Digital Commons Network^™

Fluid Interactions That Enable Stealth Predation By The Upstream-Foraging Hydromedusa Craspedacusta Sowerbyi, K. Lucas, S. P. Colin, J. H. Costello, K. Katja, E. Klos

Graduate School of Oceanography Faculty Publications

Unlike most medusae that forage with tentacles trailing behind their bells, several species forage upstream of their bells using aborally located tentacles. It has been hypothesized that these medusae forage as stealth predators by placing their tentacles in more quiescent regions of flow around their bells. Consequently, they are able to capture highly mobile, sensitive prey. We used digital particle image velocimetry (DPIV) to quantitatively characterize the flow field around Craspedacusta sowerbyi, a freshwater upstream-foraging hydromedusa, to evaluate the mechanics of its stealth predation. We found that fluid velocities were minimal in front and along the sides of the …

Equatorial Pacific Peak In Biological Production Regulated By Nutrient And Upwelling During The Late Pliocene/Early Pleistocene Cooling, J. Etourneau, Rebecca S. Robinson, P. Martinez, R. Schneider

Graduate School of Oceanography Faculty Publications

The largest increase in export production in the eastern Pacific of the last 5.3 Myr (million years) occurred between 2.2 and 1.6 Myr, a time of major climatic and oceanographic reorganization in the region. Here, we investigate the causes of this event using reconstructions of export production, nutrient supply and oceanic conditions across the Pliocene–Pleistocene in the eastern equatorial Pacific (EEP) for the last 3.2 Myr. Our results indicate that the export production peak corresponds to a cold interval marked by high nutrient supply relative to consumption, as revealed by the low bulk sedimentary ¹⁵N/¹⁴N (δ^{15 …}

Divergent Eddy Heat Fluxes In The Kuroshio Extension At 144°–148°E. Part I: Mean Structure, Stuart P. Bishop, D. Randolph Watts, Kathleen A. Donohue

Graduate School of Oceanography Faculty Publications

The Kuroshio Extension System Study (KESS) provided 16 months of observations to quantify eddy heat flux (EHF) from a mesoscale-resolving array of current- and pressure-equipped inverted echo sounders (CPIES). The mapped EHF estimates agreed well with point in situ measurements from subsurface current meter moorings. Geostrophic currents determined with the CPIES separate the vertical structure into an equivalent-barotropic internal mode and a nearly depth-independent external mode measured in the deep ocean. As a useful by-product of this decomposition, the divergent EHF (DEHF) arises entirely from the correlation between the external mode and the upper-ocean thermal front. EHFs associated with the …

A Low‐Relief Shield Volcano Origin For The South Kaua‘I Swell, Garrett Ito, Michael O. Garcia, John R. Smith, Brian Taylor, Ashton Flinders, Brian Jicha, Seiko Yamasaki, Dominique Weis, Lisa Swinnard, Chuck Blay

Graduate School of Oceanography Faculty Publications

The South Kaua‘i Swell (SKS) is a 110 km x 80 km ovoid bathymetric feature that stands >2 km high and abuts the southern flank of the island of Kaua‘i. The origin of the SKS was investigated using multibeam bathymetry and acoustic backscatter, gravity data, radiometric ages, and geochemistry of rock samples. Most of the SKS rock samples are tholeiitic in composition with ages of 3.9–5.4 Ma indicating they were derived from shield volcanism. The ages and compositions of the SKS rocks partially overlap with those of the nearby Ni‘ihau, Kaua‘i and West Ka‘ena volcano complexes. The SKS was originally …

New Insights Into Hydrothermal Vent Processes In The Unique Shallow-Submarine Arc-Volcano, Kolumbo (Santorini), Greece, Stephanos P. Kilias, Paraskevi Nomikou, Dimitrios Pappanikolaou, Paraskevi N. Polymenakou, Athanasios Godelitsas, Ariadne Argyraki, Steven Carey, Platon Gamaletsos, Theo J. Mertzimekis, Elenie Stathopoulou, Joerg Goettlicher, Ralph Steininger, Konstantina Betzelou, Isidoros Livanos, Christos Christakis, Katherine Croff Bell, Michael Scoullos

Graduate School of Oceanography Faculty Publications

We report on integrated geomorphological, mineralogical, geochemical and biological investigations of the hydrothermal vent field located on the floor of the density-stratified acidic (pH ~ 5) crater of the Kolumbo shallow-submarine arc-volcano, near Santorini. Kolumbo features rare geodynamic setting at convergent boundaries, where arc-volcanism and seafloor hydrothermal activity are occurring in thinned continental crust. Special focus is given to unique enrichments of polymetallic spires in Sb and Tl (±Hg, As, Au, Ag, Zn) indicating a new hybrid seafloor analogue of epithermal-to-volcanic-hosted-massive-sulphide deposits. Iron microbial-mat analyses reveal dominating ferrihydrite-type phases, and high-proportion of microbial sequences akin to "Nitrosopumilus maritimus", a …

Microbial Activity In The Marine Deep Biosphere: Progress And Prospects, Beth N. Orcutt, Douglas E. Larowe, Jennifer F. Biddle, Frederick S. Colwell, Brian T. Glazer, Brandi Kiel Reese, John B. Kirkpatrick, Laura L. Lapham, Heath J. Mills, Jason B. Sylvan, Scott D. Wankel, C. Geoff Wheat

Graduate School of Oceanography Faculty Publications

The vast marine deep biosphere consists of microbial habitats within sediment, pore waters, upper basaltic crust and the fluids that circulate throughout it. A wide range of temperature, pressure, pH, and electron donor and acceptor conditions exists—all of which can combine to affect carbon and nutrient cycling and result in gradients on spatial scales ranging from millimeters to kilometers. Diverse and mostly uncharacterized microorganisms live in these habitats, and potentially play a role in mediating global scale biogeochemical processes. Quantifying the rates at which microbial activity in the subsurface occurs is a challenging endeavor, yet developing an understanding of these …

The Mean Composition Of Ocean Ridge Basalts, Allison Gale, Colleen A. Dalton, Charles H. Langmuir, Yongjun Su, Jean-Guy Schilling

Graduate School of Oceanography Faculty Publications

The mean composition of mid‐ocean ridge basalts (MORB) is determined using a global data set of major elements, trace elements, and isotopes compiled from new and previously published data. A global catalog of 771 ridge segments, including their mean depth, length, and spreading rate enables calculation of average compositions for each segment. Segment averages allow weighting by segment length and spreading rate and reduce the bias introduced by uneven sampling. A bootstrapping statistical technique provides rigorous error estimates. Based on the characteristics of the data, we suggest a revised nomenclature for MORB. “ALL MORB” is the total composition of the …

Rebuilding Fish Communities: The Ghost Of Fisheries Past And The Virtue Of Patience, Jeremy Collie, Marie-Joëlle Rochet, Richard Bell

Graduate School of Oceanography Faculty Publications

The ecosystem approach to management requires the status of individual species to be considered in a community context. We conducted a comparative ecosystem analysis of the Georges Bank and North Sea fish communities to determine the extent to which biological diversity is restored when fishing pressure is reduced. First, fishing mortality estimates were combined to quantify the community‐level intensity and selectivity of fishing pressure. Second, standardized bottom‐trawl survey data were used to investigate the temporal trends in community metrics. Third, a size‐based, multispecies model (LeMans) was simulated to test the response of community metrics to both hypothetical and observed changes …

The Contribution Of Eddies To Striations In Absolute Dynamic Topography, C. E. Buckingham, Peter C. Cornillon

Graduate School of Oceanography Faculty Publications

Distinct 4 year averages of absolute dynamic topography reveal striations in all ocean basins during 1993–2008. Striations are alternating mesoscale jet‐like structures observed in time‐averaged zonal geostrophic velocity, ū. They are characterized by speeds O(1 cm s^–1) and are nominally separated by 200 km in the meridional direction. Similar patterns have been observed in sea level anomaly, mean dynamic topography, and Argo float measurements. Use of a tracked‐eddy database in concert with a contour identification and eddy removal algorithm demonstrates that eddies are a dominant source of striations in ū in the South Pacific (20°S–50°S, 200°E–280°E). Eddies …

Predation On Prerecruits Can Delay Rebuilding Of Depleted Cod Stocks, Jeremy Collie, Cóilín Minto, Boris Worm, Richard Bell

Graduate School of Oceanography Faculty Publications

Predation by clupeoid species (e.g., Atlantic herring, Clupea harengus Linnaeus, 1758) on the early life stages of gadoids is hypothesized to be an important source of mortality, especially for Atlantic cod, Gadus morhua Linnaeus, 1758. Adult cod also prey on herring, creating a positive feedback process ("trophic triangle") that may result in alternative dominance patterns of cod or herring depending on the relative levels of mortality. We estimated the effect of herring on cod recruitment with a predator-dependent Ricker stock-recruitment function, fit to time-series data. In this formulation, herring gradually reduce the per capita recruitment rate of cod, but this …

Price Bundling Opportunities For The Charleston (Sc) Tourism Market, Mark Mitchell, Michael Collins, Gregory Turner, Jordan Smith

AMTP Proceedings 2013

The Charleston area offers a rich mix of historical, cultural, educational, social, and natural entertainment options for visitors. This paper examines the possibility of price bundling of area attractions to offer a lower price to area visitors. Two options are advanced: Targeted Selections and Broader Selections. Finally, market-specific factor influencing implementation are discussed.

Influence Of Atypical Choices By Dissociative And Aspirational Reference Groups On Preferences Of Consumers Varying On Social Comparison Proneness, Magdoleen Ierlan

AMTP Proceedings 2013

Using Festinger and Tesser’s work on social comparison as the theoretical framework, this study investigates how consumer spending is influenced by atypical spending in comparative reference groups. Specifically, two experiments examine how and why consumers, who exhibit either high or low tendencies to compare themselves with others, will alter their spending when they observe their aspirational (i.e., more affluent) and dissociative (i.e., less affluent) reference groups spending money in ways that are atypical. To test the strength of the influence of these comparisons, participants are asked to make consumer decisions with regard to public products (those used in front of …

The Effects Of Housing Manipulations On Wheel Running, Feeding And Body Weight In Female Rats, Angela Mastroianni

Theses and Dissertations (Comprehensive)

Providing rats with running wheel access results in a short-term reduction in feeding and body weight relative to controls; known as the wheel-induced feeding suppression (WIFS). WIFS may parallel aspects of anorexia nervosa, an eating disorder that mostly affects females. Yet, most studies of WIFS and related models use male rats. The present study included female and male rats, where half were given wheel access to measure effects on feeding and body weight. Replication 1 females and Replication 2 males were in unisex housing. Replication 3 males and females were housed in same room. Rats were individually (IH) or pair …

Equation Of State And Isentropic Releasem Of Aluminum Foam And Fluoropolymer Composites, John Borg, Warren R. Maines, Mike Nixon, Lalit Chhabildas

Mechanical Engineering Faculty Research and Publications

There is considerable interest in developing a better understanding of the dynamic behavior of heterogeneous materials. This study investigates and compares the dynamic response of 20 and 47% dense aluminum foam systems with and without a polytetrafluoroethylene (PTFE or Teflon) fill. Experiments on 47% foam were conduced in a 60 mm bore gun in a reverse ballistic configuration at velocities ranging from 350 m/s to 2.5 km/s. The particle velocity of the backside of the anvil was monitored with a VISAR system. Mesoscale simulations are in good agreement with the available experimental data. Both the experimental and simulated data are …

Sand Penetration: A Near Nose Investigation Of A Sand Penetration Event, Andrew Van Vooren, John Borg, Joshua Felts

Mechanical Engineering Faculty Research and Publications

This paper presents experimental and computational results of a long-rod penetrating dry granular sand at velocities near 100 m/s. The objective of this work is to develop a fundamental understanding of the formation and transmission of dynamic force chains, and the motion and fracture of the individual sand grains as the projectile passes. This is accomplished by launching a projectile along a view window, backed by sand, in order to directly view and photograph the projectile/sand interactions. Within the sand system, a two-wave structure was observed, composed of a compaction wave (bow shock) that detaches from the dart and moves …

Centerline Extraction For Image Segmentation Using Gradient And Direction Vector Flow Active Contours, Shuqun Zhang, Jianyang Zhou

Publications and Research

In this paper, we propose a fast centerline extraction method to be used for gradient and direction vector flow of active contours. The gradient and direction vector flow is a recently reported active contour model capable of significantly improving the image segmentation performance especially for complex object shape, by seamlessly integrating gradient vector flow and prior directional information. Since the prior directional information is provided by manual line drawing, it can be inconvenient for inexperienced users who might have difficulty in finding the best place to draw the directional lines to achieve the best segmentation performance. This paper describes a …

Corticospinal Reorganization After Locomotor Training In A Person With Motor Incomplete Paraplegia, Nupur Hajela, Chaithanya K. Mummidisetty, Andrew C. Smith, Maria Knikou

Publications and Research

Activity-dependent plasticity as a result of reorganization of neural circuits is a fundamental characteristic of the central nervous system that occurs simultaneously in multiple sites. In this study, we established the effects of subthreshold transcranial magnetic stimulation (TMS) over the primary motor cortex region on the tibialis anterior (TA) long-latency flexion reflex. Neurophysiological tests were conducted before and after robotic gait training in one person with a motor incomplete spinal cord injury (SCI) while at rest and during robotic-assisted stepping. The TA flexion reflex was evoked following nonnociceptive sural nerve stimulation and was conditioned by TMS at 0.9 TA motor …

Larval Connectivity And The International Management Of Fisheries, Andrew S. Kough, Claire B. Paris, Mark J. Butler Iv

Biological Sciences Faculty Publications

Predicting the oceanic dispersal of planktonic larvae that connect scattered marine animal populations is difficult, yet crucial for management of species whose movements transcend international boundaries. Using multi-scale biophysical modeling techniques coupled with empirical estimates of larval behavior and gamete production, we predict and empirically verify spatio-temporal patterns of larval supply and describe the Caribbean-wide pattern of larval connectivity for the Caribbean spiny lobster (Panulirus argus), an iconic coral reef species whose commercial value approaches $1 billion USD annually. Our results provide long sought information needed for international cooperation in the management of marine resources by identifying lobster larval connectivity …

Conus: First Comprehensive Conservation Red List Assessment Of A Marine Gastropod Mollusc Genus, Howard Peters, Bethan C. O'Leary, Julie P. Hawkins, Kent E. Carpenter, Callum M. Roberts

Biological Sciences Faculty Publications

Marine molluscs represent an estimated 23% of all extant marine taxa, but research into their conservation status has so far failed to reflect this importance, with minimal inclusion on the authoritative Red List of the International Union for the Conservation of Nature (IUCN). We assessed the status of all 632 valid species of the tropical marine gastropod mollusc, Conus (cone snails), using Red List standards and procedures to lay the groundwork for future decadal monitoring, one of the first fully comprehensive global assessments of a marine taxon. Three-quarters (75.6%) of species were not currently considered at risk of extinction owing …

The Influence Of Calcium And Dissolved Organic Matter On The Acute And Chronic Toxicity Of Nickel To Hyalella Azteca, Katherine Chan

Theses and Dissertations (Comprehensive)

This study focuses on the effect of Ca and dissolved organic matter (DOM) on Ni toxicity to Hyalella azteca in soft waters (interpreted in the context of the biotic ligand model (BLM)) and is linked to a larger project directed at understanding the recovery of aquatic systems from long term smelter damage. Amphipods (source: Hannah Lake, Sudbury ON) were cultured and tested in soft waters (12 mg CaCO₃/L, pH 7.0, 21ºC) following Environment Canada standard method EPS 1/RM/33 (Environment Canada, 1997). Effects of Ca, but not Mg, were observed where a 5-fold increase in protection was a result …

“It Feels Like Home”: The Impacts Of Supportive Housing On Male Youth – Perspectives Of Youth And Service Providers At Five Beds To Home, Sarah Michelle Ogden

Theses and Dissertations (Comprehensive)

This study identifies the impacts of supportive housing on the lives of male youth. The researcher studied the Five Beds to Home (Five Beds) supportive housing facility for male youth, located in Cambridge, Ontario. The study focused on two areas: one, the current engagement of tenants and second, the long term impacts on past tenants. Impacts include areas such as progress on or achievement of goals/overcoming challenges, employment and education status, happiness and health, and housing stability. The general research questions were as follows: 1) What are the impacts of supportive housing on the lives of male youth?, 2) What …

Taking Up Space: A Case Study Exploration Of The Relationship Between Citizenship And Free Humanities Programs In Canada, Jessica L. Klassen

Theses and Dissertations (Comprehensive)

Citizenship is increasingly being utilized as the discourse to discuss inclusive and exclusive realities within a polity. This case study examines free humanities programs in Canada, which offer free university-level courses in the humanities to people experiencing marginalization in society. The stated intention of the programs is that, through education in the humanities, critical reflection, and access to the university space, students will increasingly engage in active citizenship and participate in the public sphere. This thesis explores the extent to which this intention has been realized. Primary data was collected from sixteen students, professors, and program coordinators of free humanities …

Does Ecosystem Disturbance Alter The Capacity Of Dissolved Organic Matter To Mitigate The Impact Of Copper To Hyalella Azteca?, Kelly Livingstone

Theses and Dissertations (Comprehensive)

The potential for aquatic ecosystem recovery as a result of dissolved organic matter (DOM) protecting against metal toxicity has become a significant area of research in environmental toxicology. It is a well-characterized relationship that DOM binds free metal ions in a concentration-dependant manner, making them unavailable for toxic action and a reduction in toxicity is seen. Less understood is source variability and how the upland terrestrial environment influences the protective quality of DOM. The aim of this study was to examine the influence of land disturbance (logging, fire, smelter emissions) on DOM quality by comparing the protective capacity of different …

"The Road Less Travelled;" Women's Journeys To Community Leadership In The Waterloo Region, Lyndsey A. Butcher

Theses and Dissertations (Comprehensive)

The purpose of this research study is to explore the experiences of women within the Region of Waterloo along their journeys to community leadership. The literature review reveals the predominance of deficits-based research on the barriers preventing women from attaining positions of leadership and a significant gap in scholarship on female community leaders. This qualitative study consisted of semi-structured interviews with 15 female community leaders. It was influenced by an intersectional feminist perspective and used a constructivist grounded theory approach. The findings of this study offer three groups of related factors that can encourage, support and recognize the increasing number …

"Emotional Landscapes" And The Value Of Sex: Exploring The Lived Experiences Of Sex Workers' Clients, Zoey K. Jones

Theses and Dissertations (Comprehensive)

Clients of sex workers face criminalization and stigmatization in Canada and across the globe; they are commonly depicted by their stereotypes in entertainment and news media and have become a more visible population with the advent of the internet and online erotic review boards. However, these people are infrequently represented by their own voices and stories in academic research and, as such, the reality of being a client is not encompassed by the existing literature. An accurate and comprehensive understanding of the sex industry is particularly important in the twenty-first century, as the laws surrounding sex work in Canada – …

Marketing Research Is Power In Negotiations To Sell A Small Business, Michael Latta

AMTP Proceedings 2013

Small firms are at a disadvantage in negotiations with larger firms and need to have something on their side of the table to give them power in the process. Primary marketing research can provide proprietary information for the smaller firm that may be used to support a forecasting model to be used in evaluating offers during negotiations. This paper describes such a negotiation supported by a proprietary forecasting simulator that created an advantage for the smaller firm over the larger firm. As a result, the smaller firm had a go-it-alone baseline revenue forecast to determine the incremental value of a …

Heritable Melanism And Parasitic Infection Both Result In Black-Spotted Mosquitofish, Lisa Horth, David Gauthier, Wolfgang Vogelbein

Biological Sciences Faculty Publications

Male Gamhusia holhrooki (Eastern Mosquitofish) express a heritable pigmentation polymorphism approximate to 99% of males are silver, and only approximate to 1% have a melanic, black-spotted pattern. Sex-linkage, an autosomal modifier, and temperature control the expression of this heritable melanism. In many teleosts, melanin also accumulates around the site of parasitic invasion. We have identified black-spot disease in wild mosquitofish from their native habitat. Here, we demonstrate convergence upon the black-pigmented phenotype through two means: 1) heritable melanism, and 2) melanic spotting on the silver genotype that results from infection with immature encysted trematodes. Females are silver and express greater …

Pronounced Genetic Structure In A Highly Mobile Coral Reef Fish, Caesio Cuning, In The Coral Triangle, Amanda S. Ackiss, Shinta Pardede, Eric D. Crandall, Ma Carmen A. Ablan-Lagman, Ambariyanto, November Romena, Paul H. Barber, Kent E. Carpenter

Biological Sciences Faculty Publications

The redbelly yellowtail fusilier Caesio cuning has a tropical Indo-West Pacific range that straddles the Coral Triangle, a region of dynamic geological history and the highest marine biodiversity on the planet. Previous genetic studies in the Coral Triangle indicate the presence of multiple limits to connectivity. However, these studies have focused almost exclusively on benthic, reef-dwelling species. Schooling, reef-associated fusiliers (Perciformes: Caesionidae) account for a sizable portion of the annual reef catch in the Coral Triangle, yet to date, there have been no indepth studies on the population structure of fusiliers or other mid-water, reef-associated planktivores across this region. We …

Chemical Defense Of An Asian Snake Reflects Local Availability Of Toxic Prey And Hatchling Diet, D. A. Hutchinson, A. H. Savitzky, G. M. Burghardt, C. Nguyen, J. Meinwald, F. C. Schroeder, A. Mori

Biological Sciences Faculty Publications

Species that sequester toxins from prey for their own defense against predators may exhibit population-level variation in their chemical arsenal that reflects the availability of chemically defended prey in their habitat. Rhabdophis tigrinus is an Asian snake that possesses defensive glands in the skin of its neck (nuchal glands'), which typically contain toxic bufadienolide steroids that the snakes sequester from consumed toads. In this study, we compared the chemistry of the nuchal gland fluid of R.tigrinus from toad-rich and toad-free islands in Japan and determined the effect of diet on the nuchal gland constituents. Our findings demonstrate that captive-hatched juveniles …

Cumulative Response Of Ecosystem Carbon And Nitrogen Stocks To Chronic Co2 Exposure In A Subtropical Oak Woodland, Bruce A. Hungate, Paul Dijkstra, Zhuoting Wu, Benjamin D. Duval, Frank P. Day, Alisha L.P. Brown

Biological Sciences Faculty Publications

·Rising atmospheric carbon dioxide (CO₂) could alter the carbon (C) and nitrogen (N) content of ecosystems, yet the magnitude of these effects are not well known. We examined C and N budgets of a subtropical woodland after 11 yr of exposure to elevated CO₂.

·We used open-top chambers to manipulate CO₂ during regrowth after fire, and measured C, N and tracer ¹⁵N in ecosystem components throughout the experiment.

·Elevated CO₂ increased plant C and tended to increase plant N but did not significantly increase whole-system C or N. Elevated CO₂ increased soil …