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2013

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Full-Text Articles in Life Sciences

The Role Of Gap-43 Phosphorylation In Axon Behavior In The Developing Zebrafish Visual System, Jennifer Forecki Dec 2013

The Role Of Gap-43 Phosphorylation In Axon Behavior In The Developing Zebrafish Visual System, Jennifer Forecki

Theses and Dissertations

Developing neurons extend processes to specific targets and establish connections that are essential for future function of the nervous system. One of these processes, the axon, has a motile tip called a growth cone that rearranges its membrane-associated actin cytoskeleton to turn toward or away from environmental guidance cues. Growth associated protein 43 (GAP-43) is one of the most abundant proteins associated with axonal growth cone membranes and is known to modulate the formation and stability of the actin cytoskeleton during axon guidance. Protein kinase C (PKC)-mediated phosphorylation of GAP-43 on serine 42 regulates its interactions with actin. Phosphorylated GAP-43 …


Molecular Events In The Cell Types Of The Olfactory Epithelium During Adult Neurogenesis, Paula M. Heron, Arnold J. Stromberg, Patrick Breheny, Timothy S. Mcclintock Nov 2013

Molecular Events In The Cell Types Of The Olfactory Epithelium During Adult Neurogenesis, Paula M. Heron, Arnold J. Stromberg, Patrick Breheny, Timothy S. Mcclintock

Physiology Faculty Publications

BACKGROUND: Adult neurogenesis, fundamental for cellular homeostasis in the mammalian olfactory epithelium, requires major shifts in gene expression to produce mature olfactory sensory neurons (OSNs) from multipotent progenitor cells. To understand these dynamic events requires identifying not only the genes involved but also the cell types that express each gene. Only then can the interrelationships of the encoded proteins reveal the sequences of molecular events that control the plasticity of the adult olfactory epithelium.

RESULTS: Of 4,057 differentially abundant mRNAs at 5 days after lesion-induced OSN replacement in adult mice, 2,334 were decreased mRNAs expressed by mature OSNs. Of the …


Zebrafish: An In Vivo Model For The Study Of Human Diseases, Bibhas Kar, Sivamani Subbiah Nov 2013

Zebrafish: An In Vivo Model For The Study Of Human Diseases, Bibhas Kar, Sivamani Subbiah

Emily Scott

The zebrafish (Danio rerio) is a powerful model organism for the study of vertebrate biology, being well suited to both developmental and genetic analysis. More recently, the rapid progress of various zebrafish genomics infrastructure initiatives is facilitating the development of zebrafish models of human disease. Genome organization and the pathways involved into control of signal transduction appear to be highly conserved between zebrafish and humans and therefore zebrafish may be used for modeling of human diseases. This review will highlight and describe the utility of zebrafish in the study of human diseases.


In Vivo Method For Labeling And Tracking Cells In The Mammalian Limb Bud, James T. Mccarthy, Andrew Schilb, Sarah Calve Oct 2013

In Vivo Method For Labeling And Tracking Cells In The Mammalian Limb Bud, James T. Mccarthy, Andrew Schilb, Sarah Calve

The Summer Undergraduate Research Fellowship (SURF) Symposium

The extracellular matrix (ECM) is composed of many different proteins excreted by cells and is believed to play a very important role in development as well as regeneration and wound healing. In this research, a method to determine the ECM’s effect on the migration of muscle progenitor cells into the mammalian limb bud was investigated. It has traditionally been difficult to obtain in vivo images of the limb bud, due to the difficulty of maintaining embryos in culture and limitations of imaging techniques. In this study, we have worked on optimizing the culture conditions to allow growth of mouse embryos …


Taking Tone Into Account: Cognitive Neuroscientific Investigations Of Mandarin Chinese Spoken Word Processing, Jeffrey G. Malins Oct 2013

Taking Tone Into Account: Cognitive Neuroscientific Investigations Of Mandarin Chinese Spoken Word Processing, Jeffrey G. Malins

Electronic Thesis and Dissertation Repository

To date, theories of how humans recognize spoken words have yet to account for tonal languages such as Mandarin Chinese. One reason for this is that we know relatively little about how native speakers of tonal languages process spoken words in the brain. This dissertation addresses this problem by examining Mandarin spoken word processing in both adult native speakers and typically developing children. In adults, functional magnetic resonance imaging (fMRI) was used to assess the extent to which the brain regions involved in processing tonal information are distinct from those involved in vowel processing (Chapter 2), while event related potentials …


Developmental Characterization Of Tissue Inhibitor Of Metalloproteinase Domain Functions In Xenopus Laevis, Michelle A. Nieuwesteeg Sep 2013

Developmental Characterization Of Tissue Inhibitor Of Metalloproteinase Domain Functions In Xenopus Laevis, Michelle A. Nieuwesteeg

Electronic Thesis and Dissertation Repository

During development the extracellular matrix is cleaved and remodeled to facilitate the large-scale cell rearrangements that are necessary for processes like gastrulation, neurulation, angiogenesis and organogenesis. ECM remodeling occurs primarily through secreted enzymes called matrix metalloproteinases (MMPs). Regulation of MMP activity is achieved through the tissue inhibitor of metalloproteinases (TIMPs), a small family of secreted proteins that bind MMPs in a 1:1 manner to inhibit their activity. Although TIMPs were originally characterized based on their MMP-inhibitory activities, in vitro studies have revealed that TIMPs are multifunctional proteins, with structurally and functionally distinct N- and C-terminal domains. TIMP N-terminal domains bind …


Understanding Less Than Nothing: Children's Neural Response To Negative Numbers Shifts Across Age And Accuracy, Margaret M. Gullick, George Wolford Sep 2013

Understanding Less Than Nothing: Children's Neural Response To Negative Numbers Shifts Across Age And Accuracy, Margaret M. Gullick, George Wolford

Dartmouth Scholarship

We examined the brain activity underlying the development of our understanding of negative numbers, which are amounts lacking direct physical counterparts. Children performed a paired comparison task with positive and negative numbers during an fMRI session. As previously shown in adults, both pre-instruction fifth-graders and post-instruction seventh-graders demonstrated typical behavioral and neural distance effects to negative numbers, where response times and parietal and frontal activity increased as comparison distance decreased. We then determined the factors impacting the distance effect in each age group. Behaviorally, the fifth-grader distance effect for negatives was significantly predicted only by positive comparison accuracy, indicating that …


Biotic Potential And Reproductive Parameters Of Spodoptera Eridania (Stoll) (Lepidoptera, Noctuidae) In The Laboratory, Débora G. Montezano, Alexandre Specht, Daniel Ricardo Sosa-Gómez, Vânia F. Roque-Specht, Neiva M. Barros Sep 2013

Biotic Potential And Reproductive Parameters Of Spodoptera Eridania (Stoll) (Lepidoptera, Noctuidae) In The Laboratory, Débora G. Montezano, Alexandre Specht, Daniel Ricardo Sosa-Gómez, Vânia F. Roque-Specht, Neiva M. Barros

Department of Entomology: Faculty Publications

Biotic potential and reprodutcive parameters of Spodoptera eridania (Stoll) (Lepidoptera, Noctuidae) in the laboratory: This study aimed to evaluate the biotic potential and reproductive parameters of Spodoptera eridania (Stoll, 1782) under controlled conditions (25 ± 1°C, 70 ± 10% RH and 14 hour photophase). The longevity, pre-, post- and oviposition periods, fecundity and fertility of 15 couples was evaluated. The longevity of females (10.80 days) was not significantly higher than those of males (9.27 days). The mean durations of the pre, post and oviposition periods were 2.067, 0.600 and 8.133 days, respectively. The mean fecundity per female was 1,398 eggs …


Beyond Climate-Smart Agriculture: Toward Safe Operating Spaces For Global Food Systems, Henry Neufeldt, Molly Jahn, Bruce M. Campbell, John R. Beddington, Fabrice Declerck, Alessandro De Pinto, Jay Gulledge, Jonathan Hellin, Mario Herrero, Andy Jarvis, David Lezaks, Holger Meinke, Todd Rosenstock, Mary Scholes, Robert Scholes, Sonja Vermeulen, Eva Wollenberg, Robert Zougmoré Aug 2013

Beyond Climate-Smart Agriculture: Toward Safe Operating Spaces For Global Food Systems, Henry Neufeldt, Molly Jahn, Bruce M. Campbell, John R. Beddington, Fabrice Declerck, Alessandro De Pinto, Jay Gulledge, Jonathan Hellin, Mario Herrero, Andy Jarvis, David Lezaks, Holger Meinke, Todd Rosenstock, Mary Scholes, Robert Scholes, Sonja Vermeulen, Eva Wollenberg, Robert Zougmoré

Rubenstein School of Environment and Natural Resources Faculty Publications

Agriculture is considered to be "climate-smart" when it contributes to increasing food security, adaptation and mitigation in a sustainable way. This new concept now dominates current discussions in agricultural development because of its capacity to unite the agendas of the agriculture, development and climate change communities under one brand. In this opinion piece authored by scientists from a variety of international agricultural and climate research communities, we argue that the concept needs to be evaluated critically because the relationship between the three dimensions is poorly understood, such that practically any improved agricultural practice can be considered climate-smart. This lack of …


The Creation Of Α2nc1 Transgenic Drosophila Melanogaster, Jordan Olberding Aug 2013

The Creation Of Α2nc1 Transgenic Drosophila Melanogaster, Jordan Olberding

Mahurin Honors College Capstone Experience/Thesis Projects

The α2 isoform of collagen IV’s noncollagenous 1 domain (α2NC1 or canstatin) has shown promise as an anti-cancer molecule, possessing both angiostatic and pro-apoptotic properties. This work aims to further the knowledge of α2NC1 by conducting a truly in vivo study in which the Gal4-induced endogenous overexpression of α2NC1 in Drosophila melanogaster will be used to assess the effects of α2NC1 upon normal development as well as tumorigenesis. To this end, transgenic fly lines capable of overexpressing α2NC1 were created. Initial overexpression studies indicated no developmental phenotype was caused by abundance of α2NC1. However, future overexpression studies in which α2NC1 …


Autism As The Early Closure Of A Neuroplastic Critical Period Normally Seen In Adolescence, Julia Marie Berger, Troy T. Rohn, Julia Thom Oxford Aug 2013

Autism As The Early Closure Of A Neuroplastic Critical Period Normally Seen In Adolescence, Julia Marie Berger, Troy T. Rohn, Julia Thom Oxford

Biology Faculty Publications and Presentations

The most severe cases of autism are diagnosed by extreme social dysfunction and other behavioral abnormalities. A number of genetic studies have been conducted to correlate behavioral phenotypes to genetic dysfunctions, but no “autism gene” has yet been discovered. In addition, environmental factors have been found to influence the development of autistic traits with high probability. This review will examine the role of a shortened period of neuroplasticity as a unifying feature of the autistic phenotype. The neuroplastic period of interest normally extends into adolescence, allowing for neural integration and the development of language and social skills. Early closure of …


Confocal Microscopy Study Of The Embryonic Development Of The Viviparous Nemertean Prosorhochmus Americanus Reveals Larval Features Supporting Indirect Development In Hoplonemerteans, S Tyler Spindle Aug 2013

Confocal Microscopy Study Of The Embryonic Development Of The Viviparous Nemertean Prosorhochmus Americanus Reveals Larval Features Supporting Indirect Development In Hoplonemerteans, S Tyler Spindle

Theses and Dissertations

Recent studies of hoplonenemertean planuliform larvae have clarified their development and provided insight into larval evolution within the phylum. However, an assessment of viviparous development using modern techniques is lacking. To help facilitate a comprehensive comparative evaluation of developmental diversity within hoplonemerteans, we have conducted a confocal laser scanning microscopy investigation of the development in Prosorhochmus americanus, one of the few viviparous hoplonemertean species. Phalloidin staining provides evidence of a modified transitory larval epidermis, and reveals that the foregut, midgut, proboscis, central nervous system, and body wall musculature form early in development, consistent with observations for planktonic and encapsulated hoplonemertean …


The Importance Of Epigenetic Phenomena In Regulating Activity Of The Genetic Material, Sin Chan Aug 2013

The Importance Of Epigenetic Phenomena In Regulating Activity Of The Genetic Material, Sin Chan

Senior Honors Projects

Genetics has taught us that genes are represented as discrete sequences within a larger DNA molecule found embedded within the chromosomes of a living cell. Collectively these chromosomes and their associated genes carry all of the instructions for life. Until recently, the prevailing thought has been that genes are destiny in the life of an individual since the genes carry the information that determines the general traits and characteristics associated with that individual. The relatively recent understanding of mechanisms that underlie epigenetic phenomena has led to a rethinking of this concept. Epigenetics describes cellular mechanisms that explain how two individuals …


Alternations Of Nmda And Gabab Receptor Function In Development: A Potential Animal Model Of Schizophrenia, Monica Bolton Aug 2013

Alternations Of Nmda And Gabab Receptor Function In Development: A Potential Animal Model Of Schizophrenia, Monica Bolton

UNLV Theses, Dissertations, Professional Papers, and Capstones

Schizophrenia is a debilitating mental disorder that affects up to 3% of the world population. The behavioral symptoms are categorized into positive and negative symptoms, which appear during late adolescence/early adulthood. Unfortunately, the underlying cellular and molecular mechanisms of the disease are poorly understood. Several hypotheses exist to explain mechanisms contributing to these behavioral alterations. One model proposes that a reduced function of the NMDA glutamate receptor on specific GABAergic interneurons may be responsible for deficits in schizophrenia. Post-mortem investigations provide evidence of reductions in both glutamate and GABA-related proteins in patients with schizophrenia. Further, GABAergic interneurons that are activated …


"Taking Care Of Yourself" -A Student Programme For Personal And Professional Development Using Reflective Journaling In The University Of Wollongong Graduate School Of Medicine, Lyndal Parker-Newlyn, Coralie Wilson, Peter Kelly Jul 2013

"Taking Care Of Yourself" -A Student Programme For Personal And Professional Development Using Reflective Journaling In The University Of Wollongong Graduate School Of Medicine, Lyndal Parker-Newlyn, Coralie Wilson, Peter Kelly

Coralie J Wilson

No abstract provided.


"Taking Care Of Yourself" -A Student Programme For Personal And Professional Development Using Reflective Journaling In The University Of Wollongong Graduate School Of Medicine, Lyndal Parker-Newlyn, Coralie Wilson, Peter Kelly Jul 2013

"Taking Care Of Yourself" -A Student Programme For Personal And Professional Development Using Reflective Journaling In The University Of Wollongong Graduate School Of Medicine, Lyndal Parker-Newlyn, Coralie Wilson, Peter Kelly

Peter Kelly

No abstract provided.


Effects Of Experimentally Elevated Traffic Noise On Nestling White-Crowned Sparrow Stress Physiology, Immune Function And Life History, Ondi L. Crino, Erin E. Johnson, Jessica L. Blickley, Gail L. Patricelli, Creagh W. Breuner Jun 2013

Effects Of Experimentally Elevated Traffic Noise On Nestling White-Crowned Sparrow Stress Physiology, Immune Function And Life History, Ondi L. Crino, Erin E. Johnson, Jessica L. Blickley, Gail L. Patricelli, Creagh W. Breuner

Biological Sciences Faculty Publications

Roads have been associated with behavioral and physiological changes in wildlife. In birds, roads decrease reproductive success and biodiversity and increase physiological stress. Although the consequences of roads on individuals and communities have been well described, the mechanisms through which roads affect birds remain largely unexplored. Here, we examine one mechanism through which roads could affect birds: traffic noise. We exposed nestling mountain white-crowned sparrows (Zonotrichia leucophrys oriantha) to experimentally elevated traffic noise for 5 days during the nestling period. Following exposure to traffic noise we measured nestling stress physiology, immune function, body size, condition and survival. Based …


The Effects Of Soil Ph And Composition On Blacklegged Tick Molting Success Avian Window Strike Mortality On Union College Campus, Kaleigh Ahern Jun 2013

The Effects Of Soil Ph And Composition On Blacklegged Tick Molting Success Avian Window Strike Mortality On Union College Campus, Kaleigh Ahern

Honors Theses

The blacklegged tick (Ixodes scapularis) is the one of the most significant vectors of infectious disease in the world and most notorious for its ability to transmit Borrelia burgdorferi, the bacteria that causes Lyme disease. Because both the range of the blacklegged tick and the annual incidence of Lyme disease have been increasing in North America over the past several decades, it is becoming increasingly important to better understand how environmental factors contribute to blacklegged tick survival. Past studies have shown that these factors include precipitation levels, extent of groundcover, plant and animal community composition, temperature, and soil type. Because …


Geographic And Ontogenetic Variation In The Contact Calls Of The Kea, Alan B. Bond, Judy Diamond May 2013

Geographic And Ontogenetic Variation In The Contact Calls Of The Kea, Alan B. Bond, Judy Diamond

Alan B. Bond

Regional and ontogenetic variation in the contact calls of the kea (Nestor notabilis), an omnivorous and socially complex New Zealand parrot, were examined throughout the range of the species. We recorded samples of kee-ah contact calls from sixteen resident adults and eleven juveniles and demonstrated significant differences between age classes in the acoustic form of the vocalization. Canonical correlation analysis revealed a gradient in the form of the kee-ah call in both adults and juveniles along and across the escarpment of the Southern Alps, the primary longitudinal mountain range on the South Island of New Zealand. Although the juvenile call …


Early Complexity Supports Development Of Motor Behaviors In The First Months Of Life, Stacey C. Dusing, Leroy R. Thacker, Nikolaos Stergiou, James C. Galloway May 2013

Early Complexity Supports Development Of Motor Behaviors In The First Months Of Life, Stacey C. Dusing, Leroy R. Thacker, Nikolaos Stergiou, James C. Galloway

Journal Articles

Complexity in motor behavior is a hallmark of healthy systems. The purpose of this study was to investigate postural complexity during development of early motor behaviors and under two conditions. Twenty-two infants participated from 1 to 6 months of age. Linear and nonlinear measures of displacement of the center of pressure at the base of support were used to quantify magnitude and temporal structure of postural control. Behavioral coding was used to quantify the emergence of midline head control and early reaching. Results suggest that infants have complexity in postural control strategies early in development. This complexity decreases as infants …


Agricultural Development In The Northern Savannah Of Ghana, Tara N. Wood May 2013

Agricultural Development In The Northern Savannah Of Ghana, Tara N. Wood

Doctor of Plant Health Program: Dissertations and Student Research

Since declaring independence in 1957, the Republic of Ghana has become a stable constitutional democracy. Ghana’s economy has grown substantially over the past decade, yet remains primarily agrarian, accounting for 50% of the total employment and 25% of the country’s Gross Domestic Product. Smallholder rain-fed farming using rudimentary technologies dominates the agricultural sector accounting for 80% of total agricultural production. Approximately 90% of smallholder farms are less than two hectares in size, and produce a diversity of crops. The major crops cultivated in Ghana include numerous cereal, root and tuber, leguminous, fruit, vegetable and industrial crops. Maize is the most …


Nutritional And Economic Analysis Of Small-Scale Agriculture In Imbabura, Ecuador, Jake Erickson May 2013

Nutritional And Economic Analysis Of Small-Scale Agriculture In Imbabura, Ecuador, Jake Erickson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Intervention projects in the developing world normally aim to satisfy either the nutritional needs of a group, or advancing the economic stability, but not both. One of the many issues that may arise by narrowly focusing and creating an aid program is that although a group may be fed, they are not equipped to mitigate risks that will arise after project completion and thus continue or revert back to a malnourished state. A bridge is required to join the economic and nutritional programs to create aid interventions that are sustainable past the point of donor separation.

This paper proposes the …


Evaluation Of Survey Methods And Development Of Species Distribution Models For Kit Foxes In The Great Basin Desert, Stephen J. Dempsey May 2013

Evaluation Of Survey Methods And Development Of Species Distribution Models For Kit Foxes In The Great Basin Desert, Stephen J. Dempsey

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Historically, kit foxes (Vulpes macrotis) once occupied the desert and semi-arid regions of southwestern North America, ranging from Idaho to central Mexico. Their range-wide decline has warranted the kit fox to be designated as a state sensitive species in Utah. Once considered the most abundant carnivore in western Utah, the kit fox has been in steep decline over the past decade, creating a demand to determine kit fox presence in the Great Basin desert. Currently there is little consensus on which survey methodology is best for detecting kit fox presence. We tested 4 survey methods (scat deposition, scent …


Development Of The Sar Tt-Osl Procedure For Dating Middle Pleistocene Dune And Shallow Marine Deposits Along The Southern Cape Coast Of South Africa, Zenobia Jacobs, Richard Roberts, Terry Lachlan, Panagiotis Karkanas, Curtis Marean, David Roberts Mar 2013

Development Of The Sar Tt-Osl Procedure For Dating Middle Pleistocene Dune And Shallow Marine Deposits Along The Southern Cape Coast Of South Africa, Zenobia Jacobs, Richard Roberts, Terry Lachlan, Panagiotis Karkanas, Curtis Marean, David Roberts

Richard G Roberts

Optically stimulated luminescence (OSL) dating is now commonly used to estimate the depositional age of Quaternary landforms along the southern Cape coast of South Africa. Due to the early onset of dose saturation in the quartz-rich sediments from this region, determining the age of deposits much older than the last three glacio-eustatic sea-level high stands has been a challenge. In this study, we explored the feasibility of using the thermally-transferred OSL (TT-OSL) dating method to obtain ages for aeolian and shallow marine deposits at three different localities that hold promise to further illuminate the long and complex Late Quaternary sea-level …


Synthesizing Larval Competence Dynamics And Reef-Scale Retention Reveals A High Potential For Self-Recruitment In Corals, Joana Figueiredo, Andrew H. Baird, Sean R. Connolly Mar 2013

Synthesizing Larval Competence Dynamics And Reef-Scale Retention Reveals A High Potential For Self-Recruitment In Corals, Joana Figueiredo, Andrew H. Baird, Sean R. Connolly

Marine & Environmental Sciences Faculty Articles

Many organisms have a complex life-cycle in which dispersal occurs at the propagule stage. For marine environments, there is growing evidence that high levels of recruitment back to the natal population (self-recruitment) are common in many marine organisms. For fish, swimming behavior is frequently invoked as a key mechanism allowing high self-recruitment. For organisms with weak-swimming larvae, such as many marine invertebrates, the mechanisms behind self-recruitment are less clear. Here, we assessed whether the combination of passive retention of larvae due to re-circulation processes near reefs, and the dynamics of settlement competence, can produce the high levels of self-recruitment previously …


Bryophyte Species Composition Over Moisture Gradients In The Windmill Islands, East Antarctica: Development Of A Baseline For Monitoring Climate Change Impacts, J Wasley, S A. Robinson, J D. Turnbull, D H. King, W Wanek, M Popp Feb 2013

Bryophyte Species Composition Over Moisture Gradients In The Windmill Islands, East Antarctica: Development Of A Baseline For Monitoring Climate Change Impacts, J Wasley, S A. Robinson, J D. Turnbull, D H. King, W Wanek, M Popp

Sharon Robinson

Extreme environmental conditions prevail on the Antarctic continent and limit plant diversity to cryptogamic communities, dominated by bryophytes and lichens. Even small abiotic shifts, associated with climate change, are likely to have pronounced impacts on these communities that currently exist at their physiological limit of survival. Changes to moisture availability, due to precipitation shifts or alterations to permanent snow reserves, will most likely cause greatest impact. In order to establish a baseline for determining the effect of climate change on continental Antarctic terrestrial communities and to better understand bryophyte species distributions in relation to moisture in a floristically important Antarctic …


Immature Stages Of Spodoptera Albula (Walker) (Lepidoptera: Noctuidae): Developmental Parameters And Host Plants, Débora G. Montezano, Alexandre Specht, Tarciso M. Bortolin, Edegar Fronza, Daniel Ricardo Sosa-Gómez, Vânia F. Roque-Specht, Patricia Pezzi, Priscila C. Luz, Neiva M. Barros Jan 2013

Immature Stages Of Spodoptera Albula (Walker) (Lepidoptera: Noctuidae): Developmental Parameters And Host Plants, Débora G. Montezano, Alexandre Specht, Tarciso M. Bortolin, Edegar Fronza, Daniel Ricardo Sosa-Gómez, Vânia F. Roque-Specht, Patricia Pezzi, Priscila C. Luz, Neiva M. Barros

Department of Entomology: Faculty Publications

This study aimed to detail the temporal and morphological parameters of the immature stages of Spodoptera albula (Walker 1857) under controlled conditions (25 ± 1°C, 70 ± 10% RH and 14 hour photophase) and to gather information about their larval host plants. For this purpose, a new rearing method and artificial diet was employed and validated. The viability of the egg, larval, pupal and pre-pupal stages was 94.54, 97.33, 93.84 and 92.34%, respectively. The average duration of the egg, larval, pupal and pre-pupal stages was 4.14, 16.37, 1.69, and 9.34 days, respectively. During the larval stage, 80.85% of females and …


The Pea Aphid Uses A Version Of The Terminal System During Oviparous, But Not Viviparous, Development, Ryan D. Bickel, Hillary C. Cleveland, Joanna Barkas, Caitlin C. Jeschke, Amelie A. Raz, David L. Stern, Gregory K. Davis Jan 2013

The Pea Aphid Uses A Version Of The Terminal System During Oviparous, But Not Viviparous, Development, Ryan D. Bickel, Hillary C. Cleveland, Joanna Barkas, Caitlin C. Jeschke, Amelie A. Raz, David L. Stern, Gregory K. Davis

Biology Faculty Research and Scholarship

Background: In most species of aphid, female nymphs develop into either sexual or asexual adults depending on the length of the photoperiod to which their mothers were exposed. The progeny of these sexual and asexual females, in turn, develop in dramatically different ways. The fertilized oocytes of sexual females begin embryogenesis after being deposited on leaves (oviparous development) while the oocytes of asexual females complete embryogenesis within the mother (viviparous development). Compared with oviparous development, viviparous development involves a smaller transient oocyte surrounded by fewer somatic epithelial cells and a smaller early embryo that comprises fewer cells. To investigate …


Developmental Changes In Postural Stability During The Performance Of A Precision Manual Task, Jeffrey M. Haddad, Laura J. Claxton, Dawn Melzer, Joseph Hamill, Richard E. A. Van Emmerik Jan 2013

Developmental Changes In Postural Stability During The Performance Of A Precision Manual Task, Jeffrey M. Haddad, Laura J. Claxton, Dawn Melzer, Joseph Hamill, Richard E. A. Van Emmerik

Psychology Faculty Publications

Posture becomes integrated with other goal-directed behaviors early in infancy and continues to develop into the second decade of life. However, the developmental time course over which posture is stabilized relative to the base of support during a dynamic manual precision task has not been examined. Postural-manual integration was assessed in 7-year-olds, 10-year-olds, and adults using a postural-manual task in which task precision (target fitting size) and postural difficulty (reaching distance to a target) were manipulated. The main dependent variable was postural time-to-contact (TtC). Results indicated systematic age effects in which TtC was shortest in the 7-year-olds, increased in the …


First Record Of Pond Sliders (Trachemys Scripta Scripta And T. S. Elegans) At Fredericksburg, Virginia With Observations On Population Size, Age And Growth, Werner Wieland, Yoshinori Takeda Jan 2013

First Record Of Pond Sliders (Trachemys Scripta Scripta And T. S. Elegans) At Fredericksburg, Virginia With Observations On Population Size, Age And Growth, Werner Wieland, Yoshinori Takeda

Virginia Journal of Science

We conducted a turtle mark-recapture program within a 160 m stretch of the Fredericksburg Canal with standard, baited hoop nets from May to July 2012 to determine if a population of the introduced Red-eared Slider (Trachemys scripta elegans) and Yellow-bellied Slider (Trachemys s. scripta) are established in this area. We captured and marked nine Red-eared Sliders (1 male, 8 females) and estimated a population size of 23 individuals. Most were reproductively mature. The established population in the canal may be a source of introduction into the Rappahannock River.