City College of New York

Understanding how peptide sequence relates to supramolecular dynamics and consequent solid-state material properties remains a central challenge for rational peptide materials design. Here, we use N-terminal proline as a strategic conformational constraint in minimalist tripeptides (PXX; P = proline, X = phenylalanine (F) or tryptophan (W)) to isolate side-chain contributions from backbone and show that simple aromatic exchange dictates crystallization pathways and solid-state dynamics. In this design, proline rigidifies the backbone, the central residue supports assembly, and the C-terminal aromatic residue dictates conformational adaptability. Combining molecular dynamics simulations with NMR and fluorescence spectroscopy, we show that peptides with W at the C-terminus, with a diverse interaction space, display shallow energy landscapes with multiple accessible states, whereas a C-terminal F, with a stringent hydrophobic nature and limited interaction space, restricts the peptide into fewer conformations. As a result, PXF peptides form soluble supramolecular aggregates, while PXW peptides access more adaptable conformations that promote crystallization. Solid-state characterization reveals that these sequence-encoded supramolecular dynamics directly influence bulk properties: W-containing peptides form stiff crystals with dynamic, wettable surfaces, whereas F analogues yield static, hydrophobic materials. Together, these results establish how aromatic-residues dictate supramolecular assembly and crystallization, offering a straightforward approach to engineering dynamic properties in solid-state peptide materials.

I give a short proof of a recent result due to Kiefer and Ryzhikov showing that a finite irreducible semigroup of matrices has cardinality at most 3 2 .

Abstract Brain tumors, particularly high-grade gliomas such as glioblastoma multiforme (GBM), remain among the most aggressive and treatment-resistant malignancies. Their poor prognosis is driven by extreme cellular heterogeneity, rapid proliferation, infiltrative growth, and the presence of therapy-resistant cancer stem cells (CSCs). Increasing evidence highlights a central role for epigenetic dysregulation—especially abnormal histone deacetylase (HDAC) activity—in tumor initiation, progression, and therapeutic resistance. HDAC overexpression, particularly HDAC1, HDAC2, HDAC6, and several SIRT family members, is frequently observed in GBM and correlates with tumor aggressiveness, metabolic plasticity, and enhanced survival signaling. Histone deacetylase inhibitors (HDACi) have emerged as promising therapeutic agents capable of targeting multiple malignant features simultaneously. Preclinical studies demonstrate that HDACi can reduce CSC viability, promote apoptosis and autophagy, induce cell-cycle arrest, and impair angiogenesis and tumor invasion. HDACi also modulate pathways such as STAT3, SIRT, and SHH, thereby disrupting essential networks that support glioma growth. Importantly, several HDAC inhibitors have demonstrated the ability to cross the blood–brain barrier, increasing their potential for use in primary brain tumor therapy. Furthermore, combining HDACi with radiotherapy or chemotherapy has shown synergistic effects, improving tumor sensitivity and overcoming resistance mechanisms. Although current clinical progress is preliminary, accumulating data suggest that HDAC inhibitors may represent a valuable addition to future multimodal strategies for GBM and other central nervous system tumors. Continued investigation is needed to optimize their therapeutic integration and identify the most responsive patient populations. Citation Format: Laila T A. Metwaly. Histone deacetylase inhibitors as emerging therapeutic strategies for glioblastoma and other brain tumors [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Brain Cancer; 2026 Mar 23-25; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2026;86(6_Suppl):Abstract nr A037.

The GEO-ring constellation of atmospheric composition missions was established to deliver continuous, diurnally resolved observations of trace gases and aerosols at regional scales. Since the launch of GK2B in 2020, the constellation has expanded to include TEMPO in 2023 and Sentinel-4 in 2025, with additional missions planned. This growing number of operating sensors emphasizes the need for cross-mission consistency and long-term radiometric stability across the GEO-ring framework.As the first GEO-ring sensor, the Geostationary Environment Monitoring Spectrometer (GEMS) onboard GK-2B has been operating for more than five years under harsh space environmental conditions. Over this period, the optical and electronic components of the sensor have experienced degradation of up to 30%, particularly at shorter wavelengths around 300 nm. Given that this sensor has undergone the longest period of degradation, its characterization and correction provide a valuable basis for other GEO-ring sensors with similar instrumental characteristics. In this regard, this study presents post-launch calibration and evaluation methodologies for GEMS with a focus on Level 1 products, including solar irradiance and Earth reflectance. Calibration updates address long-term degradation along with angular dependence and systematic biases of the onboard solar diffuser.For validation of the updates, GEMS is inter-calibrated with both geostationary and low Earth orbit sensors, including the Advanced Meteorological Imager (AMI) onboard the twin satellite GK2A, as well as the Tropospheric Monitoring Instrument (TROPOMI) and Ozone Mapping and Profiler Suite (OMPS). Each reference instrument provides unique strengths in spatial, spectral, and temporal coverage, enabling a comprehensive assessment of GEMS performance. The validation results indicate that the updated GEMS reflectance exhibits spectral biases within 5%, except at wavelengths below 320 nm, where straylight effects dominate.These results demonstrate that the applied calibration and inter-calibration strategies effectively improve the radiometric consistency of GEMS Level 1 products. Building on these approaches, this work highlights the importance of in-flight calibration of Level 1 products for accurate Level 2 retrievals and long-term GEO-ring consistency.

While induced pluripotent stem cells (iPSCs) have gained popularity in studying neurodegenerative diseases, the heterogeneity of stem cells used across studies impacts cross-study comparison. The iPSC Neurodegenerative Disease Initiative (iNDI) selected the KOLF2.1J cell line and prioritized its use as a reference standard for studying the effects of pathogenic variants on cell biology due to its stability and neutral neurodegenerative disease genetic risk. This cell line, and its derivatives expressing over 100 variants related to Alzheimer’s disease, Parkinson’s disease, and other neurological diseases, are available for academic and industry access. Current genomic data analyses are limited by the use of a human reference genome that does not capture the complete genetic background of a given iPSC line. While in the future this issue may be partially mitigated by the creation of a comprehensive human pangenome, previous work has shown that generating custom genomes is of value both to characterize the variation present and to serve as a more appropriate genomic reference. Here, we generated and characterized a custom complete genome assembly from KOLF2.1J. Mapping of sequencing reads to a personalized diploid assembly results in more comprehensive mapping compared to traditional linear references (i.e GRCh38). In addition, we provide a comprehensive custom gene annotation along with isoform expression and differential methylation analyses across multiple cell types. The assembly and all additional data is browsable and publicly available. This resource will enable more accurate investigation of the KOLF2.1J cell line and any genomics data generated compared to using traditional generalized references, while also serving as a foundational approach for establishing custom reference assemblies for other high-value iPSC lines.

Abstract. NASA's Tropospheric Emissions: Monitoring of Pollution (TEMPO) geostationary satellite sensor provides high temporal and spatial resolution measurements critical for monitoring air quality. During the Synergistic TEMPO Air Quality Science (STAQS) component of the 2023 AGES+ campaign, extensive surface, airborne, and remote-sensing observations were collected over the New York City/Long Island Sound region, enabling comprehensive investigation of ozone and its precursors, including nitrogen dioxide (NO2) and formaldehyde (HCHO). Evaluating TEMPO (version 3) NO2 and HCHO column retrievals against Pandora and GEO-CAPE Airborne Simulator (GCAS) observations shows TEMPO can capture urban-suburban pollution gradients and exhibits biases comparable to previous satellite validation studies with strong agreements for NO2 (R ≈ 0.79–0.81), though sharp transitions between high and low emission regions remain challenging. The high-resolution (1.33 km × 1.33 km) WRF-Chem simulation reproduces the major spatiotemporal patterns of surface ozone and NO2 (R ≈ 0.56–0.73), supporting its use to fill observational gaps. By integrating TEMPO, WRF-Chem, in situ measurements, and Tropospheric Ozone Lidar network and Doppler wind lidar observations, we characterize the spatiotemporal dynamics of ozone under different pollution regimes. High-pollution days involve early urban precursor accumulation, entrainment of pollutant-rich residual-layer air, and sea-breeze-driven recirculation toward coastal regions. Moderate days exhibit localized enhancements driven by transport, such as downwind plume transport, while low-pollution days show efficient dispersion and limited ozone formation. This multi-platform framework highlights the importance of resolving fine-scale variability in coastal and transition zones and demonstrates TEMPO's value for improving ozone forecasting and mitigation in complex environments