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Uniqueness of p-local truncated Brown-Peterson spectra
No full textWhen p is an odd prime, we prove that the Fp-cohomology of BP⟨n⟩ as a module over the Steenrod algebra determines the p-local spectrum BP⟨n⟩. In particular, we prove that the p-local spectrum BP⟨n⟩ only depends on its p-completion BP⟨n⟩p̂. As a corollary, this proves that the p-local homotopy type of BP⟨n⟩ does not depend on the ideal by which we take the quotient of BP. In the course of the argument, we show that there is a vanishing line for odd degree classes in the Adams spectral sequence for endomorphisms of BP⟨n⟩. We also prove that there are enough endomorphisms of BP⟨n⟩ in a suitable sense. When p = 2, we obtain the results for n ≤ 3.Ph.D
Integrated Modeling Approaches to Quantify Vehicle-to-Grid Services in an Evolving Power Sector
No full textThe U.S. transportation sector emitted 27% of nationwide greenhouse gas (GHG) emissions in 2020. In addition to cleaner fuels and more efficient powertrains, vehicle electrification is poised to be a key driver of sector decarbonization. However, fleet electrification poses an unprecedented coupling of the transportation sector and electric grid. Electric vehicle charging and other new loads, if not sufficiently managed, are anticipated to add significant strain to the grid. In light of these challenges, vehicle-to-grid (V2G) has been proposed as a form of flexible load and decentralized energy storage. Within a V2G framework, grid-connected electric vehicles provide services to power grids, for example by shifting when they charge or discharging their batteries to the grid when power demand is high. Conceptually, V2G can reduce the costs of intermittency, facilitate renewables growth, and provide storage services to the grid.
While V2G continues to evolve and gain market traction, there remain several aspects of the technology, both operational and economic, that stand to be better understood and improved upon to best facilitate widespread adoption. For instance, EVs can theoretically displace stationary energy storage, but to what extent? What are demand side implications for the grid? For early technology adopters, particularly commercial fleets, how do travel needs and network tariffs affect V2G revenues? How can one practically simulate V2G and other service outcomes and do the potential revenues justify initial investment?
This thesis addresses such questions and concerns through the development and application of methods that (1) quantify the technology's ultimate value proposition at the systems level, and (2) enable risk-informed market participation and financial analysis.Ph.D
Report to the President for year ended June 30, 2025, MIT Audit Division
No full textThis report contains the following sections: Fiscal Year Audit Plan, Quality Assurance Improvement Program, Implementation of Global Internal Audit Standards; Risk Assessment for and Management of 2026 Audit Plan; Advancement of Technology and Data Analytics; Departmental and Staff Transitions; Professional Development and Engagement; and Institute Activities
Analyzing the Role of Emotions on Performance in Hybrid Capstone Projects
No full textFSE Companion ’25, Trondheim, NorwayIn hybrid project-based learning environments when students collaborate both in-person and remotely to perform shared tasks, they often experience a wide range of emotions. These emotions significantly influence their performance and collaboration as they navigate team dynamics. This study aimed to investigate the emotions expressed during Scrum retrospective meetings, explore their underlying triggers, and examine their relationship with perceived performance. We conducted our study with 24 participants, divided into three teams, enrolled in a hybrid capstone course. Using a BERT model fine-tuned on the GoEmotions dataset, we analyzed retrospective meeting transcripts and open-ended survey responses to identify emotions. Quantitative analysis assessed the relationship between these emotions and self-reported performance metrics collected through survey responses. To further understand the emotional context, thematic analysis was performed to identify events that triggered these emotions. We observed (1) approval, admiration and curiosity as the most prevalent emotions expressed during retrospective meetings; (2) significant correlations between positive emotions and perceived performance; and (3) milestone achievements, collaboration, and communication and coordination issues as common emotional triggers. Our findings emphasize the role of emotions in relation to performance and collaboration in hybrid learning environments. These findings offer insights into emotional dynamics for designing more effective and supportive hybrid project-based learning environments
Decarbonizing of power plants by ammonia co-firing: design, techno-economic, and life-cycle analyses
No full textThis research investigates the decarbonization of India’s electricity grid using ammonia in power plants. It focuses on ammonia produced in Western Australia and transported to India, co-fired with high rank coal, and compared with power plants utilizing carbon capture and sequestration (CCS). The study assesses the overall costs and the life cycle greenhouse gas (LC GHG) emissions for both new plants and retrofits. For 20% gray, blue, and green ammonia, the levelized cost of electricity is 86, 89, 125 84/MWh and a LC GHG emission of 1,227 kg CO2e/MWh. While CCS is cheaper, it results in higher LC GHG. There is a trade-off between cost and emissions across the strategies. Under scenarios with low capacity factors or reduced ammonia production costs, coal-ammonia co-firing could become more economical and greener than the CCS. This study provides quantitative insights for policymakers and project developers. However, it is crucial for decision-makers to consider several factors: (1) the potential impact of social resistance to CCS; (2) the time required for large-scale commercialization of CCS technology, which is expected to be significantly longer than the implementation time for a coal-ammonia co-firing decarbonization strategy; (3) the potential of either CCS or ammonia-coal co-firing strategy to enhance India’s electricity mix, thus contributing to energy security
Origin and Correlates of Viral Rebound in SIV-Infected Rhesus Macaques Following Discontinuation of ART
No full textThe earliest events of viral rebound following discontinuation of ART in people living with Human Immunodeficiency Virus-1 remain largely unknown. We investigated detailed reservoir characteristics and viral rebound dynamics in 18 Simian Immunodeficiency Virus-infected rhesus macaques treated with antiretroviral therapy for 70 weeks and then necropsied after a 12-day analytical treatment interruption (ATI). Using molecularly barcoded SIVmac239M, we tracked viral clonotypes following ATI in both peripheral blood and tissues at necropsy. Viral rebound appeared to originate by reactivation of a single or a few barcode clonotypes from a limited number of deep lymph nodes or gastrointestinal tissues, followed by rapid virus replication of this clonotype in peripheral blood and tissues as well as serial reactivation of multiple additional barcode clonotypes from different anatomic sites, resulting in oligoclonal plasma viremia. Daily transcriptomic and proteomics profiling in peripheral blood following ATI identified early upregulation of pathways related to T cell signaling, cytokine responses, and metabolism prior to detectable plasma viremia, presumably reflecting initial viral replication in tissues. Taken together, these data provide a detailed anatomic, virologic, and immunologic characterization of viral rebound in SIV-infected macaques following ATI, which provides critical information to inform the development of next generation HIV-1 cure strategies.Ph.D
New physics at the Muon (Synchrotron) Ion Collider: MuSIC for several scales
No full textA Muon (Synchrotron) Ion Collider (MuSIC) can be the successor to the Electron-Ion Collider at Brookhaven National Laboratory, as well as the ideal demonstrator facility for a future multi-TeV Muon Collider. Besides its rich nuclear physics and Standard Model particle physics programs, in this work we show that the MuSIC with a TeV-scale muon beam offers also a unique opportunity to probe New Physics. In particular, the relevant searches have the potential to surpass current experimental limits and explore new regimes of the parameter space for a variety of Beyond the Standard Model scenarios including: lepton-flavor violating leptoquarks, muonphilic vector boson interactions, axion-like particles coupling to photons, and heavy sterile neutrinos. Depending on the particular case, the sensitivity of the searches in the MuSIC may span a wide range of energy scales, namely from sub-GeV particles to the few TeV New Physics mediators. Our analysis demonstrates that the MuSIC can strike a powerful chord in the search for New Physics, thanks to unique combination of features that amplify its capabilities
Diversity in the medical research ecosystem: a descriptive scientometric analysis of over 49 000 studies and 150 000 authors published in high-impact medical journals between 2007 and 2022
No full textObjectives Health research that significantly impacts
global clinical practice and policy is often published in
high-impact factor (IF) medical journals. These outlets
play a pivotal role in the worldwide dissemination of novel
medical knowledge. However, researchers identifying as
women and those affiliated with institutions in low- and
middle-income countries (LMICs) have been largely
under-represented in high-IF journals across multiple
fields of medicine. To evaluate disparities in gender and
geographical representation among authors who have
published in any of five top general medical journals, we
conducted scientometric analyses using a large-scale
dataset extracted from the New England Journal of
Medicine, Journal of the American Medical Association,
The BMJ, The Lancet and Nature Medicine.
Methods Author metadata from all articles published
in the selected journals between 2007 and 2022 were
collected using the DimensionsAI platform. The Genderize.
io Application Programming Interface was then used to
infer each author’s likely gender based on their extracted
first name. The World Bank country classification was used
to map countries associated with researcher affiliations
to the LMIC or the high-income country (HIC) category.
We characterised the overall gender and country income
category representation across the five medical journals.
In addition, we computed article-level diversity metrics and
contrasted their distributions across the journals.
Results We studied 151 536 authors across 49 764
articles published in five top medical journals, over a
period spanning 15 years. On average, approximately
one-third (33.1%) of the authors of a given paper were
inferred to be women; this result was consistent across
the journals we studied. Further, 86.6% of the teams
were exclusively composed of HIC authors; in contrast,
only 3.9% were exclusively composed of LMIC authors.
The probability of serving as the first or last author was
significantly higher if the author was inferred to be a
man (18.1% vs 16.8%, p<0.01) or was affiliated with an
institution in a HIC (16.9% vs 15.5%, p<0.01). Our primary
finding reveals that having a diverse team promotes further diversity, within the same dimension (ie, gender or geography) and
across dimensions. Notably, papers with at least one woman among the
authors were more likely to also involve at least two LMIC authors (11.7%
vs 10.4% in baseline, p<0.001; based on inferred gender); conversely,
papers with at least one LMIC author were more likely to also involve at
least two women (49.4% vs 37.6%, p<0.001; based on inferred gender).
Conclusion We provide a scientometric framework to assess authorship
diversity. Our research suggests that the inclusiveness of high-impact
medical journals is limited in terms of both gender and geography. We
advocate for medical journals to adopt policies and practices that promote
greater diversity and collaborative research. In addition, our findings offer
a first step towards understanding the composition of teams conducting
medical research globally and an opportunity for individual authors to
reflect on their own collaborative research practices and possibilities to
cultivate more diverse partnerships in their work
Report to the President for year ended June 30, 2025, MIT Center for Transportation & Logistics
No full textThis report contains the following sections: AY2025 Accomplishments & Awards; Education; Research; Outreach; Personnel Changes; and Appendix
Housing in European Metropolises: supply dynamics and planning frameworks in large Urban Areas of the EU
No full textEurope’s housing affordability crisis presents significant territorial challenges, particularly as housing demand increasingly spills over from inner cities to surrounding municipalities at the metropolitan scale. This study addresses key policy questions regarding the coordination of housing supply and planning instruments in large urban areas of the European Union.
Focusing on 23 large Functional Urban Areas (FUAs), the research follows a three part approach: a quantitative analysis of municipal-level housing production and demographic growth between 2011 and 2021 based on Census data; an analysis of the effects of housing supply on housing prices; and an AI-powered quantitative examination of urban plans, at municipal, metropolitan, and regional scales to observe whether they establish housing supply goals. This methodology generates evidence on the spatial dynamics of housing development, by creating an EU-wide database at municipal granularity, while providing a novel focus and analytical approach to institutional urban plans as drivers of housing supply.
Findings prove mixed alignments between housing supply and demographic growth, with Southern and coastal urban areas falling short on housing supply. In most cases, there is a pronounced metropolitan effect, where peripheral municipalities experience larger housing and population growth. When analyzing the plans, more frequent planning relates to larger housing provision. In addition, the research highlights that housing goals are usually determined at local plans, showing a mismatch between planning efforts and housing dynamics, which tend to be metropolitan or regional. Therefore, the research deepens the understanding of European housing provision and the planning of urban territories, highlighting the need for stronger housing policy mechanisms at the metropolitan level.M.C.P