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- Bounding anisotropic Lorentz invariance violation from measurements of the effective energy scale of quantum gravityPublication . Guerrero, Merce; Campoy-Ordaz, Anna; Potting, Robertus; Gaug, MarkusObservations of energy-dependent photon time delays from distant flaring sources provide significant constraints on Lorentz invariance violation (LIV). Such effects originate from modified vacuum dispersion relations causing differences in propagation times for photons emitted simultaneously from gamma-ray bursts, active galactic nuclei, or pulsars. These modifications are often parametrized within a general framework by an effective quantum gravity energy scale EQG;n. While such general constraints are well established in the LIV literature, their translation into specific coefficients of alternative theoretical frameworks, such as the Standard-Model extension (SME), is rarely carried out. In particular, existing bounds on the quadratic case (n ¼ 2) of EQG;n can be systematically converted into constraints on the nonbirefringent, CPT-conserving SME coefficients c ð6Þ ðIÞjm. This work provides a concise overview of the relevant SME formalism and introduces a transparent conversion method from EQG;2 to SME parameters. We review the most stringent time-of-flight-based bounds on EQG;n and standardize them by accounting for systematics, applying missing prefactors, and transforming results into two-sided Gaussian uncertainties where needed. We then use these standardized constraints, along with additional bounds from the literature, to improve bounds on the individual SME coefficients of the photon sector by about an order of magnitude. A consistent methodology is developed to perform this conversion from the general LIV framework to the SME formalism.
- Early oldowan technology thrived during pliocene environmental change in the Turkana Basin, Kenya.Publication . Braun, David R.; Palcu Rolier, Dan V.; Advokaat, Eldert L.; Archer, Will; Baraki, Niguss G.; Biernat, Maryse D.; Beaudoin, Ella; Behrensmeyer, Anna K.; Bobe, René; Elmes, Katherine; Forrest, Frances; Hammond, Ashley S.; Jovane, Luigi; Kinyanjui, Rahab N.; de Martini, Ana P.; Mason, Paul R D.; McGrosky, Amanda; Munga, Joanne; Ndiema, Emmanuel K.; Patterson, David B.; Reeves, Jonathan S.; Roman, Diana C.; Sier, Mark J.; Srivastava, Priyeshu; Tuosto, Kristen; Uno, Kevin T.; Villaseñor, Amelia; Wynn, Jonathan G.; Harris, John W. K.; Carvalho, SusanaApproximately 2.75 million years ago, the Turkana Basin in Kenya experienced environmental changes, including increased aridity and environmental variability. Namorotukunan is a newly discovered archaeological site which provides a window into hominin behavioral adaptations. This site lies within the upper Tulu Bor and lower Burgi members of the Koobi Fora Formation (Marsabit District, Kenya), presently a poorly understood time interval due to large-scale erosional events. Moreover, this locale represents the earliest known evidence of Oldowan technology within the Koobi Fora Formation. Oldowan sites, older than 2.6 million years ago, are rare, and these typically represent insights from narrow windows of time. In contrast, Namorotukunan provides evidence of tool-making behaviors spanning hundreds of thousands of years, offering a unique temporal perspective on technological stability. The site comprises three distinct archaeological horizons spanning approximately 300,000 years (2.75 − 2.44 Ma). Our findings suggest continuity in tool-making practices over time, with evidence of systematic selection of rock types. Geological descriptions and chronological data, provide robust age control and contextualize the archaeological finds. We employ multiple paleoenvironmental proxies, to reconstruct past ecological conditions. Our study highlights the interplay between environmental shifts and technological innovations, shedding light on pivotal factors in the trajectory of human evolution.
- Análise Bioinformática da Via Hedgehog em Cancros Humanos: Expressão, Metilação e Impacto Prognóstico no KIRC e LGGPublication . Aguiar, Diogo Gonçalo Ribeiro Paulo e Soares; Tavares, ÁlvaroO cancro é um dos maiores desafios da saúde global, resultando de alterações genéticas, epigenéticas e da desregulação de vias de sinalização. Esta tese centrou-se na via Hedgehog (HH), conservada evolutivamente e crucial no desenvolvimento embrionário, frequentemente desregulada em vários tipos de neoplasias. O objetivo principal foi analisar a expressão diferencial dos genes da via HH e associados em diversos cancros, com foco no carcinoma renal de células claras (KIRC) e no glioma de baixo grau (LGG), avaliando também o seu impacto prognóstico e potenciais mecanismos regulatórios. Utilizando abordagens bioinformáticas e bases de dados públicas (TCGA, GTEx, GEPIA2, cBioPortal, MethSurv, STRING, TIMER2.0, UCSC Xena Browser e UALCAN), foram analisados dados de expressão génica, metilação de DNA, mutações, infiltração imune e interações moleculares. Verificaram-se diferenças relevantes na expressão de CDON e LRP2 (KIRC) e de KIF7, BOC, CSNK1A1, CSNK1G3, PTCH1, GAS1, SMO e SUFU (LGG) entre tecidos tumorais e normais. A expressão elevada de LRP2 e CDON associou-se a melhor sobrevivência em KIRC, enquanto SUFU e PTCH1 mostraram efeito protetor em LGG. Por outro lado, SMO e GAS1 foram associados a pior prognóstico em LGG. Foi ainda observada hipermetilação dos promotores de CDON e LRP2 em KIRC, sugerindo regulação epigenética, enquanto em LGG a desregulação parece ocorrer por mecanismos não mutacionais. As redes de coexpressão revelaram interações com vias como Wnt e PI3K/AKT. Conclui-se que a via HH tem impacto distinto consoante o subtipo tumoral, e alguns genes, como LRP2 e CSNK1A1, podem constituir biomarcadores ou alvos terapêuticos promissores, reforçando a importância de análises multi-ómicas aplicadas à oncologia de precisão.
- Mesozooplankton community dynamics in response to suppressed upwelling: a case study comparing the gulf of panama and the Gulf of Chiriquí using automated image analysisPublication . Becker, Lina; Mendes, Isabel Maria de Paiva Pinto; Schiebel, RalfThis thesis investigates mesozooplankton community dynamics in response to anomalous oceanographic conditions, focusing on the 2025 collapse of the seasonal upwelling in the Gulf of Panama. Using a comparative approach with the neighboring Gulf of Chiriquí, the study integrates semi-automated FlowCam imaging with supervised machine learning classifiers to process over 750,000 plankton images. This methodology enabled reliable abundance, and biomass estimates for dominant taxa, particularly copepods, at resolutions and scales unattainable through traditional microscopy. Hydrographic measurements revealed strongly stratified conditions in the Gulf of Panama, with suppressed nutrient input into the euphotic zone. In contrast, the Gulf of Chiriquí maintained relatively stable conditions. Ecological consequences were profound: the Gulf of Panama, typically characterized by high productivity due to upwelling, exhibited markedly reduced mesozooplankton abundance and biomass. Conversely, the Gulf of Chiriquí showed unexpectedly higher biomass across most depths, highlighting its role as a potential analogue for future oligotrophic states under climate-driven variability. Copepods remained the numerically and functionally dominant group, underscoring their resilience and central role in trophic transfer. However, size-structured analyses revealed that biomass patterns were not solely linked to abundance but strongly influenced by ontogenetic stage distribution. The disproportionate contribution of larger size fractions to carbon stocks emphasizes the importance of monitoring size structure in addition to abundance. Methodologically, the study demonstrates the value of hybrid workflows combining automated imaging with targeted manual curation. Despite challenges such as misclassification of transparent taxa and debris, semi-automated imaging proves scalable and essential for long-term ecological monitoring. Ultimately, the findings provide critical baseline data for understanding mesozooplankton dynamics under anomalous conditions. They highlight both resilience and vulnerability: while copepods persist, the productivity of short food chains may increasingly be at risk in a warming and more variable ocean.