Geometric models for Lie--Hamilton systems on R2\mathbb{R}^2

This paper provides a geometric description for Lie--Hamilton systems on $\mathbb{R}^2$ with locally transitive Vessiot--Guldberg Lie algebras through two types of geometric models. The first one is the restriction of a class of Lie--Hamilton systems on the dual of a Lie algebra to even-dimensional symplectic leaves relative to the Kirillov-Kostant-Souriau bracket. The second is a projection onto a quotient space of an automorphic Lie--Hamilton system relative to a naturally defined Poisson structure or, more generally, an automorphic Lie system with a compatible bivector field. These models give rise to a natural framework for the analysis of Lie--Hamilton systems on $\mathbb{R}^2$ while retrieving known results in a natural manner. Our methods may be extended to study Lie--Hamilton systems on higher-dimensional manifolds and provide new approaches to Lie systems admitting compatible geometric structures.Comment: 15 pages, 1 figur

Privacy in Practice: Private COVID-19 Detection in X-Ray Images

Machine learning (ML) can help fight the COVID-19 pandemic by enabling rapid screening of large volumes of chest X-ray images. To perform such data analysis while maintaining patient privacy, we create ML models that satisfy Differential Privacy (DP). Previous works exploring private COVID-19 ML models are in part based on small or skewed datasets, are lacking in their privacy guarantees, and do not investigate practical privacy. In this work, we therefore suggest several improvements to address these open gaps. We account for inherent class imbalances in the data and evaluate the utility-privacy trade-off more extensively and over stricter privacy budgets than in previous work. Our evaluation is supported by empirically estimating practical privacy leakage through actual attacks. Based on theory, the introduced DP should help limit and mitigate information leakage threats posed by black-box Membership Inference Attacks (MIAs). Our practical privacy analysis is the first to test this hypothesis on the COVID-19 detection task. In addition, we also re-examine the evaluation on the MNIST database. Our results indicate that based on the task-dependent threat from MIAs, DP does not always improve practical privacy, which we show on the COVID-19 task. The results further suggest that with increasing DP guarantees, empirical privacy leakage reaches an early plateau and DP therefore appears to have a limited impact on MIA defense. Our findings identify possibilities for better utility-privacy trade-offs, and we thus believe that empirical attack-specific privacy estimation can play a vital role in tuning for practical privacy

Privacy at Risk: Exploiting Similarities in Health Data for Identity Inference

Smartwatches enable the efficient collection of health data that can be used for research and comprehensive analysis to improve the health of individuals. In addition to the analysis capabilities, ensuring privacy when handling health data is a critical concern as the collection and analysis of such data become pervasive. Since health data contains sensitive information, it should be handled with responsibility and is therefore often treated anonymously. However, also the data itself can be exploited to reveal information and break anonymity. We propose a novel similarity-based re-identification attack on time-series health data and thereby unveil a significant vulnerability. Despite privacy measures that remove identifying information, our attack demonstrates that a brief amount of various sensor data from a target individual is adequate to possibly identify them within a database of other samples, solely based on sensor-level similarities. In our example scenario, where data owners leverage health data from smartwatches, findings show that we are able to correctly link the target data in two out of three cases. User privacy is thus already inherently threatened by the data itself and even when removing personal information

A calcium ion in a cavity as a controlled single-photon source

We present a single calcium ion, coupled to a high-finesse cavity, as an almost ideal system for the controlled generation of single photons. Photons from a pump beam are Raman-scattered by the ion into the cavity mode, which subsequently emits the photon into a well-defined output channel. In contrast with comparable atomic systems, the ion is localized at a fixed position in the cavity mode for indefinite times, enabling truly continuous operation of the device. We have performed numeric calculations to assess the performance of the system and present the first experimental indication of single-photon emission in our set-up

Comparativo orçamentário entre composições de paredes em bloco cerâmico vazado com instalações em PVC rígido e bloco cerâmico estrutural com instalações em PP-R

A grande incidência de manifestações patológicas das mais diversas origens fazem com que exploramos outras técnicas construtivas sempre procurando otimizar os processos. A busca incansável por novos meios de resolver os problemas despertou um desejo de pesquisa buscando uma estrutura mista de materiais. Foram verificados materiais dos mais diversos tipos sempre buscando reduzir os processos e de certa forma otimizar a mão de obra. Inicialmente fora proposto duas alternativas para que fosse realizado o estudo, ao longo deste trabalho alguns dos sistemas não puderam ser implantados pela difícil obtenção e pelo seu elevado custo além da exigência de grandes prazos para a compra. A planta inicial caracteriza uma edificação padrão normal cujas dimensões tiveram de ser alteradas para fins de projeto, a adequação aos padrões modulares dos blocos teve consequências arquitetônicas na planta original, porém o custo e o prazo se mostraram altamente atrativos. A modulação de blocos passou por diversas revisões, tiveram de ser alterados dimensões de janelas e portas assim como as dimensões laterais dos cômodos para que pudesse ser concluído o projeto de alvenaria estrutural. As instalações hidros-sanitárias foram dimensionadas sempre procurando uniformizar o número de diâmetros evitando o desperdício e sempre que possível pensando nas futuras manutenções. Os projetos foram feitos com composição de diversos materiais e estes foram orçados comparando suas propriedades, técnicas construtivas, prazos e principalmente custos. Os estudos concluíram que decisões prévias de projeto podem gerar economias significativas em edificações de pequeno porte, definições de paredes, janelas, quartos, reservatórios, podem ser solucionáveis com estruturas mistas de alvenaria estrutural e concreto armado gerando grande economia em prazo e custo. Para as instalações hidros-sanitárias, a utilização do material PPR, para água fria e quente, mostrou-se viável quando em composição com supraestrutura composta por alvenaria estrutural

Reproducibility of straylight measurement by C-Quant for assessment of retinal straylight using the compensation comparison method

Background: Straylight gives the appearance of a veil of light thrown over a person's retinal image when there is a strong light source present. We examined the reproducibility of the measurements by C-Quant, and assessed its correlation to characteristics of the eye and subjects' age. Participants and Methods: Five repeated straylight measurements were taken using the dominant eye of 45 healthy subjects (age 21-59) with a BCVA of 20/20: 14 emmetropic, 16 myopic, eight hyperopic and seven with astigmatism. We assessed the extent of reproducibility of straylight measures using the intraclass correlation coefficient. Results: The mean straylight value of all measurements was 1.01 (SD 0.23, median 0.97, interquartile range 0.85-1.1). Per 10years of age, straylight increased in average by 0.10 (95%CI 0.04 to 0.16, p < 0.01]. We found no independent association of refraction (range −5.25 dpt to +2 dpt) on straylight values (0.001; 95%CI −0.022 to 0.024, p = 0.92). Compared to emmetropic subjects, myopia reduced straylight (−.011; −0.024 to 0.02, p = 0.11), whereas higher straylight values (0.09; −0.01 to 0.20, p = 0.09) were observed in subjects with blue irises as compared to dark-colored irises when correcting for age. The intraclass correlation coefficient (ICC) of repeated measurements was 0.83 (95%CI 0.76 to 0.90). Conclusions: Our study showed that straylight measurements with the C-Quant had a high reproducibility, i.e. a lack of large intra-observer variability, making it appropriate to be applied in long-term follow-up studies assessing the long-term effect of surgical procedures on the quality of visio

Conference on International Agricultural Research for Development Water resources under global change: Process-based hydrological modelling for the lower catchment of the

Abstract Downstream of Lake Kinneret the climatic regime of the Jordan river catchment changes to semiarid or even arid conditions. Hence specific tools are required to cope with enhanced spatial and temporal variability of rainfall and adequate modelling of generated overland flow by saturation or infiltration excess. To simulate climatological variability, historical extremes (dry and wet seasons) are modelled using C-band rainfall radar data as model input. A parsimonious model concept (the ZIN-model) was successfully tested in a neighbouring 680 km 2 catchment. It was run both in a single event and continuous mode using a constant set of field derived parameters. When model runs were started at high antecedent moisture conditions, single event simulations were promising, while longer term continuous simulations were less accurate both under-and overestimating the catchment scale runoff response. For the Jordan River it is envisaged to couple this process-based approach with the hydrological model TRAIN. This model focuses on the continuous simulation of processes at the interface between soil, vegetation and atmosphere and thus helps to identify e.g. water use from vegetated surfaces and related water stress conditions. The model combination leads to improved simulations of longer term components (evapotranspiration, soil moisture, ground water recharge) of the water cycle. As such, detailed patterns of available water resources for historical extremes are expected. These will be correlated to climatic change scenarios to arrive at sound estimates of induced changes in water availability all across the lower Jordan River

A Scoping Review and Meta-Analysis of Anti-CGRP Monoclonal Antibodies: Predicting Response

Calcitonin gene-related peptide-targeted monoclonal antibodies (CGRP mAbs) are increasingly being used as preventive treatments for migraine. Their effectiveness and safety were established through numerous randomized placebo-controlled trials and real-world studies, yet a significant proportion of patients do not respond to this treatment, and currently, there is a lack of accepted predictors of response to guide expectations, as data from studies so far are lacking and inconsistent. We searched Embase and MEDLINE databases for studies reporting on predictors of response to CGRP and/or CGRP-receptor (CGRP-R) mAbs, defined as a 30% or 50% reduction in monthly headache or migraine days at varying durations of follow-up. Quantitative synthesis was performed where applicable. We found 38 real-world studies that investigated the association between various predictors and response rates. Based on these studies, good response to triptans and unilateral pain with or without unilateral autonomic symptoms are predictors of a good response to CGRP(-R) mAbs. Conversely, obesity, interictal allodynia, the presence of daily headaches, a higher number of non-successful previous prophylactic medications, and psychiatric comorbidities including depression are predictive of a poor response to CGRP(-R) mAbs. Future studies should confirm these results and help to generate more tailored treatment strategies in patients with migraine