Anthropogenic impacts on the reproductive ecology of the diamondback terrapin, Malaclemys terrapin

Diamondback terrapins, Malaclemys terrapin, inhabit estuaries along the east and Gulf coasts of North America. One such estuary, Barnegat Bay, New Jersey, is considered one of the most anthropogenically altered estuaries in the United States. Barnegat Bay’s marsh and shoreline habitats have been filled with anthropogenically impacted substrate dredged from the bay floor, called dredged sediment. Terrapins use anthropogenically impacted areas for nesting that can negatively impact hatching success of terrapins. The introduction of non-native plants and structures (i.e., fences) shade nest sites, reducing nest temperature which affects the incubation duration and gender of terrapin embryos. This study investigated population sizes, hatching success, incubation duration of terrapin embryos in nests in different soil treatments including dredged substrate; and nests exposed to shade at North Sedge Island, Barnegat Bay. Microhabitat nest factors including: temperature, soil conductivity (SC), water potential, and gas composition in different soil types were studied. Our results indicated that freshlydredged substrate had the lowest water potential (MPa) and highest soil conductivity (mS/cm) than all other soil treatments with a100% embryo mortality with no embryonic development past the first stage of development. Nest temperatures at North Sedge Island were at the pivotal incubation temperature in non-shaded treatments and were below the pivotal temperature with 50% shade. Shading of nests caused significantly longer incubation durations and delayed emergence for terrapin embryos compared to non-shaded nests. Terrapin population estimates at N. Sedge Island indicated that 430 + 23 female terrapins utilize the island for nesting, and the earliest reproductive age of females on the island was six years. Increased body size and earlier age of maturity at N. Sedge Island may be a result of the area being located within a marine conservation zone, which has a large expanse of marsh, limited commercial operations, and ample estuarine food resources.This study showed that nest site conditions (i.e., soil texture, shading) are important for the success of diamondback terrapin populations. Effective management practices including the analysis of dredged substrate and washing it prior to its utilization to enhance or restore wildlife habitat are recommended based on the results of this study.Ph.D., Environmental Science -- Drexel University, 201

Vegetation effects on coastal foredune initiation: Wind tunnel experiments and field validation for three dune-building plants

As the land-sea interface, foredunes buffer upland habitats with plants acting as ecosystem engineers shaping topography, and thereby affecting storm response and recovery. However, many ecogeomorphic feedbacks in coastal foredune formation and recovery remain uncertain in this dynamic environment. We carried out a series of wind tunnel experiments testing how the morphology, density, and configuration of three foredune pioneer dune building plant species influence the most basic stage of dune initiation — nebkha formation around individual plants. We established monocultures of native Ammophila breviligulata and Panicum amarum and invasive Carex kobomugi in 1 m × 1 m planter boxes of sand to simulate approximate natural and managed densities and planting configurations on the US Mid-Atlantic coast. We subjected each box to constant 8.25 m/s wind for 30 min in a moveable-bed unilateral-flow wind tunnel with an unvegetated upwind sand bed. We quantified resulting topography with sub-millimeter precision and related it to plant morphology, density, and configuration. Plant morphology, density, and configuration all influenced the resulting topography. Larger plants produced larger nebkha with greater relief, height, and sand volume. However, nebkha area, height, and planform shape varied among species, and taller plants did not necessarily produce taller nebkha. The erect grasses, Ammophila and Panicum, produced more elongated, high-relief nebkha compared to the low-lying Carex, which produced lower and more symmetrical equant nebkha. A staggered planting configuration produced greater net sediment accumulation than non-staggered. We validated these results against high-resolution field topographies of foredune nebkha and found strong agreement between the datasets. Our results provide species-specific parameters useful in designing foredune plantings and beach management and can be used to parameterize vegetation in models of foredune evolution associated with different plant species. By first understanding the underlying ecogeomorphic feedbacks involved in nebkha formation, we can more effectively scale up to forecast coastal foredune evolution and recovery

Immunocompetent 3D Model of Human Upper Airway for Disease Modeling and In Vitro Drug Evaluation

The development of more complex in vitro models for the assessment of novel drugs and chemicals is needed because of the limited biological relevance of animal models to humans as well as ethical considerations. Although some human-cell-based assays exist, they are usually 2D, consist of single cell type, and have limited cellular and functional representation of the native tissue. In this study, we have used biomimetic porous electrospun scaffolds to develop an immunocompetent 3D model of the human respiratory tract comprised of three key cell types present in upper airway epithelium. The three cell types, namely, epithelial cells (providing a physical barrier), fibroblasts (extracellular matrix production), and dendritic cells (immune sensing), were initially grown on individual scaffolds and then assembled into the 3D multicell tissue model. The epithelial layer was cultured at the air–liquid interface for up to four weeks, leading to formation of a functional barrier as evidenced by an increase in transepithelial electrical resistance (TEER) and tight junction formation. The response of epithelial cells to allergen exposure was monitored by quantifying changes in TEER readings and by assessment of cellular tight junctions using immunostaining. It was found that epithelial cells cocultured with fibroblasts formed a functional epithelial barrier at a quicker rate than single cultures of epithelial cells and that the recovery from allergen exposure was also more rapid. Also, our data show that dendritic cells within this model remain viable and responsive to external stimulation as evidenced by their migration within the 3D construct in response to allergen challenge. This model provides an easy to assemble and physiologically relevant 3D model of human airway epithelium that can be used for studies aiming at better understanding lung biology, the cross-talk between immune cells, and airborne allergens and pathogens as well as drug delivery

A preliminary randomized double blind placebo-controlled trial of intravenous immunoglobulin for Japanese encephalitis in Nepal

BACKGROUND: Japanese encephalitis (JE) virus (JEV) is a mosquito-borne flavivirus found across Asia that is closely related to West Nile virus. There is no known antiviral treatment for any flavivirus. Results from in vitro studies and animal models suggest intravenous immunoglobulin (IVIG) containing virus-specific neutralizing antibody may be effective in improving outcome in viral encephalitis. IVIG's anti-inflammatory properties may also be beneficial. METHODOLOGY/PRINCIPAL FINDINGS: We performed a pilot feasibility randomized double-blind placebo-controlled trial of IVIG containing anti-JEV neutralizing antibody (ImmunoRel, 400mg/kg/day for 5 days) in children with suspected JE at two sites in Nepal; we also examined the effect on serum neutralizing antibody titre and cytokine profiles. 22 children were recruited, 13 of whom had confirmed JE; 11 received IVIG and 11 placebo, with no protocol violations. One child (IVIG group) died during treatment and two (placebo) subsequently following hospital discharge. Overall, there was no difference in outcome between treatment groups at discharge or follow up. Passive transfer of anti-JEV antibody was seen in JEV negative children. JEV positive children treated with IVIG had JEV-specific neutralizing antibody titres approximately 16 times higher than those treated with placebo (p=0.2), which was more than could be explained by passive transfer alone. IL-4 and IL-6 were higher in the IVIG group. CONCLUSIONS/SIGNIFICANCE: A trial of IVIG for JE in Nepal is feasible. IVIG may augment the development of neutralizing antibodies in JEV positive patients. IVIG appears an appealing option for JE treatment that warrants further study. TRIAL REGISTRATION: ClinicalTrials.gov NCT01856205

Electrochemically synthesized polymers in molecular imprinting for chemical sensing

This critical review describes a class of polymers prepared by electrochemical polymerization that employs the concept of molecular imprinting for chemical sensing. The principal focus is on both conducting and nonconducting polymers prepared by electropolymerization of electroactive functional monomers, such as pristine and derivatized pyrrole, aminophenylboronic acid, thiophene, porphyrin, aniline, phenylenediamine, phenol, and thiophenol. A critical evaluation of the literature on electrosynthesized molecularly imprinted polymers (MIPs) applied as recognition elements of chemical sensors is presented. The aim of this review is to highlight recent achievements in analytical applications of these MIPs, including present strategies of determination of different analytes as well as identification and solutions for problems encountered

Reactionary fence installation for post-Superstorm Sandy dune recovery

Dunes are invaluable to coastal areas as dynamic buffers to erosion during high tides and storms, but do not accrue naturally in developed areas without assistance. Wood paling fencing is commonly used to cultivate dune development and thereby increase the protection afforded to coastal areas. In 2012, Superstorm Sandy devastated the mid-Atlantic, especially New Jersey where many areas are still recovering. At Island Beach State Park, NJ parts of the primary dune system were destroyed and efforts were made to rebuild these areas as an emergency response. These efforts consisted of the installation of fencing in straight and zigzag patterns to catch-windblown sand and rebuild dunes. We collected field measurements of the short-term vertical sand accretion of recovering fenced localities and non-destroyed established dunes receiving no management intervention. We also collected 1.5 m cores to examine particle size after sieving in a Ro-Tap cascade shaker. There was high stochasticity among weekly changes in dune height and fence configuration affected growth rates. Zigzag fenced areas increased in height over time whereas straight fenced dunes did not. The sand composition of the dunes varied with height such that coarse sand decreased with height whereas finer sediments increased. At the initial stage of recovery fencing configuration seems to be an important factor in determining dune growth and assessing particle size can give insight into the means of sand transport. These results have implications for coastal management and restoration aimed at accruing the most sand in least time for immediate post-storm recovery efforts

Induction studies with Escherichia coli expressing recombinant interleukin-13 using multi-parameter flow cytometry

The expression of interleukin -13 following induction with IPTG in E. coli results in metabolic changes as indicated by multi-parameter flow cytometry and traditional methods of fermentation profiling (O2 uptake rate, CO2 evolution rate and optical density measurements). Induction early in the rapid growth phase was optimal although this led to lower overall biomass concentrations and lower maximum specific growth rates. In contrast, induction in the mid-rapid growth phase was the most detrimental to cell quality as measured by cytoplamsic membrane depolarisation