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Biomedical Engineering and Bioengineering Commons

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2009

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Articles 1 - 30 of 288

Full-Text Articles in Biomedical Engineering and Bioengineering

Peak Traction Coefficients Of Cleated Athletic Shoes At Various Angles Of Internal Rotation On Artificial Turf, Ben Cooper, Ronald Pfeiffer, Michelle Sabick, Seth Kuhlman, Shawn Simonson, Kevin Shea Apr 2010

Peak Traction Coefficients Of Cleated Athletic Shoes At Various Angles Of Internal Rotation On Artificial Turf, Ben Cooper, Ronald Pfeiffer, Michelle Sabick, Seth Kuhlman, Shawn Simonson, Kevin Shea

Shawn R. Simonson

As an alternative to natural grass playing fields, the installation of artificial turf surfaces has grown exponentially over the past several decades. Despite the growing popularity of artificial turf, little is known about the interaction between the player’s shoe and the turf surface. Previous research has cited the difficulty in maximizing performance (high traction), yet minimizing the risk of injury (low traction) [2]. Due to numerous factors that affect the turf-shoe interaction, determining safe traction ranges for artificial turf is very difficult. However, the first step needs to be taken to determine the safe range between performance and risk ...


Development Of A Device For Whole Body Stimulation Of The Otoliths, Jon Edward Weimer Dec 2009

Development Of A Device For Whole Body Stimulation Of The Otoliths, Jon Edward Weimer

Theses

Over the past few decades, research has been conducted to explore the effects of microgravity on human musculature, As seen in astronauts upon their return to Earth after prolonged spaceflight, extensive muscle atrophy due to adaptation to conditions of microgravity many times decreases a person's ability to walk or even stand, With an understanding of the anatomical mechanisms that provide postural control, the proper stimulation, resulting in a reduction in spasticity, could be provided by simulating these conditions of microgravity.

In order to simulate microgravity, a device has been developed that is capable of providing whole body stimulation of ...


Stiffness Of Vascular Smooth Muscle Cells From Aged Primates Measured Using Reconstituted Tissue Model, Shilpa Nagendra Dec 2009

Stiffness Of Vascular Smooth Muscle Cells From Aged Primates Measured Using Reconstituted Tissue Model, Shilpa Nagendra

Theses

Increased stiffness of the aorta is an important detrimental change that occurs with aging. Most previous research has implicated stiffening of the extracellular collagen matrix with age. The study reported in this thesis focused instead on the potential contribution from stiffening of the vascular smooth muscle cells (VSMCs) with age.

VSMCs previously obtained from young and old monkeys (macaca fascicularis) were seeded into a collagen gel to form a reconstituted tissue. The aim of this study was to quantitatively characterize the mechanical properties of this reconstituted tissue model via uniaxially stretching each ring to defined levels of strain. The total ...


A Comparative Analysis Of Haptic And Eeg Devices For Evaluation And Training Of Post-Stroke Patients Within A Virtual Environment, Gregory Nicholas Ranky Dec 2009

A Comparative Analysis Of Haptic And Eeg Devices For Evaluation And Training Of Post-Stroke Patients Within A Virtual Environment, Gregory Nicholas Ranky

Theses

Virtual Rehabilitation benefits from the usage of interfaces other than the mouse and keyboard, but also possess disadvantages: haptic peripherals can utilize the subject's hand to provide position information or joint angles, and allow direct training for specific movements; but can also place unneeded strain on the limbs; brain-machine interfaces (BMI) can provide direct connections from the user to external hardware or software, but are currently inaccurate for the full diversity of user movements in daily life and require invasive surgery to implement. A compromise between these two extremes is a BMI that can be adapted to specific users ...


Degeneration Affects The Structural And Tissue Mechanics Of The Intervertebral Disc, Grace D. O'Connell Dec 2009

Degeneration Affects The Structural And Tissue Mechanics Of The Intervertebral Disc, Grace D. O'Connell

Publicly Accessible Penn Dissertations

The intervertebral disc is comprised of mechanically and structurally unique substructures including the annulus fibrosus and the nucleus pulposus, which function together to support and absorb the large complex spinal loads. Disc degeneration causes drastic changes in the composition and may lead to altered mechanics; however, the changes in the internal mechanical function of the nucleus and annulus are not well understood. Moreover, herniation of nucleus pulposus material through the posterior annulus causes low back pain and may alter the mechanical function of the disc. Discectomy, a procedure to relieve the pain by removing the herniated material; however, the effect ...


Biochemical And Biomechanical Modulation Of Nucleus Pulposus Cells Encapsulated In Novel Cellulose-Based Hydrogels, Anna T. Reza Dec 2009

Biochemical And Biomechanical Modulation Of Nucleus Pulposus Cells Encapsulated In Novel Cellulose-Based Hydrogels, Anna T. Reza

Publicly Accessible Penn Dissertations

Low back pain may be caused by a direct, acute injury or degeneration of the intervertebral disc (IVD). Intradiscal replacement of the nucleus pulposus (NP) with a tissue engineered hydrogel scaffold may provide a biologic therapy capable of restoring the structure and mechanical function of the IVD. Therefore, the global objective of this dissertation was to develop and optimize a novel, cell-laden, covlently crosslinkable carboxymethylcellulose (CMC) hydrogel construct as a functional tissue engineered NP replacement. The versatility of the photocrosslinkable CMC system was explored by examining the resultant differences in material and mechanical properties due to varying the macromer concentration ...


Monitoring Of Immune Cell Response To B Cell Depletion Therapy And Nerve Root Injury Using Spio Enhanced Mri, Daniel L. Thorek Dec 2009

Monitoring Of Immune Cell Response To B Cell Depletion Therapy And Nerve Root Injury Using Spio Enhanced Mri, Daniel L. Thorek

Publicly Accessible Penn Dissertations

Magnetic resonance (MR) is a robust platform for non-invasive, high-resolution anatomical imaging. However, MR imaging lacks the requisite sensitivity and contrast for imaging at the cellular level. This represents a clinical impediment to greater diagnostic accuracy. Recent advances have allowed for the in vivo visualization of populations and even of individual cells using superparamagnetic iron oxide (SPIO) MR contrast agents. These nanoparticles, commonly manifested as a core of a single iron oxide crystal or cluster of crystals coated in a biocompatible shell, function to shorten proton relaxation times. In MR imaging these constructs locally dephase protons, resulting in a decrease ...


Differential Cellular Response To Linear And Strain Stiffening Hydrogel Substrates, Jessamine P. Winer Dec 2009

Differential Cellular Response To Linear And Strain Stiffening Hydrogel Substrates, Jessamine P. Winer

Publicly Accessible Penn Dissertations

The mechanical properties of the substrate upon which cells are cultured have been shown to influence a variety of cell properties including cell adhesion, spreading, protein expression and differentiation. The work presented here examines how the nonlinear mechanical properties of biopolymer gels affect the cellular responses to substrate stiffness. Cell spread area decreases with decreasing substrate stiffness when cells are cultured on linearly elastic polyacrylamide gels but display no spread area sensitivity when cultured on fibrin gels of various moduli. Fibrin gels, and other semiflexible biopolymer networks, exhibit strain stiffening, whereby the elastic modulus of the gel increases with increasing ...


Neural Vs. Statistical Classifier In Conjunction With Genetic Algorithm Based Feature Selection, Ping Zhang, Brijesh Verma, Kuldeep Kumar Dec 2009

Neural Vs. Statistical Classifier In Conjunction With Genetic Algorithm Based Feature Selection, Ping Zhang, Brijesh Verma, Kuldeep Kumar

Kuldeep Kumar

Digital mammography is one of the most suitable methods for early detection of breast cancer. It uses digital mammograms to find suspicious areas containing benign and malignant microcalcifications. However, it is very difficult to distinguish benign and malignant microcalcifications. This is reflected in the high percentage of unnecessary biopsies that are performed and many deaths caused by late detection or misdiagnosis. A computer based feature selection and classification system can provide a second opinion to the radiologists in assessment of microcalcifications. The research in this paper proposes and investigates a neural-genetic algorithm for feature selection in conjunction with neural and ...


A Hybrid Classifier For Mass Classification With Different Kinds Of Features In Mammography, Ping Zhang, Kuldeep Kumar, Brijesh Verma Dec 2009

A Hybrid Classifier For Mass Classification With Different Kinds Of Features In Mammography, Ping Zhang, Kuldeep Kumar, Brijesh Verma

Kuldeep Kumar

This paper proposes a hybrid system which combines computer extracted features and human interpreted features from the mammogram, with the statistical classifier’s output as another kind of feature in conjunction with a genetic neural network classifier. The hybrid system produced better results than the single statistical classifier and neural network. The highest classification rate reached 91.3%. The area value under the ROC curve is 0.962. The results indicated that the mixed features contribute greatly for the classification of mass patterns into benign and malignant.


Oculomotor Control In Patients With Parkinson's Disease, George Gitchel Dec 2009

Oculomotor Control In Patients With Parkinson's Disease, George Gitchel

Theses and Dissertations

There have been few studies investigating the eye movement behavior of Parkinson’s disease patients during fixation. This study objectively measured the eye movements of 36 patients with Parkinson’s disease, and 20 age matched controls. Stimuli consisted of ten standardized text passages first organized by Miller and Coleman. In addition, subjects followed a randomly displaced step jump target motion. Pendular nystagmus was found in all Parkinson’s subjects, with an average frequency of 7.44 Hz. Saccadic peak velocity and duration along the main sequence were not statistically different from controls. A slower rate of reading was also noted ...


Automated Methods For Fiber Diameter Measurement Of Fibrous Scaffolds, Anna Bulysheva Dec 2009

Automated Methods For Fiber Diameter Measurement Of Fibrous Scaffolds, Anna Bulysheva

Theses and Dissertations

The purpose of this work was to develop an automated method of measuring fiber diameters of electrospun scaffolds from scanning electron microscopy images of these scaffolds. Several automated methods were developed and evaluated by comparison to known values and data obtained via the standard manual method. Simulated images with known diameters were used as test images to evaluate the accuracy of each measurement technique. Eight scanning electron microscopy images were also used for the evaluation of the automated methods compared to the standard manual method. All diameter measurements were made in pixels. Five new automated methods coded in MATLAB were ...


Automatic Exposure Control And Estimation Of Effective System Noise In Diffuse Fluorescence Tomography, Dax L. Kepshire, Hamid Dehghani, Frederic Leblond, Brian W. Pogue Dec 2009

Automatic Exposure Control And Estimation Of Effective System Noise In Diffuse Fluorescence Tomography, Dax L. Kepshire, Hamid Dehghani, Frederic Leblond, Brian W. Pogue

Open Dartmouth: Faculty Open Access Scholarship

A diffuse fluorescence tomography system, based upon time-correlated single photon counting, is presented with an automated algorithm to allow dynamic range variation through exposure control. This automated exposure control allows the upper and lower detection levels of fluorophore to be extended by an order of magnitude beyond the previously published performance and benefits in a slight decrease in system effective noise. The effective noise level is used as a metric to characterize the system performance, integrating both model-mismatch and calibration bias errors into a single parameter. This effective error is near 7% of the reconstructed fluorescent yield value, when imaging ...


Development Of The Mask Scentometer, A Comparison Of Ambient Odor Assessment Methods, And Their Application In Ground Truthing Atmospheric Dispersion Models, Christopher G. Henry Dec 2009

Development Of The Mask Scentometer, A Comparison Of Ambient Odor Assessment Methods, And Their Application In Ground Truthing Atmospheric Dispersion Models, Christopher G. Henry

Biological Systems Engineering--Dissertations, Theses, and Student Research

This dissertation is organized as four stand-alone papers. Paper No. 1 describes the development of the Mask Scentometer and reports dilution ratios measured during use by twelve different people. Dilution ratios at the Mask Scentometer’s five dilution-to-threshold (D/T) settings were found to be 0.35, 1, 2, 4.5 and 18. In Paper No.’s 2 and 4, ambient odor assessment methods were compared in both controlled laboratory conditions and in the field. Laboratory analysis of ambient air samples using dynamic triangular forced-choice olfactometry (DTFCO) did not correlate well with any of the ambient odor assessment methods. Average ...


Responses To “Comment On ‘Response To Plevin: Implications For Life Cycle Emissions Regulations’” And “Assessing Corn Ethanol: Relevance And Responsibility”, Adam Liska, Kenneth Cassman Dec 2009

Responses To “Comment On ‘Response To Plevin: Implications For Life Cycle Emissions Regulations’” And “Assessing Corn Ethanol: Relevance And Responsibility”, Adam Liska, Kenneth Cassman

Adam Liska Papers

This letter responds to two issues concerning the greenhouse gas (GHG) emissions intensity of corn-ethanol that were raised in discussions of our response (Liska and Cassman 2009) to Plevin’s article (2009), which critiques our original research (Liska et al. 2009) published in the Journal of Industrial Ecology. ... The suggestion by Anex and Lifset (2009) that corn-ethanol does not reduce GHG emissions by 47% compared to gasoline, but instead by “somewhere between” 35 to 40%, is unsubstantiated.


The Development Of A Mesenchymal Stem Cell Based Bone Graft System, Sarina Sinclair Dec 2009

The Development Of A Mesenchymal Stem Cell Based Bone Graft System, Sarina Sinclair

All Dissertations

Greater than 5.5 million fractures are sustained by Americans each year, accounting for more than 500,000 bone graft surgeries. Bone grafts are the second most transplanted material, surpassed only by blood. The current 'gold standard' for bone grafting involves harvesting bone material from the patient's iliac crest, due to its osteoinductive properties. Unfortunately, the surgery required to harvest material from the iliac crest causes additional pain for the patient, relies on a limited amount of available bone tissue, and results in, on average, a 30% rate of donor site morbidity. Both natural and synthetic substitutes have been ...


Identification And Quantification Of Cotton Yield Monitor Errors, Jason Clay Head Dec 2009

Identification And Quantification Of Cotton Yield Monitor Errors, Jason Clay Head

Masters Theses

Cotton yield monitors are an important part of a precision agriculture program and are becoming widely used by cotton producers for making management decisions. Members of the cotton industry have shown interest in using cotton yield monitors for collecting data from production scale variety yield trials (experiments that test yield performance for numerous varieties). Weighing boll buggies are the current industry standard for measuring yield in variety trials. This process is time consuming and requires extra equipment and labor. The ability to use a yield monitor for measuring yield would streamline variety trial harvesting. Recommendations for the Ag Leader cotton ...


Hydrogel Compositions For Nonviral Gene Delivery, Eunhee Cho Dec 2009

Hydrogel Compositions For Nonviral Gene Delivery, Eunhee Cho

All Dissertations

The incorporation of nonviral vectors into biomaterial matrices has been employed to improve localization at the implant site and to protect from loss by clearance or extracellular barriers. However, several limitations such as detrimental crosslinking mechanisms, uncontrolled burst release require improved design of matrix-based gene delivery systems that provides sustained and controlled vector release as well as overcomes extracellular barriers to gene transfer in proximity to target cells. The long-term objective of this dissertation project is to provide the basis for the eventual creation of tissue engineering scaffolds that combine structural and biological activity through the creation of composite materials ...


Covalent Immobilization Of L1 Neural Cell Adhesion Molecule To Acrylated Tetronicâ® Hydrogels For Neural Regeneration, Rebecca Cribb Dec 2009

Covalent Immobilization Of L1 Neural Cell Adhesion Molecule To Acrylated Tetronicâ® Hydrogels For Neural Regeneration, Rebecca Cribb

All Dissertations

Spinal cord injuries cost the United States $20 billion per year, with an existing patient population of 256,000 growing by an estimated 12,000 each year. Current clinical therapies for spinal cord injury are limited to spinal immobilization and realignment via traction, surgery, administration of methylprednisolone sodium succinate (MPSS) within eight hours post-injury, and rehabilitation exercises. While these therapies are important and may minimize damage and restore limited function, there is a dire clinical need for treatments to address the growing population of chronically-injured patients.
Varying degrees of axonal regeneration and functional recovery following spinal cord injury have been ...


Multistructure Segmentation Of Multimodal Brain Images Using Artificial Neural Networks, Eun Young Kim Dec 2009

Multistructure Segmentation Of Multimodal Brain Images Using Artificial Neural Networks, Eun Young Kim

Theses and Dissertations

A method for simultaneously segmenting multiple anatomical brain structures from multi-modal MR images has been developed. An artificial neural network (ANN) was trained from a set of feature vectors created by a combination of high-resolution registration methods, atlas based spatial probability distributions, and a training set of 16 expert traced data sets. A set of feature vectors were adapted to increase performance of ANN segmentation; 1) a modified spatial location for structural symmetry of human brain, 2) neighbors along the priors' descent for directional consistency, and 3) candidate vectors based on the priors for the segmentation of multiple structures. The ...


Vibration Analysis Of Heavy-Duty Diesel Vehicles, Christopher Jack Campbell Dec 2009

Vibration Analysis Of Heavy-Duty Diesel Vehicles, Christopher Jack Campbell

Masters Theses

Truck drivers are more susceptible than other workers to lower back pain and spinal disorders caused by whole body vibrations, which are among the most common long term health effects for drivers. The dynamic behavior of trucks can be modeled and simulated to improve the design of the trucks, which can reduce the exposure of drivers to whole body vibrations.

The main purposes of this study are to analyze vibrations for different manufacturers and road types, and to create a computer-based model using Adams to predict vibration anywhere on the model using acceleration data collected previously from on-road tests of ...


Creation Of Bioactive Surfaces To Modulate Cell Behavior Using Surface Initiated Photoiniferter-Mediated Graft Photopolymerization, Nihar Shah Dec 2009

Creation Of Bioactive Surfaces To Modulate Cell Behavior Using Surface Initiated Photoiniferter-Mediated Graft Photopolymerization, Nihar Shah

All Dissertations

Biomaterials widely used in biomedical applications still face biocompatibility issues arising from non-specific protein adsorption on the foreign surface, and the consequent undesired cell response. Emerging evidence suggests that imparting specific bioactivity to the biomaterial's surface to elicit favorable response from cells, (like osseointegration of joint implants and endothelialization of stents) can yield much better biocompatibility results when combined with passive prevention of protein adsorption. In more complex diseases like spinal cord injury and cardiomyopathy, specific biomolecules are required to elicit desired cell responses for successful regeneration. However, for success of such biomolecule based strategies, the effects of various ...


Laser Scanning Confocal Microscopy (Lscm): An Application For The Detection Of Morphological Alterations In Skin Structure, Shea C. Smith Dec 2009

Laser Scanning Confocal Microscopy (Lscm): An Application For The Detection Of Morphological Alterations In Skin Structure, Shea C. Smith

Master's Theses and Project Reports

Laser scanning confocal microscopy (LSCM) is an optical imaging technique that provides improved resolution and sensitivity over conventional methods of optical microscopy. However, the cost of most commercial LSCM systems exceeds the financial limitations of many smaller laboratories. The design of a custom LSCM created at a fraction of the cost of a commercial model is discussed in this paper.

The increase in the incidence rate of skin cancer in the world today is alarming, as such, it is essential to provide an early, rapid and effective method for in vivo diagnostics of human skin tissue. LSCM is capable of ...


Neomycin Enhances Glutaraldehyde Crosslinking And Glycosaminoglycan Stability In Bioprosthetic Heart Valves, Vincent Friebe Dec 2009

Neomycin Enhances Glutaraldehyde Crosslinking And Glycosaminoglycan Stability In Bioprosthetic Heart Valves, Vincent Friebe

All Theses

The native heart valve will open and close an astonishing 3 billion times in the average lifetime, implicating immense biomechanical ramifications that necessitate near-flawless structure and functional behavior. Deviations from this idyllic function as a result of heart valve disease (HVD) affect millions of individuals worldwide and result in over 275,000 heart valve replacements worldwide every year. Glutaraldehyde (GLUT) cross-linked porcine aortic heart valves, a common type of bioprosthetic heart valve (BHV), are used frequently in these valve replacement surgeries. The native valve leaflets entail a tri-composite design of type I collagen, elastin and glycosaminoglycans (GAGs), each of which ...


Single Cell Impedance Measurements Using Microfabricated Electrodes And Labview Graphical Programming, Stephanie Sophia Hernandez Dec 2009

Single Cell Impedance Measurements Using Microfabricated Electrodes And Labview Graphical Programming, Stephanie Sophia Hernandez

Master's Theses and Project Reports

This Master’s Thesis project consists of the research, design, and fabrication of a system that could perform broadband impedance measurements (1kHz-20Mhz) of single cells using National Instruments Labview data acquisition and programming in coordination with a single cell capture device. Presented first is the background information on cells and their electrical properties, along with background in micro-total-analysis systems as well as impedance spectroscopy. Experimental Methods are then discussed for the electrode design, cellular modeling in COMSOL, fabrication methods, and Labview 8.0 Set-up and programming. Measurements were performed using the single-cell capture device on saline, yeast cells, and a ...


Live Cell Imaging Technology Development For Cancer Research, Elizabeth Anne Kosmacek Dec 2009

Live Cell Imaging Technology Development For Cancer Research, Elizabeth Anne Kosmacek

Theses and Dissertations

Live cell imaging is a unique tool for cellular research with a wide variety of applications. By streaming digital microscopic images an investigator can observe the dynamic morphology of a cell, track cell movement on a surface, and measure quantities or localization patterns of fluorescently labeled proteins or molecules. Digital image sequences contain a vast amount of information in the form of visually detectable morphological changes in the cell. We designed computer programs that allow the manual identification of visible events in live cell digital image sequences [Davis et al. 2007]. Once identified, the data are analyzed using algorithms to ...


The Electrical Properties Of Human Tissue For The Diagnosis And Treatment Of Melanoma Skin Cancer, Glenn Cameron Stante Dec 2009

The Electrical Properties Of Human Tissue For The Diagnosis And Treatment Of Melanoma Skin Cancer, Glenn Cameron Stante

Master's Theses and Project Reports

This thesis discusses the research, experimental methods, and data gathered for the investigation of a novel method for the diagnosis of melanoma skin cancer. First, a background about human skin tissue is presented. Then, a detailed description of melanoma along with current diagnosis techniques and treatment options are presented. In the experimental methods, the electrical properties of several types of tissue were analyzed, the purpose of which was to discover if a tissue type can be distinguished by its electrical properties alone. This would allow for the diagnosis of melanoma to be done by examining the electrical properties of the ...


A Computational Model Of Apoptotic Osteocyte Correlation To Cortical Bone Remodeling Parameters, Michael Stephen Alexander Dec 2009

A Computational Model Of Apoptotic Osteocyte Correlation To Cortical Bone Remodeling Parameters, Michael Stephen Alexander

Master's Theses and Project Reports

The onset of osteoporosis caused by aging, disease states, and post-menopausal conditions significantly impacts patient quality of life, required healthcare funding, personal autonomy losses from increased fracture risk and the subsequent corrective surgery. Research has indicated that osteocyte apoptosis may be a key parameter in bone remodeling, raising the possibility of remodeling rate modulation for the mitigation of bone mass resorption. By developing therapies that target osteocyte apoptosis, it may be possible to prevent undesired bone remodeling activity while maintaining a healthy balance between damage formation in the form of microcracks induced by the strain environment and the removal of ...


Synchronization And Media Exchange In Large-Scale Caenorhabditis Elegans Cultures, Jason D. Brown Dec 2009

Synchronization And Media Exchange In Large-Scale Caenorhabditis Elegans Cultures, Jason D. Brown

All Graduate Theses and Dissertations

The nematode Caenorhabditis elegans is a model organism for understanding sensory molecules of multicellular organisms. Ovulating hermaphrodites produce putative pheromone(s) that cause male attraction. Because pheromones are produced in such small quantities, adult conditioned-media from large-scale synchronous culture is necessary to analyze these pheromones. Current protocols for culture synchronization have volume constraints that limit large-scale synchronous cultures and current methodology for adult conditioned-media production is impractical.

Modification of Tangential Flow Filtration (TFF) systems was investigated for use as a method to increase the volume limits of bleach egg harvest for C. elegans culture synchronization. Also, an adult retention device ...


Designing An Instrument Based Nn Native Fluorescence To Determine Soil Microbial Content At A Mars Analog Site, Heather D. Smith Dec 2009

Designing An Instrument Based Nn Native Fluorescence To Determine Soil Microbial Content At A Mars Analog Site, Heather D. Smith

All Graduate Theses and Dissertations

For this research project we designed an instrument to detect bacteria via biomolecular fluorescence. We introduce the current understanding of astrobiology, our knowledge of life beyond Earth, and the commonality of Earth life as it pertains to the search for life on Mars. We proposed a novel technique for searching for direct evidence of life on the surface of Mars using fluorescence. We use the arid region of the Mojave Desert as an analog of Mars. Results indicate the fluorescence of the biotic component of desert soils is approximately as strong as the fluorescence of the mineral component. Fluorescence laboratory ...