gebhart/patrepeval huggingface dataset:
Constrained Reinforcement Learning and Formal Verification for Safe Colonoscopy Navigation (2023)

The field of robotic Flexible Endoscopes (FEs) has progressed significantly, offering a promising solution to reduce patient discomfort. However, the limited autonomy of most robotic FEs results in non-intuitive and challenging manoeuvres, constraining their application in clinical settings. While previous studies have employed lumen tracking for autonomous navigation, they fail to adapt to the presence of obstructions and sharp turns when the endoscope faces the colon wall. In this work, we propose a Deep Reinforcement Learning (DRL)-based navigation strategy that eliminates the need for lumen tracking. However, the use of DRL methods poses safety risks as they do not account for potential hazards associated with the actions taken. To ensure safety, we exploit a Constrained Reinforcement Learning (CRL) method to restrict the policy in a predefined safety regime. Moreover, we present a model selection strategy that utilises Formal Verification (FV) to choose a policy that is entirely safe before deployment. We validate our approach in a virtual colonoscopy environment and report that out of the 300 trained policies, we could identify three policies that are entirely safe. Our work demonstrates that CRL, combined with model selection through FV, can improve the robustness and safety of robotic behaviour in surgical applications.
Student-Led Engagement of Journal Article Authors in the Classroom Using Web-Based Videoconferencing (2014)

The learning environment described here uses Web-based videoconferencing technology to merge the traditional classroom journal article discussion with student-led interviews of journal article authors. Papers that describe recent applications of a given technique are selected, with the author engagement occurring at the end of a three or four week module covering the technique and its applications. Students prepare for the author engagements by reading the paper, discussing it as a class with the instructor, and developing a set of consensus questions to provide a framework for their conversation. Authors do not make formal presentations to the students, but instead answer questions. The smaller class sizes of upper-division undergraduate courses provide an intimate setting for these student-led conversations. Author engagements are designed to improve critical thinking skills in the content areas studied, improve interactive scientific communication skills, build scientific self-confidence in young scientists, and expose students to established scientist role models. The student–author interactions described here provide a cost-effective mechanism to expose students to diverse areas of chemistry and to bring expert scientists into the classroom. In situations where videoconferencing is not available or permitted, teleconferences provide a reasonable substitution.
Reintroducing the concept of force into relativity theory (1979)

It is suggested that re-introducing forces into relativity theory may provide new insights and results. A look at the Kerr-Newmann geometry, and special cases of it, from this viewpoint indicates that there can be a short range repulsion in general. This repulsion suggests that naked singularities may be physically feasible. It is also found that there is a gravito-electric repulsion which would be important to consider in a grand unification scheme of strong, weak and electromagnetic forces. 8 references.
A Real Time Coincidence System for High Count-Rate TOF or Non-TOF PET Cameras Using Hybrid Method Combining AND-Logic and Time-Mark Technology (2010)

A fully digital FPGA-based high count-rate coincidence system has been developed for TOF (Time of Flight) and non-TOF PET cameras. Using a hybrid of AND-logic and Time-mark technology produced both excellent timing resolution and high processing speed. In this hybrid architecture, every gamma event was synchronized by a 125 MHz system clock and generating a trigger associated with a time-mark given by an 8-bit high-resolution TDC (68.3 ps/bin). AND-logic was applied to the synchronized triggers for the real-time raw sorting of coincident events. An efficient FPGA based Time-mark fine-sort algorithm is used to select all the possible coincidence events within the preset coincidence time window. This FPGA-based coincidence system for a modular PET camera offers reprogrammable flexibility and expandability, so the coincidence system is easily employed, regardless of differences in the scale of the PET camera detector setup. A distributed processing method and pipeline technology were adopted in the design to obtain very high processing speed. In this design, both prompt and time-delayed accidental coincidences are simultaneously processed in real time. The real-time digital coincidence system supports coincidence in 2 to 12 detector module setups, capable of processing 72 million single events per second with no digital data loss and captures multiple-event coincidence for better imaging performance evaluation. The coincidence time window-size and time-offset of each coincidence event pair can be programmed independently in 68.3 ps increments (TDC LSB) during the data acquisition in different applications to optimize the signal-to-noise ratio. The complex coincidence system is integrated in one circuit board with 1.5 Gbps fiber optic interface. We demonstrated the system performance using the actual circuit and Monte Carlo simulations.
Imaging properties of axicon in a scanning optical system (1992)

The imaging properties of a scanning optical system that incorporates an axicon are presented. Beamshape characteristics including the axial distribution of the J(0) beam and its control and aberration effects arising from off-axis illumination are experimentally studied. These parameters are relevant when the axicon is used in an imaging system operating in the beam-scanning mode. The J(0) pattern produced by a blazed axicon transmittance grating is also presented.
Development of digoxin dry elixir as a novel dosage form using a spray-drying technique (1995)

A rapidly absorbed new novel oral dosage form for digoxin termed 'digoxin dry elixir' was developed by the spray-drying technique. Digoxin, dextrin and sodium lauryl sulphate were dissolved in a ethanol-water mixture (20:25 w/w) and therefore spray-dried to form the digoxin dry elixir. According to scanning electron micrographs, digoxin dry elixir is spherical in shape with a smooth surface. The geometric mean diameter of dry elixir determined by laser particle size analysis was about 13 microns. The appearance and flow properties were almost unchanged and about 10% of ethanol contents in the dry elixir decreased during 180 days in a sealed bottle at room temperature. Comparative studies on the in vitro dissolution and in vivo absorption of digoxin in the form of digoxin dry elixir, digoxin elixir and digoxin powder were carried out. Digoxin in the dry elixirs was completely dissolved within 2 min. On the other hand, only about 87% of digoxin powder dissolved in 60 min. The initial dissolution rates of digoxin in the dry elixirs markedly increased in distilled water at 37 degrees C, which were over 100 fold higher than that of digoxin powder alone. The maximal plasma concentration of digoxin (Cmax) and area under the digoxin concentration-time curve from zero to 6 h (AUC0-6h) after the oral administration of digoxin dry elixir were almost 3.8 and 5.5 fold increased compared to digoxin powder alone. No significant difference of AUC0-6 h between dry elixir and elixir was observed, but the Cmax of digoxin in the form of dry elixir was significantly reduced compared to the digoxin elixir (0.57 versus 0.83). Digoxin dry elixir might be a useful solid dosage form to improve the dissolution rate and bioavailability of poorly water-soluble digoxin compared to digoxin powder alone. It also indicates that dry elixir might reduce the side effects in oral digitalis glycoside therapy compared to the digoxin elixir due to the reduction of Cmax.
High performance liquid chromatographic assays of the illicit designer drug "Ecstasy", a modified amphetamine, with applications to stability, partitioning and plasma protein binding. (1991)

Specific, sensitive, reverse-phase high-performance liquid chromatographic (HPLC) assays of 3,4-methylenedioxymethamphetamine (MDMA) and 3,4-methylenedioxyamphetamine (MDA) have been devised with analytical sensitivities as low as 2.7 ng/ml of plasma for MDMA and 1.6 ng/ml for MDA, using spectrophotometric detection at 280 nm. The assays were used to determine some properties of MDMA and MDA. Both drugs were stable in aqueous 1 M HCl, and 1 M NaOH solutions at room temperature. The half-life for MDMA was 6.6 h and for MDA was 7.1 h under the extreme conditions of 90 degrees C and 6 M HCl. MDMA and MDA were highly stable for 28 h in plasma at 25 degrees and 39 degrees C. The concentrations of the drugs were unchanged in frozen plasma after 47 days. The apparent red blood cell-plasma partition coefficient determined from assayed concentrations of the drugs in plasma and erythrocytes was 1.45 for both MDMA and MDA. An equation is presented to correct drug concentration in erythrocytes for the trapped equilibrated plasma/buffer in the packed red blood cells. The fraction of MDMA and MDA bound to dog plasma proteins was determined by several methods and it is 0.34-0.40 for both drugs. The extent of protein binding was independent of the drugs' concentration.
Vertical Integration Technologies for Optical Transmissive 3-D Microscanner based on Glass Microlenses (2012)

This paper describes crucial technological aspects of development of an optical, transmissive, vertically-integrated 3-D microscanner: chip-level bonding of micro-optical components and wafer-level anodic bonding of deeply structurized substrates. We present two methods of hybrid integration of glass microlenses with fragile movable parts of silicon microactuators, based on glass frit bonding or direct thermal bonding, that have been experimentally validated in terms of bonding strength, anodic bonding compatibility and change of optical performance of microlens. We also demonstrate the 3D stacking technology, based on sequential multi-level anodic bonding, successfully tested with deeply structurized silicon/glass wafers. Presented methods are of general importance for vertically integrated M(O)EMS Si/glass devices.
5-HIAA in the Cerebrospinal Fluid (1976)

The incidence of suicidal acts was studied in 68 depressed patients and related to the level of 5-hydroxyindoleacetic acid (5-HIAA) in the cerebrospinal fluid. The distribution of 5-HIAA levels was bimodal. Patients in the low 5-HIAA mode (below 15 ng/ml) attempted suicide significantly more often than those in the high mode, and they used more violent means. Two of the 20 patients in the low mode, and none of the 48 patients in the high mode died from suicide.
RIS Assisted Wireless Powered IoT Networks With Phase Shift Error and Transceiver Hardware Impairment (2022)

Considering a reconfigurable intelligent surface (RIS) aided wireless powered Internet of Things (WP IoT) network. To address the energy-limitation issue, IoT devices in such a network can be wirelessly powered by a power station (PS) first and then connect with an access point (AP) using their own harvested energy. The RIS helps enhance energy and information receptions in the downlink wireless energy transfer (WET) and uplink wireless information transfer (WIT), respectively. This work unveils the impact of phase shift error (PSE) and transceiver hardware impairment (THI) on the considered network. Our investigation starts with a scenario where only the impact of the PSE on system under study is considered, then moves toward a scenario with the compound effect of both PSE and THI. A maximization problem of the system sum throughput is formulated to evaluate the overall performance for these two scenarios, subject to the constraints of the adjustable RIS phase shifts, the statistical PSE and the transmission time scheduling. To handle the non-convexity of the formulated problem due to those coupled variables, we first adopt the Lagrange dual method and Karush-Kuhn-Tucker (KKT) conditions to derive the optimal time scheduling in closed-form. Next, we recast the stochastic PSE into the deterministic counterpart for its tractability. Then, we adopt a successive convex approximation (SCA) to iteratively derive the optimal WIT’s phase shifts, and element-wise block coordinate decent (EBCD) and complex circle manifold (CCM) methods to iteratively derive the optimal WET’s phase shifts. Finally, we complete our solution approach for the scenario with both PSE and THI. Simulation results highlight the performance of the proposed scheme and the benefits induced by the RIS in comparison to benchmark schemes.
Performance of antenna diversity reception with correlated Rayleigh fading signals (2003)

This paper studies the performance of antenna diversity reception with selection combining (SC) and maximal ratio combining (MRC) in a correlated Rayleigh fading environment. Simple PDF expressions are derived for the output SNR of the SC and MRC diversity receivers. Based on the PDF, the average BERs for DPSK and NCFSK modulation are calculated to show the effects of the correlation. Moreover, the relationship between the average BER and the diversity antennas' separation is given. The presented numerical results show that SC and MRC diversity reception can achieve a good performance only if the distance between two diversity antennas is larger than 0.3/spl lambda/.
The use of PEG-Hirudin in chronic hemo-dialysis monitored by the Ecarin Clotting Time: influence on clotting of the extracorporeal system and hemostatic parameters (2006)

The aim of our study was to investigate the use of polyethylene glycol (PEG)-Hirudin (PEG-H) as an anticoagulant in hemodialysis including drug monitoring with the Ecarin Clotting Time (ECT) in whole blood and to compare this regimen with standard anticoagulant unfractionated heparin (UFH) for influence on hemostatic parameters and clot frequency of the extracorporeal system.The application of PEG-H as an anticoagulant in patients on chronic HD was studied in 20 patients (12 males, 8 females) from a single center in an exploratory, open-label, controlled, single-blind, dose-finding study. The patients were divided in 2 groups with 10 patients each (Group I and II); both received 3 dialyses with UFH, thereafter Group I received 5 dialyses with PEG-H and Group II 10 dialyses with PEG-H. Starting dose of PEG-H in the first dialysis was a bolus of 0.08 mg/kg bwt, the mean dose of the following HD was 0.041 mg/kg bwt (range 0.026 0.065 mg/kg bwt). PEG-H was applied as an intravenous bolus-dose followed by a 0.9% saline as a placebo-infusion. HD was performed regularly 3 times a week. All dialysis treatments were performed exclusively with a hollow fiber dialyzer type. Fibrinogen, antithrombin III, prothrombin fragments, thrombin-antithrombin and soluble fibrin were measured with commercial tests. ECT was determined in a mechanical coagulometer. A semiquantitative score was given for the presence of clots in the extracorporeal system after each dialysis.PEG-H was effectively used as an anticoagulant in 150 chronic dialysis treatments using ECT as a simple monitoring method. The optimal whole blood concentration for PEG-H is 600-1000 ng/ml. Clotting in the whole extracorporeal system was decreased by 45% (p = 0.059) with PEG-H anticoagulated HD in comparison to UFH. Fibrinogen, prothrombin fragments (F1+2-fragments) and thrombin-antithrombin-complex showed no significant change in comparison with UFH, antithrombin III (AT III) increased to normal concentrations. Highly sensitive coagulation markers such as a soluble fibrin showed a significant decrease (p < 0.001) before and after HD with PEG-H compared with UFH.PEG-H can be used effectively as an alternative anticoagulant in patients on chronic HD using ECT as a simple drug monitoring method. The lower frequency of clots in the extracorporeal system, the stronger and more efficient inhibition of coagulation during HD as indicated by soluble fibrin, may have a positive influence on the disturbed blood coagulation of these patients.
Mechanistic Aspects of Cobalt–Oxo Cubane Clusters in Oxidation Chemistry (2022)

Cobalt oxides are recognized as one of the most efficient earth-abundant catalysts for challenging oxidation chemistry, with substrates ranging from water to organic compounds. In these oxidations, cobalt-oxo species with formal oxidation states greater than 3 are commonly invoked as reactive intermediates. However, there is a dearth of mechanistic information regarding how these high-valent cobalt catalysts operate. This Perspective describes how the study of molecular cobalt oxo clusters, with an emphasis on [Co<sub>4</sub>O<sub>4</sub>] oxo cubane complexes, has helped to shed light on the operative mechanisms of cobalt-catalyzed oxidation reactions. Implications for high-valent Co<sup>IV</sup>-oxo and Co<sup>V</sup>-oxo intermediates and remaining mechanistic questions concerning how these intermediates mediate O-O bond formation are also discussed. Furthermore, structural modifications of these oxo cubane clusters (i.e., incorporation of heteroatoms and modulation of ligands) have provided insight into multimetallic cooperativity, but the influence of such metal-metal interactions on oxidation activity remains to be explored. A more detailed understanding of these structure-activity relationships may enable fine-tuning of reactivity and stability of synthetic multimetallic catalysts for energy storage and challenging organic transformations.
Mitral Valve Diseases (2006)

This DOI is not currently attached to any metadata records. DOIs can’t actually ever be deleted (they’re persistent), but sometimes our members create DOIs in error. We do have a process to approximate deletion which we follow only in rare cases where the DOI has been genuinely created in error, and most crucially, if the DOI has never been published anywhere online or in print and never otherwise distributed to or communicated with anyone (authors, readers, reviewers, etc.
Germline pharmacogenomics of thymidylate synthase gene in patients with gastrointestinal malignancies treated with fluoropyrimidines-based chemotherapy regimens. (2019)

545 Background: Fluoropyrimidines are antimetabolites that target the S phase of the cell cycle. The active metabolite, 5-fluorodeoxyuridine monophosphate inhibits thymidylate synthase (TS) enzyme, thus preventing DNA synthesis and ultimately cell death. While controversy exists in the literature, polymorphism in the promoter region of thymidylate synthase gene (TYMS) that decrease TS expression has been associated with increased fluoropyrimidines-associated toxicities. This study explored the association between polymorphism in the promoter region of TYMS gene and fluoropyrimidines-associated toxicities in patients with gastrointestinal malignancies with mixed racial background. Methods: Between 2011 and 2018, 126 patients were genotyped for TYMS. Patients with known high-risk dihydropyrimidine dehydrogenase gene variants were excluded. Fluoropyrimidines-associated toxicity was graded according to the National Cancer Institiute Common Terminology Criteria for Adverse Events (v 5.0). Fisher’s exact test was used for statistical analysis. Results: TYMS genotypes that predict increased TS expression (3RG/3RG, 3RG/3RC, 2R/3RG, 2R/4R, 3R/4R, 4R/3RG) were identified in 55 patients (44%). TYMS genotypes that predict decreased TS expression (2R/2R, 2R/3RC, 3RC/3RC) were seen in 71 patients (56%). Among patients with genotypes that predict increased TS expression (N = 55), 12 patients had grade 3-4 toxicity (22%) while among patients with genotypes that predict decreased TS expression, 30 patients had grade 3-4 toxicities (42%) (P = 0.0219). Compared to patients with genotypes predicting increased TS expression, 17 out of 31 patients (55%) with 2R/2R TYMS genotype had grade 3-4 toxicity (P = 0.0039) and 15 out 40 patients (38%) with 2R/3RC and 3RC/3RC TYMS genotype had grade 3-4 toxicity (P = 0.1108). Among patients with 2R/2R TYMS, Caucasians represented 61% and African Americans represented 39%. Females represented 65% of the patients. Conclusions: Polymorphism in the promoter region of TYMS gene that predict decreased TS expression due to 2R/2R variant was associated with grade 3-4 fluoropyrimidines-associated toxicities.
Autonomic position-based QoS routing protocol for mobile wireless networks with a cross-layerarchitecture (2010)

The provision of Quality of Service (QoS) over wireless networks has recently been the subject of intensive research. The emerging solutions recommend combining the cross-layer and the autonomic paradigms. Most proposed cross-layer solutions consider purely local information in their adaptations and do not care about the effects of such egoistic behavior on other network nodes. This non-collaborative behavior limits the overall system performance. In this work, we develop a new QoS routing protocol called QoS-PAR (QoS Position Aided Routing protocol) to prove the importance of combining cross-layering and adaptations based on network knowledge for autonomous organization of wireless networks. QoS-PAR integrates admission control as well as resources reservation mechanisms. We consider two QoS metrics: the minimum required bandwidth and the maximum end to end delay. The bandwidth availability test takes into account the intra-flow interference and the interferences of one hop as well as the carrier sensing neighbors. To evaluate the efficiency of our proposal, extensive simulations have been done. Results show, that our XLEngine-based QoS-PAR protocol significantly outperforms the AODV protocol, which is based on the TCP/IP layered architecture.
Macromedia director as a prototyping and usability testing tool (2000)

article Free Access Share on Macromedia director as a prototyping and usability testing tool Author: Stephanie Ludi View Profile Authors Info & Claims XRDS: Crossroads, The ACM Magazine for StudentsVolume 6Issue 5August 2000 - Late Summer Edition pp 7–eshttps://doi.org/10.1145/345107.345118Published:15 July 2000Publication History 0citation195DownloadsMetricsTotal Citations0Total Downloads195Last 12 Months26Last 6 weeks2 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my Alerts New Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteView all FormatsPDF
A Strip Adjustment Approach for Precise Georeferencing of ALOS Optical Imagery (2009)

Precise georeferencing is one of the prerequisites for orthoimage generation from high-resolution satellite imagery. This requires the availability of a small number of GCPs that have to be visible in each scene. In this paper, it is shown how the number of GCPs required for the precise georeferencing of Advanced Land Observation Satellite (ALOS) imagery can be reduced by up to 90% using a generic pushbroom sensor model and strip adjustment while still achieving an accuracy of better than 1 pixel. A fully automatic work flow requiring an existing digital orthophoto and a digital elevation model (DEM) is also presented. Using an orthophoto mosaic generated from Landsat-7 panchromatic imagery for automatic GCP measurement, pixel-level accuracy can be achieved for images from the Advanced Visible and Near Infrared Radiometer type 2 (AVNIR-2) instrument. For images from the Panchromatic Remote-sensing Instrument for Stereo Mapping (PRISM), the accuracy of the automated procedure is only about 2 pixels due to the poor resolution of the orthoimage, compared with PRISM.