cssi/SciSciGPT-SciSciNet huggingface dataset:
Assessing impacts of improved signal timing as a transportation control measure using an activity-specific modeling approach

Metropolitan areas in nonattainment for transportation-related air pollutants rely on transportation control measures (TCMs) to reduce emissions and meet clean-air goals. However, since traditional transportation-related air quality models use emission rates based on average speeds, only TCMs that either increase or decrease vehicle activity to speeds in which emissions are lower show reductions in output of air pollutants. In recent years, transportation air quality analysis has shifted to an activity-specific modeling approach that correlates emissions to vehicle operating mode. With an activity-specific approach, the emission reduction potential of a TCM can be evaluated by its ability to decrease time spent in modes in which emissions are disproportionately elevated. Signal timing improvements are attractive TCMs for traffic flow improvement. However, with traditional modeling, they may greatly decrease extremes in modal activity yet not show significant emission reduction if only moderate changes in average speed are realized. The benefits of using activity-specific modeling for evaluation of improved signal coordination as a TCM are described. A brief overview of the development of an activity-specific carbon monoxide emission rate model is provided, data collection for on-road vehicle activity estimates is briefly outlined, and a comparison of traditional emission modeling versus activity-specific modeling is provided to estimate the air quality benefits from improved coordination at a study intersection. Results for the study intersection indicate that more significant reductions in carbon monoxide emissions are realized using an activity-specific approach than with traditional methods.
Effect of climate variability on estimation of greenhouse parameters: Usefulness of a pre-instrumental temperature record

To estimate the strength of the greenhouse warming signal embedded in the noise of natural climate variability, a statistical methodology is applied to a functional model of the signal and stochastic models of the noise. The confidence of greenhouse parameter estimates, namely climate sensitivity, obtained from a record of global near-surface temperature is highly dependent on natural climate variability with a time scale of roughly a century. A pre-instrumental temperature record is needed to construct empirically a model for natural variability of century time-scale which, in turn, is needed to determine the confidence of parameter estimates. However, for assumed models for climate variability, data prior to 1950 does not significantly improve the confidence of estimates. In fact, addition of an accurate pre-instrumental record is not expected to have a large impact on climate sensitivity estimates made with only the instrumental temperature record.
The effective interfacial shear strength characteristics of copper telluride, copper sulphide and lead coated SAE 1045 steel-high speed steel materials when subjected to load conditions causing bulk plastic deformation

Abstract Free-machining additions have been added to ferrous and non-ferrous materials for many years. One explanation of their effect in machining is that they reduce the effective interfacial shear strength between chip and tool. A unique friction test was used to measure the fractional characteristics of Cu2Te, Cu2S and Pb coated SAE 1045 steel-high speed steel materials at room temperature. All the coatings showed a reduction in initial torque requirements and this is cited as evidence of the initial low friction characteristics of the films. During the test the effective shear strength of Cu2Te and Cu2S coated material reached that of the uncoated material while the lead coating continued at a low level. It is suggested that this phenomenon is associated with the brittle behaviour of the compound films.
Coats-type retinitis pigmentosa in a 4-year-old child.

Purpose To describe the occurrence of Coats-like exudative retinopathy secondary to underlying retinitis pigmentosa in a 4-year-old child. Method Case report. Results A 4-year-old girl had bilateral exudative retinal telangiectasia requiring photocoagulation. She subsequently developed progressive nyctalopia, photophobia, and reduced peripheral vision. Electroretinography and dark adaptometry at age 8 years confirmed the diagnosis of retinitis pigmentosa. Conclusions Coats-like exudative retinopathy secondary to retinitis pigmentosa can manifest as early as age 4 years and can precede the diagnosis of the underlying retinal dystrophy.
Signs of Learning: Child Nonnative Speakers in Tutoring Sessions with a Child Native Speaker.

Learning acts, which included conversation-maintaining acts and language-learning acts, were coded and compared in a group of native Spanish-speaking children (n= 9) during individual tutoring sessions with a native English speaker. In each session, an 8 year-old NS of English tutored one kindergartener for about twenty-five minutes at an elementary school. Three kindergarteners had been rated high, three average and three low in overall achievement by their teachers. For each child, the total number of words and number of unique words were computed. In the nine tape recordings, the high group ranked ahead of the low group in the quantity and sophistication of their English, and the number of learning acts produced. The medium group resembled the high group more than the low group on most features. Each group had a characteristic pattern of learning act use.
A motorized microdrive for recording of neural ensembles in awake behaving rats

The recording of neural ensembles in awake, behaving rats has been an extremely successful experimental paradigm, providing demonstrable scientific advances. Dynamic control of the position of the implanted electrodes is of key importance as mobile electrodes provide a better signal-to-noise ratio and a better cell/ electrode yield than nonmobile electrodes. Here we describe the use of low cost soon to be commercially available dc motors to successfully control the depth of electrodes. The prototype designed is approximately 30 mm in diameter and 50 mm in length and weighed about 30 gins. This paper presents the results of linear displacements of electrodes achievable with this motorized microdrive.
House Price Differentials in U.S. Cities: Household and Neighborhood Racial Effects ☆

Abstract Three cities are examined for evidence of housing market discrimination and prejudice using the American Housing Survey for 1978–1991, supplemented with information on neighborhood quality from the 1980 and 1990 Censuses. We show that incorrect inferences about the magnitude of racial price differentials are possible when neighborhood characteristics are excluded. When this information is included and the racial indicators are allowed to vary over time and submarkets, there is evidence of increasing prejudice in Denver and Philadelphia and decreasing prejudice in Chicago. There also appears to be a trend toward lower levels of price discrimination against nonwhites in ghetto areas in all three cities, though exclusionary practices have increased in suburban areas in Philadelphia.
Big (chemistry) data.

Bruce Gibb ponders what the future of chemistry research might look like if we take a more data-driven approach.
Does Mission Matter? An Analysis of Private School Achievement Differences

Using student achievement data from British Columbia, Canada, this study is an exploration of the differences that lie within the private school sector using hierarchical linear modeling to analyze the data. The analysis showed that when controlling for language, parents' level of educational attainment, and prior achievement, the private school subsectors had small but important differences in average performance compared to one another and to public schools. The study suggests that mission might matter more in parental school choice decisions than academic achievement and implications of this for school choice are explored.
Creating Accountability in Image Quality Analysis. Part 2: Medical Imaging Accreditation

The Medicare Improvements for Patients and Providers Act of 2008 (MIPPA) requires all non-hospital providers of advance diagnostic imaging (ADI) submitting technical reimbursement claims to Medicare to undergo a formal accreditation in order to qualify for continued Medicare reimbursement (http://www.govtrack.us/congress/bills/110/hr6331/text). ADI includes MRI, CT, and nuclear medicine imaging and does not include X-ray, ultrasound, and fluoroscopy. Mammography is covered separately by the Mammography Quality Standards Act (http://www.fda.gov/CDRH/MAMMOGRAPHY). The quality standards which must be demonstrated by medical imaging providers in this accreditation process include the following (http://www.cms.gov/outreach-and-education/medicare-learning-network-MLN/MLNI): Qualifications of medical personnel who are not physicians Qualifications and responsibilities of medical directors and supervisory physicians Procedures to ensure equipment being used meets performance specifications Procedures to ensure the safety of both medical imaging beneficiaries and personnel Establishment and maintenance of a quality assurance and quality control program to ensure reliability, clarity, and accuracy of image technical quality The accreditation process is triennial and averages US$3,500 per imaging modality being evaluated. In the event that an applicant is determined to be noncompliant with the established standards, a corrective action plan is required, with the possibility of a site visit. After the accreditation process has been successfully completed, the provider is required to notify the accreditation organization of any change in service (e.g., equipment change).
Fistulojejunostomy for the management of refractory pancreatic fistula.

Background Pancreatic fistula (PF) formation is a known complication of pancreatic surgery, pancreatitis, and pancreatic injury. When medical or endoscopic interventions fail to resolve PF, operation remains the only viable treatment option. Unfortunately, operation for the correction of PF is often difficult and associated with significant morbidity. Methods Herein, we report on our experience with a previously described technique for the management of PF that is performed easily and is associated with reduced morbidity. During the period of 2003-2006, 8 patients (males = 6, female = 2) with PF were treated with prolonged percutaneous drainage. Once a mature scar tract formed around the percutaneous drain, patients underwent a fistulojejunostomy. Results The age of these patients ranged from 43 to 61 years. Of the 8 patients, 5 had fistulas secondary to necrotizing pancreatitis. The remaining 3 patients had fistulas resulting from previous pancreatic surgery. The average interval between drain placement and fistulojejunostomy was 6 months (range, 4-7 months). The average duration of operation was 2.5 h (range, 1-4.5 h). The average blood loss was 280 mL (range, 50-600 mL). Average duration of stay was 9 days (average, 4-14 days). At a mean follow-up of 17 months (range, 2-58 months), 6 of 8 patients had resolution of their pancreatic fistulas, could resume regular diet, and were free of narcotic use. One patient developed a recurrent pseudocyst and required a distal pancreatectomy, and the final patient was lost to follow-up. Conclusions Fistulojejunostomy is an effective therapy for the definitive treatment of pancreatic fistulas.
Activation and deactivation of sarcoplasmic reticulum calcium release channels: Molecular dissection of mechanisms via novel semi-synthetic ryanoids

The plant alkaloids ryanodine and dehydroryanodine are high affinity, biphasic modulators of the intracellularly located, calcium- regulated calcium release channels of a variety of cell types. To date, little is certain about the molecular basis of the interactions that prompt low concentrations of ryanodine (nanomolar to low micromolar) to activate (open) the channels and higher concentrations to deactivate (functionally close) the sarcoplasmic reticulum calcium release channel. In the present study, we approached this question using novel, semi-synthetic C10-Oeq ester derivatives of ryanodine and dehydroryanodine as molecular probes of the ryanodine binding sites on the calcium release channel.
Three-dimensional NOESY-HMQC spectroscopy of a 13C-labeled protein

The analysis of NMR spectra of med ium-size ( lo-20 kDa) proteins is often difficult because of severe signal overlap. A number of isotope-edited 2D experiments (I7) and, more recently, 3D NMR experiments have been used to alleviate this problem (8-12). Spreading spectral information in three independent frequency dimensions greatly reduces spectral overlap and thereby simplifies the process of analysis. The heteronuclear 3D experiments (I.?, 10-12) are particularly useful in this respect, because the total number of resonances remains unchanged relative to the corresponding homonuclear ‘H 2D spectrum; the chemical shift of the heteronucleus is merely used to disperse the resonances in the regular 2D spectrum along a third axis. All applications of heteronuclear 3D experiments to proteins publ ished to date combine the commonly used homonuclear ‘H experiments NOESY (14,15) and HOHAHA ( 16, 17) with the ‘H-detected heteronuclear mu ltiplequantum correlation (HMQC) experiment ( 18-20). Recently, it has been shown that the HMQC experiment does not provide as high a resolution as some more complex pulse sequences (21). However, the resolution in the dimension of the heteronuclear chemical shift is usually lim ited by digital resolution, and the potentially lower resolution does not play a role. So far, all protein applications of heteronuclear 3D NMR have utilized 15N as the heteronucleus. Here we report the first use of heteronuclear 3D protein NMR using the r3C chemical shift to spread the ‘H resonances. Although at first sight, the change from “N to 13C may appear simple, there were a number of problems that had made it uncertain whether this approach would be successful. F irst, the heteronuclear dipolar l ine-broadening effect of 13C on the resonance of its directly attached proton(s) is severe, typically causing a twofold increase of the regular proton linewidth. This sharply reduces sensitivity in those 3D experiments where one of the magnetization transfer steps relies on ‘H‘H Jcoupling. Our experiments with fully (about 95%) ‘3C-labeled protein also showed a reduction in the proton T, by about 30% relative to the unlabeled protein, and it was not certain a priori whether this strong heteronuclear dipolar relaxation would have a negative influence on the quality of the NOESY spectrum. A second problem arises from the presence of relatively large r Jcc couplings, varying from about 60 Hz for C,-carbonyl and aromatic couplings to about 35 Hz for couplings between aliphatic carbons. Attempting to resolve these splittings in the 3D experiment would increase the number of resonances and thus decrease signal-to-noise. As shown by Markley and co-workers ( 22-24)) using a relatively low level of 13C labeling reduces the * 3Cr3C broaden-
Molecular genetics and transgenic model of Gertsmann-Sträussler-Scheinker disease.

Gerstmann-Straussler-Scheinker disease (GSS) is a rare, dominantly inherited neurodegenerative disease that can sometimes be transmitted to experimental animals through intracerebral inoculation of brain homogenates from patients. Substitution of leucine for proline at codon 102 of the prion protein gene has been found in several families with the disease; this mutation is genetically linked to GSS. Mice containing murine prion protein transgenes with this mutation spontaneously develop neurologic symptoms of ataxia, lethargy, and rigidity accompanied by spongiform degeneration throughout the brain. Thus, many of the clinical and pathological features of the GSS have been reproduced in this transgenic mouse paradigm; to our knowledge, this study illustrates, for the first time, that a neurodegenerative process similar to a human disease can be genetically modeled in animals. Whether or not this transgenic mouse model of GSS may facilitate the understanding of common neurodegenerative disorders such as Alzheimer disease remains to be established.
Adding fuel to the fire: NASA’s crisis communications regarding Apollo 1

Abstract In January 1967, NASA faced its first major crisis when a flash fire killed the three-man crew of Apollo 1 during a routine, preflight test. Unprepared for a fire on the ground and desperate to manage its image, the space agency responded poorly to the crisis: it waited 2 h to report the deaths; it communicated inaccurate, contradictory, and purposefully misleading information to Congress and the media; it lied, and refused to release information, to congressional committees investigating the fire; and it stacked the official board investigating the fire with its own personnel and people who had close ties to the agency. NASA’s poor crisis communications exacerbated the tragedy, tarnishing its image, hurting its credibility, and prolonging the crisis. This study provides an example of an unsuccessful response to a crisis and demonstrates how much damage can occur when an organization fails to communicate openly and honestly. James Kauffman is an associate professor of communication studies at Indiana University Southeast.
High-Resolution Crystal Structures of Protein Helices Reconciled with Three-Centered Hydrogen Bonds and Multipole Electrostatics

Theoretical and experimental evidence for non-linear hydrogen bonds in protein helices is ubiquitous. In particular, amide three-centered hydrogen bonds are common features of helices in high-resolution crystal structures of proteins. These high-resolution structures (1.0 to 1.5 A nominal crystallographic resolution) position backbone atoms without significant bias from modeling constraints and identify Φ = -62°, ψ = -43 as the consensus backbone torsional angles of protein helices. These torsional angles preserve the atomic positions of α-β carbons of the classic Pauling α-helix while allowing the amide carbonyls to form bifurcated hydrogen bonds as first suggested by Nemethy et al. in 1967. Molecular dynamics simulations of a capped 12-residue oligoalanine in water with AMOEBA (Atomic Multipole Optimized Energetics for Biomolecular Applications), a second-generation force field that includes multipole electrostatics and polarizability, reproduces the experimentally observed high-resolution helical conformation and correctly reorients the amide-bond carbonyls into bifurcated hydrogen bonds. This simple modification of backbone torsional angles reconciles experimental and theoretical views to provide a unified view of amide three-centered hydrogen bonds as crucial components of protein helices. The reason why they have been overlooked by structural biologists depends on the small crankshaft-like changes in orientation of the amide bond that allows maintenance of the overall helical parameters (helix pitch (p) and residues per turn (n)). The Pauling 3.613 α-helix fits the high-resolution experimental data with the minor exception of the amide-carbonyl electron density, but the previously associated backbone torsional angles (Φ, Ψ) needed slight modification to be reconciled with three-atom centered H-bonds and multipole electrostatics. Thus, a new standard helix, the 3.613/10-, Nemethy- or N-helix, is proposed. Due to the use of constraints from monopole force fields and assumed secondary structures used in low-resolution refinement of electron density of proteins, such structures in the PDB often show linear hydrogen bonding.
Potential of Blood Eosinophils, Eosinophil-Derived Neurotoxin, and Eotaxin-3 as Biomarkers of Eosinophilic Esophagitis

Background & Aims: Eosinophilic esophagitis (EE) is an increasingly recognized disorder characterized by eosinophilic inflammation of the esophageal mucosa, and typically requires serial invasive endoscopic biopsy examinations to document the characteristic histologic features of the disorder. The aim of this study was to identify noninvasive biomarkers that correlated with disease activity and response to treatment as measured by esophageal eosinophilia. Methods: A prospective, cross-sectional analysis was performed on 47 pediatric patients undergoing endoscopic evaluation of possible EE. Blood samples were collected for measurement of peripheral blood absolute eosinophil count (AEC) and levels of eosinophil-derived neurotoxin (EDN), eotaxin-1, -2, and -3, and interleukin-5. Stool samples were collected for measurement of EDN. Biomarker levels were correlated with esophageal eosinophil density, and differences in biomarker levels based on disease activity and treatment were determined. Results: AEC, plasma EDN levels, and eotaxin-3 levels significantly correlated with esophageal eosinophil density (AEC: r = 0.56, P r = 0.54, P r = 0.32, P = .04), and were increased in patients with active EE vs controls (AEC: 440 vs 140 eosinophils/μL, P P = .01; eotaxin-3: 37.7 vs 11.5 pg/mL, P = .01). Cut-off values were established to maximize the sensitivity, specificity, and predictive values of these biomarkers alone and in combination. Eotaxin-1, eotaxin-2, interleukin-5, and fecal EDN levels did not correlate with esophageal eosinophil density, and were not increased in active EE vs controls or those with inactive EE. Conclusions: These data show that blood levels of AEC, EDN, and eotaxin-3 may have value as noninvasive biomarkers for monitoring EE.
VIX changes and derivative returns on FOMC meeting days

We examine the link between scheduled Federal Open Market Committee (FOMC) meetings and the VIX measure. Our results indicate that VIX declines significantly on scheduled meeting dates. Unlike prior studies suggesting that the drop in VIX is mechanical, we attribute the decline to the resolution of uncertainty regarding future interest rates provided by the meetings. We examine returns to investable positions on VIX. Though a decline in the VIX level commonly occurs on FOMC meeting dates, we find that significant returns may still be garnered from taking short-VIX positions in derivative markets, even after accounting for the bid-ask spread.
Multimodality Imaging of Hypertrophic Cardiomyopathy in a Transplanted Heart

A 66-year-old woman who had undergone heart transplantation 19 years ago for dilated cardiomyopathy presented to the ambulatory clinic with weight gain and worsening dyspnea on exertion. She had experienced an excellent posttransplant course that was free of significant rejection or graft dysfunction. The patient had undergone annual angiography with no evidence of significant epicardial coronary artery disease, and annual right ventricle biopsy revealed only a single abnormal demonstration of mild cellular vacuolization in 2008. Her immunosuppressive regimen had initially included cyclosporine, prednisone, and azathioprine, which was ultimately transitioned to mycophenolate mofetil. Physical examination revealed a regular pulse of 92 beats per minute, a blood pressure of 130/86 mm Hg, and a weight of 209 pounds (increased 7 pounds from a year prior). Cardiac auscultation was remarkable for an S4 gallop with no murmurs. The lungs were clear to auscultation, and her extremities were warm and without pitting edema. Electrocardiography revealed normal sinus rhythm, an rSR′ pattern suggestive of right ventricle conduction delay, voltage criteria for left …
Nuclear quadrupole resonance in 5-membered heterocycles: Pyrazole, imidazole, 1, 2, 4-triazole

Abstract Nitrogen-14 nuclear quadrupole coupling constants and asymmetry parameters have been measured in several elementary aromatic azoles. Ring nitrogens ortho to the imino nitrogen have e 2 qQ ≈4.2 MHz and η ≈66%; nitrogens in the meta position give e 2 qQ ≈3.5 MHz and η ≈12%.
Big Grains in the Red Rectangle

We report VLA observations at 3.6 cm, 2 cm, and 1.3 cm of the Red Rectangle and Hα spectroscopy of HD 44179, the central binary star in the nebulosity. Emission is detected at all three radio wavelengths, and the source is resolved at 2 cm and 1.3 cm. Convolved to the same beam, the radio spectrum of the inner 076 × 049 is characteristic of thermal emission from ionized gas which becomes optically thin near 2 cm. The diameter of the bulk of the ionized gas producing this radio emission is between 1.3 × 1014 cm (~10 AU) and 2 × 1015 cm (~100 AU); in this region we estimate that 106 cm-3 ≤ ne ≤ 4 × 106 cm-3. The Hα profile has both a wide (200 km s-1 full-width zero-intensity) plateau which is probably associated with a small circumstellar region (<1013 cm or ~1 AU) and a spike (FWHM ≈ 20 km s-1) which we suggest is produced in the extended ionized gas (≥1014 cm) detected at radio wavelengths. We also detect low surface brightness radio emission at 2 cm and 1.3 cm, but not at 3.6 cm, that is extended well beyond 1'' from the source. This extended radio emission has a spectral index between 1.3 cm and 3.6 cm greater than 3.2 and is therefore produced by grains. Our VLA data also indicate that the previously observed millimeter continuum flux cannot result from ionized gas and therefore is emitted by dust. Although uncertain, it is possible that the centimeter and millimeter wavelength continuum arise from the same dust, in which case there is probably little frequency variation in the emissivity of the dust between 1.3 cm and 0.13 cm. We propose that there is an orbiting, long-lived gravitationallly bound disk of dust grains with radii ≥0.02 cm.
Single-molecule microscopy studies of electric-field poling in chromophore-polymer composite materials

One strategy for increasing the efficiency of organic electrooptic devices based on chromophore-polymer composite materials is to improve chromophore ordering. In these materials, ordering is induced through the interaction of the chromophore dipole moment with an external electric field, applied at temperatures near the Tg of the polymer host, a process referred to as "poling". To provide insight into the molecular details of the poling process under conditions representative of device construction, the rotational dynamics of single 4-dicyano-methylene-2-methyl-6-(p-(dimethylamino)styryl)-4H-pyran (DCM) molecules in poly(methyl acrylate) at T = Tg + 11 degrees C in the presence and absence of an electric field are investigated using single-molecule confocal fluorescence microscopy. Single-molecule rotational dynamics are monitored through the time evolution of the fluorescence anisotropy. The anisotropy correlation function demonstrates nonexponential decay, with beta values derived from fits using the Kohlrausch-Williams-Watts law ranging from 0.7 to 1 with beta(KWW) = 0.83. This observation is consistent with previous studies of molecular rotation dynamics in polymer melts and reflects the dynamical heterogeneity provided by the polymer host. The rotational dynamics of DCM are weakly perturbed in the presence of a 50 V/microm electric field, typical of the field strength employed in device construction. The expected perturbation of the rotational dynamics is determined and found to be consistent with the alignment potential created by the electric field relative to the amount of thermal energy available. The relevance of these findings with respect to current models of the poling process is discussed. This work demonstrates the utility of polarization-sensitive single-molecule microscopy in elucidating the details of molecular reorientation during poling.
The Heat of Dissociation of Nitrogen

IN a recent letter to NATURE (122, 313; Sept. 1, 1928) E. Gaviola has presented some evidence indicating that the heat of dissociation (D) of N2 is not more than 9.8 volts, as contrasted with the 11.4 volt value calculated by Birge and Sponer (Phys. Rev., 28, 259; 1926). It seems desirable to state that some months ago R. S. Mulliken and I independently reached the conclusion that the value of D for N2 is probably about 9.5 volts. The evidence on which I reached this conclusion, which seems to me quite direct and unambiguous, is contained implicitly in a recent article by G. Herzberg (Ann. d. Physik, 86, 189; 1928) on the negative N2 bands.
Does proximity to coal-fired power plants influence fish tissue mercury?

Much of the mercury contamination in aquatic biota originates from coal-fired power plants, point sources that release mercury into the atmosphere. Understanding mercury dynamics is primarily important because of the toxic threat mercury poses to wildlife and humans through the consumption of contaminated fish. In this study, we quantified the relative importance of proximity to coal-fired power plants on mercury accumulation in two fish species of different trophic positions. Fish, water and sediment were collected and analyzed from 14 lakes, seven near to ( 30 km) coal-fired power plants. Lower tissue mercury and higher tissue selenium concentrations were measured in fish collected near power plants. Moreover, mercury accumulation in fish was driven by biotic characteristics (e.g., trophic position, total length, age), waterbody characteristics (e.g., pH, dissolved organic carbon and sulfate) and distance from power plants. Proximity to an atmospheric point-source of mercury and selenium, such as a coal-fired power plant, affects the quantities of mercury and selenium accumulated in fish tissue. Differences in accumulation are hypothesized to be driven in part by selenium-mitigated reductions in fish tissue mercury near power plants. Although reduced fish tissue mercury in systems near power plants may decrease mercury-specific risks to human consumers, these benefits are highly localized and the relatively high selenium associated with these tissues may compromise ecological health.
How does DNA methylation repress transcription

DNA methylation has an essential regulatory function in mammalian development, serving to repress nontranscribed genes stably in differentiated adult somatic cells. Recent data implicate transcriptional repressors specific for methylated DNA and chromatin assembly in this global control of gene activity. The assembly of specialized nucleosomal structures on methylated DNA helps to explain the capacity of methylated DNA segments to silence transcription more effectively than conventional chromatin. Specialized nucleosomes also provide a potential molecular mechanism for the stable propagation of DNA methylation-dependent transcriptional silencing through cell division.
Five-Factor Model personality traits and executive functioning among older adults

Recent theoretical interest in the neuropsychological underpinnings of major personality factors, along with the identification of both personality and executive functioning (EF) as significant predictors of dementia onset, suggest the need to examine personality-EF associations. The current study assessed Five-Factor Model personality traits (NEO Personality Inventory-Revised) and EF in 58 healthy, community-dwelling, older adults (Mage = 69.8, SD = 6.3) using well-validated neuropsychological tests. Results indicated that EF was positively associated with Neuroticism, and negatively associated with Openness to Experience and Agreeableness. Personality facets associated with interpersonal antagonism vs. affiliation (e.g., Angry-Hostility, Warmth, Trust, Tender-Mindedness) were most strongly associated with EF. These findings contribute to a growing literature on the neuropsychological foundations of personality.
L-thyroxine in subcalorigenic doses: rapid potentiation of dinitrophenol-induced calorigenesis in hypothyroid rats.

The calorigenic action of 2,4-dinitrophenol (DNP), measured as percentage of increase in BMR 30-45 min after ip injection of 10 μg/g body wt, was less in about 40% of the hypothyroid rats in this study than it was in euthyroid ones. The remaining hypothyroid rats, with a similar BMR to those responding subnormally, had a normal percentage of calorigenic response to DNP; in these rats L-thyroxine (L-T4), 50-300 mμg/g given over 3 days, raised the BMR and increased DNP-induced calorigenesis above normal. Those hypothyroid rats with low DNP-induced calorigenesis were more sensitive to L-T4: a single ip dose of 5.2 mμ/g of L-T4, with no calorigenic action itself, restored 85 % of their calorigenic response to DNP in 6 hr, but did not change the response of rats with normal DNP-induced calorigenesis. The restored calorigenic response to DNP lasted 1–2 weeks and could again be raised with L-T4. Since DNP is calorigenic by acting on mitochondrial oxidative phosphorylation in vivo, L-T4 acts here either to allow ...
Precision of measuring body fat distribution in adolescent African American girls from the ‘healthy growth study’

Precision estimates are given for anthropometric assessment of body fat distribution in participants (n = 86) of the Healthy Growth Study (total n = 154). This five year longitudinal study explored the psychosocial and biologic influences on activity levels in urban adolescent African American girls. The basic anthropometric data include height, weight, four body and limb circumferences, and five skinfold measurements. It is proposed that ratio indices of body fat distribution are likely to have poorer precisions than the single variables which they comprise, and that ratios based on skinfolds may be particularly sensitive to this problem. The precision of the body mass index (BMI) and principal components of skinfold fatness and fat distribution are also considered. Precisions were greater than 0.95 (intraclass correlation from a random-effects analysis of variance) for most anthropometric dimensions and indices, including the BMI and the first principal component of fatness. However, three of the five skinfolds had lower precisions (0.84-0.93). In contrast, the precisions of all indices of body fat distribution were 0.90 or less (range: 0.57-0.87 skinfold ratios; 0.83-0.90 circumference ratios). Of the ratios, conicity was most stable at 0.90 for repeated measures by both the same and different observers. A second principal component of central fat did not have precisions noticeably better than skinfold ratios (0.79-0.82). Indices of fat distribution may have lower reliabilities than the single variables that they comprise, because errors may be compounded when dividing one variable by another or in linear combinations of measurements other than the first principal component. This problem should be taken into account in clinical and epidemiologic investigations of body fat distribution. © 1996 Wiley-Liss, Inc.
Scaling of suction-induced flows in bluegill: morphological and kinematic predictors for the ontogeny of feeding performance.

SUMMARY During ontogeny, animals undergo changes in size and shape that result in shifts in performance, behavior and resource use. These ontogenetic changes provide an opportunity to test hypotheses about how the growth of structures affects biological functions. In the present study, we ask how ontogenetic changes in skull biomechanics affect the ability of bluegill sunfish, a high-performance suction feeder, to produce flow speeds and accelerations during suction feeding. The flow of water in front of the mouth was measured directly for fish ranging from young-of-year to large adults, using digital particle imaging velocimetry (DPIV). As bluegill size increased, the magnitude of peak flow speed they produced increased, and the effective suction distance increased because of increasing mouth size. However, throughout the size range, the timing of peak fluid speed remained unchanged, and flow was constrained to approximately one gape distance from the mouth. The observed scaling relationships between standard length and peak flow speed conformed to expectations derived from two biomechanical models, one based on morphological potential to produce suction pressure (the Suction Index model) and the other derived from a combination of morphological and kinematic variables (the Expanding Cone model). The success of these models in qualitatively predicting the observed allometry of induced flow speed reveals that the scaling of cranial morphology underlies the scaling of suction performance in bluegill.
Implementing Performance‐Based Program Budgeting: A System‐Dynamics Perspective

The article proposes a model for evaluating budget reforms that combines insights from budgeting, policy implementation, and system-dynamics literatures. System-dynamics modeling combines both quantitative and qualitative research techniques to provide a new framework for applied research; its use is illustrated using performance budgeting as an example. Applied to the implementation of Florida's performance-based program budget, the model identifies actions in the short run that will increase the reform's likelihood of success: providing clear communications; facilitative budget and accounting routines; reliable performance information. The model also identifies critical legislative behaviors that influence executive implementation: how the legislature in the long-run uses performance information to inform resource allocation and how it applies incentives or sanctions to programs that achieve or fail to achieve their performance standards. The legislature has the opportunity to use program reviews prepared by legislative staff to invigorate the executive branch's resolve to continue implementing the reform.
Partitioning of elements among two silicate perovskites, superphase B, and volatile-bearing melt at 23 GPa and 1500–1600°C

The partitioning of Si, Mg, and Ca in major concentrations, and Al, Ti, Sc and Sm in minor concentrations among MgSiO3 perovskite, CaSiO3 perovskite, superphase B -Mg10Si3O14[OH,F]4, and melt containing H2O and fluorine, was determined experimentally at 23 GPa and temperatures of 1500–1600°C with a split-sphere anvil apparatus (USSA-2000). MgSiO3 perovskite is the main repository for Sc, while Ti and Sm are primarily concentrated in CaSiO3 perovskite. Superphase B excludes all cations other than Mg and Si, except at high volatile contents of the melt when Ti and Al become compatible. Volatile-bearing melt is conspicuous by its high Mg content and low content of all other cations. This observation raises the possibility that the Mg/Si ratio of the Earth's upper mantle, which is elevated relative to most classes of primitive meteorites, was established by upward segregation of Mg-rich volatile-bearing melts from the lower to upper mantle. The most plausible scenario involves degassing of the lower mantle by removal of 6% of the melt produced by a low degree of partial melting. The possibility that the elevated Mg/Si ratio of the upper mantle could have resulted from upward segregation of residual Mg-rich volatile-bearing melts from a terrestrial magma ocean has been evaluated and shown to be unlikely. If the Earth ever had a magma ocean, it seems more probable that the elevated Mg/Si ratio of the observable upper mantle is either characteristic of the entire silicate portion of the planet, or that the magma ocean was limited in depth to the upper mantle.
A Mission to test the Pioneer anomaly

Analysis of the radio tracking data from the Pioneer 10/11 spacecraft has consistently indicated the presence of an anomalous small Doppler frequency drift. The drift can be interpreted as being due to a constant acceleration of aP = (8.74 ± 1.33) × 10-8cm/s2 directed towards the Sun. Although it is suspected that there is a systematic origin to the effect, none has been found. The nature of this anomaly has become of growing interest in the fields of relativistic cosmology, astro- and gravitational physics as well as in the areas of spacecraft design and high-precision navigation. We present a concept for a designated deep-space mission to test the discovered anomaly. A number of critical requirements and design considerations for such a mission are outlined and addressed.
Endogenous metallothionein as determinant of intestinal cadmium absorption: A reevaluation

Isolated segments of rat jejunum were perfused in situ with glucosesaline containing varying amounts of CdC12. At low Cd concentrations the endogenous Cd-binding capacity sufficed to trap almost all Cd taken up in the mucosa. At higher Cd levels, induction of metallothionein synthesis by Zn increased fractional trapping of Cd. Pretreatment with Zn did not induce protein synthesis in any fraction other than the low molecular weight heatstable cytosol fraction. Acutely Zn did not affect Cd extrusion from the mucosa. Finally, Cd-metallothionein itself crosses the mucosa only very slowly. An earlier conclusion that metallothionein does not contribute to Cd trapping was based on low Cd concentrations in the perfusate; at higher concentrations metallothionein appears to be a major determinant of mucosal Cd retention.
Implementation challenges and successes of a population-based colorectal cancer screening program: a qualitative study of stakeholder perspectives

Few studies describe system-level challenges or facilitators to implementing population-based colorectal cancer (CRC) screening outreach programs. Our qualitative study explored viewpoints of multilevel stakeholders before, during, and after implementation of a centralized outreach program. Program implementation was part of a broader quality-improvement initiative. During 2008–2010, we conducted semi-structured, open-ended individual interviews and focus groups at Kaiser Permanente Northwest (KPNW), a not-for-profit group model health maintenance organization using the practical robust implementation and sustainability model to explore external and internal barriers to CRC screening. We interviewed 55 stakeholders: 8 health plan leaders, 20 primary care providers, 4 program managers, and 23 endoscopy specialists (15 gastroenterologists, 8 general surgeons), and analyzed interview transcripts to identify common as well as divergent opinions expressed by stakeholders. The majority of stakeholders at various levels consistently reported that an automated telephone-reminder system to contact patients and coordinate mailing fecal tests alleviated organizational constraints on staff’s time and resources. Changing to a single-sample fecal immunochemical test (FIT) lessened patient and provider concerns about feasibility and accuracy of fecal testing. The centralized telephonic outreach program did, however, result in some screening duplication and overuse. Higher rates of FIT completion and a higher proportion of positive results with FIT required more colonoscopies. Addressing barriers at multiple levels of a health system by changing the delivery system design to add a centralized outreach program, switching to a more accurate and easier-to-use fecal test, and providing educational and electronic support had both benefits and problematic consequences. Other health care organizations can use our results to understand the complexities of implementing centralized screening programs.
A finite element method for determining the angular variation of asymptotic crack tip fields

A finite element method for computing the angular variation of asymptotic singular solutions is presented. For the method to be applicable, the asymptotic fields must admit a separable form in polar coordinates. The radial dependence of the fields is assumed known. We provide details of the application of the method to the problem of a stationary semi-infinite crack in a Ramberg-Osgood material subjected to in-plane remote mixed mode elastic fields. This example demonstrates the primary strengths of the method: the material model is easily implemented and accurate solutions are obtained using coarse meshes.
Irradiation of dental enamel with Q-switched λ = 355-nm laser pulses: Surface morphology, fluoride adsorption, and adhesion to composite resin

Background and Objectives Lasers can be used to modify the chemical composition of dental enamel to increase the bond strength to restorative materials and to render the mineral phase more resistant to acid dissolution. Previous studies have suggested a synergistic relationship between CO2 laser irradiation and fluoride treatment on increased resistance to acid dissolution. In this study a near-UV laser operating with λ = 355-nm laser pulses of 3–5 nanoseconds duration was used to modify the surface morphology of dental enamel to increase the bond strength to restorative materials and increase the uptake of topical fluoride to render the surface more resistant to acid dissolution. We hypothesize that the short UV laser pulses are primarily absorbed by protein and lipid localized between the enamel prisms resulting in removal of intact mineral effectively etching the surface without thermal modification of the mineral phase. Such modification is likely to increase the permeability of the enamel surface and the subsequent absorption of fluoride. In addition, there is an increase in surface roughness without the formation of a layer of loosely adherent, thermally modified enamel that increases the bond strength to composite restorative materials. Study Design/Materials and Methods The surfaces of blocks of bovine enamel, 5 × 5 mm2, were uniformly irradiated by 355-nm laser pulses and subsequently bonded to composite. The shear bond test was used to assess the bond strength of non-irradiated blocks (negative control), acid etched blocks (positive control), and laser irradiated blocks. The resistance to acid dissolution was evaluated using controlled surface dissolution experiments on irradiated samples, irradiated samples exposed to topical fluoride, and non-irradiated control samples with and without fluoride. Results The laser surface treatments significantly increased the shear-bond strength of enamel to composite, to a level exceeding 20 MPa which was significantly more than the non-irradiated control samples and significantly less than the acid etch. Laser irradiation alone and topical fluoride application alone did not significantly increase the resistance to acid dissolution. The laser treatment followed by topical application of fluoride significantly increased the resistance to acid dissolution to a level of over 50% versus the control samples. Conclusions We present a novel method for increasing bond strength to restorative materials and enhancing fluoride delivery to enamel surfaces and shed some light on the underlying mechanisms of caries inhibition via laser treatment and topical application of fluoride. Lasers Surg. Med. 32:310–317, 2003. © 2003 Wiley-Liss, Inc.
Use of pattern recognition and Bayesian classification for earthquake intensity and damage estimation

Abstract Empirical methods, which correlate intensity with a damage index based on statistical observations of past events, have been conventionally used to forecast or estimate damage of structures that might result from future earthquakes. However, difficulties often arise in the quantitative precision of such estimates because intensity scales are usually not rigorously defined, particularly with respect to the damage distribution of modern structures. This paper presents a consistent method for earthquake intensity classification based on the theory of statistical pattern recognition. A discriminative function is developed for such identifications based on the Bayesian criterion. All statistical data required is obtained from past earthquake investigations. The method developed can be used to identify the intensity levels of an earthquake as well as to verify the intensity classification of the past earthquakes.