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Purdue University

2017

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Articles 31 - 60 of 100

Full-Text Articles in Life Sciences

Ecological Responses Of Midwestern Snakes To Prescribed Fire, Zachary T. Truelock, Chelsea E. Clyde-Brockway, Elizabeth A. Flaherty Aug 2017

Ecological Responses Of Midwestern Snakes To Prescribed Fire, Zachary T. Truelock, Chelsea E. Clyde-Brockway, Elizabeth A. Flaherty

The Summer Undergraduate Research Fellowship (SURF) Symposium

Prescribed burning is a commonly used land management tool to reduce the risk of hazardous wildfires and improve wildlife habitat, especially for grassland ecosystems. However, prescribed fire has widely varying effects on differing wildlife taxa. The effects of prescribed fire on herpetofaunal biodiversity have been examined, but the responses of a common and wide-ranging species, the common garter snake (Thamnophis sirtalis), to fire and subsequent effects on its ecology have not been closely studied. The primary goal of this research was to evaluate differing resource use or movement patterns of common garter snakes in burned and unburned habitats. …


Co-Modulation Masking Release Begins In The Auditory Periphery, Kareem R. Hussein, Agudemu Borjigan, Mark Sayles Aug 2017

Co-Modulation Masking Release Begins In The Auditory Periphery, Kareem R. Hussein, Agudemu Borjigan, Mark Sayles

The Summer Undergraduate Research Fellowship (SURF) Symposium

Understanding speech in noisy environments can be difficult, especially for people with hearing loss. The background noise can cover up the sounds of interest. Normally, the auditory system works to alleviate this problem by tagging and then cancelling the noise. Our experiments are aimed at understanding the mechanism of this noise cancellation process. We hypothesize that non-linear signal processing in the mammalian cochlea (the most peripheral part of the auditory system) is the basis of noise cancellation. To test this hypothesis, we measured the responses of auditory-nerve fibers (ANFs) to sounds embedded in background noise with different statistical properties. ANFs …


Defining The Destruction Box: Understanding How The Apc Recognizes Its Substrates, Hana Maldivita Tambrin, Mark C. Hall Aug 2017

Defining The Destruction Box: Understanding How The Apc Recognizes Its Substrates, Hana Maldivita Tambrin, Mark C. Hall

The Summer Undergraduate Research Fellowship (SURF) Symposium

Cell division is the process by which mother cells give rise to two genetically identical daughter cells. All cells have protein networks to ensure that cell division is completed correctly because mistakes during cell division may cause diseases. The Anaphase-promoting complex (APC) is an important regulatory enzyme that ensures successful completion of mitosis. It acts by removing inhibitors of chromosomal segregation and cytokinesis, as well as other important cell division regulators. Existing chemotherapies, like taxol, act by indirectly inhibiting APC function. This makes APC a potential target for new cancer chemotherapies. However, designing APC inhibitors is challenging because how APC …


How Strongly Do Oysters Stick?, Nicolás M. Morato, Andrés M. Tibabuzo, Jonathan J. Wilker Aug 2017

How Strongly Do Oysters Stick?, Nicolás M. Morato, Andrés M. Tibabuzo, Jonathan J. Wilker

The Summer Undergraduate Research Fellowship (SURF) Symposium

Biological adhesives are a type of interfacial material that has incredible potential to generate new biomimetic compounds that can replace current strong, but toxic, adhesives. Therefore, a study of the chemical composition and mechanical properties of those bio-adhesives is necessary. However, in the case of oysters, despite known chemical characterization of the adult’s adhesive, there are almost no studies on its mechanical properties. Furthermore, there is no available information on the adhesive properties of spat (oysters in their larvae state). Herein, we present the first mechanical characterization of the spat adhesive, measuring its adhesion strength by hydrodynamic determination using a …


A Spatial Stochastic Model Of Ampar Trafficking And Subunit Dynamics, Tyler Vandyk, Matthew C. Pharris, Tamara L. Kinzer-Ursem Aug 2017

A Spatial Stochastic Model Of Ampar Trafficking And Subunit Dynamics, Tyler Vandyk, Matthew C. Pharris, Tamara L. Kinzer-Ursem

The Summer Undergraduate Research Fellowship (SURF) Symposium

In excitatory neurons, the ability of a synaptic connection to strengthen or weaken is known as synaptic plasticity and is thought to be the cellular basis for learning and memory. Understanding the mechanism of synaptic plasticity is an important step towards understanding and developing treatment methods for learning and memory disorders. A key molecular process in synaptic plasticity for mammalian glutamatergic neurons is the exocytosis (delivery to the synapse) of AMPA-type glutamate receptors (AMPARs). While the protein signaling pathways responsible for exocytosis have long been investigated with experimental methods, it remains unreasonable to study the system in its full complexity …


Bacterial Motility And Its Role In Biofilm Formation, Clayton J. Culp, Arezoo M. Ardekani, Adib Ahmadzadegan Aug 2017

Bacterial Motility And Its Role In Biofilm Formation, Clayton J. Culp, Arezoo M. Ardekani, Adib Ahmadzadegan

The Summer Undergraduate Research Fellowship (SURF) Symposium

Bacterial biofilms are known to cause millions of dollars in damage in the medical industry per year via infection of central venous catheters, urinary catheters, and mechanical heart valves. Unfortunately, there are some characteristics of biofilm formation that are yet to be fully understood. Recently much work has been done to investigate the motility characteristics of bacteria with hopes of better understanding the phenomena of biofilm formation. Still, one of the least understood stages is bacterial attachment or adhesion, a process designed to anchor bacteria in an advantageous environment. Providing a better understanding of bacterial motility near solid interfaces will …


The Effects Of Compaction On Reconstitution Characteristics Of Dairy Powder, Michelle P. Dixon, Rose Prabin Kingsly Ambrose, Dhananjay Ashok Pai Aug 2017

The Effects Of Compaction On Reconstitution Characteristics Of Dairy Powder, Michelle P. Dixon, Rose Prabin Kingsly Ambrose, Dhananjay Ashok Pai

The Summer Undergraduate Research Fellowship (SURF) Symposium

Milk powders are becoming more ubiquitous within the food industry, and they offer consumers a convenient form for direct intake of dairy. The costs associated with dairy are reduced when products are converted to powder, which markedly increases shelf life at ambient temperatures. Creating compacts from powders further improves cost efficiency by reducing volume. However, milk powders typically possess poor rehydration properties, such as a slow dispersion rate and low solubility, and powder compaction additionally prolongs rehydration time, reducing consumer acceptability. Previous studies have shown that modifying dairy products before or during the drying process can improve rehydration properties, but …


Determining The Role Of Epigenetic Factors In Antifungal Drug Resistance, Abigail R. Gress, Scott D. Briggs, Nina Serratore Aug 2017

Determining The Role Of Epigenetic Factors In Antifungal Drug Resistance, Abigail R. Gress, Scott D. Briggs, Nina Serratore

The Summer Undergraduate Research Fellowship (SURF) Symposium

Epigenetic factors are proteins that regulate gene expression by altering transcriptional machinery access to nucleosomes, DNA wrapped around histone proteins. Two classes of epigenetic factors are ATP-dependent chromatin remodelers and histone modifiers such as histone methyltransferases (HMTs), proteins that add methyl groups to histone tails. This study focuses on AIF4 (Antifungal-Induced Factor 4), a possible HMT induced upon neutral lipid depletion that we hypothesize is regulating antifungal drug resistance genes. Overexpression of AIF4 results in hypersensitivity to antifungal drugs. Studying epigenetic factors in the yeast Saccharomyces cerevisiae, including AIF4, can lead to better understanding of cell adaptation to their environments …


Mobility Characteristics Of Azithromycin In Soil, Ryan Minter, Jihyun Kim, Linda Lee Aug 2017

Mobility Characteristics Of Azithromycin In Soil, Ryan Minter, Jihyun Kim, Linda Lee

The Summer Undergraduate Research Fellowship (SURF) Symposium

The presence of pharmaceutical and personal care products (PPCPs) in the environment has become a widespread problem in recent decades. Azithromycin, a macrolide antibiotic commonly prescribed for infections in humans, has been detected in waste treatment plant discharge and surface waters across the world. Data on the mobility characteristics of azithromycin in soil is scarce, and further studies must be performed to explore the potential for azithromycin leaching to groundwater or becoming available for plant uptake. In this study, azithromycin sorption isotherms were measured on eight soils varying in pH, organic carbon content, and clay content. Soil was equilibrated with …


Secreted Ns1 Aids In Dengue Virus Entry By Binding Heparan Sulfate, Morgan E. Schafer, Michael Dibiasio-White, Richard J. Kuhn Aug 2017

Secreted Ns1 Aids In Dengue Virus Entry By Binding Heparan Sulfate, Morgan E. Schafer, Michael Dibiasio-White, Richard J. Kuhn

The Summer Undergraduate Research Fellowship (SURF) Symposium

A large portion of the world’s population lives in an area where they are at risk of contracting Dengue Virus (DENV). While infection with DENV can result in a wide range of clinical manifestations, from flu-like symptoms to hemorrhagic shock, vascular leakage, and even death, no treatments currently exist. Previous studies have shown that higher levels of viral non-structural protein 1 (NS1) in the blood of infected patients correlate with more severe disease. NS1 has been shown to play many roles in the viral lifecycle, but the mechanisms by which NS1 executes these functions are unknown. Preliminary data from our …


A Touchscreen Assay To Probe The Role Of The Serotonergic System In Learning And Visual Information Processing, Jeffrey M. Dorsch, Alexandr Pak, Alexander A. Chubykin Aug 2017

A Touchscreen Assay To Probe The Role Of The Serotonergic System In Learning And Visual Information Processing, Jeffrey M. Dorsch, Alexandr Pak, Alexander A. Chubykin

The Summer Undergraduate Research Fellowship (SURF) Symposium

The neurotransmitter serotonin is involved in numerous processes in the brain such as behavior, learning, memory, mood, and neurodevelopment. Serotonin signaling is regulated by the serotonin transporter protein (SERT), which maintains normal serotonin levels. Mutations in the SERT gene are known to correlate with cognitive and behavioral deficits seen in psychiatric disorders, such as anxiety disorders, depression, and autism spectrum disorder. Researchers study these deficits using SERT knockout (KO) mice, a model that lacks functional SERT and displays changes in anxiety, learning, and motivation. We are interested in how the absence of SERT affects visual processing and learning. A popular …


Predictive Power And Validity Of Connectome Predictive Modeling: A Replication And Extension, Michael Wang, Joaquin Goni, Enrico Amico Aug 2017

Predictive Power And Validity Of Connectome Predictive Modeling: A Replication And Extension, Michael Wang, Joaquin Goni, Enrico Amico

The Summer Undergraduate Research Fellowship (SURF) Symposium

Neuroimaging, particularly functional magnetic resonance imaging (fMRI), is a rapidly growing research area and has applications ranging from disease classification to understanding neural development. With new advancements in imaging technology, researchers must employ new techniques to accommodate the influx of high resolution data sets. Here, we replicate a new technique: connectome-based predictive modeling (CPM), which constructs a linear predictive model of brain connectivity and behavior. CPM’s advantages over classic machine learning techniques include its relative ease of implementation and transparency compared to “black box” opaqueness and complexity. Is this method efficient, powerful, and reliable in the prediction of behavioral measures …


Analysis Of The Flow Behaviors Of Corn Meal During Extrusion, Daniel N. Hauersperger, Martin R. Okos, Troy Tonner Aug 2017

Analysis Of The Flow Behaviors Of Corn Meal During Extrusion, Daniel N. Hauersperger, Martin R. Okos, Troy Tonner

The Summer Undergraduate Research Fellowship (SURF) Symposium

Food extrusion can be used to make many products we consume today, including pasta, cereals and more. The ability to predict the characteristics of the final product from an extruder using raw material characteristics and operating conditions is vital to the extrusion process. In order to answer this need, the flow behavior of corn meal was measured in a lab viscometer (off-line) and compared to the flow behaviors from an extruder (in-line) at three different moisture contents (32.5%, 35%, 37.5% wet basis). The extruder and product are heated through the friction of the corn meal passing through the barrel not …


Computational Drug Design: A Multitargeted Approach In Bladder Cancer, Travis C. Lantz, Joydeb Majumder, Gaurav Chopra Aug 2017

Computational Drug Design: A Multitargeted Approach In Bladder Cancer, Travis C. Lantz, Joydeb Majumder, Gaurav Chopra

The Summer Undergraduate Research Fellowship (SURF) Symposium

Cancer is a complex, robust disease with multiple redundant disease pathways which lead to tumor development, growth, and eventually even death. Despite known redundancies, cancer therapeutics continue to be developed against a single protein target. Initial disease regression occurs followed by relapse in a drug resistant disease state. In response, combinational drug clinical trial targeting multiple pathways began, and have failed due to increased toxicity caused by adverse drug interactions. Development of a single drug that differentially targets multiple disease pathways will result in a more potent therapeutic while inducing minimal toxicity. This was done computationally through in-lab software packages, …


Establishing A Lung Model For Evaluation Of Engineered Lung Microbiome Therapies, Kathryn F. Atherton, Stephen Miloro, Jenna Rickus Aug 2017

Establishing A Lung Model For Evaluation Of Engineered Lung Microbiome Therapies, Kathryn F. Atherton, Stephen Miloro, Jenna Rickus

The Summer Undergraduate Research Fellowship (SURF) Symposium

Benzene, a toxin and carcinogen found in air polluted by cigarette smoke, car exhaust, and industrial processes, is associated with the development of leukemia and lymphoma. Other than avoiding exposure, there is no current method to deter the effects of benzene. One potential strategy to prevent these effects is to engineer the bacteria of the human lung microbiome to degrade benzene. To evaluate this novel approach, we must verify that the bacteria remain viable within the lung microenvironment. To do so, lungs were harvested from rats and swabbed to determine the contents of the original lung microbiome. Then green fluorescent …


Gas-Based Perfusion Fmri Cerebrovascular Reactivity Maps And Time Of Arrival Maps, Jinxia Yao, Yunjie Tong, Matthew Robert Derdak Aug 2017

Gas-Based Perfusion Fmri Cerebrovascular Reactivity Maps And Time Of Arrival Maps, Jinxia Yao, Yunjie Tong, Matthew Robert Derdak

The Summer Undergraduate Research Fellowship (SURF) Symposium

Perfusion MRI is a promising tool used in assessing stroke, brain tumors, and patients with neurodegenerative diseases. However, common perfusion MRI techniques have several disadvantages, such as using exogenous contrast agents, low signal-to-noise ratio and long acquisition time. In this study, we used a computer-controlled gas delivery system RespirAct TM. This system provides a reliable carbon dioxide based vasoactive stimulus. This stimulus will immediately generate large and reliable functional magnetic resonance imaging (fMRI) signals, which can be used for perfusion imaging. Each subject was required to have three sequential magnetic resonance imaging (MRI) scans, which are structural scan, resting state …


A Programmable Optical Stimulator For The Drosophila Eye, Xinping Chen, Walter D. Leon-Salas, Taylor Zigon, Donald F. Ready, Vikki M. Weake Jul 2017

A Programmable Optical Stimulator For The Drosophila Eye, Xinping Chen, Walter D. Leon-Salas, Taylor Zigon, Donald F. Ready, Vikki M. Weake

Department of Biochemistry Faculty Publications

A programmable optical stimulator for Drosophila eyes is presented. The target application of the stimulator is to induce retinal degeneration in fly photoreceptor cells by exposing them to light in a controlled manner. The goal of this work is to obtain a reproducible system for studying age-related changes in susceptibility to environmental ocular stress. The stimulator uses light emitting diodes and an embedded computer to control illuminance, color (blue or red) and duration in two independent chambers. Further, the stimulator is equipped with per-chamber light and temperature sensors and a fan to monitor light intensity and to control temperature. An …


Exposing Problems Teaching Students Morphological Species Identification, Trevor Stamper, Lauren Weidner, Gregory Nigoghosian, Ludmila D. Nunes Jun 2017

Exposing Problems Teaching Students Morphological Species Identification, Trevor Stamper, Lauren Weidner, Gregory Nigoghosian, Ludmila D. Nunes

IMPACT Presentations

When dealing with physical remains, morphological assessment for species is a traditional approach to entomological specimen identification. A dichotomous key guides the user through taxa determination for a specimen by providing a series of dual-choice nodes that center around morphological differences. Each nodal choice leads to either a new set of dichotomous choices or a taxa decision. We evaluated student’s ability to utilize a dichotomous key down to species for a limited set of taxa, by reviewing their nodal decisions along with their confidence level using a Likert scale (1-5).

Along with individual decision recording, students conducted a post-decision group …


Central And Peripheral Difference In Perceptual Bias In Ambiguous Perception Using Dichoptic Stimuli --- Implications For The Analysis-By-Synthesis Process In Visual Recognition, Li Zhaoping Prof May 2017

Central And Peripheral Difference In Perceptual Bias In Ambiguous Perception Using Dichoptic Stimuli --- Implications For The Analysis-By-Synthesis Process In Visual Recognition, Li Zhaoping Prof

MODVIS Workshop

No abstract provided.


Predicting Fixations From Deep And Low-Level Features, Matthias Kümmerer, Thomas S.A. Wallis, Leon A. Gatys, Matthias Bethge May 2017

Predicting Fixations From Deep And Low-Level Features, Matthias Kümmerer, Thomas S.A. Wallis, Leon A. Gatys, Matthias Bethge

MODVIS Workshop

Learning what properties of an image are associated with human gaze placement is important both for understanding how biological systems explore the environment and for computer vision applications. Recent advances in deep learning for the first time enable us to explain a significant portion of the information expressed in the spatial fixation structure. Our saliency model DeepGaze II uses the VGG network (trained on object recognition in the ImageNet challenge) to convert an image into a high-dimensional feature space which is then readout by a second very simple network to yield a density prediction. DeepGaze II is right now the …


Mapping The Spatio-Temporal Dynamics Of Vision In The Human Brain, Aude Oliva May 2017

Mapping The Spatio-Temporal Dynamics Of Vision In The Human Brain, Aude Oliva

MODVIS Workshop

Recognition of objects and scenes is a fundamental function of the human brain, necessitating a complex neural machinery that transforms low level visual information into semantic content. Despite significant advances in characterizing the locus and function of key visual areas, integrating the temporal and spatial dynamics of this processing stream has posed a decades-long challenge to human neuroscience. In this talk I will describe a brain mapping approach to combine magnetoencephalography (MEG), functional MRI (fMRI) measurements, and convolutional neural networks (CNN) by representational similarity analysis to yield a spatially and temporally integrated characterization of neuronal representations when observers perceive visual …


Neural Computation Of Statistical Image Properties In Peripheral Vision, Christoph Zetzsche, Ruth Rosenholtz, Noshaba Cheema, Konrad Gadzicki, Lex Fridman May 2017

Neural Computation Of Statistical Image Properties In Peripheral Vision, Christoph Zetzsche, Ruth Rosenholtz, Noshaba Cheema, Konrad Gadzicki, Lex Fridman

MODVIS Workshop

No abstract provided.


Similarity-Based Fusion Of Meg And Fmri Discerns Early Feedforward And Feedback Processing In The Ventral Stream, Yalda Mohsenzadeh Dr., Radoslaw Martin Cichy Dr., Aude Oliva Dr., Dimitrios Pantazis Dr. May 2017

Similarity-Based Fusion Of Meg And Fmri Discerns Early Feedforward And Feedback Processing In The Ventral Stream, Yalda Mohsenzadeh Dr., Radoslaw Martin Cichy Dr., Aude Oliva Dr., Dimitrios Pantazis Dr.

MODVIS Workshop

Successful models of vision, such as DNNs and HMAX, are inspired by the human visual system, relying on a hierarchical cascade of feedforward transformations akin to the ventral stream. Despite these advances, the human visual cortex remains unique in complexity, with feedforward and feedback pathways characterized by rapid spatiotemporal dynamics as visual information is transformed into semantic content. Thus, a systematic characterization of the spatiotemporal and representational space of the ventral visual pathway can offer novel insights in the duration and sequencing of cognitive processes, suggesting computational constraints and new architectures for computer vision models.

To discern the feedforward and …


Using Classification Images To Understand Models Of Lightness Perception, Minjung Kim, Jason M. Gold, Richard F. Murray May 2017

Using Classification Images To Understand Models Of Lightness Perception, Minjung Kim, Jason M. Gold, Richard F. Murray

MODVIS Workshop

No abstract provided.


Edge Integration And Image Segmentation In Lightness And Color: Computational And Neural Theory, Michael E. Rudd May 2017

Edge Integration And Image Segmentation In Lightness And Color: Computational And Neural Theory, Michael E. Rudd

MODVIS Workshop

No abstract provided.


Modeling Accommodation Control Of The Human Eye: Chromatic Aberration And Color Opponency, Agostino Gibaldi, Steven A. Cholewiak, Marty S. Banks May 2017

Modeling Accommodation Control Of The Human Eye: Chromatic Aberration And Color Opponency, Agostino Gibaldi, Steven A. Cholewiak, Marty S. Banks

MODVIS Workshop

Accommodation is the process by which the eye lens changes optical power to maintain a clear retinal image as the distance to the fixated object varies. Although luminance blur has long been considered the driving feature for accommodation, it is by definition unsigned (i.e., there is no difference between the defocus of an object closer or farther than the focus distance). Nonetheless, the visual system initially accommodates in the correct direction, implying that it exploits a cue with sign information. Here, we present a model of accommodation control based on such a cue: Longitudinal Chromatic Aberration (LCA). The model relies …


Can Cone Signals In The Wild Be Predicted From The Past?, David H. Foster, Iván Marín-Franch May 2017

Can Cone Signals In The Wild Be Predicted From The Past?, David H. Foster, Iván Marín-Franch

MODVIS Workshop

In the natural world, the past is usually a good guide to the future. If light from the sun and sky is blue earlier in the day and yellow now, then it is likely to be more yellow later, as the sun's elevation decreases. But is the light reflected from a scene into the eye as predictable as the light incident upon the scene, especially when lighting changes are not just spectral but include changes in local shadows and mutual reflections? The aim of this work was to test the predictability of cone photoreceptor signals in the wild over the …


Role Of The Cost Of Plasticity In Determining The Features Of Fast Vision In Humans., Maria M. Del Viva Phd, Renato Budinich M. Sc, Laura Palmieri M. Sc, Vladimir S Georgiev Phd, Giovanni Punzi Phd May 2017

Role Of The Cost Of Plasticity In Determining The Features Of Fast Vision In Humans., Maria M. Del Viva Phd, Renato Budinich M. Sc, Laura Palmieri M. Sc, Vladimir S Georgiev Phd, Giovanni Punzi Phd

MODVIS Workshop

No abstract provided.


Modeling The Mechanisms Of Reward Learning That Bias Visual Attention, Jason Hays, Fabian Soto Phd May 2017

Modeling The Mechanisms Of Reward Learning That Bias Visual Attention, Jason Hays, Fabian Soto Phd

MODVIS Workshop

No abstract provided.


Heuristics From Statistics—Modeling The Behavior And Perception Of Non-Rigid Materials, Vivian C. Paulun, Roland W. Fleming May 2017

Heuristics From Statistics—Modeling The Behavior And Perception Of Non-Rigid Materials, Vivian C. Paulun, Roland W. Fleming

MODVIS Workshop

No abstract provided.