cssi/SciSciGPT-SciSciNet huggingface dataset:
A hidden semi-Markov model with missing data and multiple observation sequences for mobility tracking

A hidden Markov model (HMM) encompasses a large class of stochastic process models and has been successfully applied to a number of scientific and engineering problems, including speech and other pattern recognition problems, and DNA sequence comparison. A hidden semi-Markov model (HSMM) is an extension of HMM, designed to remove the constant or geometric distributions of the state durations assumed in HMM. A larger class of practical problems can be appropriately modeled in the setting of HSMM. A major restriction is found, however, in both conventional HMM and HSMM, i.e., it is generally assumed that there exists at least one observation associated with every state that the hidden Markov chain takes on. We will remove this assumption and consider the following situations: (i) observation data may be missing for some intervals; and (ii) there are multiple observation streams that are not necessarily synchronous to each other and may have different "emission distributions" for the same state. We propose a new and computationally efficient forward-backward algorithm for HSMM with missing observations and multiple observation sequences. The required computational amount for the forward and backward variables is reduced to O(D), where D is the maximum allowed duration in a state. Finally, we will apply the extended HSMM to estimate the mobility model parameters for the Internet service provisioning in wireless networks.
Adaptation to Visuomotor Rotation Through Interaction Between Posterior Parietal and Motor Cortical Areas

Studying how motor adaptation to visuomotor rotation for one reach direction generalizes to other reach directions can provide insight into how visuomotor maps are represented and learned in the brain. Previous psychophysical studies have concluded that postadaptation generalization is restricted to a narrow range of directions around the training direction. A population-coding model that updates the weights between narrow Gaussian-tuned visual units and motor units on each trial reproduced experimental trial-by-trial learning curves for rotation adaptation and the generalization function measured postadaptation. These results suggest that the neurons involved in rotation adaptation have a relatively narrow directional tuning width (∼23°). Population coding models with units having broader tuning functions (such as cosine tuning in motor cortex and Gaussian sum in the cerebellum) could not reproduce the narrow single-peaked generalization pattern. Visually selective neurons with narrow Gaussian tuning curves have been identified in posterior parietal cortex, making it a possible site of adaptation to visuomotor rotation. We propose that rotation adaptation proceeds through changes in synaptic weights between neurons in posterior parietal cortex and motor cortex driven by a prediction error computed by the cerebellum.
Peer Status and Victimization as Possible Reinforcements of Adolescent Girls’ and Boys’ Weight-Related Behaviors and Cognitions

Objective Reciprocal longitudinal associations among weight-related behaviors and cognitions and peer relations constructs were examined among adolescent males and females. Methods Participants included 576 adolescents aged 10–14 years, in grades 6–8. Measures assessed body dissatisfaction, negative weightrelated cognitions, weight management behaviors, muscle-gaining behaviors, body mass index (BMI), likeability, popularity, and victimization at two time points, approximately 11 months apart. Multiple group path analyses were conducted to examine the reciprocal longitudinal associations between the peer relations constructs and weight-related behaviors and cognitions, controlling for participants’ Time 1 BMI, pubertal development, and age. Results Higher levels of body dissatisfaction were associated longitudinally with decreases in popularity. Higher popularity and lower likeability each were associated longitudinally with increases in negative body-related cognitions. Higher popularity was associated longitudinally with muscle-gaining behaviors for boys. Conclusions Findings suggest highly popular and disliked adolescents may be at greater risk of weight-related behaviors and cognitions than other adolescents.
Discrimination learning and extinction in toads1

Toads (Bufo woodhousii woodhousii and Bufo valliceps) were trained for position discrimination in a T maze. One hundred-ninety acquisition trials were followed by 40 extinction trials. The curve obtained differed somewhat from the usual mammalian results. The Ss were performing at 60% correct response level at the end of the acquisition trials and extinguished very rapidly. The study also indicated species differences in adaptability to the lab situation.
Measuring the user acceptance of generic manufacturing simulation models by review of modeling assumptions

A measure of user acceptance for generic discrete manufacturing models is introduced. This measure is based on review of modeling assumptions and computed as the percentage of assumptions that are acceptable to the user. The assumptions, which describe the modeling options that are available in generic models, give the user a detailed account of the capabilities and limitations of the generic models. The assumption review process and the user acceptance measure are implemented within the framework of an intelligent simulation environment. GUIDES, an expert system, guides the user through the review of assumptions and generates the user acceptance scores. It is concluded that, although certain modifications can be made in the generic models to eliminate some of the rejections concerning the assumptions, the model acceptance, in general, is fairly high (91.78%). >
User-centric Web crawling

Search engines are the primary gateways of information access on the Web today. Behind the scenes, search engines crawl the Web to populate a local indexed repository of Web pages, used to answer user search queries. In an aggregate sense, the Web is very dynamic, causing any repository of Web pages to become out of date over time, which in turn causes query answer quality to degrade. Given the considerable size, dynamicity, and degree of autonomy of the Web as a whole, it is not feasible for a search engine to maintain its repository exactly synchronized with the Web.In this paper we study how to schedule Web pages for selective (re)downloading into a search engine repository. The scheduling objective is to maximize the quality of the user experience for those who query the search engine. We begin with a quantitative characterization of the way in which the discrepancy between the content of the repository and the current content of the live Web impacts the quality of the user experience. This characterization leads to a user-centric metric of the quality of a search engine's local repository. We use this metric to derive a policy for scheduling Web page (re)downloading that is driven by search engine usage and free of exterior tuning parameters. We then focus on the important subproblem of scheduling refreshing of Web pages already present in the repository, and show how to compute the priorities efficiently. We provide extensive empirical comparisons of our user-centric method against prior Web page refresh strategies, using real Web data. Our results demonstrate that our method requires far fewer resources to maintain same search engine quality level for users, leaving substantially more resources available for incorporating new Web pages into the search repository.
Evaluation of PFO formation from the biodegradation of a fluorotelomer-based urethane polymer product in aerobic soils

Abstract This study is the first to evaluate the rate of formation of perfluorooctanoate (PFO) from the aerobic biodegradation of a fluorotelomer-based urethane polymer and to use this information to assess the global environmental significance of this source. A fluorotelomer-based urethane polymer product test substance was studied in four aerobic soils over two years to determine the rate at which the fluorotelomer side-chains covalently bonded to the polymer backbone were cleaved and subsequently transformed to form the anions of perfluorocarboxylic acids including PFO. Over the two year duration of the experimental study, a polymer biodegradation half-life of 102 years (range: 28–241) was calculated for the urethane polymer based on regression analysis of the rate of PFO formation in four test soils. When this half-life was applied to the estimated total historic production, use and disposal of fluorotelomer-based urethane polymer, the annual potential global generation of PFO was estimated to be less than one tonne per year.
Graph embedding and nonlinear dimensionality reduction

Traditionally, spectral methods such as principal component analysis (PCA) have been applied to many graph embedding and dimensionality reduction tasks. These methods aim to find low-dimensional representations of data that preserve its inherent structure. However, these methods often perform poorly when applied to data which does not lie exactly near a linear manifold. In this thesis, I present a set of novel graph embedding algorithms which extend spectral methods, allowing graph representations of high-dimensional data or networks to be accurately embedded in a low-dimensional space. I first propose minimum volume embedding (MVE) which, like other leading dimensionality reduction algorithms, first encodes the high-dimensional data as a nearest-neighbor graph, where the edge weights between neighbors correspond to kernel values between points, and then embeds this graph in a low-dimensional space. Next I present structure preserving embedding (SPE), an algorithm for embedding unweighted graphs where similarity between nodes is not known. SPE finds low-dimensional embeddings which explicitly preserve graph topology, meaning a connectivity algorithm, such as k-nearest neighbors, will recover the edges of the input graph from only the coordinates of the nodes after embedding. I further explore preserving graph structure during embedding, and find the concept applicable to dimensionality reduction, large-scale network visualization, and metric learning for link prediction. This thesis posits that simply preserving pairwise distances, as with many spectral methods, is insufficient for capturing the structure of many datasets and that preserving both local distances and graph topology is crucial for producing accurate low-dimensional representations of networks and high-dimensional data.
Iterative technique for the synthesis of optical-correlation filters

Optical-correlation filters that are translationally and rotationally invariant are made target specific by incorporating all the angular harmonics of the target image. An iterative design method similar to the technique of convex projections allows the image angular harmonics to be rephased so that the filter exhibits a constant-amplitude rotational response. Rotating this filter in the Fourier plane forms the Fourier summation of all angular harmonics of the input image. Ari image to be detected must have angular-harmonic terms that have an amplitude and a phase that are keyed exactly to the target image. This lock-and-tumbler filter exhibits excellent discrimination capability while preserving rotational invariance.
Ecological genetics of range size variation in Boechera spp. (Brassicaceae)

Many taxonomic groups contain both rare and widespread species, which indicates that range size can evolve quickly. Many studies have compared molecular genetic diversity, plasticity, or phenotypic traits between rare and widespread species; however, a suite of genetic attributes that unites rare species remains elusive. Here, using two rare and two widespread Boechera (Brassicaceae) species, we conduct a simultaneous comparison of quantitative trait diversity, genetic diversity, and population structure among species with highly divergent range sizes. Consistent with previous studies, we do not find strong associations between range size and within-population genetic diversity. In contrast, we find that both the degree of phenotypic plasticity and quantitative trait structure (Q ST) were positively correlated with range size. We also found higher F ST: Q ST ratios in rare species, indicative of either a greater response to stabilizing selection or a lack of additive genetic variation. While widespread species occupy more ecological and climactic space and have diverged at both traits and markers, rare species display constrained levels of population differentiation and phenotypic plasticity. Combined, our results provide evidence for a specialization-generalization trade-off across three orders of magnitude of range size variation in the ecological model genus, Boechera.
Time‐dependent characteristics of sulfonated EPDM containing zinc stearate. I. Thermal behavior

Synopsis The crystallization and melting of zinc stearate (ZnSt) in ZnSt-plasticized compositions of ethylene-propylene-diene terpolymer (EPDM) and sulfonated EPDM (S-EPDM) have been studied by differential scanning calorimetry. While immiscible in both EPDM and S-EPDM, ZnSt is compatible with the latter. This compatibility presumably arises from either electrostatic or dipoledipole interactions between the carboxylate functionality of ZnSt and the sulfonate groups of the polymer. The crystallization behavior of ZnSt is significantly perturbed when the material is added to S-EPDM, and the crystalline ZnSt phase that results is strongly time dependent. ZnSt first crystallizes as small imperfect crystals when the compositions are cooled from the melt, but it eventually anneals at room temperature into larger, more perfect crystals. Time dependent changes in the mechanical properties of these compositions are also demonstrated and it is suggested that this may be due in part to changes in the ZnSt morphology.
Pro: early endotracheal extubation is preferable to late extubation in patients following coronary artery surgery.

PIOID-BASED anesthesia continues to be the most popular technique for patients undergoing coronary artery bypass grafting (CABG), primarily since this approach promotes hemodynamic stability. High-dose opioid anesthesia is technically straightforward, leaving the anesthesiologist free to concentrate on other aspects of patient care. The tost of these advantages, prolonged mechanica1 ventilatory support, has been accepted by many anesthesiologists and surgeons, partly because of habit, and partly due to the belief that overnight ventilation is somehow beneficial to the patient’s respiratory and cardiovascular systems. Observations that early postoperative ischemia is related to adverse cardiac outcomei have prompted interest in continuing an infusion of high-dose opioids wel1 into the postoperative period,* potentially expanding the period of ventilatory support. Whereas control of the stress response probably reduces ischemia, this may not provide sufficient justification for prolonged mechanica1 ventilation, particularly because other methods of stress control and hemodynamic control may accomplish the task without the disadvantages of prolonged mechanica1 ventilation. The author hopes to convince the reader that early trachea1 extubation following CABG is not only possible, but preferable to intentionally delayed extubation, once the risks and benefits of prophylactic ventilation are fully taken into account. What constitutes “early” extubation? For the purposes of this discussion, early extubation wil1 be defined as removal of the endotracheal tube from the patient within 8 hours of the patient’s arrival in the postoperative unit, an arbitrary time limit that encompasses data from prior studies (Table 1).3-7 Early extubation, by this definition, is more commonly used than assumed, often because of local habit or staffing considerations. Overnight ventilation with extubation on the first postoperative day has many adherents, particularly in institutions with a high volume of complex cases, and also when postoperative care and the decision to extubate are controlled by individuals other than the operating room
Optical Properties of Self-Organizing Quantum-Dot Structures

We present experimental evidence that directly demonstrates the discrete nature of the density-of-states (broadened delta functions) in InGaAs ultrasmall quantum dots (diameter as small as 13 nm) epitaxially grown on GaAs by the coherent islanding effect. From the photoluminescence and the photoluminescence excitation spectra, we deduce an interlevel spacing of ~30 meV between the ground state and the first excited state arising from the lateral confinement, for quantum dots having a diameter of ~20 nm.
The construction of empirical credit scoring rules based on maximization principles

Abstract We examine the econometric implications of the decision problem faced by a profit/utility-maximizing lender operating in a simple “double-binary” environment, where the two actions available are “approve” or “reject”, and the two states of the world are “pay back” or “default”. In practice, such decisions are often made by applying a fixed cutoff to the maximum likelihood estimate of a parametric model of the default probability. Following ( Elliott and Lieli, 2007 ), we argue that this practice might contradict the lender’s economic objective and, using German loan data, we illustrate the use of “context-specific” cutoffs and an estimation method derived directly from the lender’s problem. We also provide a brief discussion of how to incorporate legal constraints, such as the prohibition of disparate treatment of potential borrowers, into the lender’s problem.
A doublet microlens array for imaging micron-sized objects

We present a high-numerical aperture, doublet microlens array for imaging micron-sized objects. The proposed doublet architecture consists of glass microspheres trapped on a predefined array of silicon microholes and covered with a thin polymer layer. A standard silicon microfabrication process and a novel fluidic assembly technique were combined to obtain an array of 56 μm diameter microlenses with a numerical aperture of ~0.5. Using such an array, we demonstrated brightfield and fluorescent image formation of objects directly on a CCD sensor without the use of intermediate lenses. The proposed technology is a significant advancement toward the unmet need of inexpensive, miniaturized optical modules which can be further integrated with lab-on-chip microfluidic devices and photonic chips for a variety of high-end imaging/detection applications.
High-Temperature Superconducting Multilayers and Heterostructures Grown by Atomic Layer-By-Layer Molecular Beam Epitaxy

Atomic layer-by-layer molecular beam epitaxy (ALL-MBE) ofhigh-tem­ perature superconductors (HTSC) and other complex oxides has been developed. Thin films with atomically flat surfaces and abrupt interfaces can be produced an atomic layer at a time. Samples are engineered by stacking molecular layers of diff erent compounds, by adding or omitting atomic monolayers, and by doping within specified monolayers. Novel artificial HTSC compounds such as Bi2Sr2 Ca7CugOx (2278), as well as various heterostructures , have been synthesized in this way. This unique synthetic capability has allowed several fundamental physics issues, such as the dimensionality of the HTSC state, long-range proximity effects, resonant tunneling with a specified number of hops, etc, to be addressed. Trilayer Josephson junctions with uniform and reproducible properties have been fabricated; phase-locked operation of two junctions has also been demonstrated. Finally, titanate slabs only 4-A thick have been grown without pin-holes and shown to provide tunneling barriers for c-axis transport.
Corporate Earnings And Financings: An Analysis Of Cancelled Versus Completed Offerings

Testing the earnings downturn and overvaluation hypotheses, we examine the long-term behavior of earnings around cancelled offers of firm financings of straight debt, convertible debt, and common stock. Although we find evidence consistent with both hypotheses in our completed offerings, the earnings pattern around cancelled offerings is consistent with overvaluation rather than earnings downturn. We find an unexpected earnings drop following the cancellation, however, we find no evidence shareholders correctly anticipate the size of the earnings downturn.
Therapeutic Recreation and Disability Studies: Seeking an Alliance

The disciplines of therapeutic recreation and disability studies are committed to studying and acting on the effects of disability in the lives of people. Ironically, there is little intersection between the two disciplines, which is the result of their fundamentally different approaches to disability. This analysis examines the detachment between therapeutic recreation and disability studies. After an introduction to its origin, principles, and main themes, the status of disability studies in therapeutic recreation is assessed by a selective review of literature. Key implications from the framework of the International Classification of Functioning, Disability, and Health are then addressed, followed by recommendations. An alliance with disability studies would enable therapeutic recreation to better understand and serve disabled people while bringing therapeutic recreation into the body of disability studies.
Attributes and Frames of the Aurora Shootings National and Local News Coverage Differences

The present study examined frames and second-level agenda-setting attributes used by national and local newspapers to cover the 2012 Aurora, Colorado shootings. Unlike research examining coverage of school shootings, this study examined a mass shooting that did not occur at a school. Both newspaper types published a similar number of articles—though national articles tended to be longer—and virtually stopped coverage after 18 days. While previous coverage tended to focus on shootings’ societal implications, Aurora coverage focused more on individuals involved in the time immediately surrounding the shootings. National papers focused on the gunman, while the local press tended to focus on victims. Mass shootings in general tend to be salient news items, but the present study further shows news outlets may now focus on incidents’ specifics instead of common characteristics they might share, perhaps because audiences have an existing understanding of them. The shootings were framed in terms of gun control; n...
The nanocrystal superlattice pressure cell: a novel approach to study molecular bundles under uniaxial compression.

Ordered assemblies of inorganic nanocrystals coated with organic linkers present interesting scientific challenges in hard and soft matter physics. We demonstrate that a nanocrystal superlattice under compression serves as a nanoscopic pressure cell to enable studies of molecular linkers under uniaxial compression. We developed a method to uniaxially compress the bifunctional organic linker by attaching both ends of aliphatic chains to neighboring PbS nanocrystals in a superlattice. Pressurizing the nanocrystal superlattice in a diamond anvil cell thus results in compression of the molecular linkers along their chain direction. Small-angle and wide-angle X-ray scattering during the compression provide insights into the structure of the superlattice and nanocrystal cores under compression, respectively. We compare density functional theory calculations of the molecular linkers as basic Hookean springs to the experimental force–distance relationship. We determine the density of linkers on the nanocrystal surfaces. We demonstrate our method to probe the elastic force of single molecule as a function of chain length. The methodology introduced in this paper opens doors to investigate molecular interactions within organic molecules compressed within a nanocrystal superlattice.
Three-dimensional spatial compounding of ultrasound scans with weighting by incidence angle

A three-dimensional (3D) ultrasound imaging system has been used to study spatial compounding of images acquired with different scanhead positions and orientations. A compounding algorithm has been developed that assigns regional weights depending on the local incidence angle of the ultrasound beam. Compound scans were performed of bones in vitro and the shoulder rotator cuff in volunteer subjects. Border measurements (peak value and width) were compiled as a function of ultrasound beam incidence angle and compared for single views and for maximum, mean and weighted mean compounding techniques. The weighted mean produces less variability than that of the maximum and mean for both intensity and border width. The weighted method also demonstrates less blurring of borders than the maximum and mean methods. Surfaces derived from the weighted reconstructions exhibited fewer gaps and fewer spurious connections between surfaces, which could be of particular importance for automated image analysis.
Pulmonary embolism. Prevention, detection, and nonoperative management.

Heparin remains the therapeutic agent of choice. Investigations of platelet inhibiting agents, prothrombinopenic agents, fibrinolytic agents, and defibrinogenating agents have failed to show the superiority of any of these substances over heparin, although fibrinolytic agents may be more beneficial in the patient with massive pulmonary embolism and cardiopulmonary decompensation.
Group Additivity for Thermochemical Property Estimation of Lignin Monomers on Pt(111)

Conversion of biomass has received considerable attention, but theoretical investigation is challenging due to the large computational burden. In this contribution, we explore group additivity for computing the thermochemistry of lignin monomers, and by extension to single-ring aromatic hydrocarbons, on Pt(111). We find that the previous framework developed for open-chain molecules and furanics is inadequate for lignin monomers due to conjugation. Using quantum theory of atoms in molecules (QTAIM), we find that the type of binding of the adsorbate atoms with the surface sites, for example, σ, σσ, or σπ, has an important impact on the conjugation of bonds in adsorbates. We introduce two new models that account for the type of binding of the central atom and its nearest neighbors, namely, a conjugation-based and a site-based scheme, which result in significant improvement. A total of 591 density functional theory data points were regressed; cross-validation of the site-based scheme reveals that mean absolut...
Higher-order MDOF time integration methods

Publisher Summary This chapter presents a general procedure for the use of higher-order Lagrange polynomials to represent the variation of the accelerations in MDOF time integration methods. Additionally, the well known first-order variation over the time-step θΔt, equations are presented for the implementation of a numerical algorithm with second-order and third-order polynomial variations for the acceleration over θΔt. Amplitude decay and period elongation plots are used to compare the accuracy of the solutions for SDOF and MDOF problems. The relative merits and stability aspects of the methods are described. The development and use of higher-order approximations of a system's dynamic response are compared with commonly used methods for dynamic analyses. The new methods are conditionally stable and are not self-starting. However, it was found that the higher-order methods can provide more accurate results than the commonly used Newmark and Wilson-θ methods when larger time steps are used in the analyses.
Behavior of high-temperature dielectric materials in advanced energy converters

Dielectric materials in direct energy conversion systems are usually in the form of metal-oxide insulating bodies which are used to achieve electrical isolation within the system.
Adversarial versus Inquisitorial Systems: Error and Valuation

This paper discusses valuation within the judicial processes by comparing the adversarial and inquisitorial systems of litigation. It evaluates adversarial and inquisitorial litigation on the legal systems’ ability to aid processes that lead to discovery of knowledge. It argues that much of the information required for accurate valuation must be discovered. While the adversarial method of litigation is essentially a competitive model of evidence production; the inquisitorial system comprises only the expert/principle searcher, and lacks a competitive discovery process. Therefore, as a system, adversarial litigation may be more conducive for error minimization in enforcing rules than inquisitorial litigation. On the question of business valuation of firms under Chapter 11, both the adversarial and inquisitorial systems are problematic, given that market competition leading to discovery of prices and valuation is impossible within the judicial system of valuation.
Microfabrication Technology for Vascularized Tissue Engineering

This work describes the application of advanced microfabrication technologies including silicon micromachining and polymer replica molding towards the field of tissue engineering of complex tissues and organs. As a general approach, tissue engineering of skin, bone and cartilage using cell transplantation on biodegradable matrices has achieved great success. However, such techniques encounter difficulties when applied to complex tissues and vital organs. The principal limitation for such applications is the lack of an intrinsic blood supply for the tissue engineered organ, which experiences significant cell death when the tissue thickness is increased above the 1–2 mm range. In this work, the concept of microfabricated scaffolds is introduced, with the goal of producing organ templates with feature resolution of 1 micron, well in excess of that necessary to fashion the capillaries which comprise the microcirculation of the organ. Initial efforts have resulted in high resolution biocompatible polymer scaffolds produced by replica molding from silicon micromachined template wafers. These scaffolds have been successfully seeded with endothelial cells in channels with dimensions as small as the capillaries.
DQ-axis current-based droop controller

During an islanding operation of a microgrid comprised of multiple distributed generation (DG) units serving a load, DG units interfaced with voltage-sourced converters (VSC) are regarded as the only energy sources. Hence, DG units should be controlled to form the frequency and voltage, pick up the full load, and respond to any load changes. Conventional P — f/Q — V droop controller enables a communication-less load sharing among DGs while maintaining close deviations of frequency and voltage. Utilizing the d q -frame power flow analysis, this paper presents an equivalent primary droop controller i d — f/i q — V based on the direct and quadrature components of the feeder currents, which are already existent in each voltage controller for disturbance rejection. More emphasis is placed on the phenomenon of inaccurate reactive power sharing caused by mismatched feeder impedances. Analysis is presented in terms of the droop equation, and compensation methods are examined with focus on computation and communication requirements, and PCC voltage profile. For validation of the controller's response, a testbed model exhibiting the dynamics of a two-DG microgrid is developed and simulated in Matlab/Simulink.
Robofest carnival — STEM learning through robotics with parents

It has been widely known that introducing robotics in formal and informal learning environments improves STEM learning as well as problem solving skills. An underutilized resource in this process of teaching STEM is parents. Robofest Carnival is an informal learning program with multiple interactive challenge learning stations where students are challenged to complete robotics tasks. A new approach for the Carnival was explored. Instead of technical staff, parents of participants were trained to manage the challenge learning stations. Ongoing research shows that the Carnival program increased the students' knowledge of STEM subjects. In addition, it dramatically increased STEM confidence level of parents who took training and assisted the Carnival learning stations. We believe the Carnival model is a practical and effective informal robotics learning environment to improve student achievement in STEM and increase parents' confidence in their children's education.
Risk factors for and timing of adverse events after revision total shoulder arthroplasty.

BackgroundDespite increasing rates of revision total shoulder arthroplasty (RTSA), there is a paucity of literature on optimizing perioperative outcomes. The purposes of this study were to identify...
Protein degradation in mitochondria: implications for oxidative stress, aging and disease:: a novel etiological classification of mitochondrial proteolytic disorders

The mitochondrial genome encodes just a small number of subunits of the respiratory chain. All the other mitochondrial proteins are encoded in the nucleus and produced in the cytosol. Various enzymes participate in the activation and intramitochondrial transport of imported proteins. To finally take their place in the various mitochondrial compartments, the targeting signals of imported proteins have to be cleaved by mitochondrial processing peptidases. Mitochondria must also be able to eliminate peptides that are internally synthesized in excess, as well as those that are improperly assembled, and those with abnormal conformation caused by mutation or oxidative damage. Damaged mitochondrial proteins can be removed in two ways: either through lysosomal autophagy, that can account for at most 25-30% of the biochemically estimated rates of average mitochondrial catabolism; or through an intramitochondrial proteinolytic pathway. Mitochondrial proteases have been extensively studied in yeast, but evidence in recent years has demonstrated the existence of similar systems in mammalian cells, and has pointed to the possible importance of mitochondrial proteolytic enzymes in human diseases and ageing. A number of mitochondrial diseases have been identified whose mechanisms involve proteolytic dysfunction. Similar mechanisms probably play a role in diminished resistance to oxidative stress, and in the aging process. In this paper we review current knowledge of mammalian mitochondrial proteolysis, under normal conditions and in several disease states, and we propose an etiological classification of human diseases characterized by a decline or loss of function of mitochondrial proteolytic enzymes.
Conversion of N2O to N2 on TiO2(1 1 0)

Abstract In this study, we examine the interaction of N2O with TiO2(1 1 0) in an effort to better understand the conversion of NOx species to N2 over TiO2-based catalysts. The TiO2(1 1 0) surface was chosen as a model system because this material is commonly used as a support and because oxygen vacancies on this surface are perhaps the best available models for the role of electronic defects in catalysis. Annealing TiO2(1 1 0) in vacuum at high temperature (above about 800 K) generates oxygen vacancy sites that are associated with reduced surface cations (Ti3+ sites) and that are easily quantified using temperature programmed desorption (TPD) of water. Using TPD, X-ray photoelectron spectroscopy (XPS) and electron energy loss spectroscopy (EELS), we found that the majority of N2O molecules adsorbed at 90 K on TiO2(1 1 0) are weakly held and desorb from the surface at 130 K. However, a small fraction of the N2O molecules exposed to TiO2(1 1 0) at 90 K decompose to N2 via one of two channels, both of which are vacancy-mediated. One channel occurs at 90 K, and results in N2 ejection from the surface and vacancy oxidation. We propose that this channel involves N2O molecules bound at vacancies with the O-end of the molecule in the vacancy. The second channel results from an adsorbed state of N2O that decomposes at 170 K to liberate N2 in the gas phase and deposit oxygen adatoms at non-defect Ti4+ sites. The presence of these O adatoms is clearly evident in subsequent water TPD measurements. We propose that this channel involves N2O molecules that are bound at vacancies with the N-end of the molecule in the vacancy, which permits the O-end of the molecule to interact with an adjacent Ti4+ site. The partitioning between these two channels is roughly 1:1 for adsorption at 90 K, but neither is observed to occur for moderate N2O exposures at temperatures above 200 K. EELS data indicate that vacancies readily transfer charge to N2O at 90 K, and this charge transfer facilitates N2O decomposition. Based on these results, it appears that the decomposition of N2O to N2 requires trapping of the molecule at vacancies and that the lifetime of the N2O–vacancy interaction may be key to the conversion of N2O to N2.
Determination of polychlorinated biphenyls in sediments, using sonication extraction and capillary column gas chromatography-electron capture detection with internal standard calibration.

A sonication technique is presented for the extraction of polychlorinated biphenyls (PCBs) from sediments. In addition, a quantitation scheme is described which allows peak-specific and, in many cases, congener-specific determination of PCBs. PCBs are quantitated by capillary column gas chromatography-electron capture detection, with internal standard calibration. Results utilizing sonication extraction were compared with those obtained by Soxhlet and steam distillation extractions of 3 U.S. Environmental Protection Agency (EPA) quality control sediment samples and 3 lake sediments known to be contaminated with PCBs. Environmental lake sediments were extracted wet, with no drying prior to extraction. Recoveries by each technique varied depending on the sediment sample being extracted and degree of chlorination of PCB congeners. With proper selection of extraction solvent, the sonication technique can recover amounts of PCBs equivalent to and sometimes greater than recoveries by the Soxhlet or steam distillation techniques. A 24-h quiescent period in the extraction solvent between 2 sonications improved extraction efficiency for 2 freeze-dried sediments but did not affect results obtained for 3 environmentally contaminated sediments that were extracted without drying. Replacement of Soxhlet extraction with the sonication technique results in reduced sample preparation time, decreased volumes of solvents and sample, and substitution of common laboratory glassware in place of fragile, expensive Soxhlet glassware. Sonication extraction can also improve precision compared with Soxhlet extraction.
A Common-Ground Review of the Potential for Machine Learning Approaches in Electrocardiographic Imaging Based on Probabilistic Graphical Models

Machine learning (ML) methods have seen an explosion in their development and application. They are increasingly being used in many different fields with considerable success. However, although the interest is growing, their impact in the field of electrocardiographic imaging (ECGI) remains limited. One of the main reasons that ML has yet to become more prevalent in ECGI is that the published literature is scattered and there is no common ground description and comparison of these methods in an MLframework. Here we address this limitation with a review of ECGI methods from the perspective of ML. We will use probabilistic modeling to provide a common ground framework to compare different methods and well known approaches. Finally, we will discuss which approaches have been used to do inference on these models and which alternatives could be utilized as the methods in ML become more mature.
Revascularization of the heart; a study of mortality and infarcts following multiple coronary artery ligation.

This report on revascularization of the heart is based on work done in this laboratory in the period from Sept. 1, 1949 to Sept. 1, 1951. A brief description of the operation is given. After the operation was done an attempt was made to shift the inflow from the coronary arteries to the graft from the aorta. An attempt was made to occlude all coronary arteries. Four hundred operations were done on 100 dogs. Data on mortality and infarcts are given in this paper.
Mechanisms and Risks of Electrocardiographic QT Interval Prolongation When Using Antipsychotic Drugs

This article reviews cardiac electrophysiology, with a focus on the assessment of the electrocardiographically determined corrected QT (QTc) interval and its role as a marker for potentially life-threatening cardiac arrhythmias such as torsades de pointes. Presently, using the QTc interval as a surrogate for polymorphic ventricular tachycardia is handicapped, in part, by the limitations of currently available group-derived formulas to estimate the QTc interval. Regulatory agencies have sharpened their interest in this arena. Substantial progress almost certainly awaits the application of individual rather than group-derived formulas to estimate the QTc interval. Until this refinement arrives, clinicians are advised to exercise caution when administering antipsychotic drugs with the potential to significantly prolong the QT interval. Caution is particularly urged in patients with cardiovascular disease or risk factors for cardiovascular disease.
Decreased incidence of marrow graft rejection in patients with severe aplastic anemia: changing impact of risk factors.

Patients with severe aplastic anemia were conditioned with cyclophosphamide (200 mg/kg) and given marrow grafts from HLA-identical family members. Among 233 patients transplanted, 225 survived greater than or equal to 14 days and could be evaluated for engraftment. Forty- four of the 225 rejected their graft; 33 of these died and 11 survive. One hundred eighty-one patients had sustained engraftment; of these, 46 died and 135 survived. Binary logistic regression analyses revealed five risk factors for graft rejection: year of transplant, a large number of platelet transfusions, a positive relative response in mixed leukocyte culture, a low marrow cell dose, and omission of donor buffy coat cell infusion for transfused patients. These data show that patients transplanted recently had a lower likelihood of graft rejection than did patients transplanted in earlier years. Conceivably, this was related to changes in transfusion practices, but other factors as yet unidentified are likely to be involved. The data confirm that the largest possible number of marrow cells should be transplanted. Although the difference in the incidence of graft rejection between untransfused and transfused patients was not significant, it should be noted that transfused patients were given buffy coat cells. Because the addition of buffy coat cells results in a higher incidence of chronic graft-v-host disease (GVHD), it is still desirable to transplant patients with marrow alone early in their course before they have been transfused.
Computationally Efficient Implementation of Aperture Domain Model Image Reconstruction

Aperture domain model image reconstruction (ADMIRE) is a useful tool to mitigate ultrasound imaging artifacts caused by acoustic clutter. However, its lengthy run-time impairs its usefulness. To overcome this drawback, we evaluated the reduced model methods with otherwise similar performance to ADMIRE. We also assessed other approaches to speed up ADMIRE, including the use of different levels of short-time Fourier transform (STFT) window overlap and examining the degrees of freedom of the model fit. In this study, we conducted an analysis of the reduced models, including those using Gram–Schmidt orthonormalization (GSO), singular value decomposition (SVD), and independent component analysis (ICA). We evaluated these reduced models using the data from simulations, experimental phantoms, and in vivo liver scans. We then tested ADMIRE’s performance using full, GSO, SVD, and ICA–fourth-order blind identification (ICA-FOBI) models. The results from simulations, experimental phantoms, and in vivo data indicate that a model reduced using the ICA-FOBI method is the most promising for accelerating ADMIRE implementation. In the in vivo liver data, the improvements in contrast relative to delay-and-sum (DAS) using a full model, GSO, SVD, and ICA-FOBI models are 6.29 ± 0.25 dB, 11.88 ± 0.90 dB, 9.01 ± 0.67 dB, and 6.36 ± 0.27 dB, respectively; whereas, the contrast-to-noise ratio (CNR) improvement values in the same order are 0.04 ± 0.06 dB, −1.70 ± 0.17 dB, −1.51 ± 0.19 dB, and 0.12 ± 0.07 dB, respectively. The implementation of ADMIRE using the reduced model methods can decrease ADMIRE’s computational complexity over three orders of magnitude. The use of a 50% STFT window overlap reduces ADMIRE’s serial run time by more than one order of magnitude without any remarkable loss of image quality, when compared to the use of a 90% window overlap used previously. Based on these findings, a combination of the ICA-FOBI model and the use of a 50% STFT window overlap makes the ADMIRE algorithm more computationally efficient.
Determining a Framework for the Generation and Evaluation of Ambient Intelligent Agent System Designs

The design and realization of Ambient Intelligence (AmI) systems using Artificially Intelligent (AI) agents is a rising field of research. However, the absence of clearly defined working criteria, supporting the generation and evaluation of AmI agent system designs, is a conspicuous obstacle to their advancement. The contribution of this paper is that we determine and test a framework for the generation and evaluation of AmI system designs, based on user experience and business criteria. Specifically, the process of designing a personal lighting AI agent, in collaboration with a leading lighting design company, is used as a case study to determine and test a framework for the generation and evaluation of AmI system designs based on feasibility and acceptability. First, we use storytelling videos to describe and communicate the user values and design scenarios to the stakeholders. Second, we generate design proposals for a lighting AmI agent based on five distinct systemic factors, namely: (a) the context of interaction; (b) the required system data; (c) the required sensing input; (d) the required user input; and (e) the desired system output. Finally third we determine an evaluation framework that is based on three distinct levels of in-built system intelligence, from lower to higher. The three levels reflect the feasibility and acceptability of the system. Feasibility is what a specific company is capable of producing, and in what timeframe. Acceptability is the potential of familiarity and trust that the users can feel while interacting with the AI agent.
Flexible design at Batoka Dam: How Real Options Analysis compares to other decision-making tools

Infrastructure development strategies on the African continent include significant hydropower investment to meet growing energy demand. However, long-lived assets such as hydro facilities face climate and other risks that shorter-term investments may not. Decision-makers are looking for appropriate tools to quantify these risks and evaluate policy choices and investment decisions under climate uncertainty. We investigate three methods of analysis to assess whether they are effective for capturing the full implications of climate risk for infrastructure investment: Benefit-Cost Analysis under uncertainty (BCA), Robust Decision Making (RDM), and Real Options Analysis (ROA). The paper then illustrates each within the same project opportunity – the Batoka Gorge Hydropower Facility. We find that within the context of Batoka, the three analyses point to similar design choices with one important exception: Real Options offers values for the flexibilities embedded in projects or suites of projects, whereas the others do not necessarily incorporate these valuations.
Chest Computed Tomography for Detection of Coronavirus Disease 2019 (COVID-19): Don't Rush the Science.

This commentary discusses the findings of early studies that addressed the use of chest computed tomography for the detection of COVID-19. The authors urge caution in rushing science and overinterp...
Clofazimine Reduces the Survival of Salmonella enterica in Macrophages and Mice.

Drug resistant pathogens are on the rise and new treatments are needed for bacterial infections. Efforts toward antimicrobial discovery typically identify compounds that prevent bacterial growth in...