cssi/SciSciGPT-SciSciNet huggingface dataset:
A hybrid theory of muscle contraction.

Abstract A new theory of muscle contraction is presented which combines the advantages of the crossbridge theories with those of the electrostatic theories. Negatively charged phosphoryl groups are enzymically deposited on the actin filament by crossbridges from the myosin filaments. The resulting electrostatic repulsion between the phosphates and the normally negatively charged myosin filaments causes lateral expansion of the myofilament lattice. Since the process is known to take place isovolumetrically, contraction results. Model calculations indicate that these electrostatic repulsions can generate adequate tension. This hybrid theory also provides a natural explanation for virtually every other important property of muscle contraction.
Elemental signatures in the vertebral cartilage of the round stingray, Urobatis halleri, from Seal Beach, California

Although numerous studies have utilized elemental analysis techniques for age determination in bony fishes, little work has been conducted utilizing these procedures to verify age assessments or temporal periodicity of growth band formation in elasmobranchs. The goal of this study was to determine the potential of laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS) to provide information on the seasonal deposition of elements in the vertebrae of the round stingray collected from Seal Beach, California. Spatially resolved time scans for elements across the round stingray vertebrae showed peaks in calcium intensity that aligned with and corresponded to the number of seasonal growth bands identified using standard light microscopy. Higher signals of calcium were associated with the wide opaque bands while lower signals of calcium corresponded to the narrow translucent bands. While a close alignment between the numbers of calcium peaks and annual growth bands was observed in round stingray samples aged 5 years or younger, this relationship was less well defined in vertebral samples from round stingrays over 11 years old. To the best of our knowledge, this is the first study of its kind to utilize ICP-MS to verify age assessments and seasonal band formation in an elasmobranch. The results from this preliminary study indicate that LA-ICP-MS elemental analysis of the vertebral cartilage of the round stingray may have potential to independently verify optically derived age assessments and seasonal banding patterns in elasmobranch vertebrae.
Observer design for nonlinear systems by using Input-to-State Stability

The problem of constructing full-order state observers for a class of systems with Lipschitz nonlinearities is addressed. By performing a suitable decomposition of the estimation error dynamics into cascaded systems, conditions have been found that guarantee the asymptotic stability of the estimation error in the absence of disturbances. These conditions can be conveniently expressed by means of linear matrix inequalities (LMIs). In the presence of system and measurement perturbations, when such noises are regarded as unknown deterministic inputs acting on the error dynamics, the estimator can be designed so as to be input-to-state stable (ISS) with respect to the estimation error.
Maternal body volume constrains water uptake by lizard eggs in utero

Summary 1. Flexible shelled eggs of squamate reptiles normally take up substantial amounts of water, and swell accordingly, during development. However, most water uptake occurs after oviposition, beginning immediately or soon after oviposition, and water uptake is severely restricted in eggs that are retained in utero past the normal time of oviposition. 2. These observations suggest that some aspect of retention in the oviductal environment limits the amount of water eggs can absorb prior to oviposition. 3. This paper presents evidence, from two species of Sceloporuslizard, supporting the hypothesis that limited space within the mother’s body cavity physically constrains the ability of eggs to expand, and thereby their ability to absorb water. When adjusted for maternal body size, the water content of a female’s clutch of eggs is negatively correlated with the dry mass of her clutch (the space available in the body cavity is finite, and thus a greater dry mass content leaves less volume for water). 4. If such a constraint on water uptake is widespread, it can have important implications for our understanding of the evolution of viviparity, the costs of reproduction, and the determinants of reproductive output in squamate reptiles.
Constantly Compromised: The Impact of Homelessness on Children

This review summarizes the small body of research and literature to date that focuses on the specific effects of homelessness on children. In each of the major areas surveyed—health, development, and education—studies reveal that homeless children are not simply at risk; most suffer specific physical, psychological, and emotional damage due to the circumstances that usually accompany episodes of homelessness for families and children. The article concludes with a brief consideration of the research and policy implications of this research.
Systems theory instrumented simulation modeling

The paper reviews the impact of systems theory-based representation methods in the context of discrete event simulation modeling. Tools for formal system specification and methods for model static and dynamic structure description are presented. Recent efforts in implementing the systems theory instrumented multifacetted methodology are also discussed.
Precessional stabilization of the m = 1 interchange mode in low density migma plasmas

Abstract The results of computer simulations of migma and simple mirror plasmas indicate that the stabilization of Migma IV to the m = 1 interchange mode is likely due to precession and that the interchange mode may develop at higher densities.
Increased Ethanol Self‐Administration after a Period of Imposed Ethanol Deprivation in Rats Trained in a Limited Access Paradigm

A predominant feature in human alcohol abuse is the reported desire or "craving" to consume ethanol along with frequent episodes of drinking after periods of abstinence. These and other factors may be responsible for relapse to uncontrolled ethanol drinking. When relapse occurs after a period of abstinence, ethanol drinking has been shown to be temporarily increased. Two aspects of drug dependence could contribute to these increases. One may be the development of a need state; the other may involve changes in the perception of the positive reinforcing effects of ethanol when reinforcer access is limited. To investigate this phenomenon further, the present study was conducted to examine in nondependent rats the effect of forced time-off on oral ethanol self-administration in a limited access paradigm (30 min/day). Male Wistar rats were trained to respond for ethanol (10% w/v) or water in a two-lever, free-choice condition using a saccharin fading procedure. After the establishment of stable baseline responding for ethanol, various ethanol deprivation periods (3, 5, 7, 14, or 28 days) were imposed, during which no ethanol was available. Responding for ethanol increased as a function of the duration of the deprivation period when compared with baseline levels. This increase was temporary and returned to baseline levels within 2 to 3 days. Given that the shortest time-off period was 5 days and the rats showed no signs of withdrawal, this transient increase in ethanol responding does not seem to be related to the manifestation of dependence and withdrawal, and may be related to changes in ethanol's reinforcement properties. These results with rats may provide a useful tool to elucidate mechanisms underlying human alcohol seeking behavior and relapse.
Electrokinetic analysis of hydroentangled greige cotton–synthetic fiber blends for absorbent technologies

Through nonwoven hydroentanglement of greige cotton blends with polyester and nylon, varying degrees of fiber surface polarity, swelling, and absorbance can be achieved. Electrokinetic properties o...
Unique ultrastructure in the elementary body of Chlamydia sp. strain TWAR.

The ultrastructure of two prototype strains (TW-183 and AR-39) of Chlamydia sp. strain TWAR was described. The TWAR elementary body (EB) demonstrated a unique morphology and structure distinct from those of other chlamydial organisms. It was pleomorphic but typically pear shaped. The average size was 0.38 micron, with a long axis of 0.44 micron, a short axis of 0.31 micron, and a ratio of the long to the short axes of 1.42. The cytoplasmic mass was round, with an average diameter of 0.24 micron. There was a large periplasmic space. Small, round electron-dense bodies (0.05 micron in diameter), which were attached to the cytoplasm by a stringlike structure, were seen in the periplasmic space. These features are in contrast to those of other chlamydiae, which are typically round with a narrow or barely discernible periplasmic space. The TWAR reticulate body (RB) was morphologically and structurally similar to those of other Chlamydia species, having an average diameter of 0.51 micron and being circular in shape. The ultrastructural observations of the intracellular growth of TWAR in HeLa cells revealed that TWAR underwent the same developmental cycle as do other chlamydiae, i.e., transformation of EB to RB, multiplication by binary fission, and maturation by transformation of RB to EB via the intermediate-form stage.
Evoked response correlates of meaningful visual stimuli in children.

Photographic slides of familiar objects or cartoons were tachistoscopically presented to a group of 79 normal children (age 5-11 years) in a study of the evoked response correlates of meaningful visual stimuli. Control stimuli consisted of blank slides or defocused cartoons matched for brightness. A warning flash preceded the slides by 1 sec. EEG and eye movement potentials were recorded on line with a 9.5 sec time constant and averaged off-line. The principal finding was a vertex negative slow potential peaking about 500 msec after slide presentation which correlated with reports of interest in and recall of both objects and cartoons. Responses in the occipital region changed less consistently with pictorial material, and were the same to the warning flash whether it preceded control or test stimuli. The vertex negative response appears to be a corollary of perceptual integration of meaningful stimuli. Among alternative explanations nonspecific differences in arousal level and/or expectancy appear to be unlikely on the basis of our data. A primary role of edge contrast in generating these late negative responses would not be predicted on the basis of published evidence, but our attempt to control for this alternative yielded equivocal results.
Aberrant reduction of telomere repetitive sequences in plasma cell-free DNA for early breast cancer detection

Excessive telomere shortening is observed in breast cancer lesions when compared to adjacent non-cancerous tissues, suggesting that telomere length may represent a key biomarker for early cancer detection. Because tumor-derived, cell-free DNA (cfDNA) is often released from cancer cells and circulates in the bloodstream, we hypothesized that breast cancer development is associated with changes in the amount of telomeric cfDNA that can be detected in the plasma. To test this hypothesis, we devised a novel, highly sensitive and specific quantitative PCR (qPCR) assay, termed telomeric cfDNA qPCR, to quantify plasma telomeric cfDNA levels. Indeed, the internal reference primers of our design correctly reflected input cfDNA amount (R(2) = 0.910, P = 7.82 × 10(-52)), implying accuracy of this assay. We found that plasma telomeric cfDNA levels decreased with age in healthy individuals (n = 42, R(2) = 0.094, P = 0.048), suggesting that cfDNA is likely derived from somatic cells in which telomere length shortens with increasing age. Our results also showed a significant decrease in telomeric cfDNA level from breast cancer patients with no prior treatment (n = 47), compared to control individuals (n = 42) (P = 4.06 × 10(-8)). The sensitivity and specificity for the telomeric cfDNA qPCR assay was 91.49% and 76.19%, respectively. Furthermore, the telomeric cfDNA level distinguished even the Ductal Carcinoma In Situ (DCIS) group (n = 7) from the healthy group (n = 42) (P = 1.51 × 10(-3)). Taken together, decreasing plasma telomeric cfDNA levels could be an informative genetic biomarker for early breast cancer detection.
Computational characterization of fracture healing under reduced gravity loading conditions

The literature is deficient with regard to how the localized mechanical environment of skeletal tissue is altered during reduced gravitational loading and how these alterations affect fracture healing. Thus, a finite element model of the ovine hindlimb was created to characterize the local mechanical environment responsible for the inhibited fracture healing observed under experimental simulated hypogravity conditions. Following convergence and verification studies, hydrostatic pressure and strain within a diaphyseal fracture of the metatarsus were evaluated for models under both 1 and 0.25 g loading environments and compared to results of a related in vivo study. Results of the study suggest that reductions in hydrostatic pressure and strain of the healing fracture for animals exposed to reduced gravitational loading conditions contributed to an inhibited healing process, with animals exposed to the simulated hypogravity environment subsequently initiating an intramembranous bone formation process rather than the typical endochondral ossification healing process experienced by animals healing in a 1 g gravitational environment. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1206-1215, 2016.
Model Predictive Neural Control for Aggressive Helicopter Maneuvers

This chapter contains sections titled: Introduction MPC Control MPNC Experimental Results Conclusion References ]]>
The Practical Science of Medicine

Contemporary medicine, it is argued here, employs reductive explanations, but at the same time resists wholesale reduction to "deeper" biochemical and physical fields or theories. In its own reductive explanations, to be sure, medicine borrows causal concepts from other fields and so necessarily shares certain explanatory goals with those deeper fields. However, because medicine has additional, distinctive goals as well as a special subject matter and problems (it is a practical science), the field of medicine is ultimately irreducible.
Development of Discrete Blade Momentum Source Method for Rotors in an Unstructured Solver

An unstructured, time-accurate solution methodology for rotorcraft ows is presented. The incompressible, unsteady, three-dimensional Navier-Stokes equations are solved in the primitive variable formulation, using a vertex-centered, median-dual based nite volume method. The physical domain is discretized into tetrahedrons and the discretized equations are solved using the SIMPLER solution algorithm. To correctly model the unsteady aerodynamics of discrete rotor blades, a novel rotor modeling technique, based on the momentum source approach, is developed and integrated with the unstructured ow solver. The rotor blades are simulated as a distribution of momentum sources, the strengths of which are determined from the instantaneous position of the rotor, oweld properties, rotor geometry and the aerodynamic characteristics of the blade cross-section. The new solution procedure is shown to capture unsteady eects of discrete rotor blades and results for rotors hovering in and out-of-ground eect are presented.
Presence of 2 different viral agents in brain cells of patients with subacute sclerosing panencephalitis.

SummaryA measles-related virus was isolated from two out of three brain biopsies of patients with SSPE by the fusion of brain cells with susceptible cells. β-propiolactone-inactivated Sendai virus was used in the fusion experiments. The mechanism of activation and the characterization of the isolated agents are discussed. Their association with another virus is reported in light of the etiology of SSPE.
Biological and Epidemiological Features of Antibiotic-Resistant Streptococcus pneumoniae in Pre- and Post-Conjugate Vaccine Eras: a United States Perspective

Streptococcus pneumoniae inflicts a huge disease burden as the leading cause of community-acquired pneumonia and meningitis. Soon after mainstream antibiotic usage, multiresistant pneumococcal clones emerged and disseminated worldwide. Resistant clones are generated through adaptation to antibiotic pressures imposed while naturally residing within the human upper respiratory tract. Here, a huge array of related commensal streptococcal strains transfers core genomic and accessory resistance determinants to the highly transformable pneumococcus. β-Lactam resistance is the hallmark of pneumococcal adaptability, requiring multiple independent recombination events that are traceable to nonpneumococcal origins and stably perpetuated in multiresistant clonal complexes. Pneumococcal strains with elevated MICs of β-lactams are most often resistant to additional antibiotics. Basic underlying mechanisms of most pneumococcal resistances have been identified, although new insights that increase our understanding are continually provided. Although all pneumococcal infections can be successfully treated with antibiotics, the available choices are limited for some strains. Invasive pneumococcal disease data compiled during 1998 to 2013 through the population-based Active Bacterial Core surveillance program (U.S. population base of 30,600,000) demonstrate that targeting prevalent capsular serotypes with conjugate vaccines (7-valent and 13-valent vaccines implemented in 2000 and 2010, respectively) is extremely effective in reducing resistant infections. Nonetheless, resistant non-vaccine-serotype clones continue to emerge and expand.
Software security education at scale

Massively Open Online Courses (MOOCs) provide a unique opportunity to reach out to students who would not normally be reached by alleviating the need to be physically present in the classroom. However, teaching software security coursework outside of a classroom setting can be challenging. What are the challenges when converting security material from an on-campus course to the MOOC format? The goal of this research is to assist educators in constructing software security coursework by providing a comparison of classroom courses and MOOCs. In this work, we compare demographic information, student motivations, and student results from an on-campus software security course and a MOOC version of the same course. We found that the two populations of students differed, with the MOOC reaching a more diverse set of students than the on-campus course. We found that students in the on-campus course had higher quiz scores, on average, than students in the MOOC. Finally, we document our experience running the courses and what we would do differently to assist future educators constructing similar MOOC’s.
Atrial natriuretic factor and salt adaptation in the teleost fish Gila atraria

It is unknown whether atrial natriuretic factor (ANF) is a mediator of environmental salt tolerance in euryhaline teleost fish. This was investigated in anesthetized Gila atraria, a euryhaline teleost native to springs of pleistocene Lake Bonneville. Plasma levels of immunoreactive (ir) ANF [using anti-human ANF-(99-126) antibodies] in fish obtained from a "fresh water" spring were significantly lower (146 +/- 27) than those in fish obtained from a "1% NaCl" spring (347 +/- 21 pg/ml, P less than 0.01). Electron micrographs of fish atrial and ventricular cardiocytes demonstrated many perinuclear granules, which closely resembled ANF-containing secretory granules seen in mammalian atriocytes. Fish heart extract contained ANF-like material of 3 kDa, which caused a marked diuresis and natriuresis in rats. In a second study, fish from a 1% NaCl spring were kept in tanks. One-third of the fish were maintained in 1% NaCl and one-third each were either adapted to fresh- or high-salt water. After 12 days, plasma irANF levels in 1% NaCl fish were 343 +/- 55, in fresh water fish 213 +/- 20 and in high-NaCl fish 691 +/- 79 pg/ml. These values differed significantly from each other (P less than 0.01). There was a close correlation between plasma irANF levels and both environmental and internal salt concentration. These data suggest that piscine ANF is an as yet unrecognized mediator of salt tolerance in this teleost and that ANF in these animals closely resembles mammalian ANF.
Comparison of implosion core metrics: A 10 ps dilation X-ray imager vs a 100 ps gated microchannel plate

The dilation x-ray imager (DIXI) [T. J. Hilsabeck et al., Rev. Sci. Instrum. 81, 10E317 (2010); S. R. Nagel et al., ibid. 83, 10E116 (2012); S. R. Nagel et al., ibid. 85, 11E504 (2014)] is a high-speed x-ray framing camera that uses the pulse-dilation technique to achieve a temporal resolution of less than 10 ps. This is a 10 × improvement over conventional framing cameras currently employed on the National Ignition Facility (NIF) (100 ps resolution), and otherwise only achievable with 1D streaked imaging. A side effect of the dramatically reduced gate width is the comparatively lower detected signal level. Therefore we implement a Poisson noise reduction with non-local principal component analysis method [J. Salmon et al., J. Math. Imaging Vision 48, 279294 (2014)] to improve the robustness of the DIXI data analysis. Here we present results on ignition-relevant experiments at the NIF using DIXI. In particular we focus on establishing that/when DIXI gives reliable shape metrics (P0, P2, and P4 Legendre modes, and their temporal evolution/swings).
Radiation Leakage Control of Industrial Microwave Power Devices

ABSTRACTThis paper discusses the current responsibilities and activities of the Bureau of Radiological Health in carrying out the requirements of the Radiation Control for Health and Safety Act of 1968, especially in relation to industrial uses of microwave power. It assesses the public health significance of industrial versus other types of applications and describes past, current, and anticipated investigations which are believed to be necessary to properly evaluate potential hazards and develop Federal standards. The responsibilities of the manufacturer, user, and regulatory agencies in cooperatively safeguarding the public health and safety are delineated.
Cancer biomarker discovery is improved by accounting for variability in general levels of drug sensitivity in pre-clinical models

We show that variability in general levels of drug sensitivity in pre-clinical cancer models confounds biomarker discovery. However, using a very large panel of cell lines, each treated with many drugs, we could estimate a general level of sensitivity to all drugs in each cell line. By conditioning on this variable, biomarkers were identified that were more likely to be effective in clinical trials than those identified using a conventional uncorrected approach. We find that differences in general levels of drug sensitivity are driven by biologically relevant processes. We developed a gene expression based method that can be used to correct for this confounder in future studies.
Understanding factors affecting users social networking site continuance

Social networking sites (SNSs) have attracted more and more people to interact on line. Because of their popularity, firms and organizations are now marketing their business on SNS pages. It is essential for both SNS providers and firms to retain their current members. Consequently, use continuity of SNSs has gained the attention of both practitioners and researchers. However, few studies have systematically examined gender differences in such a context. To address this gap, we have developed an advanced framework to explain and analyze gender differences in users SNS continuance decisions. We propose an SNS continuance model by integrating SNS-oriented constructs (perceived privacy risk, perceived enjoyment, perceived reputation, and community identification) into the established ECM-ISC model and introduce gender as a key moderator. Our research results indicate that all the added SNS-oriented constructs influence users SNS continuance directly and indirectly. Furthermore, the impact of each factor on SNS continuance varies by gender. Each gender bases SNS continuance decisions on a different set of factors and/or different weights of the same factors. This study provides evidence that gender effects should be considered in understanding the continued usage of SNSs. It also provides an opportunity to develop a deeper understanding of gender differences in SNS continuance and fills the research gap regarding this. The theoretical and practical implications of these results are discussed.
Developing an Inquiry Stance toward Instructional Improvement: Teacher-Leader Action Research

ABSTRACTThis special issue explores the relationship between practice-based research and the work of teacher leaders. Although teachers are called on with increasing regularity to share leadership in our nation’s districts and schools, it is not clear how teachers learn to practice effective leadership. The articles presented in this issue argue that systematic inquiry can help teacher leaders understand problems of leadership practice, implement support for professional learning, collect data related to their efforts and reflect on the outcomes of their leadership work.
Observations on the biology ofThiothrix

Thiothrix nivea grows profusely in tufts of greyish white material on pebbles in a local sulfide spring. The spring remained a constant 10.8° C during the course of the study. Chemical analyses indicated that the spring water contained 0.27 mg/l sulfide, 0.37 mg/l oxygen, and 0.77 mg/l dissolved organic carbon. Tufts ofThiothrix growth were removed from the pebbles and examined by phase and electron microscopy. The cell filaments contained numerous sulfur granules which disappeared upon incubation in the refrigerator. The average cell diameter was 1.5 μm and the length 4.0 μm. When cells were lysed by hyperplasmolysis a sheath was readily discernible. The presence of a sheath, 60 nm thick, was confirmed in thin sections. Fine structure analysis also revealed that the organism was a gram negative bacterium. Sulfur granules were bound by a unit membrane extending from the cytoplasmic membrane.Thiothrix nivea was grown for short periods of time in slide culture. In some cases the filaments fragmented into short segments ca 15μm long. These may represent gonidia as initially reported by Winogradsky.
Biomarkers that predict sensitivity to heat shock protein 90 inhibitors (HSP90i).

10618 Background: HSP90 is an attractive target in tumors as it mediates the maturation and stabilization of client oncoproteins. HSP90i are potentially active in a variety of tumors, but therapeut...
Second trimester levothyroxine treatment for subclinical hypothyroidism or hypothyroxinaemia of pregnancy does not improve cognitive outcomes of children

Overt thyroid disease, be it overt hypothyroidism or overt hyperthyroidism, is associated with a multitude of adverse outcomes during pregnancy including miscarriage, gestational hypertension, gestational diabetes, preterm delivery and decreased IQ in the offspring.1 In its most severe form, overt hypothyroidism results in cretinism. The impact of subclinical hypothyroidism (SCH) on pregnancy outcomes is complex. Observational and retrospective studies have shown a correlation with adverse maternal and fetal events.2 In 1999, Pop et al 3 and Haddow et al 4 reported a correlation between hypothyroidism and isolated hypothyroxinaemia (IH) with decreased neurocognitive function in the offspring. However, only two prospective randomised studies have evaluated the impact of levothyroxine therapy for SCH or IH on pregnancy outcomes. In an Italian study, levothyroxine therapy for SCH in thyroid antibody-positive women in the first trimester of pregnancy …
Phytochemical induction of cell cycle arrest by glutathione oxidation and reversal by N-acetylcysteine in human colon carcinoma cells

3340 Cancer prevention by dietary phytochemicals has been shown to involve decreased cell proliferation and cell cycle arrest in cancer cell lines. However, there is limited understanding of the mechanisms. Previously, we have shown that a common effect of phytochemicals investigated is to oxidize the intracellular glutathione (GSH) pool. Therefore, the objective of this study was to evaluate whether changes in the glutathione redox potential in response to select dietary phytochemicals was related to their induction of cell cycle arrest. Human colon carcinoma (HT29) cells were treated with benzyl isothiocyanate (BIT), diallyl disulfide (DADS), dimethyl fumarate (DMF), lycopene (LYC), sodium butyrate (NaB) or buthione sulfoxamine (BSO, a GSH synthesis inhibitor) at concentrations known to cause oxidation of the GSH: glutathione disulfide pool. After 16 h, cells were harvested, fixed in ethanol, centrifuged and ethanol removed by aspiration. Cell cycle analysis was performed using a Becton Dickinson FACS Calibur and data analyzed by ModFit LT™ software. The dietary phytochemicals resulted in increased percentage (ranging from 75% to 30% for benzyl isothiocyanate and lycopene, respectively) of cells at G2/M arrest (BIT > NaB > DADS > BSO >DMF > LYC) compared to control treatments (dimethylsulfoxide). Pretreatment for 6 h with the antioxidant N-acetylcysteine (NAC) resulted in a partial reversal of the G2/M arrest. Accompanying the increase in cells in G2/M, there was a decrease in the percentage of cells in G1 and S phases of the cell cycle in response to the phytochemical and BSO treatments. This was also partially reversed by pretreatment with NAC. As these phytochemical treatments cause GSH oxidation, reversible by NAC, we conclude that the cell cycle arrest is also mediated, in part, by intracellular oxidation. This conclusion is supported by the reversal in cell cycle arrest with treatment by the antioxidant, NAC. Thus, one potential mechanism for cancer prevention by dietary phytochemicals is inhibition of the growth of cancer cells through modulation of their intracellular redox environment. (Support: NIH MBRS/GM; RCMI RR033032)
The 7 Reasons Most Machine Learning Funds Fail (Presentation Slides)

The rate of failure in quantitative finance is high, and particularly so in financial machine learning. The few managers who succeed amass a large amount of assets, and deliver consistently exceptional performance to their investors. However, that is a rare outcome, for reasons that will become apparent in this presentation. Over the past two decades, I have seen many faces come and go, firms started and shut down. In my experience, there are 7 critical mistakes underlying most of those failures. This paper is partly based on the book Advances in Financial Machine Learning (Wiley, 2018). A full paper can be downloaded at: http://ssrn.com/abstract=3104816.
Bruton's tyrosine kinase inhibitors: first and second generation agents for patients with Chronic Lymphocytic Leukemia (CLL).

Introduction: The BTK inhibitor ibrutinib is effective in both low- and high-risk CLL patients, achieving durable remissions with continuous therapy in the majority of patients. Ibrutinib lacks mye...
A Model for Optimal Reinforcement of Error- and Attack-Resilient Clusters in Networks Under Uncertainty

Network robustness issues are crucial in a variety of application areas, such as energy, defense, communications, and so on. Unpredictable failures of network components (nodes and/or edges) can be caused by a variety of factors, including man-made and natural disruptions, which may significantly affect or inhibit network’s functionality. In many situations, one of the key robustness requirements is that every pair of nodes is connected, with the number of intermediate links between them being as small as possible. Additionally, if nodes in a cluster are connected by several different paths, such a cluster will be more robust with respect to potential network component disruptions. In this work, we study the problem of identifying error- and attack-resilient clusters in graphs, particularly power grids. It is assumed that the cluster represents a R-robust 2-club, which is defined as a subgraph with at least R node/edge disjoint paths connecting each pair of nodes, where each path consists of at most two edges. Uncertain information manifests itself in the form of stochastic number of errors/attacks that could happen in different nodes. If one can reinforce the network components against future threats, the goal is to determine optimal reinforcements that would yield a cluster with minimum risk of disruptions. A combinatorial branch-and-bound algorithm is developed and compared with an equivalent mathematical programming approach on simulated and real-world networks.
Electrocatalytic water oxidation by single site and small nuclearity clusters of cobalt

Author(s): Swierk, JR; Tilley, TD | Abstract: Cobalt oxides are an earth abundant material that exhibits high electrocatalytic activity for the oxygen evolution reaction (OER) across a wide pH range. Recent studies suggest that OER catalysis can proceed through an active site comprised of one or two cobalt atoms but that multiple adjacent cobalt centers are preferred to stabilize high valent cobalt oxo-intermediates by delocalization. Utilizing molecular precursors to prepare single, isolated cobalt atoms (SS-Co) and small clusters of Co3O4 we find that OER proceeds more efficiently on Co3O4. Using electrochemical impedance spectroscopy (EIS), these results were rationalized at an atomic level. The EIS results support a hypothesis that charge transfer related to the formation of reaction intermediates proceeds more easily on Co3O4 than on SS-Co, which is attributed to the difficulty in forming Co(IV) = O and unlikely nucleophilic attack by water to form Co(II)-OOH.
Sulfite-induced protein radical formation in LPS aerosol-challenged mice: Implications for sulfite sensitivity in human lung disease

Exposure to (bi)sulfite (HSO3-) and sulfite (SO32-) has been shown to induce a wide range of adverse reactions in sensitive individuals. Studies have shown that peroxidase-catalyzed oxidation of (bi)sulfite leads to formation of several reactive free radicals, such as sulfur trioxide anion (.SO3-), peroxymonosulfate (-O3SOO.), and especially the sulfate (SO4. -) anion radicals. One such peroxidase in neutrophils is myeloperoxidase (MPO), which has been shown to form protein radicals. Although formation of (bi)sulfite-derived protein radicals is documented in isolated neutrophils, its involvement and role in in vivo inflammatory processes, has not been demonstrated. Therefore, we aimed to investigate (bi)sulfite-derived protein radical formation and its mechanism in LPS aerosol-challenged mice, a model of non-atopic asthma. Using immuno-spin trapping to detect protein radical formation, we show that, in the presence of (bi)sulfite, neutrophils present in bronchoalveolar lavage and in the lung parenchyma exhibit, MPO-catalyzed oxidation of MPO to a protein radical. The absence of radical formation in LPS-challenged MPO- or NADPH oxidase-knockout mice indicates that sulfite-derived radical formation is dependent on both MPO and NADPH oxidase activity. In addition to its oxidation by the MPO-catalyzed pathway, (bi)sulfite is efficiently detoxified to sulfate by the sulfite oxidase (SOX) pathway, which forms sulfate in a two-electron oxidation reaction. Since SOX activity in rodents is much higher than in humans, to better model sulfite toxicity in humans, we induced SOX deficiency in mice by feeding them a low molybdenum diet with tungstate. We found that mice treated with the SOX deficiency diet prior to exposure to (bi)sulfite had much higher protein radical formation than mice with normal SOX activity. Altogether, these results demonstrate the role of MPO and NADPH oxidase in (bi)sulfite-derived protein radical formation and show the involvement of protein radicals in a mouse model of human lung disease.
Charge Optimized Many Body (COMB) potentials for simulation of nuclear fuel and clad

Abstract We briefly outline the Charge Optimized Many Body (COMB) potential formalism, which enables the molecular dynamics simulation of complex materials structures in which multiple types of bonding (metallic, covalent, ionic and secondary bonding) coexist. We illustrate its capabilities to address critical issues in the area of nuclear fuel. In particular, we look at U, UO2 and the process of oxidation of U. Further, we characterize the mechanical behavior of Zr, representing LWR clad, and explore the effects of oxidation and hydridation on the mechanical response and briefly illustrate the capabilities of COMB simulations of corrosion. Finally, we briefly assess the materials fidelity of the COMB approach by examining the COMB description for the Zr-H system.
Paired immunoglobulin-like receptors of activating and inhibitory types.

A distinguishing feature of the immune system is the ability to respond rapidly and efficiently to pathogenic insult. Cellular immune responses, which may include proliferation, elaboration of cytokines, and cytotoxicity, are initiated by receptor-ligand interactions. To maintain immune system homeostasis, the responses initiated by activating receptors are normally counterbalanced by signals propagated through ligation of corresponding inhibitory receptors. Protein motifs that nucleate the activating or inhibitory cascade following receptor ligation have been identified in the cytoplasmic tails of many immune system molecules (Weiss and Schles-singer 1998). The immunoreceptor tyrosine-based activation motif (ITAM), with the consensus sequence of D/E-x7-D/E-x-x-Y-x-x-L/I-x7-Y-x-x-L/I, was first identified in the signal transducing components of the antigen receptor complexes on B and T lymphocytes (Reth 1989; Cambier 1995). The immunoreceptor tyrosine-based inhibitory motif (ITIM), with the consensus sequence of I/V/L/S-x-Y-x-x-V/L, which is the focus of this volume, was originally described in the cytoplasmic tails of the low affinity Fc receptor for IgG antibodies (FcγRUB) on B cells and the killer inhibitory receptors (KIR) on NK cells (Ravetch 1994; Daeron 1997; Vely and Vivier 1997).
Impact of Drug-Eluting Stents Among Insulin-Treated Diabetic Patients: A Report From the National Heart, Lung, and Blood Institute Dynamic Registry

Objectives This study sought to evaluate the safety and efficacy of drug-eluting stents (DES) compared with bare-metal stents (BMS) in patients with insulin- and noninsulin-treated diabetes. Background Diabetes is a powerful predictor of adverse events after percutaneous coronary interventions (PCI), and insulin-treated diabetic patients have worse outcomes. The DES are efficacious among patients with diabetes; however, their safety and efficacy, compared with BMS, among insulin-treated versus noninsulin-treated diabetic patients is not well established. Methods Using the National Heart, Lung, and Blood Institute Dynamic Registry, we evaluated 1-year outcomes of insulin-treated (n = 817) and noninsulin-treated (n = 1,749) patients with diabetes who underwent PCI with DES versus BMS. Results The use of DES, compared with BMS, was associated with a lower risk for repeat revascularization for both noninsulin-treated patients (adjusted hazard ratio [HR] = 0.59, 95% confidence interval [CI] 0.45 to 0.76) and insulin-treated subjects (adjusted HR = 0.63, 95% CI 0.44 to 0.90). With respect to safety in the overall diabetic population, DES use was associated with a reduction of death or myocardial infarction (adjusted HR = 0.75, 95% CI 0.58 to 0.96). However, this benefit was confined to the population of noninsulin-treated patients (adjusted HR = 0.57, 95% CI 0.41 to 0.81). Among insulin-treated patients, there was no difference in death or myocardial infarction risk between DES- and BMS-treated patients (adjusted HR = 0.95, 95% CI 0.65 to 1.39). Conclusions Drug-eluting stents are associated with lower risk for repeat revascularization compared with BMS in treating coronary artery disease among patients with either insulin- or noninsulin-treated diabetes. In addition, DES use is not associated with any significant increased safety risk compared with BMS. These findings suggest that DES should be the preferred strategy for diabetic patients.
Current Ideas and Future Prospects in Metal-Catalyzed Methane Conversion

In the future, natural gas is likely to become increasingly important as a feedstock for the chemical industry. The standard approach to methane conversion is steam reforming to give syngas (H 2 + CO), then a water gas shift step to adjust the H 2 /CO ratio, followed by CO hydrogenation to methanol or a Fisher-Tropsch oligomerization to give n-alkanes. This procedure is rather costly and direct conversion of methane to any of a variety of simple compounds, such as methanol, glycol or acetic acid would be a very useful contribution. Unfortunately, methane has proved to be resistant to a variety of reagents and conditions. Typically, either the alkane is untouched, or it reacts but is overoxidized to CO and CO 2 . Conversions sufficiently low to give good yields are usually uneconomic. In this review, we look at some of the more recent advances in methane chemistry.
Nanostructured Light Management for Advanced Photovoltaics

The ultimate success of photovoltaic technologies requires great improvement in both efficiency improvement and cost reduction. One of the most effective ways to achieve these two objectives simultaneously is to use light-trapping scheme. Here we discuss a novel solar cell structure with an efficient light-trapping design, involving both absorption enhancement and reflection reduction. The centerpiece of the design is the nanocone structure, which can be fabricated by a scalable low-temperature process. With this design, devices with a very thin active layer can achieve near-perfect absorption because of both efficient antireflection and absorption enhancement over a broadband of spectra and a wide range of angles of incidence. The device performance of this design is significantly superior to that of conventional devices. More strikingly, the design and process is in principle not limited to any specific material; hence, it opens up exciting opportunities for a variety of photovoltaic devices to further improve the performance, reduce material usage, and relieve the abundance limitation. Fundamental limit of absorption enhancement at sub-wavelength regime is also discussed. It is found that light trapping can greatly enhance absorption, even beyond the conventional limit 4n 2. Therefore, engineering nanostructures presents new opportunities for advanced photon management to significantly improve the performance of solar cell devices.
Barrett's esophagus and esophageal cancer: Links to microbes and the microbiome.

Esophageal cancer represents a major problem globally, with an estimated 398,000 esophageal squamous cell cancers (ESCC) and 52,000 esophageal adenocarcinomas (EAC) diagnosed worldwide in 2012 [1]. In the United States, EAC is more common than ESCC, and EAC in the US increased dramatically between 1997 and 2006 before stabilizing [2]. Furthermore, esophageal cancer remains particularly deadly, with a five-year survival rate of less than 20% [3]. EAC is thought to arise from Barrett’s esophagus (BE), a metaplastic differentiation from normal squamous epithelium to a columnar phenotype. Accepted risk factors for BE and progression to EAC include age, male sex, obesity, gastroesophageal reflux disease (GERD), and smoking [4, 5]. Unfortunately, less is known about the association between esophageal dysbiosis, inflammation, and the pathogenesis of BE and EAC. Most of the existing data on esophageal microbiota in BE and esophageal cancer are derived from small cross-sectional studies with limited information on causality. As such, this represents an important area for future research because changes in the esophageal microbiota may relate to modifiable factors such as antibiotic use and proton pump inhibitors (PPIs). The esophageal microbiota was initially thought to be primarily related to transient esophageal exposure to the oral microbiota [6], but more recently, culture-independent studies have shown the esophageal microbiota to represent its own niche [7]. In addition to swallowed oral bacteria, the esophagus is also exposed to refluxed gastric microbes, and while the esophageal microbiota resembles both oral and gastric microbiota, it is equal to neither [7, 8]. This review provides an overview of differences that have been described between the normal esophageal microbiota, BE, and EAC. We also discuss novel approaches to esophageal microbial sampling and consider clinical exposures that may alter the esophageal microbiota.
Protected login

Despite known problems with their security and ease-of-use, passwords will likely continue to be the main form of web authentication for the foreseeable future. We define a certain class of password-based authentication protocols and call them protected login. Protected login mechanisms present reasonable security in the face of real-world threat models. We find that some websites already employ protected login mechanisms, but observe that they struggle to protect first logins from new devices --- reducing usability and security. Armed with this insight, we make a recommendation for increasing the security of web authentication: reduce the number of unprotected logins, and in particular, offer opportunistic protection of first logins. We provide a sketch of a possible solution.
Policy Regimes and Economic Accountability in Latin America

The shifts from state-led development to neoliberalism in Latin America have prompted debates on the quality of democracy. Although most discussions focus on responsiveness, we examine how economic...
A comparison of material flow strength models using Bayesian cross-validation

Abstract Predicting material flow strength over a range of conditions, such as temperature and strain rate, is necessary for many engineering applications. This paper considers how to compare the predictiveness of several different strength models using a statistical technique called Bayesian cross-validation. Given a dataset of flow strength measurements obtained from mechanictesting experiments, the procedure consists of performing a Bayesian calibration of each strength model on a subset of the data and evaluating how well the trained models predict the remaining data. The predictiveness of a calibrated strength model is quantifiable probabilistically, which provides an interpretable metric for comparing the different models. As an illustrative example, we compare the Johnson-Cook (JC), Zerilli-Armstrong (ZA), Preston-Tonks-Wallace (PTW), and Mechanical Threshold Stress (MTS) flow strength models for the tantalum stress-strain curve data from Chen and Gray (1996). We show that prediction intervals for the four strength models cover the held-out data at most experimental conditions, but also that prediction interval coverage and prediction uncertainty varies by model and experimental condition. The analysis further allows us to identify experimental regimes for which one of the strength models predicts better than the other three.
Cross-Cultural Study of Education

Abstract This article summarizes the contemporary research on cross-cultural study of education. Specifically, a summary of large-scale international assessments of academic achievement and teaching is presented, along with a cultural analysis of how home, school, and individual factors relate to academic performance.