Life Sciences Commons^™

Fgf4 And Wnt5a/Pcp Signaling Promote Limb Outgrowth By Polarizing Limb Mesenchyme, Keri Lynn Low

Theses and Dissertations

The focus of this study was to elucidate the molecular and cellular mechanisms whereby fibroblast growth factors (FGFs) mediate outgrowth of the limb. Specifically, we examined the epistatic relationship between FGF and Wnt/Planar cell polarity (PCP) signaling in establishing cell polarity as a mechanism for outgrowth. By implanting beads into embryonic limbs and lateral plate mesoderm, we established that FGF activates Wnt5a in a gradient fashion. Once it was established that Wnt5a was expressed at the right time and place to turn on PCP signaling, we investigated the ability of Wnt5a to influence cell migration and/or cell polarity. Our analysis …

Policy Tools For Smart Growth In New England, New England Environmental Finance Center

Smart Growth

Across New England communities have been experiencing a rapid outward surge of development away from our community and downtown centers. Effects of sprawl include a loss of wildlife habitat, farm and timber lands; increased costs of community services and higher taxes; auto-dependency, longer commutes, and increased congestion; increases in air and water pollution; a sedentary lifestyle and increased obesity; and losses to one’s sense of place and social ties.

State-level responses to sprawl have surfaced throughout New England in recent years. This report describes 11 examples of these responses, representing all six New England states and a diversity of recent …

Interval Timer Control Of Puberty In Photoinhibited Siberian Hamsters, Ho Park Jin, Alexander S. Kauffman, Matthew J. Paul, Matthew P. Butler, Annaliese K. Beery, Ruth M. Costantini, Irving Zucker

Neuroscience: Faculty Publications

Puberty, which is markedly delayed in male Siberian hamsters (Phodopus sungorus) born into short day lengths, is controlled by an interval timer regulated by the duration of nocturnal melatonin secretion. Properties of the interval timer were assessed by perturbing normal patterns of melatonin secretion in males gestated and maintained thereafter in 1 of 2 short day lengths, 10 h light/day (10L) or 12L. Melatonin secretion of short-day hamsters was suppressed by constant light treatment or modified by daily injection of propranolol to mimic nocturnal melatonin durations typical of long-day hamsters. Constant light treatment during weeks 3 to 5 induced early …

Testing An Ecophysiological Mechanism Of Morphological Plasticity In Pupfish And Its Relevance To Conservation Efforts For Endangered Devils Hole Pupfish, Sean C. Lema, Gabrielle A. Nevitt

Biological Sciences

Imperiled species that have been translocated or established in captivity can show rapid alterations in morphology and behavior, but the proximate mechanisms of such phenotypic changes are rarely known. Devils Hole pupfish (Cyprinodon diabolis) are endemic to a single desert pool and are characterized by a small body, large head and eyes, and lack of pelvic fins. To lessen the risk of extinction, additional populations of C. diabolis were established in artificial refuges. Yet, pupfish in these refuges rapidly shifted to a larger body, smaller head and eyes, and greater body depth. Here we examined how food availability …

The Growing Together Guide: A Companion Resource To The New England Environmental Finance Center/Melissa Paly Film, New England Environmental Finance Center

Smart Growth

What local leader or public official wants to be faced with an SOS the “same old story” of public discord and confrontation over growth and development in one’s community? That situation has become a problem for efforts to promote smart growth. Investments are needed in the walkable, compact, traditional‐streetscape and mixed use neighborhoods and developments that are more sustainable and healthy than sprawl, for both people and the landscape. Yet attempts at such change all too often end up mired in costly public controversy and stalemate.

Population Divergence In Plasticity Of The Avt System And Its Association With Aggressive Behaviors In A Death Valley Pupfish, Sean C. Lema

Biological Sciences

Behavioral differences can evolve rapidly in allopatry, but little is known about the neural bases of such changes. Allopatric populations of Amargosa pupfish (Cyprinodon nevadensis) vary in aggression and courtship behaviors in the wild. Two of these wild populations were recently found to differ in brain expression of arginine vasotocin (AVT)—a peptide hormone shown previously to modulate aggression in pupfish. These populations have been isolated for less than 4000 years, so it remained unclear whether the differences in behavior and neural AVT phenotype were evolved changes or plastic responses to ecologically dissimilar habitats. Here, I tested whether these …

Evolutionary Genetics Of Juvenile Hormone And Ecdysteroid Regulation In Gryllus: A Case Study In The Microevolution Of Endocrine Regulation, Anthony J. Zera

Anthony Zera Publications

During the past 15 years the first detailed synthesis of endocrinology and population genetics has begun, in which natural genetic variations for endocrine regulators have been characterized, almost exclusively in species of the cricket genus Gryllus. Artificial selection studies have documented that regulators of the juvenile hormone titer can rapidly evolve and exhibit levels of genetic variability similar to other physiological traits. Strong genetic correlations exist between some but not all regulators of the JH titer during the juvenile stage. No genetic correlation exists between regulators functioning in juvenile and adult stages, and thus, endocrine regulation can evolve independently in …

The Role Of Fgfr4 In Trigeminal Placode Cell Development, Stephanie Beth Reynolds

Theses and Dissertations

In vertebrate embryos, the ophthalmic trigeminal (opV) placode contributes sensory neurons to the trigeminal ganglion during development of the peripheral nervous system. FGFR4 is expressed transiently in the trigeminal placode as cells undergo an epithelial-mesenchymal transition and begin to migrate toward the condensing ganglion. Because of the restricted spatiotemporal expression of FGFR4 in the opV placode, it was hypothesized that FGFR4 is necessary for the process of epithelial-mesenchymal transition in the opV placode. Using electroporation, an FGFR4 inhibitory gene construct was introduced into 6—10 somite stage chick embryos. This secreted inhibitory form of the FGFR4 gene blocked endogenous FGFR4 signaling, …

Patterns Of Floral Structure And Orientation In Japonolirion , Narthecium, And Tofieldia, Margarita V. Remizowa, Dmitry D. Sokoloff, Paula J. Rudall

Aliso: A Journal of Systematic and Floristic Botany

Floral evolution requires reassessment in basal monocots, including species formerly assigned to Melanthiaceae, in the light of recent developments in the molecular phylogenetics of monocots. We have investigated flowers of Tofieldia (Tofieldiaceae), Japonolirion (Petrosaviaceae), and Narthecium (Nartheciaceae). We confirm Engler's (1888) hypothesis that orientation of lateral flowers in monocots is dependent on presence and position of additional phyllomes on the pedicel. The type of floral orientation that occurs in Tofieldia is unusual for monocots, since the additional phyllomes are represented by calyculus scales rather than a bracteole, and the outer whorl tepals are initiated alternating with the calyculus scales. In …

Knee Valgus In Self-Initiated Vertical Jump Landings: Developmental And Gender Comparisons, Pamela J. Russell, Erik E. Swartz, Laura C. Decoster, Ron V. Croce

Movement Arts, Health Promotion and Leisure Studies Faculty Publications

The study examined gender and developmental differences in knee valgus angle and external knee valgus moment at the time of maximal vertical ground reaction force (MGRFz) in self-initiated vertical jump (VJ) landings. Fifty-six subjects grouped by age (pre-pubescent (8-11 yrs); post-pubescent (19-29 yrs)) and gender jumped for a ball set at 50% of their maximum VJ height then landed on two feet with only their dominant foot on the force plate. Statistical analyses of motion analysis (3-D) and GRF data showed that children had greater valgus angles (p = .003) and moments (p = .026) at MGRFz compared to adults. …

Neuronal Pentraxins Mediate Synaptic Refinement In The Developing Visual System, Lisa Bjartmar, Andrew Huberman, Erik Ullian, Rene Renterıa, Xiaoqin Liu, Weifeng Xu, Jennifer Prezioso, Michael Susman, David Stellwagen, Caleb Stokes, Richard Cho, Paul Worley, Robert Malenka, Sherry Ball, Neal Peachey, David Copenhagen, Barbara Chapman, Masaru Nakamoto, Ben Barres, Mark Perin

Biology Faculty Publications

Neuronal pentraxins (NPs) define a family of proteins that are homologous to C-reactive and acute-phase proteins in the immune system and have been hypothesized to be involved in activity-dependent synaptic plasticity. To investigate the role of NPs in vivo , we generated mice that lack one, two, or all three NPs. NP1/2 knock-out mice exhibited defects in the segregation of eye-specific retinal ganglion cell (RGC) projections to the dorsal lateral geniculate nucleus, a process that involves activity-dependent synapse formation and elimination. Retinas from mice lacking NP1 and NP2 had cholinergically driven waves of activity that occurred at a frequency similar …

Clinician Optimism: Development And Psychometric Analysis Of A Scale For Mental Health Clinicians, Mitchell K. Byrne, Nichole L. Sullivan, Stephen J. Elsom

Faculty of Health and Behavioural Sciences - Papers (Archive)

Clinician optimism is an important factor in achieving treatment outcomes in psychotherapy. Currently there are no measures of mental health clinician optimism which report substantial psychometric validation. This study sought to assesses the validity and reliability of the Therapeutic Optimism Scale (TOS). 223 mental health clinicians working in a range of clinical settings were administered the TOS and convergent and discriminate validity were established. Test-retest reliability was established over a period of one month. The Therapeutic Optimism Scale was found to achieve acceptable reliability (Chronbach's alpha = .68) and yielded consistent scores over a one month period (r = .68, …

Stages Of Recovery Instrument: Development Of A Measure Of Recovery From Serious Mental Illness., Retta Andresen, Peter Caputi, Lindsay G. Oades

Faculty of Health and Behavioural Sciences - Papers (Archive)

Objective: In order to realize the vision of recovery-orientated mental health services, there is a need for a model and a method of measuring recovery as the concept is described by mental health consumers. A preliminary five-stage model based on consumer accounts was developed in an earlier study by the authors. This next stage of the research program describes the development and initial testing of a stage measure which, when validated, can be used in testing that model. Method: Existing measures of recovery were reviewed to assess their concordance with the model, and a new measure, the Stages of Recovery …

Development Of Robust Guidelines And Assessment Procedures For Metal Contaminated Sediments, David Strom, Stuart L. Simpson, Dianne F. Jolley

Faculty of Science - Papers (Archive)

Assessment of contaminated sediments and development of remediation strategies is becoming an important priority for regulators and industries worldwide. Although sediment quality assessment frameworks exist, poor scientific procedures and a limited understanding of species sensitivity to common contaminants hinders most assessment programs. Globally, sediment quality guidelines (SQGs) for metals vary over several orders of magnitude and are not based on clear cause-effect relationships. Although equilibrium partitioning approaches to developing SQGs have been attempted, the cause-effect relationships are weak due to the many other modifying factors that influence metal bioavailability and toxicity. The inherent lack of defensible SQGs for metals currently …

A Comparison Of The Development Times Of Trissolcus Rufiventris (Mayr) And Trissolcus Simoni Mayr (Hym.: Scelionidae) At Three Constant Temperatures, Müjgan Kivan, Ni̇hal Kiliç

Turkish Journal of Agriculture and Forestry

The effects of temperature on the development of the egg parasitoids Trissolcus rufiventris (Mayr) and Trissolcus simoni Mayr (Hym.: Scelionidae) were determined at 3 constant temperatures. Female development ranged from 6.9 days at 32 °C to 22.5 days at 20 °C for T. rufiventris, and from 9.2 days at 32 °C to 24.7 days at 20 °C for T. simoni. The average development time of males was shorter than that of females for each parasitoid species. The development of female T. rufiventris required 125.0 degree-days above the theoretical threshold of 15.5 °C and that of males required 111.1 degree-days above …

The Biology Of Canadian Weeds. 133. Cuscuta Campestris Yuncker, C. Gronovii Willd. Ex Schult., C. Umbrosa Beyr. Ex Hook., C. Epithymum (L.) L. And C. Epilinum Weihe, Mihai Costea, François J. Tardif

Biology Faculty Publications

Cuscuta spp. (dodders) are rootless, holoparasitic herbs with filiform stems attached to the host by numerous haustoria. In Canada, Cuscuta gronovii is the most common native species of the genus followed by Cuscuta campestris and C. umbrosa. Cuscuta epithymum and C. epilinum, both introduced species in Canada, occur occasionally. Infestation by Cuscuta spp. can result in serious yield losses and dodders are listed as noxious weeds in British Columbia, Ontario and Québec, and as restricted weeds in Alberta. These plants have evolved special adaptations to ensure their success: germination occurs late in the season when potential hosts are …

Sexual Dimorphic Social Development And Female Intrasexual Chemical Signaling Of African Elephants (Loxodonta Africana), Jordana M. Meyer

Electronic Theses and Dissertations

Author's abstract: African elephants are a polygynous species in which males and females carry out dimorphic lifestyles. Males search and compete for reproductively active females, while females care for offspring and facilitate group cohesion. The objectives of this study was a) to compare the development of sexually dimorphic behaviors and developmental trends between young male and female wild African elephants and b) to determine the ability of captive female African elephants to discern between the follicular and luteal phase of conspecifics through trunk-tip contacts and the investigation of urine, and whether the reproductive phase of the receiver affected the response …