cssi/SciSciGPT-SciSciNet huggingface dataset:
The CLC 'chloride channel' family: revelations from prokaryotes.

Members of the CLC ‘chloride channel’ family play vital roles in a wide variety of physiological settings. Research on prokaryotic CLC homologues provided long-anticipated high-resolution structures as well as the unexpected discovery that some CLCs are not chloride channels, but rather are proton-chloride antiporters. Hence, CLCs encompass two functional classes of transport proteins once thought to be fundamentally different from one another. In this review, we discuss the structural features and molecular mechanisms of CLC channels and antiporters. We focus on ClC-0, the most thoroughly studied CLC channel, and ClC-ec1, the prokaryotic antiporter of known structure. We highlight some striking similarities between these CLCs and discuss compelling questions that remain to be addressed. Prokaryotic CLCs will undoubtedly continue to shed light upon this understudied family of proteins.
Homoclinic Bifurcation in an SIQR Model for Childhood Diseases

Abstract We consider a system of ODEs which describes the transmission dynamics of childhood diseases. A center manifold reduction at a bifurcation point has the normal form x′=y, y′=axy+bx2y+O(4), indicating a bifurcation of codimension greater than two. A three-parameter unfolding of the normal form is studied to capture possible complex dynamics of the original system which is subjected to certain constraints on the state space due to biological considerations. It is shown that the perturbed system produces homoclinic bifurcation.
AN ALBINO MUTANT IN PLANTAGO INSULARIS REQUIRING THIAMINE PYROPHOSPHATE—ROLE OF TPP IN PIGMENT AND PROTEIN SYNTHESIS

SUMMARY Seedlings of Plantago insularis were grown in darkness for 5 days and then exposed to white light for 24 h. At the beginning of the light period some plants were treated with thiamine pyrophosphate (TPP). Light exposure caused a marked development of both chlorophyll a and b in the normal (al+/al+) plant, but only a slight formation of chlorophyll in the mutant (al/al) TPP plus light induced the formation of chlorophyll a and b in the mutant to near normal levels. Light alone increased the level of carotenoids in the normal type, but not in the mutant; but TPP plus light increased the carotenoids in the mutant to near normal. Albinism in Plantago is due, in part, to a deficiency in TPP and a consequent deficiency in chlorophyll and carotenoid pigments. Acid-soluble nitrogen was distinctly lower in the albino mutant than in normal plants, but increased in the mutant after treatment with TPP and exposure to light. Exposure of dark-grown normal seedlings to light alone caused a marked increase in acid-insoluble nitrogen. Recovery in the mutant appeared to be at the expense of the soluble nitrogen fraction, and is attributed to the synthesis of chloroplast proteins. The light-yellow mutant grown in the dark became bleached on exposure to light, yet a moderate increase in nitrogen occurred during exposure, indicating that some protein synthesis is independent of chlorophyll and carotenoid development in the plastids. A pathway initially involving TPP appears to be affected by light in the formation of chloroplast proteins.
Multi-media applications and imprecise computation

As feature sizes continue to decrease and clock rates and device count on a VLSI chip increase, it becomes increasingly more difficult to maintain yields at their present levels. Process variation, noise and spot defects create very costly problems for our industry. Luckily, in the domain of multi-media, there exists a large body of functions where computational results need not always be correct. We show that for many VLSI implementations of signal processing algorithms, such as MPEG and JPEG encoders, a significant proportion of chips having low levels of defects provide erroneous but acceptable results. We introduce the concept of error-tolerance, and mention related issues needed to support this concept, including ways for specifying performance, design techniques that consider yield, test techniques for quantifying erroneous behavior, and finally the issue of marketing. The motivation for this work is to significantly increase the effective yield of a process, encourage the implementation of complex data processing chips, and drastically reduce chip costs.
CEO Compensation and the Role of In-House Experience

We hand collect a database that includes a direct measure of the incoming CEO’s in-house experience at the time of succession. In contrast to previous studies that rely on an insider-outsider binary variable, our continuous variable allows us to examine compensation incentives following CEO successions across a continuum of in-house experience. We hypothesize and confirm that more in-house experience prior to succession leads to lower CEO total compensation at succession. In addition to total compensation, we find significant differences in the components of compensation. CEOs with more in-house experience receive larger cash-based incentives and smaller performance-based incentives than CEOs with little or no in-house experience at succession. Consistent with expectations, CEOs with substantial in-house experience also have lower wealth-to-risk sensitivities. Overall, our results show that CEO incentive contacts are significantly influenced by the level of in-house experience.
An Analysis of the Effect of Component Tolerances on the Amplification of the Balanced-Pair Tunnel-Diode Circuit

The purpose of the present study is to determine for the balanced-pair tunnel-diode circuit the minimum amount of control required when specified parameter imbalances are present in the system. The problem is formulated and the minimum control is determined numerically. These results are compared with an analytic formula for the minimum control which is presented here but is derived in another paper. The results obtained may be used to determine allowable tolerances on the circuit components for a given requirement on the maximum amplification or the total number of input and output connections.
Gross hematuria in children: a ten-year review.

OBJECTIVES Gross hematuria in children is uncommon. We reviewed our experience characterizing its clinical presentation and diagnosis. METHODS The charts of all patients who presented for the 10-year period of 1994 through 2003 were reviewed, and 342 patients were identified. Of these 342 patients, 272 were boys (80%) and 70 (20%) were girls. At presentation, 21 patients (6%) were younger than 3 years (17 were boys and 4 were girls); 199 (58%) were 3 to 12 years old (155 were boys and 44 were girls); and 122 (36%) were 13 to 20 years old (100 were boys and 22 were girls). RESULTS Of the 272 male patients, 52 (19%) had benign urethrorrhagia; 48 (14%) had trauma; and 48 had a urinary tract infection (14%), and 10 of those also had urologic anomalies. Of the 342 patients, 45 (13%) had one or more congenital urologic anomalies. Of these 45 patients, 20 boys and 2 girls had vesicoureteral reflux, 10 boys had posterior urethral valves, 7 boys and 1 girl had ureteropelvic junction obstruction, 7 boys had proximal hypospadias, 2 boys and 1 girl had ureterovesical junction obstruction, 2 boys and 1 girl had ureterocele, and 1 boy had caliceal diverticulum. Also, 18 patients (5%) had stones; 3 had low-grade bladder transitional cell carcinoma; and 1 had a Wilms tumor. For 118 patients (34%; 95 boys and 23 girls), no etiology was found. CONCLUSIONS Gross hematuria most often had a benign cause in children and adolescents. It was more common in boys for almost all etiologic categories and ages. The extent of the urologic evaluation should depend on the clinical setting. Voiding cystourethrography is useful in those with suspicious ultrasound findings, urinary tract infection, or voiding symptoms. Cystoscopy should be reserved for the minority in whom hematuria persists or those with ambiguous imaging study findings.
Proficiency Assessment Programs in Toxicology

The current state of proficiency testing programs for clinical laboratories with special emphasis on those programs related to toxicology are presented. The content includes a discussion of the need for such programs, the reasons for their creation, the types of programs offered, and their administration. The federal and state laws pertaining to proficiency testing are mentioned but not discussed in detail.
On Power and Responsibility

The article focuses on Lukes' treatment of the relation between power and responsibility. By attempting to draw a sharp distinction between power and structural constraint, I argue, Lukes unnecessa...
Perceptual processing using oscillatory chaotic dynamics

The author discusses various aspects of modeling brain wave activity using chaotic dynamics. The role that chaotic activity plays in the brain is also discussed. Some comparisons between biological and artificial intelligence systems are made. >
Auditory Brainstem Responses in Young Males With Fragile X Syndrome

Fragile X syndrome (FXS) is the most common inherited cause of mental retardation resulting in developmental delays in males. Atypical outer ear morphology is characteristic of FXS and may serve as a marker for abnormal auditory function. Despite this abnormality, studies of the hearing of young males with FXS are generally lacking. A few studies have suggested that a significant proportion of individuals with FXS demonstrate prolonged auditory brainstem response (ABR) latencies. The purpose of this study was to determine whether young males with FXS display atypical auditory brainstem function compared to typically developing males when conductive and sensorineural hearing loss are ruled out as possible contributors to atypical findings. Participants were 23 males with FXS, 21 typically developing males who were matched for developmental age, and 17 typically developing males who were matched for chronological age. A battery of tests to assess peripheral hearing, cochlear function, and auditory pathway integrity through the level of the brainstem was completed. Males with FXS were similar to typically developing males who were matched for developmental age level or chronological age level on all measures. They had normal hearing sensitivity and middle ear function and scored similar to the typically developing children on the measures of auditory brainstem pathway integrity. In summary, ABRs in young males with FXS were within normal limits.
Community Organizing in Britain: The Political Engagement of Faith-Based Social Capital

Faith–based community organizing in the United States has emerged as one of the most effective ways to rebuild democratic life in urban communities. Scholars have argued that the success of modern ...
Selection and management of DNA markers for use in genomic evaluation.

To facilitate routine genomic evaluation, a database was constructed to store genotypes for 50,972 single nucleotide polymorphisms (SNP) from the Illumina BovineSNP50 BeadChip (Illumina Inc., San Diego, CA). Multiple samples per animal are allowed. All SNP genotypes for a sample are stored in a single row. An indicator specifies whether the genotype for a sample was selected for use in genomic evaluation. Samples with low call rates or pedigree conflicts are designated as unusable. Among multiple samples that qualify for use in genomic evaluation, the one with the highest call rate is designated as usable. When multiple samples are stored for an animal, a composite is formed during extraction by using SNP genotypes from other samples to replace missing genotypes. To increase the number of SNP available, scanner output for approximately 19,000 samples was reprocessed. Any SNP with a minor allele frequency of > or = 1% for Holsteins, Jerseys, or Brown Swiss was selected, which was the primary reason that the number of SNP used for USDA genomic evaluations increased. Few parent-progeny conflicts ( or = 90%) were additional requirements that eliminated 2,378 SNP. Because monomorphic SNP did not degrade convergence during estimation of SNP effects, a single set of 43,385 SNP was adopted for all breeds. The use of a database for genotypes, detection of conflicts as genotypes are stored, online access for problem resolution, and use of a single set of SNP for genomic evaluations have simplified tracking of genotypes and genomic evaluation as a routine and official process.
Assessing Response to Basic Concept Instruction: Preliminary Evidence With Children Who Are Deaf

Research has demonstrated that academic success is significantly related to word knowledge. Basic concept words are important because of their use in classroom directions and assessment instructions. It is important that educators assess a child’s understanding of basic concept vocabulary at school entry. For children who demonstrate basic concept deficits, progress monitoring is needed to make certain that they acquire these vocabulary items through instruction. This preliminary study used a single-participant design to determine whether an experimental basic concept–curriculum based measure (BC-CBM) was able to accurately assess and monitor progress in basic concept acquisition as a result of instruction. Four children who were deaf or hard of hearing (M age = 4 years 6 months) participated in the experiment. Results revealed that the BC-CBM scores improved during intervention. The results of this experiment provide evidence to support the development of additional larger scale field-testing of the BC-CBM.
Dyadic brain modelling, mirror systems and the ontogenetic ritualization of ape gesture

The paper introduces dyadic brain modelling, offering both a framework for modelling the brains of interacting agents and a general framework for simulating and visualizing the interactions generated when the brains (and the two bodies) are each coded up in computational detail. It models selected neural mechanisms in ape brains supportive of social interactions, including putative mirror neuron systems inspired by macaque neurophysiology but augmented by increased access to proprioceptive state. Simulation results for a reduced version of the model show ritualized gesture emerging from interactions between a simulated child and mother ape.
Revised estimates for the probabilities of earthquakes following observation of unreliable precursors

abstract This paper treats, in a statistical manner, the class of geophysical observations that sometimes are precursors to a large earthquake, but at other times occur apparently unrelated to any earthquakes in time or space. Each such observation is handled by associating it with the largest ensuing earthquake in a definite time and spatial window; then the probability that the observation is useful is estimated from the difference between this extreme value distribution and the long-term average extreme value distribution for the same region. This probability that the precursor is useful can then be incorporated into calculations of the revised probability of an earthquake following observation of one (a trivial case) or several unreliable precursors to derive the revised probability of a significant earthquake. The model takes full account of the magnitude distribution of earthquakes and of discrete levels of precursor observations. The United States earthquake prediction program is still many years from being able to obtain the full benefits of the model. However, the model suggests useful statistics which the program should gather on unreliable precursors.
The Folded Logistic Distribution

ABSTRACT Physical measurements like dimensions, including time, and angles in scientific experiments are frequently recorded without their algebraic sign. The directions of those physical quantities measured with respect to a frame of reference in most practical applications are considered to be unimportant and are ignored. As a consequence, the underlying distribution of measurements is replaced by a distribution of absolute measurements. When the underlying distribution is logistic, the resulting distribution is called the “folded logistic distribution”. Here, the properties of the folded logistic distribution will be presented and the techniques for estimating parameters will be given. The advantages of using this folded logistic distribution over the folded normal distribution will be discussed and some examples will be cited.
Physician colorectal cancer screening recommendations: an examination based on informed decision making.

Objective The purpose of this research was to examine the content of physicians’ colorectal cancer screening recommendations. More specifically, using the framework of informed decision making synthesized by Braddock and colleagues, we conducted a qualitative study of the content of recommendations to describe how physicians are currently presenting this information to patients.
Real-time particle swarm optimization based current harmonic cancellation

As a powerful optimization algorithm, Particle Swarm Optimization (PSO) has been widely applied to power systems researches. However, because of the unavoidable evaluation time for tentative solutions, most of these applications have been implemented offline. Recently, PSO was realized in real time to identify parameters of a PMSM control systems. In this paper, the Real-Time PSO (RT-PSO) algorithm was applied to current harmonic cancellation problem. RT-PSO is used to identify the fundamental current from a measured current that contains harmonics. The identified fundamental current is then used as a reference current for current harmonics cancellation. Simulation studies show that the RT-PSO algorithm can provide accurate estimation of the reference current for harmonics cancellation control using active power filters. As a capable online optimization algorithm, RT-PSO can be extensively applied to many optimization and control problems.
Widows as Obstacles to Business: British Objections to Brazilian Marriage and Inheritance Laws

Implicit in the hegemonic “civilizing” discourse of nineteenth-century British imperialism was the assumption that Great Britain was a model to be followed by backward societies. Included in the British characterisics to be emulated was the status of their women. In this article I turn this assumption on its head by arguing that the capital accumulation permitting the Industrial Revolution in Great Britain was furthered not only by primogeniture, as many scholars have correctly argued, but also by a marriage regime in which wives and widows had few rights to property, for husbands were usually sole owners of all marital property and had full testamentary freedom. This arrangement permitted property to concentrate in male hands. In contrast, the marriage system based on Portuguese and Brazilian law was one of full community property, which gave wives veto power in the sale or mortgaging of all real estate and assured widows rights of succession to one-half of the marital property. This system was combined with limited testamentary freedom and equally partible inheritance for both sons and daughters. I argue that, though it was more equitable than the British system, it worked against the accumulation of capital.
Fatigue of dentin-composite interfaces with four-point bend

Abstract Objectives The objective was to determine the fracture and cyclic fatigue properties of composite–dentin beams bonded with a self-etching adhesive in four-point bend. Methods Beams of rectangular cross-section were shaped to a size of ∼0.87 mm × 0.87 mm × 10 mm and placed in a four-point bending apparatus, with the loading points 1.8 and 7.2 mm apart, with the interface centered between the inner rollers. Cyclical loading was performed in Hanks’ Balanced Salt Solution at 25 °C, with forces between 54% and 99% of the bending strength of the bonded beams. Results Solid dentin and solid composite beams [n = 6] had bending strengths of 164.4 and 164.6 MPa, respectively, under monotonically increasing loads. Bonded beams [n = 6] had strengths of 90.6 MPa. No significant difference was found between solid composite and solid dentin beams, the bonded beams were different (ANOVA, p Significance Fatigue may be a significant mechanism of dentin–composite bond degradation.
Job analysis: The composition of SME samples.

It is common for job analysts to solicit information from incumbents and supervisors (Subject Matter Experts or SMEs) when conducting a job analysis. These SMEs are asked to provide ratings on salient dimensions (e.g., frequency and importance of tasks that comprise the job). In constructing samples of SMEs for this purpose, it is reasonable to consider any possible influences that might bias or systematically influence the task ratings. The present paper considers the possible influence of SME demographic characteristics on task ratings of frequency. The tasks comprising the job of patrol officer in a large city were rated for frequency by approximately 700 incumbents. These ratings were gathered in two different years, 1982 and 1984. The total data set was used to conduct a components analysis of the 444-item task inventory. The first eight principal components were considered the dependent variables and four demographic characteristics the independent variables in an analysis of the 1982 data set. Analysis of variance and follow-up tests indicated that incumbent experience had a substantial influence on task ratings. Educational level and race had minimal effects on ratings. The sex factor was confounded by the experience factor, making interpretation of the sex effect equivocal. Mechanisms that might account for the experience effect are discussed. It was concluded that incumbent experience is a salient issue in job analysis using SME groups.
Online Education for Improving Communication and Documentation of Dietary Supplements Among Health Professionals Practicing in a Hospital Setting.

Abstract Background: Little is known about the feasibility of online education in improving communication and documentation of dietary supplements (DS) among clinicians. Methods: This prospective educational study included clinicians at an urban teaching hospital. The curriculum included video streams, didactics, and interactive case presentations to discuss (1) DS safety and effectiveness, (2) cultural competency, (3) managing DS in a hospital setting, and (4) DS adverse events. Participants were surveyed, at baseline and after training, about DS knowledge, confidence, communication, and documentation practices. Results: Thirty-nine of 61 (64%) recruited clinicians completed all four patient cases and post-tests. Most (82%) were women and 59% were physicians. The mean DS knowledge test score increased after the curriculum (p < 0.0001), and the clinician confidence score also increased (p < 0.0001). Most (82%) participants reported that curriculum changed their use of evidence-based resources (p = 0.01). ...
Major Abdominal Vascular Trauma

The increasing popularity of non-operative management for trauma patients is predicated on excellent imaging, the ability to percutaneously control bleeding and repair blood vessels, and the resources to closely monitor patients in a well-stocked intensive care unit. For example, whereas just a few years ago a patient with a gunshot wound to the flank that was hemodynamically stable would likely proceed directly to the operating room for an exploratory laparotomy, it is now acceptable to observe this patient if triple phase CT scan is normal. Unfortunately, this is not the situation in a combat setting. Although you may have a CT scanner, it may overheat; you may have a C-arm and feel comfortable performing endovascular procedures, but nobody else around you does; and you will have an ICU that is efficient but can easily be overwhelmed by a mass casualty event. It is therefore incumbent upon you and your operating team to be prepared to deal with whatever is brought to the ER, because if you are in a combat support hospital YOU are the highest level of care in country. The goal of this chapter is to assist you with major abdominal vascular trauma and pass on these lessons learned (often the hard way) from combat surgery.
Limiting Friction in a Slider-Disk Interface with Nanometer-Scale Lubricant Films

Previous studies involving a “starved” liquid-lubricated slider-disk interface with film thicknesses on the scale of 10-100 ran showed unusual results. The friction force, after increasing nearly linearly with speed was found to decrease beyond a certain sliding speed and then reach a plateau. Similarly, the interface capacitance was found to decrease and plateau. The reason for these effects has not yet been established. In the current work, friction and capacitance measurements are conducted in both starved and nominally fully flooded modes. In the fully flooded case, the friction force exhibits behavior similar to that of the starved condition, but with a much less significant drop in friction once the peak is reached. A theoretical analysis is performed in conjunction with the experiments. The results of this study suggest that the lubricant can sustain a peak shear stress at a lower shear rate that is higher than the maximum shear stress that can be supported at higher shear rates.
Stroking human jejunal mucosa induces 5-HT release and Cl− secretion via afferent neurons and 5-HT4receptors

5-Hydroxytryptamine (5-HT) release and neural reflex pathways activated in response to mucosal stroking were investigated in muscle-stripped human jejunum mounted in modified Ussing chambers. The m...
Dynamics of Energy Transfer from CdSe Nanocrystals to Triplet States of Anthracene Ligand Molecules

The combination of CdSe semiconductor nanocrystals with 9-anthracene carboxylic acid ligands can sensitize triplet–triplet annihilation on the emitter molecule diphenylanthracene. This hybrid system has recently been shown to upconvert visible light (532 nm) to ultraviolet light (420 nm) (Huang, Z., et al. Nano Lett. 2015, 15, 5552–5557). In the current paper, time-resolved photoluminescence measurements are used to characterize the kinetics of the energy transfer from the CdSe exciton state to the triplet state of the anthracene ligand. We find that 9-anthracene carboxylic acid binds to CdSe according to Poisson statistics with a maximum number of 2–3 ligands per nanocrystal. The CdSe-to-ligand energy transfer rate is 1.5 × 107 s–1. The overall efficiency of the energy transfer appears to be limited by the presence of fast nonradiative decay channels in the nanocrystals and the low coverage of anthracene ligands, resulting from the specific ligand exchange conditions used in this paper. Possible strategi...
Sex Pheromone for Attracting Western Grapeleaf Skeletonizer (Lepidoptera: Zygaenidae)

The sex pheromone of Harrisina brillians Barnes and McDunnough was bioassayed. Of four compounds from female tip dip extracts, only d,l-sec-butyl (Z)-7-tetradecenoate attracted male moths. Further testing showed that the d isomer was the attractant; when the l isomer was added to the d isomer, male attraction was reduced. Dose-response studies showed increased moth attraction with increased amounts of d,l-sec-butyl (Z)-7- tetradecenoate. A 100-μg dose of the d,l pheromone compared to the attraction of two virgin females resulted in an average daily male moth capture of 62% to the 100 μg dose and 38% to the two virgin females. Daily capture peaked at ca. 0845 hours (ca. 3 h into photophase [i.e., after sunrise]).
The Indiscretions of Desdemona

N these words, Iago tells his plans to destroy Desdemona's c "credit with the Moor" by using evidence taken from her own conduct. This paper plans to discuss the manner in which Iago manages to carry out his satanically clever plan by making Desdemona's "goodness" contribute to her own downfall and tZ9 to that of Othello. For this purpose it would be profitable to examine Desdemona's conduct against a background of Elizabethan attitudes towards women in general and matrimonial conduct in particular. In this way one will be able to see that Desdemona does act in a manner capable of deliberate misconstruction by Iago. Further, these very actions arise in large measure from her womanly virtues of sympathy, kindheartedness, and fidelity in friendship. Shakespeare's use of common Elizabethan attitudes towards women in Othello has been noted by such critics as John W. Draper, Georges Bonnard, Thomas D. Bowman, and Carroll Camden. Draper notes a dichotomy in the character of Desdemona and feels that Shakespeare "deliberately anglicized Desdemona's background early in the play in order to give the story a realism more immediate to his audience."2 Bonnard believes that both the major characters are guilty: Desdemona of being "a rebellious child", and Othello of a "lack of wisdom in his love".3 Bowman notes Iago's comments on women, II. i. io4ff., and sees the rehearsal of these commonplaces as merely an opportunity to demonstrate Cassio's superiority to the ensign,4 while Carroll Camden discusses at length the sources and analogues of Iago's cynical statements, commenting further, "that Shakespeare has been at some pains to set forth Desdemona as an example of the ideal wife", and "that Desdemona shows by her very actions that she is an example of the perfect wife."5 These remarks are at variance with the opinions of Draper that "Probably Desdemona never really understood Othello,
HEAT TRANSFER ENHANCEMENT BY UTILIZING STANDING AND TRAVELING WAVES TO GENERATE ACOUSTIC STREAMING IN A RECTANGULAR GAP

The acoustic streaming flow and heat exchange mechanisms are investigated between a chip as a heat source and a PZT-covered beam scattering acoustic sound waves into the gap. Convective-like acoustic streaming forms in the gap and heat exchange between the two beams is enhanced because of that. The governing equations are asymptotically decomposed into the first order hyperbolic wave equations and second order time-independent acoustic streaming equations by a small parameter, which is defined as the ratio of the characteristic vibration velocity and the local sound speed. The first order harmonic equations are numerically solved in the reduced wave equation form. The steady acoustic streaming equations are then driven by the first order harmonic field and are solved by the SIMPLER method. Two types of acoustic waveforms from the acoustic source at the lower beam are compared in the flow pattern and heat exchange effect. The results show that although the flow patterns differ very much for different waveforms, there are only slight differences in the effect of the cooling effect.
Increased fragility of pulmonary capillaries in newborn rabbit.

The pulmonary capillaries of neonatal lungs are potentially vulnerable to stress failure because of the complex changes in the pulmonary circulation that occur at birth. We perfusion fixed the lung...
Mercury Ion Clock for a NASA Technology Demonstration Mission

There are many different atomic frequency standard technologies but only few meet the demanding performance, reliability, size, mass, and power constraints required for space operation. The Jet Propulsion Laboratory is developing a linear ion-trap-based mercury ion clock, referred to as DSAC (Deep-Space Atomic Clock) under NASA’s Technology Demonstration Mission program. This clock is expected to provide a new capability with broad application to space-based navigation and science. A one-year flight demonstration is planned as a hosted payload following an early 2017 launch. This first-generation mercury ion clock for space demonstration has a volume, mass, and power of 17 L, 16 kg, and 47 W, respectively, with further reductions planned for follow-on applications. Clock performance with a signal-to-noise ratio (SNR)*Q limited stability of $1.5{\rm E}-13/\tau^{1/2}$ has been observed and a fractional frequency stability of 2E–15 at one day measured (no drift removed). Such a space-based stability enables autonomous timekeeping of $\Delta t with a technology capable of even higher stability, if desired. To date, the demonstration clock has been successfully subjected to mechanical vibration testing at the $14\,{\rm g}_{\rm rms}$ level, thermal-vacuum operation over a range of $42^\circ{\rm C}$ , and electromagnetic susceptibility tests.
Spatial Patterns in Two Syntopic Species of Microtines: Microtus ochrogaster and Synaptomys cooperi

Two years of live-trapping data were analyzed for spatial patterns within and between the species Microtus ochrogaster and Synaptomys cooperi in eastern Kansas. Within species, each sex was frequently overdispersed and nearest neighbors were of the opposite sex. When sexes were combined, each species was frequently overdispersed. There was also frequent evidence of a negative association between species. However, there was no indication of seasonal or density dependent trends in any of the spacing indices. Although M. ochrogaster was often overdispersed within a season, on one of the study areas successive inhabitants tended to select the same locations. This result is suggestive of microhabitat selection, even though the study site had been selected to minimize spatial heterogeneity. S. cooperi did not exhibit any evidence of microhabitat selection.
Membrane Protein Folding and Structure

Seminal structural and biochemical studies demonstrated that proteins are organized by specific structural elements and that the information necessary to form these ordered structures is encoded in the polypeptide chain. Questions related to the mechanisms of protein folding for both soluble and transmembrane proteins remain a large field of research utilizing a combination of biochemical, biophysical, genetic, and large-scale computational approaches. Understanding these processes has broad implications for the functional identification of unknown and putative proteins found in sequenced genomes, for the characterization of disease-causing mutations identified in genetic studies, and for rational design and protein engineering efforts to introduce novel biological function. This chapter will outline the basic principles related to transmembrane protein folding and provide an overview of transmembrane protein structure determination.
Toxicological study of Momordica Charantia L. and Folium Mori Mixture

Objective Toxicity tests of Momordica Charantia L. and Folium Mori Mixture were conducted. Methods The safety of Momordica Charantia L. and Folium Mori Mixture was evaluated systematically by a series of acute,mutagenic and sub-chronic toxicological tests. Results The acute toxicity test showed that the oral maximum tolerated dose of Momordica Charantia L. and Folium Mori Mixture was more than 20. 0 g / kg body weight in mice. No mutagenicity was found,as judged by mouse bone marrow cell micronucleus test and mouse sperm abnormality test. In the subchronic study,no deaths or clinical signs,or abnormal hematological,clinical,chemical and histopathological changes had been found in rats after being treated using 25,50,100 times as recommended dosage for adult for 30 days. Conclusions The results indicated that no significant toxicological effect was found using Momordica Charantia L. and Folium Mori Mixture.
Proton occupation numbers in 206Pb from the (d

Angular distributions of the differential cross section and vector analyzing power have been measured for the $^{206}\mathrm{Pb}$(d\ensuremath{\rightarrow}${,}^{3}$He${)}^{205}$Tl reaction at an incident deuteron energy of 79.4 MeV. Spin-parity assignments have been made for seventeen transitions to residual nuclear states up to 2.8 MeV in excitation. Optical-model parameters have been obtained for both the entrance and exit channels by fitting elastic scattering data measured to large angles. Exact finite-range distorted-wave Born-approximation calculations have been performed and spectroscopic strengths have been deduced for all the observed transitions. The proton occupation numbers in $^{206}\mathrm{Pb}$ for 3${s}_{1/2}$, 2${d}_{3/2}$, 2${d}_{5/2}$, and 1${h}_{11/2}$ orbitals indicate a general depletion of about 30%, to be compared to 18% depletion previously reported in $^{208}\mathrm{Pb}$. The 3${s}_{1/2}$ proton occupation number in $^{206}\mathrm{Pb}$ deduced from this experiment is in good agreement with the results of recent (e,e'p) experiments.
Mechanisms and management of bone cancer pain

Publisher Summary Two main types of cancer pain exist: ongoing pain and incident or breakthrough pain. Ongoing pain is typically described as a dull and aching pain that is constant in nature and progresses in accordance with the disease process. Incident or breakthrough pain is most commonly associated with bone metastases and is characterized by sharp pains that are intermittent in nature and exacerbated by both volitional and non-volitional movements. Pain generally occurs during tissue ischemia and/or damage and is a result of release of neurotransmitters, cytokines and factors from damaged cells, adjacent blood vessels and nerve terminals. Pain is transduced at the level of the primary afferent nerve fiber which innervates peripheral tissues including bone. Recently, it has been shown that bone is densely innervated by both sensory and sympathetic nerve fibers within bone marrow, mineralized bone and periosteum. Sensory and sympathetic neurons are present within all three anatomic locations and are influenced by fractures, ischemia or the presence of tumor cells and may play a unique but coordinated role in the generation of bone cancer pain. Pain research has significantly improved our understanding of acute and chronic pain mechanisms. By highlighting key molecular mechanisms involved in pain transmission, new drugs are currently being investigated as potential novel and selective therapies. Currently available medications such as the opioids are certainly fraught with side effect profiles that may limit their clinical efficacy and patient quality of life. Research is now focused on specific receptor or channel targets within the nervous system that limits systemic complications.
Befuddled by Aspirin

This case discusses dual pharmacokinetic drug–drug interactions that occur with coadministration of valproic acid and aspirin. There is mutual plasma-protein–binding displacement that will increase free valproic acid. Also, valproic acid is a substrate of mitochondrial β-oxygenase and aspirin is an inhibitor of mitochondrial s-oxygenase.
Li 7 ( p , n 0 ) Be 7 angular distributions to E p = 3.8 MeV

Differences between results from earlier measurements of the $^{7}\mathrm{Li}(p,{n}_{0})^{7}\mathrm{Be}$ differential cross section have prevented use of the neutron spectrum from this reaction as a standard of neutron intensity. Differential excitation curves for the reaction were obtained at 17 angles for proton energies between 2.1 and 3.8 MeV. A pulsed proton beam incident upon a thick lithium metal target produced continuous neutron spectra which were measured by time of flight. The data were corrected for neutron scattering from the target. The neutron detector efficiency was determined through a simultaneous normalization of the measured angular distributions to the known total cross section at all proton energies. The efficiency determination was judged to be uncertain to about 5%. Resultant differential excitation curves have uncertainties between 5 and 8%. The zero degree differential cross section (${E}_{p}=1.89 \mathrm{to} 3.8$ MeV), and the excitation functions and Legendre coefficients (${E}_{p}=2.09 \mathrm{to} 3.80$ MeV), are presented in 10-keV increments and compared with other measurements.NUCLEAR REACTIONS $^{7}\mathrm{Li}(p,{n}_{0})$, $E=\mathrm{threshold}\mathrm{to} 3.8$ MeV; time of flight, plastic scintillator, deduced efficiency; measured $\ensuremath{\sigma}(\ensuremath{\theta})$. Natural target.
Young Africans' representations of the origins of same-sex attraction and implications for sexual and mental health.

AbstractSexual minorities are stigmatised in much of sub-Saharan Africa, restricting their access to sexual health services and undermining their mental health. Although public attitudes and social representations inform the experience of sexual stigma, little is known about how young Africans make sense of sexual diversity. We conducted a thematic analysis of 56 texts contributed by young people from 10 countries in response to a prompt in a scriptwriting competition inviting participants to ‘tell a story about someone who is attracted to people of the same sex’. We analysed accounts of the origins of same-sex attraction, a prominent theme in the narratives. Two-thirds of the texts provide an explicit or implicit explanation, presenting same-sex attraction as innate (15/38) and/or the consequence of environmental influences (32/38), including parental behaviour, gender separation, trauma, foreign influences and evil spirits. Expressions of the potential to avert or cure same-sex attraction are common. Yo...
Variance Reduction in Stochastic Gradient Langevin Dynamics

Stochastic gradient-based Monte Carlo methods such as stochastic gradient Langevin dynamics are useful tools for posterior inference on large scale datasets in many machine learning applications. These methods scale to large datasets by using noisy gradients calculated using a mini-batch or subset of the dataset. However, the high variance inherent in these noisy gradients degrades performance and leads to slower mixing. In this paper, we present techniques for reducing variance in stochastic gradient Langevin dynamics, yielding novel stochastic Monte Carlo methods that improve performance by reducing the variance in the stochastic gradient. We show that our proposed method has better theoretical guarantees on convergence rate than stochastic Langevin dynamics. This is complemented by impressive empirical results obtained on a variety of real world datasets, and on four different machine learning tasks (regression, classification, independent component analysis and mixture modeling). These theoretical and empirical contributions combine to make a compelling case for using variance reduction in stochastic Monte Carlo methods.
Phenyldithiocarbamate Ligands Decompose During Nanocrystal Ligand Exchange

Exchanging the native surface ligands of CdSe nanocrystals with phenyldithiocarbamate molecules is known to red-shift the absorption spectrum and improve the conductivity of nanocrystal films. However, the mechanism of exchange and the details on the interaction between the nanocrystal surface and phenyldithiocarbamates have not been fully resolved. Using NMR and density functional theory calculations, we show that phenyldithiocarbamates decompose during exchange with native ligands. Phenyldithiocarbamate salts decompose when the cation (triethylammonium in this study) acts as an acid, donating a proton to the 3,5-dimethylphenyldithiocarbamate ligand (DMPTC) producing 3,5-dimethylaniline, carbon disulfide, and other decomposition products. While most decomposition products negligibly interact with the nanocrystal surface, 3,5-dimethylaniline chemically binds to the CdSe nanocrystals. This work demonstrates that the ligand exchange between colloidal nanocrystals and phenyldithiocarbamate ligands occurs in ...
Noise suppression in cell-size control

Diverse cell types employ mechanisms to maintain size homeostasis and minimize aberrant fluctuations in cell size. It is well known that exponential cellular growth can drive unbounded intercellular variations in cell size, if the timing of cell division is size independent. Hence coupling of division timing to size is an essential feature of size control. We formulate a stochastic model, where exponential cellular growth is coupled with random cell division events, and the rate at which division events occur increases as a power function of cell size. Interestingly, in spite of nonlinearities in the stochastic dynamical model, statistical moments of the newborn cell size can be determined in closed form, providing fundamental limits to suppression of size fluctuations. In particular, formulas reveal that the magnitude of fluctuations in the newborn size is determined by the inverse of the size exponent in the division rate, and this relationship is independent of other model parameters, such as the growth rate. We further expand these results to consider randomness in the partitioning of mother cell size among daughters at the time of division. The sensitivity of newborn size fluctuations to partitioning noise is found to monotonically decrease, and approach a non-zero value, with increasing size exponent in the division rate. Finally, we discuss how our analytical results provide limits on noise control in commonly used models for cell size regulation.
Propagation of electrohydrodynamic surface waves in a conducting fluid

A comprehensive study is made of the electrohydrodynamic surface wave phenomena in an inviscid, incompressible conducting fluid in the presence of an external steady electric field due to an arbitrary periodic surface pressure distribution. The initial value wave problem has been solved by the Laplace and the generalized Fourier transforms in conjunction with asymptotic techniques — as advanced in a previous work ofDebnath andRosenblat [12]. An explicit steady state solution related to short and long wave approximations is found. The asymptotic behaviour of the transient solution for large time is demonstrated. It is shown that there are two surface wave-trains propagating in the conducting medium, one of which corresponds to the classical surface wave train and the other is originated entirely due to the interactions of the electric field with gravity. The simultaneous effects of the electric field and surface tension on the propagation of small amplitude surface waves are analyzed. The implications of the wave solutions related to very deep and shallow fluids are explored. A discussion of the electrohydrodynamic wave motions with their characteristic features is presented.
Tracking the fate of nitrate through pulse-flow wetlands: A mesocosm scale 15N enrichment tracer study

Abstract Quantitative information about the fate of applied nitrate (NO 3 -N) in pulse-flow constructed wetlands is essential for designing wetland treatment systems and assessing their nitrogen removal services for agricultural and stormwater applications. Although many studies have documented NO 3 -N losses in wetlands, controlled experiments indicating the relative importance of different processes and N sinks are scarce. In the current study, 15 NO 3 -N isotope enrichment tracer experiments were conducted in wetland mesocosms of two different wetland soil types at two realistic agricultural NO 3 -N source loads. The 15 N label was traced from the source NO 3 -N into plant biomass, soil (including organic matter and ammonium), and N-gas constituents over 7–10 day study periods. All sinks responded positively to higher NO 3 -N loading. Plant uptake exceeded denitrification 2–3 fold in the low NO 3 -N loading experiments, while both fates were nearly equivalent in the high loading experiments. One to two years later, soils largely retained the assimilated tracer N, whereas plants had lost much of it. Results demonstrated that plant and microbial assimilation in the soil (temporary N sinks) can exceed denitrification (permanent N loss) in pulse-flow environments and must be considered by wetland designers and managers for optimizing nitrogen removal potential.
Differential carrier lifetime and transport effects in electrically injected III-nitride light-emitting diodes

This work describes a small-signal microwave method for determining the differential carrier lifetime and transport effects in electrically injected InGaN/GaN light-emitting diodes (LEDs). By considering the carrier diffusion, capture, thermionic escape, and recombination, the rate equations are used to derive an equivalent small-signal electrical circuit for the LEDs, from which expressions for the input impedance and modulation response are obtained. The expressions are simultaneously fit to the experimental data for the input impedance and modulation response for nonpolar InGaN/GaN micro-LEDs on free-standing GaN substrates. The fittings are used to extract the transport related circuit parameters and differential carrier lifetimes. The dependence of the parameters on the device diameter and current density is reported. We also derive approximations for the modulation response under low and high injection levels and show that the transport of carriers affects the modulation response of the device, espe...