Trent D. Ridder, Benjamin J. Ver Steeg, Bentley D. Laaksonen, "Comparison of spectroscopically measured tissue alcohol concentration to blood and breath alcohol measurements," 2009, Journal of Journal of Biomedical Optics, 14(5), (2009).
Alcohol testing is an expanding area of interest due to the impacts of alcohol abuse that extend well beyond drunk driving. However, existing approaches such as blood and urine assays are hampered in some testing environments by biohazard risks. A noninvasive, in vivo spectroscopic technique offers a promising alternative, as no body fluids are required. The purpose of this work is to report the results of a 36-subject clinical study designed to characterize tissue alcohol measured using near-infrared spectroscopy relative to venous blood, capillary blood, and breath alcohol. Comparison of blood and breath alcohol concentrations demonstrated significant differences in alcohol concentration [root mean square of 9.0 to 13.5 mg/dL] that were attributable to both assay accuracy and precision as well as alcohol pharmacokinetics. A first-order kinetic model was used to estimate the contribution of alcohol pharmacokinetics to the differences in concentration observed between the blood, breath, and tissue assays. All pair-wise combinations of alcohol assays were investigated, and the fraction of the alcohol concentration variance explained by pharmacokinetics ranged from 41.0% to 83.5%. Accounting for pharmacokinetic concentration differences, the accuracy and precision of the spectroscopic tissue assay were found to be comparable to those of the blood and breath assays.
Anita Krishnamurthi, D. M. Terndrup, M. H. Pinsonneault, K. Sellgren, John R. Stauffer, Rudolph Schild, D. E. Backman, K. B. Beisser, D. B.Dahari, A.Dasgupta, J. T. Hagelgans, M. A. Seeds, Rajan Anand, Bentley D. Laaksonen, Laurence A. Marschall, T. Ramseyer, "New Rotation Periods in the Pleiades: Interpreting Activity Indicators," The Astrophysical Journal, 493, pp. 914-925, (1998).
We present results of photometric monitoring campaigns of G, K, and M dwarfs in the Pleiades carried out in 1994-1996. We have determined rotation periods for 18 stars in this cluster. In this paper we examine the validity of using observables such as X-ray activity and the amplitude of photometric variations as indicators of angular momentum loss. We report the discovery of cool, slow rotators with high amplitudes of variation. This contradicts previous conclusions about the use of amplitudes as an alternate diagnostic of the saturation of angular momentum loss. We show that the X-ray data can be used as observational indicators of mass-dependent saturation in the angular momentum loss proposed on theoretical grounds.
S. Allain, J. Bouvier, C. Prosser, L. A. Marschall, B. D. Laaksonen, "Rotational periods and starspot activity of young solar-type dwarfs in the open cluster IC4665," Astronomy and Astrophysics, 305, pp. 498-506, (1996).
We present the results of a V-band photometric monitoring survey of 15 late-type dwarfs in the young open cluster IC 4665. Low-amplitude periodic light variations are found for 8 stars and ascribed to the modulation by starspots that cover typically a few percent of the stellar disk. Periods range from 0.6 to 3.7d, translating to equatorial velocities between 13 and 93km/s. That no period longer than 4d was detected suggests a relative paucity of extremely slow rotators (V_eq_<<10km/s) among late-type dwarfs in IC4665. The fractional number of slow rotators in IC 4665 is similar to that of Alpha Per cluster, suggesting that IC 4665 is close in age to Alpha Per (~50Myr).
Geoffrey S. Burks, Paul Clark, Bentley D. Laaksonen, "Astronomy in Cyberspace, an Experiment: the Online Journal of Astronomy Education," American Astronomical Society Meeting, 187, #05.01, (1995).
The Online Journal of Astronomy Education has been formed as an experiment whose aim is to fill in a need for information exchange in astronomy education. There is a lack of forums for the publication of innovative astronomy teaching techniques. With this journal, we hope to meet the needs of the astronomy teaching community. The Online Journal of Astronomy Education (OJAE) is made up of three main parts: 1. The Main Journal, a peer reviewed journal. 2. The Forum, an open section for those who want to make contributions and ask questions, without having to deal with the peer review process. And 3. Other Astronomy Resources, pointers to other astronomy sources. The journal is in hypertext format and is availible over the world wide web. Submissions to the main journal are accepted in plain text and html format. Submissions to the forum are accepted in plain text, html format, and postscript format. The address of OJAE is: .
Michael W. Richmond, Richard R. Treffers, Alexei V. Filippenko, Schuyler D. van Dyk, Young Paik, Chien Peng, Laurence A. Marschall, Bentley D.Laaksonen, Bruce Macintosh, Ian S. McLean, "UBVRI Photometry of the Type Ia SN 1994D in NGC 4526," The Astrophysical Journal, 109(5), pp. 2121-33, (1995).
We present optical photometry for the type Ia SN 1994D in NGC 4526 from 1994 March 7 to June 4 starting 13 days before B-band maximum. The light curves of this SN resemble closely those of the "normal" type Ia events SNe 1989B and 1980N, differing only in a slightly faster decline after maximum in VRI. The optical absolute magnitudes of SN 1994D, however, are significantly brighter than those of its near twins, and brighter than those predicted by Phillips [ApJ, 413, L105 (1993)] relationship between decline rate and luminosity. Our small amount of IR photometry of SN 1994D is not inconsistent with that of other type Ia SNe.
Charles F. Prosser, Matthew D. Shetrone, Amil Dasgupta, Dana E. Backman, Bentley D. Laaksonen, Shawn W. Baker, Laurence A. Marschall, Barbara A. Whitney, Konrad Kuijken, John R. Stauffer, "Rotation Periods of Open-Cluster Stars. III.," Publications of the Astronomical Society of the Pacific, 107(709), pp. 211-18, (1995).
We present the results from a photometric monitoring program of 15 open cluster stars and one weak-lined T Tauri star during late 1993/early 1994. Several show rotators which are members of the Alpha Persei, Pleiades, and Hyades open clusters have been monitored and period estimates derived. Using all available Pleiades stars with photometric periods together with current X-ray flux measurements, we illustrate the X-ray activity/rotation relation among Pleiades late-G/K dwarfs. The data show a clear break in the rotation-activity relation around P approximately 6-7 days -- in general accordance with previous results using more heterogeneous samples of G/K stars.
B. Laaksonen, W. Romanishin, L. Marschall, "BVRI Photometry of supernovae 1993G, 1994D, 1994I, 1994M, 1994S, and 1994Q," American Astronomical Society Meeting, 185, #79.13, (1995).
Using a 512 x 512 Photometrics CCD camera on the 31" telescope operated by the National Undergraduate Research Observatory in Flagstaff, Arizona, we have obtained B,V,R,and I frames of several recent supernovae, most of them observed near peak brightness. The most extensive of these observations, of SN1994D, cover 15 days in March and April, 1994, while the other supernovae, 1993G, 1994I, 1994M, 1994S, and 1994Q, are only sparsely sampled. We present light curves of SN 1994D, along with tables of all the observed magnitudes. We also discuss several alternative procedures used to minimize contamination from the background galaxies and we outline the methods used to reduce our instrumental magnitudes to the standard system. This work was supported by grants from the National Science Foundation RUE program, the NASA Space Grant program, and Gettsyburg College. We acknowledge the support of Lowell Observatory for the use of the 31" telescope on Anderson Mesa by students and faculty of NURO.
Charles F. Prosser, Matthew D. Shetrone, Ettore Marilli, Santo Catalano, Scott D. Williams, Dana E. Backman, Bentley D. Laaksonen, Vikram Adige, Laurence A. Marschall, John R. Stauffer, "Rotation Periods of Open-Cluster Stars. II.," Publications of the Astronomical Society of the Pacific, 105(694), pp. 1407-14, (1993).
We present the results from a photometric monitoring program of 21 stars observed during 1992 in the Pleiades and Alpha Persei open clusters. Period determinations for 16 stars are given, 13 of which are the first periods reported for these stars. Brightness variations for an additional five cluster stars are also given. One K dwarf member of the alpha Per cluster is observed to have a period of rotation of only 4.39 hr. perhaps the shortest period currently known among BY Draconis variables. The individual photometric measurements have been deposited with the NSSDC. Combining current X-ray flux determinations with known photometric periods, we illustrate the X-ray activity/rotation relation among Pleiades K dwarfs based on available data.
Laaksonen, Bentley D., Color image of NGC 3627, CCD Astronomy, Spring 1995, 2(1), 44.
Laaksonen, Bentley D., Color image of NGC 3486, CCD Astronomy, Summer 1995, 2(2), 45.
Laaksonen, Bentley D., Color image of the Crab Nebula & SN 1994D, CCD Astronomy, Spring 1994, 1(2), 27.
Course Work
Computer Science (Master of Science)
AIntroduction to Computing (103)1991Gettysburg College
A+Introduction to Computer Science (104)1992Gettysburg College
AComputer Organization & Assembly Language Programming (221)1992Gettysburg College
A-Data Structures (216)1993Gettysburg College
A+Introduction to Artificial Intelligence (371)1993Gettysburg College
A-Software Engineering (335)1994Gettysburg College
ASoftware Systems and Design (340)1995Gettysburg College
ASelected Topics (Software Development Project) (392)1995Gettysburg College
AUNIX Administration and Tools (484)1996University of New Mexico
AGeometric and Probabilistic Methods in Computer Science (530)2009University of New Mexico
ADigital Image Processing (522)2010University of New Mexico
AComputer Networks (585)2010University of New Mexico
A-Advanced Operating Systems (587)2010University of New Mexico
AComputer Vision (532)2011University of New Mexico
CRColloquium 1 (592)2011University of New Mexico
ANumerical Analysis: Approximation and Differential Equations (576)2011University of New Mexico
A+Fundamentals of Software Testing (581)2012University of New Mexico
CRColloquium 2 (592)2012University of New Mexico
AIntro to AI (527)2013University of New Mexico
A+Software Foundations (558)2016University of New Mexico
A+Introduction to Cybersecurity (544)2017University of New Mexico
Physics (Bachelor of Science with honors)
AMechanics & Heat (111)1991Gettysburg College
A+Waves, Electricity, & Magnetism (112)1992Gettysburg College
A-Electronics w/ Lab (240)1992Gettysburg College
B+Relativity & Modern Physics w/ Lab (213)1993Gettysburg College
B+Classical Mechanics (319)1993Gettysburg College
A-Atomic & Nuclear Physics w/ Lab (310)1993Gettysburg College
A+Individualized Study-Research (Astrophysics) (462)1994Gettysburg College
AAdvanced Physics Laboratory (325)1994Gettysburg College
AQuantum Mechanics (341)1994Gettysburg College
BSpecial Topics in Physics (381)1994Gettysburg College
ASummer Internship (Astrophysics) (474)1994Northern Arizona University
A-Electricity & Magnetism (330)1995Gettysburg College
AConcepts of Astronomy (421)1995University of New Mexico
CRSeminar 1 (400)1995University of New Mexico
BClassical Mechanics I (503)1995University of New Mexico
CRPhysics Problems Course (400)1995University of New Mexico
A+Stars & Stellar Systems (422)1996University of New Mexico
CRSeminar 2 (400)1996University of New Mexico
A+Calculus I (111)1991Gettysburg College
A+Calculus II (112)1992Gettysburg College
AMultivariate Calculus (211)1992Gettysburg College
ALinear Algebra (212)1993Gettysburg College
ADifferential Equations & Special Functions (363)1993Gettysburg College
ADiscrete Structures (208)1994Gettysburg College
A-Mathematical Methods for Scientists & Engineers (466)1996University of New Mexico
Electrical & Computer Engineering
ASignals and Communications (314)1998University of New Mexico
A+Probabilistic Methods (340)1998University of New Mexico
Fine Arts
AModern Dance I (110)1996University of New Mexico
CRModern Dance I (110)1997University of New Mexico
AHip-Hop Dance I (308)1997University of New Mexico
A-African Dance I (308)1997University of New Mexico
AMexican Folk (308)1998University of New Mexico
AFlamenco I (169)1998University of New Mexico
AFlamenco I (169)1999University of New Mexico
A-Hip-Hop Dance I (308)1999University of New Mexico
Physical Education, Non-Professional
A+Ballroom I (124)1999University of New Mexico
A+Aerobic Dance I (158)1999University of New Mexico
A+Aerobic Dance II (159)1999University of New Mexico
AAerobic Dance II (159)2000University of New Mexico
ABeginning Country Western Dance (128)2000University of New Mexico
AIntermediate Country Western Dance (129)2000University of New Mexico
CRIntermediate Ballroom Dance (125)2001University of New Mexico
CRBeginning Country Western Dance (128)2001University of New Mexico
CRIntermediate Country Western Dance (129)2001University of New Mexico
CRIndividual Tumbling (118)2003University of New Mexico
CRBallroom Dance I (124)2004University of New Mexico
CRBeginning Tennis (143)2004University of New Mexico
AIntermediate Tennis (144)2006University of New Mexico
AEnglish Composition (101)1991Gettysburg College
AColloquy (English/Writing) (100)1992Gettysburg College
B+Fundamental Spanish (104)1992Gettysburg College
AIntermediate Spanish (201)1992Gettysburg College
B+Theory of Visual Arts (120)1992Gettysburg College
BIntermediate Spanish (202)1993Gettysburg College
AIntroduction to Philosophy (101)1993Gettysburg College
ALiterary Foundations of Western Culture (103)1994Gettysburg College
A-Religions of Japan (249)1994Gettysburg College
AWorld Prehistory and Human Evolution (105)1995Gettysburg College
AGreek Religion and Literature (315)1999University of New Mexico
AGreek Mythology (411)1999University of New Mexico
AEconomics Personal Investing (212)2002University of New Mexico
APsychology of Alcoholism (430)2007University of New Mexico
A+Human Geography (102)2008University of New Mexico
A+Physical Geography (101)2009University of New Mexico
International Exploration
Spain1990Herndon High School
Greece1999University of New Mexico
United Kingdom: England, Scotland, Northern Ireland2000Independent
Canada: Quebec2000Independent
West Africa: Senegal, Gambia2001Mussukeba Sane Research Tours
Costa Rica2003Independent
Mexico: Oaxaca2016Independent