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Participating Faculty Mentors

April Blakeslee, Ph.D. Marc Fink, Ph.D. Daniel Ginsburg, Ph.D. Kent Hatch, Ph.D. Luis R. Martinez, Ph.D.
Karin Melkonian, Ph.D. Grace Rossi, Ph.D. Scott Santagata, Ph.D. Jennifer L. Snekser, Ph.D. Stephen Tettelbach, Ph.D.

April Blakeslee, Ph.D.

Blakeslee with Summer InternDr. April Blakeslee's research centers around global distribution patterns and processes in marine systems, including biodiversity, conservation biology, population genetics, parasite ecology, and biogeography – with a special focus on the unique and integrative insight that can be gained from studying biological invasions. Recently, biological invasions have become recognized as a major contributor to the global (and often disjunct) distributions of many marine species as a result of their movement and establishment via human transport mechanisms. Over the years, Dr. Blakeslee has examined many integrative aspects of invasion biology and has used intertidal marine invertebrates, especially mollusks and crustaceans, as model organisms because they have contributed numerous marine introductions globally. This summer she plans to continue that research, exploring competitive interactions of invasive species with natives. This project includes field work, lab work, and travel, and interested students will learn various aspects of marine ecology, behavioral ecology, parasitology, and invasion biology. In addition, there may be opportunities to explore population genetics related research in Dr. Blakeslee's lab.

Relevant Publications:

Blakeslee, A.M.H., A.E. Fowler & C.L. Keogh (2013) Marine invasions and parasite escape: updates and new perspectives. Advances in Marine Biology. 66: 87-169.

Freeman, A.S., A.M.H. Blakeslee & A.E. Fowler (2013) Range expansion of the rhizocephalan Loxothylacus panopaei (Gissler, 1884) in the northwest Atlantic. Aquatic Invasions. 8: 347-353.

Blakeslee, A.M.H., I. Altman, A.W. Miller, J.E. Byers, C.E. Hamer & G.M. Ruiz (2012) Parasites and invasions: a biogeographic examination of parasites and hosts in native and introduced ranges. Journal of Biogeography 39: 609-622.

Pringle, J., A.M.H. Blakeslee, J.E. Byers & J. Roman (2011) Asymmetric dispersal allows an upstream region to control population structure throughout a species' range. PNAS 108: 15288-15293.

Panova M., A.M.H. Blakeslee, A.W. Miller, T. Mäkinen, G.M. Ruiz, K. Johannesson & C. André (2011) Survival of a North Atlantic marine snail in multiple glacial refugia—implications for phylogeographic patterns. PLOS One 6(3): e17511.

Blakeslee, A.M.H., C.H. McKenzie, J.A. Darling, J.E. Byers, J.M. Pringle & J. Roman (2010) A hitchhiker's guide to the Maritimes: anthropogenic transport facilitates long-distance dispersal of an invasive marine crab to Newfoundland. Diversity and Distributions 16: 879–891.

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Marc Fink, Ph.D.

The lab is focused on elucidating the mechanisms underlying oncogenesis in breast cancer.  HER2 is an oncogene that is amplified in ~25% of breast cancers and is currently targeted by several drugs including Trastuzumab (HerceptinTM) and Lapatinib (TykerbTM).  HER2 belongs to the EGFR (Epidermal Growth Factor Receptor) family of receptor tyrosine kinases and forms heterodimers, with EGFR and HER3, upon ligand stimulation.  These events trigger a cascade of events that increase proliferation, survival, and migration of mammary epithelial cells.  Breast cancer cells develop resistance to the current drugs and newer drugs are needed to treat these patients.

The laboratory is focusing on the following projects:

1. Heregulin stimulation of several HER2+ breast cancer cell lines leads to increased proliferation and activation of the MAP Kinase pathway.  We have identified p90RSK activation upon Heregulin exposure in breast cancer cell lines.  Current projects are focused on identifying how RSK regulates proliferation in HER2+ breast cancers.

2. Several approaches are being used to identify novel signaling molecules in HER2+ breast cancer.

3. Systems biology approaches are being developed to map the global response of breast cancer cells to growth factor stimulation.  Of particular interest is the cellular response to multiple inputs.

Undergraduate and graduate students participate in the research by performing experiments on their own projects.  Techniques used in the laboratory include cell culture, cell signaling analysis, molecular pharmacology, microscopy, molecular biology, and protein biochemistry.  Several students choose to participate in projects that utilize bioinformatics techniques and gene expression analysis.

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Daniel Ginsburg, Ph.D.

Humans have 25,000 different genes, but not all of them are being expressed in all cells.  In fact, the regulation of gene expression is crucial in many aspects of cell regulation and metabolism. The ability to turn on and off genes allows cells to respond to external stimuli, differentiate, survive, and grow. The first step in gene expression is transcription, synthesizing an RNA molecule from a DNA template.  Our lab studies the molecular mechanism of transcription.  One of the primary regulators of transcription is chromatin, the protein-DNA complex that makes up the chromosomes in eukaryotic cells. Chromatin limits what proteins have access to the DNA, so it must be altered for transcription to take place. We investigate how changes in chromatin and transcription are linked. We focus on a couple specific chromatin changes and look at how they affect the binding of different protein complexes to chromatin.  We use yeast as our model organism, because they are fast-growing, easy to manipulate, and at the level of transcription, identical to higher eukaryotes. Our lab carries out experiments involving molecular biology, genetics, and biochemistry, and we are looking for motivated students to contribute to our ground-breaking research.

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Kent Hatch, Ph.D.

Background for Project 1

Stable isotopes have been used extensively to study migration, diet, and trophic levels (steps up the food chain) among wild animals. However, these studies are based on many assumptions that have gone untested in either the lab or the field. This is particularly true concerning the study of trophic levels based on 15N/14N ratios of tissues. As one moves up the food chain the 15N/14N ratio of the animals increases. It is commonly assumed that the 15N/14N ratio increases by 3.4 parts per thousand (relative to a standard) with each complete step up the food chain. However, it has become increasingly apparent that this does not hold true across species. Interestingly, very few controlled laboratory studies have actually been done to assess how 15N/14N ratios increase as trophic level increases.

We propose to study the effect of trophic level on 15N/15N ratios in the most clear manner possible by studying the effects of cannibalism in insects on trophic levels. This eliminates any confounding factors that may be caused by feeding different prey species to different predators. Prey species may not all be at the same trophic level, and therefore neither might the predator species. By examining the effect of cannibalism on 15N/14N ratios we know we will be measuring the pure effect of trophic level on the stable isotope ratios. To do this, we will use crickets and mealworms. Each species will be set in an isolated system where they will be fed a previous generation of the same species in an effort to generate the pure effect of trophic level on the stable isotope ratios of 15N. We predict a constant increase within a species of the 15N/14N ratio of the tissues with increased trophic level. However, we predict that this value will differ between the species.

Background for Project 2

Toe clipping is widely used as a method of marking amphibians typically for mark and recapture studies. It has more recently been utilized to gather information on genetic studies, histological examinations and age determination of the amphibian. However, there is little data on the survival rates or overall fate of toe clipped individuals. There has been previous research suggesting that with the increase of toes clipped, the overall recapture rates significantly decrease. (McCarthy and Parris 2004) These decreased recapture rates may have different causes, not related to survival.

This study aims to look at the overall survival rates of toe clipped frogs by measuring activity rate, growth rate, recapture avoidance and death. Currently it is unknown if toe clipping has a detrimental affect of these animals. This is important to look at because toe clipping is often used for population estimations. By gaining a better understanding of what happens to the animals after toe clipping we can determine if these estimates are indeed correct or if there is something else occurring.

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Luis R. Martinez, Ph.D.

The Martinez laboratory at LIU-Post studies host-pathogen interactions.  We are interested in understanding two basic questions:

Which mechanisms are used by microbes to invade, survive, and cause disease to the host?

How does the host defend itself against microbial assault?

We approach our research in an interdisciplinary manner; undergraduate students that join the lab will be trained on basic microbiology, microscopy, immunological and tissue culture techniques, molecular biology, antimicrobial research, and animal models of infection.

Research Projects:

Impact of Methamphetamine Abuse on Innate Immunity and Blood Brain Barrier Integrity

Methamphetamine (METH) is a major public health and safety problem in the United States. METH is a strong addictive central nervous system (CNS) stimulant that mimics the pharmacological effects of cocaine. However, the pharmacological effects of METH are longer lasting than cocaine. The blood brain barrier (BBB) is a unique interface that in part functions to prevent microbial invasion of the CNS. Due to the modification of the expression of adhesion molecules at the level of the endothelial cells of the BBB, cocaine modulates the transmigration of leukocytes resulting in BBB dysfunction and increased cell emigration from the blood vessels to the brain. These effects increase the probability of invasion of pathogens into the brain. Although there is substantial evidence of the effects of cocaine on BBB function, the effects of METH on brain vasculature have not been studied extensively.

We were the first to demonstrate the detrimental impact of METH on host immune function in response to a systemic microbial challenge.  We now have preliminary results suggesting that, like cocaine, METH modifies the expression of adhesion molecules at the level of the endothelial cells of the BBB. Hence, METH likely modulates the transmigration of leukocytes. Thus, METH could impair the function of the BBB leading to cell emigration from the blood vessels to the brain, which would increase the probability of dissemination of pathogens to the brain.

The encapsulated AIDS-associated pathogenic fungus Cryptococcus neoformans frequently infects the CNS; globally there are ~1 million cases of CNS cryptococcosis every year. In addition, C. neoformans is an excellent model organism for the study of CNS susceptibility due to the availability of tools such as specific antibodies and well-established animal models.

We hypothesized that METH alters the innate immunity function and BBB integrity increasing susceptibility to infectious diseases, including CNS infection. We anticipate that our findings will result in a deeper understanding of the mechanisms for the increased severity of microbial disease in METH abusers and lead to the development of more effective public health strategies to deal with this scourge of our society.

Relevant Publications:

Patel, D., G. M. Desai, S. Frases, R. J. Cordero, C. M. DeLeon-Rodriguez, E. A. Eugenin, J. D. Nosanchuk, and L. R. Martinez. 2013. Methamphetamine enhances Cryptococcus neoformans pulmonary infection and dissemination to the brain. MBio. 4:e00400-13.

Eugenin, E. A., J. M. Greco, S. Frases, J. D. Nosanchuk, and L. R. Martinez. 2013. Methamphetamine Alters Blood Brain Barrier Protein Expression Facilitating Central Nervous System Infection by Neurotropic Cryptococcus neoformans. J Infect Dis. 208: 699-704.

Martinez, L. R., M. R. Mihu, A. Gacser, L. Santambrogio, and J. D. Nosanchuk. 2009. Methamphetamine enhances histoplasmosis by immunosuppression of the host. J Infect Dis. 200:131-41.

Effect of Alcohol Abuse on Microbial Pathogenesis

We utilize the pathogenic and medically relevant pathogen Acinetobacter baumannii to investigate alcohol-related abuse and host-pathogen interaction questions. This Gram-negative bacterium has gained particular notoriety as one of the leading causes of opportunistic nosocomial infections worldwide. As a consequence of its notorious ability to acquire or upregulate antibiotic drug resistance determinants, it has justifiably been propelled to the forefront of medical attention. The organism commonly targets the most vulnerable hospitalized patients, those who are critically ill with breaches in skin integrity and airway protection. A particular at risk group for A. baumannii-associated pneumonia are individuals with a history of alcohol abuse who characteristically have a fulminant clinical course with secondary bloodstream infection and mortality rate of 40 to 60%. The source of infection may be carriage in the nasopharynx, which occurs in up to 10% of community residents with excessive alcohol consumption.

The ability of A. baumannii to cause disease in alcoholics makes the study of its virulence mechanisms and host interactions crucial in order to develop better public health strategies to decrease the susceptibility to disease of individuals at risk as well as generate novel approaches to patient care. Key questions include: Does alcohol enhances the susceptibility of the host's immune system to A. baumannii? Are there host-specific factors that contribute to A. baumannii pathogenesis in alcoholic individuals? Relative to other Gram-negative organisms, such as P. aeruginosa, very little is known about the host-pathogen interactions involving A. baumannii. Identification of such factors could expose new virulence factors and important characteristics of A. baumannii pathogenesis.

Relevant Publications:

Orsinger-Jacobsen, S. J., S. S. Patel, E. M. Vellozzi, P. Gialanella, L. Nimrichter, K. Miranda, and L. R. Martinez. 2013. Use of a stainless steel washer platform to study Acinetobacter baumannii adhesion and biofilm formation on abiotic surfaces. Microbiology. 159:2594-2604.

Asplund, M. B., C. Coelho, R. J. Cordero, and L. R. Martinez. 2013. Alcohol impairs J774.16 macrophage-like cell antimicrobial functions in Acinetobacter baumannii infection. Virulence. 4:467-47.

Mihu, M. R. and L. R. Martinez. 2011. Novel therapies for treatment of multi-drug resistant Acinetobacter baumannii skin infections.  Virulence. 2:97-102.

Mihu, M. R., U. Sandkovsky, G. Han, J. M. Friedman, J. D. Nosanchuk, and L. R. Martinez. 2010. Nitric oxide releasing nanoparticles are therapeutic for Acinetobacter baumannii wound infections. Virulence. 1:62-67.

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Karin Melkonian, Ph.D.

My laboratory has focused for many years on the antimicrobial testing of modified carbohydrate- and protein-based surfaces (wood, paper, cotton, silk, wool, etc.).  The novel modification destroys microorganisms through first a pirecing then and electrocution mechanism.  These surfaces have been found to be antibacterial and antifungal against a number of pathogenic organisms (including P. aeruginosa, S. aureus, E.coli and B. anthrasis, the bacteria that causes anthrax and C. albicans). The lab is currently examining the antiviral  effect of these surfaces. We are infecting eukaryotic dog kidney cells with influenza virus and testing whether they provide any antiviral protection to the cells.

Additionally, we have shown these surfaces to be anticoagulating.  Having both antimicrobial and anticoagulating properties provide many potential important medical uses for these surfaces, such as production of blood bags, wound dressings, etc.  We are interested in further characterizing the anticoagulating effect and understand the biochemical reactions involved for future therapeutic use.

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Grace Rossi, Ph.D.

Dr. Rossi's laboratory focuses on the pharmacological characteristics of the opioid system through the use of molecular and behavioral techniques.  Over the past year Dr. Rossi and her collaborators at Memorial Sloan Kettering Cancer Center have identified and characterized spliced variants of the mu-opioid receptor that are involved in chronic pain and analgesia. These studies involve detailed micro-injections while analyzing blood pressure, analgesia, inflammation, motor skills, and place-preference conditioning. Studies are performed on mice that have been genetically modified and lacking a selective opioid gene.

Since the cloning of the first opiate receptor, opiate pharmacology has become increasingly complex while the population of chronic pain sufferers increases. The overall goal in this laboratory is to further characterize the opioid receptor system in order to better treat chronic pain conditions without producing side effects such as tolerance, dependence and addiction. To do this, one must examine the actions of several known opiates as well as newly synthesized compounds at the level of the spinal and supraspinal nervous systems.

Requirements: Person must be at least 15 years of age, willing to handle mice, and adeptly skilled in basic handling techniques.

Selected Publications

Xu, J., Xu, M., Rossi, GC., Pasternak, G.W., and Pan, Y-X. Identification and characterization of seven new exon 11-associated splice variants of the rat mu opioid receptor gene, OPRM1. Molecular Pain; (2011), Jan 21;7(1):9.

Rossi, G., Barbut, D., Richelson, E., Matulonis, J., and Pasternak, GW.  Systemically and topically active antinociceptive neurotensin compounds, Journal of Pharmacology and Experimental Therapeutics, (2010) Sep 1;334(3):1075-9.

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Scott Santagata, Ph.D.

Project Title: Invertebrate Biodiversity of Antarctic Shelf Communities

Electron Microscope Image of ZooidThe marine invertebrate communities found on the Antarctic shelf are utterly fantastic, filled with amazing species not found anywhere else on the planet.  To some degree Antarctic marine invertebrate communities appear more similar to those of the Paleozoic Era, when bryozoans, brachiopods, and sponges built large reefs as opposed to the coral dominated reefs we are more familiar with today.  Therefore, Antarctic marine environments provide key insights into our planet's biological past, and also the realization that the Antarctic's fragile biodiversity is threatened by global environmental change and ocean acidification.  Recently, I collaborated on a project exploring the biodiversity of Antarctica; in particular, we collected numerous species of invertebrates from the Bellingshausen, Amundsen, and Ross Seas for morphological and genetic research.  Undergraduate students participating in this project would learn both morphological (scanning electron microscopy) and molecular (DNA extraction, PCR, and molecular phylogenetics) methods for assessing the biodiversity Antarctic bryozoans and brachiopods.  One question we will address is whether particular species are truly circumpolar in their distributions (i. e. a single species that is found around the entire shelf region of Antarctica) or some bryozoan and brachiopod morphotypes are really cryptic species complexes (species that look morphologically similar but are genetically distinct).

Selected Publications

Santagata S, Cohen B: Phoronid phylogenetics (Brachiopoda; Phoronata): evidence from morphological cladistics, small and large subunit rDNA sequences, and mitochondrial cox1. Zoological Journal of the Linnean Society 2009, 157:34-50.

Santagata S, Zimmer R: Comparison of the neuromuscular systems among actinotroch larvae: systematic and evolutionary implications. Evol Dev 2002, 4:43-54.

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Jennifer L. Snekser, Ph.D.

The focus of Dr. Snekser’s research program is to understand the ecological and evolutionary implications of different individual behavioral types within populations (i.e., behavioral syndromes).  Anyone that has had a pet or spent time at a zoo has probably thought that animals seem to have specific personalities.  Individual animals respond consistently and predictively based on their temperament, also called a “personality” or “behavioral type”.  Early work on animal personality and behavioral syndromes has focused on description and we now seek to understand personality within the context of ecological systems and evolution.  It is debated what influence (if any) behavioral syndromes may have on evolution.  On one hand, consistent personalities would seem to constrain individuals from adapting.  Conversely, the correlation of behaviors may actually drive evolution by supplying a proportion of the population that has ideal behavioral traits all linked together, making them more suitable to establish new, stable populations. Previous projects have shown that significant correlations can exist among behaviors, implying that behavioral types can be maintained over time, within specific contexts.  However, individuals are able to assess the quality of their current territory and adaptively adjust their behaviors (Snekser et al 2009).  Thus, while it may appear that behaviors are linked within a syndrome, changes in the environment can disintegrate correlations.  Currently, large gaps exist as to the influence of the environment on behavioral syndromes.  Additionally, a minimal amount of work has been done to understand behavioral syndromes in animals that live in groups or work as pairs, or that interact with each other.  Through laboratory and field work with various species of fishes, the goal of Dr Snekser’s multiple research projects is to better understand the relationship of ecology, genetics, neuroendocrinology, evolution, and behavioral syndromes.

Relevant Publications

Snekser JL, Leese J, Ganim A & Itzkowitz M. 2009. Caribbean damselfish with varying territory quality: correlated behaviors, but not a syndrome. Behavioral Ecology. 20, 124-130.

Snekser JL & Itzkowitz M. 2009. Sex differences in retrieval behavior by the biparental convict cichlid. Ethology. 115, 457-464.

Gumm JM, Snekser JL, Leese JM, Little KP, Leiser JK, Imhoff VE, Westrick B & Itzkowitz, M. 2011. Management of interactions between endangered species using habitat restoration. Biological Conservation. 144, 2171-2176.

Kiesel A, Snekser JL, Ruhl N & McRobert SP. 2012. Behavioural syndromes and shoaling: connections between aggression, boldness and social behaviour in three different Danios. Behaviour. 149, 1155-1175.

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Stephen Tettelbach, Ph.D.

Interns ScubaThe research that my students and I do seeks to better understand how and why marine populations vary in a changing environment; in turn, we have applied our findings toward the development and improvement of management and culture strategies for commercially important shellfish species. In particular, as part of our bay scallop restoration efforts in eastern Long Island waters, we have worked to develop and improve techniques for planting bay scallops and enhancing their survival, growth and reproductive success. This work has contributed significantly to increases in larval recruitment and has helped rebuild population sizes/densities and the commercial scallop fishery of New York. We do a great deal of Scuba diving and other fieldwork to monitor populations and conduct manipulative experiments; in addition, we have documented new discoveries about the basic biology and ecology of several marine species. Current research projects include: restoration of Peconic bay scallop populations and fisheries; habitat utilization by juvenile bay scallops; age, growth and initial reproductive maturity of the channeled whelk; predation of planted bay scallops by channeled whelk; locomotory behavior of adult hard clams.

Recent Publications

Tettelbach, S.T., K. Tetrault & J. Carroll. in press. Efficacy of Netminder® silicone release coating for biofouling reduction in bay scallop grow-out and comparative effects on scallop survival, growth and reproduction. Aquaculture Research. Article first published online: 11 JUL 2012 DOI:10.1111/j.1365-2109.2012.03220.x

Tettelbach S.T., B.J. Peterson, J.M. Carroll, S.W.T. Hughes, D.M. Bonal, A.J. Weinstock, J.R. Europe, B.T. Furman & C.F. Smith. 2013. Priming the larval pump: resurgence of bay scallop recruitment following initiation of intensive restoration efforts. Marine Ecology Progress Series 478:153-172.

Carroll, J.M., B.T. Furman, S.T. Tettelbach, B.J. Peterson. 2012. Balancing the edge effects budget: bay scallop settlement and loss along a seagrass edge. Ecology 93:1637–1647.

Tettelbach, S.T., D. Barnes, J. Aldred, G. Rivara, D. Bonal, A. Weinstock, C. Fitzsimons-Diaz, J. Thiel, M.C. Cammarota, A. Stark, K. Wejnert, R. Ames, J. Carroll. 2011. Utility of high density plantings in bay scallop, Argopecten irradians irradians, restoration. Aquaculture International. 19(4):715-739.

Carroll, J. M., B. J. Peterson, D. Bonal, A. Weinstock, C. F. Smith and S. T. Tettelbach. 2010. Comparative survival of bay scallops in eelgrass and the introduced alga, Codium fragile, in a New York estuary. Marine Biology 157:249–259.

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