402 research outputs found

    A radiative transfer framework for non-exponential media

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    We develop a new theory of volumetric light transport for media with non-exponential free-flight distributions. Recent insights from atmospheric sciences and neutron transport demonstrate that such distributions arise in the presence of correlated scatterers, which are naturally produced by processes such as cloud condensation and fractal-pattern formation. Our theory accommodates correlations by disentangling the concepts of the free-flight distribution and transmittance, which are equivalent when scatterers are statistically independent, but become distinct when correlations are present. Our theory results in a generalized path integral which allows us to handle non-exponential media using the full range of Monte Carlo rendering algorithms while enriching the range of achievable appearance. We propose parametric models for controlling the statistical correlations by leveraging work on stochastic processes, and we develop a method to combine such unresolved correlations (and the resulting non-exponential free-flight behavior) with explicitly modeled macroscopic heterogeneity. This provides a powerful authoring approach where artists can freely design the shape of the attenuation profile separately from the macroscopic heterogeneous density, while our theory provides a physically consistent interpretation in terms of a path space integral. We address important considerations for graphics including energy conservation, reciprocity, and bidirectional rendering algorithms, all in the presence of surfaces and correlated media

    Synthesis and characterization of rigid [2.2]paracyclophane-porphyrin conjugates as scaffolds for fixed-distance bimetallic complexes

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    This work presents a new approach to prepare mono- and disubstituted linear rigid bimetallic [2.2]paracyclophane-porphyrin conjugates via palladium-mediated Stille cross-coupling reaction. The metalated porphyrin moiety can be varied allowing convenient access to modular metal-metal fixed-distance Cu/Zn complexes.Peer reviewe

    Assessing the effect of organic residue quality on active decomposing fungi in a tropical Vertisol using 15N-DNA stable isotope probing

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    15N-DNA stable isotope probing (15N-DNA-SIP) combined with 18S rRNA gene-based community analysis was used to identify active fungi involved in decomposition of 15N-labeled maize and soybean litter in a tropical Vertisol. Phylogenetic analysis of 15N-labeled DNA subjected to 18S rRNA gene-based community fingerprinting showed that organic residue quality promoted either slow (i.e. Penicillium sp., Aspergillus sp.) or fast growing (i.e. Fusarium sp., Mortierella sp.) fungal decomposers in soils treated with maize or soybean residues, respectively, whereas Chaetomium sp. were found as dominant decomposers in both residue treatments. Therefore, we have clear evidence that specific members of the fungal community used 15N derived from the two different organic resources for growth and stimulated early decomposition of maize or soybean decomposition. In conclusion, our study showed that 15N-DNA-SIP-based community analyses cannot only follow the flow of N from organic resources into bacteria, but also into the actively decomposing fungal communities of soils

    Advanced Edge Roughness Measurement Application for Mask Metrology

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    ABSTRACT With decreasing C qD dimensions the negative influence of line edge roughness (LER) and linewidth roughness (LWR) on CD uniformity and mean-to-target CD becomes more pronounced, since there is no corresponding reduction of roughness with dimension reduction. This applies to wafer metrology as well as to mask metrology. In order to better understand the types of roughness as well as the impact of the CD-SEM roughness measurement capabilities on the control of the mask process, the sensitivity and accuracy of the roughness analysis were qualified by comparing the measured mask roughness to the design for a dedicated LER test mask. This comparison is done for different LER amplitude and periodicity values and for reference structures without nominal LER using the built-in CD-SEM algorithms for LER characterization

    Second International Consensus Conference on Advanced Breast Cancer (ABC2), Lisbon, 11/09/2013: The German Perspective

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    The Advanced Breast Cancer Second International Consensus Conference (ABC2) on diagnosis and treatment of advanced breast cancer took place in Lisbon, Portugal, on November 7-9, 2013. The focus of the conference was inoperable, locally advanced breast cancer. The diagnosis and treatment of metastatic breast cancer had already been discussed 2 years before at the ABC1 Consensus and were only updated regarding special issues as part of this year's ABC2 Consensus. Like 2 years ago, a working group of German breast cancer experts commented on the voting results of the ABC panelists, with special consideration of the German guidelines for the diagnosis and treatment of breast cancer (German Gynecological Oncology Working Group (AGO) recommendations, S3 Guideline) in order to adapt them for daily clinical practice in Germany. The goal of both the ABC Consensus and the German comments is to facilitate evidence-based therapy decisions

    Occlusion-aware 3D Morphable Models and an Illumination Prior for Face Image Analysis

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    Faces in natural images are often occluded by a variety of objects. We propose a fully automated, probabilistic and occlusion-aware 3D morphable face model adaptation framework following an analysis-by-synthesis setup. The key idea is to segment the image into regions explained by separate models. Our framework includes a 3D morphable face model, a prototype-based beard model and a simple model for occlusions and background regions. The segmentation and all the model parameters have to be inferred from the single target image. Face model adaptation and segmentation are solved jointly using an expectation-maximization-like procedure. During the E-step, we update the segmentation and in the M-step the face model parameters are updated. For face model adaptation we apply a stochastic sampling strategy based on the Metropolis-Hastings algorithm. For segmentation, we apply loopy belief propagation for inference in a Markov random field. Illumination estimation is critical for occlusion handling. Our combined segmentation and model adaptation needs a proper initialization of the illumination parameters. We propose a RANSAC-based robust illumination estimation technique. By applying this method to a large face image database we obtain a first empirical distribution of real-world illumination conditions. The obtained empirical distribution is made publicly available and can be used as prior in probabilistic frameworks, for regularization or to synthesize data for deep learning methods

    PRECYCLE: multicenter, randomized phase IV intergroup trial to evaluate the impact of eHealth-based patient-reported outcome (PRO) assessment on quality of life in patients with hormone receptor positive, HER2 negative locally advanced or metastatic breast cancer treated with palbociclib and an aromatase inhibitor or palbociclib and fulvestrant

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    Background Efficacy and quality of life (QoL) are key criteria for therapy selection in metastatic breast cancer (MBC). In hormone receptor positive (HR +) human epidermal growth factor receptor 2 negative (HER2 −) MBC, addition of targeted oral agents such as everolimus or a cycline-dependent kinase 4/6 (CDK 4/6) inhibitor (e.g., palbociclib, ribociclib, abemaciclib) to endocrine therapy substantially prolongs progression-free survival and in the case of a CDK 4/6i also overall survival. However, the prerequisite is adherence to therapy over the entire course of treatment. However, particularly with new oral drugs, adherence presents a challenge to disease management. In this context, factors influencing adherence include maintaining patients’ satisfaction and early detection/management of side effects. New strategies for continuous support of oncological patients are needed. An eHealth-based platform can help to support therapy management and physician–patient interaction. Methods PreCycle is a multicenter, randomized, phase IV trial in HR + HER2 − MBC. All patients (n = 960) receive the CDK 4/6 inhibitor palbociclib either in first (62.5%) or later line (37.5%) together with endocrine therapy (AI, fulvestrant) according to national guidelines. PreCycle evaluates and compares the time to deterioration (TTD) of QoL in patients supported by eHealth systems with substantially different functionality: CANKADO active vs. inform. CANKADO active is the fully functional CANKADO-based eHealth treatment support system. CANKADO inform is a CANKADO-based eHealth service with a personal login, documentation of daily drug intake, but no further functions. To evaluate QoL, the FACT-B questionnaire is completed at every visit. As little is known about relationships between behavior (e.g., adherence), genetic background, and drug efficacy, the trial includes both patient-reported outcome and biomarker screening for discovery of forecast models for adherence, symptoms, QoL, progression free survival (PFS), and overall survival (OS). Discussion The primary objective of PreCycle is to test the hypothesis of superiority for time to deterioration (TTD) in terms of DQoL = “Deterioration of quality of life” (FACT-G scale) in patients supported by an eHealth therapy management system (CANKADO active) versus in patients merely receiving eHealth-based information (CANKADO inform). EudraCT Number: 2016–004191-2

    14th St. Gallen International Breast Cancer Conference 2015: Evidence, Controversies, Consensus - Primary Therapy of Early Breast Cancer: Opinions Expressed by German Experts

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    The key topics of this year's 14th St. Gallen Consensus Conference on the diagnosis and therapy of primary breast cancer were again questions about breast surgery and axillary surgery, radio-oncology and systemic therapy options in consideration of tumor biology, and the clinical application of multigene assays. This year, the consensus conference took place in Vienna. From a German perspective, it makes sense to substantiate the results of the vote of the international panel representing 19 countries in light of the updated national therapy recommendations of the AGO (Arbeitsgemeinschaft GynÀkologische Onkologie). Therefore, 14 German breast cancer experts, 3 of whom are members of the International St. Gallen Panel, have commented on the voting results of the St. Gallen Consensus Conference 2015 in relation to clinical routine in Germany

    A Multicenter Evaluation of Different Chemotherapy Regimens in Older Adults With Head and Neck Squamous Cell Carcinoma Undergoing Definitive Chemoradiation

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    PURPOSE: The number of older adults with head-and-neck squamous cell carcinoma (HNSCC) is increasing, and treatment of these patients is challenging. Although cisplatin-based chemotherapy concomitantly with radiotherapy is considered standard regimen for patients with locoregionally advanced HNSCC, there is substantial real-world heterogeneity regarding concomitant chemotherapy in older HNSCC patients. METHODS: The XXX study is an international multicenter cohort study including older (≄65 years) HNSCC patients treated with definitive radiotherapy at 13 academic centers in the United States and Europe. Here, patients with concomitant chemoradiation were analyzed regarding overall survival (OS) and progression-free survival (PFS) using Kaplan-Meier analyses, while Fine-Gray competing risks regressions were performed regarding the incidence of locoregional failures (LRFs) and distant metastases (DMs). RESULTS: Six hundred ninety-seven patients with a median age of 71 years were included in this analysis. Single-agent cisplatin was the most common chemotherapy regimen (n=310; 44%), followed by cisplatin plus 5-fluorouracil (n=137; 20%), carboplatin (n=73; 10%), and mitomycin c plus 5-fluorouracil (n=64; 9%). Carboplatin-based regimens were associated with diminished PFS (HR=1.39 [1.03-1.89], p.05). Median cumulative dose of cisplatin was 180 mg/m2 (IQR, 120-200 mg/m2). Cumulative cisplatin doses ≄200 mg/m2 were associated with increased OS (HR=0.71 [0.53-0.95], p=.02), PFS (HR=0.66 [0.51-0.87], p=.003), and lower incidence of LRFs (SHR=0.50 [0.31-0.80], p=.004). Higher cumulative cisplatin doses remained an independent prognostic variable in the multivariate regression analysis for OS (HR=0.996 [0.993-0.999], p=.009). CONCLUSIONS: Single-agent cisplatin can be considered as the standard chemotherapy regimen for older HNSCC patients who can tolerate cisplatin. Cumulative cisplatin doses are prognostically relevant also in older HNSCC patients
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