cssi/SciSciGPT-SciSciNet huggingface dataset:
Sub-critical two-phase seawater convection near a dike

Abstract We address the circulation of hydrothermal seawater near an igneous dike emplaced in the oceanic crust. By using the two-phase finite difference hydrothermal code GTHM, we are able to treat the sub-critical two-phase flow that occurs just after emplacement as well as the later single-phase circulation, which occurs as the dike cools. We investigate the effects of bulk rock permeability and dike width. The simulations show that for a 2 m wide dike emplaced in country rock with uniform permeability of 10−9 m2, two-phase flow may occur briefly adjacent to the dike margin in a region that is less than 0.1 m across. The width of the two-phase region and the duration of two-phase flow vary inversely with permeability, but they increase as the dike width increases. During two-phase flow, the advective heat flux at the seafloor fluctuates about its mean and the temperature near the seafloor remains nearly constant. The mean heat flux increases with permeability, but is independent of dike width. The model is used in conjunction with chlorinity data from ‘A’ vent near 9°N on the East Pacific Rise to indicate that the permeability there is ∼10−12 m2. The model suggests, however, that an additional heat source is required to account for the high-temperature vent fluids at 9°N that have persisted for more than 3 years. The calculations also show that heat transport near a high permeability dike (i.e., ≥10−9 m2) is consistent with the heat transport measured for the CoAxial event plumes. The calculations further suggest, however, that for a dike to generate an event plume, the zone of high permeability should be concentrated near the dike margin.
High molecular weight hyaluronan promotes repair of IL-1β-damaged cartilage explants from both young and old bovines

Abstract Objective: The addition of exogenous high molecular weight hyaluronic acid (HA) reverses cartilage damage caused by fibronectin fragments (Fn-fs) added to explant cultures of bovine and human cartilage and by Fn-fs in an experimental in vivo model of rabbit knee joint damage. Our objective was to test whether HA was also effective in an IL-1 damage model and whether this repair was stable and occurred in older bovine cartilage. Design: Bovine cartilage explants from 18-month-old or 6-year-old bovines in 10% serum/Dulbecco's modified Eagle's medium were exposed to Fn-f or to IL-1 and the ability of 1mg/ml HA of 800kDa to block damage or promote restoration of proteoglycan (PG) after the damage was measured. The damage phase as well as the exposure to HA were varied. Results: Exposure of exogenous HA decreased Fn-f-mediated damage, but did not decrease IL-1β-induced cartilage damage. If explants from 18-month-old bovines were damaged by a 7-day exposure to Fn-f or IL-1β and then exposed for 7 days to HA, PG was restored. This reparative activity persisted up to 4 weeks after the removal of HA from the culture medium. The restoration of PG did not occur in 0.1% serum-free cultures, was less when the exposure to the Fn-f was doubled and failed when exposure to IL-1β was doubled. In explants from 6-year-old bovines damaged with IL-1β for 7 days, HA fully restored PG content to normal levels. Conclusions: The reparative activities of HA occur not only in a Fn-f damage model, but also in an IL-1 damage model and occur with older bovine cartilage.
Evaluation of parasitic coupling among coupled microstrip line discontinuities using a multiport network modeling approach

This paper presents a convenient method for evaluating parasitic coupling caused by coupled microstrip line discontinuities. A Multiport Network Model and a Planar Lumped Model are used to evaluate voltage distributions around the discontinuity edges and along the coupled line section. This voltage distribution is expressed as an equivalent magnetic current distribution which is used to compute the terms of the mutual coupling matrix [Ym] representing the Mutual Coupling Network, MCN. The multiport network modeling approach for evaluation of parasitic coupling among single and coupled microstrip discontinuities is presented in this paper. Results of parasitic coupling caused by coupled microstrip line discontinuities are given in this paper.
Prevention of Drug Abuse: Theory and Application

Prevention efforts in alcohol and drug abuse have typically focused on the general population. However, most individuals who abuse addictive drugs either terminate consumption voluntarily or do not progress to a clinical diagnosis of psychoactive substance use disorder (PSUD). Because PSUD has such adverse effects on costs to society, prevention research and practice should emphasize the development and implementation of interventions for individuals who are at high risk for this disorder. This article purposes a conceptual framework for better understanding of the etiology of PSUD and for implementing prevention efforts that are targeted to specific vulnerabilities of an individual. These vulnerabilities are discussed with respect to their spatial organization (i.e., manifestations across multiple levels of biobehavioral organization) and temporal organization (i.e., manifestations across an individual's life span).
The inverse relationship between the activity of pyridoxal kinase and the level of biogenic amines in rabbit brain.

— In a series of experiments, an inverse relationship was found to exist between the activity of pyridoxal kinase and the concentrations of brain norepinephrine, dopamine, and serotonin. When the biogenic amine content of the brain is lowered, the activity of pyridoxal kinase rises. Conversely, when the concentration of brain biogenic amines is elevated, a depression occurs in the activity of pyridoxal phosphokinase. This relationship, which resembles an in vivo allosteric inhibition phenomenon, not only is highly suggestive of a definite relation between the brain vitamin B6 content and the metabolism of the biogenic amines, but also suggests that the concentration of brain biogenic amines might control the production of coenzyme pyridoxal phosphate.
Regulation of Alternative Splicing: More than Just the ABCs

Alternative pre-mRNA splicing, the differential inclusion or exclusion of portions of a nascent transcript into the final protein-coding mRNA, is widely recognized to be a ubiquitous mechanism for controlling protein expression. Thus, understanding the molecular basis of alternative splicing is essential for deciphering post-transcriptional control of the genome. Pre-mRNA splicing in general is catalyzed by a large dynamic macromolecular machine known as the spliceosome. Notably, the recognition of the intron substrate by spliceosomal components and the assembly of these components to form a catalytic spliceosome occur through a network of highly combinatorial molecular interactions. Many, if not all, of these interactions are subject to regulation, forming the basis of alternative splicing. This minireview focuses on recent advances in our understanding of the diversity of mechanisms by which the spliceosome can be regulated so as to achieve precise control of alternative splicing under a range of cellular conditions.
Interaction of Sororin protein with polo-like kinase 1 mediates resolution of chromosomal arm cohesion.

Unlike in budding yeast, sister chromatid cohesion in vertebrate cells is resolved in two steps: cohesin complexes are removed from sister chromatid arms during prophase via phosphorylation, whereas centromeric cohesins are removed at anaphase by Separase. Phosphorylation of cohesin subunit SA2 by polo-like kinase 1 (Plk1) is required for the removal of cohesins at prophase, but how Plk1 is recruited to phosphorylate SA2 during prophase is currently not known. Here we report that Sororin, a cohesin-interacting protein essential for sister chromatid cohesion, plays a novel role in the resolution of sister chromatid arms by direct interaction with Plk1. We identified an evolutionarily conserved motif (ST159P) on Sororin, which was phosphorylated by Cdk1/cyclin B and bound to the polo box domain of Plk1. Mutating Thr159 into alanine prevented the interaction of Plk1 and Sororin and inhibited the resolution of chromosomal arm cohesion. We propose that Sororin is phosphorylated by Cdk1/cyclin B at prophase and acts as a docking protein to bring Plk1 into proximity with SA2, resulting in the phosphorylation of SA2 and the removal of cohesin complexes from chromosomal arms.
Effect of alcohol on cellular membranes

Ethanol disrupts the physical structure of cell membranes. The most fluid membranes, including those that are low in cholesterol, are the most easily disordered by ethanol. Although the membrane-disordering effect is small, there is pharmacological, temporal, and genetic evidence that it is important. Animals that are resistant to ethanol intoxication because of their genetic background or because of previous exposure to ethanol are found to have brain membranes that are not easily disordered in vitro. An exception is the increased behavioral sensitivity in aging animals, which is not matched by changes in their membranes. When animals are treated chronically with ethanol, their membranes become stiffer, a response that can be regarded as adaptive. Ethanol may favor the uptake of cholesterol or saturated fatty acids into membranes, thus reducing its own effect.
Sensor Augmented Virtual Reality Based Teleoperation Using Mixed Autonomy

A multimodal teleoperation interface is introduced, featuring an integrated virtual reality (VR) based simulation augmented by sensors and image processing capabilities onboard the remotely operated vehicle. The proposed virtual reality interface fuses an existing VR model with live video feed and prediction states, thereby creating a multimodal control interface. VR addresses the typical limitations of video based teleoperation caused by signal lag and limited field of view, allowing the operator to navigate in a continuous fashion. The vehicle incorporates an onboard computer and a stereo vision system to facilitate obstacle detection. A vehicle adaptation system with a priori risk maps and a real-state tracking system enable temporary autonomous operation of the vehicle for local navigation around obstacles and automatic reestablishment of the vehicle's teleoperated state. The system provides real time update of the virtual environment based on anomalies encountered by the vehicle. The VR based multimodal teleoperation interface is expected to be more adaptable and intuitive when compared with other interfaces.
A pilot study of pentoxifylline for the treatment of primary sclerosing cholangitis.

OBJECTIVE: There is no effective therapy for patients with primary sclerosing cholangitis (PSC). Rats with experimental small bowel bacterial overgrowth develop hepatobiliary injury similar to PSC. The hepatobiliary injury results from peptidoglycan-polysaccharide–mediated activation of Kupffer cells, release of cytokines such as tumor necrosis factor (TNF-α), and is prevented by pentoxifylline. Our aims were to assess the safety and effects of pentoxifylline on symptoms and biochemical liver tests in patients with PSC. METHODS: A total of 20 patients with clinical, cholangiographic, and histological features of PSC of varying severity were treated with pentoxifylline sustained release (SR) tablets (400 mg q.i.d.) for ≤1 yr. Serum alkaline phosphatase, aspartate aminotransferase, and bilirubin were monitored every 3 months for 1 year; serum TNF-α and TNF receptor subtypes I and II were assessed at baseline and 1 year. RESULTS: Of 20 patients, 16 tolerated pentoxifylline and completed the study. Two patients were withdrawn because of severe nausea, and two patients were noncompliant with medication and withdrew. Pentoxifylline did not significantly alter symptoms of fatigue or pruritus, serum liver tests, serum TNF-α or TNF receptor levels. CONCLUSIONS: In the current regimen, pentoxifylline alone does not significantly improve symptoms or liver tests in patients with PSC.
Practice and transfer of the frequency structures of continuous isometric force

Abstract The present study examined the learning, retention and transfer of task outcome and the frequency-dependent properties of isometric force output dynamics. During practice participants produced isometric force to a moderately irregular target pattern either under a constant or variable presentation. Immediate and delayed retention tests examined the persistence of practice-induced changes of force output dynamics and transfer tests investigated performance to novel (low and high) irregular target patterns. The results showed that both constant and variable practice conditions exhibited similar reductions in task error but that the frequency-dependent properties were differentially modified across the entire bandwidth (0–12 Hz) of force output dynamics as a function of practice. Task outcome exhibited persistent properties on the delayed retention test whereas the retention of faster time scales processes (i.e., 4–12 Hz) of force output was mediated as a function of frequency structure. The structure of the force frequency components during early practice and following a rest interval was characterized by an enhanced emphasis on the slow time scales related to perceptual–motor feedback. The findings support the proposition that there are different time scales of learning at the levels of task outcome and the adaptive frequency bandwidths of force output dynamics.
Long-term survival after the Bentall procedure in 206 patients with bicuspid aortic valve.

Background The recognition that patients with a bicuspid aortic valve (BAV) are at risk for aorta-related death (rupture or dissection) has favored composite aortic root replacement in BAV patients who undergo aortic valve replacement for valve dysfunction as well as in asymptomatic BAV patients with significant aortic root dilatation. We report the results of Bentall operations in 206 BAV patients during an 18-year interval. Methods Two hundred six BAV patients (mean, 53 ± 14 years, 84% male) underwent composite aortic root replacement between September 1987 and May 2005. One hundred nine patients (53%) presented with aortic regurgitation, 24 patients (12%) presented with aortic stenosis, and 55 patients (26%) presented with combined aortic stenosis and aortic regurgitation. Median preoperative aortic diameter was 5.5 cm (range, 3 to 9 cm). Twenty-two patients (11%) underwent urgent or emergent procedures; 11 had acute type A dissection (5%). Sixty-one percent had a mechanical valve Bentall prosthesis; in 39%, a biologic valve was implanted. Thirty-two percent had concomitant procedures. Results Overall hospital mortality was 2.9% (n = 6), and stroke rate was 1.9% (n = 4). Risk factors for adverse outcome (death or stroke), which occurred in 4.8% (n = 10), were presence of clot or atheroma ( p = 0.02) and age older than 65 years ( p = 0.05). During a mean follow-up of 5.9 years (1,200 patient-years; range, 5 to 18 patient-years), no patient required ascending aortic reoperation. Long-term survival was 93% after 5 years and 89% after 10 years. Discharged patients enjoyed survival equivalent to a normal age- and sex-matched population and superior to survival reported for a series of patients with aortic valve replacement alone. Conclusions In patients with BAV, the Bentall procedure has an operative mortality no worse than that for aortic valve replacement, with superior long-term survival and a lower rate of aortic reoperation.
Identification of "surgical" coronary anatomy by exercise radionuclide cineangiography.

Abstract Radionuclide cineangiography with exercise has been used to identify patients with coronary arteriographic patterns for which bypass grafting has been shown to prolong life. However, patients with severe prior myocardial damage were included in these studies, although the randomized medicine versus surgery trials recognized an effect of resting ejection fraction on operative risk and excluded patients with severely compromised function. Moreover, continuing reports from trials of surgery and from an ancillary evaluation of angioplasty have refined the set of coronary anatomic patterns for which mechanical therapy prolongs life, although stenosis severity criteria varied (50 vs 70 to 75%) between these trials. In this study, we have focused on patients who would have been eligible for the randomized trials of surgical therapy, and included only those with at least moderately preserved ventricular function at rest (ejection fraction ≥30%). In such patients, exercise parameters were significantly more accurate than rest variables in identifying all anatomic patterns appropriately treated mechanically; logistic regression selected ejection fraction change with exercise, followed by systolic blood pressure change with exercise, as the 2 most powerful independent covariates among patients with “surgical” coronary anatomy defined by a 70% stenosis criterion; absolute exercise ejection fraction contributed no significant independent information. When defined at a 50% stenosis severity level, blood pressure change and angina class were more powerful than absolute exercise ejection fraction, but a crude, noninvasively determined analog of stroke work, incorporating change in both ejection fraction and blood pressure, was most accurate. Coronary anatomic patterns appropriately managed mechanically are identifiable by results of radionuclide cineangiography with exercise most efficiently by use of change in ejection fraction and blood pressure induced by exercise.
Separated Flow Transition in a Low Pressure Turbine Cascade: Mean Flow and Turbulence Spectra

Boundary layer separation, transition and reattachment have been studied experimentally in a low-pressure turbine cascade. Cases with Reynolds numbers (Re) ranging from 50,000 to 200,000 (based on suction surface length and exit velocity) have been considered under low free-stream turbulence conditions. Mean and fluctuating velocity profiles and turbulence spectra are presented for streamwise locations along the suction side of one airfoil and in the wake downstream of the airfoils. Hot film gages on the suction side surface of the airfoil are used to measure the fluctuation level and the spectra of the fluctuations on the surface. Higher Re moves transition upstream. Transition is initiated in the shear layer over the separation bubble and leads to boundary layer reattachment. Peak frequencies in the boundary layer spectra match those found in similar cases in the literature, indicating that the important frequencies may be predictable. Spectra in the wake downstream of the airfoils were similar to the spectra in the boundary layer near the trailing edge of the airfoil. Comparisons to the literature indicate that small but measurable differences in the spectra of the low free-stream turbulence can have a significant effect on boundary layer reattachment.Copyright © 2003 by ASME
Interactions Between La Crosse Virus and Bacteria Isolated From the Digestive Tract of Aedes albopictus (Diptera: Culicidae)

Aedes albopictus (Skuse) is a potential vector for many arboviruses, including La Crosse virus (LACV), the leading cause of pediatric encephalitis in North America. Bacteria isolated from the midgut and diverticula of field-caught female Ae. albopictus were cultured and identified using 16S ribosomal RNA gene amplification and sequencing. Members of seven and six bacterial families were identified from the midguts and diverticula, respectively, with nearly half of the isolates identified to the family Enterobacteriaceae. Many are related to bacteria identified in other invertebrates, and several may represent previously unknown species or genera. Of the 24 isolated bacteria, 12 (50%) showed a significant reduction in infectivity of LACV for Vero cells. Inhibition of infectivity ranged from 0 to 44% and was not dependent on bacterial classification. The antiviral activity of these bacteria warrants further investigation as an alternate means to interrupt the LACV transmission cycle.
Multiple Principals, Multiple Signals: A Signaling Approach to Principal‐Agent Relations

This study suggests a key element of the principal-agent relationship involves communication between potential principals and their agents. We suggest communications often resemble a signaling process in which potential principals indicate their interest in policy matters through multiple venues. This study models changes in the levels of rulemaking activity by the Bureau of Indian Affairs and the Federal Energy Regulatory Commission as a function of increased salience in public, congressional and executive venues.
Pharmaceutical Sales Representatives and Patient Safety

To the Editor: In the first study to use identical data collection methods over the same period in three different jurisdictions, Mintzes et al. found that 98 % of the time, pharmaceutical reps failed to provide minimally adequate safety information about drugs to physicians.1 Worse, serious harms were rarely mentioned for drugs identified as harmful, and companies kept promoting them. This represents systematic untruthful abuse of First Amendment commercial free speech. Patients are harmed. Because numerous studies show that companies bias clinical trials, then further bias published articles about trial results, and bias a third time the marketing material used by drug reps, in order to understate risks of harm, while overstating benefits, prescription drugs have become a major cause of hospitalization, falls, accidents, and death in the United States.2,3 The Food and Drug Administration (FDA) does little to correct this misinformation and allocates only a small fraction of its budget to prevent physicians from receiving inaccurate information about clinical risks of harm. Yet, about 90 % of new pharmaceutical products approved by the FDA each year are judged by independent experts to be little or no better than existing ones.4 Thus, the mission and legal power of prescribing physicians to improve the health of patients is seriously distorted or corrupted, as evidenced by the authors finding that most physicians rate this harm-inducing commercial information as “good or excellent.” When will this risk-proliferating syndrome stop, as it has in the few health care systems where drug reps and free samples are prohibited and replaced by commercial-free information?5 Patients and physicians want superior new drugs whose risks of harm are fully considered, not minor variations with few advantages to offset their hidden risks of harm.
Adaptive Filtering Of Target Features In A Time-Sequence Of Forward-Looking Infrared (FLIR) Images

This paper addresses the problem of estimating the profile of a ship target from a sequence of forward-looking infrared (FLIR) imagery obtained at video rates. Signal processing takes place in two stages: first, a profile vector is extracted from each image frame by edge-detection processing; second, the resulting sequence of profile vectors is adaptively filtered in order to increase the signal-to-noise ratio. Several factors peculiar to FLIR data preclude the use of an otherwise straightforward temporal averaging approach. First, target resolution increases slowly over a sequence of image frames, gradually revealing details of the target profile. Second, over the course of a long sequence of frames a target may be affected by FLIR noise - random speckle, occlusions, and flaring - caused by various atmospheric and background phenomena. These factors must be met by a reliable, adaptive, nonlinear vector smoothing technique. In this paper we discuss techniques for simulating long sequences of realistic ship profiles, based on actual FLIR ship imagery. Profile extraction by hypothesis testing is also discussed. A number of adaptive and nonadaptive vector filtering techniques are considered. These are based on recursive filters, median filters, LMS filters, the shift-and-add method, segmenting algorithms, and combinations of these. We suggest operating constraints under which these algorithms are likely to be successful.
Tenascin in the developing chick visual system : distribution and potential role as a modulator of retinal axon growth

Abstract The distribution of the extracellular matrix protein tenascin was studied in the developing chick visual system to determine its possible regulatory role in retinotectal development. Little tenascin was present in the retinal optic fiber layer, and the optic nerve and tract, but was abundant in the stratum opticum of the tectum, the target of retinal axons in the brain. A high concentration of tenascin was found in areas bordering the developing visual pathway, such as the optic disc, the outer surface of the optic nerve, and the supraoptic commissure. In vitro studies showed that tenascin did not promote neurite outgrowth of retinal axons. When optic axons were confronted with a tenascin substrate in culture, they did not grow onto the tenascin suggesting that this protein inhibited optic oxon outgrowth. Furthermore, the addition of tenascin to retinal explants in collagen gels slowed the growth rate of optic axons by as much as 50%. The distribution of tenascin in vivo and its inhibitory function in several in vitro systems suggest that this protein acts as a modulator of axonal growth in vivo. Tenascin may act as a barrier at specific sites along the visual pathway, and at the target, may slow the rate of oxon outgrowth, and ultimately act as a stop molecule. The growth inhibitory activity of tenascin in retinal and tectal synaptic layers may also serve to stabilize synapses once appropriate connections have been made.
Analysis of the circadian rhythm of body temperature

Currently available methods for the analysis of circadian rhythms provide little help in the evaluation of the circadian rhythm of body temperature because they either assume that the circadian rhythm of body temperature approximates a cosine wave (which for many species is not true) or simply do not address important parameters, such as the amplitude and the shape of the temperature rhythm. The present paper presents methods for the computation and statistical evaluation of the period, amplitude, mean level, and general shape of the circadian rhythm of body temperature. The period is analyzed by the periodogram procedure, whereas the other parameters are analyzed by the histogram method. Both procedures are simple to implement and relatively insensitive to spurious data points. A simplified but fully operational program in BASIC is provided.
A New Strategy for Effecting Change in Schools

(1975). A New Strategy for Effecting Change in Schools? The Review of Education: Vol. 1, No. 2, pp. 182-194.
Amorphous carbon as a diffusion barrier to copper

Amorphous carbon was evaluated as a diffusion barrier between Cu and Si. Samples were annealed at 500 oC for 1 hour in vacuum. Barrier properties were characterized for metallurgical failure with RBS and XTEM, and electrical properties were characterized with pn junction diodes and MOS capacitors. RBS and X-TEM showed that a barrier 13.5 nm thick prevented Cu and Si diffusion during the anneal. The diodes remained rectifying after annealing, although the series resistance went up. C-V measurements of the capacitors did not show the hysteresis that is typical of mobile charge in the oxide. The barrier breakdown mechanism is diffusion through the amorphous structure.
The effect of organic carbon on the sequential reductive dehalogenation of tetrachloroethylene in landfill leachates

Abstract The effect of organic carbon content on the sequential reductive dehalogenation of tetrachloroethylene (PCE) in landfill leachates was studied using anaerobic microcosms. Microcosms were constructed using leachates from adjacent landfill cells which differed in age and organic carbon content. The landfill which was sampled had no history of contamination with chloroaliphatic (CAH) compounds. Dehalogenation was measured in both unamended leachate and in leachate supplemented with a mixture of organic carbon compounds. Results showed that significant degradation of PCE occurred within 14 days in all cases, and that most or all of the PCE was dehalogenated to TCE, cis -1,2-DCE, and/or vinyl chloride by the 30th day. The extent of dehalogenation was correlated with the availability or quality of organic carbon in the leachates, as measured by BOD analysis. Supplementation with exogenous carbon promoted degradation in the low carbon leachate from the older landfill cell, but not the higher carbon leachate from the younger cell. Conversely, accumulation of cis -1,2-DCE occurred in the unsupplemented and supplemented leachate from the younger cell, but not in supplemented leachate from the older cell. In general, our findings show that landfill communities may be well adapted for the degradation of CAH contaminants, even without prior contamination by these compounds, and that the amount of organic carbon able to serve as an electron donor may be the most important factor influencing rates of CAH removal via dehalogenation. Moreover, supplementation with exogenous sources of organic carbon appears to be a viable method for enhancing rates of CAH degradation in carbon-limited landfills.
Finite amplitude longitudinal waves in lattices

Abstract The system analyzed in this paper consists of a semi-infinite chain of mass points with linear and nonlinear nearest neighbor interaction. There is no dissipation in the system. A finite velocity step is applied at the first mass point at zero time to generate a shock-like disturbance in the system. Explicit solution of the linear case is extended to the nonlinear case by a time-averaging procedure. The approximate solution thus obtained compares favorably with numerical solutions and provides enhanced understanding of the physics of the system.
The School Readiness of Children Born to Low‐Income, Adolescent Latinas in Miami

Although studies show teenage parenting and low socioeconomic status predict poor child academic performance, limited research has examined relations between teen parenting and children’s school readiness within low-income Latina mothers. In the context of the Miami School Readiness Project, low-income preschoolers (N = 3,023) attending subsidized child-care programs were assessed on cognitive, language, and fine motor skills, and parents and teachers reported on children’s social skills and behavior concerns. Maternal teenage status at time of birth, maternal education, child attachment, child immigrant generational status, language, and other demographic variables were explored, as they uniquely and interactively predicted children’s school readiness. Teenage parenting among low-income Latinas in this sample was less frequent (15%) than national estimates and more common among mothers born in the United States. Teen parenting was negatively associated with child cognitive and language competence at age 4, controlling for background variables. Maternal receipt of a high school diploma contributed additively, rather than interactively, to child outcomes. Parent-reported strong child attachment served as a buffer against the negative effects of teen parent status on child outcomes. Implications for intervention are discussed.
A Conductivity Liquid Level Detector for the Nuclear Reactor Environment

An electrical conductivity-sensitive liquid level transducer (LLT) has been developed for and used in the pressurized water reactor (PWR) environment. Local conductivity at each of a vertical stack of electrodes is sampled in continual sequence and the presence or absence of water during each sample interval at each electrode is determined. The LLT was developed for use in test facilities which replicate the PWR environment. Qualification of the LLT for use in commercial nuclear generating stations is not and never was an objective. However, accumulated operating experience with the LLT plus recent improvements in data reduction and in materials processing indicate that an LLT could probably be fabricated and qualified for use in commercial reactors. The transducer and its operating history and performance are described and the data reduction technique and recent improvements explained.
Revisiting Economies of Size in American Education: Are We Any Closer to a Consensus?.

Abstract Consolidation remains a common policy recommendation of state governments looking to improve efficiency, especially in rural school districts. However, state policies encouraging consolidation have increasingly been challenged as fostering learning environments that hurt student performance. Does the empirical research on economies of size support for this policy? The objective of this paper is to define the factors affecting economies of size and update the literature since 1980. The best of the cost function studies suggest that sizeable potential cost savings in instructional and administrative costs may exist by moving from a very small district (500 or fewer pupils) to a district with ca 2000–4000 pupils. The findings from production function studies of schools are less consistent, but there is some evidence that moderately sized elementary schools (300–500 students) and high schools (600–900 students) may optimally balance economies of size with the potential negative effects of large schools. Since program evaluation research on school consolidation is limited, it is time for researchers on both sides of this debate to make good evaluation research on consolidation a high priority. In addition, the potential diseconomies of size in large central city school districts needs increased attention in academic research.
The enskog modulus for p-hydrogen in the gaseous and liquid states

The recent PVT measurements of p-hydrogen reported by the National Bureau of Standards(1,2,3) have been utilized to establish the Enskog modulus, bpx, for pressures up to 350 atm and temperatures up to 100°K. These conditions define both the gaseous and liquid regions and also include the saturation envelope from the triple point to the critical point of this substance. This modulus is expressed graphically as a function of reduced pressure and reduced temperature. The best available PVT measurements coupled with a precise calculational procedure conducted on an IBM 709 computer have produced a bpx correlation which readily permits the calculation of the pressure dependence of the transport properties of p-hydrogen according to the Enskog theory for the dense gaseous and liquid regions. Les valeurs de pression-volume-temperature du p-hydrogene recemment obtenues par le National Bureau of Standards(1,2,3) ont ete utilisees pour le calcul du module de Enskog, bpx, pour des pressions allant jusqu'a 350 atmospheres et des temperatures jusqu'a 100°K. Ces conditions correspondent aux etats liquide et gazeaux et incluent la courbe d'equilibre liquide-gaz entre le point triple et le point critique de cette substance. Ce module est represente graphiquement en fonction des conditions reduites de pression-volume-temperature disponibles utilisees avec un procede precis de calculs realises sur un ordinateur IBM 709 ont conduit a une correlation de bpx permettant l'evaluation des proprietes de transport du para-hydrogene en fonction de la pression selon la theorie d'Enskog.
Protective effects of inhaled aminophylline on methacholine-induced airway responses in greyhound dogs

Abstract Aminopylline can be delivered as a heated aerosol via an air-powered small-volume nebulizer. We tested the hypothesis that inhaled aminophylline could attenuate the effects of inhaled methacholine on the airways. Five greyhound dogs were anesthetized, intubated, and ventilated. An esophageal balloon and flow transducer were placed in the ventilator circuit and connected to a BICORE CP-100 respiratory monitor. We measured mean lung resistance, lung dynamic compliance, and work of breathing. Each dog was pretreated for 30 minutes with three different formulations given randomly on separate days: aerosolized saline and intravenous saline, aerosolized aminophylline and intravenous saline, and aerosolized saline and intravenous aminophylline. The dogs were then exposed to a series of five inhalations of methacholine of increasing concentrations given at 15-minute intervals. The results demonstrated a significant reduction in the work of breathing and lung resistance and significantly increased compliance after treatment with aerosolized aminophylline but not with intravenous aminophylline. These findings support our hypothesis that aerosolized aminophylline has a protective effect against methacholine-induced bronchospasm. The results further suggest the possible use of aerosolized aminophylline for the treatment of obstructive lung disease.
About the cover: Laplace and his American translator

Pierre Simon, Marquis de Laplace (1749–1827), has often been referred to as the “French Newton”. Much of his scientific work was in extending the work of Newton on the movement of the planets. He was, along with Lagrange, one of the two most able mathematicians in France in the 18th century, though identifying him as a mathematician may be misleading, since he did a combination of what we would today call mathematics, physics, and astronomy. Nevertheless, as R. Hahn, Laplace’s biographer, points out, “Laplace’s fundamental message . . . was the same: Newton’s principle of gravitation was the basic true law of nature that fully governed the solar system” [2, p. 144]. He came from a family of modest means, farmers in the Calvados district (Normandy). Not surprisingly the family produced cider. He most certainly was not a marquis from birth. The title came much later after he had been made a count in 1806 by Napoleon I during the First Empire and later a marquis in 1821 by Louis XVIII during the Bourbon Restoration. (Lagrange, his long-time rival, was made a count by Napoleon in 1808 but did not make it to the next step—he died before the Bourbons came back into power.) Early in life he had been interested in some number theory problems and differential equations, but in the period between 1796 and 1812 he published four major books: his Exposition du systeme du monde (1796—l’an IV), the Theorie de mecanique celeste (the first two volumes in 1798 or 1799—l’an VII, the third in 1802, and the fourth in 1805; a fifth volume, mainly devoted to commentary, came out considerably later, in 1825). Two books were on probability: the Theorie analytique des probabilites and the Essai philosophique sur les probabilites. The Exposition du systeme du monde is sometimes described as the Mecanique Celeste without the mathematics. It was much easier to read. Of the two books on probability, the Theorie analytique is the more important. The work in these is relevant to Laplace’s Mecanique Celeste, which was, without doubt, his masterpiece.
Promotion of reaction of NH boths with triarylbismuth and cupric acetate

Abstract Arylation of a diverse group of NH containing compounds at room temperature with triarylbismuth and cupric acetate in the presence of a tertiary amine promoter, such as triethylamine or pyridine, is described. This mild and highly efficient procedure, which is based on Barton's earlier work on the arylation of amines, can be applied to amides, imides, ureas, carbamates, and sulfonamides.
Comparisons of Five Performance Validity Indices in Bona Fide and Simulated Traumatic Brain Injury

A number of performance validity tests (PVTs) are used to assess memory complaints associated with traumatic brain injury (TBI); however, few studies examine the concordance and predictive accuracy of multiple PVTs, specifically in the context of combined models in known-group designs. The present study compared five widely used PVTs: the Test of Memory Malingering (TOMM), Medical Symptom Validity Test (MSVT), Reliable Digit Span (RDS), Word Choice Test (WCT), and California Verbal Learning Test - Forced Choice (CVLT-FC). Participants were 51 adults with bona fide moderate to severe TBI and 58 demographically comparable healthy adults coached to simulate memory impairment. Classification accuracy of individual PVTs was evaluated using logistic regression and receiver operating characteristic (ROC) curves, examining both the dichotomous cutting scores as recommended by the test publishers and continuous scores for the measures. Results demonstrated nearly equivalent discrimination ability of the TOMM, MSVT, and CVLT-FC as individual predictors, all of which markedly outperformed the WCT and RDS. Models of combined PVTs were examined using Bayesian information criterion statistics, with results demonstrating that diagnostic accuracy showed only small to modest growth when the number of tests was increased beyond two. Considering the clinical and pragmatic issues in deriving a parsimonious assessment battery, these findings suggest that using the TOMM and CVLT in conjunction or the MSVT and CVLT in conjunction maximized predictive accuracy as compared to a single index or an assortment of these widely used measures.
A review of atomic force microscopy imaging systems: application to molecular metrology and biological sciences

The atomic force microscope (AFM) system has evolved into a useful tool for direct measurements of micro-structural parameters and unraveling the intermolecular forces at nanoscale level with atomic-resolution characterization. Typically, these micro-cantilever systems are operated in three open-loop modes; non-contact mode, contact mode, and tapping mode. In order to probe electric, magnetic, and/or atomic forces of a selected sample, the non-contact mode is utilized by moving the cantilever slightly away from the sample surface and oscillating the cantilever at or near its natural resonance frequency. Alternatively, the contact mode acquires sample attributes by monitoring interaction forces while the cantilever tip remains in contact with the target sample. The tapping mode of operation combines qualities of both the contact and non-contact modes by gleaning sample data and oscillating the cantilever tip at or near its natural resonance frequency while allowing the cantilever tip to impact the target sample for a minimal amount of time. Recent research on AFM systems has focused on many manufacturing and metrology processes at molecular levels due to its tremendous surface microscopic capabilities. This paper provides a review of such recent developments in AFM imaging system with emphasis on operational modes, micro-cantilever dynamic modeling and control. Due to the important contributions of AFM systems to metrology and biological sciences, this study also provides a comprehensive review of recent applications of different AFM systems in these two important areas.
Family Rejection as a Predictor of Negative Health Outcomes in White and Latino Lesbian, Gay, and Bisexual Young Adults

OBJECTIVE. We examined specific family rejecting reactions to sexual orientation and gender expression during adolescence as predictors of current health problems in a sample of lesbian, gay, and bisexual young adults. METHODS. On the basis of previously collected in-depth interviews, we developed quantitative scales to assess retrospectively in young adults the frequency of parental and caregiver reactions to a lesbian, gay, or bisexual sexual orientation during adolescence. Our survey instrument also included measures of 9 negative health indicators, including mental health, substance abuse, and sexual risk. The survey was administered to a sample of 224 white and Latino self-identified lesbian, gay, and bisexual young adults, aged 21 to 25, recruited through diverse venues and organizations. Participants completed self-report questionnaires by using either computer-assisted or pencil-and-paper surveys. RESULTS. Higher rates of family rejection were significantly associated with poorer health outcomes. On the basis of odds ratios, lesbian, gay, and bisexual young adults who reported higher levels of family rejection during adolescence were 8.4 times more likely to report having attempted suicide, 5.9 times more likely to report high levels of depression, 3.4 times more likely to use illegal drugs, and 3.4 times more likely to report having engaged in unprotected sexual intercourse compared with peers from families that reported no or low levels of family rejection. Latino men reported the highest number of negative family reactions to their sexual orientation in adolescence. CONCLUSIONS. This study establishes a clear link between specific parental and caregiver rejecting behaviors and negative health problems in young lesbian, gay, and bisexual adults. Providers who serve this population should assess and help educate families about the impact of rejecting behaviors. Counseling families, providing anticipatory guidance, and referring families for counseling and support can help make a critical difference in helping decrease risk and increasing well-being for lesbian, gay, and bisexual youth.
Evaluation of genetic risk score models in the presence of interaction and linkage disequilibrium

In the area of genetic epidemiology, genetic risk predictive modeling is becoming an important area of translational success. As an increasing number of genetic variants are successfully discovered, the use of multiple genetic variants in constructing a genetic risk score (GRS) for modeling has been widely applied using a variety of approaches. Previously, we compared the performance of a simple, additive GRS with weighted GRS approaches, but our initial simulation experiment assumed very simple models without many of the complications found in real genetic studies. In particular, interactions between variants and linkage disequilibrium (LD) (indirect mapping) remain important and challenging problems for GRS modeling. In the present study, we applied two simulation strategies to mimic various types of epistasis to evaluate their impact on the performance of the GRS models. We simulated a range of models demonstrating statistical interaction and linkage disequilibrium. Three genetic risk models were compared in terms of power, type I error, C-statistic and AIC, including a simple count GRS (SC-GRS), an odds ratio weighted GRS (OR-GRS) and an explained variance weighted GRS (EV-GRS). Simulation factors of interest included allele frequencies, effect sizes, strengths of interaction, degrees of LD and heritability. We extensively examined the extent to how these interactions could influence the performance of genetic risk models. Our results show that the weighted methods outperform simple count method in general even if interaction or LD is present, with well controlled type I error.
Mechanical limits to microbial activity in deep sediments

The observed decline in microbial abundance with increasing depth has been associated to various environmental factors. Meanwhile, the role of geometrical constraints and soil-bacteria mechanical interactions remains poorly analyzed. Pore and pore-throat sizes may restrict habitable pore space and traversable interconnected porosity, and sediment-cell interaction may cause puncture or tensile failure of the cell membrane. In this study we compile published evidence on the presence of bacteria in deep sediments as well as pore and pore-throat size data in sediments at different depths to establish possible geometrical conditions for the sediment-cell complex. Compiled data are complemented with experimental results gathered through controlled axial compression experiments that reproduce the mechanical consolidation of deep sediment sequences. Then, we analyze the mechanical interaction between bacteria and sediments that may cause cell death. Finally, we combine data and model predictions to define the main regions in a particle-size versus depth space that characterize the fate of bacteria: “active and motile,” “trapped inside pores,” and “dead or dormant.” These regions constrain hypotheses related to the role of biological activity in deep sediments, research protocols and sampling methods, the viability of bioremediation strategies for contaminated sites, and the potential development of bioengineered sediments.