cssi/SciSciGPT-SciSciNet huggingface dataset:
A Generic Algorithm for Sleep-Wake Cycle Detection using Unlabeled Actigraphy Data

One key component when analyzing actigraphy data for sleep studies is sleep-wake cycle detection. Most detection algorithms rely on accurate sleep diary labels to generate supervised classifiers, with parameters optimized for a particular dataset. However, once the actigraphy trackers are deployed in the field, labels for training models and validating detection accuracy are often not available. In this paper, we propose a generic, training-free algorithm to detect sleep-wake cycles from minute-by-minute actigraphy. Leveraging a robust nonlinear parametric model, our proposed method refines the detection region by searching for a single change point within bounded regions defined by the parametric model. Challenged by the absence of ground truth labels, we also propose an evaluation metric dedicated to this problem. Tested on week-long actigraphy from 112 children, the results show that the proposed algorithm improves on the baseline model consistently and significantly $(\mathbf{p} . Moreover, focusing on the commonality in human circadian rhythm captured by actigraphy, the proposed method is generic to data collected by various actigraphy trackers, circumventing the laborious label collection step in developing customized classifiers for sleep detection.
Sitagliptin Decreases Visceral Fat and Blood Glucose in Women With Polycystic Ovarian Syndrome

CONTEXT Women with polycystic ovarian syndrome (PCOS) have decreased growth hormone (GH), which can result in increased visceral adiposity (VAT) and impaired vascular function. GH-releasing hormone, a dipeptidyl peptidase-4 (DPP4) substrate, stimulates GH secretion. OBJECTIVE We tested the hypothesis that DPP4 inhibition increases GH and improves glucose levels and vascular function in women with PCOS. METHODS Eighteen women with PCOS participated in a double-blind, crossover study. They received sitagliptin either 100 mg or placebo daily for 1 month, with crossover treatments separated by an 8-week washout. During each treatment, women underwent a 75-gram oral glucose tolerance test (OGTT) and assessments of vascular function and body composition. Overnight GH secretion was assessed via venous sampling every 10 minutes for 12 hours and analyzed using an automated deconvolution algorithm. RESULTS During OGTT, sitagliptin increased glucagon-like peptide-1 (P < 0.001), early insulin secretion (from mean [± SD] insulinogenic index 1.9 ± 1.2 to 3.2 ± 3.1; P = 0.02), and decreased peak glucose (mean -17.2 mg/dL [95% CI, -27.7 to -6.6]; P < 0.01). At 1 month, sitagliptin decreased VAT (from 1141.9 ± 700.7 to 1055.1 ± 710.1 g; P = 0.02) but did not affect vascular function. Sitagliptin increased GH half-life (from 13.9 ± 3.6 to 17.0 ± 6.8 min, N = 16; P = 0.04) and interpulse interval (from 53.2 ± 20.0 to 77.3 ± 38.2 min, N = 16; P < 0.05) but did not increase mean overnight GH (P = 0.92 vs placebo). CONCLUSIONS Sitagliptin decreased the maximal glucose response to OGTT and VAT. Sitagliptin did not increase overnight GH but increased GH half-life and the interpulse interval. CLINICAL TRIAL REGISTRATION This study was registered at www.clinicaltrials.gov as NCT02122380 prior to enrollment of the first participant.
Sinonasal Chondromyxoid Fibroma: Case Report and Literature Review

Chondromyxoid fibroma (CMF) is a rare, benign neoplasm of the chondroid, myxoid, and fibrous tissue. It characteristically affects the lower extremity long bones, although it may rarely arise within the craniofacial skeleton. We report the diagnosis and management of a 31-year-old male with a large, incidentally discovered CMF originating from the sphenoid sinus. A subsequent review of the literature reveals the need to differentiate from more aggressive neoplasms, such as chondrosarcoma and chondroma, which share radiographic features. A histopathologic examination is crucial for proper diagnosis and treatment. We discuss clinical sequelae, highlight the importance of a thorough pre-operative evaluation, and summarize previously suggested treatment paradigms.
Targeting Lysophosphatidic Acid in Cancer: The Issues in Moving from Bench to Bedside

Since the clear demonstration of lysophosphatidic acid (LPA)’s pathological roles in cancer in the mid-1990s, more than 1000 papers relating LPA to various types of cancer were published. Through these studies, LPA was established as a target for cancer. Although LPA-related inhibitors entered clinical trials for fibrosis, the concept of targeting LPA is yet to be moved to clinical cancer treatment. The major challenges that we are facing in moving LPA application from bench to bedside include the intrinsic and complicated metabolic, functional, and signaling properties of LPA, as well as technical issues, which are discussed in this review. Potential strategies and perspectives to improve the translational progress are suggested. Despite these challenges, we are optimistic that LPA blockage, particularly in combination with other agents, is on the horizon to be incorporated into clinical applications.
Distinct molecular etiologies of male and female hepatocellular carcinoma

Sex-differences in cancer occurrence and mortality are evident across tumor types; men exhibit higher rates of incidence and often poorer responses to treatment. Targeted approaches to the treatment of tumors that account for these sex-differences require the characterization and understanding of the fundamental biological mechanisms that differentiate them. Hepatocellular Carcinoma (HCC) is the second leading cause of cancer death worldwide, with the incidence rapidly rising. HCC exhibits a male-bias in occurrence and mortality, but previous studies have failed to explore the sex-specific dysregulation of gene expression in HCC. Here, we characterize the sex-shared and sex-specific regulatory changes in HCC tumors in the TCGA LIHC cohort using combined and sex-stratified differential expression and eQTL analyses. By using a sex-specific differential expression analysis of tumor and tumor-adjacent samples, we uncovered etiologically relevant genes and pathways differentiating male and female HCC. While both sexes exhibited activation of pathways related to apoptosis and cell cycle, males and females differed in the activation of several signaling pathways, with females showing PPAR pathway enrichment while males showed PI3K, PI3K/AKT, FGFR, EGFR, NGF, GF1R, Rap1, DAP12, and IL-2 signaling pathway enrichment. Using eQTL analyses, we discovered germline variants with differential effects on tumor gene expression between the sexes. 24.3% of the discovered eQTLs exhibit differential effects between the sexes, illustrating the substantial role of sex in modifying the effects of eQTLs in HCC. The genes that showed sex-specific dysregulation in tumors and those that harbored a sex-specific eQTL converge in clinically relevant pathways, suggesting that the molecular etiologies of male and female HCC are partially driven by differential genetic effects on gene expression. Sex-stratified analyses detect sex-specific molecular etiologies of HCC. Overall, our results provide new insight into the role of inherited genetic regulation of transcription in modulating sex-differences in HCC etiology and provide a framework for future studies on sex-biased cancers.
Knot Floer homology obstructs ribbon concordance

We prove that the map on knot Floer homology induced by a ribbon concordance is injective. As a consequence, we prove that the Seifert genus is monotonic under ribbon concordance. We also generalize a theorem of Gabai about the super-additivity of the Seifert genus under band connected sum. Our result gives evidence for a conjecture of Gordon that ribbon concordance is a partial order on the set of knots.
Note on the Shape of Level Curves of Green's Function

(1953). Note on the Shape of Level Curves of Green's Function. The American Mathematical Monthly: Vol. 60, No. 10, pp. 671-674.
Stability Conditions for Affine Type A

We construct maximal green sequences of maximal length for any affine quiver of type A. We determine which sets of modules (equivalently c-vectors) can occur in such sequences and, among these, which are given by a linear stability condition (also called a central charge). There is always at least one such maximal set which is linear. The proofs use representation theory and three kinds of diagrams shown in Fig. 1. Background material is reviewed with details presented in two separate papers Igusa (2017a, b).
Interplay between single phase solid solution strengthening and multi-phase strengthening in the same high entropy alloy

Abstract High entropy alloys (HEAs) offer the opportunity to achieve an unprecedented balance of properties by accessing novel multi-scale microstructural combinations. Despite the large range of combinations of strength and ductility reported in HEAs, the complex interplay between multiple strengthening mechanisms has not been addressed. The single-phase fcc solid solution state of the Al0.3CoCrFeNi alloy exhibits a strong Hall-Petch hardening effect with reducing grain size. While the same alloy can be strengthened by a composite-reinforcement effect of hard intermetallic B2 and sigma precipitates, within a fine-grained fcc matrix. Such precipitation leads to solute depletion within the parent fcc matrix, resulting in a substantially reduced Hall-Petch hardening effect. Additional formation of nano-clusters within the fcc matrix can strengthen the same alloy to 1.85 GPa at room temperature, via an Orowan strengthening mechanism. This paper presents the complex interplay between strengthening mechanisms operative at different length scales.
Combined Energy and Comfort Optimization of Air Conditioning System in Connected and Automated Vehicles

In this paper, we propose a combined energy and comfort optimization (CECO) strategy for the air conditioning (A/C) system of the connected and automated vehicles (CAVs). By leveraging the weather and traffic predictions enabled by the emerging CAV technologies, the proposed strategy is able to minimize the A/C system energy consumption while maintaining the occupant thermal comfort (OTC) within the comfort constraints, where the comfort is quantified by a modified predictive mean vote (PMV) model adapted for an automotive application. A general CECO problem is formulated and addressed using model predictive control (MPC) and weather/traffic previews. Depending on the ways of exploiting the preview information and enforcing the OTC constraint, different MPCs are developed based on solving different variations of the general CECO problem. The CECO-based MPCs are then tested in simulation using an automotive A/C system simulation model (CoolSim) as the virtual testbed. The simulation results show that, over SC03 driving cycle, the proposed CECO-based MPCs outperform the baseline cabin temperature tracking controller, reducing the A/C system energy consumption by up to 7.6%, while achieving better OTC according to the PMV-based metrics. This energy saving in A/C system translates to 3.1% vehicle fuel economy improvement. The trade-off between energy efficiency and OTC for different control scenarios is also highlighted.
Integrated Epigenome, Exome, and Transcriptome Analyses Reveal Molecular Subtypes and Homeotic Transformation in Uterine Fibroids

Summary Uterine fibroids are benign myometrial smooth muscle tumors of unknown etiology that, when symptomatic, are the most common indication for hysterectomy in the United States. Unsupervised clustering of results from DNA methylation analyses segregates normal myometrium from fibroids and further segregates the fibroids into subtypes characterized by MED12 mutation or activation of either HMGA2 or HMGA1 expression. Upregulation of HMGA2 expression does not always appear to be dependent on translocation but is associated with hypomethylation in the HMGA2 gene body. HOXA13 expression is upregulated in fibroids and correlates with expression of typical uterine fibroid genes. Significant overlap of differentially expressed genes is observed between cervical stroma and uterine fibroids compared with normal myometrium. These analyses show a possible role of DNA methylation in fibroid biology and suggest that homeotic transformation of myometrial cells to a more cervical stroma phenotype could be an important mechanism for etiology of the disease.
Beltrami Fields with Nonconstant Proportionality Factor

We consider the question raised by Enciso and Peralta-Salas (Arch Ration Mech Anal 220(1):243–260, 2016): what nonconstant functions f can occur as the proportionality factor for a Beltrami field $${{\mathbf {u}}}$$ on an open subset $$U \subset \mathbb {R}^3$$? We also consider the related question: for any such f, how large is the space of associated Beltrami fields? By applying Cartan’s method of moving frames and the theory of exterior differential systems, we are able to improve upon the results given in Peralta-Salas (2016). In particular, the answer to the second question depends crucially upon the geometry of the level surfaces of f. We conclude by giving a complete classification of Beltrami fields that possess either a translation symmetry or a rotation symmetry.
Droplet scRNA-seq is not zero-inflated.

Potential users of single cell RNA-sequencing often encounter a choice between high-throughput droplet based methods and high sensitivity plate based methods. In particular there is a widespread belief that single-cell RNA-sequencing will often fail to generate measurements for particular gene, cell pairs due to molecular inefficiencies, causing data to have an overabundance of zero-values. Investigation of published data of technical controls in droplet based single cell RNA-seq experiments demonstrates the number of zeros in the data is consistent with count statistics, indicating that over-abundances of zero-values in biological data are likely due to biological variation as opposed to technical shortcomings.
Do Feelings and Knowledge About Aging Predict Ageism

Experiencing ageism has been shown to negatively impact older adults. This study investigated predictors of ageism to examine which are most important in accounting for ageist attitudes. Participants (N = 419) between the ages of 18 and 86 completed an online survey assessing ageism and several predictors of ageism. Higher levels of anxiety about aging, lower levels of knowledge of aging, and less frequent and lower quality of contact with older adults uniquely predicted ageism beyond the influence of demographic and well-being factors. Anxiety about aging fully mediated the relationship between death anxiety and ageism, and the relationship between attitudes toward own aging and ageism. Moderation analyses showed that knowledge of aging buffered the impact of anxiety about aging on ageism such that low knowledge of aging and high anxiety about aging were particularly impactful in predicting ageism in younger adults, as compared with older adults.
Bias Correction With Jackknife, Bootstrap, and Taylor Series

We analyze bias correction methods using jackknife, bootstrap, and Taylor series. We focus on the binomial model, and consider the problem of bias correction for estimating $f(p)$ , where $f \in C[{0,1}]$ is arbitrary. We characterize the supremum norm of the bias of general jackknife and bootstrap estimators for any continuous functions, and demonstrate the in delete- $d$ jackknife, different values of $d$ may lead to drastically different behaviors in jackknife. We show that in the binomial model, iterating the bootstrap bias correction infinitely many times may lead to divergence of bias and variance, and demonstrate that the bias properties of the bootstrap bias corrected estimator after $r-1$ rounds are of the same order as that of the $r$ -jackknife estimator if a bounded coefficients condition is satisfied.
ELLIPSOIDAL CONES IN NORMED VECTOR SPACES

We give two characterizations of cones over ellipsoids in real normed vector spaces. Let C be a closed convex cone with nonempty inte- rior such that C has a bounded section of codimension 1. We show that C is a cone over an ellipsoid if and only if every bounded section of C has a center of symmetry. We also show that C is a cone over an ellipsoid if and only if the ane span of @C\@(a C) has codimension 1 for every point a in the interior of C. These results generalize the nite-dimensional cases proved in (4).
A Wearable Tactile Sensor Array for Large Area Remote Vibration Sensing in the Hand

Tactile sensing is essential for skilled manipulation and object perception. Existing sensing devices cannot capture the full range of tactile information in the naturally behaving hand, and are unable to match human abilities of perception and action. Human touch sensing is mediated via contact-generated mechanical signals in the skin. Time varying contacts elicit propagating mechanical waves that are captured via numerous vibration-sensitive neurons distributed throughout the hand, yielding a wealth of sensory information. Little engineering attention has been given to this important biological sensing system. Inspired by human sensing abilities, we present a wearable system based on a 126 channel sensor array capable of capturing high resolution tactile signals throughout the hand during natural manual activities. It employs a network of miniature three-axis sensors mounted on a flexible circuit whose geometry is adapted to the anatomy of the hand, allowing tactile data to be captured during natural manual interactions. Each sensor possesses a frequency bandwidth overlapping the entire human tactile frequency range. Data is acquired in real time via a custom FPGA and an I2C network. We also present physiologically informed signal processing methods for reconstructing whole hand tactile signals. We report experiments that demonstrate the utility of this system for collecting rich tactile signals during manual interactions.
Occurrence of cross-resistance and β-lactam seesaw effect in glycopeptide-, lipopeptide- and lipoglycopeptide-resistant MRSA correlates with membrane phosphatidylglycerol levels

BACKGROUND Glycopeptides (GPs), lipopeptides (LPs) and lipoglycopeptides (LGPs) are related antimicrobials important for the management of invasive MRSA infections. Cross-resistance among these antibiotics in MRSA is well documented, as is the observation that susceptibility of MRSA to β-lactams increases as susceptibility to GPs and LPs decreases (i.e. the seesaw effect). Efforts to understand the relationship between GP/LP/LGP cross-resistance and the seesaw effect have focused on the PBPs, but the role of lipid metabolism has not been investigated. OBJECTIVES Since the cell membrane is structurally and metabolically integrated with the cell wall and anchors associated proteins, including PBPs, we examined the relationship between membrane lipid composition and the phenomena of cross-resistance among GPs/LPs/LGPs and the β-lactam seesaw effect. METHODS We selected for daptomycin, vancomycin and dalbavancin resistance using the USA300 strain JE2 and evaluated the resulting mutants by WGS, MS-based lipidomics and antimicrobial susceptibility testing to assess the relationship between membrane composition, cross-resistance, and the seesaw effect. RESULTS We observed cross-resistance to GPs/LPs/LGPs among the selected strains and the seesaw effect against various β-lactams, depending on the PBP targets of the particular β-lactam. We found that modification of membrane composition occurs not only in daptomycin-selected strains, but also vancomycin- and dalbavancin-selected strains. Significantly, we observed that the abundance of most phosphatidylglycerols positively correlates with MICs of GPs/LPs/LGPs and negatively correlates with the MICs of β-lactams. CONCLUSIONS These studies demonstrate a major association between membrane remodelling, cross-resistance and the seesaw effect.
On an Equivalence Between Single-Server PIR with Side Information and Locally Recoverable Codes

Private Information Retrieval (PIR) problem has recently attracted a significant interest in the information-theory community. In this problem, a user wants to privately download one or more messages belonging to a database with copies stored on a single or multiple remote servers. In the single server scenario, the user must have prior side information, i.e., a subset of messages unknown to the server, to be able to privately retrieve the required messages in an efficient way.In the last decade, there has also been a significant interest in Locally Recoverable Codes (LRCs), a class of storage codes in which each symbol can be recovered from a limited number of other symbols. More recently, there is an interest in cooperative locally recoverable codes, i.e., codes in which multiple symbols can be recovered from a small set of other code symbols.In this paper, we establish a relationship between coding schemes for the single-server PIR problem and LRCs. In particular, we show the following results: (i) PIR schemes designed for retrieving a single message are equivalent to classical LRCs; and (ii) PIR schemes for retrieving multiple messages are equivalent to cooperative LRCs. These equivalence results allow us to recover upper bounds on the download rate for PIR-SI schemes, and to obtain a novel rate upper bound on cooperative LRCs. We show results for both linear and non-linear codes.
GLU3.0: Fast GPU-based Parallel Sparse LU Factorization for Circuit Simulation

Editor’s note: Many scientific computing problems, including circuit simulations, rely on efficient lower–upper (LU) decomposition of sparse matrices. Prior studies took advantage of GPUs to parallelize LU decomposition, but they suffer from nontrivial data dependencies. This article presents a new method, called GLU3.0, to accelerate GPU-based sparse LU factorization. — Umit Ogras, Arizona State University
Processivity and Velocity for Motors Stepping on Periodic Tracks

Processive molecular motors enable cargo transportation by assembling into dimers capable of taking several consecutive steps along a cytoskeletal filament. In the well-accepted hand-over-hand stepping mechanism, the trailing motor detaches from the track and binds the filament again in the leading position. This requires fuel consumption in the form of ATP hydrolysis and coordination of the catalytic cycles between the leading and the trailing heads. Alternate stepping pathways also exist, including inchworm-like movements, backward steps, and foot stomps. Whether all the pathways are coupled to ATP hydrolysis remains to be determined. Here, to establish the principles governing the dynamics of processive movement, we present a theoretical framework that includes all of the alternative stepping mechanisms. Our theory bridges the gap between the elemental rates describing the biochemical and structural transitions in each head and the experimentally measurable quantities such as velocity, processivity, and probability of backward stepping. Our results, obtained under the assumption that the track is periodic and infinite, provide expressions that hold regardless of the topology of the network connecting the intermediate states, and are therefore capable of describing the function of any molecular motor. We apply the theory to myosin VI, a motor that takes frequent backward steps and moves forward with a combination of hand-over-hand and inchworm-like steps. Our model quantitatively reproduces various observables of myosin VI motility reported by four experimental groups. The theory is used to predict the gating mechanism, the pathway for backward stepping, and the energy consumption as a function of ATP concentration.
Debt contracts in the presence of performance manipulation

Empirical evidence suggests that firms often manipulate reported numbers to avoid debt covenant violations. We study how a firm’s ability to manipulate reports affects the terms of its debt contracts and the resulting investment and manipulation decisions that the firm implements. Our model generates novel empirical predictions regarding the use and the level of debt covenant, the interest rate, the efficiency of investment decisions, and the likelihood of covenant violations. For example, the model predicts that the optimal debt contract for firms with relatively strong (weak) corporate governance (i.e., cost of manipulation) induces overinvestment (underinvestment). Moreover, for firms with strong (weak) corporate governance, an increase in corporate governance quality leads to tighter (looser) covenant, more (less) frequent covenant violations and lower (higher) interest rate. Our model highlights that the interest rate, which is a common proxy for the cost of debt, neither accounts for the distortion of investment efficiency nor the expected manipulation costs arising under debt financing. We propose a measure of cost of debt capital that accounts for these effects.
Ultranarrow Linewidth Photonic‐Atomic Laser

Lasers with high spectral purity can enable a diverse application space, including precision spectroscopy, coherent high-speed communications, physical sensing, and manipulation of quantum systems. Already, meticulous design and construction of bench Fabry-Perot cavities has made possible dramatic achievements in active laser-linewidth reduction, predominantly for optical-atomic clocks. Yet there is increasing demand for miniaturized laser systems operating with high performance in ambient environments. Here, we report a compact and robust photonic-atomic laser comprising a 2.5 cm long, 20,000 finesse, monolithic Fabry-Perot cavity integrated with a micromachined rubidium vapor cell. By leveraging the short-time frequency stability of the cavity and the long-time frequency stability of atoms, we realize an ultranarrow-linewidth laser that enables integration for extended measurements. Specifically, our laser supports a fractional-frequency stability of $1\times 10^{-13}$ at an averaging time of 20 ms, $7 \times 10^{-13}$ at 300 s, an integrated linewidth of 25 Hz that results from thermal noise, a Lorentzian linewidth as low as 0.06 Hz$^2$/Hz, and a passive vibration immunity as low as $10^{-10}$/g. Our work explores hybrid laser systems with monolithic photonic and atomic packages based on physical design.
A Communication-Efficient Multi-Agent Actor-Critic Algorithm for Distributed Reinforcement Learning *

This paper considers a distributed reinforcement learning problem in which a network of multiple agents aim to cooperatively maximize the globally averaged return through communication with only local neighbors. A randomized communication-efficient multi-agent actor-critic algorithm is proposed for possibly unidirectional communication relationships depicted by a directed graph. It is shown that the algorithm can solve the problem for strongly connected graphs by allowing each agent to transmit only two scalar-valued variables at one time.
Reverse greedy is bad for k-center

Abstract We show the reverse greedy algorithm is between a ( 2 k − 2 ) - and a 2k-approximation for k-center.
Efficient Behavior-aware Control of Automated Vehicles at Crosswalks using Minimal Information Pedestrian Prediction Model

Automotive Research Center (ARC) at the University of Michigan, with funding from government contract DoD-DoA W56HZV14-2-0001, through the U.S. Army Combat Capabilities Development Command (CCDC) /Ground Vehicle Systems Center (GVSC).
Shaping Visual Representations with Language for Few-Shot Classification

By describing the features and abstractions of our world, language is a crucial tool for human learning and a promising source of supervision for machine learning models. We use language to improve few-shot visual classification in the underexplored scenario where natural language task descriptions are available during training, but unavailable for novel tasks at test time. Existing models for this setting sample new descriptions at test time and use those to classify images. Instead, we propose language-shaped learning (LSL), an end-to-end model that regularizes visual representations to predict language. LSL is conceptually simpler, more data efficient, and outperforms baselines in two challenging few-shot domains.
Privacy of Dependent Users Against Statistical Matching

Modern applications significantly enhance user experience by adapting to each user’s individual condition and/or preferences. While this adaptation can greatly improve a user’s experience or be essential for the application to work, the exposure of user data to the application presents a significant privacy threat to the users—even when the traces are anonymized—since the statistical matching of an anonymized trace to prior user behavior can identify a user and their habits. Because of the current and growing algorithmic and computational capabilities of adversaries, provable privacy guarantees as a function of the degree of anonymization and obfuscation of the traces are necessary. Our previous work has established the requirements on anonymization and obfuscation in the case that data traces are independent between users. However, the data traces of different users will be dependent in many applications, and an adversary can potentially exploit such. In this paper, we consider the negative impact of dependency between user traces on their privacy. First, we demonstrate that the adversary can readily identify the association graph of the obfuscated and anonymized version of the data, revealing which user data traces are dependent. Next, we demonstrate that the adversary can use this association graph to break user privacy with significantly shorter traces than in the case of independent users, and that obfuscating data traces independently across users is often insufficient to remedy such leakage. In other words, we have shown that inter-user dependency is disastrous to privacy, and any non-negligible dependency between users significantly reduces the effectiveness of anonymization and obfuscation schemes. Finally, we discuss how users can improve privacy by employing joint obfuscation that removes or reduces the data dependency.
Effects of TOF Resolution Models on Edge Artifacts in PET Reconstruction from Limited Angle Data

Limited angle data, such as data obtained from a dual panel Breast-PET system, result in substantial image blur in the directions coinciding with the missing cone of the image spectrum. On systems with time-of-flight (TOF) capabilities, this blur is reduced in length as given by the TOF uncertainty, with the image spectral data correspondingly being expanded into the missing spectral cone. Modeling of the TOF uncertainty in the reconstruction is expected in turn to deconvolve the TOF blurring, at least for ideal noiseless data. We have however observed that, as a tradeoff, the TOF de-blurring process, when reconstructing limited angle data, also introduces ringing artifacts at the de-blurred objects edges, analogous to the edge effects observed with resolution modeling of the point-spread function (PSF) within image reconstruction which attempts to deconvolve the blur due to spatial resolution degradation effects. However, in the former case, the ringing artifacts are much wider due to the size of the TOF uncertainty kernel being considerably larger than the size of typical LOR resolution kernels. In this work, we illustrate and investigate the effects of using matched as well as under- and over-modeled TOF resolution kernels on edge artifacts in PET reconstruction from limited angle data, and compare those with the effects of TOF reconstruction of complete data from a conventional full-ring scanner.
Chapter 11 – Mating Systems

Publisher Summary Mating is a simple act with the most profound possible outcome: the production of the next generation. Mating is the point at which individual animals make a key evolutionary choice: how to combine their genes with the genes of another animal to give their offspring the greatest possible genetic advantage. Biologists have classified mating systems using observations of social interactions. Social monogamy is the pairing of a single male with a single female. Social polygyny is the pairing of one male—generally either a territory holder or a dominant male with a harem—and many females. Social polyandry, which is rare, is one female associated with a number of males. Polygynandry and promiscuity result from more complex patterns involving multiple mates for both males and females. Genetic characterization of mating systems leads to a far different picture. In many socially monogamous mating systems, organisms participate in extrapair copulations that result in extrapair paternity.
Acronyms in bone densitometry.

In response to our publication (Gluer et al, 1990a), Wilson and colleagues (1990) proposed the adoption of a uniform terminology and corresponding abbreviation for Dual X-ray Absorptiometry (DXA). We supported this suggestion (Gluer et al, 1990b). Since then, the number of papers on DXA has increased considerably. Still, different abbreviations (DEXA, DER, DRA, QDR and DPX) for this technique for bone densitometry are used, several of which are proprietary in origin. DXA is the upgraded version of DPA (Dual Photon Absorptiometry). The nuclear source has been replaced by an X-ray source and this improved technology has gained wide-spread acceptance and distribution.
Chapter 8 – Excretory Systems

The excretory system maintains the internal environment of the insect by separating and eliminating metabolic wastes and other toxic substances from body compartments to allow normal metabolic processes to continue. Because these wastes are often dissolved in water, excretory processes are also closely associated with osmoregulation and the maintenance of water balance. Insects are typically 60–75% water by wet weight, but can range from 17% to 90% during the various life stages of particular species. Some insects can withstand dehydration to an incredible degree: there are several chironomid midges that can survive after losing up to 70–90% of their body water. As mentioned in a previous chapter, Hinton identified a chironomid that could survive temperature extremes of −270 to +100°C once dehydrated to 3% of normal body water content and afterwards rehydrated. Water is an essential component of all living organisms, and a molecule that almost all biological molecules must interact with. Like all organisms, insects must carefully regulate their water content to maintain their physiological systems, but have an amazing capacity for extreme tolerances.
Enterprise Risk Management (ERM)

Enterprise risk management (ERM) is a recent risk-management technique for managing a portfolio of risks in a holistic manner. ERM has evoked interest from corporate executives, regulators, and rating agencies, among others. Under the ERM framework, corporations take on risks necessary to pursue their strategic objectives, consistent with their “risk appetite”. The core of the ERM process is efficient risk integration, in which interrelations among risks and risk prioritization are highlighted. Certain risk measures, aggregation methods, or other mathematical modeling approaches are usually involved in its implementation. Effective risk reporting and communications in a well-designed organizational structure are also essential for the success of ERM. The ultimate goal of ERM is to move beyond the initial incentive of fulfilling a compliance need to achieve real economic value. Keywords: enterprise risk management (ERM); risk appetite; operational risk; risk integration; risk measure; risk aggregation; holistic risk management
Cancer Risk Evaluation from Animal Studies

Data from properly designed and evaluated studies in experimental animals have been and continue to be reliable sources of information for the identification of potential human health hazards and the estimation of risks in exposed human populations. Properly designed studies must include (a) animal models that are sensitive to the endpoints under investigation, (b) adequately challenging doses, (c) adequate durations of exposure (at least 2 years for carcinogenicity studies in rats and mice), (d) sufficient numbers of animals per dose group to have adequate statistical power to detect a true effect, (e) multiple dose groups to allow characterization of dose–response relationships, (f) complete and peer-reviewed histopathological diagnoses, and (g) pair-wise comparisons with the control group and analyses of trends based on survival-adjusted tumor rates. Mechanistic information and pharmacokinetic models that have been adequately tested may have an impact on the characterization of dose–response relationships and the estimation of cancer risk at human exposure levels. Setting occupational or environmental exposure standards based on animal carcinogenicity data provides a prudent public health approach to reduce the burden of cancer in exposed populations. More work is necessary to understand the basis for interindividual differences in susceptibility and to properly establish health-based exposure standards that protect the most vulnerable segments of the general population. Keywords: cancer bioassay; laboratory animals; human cancer risk; histopathology; statistical power; survival-adjusted tumor rates; low-dose extrapolation; human susceptibility; exposure standards
On the nature of Upsilon Sagittarii.

An explanation for the nature and evolution of the extremely hydrogen deficient binary Upsilon Sagittarii which is consistent with all observational and theoretical facts. First, the system goes through a Case B mass exchange in which most of the hydrogen rich envelope of a massive primary (5 to 14 solar masses) is lost. The remaining envelope still contains about 50 percent hydrogen (by number), but is now of negligible mass, so that the star evolves like a pure helium star. If its mass is between 1 and 2 solar masses the star reaches low surface temperatures and becomes a supergiant before the onset of carbon burning. This star (the original primary) then fills its Roche lobe a second time,spilling its now helium rich envelope over onto the secondary (Case BB mass exchange). It is argued that Upsilon Sagittarii is in this state at the present time, and that the visible star is an evolved helium star of about 1 solar mass with a degenerate carbon-oxygen core and a helium burning shell which provides the high luminosity. Previously announced in Star as N26117
Simulaid: a Simulation Facilitator and Analysis Program

The poster describes the program Simulaid that performs a large number of simulation-related tasks: interconversion and modification of structure and trajectory files, optimization of orientation, and a variety of analysis functions. It can handle structures and (in most cases) trajectories in a variety of the popular formats: PDB, Charmm CRD, Amber, Macromodel, Gromos/Gromacs, InsightII, Tripos' .mol2 (only input) and the MMC.Analysis features range from simple distance calculations and hydrogen-bond analysis to calculation of 2-D RMSD maps (both as text file with the data and as a color-coded matrix) and cross RMSD maps between trajectories as well as clustering based on RMSD maps; analysis of torsion angles, Ramachandran angles, proline kink angles, pseudorotational angles; as well as novel analyses, e.g., analysis based on circular variance. Torsion angle evolutions are presented in dial plots. The complete list of features will be presented, including the theory behind them (whenever applicable) and examples of typical plots will be shown. Several of these features are unique to Simulaid.
Chapter 4 – Multi-Dimensional, Multi-Scale Modeling and Algorithms for Integrating Variable Energy Resources in Power Networks: Challenges and Opportunities

Integration of large amounts of renewable energy in electric power networks must address emerging behavior at new spatial and temporal scales. It must also address factors or dimensions, associated with resource availability, economic viability, social management, grid aspects, and regional objectives. This chapter starts by reviewing the relevant spatial, temporal, and scenario dimensions, and by listing the appropriate scales of interest. Then, it reviews the state of the art in three key areas of multi-scale, multi-dimension analysis: (1) modeling and analysis, (2) optimization and control, and (3) data management and visualization. An integrated multi-dimensional, multi-scale framework for design, deployment, operation, and management of networks with high levels of renewable energy is proposed.
Chapter 7 – Internet Security

The field of Internet security metrology is early in its development. Organizations collect many individual measures, but often do not understand how to analyze those measures and combine them into higher-level metrics that can be used for decision making. Many measures are also defined or implemented poorly, so that the data they generate is inaccurate, irrelevant, inconsistent, or misleading. Also, many measures have no meaning unless they are carefully considered within the context of other measures, but not much work has been done in identifying which measures relate to other measures. Little research has been performed to determine which measures and metrics are most relevant for determining a system or an organization’s Internet security posture, particularly, studies of empirical data from real-world operational environments and analysis of the degree of variability between different organizations security objectives. Examples of questions that this chapter will attempt to answer in a scientific manner are: How vulnerable is a particular system or a system design? What are the differences in Internet security among multiple systems or networks within an organization? How does the Internet security of one organization’s systems and networks compare to those of another organization? If particular changes are made to Internet security controls, how much does an individual systems security or the organization’s security improve?
Causes and Impacts of Job Displacements and Public Policy Responses

Across the globe, both cyclical downturns and structural changes episodically eliminate substantial numbers of jobs and in the process create serious dislocations. For instance, the rise in joblessness because of the ongoing COVID-19 crisis is projected to be extraordinarily steep. As a response to job displacements, governments have implemented a range of measures to financially compensate displaced workers, assist them in finding reemployment, or both. The challenges should not be minimized: job losses have significant economic as well as social and psychological consequences; laid-off workers often lack the skills or geographic proximity to easily transfer to sectors that are growing; and providing adequate support can be expensive. Nonetheless, careful public policy responses can help mitigate the costs of job displacements and support workers in finding productive reemployment.
Where the boys aren't: Non-cognitive skills, returns to school and the gender gap in higher education

Abstract Nearly 60 percent of college students today are women. Using longitudinal data on a nationally representative cohort of eighth grade students in 1988, I examine two potential explanations for the differential attendance rates of men and women—returns to schooling and non-cognitive skills. The attendance gap is roughly five percentage points for all high school graduates. Conditional on attendance, however, there are few differences in type of college, enrollment status or selectivity of institution. The majority of the attendance gap can be explained by differences in the characteristics of men and women, despite some gender differences in the determinants of college attendance. I find that higher non-cognitive skills and college premiums among women account for nearly 90 percent of the gender gap in higher education. Interestingly, non-cognitive factors continue to influence college enrollment after controlling for high school achievement.
WHAT WOULD YOU DO? CHALLENGES IN KNEE SURGERY

This session will present a series of challenging and complex primary and revision cases to a panel of knee arthroplasty experts. A variety of cases representing the spectrum of not uncommonly presenting pathologies will be discussed in terms of appropriate work-up, clinical management, surgical approach, and aftercare. This will be an interactive case-based session that at its conclusion should leave the attendee with a more thorough approach to these challenging issues.
Detection and quantitation of radiolabeled proteins and DNA in gels and blots

This appendix presents procedures for visualizing and quantitating radiolabeled proteins or DNA separated by polyacrylamide gel electrophoresis or affixed to filter membranes. Autoradiography is the most common method by which this is accomplished; X-ray film is the traditional recording medium. Film images can be analyzed by densitometry as described to obtain a quantitative measure of the radioactivity in the sample. The use of X-ray films for autoradiography, however, suffers from lack of sensitivity and limited linear range. Protocols are provided for overcoming these limitations using fluorography and intensifying screens, both of which enhance the radioactive signal. Sensitivity and linear ranges of measurement can be greatly extended by using a phosphor imaging system, which also makes it much faster and easier to quantify radioactive samples.
On Constrained Open-World Probabilistic Databases.

Increasing amounts of available data have led to a heightened need for representing large-scale probabilistic knowledge bases. One approach is to use a probabilistic database, a model with strong assumptions that allow for efficiently answering many interesting queries. Recent work on open-world probabilistic databases strengthens the semantics of these probabilistic databases by discarding the assumption that any information not present in the data must be false. While intuitive, these semantics are not sufficiently precise to give reasonable answers to queries. We propose overcoming these issues by using constraints to restrict this open world. We provide an algorithm for one class of queries, and establish a basic hardness result for another. Finally, we propose an efficient and tight approximation for a large class of queries.
Graph spanners: A tutorial review

Abstract This survey provides a guiding reference to researchers seeking an overview of the large body of literature about graph spanners. It surveys the current literature covering various research streams about graph spanners, such as different formulations, sparsity and lightness results, computational complexity, dynamic algorithms, and applications. As an additional contribution, we offer a list of open problems on graph spanners.
Large Optical Tunability from Charge Density Waves in 1T-TaS2 under Incoherent Illumination

Strongly correlated materials possess a complex energy landscape and host many interesting physical phenomena, including charge density waves (CDWs). CDWs have been observed and extensively studied...
Exact values of quantum violations in low-dimensional Bell correlation inequalities

Abstract The famous Clauser-Horne-Shimony-Holt (CHSH) inequality certifies a quantum violation, by a factor 2 , of correlations predicted by the classical view of the world in the simplest possible nontrivial measurement setup (two systems with two dichotomic measurements each). In such setting, this is the largest possible violation, which is known as the Tsirelson bound. In this paper we calculate the exact values of quantum violations for the other Bell correlation inequalities that appear in the setups involving up to four measurements; they are all smaller than 2 . While various authors investigated these inequalities via numerical methods, our approach is analytic. We also include tables summarizing facial structure of Bell polytopes in low dimensions.