cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Serological immune profiling using mass spectrometry
Creators: name: Bundala, Matthew Matus
Publisher: name: University of British Columbia
Year: 2017

description: The adaptive immune system is a fantastically complex system comprised of specialized cells, organs and molecules. When properly functioning, our adaptive immune system is continually responding to, and protecting us from, a myriad of disease threats ranging from viruses to cancer. Immune dysfunction leaves us vulnerable to pathogens and can result in autoimmune disorders. Despite the adaptive immune system’s central importance in health, efficient immune profiling methods, and in particular approaches capable of functional characterization of adaptive immune responses, are still in their infancy. In this thesis I present a rapid and scalable serological immune profiling protocol based on antibody mediated identification of antigens (AMIDA). Serological antibodies are extracted from serum, covalently bound to magnetic beads, and washed with a panel of antigens. The bound immunoreactive antigens are then eluted, in-gel trypsin digested, and identified by tandem mass spectrometry. I demonstrate the application of this protocol for profiling immune responses of nine patients to a set of bacterial pathogens including Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Salmonella typhimurium. The identified list of antigens includes outer membrane proteins known to cause immune reaction, as well as novel immunogenic proteins. The data allows for characterization of differences in the global antigen reactivity between different patients and identifies individuals having pronounced pathogen recognition. In a small study I show that K. pneumoniae and P. aeruginosa are generally more reactive across the pathogens tested, and that S. typhimurium showed the weakest reactivity. The improved AMIDA-based protocol allows for efficient identification of immunoreactive antigens and the profiling of patient reactivity. When coupled with complementary technologies such as immune repertoire sequencing this approach can be applied to high-value applications including vaccine development, biomarker identification, and therapeutic antibody discovery.
Limit Operators, Collective Compactness, and the Spectral Theory of Infinite Matrices
Creators: name: Chandler-Wilde, Simon N.
name: Lindner, Marko
Publisher: name: arXiv
Year: 2010
Subjects: subject: Spectral Theory (math.SP)
subject: Mathematical Physics (math-ph)
subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: Primary 47A53, 47B07, Secondary 46N20, 46E40, 47B37, 47L80

description: In the first half of this text we explore the interrelationships between the abstract theory of limit operators (see e.g. the recent monographs of Rabinovich, Roch & Silbermann and Lindner) and the concepts and results of the generalised collectively compact operator theory introduced by Chandler-Wilde and Zhang. We build up to results obtained by applying this generalised collectively compact operator theory to the set of limit operators of an operator $A$. In the second half of this text we study bounded linear operators on the generalised sequence space $\ell^p(\Z^N,U)$, where $p\in [1,\infty]$ and $U$ is some complex Banach space. We make what seems to be a more complete study than hitherto of the connections between Fredholmness, invertibility, invertibility at infinity, and invertibility or injectivity of the set of limit operators, with some emphasis on the case when the operator $A$ is a locally compact perturbation of the identity. Especially, we obtain stronger results than previously known for the subtle limiting cases of $p=1$ and $\infty$. Our tools in this study are the results from the first half of the text and an exploitation of the partial duality between $\ell^1$ and $\ell^\infty$. Results in this second half of the text include a new proof that injectivity of all limit operators (the classic Favard condition) implies invertibility for a general class of almost periodic operators, and characterisations of invertibility at infinity and Fredholmness for operators in the so-called Wiener algebra. In two final chapters our results are illustrated by and applied to concrete examples. Firstly, we study the spectra and essential spectra of discrete Schrödinger operators (both self-adjoint and non-self-adjoint), including operators with almost periodic and random potentials. In the final chapter we apply our results to integral operators on $\R^N$.
description: 110 pages, 3 figures
Indicator-Loaded Permeation-Selective Microbeads for Use in Fiber Optic Simultaneous Sensing of pH and Dissolved Oxygen
Creators: name: Vasylevska, Ganna S.
name: Borisov, Sergey M.
name: Krause, Christian
name: Wolfbeis, Otto S.
Publisher: name: Universität Regensburg
Year: 2006
Subjects: subject: 540 Chemie

description: New materials are described that lead to sensors capable of simultaneous sensing of pH and oxygen via a single-fiber optic sensor. They make use of a pH probe based on carboxyfluorescein, and of a ruthenium(II) complex acting as a probe for dissolved oxygen. The selectivity of the probes was considerably improved by incorporating them into two kinds of microparticles, each of specific permeation selectivity. The pH probe was immobilized on particles made from proton permeable amino-modified poly(hydroxyethyl methacrylate), while the oxygen probe was physically immobilized in beads made from an organically modified sol−gel. Both kinds of beads were then dispersed into a hydrogel matrix and placed at the distal end of an optical fiber waveguide for optical interrogation. A phase-modulated blue-green LED serves as the light source for exciting luminescence whose average decay times or phase shifts serve as the analytical information. Data are evaluated by a modified dual luminophore referencing (m-DLR) method which relates the phase shift (as measured at two different frequencies) to pH and to oxygen partial pressure. The dually sensing material performs best if the sensing matrix is very homogeneous and if the microbeads have a diameter of <3 μm.
Composite Material for Simultaneous and Contactless Luminescent Sensing and Imaging of Oxygen and Carbon Dioxide
Creators: name: Borisov, Sergey M.
name: Krause, Christian
name: Arain, Sarina
name: Wolfbeis, Otto S.
Publisher: name: Universität Regensburg
Year: 2006
Subjects: subject: Biosensors; Dyes; Fluorescence; Polymeric materials; Sensors, gas
subject: 540 Chemie

description: “Seeing” oxygen and carbon dioxide: A sensor material is described that enables simultaneous imaging and monitoring of carbon dioxide and oxygen (see figure). It relies on the measurement of the phase shift of the luminescence decay time of a material composed of microbead-contained indicators (with well-separated excitation and emission wavelengths) and polymers with excellent permeation selectivities as well as favorable optical and adhesive properties.
In vitro study on α-amylase and α-glucosidase inhibitory activities of a new stigmastane-type steroid saponin from the leaves of Vernonia amygdalina
Creators: name: Le Tuan Anh, Hoang
name: Le Ba Vinh
name: Le Thi Lien
name: Cuong, Pham Viet
name: Arai, Masayoshi
name: Ha, Tran Phuong
name: Lin, Hoang Ngoc
name: Dat, Ton That Huu
name: Le Canh Viet Cuong
name: Kim, Young Ho
Publisher: name: Taylor & Francis
Year: 2020
Subjects: subject: Biochemistry
subject: Space Science
subject: Pharmacology
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: Sociology
subject: FOS: Sociology
subject: 69999 Biological Sciences not elsewhere classified
subject: FOS: Biological sciences
subject: 60506 Virology

description: Using various chromatographic separations, four compounds, including one new steroid saponin named vernoamyoside E (1), were isolated from the leaves of the Vietnamese medicinal plant Vernonia amygdalina Delile (Asteraceae). Their structures were established by spectroscopic methods such as 1D- and 2D-NMR, HR-ESI-MS, and HPLC analysis. The inhibitory activities against α-glucosidase and α-amylase of the isolated compounds from V. amygdalina were reported for the first time. The results indicated that compound 1 significantly inhibited both against α-amylase and α-glucosidase activity.
Data-Quality Based Scheduling for Federated Edge Learning
Creators: name: Taik, Afaf
name: Moudoud, Hajar
name: Cherkaoui, Soumaya
Publisher: name: arXiv
Year: 2022
Subjects: subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: FOS: Computer and information sciences

description: FEderated Edge Learning (FEEL) has emerged as a leading technique for privacy-preserving distributed training in wireless edge networks, where edge devices collaboratively train machine learning (ML) models with the orchestration of a server. However, due to frequent communication, FEEL needs to be adapted to the limited communication bandwidth. Furthermore, the statistical heterogeneity of local datasets' distributions, and the uncertainty about the data quality pose important challenges to the training's convergence. Therefore, a meticulous selection of the participating devices and an analogous bandwidth allocation are necessary. In this paper, we propose a data-quality based scheduling (DQS) algorithm for FEEL. DQS prioritizes reliable devices with rich and diverse datasets. In this paper, we define the different components of the learning algorithm and the data-quality evaluation. Then, we formulate the device selection and the bandwidth allocation problem. Finally, we present our DQS algorithm for FEEL, and we evaluate it in different data poisoning scenarios.
description: 2021 IEEE 46th Conference on Local Computer Networks (LCN)
Preserving privacy in domain transfer of medical AI models comes at no performance costs: The integral role of differential privacy
Creators: name: Arasteh, Soroosh Tayebi
name: Lotfinia, Mahshad
name: Nolte, Teresa
name: Saehn, Marwin
name: Isfort, Peter
name: Kuhl, Christiane
name: Nebelung, Sven
name: Kaissis, Georgios
name: Truhn, Daniel
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: Cryptography and Security (cs.CR)
subject: Image and Video Processing (eess.IV)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Developing robust and effective artificial intelligence (AI) models in medicine requires access to large amounts of patient data. The use of AI models solely trained on large multi-institutional datasets can help with this, yet the imperative to ensure data privacy remains, particularly as membership inference risks breaching patient confidentiality. As a proposed remedy, we advocate for the integration of differential privacy (DP). We specifically investigate the performance of models trained with DP as compared to models trained without DP on data from institutions that the model had not seen during its training (i.e., external validation) - the situation that is reflective of the clinical use of AI models. By leveraging more than 590,000 chest radiographs from five institutions, we evaluated the efficacy of DP-enhanced domain transfer (DP-DT) in diagnosing cardiomegaly, pleural effusion, pneumonia, atelectasis, and in identifying healthy subjects. We juxtaposed DP-DT with non-DP-DT and examined diagnostic accuracy and demographic fairness using the area under the receiver operating characteristic curve (AUC) as the main metric, as well as accuracy, sensitivity, and specificity. Our results show that DP-DT, even with exceptionally high privacy levels (epsilon around 1), performs comparably to non-DP-DT (P>0.119 across all domains). Furthermore, DP-DT led to marginal AUC differences - less than 1% - for nearly all subgroups, relative to non-DP-DT. Despite consistent evidence suggesting that DP models induce significant performance degradation for on-domain applications, we show that off-domain performance is almost not affected. Therefore, we ardently advocate for the adoption of DP in training diagnostic medical AI models, given its minimal impact on performance.
description: Published in Radiology: Artificial Intelligence. RSNA
Cardiac nurses' knowledge, assessment practices and management of postoperative pain
Creators: name: Maglanque, Maria Jannette
Publisher: name: University of British Columbia
Year: 2017

description: Background: Pain is an important stressor for postoperative patients and remains an issue this present day. Postoperative patients continue to report moderate to severe postoperative pain following cardiac surgery. Acute postoperative pain that is not treated appropriately could potentially progress into postsurgical chronic pain which would significantly impact an individual’s overall quality of life. Nurses are at the frontlines providing direct patient care and play a major role in pain assessment and pain management, however, barriers exist that prevent postoperative patients from receiving effective pain relief. Purpose: To understand cardiac nurse’ postoperative pain knowledge, pain assessment practices and pain management in the context of cardiac surgical patients. Sample/Methods: This was a mixed methods design that was conducted on two cardiac surgical units in a tertiary hospital located in British Columbia. There were 63 nurses who accessed the online survey. Results: The findings revealed nurses have moderate pain knowledge with scores ranging from 56.1% to 91.1%. Nurses education level, experience level and age had no impact on their knowledge scores. Conclusions: A majority of nurses reported adequate pain knowledge in assessment and management, however, knowledge gaps exist in terms of pain assessment, neuropathic pain and chronic pain.
Present Limits on the Precision of SM Predictions for Jet Energies
Creators: name: Paramonov, A. A.
name: Canelli, F.
name: D'Onofrio, M.
name: Frisch, H. J.
name: Mrenna, S.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We investigate the impact of theoretical uncertainties on the accuracy of measurements involving hadronic jets. The analysis is performed using events with a Z boson and a single jet observed in $p\bar{p}$ collisions at $\sqrt{s}$ = 1.96 TeV in 4.6 $\mathrm{fb^{-1}}$ of data from the Collider Detector at Fermilab (CDF). The transverse momenta (\pt) of the jet and the boson should balance each other due to momentum conservation in the plane transverse to the direction of the $p$ and $\bar{p}$ beams. We evaluate the dependence of the measured \pt-balance on theoretical uncertainties associated with initial and final state radiation, choice of renormalization and factorization scales, parton distribution functions, jet-parton matching, calculations of matrix elements, and parton showering. We find that the uncertainty caused by parton showering at large angles is the largest amongst the listed uncertainties. The proposed method can be re-applied at the LHC experiments to investigate and evaluate the uncertainties on the predicted jet energies. The distributions produced at the CDF environment are intended for comparison to those from modern event generators and new tunes of parton showering.
description: Submitted to Nucl. Instr. and Meth. A
Temperature-Sensitive Europium(III) Probes and Their Use for Simultaneous Luminescent Sensing of Temperature and Oxygen
Creators: name: Borisov, Sergey M.
name: Wolfbeis, Otto S.
Publisher: name: Universität Regensburg
Year: 2006
Subjects: subject: 540 Chemie

description: Highly photostable and strongly luminescent europium(III) β-diketonate complexes are presented that can act as new probes for optical sensing of temperature. They can be excited with the light of a 405-nm LED and possess strong brightnesses. The decay times of the probes contained in a poly(vinyl methyl ketone) film and in poly(tert-butyl styrene) microparticles are highly temperature-dependent between 0 and 70 °C. The temperature-sensitive microparticles were dispersed, along with oxygen-sensitive microbeads consisting of a palladium porphyrin oxygen indicator in poly(styrene-co-acrylonitrile), in a thin layer of a hydrogel to give a dually sensing material which is excitable by a single light source. The two emissions can be separated by appropriate optical filters. The response to oxygen and temperature is described by 3D plots, and unbiased values can be obtained for temperature and oxygen, respectively, from the two luminescence signals if refined in an iteration step. The sensing scheme is intended for use in temperature-compensated sensing of oxygen, in contactless sensing of oxygen and temperature in (micro)biological and medical applications, in high-resolution oxygen profiling, and for simultaneous imaging of air pressure and temperature in wind tunnels.
Electrical Load Forecasting Using Edge Computing and Federated Learning
Creators: name: Taik, Afaf
name: Cherkaoui, Soumaya
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computational Engineering, Finance, and Science (cs.CE)
subject: FOS: Computer and information sciences

description: In the smart grid, huge amounts of consumption data are used to train deep learning models for applications such as load monitoring and demand response. However, these applications raise concerns regarding security and have high accuracy requirements. In one hand, the data used is privacy-sensitive. For instance, the fine-grained data collected by a smart meter at a consumer's home may reveal information on the appliances and thus the consumer's behaviour at home. On the other hand, the deep learning models require big data volumes with enough variety and to be trained adequately. In this paper, we evaluate the use of Edge computing and federated learning, a decentralized machine learning scheme that allows to increase the volume and diversity of data used to train the deep learning models without compromising privacy. This paper reports, to the best of our knowledge, the first use of federated learning for household load forecasting and achieves promising results. The simulations were done using Tensorflow Federated on the data from 200 houses from Texas, USA.
description: ICC 2020-2020 IEEE International Conference on Communications (ICC)
Composite Luminescent Material for Dual Sensing of Oxygen and Temperature
Creators: name: Borisov, Sergey M.
name: Vasylevska, A. S.
name: Krause, Christian
name: Wolfbeis, Otto S.
Publisher: name: Universität Regensburg
Year: 2006
Subjects: subject: Dyes; Luminescence; Polymer composites; Sensing, gas; Sensing, temperature
subject: 540 Chemie

description: A novel kind of composite material is presented that contains two indicators incorporated into a single polymer matrix, thus allowing simultaneous determination of oxygen partial pressure and temperature. The temperature-sensitive dye (ruthenium tris-1,10-phenanthroline) was chosen for its highly temperature-dependent luminescence which is the highest among the RuII polypyridyl complexes. A fluorinated palladium(II) tetraphenylporphyrin served as the oxygen probe. The indicators were incorporated into either poly(styrene-co-acrylonitrile) microparticles (to sense oxygen) or into poly(acrylonitrile) (for temperature sensing, since this polymer is virtually impermeable to oxygen). The luminescence of both dyes can be separated either spectrally (due to different absorption and emission spectra of the indicators) or via luminescence decay time. The material is suitable for temperature-compensated oxygen sensing, for example, in high-resolution oxygen profiling, and for imaging temperature in the range between 0 and 60 °C. This enables one to “see” (rather than to “feel”) temperature in this important range. Simultaneous imaging of pressure and temperature also has been achieved. It enables contactless imaging of the two parameters, for example, in wind tunnels. Due to the use of a biocompatible hydrogel matrix, the material conceivably is suited for biomedical applications.
Dynamical trapping of light in modulated waveguide lattices
Creators: name: Longhi, Stefano
Publisher: name: arXiv
Year: 2011
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: A discrete analogue of the dynamical (Kapitza) trapping effect, known for classical and quantum particles in rapidly oscillating potentials, is proposed for light waves in modulated graded-index waveguide lattices. As in the non-modulated waveguide lattice a graded-index potential can confine light at either normal or Bragg angle incidence, periodic modulation of the potential in the longitudinal direction enables to trap optical beams at both normal and Bragg incidence angles.
description: to be published in Optics Letters
Gravity Couplings in the Standard-Model Extension
Creators: name: Bailey, Quentin G.
Publisher: name: arXiv
Year: 2010
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The Standard-Model Extension (SME) is an action-based expansion describing general Lorentz violation for known matter and fields, including gravity. In this talk, I will discuss the Lorentz-violating gravity couplings in the SME. Toy models that match the SME expansion, including vector and two-tensor models, are reviewed. Finally I discuss the status of experiments and observations probing gravity coefficients for Lorentz violation.
description: 5 pages, Presented at the Fifth Meeting on CPT and Lorentz Symmetry, Bloomington, Indiana, June 28-July 2, 2010
Expanded Carrier Screening (ECS): Clinical and Ethical Considerations for Genetic Counseling
Creators: name: Myers, Melanie
name: Wakefield, Emily
Publisher: name: Center for ELSI Resources and Analysis
Year: 2021
Subjects: subject: Genetics
subject: FOS: Biological sciences
subject: Ethics
subject: Science
subject: ELSI
subject: ECS
subject: prenatal genetic diagnosis
subject: IVF
subject: selective reproduction

description: Targeted carrier screening began over 50 years ago with a focus on populations at increased risk for specific genetic conditions based on patient-reported racial, ethnic, or ancestral background. As genetic technologies have evolved, testing laboratories have begun offering expanded carrier screening (ECS) panels. Recently, the American College of Medical Genetics and Genomics (ACMG) recommended a universal approach to carrier screening for pregnant patients and those considering a pregnancy, due to the increased recognition that self-identified ancestry is imperfect. These guidelines utilize a tiered approach and recommend ECS screening for autosomal recessive and x-linked disorders with a carrier frequency of 1/200 or higher. Reproductive partners can be tested simultaneously or sequentially. A goal of ECS is enabling informed reproductive decision-making for a broader number of people by offering screening consistently and equitably to all patients. Those identified through expanded screening that have increased risk of producing a child with a genetic condition can choose not to have children, use a donor gamete/embryo, utilize invitro fertilization (IVF) and prenatal genetic diagnosis (PGD) for monogenic conditions, adopt, or perform prenatal diagnostic testing via chorionic villus sampling (CVS) or amniocentesis. Some religious communities integrate carrier status in the match-making process. This collection of literature outlines some of the clinical and ethical considerations associated with ECS, including evolving variant interpretations, professional and patient understanding of carrier screening, the ability of the workforce to provide informed pre- and post-test counseling, and clinical utility. Though limited examples exist, literature regarding perceptions of ECS and whether it is equally acceptable, affordable, and accessible among different populations is also presented.
Efficient Uncertainty Estimation in Spiking Neural Networks via MC-dropout
Creators: name: Sun, Tao
name: Yin, Bojian
name: Bohte, Sander
Publisher: name: arXiv
Year: 2023
Subjects: subject: Neural and Evolutionary Computing (cs.NE)
subject: Artificial Intelligence (cs.AI)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Spiking neural networks (SNNs) have gained attention as models of sparse and event-driven communication of biological neurons, and as such have shown increasing promise for energy-efficient applications in neuromorphic hardware. As with classical artificial neural networks (ANNs), predictive uncertainties are important for decision making in high-stakes applications, such as autonomous vehicles, medical diagnosis, and high frequency trading. Yet, discussion of uncertainty estimation in SNNs is limited, and approaches for uncertainty estimation in artificial neural networks (ANNs) are not directly applicable to SNNs. Here, we propose an efficient Monte Carlo(MC)-dropout based approach for uncertainty estimation in SNNs. Our approach exploits the time-step mechanism of SNNs to enable MC-dropout in a computationally efficient manner, without introducing significant overheads during training and inference while demonstrating high accuracy and uncertainty quality.
The new generation CMB B-mode polarization experiment: POLARBEAR
Creators: name: The Polarbear Collaboration
name: Errard, J.
name: Ade, P. A. R.
name: Anthony, A.
name: Arnold, K.
name: Aubin, F.
name: Boettger, D.
name: Borrill, J.
name: Cantalupo, C.
name: Dobbs, M. A.
name: Flanigan, D.
name: Ghribi, A.
name: Halverson, N.
name: Hazumi, M.
name: Holzapfel, W. L.
name: Howard, J.
name: Hyland, P.
name: Jaffe, A.
name: Keating, B.
name: Kisner, T.
name: Kermish, Z.
name: Lee, A. T.
name: Linder, E.
name: Lungu, M.
name: Matsumura, T.
name: Miller, N.
name: Meng, X.
name: Myers, M.
name: Nishino, H.
name: O'Brient, R.
name: O'Dea, D.
name: Reichardt, C.
name: Schanning, I.
name: Shimizu, A.
name: Shimmin, C.
name: Shimon, M.
name: Spieler, H.
name: Steinbach, B.
name: Stompor, R.
name: Suzuki, A.
name: Tomaru, T.
name: Tran, H. T.
name: Tucker, C.
name: Quealy, E.
name: Richards, P. L.
name: Zahn, O.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We describe the Cosmic Microwave Background (CMB) polarization experiment called Polarbear. This experiment will use the dedicated Huan Tran Telescope equipped with a powerful 1,200-bolometer array receiver to map the CMB polarization with unprecedented accuracy. We summarize the experiment, its goals, and current status.
Characterization of microtiterplates with integrated optical sensors for oxygen and pH, and their applications to enzyme activity screening, respirometry, and toxicological assays
Creators: name: Arain, Sarina
name: John, Gernot T.
name: Krause, Christian
name: Gerlach, Jochen
name: Wolfbeis, Otto S.
name: Klimant, Ingo
Publisher: name: Universität Regensburg
Year: 2006
Subjects: subject: Optical oxygen sensor; Optical pH sensor; MTP; Enzyme activity; Respiratory activity
subject: 540 Chemie

description: This paper describes properties of microplates (MTPs) with integrated, fluorescence-based sensors for pH and oxygen, and their application for enzyme screening and monitoring of bacterial respiratory activity. Thin, hydrophilic sensing films consisting of an analyte-sensitive indicator and a reference fluorophore, are deposited on the bottom of the MTP. This allows for calibration-free quantification of pH and pO2 with an acceptable accuracy and resolution for applications such as enzyme activity screening, respirometry, or toxicological assays. The sensor properties are mainly investigated with respect to their qualification for such applications. Specifically, enzyme activity screening is demonstrated for glucose oxidase using oxygen-sensitive plates, and for bacterial growth monitoring of Escherichia coli and Pseudomonas putida. Furthermore, a toxicological assay monitoring the respiration activity of P. putida was converted into a microplate format.
Submillimeter continuum observations of Sagittarius B2 at subarcsecond spatial resolution
Creators: name: Qin, S. -L.
name: Schilke, P.
name: Rolffs, R.
name: Comito, C.
name: Lis, D. C.
name: Zhang, Q.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We report the first high spatial resolution submillimeter continuum observations of the Sagittarius B2 cloud complex using the Submillimeter Array (SMA). With the subarcsecond resolution provided by the SMA, the two massive star-forming clumps Sgr B2(N) and Sgr B2(M) are resolved into multiple compact sources. In total, twelve submillimeter cores are identified in the Sgr B2(M) region, while only two components are observed in the Sgr B2(N) clump. The gas mass and column density are estimated from the dust continuum emission. We find that most of the cores have gas masses in excess of 100 M$_{\odot}$ and column densities above 10$^{25}$ cm$^{-2}$. The very fragmented appearance of Sgr B2(M), in contrast to the monolithic structure of Sgr B2 (N), suggests that the former is more evolved. The density profile of the Sgr B2(N)-SMA1 core is well fitted by a Plummer density distribution. This would lead one to believe that in the evolutionary sequence of the Sgr B2 cloud complex, a massive star forms first in an homogeneous core, and the rest of the cluster forms subsequently in the then fragmenting structure.
description: 4 pages, 2 figures, accepted by A&A letters
Prevalence of nucleic acid sequences specific for human parvoviruses, hepatitis A and hepatitis E viruses in coagulation factor concentrates
Creators: name: Modrow, Susanne
name: Wenzel, J. J.
name: Schimanski, S.
name: Schwarzbeck, J.
name: Rothe, U.
name: Oldenburg, J.
name: Jilg, W.
name: Eis-Hübinger, A. M.
Publisher: name: Universität Regensburg
Year: 2010
Subjects: subject: 610 Medizin

description: Background and Objectives Due to their high resistance to inactivation procedures, nonenveloped viruses such as parvovirus B19, human bocavirus (HBoV), human parvovirus 4 (PARV4), hepatitis A (HAV) and hepatitis E virus (HEV) pose a particular threat to blood products. Virus transmission to patients treated with blood products presents an additional burden to disease. We determined the frequency and the amount of nucleic acid specific for nonenveloped viruses in recently manufactured preparations of commercial coagulation factor concentrates. Materials and Methods At least three different batches of each of 13 different plasma-derived and recombinant coagulation factor products were tested for the presence and the amount of nucleic acid for parvovirus B19, HBoV, human parvovirus 4, hepatitis A virus and HEV by using quantitative polymerase chain reaction. Results Whereas none of the recombinant products tested positive for any of these viruses, parvovirus B19 DNA with amounts ranging between 2 × 10(1) and 1.3 × 10(3) genome equivalents/ml was detected in five plasma-derived products. In addition to parvovirus B19 genotype 1, genotypes 2 and 3 were observed in two batches of a factor VIII/von-Willebrand factor product. In two products (one factor VIII concentrate and one activated prothrombin complex concentrate), a combination of both genotypes 1 and 2 of parvovirus B19 was detected. Conclusion The data show that nucleic acids from several relevant nonenveloped viruses are not found at detectable levels in coagulation factor concentrates. In some cases, parvovirus B19 DNA was detectable at low levels. Testing of the plasma pools for the full range of parvovirus genotypes is advocated for ensuring product safety.
Temperature dependence of the plasmonic Casimir interaction
Creators: name: Intravaia, F.
name: Haakh, H.
name: Henkel, C.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Physics (quant-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We investigate the role of surface plasmons in the electromagnetic Casimir effect at finite temperature, including situations out of global thermal equilibrium. The free energy is calculated analytically and expanded for different regimes of distances and temperatures. Similar to the zero-temperature case, the interaction changes from attraction to repulsion with distance. Thermal effects are shown to be negligible for small plate separations and at room temperature, but become dominant and repulsive at large values of these parameters. In configurations out of global thermal equilibrium, we show that the selective excitation of surface plasmons can create a repulsive Casimir force between metal plates.
description: 11 pages, 13 figures
Bias dependence of spin injection into GaAs from Fe, FeCo, and (Ga,Mn)As contacts
Creators: name: Endres, Bernhard
name: Hoffmann, Frank
name: Wolf, Christian
name: Einwanger, Andreas
name: Utz, Martin
name: Schuh, Dieter
name: Woltersdorf, Georg
name: Ciorga, Mariusz
name: Weiss, Dieter
name: Back, Christian
name: Bayreuther, Günther
Publisher: name: Universität Regensburg
Year: 2011
Subjects: subject: cobalt alloys, electrical contacts, gallium compounds, III-V semiconductors, iron, iron alloys, spin polarised transport
subject: 530 Physik
subject: 72.25.-b
subject: 73.40.Vz

description: Spin injection from Fe(001) and (Ga,Mn)As(001) into n-GaAs(001) was investigated using a method which provides two-dimensional cross-sectional images of the spin polarization in GaAs. While the distribution of the spin polarization below the injecting contact is nearly uniform for (Ga,Mn)As, a strong confinement near the contact edge is observed for Fe and FeCo. The spin polarization in GaAs changes sign when the injected current is reversed. Multiple sign reversals as a function of bias voltage as reported previously for Fe injectors are not observed with (Ga,Mn)As and Fe contacts grown on clean n++−GaAs in agreement with earlier results for an epitaxial FeCo injector.
Airy beams from a microchip laser
Creators: name: Longhi, Stefano
Publisher: name: arXiv
Year: 2011
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: It is theoretically shown that an end-pumped microchip laser formed by a thin laser crystal with plane-plane but slightly tilted facets can emit, under appropriate pumping conditions and near a crystal edge, a truncated self-accelerating Airy output beam.
description: to be published in Optics Letters
A Novel Method for Time-Resolved Fluorimetric Determination and Imaging of the Activity of Peroxidase, and Its Application to an Enzyme-Linked Immunosorbent Assay
Creators: name: Lin, Zhihong
name: Wu, Meng
name: Wolfbeis, Otto S.
name: Schäferling, Michael
Publisher: name: Universität Regensburg
Year: 2006
Subjects: subject: fluorescent probes; imaging agents; immunoassays; peroxidase activity; time-resolved spectrometry
subject: 540 Chemie

description: A new type of fluorescence assay for the determination of peroxidase (POx) activity is presented. The assay is based on the indication of the enzymatic consumption of H2O2 (HP), using a fluorescent europium–tetracycline (Eu3TC) complex as indicator. On addition of HP, this complex forms a highly fluorescent adduct (Eu3TC–HP), which is decomposed in the presence of POx to form the weakly fluorescent europium–tetracycline (Eu3TC). Hence, the activity of the enzyme can be directly determined by means of the luminescent Eu3TC complex as indicator. The POx assay demonstrated herein was elaborated starting from a spectral characterization of the complex systems involved. Due to the long lifetime of lanthanide luminescence, both steady-state and time-resolved luminescence assays can easily be performed. The time-resolved assay can quantify POx in the range from 4.0×10−5 to 5.9×10−3 U mL−1, with a limit of detection of 1.0×10−5 U mL−1. The effects of POx inhibitors such as cyanide, hydroxylamine, and azide have also been studied. In addition, a time-resolved fluorescent detection method for a POx-based enzyme-linked immunosorbent assay (ELISA) has been developed, which is demonstrated in a sandwich model assay with bovine IgG serving as analyte. Furthermore, a time-resolved fluorescent imaging method is demonstrated that makes use of a straightforward imaging set-up adjusted to the optical properties of the europium reagent.
Microtiter plate assay for phosphate using a europium–tetracycline complex as a sensitive luminescent probe
Creators: name: Dürkop, Axel
name: Turel, Matejka
name: Lobnik, Aleksandra
name: Wolfbeis, Otto S.
Publisher: name: Universität Regensburg
Year: 2006
Subjects: subject: Phosphate; Microplate assay; Luminescence; Lanthanide
subject: 540 Chemie

description: A new luminescent europium probe is presented for the determination of phosphate (P) in microtiter plate format. The assay is based on the quenching of the luminescence of the europium–tetracycline (EuTc) 1:1 complex by phosphate using a reagent concentration of 20.8 μmol/L. The probe is excited at 400 nm and displays a large Stokes’ shift of 210 nm. The emission maximum is located at 616 nm. The system works best at neutral pH 7 and is therefore suitable for phosphate determination in biological and biochemical systems. The linear range of the calibration plot is from 5 × 10−6 mol/L to 7.5 × 10−4 mol/L of phosphate, and the limit of detection is 3 μmol/L.
Frequency-modulated combs via on-chip field enhancement
Creators: name: Senica, Urban
name: Dikopoltsev, Alexander
name: Forrer, Andres
name: Cibella, Sara
name: Torrioli, Guido
name: Beck, Mattias
name: Faist, Jérôme
name: Scalari, Giacomo
Publisher: name: arXiv
Year: 2023
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Frequency-modulated (FM) combs feature flat intensity spectra with a linear frequency chirp, useful for metrology and sensing applications. Generating FM combs in semiconductor lasers generally requires a fast saturable gain, usually limited by the intrinsic gain medium properties. Here, we show how a spatial modulation of the laser gain medium can enhance the gain saturation dynamics and nonlinearities to generate self-starting FM combs. We demonstrate this with tapered planarized THz quantum cascade lasers (QCLs). While simple ridge THz QCLs typically generate combs which are a mixture of amplitude and frequency modulation, the on-chip field enhancement resulting from extreme spatial confinement leads to an ultrafast saturable gain regime, generating a pure FM comb with a flatter intensity spectrum, a clear linear frequency chirp and very intense beatnotes up to -30 dBm. The observed linear frequency chirp is reproduced using a spatially inhomogeneous mean-field theory model which confirms the crucial role of field enhancement. In addition, the modified spatial temperature distribution within the waveguide results in an improved hightemperature comb operation, up to a heat sink temperature of 115 K, with comb bandwidths of 600 GHz at 90 K. The spatial inhomogeneity also leads to dynamic switching between various harmonic states in the same device.
description: 9 pages, 6 figures; corrected reference typos
Optical Sensing and Imaging of Trace Oxygen with Record Response
Creators: name: Nagl, Stefan
name: Baleizão, Carlos
name: Borisov, Sergey M.
name: Schäferling, Michael
name: Berberan-Santos, Mário N.
name: Wolfbeis, Otto S.
Publisher: name: Universität Regensburg
Year: 2007
Subjects: subject: fullerenes; imaging; oxygen sensors; polymers; time-resolved fluorescence
subject: 540 Chemie

description: Ultratrace quantities of oxygen can be determined at single spots as well as spatially resolved, and over a temperature range of more than 100 K, by exploiting the extremely efficient quenching of the delayed fluorescence of the fullerene C70 incorporated into matrices of organosilica or ethyl cellulose.
Direct Observation of Band-Gap Closure for a Semiconducting Carbon Nanotube in a Large Parallel Magnetic Field
Creators: name: Jhang, Sung Ho
name: Marganska, Magdalena
name: Skourski, Y.
name: Preusche, Dominik
name: Grifoni, Milena
name: Wosnitza, Joachim
name: Strunk, Christoph
Publisher: name: Universität Regensburg
Year: 2011
Subjects: subject: 530 Physik

description: We have investigated the magnetoconductance of semiconducting carbon nanotubes (CNTs) in pulsed, parallel magnetic fields up to 60 T, and report the direct observation of the predicted band-gap closure and the reopening of the gap under variation of the applied magnetic field. We also highlight the important influence of mechanical strain on the magnetoconductance of the CNTs.
A Dual Luminescent Sensor Material for Simultaneous Imaging of Pressure and Temperature on Surface
Creators: name: Stich, Matthias I. J.
name: Nagl, Stefan
name: Wolfbeis, Otto S.
name: Henne, Ulrich
name: Schäferling, Michael
Publisher: name: Universität Regensburg
Year: 2008
Subjects: subject: europium; imaging; luminescence; porphyrin; platinum; rare-earth complexes; sensorss
subject: 540 Chemie

description: A novel kind of composite material for simultaneous luminescent determination of air pressure and temperature is presented. The dual sensor consists of a fluorinated platinum porphyrin complex (PtTFPP) as an oxygen-sensitive probe, and of the highly temperature-sensitive europium complex Eu(tta)3(dpbt) as temperature probe. Both are incorporated into different polymer microparticles to control response characteristics and to avoid interferences. Encapsulation of PtTFPP in poly(styrene-co-acrylonitrile) (PSAN) results in a broad dynamic range from 0.05 to 2.00 bar for pressure measurements. The europium complex was incorporated into poly(vinyl chloride) to reduce the cross sensitivity towards oxygen. This system represents a new class of luminescent sensor system, where the signals are separated via the different luminescence lifetimes of the indicators. It is possible to monitor the emission of the temperature-sensitive probe by means of time-resolved fluorescence imaging without interferences, because the luminescence lifetime of the temperature indicator is tenfold longer than that of the oxygen indicator. The temperature image can then be used to compensate cross sensitivity of the pressure indicator towards temperature. In combination with an appropriate time-resolved measurement technique, this material enables simultaneous imaging of pressure (or oxygen partial pressure) and temperature distributions on surfaces. It is distinguished from other approaches of dual pressure and temperature sensitive paints because it avoids the need of signal separation by application of different cameras or by use of different optical filters or light sources.
Remarks on Boundaries, Anomalies, and Noninvertible Symmetries
Creators: name: Choi, Yichul
name: Rayhaun, Brandon C.
name: Sanghavi, Yaman
name: Shao, Shu-Heng
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Algebra (math.QA)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: What does it mean for a boundary condition to be symmetric with respect to a non-invertible global symmetry? We discuss two possible definitions in 1+1d. On the one hand, we call a boundary weakly symmetric if the symmetry defects can terminate topologically on it, leading to conserved operators for the Hamiltonian on an interval (in the open string channel). On the other hand, we call a boundary strongly symmetric if the corresponding boundary state is an eigenstate of the symmetry operators (in the closed string channel). These two notions of symmetric boundaries are equivalent for invertible symmetries, but bifurcate for non-invertible symmetries. We discuss the relation to anomalies, where we observe that it is sometimes possible to gauge a non-invertible symmetry in a generalized sense even though it is incompatible with a trivially gapped phase. The analysis of symmetric boundaries further leads to constraints on bulk and boundary renormalization group flows. In 2+1d, we study the action of non-invertible condensation defects on the boundaries of $U(1)$ gauge theory and several TQFTs. Starting from the Dirichlet boundary of free Maxwell theory, the non-invertible symmetries generate infinitely many boundary conditions that are neither Dirichlet nor Neumann.
description: 71 pages, 31 figures, 2 tables
Additive actions on hyperquadrics of corank two
Creators: name: Liu, Yingqi
Publisher: name: arXiv
Year: 2022
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14L30 (Primary) 14J50, 15A69 (Secondary)

description: For a projective variety $X$ in $\mathbb{P}^{m}$ of dimension $n$, an additive action on $X$ is an effective action of $\mathbb{G}_{a}^{n}$ on $\mathbb{P}^{m}$ such that $X$ is $\mathbb{G}_{a}^{n}$-invariant and the induced action on $X$ has an open orbit. Arzhantsev and Popovskiy have classified additive actions on hyperquadrics of corank 0 or 1. In this paper, we give the classification of additive actions on hyperquadrics of corank 2 whose singularities are not fixed by the $\mathbb{G}_{a}^{n}$-action.
Entanglement perturbation theory for the elementary excitation in one dimension
Creators: name: Chung, Sung Gong
name: Wang, Lihua
Publisher: name: arXiv
Year: 2010
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The entanglement perturbation theory is developed to calculate the excitation spectrum in one dimension. Applied to the spin-$\frac{1}{2}$ antiferromagnetic Heisenberg model, it reproduces the des Cloiseaux-Pearson Bethe ansatz result. As for spin-1, the spin-triplet magnon spectrum has been determined for the first time for the entire Brillouin zone, including the Haldane gap at $k=π$.
Europium Tetracycline as a Luminescent Probe for Nucleoside Phosphates and Its Application to the Determination of Kinase Activity
Creators: name: Schäferling, Michael
name: Wolfbeis, Otto S.
Publisher: name: Universität Regensburg
Year: 2007
Subjects: subject: ATP; fluorescent probes; kinases; lanthanides; phosphorylation
subject: 540 Chemie

description: The determination of enzyme activities and the screening of enzyme regulators is a major task in clinical chemistry and drug development. A broad variety of enzymatic reactions is associated with the consumption of adenosine triphosphate (ATP), including, in particular, phosphorylation reactions catalyzed by kinases, formation of adenosine cyclic monophosphate (cAMP) by adenylate cyclases, and ATP decomposition by ATPase. We have studied the effect of a series of adenosine (ATP, ADP, AMP, cAMP) and guanosine (GTP, GDP) phosphoric esters, and of pyrophosphate (PP) on the fluorescence emission of the europium tetracycline (EuTC) complex. We found that these compounds have strongly different quenching effects on the luminescence emission of EuTC. The triphosphates ATP and GTP behave as strong quenchers in reducing the fluorescence intensity of EuTC to 25 % of its initial value by formation of a ternary 1:1:1 complex. All other phosphate esters showed a weak quenching effect only. The applicability of this fluorescent probe to the determination of the activity of phosphorylation enzymes is demonstrated by means of creatine kinase as a model for non-membrane-bound kinases. In contrast to other methods, this approach does not require the use of radioactively labeled ATP substrates, additional enzymes, or of rather complex immunoassays.