Digital Commons Network^™

How I Teach Gender In History (Of Technology), Geoff Zylstra

Publications and Research

No abstract provided.

Predicting The Behavioral Impact Of Transcranial Direct Current Stimulation: Issues And Limitations, Archy O. De Berker, Marom Bikson, Sven Bestmann

Publications and Research

The transcranial application of weak currents to the human brain has enjoyed a decade of widespread use, providing a simple and powerful tool for non-invasively altering human brain function. However, our understanding of current delivery and its impact upon neural circuitry leaves much to be desired. We argue that the credibility of conclusions drawn with transcranial direct current stimulation (tDCS) is contingent upon realistic explanations of how tDCS works, and that our present understanding of tDCS limits the technique’s use to localize function in the human brain. We outline two central issues where progress is required: the localization of currents, …

Transposable Element Evolution In Heliconius Suggests Genome Diversity Within Lepidoptera, Christine A. Lavoie, Roy N. Platt, Peter A. Novick, Brian A. Counterman, David A. Ray

Publications and Research

Background Transposable elements (TEs) have the potential to impact genome structure, function and evolution in profound ways. In order to understand the contribution of transposable elements (TEs) to Heliconius melpomene, we queried the H. melpomene draft sequence to identify repetitive sequences. Results We determined that TEs comprise ~25% of the genome. The predominant class of TEs (~12% of the genome) was the non-long terminal repeat (non-LTR) retrotransposons, including a novel SINE family. However, this was only slightly higher than content derived from DNA transposons, which are diverse, with several families having mobilized in the recent past. Compared to the only …

Sequential Screening For Psychosocial And Behavioural Risk During Pregnancy In A Population Of Urban African Americans, Michele Kiely, Marie G. Gantz, M. Nabil El-Khorazaty, Ayman El-Mohandes

Publications and Research

Objective: Screening for psychosocial and behavioral risks, such as depression, intimate partner violence and smoking, during pregnancy is considered state-of-the-art in prenatal care (PNC). This prospective longitudinal analysis examines the added benefit of repeated screening over a one-time screen in identifying such risks during pregnancy.

Design: Data were collected as part of a randomized controlled trial to address intimate partner violence (IPV), depression, smoking and environmental tobacco smoke exposure (ETSE) in African-Americans women.

Setting: PNC sites in the District of Columbia serving mainly minority women

Population: 1044 African-American pregnant women in the District of Columbia

Methods: Mothers were classified by …

Fmri Of Working Memory Impairment After Recovery From Subarachnoid Hemorrhage, Timothy M. Ellmore, Fiona Rohlffs, Faraz Khursheed

Publications and Research

Recovery from aneurysmal subarachnoid hemorrhage (SAH) is often incomplete and accompanied by subtle but persistent cognitive deficits. Previous neuropsychological reports indicate these deficits include most prominently memory impairment, with working memory particularly affected. The neural basis of these memory deficits remains unknown and unexplored by functional magnetic resonance imaging (fMRI). In the present study, patients who experienced (SAH) underwent fMRI during the performance of a verbal working memory paradigm. Behavioral results indicated a subtle but statistically significant impairment relative to healthy subjects in working memory performance accuracy, which was accompanied by relatively increased blood-oxygen level dependent signal in widespread left …

Global Trends In Seasonality Of Normalized Difference Vegetation Index (Ndvi), 1982–2011, J. Ronald Eastman, Florencia Sangermano, Elia Axinia Machado, John Rogan, Assaf Anyamba

Publications and Research

A 30-year series of global monthly Normalized Difference Vegetation Index (NDVI) imagery derived from the Global Inventory Modeling and Mapping Studies (GIMMS) NDVI3g archive was analyzed for the presence of trends in changing seasonality. Using the Seasonal Trend Analysis (STA) procedure, over half (56.30%) of land surfaces were found to exhibit significant trends. Almost half (46.10%) of the significant trends belonged to three classes of seasonal trends (or changes). Class 1 consisted of areas that experienced a uniform increase in NDVI throughout the year, and was primarily associated with forested areas, particularly broadleaf forests. Class 2 consisted of areas experiencing …

It’S Time To Fear! Interval Timing In Odor Fear Conditioning In Rats, Kiseko Shionoya, Chloé Hegoburu, Bruce L. Brown, Regina M. Sullivan, Valérie Doyère, Anne-Marie Mouly

Publications and Research

Time perception is crucial to goal attainment in humans and other animals, and interval timing also guides fundamental animal behaviors. Accumulating evidence has made it clear that in associative learning, temporal relations between events are encoded, and a few studies suggest this temporal learning occurs very rapidly. Most of these studies, however, have used methodologies that do not permit investigating the emergence of this temporal learning. In the present study we monitored respiration, ultrasonic vocalization (USV) and freezing behavior in rats in order to perform fine-grain analysis of fear responses during odor fear conditioning. In this paradigm an initially neutral …

Fast Quantitative Real-Time Pcr-Based Screening For Common Chromosomal Aneuploidies In Mouse Embryonic Stem Cells, Charlotte D'Hulst, Irena Parvanova, Delia Tomoiaga, Maria L. Sapar, Paul Feinstein

Publications and Research

Chromosomal integrity has been known for many years to affect the ability of mouse embryonic stem cells (mESCs) to contribute to the germline of chimeric mice. Abnormal chromosomes are generally detected by standard cytogenetic karyotyping. However, this method is expensive, time consuming, and often omitted prior to blastocyst injection, consequently reducing the frequency of mESC-derived offspring. Here, we show a fast, accurate, and inexpensive screen for identifying the two most common aneuploidies (Trisomy 8 and loss of chromosome Y) in genetically manipulated mESCs using quantitative real-time PCR (qPCR). Screening against these two aneuploidies significantly increases the fraction of normal mESC …

A Novel Subnetwork Alignment Approach Predicts New Components Of The Cell Cycle Regulatory Apparatus In Plasmodium Falciparum, Hong Cai, Changjin Hong, Timothy G. Lilburn, Armando L. Rodriguez, Sheng Chen, Jianying Gu, Rui Kuang, Yufeng Wang

Publications and Research

Background According to the World Health organization, half the world's population is at risk of contracting malaria. They estimated that in 2010 there were 219 million cases of malaria, resulting in 660,000 deaths and an enormous economic burden on the countries where malaria is endemic. The adoption of various high-throughput genomics-based techniques by malaria researchers has meant that new avenues to the study of this disease are being explored and new targets for controlling the disease are being developed. Here, we apply a novel neighborhood subnetwork alignment approach to identify the interacting elements that help regulate the cell cycle of …

Β2 Adrenergic Receptor Fluorescent Protein Fusions Traffic To The Plasma Membrane And Retain Functionality, Jaclyn Bubnell, Patrick Pfister, Maria L. Sapar, Matthew E. Rogers, Paul Feinstein

Publications and Research

Green fluorescent protein (GFP) has proven useful for the study of protein interactions and dynamics for the last twenty years. A variety of new fluorescent proteins have been developed that expand the use of available excitation spectra. We have undertaken an analysis of seven of the most useful fluorescent proteins (XFPs), Cerulean (and mCerulean3), Teal, GFP, Venus, mCherry and TagRFP657, as fusions to the archetypal G-protein coupled receptor, the β2 adrenergic receptor (β2AR). We have characterized these β2AR::XFP fusions in respect to membrane trafficking and G-protein activation. We noticed that in the mouse neural cell line, OP 6, that membrane …

Lipid Metabolites Enhance Secretion Acting On Snare Microdomains And Altering The Extent And Kinetics Of Single Release Events In Bovine Adrenal Chromaffin Cells, Virginia García-Martínez, José Villanueva, Cristina J. Torregrosa-Hetland, Robert Bittman, Ashlee Higdon, Victor M. Darley-Usmar, Bazbek Davletov, Luis M. Gutiérrez

Publications and Research

Lipid molecules such as arachidonic acid (AA) and sphingolipid metabolites have been implicated in modulation of neuronal and endocrine secretion. Here we compare the effects of these lipids on secretion from cultured bovine chromaffin cells. First, we demonstrate that exogenous sphingosine and AA interact with the secretory apparatus as confirmed by FRET experiments. Examination of plasma membrane SNARE microdomains and chromaffin granule dynamics using total internal reflection fluorescent microscopy (TIRFM) suggests that sphingosine production promotes granule tethering while arachidonic acid promotes full docking. Our analysis of single granule release kinetics by amperometry demonstrated that both sphingomyelinase and AA treatments enhanced …

Cholinergic Enhancement Of Brain Activation In Mild Cognitive Impairment During Episodic Memory Encoding, Shannon L. Risacher, Yang Wang, Heather A. Wishart, Laura A. Rabin, Laura A. Flashman, Brenna C. Mcdonald, John D. West, Robert B. Santulli, Andrew J. Saykin

Publications and Research

Objective: To determine the physiological impact of treatment with donepezil (Aricept) on neural circuitry supporting episodic memory encoding in patients with amnestic mild cognitive impairment (MCI) using functional magnetic resonance imaging (fMRI).

Methods: Eighteen patients with MCI and 20 age-matched healthy controls (HC) were scanned twice while performing an event-related verbal episodic encoding task. MCI participants were scanned before treatment and after approximately 3 months on donepezil; HCwere untreated but rescanned at the same interval.Voxel-level analyses assessed treatment effects on activation profiles in MCI patients relative to retest changes in non-treated HC. Changes in task-related connectivity in medial temporal circuitry …

Specificity In The Actions Of The Ubr1 Ubiquitin Ligase In The Degradation Of Nuclear Receptors☆, Rasheda Sultana, Maria A. Theodoraki, Avrom J. Caplan

Publications and Research

The UBR1 ubiquitin ligase promotes degradation of proteins via the N-end rule and by another mechanism that detects a misfolded conformation. Although UBR1 was shown recently to act on protein kinases whose misfolding was promoted by inhibition of Hsp90, it was unknown whether this ubiquitin ligase targeted other client types of the chaperone. We analyzed the role of UBR1 in the degradation of nuclear receptors that are classical clients of Hsp90. Our results showed that UBR1 deletion results in impaired degradation of the glucocorticoid receptor and the androgen receptor but not the estrogen receptor α. These findings demonstrate specificity in …

Wave Function For Time-Dependent Harmonically Confined Electrons In A Time-Dependent Electric Field, Yu-Qi Li, Xiao-Yin Pan, Viraht Sahni

Publications and Research

The many-body wave function of a system of interacting particles confined by a time-dependent harmonic potential and perturbed by a time-dependent spatially homogeneous electric field is derived via the Feynman path-integral method. The wave function is comprised of a phase factor times the solution to the unperturbed time-dependent Schrödinger equation with the latter being translated by a time-dependent value that satisfies the classical driven equation of motion. The wave function reduces to that of the Harmonic Potential Theorem wave function for the case of the time-independent harmonic confining potential.

Fashion Vs. Function In Cultural Evolution: The Case Of Dog Breed Popularity, Stefano Ghirlanda, Alberto Acerbi, Harold Herzog, James A. Serpell

Publications and Research

We investigate the relationship between characteristics of dog breeds and their popularity between years 1926 and 2005. We consider breed health, longevity, and behavioral qualities such as aggressiveness, trainability, and fearfulness. We show that a breed's overall popularity, fluctuations in popularity, and rates of increase and decrease around popularity peaks show typically no correlation with these breed characteristics. One exception is the finding that more popular breeds tend to suffer from more inherited disorders. Our results support the hypothesis that dog breed popularity has been primarily determined by fashion rather than function.

Centrosomal Kinase Nek2 Cooperates With Oncogenic Pathways To Promote Metastasis, T K. Das, Dibyendu Dana, Suneeta S. Paroly, S. K. Perumal, S. Singh, H. Jhun, J. Pendse, R. L. Cagan, T. T. Talele, Sanjai Kumar

Publications and Research

Centrosomal kinase Nek2 is overexpressed in different cancers, yet how it contributes toward tumorigenesis remains poorly understood. dNek2 overexpression in a Drosophila melanogaster model led to upregulation of Drosophila Wnt ortholog wingless (Wg), and alteration of cell migration markers—Rho1, Rac1 and E-cadherin (Ecad)—resulting in changes in cell shape and tissue morphogenesis. dNek2 overexpression cooperated with receptor tyrosine kinase and mitogen-activated protein kinase signaling to upregulate activated Akt, Diap1, Mmp1 and Wg protein to promote local invasion, distant seeding and metastasis. In tumor cell injection assays, dNek2 cooperated with Ras and Src signaling to promote aggressive colonization of tumors into different …

Myc-Dependent Genome Instability And Lifespan In Drosophila, Christina Greer, Moonsook Lee, Maaike Westerhof, Brandon Milholland, Rebecca Spokony, Jan Vijg, Julie Secombe

Publications and Research

The Myc family of transcription factors are key regulators of cell growth and proliferation that are dysregulated in a large number of human cancers. When overexpressed, Myc family proteins also cause genomic instability, a hallmark of both transformed and aging cells. Using an in vivo lacZ mutation reporter, we show that overexpression of Myc in Drosophila increases the frequency of large genome rearrangements associated with erroneous repair of DNA double-strand breaks (DSBs). In addition, we find that overexpression of Myc shortens adult lifespan and, conversely, that Myc haploinsufficiency reduces mutation load and extends lifespan. Our data provide the first evidence …

Chimeric Rhinoviruses Displaying Mper Epitopes Elicit Anti-Hiv Neutralizing Responses, Guohua Yi, Mauro Lapelosa, Rachel Bradley, Thomas M. Mariano, Denise Elsasser Dietz, Scott Hughes, Terri Wrin, Chris Petropoulos, Emilio Gallicchio, Ronald M. Levy, Eddy Arnold, Gail Ferstandig Arnold

Publications and Research

Background: The development of an effective AIDS vaccine has been a formidable task, but remains a critical necessity. The well conserved membrane-proximal external region (MPER) of the HIV-1 gp41 glycoprotein is one of the crucial targets for AIDS vaccine development, as it has the necessary attribute of being able to elicit antibodies capable of neutralizing diverse isolates of HIV.

Methodology/Principle Findings: Guided by X-ray crystallography, molecular modeling, combinatorial chemistry, and powerful selection techniques, we designed and produced six combinatorial libraries of chimeric human rhinoviruses (HRV) displaying the MPER epitopes corresponding to mAbs 2F5, 4E10, and/or Z13e1, connected to an immunogenic …

Lizards And Lines: Selection And Demography Affect The Fate Of L1 Retrotransposons In The Genome Of The Green Anole (Anolis Carolinensis), Marc Tollis, Stéphane Boissinot

Publications and Research

Autonomous retrotransposons lacking long terminal repeats (LTR) account for much of the variation in genome size and structure among vertebrates. Mammalian genomes contain hundreds of thousands of non-LTR retrotransposon copies, mostly resulting from the amplification of a single clade known as L1. The genomes of teleost fish and squamate reptiles contain a much more diverse array of non-LTR retrotransposon families, whereas copy number is relatively low. The majority of non-LTR retrotransposon insertions in nonmammalian vertebrates also appear to be very recent, suggesting strong purifying selection limits the accumulation of non-LTR retrotransposon copies. It is however unclear whether this turnover model, …

Unconscious Priming Requires Early Visual Cortex At Specific Temporal Phases Of Processing, Marjan Persuh, Tony Ro

Publications and Research

Although examples of unconscious shape priming have been well documented, whether such priming requires early visual cortex (V1/V2) has not been established. In the current study, we used TMS of V1/V2 at varying temporal intervals to suppress the visibility of preceding shape primes while the interval between primes and targets was kept constant. Our results show that, although conscious perception requires V1/V2, unconscious priming can occur without V1/V2 at an intermediate temporal interval but not at early (5–25 msec) or later (65–125 msec) stages of processing. Because the later time window of unconscious priming suppression has been proposed to interfere …

Therapeutic Ultrasound: Osteoarthritis Symptom-Modification And Potential For Disease Modification, Daniel J. Leong, Huagang Zhang, Lin Xu, Justin Tang, David M. Hirsh, John A. Hardin, Luis Cardoso, Chandan Guha, Neil J. Cobelli, Hui B. Sun

Publications and Research

Osteoarthritis (OA) is a degenerative joint disease and a leading cause of adult disability. While joint replacement surgery is a common treatment option for end-stage disease, non-surgical management is critical for preventing disability and maintaining quality of life. Although therapeutic ultrasound, which applies mechanical and may also apply thermal energy in the form of sound waves, is widely used to treat various musculoskeletal disorders such as bone fractures, tendinopathy, and muscle contusions, its symptom- and disease-modifying effects on osteoarthritis have not been clearly demonstrated. Recent clinical evidence indicates therapeutic ultrasound is capable of relieving OAassociated pain and improving function of …

Androgen Activity And Markers Of Inflammation Among Men In Nhanes Iii, Mary Schooling

Publications and Research

Objectives
Inflammation contributes to chronic diseases. Lower serum testosterone among men is associated with less inflammation, yet immune defense is thought to trade-off against reproduction with androgens adversely affecting immune function. Anti-androgens are effective at castrate levels of serum testosterone, suggesting serum testosterone may not capture all androgen activity. The association of two androgen biomarkers with key markers of inflammation was examined.

Methods
The adjusted association of serum testosterone and androstanediol glucuronide with Creactive protein, white blood cell, granulocyte and lymphocyte count, fibrinogen and hemoglobin, as a control outcome because testosterone administration raises hemoglobin, were examined in a nationally representative …

The Variability Of Autophagy And Cell Death Susceptibility, Ben Loos, Anna-Mart Engelbrecht, Richard A. Lockshin, Daniel J. Klionsky, Zahra Zakeri

Publications and Research

Impaired autophagic machinery is implicated in a number of diseases such as heart disease, neurodegeneration and cancer. A common denominator in these pathologies is a dysregulation of autophagy that has been linked to a change in susceptibility to cell death. Although we have progressed in understanding the molecular machinery and regulation of the autophagic pathway, many unanswered questions remain. How does the metabolic contribution of autophagy connect with the cell’s history and how does its current autophagic flux affect metabolic status and susceptibility to undergo cell death? How does autophagic flux operate to switch metabolic direction and what are the …

Transitions In Nirs-Type Denitrifier Diversity, Community Composition, And Biogeochemical Activity Along The Chesapeake Bay Estuary, Christopher A. Francis, Gregory D. O'Mullan, Jeffrey C. Cornwell, Bess B. Ward

Publications and Research

Chesapeake Bay, the largest estuary in North America, can be characterized as having steep and opposing gradients in salinity and dissolved inorganic nitrogen along the main axis of the Bay. In this study, the diversity of nirS gene fragments (encoding cytochrome cd1-type nitrite reductase), physical/chemical parameters, and benthic N2-fluxes were analyzed in order to determine how denitrifier communities and biogeochemical activity vary along the estuary salinity gradient. The nirS gene fragments were PCR-amplified, cloned, and sequenced from sediment cores collected at five stations. Sequence analysis of 96–123 nirS clones from each station revealed extensive overall diversity in this estuary, as …

Polydnaviral Ankyrin Proteins Aid Parasitic Wasp Survival By Coordinate And Selective Inhibition Of Hematopoietic And Immune Nf-Kappa B Signaling In Insect Hosts, Gwenaelle Gueguen, Marta E. Kalamarz, Johnny Ramroop, Jeffrey Uribe, Shubha Govind

Publications and Research

Polydnaviruses are mutualists of their parasitoid wasps and express genes in immune cells of their Lepidopteran hosts. Polydnaviral genomes carry multiple copies of viral ankyrins or vankyrins. Vankyrin proteins are homologous to IκB proteins, but lack sequences for regulated degradation. We tested if Ichnoviral Vankyrins differentially impede Toll-NF-κB-dependent hematopoietic and immune signaling in a heterologous in vivo Drosophila, system. We first show that hematopoiesis and the cellular encapsulation response against parasitoid wasps are tightly-linked via NF-κB signaling. The niche, which neighbors the larval hematopoietic progenitors, responds to parasite infection. Drosophila NF-κB proteins are expressed in the niche, and non cell-autonomously …

Signatures Of Rapid Evolution In Urban And Rural Transcriptomes Of White-Footed Mice (Peromyscus Leucopus) In The New York Metropolitan Area, Stephen Edward Harris, Jason Munshi-South, Craig Oberfell, Rachel O'Neill

Publications and Research

Urbanization is a major cause of ecological degradation around the world, and human settlement in large cities is accelerating. New York City (NYC) is one of the oldest and most urbanized cities in North America, but still maintains 20% vegetation cover and substantial populations of some native wildlife. The white-footed mouse, Peromyscus leucopus, is a common resident of NYC’s forest fragments and an emerging model system for examining the evolutionary consequences of urbanization. In this study, we developed transcriptomic resources for urban P. leucopus to examine evolutionary changes in protein-coding regions for an exemplar “urban adapter.” We used Roche 454 …

Bax And Bak Function As The Outer Membrane Component Of The Mitochondrial Permeability Pore In Regulating Necrotic Cell Death In Mice, Jason Karch, Jennifer Q. Kwong, Adam R. Burr, Michelle A. Sargent, John W. Elrod, Pablo M. Peixoto, Sonia Martinez-Caballero, Hanna Osinskka, Emily H-Y Cheng, Jeffrey Robbins, Kathleen W. Kinnally, Jeffrey D. Molkentin

Publications and Research

A critical event in ischemia-based cell death is the opening of the mitochondrial permeability transition pore (MPTP). However, the molecular identity of the components of the MPTP remains unknown. Here, we determined that the Bcl-2 family members Bax and Bak, which are central regulators of apoptotic cell death, are also required for mitochondrial pore-dependent necrotic cell death by facilitating outer membrane permeability of the MPTP. Loss of Bax/Bak reduced outer mitochondrial membrane permeability and conductance without altering inner membrane MPTP function, resulting in resistance to mitochondrial calcium overload and necrotic cell death. Reconstitution with mutants of Bax that cannot oligomerize …

Price, Promotion, And Availability Of Nutrition Information: A Descriptive Study Of A Popular Fast Food Chain In New York City, Corey Hannah Basch, Danna Ethan, Sonali Rajan

Publications and Research

Legislation in NYC requires chain restaurants to post calorie information on menu boards in an effort to help consumers make more informed decisions about food and beverage items they are purchasing. While this is a step in the right direction in light of the current obesity epidemic, there are other issues that warrant attention in a fast food setting, namely the pricing of healthy food options, promotional strategies, and access to comprehensive nutrition information. This study focused on a popular fast-food chain in NYC. The study’s aims were threefold: (1) to determine the cost differential between the healthiest meal item …

Genome-Wide Analyses Of Shavenbaby Target Genes Reveals Distinct Features Of Enhancer Organization, Delphine Menoret, Marc Santolini, Isabelle Fernandes, Rebecca Spokony, Jennifer Zanet, Ignacio Gonzalez, Yvan Latapie, Pierre Ferrer, Hervé Rouault, Kevin P. White, Philippe Besse, Vincent Hakim, Stein Aerts, Francois Payre, Serge Plaza

Publications and Research

Background: Developmental programs are implemented by regulatory interactions between Transcription Factors (TFs) and their target genes, which remain poorly understood. While recent studies have focused on regulatory cascades of TFs that govern early development, little is known about how the ultimate effectors of cell differentiation are selected and controlled. We addressed this question during late Drosophila embryogenesis, when the finely tuned expression of the TF Ovo/Shavenbaby (Svb) triggers the morphological differentiation of epidermal trichomes.

Results: We defined a sizeable set of genes downstream of Svb and used in vivo assays to delineate 14 enhancers driving their specific expression in trichome …

Early Innate Immunity Determines Outcome Of Mycobacterium Tuberculosis Pulmonary Infection In Rabbits, Selvakumar Subbian, Nirmalya Bandyopadhyay, Liana Tsenova, Paul O'Brien, Viraj Khetani, Nicole L. Kushner, Blas Peixoto, Patricia Soteropoulos, Joel S. Bader, Petros C. Karakousis, Dorothy Fallows, Gilla Kaplan

Publications and Research

Background: Pulmonary infection of humans by Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), results in active disease in 5-10% of individuals, while asymptomatic latent Mtb infection (LTBI) is established in the remainder. The host immune responses that determine this differential outcome following Mtb infection are not fully understood. Using a rabbit model of pulmonary TB, we have shown that infection with the Mtb clinical isolate HN878 (a hyper-virulent W-Beijing lineage strain) leads to progressive cavitary disease similar to what is seen in humans with active TB. In contrast, infection with Mtb CDC1551 (a hyper-immunogenic clinical isolate) is efficiently …