About

Our faculty are engaged and dedicated educators, advisors, and mentors and have been honored with numerous university-wide and national teaching awards. Our classes emphasize the latest research coupled with cutting-edge technology and practices making our graduates among the most competitive candidates in the country for natural resource professions. Our curricula include everything from protected lands management and urban forestry, to industrial forestry operations and ecology. Small class sizes and faculty dedicated to teaching afford FREC students the chance to get to know their professors personally. Wide varieties of academic and professional opportunities are available through research, student organizations, and public outreach programs organized by the faculty.

Research topics

• Medicine
• Biology
• Physiology
• Animal science
• Andrology
• Food science
• Endocrinology
• Gynecology
• Anatomy
• Materials science

Selected publications

• Impaired glycosylation promotes rapid transition to hepatocellular carcinoma in model of diet-induced steatotic liver disease

  Journal of Clinical Investigation · 2026-03-10

  articleOpen access

  Obesity-linked steatosis is a significant risk factor for hepatocellular carcinoma (HCC); however, the molecular mechanisms underlying the transition from metabolic dysfunction-associated steatotic liver disease (MASLD) to HCC remain unclear. Here, we explored the role of the ER-associated protein NgBR, an essential component of the cis-prenyltransferase (cis-PTase) enzyme, in chronic liver disease. Hepatocyte-specific NgBR deletion in mice (N-LKO) intensified triacylglycerol (TAG) accumulation, inflammatory responses, ER/oxidative stress, and fibrosis, ultimately resulting in HCC development with 100% penetrance after 4 months on a high-fat diet. Similarly, liver-specific knockout of DHDDS, NgBR's cis-PTase partner, and a knockin model carrying a human NgBR mutation that impairs cis-PTase activity developed HCC under high-fat diet conditions, although with lower penetrance. A single-cell transcriptomic atlas from affected livers provides a detailed molecular analysis of the transition from liver pathophysiology to HCC development. Mechanistically, NgBR deficiency promoted excessive hepatic TAG accumulation by enhancing lipid uptake and impairing VLDL secretion. Importantly, pharmacological inhibition of diacylglycerol acyltransferase-2 (DGAT2), a key enzyme in TAG synthesis, abrogated diet-induced liver damage and HCC burden in N-LKO mice. Overall, our findings establish cis-PTase as a critical suppressor of MASLD-HCC conversion and suggest DGAT2 inhibition may serve as a promising therapeutic approach to delay HCC formation in advanced metabolic dysfunction-associated steatohepatitis.

  PublisherOA PDFDOI

• Learning Delays Through Gradients and Structure: Emergence of Spatiotemporal Patterns in Spiking Neural Networks

  arXiv (Cornell University) · 2024-07-07

  preprintOpen access

  We present a Spiking Neural Network (SNN) model that incorporates learnable synaptic delays through two approaches: per-synapse delay learning via Dilated Convolutions with Learnable Spacings (DCLS) and a dynamic pruning strategy that also serves as a form of delay learning. In the latter approach, the network dynamically selects and prunes connections, optimizing the delays in sparse connectivity settings. We evaluate both approaches on the Raw Heidelberg Digits keyword spotting benchmark using Backpropagation Through Time with surrogate gradients. Our analysis of the spatio-temporal structure of synaptic interactions reveals that, after training, excitation and inhibition group together in space and time. Notably, the dynamic pruning approach, which employs DEEP R for connection removal and RigL for reconnection, not only preserves these spatio-temporal patterns but outperforms per-synapse delay learning in sparse networks. Our results demonstrate the potential of combining delay learning with dynamic pruning to develop efficient SNN models for temporal data processing. Moreover, the preservation of spatio-temporal dynamics throughout pruning and rewiring highlights the robustness of these features, providing a solid foundation for future neuromorphic computing applications.

  PublisherOA PDFDOI

• Unexplained Female Infertility Associated with Genetic Disease Variants

  New England Journal of Medicine · 2023-03-15 · 24 citations

  letterOpen access
  PublisherOA PDFDOI

• Abstract 2545: Dissecting time and space dynamics within the EGF Receptor signalosome

  Journal of Biological Chemistry · 2023-01-01

  articleOpen access
  PublisherDOI

• Integrative Structural Biology to Understand Biological Complexity

  Molecular & Cellular Proteomics · 2022-08-01

  articleOpen access

  Cryogenic electron microscopy (cryoEM) has been advanced to resolve atomic structures of biochemically purified macromolecules with details equivalent to X-ray crystal structures. A unique aspect of cryoEM is to use image processing methods to sort out images of particles with heterogeneous compositions and conformations. These capabilities have been demonstrated across a spectrum of macromolecules including viruses, membrane channels, protein folding machines with and without substrates, and RNA. The reliability of these structures can be assured by using rigorous criteria that the atomic model obeys expected stereochemistry of the molecules and simultaneously matches well with the experimentally observed density maps. The resolvability of the cryoEM structures have been shown in many cases to be sufficiently good to resolve carbohydrates, lipids, ligands, ions and water molecules that are critical to understand the chemical basis of their tertiary structures and their functions involving conformational variations. We will present examples of integrating cryoEM, mass spectrometry and biological assays to guide interpretation of cryoEM structures in terms of their contents and functions.

  PublisherDOI

• The development of a dual-modality (PET/NIR) radioimmunoconjugate for image-guided sarcoma surgery

  Nuclear Medicine and Biology · 2022-05-01

  article
  PublisherDOI

• Short-term consumption of the mycotoxin zearalenone by pubertal gilts causes persistent changes in the histoarchitecture of reproductive tissues

  Journal of Animal Science · 2022 · 5 citations

  • Biology
  • Food science
  • Physiology

  Consumption of zearalenone (ZEN) detrimentally affects tissues and systems throughout the body, and these deleterious effects are especially pronounced in swine. The objectives of this project were to determine the effects of short-term consumption of ZEN (at concentrations that could be found on-farm) on growth, carcass weight, liver weight, and reproductive tissues of pubertal gilts, and to determine if the effects are transient or persistent. Cross-bred gilts (107.25 ± 2.69 kg) were randomly assigned to one of three feed treatments: 1) solvent only for 21 d (CON; n = 10), 2) ZEN for 7 d followed by 14 d of solvent (ZEN-7; 6 mg/d; n = 10), and 3) ZEN for 21 d (ZEN-21; 6 mg/d; n = 10). Body weights were collected at the beginning and end of the experiment (189.1 ± 0.8 and 211.1 ± 0.8 d of age, respectively). Carcass weights and tissues were collected at harvest. There were no treatment-based differences in growth, carcass, liver, or reproductive tissue weights. Histological analyses revealed differences based on treatment and the interaction between treatment and luteal status. The thickness of the ampullary muscularis declined with ZEN exposure (P < 0.05), while the isthmic epithelial cell height (P < 0.01) and uterine endometrial thickness (P < 0.02) increased. Interestingly, the thickness of the isthmic muscularis, uterine myometrium, and epithelial cell height only differed in the presence of a corpus luteum. Uterine epithelial cell height in the luteal phase was lowest in ZEN-7 pigs (P < 0.01). The isthmic muscularis in the luteal phase was thinner in pigs from both ZEN treatments (P < 0.01). Conversely, the luteal-stage myometrium was thicker in pigs from both ZEN treatments (P < 0.01). The discovery of these tissue-based differences during the luteal phase is particularly concerning since this corresponds with the time when embryos would be affected by the functional competency of the oviduct and uterus. The results of this work demonstrate that short-term consumption of ZEN produces microscopic, but not macroscopic alterations in reproductive organs which are likely to have negative effects on their subsequent function and that these differences persist even after ZEN consumption ceases. Taken together, these results indicate that it is insufficient to rely solely on outwardly visible symptoms as indicators of zearalenone exposure, as detrimental effects on reproductive tissues were found in the absence of phenotypic and morphologic changes.

  PublisherOA PDFDOI

• Quantification of zearalenone and α-zearalenol in swine liver and reproductive tissues using GC-MS

  Toxicon X · 2020 · 25 citations

  • Biology
  • Physiology
  • Gynecology

  The mycotoxin zearalenone (ZEN) is a common contaminant of swine feed which has been related to a wide range of reproductive anomalies in swine, such as pelvic organ prolapse, anestrous, and pseudopregnancy. New information is needed to understand how ZEN and related metabolites accumulate in swine reproductive tissues. We conducted a feeding study to track ZEN and the metabolite α-zearalenol (α-ZEL) in swine liver and reproductive tissues. Thirty pubertal gilts were randomly assigned one of three treatments, with ten pigs in each treatment group: (1) base feed with solvent for 21 days, (2) ZEN-spiked feed for seven days followed by base feed with solvent for 14 days, and (3) ZEN-spiked feed for 21 days. At the end of the trial, liver, anterior vagina, posterior vagina, cervix, uterus, ovaries, and broad ligament were collected from pigs. ZEN was found in the anterior vagina, posterior vagina, cervix, and ovaries, with significantly higher concentrations in the cervix relative to other reproductive tissues. ZEN and α-ZEL were found in liver tissue from pigs in each treatment group. Our results show that ZEN accumulates more in the cervix than other reproductive tissues. The presence of ZEN in reproductive tissues may be indicative of ZEN-related reproductive symptoms. Future work could examine how ZEN concentrations vary in reproductive tissues as a factor of the pigs age, weight, sex, or parity, to establish parameters that make pig more sensitive to ZEN.

  PublisherOA PDFDOI

• Effects of short-term moderate ZEN consumption on uterosacral ligament elasticity in pubertal gilts

  Research in Veterinary Science · 2020 · 6 citations

  • Animal science
  • Materials science
  • Biology
  PublisherDOI

• HERV1-env dependent unfolded protein response activation is a potential initiator of autoreactivity in autoimmune liver disease

  The Journal of Immunology · 2020-05-01

  article

  Abstract Regulatory T cells are not terminally differentiated but can acquire effector properties. Here we report Human Endogenous Retrovirus 1 (HERV1-env) induction of endoplasmic reticulum (ER) stress with Unfolded Protein Response (UPR) activation, through its interaction with ATF6. UPR activation cleaves ATF6 to its α and β isoforms. ATF6α up-regulates RORC, STAT3 and TBX21 and induces IL-17A and INF-γ production in regulatory T cells by binding to promoter sequences. Silencing of HERV1-env results in partial recovery of regulatory T cell suppressive function and abrogation of apoptosis. These findings identify ER stress and UPR activation as key factors driving regulatory T cell plasticity.

  PublisherDOI

Frequent coauthors

• E. T. Kornegay

  Virginia Tech

  23 shared

• F.C. Gwazdauskas

  Virginia Tech

  18 shared

• Anne‐Claude Gingras

  Lunenfeld-Tanenbaum Research Institute

  16 shared

• D. R. Notter

  Virginia Tech

  16 shared

• William H. Velander

  University of Nebraska–Lincoln

  16 shared

• Christopher D. Go

  University of Toronto

  15 shared

• Wah Chiu

  Stanford University

  15 shared

• H. P. Veit

  University of Gothenburg

  12 shared