cssi/SciSciGPT-SciSciNet huggingface dataset:
Corrigendum to “Validation of the Yale Food Addiction Scale among a weight-loss surgery population” [Eating Behaviors 14(2013) 216–219]

The Yale Food Addiction Scale (YFAS), recently validated in college students and binge eaters, is ameans to assess “food addiction” in accordancewith DSM-IV criteria for substance dependence. Using online survey methodology, we aimed to validate the use of the YFAS among weight loss surgery (WLS) patients. Participants completed measures about pre-WLS food addiction (YFAS), emotional and binge eating, behavioral avoidance and inhibition, and preand post-WLS substance use. A sample of 67WLS patients (59.7% Roux-en-Y)was recruited; participants were 62.7% female, 86.6% Caucasian, had a mean age of 42.7; and 53.7% met criteria for pre-WLS food addiction. Convergent validity was found between the YFAS and measures of emotional eating (r = .368, p b .05) and binge eating (r= .469, p b .05). Discriminant validity was supported in that problematic substance use, behavioral avoidance, and behavioral inhibition were not associated with YFAS scores. Incremental validity was supported in that the YFAS explained a significant proportion of additional variance in binge eating scores, beyond that predicted by emotional eating (EES) and disordered eating behavior (EAT-26). There was a nonsignificant trend towards those with higher food addiction beingmore likely to admit to post-WLS problematic substance use (i.e., potential “addiction transfer”; 53% vs. 39%). Results support the use of the YFAS as a valid measure of food addiction among WLS patients. Future research with a larger sample may shed light on potentially important relationships between pre-surgical food addiction and both weight and substance use outcomes.
"Obesity is the New Major Cause of Cancer": Connections Between Obesity and Cancer on Facebook and Twitter.

Social media interactions can inform public health risk perceptions. While research has examined the risk relationships between obesity and cancer, public attitudes about their associations remain largely unknown. We explored how these constructs were discussed together on two social media platforms. Publicly accessible Facebook and Twitter posts from a 2-month period in 2012 containing references to obesity (“obese/obesity,” “overweight,” and “fat”) and cancer-related words were extracted (N = 3702 posts). Data cleaning yielded a final set of 1382 posts (Facebook: N = 291; Twitter: N = 1091). Using a mixed-methods approach, themes were inductively generated, and sentiment valence, structural elements, and epistemic stance were coded. Seven relational themes emerged: obesity is associated with cancer (n = 389), additional factors are associated with both obesity and cancer (n = 335), obesity causes cancer (n = 85), cancer causes obesity (n = 6), obesity is not linked to cancer (n = 13), co-occurrence (n = 492), and obesity is valued differently than cancer (n = 60). Fifty-nine percent of posts focused on an associative or causal link between obesity and cancer. Thirty-one percent of posts contained positive and/or negative sentiment. Facebook was more likely to contain any sentiment, but Twitter contained proportionately more negative sentiment. Concurrent qualitative analysis revealed a dominance of individual blame for overweight/obese persons and more support and empathy for cancer survivors. Our study reflects wide recognition of the evidence linking obesity to increased risk of cancer, a diverse set of factors perceived to be dually associated with both conditions and differing attribution of responsibility. We demonstrate that social media monitoring can provide an important gauge of public health risk perception.
A candidate for the QCD string based on non-backtracking random walk

A new string theory is proposed as a candidate for the large N limit of QCD. In this theory, strings are constrained to be non-backtracking; a condition that is essential for the gauge invariance of the underlying field theory. This condition is implemented by first placing the theory on a lattice and then introducing fermionic variables on the world sheet. The naive continuum limit leads to a generalized Thirring model on the world sheet, and it is suggested that the application of the renormalization group should drive the coupling constants to a conformally invariant fixed point.
Evidence That Polycyclic Aromatic Hydrocarbons in Two Carbonaceous Chondrites Predate Parent Body Formation

Organic material in meteorites provides insight into the cosmochemistry of the early solar system. The distribution of polycyclic aromatic hydrocarbons (PAHs) in the Allende and Murchison carbonaceous chondrites was investigated by use of a technique called microprobe laser-desorption laser-ionization mass spectrometry, which permits spatial resolution with approximately a 40-μm spot size. Sharp chemical gradients of PAHs are associated with specific meteorite features. The ratios of various PAH intensities relative to the smallest PAH, naphthalene, are nearly constant across the sample. These findings suggest a common origin for PAHs dating before or during the formation of the parent body, consistent with proposed interstellar formation mechanisms.
The effects of tolazoline on the distribution of cardiac output in normoxemic and hypoxemic lambs.

The Effects of Tolazoline on the Distribution of Cardiac Output in Normoxemic and Hypoxemic Lambs
Perioperative outcomes of surgical procedures for symptomatic fundoplication failure: a retrospective case–control study

Anatomic failure with recurrent gastroesophageal reflux disease (GERD) or related symptoms following fundoplication is a well-described occurrence. Occasionally, reoperative surgery is required. The morbidity of revisional surgery can be quite high, and the clinical outcomes may not be as good as is observed following primary antireflux operations. Data were obtained from a prospectively maintained foregut surgery database and via follow-up survey. Patients who underwent surgery for symptomatic failed fundoplication were included. A control group consisting of the same number of patients who underwent a first-time fundoplication for GERD was randomly selected from the same database. Anatomic failure of the original fundoplication was confirmed in all cases with upper endoscopy and an upper-GI series. Perioperative outcomes were compared between study groups. Visick scores were attained via phone follow-up along with satisfaction scores related to the outcome. From January 2003 to January 2010, 38 patients underwent revisional operations for failed fundoplication at our institution. The majority of patients (74%) had one previous failed attempt at fundoplication (range = 1–3). The most common mechanism of failure was hiatal hernia with recurrent GERD (79%). Reoperative patients were similar to their controls (age, sex, and body mass index). Reoperative surgery took longer, patients remained in the hospital longer, and these patients experienced more complications. Despite this fact, satisfaction with the outcomes of surgery was high in each group. The majority of patients in each study group reported Visick scores of grade 1 (no symptoms, resolved) or grade 2 (mild occasional symptoms, easily controlled) after surgery. Compared to primary antireflux surgery, revisional operations are associated with longer mean operating times, increased length of hospital stay, and increased morbidity. Despite this fact, the majority of patients are satisfied with the outcomes of revisional surgery for failed fundoplication, and symptomatic outcomes are good.
Effects of exercise timing on sleep architecture and nocturnal blood pressure in prehypertensives.

Background During nocturnal sleep, blood pressure (BP) “dips” compared to diurnal BP, reducing stress on the cardiovascular system. Both the hypotensive response elicited by acute aerobic exercise and sleep quality can impact this dipping response.
Sarcopenia: there is a need for some steps forward.

The first articles devoted to “sarcopenia” appeared in the literature in 1993 by Evans and colleagues,1,2 and defined sarcopenia as “the agerelated loss in skeletal muscle mass, which results in decreased strength and aerobic capacity and thus functional capacity.” The same year, the word “sarcopenia” was used in other articles by Butler3 and Dehlin,4 who already began to mention, as did numerous other authors, the possible reversibility of this clinical condition.1,2,5 Twenty years later, 2290 articles have been published to date on the same topic and we still have the same questions6 concerning the following:
A test of neuroecological predictions using paperwasp caste differences in brain structure (Hymenoptera: Vespidae)

Adaptive brain architecture hypotheses predict brain region investment matches the cognitive and sensory demands an individual confronts. Social hymenopteran queen and worker castes differ categorically in behavior and physiology leading to divergent sensory experiences. Queens in mature colonies are largely nest-bound while workers depart nests to forage. We predicted social paperwasp castes would differ in tissue allocation among brain regions. We expected workers to invest relatively more than queens in neural tissues that process visual input. As predicted, we found workers invested more in visual relative to antennal processing than queens both in peripheral sensory lobes and in central processing brain regions (mushroom bodies). Although we did not measure individual brain development changes, our comparative data provide a preliminary test of mechanisms of caste differences. Paperwasp species differ in the degree of caste differentiation (monomorphic versus polymorphic castes) and in colony structure (independent- versus swarm-founding); these differences could correspond to the magnitude of caste brain divergence. If caste differences resulted from divergent developmental programs (experience-expectant brain growth), we predicted species with morphologically distinct queens, and/or swarm-founders, would show greater caste divergence of brain architecture. Alternatively, if adult experience affected brain plasticity (experience-dependent brain growth), we predicted independent-founding species would show greater caste divergence of brain architecture. Caste polymorphism was not related to the magnitude of queen-worker brain differences, and independent-founder caste brain differences were greater than swarm-founder caste differences. Greater caste separation in independent-founder brain structure suggests a role for adult experience in the development of caste-specific brain anatomy.
Asymmetric creation of matter and antimatter in the expanding universe

We consider a simple model in which the matter-antimatter asymmetry of the universe is brought about by an effective two-particle interaction that violates baryon-number conservation as well as $\mathrm{CP}$ invariance. The particle fields participating in the interaction are quantized, and their time development in an isotropically expanding universe is found to all orders in the coupling constant. Pair production by the asymmetric interaction, as well as symmetric production by the gravitational field of the expanding universe, appear simultaneously in the solution. Taking an initial state in which no particles participating in the asymmetric interaction are present, we find the created baryon-number density. We consider in more detail the case when the matter-antimatter asymmetry is produced during a stage when the radius of the universe is small with respect to its present value. We make numerical estimates of the created matter-antimatter asymmetry, and put limits on possible values of the parameters of this model.
Smart dynamic system design: an integrated approach

A dynamic system with satisfactory performance generally consists of a mechanical system (the plant) and a controller that drives the mechanical system to meet certain performance requirements. Traditionally the control engineer designs the controller only after the plant design is completed. This two-step approach to plant and controller design does not provide the best system design because the dynamics of the plant and the dynamics of the controller often oppose each other. This paper presents an application of the iterative system equivalent optimal mix algorithm to perform a smart design of a nine-member truss substructure and its accompanying controller. The objective of the design algorithm is to reduce the amount of energy used by the controller to maintain control performance, subject to the structure design constraints. Two unique features of the algorithm are that each iteration of the design problem is stated as a convex quadratic programming problem, and the control effort monotonically converges to its final value.
Nitrogen and hydrogen isotope compositions and solubility in silicate melts in equilibrium with reduced (N+H)-bearing fluids at high pressure and temperature: Effects of melt structure

Solubility and solution mechanism(s) of reduced (N+H)- and H-containing N-O-H volatile components in Na 2 O-SiO 2 composition melts in equilibrium with NH 3 +H 2 +N 2 and H 2 O+H 2 fluid and H- and N-isotope concentrations in these melts were determined experimentally at 1.5 GPa and 1400 °C as a function of hydrogen fugacity, f H 2 , and melt polymerization (composition), NBO/Si (NBO/Si = 0.4–1.18). This NBO/Si-range is similar to that between dacite and olivine tholeiite melt (NBO/Si ~0.4–1). The f H 2 was controlled between that of the iron-wustite + H 2 O [log f H 2 (IW) ~3.42 (bar)] and that of the magnetite-hematite + H 2 O [log f H 2 (MH) ~ −0.91 (bar)] buffer. The N solubility decreases from 0.98 to 0.28 wt% in the melt NBO/Si-range from 0.4 to 1.18 at f H 2 (IW) and decreases by about 50% between f H 2 (IW) and f H 2 (MH). The H solubility at f H 2 (IW) is insensitive to NBO/Si and averages 0.76±0.28 wt% and 0.48±0.07 wt% H in (N+H)-saturated and in N-free and H-saturated melts, respectively. The H solubility in the melts decreases by at least ~70% between f H 2 (IW) and f H 2 (MH). Their N and H isotope ratios are systematic functions of the abundance ratio of structurally bound N and H (as NH 2 − - and OH − -groups bonded to Si 4+ ) relative to molecular H 2 , N 2 , and NH 3 in the melts. Molecular H 2 O plays a subordinate role in these melts, the bulk H 2 O content of which is 2 − /NH 3 and OH − /H 2 abundance ratios vary by ~55 and ~500% between NBO/Si = 1.18 and 0.4 relative to the values at NBO/Si = 0.4. In this same NH 2 − /NH 3 abundance ratio range, the δ 15 N of (N+H)-saturated melts, relative to that of melts with NBO/Si = 0.4, varies by ~2‰, whereas the δ D varies by ~87‰. In N-free melts, the δ D varies by ~12‰. Changing abundance of volatiles dissolved in silicate melts in molecular form and as structural complexes that form bonds with the silicate melt structure is an important factor that can affect stable isotope fractionation during melting and crystallization at high pressure and temperature.
Sympathetic activation by fenfluramine depletes brown adipose tissue norepinephrine content in rats

The antiobesity agent fenfluramine (FEN) has been reported to produce an activation of sympathetic neurons to brown adipose tissue (BAT) resulting in thermogenesis. The present study was conducted to determine if FEN-induced activation of BAT is affected by the ambient temperature at which animals are maintained. Body temperature was determined in conscious male Sprague-Dawley rats using implanted temperature transmitters, and sympathetic activation of BAT was determined by measuring norepinephrine (NE) content. Animals maintained at 22 and 4 degrees C incurred a significant decline in core body temperature following FEN administration. FEN produced a significant depletion of BAT NE content, and the magnitude of BAT NE depletion was related to the dose of FEN (-57.4% at 3 mg/kg dose and -75.9% at 10 mg/kg dose). However, the extent of BAT NE depletion was equal at 22 and 4 degrees C. BAT NE depletion by FEN appears to depend on activation of sympathetic neurons because it was prevented by pretreatment with the ganglionic blocker pentolinium (10 mg/kg ip). Furthermore, NE depletion by FEN could be blocked with fluoxetine (10 mg/kg ip) pretreatment, indicating that the action of FEN is mediated through the release of serotonin.
The Interaction of Cinnamic Acids with 60Co Gamma Radiation

In the interest of expanding our knowledge of the interaction of cinnamic acid and its derivatives with ionizing radiation, (E)-cinnamic acid and several of its chlorinated and brominated derivatives were exposed to 60Co gamma radiation. Dimer yields were estimated from integration of the proton NMR signals of the irradiated material. (E)-Cinnamic acid itself is relatively unreactive. The largest yield of dimer was obtained with p-bromocinnamic acid where exposure to a dose of 116 megarads led to a 24% yield.
Role of the cell wall in the determination of cell polarity and the plane of cell division in Fucus embryos

Recent studies using Fucus embryos indicate that the cell wall relays positional information to the underlying plasma membrane and cytosol to establish a polar axis, initiate polar growth and orient the first cell division plane of the zygote. It is the formation and stabilization of the polar axis in the zygote — not the position of the first division plane — which is critical for the formation of the initial embryonic pattern in Fucus . The pattern of asymmetry in the cell wall set at the time of polar axis fixation may also be the basis for the determination of rhizoid and thallus characteristics in the embryo. The cell division in early Arabidopsis embryos is very similar to that in Fucus embryos, and thus these findings may be pertinent to higher plants.
The Economic Determinants of the Market Reaction to Proposed Mandatory Accounting Changes in the Oil and Gas Industry

This paper examines the economic reasons for the observed negative abnormal common stock performance of firms whose reported earnings and stockholders' equity were negatively affected by the proposed elimination of full cost accounting in the oil and gas industry. Four explanations of the market effects of this mandatory accounting change are examined: (1) naive investor theory, (2) modified naive investor theory, (3) contracting cost theory, and (4) estimation risk theory. These hypotheses are developed in detail and used to generate variables for a cross-sectional model which explains observed return behavior. The effect of the accounting change on total stockholders' equity, the existence of financial contracts denominated in terms of accounting numbers and, to a lesser extent, firm size are shown to be important explanatory variables. The importance of these variables is consistent with both the contracting cost and estimation risk theories.
An Investigation of Posttraumatic Stress Disorder and Depressive Symptomatology among Female Victimsof Interpersonal Trauma

This study examined factors associated with PTSD-depression comorbidity among a sample of 162 adult female rape or assault victims with PTSD, as well as potential differential predictors of PTSD and depression severity. PTSD-only participants reported higher levels of childhood sexual abuse than those with comorbid PTSD and depression, and the PTSD/MDD group reported relatively more distorted trauma-related beliefs, dissociation, PTSD severity, and depression severity. Distorted trauma-related beliefs and dissociation were the strongest unique predictors of higher PTSD and depressive symptoms. Rates of PTSD and depression comorbidity did not appear to be a function of symptom overlap. Study findings suggest possible explanations for the high PTSD and depression comorbidity rates commonly found among victims of interpersonal violence.
UNDERAGE DRINKING, PEER INFLUENCE, AND ESCALATION

Juvenile delinquency research has identified two vital (and related) concepts to this area of study: age of onset and escalation. In this investigation, escalation is examined as a function of early drinking. Added to this are the influences of deviant peers and the social control effects of family and church. My analysis shows that consuming alcohol at a young age is correlated with illegal drug use, committing a greater number of illegal acts, committing more serious offences, and being confronted by police for delinquent behavior. Moreover, I show that peer influence has a greater impact on individual behavior than do other social control mechanisms. In conclusion, I offer a critique of current policies aimed at teenage drinking and argue in favor of preventative, rather than prohibitive strategies.
Dissecting desaturation: plants prove advantageous

Fatty acid desaturases play important roles in controlling the physical properties o f membranes and in the synthesis of signal molecules such as prostaglandins and pheromones. Most desaturases are membrane proteins that have been recalcitrant to characterization by conventional biochemical methods. Only one enzyme o f this class has been characterized from animals or fungi. In this context, plants have proved to be useful sources of experimental materials. Substantial progress has been made in characterizing and manipulating nine classes of desaturases that control the fatty acid composition o f both plant membranes and plant storage lipids, which account for approximately -30% of the calories in the human diet.
Binding equilibrium isotope effects for glucose at the catalytic domain of human brain hexokinase.

We have utilized tritium isotope effects to probe the in vitro binding equilibrium between glucose and human brain hexokinase (E.C.2.7.1.1). Replacing a backbone hydrogen atom in glucose with tritium can significantly increase or decrease the equilibrium association constant. Specifically, the equilibrium tritium isotope effects are 1.027 +/- 0.002, 0.927 +/- 0.0003, 1.027 +/- 0.004, 1.051 +/- 0.001, 0.988 +/- 0.001, and 1.065 +/- 0.003 for [1-t]-, [2-t]-, [3-t]-, [4-t]-, [5-t]-, and [6,6-t(2)]glucose, respectively. We have shown that the existence of prebinding equilibrium isotope effects can contribute to binding isotope effect studies but that this effect is insignificant for glucose binding to hexokinase. The binding isotope effects are interpreted in the context of structural studies of hexokinase-glucose complexes. Ab initio calculations on 2-propanol with or without a hydrogen bonding partner, in steric collision with formaldehyde or methane, and on ethanol, cyclohexanol and 1-hydroxymethyl-tetrahydropyran are presented to clarify the magnitude of isotope effects possible in such interactions and the accompanying changes in free energy. Position-specific binding isotope effects provide direct evidence of the partial deprotonation and activation of O6 by Asp657, of other hydrogen bonding interactions with ionic residues, and of the steric compression of CH2 by the backbone carbonyl of Ser603.
Weight effect of saline accumulation in surgical drapes.

Abstract Background: Positive vitreal pressure during phacoemulsification is a known risk factor for posterior capsule rupture. Knowledge of modifiable causes of positive vitreal pressure is imperative to aid in its management intraoperatively. The aim of our study was to determine whether the weight from the accumulation of a large volume of saline in the surgical drapes could have an effect on intraocular pressure in patients. Such an effect could indicate a source of posterior vitreal pressure in patients undergoing prolonged phacoemulsification. Methods: In 23 adult patients undergoing phacoemulsification at the Jones Eye Institute at the University of Arkansas for Medical Sciences, intraocular pressure readings were taken before and after the addition of 500 cc of saline to the surgical drapes and taken again after removal of the saline. Results: Statistically significant differences in intraocular pressure were found between the baseline measurement, the measurement with saline, and the measurement after saline removal. No differences in the rise in intraocular pressure were found according to age, race, sex, or which eye was tested. Interpretation: Accumulation of a large volume of saline in surgical drapes has a modest effect on intraocular pressure.This may indicate a contributing cause of posterior vitreal pressure during prolonged phacoemulsification.
Lawyers' Contribution to Business Development in Early Twentieth-Century Mexico

The Mexican Revolution (1910) brought important changes to the social, political and economic spheres of Mexico. New legislation was passed to protect workers and redistribute land. The state acquired rights to petroleum, water, and subsoil minerals. For entrepreneurs this was an abrupt change from the previous regime. They had to adapt to the new policies and administrative state structure. Business lawyers aided companies in a country where the government had circumscribed the private sector’s participation in the economy. Lawyers offered their clients important services, such as lobbying and aid in corporate restructuring. This article explores how in the midst of these new revolutionary regimes an important investment group used the services of business lawyer Manuel Gomez Morin to create Mexico’s first holding company and to issue the first mortgage bonds in the country. After the Mexican Revolution of 1910 had ended, entrepreneurs faced diverse challenges in adapting to a changed environment. Enterprises had to adjust to new rules and regulations implemented from 1917 onward. Additionally, companies faced a market in which bank services had almost disappeared—because of the government’s seizure of all bank reserves—and where communications such as the railway and the telegraph had been seriously disrupted and in some places destroyed by the revolts. Even though revolutionary ideals continued to have an impact on the economy as late as the 1930s,
UPPER AIRWAY IMAGING

Upper airway imaging is a powerful technique to study the mechanisms underlying the pathogenesis, biomechanics, and efficacy of treatment options in patients with obstructive sleep apnea. Imaging studies have provided significant insight into the static and dynamic structure, and function of the upper airway and surrounding soft-tissue structure during wakefulness and sleep. Upper airway imaging modalities primarily include nasopharyngoscopy, cephalometrics, computed tomography (CT), and magnetic resonance (MR) scanning. These imaging modalities have been used to study the effect of respiration, weight loss, dental appliances, and upper airway surgery on the upper airway. MR imaging and CT have allowed quantification of the airway and surrounding soft-tissue structures in three dimensions. Clinical indications for upper airway imaging are evolving for patients being treated with dental appliances and upper airway surgery.
Relation between upper limit of vulnerability and defibrillation threshold in humans.

BACKGROUND In the canine model, an upper limit of shock strength exists that can induce ventricular fibrillation during the vulnerable period of the cardiac cycle. This shock strength (the upper limit of vulnerability) closely correlates with the defibrillation threshold and supports the "upper limit of vulnerability" hypothesis of defibrillation. It is not known whether an upper limit of vulnerability exists in humans or whether this limit correlates with the defibrillation threshold. METHODS AND RESULTS In 13 patients undergoing implantable cardioverter-defibrillator implantation, the shock strengths associated with a 50% probability of reaching the upper limit of vulnerability (ULV50) and a 50% probability of reaching the defibrillation threshold (DFT50) were determined by the up-down algorithm. The ULV50 was determined only for the mid-upslope of the positive T waves and for the mid-downslope of the negative T waves. No major complications occurred during surgery. An upper limit of vulnerability was demonstrated in each patient. The ULV50 was 300 +/- 138 V or 6.8 +/- 5.8 J, which was significantly lower than the DFT50 of 347 +/- 167 V (p = 0.038) or 9.1 +/- 7.3 J (p = 0.013). The correlation between the ULV50 and the DFT50 was significant (r = 0.90, p < 0.001 for voltage; r = 0.93, p < 0.001 for energy). CONCLUSIONS An upper limit of vulnerability is present in humans. There is a significant correlation between the ULV50 and the DFT50, and the ULV50 is significantly lower than the DFT50.
Electronic tunability of the frustrated triangular-lattice cluster magnet LiZn2−xMo3O8

LiZn2Mo3O8 is an electrically insulating geometrically frustrated antiferromagnet in which inorganic Mo3O13 clusters each behaves as a single S = 1/2 unit, with the clusters arranged on a two-dimensional triangular lattice. Prior results have shown that LiZn2Mo3O8 does not exhibit static magnetic order down to at least T = 0.05 K, and instead possesses a valence bond ground state. Here, we show that LiZn2Mo3O8 can be hole doped by oxidation with I2 and subsequent removal of Zn2+ cations to access the entire range of electron count, from one to zero unpaired electrons per site on the triangular lattice. Contrary to expectations, no metallic state is induced; instead, the primary effect is to suppress the number of sites contributing to the condensed valence-bond state. Further, diffraction and pair-distribution function analysis show no evidence for local Jahn–Teller distortions or other deviations from the parent trigonal symmetry as a function of doping or temperature. Taken together, the data and density functional theory calculations indicate that removal of electrons from the magnetic layers favors Anderson localization of the resulting hole and an increase in the electrical band-gap over the formation of a metallic and superconducting state. These results put strong constraints on the chemical conditions necessary to realize metallic states from parent insulating geometrically frustrated antiferromagnets.
Does service reliability determine transit patronage? Insights from the Los Angeles Metro bus system

Abstract We explore whether improving service reliability can be effective in increasing transit patronage. Survey data shows that reliability is highly valued by passengers, because unreliability results in unpredictable wait times, missed transfer connections, and penalties associated with arriving at the destination earlier or later than desired. Consequently, transit planners have devoted significant effort towards measuring unreliability, exploring factors that cause unreliability, and developing strategies to increase reliability. However, we still know very little about how service reliability influences demand – i.e. whether reliability can be used as a tool to increase patronage. We use data from the Los Angeles Metro bus transit system to analyze the variation in boardings across lines and find service reliability to be a significant determinant of patronage. The reliability effect appears to be stronger in the weekday peak relative to the off-peak. Our results suggest that better schedule adherence can potentially promote patronage of fixed-route fixed-schedule transit systems. Reliability improvements may lead to productivity gains for transit agencies.
Plasma turbulence as a mechanism of pulsar radiation.

RADIO signals from pulsars are characterized by (1) high intensity, with brightness temperatures of the order of 1021 K (ref. 1); (2) pronounced (mostly linear) polarizations with, in the case of PSR 0833 (ref. 2), a monotonic sweep of the polarization angle during each pulse; (3), narrow pulse widths (Δt) compared with the repetition period (P); and (4) optical, X-ray and radio pulse widths, which are virtually the same3. This report is about a pulsar model in which anisotropic plasma turbulence, produced by the onset of a two-stream instability near the light cylinder of a rotating magnetic star, is the chief radiation mechanism. The model offers a quantitative, self-consistent account of features (1)–(3) for quite different pulsars, and a qualitative explanation of feature (4).
Genome screening using extremely discordant and extremely concordant sib pairs

We applied extreme sib-pair methods in two ways to the GAW10 Problem 2A data sets to detect susceptible quantitative trait loci using extremely discordant sib pairs only, and combining them with the available extremely concordant sib pairs as suggested by the authors elsewhere. Ten successive original replicates were combined into one sampling pool so as to get the necessary number of extreme sib pairs. A total of 100 replicates were used to produce 10 such data sets for both initial detection and confirmations. Strong signals were found with markers D5G15 for Q1, D8G27-28 for Q4, and D9G7-9 for Q5.
Zones of influence in the compressible shear layer

The effect of Mach number on communication between regions of a shear layer is analyzed in the limit of geometric acoustics. Communication is quantified in terms of the acoustic intensity emitted by a point source and received by an observer moving with the flow. The generalized Snell's law is used to trace the sound rays which are shown to be highly distorted because of the Mach-number gradient. Sound-intensity calculations reveal that the influence of the source on the surrounding medium becomes confined to a smaller area as the mach number increases. The zones of influence on the Lagrangian observer are funnel-shaped and become narrower with increasing Mach number. Communication is inhibited primarily in the axial direction, both upstream and downstream, and to a lesser extent in the transverse direction. Hindrance of communication may be the fundamental reason for enhanced stability at high Mach numbers.
THE CHANGING ROLES OF EXPERIMENTAL AND COMPUTATIONAL FLUID MECHANICS

When computational fluid mechanics was in its infancy, experiments and theoretical analysis were often the primary approaches used to study flow physics. Numerical simulations were performed after an experiment was complete, and the measured, theoretical, and numerical results were compared to assess the accuracy of the numerical results. As numerical simulation techniques have matured, computational, analytic, and experimental efforts have become equal partners in fluid mechanics research. Today numerical simulations are being used to guide the design of experimental hardware, to determine those areas of the flow field in which to concentrate the measurement effort, and to complement measurements in studying flow physics. The changing roles of experimental, analytical, and computational research will be traced by reviewing several investigations in which these approaches were used in varying degrees. A case will be made for maintaining a high degree of interaction between these approaches throughout the course of an investigation. The development of prototype computing systems designed to enhance the integration of numerical simulations and flow physics experiments will also be described.
Physical studies on the structure of yeast mitochondrial DNA.

Abstract The physical conformation of DNA isolated from the mitochondria of the yeast Saccharamyces cerevisiae has been studied using the techniques of sucrose gradient zone sedimentation and CsCl density-gradient equilibrium centrifugation. The DNA appears mainly as a linear double helix 4.0 to 4.5 μ in length. Some of these molecules possess cohesive termini which interact to produce hydrogen-bonded circles. Linear dimers and trimers of the basic unit length can be seen in electron micrographs. A small percentage of the total mitochondrial DNA molecules are covalent, superhelical circles.
Growth and Microstructure of Nanoscale Amorphous Carbon Nitride Films Deposited by Electron Beam Irradiation of 1,2-Diaminopropane

The deposition and microstructure of nanoscale nitrogen containing carbon films produced by irradiating adsorbed 1,2-diaminopropane (1,2-DAP) molecules with >40 eV electrons has been studied. The growth rate of films deposited in the presence of a constant partial pressure of 1,2-DAP was directly proportional to the flux of both precursor 1,2-DAP molecules and the incident electrons, consistent with an electron beam induced deposition (EBID) process. Deposited films were highly textured and weakly adhered to the polycrystalline Au substrate. Complementary information on the electron stimulated decomposition of the precursor and the accompanying film growth was obtained from experiments performed under ultrahigh vacuum (UHV) on nanometer scale thick films of 1,2-DAP. Results from these UHV studies were consistent with the idea that decomposition was initiated by secondary electrons, produced by the interaction of the primary electron beam with the adsorbate layer and the substrate. Reactions of these low energy secondary electrons with adsorbed 1,2-DAP molecules were responsible for dehydrogenation as well as film growth. For prolonged electron exposures nitrile species were produced, supporting the idea that changes in the film’s microstructure and chemical composition were due to the effects of C-H and N-H, rather than C- Co r C-N, bond cleavage. Collectively, our results indicate that EBID initially leads to the formation of a hydrogenated carbon nitride (a:C-N(H)) film. Further electron stimulated dehydrogenation ultimately yields an amorphous carbon-nitride film (a:C-N).
WebParc: a tool for analysis of the topography and volume of stroke from MRI

The quantitative assessment of the anatomic consequences of cerebral infarction is critical in the study of the etiology and therapeutic response in patients with stroke. We present here an overview of the operation of “WebParc,” a computational system that provides measures of stroke lesion volume and location with respect to canonical forebrain neural systems nomenclature. Using a web-based interface, clinical imaging data can be registered to a template brain that contains a comprehensive set of anatomic structures. Upon delineation of the lesion, we can express the size and localization of the lesion in terms of the regions that are intersected within the template. We demonstrate the application of the system using MRI-based diffusion-weighted imaging and document measures of the validity and reliability of its uses. Intra- and inter-rater reliability is demonstrated, and characterized relative to the various classes of anatomic regions that can be assessed. The WebParc system has been developed to meet criteria of both efficiency and intuitive operator use in the real time analysis of stroke anatomy, so as to be useful in support of clinical care and clinical research studies. This article is an overview of its base-line operation with quantitative anatomic characterization of lesion size and location in terms of stroke distribution within the separate gray and white matter compartments of the brain.
Anaerobic microbial dechlorination: an approach to on-site treatment of toxaphene-contaminated soil

Enhanced microbial degradation of toxaphene by natural microorganisms occurred in soil and sediment amended with organic matter kept under anaerobic (flooded) conditions. Laboratory experiments yielded a dissipation half-life of approximately 3 and 1 week for soil and sediment, respectively, containing 10 ppm of technical toxaphene and a 1% alfalfa meal amendment. Dissipation was accompanied by an increase in early eluting gas chromatographic peaks and a decrease in later eluting peaks, indicating that dechlorination had occurred. Enhanced anaerobic dissipation also took place in soil containing 500 ppm of toxaphene, although at a lesser rate than at 10 ppm, and when cotton gin waste was used as amendment in place of alfalfa meal. Sediment in a toxaphene-contaminated pesticide waste disposal ditch was amended with 10% steer manure and flooded to ascertain field utility of the technique for on-site decontamination. Toxaphene residues were reduced from 63 to 23 ppm in 120 days, and some degradation activity still occurred up to 8 months after this single treatment.
Infrared measurements of energy transfer from energetic materials to steel substrates

Abstract Energy transfer from reacting thermites placed on a v-notch steel target was evaluated for two thermite compositions which were Boron with Iron (III) Oxide (B-Fe 2 O 3 ) and Aluminum with Iron (III) Oxide (Al-Fe 2 O 3 ). A high-speed infrared camera captured a temporally evolving temperature distribution on the substrate as the thermite reaction self propagated. Results quantified the percent of the overall energy available from the chemical reaction that was transferred into the substrate and lost via other heat transfer modes. Results showed the B-Fe 2 O 3 reaction transferred 53% of its heat of reaction into the steel substrate compared to 11% for Al-Fe 2 O 3 .
Chain Dimensions and Rheology of Poly(arylene ethers)

Dilute solution and melt viscosities of two poly(arylene ether ketones) were compared. One polymer contained all para linkages in the backbone and the other contained one meta linkage per repeat unit. Molecular dimensions were shown to agree with calculated values and entanglement spacings could be predicted using the semi-empirical formula of Graessley and Edwards. Frictional properties in the two melts differed considerably when compared in ‘corresponding states' at Tg+100°C.
Binding of N-formylated chemotactic peptides in crystals of the Mcg light chain dimer: similarities with neutrophil receptors.

Abstract X-ray crystallographic techniques were used to study the modes of binding of N-formylated chemotactic peptides to the Mcg light chain (Bence-Jones) dimer. By difference Fourier analyses at 2.7-A resolution four N-formylated tripeptides were found to occupy similar sites in the main binding cavity of the dimer. In all cases the N-formyl group appeared to form a hydrogen bond with a phenolic hydroxyl group of a tyrosine residue (No. 38, monomer 1) at the base of the cavity. N-formylation was necessary, since di-, tri- and tetrapeptides with free α-amino groups failed to bind. Although methionine in ligand position 1 was optimal for binding, it could be replaced with norieucine. Position 2 was less critical, providing the side chain was bulky and hydrophobic (e.g. leucine, methionine or phenylalanine). An aromatic residue like phenylalanine was most favorable in position 3. These bound ligands were site-filling and wedge-shaped, with their side chains swept back toward the entrance of the cavity to conform to the space available for binding. In the binding site side chains and polypeptide segments of the hypervariable loops also moved in ways improving the complementarity between protein and ligand. The stereochemical requirements for binding were markedly similar to those found in interactions of neutrophil receptors with the same series of tripeptides. An N-formylated dipeptide, N-f-Met-Trp, was bound with equal occupancies in two overlapping subsites. In the deeper site the N-formyl group and methionine side chain were situated in positions comparable to those in the N-formyl tripeptides, but the peptide bond between methionine and tryptophan was in the cis configuration. In the outer site the corresponding peptide bond was in the energetically more favourable trans configuration.
FACTORS AFFECTING THE LAG PHASE OF GROWTH OF THE FILAMENTOUS FUNGUS, ALLOMYCES MACROGYNUS

THE WATERMOLD Allomyces macrogynus grows vigorously in a simple, synthetic, nutrient medium containing mineral salts, glucose, thiamine, and methionine (Machlis, 1953a, b). When very low concentrations of any one of the amino acids comprising the ornithine cycle are added to this medium, striking changes in the behavior of the mold are observed: (a) the growth is greatly stimulated; (b) mannose, which is normally an unsatisfactory source of carbon and eneray (Machlis, 1953c; Sistronm and Machlis, 1955) is used as readily as glucose; and (c) a marked inhibition of growth by thioctic acid is prevented. The primary purpose of this report is to describe the stimulation of growth effected by the active amino acids and certain metabolically related substances. In order to more specifically charaterize the observed growth response, it was necessary to analyze the nature of the growth of this fungus under the cultural conditions used. The basis of this analysis wvas the observation of Emerson (1950) that the growth of Neuraspora, under the conditions used by Emerson, is described by a straight line when the cube root of the dry weight is plotted against time. The secondary purpose of this study is to show that the growth of Allomyces macrogynus can be similarly represented. As a result, the growth can, vith some degree of definitiveness, be divided into a lag phase and what, for want of a better term, is described as the "cubic" phase. This analysis of growth is presented first in what follows, so that it may be used subsequently in discriminating between the effects of the amino acids on the lag phase and on the cubic phase of growth. MATERIALS AND METHODS.-The organism used was Allomyces macrogynus, strain Burma IDa, obtained originally from the culture collection of Dr. Ralph Emerson. The media and general methods of culture were the same as those described by Sistrom and Machlis (1955) except for the volume of inoculum. In the present study, 1 ml. of a suspension of mitospores containing about 25,000 motile spores was added to 50 ml. of medium contained in 125-ml. Erlenmeyer flasks which were subsequently incubated at 25?C. on a horizontal shaker.
A tunable AC atom interferometer magnetometer

We demonstrate an atom interferometer designed to measure magnetic fields and field gradients. Here, we study various pulse sequences and show how they can be manipulated to filter unwanted frequencies and to enhance desired frequencies.
Analyzing Teachers' Feedback Practices in Response to Students' Work in Science Classrooms

This article presents findings from three studies of teachers' written feedback practices in students' science notebooks in 26 elementary and middle school classrooms. Three questions guided the analysis of the data: (a) Do teachers provide written feedback in response to the scientifically oriented questions students investigate in their science classrooms? (b) If teachers write feedback, what are its characteristics? (c) Do teachers interpret students' responses properly, and do they correctly identify the strengths and weaknesses to tailor the feedback to students' needs? Results indicated that 17 of the 26 teachers provided students with feedback in some form. However, the frequency of this feedback varied from teacher to teacher and across grade levels. From all feedback communications coded across the three studies, about 61% were grades, numbers, or symbols, and only 33% were comments. Furthermore, evaluative comments occurred nearly as frequently as descriptive comments (10% and 14%, respectively)...
Case Study: Small-Scale Hybrid Integrated Renewable Energy System (HI-RES): Emergency Mobile Backup Power Generation Station

The concept of examining the feasibility of small-scale integrated hybrid renewable energy systems for mobile backup power generation has expanded greatly over the past decade. Increases in large scale power outages have become a common theme across America and other parts of the world as a result of natural disasters such as earthquakes, floods, hurricanes, and other extreme environmental conditions. These outages often disrupt commerce, business, and the quality of life for many of the consumers impacted including loss of life and significant cost to the tax payers in mitigating the effects of these disruptions. In addition, increasingly hostile social climates and threats of war have exposed the need for more reliable small scale backup power plants (both renewable and non-renewable) integrated to rapid recovery systems. As greater emphasis is placed on reducing the green house effect and the emissions of pollutants into the environment, major technological advancements in renewable energy is driving innovative approaches to improving Energy Returned On Energy Invested (EROEI), thus enabling a stronger business case for renewable over strictly non-renewable power generation systems, including mobile backup hybrid renewable power generation capabilities.