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NanoManufacturing

Michael De Volder, Engineering Department - IfM
 

Tue 18 Feb 11:00: Past, present and future involvement in the ATLAS experiment

http://talks.cam.ac.uk/show/rss/5408 - Sun, 16/02/2025 - 23:13
Past, present and future involvement in the ATLAS experiment

This talk presents an overview of past, current, and future contributions to the ATLAS experiment, spanning from Standard Model precision measurements to new physics searches and the development of advanced luminosity detectors.

The discussion begins with ATLAS forward detectors, focusing on the LUCID system for luminosity monitoring. The evolution from LUCID -2 to LUCID -3 is explored, highlighting the challenges posed by HL-LHC conditions and the new detector prototypes under development: LUCID JF , LUCID JN, and Fiber. Performance studies demonstrate their potential to ensure robust and precise luminosity measurements across various beam conditions.

The second part of the talk delves into key ATLAS physics analyses, emphasising precision measurements of Standard Model processes, including W and Z boson cross sections and their role in PDF constraints. The importance of V+jets and V+ heavy-flavor jets final states is also discussed. Additionally, I will present a search for long-lived particles based on dE/dx measurements and the identification of low-β signatures, providing a potential signature of physics beyond the Standard Model

Finally, the talk will conclude with an outreach project conducted in Bologna aimed at children aged 5 to 11, designed to study gender bias in STEM fields and promote equal opportunities in science from an early age.

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Sun 16 Feb 16:00: Simplicial volume and aspherical manifolds

http://talks.cam.ac.uk/show/rss/5408 - Sun, 16/02/2025 - 18:31
Simplicial volume and aspherical manifolds

Simplicial volume is a homotopy invariant for compact manifolds introduced by Gromov that measures the complexity of a manifold in terms of singular simplices. A celebrated question by Gromov (~’90) asks whether all oriented closed connected aspherical manifolds with zero simplicial volume also have vanishing Euler characteristic. In this talk, we will describe the problem and we will show counterexamples to some variations of the previous question. Moreover, we will describe some new strategies to approach the problem as well as the relation between Gromov’s question and other classical problems in topology. This will include joint works with Clara Löh and George Raptis, and with Alberto Casali.

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Leaf Vein‐Inspired Programmable Superstructure Liquid Metal Photothermal Actuator for Soft Robots

Inspired by plant leaf veins and pulp, this work introduced superstructure (ordered grooves) into liquid metal photothermal actuators for the first time and prepared LM@PI/PDMS programmable photothermal actuators with excellent comprehensive performance utilizing laser etching, including rapid oscillation, rapid response, strong load-carrying capacity, and excellent stability, which can be utilized to create versatile smart devices and robots.


Abstract

Asymmetric-expansion photothermal actuators have attracted the attention of researchers owing to their simple structure, superior stability, rapid response, and precise controllability. However, their response speed, deformation capacity, and load-carrying capacity are mutually constrained by their thickness. Inspired by the veins and pulp in plant leaves, this study uses laser etching to apply a superstructure of ordered grooves to liquid metal (LM) photothermal actuators. The resulting LM@low-expansion polyimide (4.52 ppm K−1)/polydimethylsiloxane (LM@PI/PDMS) programmable photothermal actuators demonstrate exceptional performance, including a load-carrying capacity of 190 times their weight, a rapid oscillation frequency of 19 Hz, a response speed of 60.96 ± 3.08°/ s, and a bending angle of 159.05 ± 2.52°. Hence, the proposed design resolves the inherent conflict between the load-carrying capacity and response speed. Furthermore, incorporating LM microspheres into actuators increases their stability and allows them to endure more than 20 800 cycles without damage. The actuators are used to create versatile smart devices and robots, such as photothermally actuated robotic dogs that can function across various terrains. This study provides a novel strategy for the design and fabrication of programmable photothermal actuators and highlights their potential for applications in advanced robotics, which paves the way for their integration into complex environments.

Bio‐Inspired, Miniaturized Magnetic Heart Valve System for Superior Performance Cardiovascular Simulator

A miniaturized bioinspired soft magnetic heart valve with a fast response time is developed for blood pressure simulation. The magnetically controlled elastomeric valve enables precise regulation of fluid flow and pressure, replicating diverse pulsating waveforms. This system advances cardiovascular research and holds potential for humanoid robots, contributing to biomimetic mechanical systems and clinical applications.


Abstract

The demand for accurate vascular simulators is increasing to facilitate effective clinical studies on cardiovascular diseases. The research presents the miniaturized design and precise programable regulation of an artificial magnetic heart valve inspired by the human aortic valve, demonstrating the diverse types of pulsating waves. The heart valve is constructed using an elastomeric silicone composite embedded with neodymium magnetic micro-particles. This valve system responds rapidly to changes in magnetic fields controlled by miniaturized electromagnets, enabling precise regulation of fluid pressure and flow rate. This allows for the generation of various pressure waveforms and accurately replicates diverse blood pressure changes with a compact design. The design, working mechanism, fabrication process, and optimization of the magnetically controlled biomimetic heart valve are discussed and its performance as a cardiovascular simulator for human and animal models is evaluated. This artificial valve system has the potential to be utilized in humanoid robots to generate heart-like pressure, thereby paving the way for replicating human physiological characteristics. This research promises significant advancements in cardiovascular clinical trials and biomedical research along with the development of humanoid robots and biomimetic mechanical systems.

Triple‐Additive Strategy for Enhanced Material and Device Stability in Perovskite Solar Cells

In this report, the internal strain affecting the stability of FAPbI3 perovskite is addressed through the design of additives in the precursor solution. Instead of conventional methylammonium chloride, a triple-additive approach is employed, leading to improved phase stability and reduced strain gradient. The strategy results in enhanced durability and efficiency, with power conversion efficiency retention of 95% after 8000 h under the ISOS-D-1 condition and a maximum PCE of 24.50%.


Abstract

The stability of the FAPbI3 perovskite phase is significantly affected by internal strain. In this report, additives in the perovskite precursor solution are designed to prevent local lattice mismatch of the resulting perovskite layer. Instead of using a conventional methylammonium chloride (Control), triple additives (Target) are introduced by considering ion association and formation energy. The out-of-plane orientation for the (100) plane is less pronounced by the triple additives compared to the Control film with a highly enhanced preferred orientation, which reduces the strain gradient and the Pb─I bond distance. Moreover, the anisotropic atomic-level lattice strain along (111) plane, associated with the α-to-δ phase transition, is more uniformly distributed by the triple additives. The triple-additive strategy demonstrates exceptional phase stability under relative humidity as high as 90% and the International Summit on Organic Photovoltaic Stability (ISOS)-L-2 protocol. The device lifetime measured under the ISOS-D-1 condition shows that the Target perovskite solar cell (PSC) maintains 95% of its initial power conversion efficiency (PCE) for over 8000 h, and the best PCE of 24.50% is achieved.

Glassy Thermal Transport Triggers Ultra‐High Thermoelectric Performance in GeTe

Inhomogeneous ferroelectric instability induced confined phonon mean free path leading to glass-like thermal transport, and ultra-high thermoelectric performance in BiSe, Pb co-doped GeTe.


Abstract

The consequences of broken long-range atomic arrangement in glasses or amorphous solids are reflected in the temperature dependence of lattice thermal conductivity (κlat). However, the appearance of glassy ultralow κlat in a crystalline solid with high electrical transport like metal is unusual but can have a remarkable impact on the thermoelectric performance of a material. Here, an ultra-high thermoelectric performance is demonstrated with a maximum figure of merit, zT ≈ 2.7 (≈2.92 with Dulong–Petit heat capacity) via achieving glassy thermal transport along with significant electrical conductivity in ball milled BiSe, Pb co-doped polycrystalline Ge1.03Te followed by spark plasma sintering. The glassy thermal transport results from the inhomogeneous ferroelectric instability developed due to local polar distortions near the dopant sites, which interacts with soft polar optical modes via strain fluctuations. Resulting structural degeneracy and associated soft vibrations sink heat effectively from acoustic phonons, which along with various nanoscale defects, confine the phonon mean free path (MFP) close to the interatomic distance, rendering the thermal transport glassy. However, the material still maintains a high electrical conductivity at ambient condition due to much longer MFP of the charge carriers. A promising output power density of ≈0.8 W cm−2 for ΔT ≈441 K in double-leg thermoelectric device demonstrate the potential of this material for mid-temperature thermoelectric applications.

Waveguide Microactuators Self‐Rolled Around an Optical Fiber Taper

A novel self-rolling integration strategy mounts ultrathin (≈2 µm) poly(N-isopropylacrylamide)/Au microactuators onto optical fiber tapers, achieving unprecedented bending angles (>800°) and rapid response (≈0.55 s). This waveguide microactuator enables dynamic capture of fast-moving microorganisms and provides a high-performance, versatile platform for biomedical applications in confined, unstructured environments.


Abstract

Precisely capturing and manipulating microscale objects, such as individual cells and microorganisms, is fundamental to advancements in biomedical research and microrobotics. Photoactuators based on optical fibers serving as flexible, unobstructed waveguides are well-suited for these operations, particularly in confined locations where free-space illumination is impractical. However, integrating optical fibers with microscale actuators poses significant challenges due to size mismatch, resulting in slow responses inadequate for handling motile micro-objects. This study designs microactuators based on hydrogel/Au bilayer heterostructures that self-roll around a tapered optical fiber. This self-rolling mechanism enables the use of thin hydrogel layers only a few micrometers thick, which rapidly absorb and release water molecules during a phase transition. The resulting microactuators exhibit low bending stiffness and extremely fast responses, achieving large bending angles exceeding 800° within 0.55 s. Using this technique, this study successfully captures rapidly swimming Chlamydomonas and Paramecium, and demonstrates programmable non-reciprocal motion for effective non-contact manipulation of yeast cells. This approach provides a versatile platform for microscale manipulations and holds promise for advanced biomedical applications.

Cryo‐Shocked Tumor‐Reprogrammed Sonosensitive Antigen‐Presenting Cells Improving Sonoimmunotherapy via T Cells and NK Cells Immunity

A dead APC-4T1-N3-LipoH (DPNL) is constructed via clicking reprogrammed APC like-4T1 cells with liposome encapsulating HMME (LHs). Sonosensitive DPNL cells effectively target tumor sites and tumor draining lymph nodes (TDLNs). Upon ultrasound, DPNL cells could co-stimulate the antigen-presenting program and strikingly elicit antigen-specific T cell-mediated adaptive immunity in TDLNs as well as MHC-I unrestricted NK cell-mediated innate immunity within tumors for comprehensive sonoimmunotherapy for triple negative breast cancers.


Abstract

Ultrasound therapy has turned up as a noninvasive multifunctional tool for cancer immunotherapy. However, the insufficient co-stimulating molecules and loss of peptide-major histocompatibility complex I (MHC-I) expression on tumor cells lead to poor therapy of sonoimmunotherapies. Herein, this work develops a sonosensitive system to augment MHC-I unrestricted natural killer (NK) cell-mediated innate immunity and T cell-mediated adaptive immunity by leveraging antigen presentation cell (APC)-like tumor cells. Genetically engineered tumor cells featuring sufficient co-stimulating molecules are cryo-shocked and conjugated with a sonosensitizer, hematoporphyrin monomethyl ether, using click chemistry. These cells (DPNLs) exhibit characteristics of tumor and draining lymph node homing. Under ultrasound, NK cell-mediated innate immunity within the tumor microenvironment could be activated, and T cells in the tumor-draining lymph nodes (TDLNs) are stimulated through co-stimulatory molecules. In combination with programmed cell death ligand 1 (PD-L1) antibody, DPNLs extend the survival time and inhibited lung metastasis in triple-negative breast cancer (TNBC) models. This study provides an alternative approach for sonoimmunotherapy with precise sonosensitizer delivery and enhanced NK cell and T cell activation.

DNA‐Capturing Manganese‐Coordinated Chitosan Microparticles Potentiate Radiotherapy via Activating the cGAS‐STING Pathway and Maintaining Tumor‐Infiltrating CD8+ T‐Cell Stemness

DNA-capturing CS-Mn microparticles are prepared to potentiate radioimmunotherapy. Upon injection into the tumors after X-ray irradiation, they undergo rapid dissociation to release chitosan which assembles with the extracellular DNA fragments released from the dead cancer cells to in situ form CS-DNA complexes and synergize with Mn2+ to stimulate DC maturation via activating the cGAS-STING pathway for enhanced CD8+ T-cell stemness.


Abstract

The radiotherapy-induced release of DNA fragments can stimulate the cyclic guanosine monophosphate-adenosine monophosphate synthase-stimulator of interferon genes (cGAS-STING) pathway to prime antitumor immunity, but this pathway is expected to be less potent because of the inefficient cytosolic delivery of negatively charged DNA fragments. In this study, manganese-coordinated chitosan (CS-Mn) microparticles with selective DNA-capturing capacity are concisely prepared via a coordination-directed one-pot synthesis process to potentiate the immunogenicity of radiotherapy. The obtained CS-Mn microparticles that undergo rapid disassembly under physiological conditions can selectively bind with DNA to form positively charged DNA-CS assemblies because of the strong electrostatic interaction between linear chitosan and DNA molecules. They thus enable efficient cytosolic delivery of DNA in the presence of serum to cooperate with Mn2+ to activate the cGAS-STING pathway in dendritic cells. Upon intratumoral injection, the CS-Mn microparticles markedly enhance the efficacy of radiotherapy against both irradiated and distal tumors in different tumor models via collectively promoting tumor-infiltrating CD8+ T-cell stemness and the activation of innate immunity. The radiosensitization effect of CS-Mn microparticles can be further augmented by concurrently applying anti-programmed cell death protein 1 (anti-PD-1) immunotherapy. This work highlights an ingenious strategy to prepare Trojan horse-like DNA-capturing microparticles as cGAS-STING-activating radiosensitizers for effective radioimmunotherapy.

Ultra‐Fast Gallium Oxide Solar‐Blind Photodetector with Novel Thermal Pulse Treatment

A novel Ga2O3 solar-blind photodetector with a vertically stratified crystalline structure and VO concentration is designed to spatially separate the carrier's generation and transport channels in the device, thus achieving excellent responsivity and response speed simultaneously.


Abstract

Gallium oxide (Ga2O3) emerges as a promising solar-blind photodetector (SBPD) material if the “Response Speed (RS) dilemma” can be resolved. Devices with spatially segregated carrier generation and transport channels offer a potential solution but remain less available. This work introduces a novel thermal pulse treatment (TPT) method to achieve a vertically stratified crystalline structure and oxygen vacancies (VO) throughout the Ga2O3 film, validated through extensive characterizations. Technology Computer-Aided Design (TCAD) simulations corroborated the critical role of VO stratification in enhancing the responsivity (Rλ) and response speed simultaneously. Consequently, the TPT-processed SBPD exhibited exceptional performance, boasting a maximum  R λ of 312.6 A W−1 and a faster decay time of 40 µs, respectively. Moreover, the corresponding SBPD chips show significant potential for applications in solar-blind imaging, light trajectory tracking, and solar-blind power meters. This work thus provides a viable strategy to address the “RS dilemma” common in most wide-bandgap materials, showcasing excellent application value.

Perturbing Organelle‐Level K+/Ca2+ Homeostasis by Nanotherapeutics for Enhancing Ion‐Mediated Cancer Immunotherapy

An ion-mediated immunotherapy agent (IMIA) is engineered to achieve precise spatiotemporal control of perturbing K+/Ca2+ homeostasis at the organelle-level, which can effectively evoke tumor-associated immunogenicity, thereby stimulating the activation of DCs and potentiating the infiltration of tumor-specific cytotoxic T cells to achieve high-performance cancer immunotherapy.


Abstract

Intracellular ions are involved in numerous pivotal immune processes, but the precise regulation of these signaling ions to achieve innovative immune therapeutic strategies is still a huge challenge. Here, an ion-mediated immunotherapy agent (IMIA) is engineered to achieve precise spatiotemporal control of perturbing K+/Ca2+ homeostasis at the organelle-level, thereby amplifying antitumor immune responses to achieve high-performance cancer therapy. By taking in intracellular K+ and supplying exogenous Ca2+ within tumor cells, K+/Ca2+ homeostasis is perturbed by IMIA. In parallel, perturbing K+ homeostasis induced endoplasmic reticulum (ER) stress triggers the release of Ca2+ from ER and causes a decreased concentration of Ca2+ in ER, which further accelerates ER-mitochondria Ca2+ flux and the influx of extracellular Ca2+ (store-operated Ca2+ entry (SOCE)) via opening Ca2+ release-activated Ca2+ (CRAC) channels, thus creating a self-amplifying ion interference loop to perturb K+/Ca2+ homeostasis. In this process, the elevated immunogenicity of tumor cells would evoke robust antitumor immune responses by driving the excretion of damage-associated molecular patterns (DAMPs). Importantly, this ion-immunotherapy strategy reshapes the immunosuppressive tumor microenvironment (TME), and awakens the systemic immune response and long-term immune memory effect, thus effectively inhibiting the growth of primary/distant tumors, orthotopic tumors as well as metastatic tumors in different mice models.

All‐Climate Energy‐Dense Cascade Aqueous Zn‐I2 Batteries Enabled by a Polycationic Hydrogel Electrolyte

The practical application of aqueous Zn-I2 batteries is seriously restricted by their low energy density and poor temperature tolerance. Herein, a temperature-insensitive polycationic hydrogel electrolyte borax-bacterial cellulose / p(AM-co-VBIMBr) (denoted as BAVBr) is designed to realize an energy-dense Zn-I2 battery with cascade I0/I−, I+/I0, and Br0/Br− redox couples over a widen temperature range from −50 to 50 °C.


Abstract

The practical development of aqueous zinc-iodine (Zn-I2) batteries is greatly hindered by the low energy density resulting from conventional I0/I− conversion and the limited temperature tolerance. Here, a temperature-insensitive polycationic hydrogel electrolyte borax-bacterial cellulose / p(AM-co-VBIMBr) (denoted as BAVBr) for achieving an energy-dense cascade aqueous Zn-I2 battery over a wide temperature range from −50 to 50 °C is designed. A comprehensive investigation, combining advanced spectroscopic investigation and DFT calculations, has revealed that the presence of Br species in the gel electrolyte facilitates the conversion reaction of Br0/Br−. Simultaneously, it activates the high voltage I+/I0 redox reaction through interhalogen formation. Consequently, sequential and highly reversible redox reactions involving I0/I−, I+/I0, and Br0/Br− are achieved with the assistance of −NR3 + units in BAVBr, effectively suppressing interhalogen hydrolysis in aqueous electrolyte. The cascade reactions lead to a high area capacity of 0.76 mAh cm−2 at a low I2 loading of 1 mg cm−2 or 760 mAh g−1 based on the mass of iodine, demonstrating exceptional long-term cycling stability over a wide temperature range from −50 to 50 °C. This study offers valuable insights into the rational design of electrolytes for high-energy aqueous batteries, specifically tailored for wide-temperature operation.

A PD‐L1 siRNA‐Loaded Boron Nanoparticle for Targeted Cancer Radiotherapy and Immunotherapy

A PD-L1 siRNA-loaded boron nanoparticle (10B/siPD-L1) is developed to synergize boron neutron capture therapy (BNCT) with immunotherapy. Utilizing 10B/siPD-L1, BNCT can precisely kill tumor cells while sparing adjacent T cells. Moreover, 10B/siPD-L1 inhibits intracellular PD-L1 expression, thereby not only amplifying the BNCT-induced DNA damage but also maximizing T-cell activation, which significantly suppresses the growth of both primary and metastatic tumors.


Abstract

Although the combination of radiotherapy and immunotherapy is regarded as a promising clinical treatment strategy, numerous clinical trials have failed to demonstrate synergistic effects. One of the key reasons is that conventional radiotherapies inevitably damage intratumoral effector immune cells. Boron Neutron Capture Therapy (BNCT) is a precise radiotherapy that selectively kills tumor cells while sparing adjacent normal cells, by utilizing 10B agents and neutron irradiation. Therefore, combinational BNCT-immunotherapy holds promise for achieving more effective synergistic effects. Here it develops a 10B-containing polymer that self-assembled with PD-L1 siRNA to form 10B/siPD-L1 nanoparticles for combinational BNCT-immunotherapy. Unlike antibodies, PD-L1 siRNA can inhibit intracellular PD-L1 upregulated by BNCT, activating T-cell immunity while also suppressing DNA repair. This can enhance BNCT-induced DNA damage, promoting immunogenic cell death (ICD) and further amplifying the antitumor immune effect. The results demonstrated that BNCT using 10B/siPD-L1 nanoparticles precisely killed tumor cells while sparing adjacent T cells and induced a potent antitumor immune response, inhibiting distal and metastatic tumors.

Advances and Outlooks for Carbon Nanotube‐Based Thermoelectric Materials and Devices

The unique structure of carbon nanotubes (CNTs) offers excellent electrical, mechanical properties, and surface area, enhancing their use in flexible thermoelectric materials. This review highlights recent advances in CNT-based thermoelectrics, focusing on doping, composites, stability improvement, and applications in wearable devices, while addressing current challenges and future directions for optimization.


Abstract

The unique structure of carbon nanotubes (CNTs) endows them with exceptional electrical and mechanical properties, along with a high surface area, making them highly beneficial for use as flexible, high-performing thermoelectric materials. As a result, the application of CNTs in the thermoelectric field has become increasingly widespread. Considering the rapid advancements in this field, this review offers a timely overview of the most recent progress on CNT-based thermoelectric materials and devices over the past five years. This review begins by introducing the fundamental concepts and thermoelectric mechanisms of CNT-based thermoelectric materials. Then new strategies are explored to enhance their thermoelectric performance, focusing on doping and composites, while emphasizing the importance of CNT stability as a key research area. Additionally, the latest design concepts and expanded application scenarios for flexible and wearable CNTs-based thermoelectric devices are summarized. Finally, the current challenges are addressed and future directions for the development of CNT-based thermoelectric materials and devices are discussed.

Thu 20 Feb 16:00: “Neutrophils drive vascular occlusion, pleomorphic tumour necrosis, and metastasis”

http://talks.cam.ac.uk/show/rss/5408 - Sun, 16/02/2025 - 13:21
“Neutrophils drive vascular occlusion, pleomorphic tumour necrosis, and metastasis”

We are delighted to welcome Jose M. Adrover, The Francis Crick Institute as the speaker for this week’s Cambridge Immunology Network Seminar Series.

Talk Title: “Neutrophils drive vascular occlusion, pleomorphic tumour necrosis, and metastasis”

Abstract: Tumour necrosis is associated with poor prognosis in cancer and is thought to occur passively when tumour growth outpaces nutrient supply. We found, however, that neutrophils actively induce tumour necrosis. In multiple cancer mouse models, we found a tumour-elicited Ly6GHigh Ly6CLow neutrophil population that was unable to extravasate in response to inflammatory challenges but formed neutrophil extracellular traps (NETs) more efficiently than classical Ly6GHigh Ly6CHigh neutrophils. The presence of these “vascular restricted” neutrophils correlated with the appearance of a “pleomorphic” necrotic architecture in mice. In tumours with pleomorphic necrosis, we found intravascular aggregates of neutrophils and NETs that caused occlusion of the tumour vasculature, driving hypoxia and necrosis of downstream vascular beds. Furthermore, we found that cancer cells adjacent to these necrotic regions (i.e., in “peri-necrotic” areas) underwent epithelial-to-mesenchymal transition, explaining the paradoxical metastasis-enhancing effect of tumour necrosis. Blocking NET formation genetically or pharmacologically reduced the extent of tumour necrosis and lung metastasis. Thus, by showing that NETs drive vascular occlusion, pleomorphic necrosis, and metastasis, we critically demonstrate that tumour necrosis is not necessarily a passive byproduct of tumour growth and that it can be blocked to reduce metastatic spread.

Date: Thursday, 20 February 2025

Time: 16:00-17:00 GMT

Location: Ground Floor Lecture Theatre, Jeffrey Cheah Biomedical Centre (JCBC)

Host: Maike De La Roche, Cancer Research UK Cambridge Institute

We encourage in-person attendance. However, if you are unable to join us, please email enquiries@immunology for a Zoom link.

Refreshments are provided following the seminar for attendees.

The seminar series is a collaboration between the Cambridge Immunology Network and supported by the Cambridge Institute of Translational Immunology and Infectious Disease (CITIID).

Seminars take place weekly on Thursdays at 4pm and feature a leading speaker from the immunology field.

For more information please contact: enquiries@immunology.ac.uk

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Wed 19 Feb 14:15: Categorical Torelli for cyclic covers

http://talks.cam.ac.uk/show/rss/5408 - Sun, 16/02/2025 - 13:15
Categorical Torelli for cyclic covers

Since any Fano variety can be recovered from its derived category up to isomorphism, we ask whether less information determines the variety – this is called a categorical Torelli question. In this talk, we consider an n-fold cover X → Y ramified in a divisor Z. The cyclic group of order n acts on X. We study how a certain subcategory of Db(X) (the Kuznetsov component) behaves under this group action. We combine this with techniques from topological K-theory and Hodge theory to prove that this subcategory determines X for two new classes of Fano threefolds which arise as double covers of (weighted) projective spaces. This is joint work with Augustinas Jacovskis and Franco Rota (arXiv:2310.13651).

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Wed 19 Feb 16:30: Coherence dimension for simplicial rings

http://talks.cam.ac.uk/show/rss/5408 - Sat, 15/02/2025 - 17:18
Coherence dimension for simplicial rings

Mayer Vietoris presenations of rings let us relate the coherence properties of the rings involved, simplicial presentations conjecturally extend the Mayer Vietoris principles, allowing us to lift up in dimension the corresponding coherency relations.

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Wed 26 Feb 15:30: The Impacts of Freshwater Transport on the Weddell Gyre Carbon Budget

http://talks.cam.ac.uk/show/rss/5408 - Fri, 14/02/2025 - 17:36
The Impacts of Freshwater Transport on the Weddell Gyre Carbon Budget

The Weddell Gyre mediates carbon exchange between the abyssal ocean and atmosphere, which is critical to global climate. This region also features large and highly variable freshwater fluxes due to seasonal sea ice, net precipitation, and glacial melt; however, the impact of these freshwater fluxes on the regional carbon cycle has not been fully explored. Using a novel budget analysis of dissolved inorganic carbon (DIC) mass in the Biogeochemical Southern Ocean State Estimate and revisiting hydrographic analysis from the ANDREX cruises, we highlight two freshwater-driven transports. Where freshwater with minimal DIC enters the ocean, it displaces DIC -rich seawater outwards, driving a lateral transport of 75±5 Tg DIC /year. Additionally, sea ice export requires a compensating import of seawater, which carries 48±11 Tg DIC /year into the gyre. Though often overlooked, these freshwater displacement effects are of leading order in the Weddell Gyre carbon budget in the state estimate and in regrouped box-inversion estimates. Implications for evaluating basin-scale carbon transports are considered. [Time permitting, I’ll also share some results on the role of heat addition in driving circulation change and warming patterns in the Indian sector of the Southern Ocean.]

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Fri 28 Feb 13:00: An Introductory Guide on How to Create Beautiful Slides

http://talks.cam.ac.uk/show/rss/5408 - Fri, 14/02/2025 - 16:18
An Introductory Guide on How to Create Beautiful Slides

Frank Feng is a first-year PhD student in the Department of Computer Science and Technology at the University of Cambridge. His research interests lie at the intersection of machine learning and earth sciences, with a particular focus on the application of self-supervised learning in remote sensing.

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Wed 21 May 15:00: Title to be confirmed

http://talks.cam.ac.uk/show/rss/5408 - Fri, 14/02/2025 - 15:39
Title to be confirmed

Abstract not available

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We are hiring!

4 January 2021

We are seeking to hire a research assistant to work on carbon nanotube based microdevices. More information is available here: www.jobs.cam.ac.uk/job/28202/

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4 January 2021

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