julilili42/papers huggingface dataset:
CSF biomarker variability in the Alzheimer's Association quality control program
2013-05-01

Abstract Background The cerebrospinal fluid (CSF) biomarkers amyloid beta 1–42, total tau, and phosphorylated tau are used increasingly for Alzheimer's disease (AD) research and patient management. However, there are large variations in biomarker measurements among and within laboratories. Methods Data from the first nine rounds of the Alzheimer's Association quality control program was used to define the extent and sources of analytical variability. In each round, three CSF samples prepared at the Clinical Neurochemistry Laboratory (Mölndal, Sweden) were analyzed by single‐analyte enzyme‐linked immunosorbent assay (ELISA), a multiplexing xMAP assay, or an immunoassay with electrochemoluminescence detection. Results A total of 84 laboratories participated. Coefficients of variation (CVs) between laboratories were around 20% to 30%; within‐run CVs, less than 5% to 10%; and longitudinal within‐laboratory CVs, 5% to 19%. Interestingly, longitudinal within‐laboratory CV differed between biomarkers at individual laboratories, suggesting that a component of it was assay dependent. Variability between kit lots and between laboratories both had a major influence on amyloid beta 1–42 measurements, but for total tau and phosphorylated tau, between‐kit lot effects were much less than between‐laboratory effects. Despite the measurement variability, the between‐laboratory consistency in classification of samples (using prehoc‐derived cutoffs for AD) was high (&gt;90% in 15 of 18 samples for ELISA and in 12 of 18 samples for xMAP). Conclusions The overall variability remains too high to allow assignment of universal biomarker cutoff values for a specific intended use. Each laboratory must ensure longitudinal stability in its measurements and use internally qualified cutoff levels. Further standardization of laboratory procedures and improvement of kit performance will likely increase the usefulness of CSF AD biomarkers for researchers and clinicians.
Relationship between circulating tumor cells and peripheral T-cells in patients with primary breast cancer.
2013-05-01

Absence of T-cell help at the time of priming may result in a loss of long-term antigen-activation of CD8 lymphocytes and could lead to an ineffective anti-tumor cell response. This might contribute to systemic immunosuppression and open the door for tumor cell dormancy.
Synergistic Effects of Expectancy and Value on Homework Engagement: The Case for a Within-Person Perspective
2013-05-01

Historically, expectancy-value models of motivation assumed a synergistic relation between expectancy and value: motivation is high only when both expectancy and value are high. Motivational processes were studied from a within-person perspective, with expectancies and values being assessed or experimentally manipulated across multiple domains and the focus being placed on intraindividual differences. In contrast, contemporary expectancy-value models in educational psychology concentrate almost exclusively on linear effects of expectancy and value on motivational outcomes, with a focus on between-person differences. Recent advances in latent variable methodology allow both issues to be addressed in observational studies. Using the expectancy-value model of homework motivation as a theoretical framework, this study estimated multilevel structural equation models with latent interactions in a sample of 511 secondary school students and found synergistic effects between domain-specific homework expectancy and homework value in predicting homework engagement in 6 subjects. This approach not only brings the "×" back into expectancy-value theory but also reestablishes the within-person perspective as the appropriate level of analysis for latent expectancy-value models.
Concurrent conservative and reactive tracer tests in a stream undergoing hyporheic exchange
2013-05-01

Key Points concurrent tests of conservative and reactive tracers in streams joint analysis of the tracers improved the estimation of hyporheic parameters Markov chain Monte Carlo methods used to infer parameter distributions
Tournament Compensation Systems, Employee Heterogeneity, and Firm Performance
2013-05-01

Abstract Tournament compensation systems are widely used in practice and have been extensively analyzed theoretically. However, one major problem has hardly been studied in a company context so far: Although it is theoretically well understood that tournament compensation systems are only effective when employees are homogeneous, it has rarely been analyzed what companies can do when they are confronted with employee heterogeneity. In our article, we derive hypotheses on the performance effects of tournament compensation systems in a context of employee heterogeneity based on tournament and expectancy theory. Using personnel records from incentive travel contests, we are able to show that performance is lower in a situation with employee heterogeneity, but that in heterogeneous tournaments, incentives may still work for a subgroup of employees whom we term the “threshold group.” In addition, we also show how companies manage to design the information disclosure systems necessary to install effective “handicapping” or “league‐building” systems in order to increase the effort‐performance expectancy.
Framework for autonomous onboard navigation with the AR.Drone
2013-05-01

We present a framework for autonomous flying using the AR.Drone low cost quadrotor. The system performs all sensing and computations on-board, making the system independent of any base station or remote control. High level navigation and control tasks are carried out in a microcontroller that steers the vehicle to a desired location. We experimentally demonstrate the properties and capabilities of the system autonomously following several trajectory patterns of different complexity levels and evaluate the performance of our system.
On-board dual-stereo-vision for autonomous quadrotor navigation
2013-05-01

We present a quadrotor Micro Aerial Vehicle (MAV) capable of autonomous indoor navigation. The MAV is equipped with four cameras arranged in two stereo configurations. One camera pair is facing forward and serves as input for a reduced stereo SLAM system. The other camera pair is facing downwards and is used for ground plane detection and tracking. All processing, including sparse stereo matching, is run on-board in real-time and at high processing rates. We demonstrate the capabilities of this MAV design in several flight experiments. Our MAV is able to recover from pose estimation errors and can cope with processing failures for one camera pair. We show that by using two camera pairs instead of one, we are able to significantly increase navigation accuracy and robustness.
Production and Release of Acylcarnitines by Primary Myotubes Reflect the Differences in Fasting Fat Oxidation of the Donors
2013-05-01

Acylcarnitine production and release from primary human myotubes of donors with high fasting RQ indicate a reduced fatty acid oxidation capacity and a higher rate of incomplete fatty acid oxidation. Thus, quantitative profiling of acylcarnitine production in human myotubes can be a suitable tool to identify muscular determinants of fat oxidation in vivo.
A cross-platform comparison of visual marker based approaches for autonomous flight of quadrocopters
2013-05-01

In this paper, we compare three different marker based approaches for six degrees of freedom (6DOF) pose estimation, which can be used for position and attitude control of micro aerial vehicles (MAV). All methods are able to achieve real time pose estimation onboard without assistance of any external metric sensor. Since these methods can be used in various working environments, we compare their performance by carrying out experiments across two different platforms: an AscTec Hummingbird and a Pixhawk quadrocopter. We evaluate each method's accuracy by using an external tracking system and compare the methods with respect to their operating ranges and processing time. We finally compare each method's performance during autonomous takeoff, hovering and landing of a quadrocopter.
Low-Density Parity-Check Codes from Transversal Designs with Improved Stopping Set Distributions
2013-05-01

This paper examines the construction of low-density parity-check (LDPC) codes\\nfrom transversal designs based on sets of mutually orthogonal Latin squares\\n(MOLS). By transferring the concept of configurations in combinatorial designs\\nto the level of Latin squares, we thoroughly investigate the occurrence and\\navoidance of stopping sets for the arising codes. Stopping sets are known to\\ndetermine the decoding performance over the binary erasure channel and should\\nbe avoided for small sizes. Based on large sets of simple-structured MOLS, we\\nderive powerful constraints for the choice of suitable subsets, leading to\\nimproved stopping set distributions for the corresponding codes. We focus on\\nLDPC codes with column weight 4, but the results are also applicable for the\\nconstruction of codes with higher column weights. Finally, we show that a\\nsubclass of the presented codes has quasi-cyclic structure which allows\\nlow-complexity encoding.\\n
Impact of metabolizing enzymes on drug response of endocrine therapy in breast cancer
2013-05-01

Estrogen-receptor positive breast cancer accounts for 75% of diagnosed breast cancers worldwide. There are currently two major options for adjuvant treatment: tamoxifen and aromatase inhibitors. Variability in metabolizing enzymes determines their pharmacokinetic profile, possibly affecting treatment response. Therefore, prediction of therapy outcome based on genotypes would enable a more personalized medicine approach, providing optimal therapy for each patient. In this review, the authors will discuss the current evidence on the most important metabolizing enzymes in endocrine therapy, with a special focus on CYP2D6 and its role in tamoxifen metabolism.
A “vicious cycle” of NK-cell immune evasion in acute myeloid leukemia mediated by RANKL?
2013-05-01

Receptor activator of NFκB ligand (RANKL) is mainly known for its role in bone metabolism, constituting a target for therapeutic interventions. Increasing evidence suggests that RANKL is also involved in oncogenesis and tumor progression, including a prominent role in host-tumor interaction. Our data suggest that targeting RANKL may reinforce natural killer (NK) cell-mediated antitumor responses in patients affected by hematological malignancies.
Onboard monocular vision for landing of an MAV on a landing site specified by a single reference image
2013-05-01

This paper presents a real-time monocular vision solution for MAVs to autonomously search for and land on an arbitrary landing site. The autonomous MAV is provided with only one single reference image of the landing site with an unknown size before initiating this task. To search for such landing sites, we extend a well-known visual SLAM algorithm that enables autonomous navigation of the MAV in unknown environments. A multi-scale ORB feature based method is implemented and integrated into the SLAM framework for landing site detection. We use a RANSAC-based method to locate the landing site within the map of the SLAM system, taking advantage of those map points associated with the detected landing site. We demonstrate the efficiency of the presented vision system in autonomous flight, and compare its accuracy with ground truth data provided by an external tracking system.
Cutaneous presentation of hematological malignancies
2013-05-01

Systemic hematological malignancies can present in the skin as specific secondary cutaneous lymphoma or as non-specific skin manifestations. In the majority of cases, patients are first diagnosed with a systemic lymphoma and may subsequently develop skin involvement. Rarely, the cutaneous symptoms precede the diagnosis of systemic hematological disorders. In these patients, cutaneous infiltrates can present a challenge to both the clinician and the pathologist. We report a series of five patients with clinically and histologically heterogeneous characteristics, in which careful diagnostic procedures finally led to the diagnosis of systemic hematological malignancies. Interdisciplinary clinical and laboratory examination, including histological and molecular analysis and imaging rendered possible the diagnosis of the underlying hematological malignancy. The here-described approaches allowed the diagnosis and therapy of so-far unrecognized hematological malignancies in patients initially presenting exclusively with cutaneous symptoms.
Verifying proofs in constant depth
2013-05-01

In this paper we initiate the study of proof systems where verification of proofs proceeds by NC 0 circuits. We investigate the question which languages admit proof systems in this very restricted model. Formulated alternatively, we ask which languages can be enumerated by NC 0 functions. Our results show that the answer to this problem is not determined by the complexity of the language. On the one hand, we construct NC 0 proof systems for a variety of languages ranging from regular to NP complete. On the other hand, we show by combinatorial methods that even easy regular languages such as Exact-OR do not admit NC 0 proof systems. We also show that Majority does not admit NC 0 proof systems. Finally, we present a general construction of NC 0 proof systems for regular languages with strongly connected NFA's.
Physicochemical Characterization and in vivo Skin Performance of a Novel Alkyl Polyglucoside Emulsifier in Natural Cosmetic Cream-Bases
2013-05-01

Abstract Alkyl polyglucosides (APGs) are a perfect amphiphilic structure, with excellent surface activity and solubility feature. The aim of this study is to develop a simple system, with a relatively low emulsifier content, composed of materials mainly naturally based and with no additional fatty alcohol. Hydroxystearyl alcohol and Hydroxystearyl glucoside, prepared with Jojoba and Hazelnut oil, medium chain triglycerides with or without Xylitylglucoside and Anhydroxylitol and Xylitol, have been investigated by using microscopy, rheology, thermal analysis, pH and conductimetry. Cyclic stress and in vivo skin irritation tests were also conducted. The investigated natural APG emulsifier has a capacity to form simple and stable emulsions of desirable rheological profile with improved hydration potential and to renew damaged skin, thus it can be safely applied as stabilizer in cosmetic and prospective pharmaceutical cream-bases.
Big Banks and Macroeconomic Outcomes: Theory and Cross-Country Evidence of Granularity
2013-05-01

Does the mere presence of big banks affect macroeconomic outcomes?In this paper, we develop a theory of granularity (Gabaix, 2011) for the banking sector, introducing Bertrand competition and heterogeneous banks charging variable markups.Using this framework, we show conditions under which idiosyncratic shocks to bank lending can generate aggregate fluctuations in the credit supply when the banking sector is highly concentrated.We empirically assess the relevance of these granular effects in banking using a linked micro-macro dataset of more than 80 countries for the years 1995-2009.The banking sector for many countries is indeed granular, as the right tail of the bank size distribution follows a power law.We then demonstrate granular effects in the banking sector on macroeconomic outcomes.The presence of big banks measured by high market concentration is associated with a positive and significant relationship between bank-level credit growth and aggregate growth of credit or gross domestic product.
Analysis of peritoneal carcinomatosis with diffusion-weighted MRI and 18F-FDG-PET by a simultaneous whole-body MR/PET with histopathological correlation
2013-05-01

548 Objectives To evaluate peritoneal carcinomatosis (PC) in patients (pts) with different primary tumors by diffusion-weighted (DW) MRI and 18F-FDG PET in correlation to histopathology. Methods 43 pts with histologically proven PC underwent clinically indicated 18F-FDG PET/CT and immediately thereafter MR/PET of the abdomen with a new simultaneous whole-body MR/PET system (Biograph mMR, 3T, Siemens). Attenuation correction of MR/PET data was segmentation based with fat-water separation. In 22/43 pts measurable PC lesions >1.5 cm were selected for analysis. Patients with small-volume PC and examinations Results The MR/PET images were of diagnostic quality in all patients. The analysis, based on 49 PC lesions in 20 patients, revealed a moderate but significant inverse correlation of ADC and SUV (SUVmax/ADCmin rho=-0,46, p=0,0008; SUVmean/ADCmean rho=-0,62, p Conclusions The moderate correlation of ADC and SUV in PC suggests a rather complementary role of DWI and FDG-PET in this setting. The heterogeneity of water diffusivity and glucose metabolism in PC from different primary tumors has to be considered in image interpretation.
Improved classification of thyroid nodules by iterative deconvolution of thyroid scans
2013-05-01

38 Objectives The accuracy of scintigraphic classification of thyroid nodules is limited by spatial resolution of the used systems. Lesion detection might be improved by the use of iterative deconvolution techniques (IDT). Aim of this study was to evaluate IDT for the detection of hot or cold thyroid nodules. Methods A total of 133 thyroid scans (70 MBq Tc-99m-Pertechnetate, LFOV gamma camera with LEHR - collimator, scan time 600s, matrix: 128 x 128) of 129 patients (38m / 91w; age: 4-85a, mean: 59a) was processed by IDT. Normal and processed scans were separately evaluated (interval: 4 weeks) with regard to presence of hot (H) or cold (C) nodules and lesion contrast (1-3/low => high). Findings were validated by comparison with ultrasonography (US), clinical, and laboratory data. Results In unprocessed scans 71 H and 74 C were identified compared to 71 H and 85 C after IDT. Contrast of H was assessed “1” in 13/9 (unprocessed/after IDT) cases, “2” in 30/29 cases, and “3” in 28/33 cases. Contrast of C was assessed “1” in 30/0, “2“ in 32/34, and “3“ in 12/40 cases. Thus, in 53 cases (72%) use of IDT provided higher lesion contrast, in 21 cases contrast was unchanged. Eleven out of 85 C (13%) were exclusively detectable in processed scans (lesion size: 12-28 mm; mean: 18 mm; contrast: “1”: 6, “2”: 5; “3”: 0). 224 scan abnormalities were not confirmed by US: 2 were found in unprocessed, 97 in unprocessed scans as well as after IDT, and 125 (97 (78%) of them identified as C) exclusively after IDT. Conclusions Processing of planar thyroid scans by IDT allows for improved detectability of cold nodules suggestive for thyroid cancer. Sensitivity is particularly increased for small or medium sized nodules. The problem of false positive findings is easily solved by comparison with US, which is usually available for all patients.
In vivo estimate of myocardial work and metabolic rate of FDG as a first step to the estimation of cardiac efficiency using hybrid PET/MRI technology
2013-05-01

1661 Objectives Hybrid PET/MRI technology offers the potential to make significant advances in the study of heart function relative to metabolite substrate utilization for patients in heart failure (HF). An imbalance between oxidative metabolism and cardiac function appears to be a key factor of disease progression in HF. Fatty acids (FAs) account for 50-70% of ATP production from FA β-oxidation in the normal adult myocardium as well as in frequently utilized animal models. Methods Using hybrid PET/MRI technology, cardiac tissue efficiency is measured as the ratio of myocardial oxygen consumption (MVO2) [PET measures 11C-acetate kinetics as a surrogate for energy input] to cardiac tissue work [MRI measures tissue strain (distance) and finite element modeling estimates tissue stress (force)]. To evaluate the feasibility of our methodology, PET imaging data of 18FDG in the hearts of young normal rats were acquired simultaneously with the acquisition of tagged MRI at the University of Tubingen. Results Comparison of the mid-ventricular estimates of cardiac work and 18FDG metabolic rate for each of the three rats showed negative correlations. The three rats had r2 values of -0.38, -0.54, and -0.50. Conclusions These initial results showed that glucose metabolism was inversely related to the mechanical work of the heart for the three rats being studied suggesting that as the work increases other metabolic substrates, such as FAs, are preferred since they provide more energy per gram than glucose (9 vs. 4 kcal/gram). Our goal is to use hybrid PET/MRI to simultaneously calculate MVO2 and cardiac work and to relate the ratio (cardiac efficiency) to the metabolism of energetic substrates such as glucose and FAs.
Preface
2013-05-01

Jerome Arthur Goldstein (Jerry) was born on August 5, 1941 in Pittsburgh, PA. He attended Carnegie Mellon University, then called Carnegie Institute of Technology, where he earned his Bachelors of Science degree (1963), Masters of Science degree (1964) and Ph.D. (1967) in Mathematics. Jerry took a postdoctoral position at the Institute for Advanced Study in Princeton, followed by an Assistant Professorship at Tulane University. He became a Full Professor at Tulane University in 1975. After twenty-four years there, Jerry moved ``upriver' to join the faculty (and his wife, Gisèle) at Louisiana State University, where he was Professor of Mathematics from 1991 to 1996. In 1996 Jerry and Gisèle moved to the University of Memphis.For more information please click the “Full Text” above.
Human peripheral Vδ1+ γδ T cells can develop into αβ T cells (P4460)
2013-05-01

Abstract The T cell compartment can be divided in two large classes: αβ and γδ T cells. It is believed that they develop in the thymus from a common progenitor and that the choice between αβ and γδ T cell fate is the first lineage decision made by progenitors after they commit to the T-cell lineage. However, here we show that peripheral Vδ1+ γδ T cells in an inflammatory environment can transdifferentiate into αβ T cells. Upon their extrathymic route of differentiation, that resembles well-characterized molecular program of thymic αβ lineage development, Vδ1+ T cells upregulate CD4+ coreceptor, develop Vδ1+ CD4+CD8+ double positive cells, show heterodimeric CD8αβ, transcribe RAG, preTα and express a particular Vβchain on their surface. Simultaneously inflammation confers controlled initiation of rearrangement in the TCRα locus. Transdifferentiation of Vδ1+ T cells at the clonal and bulk-culture level into functional CD4+ or CD8+ αβ T cells via a Vδ1+TCR/αβ+TCR double positive stage suggests that, upon inflammatory stimuli, Vδ1+ T-cell conversion participates in the induction of adaptive immune responses. Identifying an innate T cell as an αβ T-cell progenitor and showing the developmental steps linking the progenitor to adaptive, thymus-independant αβ T-cell responses as inflammatory conditions is of utmost relevance and will deeply impact evaluation of immune responses in infection, malignancy and autoimmune processes.