cssi/SciSciGPT-SciSciNet huggingface dataset:
Learners' Responses to the Demands of Conceptual Change: Considerations for Effective Nature of Science Instruction

Much has been written about how effective nature of science instruction must have a significant explicit and reflective character. However, while explicitly drawing students’ attention to NOS issues is crucial, learning and teaching the NOS are essentially matters of conceptual change. In this article, how people learn and learners’ responses to the demands of conceptual change are used to explain how students may exit from instruction with fundamental NOS misconceptions left intact or only slightly altered, despite being explicitly and reflectively attended to more accurate ideas. The purpose of this concept paper is to set within a theoretical framework of learning, and bring some coherence to, what has rapidly become a large body of empirical research regarding effective NOS instruction. Toward these two ends, this article: (1) illustrates how a conceptual change framework can be used to account for learners’ responses to NOS instruction and what teachers might do to promote understanding NOS and transferring it to new contexts; (2) characterizes popularly advocated NOS instructional approaches along a continuum marked by increasing connection to the workings of science, and decreased ability to dismiss NOS lessons as extraneous to authentic science; and (3) proposes that NOS instruction would likely be more effective if teachers deliberately scaffolded classroom experiences and students’ developing NOS understanding back and forth along the continuum.
Imaging O(3P)+alkane reactions in crossed molecular beams: Vertical versus adiabatic H abstraction dynamics

We present a crossed molecular beam study of the reaction of O(3P) with alkanes, using velocity map imaging of the alkyl radical product via single photon ionization at 157 nm. We obtained the differential cross sections and translational energy distributions for reaction of O(3P) with cyclohexane, n-butane and isobutane at a range of well-defined collision energies from 4.7 to 14.8 kcal/mol. The product alkyl radicals are largely backscattered with respect to the alkane beam at all collision energies, but the scattering distribution is clearly broadened with increasing collision energy. This is consistent with a picture of direct rebound dynamics but inconsistent with a recent result for the vibrationally excited OH component [H. Tsurumaki et al., J. Chem Phys. 112, 8338 (2000)], and we explore the source of this inconsistency. More surprising is the large fraction of the available energy partitioned into internal degrees of freedom of the alkyl radical, showing that the simple triatomic picture of the r...
Pectin and charge modified pectin hydrogel beads as a colon-targeted drug delivery carrier.

Abstract The physical and chemical properties of commercial low methoxyl citrus pectins, CP 28 and CP 55, and a pectinmethylesterase (PME) charge modified citrus pectin (MP 38) were compared, and the differences in ability to encapsulate indomethacin in hydrogel beads was determined at 0.5 or 1.0% (w/v) indomethacin ratio, and 100, 200 or 300 mM CaCl 2 solution. In order to investigate the drug release characteristics, indomethacin loaded dried hydrogel beads were immersed in simulated gastric fluids (pH 1.2) for 2 h, followed by immersing in simulated intestinal fluids (pH 7.4) for 3 h. Pectin type was highly significant ( p in vitro release assay. Encapsulation efficiency was also highly affected ( p 2 concentration. The accumulative release rate of indomethacin from pectin hydrogel bead was less than 15% in simulated gastro-intestinal fluids. MP 38 beads showed significantly higher entrapment efficiency and lower release rate than beads formed from CP 28 or CP 55. MP 38 hydrogel formulated with 300 mM CaCl 2 and 0.5% indomethacin ratio showed the highest entrapment efficiency. These studies suggest that charge modification of pectin improves encapsulation efficiency of drugs for colon targeted drug delivery system through oral administration.
The E1-E2 center in gallium arsenide is the divacancy

Based on defect energy levels computed from first-principles calculations, it is shown the E1–E2 center in irradiated GaAs cannot be due to an isolated arsenic vacancy. The only simple intrinsic defect with levels compatible with E1 and E2 is the divacancy. The arsenic monovacancy is reassigned to the E3 center in irradiated GaAs. These new assignments are shown to reconcile a number of seemingly contradictory experimental observations.
Clinical picture, response to therapy, and survival of women with diffuse malignant peritoneal mesothelioma

Background and Objectives The clinical picture, response to therapy, and prognosis of women with diffuse malignant peritoneal mesotheliomas (DMPM) are ill defined. The purpose of this study is to report on the clinical picture, response to therapy, and survival of women with DMPM. Methods The study is a retrospective review of 15 women with the confirmed pathologic diagnosis of DMPM treated between 1964 and 1996. Survival curves were constructed according to the Kaplan-Meier method. The effect of different factors on survival was studied using the log-rank test. Two-tailed P values < 0.05 were considered significant. Results Clinical features included abdominal distension (11/15, 73%), abdominal pain (6/15, 40%), ascites (9/15, 60%), abdominal or pelvic masses (14/15, 93%), elevated CA-125 (4/4, 100%), thrombocytosis (4/15, 27%), and thrombo-embolic manifestations (3/15, 20%). The response rate to all first-line chemotherapy regimens was 30%. The response rate to paclitaxel/cisplatin was 66.7% and the toxicity was tolerable. The median survival of all patients was 12.5 months. Patients who underwent cytoreductive surgery survived longer than those who underwent biopsy only (median survival 13.5 vs. 6.0 months, P = 0.24). Patients who received chemotherapy survived significantly longer than those who did not receive chemotherapy (29.0 vs. 1.0 months, P = 0.03). Patients who responded to first-line chemotherapy survived significantly longer than those who did not respond (P = 0.04). Conclusions Cytoreductive surgery and chemotherapy, especially with paclitaxel and cisplatin, might be of benefit in women with DMPM. J. Surg. Oncol. 1999;70:6–12. © 1999 Wiley-Liss, Inc.
Therapeutic options for patients with clonal and idiopathic hypereosinophia

Background: The hypereosinophilic syndrome (HES) comprises a heterogeneous group of disorders characterized by chronic, unexplained hypereosinophilia with organ involvement. The discovery of novel molecular targets has changed the therapeutic paradigm in HES. Objective: This article reviews the current medical management of patients with clonal and idiopathic hypereosinophilia with a particular emphasis on emerging new targeted therapies. Methods: The information contained in this review was obtained from public sources such as journals and scientific meeting abstracts. The opinions expressed in this review are solely those of the authors. Results/Conclusion: The development of imatinib-resistant mutations in the FIP1L1-PDGFR-α kinase domain has spurred the development of an array of new tyrosine kinase inhibitors. Moreover, the elucidation of the role of interleukin-5 in the pathogenesis of the lymphocytic variant of HES and the fact that CD52 is expressed on the surface of eosinophils and T cells have l...
A generalization of the Rescorla‐Wagner model of conditioning and learning

We consider a generalization of the Rescorla-Wagner model of conditioning and learning such that the associative strength of a stimulus compound is a linear combination of the associative strengths of the stimulus components. The difference equations defined by the generalization are solved, and some properties of the solutions and their implications are discussed.
The airy stress function in curvilinear coordinates with application to the uniform flexure of a naturally curved spiral beam

Abstract In problems of plane elasticity, in the absence of body forces, the stresses are derivable from a scalar function known as the Airy stress function. By expressing this relation as a tensor equation, the use of the Airy function is generalized for any plane, orthogonal coordinate system. A general expression for the compatibility equation in terms of the stress function is given. It is found that considerable simplification results if isometric coordinates are used. The geometry of the isometric, curvilinear coordinate system is determined by a conformal mapping of the rectangular, Cartesian coordinate plane upon the curvilinear coordinate plane. For a given coordinate system the components of the metric tensor are expressible in terms of the mapping function. As an application of the preceding theory the uniform flexure of a beam whose edges are bounded by logarithmic spirals is discussed. It is found that all spiral beams may be specified by two dimensionless shape parameters. Stress distributions in a typical beam are exhibited. As limiting cases of the solution for a spiral beam, the uniform flexure of a wedge acted upon by a moment at the vertex and the uniform flexure of a sector of a circular ring are obtained.
Absolute normalization in distorted-wave Born-approximation analysis of two- nucleon-transfer-reaction cross sections

The normalization constants for two-nucleon-transfer reactions are determined by the direct and parametrization methods. The results are compared between themselves and with experiment. Both methods give rise to calculated values which fall short by at least a factor of 3.
An experimental investigation of the angular dependence of diffusion-driven flow

We present experimental results on diffusion-driven flow along an inclined wall in a stably stratified fluid. The experiments focus on the dependence of the velocity in the buoyancy layer on the angle of inclination. The increase of velocity with decreasing angle is in agreement with theory for larger angles. For small angles, where current theory breaks down, the velocity tends to zero and an angle of maximum velocity exists.
Axis measurement strip for Haag-Streit BM900 series slitlamp.

We describe a technique to measure the toric IOL axis using an axis measurement strip applied to the Haag-Streit BM900 series slitlamp. The technique was used by 3 surgeons to determine the postoperative toric IOL position in 47 eyes, and these data were compared with objective measurements derived from images made with a Galilei G2 corneal analyzer. The results indicate that the axis measurement strip provides a precise, clinically efficient measurement of toric IOL position. Financial Disclosure Neither author has a financial or proprietary interest in any material or method mentioned.
Regulation of diacylglycerol acyltransferase in developing seeds of castor

We have previously reported the cloning of castor diacylglycerol acyltransferase (RcDGAT) based on its homology to other plant type 1 diacylglycerol acyltransferases (DGATs). To elucidate the physiological role of the RcDGAT, we have investigated the regulation of RcDGAT expression in developing seeds of castor. The RcDGAT transcript appeared at 12 d after pollination (DAP), reached the highest level at 26 DAP, and declined rapidly after that. However, the RcDGAT protein started to accumulate at 26 DAP, reached its peak at 47 DAP, then remained at this high level until 54 DAP. The significant difference between the expression of mRNA and protein indicates that gene expression of RcDGAT in maturing castor seeds is controlled at the posttranscriptional level. We found that DGAT activity measured in microsomal membranes isolated from seed at different stages of development was parallel to RcDGAT protein level, suggesting DGAT activity is mainly a function of the level of RcDGAT protein. We monitored the triacylglycerol (TG) composition and content during seed development. Compared with the overall rate of TG accumulation, DGAT activity appeared coincidently with the onset of lipid accumulation at 26 DAP; the highest DGAT activity occurred during the rapid phase of lipid accumulation at 40 DAP; and a decline in DGAT activity coincided with a decline in the accumulation rate of TG after 40 DAP. The ricinoleate-containing TG content was very low (only about 7%) in oil extracted from seeds before 19 DAP; however, it increased up to about 77% of the oil at 26 DAP. The relative amount of triricinolein in oil at 26 DAP was 53 times higher than that at 19 DAP, and it was about 76% of the amount present in oil from mature castor seeds. The close correlation between profiles of RcDGAT activity and oil accumulation confirms the role of RcDGAT in castor oil biosynthesis.
Radiative transfer in anisotropically scattering nonplanar media

The effects of anisotropic scattering in one-dimensional cylindrical and spherical geometries is demonstrated within a P(3) spherical harmonics method framework, by which the angular distribution of the radiation intensity is expressed in a series of associated Legendre polynomials. The series is truncated after N terms (P/N/ approximation), and the coefficients are expressed in terms of the moments of intensity. Anisotropic scattering effects are shown to follow the same trends as the isotropic scattering cases, becoming insignificant toward the outer wall.
Automatic verification of finite state concurrent system using temporal logic specifications: a practical approach

We give an efficient procedure for verifying that a finite state concurrent system meets a specification expressed in a (propositional) branching-time temporal logic. Our algorithm has complexity linear in both the size of the specification and the size of the global transition graph for the concurrent system. We also show how the logic and our algorithm can be modified to handle fairness. We argue that this technique can provide a practical alternative to manual proof construction or use of a mechanical theorem prover for verifying many finite state concurrent systems.
Olefin/paraffin separations by adsorption: π-Complexation vs. kinetic separation

Monolayer dispersed AgNO3 on silica gel was prepared by thermal dispersion. This sorbent exhibited superior adsorption properties for olefin/parafin separations by selective adsorption of olefins through π-complexation. This sorbent, along with Ag+ ion-exchanged resin, was subjected to simulation studies for olefin/parafin separations by pressure-swing adsorption. Kinetic separations (due to differences in olefin/parafin diffusivities) using zeolite 4A and molecular-sieve carbon were also studied, Using 50/50 mixtures of C2 H4/C2 H6 and C3H6/C3H8, separations using these sorbents were compared directly based on olefin product purity, recoveiy, and throughput. The monolayer AgNO3/SiO2 sorbent showed superior separation results for C3H4/C3H8, and the Ag+-exchanged resin showed best results for C2H4/C2H6. In both cases, over 99% product purities could be obtained at reasonably high recoveries and throughputs. For C3H6/C3H6 separation on AgNO3/SiO2, multiplicity of cyclic steady states were observed within certain regions of feed and purge velocities. within these regions, two stable cyclic steady states were reached starting ffom different initial-bed conditions while all operating conditions were identical.
Body-image perception and dissatisfaction throughout phases of the female menstrual cycle

This pilot study investigated the association between the menstrual cycle and participants' body-size perception, judgments of ideal body size, detection of changes in body size, and body dissatisfaction. Thirty participants (M age=23.3 yr., SD=3.9), who did not have eating disorders, viewed digital images of their bodies. Judgments on all tasks were made during premenstrual, intermenstrual, and menstrual phases of the menstrual cycle. Participants expressed a desire for a smaller ideal body size for themselves in all three phases. Body dissatisfaction was significantly greater during the premenstrual and menstrual phases. The menstrual cycle was not associated with significant changes in body-size perception, ideal size judgments, or detection of changes in body size.
Trends in Accounting Education: Decreasing Accounting Anxiety and Promoting New Methods.

In this paper, authors (a) identified accounting anxiety for the educator and the student as a possible explanation for the decline in accounting education and (b) investigated new methods for teaching accounting at the secondary and postsecondary levels that will increase interest in accounting education as well as decrease educator and student anxiety about accounting. By becoming more familiar with course material and incorporating new methods for teaching accounting, accounting educators can reduce anxiety for themselves and their students thereby increasing student learning.
Ab initio studies of hydrocarbon adsorption on stepped diamond surfaces

We present theoretical investigations of various hydrocarbon species adsorbed on hydrogenated flat (100), flat (111), and stepped (100) surfaces of diamond. We use ab initio density-functional molecular-dynamics simulations and a dynamical quenching minimization algorithm to calculate adsorption energies and minimum-energy configurations of different binding configurations. The onefold adsorption energies of the hydrocarbon fragments on all the surfaces were found to be in the order ${\mathit{E}}_{\mathrm{C}2}$Hg${\mathit{E}}_{\mathrm{CH}2}$g${\mathit{E}}_{\mathrm{CH}3}$g${\mathit{E}}_{\mathrm{C}2}$${\mathrm{H}}_{2}$. C$ sub 2 roman H sub 2--- is predicted to have stable twofold binding sites on both the terrace site and near step edges of the diamond (100) substrate. Adsorption on the flat (111) surface is found to be weaker compared to binding on the flat and stepped (100) substrates. We found several adsorption configurations where adsorption energies on the near step edges are different from those on the flat terrace. We studied local surface relaxations due to the adsorbed molecule. The binding of the hydrocarbon admolecule in the presence of an adsorbate is investigated. In general, we found weaker binding for molecules adsorbed on adjacent surface radical sites. Preliminary results on hydrocarbon adsorption at finite temperature are discussed.
Photoinduced long-lived charge separation in a tetrathiafulvalene- porphyrin-fullerene triad detected by time-resolved electron paramagnetic resonance

Photoinduced electron transfer has been observed in a molecular triad, consisting of a porphyrin (P) covalently linked to a tetrathiafulvalene (TTF) and a fullerene derivative (C60), in the different phases of the liquid crystal E−7 and in a glass of 2-methyltetrahydrofuran (2-MeTHF) by means of time-resolved electron paramagnetic resonance (EPR) spectroscopy. In both solvents, an EPR signal observed immediately after excitation has been assigned to the radical pair TTF•+−P−C60•-, based on its magnetic interaction parameters and spin polarization pattern. In the 2-MeTHF glass and the crystalline phase of E−7, the TTF•+−P−C60•- state is formed from the TTF−1P−C60 singlet state via an initial TTF−P•+−C60•- charge-separated state. Long-lived charge separation (∼8 μs) for the singlet-born radical pair is observed in the 2-MeTHF glass at cryogenic temperatures. In the nematic phase of E−7, a high degree of ordering in the liquid crystal is achieved by the molecular triad. In this phase, both singlet- and tripl...
β-Endorphin and Adrenocorticotropin in Extrapituitary Sites: Gastrointestinal Tract

β-Endorphin and ACTH immunoassays were employed to examine the concentrations, distributions, and character of those peptides in rat gastrointestinal tissues. Sections of the gastrointestinal tract were obtained from fasted and fed animals and were extracted in 5 N acetic acid containing proteolytic enzyme inhibitors. Aliquots immunoassayed for β-endorphin and ACTH revealed highest concentrations to be present in the small bowel, with stomach and colon containing little immunoreactivity. Tissues from fasted animals contained more immunoreactivity than did those from fed animals. Gel chromatography showed the presence of large molecular weight forms of β-endorphin and ACTH in gut extracts. Concanavalin A affinity chromatography revealed that approximately 5% of gut immunoreactivity contained carbohydrate. Therefore, β-endorphin and ACTH immunoreactivities are present in the gut. The demonstration of large molecular weight and glycosylated forms of immunoreactivity suggests the presence of biosynthetic prec...
Low-temperature magnetic force microscopy of colossal magnetoresistive films

CaxMnO3 films under the influence of temperature, topographic sample defects and external magnetic field. At low temperatures, typically about 140 degrees below Tc=245 K, domains were strongly coupled to each other, but could still be affected by thermal fluctuations. As we warmed the sample up, domains became highly mobile near Tc. Near Tc, sample scratches were able to capture nearby domains, whereas they did not affect domains when temperature is much lower than Tc. Above Tc all domains disappeared, with some of them disappearing earlier.
The impact of irradiance time behaviors on inverter sizing and design

This paper investigates the time behavior of over-irradiance events in which the photovoltaic (PV) array outputs more power than the rated power of the inverter. A new dynamic interpretation of such events is proposed and is compared to the conventional static viewpoint. Facts revealed under such dynamic view may lead to new guidelines for system integrators and inverter designers in both sizing and designing inverters. A way to extend overload operation time of inverters is also proposed.
Graft Compatibility and Incompatibility in Higher Plants

Abstract Compatibility responses are features common to plant morphogenesis. Understanding the mechanisms responsible for recognition, compatibility, and incompatibility is a fundamental step towards understanding how cells and tissues interact, and, by extension, how the processes of cell and tissue differentiation are controlled and coordinated in the plant body. In this review, the literature on plant grafting is presented relative to the proposed mechanisms of graft compatibility-incompatibility, wounding, and cellular recognition and interaction.
Reinvestigation of the reaction of ethyl 4,4,4‐trifluoroacetoacetate with aldehydes and ammonia

Reaction of ethyl 4,4,4-trifluoroacetoacetate with aromatic aldehydes and ammonia gives diethyl 4-aryl-2,6-dihydroxy-2,6-bis(trifluoromethyl)-3,5-piperidinedicarboxylates (4) instead of diethyl 4-aryl-1,4-dihydro-2,6-bis(trifluoromethyl)-3,5-pyridinedicarboxylates (3) as reported previously (1).
Surface states on GaAs(110)

Abstract The electronic structure of the (110) surface of GaAs is recalculated using the relaxation geometry recently obtained from analyzing elastic low-energy electron diffraction intensity data and a self-consistent ab initio pseudopotential approach. Better agreement is found for the occupied surface states compared with photoemission data, giving support for the new structural model. The influence of convergence of the plane-wave expansion and relativistic effects on the surface states is also examined.
EMG study of hand muscle recruitment during hard hammer percussion manufacture of Oldowan tools

The activity of 17 hand muscles was monitored by electromyography (EMG) in three subjects during hard hammer percussion manufacture of Oldowan tools. Two of the subjects were archaeologists experienced in the replication of prehistoric stone tools. Simultaneous videotapes recorded grips associated with the muscle activities. The purpose of the study was to identify the muscles most likely to have been strongly and repeatedly recruited by early hominids during stone tool-making. This information is fundamental to the identification of skeletal features that may reliably predict tool-making capabilities in early hominids. The muscles most frequently recruited at high force levels for strong precision pinch grips required to control the hammerstone and core are the intrinsic muscles of the fifth finger and the thumb/index finger regions. A productive search for skeletal evidence of habitual Oldowan tool-making behavior will therefore be in the regions of the hand stressed by these intrinsic muscles and in the joint configurations affecting the relative lengths of their moment arms.
Robust Parameter Design With Feed-Forward Control

When there exists strong noise factors in the process, robust parameter design alone may not be effective, and a control strategy can be used to compensate for the effect of noise. In this article a parameter design methodology in the presence of a feed-forward control is developed. In particular, performance measures for evaluating control factor settings in measurement systems, simple response systems, and multiple target systems are developed. Strategies for the design and analysis of experiments are discussed. The approach is illustrated using an example on gold plating.
Bertrand–Edgeworth Competition, Demand Uncertainty, and Asymmetric Outcomes

Abstract We analyze investment and pricing incentives in a symmetric Bertrand– Edgeworth framework with uncertain demand. Firms choose production capacities before observing demand. Prices are chosen after demand is observed. If the extent of demand variation exceeds a threshold level then a symmetric equilibrium in pure strategies for capacities does not exist. A smaller firm has no incentive (ex ante) to expand its capacity because capacity expansion would reduce its expected revenue in the event that demand is lower than expected. Output prices are predicted to have positive variance when demand is low and zero variance when demand is high. Journal of Economic Literature Classification Numbers: D43, L13.
Experimental validation of a coupled neutron–photon inverse radiation transport solver

Abstract Sandia National Laboratories has developed an inverse radiation transport solver that applies nonlinear regression to coupled neutron–photon deterministic transport models. The inverse solver uses nonlinear regression to fit a radiation transport model to gamma spectrometry and neutron multiplicity counting measurements. The subject of this paper is the experimental validation of that solver. This paper describes a series of experiments conducted with a 4.5 kg sphere of α-phase, weapons-grade plutonium. The source was measured bare and reflected by high-density polyethylene (HDPE) spherical shells with total thicknesses between 1.27 and 15.24 cm. Neutron and photon emissions from the source were measured using three instruments: a gross neutron counter, a portable neutron multiplicity counter, and a high-resolution gamma spectrometer. These measurements were used as input to the inverse radiation transport solver to evaluate the solver's ability to correctly infer the configuration of the source from its measured radiation signatures.
Asymmetric bias in free-energy perturbation measurements using two Hamiltonian-based models

We present two model systems that are suitable for the study of bias in free-energy perturbation (FEP) calculations which are performed in molecular simulations. The models exhibit the asymmetry that is sometimes seen in these calculations, in which the magnitude of the bias is greater when the calculation is performed in one direction ($A\ensuremath{\rightarrow}B$, sampling system $A$ and perturbing into system $B$) versus the other $(B\ensuremath{\rightarrow}A)$. Both models are formulated as a system of $N$ independent particles, each sampling a space in the presence of a one-body field that is different for the $A$ and $B$ systems. In one model the field is a harmonic potential. The other model is discrete, such that each particle can be at one of two points (or states) of different energy. The neglected-tail bias model is applied to each system to estimate the average bias as a function of the amount of FEP sampling, and numerical calculations are performed to show that the bias model is effective. We show that the bias is significantly smaller when sampling is performed on the system having a broader work distribution (we designate this direction ``insertion'') compared to the bias for FEP calculations that sample the system with a narrower distribution (``deletion'').
A counterexample to aggregation based model reduction of Hidden Markov Models

This paper highlights a limitation of state space aggregation based model reduction of Hidden Markov Models. We construct an n dimensional Hidden Markov Model that is equivalent to a lower dimensional one of order n &#60; n for which aggregation based reduction of the high dimensional model is guaranteed not to produce an error free low dimensional model of order n.
Identification of two targets of the type III protein secretion system encoded by the inv and spa loci of Salmonella typhimurium that have homology to the Shigella IpaD and IpaA proteins.

An important virulence factor of Salmonella spp. is their ability to gain access to host cells. A type III secretion system encoded in the inv and spa loci of these organisms is essential for this phenotype. We have identified two proteins, SipA and SipD, whose secretion from the bacterial cells is dependent on this system. The genes encoding these proteins are located at centisome 63 on the S. typhimurium chromosome, immediately downstream of the previously identified sipB and sipC genes (K. Kaniga, S. Tucker, D. Trollinger, and J. E. Galan, J. Bacteriol. 177:3965-3971, 1995). Nucleotide sequence analysis of the genes encoding these proteins indicated that SipA and SipD have significant sequence similarity to the Shigella IpaA and IpaD proteins. A nonpolar null mutation in sipD rendered S. typhimurium severely deficient for entry into cultured epithelial cells. In addition, this mutant strain exhibited increased secretion of a selected group of proteins whose export is controlled by the inv- and spa-encoded translocon. In contrast, a nonpolar mutation in sipA did not result in an invasion defect or in a significant decreased in virulence in a mouse model of infection. In addition, we have found an open reading frame immediately downstream of SipA that encodes a predicted protein with significant similarity to a family of acyl carrier proteins.
Prostaglandin release and the interaction of platelets with the pulmonary vasculature of rat and guinea pig

Abstract We have examined the isolated perfused lung as a model for studying the role of two opposing prostaglandin derivatives, prostacyclin (PGI 2 ) and thromboxane (TXA 2 ), in regulating the interaction between platelets and the pulmonary vascular bed. On passage of a perfusate containing either rat or human platelets through the isolated perfused rat lung, no TXA 2 release was detected in the effluent from the lung, as measured by radioimmunoassay (RIA) of TXB 2 . After inhibition of pulmonary PGI 2 synthesis however, platelet perfusion resulted in the production of TXA 2 and the appearance of platelet aggregates in the perfusate. As measured in an invitro incubation system, rat lung produces PGI 2 and TXA 2 in a ratio of 1:1. Guinea pig lung however, produces PGI 2 and TXA 2 in a ratio of 1:20. Passage of human platelets through the guinea pig 2 lung resulted in TXA 2 release into the effluent. Inhibitors of pulmonary TXA 2 biosynthesis did not suppress its release, while perfusion with aspirin (ASA) treated platelets completely abolished TXA 2 release, suggesting that TXA 2 originates primarily from aggregating platelets. These results support the hypothesis that PGI 2 is an important defense against intraarterial thrombosis and suggest that our model is suitable for examining platelet-pulmonary endothelial cell interaction.
Tool and Process Improvement for High-Fidelity Compressor Simulations

Compressors for modern gas turbine engines are challenging to simulate. Disparate length and time scales exist in an aggressive adverse pressure gradient environment amongst a wide array of physical phenomena requiring refinement in both space and time. The resulting mesh sizes and CPU time required to complete time-accurate simulations have become staggering, though they will only continue to increase as the simulation strategy switches from Unsteady Reynolds-Averaged Navier-Stokes (URANS) to Detached Eddy Simulation (DES) and Large Eddy Simulation (LES). For the complex compressor flows, this transition has long been necessary. In order to more effectively simulate compressor flows, several tool developments have taken place, which result in better process and reduced engineer effort. Utilizing the Air Force Research Laboratory Department of Defense (DoD) Supercomputing Resource Center (AFRL DSRC) at Wright-Patterson AFB, improvements in geometry handling, grid generation methodologies, and solver features have reduced workload while benefiting simulation quality. Available applications such as Doxygen, Python, VTK, and Subversion created a productive collaboration environment suitable for both development and testing.
A class of iterative signal restoration algorithms

A class of iterative signal restoration algorithms is derived based on a representation theorem for the generalized inverse of a matrix. These algorithms exhibit a first or higher order of convergence, and some of them consist of an online and an offline computational part. The conditions for convergence, the rate of convergence of these algorithms, and the computational load required to achieve the same restoration results are derived. An iterative algorithm is also presented which exhibits a higher rate of convergence than the standard quadratic algorithm with no extra computational load. These algorithms can be applied to the restoration of signals of any dimensionality. The presented approach unifies a large number of iterative restoration algorithms. Based on the convergence properties of these algorithms, combined algorithms are proposed that incorporate a priori knowledge about the solution in the form of constraints and converge faster than previously published algorithms. >
Ultrastructure and synaptic organization of axon terminals from brainstem structures to the mediodorsal thalamic nucleus of the rat

The ultrastructural characteristics and synaptic organization of afferent terminals from the brainstem to the mediodorsal thalamic nucleus (MD) of the rat have been studied with the electron microscope, by means of anterograde transport of wheat germ agglutinin-horseradish peroxidase (WGA-HRP). Labeled fibers were seen predominantly in the lateral portion of MD after the injections of WGA-HRP into the substantia nigra pars reticulata (SNr), the superior colliculus (SC), and the dorsal tegmental region (DT). The boutons arising from the SC were relatively small (less than 1.5 microns in diameter), formed asymmetric synaptic contacts with small dendrites and dendritic spines, and contained round synaptic vesicles. The axon terminals from the DT were mostly large boutons (2-4.5 microns) with asymmetric synaptic specializations and round vesicles. These boutons and their postsynaptic targets formed synaptic glomeruli that were entirely or partially ensheathed by glial lamellae. The ultrastructural features are almost identical to those of boutons in the medial and central segments of MD that were previously shown to originate from the basal amygdaloid nucleus and the piriform cortex. The boutons from the SNr had a wide range in size, but the majority were medium-sized to large (1.5-4 microns). The nigral boutons established symmetric synaptic contacts with dendritic shafts and occasionally with somata, and contained pleomorphic vesicles. However, like the DT terminals, they participated in glomerular formations. The nigral terminals closely resemble previously described terminals in the medial part of MD from the ventral pallidum, except that the nigral terminals formed en passant and axosomatic synapses as well as axodendritic synapses. A combined immunohistochemistry and WGA-HRP tracing study revealed that the nigral inputs were immunoreactive for glutamic acid decarboxylase and the axon terminals from the DT were immunoreactive for choline acetyltransferase. In a separate study, the colliculothalamic fibers have been shown to take up and transport the transmitter specific tracer [3H]-D-aspartate, and are therefore putatively glutamatergic and/or aspartatergic. Taken together with this, the present results suggest that the collicular afferents are excitatory and glutamatergic and/or aspartatergic, that the inputs from the DT are also excitatory and cholinergic, while the nigral inputs are inhibitory and GABAergic.
The upper bound neural network and a class of consistent labeling problems

The upper bound neural network (UBNN) is proposed for solving a class of consistent labeling problems (CLP). Crossbar switching is used as an illustration. The set of stable attractors of the dynamical system is identically the set of feasible solutions to the problem. CLP is a general class of NP-complete (Neyman-Pearson) problems intersecting artificial intelligence, symbolic logic, and operations research. Problems which can be formulated as CLP include image segmentation as well as finding spanning trees and Euler tours in a graph. As an example, the UBNN is used to control a crossbar packet switch. The switch control problem is a maximal matching problem which is approximated by the UBNN. As switching speeds push below the nanosecond range, the O(V/sup 3/) time complexity of the maximal matching problem will be prohibitive for large switches. When viewed as an analog circuit, the UBNN scales well, guarantees convergence to a solution of the problem, and converges in near constant time, thus becoming an alternative for large crossbar switch control. >
A Decade After the Asian Financial Crisis: Regionalism and International Architecture in a Globalized World

The China-driven rise of Asia to the center of the global political economy since the Asian financial crisis under systems of political economy manifestly different from those of the Washington Consensus poses a challenge that has been met by neither helter-skelter Asian regionalism nor by American strategic inattentiveness of the past decade.
Incidence and Patterns of Extended-Course Antibiotic Therapy in Patients Evaluated for Lyme Disease

Background Most patients with Lyme disease (LD) can be treated effectively with 2-4 weeks of antibiotics. The Infectious Disease Society of America guidelines do not currently recommend extended treatment even in patients with persistent symptoms. Methods To estimate the incidence of extended use of antibiotics in patients evaluated for LD, we retrospectively analyzed claims from a nationwide US health insurance plan in 14 high-prevalence states over 2 periods: 2004-2006 and 2010-2012. Results As measured by payer claims, the incidence of extended antibiotic therapy among patients evaluated for LD was higher in 2010-2012 (14.72 per 100 000 person-years; n = 684) than in 2004-2006 (9.94 per 100 000 person-years; n = 394) (P 20% of the patients who were evaluated for LD and prescribed extended antibiotic treatment. Conclusions Insurance claims data suggest that the use of extended courses of antibiotics and multiple antibiotics in the treatment of LD has increased in recent years.
Analysis of FtsZ Assembly by Light Scattering and Determination of the Role of Divalent Metal Cations

FtsZ is an ancestral homologue of tubulin that polymerizes in a GTP-dependent manner. In this study, we used 90° angle light scattering to investigate FtsZ polymerization. The critical concentration for polymerization obtained by this method is similar to that obtained by centrifugation, confirming that the light scattering is proportional to polymer mass. Furthermore, the dynamics of FtsZ polymerization could be readily monitored by light scattering. Polymerization was very rapid, reaching steady state within 30 s. The length of the steady-state phase was proportional to the GTP concentration and was followed by a rapid decrease in light scattering. This decrease indicated net depolymerization that always occurred as the GTP in the reaction was consumed. FtsZ polymerization was observed over the pH range 6.5 to 7.9. Importantly, Mg2+ was not required for polymerization although it was required for the dynamic behavior of the polymers. It was reported that 7 to 25 mM Ca2+ mediated dynamic assembly of FtsZ (X.-C. Yu and W. Margolin, EMBO J. 16:5455–5463, 1997). However, we found that Ca2+ was not required for FtsZ assembly and that this concentration of Ca2+ reduced the dynamic behavior of FtsZ assembly.
Stress, antidepressant drugs, and the locus coeruleus

This review presents a synthesis of a large body of seemingly inconsistent literature on the role of the locus coeruleus-norepinephrine (LC-NE) system and the corticotropin-releasing hormone (CRH)-median eminence system in mediating the CNS effects of stress and the therapeutic effects of antidepressant drugs. The clinical implications of these findings for the etiology and treatment of stress-related psychiatric disorders such as depression will be discussed.
Genomic Characterization of the Mouse Ribosomal DNA Locus

The transcription of rRNA is critical to all living cells and is tightly controlled at the level of chromatin structure. Although the widespread adoption of genomic technologies including chromatin immunoprecipitation with massively parallel short-read sequencing (ChIP-seq) has allowed for the interrogation of chromatin structure on a genome-wide scale, until recently rDNA has not been analyzed by this technique. We extended genomic analysis of rDNA to mouse (Mus musculus), in which rDNA is similar in structure but highly divergent in sequence compared with human rDNA. Comparison of rDNA histone marks between mouse embryonic stem cells (mESCs) and more differentiated mouse cell types revealed differences between pluripotent and differentiated states. We also observed substantial divergence in rDNA histone modification patterns between mESCs and human embryonic stem cells (hESCs). Surprisingly, we found that the pluripotency factor OCT4 was bound to rDNA in similar patterns in mESCs and hESCs. Extending this analysis, we found that an additional 17 pluripotency-associated factors were bound to rDNA in mESCs, suggesting novel modes of rDNA regulation in pluripotent cells. Taken together, our results provide a detailed view of rDNA chromatin structure in an important model system and enable high-resolution comparison of rDNA regulation between mouse and human.
A statistical approach for detection and localization of a fluorescing mouse tumor in intralipid

A statistical approach is presented for detecting and localizing a fluorescing tumor obscured underneath millimeters of turbid medium. The method is validated in an experimental study using a mouse tumor and folate-iridocyanine dye.
Comparative DFT Study of van der Waals Complexes: Rare-Gas Dimers, Alkaline-Earth Dimers, Zinc Dimer, and Zinc-Rare-Gas Dimers

Recent interest in the application of density functional theory prompted us to test various functionals for the van der Waals interactions in the rare-gas dimers, the alkaline-earth metal dimers, zinc dimer, and zinc-rare-gas dimers. In the present study, we report such tests for 18 DFT functionals, including both some very recent functionals and some well-established older ones. We draw the following conclusions based on the mean errors in binding energies and complex geometries: (1) B97-1 gives the best performance for predicting the geometry of rare-gas dimers, whereas M05-2X and B97-1 give the best energetics for rare-gas dimers. (2) PWB6K gives the best performance for the prediction of the geometry of the alkaline-earth metal dimers, zinc dimers, and zinc-rare-gas dimers. M05-2X gives the best energetics for the metal dimers, whereas B97-1 gives the best energetics for the zinc-rare-gas dimers. (3) The M05 functional is unique in providing good accuracy for both covalent transition-metal dimers and van der Waals metal dimers. (4) The combined mean percentage unsigned error in geometries and energetics shows that M05-2X and MPWB1K are the overall best methods for the prediction of van der Waals interactions in metal and rare-gas van der Waals dimers.
Dinitrogen Reduction, Sulfur Reduction, and Isoprene Polymerization via Photochemical Activation of Trivalent Bis(cyclopentadienyl) Rare-Earth-Metal Allyl Complexes

Dinitrogen can be reduced by photochemical activation of the trivalent rare-earth-metal bis(pentamethylcyclopentadienyl) allyl complexes (C5Me5)2Ln(η3-C3H4R) (Ln = Y, Lu; R = H, Me) to form the (N═N)2– complexes [(C5Me5)2Ln]2(μ-η2:η2-N2). This demonstrates that productive organolanthanide photochemistry is not limited to complexes of the unusual (η3-C5Me4H)− ligand in the heteroleptic complexes (C5Me5)2(C5Me4H)Ln and (C5Me5)(C5Me4H)2Ln. Photolytic activation of (C5Me5)2Ln(η3-C3H5) (Ln = Y, Lu) in the presence of isoprene provides a rare photopolymerization route to polyisoprene. Sulfur can also be reduced by photolysis of (C5Me5)2Ln(η3-C3H5) (Ln = Y, Lu) to generate the (S)2– complexes, [(C5Me5)2Ln]2(μ-S), which have variable Ln–S–Ln angles depending on crystallization conditions.
Just-in-time: organizing the Lakota Sun Dance

Purpose – The purpose of this paper is to investigate the organizing practices of a Lakota Sun Dance, and to contribute to the literature on rituals and ceremonies in organizational culture. Design/methodology/approach – The researcher acted as participant-as-observer during this extended ceremony. Fieldnotes capturing observations and informal interviews with Lakota elders were the source of data as recording devices were not permitted on the Sun Dance grounds. Observations were conducted for approximately 45 hours over the course of five days. Findings – The Lakota Sun Dance can be understood through organizational theory, particularly through a unique integration of the concepts of agency, loosely coupled systems, and just-in-time organizing. The current research highlights the role of agency in organizational ceremonies. Originality/value – This research offers a thick description of the organizing practices of an extended Lakota ceremony. The integration of traditional Lakota organizing principles wi...
Will You Have Enough to Retire on?: The Retirement Security 'Crisis'

Americans are concerned about the state of preparedness for retirement, and many believe that retirement security is nearing a crisis. As life expectancies increase, traditional defined-benefit pensions decline, and Social Security faces significant reforms, many argue that a significant share of Americans will be at risk of an inadequate income in retirement. But despite these anxieties, most older Americans seem well prepared for retirement. Controlling for household composition, the Social Security replacement rate for typical workers born in 1940 was 63 percent of average preretirement earnings, and the median total pension replacement rate was 92 percent of prior earnings - well over financial planners' recommended rate of around 75 percent. Even among the younger 1960 birth cohort, for whom the projected median Social Security replacement rate declines to 54 percent, the median total pension replacement rate remains at 82 percent. While policymakers should work to strengthen Social Security and private pension savings, talk of a crisis in retirement income preparedness appears premature.