About

Michael R Carter is a Distinguished Professor at the Department of Agricultural and Resource Economics at UC Davis. His research focuses on development economics, poverty dynamics, rural credit and insurance markets, agricultural development, income distribution, land tenure, and land reform. His work contributes to understanding the economic challenges faced by rural communities and developing countries, with an emphasis on policies that improve economic outcomes and reduce poverty in agricultural sectors.

Research topics

• Computer Science
• Business
• Geography
• Artificial Intelligence
• Economics
• Agricultural economics
• Political Science
• Literature
• Market economy
• Software engineering
• Psychology
• Pedagogy
• Public economics
• Agronomy
• Art history
• Ecology
• Engineering management
• Philosophy
• Economic growth
• Engineering ethics
• Mathematics education
• History
• Agricultural science
• Environmental science

Selected publications

• A Comparison of Demographic and Microorganism Differences Between De Novo and Postoperative Infections

  Clinical Spine Surgery A Spine Publication · 2026-04-08

  article

  STUDY DESIGN: Retrospective cohort. OBJECTIVES: To compare demographic and microorganism culture data between primary and postoperative infections. BACKGROUND: Current literature suggests that both de novo and postoperative infection rates are increasing. At present, there is a paucity of research directly comparing de novo and postoperative spinal infections. METHODS: Patients aged 18 years or older who underwent an irrigation and debridement (I&D) for de novo spine infections and infections following elective spine surgeries from 2017 to 2023 were compared. All patients were retrospectively reviewed for demographic information, comorbidities, and social history. Tissue microbiology of both cohorts was compared by broad classes (eg, gram-positive vs gram-negative, aerobic vs anaerobic, monomicrobial vs polymicrobial) and individual microbes (eg, Staphylococcus aureus, E. Coli, Pseudomonas, etc). Statistical analysis was performed, and P-value <0.05 was considered statistically significant. RESULTS: One hundred fifty-three patients underwent an I&D in the setting of a de novo spine infection, while 239 patients underwent an I&D in the setting of a postoperative infection. Patients who developed de novo infections were on average younger (P = 0.002) with lower BMIs (P < 0.001) and were more likely to be current smokers (P = 0.005). These patients also had higher rates of hepatitis C (P < 0.001), CKD (P = 0.009), and prior IV drug use (P < 0.001). De novo infections had higher rates of gram-positive (P = 0.004), monomicrobial (P = 0.013), and aerobic (P = 0.026) infections than postoperative infections. Staphylococcusaureus infection rates were statistically similar between groups (P = 0.138), while Streptococcus was more common in the postoperative infection cohort (P = 0.002). Pseudomonas, proteus, and Corynebacterium were identified significantly more often in the postoperative infection cohort. CONCLUSIONS: Patients developing de novo and postoperative spine infections exhibit notable demographic and microorganism differences. Adequate treatment of patients with spinal infections, therefore, requires an awareness of both medical and social factors most prevalent within these two populations.

  PublisherDOI

• Impact of Chronic Preoperative Gabapentinoid Exposure on Surgical and Patient-Reported Outcome Measures Following Lumbar Fusion

  Spine · 2025-03-19

  article

  STUDY DESIGN: Retrospective cohort. OBJECTIVE: To assess the relationship between long-term gabapentinoid use and outcomes after lumbar fusion. SUMMARY OF BACKGROUND DATA: Gabapentinoids, which include gabapentin and pregabalin, are commonly prescribed for radiculopathic pain. Basic science research has indicated that gabapentinoids may be detrimental to bone health/healing and clinical works has shown that initiating gabapentinoids at the time of spine surgery may decrease postoperative opioid requirements and increase risks of adverse outcomes. Despite these findings, no literature exists examining the impact of chronic gabapentinoid prescriptions on outcomes after lumbar fusion. MATERIALS AND METHODS: Adult patients who underwent elective one/two-level lumbar fusion (2017-2022) were identified through Structured Query Language search. Patient demographic/surgical characteristics, surgical outcomes, patient-reported outcome measures (PROMs), and preoperative gabapentinoid use were collected. Perioperative opioid data were collected utilizing the Pennsylvania Prescription Drug Monitoring Program. Appropriate statistical analyses were conducted with alpha set at 0.05. RESULTS: Among 461 included patients, 47 (10.2%) and 61 (13.2%) were chronically prescribed pregabalin and gabapentin, respectively. All groups were similar in terms of demographics, and surgical type/complexity. There were no differences in surgical outcomes, including two-year revision rate. Patients taking pregabalin consumed more total MMEs compared with gabapentin (132±344 vs. 104±351, P =0.022) and nongabapentinoid patients (132±344 vs. 90.3±267, P =0.007). However, preoperative total MMEs were similar 60 days before surgery. Bivariate analysis demonstrated postoperative differences in back pain improvement at six months ( P =0.025) between groups; however, pairwise comparison did not show significance. Similarly, multivariate analysis did not show gabapentinoid usage as independently predictive of back pain scores. All other PROM comparisons were similar between groups. CONCLUSION: Despite compelling basic science literature suggesting gabapentinoid exposure hindering bone health and healing capacity, the current investigation did not find an increase in surgical revision or other adverse outcomes, including opioid use and PROMs, associated with chronic preoperative gabapentinoid use.

  PublisherDOI

• The XLZD Design Book: towards the next-generation liquid xenon observatory for dark matter and neutrino physics

  The European Physical Journal C · 2025-10-23 · 10 citations

  articleOpen access

  Abstract This report describes the experimental strategy and technologies for XLZD, the next-generation xenon observatory sensitive to dark matter and neutrino physics. In the baseline design, the detector will have an active liquid xenon target of 60 tonnes, which could be increased to 80 tonnes if the market conditions for xenon are favorable. It is based on the mature liquid xenon time projection chamber technology used in current-generation experiments, LZ and XENONnT. The report discusses the baseline design and opportunities for further optimization of the individual detector components. The experiment envisaged here has the capability to explore parameter space for Weakly Interacting Massive Particle (WIMP) dark matter down to the neutrino fog, with a 3 $$\sigma $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>σ</mml:mi> </mml:math> evidence potential for WIMP-nucleon cross sections as low as $$3\times 10^{-49}\mathrm \,cm^2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>3</mml:mn> <mml:mo>×</mml:mo> <mml:msup> <mml:mn>10</mml:mn> <mml:mrow> <mml:mo>-</mml:mo> <mml:mn>49</mml:mn> </mml:mrow> </mml:msup> <mml:mspace/> <mml:mi>c</mml:mi> <mml:msup> <mml:mi>m</mml:mi> <mml:mn>2</mml:mn> </mml:msup> </mml:mrow> </mml:math> (at 40 GeV/c $$^2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mrow/> <mml:mrow/> <mml:mn>2</mml:mn> </mml:mmultiscripts> </mml:math> WIMP mass). The observatory will also have leading sensitivity to a wide range of alternative dark matter models. It is projected to have a 3 $$\sigma $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>σ</mml:mi> </mml:math> observation potential of neutrinoless double beta decay of $$^{136}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mrow/> <mml:mrow/> <mml:mn>136</mml:mn> </mml:mmultiscripts> </mml:math> Xe at a half-life of up to $$5.7\times 10^{27}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>5.7</mml:mn> <mml:mo>×</mml:mo> <mml:msup> <mml:mn>10</mml:mn> <mml:mn>27</mml:mn> </mml:msup> </mml:mrow> </mml:math> years. Additionally, it is sensitive to astrophysical neutrinos from the sun and galactic supernovae.

  PublisherDOI

• Optimizing clear cell renal cell carcinoma tumor-infiltrating lymphocytes under controlled hypoxic conditions.

  Journal of Clinical Oncology · 2025-02-10 · 1 citations

  article

  581 Background: Adoptive cell therapy (ACT) using tumor-infiltrating lymphocytes (TILs) represents a promising approach for advanced solid tumor treatment. Historically, the success of TIL therapy in clear cell renal cell carcinoma (ccRCC) has been limited by difficulty expanding cytotoxic functional TILs. Hypoxic conditions in the ccRCC tumor microenvironment have been associated with mixed tumor characteristics, including metabolic dysregulation and tumor progression. Given the significant role of hypoxia in ccRCC progression, we investigated TIL expansion under controlled hypoxic conditions and its impact on TIL cytotoxic functions. Methods: Fragments or tumor digests from 41 ccRCC patients were cultured with high-dose (6000IU/mL) IL-2 for four weeks. TIL expansion success was defined as at least one fragment expanding to a minimum of 2 wells. Primary TIL underwent rapid expansion protocol (REP) at 20% (normoxic) or 5% (hypoxic) O 2 levels. Cells were rested in post-REP media for 3–4 days in their respective conditions (20% or 5% O 2 ) and subsequently collected for downstream analysis. Reactivity to autologous tumor, expression of activation/co-inhibitory markers, and memory phenotype were analyzed with flow cytometry and co-culture assays. Results: TILs were successfully grown in 87.8% of samples (36/41). TILs secreted IFNγ in response to autologous tumors in 88.6% (31/35) of the samples. Both TIL expansion and reactivity occurred independently of tumor stage or grade. TIL REP under hypoxic conditions (5% O2) was successful, and these conditions salvaged more CD8+ TILs compared to normoxic conditions (p=0.0382). Hypoxic REP TILs showed increased IFNγ, TNFα, and Granzyme B release in response to autologous tumor compared to normoxic conditions. Additionally, hypoxic REP TILs expressed higher LAG3 and TIM3 markers (p&lt;0.05), with significantly increased proportions of tissue-resident memory-like (TRM) CD8+ T-cells (CD69+CD103+) compared to normoxic conditions (18.2% CD69+CD103+ versus 2.6%, respectively, p&lt;0.0001). These features have been associated with clinical responders TILs in melanoma. Conclusions: This study demonstrates the feasibility of expanding tumor-reactive TILs from ccRCC despite tumors harboring exhausted CD8+ T-cells. Exposing TILs to hypoxic conditions enhanced effector functions and promoted the acquisition of a TRM T-cell phenotype. These findings suggest that ccRCC TIL expansion under controlled hypoxia is feasible and could confer improvement to the clinical efficacy of TIL therapy for ccRCC.

  PublisherDOI

• Defining the tumor-infiltrating lymphocyte antigenic landscape in head and neck cancer 4114

  The Journal of Immunology · 2025-11-01

  articleOpen access

  Abstract Description Adoptive cell transfer (ACT) with tumor-infiltrating lymphocytes (TIL) is a promising therapeutic approach for head and neck squamous cell carcinoma (HNSCC). We explored the potential to harness a polyclonal population of T cells via enriched specificity and reactivity toward tumor-derived antigens. Across 18 HNSCC samples, on average 119 somatic mutations and 89 25mers were discovered via whole exome and RNA sequencing and predicted to bind to each patient’s respective MHC. The first patient sample revealed a candidate neoantigen ‘hit’ resulting in activation of 45% of CD4+ TIL by OX40+/4-1BB+ induction. Neoantigen-reactive TIL secreted granzyme B, IFNg, and TNFa, in a dose-dependent manner, which was abrogated by HLA-DQ blockade. TCR sequencing revealed an oligoclonal T cell population. Pilot non-clinical ACT experiments in mice demonstrated TIL engraftment and tumor infiltration. Initial APC immunopeptidomics analysis found nine unique epitopes bound to MHC Class I and 17 peptides presented by MHC Class II following neoantigen pulse. Overall, expanded HNSCC TIL contain neoantigen-reactive effector T cells, and analysis of additional samples is ongoing. We aim to expand this investigation to better understand the landscape of T cell reactivity and the dynamic antigenic and cellular determinants involved in the anti-tumor immune response. Ultimately, we plan to determine the potential therapeutic benefit of an enriched antigen-reactive TIL-ACT product for HNSCC patients. Funding Sources This study was funded, at least in part, by Marshall Glenn Hoffman Oral Cancer Research Fund. Turnstone Biologics sponsored research agreement. Topic Categories Tumor Immunology: Cellular Responses and Tumor Microevironment (TIME)

  PublisherOA PDFDOI

• Dark Matter Search Results from <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mn>4.2</mml:mn><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:mtext>Tonne</mml:mtext><mml:mtext>−</mml:mtext><mml:mtext>Years</mml:mtext></mml:mrow></mml:math> of Exposure of the LUX-ZEPLIN (LZ) Experiment

  Physical Review Letters · 2025-05-12 · 115 citations

  articleOpen access

  We report results of a search for nuclear recoils induced by weakly interacting massive particle (WIMP) dark matter using the LUX-ZEPLIN (LZ) two-phase xenon time projection chamber. This analysis uses a total exposure of 4.2±0.1 tonne-years from 280 live days of LZ operation, of which 3.3±0.1 tonne-years and 220 live days are new. A technique to actively tag background electronic recoils from ^{214}Pb β decays is featured for the first time. Enhanced electron-ion recombination is observed in two-neutrino double electron capture decays of ^{124}Xe, representing a noteworthy new background. After removal of artificial signal-like events injected into the dataset to mitigate analyzer bias, we find no evidence for an excess over expected backgrounds. World-leading constraints are placed on spin-independent (SI) and spin-dependent WIMP-nucleon cross sections for masses ≥9 GeV/c^{2}. The strongest SI exclusion set is 2.2×10^{-48} cm^{2} at the 90% confidence level and the best SI median sensitivity achieved is 5.1×10^{-48} cm^{2}, both for a mass of 40 GeV/c^{2}.

  PublisherDOI

• The Impact of Crossing the Cervicothoracic Junction on Opioid Consumption, Readmission, and Revision Rates

  Journal of the American Academy of Orthopaedic Surgeons · 2025-03-25

  article

  INTRODUCTION: The risks and benefits of extending posterior cervical decompression and fusion (PCDF) constructs across the cervicothoracic junction (CTJ) remain controversial. Previous studies have used fusions beginning at different levels and varying in construct length. There are no studies that examine the effect of crossing the CTJ on opioid consumption. This study aims to compare short-term and long-term postoperative outcomes among patients undergoing PCDF at C3 and ending at C7, T1, or T2. METHODS: Adult patients who underwent C3-C7, C3-T1, and C3-T2 PCDF from 2017 to 2022 were identified. All patients were retrospectively reviewed for demographic and surgical information. Perioperative opioid utilization from 1 year preoperatively to 1 year postoperatively was obtained from the Pennsylvania Prescription Drug Monitoring Program (PDMP). Acute postoperative outcomes included rates of 30-day and 90-day readmission and any revision surgery. RESULTS: This study included 72 (C3-C7: 30.2%), 143 (C3-T1: 60.1%), and 23 (C3-T2: 9.7%) patients-groups were demographically similar. The average length of follow-up was 503 ± 433 days. Cut-to-close time differed between groups (166 ± 37.9 [C3-C7] vs. 182 ± 43.2 vs. 199 ± 40.9 minutes [C3-T2]; P = 0.003). Total in-hospital morphine milligram equivalents (205 ± 136 [C3-C7] vs. 247 ± 191 vs. 285 ± 136 [C3-T2]; P = 0.007) and average daily in-hospital morphine milligram equivalents (59.5 ± 29.9 [C3-C7] vs. 73.2 ± 52.1 vs. 81.0 ± 22.9 [C3-T2]; P = 0.008) were highest among C3-T2 fusions. Patients who underwent C3-T2 fusion consumed higher MMEs from 0 to 90 days postoperatively (148 ± 197 [C3-C7] vs. 223 ± 307 vs. 260 ± 363 [C3-T2]; P = 0.027). Length of stay, opioid use beyond 90 days, 30-day and 90-day readmission rates, revision surgery rates, and revision rates were similar between groups. CONCLUSION: Crossing the CTJ increased cut-to-close time and early postoperative opioid consumption but did not affect length of stay, readmission rates, long-term opioid misuse, or revision surgery rates.

  PublisherDOI

• The impact of foraminotomy on patient-reported outcomes following 3+ level posterior cervical decompression and fusion for myeloradiculopathy

  Journal of Craniovertebral Junction and Spine · 2025-07-01

  articleOpen access

  ABSTRACT Objective: To evaluate whether patients with myeloradiculopathy experience better improvement in patient-reported outcome measures (PROMs) from the addition of foraminotomy in the setting of posterior cervical decompression and fusion (PCDF). Methods: Adult patients who underwent ≥≥ 3-level PCDF (2017–2022) at a single tertiary center were retrospectively identified. Patients were included if their indication was myeloradiculopathy – patients were excluded if they had a combined anterior/posterior approach, an indication of infection/tumor/trauma, or incomplete 1-year PROMs. Operative notes were evaluated to identify the patients who had a foraminotomy specifically for neuro-decompression. Patients with or without foraminotomy were evaluated for demographic/surgical variables, surgical outcomes, and PROMs. Appropriate statistics were performed, alpha was set at 0.05. Results: One hundred and seven PCDF patients were identified (33.6% foraminotomy and 66.4% nonforaminotomy). The two groups were similar regarding demographics and surgical metrics including cut-to-close and OR time and estimated blood loss. The two groups were similar in readmission rate at 30- and 90-days postoperatively, 1-year reoperation, and discharge disposition. Modified Japanese orthopedic association, short form-12 physical component score and mental component score, neck disability index, and visual analog scale (VAS) neck scores were similar between groups at all time points. The foraminotomy group had worse baseline VAS arm scores (5.56 ± 2.63 vs. 4.00 ± 2.69, P = 0.015) as well as greater improvement in VAS arm scores (−2.99 ± 3.22 vs. −1.25 ± 3.06, P = 0.035) at 1 year. Conclusion: Patients who had a foraminotomy experienced greater improvement in arm pain at 1-year follow-up without an increase in surgical time, hospital stay, or complications. The present study suggests that, for the appropriately selected patient undergoing PCDF for myeloradiculopathy, performing intentional foraminal decompression leads to improved outcomes at 1 year without altering surgical morbidity.

  PublisherDOI

• Delayed yet Durable Functional Recovery Following Posterior Cervical Decompression and Fusion for Mild Degenerative Cervical Myelopathy

  Spine · 2025-12-11

  article

  STUDY DESIGN: Retrospective Cohort. OBJECTIVE: This study was designed to: (1) compare functional recovery after PCDF across baseline severity groups, (2) determine the rate of achieving a severity-adjusted minimum clinically important difference (MCID) in modified Japanese Orthopaedic Association (mJOA) scores, and (3) assess how these outcomes evolve over two years. BACKGROUND: Degenerative cervical myelopathy (DCM) is the leading cause of spinal cord dysfunction in older adults. Posterior cervical decompression and fusion (PCDF) is a well-accepted option for moderate and severe disease, yet its role in mild DCM remains uncertain. METHODS: We retrospectively reviewed adults undergoing elective PCDF for DCM at a single tertiary care center from 2010-2022. Patients were stratified by preoperative mJOA score as mild (15-17), moderate (12-14), or severe (<12). Severity-adjusted MCID thresholds were defined as mJOA increases of +1, +2, and +3 points, respectively. Patient-reported outcomes were collected preoperatively and at 6, 12, and 24 months postoperatively. Multivariate logistic regression identified predictors of MCID achievement at 1 year. RESULTS: 137 patients were included (62 mild, 48 moderate, 27 severe) with similar baseline demographics across groups. At 12 months, moderate (OR 2.92, 95% CI 1.25-7.02) and severe (OR 3.40, 95% CI 1.26-9.48) patients were significantly more likely to achieve MCID than mild cases (P < 0.02). By 24 months, MCID achievement rates converged (41.9% mild, 42.9% moderate, 46.7% severe; P = 0.95). CONCLUSIONS: Greater preoperative myelopathy severity predicts larger early functional gains and higher MCID achievement after PCDF. However, by two years, patients with mild disease achieve MCID at similar rates to more severe cases, suggesting a delayed but meaningful benefit. These findings may guide surgical decision-making and patient counseling, particularly in the mild DCM population. LEVEL OF EVIDENCE: III.

  PublisherDOI

• Severe refractory thrombocytopenia post full matched female sibling donor hematopoietic stem cell transplant

  Human Immunology · 2025-09-01

  article
  PublisherDOI

Recent grants

• LabWrite: A National Web-Based Initiative to Use the Lab Report to Improve the Way Students Write, Visualize, and Understand Science

  NSF · $489k · 2003–2007

Frequent coauthors

• Gregory D. Schroeder

  66 shared

• Alan S. Hilibrand

  Rothman Institute

  65 shared

• José A. Canseco

  Thomas Jefferson University

  64 shared

• Alexander R. Vaccaro

  Rothman Institute

  56 shared

• Christopher K. Kepler

  Thomas Jefferson University

  56 shared

• Brian A. Karamian

  41 shared

• Barrett I. Woods

  Thomas Jefferson University

  41 shared

• Mark J. Lambrechts

  Thomas Jefferson University Hospital

  41 shared

Education

• Ph.D., Agricultural and Resource Economics

  University of California, Davis

• B.A., Economics

  University of Cape Town, South Africa

Awards & honors

• Fellow Agricultural & Applied Economics Association
• Fellow BREAD