1,041 research outputs found

    On Calibration of a Low-Cost Time-of-Flight Camera

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    Abstract. Time-of-flight (ToF) cameras are becoming more and more popular in computer vision. In many applications 3D information de-livered by a ToF camera is used, and it is very important to know the camera’s extrinsic and intrinsic parameters, as well as precise depth in-formation. A straightforward algorithm to calibrate a ToF camera is to use a standard color camera calibration procedure [12], on the amplitude images. However, depth information delivered by ToF cameras is known to contain complex bias due to several error sources [6]. Additionally, it is desirable in many cases to determine the pose of the ToF camera relative to the other sensors used. In this work, we propose a method for joint color and ToF camera cali-bration, that determines extrinsic and intrinsic camera parameters and corrects depth bias. The calibration procedure requires a standard cali-bration board and around 20-30 images, as in case of a single color camera calibration. We evaluate the calibration quality in several experiments

    Network Physiology reveals relations between network topology and physiological function

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    The human organism is an integrated network where complex physiologic systems, each with its own regulatory mechanisms, continuously interact, and where failure of one system can trigger a breakdown of the entire network. Identifying and quantifying dynamical networks of diverse systems with different types of interactions is a challenge. Here, we develop a framework to probe interactions among diverse systems, and we identify a physiologic network. We find that each physiologic state is characterized by a specific network structure, demonstrating a robust interplay between network topology and function. Across physiologic states the network undergoes topological transitions associated with fast reorganization of physiologic interactions on time scales of a few minutes, indicating high network flexibility in response to perturbations. The proposed system-wide integrative approach may facilitate the development of a new field, Network Physiology.Comment: 12 pages, 9 figure

    Prostaglandin D2-supplemented “functional eicosanoid testing and typing” assay with peripheral blood leukocytes as a new tool in the diagnosis of systemic mast cell activation disease: an explorative diagnostic study

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    Background: Systemic mast cell activation disease (MCAD) is characterized by an enhanced release of mast cell-derived mediators, including eicosanoids, which induce a broad spectrum of clinical symptoms. Accordingly, the diagnostic algorithm of MCAD presupposes the proof of increased mast cell mediator release, but only a few mediators are currently established as routine laboratory parameters. We thus initiated an explorative study to evaluate in vitro typing of individual eicosanoid pattern of peripheral blood leukocytes (PBLs) as a new diagnostic tool in MCAD. Methods: Using the “functional eicosanoid testing and typing” (FET) assay, we investigated the balance (i.e. the complex pattern of formation, release and mutual interaction) of prostaglandin E2 (PGE2) and peptido-leukotrienes (pLT) release from PBLs of 22 MCAD patients and 20 healthy individuals. FET algorithms thereby consider both basal and arachidonic acid (AA)-, acetylsalicylic acid (ASA)-, and substance P (SP)-triggered release of PGE2 and pLT. The FET assay was further supplemented by analyzing prostaglandin D2 (PGD2), as mast cell-specific eicosanoid. Results: We observed marked PGE2-pLT imbalances for PBLs of MCAD patients, as indicated by a markedly enhanced mean FET value of 1.75 ± 0.356 (range: 1.14–2.36), compared to 0.53 ± 0.119 (range: 0.36-0.75) for healthy individuals. In addition, mean PGD2 release from PBLs of MCAD patients was significantly, 6.6-fold higher than from PBLs of healthy individuals (946 ± 302.2 pg/ml versus 142 ± 47.8 pg/ml; P < 0.001). In contrast to healthy individuals, PGD2 release from PBLs of MCAD patients was markedly triggered by SP (mean: 1896 ± 389.7 pg/ml; P < 0.001), whereas AA and ASA caused individually varying effects on both PGD2 and pLT release. Conclusions: The new in-vitro FET assay, supplemented with analysis of PGD2, demonstrated that the individual patterns of eicosanoid release from PBLs can unambiguously distinguish MCAD patients from healthy individuals. Notably, in our analyses, the FET value and both basal and triggered PGD2 levels were not significantly affected by MCAD-specific medication. Thus, this approach may serve as an in-vitro diagnostic tool to estimate mast cell activity and to support individualized therapeutic decision processes for patients suffering from MCAD

    Double-logs, Gribov-Lipatov reciprocity and wrapping

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    We study analytical properties of the five-loop anomalous dimension of twist-2 operators at negative even values of Lorentz spin. Following L. N. Lipatov and A. I. Onishchenko, we have found two possible generalizations of double-logarithmic equation, which allow to predict a lot of poles of anomalous dimension of twist-2 operators at all orders of perturbative theory from the known results. Second generalization is related with the reciprocity-respecting function, which is a single-logarithmic function in this case. We have found, that the knowledge of first orders of the reciprocity-respecting function gives all-loop predictions for the highest poles. Obtained predictions can be used for the reconstruction of a general form of the wrapping corrections for twist-2 operators.Comment: 17 pages, references adde

    Articular cartilage mineralization in osteoarthritis of the hip

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    <p>Abstract</p> <p>Background</p> <p>The aim of this study was to examine the frequency of articular cartilage calcification in patients with end-stage hip OA. Further, its impact on the clinical situation and the OA severity are analyzed.</p> <p>Methods</p> <p>Eighty patients with OA of the hip who consecutively underwent total hip replacement were prospectively evaluated, and 10 controls were included. The patients' X-rays were analyzed for the presence of articular cartilage mineralization. A Harris Hip Score (HHS) was preoperatively calculated for every patient.</p> <p>Slab specimens from the femoral head of bone and cartilage and an additional square centimeter of articular cartilage from the main chondral defect were obtained from each patient for analysis of mineralization by digital contact radiography (DCR). Histological grading was also performed. In a subset of 20 patients, minerals were characterized with an electron microscope (FE-SEM).</p> <p>Results</p> <p>Calcifications were seen in all OA cartilage and slab specimens using DCR, while preoperative X-rays revealed calcification in only 17.5%. None of the control cartilage specimens showed mineralization. There was a highly significant inverse correlation between articular cartilage calcification and preoperative HHS. Histological OA grade correlated positively with the amount of matrix calcification. FE-SEM analysis revealed basic calcium phosphate (BCP) as the predominant mineral; CPPD crystals were found in only two patients.</p> <p>Conclusions</p> <p>Articular cartilage calcification is a common event in osteoarthritis of the hip. The amount of calcification correlates with clinical symptoms and histological OA grade.</p

    Glucose-Raising Genetic Variants in MADD and ADCY5 Impair Conversion of Proinsulin to Insulin

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    Recent meta-analyses of genome-wide association studies revealed new genetic loci associated with fasting glycemia. For several of these loci, the mechanism of action in glucose homeostasis is unclear. The objective of the study was to establish metabolic phenotypes for these genetic variants to deliver clues to their pathomechanism.) and insulin resistance (HOMA-IR, Matsuda-Index) were assessed.. on proinsulin-to-insulin conversion. These effects may also be related to neighboring regions of the genome

    Identification of dimethylamine monooxygenase in marine bacteria reveals a metabolic bottleneck in the methylated amine degradation pathway

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    Methylated amines (MAs) are ubiquitous in the marine environment and their subsequent flux into the atmosphere can result in the formation of aerosols and ultimately cloud condensation nuclei. Therefore, these compounds have a potentially important role in climate regulation. Using Ruegeria pomeroyi as a model, we identified the genes encoding dimethylamine (DMA) monooxygenase (dmmABC) and demonstrate that this enzyme degrades DMA to monomethylamine (MMA). Although only dmmABC are required for enzyme activity in recombinant Escherichia coli, we found that an additional gene, dmmD, was required for the growth of R. pomeroyi on MAs. The dmmDABC genes are absent from the genomes of multiple marine bacteria, including all representatives of the cosmopolitan SAR11 clade. Consequently, the abundance of dmmDABC in marine metagenomes was substantially lower than the genes required for other metabolic steps of the MA degradation pathway. Thus, there is a genetic and potential metabolic bottleneck in the marine MA degradation pathway. Our data provide an explanation for the observation that DMA-derived secondary organic aerosols (SOAs) are among the most abundant SOAs detected in fine marine particles over the North and Tropical Atlantic Ocean

    The great time series classification bake off: a review and experimental evaluation of recent algorithmic advances

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    In the last five years there have been a large number of new time series classification algorithms proposed in the literature. These algorithms have been evaluated on subsets of the 47 data sets in the University of California, Riverside time series classification archive. The archive has recently been expanded to 85 data sets, over half of which have been donated by researchers at the University of East Anglia. Aspects of previous evaluations have made comparisons between algorithms difficult. For example, several different programming languages have been used, experiments involved a single train/test split and some used normalised data whilst others did not. The relaunch of the archive provides a timely opportunity to thoroughly evaluate algorithms on a larger number of datasets. We have implemented 18 recently proposed algorithms in a common Java framework and compared them against two standard benchmark classifiers (and each other) by performing 100 resampling experiments on each of the 85 datasets. We use these results to test several hypotheses relating to whether the algorithms are significantly more accurate than the benchmarks and each other. Our results indicate that only 9 of these algorithms are significantly more accurate than both benchmarks and that one classifier, the Collective of Transformation Ensembles, is significantly more accurate than all of the others. All of our experiments and results are reproducible: we release all of our code, results and experimental details and we hope these experiments form the basis for more rigorous testing of new algorithms in the future

    The disease management program for type 2 diabetes in Germany enhances process quality of diabetes care - a follow-up survey of patient's experiences

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    <p>Abstract</p> <p>Background</p> <p>In summer 2003 a disease management program (DMP) for type 2 diabetes was introduced on a nationwide basis in Germany. Patient participation and continuity of care within the DMP are important factors to achieve long-term improvements in clinical endpoints. Therefore it is of interest, if patients experience any positive or negative effects of the DMP on their treatment that would support or hamper further participation. The main objective of the study was to find out if the German Disease Management Program (DMP) for type 2 diabetes improves process and outcome quality of medical care for patients in the light of their subjective experiences over a period of one year.</p> <p>Methods</p> <p>Cohort study with a baseline interview and a follow-up after 10.4 ± 0.64 months. Data on process and outcome measures were collected by telephone interviews with 444 patients enrolled and 494 patients not enrolled in the German DMP for type 2 diabetes. Data were analyzed by multivariate logistic regression analyses.</p> <p>Results</p> <p>DMP enrolment was significantly associated with a higher process quality of care. At baseline enrolled patients more often reported that they had attended a diabetes education course (OR = 3.4), have ≥ 4 contacts/year with the attending physician (OR = 3.3), have at least one annual foot examination (OR = 3.1) and one referral to an ophthalmologist (OR = 3.4) and possess a diabetes passport (OR = 2.4). Except for the annual referral to an ophthalmologist these parameters were also statistically significant at follow-up. In contrast, no differences between enrolled and not enrolled patients were found concerning outcome quality indicators, e.g. self-rated health, Glycated hemoglobin (GHb) and blood pressure. However, 16-36% of the DMP participants reported improvements of body weight and/or GHb and/or blood pressure values due to enrolment - unchanged within one year of follow-up.</p> <p>Conclusions</p> <p>In the light of patient's experiences the DMP enhances the process quality of medical care for type 2 diabetes in Germany. The lack of significant differences in outcome quality between enrolled and not enrolled patients might be due to the short program duration. Our data suggest that the DMP for type 2 diabetes should not be withdrawn unless an evidently more promising approach is found.</p
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