Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

145344 Full-Text Articles 176476 Authors 18103694 Downloads 345 Institutions

All Articles in Life Sciences

Faceted Search

145344 full-text articles. Page 3 of 3306.

Carbon Black Exposure Induces Alterations In Mitochondrial Morphology In Human Lung Cells: A Software-Based Quantitative Analysis, Jennifer D. Duff, Brianna K. LaFerney, Celina Y. Jones, Penn M. McClatchey, Jay Brewster 2017 Pepperdine University

Carbon Black Exposure Induces Alterations In Mitochondrial Morphology In Human Lung Cells: A Software-Based Quantitative Analysis, Jennifer D. Duff, Brianna K. Laferney, Celina Y. Jones, Penn M. Mcclatchey, Jay Brewster

Seaver College Research And Scholarly Achievement Symposium

Nanoparticulates of pure carbon, carbon black (CB), are a common atmospheric pollutant in industrialized and heavily populated areas. They are produced primarily via combustion of fossil fuels, and represent a significant health hazard. They are known to worsen asthma and bronchitis when inhaled and to cause inflammation, heart dysfunction, and oxidative stress when incorporated into other organs. The key focal point of this work was to examine markers of stress signaling and cellular dysfunction when human bronchial epithelial cells (16HBE14o-) were exposed to CB particles ranging in size from 70 nm and averaging 130 nm in diameter. BrdU incorporation and ...


The Effect Of Water Levels On Crayfish Aggression, Emory B. Johnson, Sarah E. Blase 2017 Pepperdine University

The Effect Of Water Levels On Crayfish Aggression, Emory B. Johnson, Sarah E. Blase

Seaver College Research And Scholarly Achievement Symposium

Crayfish are a very prevalent invasive species that affect many different environments all over the world. Crayfish, specifically Procambarus clarkii, are an invasive species that have currently taken a foothold in the Santa Monica mountains and are threatening native stream species. There is currently a severe drought occurring in the Santa Monica mountains. The drought has been reshaping many aquatic environments by limiting space and resources such as food and shelter. Crayfish are a very aggressive species and adversely affect the habitat they inhabit by rapidly colonizing, burrowing, and their voracious diets. Due to the adverse effects crayfish can have ...


Effect Of Drought On Resin Production In Woody Stems Of Rhus Ovata, Sydney T. Adams, Melody Young, Moriah Hall 2017 Pepperdine University

Effect Of Drought On Resin Production In Woody Stems Of Rhus Ovata, Sydney T. Adams, Melody Young, Moriah Hall

Seaver College Research And Scholarly Achievement Symposium

Resin production in stems of woody plants is generated from resin canal secretions and is thought to play a significant role in protection from fungal infection and spread. This may be one of several factors associated with fungal infection and fungal induced dieback in plants during severe water stress or drought. We set out to determine if reduction in resin production in a chaparral shrub, Sugar Bush (Rhus ovata), was associated with severe drought in southern California. We hypothesized that dehydrated R. ovata would produce less resin than hydrated plants. Our null hypothesis was that there is no significant difference ...


Genetic Effect Of Drought On The California Newt, Taricha Torosa, Madeleine M. Perrault, Samantha Fiallo, Alero Arueyingho, Cindy Kim, Laiken Ritchie 2017 Pepperdine University

Genetic Effect Of Drought On The California Newt, Taricha Torosa, Madeleine M. Perrault, Samantha Fiallo, Alero Arueyingho, Cindy Kim, Laiken Ritchie

Seaver College Research And Scholarly Achievement Symposium

Droughts are now a common occurrence in Southern California and are known to cause population declines in many species, and such bottlenecks can cause a loss of genetic variation. Genetic variation was examined in a population of the California newt located in Arroyo Sequit Creek in the Santa Monica Mountains. Genetic data from animals examined prior to the current drought were compared to similar data collected from the population after it experienced several years of severe drought. We hypothesized that the drought impacted population should show less genetic variation in comparison to the pre-drought population. Nevertheless, there were no genetic ...


Plant Water Relations During Drought-Induced Dieback In Greenbark Ceanothus, Ceanothus Spinosus, In The Santa Monica Mountains, Christopher F. Ross, Andrew Palaski 2017 Pepperdine University

Plant Water Relations During Drought-Induced Dieback In Greenbark Ceanothus, Ceanothus Spinosus, In The Santa Monica Mountains, Christopher F. Ross, Andrew Palaski

Seaver College Research And Scholarly Achievement Symposium

This experiment investigated Ceanothus spinosus dieback in the natural landscape of Pepperdine University’s campus in Malibu, California. We measured midday water potential, gas-exchange rates (photosynthesis and transpiration), chlorophyll fluorescence, and native embolism levels of stem xylem, comparing irrigated controls on campus to plants undergoing severe water stress in the natural landscape of our campus. The water potentials for naturally occurring C. spinosus (-6.6 MPa) was much lower than for irrigated controls (-3.4 MPa). Water stressed plants experience 47.2% embolism in their stem xylem that blocks water transport to leaves compared to 12.6% embolism in irrigated ...


Progression Of Activity And Predator Avoidance In California Grunion Larvae, Callyn E. Shelley 2017 Pepperdine University

Progression Of Activity And Predator Avoidance In California Grunion Larvae, Callyn E. Shelley

Seaver College Research And Scholarly Achievement Symposium

No abstract provided.


15. Enumeration And Gene Identification Of Extended-Spectrum-Beta-Lactamase-Producing Enterobacteriaceae From Impacted Urban Streams In Hall County, Georgia, Usa., Monica Leavell 2017 University of North Georgia

15. Enumeration And Gene Identification Of Extended-Spectrum-Beta-Lactamase-Producing Enterobacteriaceae From Impacted Urban Streams In Hall County, Georgia, Usa., Monica Leavell

University of North Georgia Annual Research Conference

Extended-spectrum beta-lactamases (ESBLs) are a group of enzymes shown to rapidly evolve and confer resistance to a number of antibiotics, including beta lactams. Organisms that produce ESBLs pose both threats and challenges in the administration of appropriate agents to treat infections. ESBLs exhibit antibiotic resistance by destructing the antibiotics’ structure and are typically found encoded on bacterial plasmids that can easily be transferred between bacteria from the family Enterobacteriaceae. Water environments such as streams can help the spread of antibiotic-resistant bacteria which can originate from a variety of sources, including wastewater treatment plants, agricultural sources, and residential septic tank systems ...


Distribution And Conservation Status Of The Freshwater Gastropods Of Nebraska, Bruce J. Stephen 2017 University of Nebraska-Lincoln

Distribution And Conservation Status Of The Freshwater Gastropods Of Nebraska, Bruce J. Stephen

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

This survey of freshwater gastropods within Nebraska includes 159 sample sites and encompasses the four primary level III ecoregions of the State. I identified sixteen species in five families. Six of the seven species with the highest incidence, Physa gyrina, Planorbella trivolvis, Stagnicola elodes, Gyraulus parvus, Stagnicola caperata, and Galba humilis were collected in each of Nebraska’s four major level III ecoregions. The exception, Physa acuta, was not collected in the Western High Plains ecoregion. Seven indigenous species, Valvata tricarinata, Helisoma anceps, Campeloma decisum, Galba bulimoides, Physa jennessi, Ferrissia rivularis, and Planorbula armigera, display incidence rarity, being collected at ...


The North American Whistling-Ducks, Pochards, And Stifftails, Paul A. Johnsgard 2017 University of Nebraska - Lincoln

The North American Whistling-Ducks, Pochards, And Stifftails, Paul A. Johnsgard

Zea E-Books

Although the 12 species representing three waterfowl tribes described in this volume are not closely related, they fortuitously provide an instructive example of adaptive evolutionary radiation within the much larger waterfowl lineage (the family Anatidae), especially as to their divergent morphologies, life histories, and social behaviors.

The whistling-ducks (Dendrocygna), with three known North American species, are notable for their permanent pair-bonds, extended biparental family care, and strong social cohesion. In contrast, males of the five typical pochards of North American diving ducks (Aythya) establish monogamous pair-bonds that are maintained only long enough to assure that the female’s eggs are ...


Creation, Sex, Gender, And Jesus, Gregory A. Couser 2017 Cedarville University

Creation, Sex, Gender, And Jesus, Gregory A. Couser

Gregory A. Couser, Ph.D.

No abstract provided.


Corn Nitrogen Fertilization Requirement And Corn–Soybean Productivity With A Rye Cover Crop, Jose L. Pantoja, Krishna P. Woli, John E. Sawyer, Daniel W. Barker 2017 Universidad de las Fuerzas Armadas Pichincha

Corn Nitrogen Fertilization Requirement And Corn–Soybean Productivity With A Rye Cover Crop, Jose L. Pantoja, Krishna P. Woli, John E. Sawyer, Daniel W. Barker

John E. Sawyer

Winter rye (Secale cereale L.) cover crop (RCC) has potential to reduce NO3–N loss from corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] fields. However, RCC effects on annual crop productivity and corn optimal N fertilization requirement are unclear. The objectives were to evaluate corn and soybean yield response to RCC and corn optimal N rate. Treatments were no-RCC and RCC with six fertilizer N rates (0–225 kg N ha-1) applied to corn in a no-till corn–soybean (CS) rotation at four Iowa sites in 2009 through 2011. The RCC biomass and N uptake was low ...


Agronomic Comparison Of Anhydrous Ammonia Applied With A High Speed-Low Draft Opener And Conventional Knife Injection In Corn, Krishna P. Woli, Fabián G. Fernández, John E. Sawyer, Joshua D. Stamper, David B. Mengel, Daniel W.. Barker, Mark H. Hanna 2017 Iowa State University

Agronomic Comparison Of Anhydrous Ammonia Applied With A High Speed-Low Draft Opener And Conventional Knife Injection In Corn, Krishna P. Woli, Fabián G. Fernández, John E. Sawyer, Joshua D. Stamper, David B. Mengel, Daniel W.. Barker, Mark H. Hanna

John E. Sawyer

Anhydrous ammonia (AA) is an important N fertilizer in the U.S., and with large farming operations rapid application is needed. This study evaluated the impact of AA application timing and N rates when applied with a high speed low draft (HSLD) or a conventional till knife (CTKI) on corn (Zea Mays L.) production in no-tillage fields. The study was conducted at sites located in Illinois, Iowa, and Kansas from 2007 to 2009. The experimental design was a split-plot factorial arrangement of application method, timing (fall; spring preplant, SP; and sidedress, SD), and five N rates. Fall AA application was ...


Phosphorus Indexing For Cropland: Overview And Basic Concepts Of The Iowa Phosphorus Index, A. P. Mallarino, B. M. Stewart, J. L. Baker, J. D. Downing, J. E. Sawyer 2017 Iowa State University

Phosphorus Indexing For Cropland: Overview And Basic Concepts Of The Iowa Phosphorus Index, A. P. Mallarino, B. M. Stewart, J. L. Baker, J. D. Downing, J. E. Sawyer

John E. Sawyer

Excessive phosphorus (P) loss from soils impairs surface water resources. An assessment tool or index has been proposed to identify fields with high potential risk of P delivery. The P index integrates P source and transport factors into a decision making process that may lead to changes in current P management and soil conservation practices. The index recognizes that a single soil P threshold alone is not an appropriate evaluation factor because of the varying conditions across fields. Although most indices being developed in the United States include similar factors, source and transport characteristics are considered in various ways to ...


Does Nitrogen Fertilizer Application Rate To Corn Affect Nitrous Oxide Emissions From The Rotated Soybean Crop?, Javed Iqbal, David C. Mitchell, Daniel W. Barker, Fernando Miguez, John E. Sawyer, Jose Pantoja, Michael J. Castellano 2017 Iowa State University

Does Nitrogen Fertilizer Application Rate To Corn Affect Nitrous Oxide Emissions From The Rotated Soybean Crop?, Javed Iqbal, David C. Mitchell, Daniel W. Barker, Fernando Miguez, John E. Sawyer, Jose Pantoja, Michael J. Castellano

John E. Sawyer

Little information exists on the potential for N fertilizer application to corn (Zea mays L.) to affect N2O emissions during subsequent unfertilized crops in a rotation. To determine if N fertilizer application to corn affects N2O emissions during subsequent crops in rotation, we measured N2O emissions for 3 yr (2011–2013) in an Iowa, corn–soybean [Glycine max (L.) Merr.] rotation with three N fertilizer rates applied to corn (0 kg N ha−1, the recommended rate of 135 kg N ha−1, and a high rate of 225 kg N ha−1); soybean ...


Standardized Research Protocols Enable Transdisciplinary Research Of Climate Variation Impacts In Corn Production Systems, E. J. Kladivko, M. J. Helmers, L. J. Abendroth, D. Herzmann, R. Lal, M. J. Castellano, D. S. Mueller, J. E. Sawyer, R. P. Anex, R. W. Arritt, B. Basso, J. V. Bonta, L. C. Bowling, R. M. Cruse, N. R. Fausey, J. R. Frankenberger, P. W. Gassman, A. J. Gassmann, C. L. Kling, A. Kravchenko, J. G. Lauer, F. E. Miguez, E. D. Nafziger, N. Nkongolo, M. O'Neal, L. B. Owens, P. R. Owens, P. Scharf, M. J. Shipitalo, J. S. Strock, M. B. Villamil 2017 Purdue University

Standardized Research Protocols Enable Transdisciplinary Research Of Climate Variation Impacts In Corn Production Systems, E. J. Kladivko, M. J. Helmers, L. J. Abendroth, D. Herzmann, R. Lal, M. J. Castellano, D. S. Mueller, J. E. Sawyer, R. P. Anex, R. W. Arritt, B. Basso, J. V. Bonta, L. C. Bowling, R. M. Cruse, N. R. Fausey, J. R. Frankenberger, P. W. Gassman, A. J. Gassmann, C. L. Kling, A. Kravchenko, J. G. Lauer, F. E. Miguez, E. D. Nafziger, N. Nkongolo, M. O'Neal, L. B. Owens, P. R. Owens, P. Scharf, M. J. Shipitalo, J. S. Strock, M. B. Villamil

John E. Sawyer

The important questions about agriculture, climate, and sustainability have become increasingly complex and require a coordinated, multifaceted approach for developing new knowledge and understanding. A multistate, transdisciplinary project was begun in 2011 to study the potential for both mitigation and adaptation of corn-based cropping systems to climate variations. The team is measuring the baseline as well as change of the system's carbon (C), nitrogen (N), and water footprints, crop productivity, and pest pressure in response to existing and novel production practices. Nine states and 11 institutions are participating in the project, necessitating a well thought out approach to coordinating ...


Visionary Science Of The “Harvard Barbarians”, Catherine Schmitt 2017 University of Maine

Visionary Science Of The “Harvard Barbarians”, Catherine Schmitt

Catherine Schmitt

For over two months during the summer of 1880, eight young members of the Champlain Society made daily excursions, on foot and by boat, around Mount Desert Island. They collected plants and birds, and dredged small animals from the mud of Somes Sound. They stared at the rocks along shore and took photographs. Under the leadership of “Captain” Charles Eliot, son of Harvard President Charles William Eliot, the students were on the Island for the summer to “do some work in some branch of natural history or science.”


Adrift In A Sea Of Information About Sustainable Seafood: The Maine Consumer Perspective, Catherine V. Schmitt 2017 Maine Sea Grant

Adrift In A Sea Of Information About Sustainable Seafood: The Maine Consumer Perspective, Catherine V. Schmitt

Catherine Schmitt

The desire for a sustainable seafood industry that protects the environment and the future of fishing is certainly of interest to consumers, but even here there are conflicting standards, as Catherine Schmitt explores in this article.


A Sumo-Targeted Ubiquitin Ligase Is Involved In The Degradation Of The Nuclear Pool Of The Sumo E3 Ligase Siz1, Oliver Kerscher, Jason W. Westerbeck, Nagesh Pasupala, Mark Guillotte, Eva Szymanski, Brooke C. Matson, Cecilia Esteban 2017 College of William and Mary

A Sumo-Targeted Ubiquitin Ligase Is Involved In The Degradation Of The Nuclear Pool Of The Sumo E3 Ligase Siz1, Oliver Kerscher, Jason W. Westerbeck, Nagesh Pasupala, Mark Guillotte, Eva Szymanski, Brooke C. Matson, Cecilia Esteban

Oliver Kerscher

The Slx5/Slx8 heterodimer constitutes a SUMO-targeted ubiquitin ligase (STUbL) with an important role in SUMO-targeted degradation and SUMO-dependent signaling. This STUbL relies on SUMO-interacting motifs in Slx5 to aid in substrate targeting and carboxy-terminal RING domains in both Slx5 and Slx8 for substrate ubiquitylation. In budding yeast cells, Slx5 resides in the nucleus, forms distinct foci, and can associate with double-stranded DNA breaks. However, it remains unclear how STUbLs interact with other proteins and their substrates. To examine the targeting and functions of the Slx5/Slx8 STUbL, we constructed and analyzed truncations of the Slx5 protein. Our structure–function ...


Budding Yeast Protein Extraction And Purification For The Study Of Function, Interactions, And Post-Translational Modifications, Eva P. Szymanski, Oliver Kerscher 2017 College of William and Mary

Budding Yeast Protein Extraction And Purification For The Study Of Function, Interactions, And Post-Translational Modifications, Eva P. Szymanski, Oliver Kerscher

Oliver Kerscher

Homogenization by bead beating is a fast and efficient way to release DNA, RNA, proteins, and metabolites from budding yeast cells, which are notoriously hard to disrupt. Here we describe the use of a bead mill homogenizer for the extraction of proteins into buffers optimized to maintain the functions, interactions and post-translational modifications of proteins. Logarithmically growing cells expressing the protein of interest are grown in a liquid growth media of choice. The growth media may be supplemented with reagents to induce protein expression from inducible promoters (e.g. galactose), synchronize cell cycle stage (e.g. nocodazole), or inhibit proteasome ...


Sumo-Targeted Ubiquitin Ligase (Stubl) Slx5 Regulates Proteolysis Of Centromeric Histone H3 Variant Cse4 And Prevents Its Mislocalization To Euchromatin, Kentaro Ohkuni, Yoshimitsu Takahashi, Alyona Fulp, Josh Lawrimore, Wei-Chun Au, Nagesh Pasupala, Reuben Levy-Myers, Jack Warren, Alexander Strunnikov, Richard E. Baker, Oliver Kerscher, Kerry Bloom, Munira A. Basrai 2017 National Cancer Institute

Sumo-Targeted Ubiquitin Ligase (Stubl) Slx5 Regulates Proteolysis Of Centromeric Histone H3 Variant Cse4 And Prevents Its Mislocalization To Euchromatin, Kentaro Ohkuni, Yoshimitsu Takahashi, Alyona Fulp, Josh Lawrimore, Wei-Chun Au, Nagesh Pasupala, Reuben Levy-Myers, Jack Warren, Alexander Strunnikov, Richard E. Baker, Oliver Kerscher, Kerry Bloom, Munira A. Basrai

Oliver Kerscher

Centromeric histone H3, CENP-ACse4, is essential for faithful chromosome segregation. Stringent regulation of cellular levels of CENP-ACse4 restricts its localization to centromeres. Mislocalization of CENP-ACse4 is associated with aneuploidy in yeast, flies and tumorigenesis in human cells; thus, defining pathways that regulate CENP-A levels is critical for understanding how mislocalization of CENP-A contributes to aneuploidy in human cancers. Previous work in budding yeast has shown that ubiquitination of overexpressed Cse4 by Psh1, an E3 ligase, partially contributes to proteolysis of Cse4. Here, we provide the first evidence that Cse4 is sumoylated by E3 ligases Siz1 and Siz2 in vivo and ...


Digital Commons powered by bepress