cssi/SciSciGPT-SciSciNet huggingface dataset:
Invasion by Ammophila arenaria alters soil chemistry, leaving lasting legacy effects on restored coastal dunes in California

Many restoration projects rely on invasive plant removal to restore ecosystems. However, success of restoration efforts relying on invasive removal can be jeopardized, because in addition to displacing native plants, invasives can also dramatically impact soils. Many studies have documented invasives’ effects on soil chemistry and microbiota. While European beachgrass [Ammophila arenaria (L.) Link] is a worldwide invasive problem in coastal dunes outside northern Europe, little attention has been paid to effects of this species on soil chemistry following invasion, even though it establishes persistent, dense monocultures. In our study, we evaluated effects of A. arenaria invasion on soil chemistry of coastal dunes at Point Reyes National Seashore (PRNS); persistence of effects following removal by mechanical or herbicide treatment (legacy effects); and effects of treatment independent of invasion. Dune restoration efforts at PRNS have met with mixed success, especially in herbicide-treated backdunes, where decomposition of dead A. arenaria has been greatly delayed. Based on results, invasion impacted 74% of 19 variables assessed, although there was a significant interaction in many cases with successional status (earlier vs. later). Almost 60% of invasion effects persisted after restoration, with legacy effects prevalent in herbicide-treated backdunes where sand deposition from adjacent beaches could not mitigate effects as it could in herbicide-treated foredunes. Mechanical removal—or inversion of invaded surface soils with less-contaminated subsoils—resulted in fewer legacy effects, but more treatment effects, primarily in backdunes. Soil chemistry may decelerate decomposition of A. arenaria due to the limited nitrogen (N) available to enable microbial breakdown of the high carbon(C):N (70.8:1) material, but microbial factors probably play a more important role. Success of restoration at PRNS may not be fully realized until legacy effects are resolved through additional actions such as inoculation with healthy microbiomes or necromass reduction through controlled burning.
Comparing Estimates of the Impact of Bovine Viral Diarrhea Virus (BVDV) Infection on the Weaning Weights of Beef Calves reported in Primary Research with Economic Models of BVDV in Beef Cattle

The objective of this project was to compare estimates of the impact of bovine viral diarrhea virus (BVDV) infection on the weaning weights of beef calves reported in primary research to the estimates used in economic models of BVDV in beef cattle. Models can help clarify the impact of infectious disease on production and financial outcomes; however the usefulness of economic models depends on the validity of the assumptions of lost production attributable to infection. In dairy herds, the major source of income is milk therefore BVDV transmission models often include calves only as a source for continued herd infection and economic models frequently only consider the impact of infection on milk production. In beef herds, the sale of calves is a primary income source and estimates of the impacts on BVDV infection on calf weight at weaning are of greater importance in economic impact models on BVDV infection in the beef cattle industry than the dairy cattle industry.
NOAA-20 VIIRS Relative Spectral Response Effects on Solar Diffuser Degradation and On-Orbit Radiometric Calibration

The Visible Infrared Imaging Radiometer Suite (VIIRS) on the National Oceanic and Atmospheric Administration-20 (NOAA-20) satellite performs on-orbit radiometric calibration based on regular solar diffuser (SD) observations illuminated by the Sun at the termination point near the South Pole. Due to exposure to the ultraviolet portion of the solar irradiance spectrum, the SD bidirectional reflectance distribution function (BRDF) has been degrading over time. The SD degradation (called H-factor) was measured by the on-board calibrator called the SD stability monitor (SDSM). Nevertheless, over two years of operation, there have been systematic on-orbit calibration differences between the SD-based and independent moon-based calibration results. In this study, the NOAA VIIRS team used a surface roughness Rayleigh scattering (SRRS) model as a baseline SD degradation, simulated on-orbit center wavelength-based approach of SD degradation, and a new SDSM relative spectral response (RSR)-dependent SD degradation estimation method to evaluate the degradation. There were time-dependent growing differences between the SDSM RSR-applied H-factors and center wavelength interpolated H-factors especially in the short wavelength detectors (SDSM detector 1-4). The NOAA-20 SD-based calibration coefficients (SD F-factors) were reprocessed using the RSR-applied H-factors, and the new SD F-factors show similar long-term trends compared with the independent monthly lunar F-factors. The newly processed SD F-factor suggested that the NOAA-20 VIIRS detectors in the reflective solar bands (M1-M11 and I1-I3) showed very stable responses within 0.5% level over the two years of on-orbit operation.
Review of Stephanie Kelton’s The Deficit Myth

Review of Stephanie Kelton, The Deficit Myth: Modern Monetary Theory and the Birth of the People's Economy. The ideas of Modern Monetary Theory (MMT) have gained popularity in certain political circles. While claiming to overturn well-known economic principles, MMT has never been formally laid out in a coherent way, making this “theory” difficult to evaluate. As Colander (2019, p.133) describes, “MMT is not a precisely spelled out formal theory, but more a narrative about the nature and development of money and government finance.” Stephanie Kelton’s (2020) The Deficit Myth (TDM) does little to resolve the ambiguities. It provides no clear theory of MMT. It argues, unconvincingly and with little evidence, that we should reject well-established economic research on public finance and the quantity theory of money in favor of MMT’s vague policy pronouncements. Kelton discusses six supposed “myths” about economics, followed by proposals, based on MMT principles, to massively expand government spending and control of the economy. I will discuss three major claims in TDM that I believe are mistaken (there are many more) plus a few points I like or dislike about the book.
Context matters: The social effects of anger in cooperative, balanced, and competitive negotiation situations

Abstract When does expressing anger in negotiations lead to concessions? Although research has begun to address this question, it has not yet examined the influence of the negotiation context. We propose that the effect of expressing anger depends on the competitiveness of the negotiation situation. Specifically, when the negotiation situation balances cooperative and competitive elements, expressing anger elicits larger concessions than no anger, and responses are driven by cooperation-inducing strategic inferences (e.g., a perception that the anger expresser is tough and threatening). However, when the negotiation context is predominantly cooperative or predominantly competitive, expressing anger does not elicit larger concessions than no anger, and responses are driven by cooperation-inhibiting affective reactions (e.g., reciprocal anger and a desire to retaliate against the anger expresser). Results from two computer-mediated negotiation experiments using different negotiation scenarios, different manipulations of the competitiveness of the situation, and different subject populations supported our hypotheses.
Long term outcomes of cemented endoprosthetic reconstruction for periarticular tumors of the distal femur.

Abstract Background In order to achieve an oncological margin during limb salvage surgery for tumors of the distal femur, part or the entire knee joint is frequently sacrificed. Endoprosthetics make limb salvage possible through restoration of a functional extremity. Currently there remains a paucity of data concerning their long-term outcomes and associated risk factors for failure. Methods We identified 152 patients who underwent an endoprosthetic reconstruction for an oncological process of the distal femur between 1972 and 2013. The mean follow-up was 10years. Mean age and body mass index (BMI) were 39years and 25.8 respectively. The most common pathology was osteosarcoma (n=78, 48%). Outcomes were compared to a control group of 20,643 patients undergoing total knee arthroplasty (TKA) for degenerative joint disease (DJD) during the same time period. Results The mean five-, 10-, 15-, 20-, and 25-year revision-free survival for an endoprosthesis was 76%, 63%, 51%, 36%, and 28%. Compared to the five-, 10-, 15-, 20-, and 25-year survival of 95%, 90%, 82%, 74%, and 67% for control TKAs (p Conclusion The results of this study show that given the complexity of these operations, the rate of revision surgery following endoprosthetic replacement is high. Nevertheless, the use of these modular reconstructions leads to a high rate of limb salvage (93%) over a 25-year period at our institution. Level of Evidence Level III.
A Toolkit for Usability Testing of Mobile Applications

The usability of mobile applications is critical for their adoption particularly because of the relatively small screen and awkward (sometimes virtual) keyboard, despite the recent advances of smartphones. Traditional laboratory-based usability testing is often tedious, expensive, and does not reflect real use cases. In this paper, we propose a toolkit that embeds into mobile applications the ability to automatically collect user interface (UI) events as the user interacts with the applications. The events are fine-grained and useful for quantified usability analysis. We have implemented the toolkit on Android devices and we evaluated the toolkit with a real deployed Android application by comparing event analysis (state-machine based) with traditional laboratory testing (expert based). The results show that our toolkit is effective at capturing detailed UI events for accurate usability analysis.
Efficacy of Commercial Weight-Loss Programs.

Commercial and proprietary weight-loss programs are popular options for obesity treatment, but their efficacy is unclear. This systematic review examined the benefits, adherence, and harms of comme...
Uptake of Synthetic Polynucleotides by Competent Cells of Bacillus subtilis

A survey was made of the capacity of competent cells of Bacillus subtilis to take up synthetic polynucleotides. Polydeoxyribonucleotides but not polyribonucleotides are taken up by the cells. Both types of polynucleotide failed to compete with transforming deoxyribonucleic acid in the transformation assay whereas both stimulated amino acid incorporation. The latter phenomenon appears to be nonspecific as there is no correlation between the codon composition of the polynucleotides employed and the amino acids whose incorporation was stimulated.
Design and benchmark testing of a bicorporal pump for the treatment of normal-pressure hydrocephalus and idiopathic intracranial hypertension: Laboratory investigation

Object Addressing overdrainage and its associated complications is still one of the greatest challenges for future shunt designs for normal-pressure hydrocephalus and idiopathic intracranial hypertension. Nevertheless, as evidenced by tap test procedures, a small amount of CSF drainage seems to be enough to relieve patients' symptoms in most cases and, therefore, in opposition to other types of hydrocephalus, continuous CSF drainage may not be absolutely warranted. In such a clinical scenario, intermittent controlled drainage of a small amount of CSF during specific periods of the day through a 2-system pump may provide several advantages over continuous drainage of current single-system shunts. The goal in this study was to design and test an innovative concept of a bicorporal pump composed of a 2-part system. The first component was designed to be implanted in the patient and act as a pump connected to standard catheter tubing. The second component was designed to be used as an external device outside o...
Evaluación del crecimiento vegetativo de cultivares de vid para mesa bajo condiciones de trópico semiárido de Venezuela

Se estudio el crecimiento vegetativo de los cultivares de vid para mesa Italia, Regina, Napoleon, Sultanina, Alphonse Lavallee, Red Globe, Datal, Perlon, Matilde, Michelli Palieri, Moscatel de Alejandria y Queen, injertados sobre el patron ”˜Criolla negra”™ durante los tres primeros ciclos productivos despues de su formacion, en la Estacion Experimental de El Tocuyo, estado Lara, Venezuela (9Âo 48”™ N; 69Âo 47”™ W; a 630 msnm). Se evaluaron algunas caracteristicas horticolas representadas por variables del crecimiento vegetativo, tales como crecimiento longitudinal del brote, numero de nudos, perimetro del tallo y el peso del desecho de poda. La plantacion se apoyo en espaldera vertical, se condujo en cordon bilateral y se rego por gravedad mediante surcos. El crecimiento longitudinal de los brotes en todos los cultivares correspondio a curvas sigmoidales con respecto al tiempo. El mayor crecimiento en longitud lo presentaron los brotes de los cultivares Sultanina y Alphonse Lavallee en los tres ciclos, mientras que ”˜Moscatel de Alejandria”™ y ”˜Queen”™ fueron los menores. La elongacion de las ramas se incremento lenta y sostenidamente entre ciclos, mientras que el numero de nudos al final de cada ciclo vario entre cultivares. El mayor perimetro al final de los tres ciclos, se observo en el cultivar Michelle Palieri, seguido por Sultanina y Napoleon, los cuales presentaron tambien los mas altos pesos de poda.
Increasing risks of introduction of heartwater onto the American mainland associated with animal movements.

: Opportunities to introduce heartwater onto the American mainland through animal movements include importation from Africa of tick-infested reptiles and of subclinically infected wild ungulates and importation of livestock from islands in the Caribbean infested with Amblyomma variegatum ticks. Measures to control importation of heartwater vectors on reptiles include importation bans of infested species, treatment of imported reptiles, and eradication of established infestations on the American mainland. Measures to control importation of infected wildlife must focus on improved methods, such as the PCR assay, of screening animals to prevent the entry of carriers of Cowdria ruminantium. Measures to control importation of infected animals from the Caribbean must be based on knowledge of the islands that are infected with C. ruminantium so that the risk of dissemination of heartwater can be established.
Elevation of serum placental alkaline phosphatase levels in cigarette smokers

In an ongoing longitudinal study for tumor markers in breast cancer patients, levels of placental alkaline phos-phatase (PAP) measured by RIA were found to be elevated in 34% of patients who smoked cigarettes as opposed to 5 % of non-smoking subjects. A normal range was established (0-2.14 ng/ml) using healthy non-smoking females. In an expanded analysis by disease state, PAP levels were found to be elevated significantly (p<0.02) in the smoking groups of each category. This isoenzyme, when detected at elevated serum levels by RIA, was enzymatically active in 48% of the patients as analyzed by immunoenzymatic assay. One smoker with high PAP levels discontinued smoking following a myocardial infarction. Her PAP levels returned to normal within 2 months.
The advanced dementia prognostic tool: a risk score to estimate survival in nursing home residents with advanced dementia.

Abstract Context Estimating life expectancy is challenging in advanced dementia. Objectives To create a risk score to estimate survival in nursing home (NH) residents with advanced dementia. Methods This was a retrospective cohort study performed in the setting of all licensed U.S. NHs. Residents with advanced dementia living in U.S. NHs in 2002 were identified using Minimum Data Set (MDS) assessments. Mortality data from Medicare files were used to determine 12-month survival. Independent variables were selected from the MDS. Cox proportional hazards regression was used to model survival. The accuracy of the final model was assessed using the area under the receiver operating characteristic curve (AUROC). To develop a risk score, points were assigned to variables in the final model based on parameter estimates. Residents meeting hospice eligibility guidelines for dementia, based on MDS data, were identified. The AUROC assessed the accuracy of hospice guidelines to predict six-month survival. Results Over 12 months, 40.6% of residents with advanced dementia ( n =22,405) died. Twelve variables best predicted survival: length of stay, age, male, dyspnea, pressure ulcers, total functional dependence, bedfast, insufficient intake, bowel incontinence, body mass index, weight loss, and congestive heart failure. The AUROC for the final model was 0.68. The risk score ranged from 1 to 32.5 points (higher scores indicate worse survival). Only 15.9% of residents met hospice eligibility guidelines for which the AUROC predicting six-month survival was 0.53. Conclusion A mortality risk score derived from MDS data predicted six-month survival in advanced dementia with moderate accuracy. The predictive ability of hospice guidelines, simulated with MDS data, was poor.
Fourniers gangrene in children

Necrotizing fasciitis of the genitalia is a rare urologic emergency that is especially uncommon in children. We report a case of Fournier's gangrene in a four-year-old boy and analyze the data from 55 previously reported cases. Pediatric cases have been successfully managed with a more conservative surgical approach and have had a significantly lower mortality rate than adult cases.
Clonidine inhibits the isoproterenol-induced desensitization of the beta noradrenergic activated adenylate cyclase system in astrocytes

Studies were conducted to determine if alpha agonists could influence the desensitization of the beta-noradrenergic receptor activated adenylate cyclase system. Pretreatment of astrocyte cultures with isoproterenol results in a rapid decrease in the cyclic AMP response to subsequent re-exposure to this agonist. The cyclic AMP response to isoproterenol in astrocytes pre-exposed for 2 h to isoproterenol plus clonidine was 2-3 times higher than in cells pre-exposed to isoproterenol alone. The response in astrocytes pretreated with phenylephrine plus isoproterenol was not different from that in cells pretreated with isoproterenol alone. Cyclic AMP may be involved in the effects elicited by clonidine, since this agonist can inhibit the accumulation of cyclic AMP in these cells. Also pretreatment with isobutylmethylxanthine decreases the cyclic AMP response to isoproterenol. The results suggest that clonidine can effect the desensitization of the noradrenergic receptor coupled adenylate cyclase system independent of effects on neurotransmitter release.
Models of Computation - Enabling Exascale

A model of computation provides a set of governing principles and a discipline determining the objects, their interrelationships, parallel flow control, and distribution. In so doing it provides a conceptual framework for the co-design and operation for all layers of the software and hardware architecture system stack from programming model through system software to processor core instruction set and structures. As enabling technologies advance changing capabilities, balance, and design challenges, the response has been a phase change in how HPC systems are realized reflected by the development and adoption of new models of computation to best fit the emerging underlying technology conditions. This has occurred at least through five technology epochs in the past and the field is entering a sixth such with the heterogeneous multicore Petaflops decade. A brief presentation of the nature and characteristics of models of computation is offered here to contribute to the current community discussions on how to proceed towards the realization of the promise of practical Exascale computing by the end of the next decade.
Reactions involving alkynes and tungsten-tungsten triple bonds supported by alkoxide ligands

Abstract W2(OR)6Ln compounds [R = But n = 0; R = Pri or Np (Np = neopentyl), L = py (py = pyridine) or HNMe2, n = 2] react with alkynes (R′C-CR′) under mild conditions (hexane solutions, room temperature or below) to yield a variety of products depending upon the nature of the alkoxide, the alkyne and the mole ratio of the reactants. The products include alkylidyne complexes Ln(RO)3W CR′ (n = 1 or 0) (Schrock et al., Organometallics 1985, 4, 74), alkyne adducts, W2(OR)6(py)n(μ-C2R′2), alkylidyne-capped tritungsten complexes, W3(μ3-CR′)(OR)9, and W2(OR)6(L)(μ-C4R′4) or W2(OR)6(μ-C4R′4) (μ2-C2R′2) compounds. Evidence for equilibria involving alkyne adducts and alkylidyne species is found for certain combinations of R and R′. (1) The alkylidyne complexes (ButO)3 WCMe and (py)2(PriO)3 W CNMe2 react with CO (1 atm 22°C, in hexane) to yield alkyne adducts W2(OBut)6(μ-C2Me2)(CO) and W2[(OPri)6(CO)2(η2-C2(NMe2)2], respectively. (2) The alkylidyne complexes [PriO)2(HNMe2)(R′C)W(μ-OPri)]2 react with alkynes R′CCR′ (> 2 equiv, hexane, 22°C) to give W2(OPri)6(μ-C4R′4)(η2-C2R′2) compound (R′ = Me or Et). (3) The alkyne adducts W2(ONp)6(py)n(μ-C2R′2) (R′ = Et or Ph, n = 1; R′ = Me, n = 2) react with W2(ONp)6(py)2 in a 1:2 mole ratio at 22°C in hexane to yield W3(μ3-CR′)(ONp)(9 compounds. In related reactions involving 1,2-bishydrocarbyl-tetraalkoxides, W2(CH2R″)2(OR)4, and alkynes (R′CCR′) (2 equiv), alkyne adducts of formula W2(CH2R″)2(η2-C2R′2)2(OPri)4 and W2(CH3)2(μ-C2R′2)(OBut)4(py), alkylidyne-bridged complexes HW2(μ-CR″)(μ-C4R′4)(OPri)4 and products of WW and CC metathesis have been isolated for various combinations of R, R′ and R″.
Factors involved in the generation of tension during contraction to high potassium in the rat vas deferens.

Abstract A large number of studies indicate that K + -induced contractions of smooth muscle depend on extracellular calcium. If these contractions depend exclusively on extracellular calcium then contractile responses to 140 mM K + , which are larger than the response to 35 mM K + , should be associated with a larger influx of 45 Ca. This is not the case in the vas deferens from reserpine pretreated rats. During a 2 min interval, 45 Ca influx induced by 140 mMK + was identical to that produced by 35 mM K + . This suggests that a second mechanism may be involved in responses to high K + . Indeed, 140 mM K + caused an approximately 300% increase above control in the formation of inositol trisphosphate (IP 3 ) in tissues prelabelled with 3 H-myoionositol whereas 35 mM K + did not increase IP 3 . IP 3 is thought to cause the release of calcium from internal stores which is consistent with our finding of an increase in 45 Ca efflux into calcium-free medium from tissues prelabelled with 45 Ca and stimulated with 140 mM K + . Stimulation with 35 mM K + did not influence 45 Ca efflux. We conclude that in the rat vas deferens high K + promotes tension development by smooth muscle by a dual mechanism: influx of extracellular calcium and release of calcium from internal stores via a IP 3 mechanism.
Elimination of Artifactual Acetaldehyde in the Measurement of Human Blood Acetaldehyde by the Use of Polyethylene Glycol and Sodium hide: Normal Blood Acetaldehyde Levels in the Dog and Human after Ethanol

A new procedure is described for the preparation of human blood samples for analysis of acetaldehyde and ethanol by head space gas chromatography. High concentrations of polyethylene glycol were used to remove the hemoglobin and approximately 50% of the plasma protein. Artifactual formation of acetaldehyde from ethanol was inhibited by sodium azide. Using this method, no artifactual acetaldehyde was detectable in human, dog, sheep, and rat blood when spiked with ethanol in final concentrations of 65 mM. The recovery of added acetaldehyde was approximately 80% for human dog, and sheep blood, whereas it was only 30% for rat blood. Following ethanol administration, acetaldehyde levels were determined in blood taken from the pulmonary artery and descending aorta of the dog and human, and also from the hepatic vein of the latter. The relative blood acetaldehyde concentrations at these sites were hepatic vein greater than pulmonary artery greater than descending aorta.
Abstract 4609: MEF2 plays a critical role in RENCA macrobead-induced tumor cell growth inhibition

Regulation of cell proliferation and cell death is often dependent on the coupling of extracellular signals to the activation or repression of specific intracellular signaling pathways. We have previously demonstrated the capacity of mouse renal adenocarcinoma (RENCA) cells encapsulated in agarose macrobeads to form numerous small tumor colonies within the macrobeads over a period of several months. As the encapsulated tumor colonies mature and reach a maximum size, the macrobeads themselves, or conditioned media from cultured macrobeads, markedly inhibit the in vitro and in vivo growth of epithelial-derived tumor cells outside the macrobead microenvironment. Myocyte enhancer factor 2 (MEF2) is a family of four transcription factors that have been shown to play a central role in linking signaling pathways to the genes responsible for cell division, differentiation and death. In this study, we evaluated the expression and role of MEF2 in regulating cell proliferation in mouse (RENCA) and human cell lines (J82, MCF7) in response to RENCA macrobeads. Freely growing RENCA target cells transiently transfected with a MEF2 transcriptional response element and exposed to conditioned media from variously aged macrobeads demonstrated increased response element activation in parallel with the increasing age of the macrobeads. Similarly, growth inhibition of the freely growing RENCA cells increased with older macrobeads. Suppression of the expressed MEF2 isoforms in target RENCA cells, either individually (MEF2a, MEF2b, and MEF2d) or in combination (MEF2pool) using synthetic small interfering RNA (siRNA) markedly reduced the growth inhibitory effects of RENCA macrobeads. In J82 and MCF7 cell lines, MEF2D expression was responsive to replete media from RENCA macrobeads, increasing 2.0-fold and 2.7-fold respectively. Degradation of MEF2D mRNA transcripts in the human cell lines studied resulted in abatement of the growth inhibitory effect of the RENCA macrobeads. These findings reveal an essential role for MEF2 in RENCA macrobead-induced cancer cell growth inhibition and raise interesting questions about the molecular basis of this response. Citation Format: Prithy C. Martis, Atira Dudley, Melissa A. Laramore, Barry H. Smith, Lawrence S. Gazda. MEF2 plays a critical role in RENCA macrobead-induced tumor cell growth inhibition. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4609. doi:10.1158/1538-7445.AM2014-4609
Human dopamine transporter gene polymorphism (VNTR) and alcoholism

The dopamine transporter (DAT1) is responsible for taking released dopamine back up into presynaptic terminals and terminating dopaminergic activity. It has been shown that cocaine binds to the dopamine transporter and blocks dopamine reuptake in a fashion that correlates with cocaine reward and reinforcement. To determine the role of this gene in the development of alcoholism, we have used two approaches, relative risk and haplotype relative risk. The relative risk approach involved 162 alcoholic probands who were categorized into type I and type II, and 89 unrelated normal controls. In the haplotype relative risk approach, 29 trios (father, mother, and proband) were genotyped with dopamine transporter gene polymorphism. Comparison of allele frequencies between total alcoholics, subtypes of alcoholics, and normal controls were negative. The results of haplotype relative risk, differences between alleles transmitted and nontransmitted, were also negative. However, both approaches produced similar results. Therefore, we concluded that the VNTR polymorphism in DAT1 gene is not associated with alcoholism susceptibility genes in our samples.
The Origin of Large Cosmic-Ray Bursts

Integral size-frequency distribution curves for cosmic-ray bursts of more than 100 particles were obtained by using an ionization chamber shielded by 1.25, 12, and 35 cm of iron. These distribution curves can all be represented by an inverse power law with exponent = 2.0\ifmmode\pm\else\textpm\fi{}0.2. The transition curve plotted from these data shows a pronounced maximum. Five G-M counter coincidence sets were arranged to register on the ionization chamber trace so that coincidences between bursts and air showers could be measured. For a thickness of 1.25 cm of iron, about 85 percent of the bursts were coincident with air showers, while for 12 cm of iron, this fraction was about 20 percent and for 35 cm of iron, only 5 percent of the bursts were observed to be coincident with extensive showers. A discussion is given to account for the origin of the bursts which were not coincident with air showers. For the analysis of the transition curve three different types of bursts are considered: bursts due to extensive atmospheric showers, bursts produced by narrow air showers or single high energy electrons, and bursts produced by mesotrons (knock-on and bremsstrahlung processes). Data for bursts of more than 500 particles under 12 cm of lead are compared with the corresponding data obtained under 35 cm of iron in order to determine the dependence of burst frequency on atomic number; the results are in substantial agreement with production of these bursts by bremsstrahlung of the mesotron. Integral size-frequency distribution curves are also plotted for data obtained during a five-year period at Huancayo (3350-meters elevation) and at Cheltenham (72 meters) for bursts under 12 cm of lead. The Cheltenham data are compared with the theoretical calculations of Christy and Kusaka for burst production by mesotrons of spin 0, \textonehalf{}, and 1 and it is concluded that either the spin 0 or the spin \textonehalf{} curve fits the experimental data but the evidence definitely excludes spin 1. The altitude dependence for burst under 12 cm of lead shows that the ratio of the burst frequencies at Huancayo and Cheltenham is constant for bursts up to 2400 particles, but increases sharply for still larger bursts. This increase is discussed on the basis that bursts under thick shields at higher altitudes may be caused either by extensive showers or by possible spin 1 mesotrons having so short a mean life that most of them fail to reach sea level.
Control of cell adhesion on poly(methyl methacrylate)

Keratoprostheses have been constructed from a wide variety of transparent materials, including poly(methyl methacrylate) (PMMA). However, the success of keratoprosthesis has been plagued by numerous shortcomings that include the weakening of the implant-host interface due to weak cell adhesion and opaque fibrous membrane formation over the inner surface of the implant due to fibroblast attachment. An effective solution requires a surface modification that would selectively allow enhanced cell attachment at the implant-host interface and reduced cell attachment over the interior surface of the implant. Here, we have developed a novel and simple peptide conjugation scheme to modify PMMA surfaces, which allowed for region-specific control of cell adhesion. This method uses di-amino-PEG, which can be grafted onto PMMA using hydrolysis or aminolysis method. PEG can resist cell adhesion and protein adsorption. The functionalization of grafted di-amino-PEG molecules with RGD peptide not only restored cell adhesion to the surfaces, but also enhanced cell attachment and spreading as compared to untreated PMMA surfaces. Long-term cell migration and micropatterning studies clearly indicated that PEG-PMMA surfaces with and without RGD conjugation can be used to differentiate cell adhesion and control cell attachment spatially on PMMA, which will have potential applications in the modification of keratoprostheses.
Light scattering in plant canopies: The method of Successive Orders of Scattering Approximations (SOSA)

Abstract The method of Successive Orders of Scattering Approximations (SOSA) involves computation of photons scattered once, twice, three times, etc., with the total intensity obtained as the sum over all orders. The method SOSA is briefly presented. The implemented formulation was tested for energy conservation in a conservatively scattering medium. The scattered fluxes for each order of scattering are presented to help understand the process of multiple scattering in plant canopies. The method was tested against measured values of canopy reflectance for a soybean canopy and also against the predictions of other established formulations published in the literature. Finally, some theoretical relationships between spectral indices, LAI and absorbed radiant energy are presented.
Observation of strong second harmonic generation from a single wurtzite GaAs nanoneedle

We demonstrate second harmonic generation from a single GaAs nanoneedle with a wurtzite crystal structure. The optical anisotropy of the polar crystal results in strong nonlinear optical conversion compared to normal zincblende GaAs.
ΔS=±1 Magnetic Quadrupole Radiative Transitions in Atoms and Molecules

The probabiliy of the spontaneous transition n 1 → n 2 through the magnetic quadrupole moment Q 2 m (mg) is \({P_{2m}}^{\text{(mg)}}(n_{1}{\rightarrow}n_{2}){=}(60\pi\hbar\varepsilon_{0})^{-1}\omega^{5}|(n_{1}|{Q_{2m}}^{\text{(mg)}}|n_{2})|^{2}{\cdot}{Q_{2m}}^{\text{(mg)}}\) is a tensor operator of order 2, and Q 20 (mg) =( e /µ)∑ i [3 z i s z i - r i · s i + z i l z i -( r i · l i /3)], where e 0 is the capacitivity of the vacuum, e and µ are electron charge and mass, respectively, r i , s i , and l i are coordinate, spin, and orbital angular momenta, respectively, of i -th electron. When the total spin S is a good quantum number the magnetic quadrupole moment can produce Δ S =±1 radiative transitions. Selection rules are J + J '≥2≥| J - J '|, L + L '≥1≥ L - L '|, and parity change. In many cases the resulting transition probability competes with that by spin-orbit electric dipole moment. Numerical values of these transition probabilities are calculated for many atoms, ions, and molecules using simple wa...
Analysis of microstructures in the meade plate of the Idaho-Wyoming foreland thrust belt, U.S.A.

Abstract Kinematic histories of several imbricate slices of the Meade plate in the Idaho-Wyoming foreland thrust belt were determined using analyses of e- lamellae in calcite, f- lamellae in dolomite, and sub-basal I deformation lamellae in quartz. Supporting these data were analyses of stylolites, strained fossils and other markers, and vein-filled extension fractures. Compression was always parallel or sub-parallel to bedding on upright fold limbs, and on overturned fold limbs was either sub-parallel or more commonly at a high angle to bedding. Extension in both limbs was generally either perpendicular to bedding or parallel to the fold axes. Observations in the hinge zones of folds were inconsistent, while near thrust faults the microstructures record compression at a high-angle to the nearby thrust surface. Measurement of different minerals in the same sample as well as cross-cutting stylolite-vein relations indicate that early compression was parallel to bedding while later compression was at a high angle to bedding. These data suggest that regional shortening and probably compressive stress was horizontal or sub-horizontal throughout the deformation, and that most of the strain within thrust plates is directly related to folding and not thrusting. The following structural history is proposed: 1. (1) initial layer-parallel compression; 2. (2) buckle-folding, soon yielding to more complex folding in a three-dimensional strain field; 3. (3) locking of folds; and 4. (4) locking(?) of thrusts. The fold locking angle as well as fold geometry indicates that these structures might be characterized as kink-folds, but the asymmetry is not consistent with theoretical analyses of kink-folds. Strain due to basal traction along the fault surface is only important within 50–200 m of that surface, depending on lithology.
Isolation of integrin αIIbβ3 (glycoprotein IIb-IIIa) from human platelets

This report describes a method for the purification of the platelet fibrinogen receptor, integrin αIIbβ3. The procedure involves lectin affinity chromatography on concanavalin-A agarose followed by heparin-agarose and gelatin-agarose. The integrin is further purified by gel filtration chromatography on Sephacryl S-300. Substantial amounts of purified αIIbβ3 are obtained (∼5 mg/10 units of platelets) and the procedure is easily scaled up or down.
CO2 hydrogenation to formic acid on Ni(110)

Periodic, self-consistent, density functional theory (DFT) calculations are employed to study CO2 hydrogenation on Ni(111). CO2 hydrogenation with H adsorbed on the surface and with H absorbed in the subsurface is investigated systematically, and the respective microscopic reaction mechanisms are elucidated. We show that on Ni(111) CO2 hydrogenation to formate intermediate is more favorable than to carboxyl intermediate. The hydrogenation to formate goes through the unidentate structure that rapidly transforms into the bidentate structure. Further hydrogenation from formate to formic acid is energetically more difficult than formate formation. Formation of adsorbed formic acid from adsorbed CO2 and surface hydrogen is an endothermic reaction. Because subsurface H in Ni(111) is substantially less stable compared to surface H, its reaction with adsorbed CO2 to adsorbed formic acid is an exothermic one. Our results may have significant implications for the synthesis of liquid fuels from CO2 and for catalytic...
Percutaneous balloon fenestration and stenting for life-threatening ischemic complications in patients with acute aortic dissection

Abstract Objectives: Acute aortic dissection frequently causes life-threatening ischemia of end-organs, historically associated with mortality exceeding 60%. Reperfusion with the use of interventional radiologic methods has evolved as a promising treatment. We report results of our initial 6 years of experience with percutaneous balloon fenestration of the intimal flap and endovascular stenting. Methods: Forty patients (32 male and 8 female) with a median age of 53 years (range 16-86 years) underwent percutaneous treatment for peripheral ischemic complications of 10 type A and 30 type B acute aortic dissections since 1991. Twenty patients had ischemia of multiple organ systems. Thirty patients had renal, 22 had leg, 18 had mesenteric, and 1 had arm ischemia. Results: Fourteen patients were treated with stenting of either the true or false lumen combined with balloon fenestration of the intimal flap, 24 with stenting alone, and 2 with fenestration alone. Successful revascularization was achieved in 93% ± 4% (±70% confidence levels) of patients (37/40). Nine patients had procedure-related complications. The 30-day mortality rate was 25% ± 7% (10/40), often related to irreversible ischemia of intra-abdominal organs that was present before the procedure. Of the remaining 30 patients, 5 have died and the remaining 25 continue to have relief of ischemic symptoms at a mean follow-up of 29 months. Conclusion: Percutaneous balloon fenestration of the intimal flap and endovascular stenting is an effective treatment for life-threatening ischemic complications of acute aortic dissection. (J Thorac Cardiovasc Surg 1999;117:1118-27)
Active Galactic Nucleus Feedback and Gas Mixing in the Core of NGC 4636

Chandra observations of NGC 4636 show disturbances in the galaxy X-ray halo, including armlike high surface brightness features (tentatively identified as active galactic nucleus-driven shocks) and a possible cavity on the west side of the galaxy core. We present Chandra and XMM-Newton spectral maps of NGC 4636 that confirm the presence of the cavity and show it to be bounded by the arm features. The maps also reveal a ~15 kpc wide plume of low-temperature, high-abundance gas extending 25-30 kpc to the southwest of the galaxy. The cavity appears to be embedded in this plume, and we interpret the structure as being entrained gas drawn out of the galaxy core during previous episodes of active galactic nucleus (AGN) activity. The end of the plume is marked by a well-defined edge, with significant falls in surface brightness, temperature, and abundance, indicating a boundary between galaxy and group/cluster gas. This may be evidence that as well as preventing gas cooling through direct heating, AGN outbursts can produce significant gas mixing, disturbing the temperature structure of the halo and transporting metals out from the galaxy into the surrounding intragroup medium.
Possible South-westward Continuations of the Cabot Fault

RECENTLY, Wilson1 directed attention to the Cabot (Palaeozoic) fault through Newfoundland, the Bay of Fundy, and along the New England coast. He compared it tentatively with the San Andreas of California and the Great Glen of Scotland. My colleagues and I2–5 have suggested similar faults of sub-parallel trend to the south-westward.
Prediction of stall and post-stall behavior of airfoils at low and high Reynolds numbers

An interactive boundary-layer method, together with the e(super n)-approach to the calculation of transition, has been used to predict the stall and post-stall behavior of airfoils at low and high Reynolds numbers. The turbulence model is based on the Cebeci-Smith algebraic eddy-viscosity formulation with improvements for strong pressure gradient effects and transitional flows at low Reynolds numbers. Comparison of calculated results for incompressible flows indicate good agreement with experiment for a wide range of Reynolds numbers. Preliminary calculations for low Mach number flows with this interactive method with compressibility corrections to the panel method indicate that, at a Mach number of 0.3, the compressibility effect on (C sub Q)max is not negligible.
Portal Hypertension and Granulomatous Liver Disease in a Lung Transplant Recipient due to Disseminated Atypical Mycobacterial Infection

The incidence of atypical mycobacterial infection among solid organ transplant recipients is increasing. While lung transplant recipients in particular are at greater risk of atypical mycobacterial infection than other solid organ transplant recipients, it is typically confined to the lung and disseminated infection remains quite rare. We describe a case of disseminated Mycobacterium avium-complex (MAC) in a lung transplant recipient presenting as granulomatous liver disease with signs of portal hypertension. After identification of the infection and institution of proper therapy, the patient had significant improvement in both clinical signs of portal hypertension and liver function tests. Current literature suggests a favorable prognosis in most cases of MAC infection in lung transplant recipients with appropriate treatment. This case highlights the need to maintain an elevated index of suspicion for atypical pathogens with unusual clinical presentations among the lung transplant population.
Tombusvirus-yeast interactions identify conserved cell-intrinsic viral restriction factors

To combat viral infections, plants possess innate and adaptive immune pathways, such as RNA silencing, R gene and recessive gene-mediated resistance mechanisms. However, it is likely that additional cell-intrinsic restriction factors (CIRF) are also involved in limiting plant virus replication. This review discusses novel CIRFs with antiviral functions, many of them RNA-binding proteins or affecting the RNA binding activities of viral replication proteins. The CIRFs against tombusviruses have been identified in yeast (Saccharomyces cerevisiae), which is developed as an advanced model organism. Grouping of the identified CIRFs based on their known cellular functions and subcellular localization in yeast reveals that TBSV replication is limited by a wide variety of host gene functions. Yeast proteins with the highest connectivity in the network map include the well-characterized Xrn1p 5’-3’ exoribonuclease, Act1p actin protein and Cse4p centromere protein. The protein network map also reveals an important interplay between the pro-viral Hsp70 cellular chaperone and the antiviral co-chaperones, and possibly key roles for the ribosomal or ribosome-associated factors. We discuss the antiviral functions of selected CIRFs, such as the RNA binding nucleolin, ribonucleases, WW-domain proteins, single- and multi-domain cyclophilins, TPR-domain co-chaperones and cellular ion pumps. These restriction factors frequently target the RNA-binding region in the viral replication proteins, thus interfering with the recruitment of the viral RNA for replication and the assembly of the membrane-bound viral replicase. Although many of the characterized CIRFs act directly against TBSV, we propose that the TPR-domain co-chaperones function as “guardians” of the cellular Hsp70 chaperone system, which is subverted efficiently by TBSV for viral replicase assembly in the absence of the TPR-domain co-chaperones.
Banding and the nature of large, irregular pearlite nodules in a hot-rolled low-alloy plate steel: A second report

The microstructure of a hot-rolled low-carbon plate steel has been examined using a combination of light microscopy and scanning electron microscopy. It has been found that in the hot-rolled condition, the microstructure consists of alternate bands of ferrite and pearlite, together with relatively large, irregular pearlite nodules. These large nodules were found to be comprised of pearlite, intragranularly nucleated ferrite (both Widmanstatten and idiomorphic), together with carbide-deficient and/or carbide-free regions. It is argued that the carbide-deficient and carbide-free regions form as a result of the premature initiation of the pearlite reaction, i.e. pearlite forms prior to the body of the austenite grains attaining the eutectoid composition. In order to model the formation of the banded structure, specimens were reaustenitized at 1050 °C for 10 min and furnace cooled. This heat-treatment cycle produced an austenite grain size which was less than the chemical banding wavelength. A model for the decomposition of austenite, under these conditions, is presented.
Continuous duty solar coal gasification system using molten slag and direct-contact heat exchange.

Abstract A new, very high temperature solar energy conversion technique which offers the potential of increasing the throughput and decreasing the cost of solar thermal coal gasification is described. Feedgas (CO2 or steam) is heated to very high temperatures in a direct-contact droplet heat exchanger using slag droplets melted in a solar central receiver. The heated feedgas is then reacted with coal in conventional reaction vessels. Thermal storage at the full thermodynamic potential of the solar receiver is an integral feature of this approach and permits operation of the gasifier at full capacity during periods of no sun.