cssi/SciSciGPT-SciSciNet huggingface dataset:
Ultrafine high performance polyethylene fibers

Stiff, strong and tough ultrafine polyethylene fibers that rival the best high performance fibers, but with diameters less than one micron, are fabricated for the first time by “gel-electrospinning.” In this process, solution concentration and process temperatures are chosen to induce the formation of gel filaments “in flight,” which are subsequently drawn at high rates as a consequence of the whipping instability. The resulting submicron-diameter fibers exhibited Young’s moduli of 73 ± 13 GPa, yield strengths of 3.5 ± 0.6 GPa, and toughnesses of 1.8 ± 0.3 GPa, on average. Among the smallest fibers examined, one with a diameter of 490 ± 50 nm showed a Young’s modulus of 110 ± 16 GPa, ultimate tensile strength of 6.3 ± 0.9 GPa, and toughness of 2.1 ± 0.3 GPa, a combination of mechanical properties that is unparalleled among polymer fibers to date. The correlation of stiffness, strength and toughness with fiber diameter is attributed to high crystallinity and crystallite orientation, combined with fewer defects and enhanced chain slip associated with small diameter and high specific surface area. Gel-electrospinning improves the prospects for production of such fibers at scale.
Plasma modification of vertically aligned carbon nanotubes: Superhydrophobic surfaces with ultra-low reflectance

Abstract Vertically aligned carbon nanotubes (VACNTs) are excellent broadband (UV–VIS–IR) absorbers of light that can be made even darker with plasma treatments. Modification of VACNTs using O2 and/or CF4 plasmas is shown to have a significant impact on the reflectance and water repellency. Unfortunately, while O2 plasma treatment reduces the reflectance of VACNTs by changing the top surface morphology, it also makes the VACNTs superhydrophilic. Using an additional CF4 plasma treatment, we show that low reflectance and superhydrophobic surfaces are possible — qualities that are desirable when utilizing VACNTs as black body absorbers in cryogenic environments due to the potential for adsorbed water or ice. Using scanning electron microscopy we show that both plasma treatments can change the surface morphology of the VACNTs similarly, which is associated with a corresponding measured reduction in spectral reflectance. Raman spectroscopy of as-grown and plasma treated samples suggest that plasma treatment is introducing defects and functionalizing the nanotube walls and thereby affecting the water repellency. O2 plasma treated VACNTs have a directional-hemispherical reflectance (d/h) at normal incidence (d = 0°) of 94 ± 4 ppm (with a coverage factor of k = 2) at 660 nm and are superhydrophilic. O2 and CF4 plasma treated VACNTs have a 0°/h reflectance of 163 ± 7 ppm (k = 2) at 660 nm and are superhydrophobic with a contact angle of 159°.
Gender and enterprise development in Sub-Saharan Africa : a review of constraints and effective interventions

Female participation in entrepreneurial activities is higher in Sub-Saharan Africa than in any other region. However, women-owned businesses significantly underperform those owned by men. This paper identifies the main constraints that women face in developing their businesses in Africa and discusses how these constraints influence strategic choices in areas such as level of investment and sector of operations. The paper synthesizes the emerging lessons about what works and what does not work to address the underlying constraints to the performance of women-owned firms. Moreover, it identifies knowledge gaps and priority research questions. The paper aims to support the development of a gender-informed policy and research agenda on enterprise development that can guide practitioners, development partners, and researchers who seek to advance women's economic empowerment in Africa.
More Than Just a Number? The Conceptualization and Measurement of Firm Age in an Era of Temporary Organizations

Despite the long history of research on firm age, recent theorizing on firm age has been rare. Meanwhile, significant shifts in the business landscape have altered how firms age and limited the age they are likely to reach. This article seeks to reinvigorate research on firm age by providing the first comprehensive review of the construct while considering how recent studies on time and organizing may be pertinent. We identify important work, integrate what we know, and identify gaps and inconsistencies along five themes in the literature: age-dependence in organizational mortality rates; age-related differences in firm processes or structures; research enriching the theoretical understanding of firm age; research that includes firm age as a control variable; and methodological issues in the study of firm age. We provide evidence that certain long-held assumptions about age have changed as organizations have become increasingly temporary and discuss what this means for organizational research going forward. While we believe the implications we discuss hold value for a broad spectrum of research, we derive more specific recommendations for two streams of research in particular, research on entrepreneurial success and failure, which is directly tied to the liability of newness, and the literature on temporary organizations.
More is less: Increased processing of unwanted memories facilitates forgetting

The intention to forget can produce long-lasting effects. This ability has been linked to suppression of both rehearsal and retrieval of unwanted memories, processes mediated by the prefrontal cortex and hippocampus. Here, we describe an alternative account in which the intention to forget is associated with increased engagement with the unwanted information. We used pattern classifiers to decode human functional magnetic resonance imaging data from a task in which male and female participants viewed a series of pictures and were instructed to remember or forget each one. Pictures followed by a forget instruction elicited higher levels of processing in the ventral temporal cortex compared with those followed by a remember instruction. This boost in processing led to more forgetting, particularly for items that showed moderate (vs weak or strong) activation. This result is consistent with the nonmonotonic plasticity hypothesis, which predicts weakening and forgetting of memories that are moderately activated.SIGNIFICANCE STATEMENT The human brain cannot remember everything. Forgetting has a critical role in curating memories and discarding unwanted information. Intentional forgetting has traditionally been linked to passive processes, such as the withdrawal of sustained attention or a stoppage of memory rehearsal. It has also been linked to active suppression of memory processes during encoding and retrieval. Using functional magnetic resonance imaging and machine-learning methods, we show new evidence that intentional forgetting involves an enhancement of memory processing in the sensory cortex to achieve desired forgetting of recent visual experiences. This enhancement temporarily boosts the activation of the memory representation and renders it vulnerable to disruption via homeostatic regulation. Contrary to intuition, deliberate forgetting may involve more rather than less attention to unwanted information.
DEGRADACION AMBIENTAL EN BOHOL, FILIPINAS: PARALELOS CON EL PERU

Los paises en desarrollo como el Peru y las Filipinas comparten similares problemas ambientales. La degradacion de los recursos ambientales en Bohol, Filipinas ha avanzado hasta un estado critico debido a la sobrepoblacion, la guerra civil, deforestacion y falta de estrategias y politicas de proteccion y manejo ambiental. En el Peru se esta produciendo una degradacion ambiental que, sin embargo, no ha llegado al estado critico. Debido a semejanzas en el crecimiento poblacional, uso de la tierra y fisiografia, la informacion obtenida mediante el estudio sistematico de la degradacion ambiental y de la ampliacion agricola en las Filipinas, es aplicable al Peru. Se determino que para ambas localidades el aspecto mas importante de la proteccion, manejo y ampliacion del uso de los recursos ambientales es el desarrollo de una educacion ambiental y de programas de toma de conciencia en los cuales los profesores, funcionarios de gobierno, estudiantes y publico en general son educados acerca de las intricancias de su ambiente y sobre por que y como proteger, preservar y administrar los recursos ambientales. The developing nations of Peru and the Philippines share similar environmental problems. Because of overpopulation, civil war deforestation, and policies, environmental protection and management strategies and policies, environmental resource degradation in Bohol, the Philippines has advanced to a critical stage. Environmental degradation in Peru is occurring, but it has not yet advanced to this critical stage. Because of similarities in population growth, land use, and physiography, information gained by systematically studying environmental degradation and reclamation in the Philippines is applicable to Peru. It was determined for both locales that the most important aspect of environmental resource protection, management, and reclamation was the development of environmental education and awareness programs wherein teachers, government officials, students, and the general public are educated about the intricacies of their environment, and why and how to protect, preserve, and manage environmental resources.
Human-Centric Indoor Scene Synthesis Using Stochastic Grammar

We present a human-centric method to sample and synthesize 3D room layouts and 2D images thereof, to obtain large-scale 2D/3D image data with the perfect per-pixel ground truth. An attributed spatial And-Or graph (S-AOG) is proposed to represent indoor scenes. The S-AOG is a probabilistic grammar model, in which the terminal nodes are object entities including room, furniture, and supported objects. Human contexts as contextual relations are encoded by Markov Random Fields (MRF) on the terminal nodes. We learn the distributions from an indoor scene dataset and sample new layouts using Monte Carlo Markov Chain. Experiments demonstrate that the proposed method can robustly sample a large variety of realistic room layouts based on three criteria: (i) visual realism comparing to a state-of-the-art room arrangement method, (ii) accuracy of the affordance maps with respect to ground-truth, and (ii) the functionality and naturalness of synthesized rooms evaluated by human subjects.
Immigration: Europe’s Normative Challenge

To absorb millions of immigrants into European societies requires a normative integration. This paper examines the dominant paradigms which characterize integrations, situating assimilation and unbounded pluralism at opposite ends of a continuum. Diversity Within Unity (DWU) is offered as a third approach. It calls for adherence to core values from all (the Unity realm), but beyond these shared values, diversity is fully accepted. The implications for religious practice, education, language, and communal loyalties are explored.
A Driver Behavior Modeling Structure Based on Non-Parametric Bayesian Stochastic Hybrid Architecture

Heterogeneous nature of the vehicular networks, which results from the co-existence of human-driven, semi-automated, and fully autonomous vehicles, is a challenging phenomenon toward the realization of the intelligent transportation systems with an acceptable level of safety, comfort, and efficiency. Safety applications highly suffer from communication resource limitations, specifically in dense and congested vehicular networks. The idea of model-based communication (MBC) has been recently proposed to address this issue. In this work, we propose Gaussian Process based Stochastic Hybrid System with Cumulative Relevant History (CRH-GP-SHS) framework, which is a hierarchical stochastic hybrid modeling structure, built upon a non-parametric Bayesian inference method, i.e. Gaussian processes. This framework is proposed in order to be employed within the MBC context to jointly model driver/vehicle behavior as a stochastic object. Non-parametric Bayesian methods relieve the limitations imposed by non-evolutionary model structures and enable the proposed framework to properly capture different stochastic behaviors. The performance of the proposed CRH-GP-SHS framework at the inter-mode level has been evaluated over a set of realistic lane change maneuvers from the NGSIM-US101 dataset. The results show a noticeable performance improvement for GP in comparison to the baseline constant speed model, specifically in critical situations such as highly congested networks. Moreover, an augmented model has also been proposed which is a composition of GP and constant speed models and capable of capturing the driver behavior under various network reliability conditions.
A retrospective segmentation analysis of placental volume by magnetic resonance imaging from first trimester to term gestation

Abnormalities of the placenta affect 5–7% of pregnancies. Because disturbances in fetal growth are often preceded by dysfunction of the placenta or attenuation of its normal expansion, placental health warrants careful surveillance. There are limited normative data available for placental volume by MRI. To determine normative ranges of placental volume by MRI throughout gestation. In this cross-sectional retrospective analysis, we reviewed MRI examinations of pregnant females obtained between 2002 and 2017 at a single institution. We performed semi-automated segmentation of the placenta in images obtained in patients with no radiologic evidence of maternal or fetal pathology, using the Philips Intellispace Tumor Tracking Tool. Placental segmentation was performed in 112 women and had a high degree of interrater reliability (single-measure intraclass correlation coefficient =0.978 with 95% confidence interval [CI] 0.956, 0.989; P<0.001). Normative data on placental volume by MRI increased nonlinearly from 6 weeks to 39 weeks of gestation, with wider variability of placental volume at higher gestational age (GA). We fit placental volumetric data to a polynomial curve of third order described as placental volume = –0.02*GA3 + 1.6*GA2 – 13.3*GA + 8.3. Placental volume showed positive correlation with estimated fetal weight (P=0.03) and birth weight (P=0.05). This study provides normative placental volume by MRI from early first trimester to term gestation. Deviations in placental volume from normal might prove to be an imaging biomarker of adverse fetal health and neonatal outcome, and further studies are needed to more fully understand this metric. Assessment of placental volume should be considered in all routine fetal MRI examinations.
The Impact of Nicotine and Cigarette Smoke Condensate on Metabolic Activity and Biofilm Formation of Candida albicans on Acrylic Denture Material.

Purpose Smokers have increased denture stomatitis caused primarily by Candida albicans. The primary aim of this study was to demonstrate the impact of a wide range of nicotine and cigarette smoke condensate (CSC) concentrations on biofilm formation and metabolic activity of C. albicans on acrylic denture material. Materials and methods C. albicans (ATCC strain 10231) was used. Standardized denture acrylic (PMMA) specimens (total of 135 specimens) were incubated with C. albicans and exposed to nicotine and CSC at different concentrations (0, 0.25, 0.5, 1, 2, 4, 8, 16, and 32 mg/ml) and (0, 0.25, 0.5, 1, 2, and 4 mg/ml), respectively. For each experiment, 3 samples per nicotine and CSC concentration and a total of 45 specimens (27 specimens for the nicotine and 18 specimens for the CSC-treated samples) were used and were selected randomly for each group. The control group consisted of 0 mg/ml of nicotine or CSC. The viability of C. albicans was measured using spiral plating on blood agar plates. The effect of nicotine and CSC concentrations on planktonic cells was were measured using a microplate reader. Metabolic activity of 24-hour-old established C. albicans biofilm exposed to nicotine and CSC for 24 hours in microtiter plates was determined using a 2,3-bis (2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-carboxanilide (XTT) reduction assay. Results The viability of C. albicans increased concomitant with increasing concentrations of CSC and nicotine, particularly at 0.5 and 2 mg/ml, respectively. Concentrations of CSC and nicotine above this resulted in an inhibitory effect on C. albicans viability. CSC and nicotine at 4 and 16 mg/ml, respectively, increased C. albicans biofilm metabolic activity. Conclusion Nicotine and CSC up to certain concentrations caused increases in biofilm formation, metabolic activity, viability, and planktonic cell absorbance of C. albicans. This in vitro study demonstrates the effectiveness of tobacco on promoting the growth of C. albicans and suggests their potential contributing factor in C. albicans biofilm related infections in smokers.
What Goes Where: Predicting Object Distributions from Above

In this work, we propose a cross-view learning approach, in which images captured from a ground-level view are used as weakly supervised annotations for interpreting overhead imagery. The outcome is a convolutional neural network for overhead imagery that is capable of predicting the type and count of objects that are likely to be seen from a ground-level perspective. We demonstrate our approach on a large dataset of geotagged ground-level and overhead imagery and find that our network captures semantically meaningful features, despite being trained without manual annotations.
Solution of the Navier–Stokes problem

Abstract A new a priori estimate for solutions to Navier–Stokes equations is derived. Uniqueness and existence of these solutions in R 3 for all t > 0 is proved in a class of solutions locally differentiable in time with values in H 1 ( R 3 ) , where H 1 ( R 3 ) is the Sobolev space. By the solution a solution to an integral equation is understood. No smallness restrictions on the data are imposed.
A 14-b 2.5 MSPS pipelined ADC with on-chip EPROM

A 14-b 2.5 MSPS, multistage pipeline, subranging analog-to-digital converter is presented. In addition to conventional laser-wafer-trim, on chip, "write once" EPROM is used to calibrate inter-stage gain errors at package sort. Integral nonlinearity errors as small as /spl plusmn/1.5 LSB and differential nonlinearity errors of /spl plusmn/0.5 LSB have been achieved. The 5.4 mm by 4.4 mm device includes a 2.5 V reference and is built on a 2 /spl mu/m 10 V BiCMOS process and consumes 500 mW of power.
Query Complexity of Bayesian Private Learning

We study the query complexity of Bayesian Private Learning: a learner wishes to locate a random target within an interval by submitting queries, in the presence of an adversary who observes all of her queries but not the responses. How many queries are necessary and sufficient in order for the learner to accurately estimate the target, while simultaneously concealing the target from the adversary? Our main result is a query complexity lower bound that is tight up to the first order. We show that if the learner wants to estimate the target within an error of ϵ, while ensuring that no adversary estimator can achieve a constant additive error with probability greater than 1/L, then the query complexity is on the order of Llog(1/ϵ) as ϵ→0. Our result demonstrates that increased privacy, as captured by L, comes at the expense of a \emph{multiplicative} increase in query complexity. The proof builds on Fano's inequality and properties of certain proportional-sampling estimators.
Realizing Information Erasure in Finite Time

In this article, we focus on erasure of a bit of information in finite time. Landauer's principle states that the average heat dissipation due to erasure of information is $k_{B}T\ln 2$ , which is achievable only in an asymptotic manner. Recent theoretical developments in non-equilibrium thermodynamics and stochastic control, predict a more general bound for finite time erasure dependent on the Wasserstein distances between the initial and final configurations. These predictions suggest improvements to experimental protocol with regards to minimizing average heat dissipation for bit erasure in finite time from a bistable well, under overdamped Langevin dynamics. We present a comparative study of a theoretically optimal protocol with an existing protocol, and highlight the closeness and deviation from optimality.
Leveraging Product as an Activation Function in Deep Networks

Product unit neural networks (PUNNs) are powerful representational models with a strong theoretical basis, but have proven to be difficult to train with gradient-based optimizers. We present windowed product unit neural networks (WPUNNs), a simple method of leveraging product as a nonlinearity in a neural network. Windowing the product tames the complex gradient surface and enables WPUNNs to learn effectively, solving the problems faced by PUNNs. WPUNNs use product layers between traditional sum layers, capturing the representational power of product units and using the product itself as a nonlinearity. We find the result that this method works as well as traditional nonlinearities like ReLU on the MNIST dataset. We demonstrate that WPUNNs can also generalize gated units in recurrent neural networks, yielding results comparable to LSTM networks.
Non-Asymptotic Uniform Rates of Consistency for k-NN Regression

We derive high-probability finite-sample uniform rates of consistency for k-NN regression that are optimal up to logarithmic factors under mild assumptions. We moreover show that k-NN regression adapts to an unknown lower intrinsic dimension automatically in the sup-norm. We then apply the k-NN regression rates to establish new results about estimating the level sets and global maxima of a function from noisy observations.
Improved Mars Helicopter Aerodynamic Rotor Model for Comprehensive Analyses

The Mars Helicopter is part of the NASA Mars 2020 rover mission scheduled to launch in July of 2020. Its goal is to demonstrate the viability and potential of heavier-than-air vehicles in the Marti...
Understanding the impact of reoccurring and non-financial incentives on plug-in electric vehicle adoption – A review

Abstract The market introduction of plug-in electric vehicles (PEVs) is being partially driven by policy interventions. One type of intervention is reoccurring and non-financial incentives, these differ from financial purchase incentives which are a one-time financial incentive associated with the purchase of a PEV. Reoccurring and non-financial incentives include special lane access for PEVs (e.g. HOV/carpool lanes, bus lanes), parking incentives, charging infrastructure development, road toll fee waivers, and licensing incentives. They also include disincentives such as gasoline tax or annual vehicle taxes. The impact of these incentives differs between regions partially due to differences in traffic conditions, travel patterns, consumer preferences, and other local variations. Due to these differences, it is challenging to rank the importance of these incentives, however existing research shows that they all can have a positive impact on PEV adoption. Policymakers wishing to promote the introduction of PEVs will need to consider local travel patterns, the regulatory environment, and consumer preferences to determine the most viable policy interventions for their region.
Manipulating optical nonlinearities of molecular polaritons by delocalization

Optical nonlinearities are key resources in the contemporary photonics toolbox, relevant to quantum gate operations and all-optical switches. Chemical modification is often used to control the nonlinear response of materials at the microscopic level, but on-the-fly manipulation of such response is challenging. Tunability of optical nonlinearities in the mid-infrared (IR) is even less developed, hindering its applications in chemical sensing or IR photonic circuitry. Here, we report control of vibrational polariton coherent nonlinearities by manipulation of macroscopic parameters such as cavity longitudinal length or molecular concentration. Further two-dimensional IR investigations reveal that nonlinear dephasing provides the dominant source of the observed ultrafast polariton nonlinearities. The reported phenomena originate from the nonlinear macroscopic polarization stemming from strong coupling between microscopic molecular excitations and a macroscopic photonic cavity mode.
Burdens and Balancing in Multisided Markets: The First Principles Approach of Ohio v. American Express

Multisided platforms have distinct and critical features that set them apart from single-sided markets. This realization has led to a split among courts, antitrust practitioners, and economists as to the best method to assess whether mergers or conduct that involve platforms result in the creation or maintenance of monopoly power and violate the antitrust laws. Some argue that each side of a platform constitutes a separate relevant product market. Others argue for a single, integrated market that incorporates all sides. We argue that any prima facie antitrust assessment of competitive harm must incorporate the impact to consumers on all sides regardless of market definition. We also explain why output effects should be the primary emphasis of competitive effects analyses. The Supreme Court recently and correctly adopted this approach in Ohio v. American Express.
Do you trust your insurer? Ambiguity about contract nonperformance and optimal insurance demand

Abstract We study optimal insurance demand for a risk- and ambiguity-averse consumer under ambiguity about contract nonperformance. Ambiguity aversion lowers optimal insurance demand and the consumer’s degree of ambiguity aversion is negatively associated with the optimal level of coverage. A more pessimistic belief and greater ambiguity may increase or decrease the optimal demand for insurance, and we determine sufficient conditions for a negative effect. We also discuss wealth effects and evaluate the robustness of our results by considering several alternative models of ambiguity aversion. Our findings show how ambiguity about contract nonperformance can undermine the functioning of insurance markets, making it a concern for regulators. Caution is required though because demand reactions are only imperfectly informative about the welfare effects of ambiguity about contract nonperformance.
The adverse childhood experiences questionnaire: Two decades of research on childhood trauma as a primary cause of adult mental illness, addiction, and medical diseases

Objective. In 1998, Felitti and colleagues published the first study of the Adverse Childhood Experiences-Questionnaire (ACE-Q), a 10-item scale used to correlate childhood maltreatment and adverse...
Integrating Microsimulation Models of Tax Policy into a DGE Macroeconomic Model

This article proposes a method for integrating individual effective tax rates and marginal tax rates computed from a microsimulation (partial equilibrium) model of tax policy with a dynamic general...
Testing local bias in food consumption: The case of fluid milk

This article provides the first set of estimates of the degree of local bias in food consumption, by adapting the international trade notion of home bias, or consumers' tendency to favor domestic over imported goods, to local bias, which describes the tendency of consumers to favor local over nonlocal food. Using state boundaries to define local and household data on cow milk purchases from 2007 until 2016 in the New England region, estimates from the Armington model confirm a bias for fluid milk brands identified as local. [EconLit classifications: D12, L6, Q18].
Verbal Learning and Memory in Early-Implanted, Prelingually Deaf Adolescent and Adult Cochlear Implant Users

Purpose The purpose of this study was to investigate the information-processing strategies of early-implanted, prelingually deaf cochlear implant (CI) users with the California Verbal Learning Test-Second Edition (CVLT-II; Delis, Kramer, Kaplan, & Ober, 2000 ), a well-established normed measure of verbal learning and memory used in neuropsychological assessments of memory loss. Method Verbal learning and memory skills were compared in 20 older adolescent and young adult prelingually deaf long-term early-implanted CI users and their 24 normal hearing (NH) peers using the CVLT-II, a widely used multitrial free recall test of verbal learning and memory. Results On average, CI users recalled fewer words than their NH peers across the immediate, delayed, and cued recall trials of the CVLT-II but were comparable to their NH peers on yes/no recognition memory. CI users showed little evidence of semantic clustering of words during free recall but greater serial clustering compared to their NH peers, suggesting fundamental disturbances in automatic semantic activation of words from long-term memory. No differences were found in verbal memory between CI users and their NH peers on measures of retroactive interference and encoding/retrieval interactions. Performance on the 2nd word list of the CVLT-II (List B) and amount of semantic clustering of words during recall were correlated with sentence recognition in the CI group. Conclusion Study findings demonstrate significant differences in free recall performance and information-processing strategies that early-implanted, prelingually deaf CI users use to encode, organize, store, and retrieve spoken words in conventional verbal list learning paradigms, compared to their NH peers. Because verbal learning and memory are core foundational processes routinely used in daily functioning for a wide range of neurocognitive and language processing operations, these findings suggest potential domains for assessment and novel interventions to promote the development of optimal outcomes in prelingually deaf early-implanted long-term CI users.
Plan Choice And Affordability In The Individual And Small-Group Markets: Policy And Performance-Past And Present.

The individual and small-group health insurance markets have experienced considerable changes since the passage of the Affordable Care Act in 2010, affecting access, choice, and affordability for e...
“Is It Safe?” — The Many Unanswered Questions about Medications and Breast-Feeding

“Is It Safe?” More than half of new mothers take one or more medications in the months after delivery. But health care providers often lack the evidence they need to counsel breast-feeding women on...
Advances and limitations of using satellites to monitor cyanobacterial harmful algal blooms

Abstract The use of satellites for monitoring forests is common and well-known practice. However, the operational remote monitoring of water quality from space is still under development. In the United States of America (USA), the use of this type of data is just now being applied to operationally monitor cyanobacterial harmful algal blooms (CHABs). This powerful tool can be used to generate temporal and spatial assessments of CHABs, however the validation of the retrieved information is still a challenge - especially in tropical and equatorial countries. This commentary discusses the advantages and challenges of current initiatives that use Earth Observation data for managing CHABs such as “Lake Erie’s HAB Bulletin” and “Project CYAN” - both in the USA. Additionally, it was also discussed the application of remote sensing techniques to monitor CHABs in Brazilian inland waters.
Barnette and Masterpiece Cakeshop: Some Unanswered Questions

This symposium piece addresses three issues stemming from the Court’s Masterpiece Cakeshop case and that case’s relationship to West Virginia v. Barnette. First, it discusses the relationship between claims for exemption from laws of general applicability and as-applied claims. Second, it addresses the issue most discussed in the Cakeshop briefs and oral argument, but not ultimately resolved by the Court: what counts as compelled speech in the setting of provision of services such as custom-made wedding cakes? Third, it intervenes in the fascinating sidebar between Justice Kagan and Justice Gorsuch regarding the state commission’s refusal to sanction bakers who wouldn’t make cakes condemning homosexuality, and the relationship between that refusal and the commission’s deeming Jack Phillips in violation of state law by declining to make a custom cake for a same-sex wedding celebration.
Catalytic, Enantioselective Cyclopropanation of Allylic Alcohols. Substrate Generality.

Catalytic, enantioselective cyclopropanation of a broad range of allylic alcohols and one homoallylic alcohol was carried out. The cyclopropanation reagent employed was bis(iodomethyl)zinc generated by the method of Furukawa, and the chiral promoter used (10 mol %) was the N,N-bis(methanesulfonyl) derivative of (R,R)-1,2-diaminocyclohexane. Three experimental features were found to be critical for the rapid and selective cyclopropanation: (1) use of the ethylzinc alkoxide of the allylic alcohol as the substrate by prior deprotonation of the allylic alcohols by diethylzinc, (2) the formation of the zinc complex of the promoter by prior deprotonation of the bis-sulfonamide with diethylzinc, and (3) the use of added zinc iodide generated in situ from diethylzinc and iodine. The stereoselectivity of cyclopropanation was found to be independent of olefin geometry and worked well for substrates bearing both aliphatic and aromatic substituents at either or both 3-positions of the allylic alcohol. However, a met...
Multiple factors influence population sex ratios in the Mojave Desert moss Syntrichia caninervis

Premise of research Natural populations of many mosses appear highly female-biased based on the presence of reproductive structures. This bias could be caused by increased male mortality, lower male growth rate, or a higher threshold for achieving sexual maturity in males. Here we test these hypotheses using samples from two populations of the Mojave Desert moss Syntrichia caninervis. Methods We used double-digest restriction-site associated DNA (RAD) sequencing to identify candidate sex-associated loci in a panel of sex-expressing plants. Next, we used putative sex-associated markers to identify the sex of individuals without sex structures. Key results We found a 17:1 patch-level phenotypic female to male sex ratio in the higher elevation site (Wrightwood) and no sex expression at the low elevation site (Phelan). In contrast, on the basis of genetic data, we found a 2:1 female bias at the Wrightwood site and only females at the Phelan site. The relative area occupied by male and female genets was indistinguishable, but males were less genetically diverse. Conclusions Our data suggest that both male-biased mortality and sexual dimorphism in thresholds for sex expression could explain genetic and phenotypic sex ratio biases and that phenotypic sex expression alone over-estimates the extent of actual sex ratio bias present in these two populations of S. caninervis.
Recent developments in the chemistry of stable silylenes

Abstract This paper reviews progress in the field of thermally stable silylenes since 2000. Developments in the synthesis and characterization of new stable silylenes are discussed, followed by a summary of recent theoretical calculations upon model silylenes. The main part of the article concerns the reactivity patterns displayed by silylenes 1 – 4 , which are discussed in terms of their behavior toward radical, organic, inorganic, and organometallic species.
A convenient and asymmetric protocol for the synthesis of natural products containing chiral alkyl chains via Zr-catalyzed asymmetric carboalumination of alkenes. Synthesis of phytol and vitamins E and K

[reaction: see text]. A convenient and asymmetric protocol for the synthesis of chiral oligoisoprenoids is described. Typically, a C14 vitamin E side chain 5 was synthesized in 47% yield over four steps. Isomeric purity of 5 was upgraded to >99% R at C-2 and 97% R at C-6 by the statistical formation of stereoisomeric p-phenylenebisurethanes and their diastereomeric separation. In addition, phytol and vitamin K were synthesized in 21% and 28% overall yields, respectively, over five steps from 1.
A column-based ‘flush and flow’ system for the asymmetric α-chlorination of acid halides

We describe a column based flow system in which a cinchona alkaloid based reagent/catalyst solid-phase promotes the asymmetric α-chlorination of acid chlorides to afford highly optically active α-chloroesters in high enantiomeric excess and in good yields.
Novel metrics for quantifying bacterial genome composition skews

Bacterial genomes have characteristic compositional skews, which are differences in nucleotide frequency between the leading and lagging DNA strands across a segment of a genome. It is thought that these strand asymmetries arise as a result of mutational biases and selective constraints, particularly for energy efficiency. Analysis of compositional skews in a diverse set of bacteria provides a comparative context in which mutational and selective environmental constraints can be studied. These analyses typically require finished and well-annotated genomic sequences. We present three novel metrics for examining genome composition skews; all three metrics can be computed for unfinished or partially-annotated genomes. The first two metrics, (dot-skew and cross-skew) depend on sequence and gene annotation of a single genome, while the third metric (residual skew) highlights unusual genomes by subtracting a GC content-based model of a library of genome sequences. We applied these metrics to 7738 available bacterial genomes, including partial drafts, and identified outlier species. A phylogenetically diverse set of these outliers (i.e., Borrelia, Ehrlichia, Kinetoplastibacterium, and Phytoplasma) display similar skew patterns but share lifestyle characteristics, such as intracellularity and biosynthetic dependence on their hosts. Our novel metrics appear to reflect the effects of biosynthetic constraints and adaptations to life within one or more hosts on genome composition. We provide results for each analyzed genome, software and interactive visualizations at http://db.systemsbiology.net/gestalt/ skew_metrics .
Comet and Asteroid Hazard to the Terrestrial Planets

Abstract We estimated the rate of comet and asteroid collisions with the terrestrial planets by calculating the orbits of 13,000 Jupiter-crossing objects (JCOs) and 1300 resonant asteroids and computing the probabilities of collisions based on random-phase approximations and the orbital elements sampled with a 500 years step. The Bulirsh–Stoer and a symplectic orbit integrator gave similar results for orbital evolution, but may give different collision probabilities with the Sun. A small fraction of former JCOs reached orbits with aphelia inside Jupiter's orbit and some reached Apollo orbits with semi-major axes less than 2 AU, Aten orbits and inner-Earth orbits (with aphelia less than 0.983 AU) and remained there for millions of years. Though less than 0.1% of the total, these objects were responsible for most of the collision probability of former JCOs with Earth and Venus. We conclude that a significant fraction of near-Earth objects could be extinct comets that came from the trans-Neptunian region or most of such comets disintegrated during their motion in near-Earth object orbits.
1,3-DIPOLAR CYCLOADDITIONS OF ELECTRON-RICH BENZOTRIAZOL-1-YLPROPENES

The preparation of trans-3-benzotriazol-1-yl-1-(N-rnorpholino)prop-1-ene (1), trans-3-benzotriazol-1-yl-1-ethoxyprop-1-ene (2) and trans-1,3-bis-(benzotriazol-1-yl)propene (3) and their reactions with a benzonitrile oxide (4), N-(2,4-dibromophenyl)-1-phenylnitrilimine (5), and p-nitrophenyl azide (6) are described.
Diastereoselective synthesis of hydantoin- and isoxazoline-substituted dispirocyclobutanoids.

Synthetic strategies for constructing novel achiral cyclobutanoid isoxazolidinoimidazolidinedione heterocycles, with a generalized structure of II, have been developed via 1,3-dipolar cycloaddition and carbanilide cyclization transformations from methylenecyclobutane 13. The exo methylene cyclobutane system has made the realization of some diasteroselectivity possible, such that the H-bond (Boc-NH) directed product (i.e., 14) was obtained with 3:1 selectivity relative to the non-H-bond directed product (i.e., 15).
Termination of Mn(III)-Based Oxidative Cyclizations by Trapping with Azide

The radicals formed in Mn(III)-based oxidative free-radical cyclizations of beta-keto esters and malonate esters can be trapped with sodium azide and Mn(III) to give cyclic and bicyclic azides in 30-80% yield. Reduction of the azide gives bi- and tricyclic lactams. [reaction: see text]
Total synthesis of (ent)-korupensamine D

The first total synthesis of the enantiomer of the natural product, korupensamine D (16R), is described. The key steps include a highly efficient preparation of the enantiomerically pure primary amine 4 via the ring opening of aziridine 2 with an arylcuprate reagent and the development of a one-pot selective functionalization of a hindered secondary amine in the presence of phenolic hydroxyl groups (i.e., 8 to 9).
A shared limiting resource leads to competitive exclusion in a cross‐feeding system

Species interactions and coexistence are often dependent upon environmental conditions. When two cross-feeding bacteria exchange essential nutrients, the addition of a cross-fed nutrient to the environment can release one species from its dependence on the other. Previous studies suggest that continued coexistence depends on relative growth rates: coexistence is maintained if the slower-growing species is released from its dependence on the other, but if the faster-growing species is released, the slower-growing species will be lost (a hypothesis that we call 'feed the faster grower' or FFG). Using invasion-from-rare experiments with two reciprocally cross-feeding bacteria, genome-scale metabolic modelling and classical ecological models, we explored the potential for coexistence when one cross-feeder became independent. We found that whether nutrient addition shifted an interaction from mutualism to commensalism or parasitism depended on whether the nutrient that limited total growth was required by one or both species. Parasitism resulted when both species required the growth-limiting resource. Importantly, coexistence was only lost when the interaction became parasitism, and the obligate species had a slower growth rate. Under these restricted conditions, the FFG hypothesis applied. Our results contribute to a mechanistic understanding of how resources can be manipulated to alter interactions and coexistence in microbial communities.
Microwave-assisted cleavage of phosphate, phosphonate and phosphoramide esters

A mild and rapid protocol for cleavage of phosphate, phosphonate and phosphoramide esters. The scope and limitations of this microwave-assisted reaction is explored here.
The Anion-Binding Approach to Catalytic Enantioselective Acyl Transfer

This account details the development of a dual-catalysis approach and its application to the kinetic resolution of amines and other enantioselective acyl-transfer reactions. Anion recognition is an essential design element of these processes, which are enabled by the combined action of an achiral 4-(N,N-dimethylamino)pyridine (DMAP) derivative and a chiral anion receptor catalyst. 1 Introduction 2 Kinetic Resolution of Amines 2.1 Benzylic Amines 2.2 Propargylic Amines 2.3 Allylic Amines 2.4 Benzylic Amines Revisited 2.5 Racemic Diamines 3 Desymmetrization of meso-Diamines 4 Miscellaneous Acyl Transfer Reactions 4.1 Steglich Reaction 4.2 Reactions of Isoquinolines with Azlactones 4.3 Acylation of Silyl Ketene Acetals 5 Conclusions
Large Propulsion Demands Increase Locomotor Adaptation at the Expense of Step Length Symmetry

There is an interest to identify factors facilitating locomotor adaptation induced by split-belt walking (i.e., legs moving at different speeds) because of its clinical potential. We hypothesized that augmenting braking forces, rather than propulsion forces, experienced at the feet would increase locomotor adaptation during and after split-belt walking. To test this, forces were modulated during split-belt walking with distinct slopes: incline (larger propulsion than braking), decline (larger braking than propulsion), and flat (similar propulsion and braking). Step length asymmetry was compared between groups because it is a clinically relevant measure robustly adapted on split-belt treadmills. Unexpectedly, the group with larger propulsion demands (i.e., the incline group) changed their gait the most during adaptation, reached their final adapted state more quickly, and had larger after-effects when the split-belt perturbation was removed. We also found that subjects who experienced larger disruptions of propulsion forces in early adaptation exhibited greater after-effects, which further highlights the catalytic role of propulsion forces on locomotor adaptation. The relevance of mechanical demands on shaping our movements was also indicated by the steady state split-belt behavior, during which each group recovered their baseline leg orientation to meet leg-specific force demands at the expense of step length symmetry. Notably, the flat group was nearly symmetric, whereas the incline and decline group overshot and undershot step length symmetry, respectively. Taken together, our results indicate that forces propelling the body facilitate gait changes during and after split-belt walking. Therefore, the particular propulsion demands to walk on a split-belt treadmill might explain the gait symmetry improvements in hemiparetic gait following split-belt training.
Palladium-catalyzed oxidative alkoxylation of α-alkenyl β-diketones to form functionalized furans

Treatment of 4-allyl-2,6-dimethyl-3,5-heptanedione with a catalytic amount of PdCl2(CH3CN)2 (5 mol %) and a stoichiometric amount of CuCl2 (2.2 equiv) in dioxane at 60 °C for 12 h formed 3-isobutyryl-2-isopropyl-5-methylfuran in 77% isolated yield. A number of α-alkenyl β-diketones underwent oxidative alkoxylation under these conditions to form 2,3,5-trisubsituted furans in moderate to good yield.
An alternate proof of idempotent relations among periodic points and quotients

Abstract We give a short proof of an idempotent relation formula for counting periodic points of endomorphisms defined over finite fields. The original proof of this result, due to Walton, uses formal manipulation of arithmetic zeta functions, whereas we deduce the result directly from a related theorem of Kani and Rosen.
Stereoselective hydrogen transfer reactions of vinyl radicals: Cyclization of alkynyl iodides by Unimolecular Chain Transfer from silicon hydrides

Abstract The cyclization of several substituted hexynyl and heptynyl iodides proceeds stereoselectively to give either E- or Z-exocyclic double bonds depending on the type of precursor and radical chain used. In UniMolecular Chain Transfer (UMCT) reactions, the intramolecular abstraction of hydrogen by the intermediate vinyl radical leads exclusively to the E-isomer while the traditional tin hydride method usually provides the Z-isomer with good selectivity.
Characterization of gene expression changes over healthy term pregnancies.

During pregnancy, women experience numerous physiological changes but, to date, there is limited published data that characterize accompanying changes in gene expression over pregnancy. This study sought to characterize the complexity of the transcriptome over the course of pregnancy among women with healthy pregnancies. Subjects provided a venous blood sample during early (6–15 weeks) and late (22–33 weeks) pregnancy, which was used to isolate peripheral blood mononuclear cells prior to RNA extraction. Gene expression was examined for 63 women with uncomplicated, term deliveries. We evaluated the association between weeks gestation at sample collection and expression of each transcript. Of the 16,311 transcripts evaluated, 439 changed over pregnancy after a Bonferroni correction to account for multiple comparisons. Genes whose expression increased over pregnancy were associated with oxygen transport, the immune system, and host response to bacteria. Characterization of changes in the transcriptome over the course of healthy term pregnancies may enable the identification of genes whose expression predicts complications or adverse outcomes of pregnancy.