway or air. The plan does indeed succeed in calling for TOD around high-speed rail stations. The HSIPR Program must, however, encourage local planning jurisdictions to broadly liberalize land use controls to allow for compact development rather than writing new zoning codes to require the intensive land uses developers desire anyway. Trains must truly be fast, with stations surrounded by dense development, for America's high-speed rail plan to realize its full potential. © 2012 Elsevier Ltd.
Esco M.R.,Auburn University at Montgomery
Journal of Strength and Conditioning Research | Year: 2011
Esco, MR, Williford, HN, and Olson, MS. Skinfold thickness is related to cardiovascular autonomic control as assessed by heart rate variability and heart rate recovery. J Strength Cond Res 25(8): 2304-2310, 2011-The purpose of this study was to determine if heart rate recovery (HRR) and heart rate variability (HRV) are related to maximal aerobic fitness and selected body composition measurements. Fifty men (age = 21.9 ± 3.0 years, height = 180.8 ± 7.2 cm, weight = 80.4 ± 9.1 kg, volunteered to participate in this study. For each subject, body mass index (BMI), waist circumference (WC), and the sum of skinfolds across the chest, abdomen, and thigh regions (SUMSF) were recorded. Heart rate variability (HRV) was assessed during a 5-minute period while the subjects rested in a supine position. The following frequency domain parameters of HRV were recorded: normalized highfrequency power (HFnu), and low-frequency to high-frequency power ratio (LF:HF). To determine maximal aerobic fitness (i.e., V̇O 2max), each subject performed a maximal graded exercise test on a treadmill. Heart rate recovery was recorded 1 (HRR1) and 2 (HRR2) minutes during a cool-down period. Mean V̇O 2max and BMI for all the subjects were 49.5 ± 7.5 ml·kg -1·min -1 and 24.7 ± 2.2 kg·m -2, respectively. Although V̇O 2max, WC, and SUMSF was each significantly correlated to HRR and HRV, only SUMSF had a significant independent correlation to HRR1, HRR2, HFnu, LF:HF (p < 0.01). The results of the regression procedure showed that SUMSF accounted for the greatest variance in HRR1, HRR2, HFnu, and LF:HF (p < 0.01). The results of this study suggest that cardiovascular autonomic modulation is significantly related to maximal aerobic fitness and body composition. However, SUMSF appears to have the strongest independent relationship with HRR and HRV, compared to other body composition parameters and V̇O 2max. © 2011 National Strength and Conditioning Association.
Winters J.V.,Auburn University at Montgomery
Journal of Regional Science | Year: 2011
This paper examines why smart cities are growing by investigating who moves to smart cities and who stays. Smart cities are often centers of higher education, so students moving to pursue higher education may play an important role. I find that the greater in-migration to smart cities is mostly due to persons enrolled in higher education. Smart cities are growing in part because in-migrants often stay in the city after completing their education. The growth of smart cities is also mostly attributable to population redistribution within the same state and has little effect on population growth at the state level. © 2010, Wiley Periodicals, Inc.
Esco M.R.,Auburn University at Montgomery
Journal of Strength and Conditioning Research | Year: 2013
The body adiposity index (BAI) is a new simplistic method for predicting body fat percentage (BF%) via a simple equation of hip circumference to height. A scientific study of this novel method in athletic groups is warranted because of the possibility of it serving as an inexpensive field technique. The purpose of this study was to cross-validate the BAI for predicting BF% in a group of collegiate female athletes by using dual-energy X-ray absorptiometry (DXA) as the criterion variable. Thirty college-aged female athletes (age = 20.0 ± 1.3 years) participated in this study. For each participant, BF% was obtained with the BAI method and compared with DXA. The mean BF% was 27.1 ± 3.4 by the BAI and 26.7 ± 5.9 from DXA, which was not significantly different (p > 0.05). However, the BAI did not provide a significant correlation with the DXA (r = 0.28, R2 = 0.08, p > 0.05) and resulted in a standard error of estimate = 5.78% and total error = 5.84%. Bland-Altman plot showed that the limits of agreement (95% confidence intervals) between the DXA and BAI ranged between-10.2 and 11.8%, and there was a significant negative association between the difference and mean of the 2 methods (r = 20.52, p < 0.01). The results of this investigation indicate that BAI results in large individual errors when predicting BF% in female athletes and has a tendency to provide overestimated values as BF% decreases. Therefore, this method should not be used for predicting individual BF% in athletic women. © 2013 National Strength and Conditioning Association.