cssi/SciSciGPT-SciSciNet huggingface dataset:
Shaping amine-based solid CO2 adsorbents: Effects of pelletization pressure on the physical and chemical properties

Abstract Amine-based solid adsorbents are promising candidates for the separation of CO2 from dilute gas streams. Here we report the effect of pelletization pressure on the physical and chemical properties of an array of supported amine adsorbents, based on mesoporous silica and γ-alumina supports. The virgin powders based on poly(ethyleneimine) (PEI) and 3-aminopropyltrimethoxysilane (APS) functionalized oxides are pressed at 1000 and 5000 psig pressure to form self-supporting pellets and their physical and chemical properties are compared. No change in chemical structure of the adsorbents is observed after pelletization, though the porosity of each material changes to some degree. Of the three mesoporous supports examined in this study, the commercial porous silica is the most stable support for both class 1 and class 2 adsorbents, whereas lab synthesized mesoporous SBA-15 silica and lab synthesized mesoporous γ-alumina are found to be the least stable supports for class 1 and class 2 adsorbents, respectively. The CO2 uptake results show a significant drop in equilibrium capacity for the pellets pressed at 5000 psig, regardless of the support used, while the 1000 psig pellets retain their capacity and show comparable performance to their powder counterparts. CO2 breakthrough experiments suggest an increase in mass transfer resistance for the pellet samples as compared with virgin powders, resulting in the dispersion of the concentration fronts during CO2 breakthrough using a fixed bed. These findings suggest that shaping solid supported amine adsorbents into binderless pellets requires pressing the powders at low to moderate pressures to ensure that these materials retain their performance in processes that require pelletized samples.
Analytical performance and economic evaluation of residential wind or wind and solar powered heating systems

Abstract A performance and cost model for a variety of wind powered space and water heating systems for single family residences is presented. In addition to wind powered systems, combined wind and solar systems are modeled and compared to conventional and solar only heating systems. Analytical results are presented for a site in Amherst, Massachusetts. System capital economic details include an itemized cost breakdown of the wind heating system components. The results demonstrate that wind powered systems are presently competitive with electric based heating systems and will be competitive with oil or gas systems in the future.
First-order random coefficient integer-valued autoregressive processes

A first-order random coefficient integer-valued autoregressive (RCINAR(1)) model is introduced. Ergodicity of the process is established. Moments and autocovariance functions are obtained. Conditional least squares and quasi-likelihood estimators of the model parameters are derived and their asymptotic properties are established. The performance of these estimators is compared with the maximum likelihood estimator via simulation.
A Jamesonian analysis of “flat world” imagery in education discourse

This article presents a discourse analysis of Kylene Beers’ presidential address to the 2009 conference of the National Council of Teachers of English (NCTE-USA). The address, titled “Sailing over the Edge: Navigating the Uncharted Waters of a World Gone Flat,” calls teachers to reject the standardized education of the industrial order and to harness the creativity at the heart of the “flat world” (i.e. global, knowledge-based capitalism). The discourse analysis focuses on the figure of the “flat world” – an increasingly common image in education research – and asks how the speech uses the figure of the “flat world” to reimagine the role of education under global capitalism. Mobilizing the ideas of Fredric Jameson, the Marxist literary critic, the article asks how the speech's story of education in the “flat world” offers “an imaginary resolution of a real contradiction” between industrial and knowledge-based capitalisms.
A 310‐helical pentapeptide in water: Interplay of α,α‐disubstituted amino acids and the central residue on structure formation

Cα,α-disubstituted amino acids (ααAAs) are widely used to conformationally constrain peptides. A series of pentapeptides containing dipropylglycine (Dpg) at alternating positions and their α-amino acid counterpart L-norvaline (Nva) analogues were synthesized to fully investigate the impact of Dpg on peptide backbone structure in aqueous solution. CD, VCD, and NMR spectral analysis suggest that Dpg containing peptides adopt more ordered structures relative to their Nva containing analogues. The central residues (Ala, Thr, Tyr, Val) and the charged side-chains of Glu and Lys play important roles in the degree of peptide folding. Hydrophobic and branched residues (Val, Tyr) at the central position of the peptide produce greater folding as judged by CD and NMR. Variation of the chemical shift with temperature (Δδ/ΔT NH) of Ac-Glu-Dpg-Tyr-Dpg-Lys-NH2 suggests a series of i → i + 3 hydrogen bonds between the N-terminal acetyl carbonyl and the Tyr3 NH, and the Glu1 carbonyl and the Dpg4 NH. The solution conformation of Ac-Glu-Dpg-Tyr-Dpg-Lys-NH2 calculated from NMR-derived constraints shows a 310-helical structure (two repetitive type-III β-turns) at residues 1-4, which is supported by 2D NMR, CD, and VCD spectra. Analysis of NMR-derived models of these peptides suggest that there is a strong hydrophobic interaction of the pro-S propyl side chain of Dpg2 and the Tyr3 side-chain that may be a strong stabilizing force of the peptide folding in water. © 2009 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 92: 452–464, 2009. This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Ostreococcus tauri ADP-glucose Pyrophosphorylase Reveals Alternative Paths for the Evolution of Subunit Roles

ADP-glucose pyrophosphorylase controls starch synthesis in plants and is an interesting case to study the evolution and differentiation of roles in heteromeric enzymes. It includes two homologous subunits, small (S) and large (L), that originated from a common photosynthetic eukaryotic ancestor. In present day organisms, these subunits became complementary after loss of certain roles in a process described as subfunctionalization. For instance, the potato tuber enzyme has a noncatalytic L subunit that complements an S subunit with suboptimal allosteric properties. To understand the evolution of catalysis and regulation in this family, we artificially synthesized both subunit genes from the unicellular alga Ostreococcus tauri. This is among the most ancient species in the green lineage that diverged from the ancestor of all green plants and algae. After heterologous gene expression, we purified and characterized the proteins. The O. tauri enzyme was not redox-regulated, suggesting that redox regulation of ADP-glucose pyrophosphorylases appeared later in evolution. The S subunit had a typical low apparent affinity for the activator 3-phosphoglycerate, but it was atypically defective in the catalytic efficiency (Vmax/Km) for the substrate Glc-1-P. The L subunit needed the S subunit for soluble expression. In the presence of a mutated S subunit (to avoid interference), the L subunit had a high apparent affinity for 3-phosphoglycerate and substrates suggesting a leading role in catalysis. Therefore, the subfunctionalization of the O. tauri enzyme was different from previously described cases. To the best of our knowledge, this is the first biochemical description of a system with alternative subfunctionalization paths.
Carotenoids and tocols of corn grain determined by HPLC

A high performance liquid chromatographic (HPLC) procedure has been developed that permits determinationof carotenoids and tocols in the same sample preparation of corn grain. For 15 inbreds, the total carotenoids ranged from 16 to 77 µg/g dry wt and the total tocols from 30 to 128 µg/g dry wt. For four inbreds, total carotenoids were concentrated in the horny endosperm (83±2%) and total tocols in the germ (77±6%). After six months storage at room temperature, the mean loss of total carotenoids for four inbreds was 42±4%, while the tocols had a mean loss of 5%.
Drivers of social media use among African Americans in the event of a crisis

Research has examined the role of social media during the time of a crisis in various fields; however, there is a paucity of research in this area as it relates to tourism. Moreover, few studies have examined at-risk populations, such as tourists, in times of crisis. To assess the drivers of turning to social media during a crisis, a national survey of 1,018 African American travelers was conducted. Respondents were asked to indicate on a 5-point scale the likelihood of turning to social media for information “if they were currently in the middle of their trip and heard that a crisis has just occurred within the immediate vicinity of their current location.” Hierarchical regression analysis was conducted to determine drivers on African American travelers’ decisions to use social media during a crisis. These drivers were age, perceptions of risk during their trip, and frequency and type of social media use engaged in on a regular basis. Overall, findings suggested that when controlling for age only, crime, financial, and physical perceptions of risk drove social media use during a crisis, while controlling for age and perception of risk, use of social media in one's daily life showed no influence.
Surgical management of overactive bladder.

The majority of patients with overactive bladder (OAB) can be managed with office-based techniques. When medical therapy fails as treatment for OAB, surgical intervention ranging from electric stimulation administered in the office to extensive procedures, such as augmentation or urinary diversion, may be needed. Any surgical intervention should be tailored to the patient with consideration of the degree of his or her discomfort, underlying pathology, general health, and obviously, the patient’s own motivation.
Stratigraphic responses to geologic processes: Late Pennsylvanian eustasy and tectonics in the Pedregosa and Orogrande basins, Ancestral Ricky Mountains

The primary factors that influence stratigraphy are tectonics, eustasy, and sediment supply. Because a change in any of these factors produces a concomitant change in relative base level or accommodation space, the link between a given process and its stratigraphic response is nonunique. Despite this ambiguity, distinguishing the origins of stratigraphic signals is theoretically possible by examining the temporal and especially the spatial scales of the signal. Correlation is a particularly critical tool for distinguishing global eustasy from regional tectonism. Upper Pennsylvanian strata of the Pedregosa and Orogrande basins (southern Ancestral Rocky Mountains) were deposited during a time of major continental collision coincident with extensive continental glaciation, and thus they contain a composite record of significant changes in tectonism, eustasy, and sediment supply. High-frequency stratigraphic cyclicity expressed as repetitive successions of lithofacies at the 10 m scale is prevalent in all sections and displays several features that collectively imply a primarily glacioeustatic origin: (1) abrupt juxtaposition of dissimilar lithofacies, signaling rates of base-level change best attributed to glacioeustasy; (2) apparent intrabasinal, interbasinal, and (provisional) interregional correlation of high-frequency cycles across and between contrasting tectonic environments; and (3) apparent cycle frequencies that bracket the 413 k.y. periodicity typical of orbital eccentricity, the probable forcing mechanism for Pennsylvanian glaciations. Aside from the prevalent high-frequency "cyclostratigraphy," multiple-cycle trends in facies and/or thicknesses define low-frequency stratigraphic patterns at the 10 2 m scale. Isolating and identifying the controlling factors for these patterns is not straightforward; nevertheless, qualitative analysis of multicyclic trends implicates distinct eustatic and tectonic processes as contributing influences. The eustatic component may derive partially from low-frequency glacioeustasy. The tectonic component almost certainly reflects Marathon-Ouachita collisional orogenesis.
HDAC4 Represses Vascular Endothelial Growth Factor Expression in Chondrosarcoma by Modulating RUNX2 Activity

Chondrosarcoma is a primary bone tumor with a dismal prognosis; most patients with this disease develop fatal pulmonary metastases, suggesting the need for a better systemic treatment. Anti-angiogenesis treatment may be useful, because angiogenesis is critical for both tumor growth and metastasis. Vascular endothelial growth factor (VEGF) is the most potent pro-angiogenic factor and is regulated by pathways related to the normal physiologic response to hypoxia and genetic alterations related to the malignant phenotype. Our prior work has shown that VEGF is overexpressed in high grade chondrosarcoma and chondrosarcoma cell lines. Working on the premise that developmental pathways giving a selective growth advantage are often recapitulated in tumors, we investigated the regulation of VEGF by HDAC4 and Runx2 in chondrosarcoma. We tested the hypothesis that there is dysregulation of HDAC4/Runx2/VEGF gene expression and that decreased HDAC4 expression accounts for at least some of the increased VEGF expression seen in chondrosarcoma. We show that reduced expression of HDAC4 in chondrosarcoma cells increases expression of Runx2 leading to increased expression of VEGF and in vitro angiogenesis. Thus, both hypoxia and dysregulated expression of a developmental pathway are causes of increased VEGF expression in chondrosarcoma.
Adolescents' text message communication and growth in antisocial behavior across the first year of high school

This study examined whether adolescents communicate about antisocial topics and behaviors via text messaging and how adolescents’ antisocial text message communication relates to growth in rule-breaking and aggression as reported by youth, parents, and teachers. Participants (n = 172; 82 girls) received BlackBerry devices configured to capture all text messages sent and received. Four days of text messages during the 9th grade year were coded for discussion of antisocial activities. The majority of participants engaged in at least some antisocial text message communication. Text messaging about antisocial activities significantly predicted increases in parent, teacher, and self-reports of adolescents’ rule-breaking behavior, as well as teacher and self-reports of adolescents’ aggressive behavior. Text message communication may provide instrumental information about how to engage in antisocial behavior and reinforce these behaviors as normative within the peer group.
Resistance to azoxystrobin in Alternaria isolates from pistachio in California

Abstract Failure to control Alternaria late blight in a few California pistachio orchards was observed after only 3–4 years of consecutive applications of azoxystrobin-based fungicide programs. A total of 72 isolates of Alternaria alternata, Alternaria tenuissima, and Alternaria arborescens, the causal organisms of Alternaria late blight, were collected from pistachio orchards with (58 isolates) and without (14 isolates) a prior history of azoxystrobin applications. The sensitivity to azoxystrobin was determined in conidial germination assays. Isolates from orchards with a history of azoxystrobin applications had EC50 values greater than 100 μg/ml, whereas isolates from orchards without a prior history of azoxystrobin usage had EC50 values ranging from 0.008 to 0.045 μg/ml. Azoxystrobin resistance correlated with a single mutation in the cytochrome b (cyt b) gene causing a change of glycine to alanine at amino acid position 143. A pair of PCR primers AF and AR was developed that amplified a 226-bp DNA fragment of the cyt b gene containing the mutation site from all three Alternaria species but not from 30 other fungal species frequently found on pistachio. PCR-restriction fragment length polymorphism (PCR-RFLP) analysis using the restriction enzyme Fnu4HI allowed differentiation of the PCR fragment of wild type cyt b gene from that of mutated gene. This method will aid in a fast detection of azoxystrobin resistance in these three Alternaria species.
Myocardial protection in reperfusion with postconditioning

Reperfusion is the definitive treatment for coronary occlusive disease. However, reperfusion carries the potential to exacerbate lethal injury, termed 'reperfusion injury'. Studies have suggested that reperfusion injury events are triggered during the early moments of reflow, and determine, in part, the severity of downstream manifestations of postischemic injury, including endothelial dysfunction, infarction and apoptosis. The application of brief iterative episodes of reflow (reoxygenation) and reocclusion (ischemia, hypoxia) at the immediate onset of reperfusion, which has been termed 'postconditioning' by the authors, reduces many manifestations of postischemic injury, notably infarct size, apoptosis, coronary vascular endothelial injury and reperfusion arrhythmias. Cardioprotection with postconditioning has been reported to be comparable with that observed using the gold standard maneuver ischemic preconditioning. In contrast to preconditioning, which exerts its effects primarily during the index ischemia, postconditioning appears to exert its effects during reperfusion alone. Postconditioning modifies the early phase of reperfusion in ways that are just beginning to be understood. It appears to first: reduce the oxidant burden and consequent oxidant-induced injury; secondly, attenuate the local inflammatory response to reperfusion; and thirdly, engage end effectors and signaling pathways implicated in other cardioprotective maneuvers, such as ischemic and pharmacologic preconditioning. Postconditioning seems to trigger the upregulation of survival kinases principally known to attenuate the pathogenesis of apoptosis and possibly necrosis. The postconditioning phenomenon has been reproduced by a number of independent laboratories and has been observed in both large and small animal in vivo models, as well as in ex vivo and cell culture models. In contrast to preconditioning, postconditioning may have widespread clinical application because it can be applied during reperfusion at the point of service for angioplasty, stenting, cardiac surgery and organ transplantation.
Status of Approval Plans in College Libraries

The author surveyed college libraries in the United States to determine their use of approval plans as a method of acquiring printed books for their collections. Survey results indicate recent trends over a five-year period, including shelf-ready books, e-notifications, and virtual approval plans as well as impending use of approval plans for e-books. Findings show a correlation between the size of the library book budget and the likelihood of having an approval plan. The author also presents results from an informal survey of domestic approval plan vendors on the status of the scholarly monograph market and its effect on approval plan use. While the number of books acquired through approval plans may have decreased slightly, overall approval plan use in college libraries has not declined. The approval plan continues to evolve and is an effective, time-saving tool for librarians pressed for time in a rapidly changing digital world.
Effectiveness of a silane coating against microbiologically influenced corrosion of an alumina-particle-reinforced aluminum 6061-matrix composite

Abstract The effectiveness of a self-assembled silane monolayer as protection for an alumina (aluminum oxide [Al2O3])-particle-reinforced aluminum-matrix composite against microbiologically influenced corrosion (MIC) was investigated. Tensile tests on coated and uncoated composite samples were conducted after microbiological exposures, and the effectiveness of these coatings against MIC was reported through mechanical strength and strain-to-failure measurements. Application of the silane monolayer to the composite surfaces was found to prevent degradation of the ultimate tensile strength (UTS) and strain-to-failure of the composite material in the fully annealed (temper designation: O) condition. In contrast, the UTS and strain-to-failure of the as-received extruded material (temper designation: F) were relatively insensitive to the corrosive effects of the marine Pseudomonas bacteria. Potentiodynamic corrosion measurements showed that the uncoated samples had a slightly lower pitting potential than the c...
A stochastic programming model to find optimal sample sizes to estimate unknown parameters in an LP

An LP is considered where the technology coefficients are unknown and random samples are taken to estimate them. A stochastic programming problem is formulated to find the optimal sample sizes where it is required that a confidence interval should cover the unknown deterministic optimum value by a given probability and the cost of sampling be minimum.
Contact analysis of biphasic transversely isotropic cartilage layers and correlations with tissue failure

Failure of articular cartilage has been investigated experimentally and theoretically, but there is only partial agreement between observed failure and predicted regions of peak stresses. Since trauma and repetitive stress are implicated in the etiopathogenesis of osteoarthritis, it is important to develop cartilage models which correctly predict sites of high stresses. Cartilage is anisotropic and inhomogeneous, though it has been difficult to incorporate these complexities into engineering analyses. The objectives of this study are to demonstrate that a transversely isotropic, biphasic model of cartilage can provide agreement between predicted regions of high stresses and observed regions of cartilage failure and that with transverse isotropy cartilage stresses are more sensitive to convexity and concavity of the surfaces than with isotropy. These objectives are achieved by solving problems of diarthrodial joint contact by the finite-element method. Results demonstrate that transversely isotropic models predict peak stresses at the cartilage surface and the cartilage-bone interface, in agreement with sites of fissures following impact loading; isotropic models predict peak stresses only at the cartilage-bone interface. Also, when convex cartilage layers contacted concave layers in this study, the highest tensile stresses occur in the convex layer for transversely isotropic models; no such differences are found with isotropic models. The significance of this study is that it establishes a threshold of modeling complexity for articular cartilage that provides good agreement with experimental observations under impact loading and that surface curvatures significantly affect stress and strain within cartilage when using a biphasic transversely isotropic model.
Constitutive differences in Cu/Zn superoxide dismutase mRNA levels and activity in hemocytes of Biomphalaria glabrata (Mollusca) that are either susceptible or resistant to Schistosoma mansoni (Trematoda)

Genetic strains of the snail Biomphalaria glabrata vary in their resistance to the parasite Schistosoma mansoni. Phagocytic cells (hemocytes) circulating in the hemolymph of B. glabrata play an essential role in the snail's innate immune response. Hemocytes of resistant B. glabrata kill S. mansoni in vitro via a mechanism which involves a respiratory burst. Reactive oxygen species (ROS), which are products of the respiratory burst, can act as mediators of both oxidative damage and of immune-related intracellular signaling pathways. One specific ROS, hydrogen peroxide (H2O2), has been shown to be involved in hemocyte-mediated sporocyst killing. We tested the hypothesis that Cu/Zn superoxide dismutase (SOD), a cytosolic enzyme that catalyzes the conversion of superoxide anion to H2O2, is somehow different between resistant and susceptible snail strains. We report a hemocyte transcript with all the features of a typical cytosolic Cu/Zn SOD (GenBank accession numbers AY505496 and AY505497). The amount of Cu/Zn SOD mRNA in hemocytes from resistant snails was double that of hemocytes from susceptible snails, and this correlated directly with an increased Cu/Zn SOD enzymatic activity in resistant hemocytes. Additional experiments determined that in vitro interaction/encapsulation of sporocysts did not influence Cu/Zn SOD mRNA levels in hemocytes from either snail strain. Thus, resistance in this host-parasite system does not appear to depend on a transcriptional response of hemocyte Cu/Zn SOD, but may be due, at least in part, to a constitutively elevated enzymatic level of Cu/Zn SOD.
Epidemiology of sinusitis in the primary care setting: results from the 1999-2000 respiratory surveillance program

The Respiratory Surveillance Program (RESP) was undertaken over a 10-month period (July to April) during the 1999-2000 respiratory infection season. A total of 16,213 nasal swab samples were taken by primary care physicians in outpatient settings from patients diagnosed as having acute bacterial rhinosinusitis. The samples were sent to a central laboratory where a pathogen was identified and antibiotic susceptibilities were determined. A pathogen could be isolated from 34% of the samples submitted. Four pathogens accounted for 79.7% of all identifiable isolates: Streptococcus pneumoniae (11.3%), Haemophilus influenzae (21.7%), Moraxella catarrhalis (28.9%), and Staphylococcus aureus (17.9%). Resistance to penicillin was found for S pneumoniae (16% fully resistant, 20% intermediate resistance). S pneumoniae had a 32% to 35% rate of resistance to erythromycin, azithromycin, and clarithromycin. H influenzae showed a high rate of resistance to clarithromycin (36%). M catarrhalis had a 15% rate of resistance to erythromycin and a 91.5% rate of resistance to penicillin. Low levels of resistance were seen to the newer fluoroquinolones levofloxacin (minimum inhibitory concentration [MIC](90) = 2 microg/mL) and gatifloxacin (MIC(90) = 0.5 microg/mL), with the 4 major bacterial isolates having a 95% to 100% rate of susceptibility to these medications. The results from the RESP study can give practicing physicians vital information about pathogen profiles and susceptibilities within their communities and help them in making appropriate treatment choices for their patients with acute rhinosinusitis. Patients with previous antibiotic exposure had a higher incidence of nonsusceptible strains than patients who did not receive prior therapy.
Algorithms for fast multidimensional signal extraction

Abstract In recent studies operator factorization techniques have been developed for problems associated with multidimensional control and image processing. In particular the “special factorization” of Gohberg and Krein and the Schur-Coleski factorization have both been extended to the multivariate setting. The present study focuses on computational aspects of the earlier results. Also of interest are implications for designing computer architectures which facilitate high-speed, online computation of the operator factors.
Tension Lung Cyst as a Complication of Postoperative Positive Pressure Ventilation Therapy

A patient with bilateral pneumothorax is presented in whom staged, bilateral pleural abrasions were planned. Following the removal of Webs from one lung, postoperative IPPV produced a tension lung cyst in the opposite lung causing compression of the lung and mediastinum, requiring emergency operation on the opposite thorax and resection of a giant bullae. The case is an unusual complication of IPPV therapy in a patient with chronic obstructive lung disease.
AN ANALYSIS OF THE HYDRODYNAMIC SEMICONDUCTOR DEVICE MODEL — BOUNDARY CONDITIONS AND SIMULATIONS

A mathematical analysis of the time‐dependent multi‐dimensional Hydrodynamic model is performed to determine the well‐posed boundary conditions for semiconductor device simulation. The number of independent boundary conditions that need to be specified at electrical contacts of a semi‐conductor device are derived. Using the classical energy method, a mathematical relation among the physical parameters is established to define the well‐posed boundary conditions for the problem. Several possible sets of boundary conditions are given to illustrate the proper boundary conditions. Natural boundary conditions that can be specified are obtained from the boundary integrals of the weak‐form finite element formulations. An example is included to illustrate the importance of well‐posedness of the boundary conditions for device simulation.
Analysis of Tricyclic Antidepressants in Human Plasma by GLC–Chemical-Ionization Mass Spectrometry with Selected Ion Monitoring

A method is described for the analysis of amitriptyline, doxepin, imipramine, nortriptyline, desmethyldoxepin, desipramine, and protriptyline in human plasma utlizing GLC-chemical-ionization mass spectrometry with selected ion monitoring. The assay is highly specific and is quantitative to at least 1 ng/ml with a standard error typically less than 5%. Representative concentrations of the parent compounds and their monodemethylated metabolites, as meeasured in plasma samples from patients under treatment with tertiary amine tricyclic antidepressants, are given.
Non-tuberculous mycobacterial infections after solid organ transplantation: a survival analysis.

Abstract The relationship of non-tuberculous mycobacterial (NTM) infections and survival among solid organ transplant recipients is unknown. We conducted a retrospective cohort study to measure the impact of NTM infection on survival in this patient population, comparing the effect of Mycobacterium abscessus infection with that of infections due to other pathogenic NTM species. We identified 33 patients with NTM infection post-transplantation, 18 with infection that was diagnosed within the first year. Although drug resistance was common among M. abscessus isolates, patients with M. abscessus infection did not have increased mortality compared with patients with other types of NTM infections (p 0.64). In contrast, we observed a significant association overall between early NTM infection and 3-year mortality post-transplantation (hazard ratio 8.76, 95% CI 2.69–28.57). The mortality burden of NTM infection following transplantation may be due to factors other than the virulence of the organisms. Multicentre studies are needed to identify the optimal approach for diagnosing and treating these uncommon but serious infections.
Spin Exchange Optical Pumping Enhanced 129Xe NMR Spectroscopy of SF6/Xe and Acetone-d6/Xe Mixed Type-II Clathrate Hydrates

Spin exchange optical pumping enhanced 129Xe NMR is applied to the study of SF6/Xe and acetone/Xe mixed type-II clathrate hydrate formation at 223 K. The highly polarized (i.e., hyperpolarized) 129Xe gas was reacted with the type-II structure that had been preformed by reaction of SF6 or acetone-d6 with solid ice at 205 K. At 223 K, enclathration into the preformed type-II structure was observed to occur on the time-scale of several minutes. The spectra show that Xe is excluded from the larger hexakaidecahedral cavities, and that the degree of exclusion appears to be more complete in the case of acetone-d6. A comparison of the 129Xe NMR line shapes in the acetone-d6/Xe and SF6/Xe mixed clathrate hydrates at 223 K reveals a reduction of symmetry of the dodecahedral cavities in the latter, apparently due to differences in the water reorientation dynamics.
Geography of invasion in mountain streams: consequences of headwater lake fish introductions

The introduction of fish into high-elevation lakes can provide a geographic and demographic boost to their invasion of stream networks, thereby further endangering the native stream fauna. Increasingly, remaining populations of native salmonids are concentrated in fragmented headwater refugia that are protected by physical or biological barriers from introduced fishes that originate in the pervasive source populations established at lower elevations. Although fish introduced near mainstem rivers frequently encounter obstacles to upstream dispersal, such as steep slopes or falls, we found that brook trout (Salvelinus fontinalis) dispersed downstream through channel slopes of 80% and 18-m-high falls. Thus, headwater lake stocking provides source populations that may be capable of invading most downstream habitats, including headwater refugia of native fishes. The extent of additional area invasible from lakes, beyond that invasible from downstream, depends on the geography of the stream network, particularly the density and distribution of headwater lakes and their location relative to barriers inhibiting upstream dispersal. In the thermal and trophic environments downstream of lakes, fish commonly grow faster and thus mature earlier and have higher fecundity-at-age than their counterparts in other high-elevation streams. The resulting higher rates of population growth facilitate invasion. Larger body sizes also potentially aid the fish in overcoming barriers to invasion. Trout introductions to high-elevation headwater lakes thus pose disproportionately large risks to native fishes—even when the place of introduction may appear to be spatially dissociated from populations of the native species. Mapping the potential invasible area can help to establish priorities in stocking and eradication efforts.
A novel reconfigurable origami accordion antenna

An accordion origami structure is presented, which can be expanded and collapsed. Based on this structure, one origami antenna is designed with operating frequency that can be changed based on its height. A prototype antenna model is manufactured to validate the simulation model. The return loss, far-field radiation pattern and peak gain of this antenna are reported using simulations and measurements.
Numerical simulations of a shock interacting with successive interfaces using the Discontinuous Galerkin method: the multilayered Richtmyer–Meshkov and Rayleigh–Taylor instabilities

In this work, we investigate the growth of interface perturbations following the interaction of a shock wave with successive layers of fluids. Using the Discontinuous Galerkin method, we solve the two-dimensional multifluid Euler equations. In our setup, a shock impacts up to four adjacent fluids with perturbed interfaces. At each interface, the incoming shock generates reflected and transmitted shocks and rarefactions, which further interact with the interfaces. By monitoring perturbation growth, we characterize the influence these instabilities have on each other and the fluid mixing as a function of time in different configurations. If the third gas is lighter than the second, the reflected rarefaction at the second interface amplifies the growth at the first interface. If the third gas is heavier, the reflected shock decreases the growth and tends to reverse the Richtmyer–Meshkov instability as the thickness of the second gas is increased. We further investigate the effect of the reflected waves on the dynamics of the small scales and show how a phase difference between the perturbations or an additional fluid layer can enhance growth. This study supports the idea that shocks and rarefactions can be used to control the instability growth.
β-N-Oxalylamino-L-Alanine Action on Glutamate Receptors

beta-N-Oxalylamino-L-alanine (L-BOAA) is a non-protein excitatory amino acid present in the seed of Lathyrus sativus L. This excitotoxin has been characterized as the causative agent of human neurolathyrism, an upper motor neuron disease producing corticospinal dysfunction from excessive consumption of the lathyrus pea. Previous behavioral, tissue-culture, and in vitro receptor binding investigations revealed that L-BOAA might mediate acute neurotoxicity through quisqualate (QA)-preferring glutamate receptors. The present study demonstrates the stereospecific action of L-BOAA on glutamate receptor binding in whole mouse brain synaptic membranes. L-BOAA was most active in displacing thiocyanate (KSCN)-sensitive specific tritiated (RS)-alpha-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) binding (i.e., QA receptor) (Ki = 0.76 microM) with a rank-order potency of QA greater than kainate greater than N-methyl-D-aspartate (NMDA). By contrast, the nonneurotoxic D-BOAA isomer (100 microM) was essentially inactive in displacing radioligands for glutamate receptors, except the NMDA site, where it was equipotent with L-BOAA. Scatchard analysis of L-BOAA displacement of specific [3H]AMPA binding indicated competitive antagonism (KD: control, 135 nM; L-BOAA, 265 nM) without a significant change in QA-receptor density, and Hill plots yielded coefficients approaching unity. Differential L-BOAA concentration-dependent decreases in specific [3H]AMPA binding were observed in synaptic membranes, indicating that the neurotoxin was more potent in displacing specific binding from frontal cortex membranes, followed by that for corpus striatum, hippocampus, cerebellum, and spinal cord. (ABSTRACT TRUNCATED AT 250 WORDS)
Determination of Sugars in Aqueous Mixtures Using Mid-infrared Spectroscopy

The combination of mid-infrared (MIR) spectroscopy and multivariate statistics for determination of glucose, fructose, and sucrose in aqueous mixtures was investigated. Spectra of different samples were recorded in the MIR range between 400 and 4000 nm. Aqueous mixtures of 10, 20, and 40% total sugars with different combinations of glucose, fructose and sucrose were used for calibration and validation studies. Spectral wavenumber region from 700 to 1530 cm –1 was selected for Principal Component Regression (PCR) and Partial Least Square regression (PLS) to develop calibration models for sugar content determination (%, w/v) in liquid foods. Results from the PLS-1 (first derivative) models were slightly better than those obtained with other used calibration models. Merging of the 10, 20, and 40% calibration data into single calibration set enabled the prediction (average standard error of calibration, SEC = 0.34) of individual sugars in the entire range accurately. The squared correlation (R 2 ) values for the calibrated models for glucose, fructose and sucrose were 0.997, 0.998, and 0.997, respectively, between the predicted values and actual values. The calibrations were successfully applied to predict sugar contents in complex mixtures and commercial beverages. Results indicated that fourier transform infrared (FTIR) spectroscopy can be used for rapid detection of sugars in complex mixtures.
Conceptual and empirical developments of marketing channel conflict

Managers regularly have to struggle with conflict within the marketing channel and it is therefore important that marketing managers should have an understanding of conflict and its meaning in the channel setting. This paper attempts to provide a background to this understanding by reviewing the conceptual and empirical developments in the field of marketing channel conflict. These developments are drawn together into an integrated model of current research into channel conflict.
WISC-R factor scores and student self-ratings of behavior as predictors of academic achievement

The capability of WISC-R Verbal Comprehension (VC), Perceptual Organization (PO), and Freedom from Distractibility (FD) factor scores and student self-ratings of behavior from the Behavior Rating Profile Student Rating Scales (BRP-SRS) to predict academic achievement was investigated. Previous research found that intellectual ability accounted for about 50% of the variance in achievement. Other noncognitive variables are expected to account for a portion of the remaining variance and add significantly to the prediction of achievement. Subjects were public school students referred for psychological evaluations due to learning and behavior problems in the classroom. The results of a multivariate multiple regression analysis indicated that VC and FD factors significantly predicted Woodcock-Johnson Reading, Mathematics, and Written Language cluster scores. The VC and FD factors accounted for a major portion of the variance in achievement. Behavioral self-ratings did not contribute significantly to the prediction of achievement scores.
Diffusion-weighted sequence on MRI for the diagnosis of Creutzfeldt-Jakob disease

Creutzfeldt-Jakob disease (CJD) is a progressive and fatal dementing illness caused by a virus like agent called prion. Currently, the definitive diagnosis can only be made through brain biopsy. Given its potential transmissibility, it is paramount to have noninvasive and reliable means to detect the disease. The present case reports on a 63 year-old man with biopsy proven CJD, and evaluates the dependability of diffusion-weighted MRI in this condition, stressing the importance of this particular sequence to its diagnosis.
Neuropeptidomics of the Supraoptic Rat Nucleus

The mammalian supraoptic nucleus (SON) is a neuroendocrine center in the brain regulating a variety of physiological functions. Within the SON, peptidergic magnocellular neurons that project to the neurohypophysis (posterior pituitary) are involved in controlling osmotic balance, lactation, and parturition, partly through secretion of signaling peptides such as oxytocin and vasopressin into the blood. An improved understanding of SON activity and function requires identification and characterization of the peptides used by the SON. Here, small-volume sample preparation approaches are optimized for neuropeptidomic studies of isolated SON samples ranging from entire nuclei down to single magnocellular neurons. Unlike most previous mammalian peptidome studies, tissues are not immediately heated or microwaved. SON samples are obtained from ex vivo brain slice preparations via tissue punch and the samples processed through sequential steps of peptide extraction. Analyses of the samples via liquid chromatography mass spectrometry and tandem mass spectrometry result in the identification of 85 peptides, including 20 unique peptides from known prohormones. As the sample size is further reduced, the depth of peptide coverage decreases; however, even from individually isolated magnocellular neuroendocrine cells, vasopressin and several other peptides are detected.
Inhibitory Transmission Mediated by Asynchronous Transmitter Release

At fast CNS synapses, the role of asynchronous release following initial synchronous release is poorly understood. We examined the contribution of asynchronous release to GABAergic transmission in the cochlear nucleus across a 40-fold range of electrical stimulus frequencies. Whereas quantal release was highly synchronized at low frequencies, it was largely continuous and desynchronized at high frequencies. Despite the change in release mode, intense and steady inhibitory transmission was virtually maintained. Experimental analyses and modeling studies indicated that this "desynchronization" process was dependent on presynaptic Ca2+ accumulation, facilitation of vesicle release, and short-term depletion of available vesicles. Asynchronous release at high frequencies may help generate a smooth inhibitory "tone" by minimizing the consequences of random timing of presynaptic action potentials.
E-science meets computational science and information technology

Over the last decade or so, there has been much discussion of and progress in computational science. The US High Performance Computing and Communications Initiative and the National Science Foundation (NSF) grand challenge programs largely focused on this trend. Now the NSF has a new cyber infrastructure report continuing the same emphasis on distributed systems. The author looks at the impact of these trends on computational science and its associated technology and research.
Markov decisions in urban modelling

In urban fire departments, fire companies are dispatched to respond to alarms which occur spatially and temporally in a generally unpredictable way. Also, the time during which one of the responding units is busy on a call, and hence unavailable to other alarms, is itself a random variable. This variability in demand and service time makes it difficult to maintain a balance between the need for effective response to alarms which occur now and those which may arrive in the future. In this paper, we discuss two specific mathematical models, based on work done by the Rand Institute in New York City, for determining not only how many but also which of the available fire-fighting units to deploy to any given alarm. Each is a Markovian decision model in which the conflicting objectives of adequate response to present or future incidents are explicity accounted for. Similar considerations are applicable to other municipal emergency services.
Cortical development and topographic maps: patterns of cell dispersion in developing cerebral cortex

Cortical neurons are organized into highly patterned ensembles of cells, each with a distinct physiological function. The precursors of these cells arise in the ventricular zone, itself a highly patterned mosaic of cells. To determine whether the ventricular pattern presages the adult, investigators examine the process of cell migration. Recent evidence suggests that both radial (pattern-preserving) and tangential (pattern-blurring) cell movements occur during development.
Generational Identity and Memory in American Newsmagazines

This article examines the role of journalism in constructing generational labels - such as the Baby Boom, Generation X, Generation Y and the ‘Greatest Generation’ - and in articulating their meaning over time. Through narrative and rhetorical analysis, it examines 20 years of cover stories about generational identity in leading American newsmagazines. The study contends that, even while they situate particular people within particular historical contexts, such ‘special reports’ employ common narrative devices and themes of youth and nostalgia, blending the stories of individual groups into broader notions about generational and national identity. This kind of reporting extends journalists’ cultural authority and is a matter of memory as well as ‘news’, offering not just definitions of current social identity but also future understandings of a shared past.
The solution and solid state stability and excipient compatibility of parthenolide in feverfew.

The objectives of this research were to evaluate the stability of parthenolide in feverfew solution state and powdered feverfew (solid state), and explore the compatibility between commonly used excipients and parthenolide in feverfew. Feverfew extract solution was diluted with different pH buffers to study the solution stability of parthenolide in feverfew. Powdered feverfew extract was stored under 40°C/0%∼75% relative humidities (RH) or 31% RH/5∼50°C to study the influence of temperature and relative humidity on the stability of parthenolide in feverfew solid state. Binary mixtures of feverfew powered extract and different excipients were stored at 50°C/ 75% RH for excipient compatibility evaluation. The degradation of parthenolide in feverfew solution appears to fit a typical first-order reaction. Parthenolide is comparatively stable when the environmental pH is in the range of 5 to 7, becoming unstable when pH is less than 3 or more than 7. Parthenolide degradation in feverfew in the solid state does not fit any obvious reaction model. Moisture content and temperature both play important roles affecting the degradation rate. A fter 6 months of storage, parthenolide in feverfew remains constant at 5°C/31% RH. However, ∼40% parthenolide in feverfew can be degraded if stored at 50°C/31% RH. When the moisture changed from 0% to 75% RH, the degradation of parthenolide in feverfew increased from 18% to 32% after 6-month storage under 40°C. Parthenolide in feverfew exhibits good compatibility with commonly used excipients under stressed conditions in a 3-week screening study.