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Full-Text Articles in Life Sciences

Fabrication Of Miniaturized Paper-Based Microfluidic Devices (Micropads), E. Brandon Strong, Spencer A. Schultz, Andres Martinez, Nathaniel W. Martinez Jan 2019

Fabrication Of Miniaturized Paper-Based Microfluidic Devices (Micropads), E. Brandon Strong, Spencer A. Schultz, Andres Martinez, Nathaniel W. Martinez

Chemistry and Biochemistry

Microfluidic paper-based analytical devices (microPADs) are emerging as cost-effective and portable platforms for point-of-care assays. A fundamental limitation of microPAD fabrication is the imprecise nature of most methods for patterning paper. The present work demonstrates that paper patterned via wax printing can be miniaturized by treating it with periodate to produce higher-resolution, high-fidelity microPADs. The optimal miniaturization parameters were determined by immersing microPADs in various concentrations of aqueous sodium periodate (NaIO4) for varying lengths of time. This treatment miniaturized microPADs by up to 80% in surface area, depending on the concentration of periodate and length of the reaction time ...


Adapting Cell-Free Protein Synthesis As A Platform Technology For Education, Grace W. Chu, Max Z. Levine, Nicole E. Gregorio, Javin P. Oza Oct 2018

Adapting Cell-Free Protein Synthesis As A Platform Technology For Education, Grace W. Chu, Max Z. Levine, Nicole E. Gregorio, Javin P. Oza

STAR (STEM Teacher and Researcher) Presentations

Cell-free protein synthesis (CFPS) has emerged as an enabling biotechnology for research and biomanufacturing as it allows for the production of protein without the need for a living cell. Applications of CFPS include the construction of libraries for functional genomics and structural biology, the production of personalized medicine, and the expression of virus-like particles. The absence of a cell wall provides an open platform for direct manipulation of the reaction conditions and biological machinery. This project focuses on adapting the CFPS biotechnology to the classroom, making a hands-on bioengineering approach to learning protein synthesis accessible to students grades K-16 through ...


Tof-Sims Analysis Of Plant Seed Interactions With Plant Growth-Promoting Bacteria, Tammy Pheuphong, Rachel Komorek, Xiao-Ying Yu Aug 2018

Tof-Sims Analysis Of Plant Seed Interactions With Plant Growth-Promoting Bacteria, Tammy Pheuphong, Rachel Komorek, Xiao-Ying Yu

STAR (STEM Teacher and Researcher) Presentations

The use of time-of-flight secondary ion mass spectrometry (ToF-SIMS) in plant biology is a relatively unexplored and quickly developing field. The majority of research in plant SIMS involves the application of ToF-SIMS to study dried wood tissues, and only a handful of studies apply SIMS on plant stems, roots, and/or seeds. Our project provides a brief description and review of previous work using SIMS on plant stems, roots, and/or seeds, along with an emphasis on the sample preparation in each study. Additionally, the use of Brachypodium distachyon (Brachypodium) as a model system for research on grasses has also ...


Scale-Invariant Geometric Data Analysis (Sigda), Marina Girgis, Max Robinson Aug 2018

Scale-Invariant Geometric Data Analysis (Sigda), Marina Girgis, Max Robinson

STAR (STEM Teacher and Researcher) Presentations

The purpose of this research is to introduce a new data analysis method called Scale Invariant Geometric Data Analysis (SIGDA). SIGDA has been shown to be more informative than more common data analysis methods, such as Principal Component Analysis (PCA). SIGDA is used to visualize complex data sets in a way that accurately preserves data patterns and behavior. SIGDA is designed to preserve relative ratios in a numerical matrix, and the number of entries has to be more than the total number of rows and columns. Our research involved providing a simple explanation of SIGDA's mathematical process—simple enough ...


Characterization Of Reagent Pencils For Deposition Of Reagents Onto Paper-Based Microfluidic Devices, Cheyenne H. Liu, Isabelle C. Noxon, Leah E. Cuellar, Amanda L. Thraen, Chad Immoos, Andres W. Martinez, Philip J. Costanzo Aug 2017

Characterization Of Reagent Pencils For Deposition Of Reagents Onto Paper-Based Microfluidic Devices, Cheyenne H. Liu, Isabelle C. Noxon, Leah E. Cuellar, Amanda L. Thraen, Chad Immoos, Andres W. Martinez, Philip J. Costanzo

Chemistry and Biochemistry

Reagent pencils allow for solvent-free deposition of reagents onto paper-based microfluidic devices. The pencils are portable, easy to use, extend the shelf-life of reagents, and offer a platform for customizing diagnostic devices at the point of care. In this work, reagent pencils were characterized by measuring the wear resistance of pencil cores made from polyethylene glycols (PEGs) with different molecular weights and incorporating various concentrations of three different reagents using a standard pin abrasion test, as well as by measuring the efficiency of reagent delivery from the pencils to the test zones of paper-based microfluidic devices using absorption spectroscopy and ...


Paper Microzone Plates As Analytical Tools For Studying Enzyme Stability: A Case Study On The Stabilization Of Horseradish Peroxidase Using Trehalose And Su-8 Epoxy Novolac Resin, Kirsten A. Ganaja, Cory Chaplan, Jingyi Zhang, Nathaniel W. Martinez, Andres W. Martinez May 2017

Paper Microzone Plates As Analytical Tools For Studying Enzyme Stability: A Case Study On The Stabilization Of Horseradish Peroxidase Using Trehalose And Su-8 Epoxy Novolac Resin, Kirsten A. Ganaja, Cory Chaplan, Jingyi Zhang, Nathaniel W. Martinez, Andres W. Martinez

Chemistry and Biochemistry

Paper microzone plates in combination with a noncontact liquid handling robot were demonstrated as tools for studying the stability of enzymes stored on paper. The effect of trehalose and SU-8 epoxy novolac resin (SU-8) on the stability of horseradish peroxidase (HRP) was studied in both a short-term experiment, where the activity of various concentrations of HRP dried on paper were measured after 1 h, and a long-term experiment, where the activity of a single concentration of HRP dried and stored on paper was monitored for 61 days. SU-8 was found to stabilize HRP up to 35 times more than trehalose ...


Paper-Based Diagnostic Devices, Spencer A. Schultz, Isabelle C. Noxon, Tyler A. Sisley, Andres W. Martinez Jan 2017

Paper-Based Diagnostic Devices, Spencer A. Schultz, Isabelle C. Noxon, Tyler A. Sisley, Andres W. Martinez

Chemistry and Biochemistry

This chapter will provide an overview of existing diagnostic devices made primarily out of paper and then focus on paper-based microfluidic devices, the next generation of paper-based diagnostic devices that promises to extend the use of paper as a material for fabricating diagnostic devices well into the future.

Chapter Contents:

  • 2.1 Introduction
  • 2.2 Current paper-based diagnostic devices
  • 2.2.1 Dipstick devices
  • 2.2.2 Lateral-flow devices
  • 2.2.2.1 Vertical-flow devices
  • 2.2.3 Paper-based arrays
  • 2.3 Paper-based microfluidic devices
  • 2.3.1 Fabrication of paper-based microfluidic devices
  • 2.3.2 Applications of paper-based microfluidic ...


Effects Of Habitat Restoration On Soil Retention On Santa Rosa Island, Michael Perez, Kathryn Mceachern, Ken Niessen Jan 2017

Effects Of Habitat Restoration On Soil Retention On Santa Rosa Island, Michael Perez, Kathryn Mceachern, Ken Niessen

STAR (STEM Teacher and Researcher) Presentations

Ranching began on Santa Rosa Island in the 1840’s, consequently introducing nonnative megafauna that put novel selective grazing pressures on endemic plant species. Their movement patterns also altered substrate integrity as the land became denuded of any stabilizing vegetation. Dense groves of island oak (Q. tomentella) are known to aid in sediment deposition and retention. The groves also function to collect water during periods of intense fog common to the island. This experiment sought to determine whether sediment is being lost or deposited on a ridge in the middle of the island containing a grove of Q. tomentella. The ...


Phthalate Plasticizers Covalently Linked To Pvc Via Copper-Free Or Copper Catalyzed Axide-Alkyne Cycloadditions, Aruna Earla, Li Longbo, Philip Costanzo, Rebecca Braslau Dec 2016

Phthalate Plasticizers Covalently Linked To Pvc Via Copper-Free Or Copper Catalyzed Axide-Alkyne Cycloadditions, Aruna Earla, Li Longbo, Philip Costanzo, Rebecca Braslau

Chemistry and Biochemistry

Plasticization of PVC was carried out by covalently linking phthalate derivatives via copper-free (thermal) or copper catalyzed azide-alkyne cycloadditions. Di(2-ethylhexyl) phthalate derivatives (DEHP-ether and DEHP-ester) were synthesized and appended to PVC at two different densities. The glass transition temperatures of the modified PVC decreased with increasing content of plasticizer. PVC-DEHP-ether gave lower glass transition temperatures than PVC-DEHP-ester, reflecting the enhanced flexibility of the ether versus ester linker.


An Examination Of Student Outcomes In Studio Chemistry, Alan L. Kiste, Gregory E. Scott, Jesse Paul Bukenberger, Miles Markmann, Jennifer Moore Dec 2016

An Examination Of Student Outcomes In Studio Chemistry, Alan L. Kiste, Gregory E. Scott, Jesse Paul Bukenberger, Miles Markmann, Jennifer Moore

Chemistry and Biochemistry

Twenty years ago, a major curriculum revision at a large, comprehensive university in the Western United States led to the implementation of an integrated lecture/laboratory (studio) experience for our engineering students taking general chemistry. Based on these twenty years of experience, construction of four purpose-built studio classrooms to house the majority of the remaining general chemistry courses was completed in 2013. A detailed study of the effects of the entire ecology of the studio experience on student success was initiated at that time. Data from content knowledge pre- and post-tests, learning attitudes surveys, and student course evaluations show positive ...


Atomic Tiles: Manipulative Resources For Exploring Bonding And Molecular Structure, Alan L. Kiste, Rebecca G. Hooper, Gregory E. Scott, Seth Bush Oct 2016

Atomic Tiles: Manipulative Resources For Exploring Bonding And Molecular Structure, Alan L. Kiste, Rebecca G. Hooper, Gregory E. Scott, Seth Bush

Chemistry and Biochemistry

A simple manipulative resource, Atomic Tiles, is described for scaffolding the learning of Lewis structures without using algorithmic, rule-based methods of drawing. Students use Atomic Tiles to (1) create models of bonding that lead to drawing Lewis structures, (2) use the structures they create to infer patterns required for rational structures and common organic functional groups, (3) translate between Lewis structures and molecular models, and (4) use molecular models to identify isomers.


Testing Predictions Used To Build An Agrivoltaics Installation On A Small-Scale Educational Model, Katie Kinney, Rebecca Minor, Greg Barron-Gafford Oct 2016

Testing Predictions Used To Build An Agrivoltaics Installation On A Small-Scale Educational Model, Katie Kinney, Rebecca Minor, Greg Barron-Gafford

STAR (STEM Teacher and Researcher) Presentations

Models are valuable tools for explaining and testing systems. Small-scale models can be especially useful for educational purposes. For models to be useful, they have to accurately depict the larger system that they are describing. A novel man-made system, known as an agrivoltaic structure, is being constructed at Biosphere 2 near Oracle, Arizona. The word agrivoltaic is a combination of agriculture and photovoltaics, or solar farming. My research involved creating a small-scale version of this system for educational purposes. The model of this system tested two predictions: that plants will grow better in the shade of a panel and that ...


Weights And Balances: Integrating Models For Prevention And Response To Southern California Offshore Oil Spills, Carmen Watts Clayton, Amoret Bunn Oct 2016

Weights And Balances: Integrating Models For Prevention And Response To Southern California Offshore Oil Spills, Carmen Watts Clayton, Amoret Bunn

STAR (STEM Teacher and Researcher) Presentations

Licensing offshore oil and gas reserves in the United States waters are overseen by the U.S. Department of the Interior’s Bureau of Safety and Enforcement (BSEE). The licensing application includes planning for any worst-case oil spill scenario between BSEE and the applicant based on lessons learned from historic offshore spills such as the Deepwater Horizon (2010), Exxon Valdez (1989), and the Union Oil Platform Blowout (1969). The process for planning to respond to oil spills involves coordination with multiple agencies, trustees, and stakeholders to ensure that oil spill responses consider multiple factors, including ecologically sensitive species, commercial transportation ...


Gc Verification Of The Spacecraft Atmosphere Monitor, Jessica S. Castro, Richard D. Kidd, Jeffrey D. Hein Sep 2016

Gc Verification Of The Spacecraft Atmosphere Monitor, Jessica S. Castro, Richard D. Kidd, Jeffrey D. Hein

STAR (STEM Teacher and Researcher) Presentations

International Space Station crew members face the unique challenge of maintaining air quality due to the volatile organic compounds (VOCs) that have the potential to accumulate at unsafe levels. The Spacecraft Atmosphere Monitor (SAM) is a miniature gas chromatograph/mass spectrometer (GCMS) designed to measure major constituents (such as N2, O2 and CO2) and trace VOCs within the cabin of the spacecraft. The gas chromatograph is responsible for separating the sample into its components in order to be characterized. The oven of the gas chromatograph must reach a temperature of 150°C in order to heat constituents ...


Citizen Science Sensor Development - Smap | Soil Moisture Active Passive, Hagop Hovhannesian Aug 2016

Citizen Science Sensor Development - Smap | Soil Moisture Active Passive, Hagop Hovhannesian

STAR (STEM Teacher and Researcher) Presentations

“Detailed monitoring of soil moisture provides a view of how our whole Earth system works.”

The Soil Moisture Active Passive (SMAP) satellite mission was launched in January 2015; its main purpose is to acquire global measurements of soil moisture. SMAP partnered with the GLOBE program (Global Learning and Observations to Benefit the Environment), which is an international program where students collect environmental variables in a scientifically methodical way. SMAP readings and maps have various uses in various fields, which include monitoring drought, predicting floods, assisting in crop productivity, and linking water, energy and carbon cycles. The goal of this project ...


Comparative Analysis Of In Situ Fibronectin Using Tof-Sims, Spi-Ms, And Dropdesi-Ms In A Microfluidic Reactor, Shannon Fasing, Xiao-Ying Yu, Juan Yao, Jiachao Yu Aug 2016

Comparative Analysis Of In Situ Fibronectin Using Tof-Sims, Spi-Ms, And Dropdesi-Ms In A Microfluidic Reactor, Shannon Fasing, Xiao-Ying Yu, Juan Yao, Jiachao Yu

STAR (STEM Teacher and Researcher) Presentations

Fibronectin is an important biomolecule due to its role in cell differentiation, growth, kinesis, and adhesion. Such biological responses are mediated through membrane recognition and signaling; where fibronectin is found. Studying the outer molecular surface of fibronectin allows deeper insight into the microbiological reactions that occur during these processes. In situ mass spectrometry analysis in aqueous solution accurately represents fibronectin’s chemical components, made possible by a vacuum compatible microfluidic reactor, SALVI (System for Analysis at the Liquid Vacuum Interface). SALVI was paired with the analytical tools: time-of-flight secondary ion mass spectrometer (ToF-SIMS), single photon ionization mass spectrometer (SPI-MS) and ...


Variations In Atmospheric 13c/14c Ratios Within A Radiocarbon Preparatory Lab And Implications For Ams Measurements, Kimberly Arias, Alexandra Hedgpeth, Karis Mcfarlane Aug 2016

Variations In Atmospheric 13c/14c Ratios Within A Radiocarbon Preparatory Lab And Implications For Ams Measurements, Kimberly Arias, Alexandra Hedgpeth, Karis Mcfarlane

STAR (STEM Teacher and Researcher) Presentations

At CAMS, we focus on measuring carbon isotopes (12/13/14C) for a variety of applications. High precision radiocarbon AMS measurements are used for measuring atmospheric radiocarbon. The problem with performing high precision radiocarbon AMS measurements is that there’s almost always background contamination introduced during preparation for the AMS. For graphite preparation, dry ice is used in an isopropyl-dry ice mixture to condense H2O in the CO2 extraction and reduction lines. Dry ice is composed of 12/13C and releases carbon into the atmosphere as it sublimes. The dry ice for preparation is held in containers inside and outside ...


Two-Ply Channels For Faster Wicking In Paper-Based Microfluidic Devices, Conor K. Camplisson, Kevin M. Schilling, William L. Pedrotti, Howard A. Stone, Andres W. Martinez Oct 2015

Two-Ply Channels For Faster Wicking In Paper-Based Microfluidic Devices, Conor K. Camplisson, Kevin M. Schilling, William L. Pedrotti, Howard A. Stone, Andres W. Martinez

Chemistry and Biochemistry

This article describes the development of porous two-ply channels for paper-based microfluidic devices that wick fluids significantly faster than conventional, porous, single-ply channels. The two-ply channels were made by stacking two single-ply channels on top of each other and were fabricated entirely out of paper, wax and toner using two commercially available printers, a convection oven and a thermal laminator. The wicking in paper-based channels was studied and modeled using a modified Lucas–Washburn equation to account for the effect of evaporation, and a paper-based titration device incorporating two-ply channels was demonstrated.


Radiocarbon Isotopic Classification Of Deep Tropical Forest Soils, Brooke Butler, Karis J. Mcfarlane, Jennifer Pett-Ridge, Katherine A. Heckman Aug 2015

Radiocarbon Isotopic Classification Of Deep Tropical Forest Soils, Brooke Butler, Karis J. Mcfarlane, Jennifer Pett-Ridge, Katherine A. Heckman

STAR (STEM Teacher and Researcher) Presentations

Tropical forest soils have an important role in global carbon (C) stocks. Small changes in the cycling of C could drastically affect atmospheric carbon dioxide (CO2) concentrations and active cycling of carbon in a forest community. Currently, little is understood of how tropical forest soils will respond to the increasing global temperatures. To examine the effects of warming/ drought on losses of older versus younger soil C pools, we implemented radiocarbon (14C) isotopic characterization of various soil plot samples and depths from the Luquillo Experimental Forest, Puerto Rico. 14C was measured using Accelerated Mass Spectrometry (AMS) from catalytically condensed carbon ...


Evaluation Of Anthropogenic Marine Debris And Sargassum Fluitans And Its Potential Impact On Sea Turtle Hatchlings At Sandy Point National Wildlife Refuge, Christina Macmillan Aug 2015

Evaluation Of Anthropogenic Marine Debris And Sargassum Fluitans And Its Potential Impact On Sea Turtle Hatchlings At Sandy Point National Wildlife Refuge, Christina Macmillan

STAR (STEM Teacher and Researcher) Presentations

Anthropogenic debris, particularly plastic, has become a significant threat for marine species with the increased use of plastics over the years. Marine birds and sea turtles, mostly green, loggerhead and leatherback turtles, are especially vulnerable to mistaking plastic debris for food and ingesting it. There has been a rise in the incidence of turtles having plastic fragments in their GI tracts; even small amounts of plastic may have major long-term health and reproductive effects. On the nesting beaches, both adults and hatchlings may become entangled in debris or have trouble navigating around beach debris during their crawl to the sea ...


The Effect Of Drought On Stomatal Conductance In The Biosphere 2 Rainforest, Justin Gay, Joost Van Haren Aug 2015

The Effect Of Drought On Stomatal Conductance In The Biosphere 2 Rainforest, Justin Gay, Joost Van Haren

STAR (STEM Teacher and Researcher) Presentations

Drought is a major climate change concern for the Earth’s rainforests; however little is currently known about how these forests and individual plants will respond to water stress. At the individual level, the ability of plants to regulate their stomatal conductance is an important preservation mechanism that helps to cool leaves, regulate water loss, and uptake carbon dioxide. At the ecosystem level, transpiration in rain forests is a major contributor to the feedback loop that returns moisture to the atmosphere for continued rains. Nearly 60% of atmospheric moisture in the Amazon rain forests has been traced back to origins ...


Poly(N-Isopropylacrylamide) Hydrogels For Storage And Delivery Of Reagents To Paper-Based Analytical Devices, Haydn T. Mitchell, Spencer Schultz, Philip Costanzo, Andres W. Martinez Jul 2015

Poly(N-Isopropylacrylamide) Hydrogels For Storage And Delivery Of Reagents To Paper-Based Analytical Devices, Haydn T. Mitchell, Spencer Schultz, Philip Costanzo, Andres W. Martinez

Chemistry and Biochemistry

The thermally responsive hydrogel N,N'-methylenebisacrylamide-cross-linked poly(N-isopropylacrylamide) (PNIPAM) was developed and evaluated as a reagent storage and delivery system for microfluidic paper-based analytical devices (microPADs). PNIPAM was shown to successfully deliver multiple solutions to microPADs in specific sequences or simultaneously in laminar-flow configuration and was found to be suitable for delivering four classes of reagents to the devices: Small molecules, enzymes, antibodies and DNA. PNIPAM was also able to successfully deliver a series of standard glucose solutions to microPADs equipped to perform a colorimetric glucose assay. The results of these tests were used to produce an external calibration ...


Reagent Pencils: A New Technique For Solvent-Free Deposition Of Reagents Onto Paper-Based Microfluidic Devices, Haydn T. Mitchell, Isabelle C. Noxon, Cory A. Chaplan, Samantha J. Carlton, Cheyenne H. Liu, Kirsten A. Ganaja, Nathaniel W. Martinez, Chad Immoos, Philip Costanzo, Andres W. Martinez Apr 2015

Reagent Pencils: A New Technique For Solvent-Free Deposition Of Reagents Onto Paper-Based Microfluidic Devices, Haydn T. Mitchell, Isabelle C. Noxon, Cory A. Chaplan, Samantha J. Carlton, Cheyenne H. Liu, Kirsten A. Ganaja, Nathaniel W. Martinez, Chad Immoos, Philip Costanzo, Andres W. Martinez

Chemistry and Biochemistry

Custom-made pencils containing reagents dispersed in a solid matrix were developed to enable rapid and solvent-free deposition of reagents onto membrane-based fluidic devices. The technique is as simple as drawing with the reagent pencils on a device. When aqueous samples are added to the device, the reagents dissolve from the pencil matrix and become available to react with analytes in the sample. Colorimetric glucose assays conducted on devices prepared using reagent pencils had comparable accuracy and precision to assays conducted on conventional devices prepared with reagents deposited from solution. Most importantly, sensitive reagents, such as enzymes, are stable in the ...


Growing Conditions For Algae, Angeles Mora, Tamar Melkonian, Alejandro Calderon-Urrea Aug 2014

Growing Conditions For Algae, Angeles Mora, Tamar Melkonian, Alejandro Calderon-Urrea

STAR (STEM Teacher and Researcher) Presentations

With the growing demands of water in California and the increasing cost of fossil fuels to operate water-cleaning equipment, Algae was cultivated in different concentrations of Nitrogen, Phosphorus, and Potassium (NPK) during different trails to identify the best growing conditions for the removal water contaminates. Before testing algae in waste water, the Algae: Dunaliella Primolecta, Chlorella Vulgaris, and Scenedesmus Dimorphus were cultivated in four different media containing distilled water and plant vitamins. The different mediums used include: Orchid Grow More (20-20-20), Miracle Grow (30-10-10), Murashige & Skoog, and Orchid Bloom Boster (11-35-15). As a result of the investigation, the algae, Scenedesmus ...


Phylogenetic Diversity Of Microbial Isolates From The Mars Pathfinder, Kyla Bradylong, Adriana Blachowicz, Parag Vaishampayan, James N. Benardini, Wayne Schubert Aug 2014

Phylogenetic Diversity Of Microbial Isolates From The Mars Pathfinder, Kyla Bradylong, Adriana Blachowicz, Parag Vaishampayan, James N. Benardini, Wayne Schubert

STAR (STEM Teacher and Researcher) Presentations

As spacecraft are sent to different planets, they take with them microscopic pieces of life from Earth. It is the task of the Biotechnology and Planetary Protection Group to keep as much of this life off other planets as possible as well as document any life that may have been sent. During the construction of the Mars Pathfinder, samples were collected from various locations on the spacecraft to test for contamination. These samples were then isolated, grown, documented, preserved and their 16S rRNA genes were sequenced for identification. The 16S rRNA gene sequence is utilized because it is a highly ...


Salinity And Temperature Distribution Of Jellyfish In The San Francisco Estuary, Trisha Huynh, Brooke Bemowski, Lindsay Sullivan, Wim Kimmerer Aug 2014

Salinity And Temperature Distribution Of Jellyfish In The San Francisco Estuary, Trisha Huynh, Brooke Bemowski, Lindsay Sullivan, Wim Kimmerer

STAR (STEM Teacher and Researcher) Presentations

Jellyfish are generally characterized by their jelly-like bodies and internal lining (two tissue layers). They found both in the phylum Ctenophora and the phylum Cnidaria. Ctenophores differ from cnidarians primarily due to the rows of “combs”, or cilia, which are used for transportation. Additionally, ctenophores possess sticky cells while cindarians possess stinging cells. Jellyfish depend on zooplankton (small floating aquatic animals) as a food source; as a result, they are potential competitors and predators to plankton-eating fish and may negatively impact fish populations.

As recently as 1950, jellyfish have entered the San Francisco Bay from the Mediterranean Sea (probably in ...


Assessment Of Salmon Habitat On The Feather River, Nathan Sweem Aug 2014

Assessment Of Salmon Habitat On The Feather River, Nathan Sweem

STAR (STEM Teacher and Researcher) Presentations

Human activity in central valley streams has had a significantly negative impact on salmon habitat (Williams 2006). The presence of dams impedes sediment transport which is critical to salmon spawning (Williams 2006; Kondolf 1997). As part of an effort to enhance salmon spawning, the California Department of Water Resources added 7000 ft3 of gravel to Cottonwood Hatchery, Upper Auditorium, and Auditorium riffles on the Lower Feather River below the Thermalito Dam Complex in July of 2014. Stream conditions at Cottonwood Hatchery riffle were assessed by conducting analysis of sediment grain size, water depth and velocity, gravel permeability, and dissolved ...


The Path To The Sea: Leatherback Hatchling Orientation At Sandy Point National Wildlife Refuge, Christina Macmillan, Kelly Stewart Aug 2014

The Path To The Sea: Leatherback Hatchling Orientation At Sandy Point National Wildlife Refuge, Christina Macmillan, Kelly Stewart

STAR (STEM Teacher and Researcher) Presentations

Once sea turtle hatchlings emerge from their nest, they must find their way to the ocean by using cues such as a bright horizon and the slope of the beach. While moving toward the water, hatchlings often must navigate past predators and through vegetation, sticks, footprints in the sand, and other dangers such as ghost crab holes. Sometimes hatchlings become confused (or disoriented) and turn in circles to find the right route to the water. Sea turtle hatchlings also may become disoriented as a result of human impacts such as town lights or trash. The purpose of our experiment was ...


Light Pollution Research Through Citizen Science, John Kanemoto Aug 2014

Light Pollution Research Through Citizen Science, John Kanemoto

STAR (STEM Teacher and Researcher) Presentations

Light pollution (LP) can disrupt and/or degrade the health of all living things, as well as, their environments. The goal of my research at the NOAO was to check the accuracy of the citizen science LP reporting systems entitled: Globe at Night (GaN), Dark Sky Meter (DSM), and Loss of the Night (LoN). On the GaN webpage, the darkness of the night sky (DotNS) is reported by selecting a magnitude chart. Each magnitude chart has a different density/number of stars around a specific constellation. The greater number of stars implies a darker night sky. Within the DSM iPhone ...


Paper-Based Standard Addition Assays, Cory A. Chaplan, Haydn T. Mitchell, Andres W. Martinez Jan 2014

Paper-Based Standard Addition Assays, Cory A. Chaplan, Haydn T. Mitchell, Andres W. Martinez

Chemistry and Biochemistry

Standard addition assays conducted on paper-based microfluidic devices are introduced as an alternative to external standards for calibrating quantitative tests. To demonstrate this technique, a colorimetric, paper-based, standard addition assay was optimized for the determination of glucose concentrations in the range of 0 to 5 mM. Comparable results were obtained from the assay via digital image colorimetry under three different lighting conditions.