cssi/SciSciGPT-SciSciNet huggingface dataset:
Probing the coordination and function of Fe 4 S 4 modules in nitrogenase assembly protein NifB

NifB is an essential radical S-adenosylmethionine (SAM) enzyme for nitrogenase cofactor assembly. Previous studies show that NifB couples a putative pair of [Fe4S4] modules (designated K1 and K2) into an [Fe8S9C] cofactor precursor concomitant with radical SAM-dependent carbide insertion through the action of its SAM-binding [Fe4S4] module. However, the coordination and function of the NifB cluster modules remain unknown. Here, we use continuous wave and pulse electron paramagnetic resonance spectroscopy to show that K1- and K2-modules are 3-cysteine-coordinated [Fe4S4] clusters, with a histidine-derived nitrogen serving as the fourth ligand to K1 that is lost upon K1/K2-coupling. Further, we demonstrate that coexistence of SAM/K2-modules is a prerequisite for methyltransfer to K2 and hydrogen abstraction from the K2-associated methyl by a 5'-deoxyadenosyl radical. These results establish an important framework for mechanistic explorations of NifB while highlighting the utility of a synthetic-cluster-based reconstitution approach employed herein in functional analyses of iron-sulfur (FeS) enzymes.
The crust and upper mantle structure of central and West Antarctica from Bayesian inversion of Rayleigh Wave and receiver functions

Author(s): Shen, Weisen; Wiens, Douglas A; Anandakrishnan, Sridhar; Aster, Richard C; Gerstoft, Peter; Bromirski, Peter D; Hansen, Samantha E; Dalziel, Ian W. D; Heeszel, David S; Huerta, Audrey D; Nyblade, Andrew A; Stephen, Ralph; Wilson, Terry J; Winberry, J. Paul
Solvent and Substrate Induced Synergistic Ordering in Block Copolymer Thin Films

Nanotechnology-based applications of block copolymers (BCPs) require a detailed understanding of microphase separation in thin films during processing. Solvent annealing is a widely employed method for BCP thin films. Quantification of microphase separation is an empirical challenge due to the nature of the buried interface and the scale of temporal dynamics. Several modeling-based approaches have been attempted, but they shed little light on capturing the overall dynamics and interactions that contribute to domain formation in BCP thin films. For the first time, we report in this article a systematic coarse-grained (CG) molecular dynamics (MD) approach that addresses both the ordering and the morphological evolution in solvent swollen thin BCP films. In this study, for an inherently lamellar BCP system, we found that a slight change in relative solvent–block interactions can generate a variety of morphologies including cylindrical, lamellar, and other transient morphologies. In addition, we correlate the...
Graphene-dielectric integrated terahertz metasurfaces

In this paper we discuss graphene–dielectric integrated terahertz metasurfaces as an alternative approach to graphene–metal metamaterials for providing effective control of electromagnetic beam propagation at terahertz wavelengths. Our structures consist of a passive lossless dielectric pattern and a reconfigurable graphene sheet whose terahertz optical conductivity could be actively tuned chemically, electrically, or optically. In particular, we investigate dielectric patterns consisting of pillar- and circular hole arrays and show that via optimizing the geometric dimensions in these patterns it is possible to attain almost complete terahertz absorption at an arbitrary frequency of interest. Furthermore, via either (i) controlling the thickness of a low-index dielectric spacer located between the dielectric pattern and the graphene sheet, or (ii) choosing a material with an appropriate index of refraction when constructing the dielectric pattern, it is possible to control the sensitivity of the overall structure to variations in the graphene sheet conductivity. Full-wave electromagnetic simulations are supported by proof-of-principle experiments on structures fabricated via patterning of a silicon-on-insulator wafer followed by graphene transfer and chemical doping. Overall, the proposed approach can lead to the construction of efficient tunable terahertz absorbers; however, other tailored electromagnetic responses might be also possible via the selection of appropriate dielectric patterns.
Adverse events following vaccination with an inactivated, Vero cell culture-derived Japanese encephalitis vaccine in the United States, 2012-2016.

Abstract Background In March 2009, the U.S. Food and Drug Administration licensed an inactivated Vero cell culture-derived Japanese encephalitis vaccine (JE-VC [IXIARO®]) for use in persons aged ≥17 years. In 2013, licensure was extended to include children aged ≥2 months. A previous analysis reviewed adverse events reported to the U.S. Vaccine Adverse Event Reporting System (VAERS) from May 2009 through April 2012. Methods We reviewed adverse events reported to VAERS following JE-VC administered from May 1, 2012 through April 30, 2016. Adverse event reporting rates were calculated using 802,229 doses distributed. Results During the 4-year period, 119 adverse event reports were received for a reporting rate of 14.8 per 100,000 doses distributed. Nine (8%) adverse events were classified as serious for a reporting rate of 1.1 per 100,000 distributed. The most commonly reported event was hypersensitivity ( n = 24; 20%) for a rate of 3.0 per 100,000 doses distributed; 1 anaphylaxis event was reported. Ten (8%) neurologic events were reported for a rate of 1.2 per 100,000 doses distributed; 2 events were classified as seizures. Sixty-three (53%) adverse events occurred after a first dose of JE-VC. Eighty (67%) adverse events occurred after administration of JE-VC with other vaccines. Eleven (9%) adverse events were reported in children; 1 was considered serious. Conclusions These data continue to support the generally favorable safety profile of JE-VC. Reporting rates of adverse events were similar to those of the previous analysis. Although reporting rates of adverse events in children could not be calculated, there were low numbers of reported events in this age group. Post-licensure adverse event surveillance for this relatively new vaccine continues to be important to monitor adverse event reporting rates and identify possible rare serious events.
Loss of Nuclear TDP-43 Is Associated with Decondensation of LINE Retrotransposons.

Summary Loss of the nuclear RNA binding protein TAR DNA binding protein-43 (TDP-43) into cytoplasmic aggregates is the strongest correlate to neurodegeneration in amyotrophic lateral sclerosis and frontotemporal degeneration. The molecular changes associated with the loss of nuclear TDP-43 in human tissues are not entirely known. Using subcellular fractionation and fluorescent-activated cell sorting to enrich for diseased neuronal nuclei without TDP-43 from post-mortem frontotemporal degeneration-amyotrophic lateral sclerosis (FTD-ALS) human brain, we characterized the effects of TDP-43 loss on the transcriptome and chromatin accessibility. Nuclear TDP-43 loss is associated with gene expression changes that affect RNA processing, nucleocytoplasmic transport, histone processing, and DNA damage. Loss of nuclear TDP-43 is also associated with chromatin decondensation around long interspersed nuclear elements (LINEs) and increased LINE1 DNA content. Moreover, loss of TDP-43 leads to increased retrotransposition that can be inhibited with antiretroviral drugs, suggesting that TDP-43 neuropathology is associated with altered chromatin structure including decondensation of LINEs.
BRESSMAN, Susan: New York/USA

Susan Bressman is Professor of Neurology at the Icahn School of Medicine at Mount Sinai, and Co-Director of the Movement Disorders Center at Mount Sinai, New York. Her graduate training was in clinical neurology with a fellowship in movement disorders. Her research focuses on identifying etiologies and disease mechanisms, especially genetic, that underlie dystonia (TORIA, THAP1, GNAL, GCH1, SGCE) and Parkinson’s disease (LRRK2, GBA, PARKIN). Her unique contribution has been in helping to create and promote translational teams and her special expertise has been clinical characterization and family studies aimed at identifying relatively homogeneous subgroups likely to share etiologies. As an extension of this work, once genetic etiologies are identified she pursued further translational research aimed at expanding understanding of gene expression; this includes using additional clinical testing, imaging, and biomarkers of pathology. Open image in new window
On the MIMO Interference Channel with Reconfigurable Antennas and Partial CSIT

In order to explore the compatibility of blind interference alignment schemes with channel knowledge based beamforming and zero-forcing schemes, in this work we initiate the study of the degrees of freedom (DoF) of the two-user MIMO interference channel (IC) where Transmitter 1 is equipped with reconfigurable antennas and has no channel knowledge while Transmitter 2 has partial channel knowledge but no reconfigurable antennas. In particular we focus on two challenging examples to show how blind interference alignment, rate-splitting and partial zero-forcing schemes may be combined in non-trivial ways. Limited generalizations of these examples to broader parameter regimes are also presented.
Estimating U.S. import penetration in sub-national regions

We develop an industry-specific model of import demand that takes into account the costs associated with international transport from the exporting country to the port of entry and also the costs a...
Exploring Age Effects on Children’s Preferences of Package Design: Curvilinearity, Figurativeness, and Complexity

Packaging as an important strategic communication tactic has a particularly strong influence on children’s preferences and purchase decisions. Drawn from the literature on international consumer ma...
Improving Students' Problem-Solving Flexibility in Non-routine Mathematics.

A key issue in mathematics education is supporting students in developing general problem-solving skills that can be applied to novel, non-routine situations. However, typical mathematics instruction in the U.S. too often is dominated by rote learning, without exposing students to the underlying reasoning or alternate ways to solve problems. As a first step in addressing this problem, we present a cognitive task analysis study that investigates how students without a mathematics-related background solve novel non-routine problems. We found that most students were able to identify the underlying pattern that yields the final solution in each problem. Furthermore, they tended to use various forms of visualization in their draft work, but occasionally made computational mistakes. Based on these results, we propose our plan for developing an instructional platform that leverages learning science principles to train students in problem-solving abilities.
Interlaminar stabilization for spinal stenosis in the Medicare population

ABSTRACT BACKGROUND CONTEXT The number of complex fusions performed on Medicare beneficiaries, defined as ≥age 65, with lumbar spinal stenosis with or without spondylolisthesis has been increasing. Typically, these procedures are longer, more invasive and pose a greater risk for complications. Interlaminar stabilization (ILS) serves as an intermediary between decompression alone and decompression with fusion. PURPOSE The purpose of this study was to prospectively examine the efficacy of ILS in patients ≥age 65 through comparison to fusion in the same age group and ILS in younger patients. STUDY DESIGN/SETTING A prospective, multicentered, randomized controlled trial comparing decompression with ILS to decompression with posterolateral fusion with bilateral pedicle screw instrumentation. PATIENT SAMPLE Patients from 21 sites in the United States underwent surgery for moderate stenosis with up to a grade 1 degenerative spondylolisthesis and failure of conservative treatment with low back pain at 1 or 2 contiguous levels from L1–L5. Preoperatively, patient-reported assessment had to meet the criteria of significant pain and disability (Visual Analog Scale [VAS back pain] ≥50 mm on a 100 mm scale; Oswestry Disability Index [ODI] of ≥20/50). OUTCOME MEASURES The primary outcome was overall Composite Clinical Success (CCS) as determined by ODI scores, incidence of postoperative epidural injections and/or reoperations, incidence of device-related complications, and persistent or progressive neurological deficit. Secondary outcomes included patient satisfaction as measured by VAS for back and worse leg pain and Zurich Claudication Questionnaire scores. Narcotic usage data and radiographic assessment of changes in postoperative posterior disc height and foraminal height were also evaluated. METHODS At 1- or 2-levels, 84 patients ≥age 65 underwent decompression with ILS, 57 patients ≥age 65 underwent decompression with fusion, and 131 patients RESULTS At 24 and 60 months, there were no statistically significant differences in CCS or any of the individual components of CCS between the ≥ age 65 ILS and fusion groups or between the CONCLUSIONS Clinically, ILS patients ≥age 65 performed as well as both those receiving fusion and those
Controller hardware in the loop testing of microgrid secondary frequency control schemes

Abstract This paper describes a controller hardware-in-the loop (C-HIL) approach for testing centralized and distributed secondary frequency control schemes of AC microgrids operating in islanded mode. We describe the formulation of the secondary frequency control problem and the theory behind the centralized and distributed implementations of the control schemes. Then, we describe the testbed utilized for C-HIL testing activities. Finally, we provide the testing results that compare the performance (in terms of the system response time), and resilience (in terms of withstanding the failure of a control device), of both schemes.
Pathology, identity, or both? Making meaning from early Christian martyrdom

Partly in response to an earlier ‘pathological approach’ that seemingly stigmatised early Christian martyrdom, recent scholarship has adopted an ‘identity approach’ that explains martyrdom as a nor...
Creating Technology-Based Mathematics Learning Environments: Extension of Teacher Knowledge and Student Achievement

Technology-based learning environments have been created based on learning content and available technologies. Creating technology-based learning environments that are content specific is a challenge many teachers have faced. The available technologies teachers have been restricted based on school resources and if the technology can be paired with the learning content. Furthermore, student abilities may have caused restriction the technologies teachers have to choose from. Teachers have been under pressure to choose technologies that contribute to learning. As technology is an affordance for assisting students in learning, examining technology-based learning environments is needed for assisting teachers with successful integration. This literature review will examine technology-based mathematics classrooms. The purpose of the literature review is to propose an algorithmic device that chooses technology based on the needs of learners in mathematics classrooms. The algorithmic device will serve as the extension of teachers’ minds for choosing technology, allowing teachers to focus their knowledge on developing students’ knowledge. Supporting theories are discussed on technology-based mathematics classrooms, algorithmic devices, and cognitive extension. Future research should investigate the effects of an algorithmic device used to help with technology integration on teacher knowledge and student achievement. Implications and recommendations are discussed for the proposed algorithmic device and for future research on the integration of the algorithmic device.
Strategic tree rewriting in attribute grammars

This paper presents strategy attributes, a seamless integration of strategic term rewriting into attribute grammars. Strategy attributes are specified using rewrite rules with strategies that control their application. The rules can reference contextual information held in attributes on the trees being rewritten. This use of attributes leads to rewriting on decorated trees instead of undecorated terms. During rewriting, attributes are (lazily) computed on new trees to ensure they are correct with respect to their defining equations. Attributes and strategic rewriting can each be used where most appropriate, thus avoiding the cumbersome aspects of each. Strategy attributes are essentially higher-order attributes for which the defining equations are automatically generated from the attributes' strategy expressions. They are thus compatible with other attribute grammar features such as reference attributes, forwarding, and attribute flow analyses for well-definedness. A conservative static analysis checks if a strategy is intended to always succeed or to be partial, thus simplifying its use and optimizing its translation. Strategy attributes are demonstrated in the optimization of a simple expression language, evaluation of the lambda calculus, and optimization of strategy attribute translations.
The molecular basis of OH-PCB estrogen receptor activation

Polychlorinated bisphenols (PCBs) continue to contaminate food chains globally where they concentrate in tissues and disrupt the endocrine systems of species throughout the ecosphere. Hydroxylated PCBs (OH-PCBs) are major PCB metabolites and high-affinity inhibitors of human estrogen sulfotransferase (SULT1E1), which sulfonates estrogens and thus prevents them from binding to and activating their receptors. OH-PCB inhibition of SULT1E1 is believed to contribute significantly to PCB-based endocrine disruption. Here, for the first time, the molecular basis of OH-PCB inhibition of SULT1E1 is revealed in a structure of SULT1E1 in complex with OH-PCB1 (4ʹ-OH-2,6-dichlorobiphenol) and its substrates, estradiol (E2), and PAP (3’-phosphoadenosine-5-phosphosulfate). OH-PCB1 prevents catalysis by intercalating between E2 and catalytic residues and establishes a new E2-binding site whose E2 affinity and positioning are greater than and competitive with those of the reactive-binding pocket. Such complexes have not been observed previously and offer a novel template for the design of high-affinity inhibitors. Mutating residues in direct contact with OH-PCB weaken its affinity without compromising the enzyme’s catalytic parameters. These OH-PCB resistant mutants were used in stable transfectant studies to demonstrate that OH-PCBs regulate estrogen receptors in cultured human cell lines by binding the OH-PCB binding pocket of SULT1E1.
Testing and Refining Scholarly Communications Workflows and Work Habits for the Digital Age

Greenhouse Studios | Scholarly Communications Design at UConn is a shared venture of the School of Fine Arts, University Library, and College of Liberal Arts and Sciences at the University of Conne...
The Ethics of Pushing the Envelope in Indian Law Cases

This research paper, prepared for the University of Colorado/Denver University symposium Native Americans, Race, and the Constitution, offers an overview of the law relating to pushing the envelope - or seeking to extend or curb federal Indian law doctrines - without entering the territory of filing sanctionable frivolous claims under FRCP 11 and Federal Appellate Rule 38. This research covers cases in which attorneys and parties faced sanctions for failing to properly alleged federal court jurisdiction in Indian law cases, bringing frivolous appeals, and relitigating tribal claims again and again. The research suggests ways to bring claims for law reform in good faith.
Aboveground and belowground impacts following removal of the invasive species baby's breath (Gypsophila paniculata) on lake Michigan sand dunes.

The removal of invasive species is often one of the first steps in restoring degraded habitats. However, studies evaluating effectiveness of invasive species removal are often limited in spatial and temporal scale, and lack evaluation of both aboveground and belowground effects on diversity and key processes. In this study, we present results of a large 3-year removal effort of the invasive species, Gypsophila paniculata, on sand dunes in northwest Michigan (USA). We measured G. paniculata abundance, plant species richness, plant community diversity, non-native plant cover, abundance of Cirsium pitcheri (a federally threatened species endemic to this habitat), sand movement, arbuscular mycorrhizal spore abundance, and soil nutrients in fifteen 1000 m 2 plots yearly from 2007 to 2010 in order to evaluate the effectiveness of manual removal of this species on dune restoration. Gypsophila paniculata cover was greatly reduced by management, but was not entirely eliminated from the area. Removal of G. paniculata shifted plant community composition to more closely resemble target reference plant communities but had no effect on total plant diversity, C. pitcheri abundance, or other non-native plant cover. Soil properties were generally unaffected by G. paniculata invasion or removal. The outlook is good for this restoration, as other non-native species do not appear to be staging a “secondary” invasion of this habitat. However, the successional nature of sand dunes means that they are already highly invasible, stressing the need for regular monitoring to ensure that restoration progresses.
Screening for Resistance to Hypoxylon Mammatum in Populus Tremuloides Callus and Micropropagated Plantlets

Two in vitro procedures are being tested for screening trembling aspen for resistance to Hypoxylon canker: (1) tissue culture response to fungal culture metabolites and (2) ascospore inoculation of moisture stressed plantlets. In the first procedure, the sensitivity of five clones to the acidic ethyl acetate (AEA) fraction of partially purified culture filtrate was determined by comparing callus growth on ACM medium containing the AEA fraction with that of a control containing non-inoculated culture filtrate. Treatments of 0.1x and 1.0x AEA concentrations were inhibitory compared with controls. The clones varied considerably in callus growth and callus inhibition, with the inhibition relative to growth of the control directly related to that growth. Correlations of the resistance responses of 10 year old ramets to artificial inoculations with mycelial-infested grain show a moderate positive correlation of both callus growth of the control and callus inhibition with canker length and with incidence of branch death.
Fannie Mae, Freddie Mac, and the Future of Federal Housing Finance Policy: A Study of Regulatory Privilege

The federal government recently placed Fannie Mae and Freddie Mac, the government-chartered, privately owned mortgage finance companies, in conservatorship. These two massive companies are profit-driven, but as government-sponsored enterprises they also have a government-mandated mission to provide liquidity and stability to the United States mortgage market and to achieve certain affordable housing goals. How the two companies should exit their conservatorship has implications that reach throughout the global financial markets and are of key importance to the future of American housing finance policy. While the American taxpayer will be required to fund a bailout of the two companies that will be measured in the hundreds of billions of dollars, the current state of affairs presents an opportunity to reform the two companies and the manner in which the residential mortgage market is structured. Few scholars, however, have provided a framework in which to conceptualize the possibilities for reform. This Article employs regulatory theory to construct such a framework. A critical insight of this body of literature is that regulatory privilege should be presumed to be inconsistent with a competitive market, unless proven otherwise. The federal government's special treatment of Fannie and Freddie is an extraordinary regulatory privilege in terms of its absolute value, its impact on its competitors and its cost to the federal government. Regulatory theory thereby clarifies how Fannie and Freddie have relied upon their hybrid public/private structure to obtain and protect economic rents at the expense of taxpayers as well as Fannie and Freddie's competitors. Once analyzed in the context of regulatory theory, Fannie and Freddie's future seems clear. They should be privatized so that they can compete on an even playing field with other financial institutions and their public functions should be assumed by pure government actors. While this is a radical solution and one that would have been considered politically na?ve until the recent credit crisis, it is now a serious option that should garner additional attention once its rationale is set forth.
The Fetish of Jury Trial in Civil Cases: A Comment on Rachal v. Hill

U tNDER the influence of Supreme Court decisions on the right to jury trial in civil cases in the federal courts,1 most observers seem to develop a Pavlovian reaction to a seventh amendment, jury trial issue whenever it arises. Any close question and sometimes one that is not so close -is resolved in favor of the jury trial right without serious analysis of history, precedent, or policy. What may be of only passing interest in the classroom or in legal commentary becomes a cause for concern when it spreads to the lower federal courts. Yet the signs of contagion are appearing 2 -perhaps the most conspicuous recent example being the decision of the Fifth Circuit in Rachal v. Hill.3 At a time of growing concern over crowded dockets, the size of judgments, and the costs of litigation, the question whether we have more trial by jury than we want or need is well worth asking -and
Blood Flow and Oxygen Distribution in a Simulated 3D Liver Lobule

Constructing computational 3D liver lobule microstructures lays the basis for understanding the spatial aspects of tissue-level events such as transport and delivery of oxygen within the liver. To satisfy the demand of liver cells for oxygen and nutrient, hepatic sinusoids that perfuse hepatocytes must maintain an appropriate network structure. Here we describe a refinement of the liver portion of our multiscale model consisting of a multi-cell 3D liver lobule that includes blood flow. The human liver is constructed of approximately one million lobules "plumbed" with blood vessels in a parallel arrangement. The parallel nature of the lobules within the liver makes it possible to simulate the entire liver by simulating a small number of lobules. We have used Compucell3D to construct representative portions of a 3D lobule consisting of portal arterial plus venous blood sources, a network of sinusoids (liver capillaries) lined with hepatocytes and a central vein drain. The lobule is stochastically constructed but directed by parameters derived from the analysis of mouse livers. The resulting network was then used to simulate flow of oxygenated blood though the lobule using Kirchhoff's law. A critical assumption in the generation of the model is that the diameter of the sinusoids is constant throughout a lobule. The spatial patterning of sinusoidal network was designed to be optimally favorable for oxygen and nutrient delivery. These assumptions, and Kirchhoff's law, result in the requirement that the linear blood velocity increases from the pericentral region to the central vein of a liver lobule. We have also modeled the diffusion of oxygen out of the sinusoidal blood and its consumption by hepatocytes, using a PDE solver. The combination of the stochastic sinusoid structure, and the changes in blood velocity in different regions of a lobule, give rise to localized differences in oxygen availability.
Results of Micro-Deval Test for Coarse Aggregates from Virginia Sources

Aggregate is the most widely used construction material, and a key aspect of aggregate quality is durability. In this study, the Micro-Deval test was studied to evaluate its suitability for assessing the durability of coarse aggregates from Virginia sources. Results obtained with the Micro-Deval test and several commonly used aggregate tests were compared. The Micro-Deval test showed a very high potential to evaluate aggregate durability with better precision than did the conventional tests. It was able to differentiate between good- and poorly-performing aggregates at least 70% of the time and was able to identify the quality difference between similar aggregate types with varying degrees of weathering. Thus, the Micro-Deval test is recommended for use as a quality control tool for aggregate assessment to supplement the current measures of aggregate quality.
Energy Transfers between Crystals and Adsorbed Dyes. II. Effect of Concentration on Efficiency of Sensitization

The effect of density of sensitizer molecules adsorbed on a cadmium sulfide surface on the efficiency of sensitization by them has been studied for malachite green, pinacyanole, erythrosin, and 3,3′ diethylthiacarbocyanine. The losses in the case of the first two are drastic and can be accounted for directly in terms of the properties of the solid dyes. The detailed process of electron transfer from a dye molecule or aggregate to a crystal substrate is considered briefly. It is concluded that there should in general be a loss of efficiency in passing from the state in which molecules are adsorbed singly and broadside, to that in which they are adsorbed as a close-packed aggregate.
Headache in the Emergency Department

Emergency-medicine clinical researchers concentrate on optimizing diagnostic workups and treatment protocols, as well as improving throughput in an emergency department. This past year has yielded a wealth of clinical research focused on headache, which should streamline the diagnostic workup of nontraumatic headaches (particularly the search for subarachnoid hemorrhage) and several comparative efficacy trials, which help clinicians determine how best to treat acute migraine with parenteral medications. Herein, we review and contextualize the most important recent developments with regard to management of headache in the acute care setting.
Electrospray versus Nebulization for Aerosolization and Filter Testing with Bacteriophage Particles

Aerosolization of bacteriophage MS2 virions by nebulization and charge-reduced electrospray were compared during testing of three filter media. Sample swatches were taken from a surgical mask, N95 filtering-facepiece respirator (FFR), and N100 FFR for use in repeated, short-duration (15 min) penetration tests with bacteriophage MS2 aerosolized by nebulizer and electrospray. Evaluated were (1) the virus suspension preparation protocol, (2) resulting particle size distribution, count stability, and count variability, and (3) the ability to generate culturable MS2 virions. While preparation of the electrospray bacteriophage suspension required additional purification and concentration steps and took more time than the nebulization protocol, it resulted in a much higher titer suspension. The nebulizer produced a polydisperse aerosol; conversely, the electrospray produced a relatively monodisperse aerosol with a count peak at the mobility size of the single virion. The nebulized aerosol particle count was 2.8 ...
Magnetic switching of phase-slip dissipation in NbSe 2 nanoribbons

The stability of the superconducting dissipationless and resistive states in single-crystalline ${\mathrm{NbSe}}_{2}$ nanoribbons is characterized by transport measurements in an external magnetic field $(\mathbf{H})$. Current-driven electrical measurements show voltage steps, indicating the nucleation of phase-slip structures. Well below the critical temperature, the position of the voltage steps exhibits a sharp, periodic dependence as a function of $\mathbf{H}$. This phenomenon is discussed in the context of two possible mechanisms: the interference of the order parameter and the periodic rearrangement of the vortex lattice within the nanoribbon.
Quantum effects in diffusion: Internal friction due to hydrogen and deuterium dissolved in α-iron

Abstract This work is an experimental and theoretical study of internal friction due to hydrogen and deuterium dissolved in α-iron. A torsion pendulum is employed which can be used in a Collins cryostat at temperatures in the range 4.2°–300°K. A peak of damping is found in the range 105°–120°K corresponding to that earlier studied by Gensamer and co-workers. An additional peak associated with hydrogen is found at 30°K and, correspondingly, one associated with deuterium is found at 35°K. Magneto-mechanical damping is found at all temperatures, with a peak in the range 4.2°–15°K depending upon treatment of the metal specimen. Theoretical arguments are advanced which suggest that the isotope-shifted peaks are due to atoms dissolved in the undistorted lattice, whose motion must be treated quantum-mechanically to account for the experimental results. Tunneling and localized lattice distortions around the dissolved atom seem to be required by the data and are within the scope of a reasonable theory.
A tool for assisting provenance search in social media

In recent years, social media sites are witnessing an information explosion. Determining the reliability of such a large amount of information is a major area of research. Information provenance (aka, sources or origin) provides a way to measure the reliability of information in social networks. The main challenge in seeking provenance is the availability of suitable data consisting of sufficient unique propagation paths. Knowledge of the actual propagation paths for a piece of information will be a valuable asset in provenance search. This paper presents a tool for capturing the propagation network of a given tweet or URL (Uniform Resource Locator) in the Twitter network. Researchers can use this tool to collect information propagation data, design effective strategies for determining the provenance, and gain information about the tweet such as impact, growth rate and users influencing the spread. Two case studies are presented to demonstrate the effectiveness of the system for seeking provenance information.
Artemisia biennis (biennial wormwood) control is influenced by plant size and weed flora at time of herbicide application

Abstract Artemisia biennis has become a major weed of several crops within the northern Great Plains of the US and Prairie Provinces of Canada. It is expanding its habitat range and is now a problem weed across the North Central region of the United States. Field and greenhouse studies were conducted to evaluate the role of weed size, weed flora, and herbicide dose and timing on control efficacy. Two separate field studies were conducted in close proximity to evaluate the effect of late post-emergence herbicide application timing on A. biennis control. The first study had an infestation of Xanthium strumarium and the second study had an additional infestation of Amaranthus retroflexus . In both field studies, X. strumarium and A. retroflexus were substantially taller than A. biennis at each application timing. When X. stumarium was present, A. biennis control was 50–90% with glyphosate, and 40–75% with bentazon. When A. retroflexus was present, A. biennis control with either bentazon or glyphosate was greater than 82%. Greenhouse studies evaluated the effect of dose of bentazon, glufosinate, and glyphosate on control of various growth sizes of A. biennis seedlings ranging from 6 to 47 cm. Glyphosate applied at 840 and 1680 g ae ha −1 provided greater than 92% control of all sizes of A. biennis seedlings, while bentazon provided at least 80% control of A. biennis up to 20 cm tall. Control with glufosinate was generally poor regardless of seedling size or herbicide dose.
Surface Functionalization Using Catalyst-Free Azide—Alkyne Cycloaddition

The utility of catalyst-free azide−alkyne [3 + 2] cycloaddition for the immobilization of a variety of molecules onto a solid surface and microbeads was demonstrated. In this process, the surfaces are derivatized with aza-dibenzocyclooctyne (ADIBO) for the immobilization of azide-tagged substrates via a copper-free click reaction. Alternatively, ADIBO-conjugated molecules are anchored to the azide-derivatized surface. Both immobilization techniques work well in aqueous solutions and show excellent kinetics under ambient conditions. We report an efficient synthesis of aza-dibenzocyclooctyne (ADIBO), thus far the most reactive cyclooctyne in cycloaddition to azides. We also describe convenient methods for the conjugation of ADIBO with a variety of molecules directly or via a PEG linker.
Protection of deoxyribonuclease from ionizing radiation by adsorbents.

THE present communication presents experimental evidence which indicates that adsorption of deoxyribonuclease on a liquid–solid interface affords protection of enzymatic activity from radiation damage. Other means of protecting enzymes in aqueous solu-tions have been described by various investigators1–6, but, to our knowledge, no information is available concerning the protective effect of adsorption.
Invariance of a two-factor model of Social Dominance Orientation across gender

Abstract This research examined the measurement and structural invariance of the 16-item Social Dominance Orientation (SDO) scale across gender. The Social Dominance Theory (SDT) invariance hypothesis proposes that men are higher than women in SDO. Tests of this hypothesis have compared summary scores with t-tests, but there is no psychometric work of measurement invariance across gender, which makes interpretation of t-test comparisons problematic. Some research suggests the scale captures two distinct factors: support for group-based dominance (GBD) and general opposition to equality (OEQ). However, gender differences in GBD and OEQ have mixed findings. Results replicated the two-factor structure. Multiple-group CFA indicated that loadings, intercepts, factor variances, and factor covariance are equivalent across gender. Males demonstrated higher latent means of GBD and OEQ, supporting the SDT invariance hypothesis.
FIGURE AND GROUND IN THE ANALYSIS OF SOCIAL MOVEMENTS

Social movements are great stinings that rattle and threaten the institutional order, attracting adherents whose motivations are diverse and producing manifold effects in society. The na’ive observer selects only certain of these motivations and effects and treats them as the significant, representative, or essential features of the movement. Commonsense explanations for the movement typically treat this highly selective picture as if it were a balanced or complete account of the movement. To a considerable extent the sophisticated observer and the social scientist follow a similar procedure, sorting adherent motivations and movement effects into figure and ground, and constructing a theory of movement dynamics to explain figure rather than ground. The assumptions underlying this separation between figure and ground are often not made explicit, and advocates of competing theories often debate their versions of movement dynamics as if they were competing explanations for the same phenomena, when this is not the case. In this article I wish to suggest that recent fashions in movement analysis incorporate to a large extent a revised image of what is figure and what is ground in movement effects. While debates have ranged explicitly about the utility of disproportionate or even exclusive attention to organization and the control of resources as explanatory variables, the reconceptualization of movement effects in terms of figure and ground has remained largely implicit. But the relevance of theory depends upon what it explains. So a clear statement of what is to be explained must preceed any assessment of the utility of competing approaches and theories. The body of recent work to which I refer consists of elaborations and applications of resource mobilization theory. In the earliest extended exposition of this approach, Oberschall ( 1973:27) suggests that social change and conflict be viewed as “mobilizing, converting, and transferring resources from one group and one arena of action to other groups and
An empirical study of slice-based cohesion and coupling metrics

Software reengineering is a costly endeavor, due in part to the ambiguity of where to focus reengineering effort. Coupling and Cohesion metrics, particularly quantitative cohesion metrics, have the potential to aid in this identification and to measure progress. The most extensive work on such metrics is with slice-based cohesion metrics. While their use of semantic dependence information should make them an excellent choice for cohesion measurement, their wide spread use has been impeded in part by a lack of empirical study.Recent advances in software tools make, for the first time, a large-scale empirical study of slice-based cohesion and coupling metrics possible. Four results from such a study are presented. First, “head-to-head” qualitative and quantitative comparisons of the metrics identify which metrics provide similar views of a program and which provide unique views of a program. This study includes statistical analysis showing that slice-based metrics are not proxies for simple size-based metrics such as lines of code. Second, two longitudinal studies show that slice-based metrics quantify the deterioration of a program as it ages. This serves to validate the metrics: the metrics quantify the degradation that exists during development; turning this around, the metrics can be used to measure the progress of a reengineering effort. Third, baseline values for slice-based metrics are provided. These values act as targets for reengineering efforts with modules having values outside the expected range being the most in need of attention. Finally, slice-based coupling is correlated and compared with slice-based cohesion.
The DØ run II luminosity monitor

Abstract The DO Run II Luminosity Monitor consists of plastic scintillation detectors with fine-mesh photomultiplier readout that cover the range 2.7
Some immunochemical properties of succinylated human transferrin and related proteins.

Abstract Fully succinylated transferrin, immune globulins, and orosomucoid lost their ability to form precipitates with antisera to their native counterparts. If used to immunize rabbits, the succinylated transferrin gave rise primarily to antibodies specific for the succinyl residues, hence, several otherwise different succinylated proteins formed precipitin patterns with partial identity characteristics on double diffusion slides. On the other hand, if succinylation was not complete ( e.g. , iron-saturated transferrin subjected to succinylation), antibodies to the non-succinylated area (“active site”?) were formed in addition to the succinyl residues.
Periscope Modification of Right Ventricle-to-Pulmonary Artery Shunt in Norwood Operation

Given the purported hemodynamic advantages of the right ventricle (RV) to pulmonary artery (PA) conduit, many surgeons have adopted it as their preferred source of pulmonary blood flow during stage I palliation for hypoplastic left heart syndrome. Potential disadvantages of the RV-PA shunt include ventricular dysfunction, pseudoaneurysm formation, arrhythmia, and conduit obstruction, which can lead to a higher rate of unplanned reinterventions. The “dunk” technique was described to reduce the RV incision and proximal conduit obstruction; however, insertion of the ringed graft from the epicardium can be cumbersome and risk RV injury. We introduce a simplified, alternative method of placing the conduit, which we call the periscope technique, whereby the graft is withdrawn from within the RV cavity.
Development of a Specialty‐wide Web‐based Medical Knowledge Assessment Tool for Resident Education

Medical knowledge is one of six core competencies identified by the Accreditation Council for Graduate Medical Education. The authors present a tool for assessment of medical knowledge developed by the Council of Emergency Medicine Residency Directors. This tool is Internet based and consists of more than 50 online tests that emergency medicine residents are able to access. Test results are available to a resident's residency, along with the mean and standard deviation of all takers of that particular test. The result is a collaborative specialty-wide approach to the common problem of formatting tests to assess medical knowledge. The tool has been widely accepted by both residents and residencies.
Executive Processes, Memory Accuracy, and Memory Monitoring: An Aging and Individual Difference Analysis.

The current study examined the neuropsychological correlates of memory accuracy in older and younger adults. Participants were tested in a memory monitoring paradigm developed by Koriat and Goldsmith (1996), which permits separate assessments of the accuracy of responses generated during retrieval and the accuracy of monitoring those responses. Participants were also administered a battery of tests designed to measure executive functioning and speed of processing. Results indicated that both age and executive measures were predictive of accuracy, while speed of processing measures accounted for little of the variability in accuracy. Path analyses demonstrated that a substantial portion of the effect of executive function measures on memory accuracy in free report was mediated by the quantity of correct responses available in forced report, which in turn was partially mediated by monitoring accuracy. These data suggest that individual differences in executive function are important in memory accuracy.
Ground-based lidar for long-term and network measurements of ozone

Attention is given to a ground-based differential absorption lidar system developed and operated at the JPL Table Mountain Facility for measurements of stratospheric ozone concentration profiles from approximately 15 to 20 km altitude. The seasonal variations observed between February 1988 and late 1990 are presented as a function of altitude. For the summer 1989 Stratospheric Ozone Intercomparison Campaign, the lidar measurements were found to agree with the average of the results obtained from seven different instruments over a 14-d period to within 5 percent over the altitude range 18 to 49 km. The status of this instrument is discussed, with emphasis on areas of improvement over the present system.
Necessary and sufficient conditions on conditional probabilities to maximize entropy

Shannon (1948) showed that, by a proper choice of the conditional probabilities of the symbols in a discrete noiseless channel of the finite-state type (which possesses certain inherent constraints), the entropy of symbols on such a channel could be maximized. To date these known sufficient conditions on the conditional probabilities have been assumed to also be the necessary conditions. In this brief paper it is shown that the sufficient conditions as originally stated by Shannon are indeed also the necessary conditions for the range of symbol lengths which are of interest.