Daniel Keenan

I have trained and worked in both statistics and applied mathematics. I also did Years I-II of MD training (financed by NIH), in order to combine math and medicine. I have had three primary collaborators, with each, a different area of research: from 1984-1995, with Ulf Grenander (Brown Univ) in imaging processing, pattern theory ( and what today would be called machine learning); from 1995-present, with Johannes Veldhuis, MD (Mayo Clinic) in neuroendocrinology; and, from 2011-present, with Don Pfaff (Rockefeller Univ) in modeling brain arousal.

In the Research Narrative (button at the top), I describe the types of research problems on which I have worked. Below I present a sampling of the papers from that research. Other buttons describe my bio (training and grants), my publications (120+) and students (PhD and undergraduates).

A Sampling of Papers (and a Book) from CV

Neurobiology and Computational Neuroscience
Keenan, DM, Gagnidze K, Proekt, A and Pfaff DW (2015). Reconstructing a stimulus-response curve, even though the stimuli are unobserved: the modeling of brain arousal (in final preparation).
Keenan, DM, Quinkert AW and Pfaff DW (2015). Stochastic modeling of mouse motor activity under deep brain stimulation: the extraction of arousal information. PLoS Comp. Biol; Feb 26;11(2):e1003883.

Translational Medicine and Systems Biology
Keenan DM, Basu R, Liu Y, Basu A, Bock G, Veldhuis JD. 2012. Logistic model of glucose-regulated C-peptide secretion: hysteresis-pathway disruption in impaired fasting glycemia. Am J Physiol.; 303(3):E397-409.
Keenan DM, Clarke IJ and Veldhuis JD. 2012. Non-invasive analytical estimation of endogenous GnRH drive: analysis using graded competitive GnRH-receptor antagonism and a calibrating pulse of exogenous GnRH. Endocrinology [Epub Nov 2011].
Keenan DM, Iranmanesh A, Veldhuis JD. 2011. Analytical construct of reversible desensitization of pituitary-testicular signaling: illustrative application in aging. Am J Physiol.; 300(2):R349-60.
Keenan DM, Roelfsema F, Carroll BJ, Iranmanesh A, Veldhuis JD. 2009. Sex defines the age dependence of endogenous ACTH-cortisol dose responsiveness. Am J Physiol; 297(2):R515-23.
Keenan D, Alexander S, Irvine C, Veldhuis JD. 2009. Quantifying nonlinear interactions within the hypothalamo-pituitary-adrenal axis in the conscious horse. Endocrinology, 150(4):1941-51.
Keenan D, Takahshi P, Liu P, Roebuck P, Nehra A and Veldhuis J. 2006. An ensemble model of the male gonadal axis: illustrative application in aging men. Endocrinology, 147: 2817-28.
Keenan D, Alexander S, Irvine C, Clarke I, Scott C, Turner A, Tilbrook A, Canny B, Veldhuis JD. 2004. Reconstruction of in vivo time-evolving neuroendocrine dose-response properties unveils admixed deterministic and stochastic elements. Proceedings of the National Academy of Sciences, 101:6740-5.
Keenan D, Licinio J, and Veldhuis JD. 2001. Interactive construct of feedback control in the stress-responsive hypothalamo-pituitary-adrenal axis. Proceedings of the National Academy of Sciences, 98: 4028-4033.

Mathematical and Statistical Biology
Keenan DM, Wang X, Pincus SM, Veldhuis JD. 2012. Modeling the nonlinear time dynamics of multidimensional hormonal systems. Journal of Time Series Analysis; 33(5): 779-796.
Chattopadhyay S, Keenan D and Veldhuis JD. 2008. Probabilistic recovery of pulsatile structure: detecting brain signaling by its downstream effects. Quarterly of Applied Mathematics, 66(3): 401-421.
Keenan D, Veldhuis JD, and Chattopadhyay C. 2005. Composite model of time-varying appearance and disappearance of neurohormone pulse signals in blood. Journal of Theoretical Biology, 236:242-55.
Keenan DM
and Shorter P. 2004. Simulation by diffusion on a manifold with boundary: applications to ultrasonic prenatal medical imaging. SIAM Journal of Applied Mathematics; 64(3): 932-960.
Keenan D, Sun W, and Veldhuis JD. 2000. A stochastic biomathematical model of the male reproductive hormone system. SIAM Journal of Applied Mathematics, 61(3):934-965.

Statistical Image Processing, Machine-Learning and Pattern Theory
Grenander U, Chow Y and Keenan D.1991. HANDS: A Pattern-Theoretic Study of Biological Shapes, Springer-Verlag,New York.
Grenander, U. and Keenan, D. 1995. Understanding variables shapes in 3-D. Stochastic Models; 11(1), 51-78.
Grenander, U. and
Keenan, D. 1989. Toward automated image understanding. Journal of Applied Statistics, 16(2), 207-221.
Hall, P. and
Keenan, D. 1989. Bootstrap methods for constructing confidence regions for hands. Stochastic Models, 5, 555-62.
Grenander, U. and
Keenan, D. 1989. A computer experiment in pattern theory. Stochastic Models, 5(4), 531-553.
Grenander, U. and
Keenan, D. 1993. On the shape of plane images. SIAM Journal of Applied Mathematics; 53: 1072-94.

Signal Processing and Time Series
Keenan, D. 1997. A central limit theorem for M(n) autocovariances. Journal of Time Series Analysis, Vol 18, 61-78.
Keenan, D. 1987. Limiting behavior of functionals of higher-order cumulant spectra. Annals of Statistics, 15, No. 1, 134-151.
Keenan, D. 1985. Asymptotic properties of minimization estimators of time series parameters, Annals of Statistics, 13, 369-382.
Keenan, D. 1985. A Tukey nonadditivity type test of time series nonlinearity. Biometrika, Vol. 72, No. 1, 39-44.
Keenan, D. 1983. Limiting behavior of functionals of the sample spectral distribution function. Annals of Statistics, 11, 1206-17.
Keenan, D. 1982. A time series analysis of binary data. Journal of the American Statistical Association, 77, 816-821.