cssi/SciSciGPT-SciSciNet huggingface dataset:
Interweaving knowledge extracting, organizing and evaluating: a concrete design for preventing logic and structure bugs while interviewing experts

The process of constructing expert systems (ESs), programs that approximate how domain experts solve problems in their specialized fields, is not at all as systematic, efficient, and verifiable as it should be. A reason is that no rigorous error-prevention interviewing method exists for structuring and testing ESs while building them. Often domain experts do implicitly ask of themselves analytical questions such as ‘Is that claim of mine always true?’ Another kind of expert — one specializing in logic analysis — explicitates, collects, and systematizes the fund of generic questions, such as ‘Are these sub-goals sufficient steps to the pre-established goal-category?’ There is a great need to make a method of interviewing, interlaced with testing and organizing, available to all domain experts and ES programmers via an interactive program. This program, which can generically be called a LAP (Logic Aids Program), plays the role of a domain-independent logic-assistant.
The concurrent use of three implicit measures (eye movements, pupillometry, and event-related potentials) to assess receptive vocabulary knowledge in normal adults

Recent years have seen the advent and proliferation of the use of implicit techniques to study learning and cognition. One such application is the use of event-related potentials (ERPs) to assess receptive vocabulary knowledge. Other implicit assessment techniques that may be well-suited to other testing situations or to use with varied participant groups have not been used as widely to study receptive vocabulary knowledge. We sought to develop additional implicit techniques to study receptive vocabulary knowledge that could augment the knowledge gained from the use of the ERP technique. Specifically, we used a simple forced-choice paradigm to assess receptive vocabulary knowledge in normal adult participants using eye movement monitoring (EM) and pupillometry. In the same group of participants, we also used an N400 semantic incongruity ERP paradigm to assess their knowledge of two groups of words: those expected to be known to the participants (high-frequency, familiar words) and those expected to be unknown (low-frequency, unfamiliar words). All three measures showed reliable differences between the known and unknown words. EM and pupillometry thus may provide insight into receptive vocabulary knowledge similar to that from ERPs. The development of additional implicit assessment techniques may increase the feasibility of receptive vocabulary testing across a wider range of participant groups and testing situations, and may make the conduct of such testing more accessible to a wider range of researchers, clinicians, and educators.
Effects of number of pellets per food delivery and pellet sucrose composition on schedule-induced drinking

Four groups of four rats were tested on a fixed-time (FT 60-sec) schedule in which one, three, or five pellets per food delivery and 0%, 8%, 16%, and 32% sucrose pellets were factorially combined. The results showed no statistically significant differences in water intake associated with sucrose content of the pellets, but did show a significant inverse relationship between water intake and number of pellets given per reinforcement. This latter finding was interpreted as a result of the direct relationship in the rat between total number of reinforcement opportunities and probability of drinking. This relationship was suggested to be an important dependent variable in studies that measure and attempt to account for collateral fluid ingestion.
Irreversible k-threshold processes: Graph-theoretical threshold models of the spread of disease and of opinion

We will consider models of the spread of disease or opinion through social networks, represented as graphs. In our models, vertices will be in one of two states, 1 (''infected'') or 0 (''uninfected'') and change of state will take place at discrete times. After describing several such models, we will concentrate on the model, called an irreversible k-threshold process, where a vertex enters state 1 if at least k of its neighbors are in state 1, and where a vertex never leaves state 1 once it is in it. We will seek sets of vertices with the property that, if they are in state 1 at the beginning, then eventually all vertices end up in state 1. Such vertex sets correspond to vertices that can be infected with a disease or opinion so as to guarantee saturation of the population with the disease or opinion. We will also discuss ways to ''defend'' against such saturating sets, for example by ''vaccination'' or designing network topologies.
Non-kin adoption and sociobiology

Abstract Adoption initially seems an anomaly for sociobiology. While adoption of kin is satisfactorily explained by an extension of kin selection, adoption of non-kin is more difficult. The explanation traditionally given for non-kin adoption, evolutionary lag, is quite weak. In this paper we propose an alternative sociobiological explanation of non-kin adoption by an extension of reciprocal alturism. Although an unrelated adoptee cannot increase an adoptive parent's reproductive success, it can increase the parent's inclusive fitness by helping the adoptive parent and that parent's relatives. Three patterns of benefits resulting from adoption are cited in support of this explanation.
Circadian Regulation of a Viral Gene Promoter in Live Transgenic Mice Expressing Firefly Luciferase

This study was conducted to test for possible circadian control of viral infection in live animals using bioluminescence imaging of a firefly luciferase transgene. Transgenic mice expressing the firefly luciferase gene under the control of the promoter and enhancer of the human cytomegalovirus major immediate-early gene (CMV::luc) were examined through whole-animal imaging. Mice were crossed with HRS/J hairless albino mice to improve imaging of deep structures. Transgene expression in the extremities and head was elevated around dusk in mice maintained in cycles of light and dark. Signal was also elevated during the animal's night in mice maintained in extended darkness. The viral promoter was induced during the active phase of the circadian locomotor rhythm in several tissues. Both the acinar cells and islets expressed the transgene in dissociated pancreas cultures. These results suggest that viruses may exploit the circadian system for optimal timing of infection at particular phases in several tissue types.
Development of an IR projector using a deformable mirror device

A current effort at the U.S. Army Missile Command (MICOM) is the development of an infrared (IR) scene projector based on spatial light modulator (SLM) technology. The three phase effort is centered around the Texas Instrument deformable mirror device (DMD) , which is a two—dimensional array of mirrors with independently controlled deflect ions.
Dendritic atrophy and remodeling of amygdaloid neurons in Alzheimer's disease

The current study examined changes in the dendritic arbor of basolateral amygdaloid neurons in Alzheimer's disease (AD). Quantitative analysis of Golgi Kopsch-impregnated tissue samples revealed a significant reduction in the total dendritic length per neuron in AD. Terminal and nonterminal dendritic segments were affected similarly. Somatofugal ordering of the same segments, however, indicated that the reductions were restricted to the inner portion of the dendritic tree, coupled with significant AD-related increases in the length and number of the highest order segments. These data suggest that despite an overall AD-related loss of dendritic length in this amygdaloid subregion, new dendritic segments continue to form. The loss of proximal segments, combined with the gain of distal segments, may be interpreted as dendritic remodeling in the course of the disorder.
Nine Children Over the Age of One Year with Full Trisomy 13: A Case Series Describing Medical Conditions †

Trisomy 13 (Patau syndrome), identified by Patau and colleagues [1960; Lancet 1: 790–793] is the third most common autosomal condition. Population studies indicate less than one in 10 children reaches their first birthday. In the face of mixed findings and recommendations for treatment, additional research is needed to further determine what contributes to longevity and implications for treatment for presenting medical conditions. The purpose of the present study is to report on presenting medical conditions and the presence or absence of the specific conditions (age at survey completion). Data on nine survivors (seven female, two male) with trisomy 13 indicated mean gestational age of approximately 36 weeks, birth weight ranging from 1100 to 3290 g and mean length of 45.3 cm. Length of hospital stay after birth varied. The majority of infants presented with well-known physical characteristics. Medical conditions and their treatment varied at birth and at survey completion. Notably, several infants' cardiac anomalies resolved without surgical intervention. Surgeries were provided for a range of conditions including gastrostomy tube placement to address feeding issues and removal of intestinal blockage. There were no reports of holoprosencephaly. Implications and recommendations are provided. © 2014 Wiley Periodicals, Inc.
Heat transfer characteristics for tubular arrays in a high-temperature fluidized bed: An experimental study of bed temperature effects

Abstract Experimental results are reported for the heat transfer between a high-temperature fluidized bed and an immersed horizontal tube array. Of specific interest in this study was the effect of bed temperature. Three bed operating temperatures were used: 705, 761, 812. At each temperature, measurements were taken to evaluate both local and average values of the total heat transfer coefficient and the radiation contribution. Mean bed particle sizes examined were 0.97, 1.53, and 2.37 mm. Superficial velocities were varied such that the heat transfer results apply over the range from packed bed conditions through minimum fluidization to well over twice the minimum fluidization velocity. A comparison is made between the heat transfer behavior of a tube with near neighbors, that is, in a bundle, and that for a single tube at the same operating conditions. This comparison illustrates the competing nature of both gas convection and radiation with neighboring tubes present.
Surveillance Colonoscopy in Ulcerative Colitis: A Surgical Perspective

The " surgical " perspective of surveillance in ulcerative colitis can vary depending on whether the surgeon is the primary individual responsible for performing surveillance colonoscopy, or only consulted when dysplasia is identified, or consulted when there is uncertainty regarding the most appropriate clinical care for a given patient. In the former case, issues such as chemoprophylactic medication, timing and frequency of surveillance, choosing the type of colonoscopic imaging, and choosing the pathologist and number of biopsies are important. In the latter situation, it is important to determine the expertise of the referring endoscopist and reviewing pathologist before proceeding. Never decide on surgery without a rereview of the pathology by a specialist gastrointestinal pathologist with experience in inflammatory bowel disease. Also, in choosing the best operation, ensure the adequate biopsies have been performed. For example, before deciding to perform a stapled ileal pouch-anal anastomosis, ensure the rectum has been adequately sampled to exclude the presence of dysplasia before proceeding. Decisions regarding management and surveillance of dysplasia should be weighed with patient age and other risk factors.
Use of digitonin fractionation to determine mitochondrial transmembrane ion distribution in cells during anoxia

A method to determine intracellular distribution of ions and metabolites under conditions of low oxygen concentration was developed. The technique involves rapid digitonin fractionation and addition of cyanide to inhibit reoxygenation. Applicability of the procedure was examined by studying the distribution of the lipophilic ion triphenylmethylphosphonium, the weak acid 5,5-dimethyloxazolidine-2,4-dione, and adenine nucleotides.
A Quantitative Analysis of Semiconductor Device Failure Rates as Graphically Indicated in Military Handbook 217

A graphical presentation of semiconductor device failure rates is made in Figs. 13B and 14B of Mil-Hdbk-217 (see Figs. 1 and 2). From this presentation, Equations may be derived which indicate interesting properties, to failure physicists, device engineers, and equipment designers. On the basis of the equations it may be concluded that: (1) extrapolating room temperature failure rates from failure rates of devices stored at elevated temperatures is not likely to be meaningful; (2) there is a definite relationship between storage failure rate and failure rate in actual use (in the temperature range of interest); (3) the storage failure rate is large enough at normal storage temperatures so that, if semiconductor device failure rates influence the reliability of equipment in which they are used, they will contribute significantly to the finite storage life of the equipment (another way of expressing the last statement is that a manufacturer with a large storage inventory of semiconductors will find a significant decrease in the percentage of usable devices with time);(4) there are some instances (as delineated earlier by equations), when increasing the number of semiconductor devices and dividing the load proportionately improves reliability, and there are other cases when it does not. While the analysis makes no claim as to the validity or accuracy of Figs. 1 and 2, the mathematics permits statements about conditions necessary to confirm the data.
Prospects for a contamination-free ultravacuum facility in low-earth orbit

The old concept of using the wake of a spacecraft to obtain an ultrahigh vacuum is revisited. A wakeshield can be configured so that a surface of interest does not subtend any walls that could become contaminated, thus it should be possible to achieve a contamination‐free, ultrahigh vacuum capability with infinite pumping speed even in the presence of high heat loads and moderate gas loads. This paper analyzes the conceptual design for a Space Ultravacuum Research Facility (SURF), both in a shuttle‐attached mode and as a free flyer. It is shown that even in the shuttle‐attached mode, it should be possible to obtain vacuum levels equivalent to 10−9 to 10−10 Torr with O and N2 as the primary constituents. As a free flyer the SURF will be limited primarily by the gas load from the process being performed. For chemical beam epitaxy it is shown that equivalent vacuum levels of 10−14 Torr should be possible at 300 km.
In utero nicotine exposure promotes M2 activation in neonatal mouse alveolar macrophages.

Background Maternal smoking in utero has been associated with adverse health outcomes including lower respiratory tract infections in infants and children, but the mechanisms underlying these associations continue to be investigated. We hypothesized that nicotine plays a significant role in mediating the effects of maternal tobacco smoke on the function of the neonatal alveolar macrophage (AM), the resident immune cell in the neonatal lung. Methods Primary AMs were isolated at postnatal day 7 from a murine model of in utero nicotine exposure. The murine AM cell line MH-S was used for additional in vitro studies. Results In utero nicotine increased interleukin-13 and transforming growth factor-β1 (TGFβ1) in the neonatal lung. Nicotine-exposed AMs demonstrated increased TGFβ1 and increased markers of alternative activation with diminished phagocytic function. However, AMs from mice deficient in the α7 nicotinic acetylcholine receptor (α7 nAChR) had less TGFβ1, reduced alternative activation, and improved phagocytic functioning despite similar in utero nicotine exposure. Conclusion In utero nicotine exposure, mediated in part via the α7 nAChR, may increase the risk of lower respiratory tract infections in neonates by changing the resting state of AM toward alternative activation. These findings have important implications for immune responses in the nicotine-exposed neonatal lung.
Groundtruth approach to accurate quantitation of fluorescence microarrays

To more accurately measure fluorescent signals from microarrays, we calibrated our acquisition and analysis systems by using groundtruth samples comprised of known quantities of red and green gene-specific DNA probes hybridized to cDNA targets. We imaged the slides with a full-field, white light CCD imager and analyzed them with our custom analysis software. Here we compare, for multiple genes, results obtained with and without preprocessing (alignment, color crosstalk compensation, dark field subtraction, and integration time). We also evaluate the accuracy of various image processing and analysis techniques (background subtraction, segmentation, quantitation and normalization). This methodology calibrates and validates our system for accurate quantitative measurement of microarrays. Specifically, we show that preprocessing the images produces results substantially closer to the known groundtruth for these samples.
Diffuse-charge dynamics of ionic liquids in electrochemical systems

We employ a continuum theory of solvent-free ionic liquids accounting for both short-range electrostatic correlations and steric effects (finite ion size) [Bazant et al., Phys. Rev. Lett. 106, 046102 (2011)] to study the response of a model microelectrochemical cell to a step voltage. The model problem consists of a 1-1 symmetric ionic liquid between two parallel blocking electrodes, neglecting any transverse transport phenomena. Matched asymptotic expansions in the limit of thin double layers are applied to analyze the resulting one-dimensional equations and study the overall charge-time relation in the weakly nonlinear regime. One important conclusion is that our simple scaling analysis suggests that the length scale √(λ*(D)l*(c)) accurately characterizes the double-layer structure of ionic liquids with strong electrostatic correlations where l*(c) is the electrostatic correlation length (in contrast, the Debye screening length λ*(D) is the primary double-layer length for electrolytes) and the response time of λ(D)(*3/2)L*/(D*l(c)(1/2)) (not λ*(D)L*/D* that is the primary charging time of electrolytes) is the correct charging time scale of ionic liquids with strong electrostatic correlations where D* is the diffusivity and L* is the separation length of the cell. With these two new scales, data of both electric potential versus distance from the electrode and the total diffuse charge versus time collapse onto each individual master curve in the presence of strong electrostatic correlations. In addition, the dependance of the total diffuse charge on steric effects, short-range correlations, and driving voltages is thoroughly examined. The results from the asymptotic analysis are compared favorably with those from full numerical simulations. Finally, the absorption of excess salt by the double layer creates a depletion region outside the double layer. Such salt depletion may bring a correction to the leading order terms and break down the weakly nonlinear analysis. A criterion which justifies the weakly nonlinear analysis is verified with numerical simulations.
A statistical algorithm for assessing cellular alignment.

Current statistical techniques for analyzing cellular alignment data in the fields of biomaterials and tissue engineering are limited because of heuristic and less quantitative approaches. For example, generally a cutoff degree limit (commonly 20 degrees) is arbitrarily defined within which cells are considered “aligned.” The effectiveness of a patterned biomaterial in guiding the alignment of cells, such as neurons, is often critical to predict relationships between the biomaterial design and biological outcomes, both in vitro and in vivo. This becomes particularly important in the case of peripheral neurons, which require precise axon guidance to obtain successful regenerative outcomes. To address this issue, we have developed a protocol for processing cellular alignment data sets, which implicitly determines an “angle of alignment.” This was accomplished as follows: cells “aligning” with an underlying, anisotropic scaffold display uniformly distributed angles up to a cutoff point determined by how effective the biomaterial is in aligning cells. Therefore, this fact was then used to determine where an alignment angle data set diverges from a uniform distribution. This was accomplished by measuring the spacing between the collected, increasingly ordered angles and analyzing their underlying distributions using a normalized cumulative periodogram criterion. The proposed protocol offers a novel way to implicitly define cellular alignment, with respect to various anisotropic biomaterials. This method may also offer an alternative to assess cellular alignment, which could offer improved predictive measures related to biological outcomes. Furthermore, the approach described can be used for a broad range of cell types grown on 2D surfaces, but would not be applicable to 3D scaffold systems in the present format. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 101A: 884–891, 2013.
Attempted suicide, LGBT identity, and heightened scrutiny.

Brown, Elliott, and Paine (2013) have provided a detailed analysis of some ethical considerations surrounding the withdrawal of lifesaving treatment for patients who have attempted suicide. They ob...
Systemic lupus erythematosus serum deposits C4d on red blood cells, decreases red blood cell membrane deformability, and promotes nitric oxide production

Objective Systemic lupus erythematosus (SLE) is characterized by intravascular activation of the complement system and deposition of complement fragments (C3 and C4) on plasma membranes of circulating cells, including red blood cells (RBCs). The aim of this study was to address whether this process affects the biophysical properties of RBCs. Methods Serum and RBCs were isolated from patients with SLE and healthy controls. RBCs from healthy universal donors (type O, Rh negative) were incubated with SLE or control serum. We used flow cytometry to assess complement fragment deposition on RBCs. RBC membrane deformability was measured using 2-dimensional microchannel arrays. Protein phosphorylation levels were quantified by Western blotting. Results Incubation of healthy universal donor RBCs with sera from patients with SLE, but not with control sera, led to deposition of C4d fragments on the RBCs. Complement-decorated RBCs exhibited significant decreases in both membrane deformability and flickering. Sera from SLE patients triggered a transitory Ca++ influx in RBCs that was associated with decreased phosphorylation of β-spectrin and with increased phosphorylation of band 3, two key proteins of RBC cytoskeleton. Finally, incubation with SLE sera led to the production of nitric oxide by RBCs, whereas this did not occur with control sera. Conclusion Our data suggest that complement activation in patients with SLE leads to calcium-dependent cytosketeletal changes in RBCs that render them less deformable, probably impairing their flow through capillaries. This phenomenon may negatively affect the delivery of oxygen to the tissues.
Childhood Risk Factors and Adolescent Drug and Alcohol Abuse

Childhood risk factors for adolescent drug and alcohol abuse are reviewed. Childhood personality manifesting the “difficult child” syndrome and psychopathological features of hyperactivity and antisocial traits are predictive of later substance abuse, especially when these traits persist into adolescence. Key interpersonal risk factors include family mismanagement, parental substance use, low academic performance and commitment, and association with substance-using peers. A schema outlines postulated predictive paths of substance use that are comprised of various risk factors. The source of origin, time of emergence, and quantity of risk factors are proposed to account for differing levels of substance involvement.
Orai1 Mutations Alter Ion Permeation and Ca2+-dependent Fast Inactivation of CRAC Channels: Evidence for Coupling of Permeation and Gating

Ca2+ entry through store-operated Ca2+ release-activated Ca2+ (CRAC) channels is an essential trigger for lymphocyte activation and proliferation. The recent identification of Orai1 as a key CRAC channel pore subunit paves the way for understanding the molecular basis of Ca2+ selectivity, ion permeation, and regulation of CRAC channels. Previous Orai1 mutagenesis studies have indicated that a set of conserved acidic amino acids in trans membrane domains I and III and in the I–II loop (E106, E190, D110, D112, D114) are essential for the CRAC channel's high Ca2+ selectivity. To further dissect the contribution of Orai1 domains important for ion permeation and channel gating, we examined the role of these conserved acidic residues on pore geometry, properties of Ca2+ block, and channel regulation by Ca2+. We find that alteration of the acidic residues lowers Ca2+ selectivity and results in striking increases in Cs+ permeation. This is likely the result of enlargement of the unusually narrow pore of the CRAC channel, thus relieving steric hindrance for Cs+ permeation. Ca2+ binding to the selectivity filter appears to be primarily affected by changes in the apparent on-rate, consistent with a rate-limiting barrier for Ca2+ binding. Unexpectedly, the mutations diminish Ca2+-mediated fast inactivation, a key mode of CRAC channel regulation. The decrease in fast inactivation in the mutant channels correlates with the decrease in Ca2+ selectivity, increase in Cs+ permeability, and enlargement of the pore. We propose that the structural elements involved in ion permeation overlap with those involved in the gating of CRAC channels.
Second-Order Linear Differential Equations with Two Turning Points

Differential equations of the form d 2 w / d x 2 = { u 2 f ( u , a , x ) + g ( u , a , x ) } w are considered for large values of the real parameter u . Here x is a real variable ranging over an open, possibly infinite, interval ( x 1 , x 2 ), and a is a bounded real parameter. It is assumed that f {u, a, x) and g{u,a, x) are free from singularity within ( x 1 , x 2 ), and f (u, a, x) has exactly two zeros, which depend continuously on a and coincide for a certain value of a . Except in the neighbourhoods of the zeros, g(u,a,x) is small in absolute value compared with u 2 f(u, a, x ). By application of the Liouville transformation, the differential equation is converted into one of four standard forms, with continuous coefficients. Asymptotic approximations for the solutions are then constructed in terms of parabolic cylinder functions. These approximations are valid for large u , uniformly with respect to x e ( x 1 , x 2 ) and also uniformly with respect to a . Each approximation is accompanied by a strict and realistic error bound. The paper also includes some new properties of parabolic cylinder functions.
Self-accelerating Massive Gravity: Time for Field Fluctuations

The ghost-free theory of massive gravity has exact solutions where the effective stress energy generated by the graviton mass term is a cosmological constant for any isotropic metric. Since they are exact, these solutions mimic a cosmological constant in the presence of any matter-induced isotropic metric perturbation. In the St\"uckelberg formulation, this stress energy is carried entirely by the spatial St\"uckelberg field. We show that any stress energy carried by fluctuations in the spatial field away from the exact solution always decays away in an expanding universe. However, the dynamics of the spatial St\"uckelberg field perturbation depend on the background temporal St\"uckelberg field, which is equivalent to the unitary gauge time coordinate. This dependence resolves an apparent conflict in the existing literature by showing that there is a special unitary time choice for which the field dynamics and energy density perturbations vanish identically. In general, the isotropic system has a single dynamical degree of freedom requiring two sets of initial data; however, only one of these initial data choices will affect the observable metric. Finally, we construct cosmological solutions with a well-defined perturbative initial value formulation and comment on alternate solutions that evolve to singularities.
Applicability of the Goodness-of-Fit Hypothesis to Coping with Daily Hassles:

This study examined the applicability of Lazarus and Folkman's (1984) goodness-of-fit hypothesis to the relationship between college students' daily hassles and psychological symptomology. Specifically, the model predicts that, given a daily hassle which one may change, it is more functional to alter the source of the daily hassle than it is to let the stressor go unchecked and simply try to manage the negative emotions produced by the event. Conversely, given a stressor one cannot alter, it is more functional to regulate the emotions produced by the event than to engage in repeated futile attempts to change an uncontrollable stressor. It was predicted that subjects who tended to violate these principles across multiple daily hassles would be characterized by the highest psychological symptomology. Although the 69 college students' frequency of daily hassles was positively associated with psychological symptomatology and students tended to match the method of coping with the appraised controllability of their daily hassles, no support for the goodness-of-fit hypothesis was found.
The reaction of trichlorosilane with enamines

Abstract A previously unknown reaction of trichlorosilane with enamines has been discovered and a preliminary study done on the possible mechanism. The products of the reaction are a regiospecific trichlorosilyl adduct resulting from addition of the trichlorosilane to the enamine unsaturation and the amine corresponding to simple reduction of the double bond. The addition of the trichlorosilane requires no catalyst and the relative percentages of the products varies in a generally inverse fashion depending on the exact structure of the enamine. Evidence is given to support the assigned structure of the trichlorosilyl species and mechanisms are hypothesized to explain the formation of both products from a common intermediate. Steric rather than electronic factors are suggested as responsible for the observed balance between them.
Neural activity and the dynamics of central nervous system development

Recent imaging studies show that the formation of neural connections in the central nervous system is a highly dynamic process. The iterative formation and elimination of synapses and neuronal branches result in the formation of a much larger number of trial connections than is maintained in the mature brain. Neural activity modulates development through biasing this process of formation and elimination, promoting the formation and stabilization of appropriate synaptic connections on the basis of functional activity patterns.
Characterization of mutants of Ceratopteris richardii selected on aluminum (Al2(SO4)3-Na2EDTA)

Abstract Mutant strains of the fern Ceratopteris richardii Brongn. were selected in vitro for tolerance to culture medium containing Al2(SO4)3-Na2EDTA at pH 4.4. Three strains, HαAT3, HαAT7, and HαAT29 showed enhanced growth relative to the wild type on selection medium. Because of the complex nature of the selection conditions, the mutants were tested for tolerance to low pH and other individual components of the selection medium. All three mutant strains were notably more tolerant to acidic conditions and slightly more tolerant to Na2EDTA, relative to the wild type. No consistent differences in response to Na2SO4 were evident. Genetic characterization indicated a single nuclear gene basis of inheritance for strain HαAT3. Strains HαAT7 and HαAT29 showed a nuclear basis of tolerance, but responses of gametophytes from F1 hybrids suggested segregation at two or more loci.
Shear and extensional rheology of entangled polymer melts: Similarities and differences

This work extends our previous understanding concerning the nonlinear responses of entangled polymer solutions and melts to large external deformation in both simple shear and uniaxial extension. Many similarities have recently been identified for both step strain and startup continuous deformation, including elastic yielding, i.e., chain disentanglement after cessation of shear or extension, and emergence of a yield point during startup deformation that involves a deformation rate in excess of the dominant molecular relaxation rate. At a sufficiently high constant Hencky rate, uniaxial extension of an entangled melt is known to produce window-glass-like rupture. The present study provides evidence against the speculation that chain entanglements tie up into “dead knots” in constant-rate extension because of the exponentially growing chain stretching with time. In particular, it is shown that even Instron-style tensile stretching, i.e., extending a specimen by applying a constant velocity on both ends, results in rupture. Yet, in the same rate range, the same entangled melt only yields in simple shear, and the resulting shear banding is clearly not a characteristic of rupture. Thus, we conclude that chain entanglements respond to simple shear in the manner of yielding whereas uniaxial extension is rather effective in causing some entanglements to lock up, making it impossible for the entanglement network to yield at high rates.
Surface and volume dielectric losses

A RELIABLE and convenient system has been devised for measuring large numbers of specimens to detect changes in dielectric constant and dissipation factor due to exposure to controlled conditions of temperature and humidity. A group of four plastic materials consisting of a molded mica-filled phenolic (MFE), a glass silicone laminate (GSG), polytetrafluoroethylene (PF) and polyethylene (PE), were selected for study over the frequency range from 60 cycles per second (cps) to 100 megacycles per second (mc). Measurements of alternating current surface and volume conduction losses, and d-c surface and volume conductivity were made, along with measurements of dielectric strength and flashover strength.1 The effect of humidity and temperature on these electrical quantities was a major objective in an extensive program. Earlier work at The Johns Hopkins University had greatly stimulated the present interest in the measurement of surface conductivity.2,3 Although the earlier efforts were made with direct current only, it was generally considered that the work could be extended to the a-c case through the use of a high-voltage Schering bridge. This has been accomplished, data having been obtained at 60 and 1,000 cps. Such measurements are possible with a high-voltage Schering bridge up to 100,000 cps. Using other types of networks, the surface measurements were also taken at 2, 18, and 100 mc. The volume determinations of dielectric constant and dissipation factor were made at the same frequencies. Perhaps the most stringent requirement met in these tasks was that all specimens had to be mounted in holders and measured on location without being disturbed during their 6-month exposures to various conditions of temperature and humidity.
Head injury as a risk factor for brain tumors in children : Results from a multicenter case-control study

Many cardiovascular drugs have been implicated as causes of depression. With the exception of beta-blockers, few have been studied in formal epidemiologic designs. I present a new approach to such analyses that effectively controls for confounders that are stable over time. I analyzed the exposure histories of 11,244 incident antidepressant users, using the Odense University PharmacoEpidemiologic Database. All persons starting both beta-blockers and antidepressants during a predefined period were identified. If beta-blockers do not cause depression, this particular population should show equal numbers of persons starting either drug first. A depression-provoking effect of beta-blockers would generate an excess of persons starting beta-blockers first, that is a nonsymmetrical distribution of prescription orders. Confounders causing the two drugs to be co-prescribed would rarely be expected to affect the symmetry. The initial screening showed nonsymmetrical prescription orders for a wide range of cardiovascular drugs. After adjustment for an increasing incidence of antidepressant prescribing, I found a depression-provoking effect only for angiotensin-converting enzyme (ACE) inhibitors (rate ratio = 1.29; 95% confidence interval = 1.08-1.56) and calcium channel blockers (rate ratio = 1.31; 95% confidence interval = 1.14-1.51). This prescription sequence symmetry analysis may be useful as a screening tool.
Desmoid tumors and current status of management

Desmoid tumors, also known as aggressive fibromatosis, are rare fibroblastic tumors that exhibit a wide range of local aggressiveness, from largely indolent to locally destructive. Understanding of the pathogenesis and the great heterogeneity in the natural history of desmoid tumors is invaluable to the development of therapeutic strategies. The optimal treatment protocol has not yet been established and, in many cases, a multidisciplinary approach including surgery, chemotherapy, and radiation therapy has been employed. The rarity of cases in even major tumor centers has traditionally limited the ability to study this disease. Several novel pharmacologic and biologic treatment approaches are actively being developed, although long-term follow-up is needed for their substantiation.
Second-site mutation at M43 (Asn→Asp) compensates for the loss of two acidic residues in the QB site of the reaction center

Two acidic residues, L212Glu and L213Asp, in the QB binding sites of the photosynthetic reaction centers of Rhodobacter capsulatus and Rhodobacter sphaeroides are thought to play central roles in the transfer of protons to the quinone anion(s) generated by photoinduced electron transfer. We constructed the site-specific double mutant L212Ala-L213Ala in R. capsulatus, that is incapable of growth under photosynthetic conditions. A photocompetent derivative of that strain has been isolated that carries the original L212Ala-L213Ala double mutation and a second-site suppressor mutation at residue M43 (Asn→Asp), outside of the QB binding site, that is solely responsible for restoring the photosynthetic phenotype. The Asp,Asn combination of residues at the L213 and M43 positions is conserved in the five species of photosynthetic bacteria whose reaction center sequences are known. In R. capsulatus and R. sphaeroides, the pair is L213Asp-M43Asn. But, the reaction centers of Rhodopseudomonas viridis, Rhodospirillum rubrum and Chloroflexus aurantiacus reverse the combination to L213Asn-M43Asp. In this respect, the QB site of the suppressor strain resembles that of the latter three species in that it couples an uncharged residue at L213 with an acidic residue at M43. These reaction centers, in which L213 is an amide, must employ an alternative proton transfer pathway. The observation that the M43Asn→Asp mutation in R. capsulatus compensates for the loss of both acidic residues at L212 and L213 suggests that M43Asp is involved in a new proton transfer route in this species that resembles the one normally used in reaction centers of Rps. virddis, Rsp. rubrum and C. aurantiacus.
Effect of Λ hyperons on the nuclear equation of state in a Dirac-Brueckner-Hartree-Fock model

We predict the energy per baryon in nuclear matter with non-zero fractions of \ensuremath{\Lambda} hyperons. We include Dirac effects on the nucleon as well as the \ensuremath{\Lambda} and describe how the latter are implemented. We use the nucleon-hyperon meson-exchange potentials from the J\"ulich group, the latest as well as an earlier version. The dependence of the results on the many-body framework and on the nucleon-hyperon interaction model is discussed.
Efficient encoding for exact symbolic automata-based scheduling

This paper presents an efficient encoding and automaton construction which improves performance of automata-based scheduling techniques. The encoding preserves knowledge of what operations occurred previously but excludes when they occurred, allowing greater sharing among scheduling traces. The technique inherits all of the features of BDD-based control dominated scheduling including systematic speculation. Without conventional pruning, all schedules for several large samples are quickly constructed.
Wall shear stress measurements using a new transducer

A new instrument has been developed for direct measurement of wall shear stress. This instrument is simple and symmetric in design with small moving mass and no internal friction. Features employed in the design of this instrument eliminate most of the difficulties associated with the traditional floating element balances. Vibration problems associated with the floating element skin friction balances have been found to be minimized by the design features and optional damping provided. The unique design of this instrument eliminates or reduces the errors associated with conventional floating-element devices: such as errors due to gaps, pressure gradient, acceleration, heat transfer and temperature change. The instrument is equipped with various sensing systems and the output signal is a linear function of the wall shear stress. Measurement made in three different tunnels show good agreement with theory and data obtained by the floating element devices.
Parametric alignment of Drosophila genomes.

The classic algorithms of Needleman–Wunsch and Smith–Waterman find a maximum a posteriori probability alignment for a pair hidden Markov model (PHMM). To process large genomes that have undergone complex genome rearrangements, almost all existing whole genome alignment methods apply fast heuristics to divide genomes into small pieces that are suitable for Needleman–Wunsch alignment. In these alignment methods, it is standard practice to fix the parameters and to produce a single alignment for subsequent analysis by biologists. As the number of alignment programs applied on a whole genome scale continues to increase, so does the disagreement in their results. The alignments produced by different programs vary greatly, especially in non-coding regions of eukaryotic genomes where the biologically correct alignment is hard to find. Parametric alignment is one possible remedy. This methodology resolves the issue of robustness to changes in parameters by finding all optimal alignments for all possible parameters in a PHMM. Our main result is the construction of a whole genome parametric alignment of Drosophila melanogaster and Drosophila pseudoobscura. This alignment draws on existing heuristics for dividing whole genomes into small pieces for alignment, and it relies on advances we have made in computing convex polytopes that allow us to parametrically align non-coding regions using biologically realistic models. We demonstrate the utility of our parametric alignment for biological inference by showing that cis-regulatory elements are more conserved between Drosophila melanogaster and Drosophila pseudoobscura than previously thought. We also show how whole genome parametric alignment can be used to quantitatively assess the dependence of branch length estimates on alignment parameters.
Visual spatial interactions between dotted line segments

Abstract This study examines the interactions that occur between dotted line segments as a function of their separation and orientation using a dotted target detection paradigm. The results of the experiment indicate that it is the separation between interacting pairs of lines rather than shifts in retinal locus that account for the observed decline in detectability as the separation increases. However, factors of global organization or figural goodness seem also to exert a powerful influence on the detectability of the pattern. The results are interpreted in terms of a central, rather than a peripheral, model.
A surface hopping quasiclassical trajectory study of the H2+ + H2 and (H2 + D2)+ systems

Abstract In this work we use a complete surface hopping quasiclassical trajectory method to determine cross sections for the reactions H2+ + H2 → H3+ + H and the isotopic variants (H2+ + D2 and D2+ + H2). Initial translational energies ranged between 0.5 and 6 eV. The vibrational quantum number (v+) of the charged diatom is either 0 or 3. Comparing these results with our previous results with a partial treatment of surface hopping, we find essentially no change for v+ = 0 and reductions in cross sections of up to 30% for v+ = 3 trajectories.
The clinical spectrum between posterior polymorphous dystrophy and iridocorneal endothelial syndromes

Abstract Background There are many conditions affecting the corneal endothelium with similar clinical appearances, though with different prognoses, management approaches, and pathophysiologic development. Case A 39-year-old black woman with a previous diagnosis of asymmetric corneal posterior polymorphous dystrophy (PPMD) presented complaining of irritation in the left eye, worsening over the last week. On examination, her left eye had profuse edema and bullous keratopathy overlying a large placoid gray lesion at the level of the endothelium. Gonioscopy of the left eye found evidence of a membranous development extending from the endothelium to the trabecular meshwork. Examination of her right eye found a perfectly clear cornea and a normal angle. The patient subsequently had Chandler's syndrome diagnosed in the left eye, an iridocorneal endothelial (ICE) syndrome, rather than PPMD. Discussion PPMD and ICE syndromes present with many similarities; these clinical entities are in fact thought to be variants of the same disease. Unlike PPMD, Chandler's syndrome is unilateral, acquired, and typically symptomatic and progressive. It also characteristically affects middle-age women. Conclusion Understanding the clinical features of PPMD and ICE syndromes is important in proper diagnosis and management.
In-vitro synergy and mechanism of interaction between vancomycin and ciprofloxacin against enterococcal isolates

In-vitro synergy between vancomycin and ciprofloxacin against 44 enterococcal isolates was studied. Synergy occurred in chequerboard MIC determinations with six Enterococcus faecium strains resistant to both vancomycin and ciprofloxacin. The combination was additive for strains susceptible to one or both antibiotics. Time-kill studies involving selected strains with different susceptibility patterns confirmed the chequerboard results. The effect of ciprofloxacin on the induction of vancomycin resistance was compared in two vancomycin-resistant strains of E. faecium. Sub-inhibitory concentrations of ciprofloxacin prevented induction of vancomycin resistance in a ciprofloxacin-resistant strain, but not in a ciprofloxacin-susceptible strain. Membranes isolated from vancomycin-resistant ciprofloxacin-resistant cultures grown with vancomycin and ciprofloxacin at < or = 8 mg/L (0.125 x MIC) expressed a 39.5-kDa membrane protein involved in the expression of vancomycin resistance, but the protein was not detected in membranes from cultures grown in ciprofloxacin 16 mg/L. These findings indicated that a vancomycin-ciprofloxacin combination can be synergic against enterococci resistant to both vancomycin and ciprofloxacin, but would be unlikely to offer any advantage in the treatment of enterococcal infections because of the high concentrations required.