cssi/SciSciGPT-SciSciNet huggingface dataset:
Stabilization and reversals of ionization

Atomic stabilization, the suppression of ionization accompanied by electron localization for increasing laser intensities, was one of the recent predictions for atoms exposed to very intense laser pulses. We discuss a fine structure on such an overall trend of stabilization. We describe how the ionization suppression may be reversed as the intensity is increased slightly. This kind of reversal of the ionization trend takes place repeatedly. We study such reversal of ionization as a function of both laser intensity or frequency. We attribute is origin to the interference of the ionizing wave initiated from various parts of the laser dressed atom.
Long-term fracture risk among children with asthma: a population-based study.

Fracture risk among patients diagnosed with asthma in childhood is greater in males and oral corticosteroid users, but most fractures are of the appendicular skeleton and may relate to impaired skeletal development. Introduction: There are no population-based data on fracture outcomes among the growing number of patients with asthma diagnosed in childhood. Materials and Methods: We conducted a population-based retrospective (historical) cohort study among 279 Rochester, Minnesota, residents who were <35 years of age (mean, 6.2 years) when first diagnosed with asthma. Fractures were ascertained by review of comprehensive community medical records, and cases were compared directly with age- and sex-matched controls in a stratified proportional hazards model. Risk factors for fractures among the asthma cases were assessed using Andersen-Gill time-to-fracture regression models. Results: During 6649 person-years of follow-up (median, 24.3 years/subject), 107 asthma patients experienced 189 fractures, for a crude fracture incidence rate of 2.8 per 100 person-years. The actuarially estimated cumulative fracture incidence after 20 years was 40% compared with 34% among controls (p = 0.122). There was no significant increase in overall fracture risk among cases compared to their age- and sex-matched controls (hazard ratio [HR], 1.3; 95% CI, 0.9-1.9), but males with asthma had a 2.6-fold greater risk of hand and finger fractures than control males. The independent predictors of overall fracture risk among the asthma patients included male gender (HR, 2.2; 95% CI, 1.5-3.2) and use of oral corticosteroids (HR, 2.0; 95% CI, 1.2-3.1) or anti-cholinergic agents (HR, 3.9; 95% CI, 1.5-10). Conclusions: Rather than osteoporotic fractures of the axial skeleton, oral corticosteroid therapy was associated here with limb fractures, suggesting a relationship with impaired development of a biomechanically competent skeleton. Additional studies are needed to assess this possibility.
Development and Application of a Dual-Impedance Radial Diffusion Model to Simulate the Partitioning of Semivolatile Organic Compounds in Combustion Aerosols

The fate of semivolatile organic compounds in the atmosphere is largely dependent on their partitioning between the gas phase and sorption to particulate matter. Since real atmospheres have been shown to deviate significantly from gas−particle equilibrium under certain conditions, dynamic mass transfer models are needed to accurately predict partitioning. In this work, a dual-impedance radial diffusion model is presented that is able to simulate the partitioning of deuterated fluoranthene in wood and diesel soot atmospheres generated in a large outdoor Teflon film chamber. It is shown that the dual-impedance model produces significantly better fits to experimental results than a one-layer model and that surface mass transfer is not rate limiting in these systems. The sensitivity of optimized apparent diffusion coefficients to key input parameters is also explored. This work lays the foundation for incorporating dynamic gas−particle partitioning models into larger atmospheric models, such as urban airshed ...
Design and modeling of waveguide-coupled microring resonator

Abstract The design and the simulation of high-Q microcavity ring resonators coupled to submicron-width waveguides are investigated. Nanofabrication results and optical properties of SiO2–TiO2 planar waveguides are presented. Key optical design parameters are characterized using Finite-Difference Time-Domain (FDTD) solutions of the full-wave Maxwell's equations.
Photon and gluon bremsstrahlung in heavy-top-quark decay.

We calculate the rate for photon and gluon bremsstrahlung in the charged-current decay $t\ensuremath{\rightarrow}\mathrm{WbV} (V = \ensuremath{\gamma},g)$ of a heavy top quark. For ${E}_{V} g 20$ GeV and ${m}_{t} l 200$ GeV the branching fraction is less than 3 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}3}$ for $t \ensuremath{\rightarrow} \mathrm{Wb}\ensuremath{\gamma}$ and 0.2 for $t \ensuremath{\rightarrow} \mathrm{Wbg}$. We also consider non-standard-model $\mathrm{WW}\ensuremath{\gamma}$ couplings ${\ensuremath{\kappa}}_{\ensuremath{\gamma}}$ and ${\ensuremath{\lambda}}_{\ensuremath{\gamma}}$; the dependence on these parameters is weak.
Increased genetic variance after a population bottleneck

A conventional view holds that population bottlenecks cause massive losses of genetic variability, thus endangering the viability of the derived population. Although some alleles that were infrequent in the parent population may be lost new empirical evidence from Drosophila and housefly populations has demonstrated that genetic variance available to selection may actually increase following a single severe bottleneck. Several theoretical models support this view, and suggest that the increase may result from conversion of balanced epistatic variance to additive variance that becomes immediately available to selection. These effects appear to be greatest on the inheritance of quantitative characters, releasing new variance through the disruption of covariance matrices that underlie and interrelate quantitative traits. Thus, character change in adaptation and speciation may, in some instances, be promoted by founder events.
Coming in to the cold

Low Temperature Methods in Biological Electron Microscopy. By A.W. Robards and U.B. Sleytr. Elsevier:1985. Pp.551. Hbk 111, Dfl. 300; pbk 48.25, Dfl. 130.
The PapSpin: a reasonable alternative to other, more expensive liquid-based Papanicolaou tests.

BACKGROUND This study was designed to optimize a liquid-based Papanicolaou (Pap) test by using common cytopathology laboratory equipment and resulted in an inexpensive test that was equivalent at least diagnostically to the conventional Papanicolaou (Pap) smear. METHODS Adult women (n = 482) were consented, enrolled, and included in this Institutional Review Board-approved study. After conventional Pap smear slides were obtained, clinicians placed the collection device with residual cells from the uterine cervix in a preservative fluid. In the cytopathology laboratory, a conventional centrifuge device was used to deposit the cells from the liquid onto a glass slide. RESULTS Among the conventional Pap smears, 43 were categorized as low-grade squamous intraepithelial lesions (LSIL), and 30 were categorized as high-grade squamous intraepithelial lesions or greater (HSIL+). Among the PapSpin samples, 49 were categorized as LSIL and 24 were categorized as HSIL+. Biopsy confirmation was obtained in 124 patients. There were 23 women diagnosed with LSIL and 27 women diagnosed with HSIL+. Diagnostic agreement between cytologic samples and biopsies is as follows: for conventional Pap smears, there was agreement on 11 of 23 LSIL diagnoses and on 15 of 27 HSIL+ diagnoses; for PapSpin samples, there was agreement on 11 of 23 LSIL diagnoses and on 14 of 27 HSIL+ diagnoses. Exact agreement was achieved between PapSpin and conventional smears in 404 patients (84%). Quality indictors were better in the PapSpin group, except for inadequate endocervical component, which was greater in the PapSpin samples, a difference that was explained by the split-sample study design, which favored the conventional smear. CONCLUSIONS The current results indicated that PapSpin is a legitimate, inexpensive alternative to the conventional Pap smear for the detection of cervical intraepithelial neoplasia, resulting in better preservation and improved cell visualization. In addition, the liquid residual allows for reflex human papillomavirus-DNA or polymerase chain reaction testing. Cancer (Cancer Cytopathol) 2006. © 2006 American Cancer Society.
A High Rate Amplifier-Digitizer System for Liquid Argon Calorimeters

A low cost charge amplifier for a liquid argon photon detector and a new method for pulse height analysis are described. This scheme is suitable for high energy photon detection with high counting rate. Samples of preamplifier output are taken just before and just after the arrival of the charge from the detector. The difference of these samples provides a stable pedestal and rejects low frequency noise. Short two-pulse resolving time (?200ns) is achieved.
New latency bounds for atomic broadcast

Tighter bounds are provided on the time required to reach agreement in a distributed system as a function of the failure model. After describing the model of a distributed system that is a context for this work the authors define several failure classes. They define a partial order on classes of failures that involves whether there is a latency penalty in converting from tolerance of one failure class to another. In this setting they distinguish clock and timing failures, showing that there can be a penalty in converting from timing failure tolerance to clock failure tolerance. The authors leave open the exact expression for the optimal latency for timing failure tolerant atomic broadcast, though it is conjectured that there is some penalty in converting from omission failure tolerance to timing failure tolerance. >
Variations in the interrenal and corpuscles of Stannius of Mugil cephalus from the Colorado river and its estuary

Abstract The interrenal and corpuscle of Stannius tissue from a natural population of striped mullet ( Mugil cephalus ) were examined in an attempt to correlate tissue activity with environmental variables, primarily salinity. The interrenal tissue of the striped mullet consists of anastomosing “tubulelike” cylindrical cords folded upon themselves. The pseudolumina within the cell cords were most distinctive in the freshwater population. Interrenal cell nuclear diameter and character, as well as the nature of the cytoplasm, indicated greater interrenal activity in fresh water. Seasonal variation was present. The corpuscles of Stannius consist of extensively folded cylindrical cell cords, often as an anastomosing mass. Corpuscle activity, as indicated by relative cytoplasmic abundance and by nuclear orientation, shape and size, was greater in saltwater than in freshwater mullet. Corpuscle activity was greatest in August and December. Mullet with pathological symptoms possessed corpuscles that differed significantly from those of apparently healthy fish. The activity of both interrenal tissuc and corpuscles of Stannius of striped mullet seems closely related to environmental factors. The influence of temperature and increased gonadal activity in stimulation of interrenal tissue appears conclusive. On the basis of histological evaluation an osmo(iono)regulatory role for the interrenal organ is strongly supported, and a relationship between corpuscle of Stannius activity and osmoregulation is also probable.
Developments with maximum-likelihood x-ray computed tomography: initial testing with real data

We investigate the potential and present limitations of a maximum-likelihood (ML) approach to x-ray computed tomography that utilizes Poisson modeling and an iterative gradient-based algorithm. This model and algorithm incorporate the finite width of the x-ray beam, and they were extended from an approach originally proposed by Lange et al. [IEEE Trans. Med. Imaging MI-6, 106–114 (1987)]. Low-count data, obtained from an industrial computed-tomography scanner, are used to reconstruct an image of a concrete cube with metal reinforcing bars. We utilize both ML and filtered backprojection to reconstruct a cross section of the internal structure of the cube. In this initial evaluation with low-count data the images reconstructed by ML show several potential advantages over those reconstructed by filtered backprojection. The advantages shown are the following: (1) there are significantly reduced noise and streak artifacts in the ML image; (2) some of the known structural detail is more apparent in the ML image; (3) there is a closer quantitative fit, based on log-likelihood and residual calculations, between the ML image and the observed data; (4) the ML approach shows the potential to achieve finer spatial resolution than filtered backprojection. We observe two present, yet addressable, limitations of the ML approach. First, the ML image currently has a peripheral smoothing artifact that seems to disappear gradually with increasing iteration numbers. This smoothing is possibly caused by the slow rate of convergence of the algorithm and may be addressed by future acceleration strategies. Second, the finer spatial resolution achieved with the ML approach currently occurs at the expense of noise and edge artifacts. This limitation may be addressed by a number of extended ML and maximum a posteriori approaches that are currently under investigation in other modalities of imaging to address similar noise and edge artifacts.
SU‐FF‐I‐145: The Effect of Brownian Motion On Nanoparticle Magetization

The magnetization of nanoparticles in a sinusoidal applied field is a balance between Lorentz forces tending to align the nanoparticle magnetizations and Brownian motion tending to randomize the nanoparticle magnetizations. The result is a distorted sinusoid where the distortion is larger for larger applied fields or smaller nanoparticleBrownian motion. The ratio of the harmonics of the magnetization is one way to characterize the distortion and therefore the Brownian motion of the nanoparticles. The harmonics can be measured in vivo because there is no other signal present and the bandwidths can be extremely small if the signal is measured over many cycles. We have explored how the material in which the nanoparticles reside affects the harmonics. We compared the effects of phase changes and viscosity changes on the harmonics and found a coherent pattern. It showed the ratio of the harmonics decreases with temperature but exhibits a very large increase as it passes through a phase change from ice to water. The change is roughly equal to what a 20°K change in temperature would produce. The measurements are accurate to less than one degree. The nanoparticle signal is very sensitive to phase changes and to viscosity changes. Further, the changes in the harmonics induced are significant enough to easily be observed in vivo. Brownian motion measurements should have a wide array of uses including identification of ablated regions in ablation therapy, identification of cellularity in cancer and inflammatory responses such as rheumatoid arthritis. Moreover it is a measure of the microscopic surroundings of the nanoparticles so antibody targeted nanoparticles can reflect the environment adjacent to the targeted cells without averaging over a wider volume such as an MRI voxel.
Acting for a Reason and Following a Principle

According to an influential view of practical reason and rational agency, a person acts for a reason only if she recognizes some consideration to be a reason, where this recognition motivates her to act. I call this requirement the guidance condition on acting for a reason. Despite its intuitive appeal, the guidance condition appears to generate a vicious regress. At least one proponent of the guidance condition, Christine M. Korsgaard, is sensitive to this regress worry, and her appeal in recent work to the constitutive principles of action can be seen, in part, as a response to it. I argue, however, that if we are to appeal to the constitutive principles of action to resolve the regress, then we must determine whether acting on such principles is also subject to the guidance condition. This raises a dilemma. If following these principles is subject to the guidance condition, then the regress remains unresolved. But if not, then the rationale for applying it to acting for a reason vanishes as well. I conclude that we should embrace an account of acting for a reason that rejects the guidance condition.
Essential glycine in the proton channel of Escherichia coli transhydrogenase.

The nicotinamide nucleotide transhydrogenases of mitochondria and bacteria are proton pumps that couple hydride ion transfer between NAD(H) and NADP(H) bound, respectively, to extramembranous domains I and III, to proton translocation by the membrane-intercalated domain II. Previous experiments have established the involvement of three conserved domain II residues in the proton pumping function of the enzyme: His91, Ser139, and Asn222, located on helices 9, 10, and 13, respectively. Eight highly conserved domain II glycines in helices 9, 10, 13, and 14 were mutated to alanine, and the mutant enzymes were assayed for hydride transfer between domains I and III and for proton translocation by domain II. One of the glycines on helix 14, Gly252, was further mutated to Cys, Ser, Thr, and Val, expression levels of the mutant enzymes were evaluated, and each was purified and assayed. The results show that Gly252 is essential for function and support a model for the proton channel composed of helices 9, 10, 13, and 14. Gly252 would allow spatial proximity of His91, Ser139, and Asn222 for proton conductance within the channel. Gly252 mutants are distinguished by high levels of cyclic transhydrogenation activity in the absence of added NADP(H) and by complete loss of proton pumping activity. The purified G252A mutant has
Fluctuating high urinary phenylethylamine excretion rates in some bipolar affective disorder patients

Five women with primary major bipolar affective disorders had variable and at times very high urinary phenylethylamine (PEA) excretion rates. The clinical picture of these patients was characterized by periodic bizarre behaviors and short psychotic episodes. These patients were generally nonresponsive to the usual treatment modalities, and their symptoms were exacerbated by nonspecific monoamine oxidase inhibitors which further increased PEA excretion rates.
The generation of a diverse suite of Late Pleistocene and Holocene basalt through dacite lavas from the northern Cascade arc at Mount Baker, Washington

Mt. Baker is a dominantly andesitic stratovolcano in the northern Cascade arc. In this study, we show that the andesites are not all derived from similar sources, and that open-system processes were dominant during their petrogenesis. To this end, we discuss petrographic observations, mineral chemistry, and whole rock major and trace element chemistry for three of Mt. Baker’s late Pleistocene to Holocene lava flow units. These include the basalt and basaltic andesite of Sulphur Creek (SC) (51.4–55.8 wt% SiO2, Mg# 57–58), the Mg-rich andesite of Glacier Creek (GC) (58.3–58.7 wt% SiO2, Mg# 63–64), and the andesite and dacite of Boulder Glacier (BG) (60.2–64.2 wt% SiO2, Mg# 50–57). Phenocryst populations in all units display varying degrees of reaction and disequilibrium textures along with complicated zoning patterns indicative of open-system processes. All lavas are medium-K and calc-alkaline, but each unit displays distinctive trace element and REE characteristics that do not correlate with the average SiO2 content of the unit. The mafic lavas of SC have relatively elevated REE abundances with the lowest (La/Yb)N (~4.5). The intermediate GC andesites (Mg- and Ni-rich) have the lowest REE abundances and the highest (La/Yb)N (~6.7) with strongly depleted HREE. The more felsic BG lavas have intermediate REE abundances and (La/Yb)N (~6.4). The high-Mg character of the GC andesites can be explained by addition of 4% of a xenocrystic olivine component. However, their depleted REE patterns are similar to other high-Mg andesites reported from Mt. Baker and require a distinct mantle source. The two dominantly andesitic units (GC and BG) are different enough from each other that they could not have been derived from the same parent basalt. Nor could either of them have been derived from the SC basalt by crystal fractionation processes. Crystal fractionation also cannot explain the compositional diversity within each unit. Compositional diversity within the SC unit (basalt to basaltic andesite) can, however, be successfully modeled by mixing of basalt with compositions similar to the dacites in the BG unit. Given that the BG dacites erupted at ~80–90 ka, and a similar composition was mixed with the SC lavas at 9.8 ka, the process that produced this felsic end-member must have been repeatedly active for at least 70 ka.
Investigation of inhomogeneity in chemical compositions and kinetics of sol–gel by near-infrared multispectral imaging technique

Abstract Inhomogeneity in kinetics of sol–gel formation of tetraethyl orthosilicate (TEOS) were studied using the recently developed near-infrared (NIR) multispectral imaging instrument. This imaging spectrometer possesses all advantages of conventional spectrometers. It also has additional features which NIR spectrometers cannot offer, namely, its ability to provide kinetic information at different positions within a sample. The spatial resolution and sensitivity of the imaging spectrometer made it possible to determine the kinetic from data recorded by a single pixel. Kinetics of sol–gel reactions, determined by this multispectral imaging instrument, show that the initial hydrolysis of the TEOS is relatively inhomogeneous. The inhomogeneity is dependent on the number of pixels used to calculate the spectrum for each spot. Data calculated from a single pixel provide the largest inhomogeneity. No inhomogeneity was observed when an average of a large number of pixels (e.g., 10×10) is used for calculation. A variety of reasons might account for the observed inhomogeneity including the differences in the relative concentrations of starting materials.
Designing a robot through prototyping in the wild

This paper describes the design and initial evaluation of Dewey, a do-it-yourself (DIY) robot prototype aimed to help users manage break-taking in the workplace. We describe the application domain, prototyping and technical implementation, and evaluation of Dewey in a real office environment to show how research using simple prototypes can provide valuable insights into user needs and practices at the early stages of socially assistive robot design.
A Convenient Synthesis of High-Purity 1-Chloro-2,6-difluorobenzene

A convenient preparation of high-purity 1-chloro-2,6-difluorobenzene has been developed. The key to the isolation of the desired isomer, without contamination of the difficult-to-separate isomer 1-chloro-2,3-difluorobenzene, is the use of sulfonyl chloride to direct fluorine substitution to the ortho and para positions of the aryl ring. Although activation with sulfonyl chloride requires additional reaction steps, the process results in good overall yield and requires only low-cost commodity chemicals. The high-purity 1-chloro-2,6-difluorobenzene is useful as an intermediate for active ingredients in agricultural and pharmaceutical applications.
Global Warming Effects on U.S. Hurricane Damage

While many studies of the effects of global warming on hurricanes predict an increase in various metrics of Atlantic basin-wide activity, it is less clear that this signal will emerge from background noise in measures of hurricane damage, which depend largely on rare, high-intensity landfalling events and are thus highly volatile comparedtobasin-widestormmetrics.Usingarecentlydevelopedhurricanesynthesizerdrivenbylarge-scale meteorological variables derived from global climate models, 1000 artificial 100-yr time series of Atlantic hurricanes that make landfall along the U.S. Gulf and East Coasts are generated for four climate models and for current climate conditions as well as for the warmer climate of 100 yr hence under the Intergovernmental Panel on Climate Change (IPCC) emissions scenario A1b. These synthetic hurricanes damage a portfolio of insured property according to an aggregate wind-damage function; damage from flooding is not considered here. Assumingthat the hurricane climate changes linearly with time, a 1000-member ensemble of time series of propertydamagewas created.Three of thefour climatemodels usedproduce increasing damagewith time, with the global warming signal emerging on time scales of 40, 113, and 170 yr, respectively. It is pointed out, however, that probabilities of damage increase significantly well before such emergence time scales and it is shownthatprobabilitydensitydistributionsofaggregatedamagebecomeappreciablyseparatedfromthoseof the control climateon time scales as shortas 25 yr. For the fourthclimatemodel, damagesdecreasewith time, but the signal is weak.
Ineffectiveness of Two Annual Legumes as Nurse Plants for Establishment of Artemisia californica in Coastal Sage Scrub

Annual legumes are often used as nurse plants for restoration projects, but two commonly used legume species were competitors at all densities with Artemisia californica (California sagebrush), a dominant shrub of southern California coastal sage scrub. Survival of Artemisia was not reduced by the lowest densities of the native Lupinus succulentus (arroyo lupine) at ratios of Artemisia to Lupinus of 1:1 or 1:3 or by the exotic Trifolium hirtum (rose clover) at the 1:1 density, but its survival was as low as 4% at the highest densities of Trifolium (1:16) and 1:32). Overall, Trifolium was more detrimental to survival of Artemisia, but the biomass of Artemisia was reduced by 90% or more in mixtures with both legumes even at the lowest densities of 1:1. The total soil nitrogen either did not change or decreased in two of the mixtures between planting and harvest dates, indicating that the legumes not only did not add nitrogen to the soil within one growing season but even depleted it in these two cases. Whereas Lupinus had greater aboveground bio-mass than Trifolium, it had a lower root density than Trifolium. The Artemisia root system was more shallow than either Trifolium or Lupinus, possibly explaining the poor growth of Artemisia in mixtures, The legumes were one to two orders of magnitude greater in aboveground biomass than Artemisia at the 1:1 ratio and therefore may be inappropriate choices as nurse plants. There is no evidence from this study that either of these legumes can act as nurse plants, even at the lowest ratio of one nurse plant to on shrub. Nurse plants are probably more important in harsher environments than in coastal sage scrub.
Material flow analysis of polyethylene terephthalate in the US, 1996-2007

Abstract We present a material flow analysis (MFA) for polyethylene terephthalate (PET), a synthetic polymer, in the United States for the years 1996–2007. We model the industrial metabolism of PET as a network of flows linking stocks and processes. The most common worldwide use of PET is in textile production, but in the US it is increasingly used to make disposable beverage containers for transporting water, carbonated soda, and other beverages. Bottles made from PET are the most-recycled plastic product in the US by mass and by recovery rate, and thus the PET material flow system constitutes an ideal case study of polymer recycling. We find that total consumption of PET resin grew at 2.7% per year over the period of the study, reaching 5.01 million metric tons in 2007. This growth was driven largely by the beverage packaging market, which accounted for 55% of consumption in 2007. About a quarter of PET bottles are collected for recycling, a number that has fluctuated widely but kept pace with consumption. However, domestic capacity for reclamation of post-consumer PET has not grown as quickly, leading recyclers to export increasing amounts of post-consumer material. Manufacturers have also imported secondary PET in increasing amounts. Reclaimed PET accounted for 6–9% of total resin demand throughout the study. While polymer recycling appears to be viable, efforts to improve material efficiency are confounded by low collection rates and a lack of reclamation infrastructure.
What Is The Nature Of Interactions Between DNA And Nanopores Fabricated In Thin Silicon Nitride Membranes

Manipulating the drag force acting on charged biopolymers, such as DNA, during their passage through solid-state nanopores is critical for various single-molecule applications for biotechnology (e.g., sequencing, genotyping, DNA/protein interactions). We have recently shown for solid-state nanopores in silicon nitride (SiN) that small variations in the nanopore diameter, temperature, and voltage, strongly affect the biopolymer's average sliding velocity, indicating that in this size regime DNA transport is governed by DNA/pore attraction[1]. However, the exact nature of these interactions has remained to date unknown. To elucidate the character of these nanopore/DNA interactions, we have performed two independent types of experiments: First, we investigated the capture rate of DNA as a function of temperature. Surprisingly, our temperature measurements reveal anti-Arrhenius behavior, suggesting a two-step capture process. Second, we mapped the spatial distribution of charged biopolymer in the vicinity of the SiN membrane, using a custom confocal microscope equipped with a nano-positioning stage. Our measurements reveal a salt-dependent enhancement of DNA concentration in the vicinity of the SiN. These combined results suggest that electrostatic DNA/pore and DNA/membrane interactions are present between the weakly positive SiN surface and the negatively-charged DNA. In this presentation, these results are discussed and a model that explains these and previously reported observations is presented.[1] Wanunu, M. Sutin, J. McNally, B. Chow, A. and A. Meller (2008) DNA Translocation Governed by Interactions with Solid State Nanopores, Biophys. J., 95 (11), in press.
Dual electroactive probes of clay film chemistry

Abstract In this paper we explore intermolecular effects on the transport of probe molecules in clays by pairing of electmactive probes. Among the interesting features of the dual-probe system, we note that analytically useful signals can be induced, by ion pairing of an electroactive cation with an electroactive anion. Such electrochemically observable ion pairing was most successful when the anion was partially aromatic in nature. The results shed light on the role of organic coadsorbates in enhancing transport of small organics in clay beds. A second important observation is that, for some dual probes, diode behavior can be noted in which all the reduction current is observed at one redox couple and all the oxidative current is observed at the second redox couple.
Blockade of cerebral blood flow response to insulin-induced hypoglycemia by caffeine and glibenclamide in conscious rats.

The possibility that adenosine and ATP-sensitive potassium channels (KATP) might be involved in the mechanisms of the increases in cerebral blood flow (CBF) that occur in insulin-induced hypoglycemia was examined. Cerebral blood flow was measured by the [14C]iodoantipyrine method in conscious rats during insulin-induced, moderate hypoglycemia (2 to 3 mmol/L glucose in arterial plasma) after intravenous injections of 10 to 20 mg/kg of caffeine, an adenosine receptor antagonist, or intracisternal infusion of 1 to 2 mumol/L glibenclamide, a KATP channel inhibitor. Cerebral blood flow was also measured in corresponding normoglycemic and drug-free control groups. Cerebral blood flow was 51% higher in untreated hypoglycemic than in untreated normoglycemic rats (P < 0.01). Caffeine had a small, statistically insignificant effect on CBF in normoglycemic rats, but reduced the CBF response to hypoglycemia in a dose-dependent manner, i.e., 27% increase with 10 mg/kg and complete elimination with 20 mg/kg. Chemical determinations by HPLC in extracts of freeze-blown brains showed significant increases in the levels of adenosine and its degradation products, inosine and hypoxanthine, during hypoglycemia (P < 0.05). Intracisternal glibenclamide had little effect on CBF in normoglycemia, but, like caffeine, produced dose-dependent reductions in the magnitude of the increases in CBF during hypoglycemia, i.e., +66% with glibenclamide-free artificial CSF administration, +25% with 1 mumol/L glibenclamide, and almost complete blockade (+5%) with 2 mumol/L glibenclamide. These results suggest that adenosine and KATP channels may play a role in the increases in CBF during hypoglycemia.
Demographic Change in a Post-Export Boom Society: The Population of Minas Gerais, Brazil, 1776-1821

The author explores "the social and economic history of Minas Gerais [Brazil] in the late 18th and early 19th centuries....This article will consider the process of demographic readjustment occurring in Mineiro society in the aftermath of the 18th-century gold mining boom....The immigration of free people seeking economic opportunity virtually ceased between 1786 and 1808 when the annual rate of population growth in the capitania declined precipitously....The slave population declined by over 20% between 1786 and 1808....By the early 19th century free peoples of color had replaced slaves as the most numerous population sector and their annual rates of demographic growth would assure population predominance in Minas Gerais from then on." (EXCERPT)
Development of a CW laser absorption diagnostic for measurement of CN in shock tube experiments

Abstract Time-histories of the CN radical were monitored using a tunable ring dye laser to measure absorption at the P -branch bandhead of the B 2 ∑ + ← X 2 ∑ + (0,0) band of CN in a shock tube. Measurements of CN resulting from the pyrolysis of highly dilute mixtures of C 2 N 2 in Ar were compared with a spectroscopic model, and the location of maximum absorption for the bandhead was determined to be 25743.72 cm -1 (λ = 388.444 nm). A second set of experiments at the maximum absorption frequency was conducted for temperatures between 2700 and 4900 K and pressures between 0.34 and 1.0 atm. These measurements were used to determine an expression for the effective collisional broadening coefficient. Correlation of the data with the spectroscopic model led to a temperature- and pressure-dependent expression for the absorption coefficient. For P = 1 atm, this expression is of the form k v ( T , 1 atm) [cm -1 atm -1 ] = a / T 3 + b / T 2 + c / T , where a = −9.95984 × 10 13 , b = 1.13891 × 10 11 , and c = −1.16132 × 10 7 ; it agrees with the spectroscopic model within 1% for the temperature range 2000 T T T > 3300 K. The detection limit of the CN diagnostic is 0.1% absorption, which corresponds to a CN detection sensitivity of 0.02 ppm at T = 3600 K, P = 1 atm, and a path lenght of 14.3 cm.
Intracaval liver with cardiac extension. A new developmental anomaly

Inferior vena cava (IVC) obstruction is uncommon in children. We report a patient with liver within a IVC extending to the right atrium who underwent successful surgical resection. A 12-year-old boy with an Arnold Chiari malformation was admitted for seizures. Premature ventricular contractions prompted an echocardiogram. This revealed a pedunculated mass in the right atrium and an IVC producing turbulent flow. He underwent a mass excision that was continuous with the liver. Histology demonstrated normal liver parenchyma. Based on the embryologic intimacy between the caudate lobe and the IVC, we postulate that the ectopic hepatic nodule was due to aberrant migration of hepatocytes into the IVC during embryogenesis.
Clark measures and operators similar to a contraction

In this article the authors study the conditions under which a certain operator is similar to a contraction. The specific question was originally posed by R. Douglas in the 1990s, and is an offshoot to a question posed by P. Halmos in the 1970s. Halmos' question arose due to Von Neumann's inequality which says that for any contraction T and any polynomial p, It follows directly from this inequality that contractions are polynomially bounded. In addition, it can be shown that if A is a bounded operator similar to a contraction, and B(z) is a Blaschke product such that the closure of the set of poles of B lies off the spectrum of A, then B(A) is also similar to a contraction. The question R. Douglas posed is whether the converse is true, that is, given the above conditions, if B(A) is similar to a contraction, is A similar to a contraction? T. Lance and M. Stessin proved it to be the case where B is a finite Blaschke product, using a method that exploits the Wold Decomposition of the Hardy Space . Later, St...
Enhanced killing of antibiotic-resistant bacteria enabled by massively parallel combinatorial genetics

New therapeutic strategies are needed to treat infections caused by drug-resistant bacteria, which constitute a major growing threat to human health. Here, we use a high-throughput technology to identify combinatorial genetic perturbations that can enhance the killing of drug-resistant bacteria with antibiotic treatment. This strategy, Combinatorial Genetics En Masse (CombiGEM), enables the rapid generation of high-order barcoded combinations of genetic elements for high-throughput multiplexed characterization based on next-generation sequencing. We created ∼34,000 pairwise combinations of Escherichia coli transcription factor (TF) overexpression constructs. Using Illumina sequencing, we identified diverse perturbations in antibiotic-resistance phenotypes against carbapenem-resistant Enterobacteriaceae. Specifically, we found multiple TF combinations that potentiated antibiotic killing by up to 106-fold and delivered these combinations via phagemids to increase the killing of highly drug-resistant E. coli harboring New Delhi metallo-beta-lactamase-1. Moreover, we constructed libraries of three-wise combinations of transcription factors with >4 million unique members and demonstrated that these could be tracked via next-generation sequencing. We envision that CombiGEM could be extended to other model organisms, disease models, and phenotypes, where it could accelerate massively parallel combinatorial genetics studies for a broad range of biomedical and biotechnology applications, including the treatment of antibiotic-resistant infections.
Plural Nature of Vitamin B

ONE group of rats was supplied with vitamin B carriers that had been subjected to intense ultraviolet irradiation. The animals developed a severe dermatitis and died. A second group received tikitiki, an alcoholic extract of rice polishings, as the sole source of vitamin B. After some ten or twelve weeks these rats became denuded, assumed a very miserable appearance, and finally they died also.
The effect of extracellular calcium on colonocytes: evidence for differential responsiveness based upon degree of cell differentiation

Calcium supplementation decreases the incidence of colon cancer in animal models and may prevent colon cancer in man. Potential mechanisms include binding of mitogens and direct effects of calcium on colonic epithelial cells. In this study, the effects of extracellular calcium on epithelial cell growth and differentiation were studied in three colon carcinoma and two colonic adenoma cell lines. The characteristics studied included morphology, cell cycle kinetics, [Ca2+]IC (intracellular calcium concentration), proliferation, and expression of differentiation markers such as carcinoembryonic antigen (CEA) and alkaline phosphatase (AP). Sodium butyrate (NaB) and 1,25-dihydroxyvitamin D3 were used as controls in the latter three assays as these two agents are known differentiating agents. Alteration of [Ca+2]EC (extracellular calcium concentration) did not affect carcinoembryonic antigen (CEA) or alkaline phosphatase (AP) expression. NaB enhanced the expression of AP three-fold and CEA five-fold. This effect was augmented by increasing [Ca2+]EC. The exposure of cells to 1,25-(OH)2-Vitamin D3 increased CEA but not AP. [Ca2+]IC increased in response to 1,25-(OH)2-vitamin D3 and NaB but not with variation in [Ca2+]EC. Increased [Ca2+]EC inhibited proliferation of well-differentiated cells, but had no effect on poorly-differentiated cells. Morphological studies showed that extracellular calcium was necessary for normal cell—cell interactions. These studies have demonstrated direct effects of calcium on colonic epithelial cells which may contribute to the protective effects of dietary calcium against colon cancer. Loss of responsivess to the antiprotective effects of [Ca2+]EC with de-differentiation suggests that calcium supplementation may be most beneficial prior to the development of neoplastic changes in colonic epithelium.
Peer versus Self Assessment of Oral Business Presentation Performance

Pedagogical practice related to oral business presentations has received little research attention despite the pervasiveness of oral presentations in business class rooms and their perceived importance to workplace success. This study collected data on three groups (self, peers, and instructor) to address four research ques tions related to (a) the usefulness of self and peer ratings as substitutes for instruc, tor evaluation of oral business presentations and (b) the relationship between vari ous content and non-content factors on overall perceptions of presentation quality. Data from this study suggest that (1) both holistic and analytical peer assessments are reasonable substitutes for instructor assessment when raters are trained; (2) self assessment does not closely reflect either peer or instructor assessments; and (3) peer assessment of delivery characteristics, command of material, and content strongly predict peer ratings of overall presentation quality.
Thermoluminescence dating of an Arctic lake core from Alaska

Abstract Eight samples were selected from a 14 m core record from Squirrel Lake in the Alaskan Arctic for fine-grain, partial bleach thermoluminescence (TL) dating. Nine radiocarbon ( 14 C) ages were available for comparison. Three TL ages of 8.8 to 11.6 ka in the upper 2.5 m do not exceed calendar-corrected 14 C ages, suggesting that zeroing of light-sensitive TL in the detrital feldspars has been effective enough in this depositional environment to allow accurate dating of deeper core samples of similar sedimentology. TL ages of 60–65 ka for two samples in the 4.9–7 m depth range are consistent with an ‘infinite’ 14 C age of >38.6 ka at 5.8 m. TL ages from 83±11 to 125±31 for three samples in the depth range 11–13.5 m suggest that this core record encompasses the last interglacial period (80–130 ka). These first TL ages for sediments from an Arctic lake core demonstrate the potential of the method for providing a directly measured chronology beyond the radiocarbon dating range in the climatically sensitive Arctic regions.
Cortical tongue area studied by chronically implanted subdural electrodes--with special reference to parietal motor and frontal sensory responses.

Motor and sensory cortical tongue representations were examined in 40 patients with intractable seizures who underwent chronic subdural electrode grid implantation. Tongue responses were observed in a wide area 4.5 cm anterior and 3 cm posterior to the central sulcus. The distribution of the responses was not influenced by whether the responses were unilateral or bilateral. In patients with fronto-parietal lesions, the tongue motor area was located significantly more superior to the Sylvian fissure and more anterior to the central sulcus than was the tongue motor area of patients without organic lesion. Both motor and sensory responses were found outside of the classic precentral or postcentral area on the lateral surface of the cortex. Motor responses (‘parietal motor responses’) could occur posterior to the central sulcus and, rarely, sensory responses (‘frontal sensory responses’) were identified anterior to the central sulcus. These paradoxical parietal motor and frontal sensory responses were seen in 17 out of 40 (42.5 %) patients. Nine of these 17 patients had no organic brain lesion on MRI. Clinical factors, such as patient's age, duration of seizures and cognitive functions (IQ, word fluency score), did not influence the frequency of the paradoxical responses. However, patients with brain lesions showed a tendency to have associated paradoxical responses (P < 0.05). In conclusion, paradoxical responses are not uncommon in epilepsy patients, particularly in those with organic lesions. The physiological and clinical implications of the paradoxical responses are discussed.
A heated stage and tissue culture chamber for electrophysiology

A simple, inexpensive heating circuit is described for use with a warmed microscope stage, small tissue bath, and heated tissue culture chamber. A major consideration in the design of the apparatus is a compatability with electrophysiological studies. Thus, proper shielding and low profile for microelectrode positioning are featured.
Pharmacologic recruitment of regulatory T cells as a therapy for ischemic acute kidney injury.

Regulatory T cells (Tregs) are key components of the peripheral tolerance system and have become an immunotherapeutic agent for treating inflammatory processes. This therapeutic option, however, is hampered by problems arising from isolating and expanding desirable Tregs. Here we used an alternative approach with a pharmacologic agent to stimulate Tregs to achieve immunosuppressive effects. Pretreatment of mice with the naturally occurring sphingosine N,N -dimethylsphingosine (DMS) was found to increase both tissue-infiltrating T effectors (Teffs, CD4 + Foxp3 - ) and Tregs (CD4 + Foxp3 + ) in the early phase of bilateral renal ischemia/reperfusion injury. DMS itself had no effects on renal function or histopathology, but rapidly and transiently increased both Teffs and Tregs and increased the expression of chemokines CXCL9, CCL5, and CXCL10 in non-ischemic kidneys (sham operation). This renoprotection was abolished by administration of the Treg suppressing agents, anti-CTLA-4 or anti-CD25 monoclonal antibodies, suggesting that Tregs play a key role in DMS-induced renoprotection. Thus, Tregs recruited to the kidney by DMS ameliorate acute kidney injury and provide a new approach to control inflammatory diseases.
Using genetic algorithms to solve construction time-cost trade-off problems

Time-cost trade-off analysis is one of the most important aspects of construction project planning and control. There are trade-offs between time and cost to complete the activities of a project; in general, the less expensive the resources used, the longer it takes to complete an activity. Using critical path method (CPM), the overall project cost can be reduced by using less expensive resources for noncritical activities without impacting the project duration. Existing methods for time-cost trade-off analysis focus on using heuristics or mathematical programming. These methods, however, are not efficient enough to solve large-scale CPM networks (hundreds of activities or more). Analogous to natural selection and genetics in reproduction, genetic algorithms (GAs) have been successfully adopted to solve many science and engineering problems and have proven to be an efficient means for searching optimal solutions in a large problem domain. This paper presents: (1) an algorithm based on the principles of GAs for construction time-cost trade-off optimization; and (2) a computer program that can execute the algorithm efficiently.