162 research outputs found
Causal Triplet: An Open Challenge for Intervention-centric Causal Representation Learning
Recent years have seen a surge of interest in learning high-level causal
representations from low-level image pairs under interventions. Yet, existing
efforts are largely limited to simple synthetic settings that are far away from
real-world problems. In this paper, we present Causal Triplet, a causal
representation learning benchmark featuring not only visually more complex
scenes, but also two crucial desiderata commonly overlooked in previous works:
(i) an actionable counterfactual setting, where only certain object-level
variables allow for counterfactual observations whereas others do not; (ii) an
interventional downstream task with an emphasis on out-of-distribution
robustness from the independent causal mechanisms principle. Through extensive
experiments, we find that models built with the knowledge of disentangled or
object-centric representations significantly outperform their distributed
counterparts. However, recent causal representation learning methods still
struggle to identify such latent structures, indicating substantial challenges
and opportunities for future work. Our code and datasets will be available at
https://sites.google.com/view/causaltriplet.Comment: Conference on Causal Learning and Reasoning (CLeaR) 202
Image retrieval outperforms diffusion models on data augmentation
Many approaches have been proposed to use diffusion models to augment
training datasets for downstream tasks, such as classification. However,
diffusion models are themselves trained on large datasets, often with noisy
annotations, and it remains an open question to which extent these models
contribute to downstream classification performance. In particular, it remains
unclear if they generalize enough to improve over directly using the additional
data of their pre-training process for augmentation. We systematically evaluate
a range of existing methods to generate images from diffusion models and study
new extensions to assess their benefit for data augmentation. Personalizing
diffusion models towards the target data outperforms simpler prompting
strategies. However, using the pre-training data of the diffusion model alone,
via a simple nearest-neighbor retrieval procedure, leads to even stronger
downstream performance. Our study explores the potential of diffusion models in
generating new training data, and surprisingly finds that these sophisticated
models are not yet able to beat a simple and strong image retrieval baseline on
simple downstream vision tasks
Image retrieval outperforms diffusion models on data augmentation
Many approaches have been proposed to use diffusion models to augment training datasets for downstream tasks, such as classification. However, diffusion models are themselves trained on large datasets, often with noisy annotations, and it remains an open question to which extent these models contribute to downstream classification performance. In particular, it remains unclear if they generalize enough to improve over directly using the additional data of their pre-training process for augmentation. We systematically evaluate a range of existing methods to generate images from diffusion models and study new extensions to assess their benefit for data augmentation. Personalizing diffusion models towards the target data outperforms simpler prompting strategies. However, using the pre-training data of the diffusion model alone, via a simple nearest-neighbor retrieval procedure, leads to even stronger downstream performance. Our study explores the potential of diffusion models in generating new training data, and surprisingly finds that these sophisticated models are not yet able to beat a simple and strong image retrieval baseline on simple downstream vision tasks
S1âGuideline: Microscopically controlled surgery
Microscopically controlled surgery (MCS) comprises various methods allowing histologically proven complete resection of malignant tumors while at the same time sparing the tumor-free tissue in the immediate vicinity as much as possible. All procedures subsumed under MCS have in common the marking of the excised tissue for topographical orientation, which provides an assignment of remaining tumor remnants. Indications for MCS are malignant skin tumors in problem localizations as well as aggressive subtypes of skin tumors. Established indications for MCS include basal cell carcinoma, cutaneous squamous cell carcinoma, Bowenâs disease as well as Bowenâs carcinoma, dermatofibrosarcoma protuberans, melanoma in chronically light-damaged skin as well as acral lentiginous melanoma and Merkel cell carcinoma. For other tumors such as extramammary Pagetâs disease and various cutaneous sarcomas, evidence exists that MCS has demonstrated benefits, such as local recurrence rates. In addition, MCS is indicated when it is foreseeable that a complex closure technique is required and complete resection of the tumor must be assured. Various methods of MCS have been described, including 3D histology, horizontal method and Mohs surgery. A close cooperation of qualified surgeons and (dermato)pathologists as well as laboratory staff is essential for the successful application of MCS
Dynamic Up-Regulation of PD-L1 in the Progression of Oral Squamous Cell Carcinoma
The introduction of immune checkpoint inhibition for recurrent and metastatic head and
neck cancer has brought a new treatment option for patients suffering from advanced oral cancers
without a chance for curation using surgery or radiotherapy. The application of immune checkpoint
inhibitors in most cases is based on the expression levels of PD-L1 in the tumor tissue. To date, there
is a lack of data on the dynamic regulation of PD-L1 during disease progression. Therefore, this study
aimed to evaluate the expression levels of PD-L1 in a large cohort of patients (n = 222) with oral
squamous cell carcinoma including primary and recurrent tumors. Semiautomatic digital pathology
scoring was used for the assessment of PD-L1 expression levels in primary and recurrent oral
squamous cell carcinoma. Survival analysis was performed to evaluate the prognostic significance
of the protein expression at different stages of the disease. We found a significant up-regulation
of PD-L1 expression from primary disease to recurrent tumors (mean PD-L1 H-scores: primary
tumors: 47.1 ± 31.4; recurrent tumors: 103.5 ± 62.8, p < 0.001). In several cases, a shift from low
PD-L1 expression in primary tumors to high PD-L1 expression in recurrent tumors was identified.
Multivariate Cox regression analysis did not reveal a significantly higher risk of death (p = 0.078)
or recurrence (p = 0.926) in patients with higher PD-L1 expression. Our findings indicate that the
exclusive analysis of primary tumor tissue prior to the application of checkpoint blockade may lead
to the misjudgment of PD-L1 expression in recurrent tumors
Free-Flap Reconstruction in Early-Stage Squamous Cell Carcinoma of the Oral Cavity : A Prospective Monocentric Trial to Evaluate Oncological Outcome and Quality of Life
Surgery is generally accepted as standard treatment in oral cancer, but the reconstructive
procedures remain a matter of debate. The aim of this study was to evaluate oncological outcome
and quality of life following surgical resection and free-flap reconstruction in patients with early oral
squamous cell carcinoma. The presented trial was performed as a prospective, single-center observation study. Inclusion criteria were primary surgery in early-stage oral squamous cell carcinoma
with free-flap reconstruction. Endpoints were overall and progression-free survival and quality of
life up to 24 months after surgery. Twenty-six patients were included. Overall survival was 100%
and progression-free survival was 92.3% in a maximum follow-up time of 21 months. Global quality
of life showed no significant alteration after surgery. Patients reported a significant reduction in
pain (p = 0.048) and a decreasing impairment of speech one year after surgery (p = 0.021). Free-flap
reconstruction is a safe procedure that results in excellent oncological outcome and quality of life.
Functional outcome is of high relevance in early-stage tumors of the head and neck and may mostly
be affected by reconstructive procedures. Therefore, a prospective evaluation to explore success and
the effects of surgical therapy is highly warranted
Life cycle assessment of innovative materials for thermal energy storage in buildings
The politically endorsed reduction of greenhouse gas emissions entails the transformation of thermal energy systems towards renewable energies, especially in the building sector. This comes along with a demand in energy storage, as there is a time offset between energy availability and demand. As sensible heat storages induce major losses and have limited energy density, current water-based solutions are only partially sufficient to meet these demands. Within the project âSpeicher-LCAâ the environmental performance of a variety of innovative materials available for energy storage in buildings is assessed. The project provides the first extensive comparison of environmental profiles of various thermal energy storage materials, including phase change, thermochemical and sorption materials. The specific performances in the storage cycle are taken into account. All results will be publically accessible through a spreadsheet tool including a comprehensive set of materials, components as well as their integration into different building types.
This paper discusses the methodological framework of the study and presents the environmental assessment results for selected materials. It highlights the main challenges in the assessment of innovative storage materials on different system levels which require specific definition of functional units accordingly. The first assessment results on material level for selected phase change (PCM) and thermo-chemical materials (TCM) allow an environmental characterization regarding their potential application in thermal storages. In addition, ranges of required numbers of storage cycles for amortization have been calculated for the non-renewable primary energy demand. For PCMs amortization cycles range between âŒ20 to 150 cycles for salt hydrates and up to âŒ280 cycles for paraffins. Regarding TCM, energetic amortization of silica gel and zeolite 13x is reached after âŒ60 and âŒ260 cycles respectively. Since the realization of storage components and systems which can actually be used in real applications will further increase the cycle number required for amortization, these storage materials may thus not be suitable for applications with a low number of cycles over lifetime, such as seasonal storage
Full-Thickness Tumor Resection of Oral Cancer Involving the Facial SkinâMicrosurgical Reconstruction of Extensive Defects after Radical Treatment of Advanced Squamous Cell Carcinoma
Advanced tumors of the head and neck are challenging for the treatment specialist due to
the need to synergize oncological and functional requirements. Free flap reconstruction has been
established as the standard of care for defects following tumor resection. However, depending on the
affected anatomic subsite, advanced tumors may impose specific difficulties regarding reconstruction,
especially when full-thickness resection is required. This study aimed to evaluate reconstructive
strategies and oncological outcomes in patients with full-thickness resection of the oral cavity. A
total of 33 patients with extensive defects due to squamous cell carcinoma of the oral cavity were
identified. Indications, reconstructive procedures, and clinical outcome were evaluated. Thirty-two
patients (97%) presented locally advanced tumors (T3/T4). Complete tumor resection was achieved
in 26 patients (78.8%). The anterolateral thigh flap was the most frequently used flap (47.1%), and the
primary flap success rate was 84.8%. The cohort demonstrated a good local control rate and moderate
overall and progression-free survival rates. Most patients regained full competence regarding oral
alimentation and speech. Full-thickness tumor resections of the head and neck area may be necessary
due to advanced tumors in critical anatomic areas. In many cases, radical surgical treatment leads
to good oncological results. Free flap reconstruction has been shown to be a suitable option for
extensive defects in aesthetically challenging regions
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