cssi/SciSciGPT-SciSciNet huggingface dataset:
Relationships between indicators of cardiovascular disease and intensity of oil and natural gas activity in Northeastern Colorado

Structured abstract Background Oil and natural gas (O&G) extraction emits pollutants that are associated with cardiovascular disease, the leading cause of mortality in the United States. Objective: We evaluated associations between intensity of O&G activity and cardiovascular disease indicators. Methods Between October 2015 and May 2016, we conducted a cross-sectional study of 97 adults living in Northeastern Colorado. For each participant, we collected 1–3 measurements of augmentation index, systolic and diastolic blood pressure (SBP and DBP), and plasma concentrations of interleukin (IL)− 1β, IL-6, IL-8 and tumor necrosis factor alpha (TNF-α). We modelled the intensity of O&G activity by weighting O&G well counts within 16 km of a participant's home by intensity and distance. We used linear models accounting for repeated measures within person to evaluate associations. Results Adjusted mean augmentation index differed by 6.0% (95% CI: 0.6, 11.4%) and 5.1% (95%CI: −0.1, 10.4%) between high and medium, respectively, and low exposure tertiles. The greatest mean IL-1β, and α-TNF plasma concentrations were observed for participants in the highest exposure tertile. IL-6 and IL-8 results were consistent with a null result. For participants not taking prescription medications, the adjusted mean SBP differed by 6 and 1 mm Hg (95% CIs: 0.1, 13 mm Hg and −6, 8 mm Hg) between the high and medium, respectively, and low exposure tertiles. DBP results were similar. For participants taking prescription medications, SBP and DBP results were consistent with a null result. Conclusions Despite limitations, our results support associations between O&G activity and augmentation index, SBP, DBP, IL-1β, and TNF-α. Our study was not able to elucidate possible mechanisms or environmental stressors, such as air pollution and noise.
In Situ Measurements of the Inhibitory Effects of Low Leaf Water Potentials on Photophosphorylation

Photosynthetic activity declines as water becomes limited and the leaf water potential (Ψl) decreases. While these losses in photosynthesis performance are due in part to partial stomatal closure, in many cases direct effects of the water deficits on chloroplasts are more important. For instance in sunflower (Helianthus annuus L. cv. 1S894), although an increase in leaf diffusive resistance from about 2 to about 8 sec-cm-1 was observed to accompany a decrease in Ψl from -0.33 to -1.63 MPa, this stomatal closure did not result in a decline in the intercellular CO2 concentration (1). Clearly the 75% reduction in rate of net photosynthesis induced by this drop in Ψl was not due to the stomatal closure. Two major contributors to the chloroplast level inhibition have been implicated, water oxidation and photophosphorylation. Previous work on isolated coupling factor (CF1) indicated that the losses in photophosphorylation activity associated with low Ψl may result from direct effects of dehydration-induced increases in the stromal concentration of cations (2, 3). In the work reported here we have extended the earlier rn vitro studies on the effects of Ψl on photophosphorylation to the level of intact leaves.
Platelet indices as biomarkers for characterization and determination of severity in canine chronic enteropathy.

Abstract Human studies have shown an association between certain platelet indices and active inflammatory bowel disease when compared to healthy controls. The objectives of this retrospective study were to determine if any platelet indices differ between dogs with chronic enteropathies and healthy age- and sex-matched control dogs and are predictive of the severity of chronic enteropathy based on canine chronic enteropathy clinical activity index (CCECAI) scores. Medical records for 22 chronic enteropathy-positive dogs and 22 healthy control dogs were reviewed for historical and physical examination findings, platelet indices, and histologic diagnoses of chronic enteropathy. Platelet indices were compared between the groups, and an association between platelet indices and CCECAI scores in dogs with chronic enteropathy was investigated. Chronic diarrhea and weight loss were common clinical signs associated with chronic enteropathy. Lymphoplasmacytic enteritis was the most common histologic diagnosis. Only one platelet index, platelet component distribution width (P = 0.045), was found to be significantly different between the groups. For predicting severity of disease, determined by CCECAI score, statistically significant differences in indices associated with higher scores were platelet count (P = 0.024) and platelet dry mass distribution width (P = 0.036). Only platelet component distribution width showed potential in characterizing dogs with chronic enteropathy compared to normal dogs. Elevated platelet count and decreased platelet dry mass distribution width had a significant effect on total CCECAI scores. These findings suggest further investigation into the utility of platelet indices as predictors of disease presence and severity in dogs with chronic enteropathy is warranted.
Authenticity Is in the Eye of the Beholder: The Exploration of Audiences’ Lay Associations to Authenticity Across Five Domains:

Existing research has proposed multiple definitions to authenticity. Instead of such a definitional approach, this article takes a bottom-up approach and provides an exploratory assessment of lay a...
Pharmacokinetics and pharmacodynamics of cinacalcet in hepatic impairment : phase I, open-label, parallel-group, single-dose, single-centre study.

The calcimimetic cinacalcet lowers blood parathyroid hormone (PTH), calcium and phosphorus levels and calcium-phosphorus product in patients with chronic kidney disease receiving dialysis. Cinacalcet is metabolized primarily through oxidative and conjugative pathways. Hepatic disease has the potential to alter cinacalcet metabolism. Thus, it is important to establish the potential for altered cinacalcet metabolism according to the level of hepatic function. This study aimed to evaluate the pharmacokinetics and pharmacodynamics of cinacalcet in subjects with different degrees of hepatic function. This was a phase I, open-label, single-dose, parallel-group, single-centre study that included 24 subjects (six with normal hepatic function and six each with mild, moderate and severe hepatic impairment according to Child-Pugh criteria). Subjects were given a single 50 mg oral dose of cinacalcet. Blood samples were taken for pharmacokinetic (pre-dose and up to 120 hours post-dose) and pharmacodynamic (pre-dose and up to 72 hours post-dose) evaluations. Plasma concentrations of cinacalcet were determined using a validated normal phase turbo ion spray liquid chromatography-mass spectrometry/mass spectrometry assay. Serum ionized calcium levels were determined by standard biochemical measures, and PTH levels were determined using an immunometric intact PTH (iPTH) assay. The primary endpoints of the study were area under the concentration-time curve from 0 to time t (AUCt), AUC from 0 to infinity (AUC∞) and maximum plasma concentration (Cmax). Other pharmacokinetic parameters (time to Cmax [tmax], terminal half-life [t1/2β], total body clearance [CL/F] and protein binding) and the effect of cinacalcet on plasma PTH and serum calcium were secondary endpoints. Results: Total cinacalcet exposure (AUC∞) was comparable in subjects with normal hepatic function and mild hepatic impairment. In subjects with moderate and severe hepatic impairment, mean AUC∞ was 2.4- and 4.2-fold higher, respectively, than in healthy subjects. Cinacalcet t1/2β was 1.3- and 1.7-fold longer in subjects with moderate and severe hepatic impairment, respectively, compared with subjects with normal hepatic function. Mean Cmax and tmax, as well as protein binding, were similar in all groups. Consistent with the increase in cinacalcet exposure, decreases in iPTH tended to be greater and prolonged in subjects with moderate and severe hepatic impairment. In this study, cinacalcet was well tolerated. These data demonstrate that cinacalcet can be used without dose adjustment in patients with mild hepatic impairment. However, increased drug exposure observed in subjects with moderate to severe hepatic impairment indicates that iPTH and serum calcium levels should be monitored closely and physicians should be more cautious about dose titration in patients with moderate or severe hepatic impairment.
Validating datacenters at scale

We describe our experiences using formal methods and automated theorem proving for network operation at scale. The experiences are based on developing and applying the SecGuru and RCDC (Reality Checker for Data Centers) tools in Azure. SecGuru has been used since 2013 and thus, is arguably a pioneering industrial deployment of network verification. SecGuru is used for validating ACLs and more recently RCDC checks forwarding tables at Azure scale. A central technical angle is that we use local contracts and local checks, that can be performed at scale in parallel, and without maintaining global snapshots, to validate global properties of datacenter networks. Specifications leverage declarative encodings of configurations and automated theorem proving for validation. We describe how intent is automatically derived from network architectures and verification is incorporated as prechecks for making changes, live monitoring, and for evolving legacy policies. We document how network verification, grounded in architectural constraints, can be integral to operating a reliable cloud at scale.
Exploratory Study of Apparent Diffusion Coefficient Histogram Metrics in Assessing Pancreatic Malignancy

Abstract Purpose To evaluate whole-lesion 3D-histogram apparent diffusion coefficient (ADC) metrics for assessment of pancreatic malignancy. Methods Forty-two pancreatic malignancies (36 pancreatic adenocarcinoma [PDAC], 6 pancreatic neuroendocrine [PanNET]) underwent abdominal magnetic resonance imaging (MRI) with diffusion-weighted imaging before endoscopic ultrasound biopsy or surgical resection. Two radiologists independently placed 3D volumes of interest to derive whole-lesion histogram ADC metrics. Mann-Whitney tests and receiver operating characteristic analyses were used to assess metrics’ diagnostic performance for lesion histology, T-stage, N-stage, and grade. Results Whole-lesion ADC histogram metrics lower in PDACs than PanNETs for both readers (P ≤ .026) were mean ADC (area under the curve [AUC] = 0.787-0.792), mean of the bottom 10th percentile (mean0-10) (AUC = 0.787-0.880), mean of the 10th-25th percentile (mean10-25) (AUC = 0.884-0.917) and mean of the 25th-50th percentile (mean25-50) (AUC = 0.829-0.829). For mean10-25 (metric with highest AUC for identifying PDAC), for reader 1 a threshold > 0.94 × 10−3 mm2/s achieved sensitivity 94% and specificity 83%, and for reader 2 a threshold > 0.82 achieved sensitivity 97% and specificity 67%. Metrics lower in nodal status ≥ N1 than N0 for both readers (P ≤ .043) were mean0-10 (AUC = 0.789-0.822) and mean10-25 (AUC = 0.800-0.822). For mean10-25 (metric with highest AUC for identifying N0), for reader 1 a threshold .195) or grade (P > .215). Conclusion Volumetric ADC histogram metrics may serve as non-invasive biomarkers of pancreatic malignancy. Mean10-25 outperformed standard mean for lesion histology and nodal status, supporting the role of histogram analysis.
Different Shades of Risk: Mortality Trends Implied by Term Insurance Prices

To infer forward-looking, market-based mortality trends, we estimate a flexible affine stochastic mortality model based on a set of U.S. term life insurance prices using a generalized method of mom...
Quantum Monte Carlo with Complex Weights

We present a diffusion quantum Monte Carlo algorithm for simulating complex systems, such as anyons or systems with external magnetic fields. In this algorithm, anyons are represented as hard-core bosons with an attached (fictitious) statistical flux tube, such that for fermions there is precisely one flux quantum attached to each bare boson. We discuss how this complexity can affect quantum Monte Carlo simulations, and present some results of simulations for small systems. We find that the sampling error due to complex weights can be continuously varied by varying the two kinds of flux (statistical, and.external), and that the two kinds of flux have roughly comparable effects on the sampling error.
Quantifying the effect of tow architecture variability on the performance of biaxially braided composite tubes

Abstract Targeted experiments are performed with stereoscopic digital image correlation to quantify the effect of irregular braid structure on the local surface mechanical response of carbon-fiber reinforced epoxy composite tubes. Virtual models comparing both nonuniform and uniform tow structure of the outer braid of each specimen are integrated into numerical simulations similar to experiments. Experimental and numerical results agree well. Statistical tests are used to support correlations between as-manufactured braid variation ranges to local increases in stress up to 18% compared to an ideal, uniform structure in the elastic regime. Results support improved manufacturing and modeling efforts of defect sensitive braided composites.
The rise of the organisational society in Canadian and U.S. textbooks: 1836-2011

This paper examines how organisations have increasingly been portrayed in textbooks as solving social problems as well as contributing to national development. Findings from 527 Canadian and U.S. t...
An Ion-Pairing Approach to Stereoselective Metal-Free Ring-Opening Metathesis Polymerization.

Stereochemistry can have a profound impact on polymer and materials properties. Unfortunately, straightforward methods for realizing high levels of stereocontrolled polymerizations are often challenging to achieve. In a departure from traditional metal-mediated ring-opening metathesis polymerization (ROMP), we discovered a remarkably simple method for controlling alkene stereochemistry in photoredox mediated metal-free ROMP. Ion-pairing, initiator sterics, and solvation effects each had profound impact on the stereochemistry of polynorbornene (PNB). Simple modifications to the reaction conditions produced PNB with trans alkene content of 25 to >98 %. High cis content was obtained from relatively larger counterions, toluene as solvent, low temperatures (-78 °C), and initiators with low Charton values. Conversely, smaller counterions, dichloromethane as solvent, and enol ethers with higher Charton values enabled production of PNB with high trans content. Data from a combined experimental and computational investigation are consistent with the stereocontrolling step of the radical cationic mechanism proceeding under thermodynamic control.
NSLS-II longitudinal impedance budget

Abstract From the beginning of the NSLS-II project, the vacuum chamber of the NSLS-II storage ring has been optimized to reduce its impedance. The optimization, performed in close collaboration with the Diagnostic, Vacuum, RF, and Mechanical Engineering groups, has been achieved via calculating the impedance of the vacuum chamber components with the use of both analytical and numerical tools, with the numerical computations carried out with the GdfidL code. For reliable NSLS-II operation with the total beam current of 500 mA, each component of the vacuum chamber has been individually optimized to minimize the beam-induced heating and to prevent single-bunch and coupled-bunch instabilities. In this article, the impedance calculation and optimization know-how are summarized for all the chamber components, and the total longitudinal impedance budget is analyzed. As a result of this extensive research and engineering effort, the design beam current of 500 mA has been recently accumulated in NSLS-II without any major problem caused by the collective effects.
A Panel Discussion of “Major Unsolved Problems of Cosmology”

I would first like to ask my distinguished co-panelists to introduce themselves briefly. I will then ask each to make a five-minute comment on “major unsolved problems of cosmology”. It will be followed by discussions among the panelists and also with the audience.
Setting the agenda: Electoral competition, commitment of policy, and issue salience

By committing policy, an incumbent in effect disowns an issue; when she maintains policy flexibility, the issue remains electorally salient. Electoral competition shapes political commitment decisions and collapses the multi-dimensional issue space into a low-dimensional space of electorally salient issues.
Transcanal approach for implantation of a cochlear nerve electrode array

Author(s): Kiumehr, Saman; Mahboubi, Hossein; Middlebrooks, John C; Djalilian, Hamid R | Abstract: Objectives/hypothesisTo evaluate a transcanal approach for placement of a stimulating electrode array in the cochlear nerve.Study designProspective cadaveric temporal bone study.MethodsTen human cadaveric temporal bones were dissected. Both a facial recess approach with mastoidectomy and a transcanal approach using the novel technique were performed in each bone. A middle fossa dissection of the internal auditory canal was performed to confirm the position of the electrode in the cochlear nerve.ResultsThe transcanal approach offered a direct approach to the cochlear nerve in all 10 bones. The procedure was quicker than the facial recess approach and did not endanger the facial or chorda tympani nerves. Inspection of the medial end of the internal auditory canal confirmed correct placement of the electrode in the cochlear nerve. In contrast, anatomical constraints, specifically the position of the facial nerve, blocked access to the cochlear nerve by the facial recess approach in three of the specimens to achieve the exposure to place the electrode at a perpendicular angle to the cochlear nerve. Sacrifice of the chorda tympani was necessary in five of the seven bones in which the cochlear nerve could be accessed.ConclusionsThe transcanal approach offers a simpler, safer approach for cochlear nerve implantation compared to the facial recess approach. This approach can be accomplished in less time and avoids the hazards of dissection around the facial nerve. Use of the proposed approach will facilitate development of intraneural stimulation for an improved auditory prosthesis.
Molecular cloning of effector cell protease receptor-1, a novel cell surface receptor for the protease factor Xa

Cellular receptors for blood proteases regulate chemotaxis, extracellular proteolysis, and growth behavior of normal and malignant cells. Binding of the coagulation protease factor Xa to leukocytes is contributed by a recently identified molecule, denominated Effector cell Protease Receptor-1 (EPR-1). Monoclonal antibodies were generated against EPR-1+ MOLT13 lymphocytes and selected for reactivity with lymphocyte surface proteins by flow cytometry and with affinity-purified EPR-1 in Western blots. Antibody-based functional cloning of the cDNA for EPR-1 reveals the sequence of a novel molecule encoded by a prominent 1.9-kilobase mRNA. The cDNA predicts a glycoprotein of 337 amino acids, characterized by a unique cysteine-rich extracellular module, a single membrane-spanning domain, and a serine-rich (26%) cytoplasmic tail featuring at least 15 potential phosphorylation sites. Genetically engineered EPR-1 transfectants were recognized by monoclonal antibodies to EPR-1 and bound 125I-factor Xa in a specific and saturable manner (Kd approximately 10-15 nM). In the absence of factor V/Va, EPR-1 transfectants promoted prothrombin activation in a factor Xa concentration-dependent reaction, inhibited by a monoclonal antibody to EPR-1. These findings define EPR-1 as a novel cell surface receptor for factor Xa potentially implicated in protease-dependent cellular effector functions.
Ru3(CO)12 and Mo(CO)6 Adsorbed on Ru(001) and Au/Ru: An Infrared Reflection-Absorption Study

Abstract We obtained IRAS and TDS data for Ru 3 (CO) 12 /Ru(001) and Mo(CO) 6 /Au/Ru systems for metal carbonyl coverages between submonolayer and approximately 20 monolayers. We characterized the C-O stretching mode of both systems (4 cm −1 FWHM) and a deformation mode of Mo(CO) 6 at 608 cm −1 (1 cm −1 FWHM). Both IRAS and TDS data suggest adsorption and desorption of metal carbonyls as molecular species with a preferential orientation in the overlayers. The IR intensity of the C-O stretch per a C-O bond projected onto the surface normal is approximately twice (five times) larger for Ru 3 (CO) 12 (Mo(CO) 6 ) at submonolayer coverages than for CO/Ru(001) at θ CO = 0.68.
Multi-source coastal data analysis

This paper presents results from the second year of a project on coastal management and decision making sponsored by the National Science Foundation Digital Government Program and carried out by a multidisciplinary research team. As one of the primary goals of the project, tide-coordinated shoreline modeling and mapping requires the integration of multi-source spatio-temporal data that include high-resolution digital elevation models (DEM) derived from IKONOS satellite images and aerial photographs, bathymetric data, water gauge data, satellite altimetric data, and water surfaces derived by a hydrodynamic hindcast model (Li et al., 2002b). Quality and accuracy assessment of these data has been made to ensure reliability of the outcomes of the data integration. The resulting shorelines derived from the integrated data are then evaluated for accuracy in comparison with traditional shorelines determined from tide-coordinated aerial surveys.
From show, to room, to world: a cross-context investigation of how children learn from media programming

We conducted a year-long, naturalistic study that investigated what actually happens when children watch television. We video-recorded children's actions and interactions while watching television and simultaneously recorded the video stream from the television screen; these data were supported with parent diaries and interviews with parents and children. This paper describes two case studies, in which we consider children's interactions with others while watching television and the ways in which their television viewing influences other parts of their everyday lives. We find that both children actively applied knowledge they obtained from visual media to other contexts. In addition, they both shared their media viewing experiences with others, either by directly teaching others about what they had viewed or by creating new content based on what they had viewed.
Review ArticleEditor's Choice Article: Comparison of human and computer performance across face recognition experiments

Since 2005, human and computer performance has been systematically compared as part of face recognition competitions, with results being reported for both still and video imagery. The key results from these competitions are reviewed. To analyze performance across studies, the cross-modal performance analysis (CMPA) framework is introduced. The CMPA framework is applied to experiments that were part of face a recognition competition. The analysis shows that for matching frontal faces in still images, algorithms are consistently superior to humans. For video and difficult still face pairs, humans are superior. Finally, based on the CMPA framework and a face performance index, we outline a challenge problem for developing algorithms that are superior to humans for the general face recognition problem.
Modified d-optimal sequential procedure in allocation problem

When an experimenter wishes to compare t treatments with M experimental units, one of the first problems he faces is how to allocate N experimental units into t treatments. When no pre treat merit information about the experimental units is available, "randomization" is the widely accepted guiding principle to deal with the allocation problem But pre treat merit information usually is available, although it is seldom fully used for allocation purposes. Recently, Harville considered the allocation problem under a covariance model. He suggested a D-optimal sequential procedure that may be used to construct nearly D-optimal allocations. However, Harville's sequential procedure requires constructing a D-optimal initial allocation at the first stages and that may be computationally unfeasible in some real situations, Such construction is not needed for a new sequential.
Iatrogenic blushing of dentin following full crown preparation

Abstract Blushing of dentin is a clinically observable reaction to tooth preparation. Blushing might be considered uncommon, but not rare. While the specific etiology is unknown, possible causative factors have been discussed. Prevention appears to rely on nonabusive cutting techniques and treatment procedures ranging from simple observation to endodontic therapy, which is judged by the individual case.
Relationship of DNA damage and embryotoxicity induced by 4-hydroperoxydechlorocyclophosphamide in postimplantation rat embryos.

4-Hydroperoxydechlorocyclophosphamide (4-OOHdeCl-CP) is a preactivated analogue of cyclophosphamide (CP) that undergoes an elimination reaction to yield acrolein and the nonalkylating derivative of phosphoramide mustard (PM), i.e., dechlorophosphoramide mustard. We used this analogue to assess the role of acrolein in CP-induced embryotoxicity. Embryotoxicity was assessed using day 10 rat embryos cultured in vitro. 4-OOHdeC1-CP was embryotoxic over a concentration range of approximately 75-150 microM and produced complete embryolethality at concentrations of 175 microM and above. This analogue induced abnormal development characterized by tail defects at low drug concentrations and microencephaly or prosencephalic hypoplasia at high concentrations. Using the technique of alkaline elution, we also assessed DNA damage induced by embryotoxic concentrations of drug. When embryos were cultured in serum-containing medium during drug exposure, no DNA damage was detected, even at embryolethal drug concentrations. However, if cellular glutathione (GSH) was depleted with buthionine sulfoximine (BSO) before drug exposure and embryos were cultured in serum-free medium during drug exposure, DNA damage, primarily DNA single-strand breaks, was detected, but only at embryolethal concentrations. Using radiolabeled CP, we showed that acrolein does reach the embryo; however, more acrolein is incorporated into the yolk sac. Binding studies revealed that acrolein binds preferentially to cellular protein, whereas PM binds preferentially to DNA. These results suggest that, unlike the case with PM, the embryotoxic target for acrolein is protein and not DNA. Furthermore, our results indicate that acrolein may mediate its effects on the embryo via the yolk sac.
Synthetic biology: from modules to systems

Synthetic biology is revolutionizing how we conceptualize and approach the engineering of biological systems. Recent advances in the field are allowing us to expand beyond the construction and analysis of small gene networks towards the implementation of complex multicellular systems with a variety of applications. In this talk I will describe our integrated computational / experimental approach to engineering complex behavior in living systems ranging from bacteria to stem cells. In our research, we appropriate useful design principles from electrical engineering and other well established fields. These principles include abstraction, standardization, modularity, and computer aided design. But we also spend considerable effort towards understanding what makes synthetic biology different from all other existing engineering disciplines and discovering new design and construction rules that are effective for this unique discipline.We will briefly describe the implementation of genetic circuits with finely-tuned digital and analog behavior and the use of artificial cell-cell communication to coordinate the behavior of cell populations for programmed pattern formation. Recent results with implementing Turing patterns with engineering bacteria will be presented. Arguably the most significant contribution of synthetic biology will be in medical applications such as tissue engineering. We will discuss preliminary experimental results for obtaining precise spatiotemporal control over stem cell differentiation. For this purpose, we couple elements for gene regulation, cell fate determination, signal processing, and artificial cell-cell communication. We will conclude by discussing the design and preliminary results for creating an artificial tissue homeostasis system where genetically engineered stem cells maintain indefinitely a desired level of pancreatic beta cells despite attacks by the autoimmune response. The system, which relies on artificial cell-cell communication, various regulatory network motifs, and programmed differentiation into beta cells, may one day be useful for the treatment (or cure) of diabetes.
Transfer of persistence in the domestic chick: Effects of imprinting experiences on later instrumental responses*

To test the effects of obstructed and unobstructed imprinting approach on subsequent instrumental responding, four groups of domestic chicks, in two separate replications, received imprinting or control treatment during the first week of life and later acquired a food-motivated running response in a runway for continuous reward. Runway acquisition results revealed no significant differences between imprinting (IM), imprinting/shock (IS), shock control (SK), and handling control (CN) Ss. However, significantly different patterns of persistence across groups and replications were evident during runway extinction. Results are explained in terms of a counterconditioning notion of response persistence.
Back to med‐arb: Survey indicates process concerns are decreasing

Gerald F. Phillips, of Los Angeles, polled dozens of leading arbitrators and mediators in an attempt to gauge the profession's current comfort level with med-arb. In this month's cover story at right–Part I of II–he analyzes how providers view the occasional use of the mediator for an arbitration to finalize agreement terms.
Solvability conditions for dendritic growth in the boundary-layer model with capillary anisotropy

This paper is concerned primarily with the development of an analytic approach to the theory of steady-state velocity selection in the boundary-layer model of dendritic solidification. The two-dimensional version of this model with a fourfold crystalline anisotropy alpha in the surface tension is considered. By extending a WKB method introduced in an earlier paper, the alpha dependence of the selected growth rate is determined in the limit of small alpha; and this rate is studied for large alphas in the limit in which the dimensionless undercooling approaches unity. Portions of the paper are devoted to a reinterpretation of the mathematical structure of the solvability condition in problems of this kind.
Bacterial Outer Membrane Ushers Contain Distinct Targeting and Assembly Domains for Pilus Biogenesis

Biogenesis of a superfamily of surface structures by gram-negative bacteria requires the chaperone/usher pathway, a terminal branch of the general secretory pathway. In this pathway a periplasmic chaperone works together with an outer membrane usher to direct substrate folding, assembly, and secretion to the cell surface. We analyzed the structure and function of the PapC usher required for P pilus biogenesis by uropathogenic Escherichia coli. Structural analysis indicated PapC folds as a β-barrel with short extracellular loops and extensive periplasmic domains. Several periplasmic regions were localized, including two domains containing conserved cysteine pairs. Functional analysis of deletion mutants revealed that the PapC C terminus was not required for insertion of the usher into the outer membrane or for proper folding. The usher C terminus was not necessary for interaction with chaperone-subunit complexes in vitro but was required for pilus biogenesis in vivo. Interestingly, coexpression of PapC C-terminal truncation mutants with the chromosomal fim gene cluster coding for type 1 pili allowed P pilus biogenesis in vivo. These studies suggest that chaperone-subunit complexes target an N-terminal domain of the usher and that subunit assembly into pili depends on a subsequent function provided by the usher C terminus.
Batch foaming of poly(ε-caprolactone) using carbon dioxide: Impact of crystallization on cell nucleation as probed by ultrasonic measurements

Abstract The effect of crystallization on the foaming of poly(e-caprolactone), a semi-crystalline biodegradable polymer, was studied using batch processing and CO 2 as the physical blowing agent (PBA). Previous work on the same system suggested that the formation of high cell population densities of small open cells was crystalline fraction dependent. In this work, ultrasonic sensors were used to investigate the effect of crystallization on the cell nucleation mechanism through the monitoring of ultrasonic velocity, attenuation and specific volume characteristics. Analysis of the ultrasonic data allowed to determine the crystallization temperature and thus determined the effect of crystallization on the pressure at which phase separation occurred (degassing pressure). Clearly, the presence of crystals leads to a 5–10-fold increase in the degassing pressure with respect to the amorphous system. In addition, it was shown that the talc content did not significantly influence the degassing pressure for a full amorphous system. However, talc particles can drastically affect the degassing conditions through their role of precursors for crystal formation. Different mechanisms are proposed as possible explanations for the enhancement of cell nucleation in such semi-crystalline polymer systems.
An evaluation of long‐term survival and treatment complications in children with Hodgkin's disease

Between April 1969 and July 1977, 83 patients, 16 years or younger, with pathologically staged IA-IIIB Hodgkin's disease were seen and treated at the Joint Center for Radiation Therapy. The five-year actuarial relapse-free and overall survivals were 82 and 95%, respectively, with a median follow-up from diagnosis of 65 months. Relapse occurred in 6/50 Stage IA-IIA, 2/9 Stage IIB, 4/9 Stage IIIA, and 3/15 Stage IIIB patients. Of patients who relapsed, 11/15 are currently disease-free following retreatment with chemotherapy. Nine patients with Stage IV disease were also evaluated. Four of seven patients initially treated with chemotherapy remain free of disease. Forty-two patients in this study were treated with mantle and para-aortic irradiation alone, thus avoiding the risk of sterility associated with pelvic irradiation or MOPP chemotherapy while retaining a high probability for long-term disease-free survival. Complications of radiation therapy included growth retardation and thyroid function abnormalities in some patients. Standing height measurements were normal regardless of age at initial treatment, however, 16 of 23 patients 3-12 years old at initial treatment had sitting heights measuring more than one standard deviation below the mean. Intraclavicular distances were shortened in some patients and examples are shown. Thyroid stimulating hormone levels were elevated in 21 of 37 patients evaluated. Radiation therapy, without adjuvant chemotherapy remains an important treatment approach for children with early stage Hodgkin's disease.
Quantifying the Soda Geyser

Although the science behind the soda geyser demonstration is well known, describing the microscopic origins of this dramatic, sticky demonstration can be difficult. In this experiment, an apparatus was designed to contain the reaction, thereby allowing for quantitative analysis of the amount of CO2 released after dropping in various initiating objects. The exploratory studies were tested with a moderate sized group of 12-17 year old participants at a summer learning event, and their data confirmed that the difference in the surface area of the initiators was a primary factor for the release of dissolved gas. Additional studies were performed to relate the soda temperature to the amount of dissolved CO2. In this laboratory experiment, students gained a greater understanding of surface area and its effect on gas nucleation and bubble formation as well as gas solubility its temperature dependence. The experimental approach provided a dramatic yet contained format for students to form and test their own hypotheses about the chemical processes behind this popular classroom demonstration.
Do Outdoor Education Experiences Contribute to Positive Development in the Affective Domain

(1981). Do Outdoor Education Experiences Contribute to Positive Development in the Affective Domain? The Journal of Environmental Education: Vol. 12, No. 4, pp. 21-29.
Through-Bond and Chain-to-Chain Coupling. Two Pathways in Electron Tunneling through Liquid Alkanethiol Monolayers on Mercury Electrodes

Formation, structure, and properties of alkanethiolate monolayers on micrometrically driven hanging mercury drop electrodes were investigated electrochemically. Alkanethiols with the chain length from C8 to C18 were shown to form densely packed (ca. 20.3 A2/molecule for C12SH), perpendicularly oriented monolayers on mercury in a process involving two electron oxidation of Hg to form mercuric thiolate, in agreement with earlier literature reports for a number of thiols. Electron tunneling rates across these films (due to Ru(NH3)63+ electro-reduction in aqueous 0.50 M KCl) exhibit characteristic exponential increase with the electrode potential (with transfer coefficient α = 0.25), and an exponential decay with the monolayer thickness (with a through-bond decay constant, βtb = 1.14 per methylene group or 0.91 A-1). Slow stepwise expansion of the mercury drop electrodes coated with alkanethiolates (C9−C14 only) results in an only small increase of the tunneling current maintaining the pin-hole free structure...
QTL Analysis of ICA Bunsi-Derived Resistance to White Mold in a Pinto × Navy Bean Cross

Breeding for genetic resistance to white mold [Sclerotinia sclerotiorum (Lib.) de Bary] in dry bean (Phaseolus vulgaris L.) is difficult because of low heritability. To facilitate breeding, researchers have sought to identify QTL underpinning genetic resistance to white mold. We identified two QTL conditioning ICA Bunsi-derived resistance to white mold in a pinto X navy bean (Aztec/ND88-106-04) recombinant inbred line (85 RILs) population. ND88-106-04 is a navy breeding line with resistance to white mold derived from ICA Bunsi navy. Aztec pinto is susceptible. The QTL were located to linkage groups B2 and B3 of the core map. The B2 QTL expressed in three of four field environments explaining 24.7, 9.0, and 8.7% of the phenotypic variation for disease severity score. The B3 QTL expressed in two of four environments, explaining 15.7 and 5.3% of the phenotypic variation. The B2 QTL was identified previously in ICA Bunsi X navy and ICA Bunsi X black bean RIL populations. The resistance conferred by the B2 QTL has a physiological basis due to association with stay green stem trait and lack of association with disease avoidance traits. The B3 QTL, undetected in previous studies, was associated with disease avoidance traits (canopy porosity, plant height), stay green stem trait, and maturity. The B2 QTL with stable expression in multiple environments and across genetic backgrounds will be most amenable to manipulation by breeders.
Stochastic simulation of transport and chemical kinetics in turbulent CO/H2/N2 flames

The one-dimensional turbulence (ODT) model is applied to the study of turbulent jet CO/H2/N2 flames. The ODT model retains the full range of length scales and no assumption of scale separation is required. In the present case, the ODT model describes the evolution of the entire flowfield; the ability of ODT to model the flowfield evolution is discussed. Predictions of the conditional means and fluctuations of temperature and the species mass fractions are compared with measurements and the level of closure required to address certain phenomena is discussed. The ODT model is shown to be useful for studying extinction/re-ignition phenomena and differential diffusion. The streamwise evolution in multidimensional flows is affected by dilatation in a manner not captured by the ODT model, and this results in discrepancies between the ODT mixing rates and the mixing rates evident in the measurements.
Effects of dexamethasone on the expression of transforming growth factor‐β in mouse embryonic palatal mesenchymal cells

The central role of TGF-beta in the development of the embryonic palate has been well characterized. TGF-beta inhibits mesenchymal cell proliferation, induces medial edge epithelial cell differentiation, and modulates the expression of extracellular matrix proteins as well as the proteases that act upon them. Mechanisms by which TGF-beta expression itself is regulated are less well understood. Glucocorticoids are recognized in several cellular systems as able to regulate the expression of TGF-beta. This study was therefore designed to examine whether glucocorticoids affect the expression of TGF-beta isoforms in embryonic palatal cells. Based on flow cytometric analysis and viability determination, confluent primary cultures of mouse embryonic palate mesenchymal (MEPM) cells exposed to up to 10(-6) M dexamethasone (dex) exhibited no signs of cytotoxicity after 24 hours of exposure. Northern blot analyses revealed that dexamethasone reduced steady-state mRNA levels of TGF-beta 3 in a dose-dependent manner as early as 4 hours after treatment but had little effect on TGF-beta 1 and TGF-beta 2 expression up to 24 hours of dex exposure. Dex also reduced the synthesis of both latent and mature forms of TGF-beta protein by approximately four-fold as determined by the mink lung epithelial cell growth inhibition bioassay. Assessment of the ratio of mature to latent protein found in conditioned medium of control compared to dex-treated cultures indicated that dexamethasone may reduce the activation of latent TGF-beta to mature biologically active TGF-beta. Dexamethasone inhibited the proliferation of MEPM cells despite the down-regulation of TGF-beta suggesting that dex-induced growth inhibition of MEPM cells is not mediated by TGF-beta. These data suggest that dex modulates TGF-beta signaling pathways directly by down-regulating TGF-beta expression and possibly indirectly by altering the availability of mature TGF-beta necessary to exert its biological effects in the developing palate.
Polarographic studies of nickel‐DL‐tryptophan solutions

The polarography of Nickel (II) in the presence of DL-tryptophan has been studied in KNO3 supporting electrolyte. Nickel yields two irreversible steps which are due to the formation of two varieties of complex in sluggish equilibrium with each other. The reduction is an irreversible, kinetically controlled process as evidenced from cyclic voltammetry and i–t curves. Rate constants of the processes are evaluated. The effect of temperature is described.
Synechoxanthin, an aromatic C40 xanthophyll that is a major carotenoid in the cyanobacterium Synechococcus sp. PCC 7002.

A major aromatic, dicarboxylate carotenoid (>15% of total) was isolated from the euryhaline cyanobacterium Synechococcus sp. PCC 7002. This compound, which was given the common name synechoxanthin (1), has been assigned the structure (all-E) χ,χ-caroten-18,18′-dioic acid by a combination of spectroscopic (UV−vis, FT-IR, 1H and 13C NMR, LC-MS) and chemical methods. This discovery conclusively establishes that some cyanobacteria are capable of synthesizing aromatic carotenoids.
Neuro Emission Controller for Minimising Cyclic Dispersion in Spark Ignition Engines with EGR Levels

Past literature shows that nitrous oxide (NO x ) emission can be reduced by operating a spark ignition (SI) engine at the stoichiometric condition with high exhaust gas recirculation (EGR) levels. However, an engine, whose dynamics are typically unknown, will exhibit instability due to cyclic dispersion in heat release. A suite of novel neural network (NN) control schemes is developed to reduce the cyclic dispersion in heat release by using fuel as the control input. A separate control loop is designed for controlling EGR levels. The first NN scheme uses the total fuel and air as state variables for feedback control whereas a heat release-based output feedback scheme is developed next to relax the need for state variable measurements. The stability analysis of the closed loop system is demonstrated for both the schemes. No offline training phase is needed since online NN learning is utilised. Simulation and experimental results demonstrate that with control, the cyclic dispersion is reduced by 30%, NO x b...
Processing of bacterial RNA

Processing of RNA is a feature of RNA metabolism which contributes to the determination of the fmal population of active RNA molecules in the cell. Pro- cessing is the sum of events which converts a primary RNA transcript into a functional molecule. RNA processing in bacteria consists mainly of two parts, modification of nucleotides and cutting and trimming of the molecule; here, we shall concentrate only on the latter. There is ample evidence that rRNA and tRNA go through extensive processing events in the bacterial cell (this area is covered by a number of articles in recent symposia
Effects of Oxygen Partial Pressure on the Oxidation of Silicon Carbide

The rate of oxidation of silicon carbide was studied at different partial pressures of oxygen. The diffusion rate constant was found to vary with the logarithm of the partial pressure of oxygen according to the theory of oxidation of thin films as proposed by Engell and Hauffe. An alternative explanation based on the change of free energy with surface coverage was also found to fit the data.
The collection of blood on filter paper and its use in the dot-immunobinding assay (DIA) for detection of antibody

The ability to collect whole blood directly onto filter paper pre-cut to the size used in the dot-immunobinding assay (DIA) is a practical adjunct to this procedure. Its applicability for field studies is suggested.
Evidence for the hybrid origin of Flaveria latifolia (Compositae)

Investigations of natural populations, cytological studies, and comparisons of herbarium specimens have been used to clarify the taxonomy of the Florida species ofFlaveria. These studies indicate thatF. latifolia is a hybrid betweenF. linearis andF. floridana. Apparently the “latifolia” plants represent stabilized populations that have become adapted to the fill material dredged from the ocean and used in road building and land development in southern Florida. The wide variation noted in populations ofF. linearis andF. floridana is attributed to introgression. The paper includes a taxonomic treatment of the six species which occur in Florida. AU taxa are diploid with 2n = 36.