cssi/SciSciGPT-SciSciNet huggingface dataset:
Motor‐unit force potentiation in adult cats during a standard fatigue test.

1. The purpose of this study was to examine the time course of tetanic force during a standard fatigue test and to distinguish between the appearance of potentiation and fatigue among the four motor-unit types of a cat hindlimb muscle. 2. Motor units of the tibialis posterior muscle in the adult cat were assigned to four categories (i.e. types S, FR, FI, FF) based on conventional criteria (Burke, Levine, Tsairis & Zajac, 1973). The mean (+/- S.D.) time course of peak force was constructed for each motor-unit type and, within each type, for those units that potentiated (a greater than 3% increase in peak force compared to the initial value) and those that did not potentiate. 3. The average time courses of force differed between motor-unit types. There was, however, considerable variability within each motor-unit type. For the same relative force output, the forces exerted by slow-twitch units were less variable than those exerted by fast-twitch units. In addition, the variability among slow-twitch units was relatively constant during the fatigue test while variability among fast-twitch units either increased or decreased with time. 4. For a given motor-unit type, the average time course of force did not depend on whether force in each tetanus was expressed as a peak value, an average peak value, or a force-time integral. 5. Some motor units within each type exhibited potentiation. Most of the variability in the time course of the peak force for each motor-unit type could be accounted for by the potentiating units. Motor units that exhibited only force decline (i.e. fatigue), regardless of unit type, had less variable time courses of peak force. Since potentiation was transient in some unit types, it was assumed that at least two opposing processes (i.e. fatigue and potentiation) occurred simultaneously in these units (see also, Krarup, 1981; Rankin, Enoka, Volz & Stuart, 1988; Garner, Hicks & McComas, 1989). 6. It is concluded that the expression of force potentiation throughout a fatiguing regimen is variable among motor units and that this is not related to conventional motor-unit types. This dissociation suggests that the mechanisms that form the basis for the conventional distinction between motor-unit types are different from those which lead to force potentiation.
Managing Fiber Connections in NGN and Applications

Increasing fiber applications such as DWDM, Ultra Long Haul and FTTH are rapidly taxing manually managed fiber infrastructure. New fiber management technologies and architectures are evaluated to meet the growth of emerging networks and applications.
MRI of the Female Pelvis Using Vaginal Gel

OBJECTIVE. Vaginal distention with aqueous gel optimizes MRI evaluation of the vaginal walls and outer contours of the cervix. The objective of this pictorial essay is to illustrate the use of vaginal gel for MRI of the female pelvis.CONCLUSION. Distention of the vagina with gel is an inexpensive, well-tolerated procedure that may improve MRI evaluation of a variety of gynecologic conditions.
eBoys: The First Inside Account of Venture capitalists at Work

The article reviews the book “eBoys: The First Inside Account of Venture Capitalists at Work,” by Randall E. Stross.
Achieving wireline random access throughput in wireless networking via user cooperation

Well appreciated at the physical layer, user cooperation is introduced here as a diversity enabler for wireless random access (RA) at the medium access control sub-layer. This is accomplished through a two-phase protocol in which active users start with a low power transmission attempting to reach nearby users, and follow up with a high power transmission in cooperation with the users recruited in the first phase. We show that such a cooperative protocol yields a significant increase in throughput. Specifically, we prove that for networks with a large number of users, the throughput of a cooperative wireless RA network operating over Rayleigh fading links approaches the throughput of a RA network operating over additive write Gaussian noise (AWGN) links. As a result, user cooperation migrates diversity benefits to the wireless RA regime, thus bridging the gap to wireline RA networks, without incurring a bandwidth or energy penalty.
Sinus Floor Elevation and Implant Placement via the Crestal and Lateral Approach in Patients With Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome: Report of Two Cases

Introduction: Implant placement in the posterior maxilla is frequently complicated by sinus proximity. Intraoral surgical procedures, including implant placement, have been described in patients with human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS). Although reported widely in the general population, there is no description of implant placement with sinus floor augmentation (SFA) in these individuals. To the best of the authors’ knowledge, these are the first cases of SFA and implant placement via the crestal and lateral approaches in patients with HIV/AIDS.Case Presentation: A 50-year-old male presented for replacement of missing left maxillary first and second molars. Three-dimensional radiography confirmed the presence of 3 to 5 mm of bone in the ideal implant positions. Lateral-window SFA using a combination of particulate xenograft and allograft resulted in 10 mm of vertical height, allowing simultaneous placement of two implants. Restoration was completed after 6 months ...
Surface display of Aggregatibacter actinomycetemcomitans autotransporter Aae and dispersin B hybrid act as antibiofilm agents.

Among the various proteins expressed by the periodontopathogen Aggregatibacter actinomycetemcomitans, two proteins play important roles for survival in the oral cavity. The autotransporter Aae facilitates the attachment of the pathogen to oral epithelial cells, which act as a reservoir, while the biofilm-degrading glycoside hydrolase dispersin B facilitates the movement of daughter cells from the mature biofilm to a new site. The objective of this study was to use the potential of these two proteins to control biofilms. To this end, we generated a hybrid construct between the Aae C-terminal translocating domain and dispersin B, and mobilized it into Escherichia coli Rosetta (DE3) pLysS cells. Immunofluorescence analysis of the modified E. coli cells confirmed the presence of dispersin B on the surface. Further, the membrane localization of the displayed dispersin B was confirmed with Western blot analysis. The integrity of the E. coli cells displaying the dispersin B was confirmed through FACS analysis. The hydrolytic activity of the surface-displayed dispersin B was confirmed by using 4-methylumbelliferyl-β-d-glucopyranoside as the substrate. The detachment ability of the dispersin B surface-displaying E. coli cells was shown using Staphylococcus epidermidis and Actinobacillus pleuropneumoniae biofilms in a microtiter assay. We concluded that the Aae β-domain is sufficient to translocate foreign enzymes in the native folded form and that the method of Aae-mediated translocation of surface displayed enzymes might be useful for control of biofilms.
Nutrient-sensing mTOR-mediated pathway regulates leptin production in isolated rat adipocytes

Leptin biosynthesis in adipose cells in vivo is increased by food intake and decreased by food deprivation. However, the mechanism that couples leptin production to food intake remains unknown. We found that addition of leucine to isolated rat adipocytes significantly increased leptin production by these cells, suggesting that postprandial leptin levels may be directly regulated by dietary leucine. The effect of leucine was inhibited by rapamycin and not by actinomycin D. Besides, leucine administration did not increase the amount of leptin mRNA in adipocytes. Therefore, we concluded that leucine activates leptin expression in adipose cells at the level of translation via a mammalian target of rapamycin (mTOR)-mediated pathway. Because leptin is a secreted protein, its biosynthesis is compartmentalized on the endoplasmic reticulum. To analyze mTOR signaling in this subcellular fraction, we separated adipose cells by centrifugation into a heavy membrane fraction that includes virtually all endoplasmic reticulum and the cytosolic extract. Phosphorylation of the major mTOR targets, the ribosomal protein S6 and the translational inhibitor 4E-binding protein (BP)/phosphorylated heat- and acid-stable protein (PHAS)-1, was stimulated by leucine in the cytosolic extract, whereas, in the heavy fraction, S6 was constitutively phosphorylated and leucine only induced phosphorylation of 4E-BP/PHAS-1. We also found that 60-70% of leptin mRNA was stably associated with the heavy fraction, and leucine administration did not change the ratio between compartmentalized and free cytoplasmic leptin mRNA. We suggest that, in adipose cells, a predominant part of leptin mRNA is compartmentalized on the endoplasmic reticulum, and leucine activates translation of these messages via the mTOR/4E-BP/PHAS-1-mediated signaling pathway.
Rate of Entropy Production as a Physical Selection Principle for Mode-Mode Transitions in Non-Equilibrium Systems: With an Application to a Non-Algorithmic Dynamic Message Buffer

We examine a generic set of amplitude equations proposed earlier by Haken that describes the emergence and bifurcations of modes and spatio-temporal patterns of selforganizing non-equilibrium systems. We relate feedback parameters occurring in the amplitude equations to pumping processes associated with entropy production. In doing so, we show that the rate of entropy production determines which mode-mode transitions are allowed and which not. Roughly speaking, transitions occur from modes of low rate of entropy production towards modes of high rate of entropy production (selection principle). In line with the recent efforts in the field of physical intelligence, we outline how physical, non-algorithmic, self-organizing systems satisfying Haken’s amplitude equations may be used to design a dynamic input-output message buffer. The functioning of such a dynamic buffer again follows the aforementioned selection principle: the buffer switches between input and output modes in order to select modes with relatively high rates of entropy production. Moreover, only mode-mode transitions are allowed that increase the rate of entropy production of the active mode.
Decreased production of interleukin-12 and other Th1-type cytokines in patients with recent-onset systemic lupus erythematosus

Objective To determine the profile of Th1-type and Th2-type cytokines produced by mononuclear cells from patients with recent-onset systemic lupus erythematosus (SLE), prior to the initiation of treatment with corticosteroids. Methods Using sensitive radioimmunoassays, interleukin-4 (IL-4), IL-10, IL-12 p40, tumor necrosis factor alpha (TNF alpha), interferon-gamma (IFN gamma), and granulocyte-macrophage colony-stimulating factor (GM-CSF) released into the culture supernatants of various unstimulated and stimulated blood mononuclear cell populations from 10 SLE patients was assessed in comparison with 10 matched healthy controls studied in parallel. Results In early SLE, monocyte-enriched cells constitutively produced increased amounts of IL-10 and decreased amounts of IL-12 following stimulation. Lymphocyte-enriched cells in SLE produced decreased amounts of IFN gamma and TNF alpha following stimulation. In "rested" cells, these defects were accentuated and a defect in IL-12 production was suggested. Depletion studies suggested that CD8+ cells were a major source of TNF alpha and IFN gamma in controls, but not in SLE patients. Increased IL-4 production or abnormalities in GM-CSF production were not observed. Conclusion This study suggests that even early in the course of SLE, monocyte production of IL-10 is increased and that of IL-12 is decreased. Decreased production of Th1-type cytokines in SLE may be secondary to this imbalance between IL-10 and IL-12. A contributory role of dysfunctional CD8+ cells is suggested.
MolProbity: all-atom structure validation for macromolecular crystallography

MolProbity is a structure-validation web service that provides broad-spectrum solidly based evaluation of model quality at both the global and local levels for both proteins and nucleic acids. It relies heavily on the power and sensitivity provided by optimized hydrogen placement and all-atom contact analysis, complemented by updated versions of covalent-geometry and torsion-angle criteria. Some of the local corrections can be performed automatically in MolProbity and all of the diagnostics are presented in chart and graphical forms that help guide manual rebuilding. X-ray crystallography provides a wealth of biologically important molecular data in the form of atomic three-dimensional structures of proteins, nucleic acids and increasingly large complexes in multiple forms and states. Advances in automation, in everything from crystallization to data collection to phasing to model building to refinement, have made solving a structure using crystallo­graphy easier than ever. However, despite these improvements, local errors that can affect biological interpretation are widespread at low resolution and even high-resolution structures nearly all contain at least a few local errors such as Ramachandran outliers, flipped branched protein side chains and incorrect sugar puckers. It is critical both for the crystallographer and for the end user that there are easy and reliable methods to diagnose and correct these sorts of errors in structures. MolProbity is the authors' contribution to helping solve this problem and this article reviews its general capabilities, reports on recent enhancements and usage, and presents evidence that the resulting improvements are now beneficially affecting the global database.
Recent French Conceptualizations of Diaspora

This book by sociologist Stephane Dufoix is a tour d’horizon of the state of contemporary scholarship concerning diasporas. It ranges across a variety of disciplines. It is particularly welcome bec...
Tests of conditional mean-variance efficiency of the U.S. stock market

Abstract We test the mean-variance efficiency (MVE) hypothesis using a method that allows conditional expected returns to vary in relatively unrestricted ways. The method takes advantage of the predictability of conditional variances. The data estimate reasonably the price of risk, and the MVE model is valuable in explaining expected equity returns. Nevertheless, we reject the restrictions imposed by MVE on the alternative hypothesis. Unlike with most tests of MVE, we can put an explicit interpretation on the alternative hypothesis — a general linear Tobin portfolio choice model.
The "Softmax" Nonlinearity: Derivation Using Statistical Mechanics and Useful Properties as a Multiterminal Analog Circuit Element

We use mean-field theory methods from Statistical Mechanics to derive the "softmax" nonlinearity from the discontinuous winner-take-all (WTA) mapping. We give two simple ways of implementing "softmax" as a multiterminal network element. One of these has a number of important network-theoretic properties. It is a reciprocal, passive, incrementally passive, nonlinear, resistive multiterminal element with a content function having the form of information-theoretic entropy. These properties should enable one to use this element in nonlinear RC networks with such other reciprocal elements as resistive fuses and constraint boxes to implement very high speed analog optimization algorithms using a minimum of hardware.
Overlap of Breeding and Molting Schedules in a Collection of African Birds

Many birds in northern temperate regions are known to have distinct and separate times of the year for breeding and for molt, but little information is available for tropical birds. Miller (1961) found a separation of molt and breeding in tropical Zonotrichia capensis, and he also described an inverse correlation in time between nesting activity and molt in an equatorial South American cloud forest (Miller 1963). Moreau (1936, 1950) reported overlap of molt and gonadal activity in less than 10 per cent of a sample of birds collected in equatorial Africa. Exceptions noted by Moreau were Colius striatus among the nonpasserines and Turdoides jardinei among the songbirds. These species had large gonads both in the breeding season and at the time of molt. In none of these studies was each of the instances of overlapping schedules discussed.
Introduction of 6-mercaptopurine in Crohn's disease patients during the perioperative period: A preliminary evaluation of recurrence of disease

Background:Recurrence of Crohn's disease after surgery is a common occurrence, pointing to the need for a strategy to prevent recurrent disease. We report the postoperative course of 10 patients who required intestinal resections for complications related to Crohn's disease.Methods:All patients had
On the Evolution of Copper Oxide Films Grown on α-A12O3 By Pulsed-Laser Ablation

Pulsed-laser ablation was used to deposit copper oxide onto single-crystal substrates of (0001) α–Αl2O3 at temperatures ranging up to 900°C. Prior to deposition, the substrates were chemically cleaned and annealed to create a surface structure of low-index terraces separated by crystallographic steps. After deposition, the samples were characterized using transmission electron microscopy and scanning electron microscopy. The deposited film evolved by an island growth process, with the morphology of the particles being dependent on the growth conditions, substrate orientation, and nature of the substrate surface. Both CuO and Cu2O were produced by the depositions. The phase observed changed from CuO to Cu2O with increasing deposition temperature, as would be expected based on the equilibrium phase diagram. In depositions performed on (0001) alumina substrates with widely spaced surface steps, it was found that on some surface terraces one characteristic particle morphology was produced whereas on others a second morphology was dominant. This suggests that the plane of surface termination in the alumina lattice, which consists of a layer of either Al or O in this orientation, is influencing the growth process.
Dystonia and Biopterin Deficiency

Five patients with childhood dystonia associated with reduced CSF biopterin, responsive to levodopa, and characterized by diurnal and exertional variation are reported from the Developmental and Metabolic Neurology Branch, National Institute of Neurological and Communicative Disorders and Stroke, Bethesda, MD.
Adaptive and Dynamic Design for MPI Tag Matching

The Message Passing Interface (MPI) standard specifies the use of (source, tag, communicator) tuple to identify whether an incoming message is what the receiver process is expecting. The cost associated with this process, commonly known as "tag matching", is tightly coupled with the communication pattern of the application and the load it generates at each individual process. Although researchers have proposed several schemes to mitigate the cost of tag matching, they have all been static and do not adapt dynamically to the communication load at individual processes and can lead to degradation in tag matching times. Such static designs can also lead to unnecessary memory overheads for queue management at processes whose communication loads do not justify enhanced tag matching schemes. In this paper, we take up this challenge and propose a tag matching design which dynamically adapts to the communication load at each individual process at runtime. Our experimental evaluation shows that the proposed adaptive and dynamic tag matching scheme is able to deliver the best performance when compared with multiple state-of-the-art tag matching schemes while limiting the memory consumed to the absolute minimum necessary to deliver the desired performance benefits. For instance, with HPCG, the adaptive scheme delivers 20, 32 and up to 2X improvements in tag matching performance when compared to the default, bin-based and rank-based schemes, respectively. To the best of our knowledge this is the first tag matching design that is capable of dynamically adapting to the communication requirements of end applications.
Post-Operative Imaging of Shoulder (20 min)

: This presentation features, modalities: plain radiographs, CT, MRI, and ultrasound; arthroplasty; hardware loosening; suture anchor migration; AVN, collapse, arthritis; rotator cuff repair; labral repair.
Implementation of Quantification of Blood Loss Does Not Improve Prediction of Hemoglobin Drop in Deliveries with Average Blood Loss.

Objective The National Partnership for Maternal Safety released a postpartum hemorrhage bundle in 2015 recommending quantification of blood loss (QBL) for all deliveries. We sought to determine whether QBL more accurately predicts hemoglobin (Hb) drop than visually estimated blood loss (EBL). Study Design This is a prospective observational study. Preintervention data (PRE) were collected on all deliveries between October 15, 2013 and December 15, 2013. Deliveries were included if EBL, admission Hb, and 12-hour postpartum Hb (12hrCBC) were available. QBL was implemented in July 2015. Postintervention data (POST) were collected between October 20, 2015 and December 20, 2015. A total of 500 mL EBL was predicted to result in 1 g/dL Hb drop at 12hrCBC. Student's t-test was used to compare the means. Results A total of 592 of 626 (95%) PRE and 583 of 613 (95%) POST deliveries were included. Overall, 278 (48%) POST deliveries had QBL recorded. In both PRE and POST, actual Hb drop differed from predicted by 0.6 g/dL in both groups of deliveries. When evaluating deliveries with EBL > 1,000 mL, QBL in POST was slightly better at predicting Hb drop versus EBL in PRE, although not statistically significant (0.2 vs. 0.5 g/dL, p = 0.17). Conclusion In all deliveries, QBL does not predict Hb drop more accurately than EBL. The decision to perform QBL needs to balance accuracy with a resource intense measurement process.
Molecular Weight Distribution Shape as a Versatile Approach to Tailoring Block Copolymer Phase Behavior

The molecular weight distributions (MWDs) of block copolymers significantly impact their morphological phase behavior, but exploiting these features as a means to tune material properties has been limited to the MWD breadth, or dispersity (Đ). Manipulation of the entire MWD has promising potential to address this challenge by providing a convenient and versatile route toward tailoring polymer nanostructure. Herein, we describe the self-assembly of poly(styrene)-block-poly(2-vinylpyridine) (PS-b-P2VP) where the PS blocks have systematically deviating compositions of molecular weights. We find that controlling the MWD shape, breadth and skew, afforded access to different morphologies in samples with the same molecular characteristics, including Đ. As such, we illustrate the generality and effectiveness of this strategy and anticipate that it will facilitate the increased deployment of disperse polymer compositions in advanced materials applications.
Biologic Effects of TBI

Purpose To review the biologic effects of total body irradiation (TBI) with regard to leukemic cell kill, immunosuppression, and toxicity to critical normal tissues of concern (lung, lens, kidney, liver).
Degenerate Four-Wave Mixing of Femtosecond Pulses in the Saturable Absorber of a Ring Dye Laser

The saturable absorber dye jet of a femtosecond ring dye laser provides an ideal candidate for the study of fast transients in de- generate four-wave mixing (DFWM). Since the counterpropagating pulses in the ring laser meet at the absorber jet, the problem of timing the DFWM pump pulses is solved. The energy of the pulses inside the cavity is such that the absorber is saturated. This meets one of the conditions for efficient DFWM in saturable media.1 Since the dye jet is thin, fast transients in DFWM are not masked by propagation effects.
In situ diagnostics for nanomaterial synthesis in carbon arc plasma

Developments in the recent application of in situ diagnostics to improve understanding of nanomaterial synthesis processes in carbon arc plasma are summarized. These diagnostics measure the plasma conditions in the arc core and the precursor species to nanoparticle formation and the presence and sizes of nanoparticles in the synthesis region surrounding the hot arc core. They provide information that could not be obtained by the ex situ diagnostics used in previous studies of nanomaterial synthesis in arc plasma. The following diagnostics are covered: optical emission spectroscopy, planar laser induced fluorescence, laser induced incandescence, fast frame imaging, coherent Rayleigh Brillouin scattering, and the nanomaterial extractor probe. The diagnostic measurements are consistent with a recently developed two-dimensional fluid model of nanomaterial synthesis in the arc plasma.
A curated corpus of simulink models for model-based empirical studies

Recent years have seen many empirical studies of model-based cyber-physical systems and commercial CPS development tool chains such as Matlab/Simulink. To benefit such research, this paper presents the by-far largest corpus of freely available Simulink models to date, containing over 1,000 models. Surprising findings based on this corpus include that (a) tool support for metric collection is not adequate and (b) users do not reuse model components as they would in object-oriented programs. The paper both confirms and contradicts earlier findings that are based on significantly fewer models, suggesting the utility of the corpus for future research. While others have not yet leveraged this model corpus, we hope that our freely available corpus and infrastructure will benefit future model-based empirical research and tool development efforts, by reducing the model-collection overhead and thus easing evaluation.
Using social dynamics to explain uptake in energy saving measures: Lessons from space conditioning interventions in Japan and California

Abstract The authors ran a pair of interventions to encourage passive cooling measures in two sustainable energy communities: E-Sogo in Japan and West Village in the United States. The interventions used proven levers for encouraging behavior change (among adult household members), but yielded modest results. Traditional methods of evaluating intervention effectiveness do not reveal why responses are weak, so the authors examined participants’ experiences using qualitative data collected during the intervention. Three critical flaws were identified; namely, the interventions had targeted a single household member, promoted measures that impact other members, and failed to support coordination within the household. To understand why those shortcomings led to weak results, the study examines the intersection of the social attributes of cooling measures (i.e., locus of decision and impact on others) and the prevailing social dynamics within households. A game-theoretical model is developed to illustrate how the varied combinations of measure attributes and social dynamics can yield different outcomes across households. By examining the failures of commonly accepted social science methods, the study sheds light on the intersection of social dynamics and household energy practices, a line of inquiry which, when extended further, could make energy interventions more effective and socially valid.
A Brief History of Space Climatology: From the Big Bang to the Present

Review of space climatology is presented with a view toward spacecraft electronics applications. The origins and abundances of space radiations are discussed and related to their potential effects. Significant historical developments are summarized leading to the inception of space climatology and into the space era. Energetic particle radiation properties and models of galactic cosmic rays, solar energetic and geomagnetic trapped particles are described. This includes current radiation effects issues that models face today.
Digestion of the Murine Liver for a Flow Cytometric Analysis of Lymphatic Endothelial Cells

Within the liver, lymphatic vessels are found within the portal triad, and their described function is to remove interstitial fluid from the liver to the lymph nodes where cellular debris and antigens can be surveyed. We are very interested in understanding how the lymphatic vasculature might be involved in inflammation and immune cell function within the liver. However, very little has been published establishing digestion protocols for the isolation of lymphatic endothelial cells (LECs) from the liver or specific markers that can be used to evaluate liver LECs on a per cell basis. Therefore, we optimized a method for the digestion and staining of the liver in order to evaluate the LEC population in the liver. We are confident that the method outlined here will be useful for the identification and isolation of LECs from the liver and will strengthen our understanding of how LECs respond to the liver microenvironment.
Improving Multi-Task Deep Neural Networks via Knowledge Distillation for Natural Language Understanding

This paper explores the use of knowledge distillation to improve a Multi-Task Deep Neural Network (MT-DNN) (Liu et al., 2019) for learning text representations across multiple natural language understanding tasks. Although ensemble learning can improve model performance, serving an ensemble of large DNNs such as MT-DNN can be prohibitively expensive. Here we apply the knowledge distillation method (Hinton et al., 2015) in the multi-task learning setting. For each task, we train an ensemble of different MT-DNNs (teacher) that outperforms any single model, and then train a single MT-DNN (student) via multi-task learning to \emph{distill} knowledge from these ensemble teachers. We show that the distilled MT-DNN significantly outperforms the original MT-DNN on 7 out of 9 GLUE tasks, pushing the GLUE benchmark (single model) to 83.7\% (1.5\% absolute improvement\footnote{ Based on the GLUE leaderboard at this https URL as of April 1, 2019.}). The code and pre-trained models will be made publicly available at this https URL.
Closed-Form Coverage Probability in Cellular Networks With Poisson Point Process

For the cellular networks with Poisson point process and general path-loss exponent, we derive a closed-form expression of the coverage probability. Its graphical profile perfectly matches with the one that is obtained by numerical integration.
Trait and phylogenetic patterns reveal deterministic community assembly mechanisms on Mount St. Helens

Primary plant succession provides an excellent natural experiment to test ecological questions about community assembly following major disturbances. Temporal phylogenetic and functional trait dispersion patterns can give insight into the relative importance of stochastic and deterministic processes, as well as the potential identity of deterministic (biotic vs. abiotic) drivers (e.g. dispersal, growth, nutrient acquisition, and herbivore resistance ability). We used 28 years of plant composition data across four primary succession sites at Mount St. Helens (collected since the 1980 volcanic eruption) to examine phylogenetic dispersion and trait patterns over time. We expected to find more evidence of clustering or random phylogenetic patterns early in succession (where environmental filtering and stochasticity are thought to dominate), with a switch to overdispersion via processes such as niche differentiation later in succession. Contrary to expectations, phylogenetic relatedness and trait dispersion patterns were idiosyncratic. We found evidence of deterministic community assembly even early in succession, suggesting that both local-scale abiotic filtering and biotic interactions start playing a role shortly after the initiating disturbance. Traits were less predictive of successional patterns, with few consistent changes in trait distribution across all sites, even though the traits we examined are linked to the processes thought to be important during succession. Together, these results suggest that the drivers of community assembly during succession may be less generalizable and more complex than previously thought. We suggest that combining experiments and these analytical tools with long-term monitoring could be a useful step forward.
Stochastic Modeling and Control of Circulatory System with a Left Ventricular Assist Device

Left ventricular assist device (LVAD) has been considered as a treatment option for end-stage congestive heart failure to assist an ailing heart to meet the circulatory demand. However, several important issues still challenge the long-term use of the LVAD as a bridge to transplantation or as a destination therapy. Specifically, the development of appropriate feedback controllers to adjust pump speed is crucial. The controller should automatically adjust the pump speed to meet different demands of blood without inducing suction. Suction means that the LVAD seeks to pump out more blood than that is available in the heart, which can collapse the failing heart and result in sudden death. In addition, hemodynamics involves variability due to patients' heterogeneity and stochastic nature of cardiovascular system. The variability poses significant challenges for the control system design of an LVAD. A self-tuning controller is developed in this work, which can adjust the pump speed to meet the physiological demands for different levels of activity, while accounting for variations in hemodynamics. A stochastic state space model will be firstly developed using a generalized polynomial chaos (gPC) expansion, which describes interactions between the LVAD and the cardiovascular system. In addition, the model can further predict the variability in pump flow for a finite future control horizon based on the current available information of pump flow. The prediction of variance is used as a tuning criterion to update the controller gain in a real time manner. The efficiency of the self-tuning control algorithm in this work is validated with two different case scenarios, representing different levels of activity for heart failure patients. The results show that the controller can successfully adjust the pump speed while avoiding suction.
A Methodology for the Early Diagnosis of Vehicle Torque Converter Clutch Degradation

Torque converters (TC) are widely used in automatic transmissions and continuous variation transmissions (CVT) to transfer the engine power to the transmission through fluid and mechanical coupling. The degradation of the TC Clutch (TCC) may result in excessive vibrations in the TC and driveline, elevated transmission temperature, and transmission shudder. The present study develops a systematic approach to detect TCC system degradation utilizing both machine learning techniques and domain expertise. The validation using vehicle data demonstrates the effectiveness of the approach. The early detection of TCC degradation may help to prolong the lifespan of TC, protect transmission components from further damage, and avoid limp-home and walk-home incidents.
'Et nata ex etymo fabula:' Cosmas of Prague, the Medieval Practice of 'Etymologia,' and the Writing of History

This article represents a larger project that seeks to understand the function and implications of the use of etymologies in the writing of history in the Middle Ages. I examine the strategy of historians to etymologize within the framework of grammatical theories and historiographic methods of Latin scholarship. I conclude that, contrary to the traditional view that medieval etymologies are literary tropes and wordplay in all contexts, medieval historians used etymology as an epistemological instrument of discovery that helped them verify anecdotal information from oral tradition in order to adapt it to Christian historical discourse. This article focuses on the earliest annalistic narrative about the history of Bohemia, the Chronica Boemorum (c. 1125), and examines how its author, Cosmas of Prague, utilizes etymologies in the legendary sections of his masterpiece, and what role he ascribes to them in the mechanism of story-telling. Close reading and formal analysis of selected passages with etymological content show that etymologies are used as evidence to recover reality outside language (i.e. discover origins), and in that capacity they motivate the story itself and expand the narrative.
Topic models over text streams: A study of batch arid online unsupervised learning

Automated unsupervised learning of topic-based clusters is used in various text data mining applications, e.g., document organization in content management, information retrieval and filtering in news aggregation services. Typically batch models are used for this purpose, which perform clustering on the document collection in aggregate. In this paper, we first analyze three batch topic models that have been recently proposed in the machine learning and data mining community – Latent Dirichlet Allocation (LDA), Dirichlet Compound Multinomial (DCM) mixtures and von-Mises Fisher (vMF) mixture models. Our discussion uses a common framework based on the particular assumptions made regarding the conditional distributions corresponding to each component and the topic priors. Our experiments on large real-world document collections demonstrate that though LDA is a good model for finding word-level topics, vMF finds better document-level topic clusters more efficiently, which is often important in text mining applications. In cases where offline clustering on complete document collections is infeasible due to resource constraints, online unsupervised clustering methods that process incoming data incrementally are necessary. To this end, we propose online variants of vMF, EDCM and LDA. Experiments on real-world streaming text illustrate the speed and performance benefits of online vMF. Finally, we propose a practical heuristic for hybrid topic modeling, which learns online topic models on streaming text data and intermittently runs batch topic models on aggregated documents offline. Such a hybrid model is useful for applications (e.g., dynamic topic-based aggregation of consumer-generated content in social networking sites) that need a good tradeoff between the performance of batch offline algorithms and efficiency of incremental online algorithms.
How Tumor Cell Dedifferentiation Drives Immune Evasion and Resistance to Immunotherapy

Immunotherapy has revolutionized cancer treatment, yet most patients do not respond. While tumor antigens are needed for effective immunotherapy, a favorable tumor immune microenvironment is also critical. In this review, we discuss emerging evidence that tumor cells exploit cellular plasticity and dedifferentiation programs to avoid immune surveillance, which in turn drives metastatic dissemination and resistance to immunotherapy. A deeper understanding of these programs may provide novel opportunities to enhance the efficacy of existing immunotherapies.
Prevalence of Vitamin D Deficiency in a Large Newborn Cohort from Northern United States and Effect of Intrauterine Drug Exposure

Vitamin D is not only a vital element in bone health but is also a prohormone. Data regarding distribution of vitamin D status among preterm and term neonates in the United States are limited. There are no data on the effect of intrauterine drug exposure on vitamin D status. Our objective was to determine the distribution of vitamin D levels among preterm and term neonates and the effect of intrauterine illicit drug exposure. We did a retrospective chart review of neonates admitted from 2009 to 2016 to our neonatal intensive care unit with serum 25-hydroxycholecalciferol (25[OH]D) levels measured during the hospital stay. Of 1517 neonates, the median 25[OH]D level was 19 ng/mL with 31% deficient and 49% insufficient, even though 75% of mothers took prenatal vitamins. In pregnant women, 38% were vitamin-D-deficient and 44% were vitamin-D-insufficient. Four hundred seventy-one neonates had intrauterine drug exposure, with a median 25[OH]D level of 22.9 ng/mL versus 17.8 ng/mL in nonexposed neonates (p = 0.001). Despite maternal prenatal vitamin intake, neonates are at risk of vitamin D deficiency. Maternal illicit drug use was not related to lower 25[OH]D levels in neonates.
COVID-19 and the 'Return of the Normative' in Economic Policy

The global health, economic and social emergency resulting from COVID-19 and the response to it has brought normative concerns, often submerged in everyday policymaking, to the forefront. We examine why the crisis has resulted in this "return of the repressed" and what it suggests about the appropriate role of expertise in democracy.
Intergenerational Economic Mobility and the Racial Wealth Gap

A growing body of research documents the importance of wealth and the racial wealth gap in perpetuating inequality across generations. We examine the impact of wealth on child income. Our two-stage least squares regressions reveal that grandparental wealth has an important effect on the younger generation's stock, which in turn affects the younger generation's household income. We further explore the relationship between income and wealth by decomposing the child's income by race. We find that the intergroup disparity in income is mainly attributable to differences in family background. These findings indicate that wealth is an important source of income inequality.
The Efficiency of Race-Neutral Alternatives to Race-Based Affirmative Action: Evidence from ChicagoAS Exam Schools

Several public K-12 and university systems have recently shifted from race-based affirmative action plans to race-neutral alternatives. This paper explores the degree to which race-neutral alternatives are effective substitutes for racial quotas using data from the Chicago Public Schools (CPS), where a race-neutral, place-based affirmative action system is used for admissions at highly competitive exam high schools. We develop a theoretical framework that motivates quantifying the efficiency cost of race-neutral policies by the extent admissions decisions are distorted more than needed to achieve a given level of diversity. According to our metric, CPS's race-neutral system is 24% and 20% efficient as a tool for increasing minority representation at the top two exam schools, i.e. about three-fourths of the reduction in composite scores could have been avoided by explicitly considering race. Even though CPS's system is based on socioeconomic disadvantage, it is actually less effective than racial quotas at increasing the number of low-income students. We examine several alternative race-neutral policies and find some to be more efficient than the CPS policy. What is feasible varies with the school's surrounding neighborhood characteristics and the targeted level of minority representation. However, no race-neutral policy restores minority representation to prior levels without substantial inefficiency, implying significant efficiency costs from prohibitions on affirmative action policies that explicitly consider race.Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.
Five-Year Post-Restoration Conditions and Simulated Climate Change Trajectories in a Warm/Dry Mixed-Conifer Forest, Southwestern Colorado, USA

Abstract Some warm/dry mixed-conifer forests are at increasing risk of uncharacteristically large, high-severity fires. As a result, managers have begun ecological restoration efforts using treatments such as mechanical thinning and prescribed fire. Empirical information on the long-term impacts of these treatments is limited, especially in light of potential climate change. We assessed changes in forest structure and composition five-years following three alternative restoration treatments in a warm/dry mixed-conifer forest: (1) thin/burn, (2) prescribe burn, and (3) control. We used the Climate-Forest Vegetation Simulator (Climate-FVS) model to quantify potential forest trajectories under alternative climate scenarios. Five years following treatments, changes in forest structure were similar to initial post-treatment conditions, with thin/burn being the only treatment to shift and maintain forest structure and composition within historical reference conditions. By 2013, the thin/burn had reduced basal area (11.3 m 2 ha −1 ) and tree density (117.2 tree ha −1 ) by 56% and 79% respectively, compared to pre-treatment values. In the burn, basal area (20.5 m 2 ha −1 ) and tree density (316.6 tree ha −1 ) was reduced by 20% and 35% respectively, from 2002 to 2013. Mortality of large ponderosa pine trees (the most fire-resistant species) throughout the duration of the experiment, averaged 6% in the burn compared to 16% in the thin/burn treatment. Changes five years following treatments were largely due to increases in sprouting species. Shrub and sapling densities were approximately two to three times higher (respectively) in the thin/burn compared to burn and control and dominated by sprouting oak and aspen. Under climate simulations, the thin/burn was more resilient in maintaining forest conditions compared to burn and control which approached meager forest conditions (3–4 m 2 ha −1 ). These results indicate that restoration treatment that include both thinning and burning can maintain forest integrity over the next few decades.
Acid-base determinations in human amniotic fluid throughout pregnancy

Abstract The pH, pCO 2 , and bicarbonate concentrations of human amniotic fluid are reported in 46 patients from 10 to 42 weeks' gestational age. A decrease in pH and bicarbonate concentration and an increase in pCO 2 was found with increasing gestational age in the human. These changes were similar to previous observations in the primate (rhesus monkey), although absolute values obtained from amniotic fluid at any stage in pregnancy were different.
A profile anonymization model for location-based services

Location-based services LBS aim at delivering point of need information. Personalization and customization of such services, based on the profiles of mobile users, would significantly increase the value of such services. Since profiles may include sensitive information of mobile users and moreover can help identify a person, such customization is allowable only when the security and privacy policies dictated by them are respected. While LBS providers are presumed to be untrusted entities, the location services that capture and maintain mobile users' location to enable communication are considered trusted, and therefore can capture and manage the profile information. The question then is, how to enable the use of location based services while protecting privacy?In this paper, we address the problem of privacy preservation via anonymization. Prior research in this area attempts to ensure k-anonymity by generalizing the location. However, a person may still be identified based on his/her profile if the profiles of all k people in the generalized region are not the same. We extend the notion of k-anonymity by proposing a profile based k-anonymization model that guarantees anonymity even when profiles of mobile users are revealed to untrusted entities. Specifically, our anonymization methods generalize both location and profiles to the extent specified by the user. We propose a novel unified index structure, called the PTPR-tree to enhance the performance during anonymization. PTPR-tree is an extension of the TPR-tree [in: SIGMOD'00: Proceedings of the 2000 ACM SIGMOD International Conference on Management of Data, New York, NY, USA, ACM, 2000, pp. 331--342] which organizes both the locations of mobile users as well as their profiles using a single index, and therefore can efficiently find candidate users for the proposed profile based anonymization models.