cssi/SciSciGPT-SciSciNet huggingface dataset:
Brunswickgrass or Paspalum nicorae: A Weed Contaminant in Southern Pastures and Bahiagrass Seed Production Fields

Brunswickgrass (Paspalum nicorae Parodi) is becoming a problematic weed in summer perennial grass pastures in the Southeast. The plant is competitive with bahiagrass and bermudagrass. Since it is less palatable, it can eventually dominate a perennial grass pasture. Brunswickgrass has become naturalized and has reportedly contaminated bahiagrass seed fields and pastures in the southeastern states, including some of the important counties for seed production in Florida, such as Gilchrist, Levy, Alachua, Citrus, and Sumter. This 4-page fact sheet provides an overview of brunswickgrass and discusses its appearance, variety/germplasm, and management. Written by Ann Blount, Marcelo Wallau, Brent Sellers, Dennis Hancock, Jose Dubeux, Cheryl Mackowiak, Joao Vendramini, and Clay Cooper, and published by the UF/IFAS Agronomy Department, April 2018. http://edis.ifas.ufl.edu/ag408
Chapter 14 – Encoders and Resolvers

Publisher Summary This chapter focuses on the feedback devices—namely, encoders and resolvers, used on servomotors, and the limitations they impose on a servo system. The three main factors in feedback devices that affect the performance of the control system are accuracy, resolution, and response. Accuracy and resolution of the position sensor as applied to the position loop are also readily understood. The position of the motor can be controlled no more accurately than the accuracy of the position sensor and no better than to one or two counts of the sensor resolution. The position feedback sensor in modern motion controllers is usually either an encoder or a resolver coupled with a resolver-to-digital converter (RDC). Software RDCs perform the conversion process in a programmable chip. The methods used are often similar to those of hardware RDCs. Software RDCs have numerous advantages over their hardware counterparts. Resolver feedback signals usually contain more position error than do encoder signals. Resolvers are constructed by winding copper wire through slots in steel rotor and stator cores.
Understanding the effect of Mo2C support on the activity of Cu for the hydrodeoxygenation of glycerol

Abstract The effect of Mo2C support on the activity of Cu has been investigated for the hydrodeoxygenation of glycerol using density functional theory and microkinetic modeling. A Cu/Mo2C surface model with a monolayer of Cu supported on a Mo2C(1 0 0) surface and a Cu(1 1 1) surface were studied under ambient pressure and vacuum pressure conditions where experimental data have previously been collected. Our microkinetic analysis predicted a one order of magnitude higher turnover frequency for the Cu/Mo2C surface relative to Cu(1 1 1). In addition, the Cu/Mo2C surface was found to be active for a single C-O bond dissociation of glycerol, i.e., it produced acetol, while the Cu(1 1 1) surface was only able to produce dehydrogenation products. The enhanced activity of the Cu/Mo2C surface for the glycerol activation was attributed to electronic modification of Cu atoms by the Mo2C support, which enhanced the adsorption strength of intermediates and reduced the activation barrier for C/O cleavage reactions.
The Fundamental Groups of Open Manifolds with Nonnegative Ricci Curvature

We survey the results on fundamental groups of open manifolds with nonnegative Ricci curvature. We also present some open questions on this topic.
Essential gene analysis in Acinetobacter baumannii by high-density transposon mutagenesis and CRISPR interference

Abstract Acinetobacter baumannii is a poorly understood bacterium capable of life-threatening infections in hospitals. Few antibiotics remain effective against this highly resistant pathogen. Developing rationally-designed antimicrobials that can target A. baumannii requires improved knowledge of the proteins that carry out essential processes allowing growth of the organism. Unfortunately, studying essential genes has been challenging using traditional techniques, which usually require time-consuming recombination-based genetic manipulations. Here, we performed saturating mutagenesis with dual transposon systems to identify essential genes in A. baumannii and we developed a CRISPR-interference (CRISPRi) system for facile analysis of these genes. We show that the CRISPRi system enables efficient transcriptional silencing in A. baumannii. Using these tools, we confirmed the essentiality of the novel cell division protein AdvA and discovered a previously uncharacterized AraC-family transcription factor (ACX60_RS03245) that is necessary for growth. In addition, we show that capsule biosynthesis is a conditionally essential process, with mutations in late-acting steps causing toxicity in strain ATCC 17978 that can be bypassed by blocking early-acting steps or activating the BfmRS stress response. These results open new avenues for analysis of essential pathways in A. baumannii. Importance New approaches are urgently needed to control A. baumannii, one of the most drug resistant pathogens known. To facilitate the development of novel targets that allow inhibition of the pathogen, we performed a large-scale identification of genes whose products the bacterium needs for growth. We also developed a CRISPR-based gene knockdown tool that operates efficiently in A. baumannii, allowing rapid analysis of these essential genes. We used these methods to define multiple processes vital to the bacterium, including a previously uncharacterized gene-regulatory factor and export of a protective polymeric capsule. These tools will enhance our ability to investigate processes critical for the essential biology of this challenging hospital-acquired pathogen.
Spectroscopy, microscopy, and other techniques for characterization of bacterial nanocellulose and comparison with plant-derived nanocellulose

Abstract Cellulose in its natural form is produced by plants, amoebae, sea animals, fungi, and bacteria. Nanocellulose, with at least one dimension less than 100 nm, has attracted interest due to its unique characteristics such as high surface area to volume ratio, high tensile modulus and strength, low coefficient of thermal expansion, and chemically active surface. In this chapter, we will focus on production methods for bacterial nanocellulose, nanocellulose from plants, and various microscopic and analytical techniques for their characterization. Imaging techniques to characterize the structure of nanocellulose include Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Confocal Laser Scanning Microscopy (CLSM), and Atomic Force Microscopy (AFM). In addition, Analytical techniques for measurement of cellulose crystallinity, including X-Ray Diffraction (XRD), Nuclear Magnetic Resonance (NMR), Fourier Transform Infrared (FTIR), and Raman spectroscopy, are discussed. The chapter also describes the thermal analysis of bacterial cellulose using Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). These techniques can be used to study the structures and properties of nanocellulose and help to identify appropriate applications.
Cellular pathogenesis of gastroparesis

Abstract Gastroparesis is a complex neuromuscular disorder characterized by delayed emptying of gastric contents. Abnormalities in distribution and function of enteric nerves, interstitial cells of Cajal (ICC), fibroblast-like cells, smooth muscle cells (SMC) and more recently the immune cells within the muscular layers of the stomach have been described. Of these cellular abnormalities, loss of ICC has been shown to be the signature defect which likely results from oxidative and paracrine mediators from pro-inflammatory immune cells, particularly macrophages. Both mice and human studies have shown loss of CD206+ anti-inflammatory macrophages in the gastric muscle and their association with ICC loss. Additionally, transcriptomic and proteomic studies have also identifying a macrophage-based immune dysregulation as central to the pathophysiology of human gastroparesis. Future studies should be aimed at determining the immune-enteric nervous system interactions and developing disease-modifying approaches to prevent or treat delayed gastric emptying.
SIW Antenna for 5G In-Band Full Duplex Applications

Ahstract-This paper presents a microstrip fed, double differential antenna based on substrate integrated waveguide (SIW) technology for In-Band Full Duplex communication at 28 GHz. Using higher order TE201 mode of the SIW cavity and differential port excitations, the proposed antenna achieves a self-interference cancellation of better than -77 dB over a 210 MHz bandwidth and a high gain of 8.2 dBi. Occupying a miniaturized size of $7.56 \times 7.56\ \mathrm{mm}^{2}$ , the antenna features a radiation efficiency of 77% and front to back ratio of 19 dB.
Environmental impact assessment of emissions from non-recycled plastic-to-energy processes

Generally, plastics pose a variety of environmental impacts due to their increased use and non-biodegradability. End-of-life treatment is a viable way of recovering energy from plastics while at the same time reducing the amount of plastics disposed of in landfills. This paper studies the environmental impact of Non-Recycled Plastics (NRP)-to-energy processes. Three waste treatment processes were considered for NRP: pyrolysis, waste-to-energy (WtE), and landfill. The environmental impact assessment results indicated that conversion technologies such as pyrolysis and WtE are preferred over landfill. The total energy consumed in the pyrolysis process was 24635.7 MJ/tonne. The conversion technologies have a lower environmental impact and produced net positive energy from NRP. The global warming potential shows that pyrolysis (3.91 kg eq. CO2) contributes the least to global warming than waste-to-energy (18.56 kg eq. CO2) and landfill (17.5 kg eq. CO2). However, sensitivity analysis suggested that the inefficiencies of the current conversion technologies should be addressed. Between the two technologies studied, pyrolysis contributed less environmental burden, having a lower global warming potential, a higher efficiency in energy conversion, and less harmful emissions such as selenium and methane.
Comparison of eGFR formulas in determining chronic kidney disease stage in bariatric patients and the impact on perioperative outcomes.

Abstract Background Chronic kidney disease (CKD) independently increases the risk of 30-day adverse outcomes following metabolic and bariatric surgery (MBS). However, no studies have evaluated the stage of CKD at which increased perioperative risk is manifested. Here, we correlate 30-day major morbidities after MBS with extent of renal disease based on CKD Stage. Objectives To determine the impact of CKD stage on perioperative outcomes after bariatric surgery. Setting Academic Hospital. Methods From the 2017 Metabolic and Bariatric Surgery Quality Improvement Program (MBSAQIP) database, we identified patients with CKD who underwent sleeve gastrectomy or laparoscopic gastric bypass surgery. Glomerular filtration rates (GFRs) were calculated and cohorts were generated based on CKD Stage. Complication rates and rates of morbidity and mortality were compared between stages, and strengths of correlation were calculated. Results GFR and CKD Stage were calculated for 150,283 patients. There was a significant increase in the risk of major morbidity at each progressive stage of CKD (P Conclusion An increased risk of perioperative complications may be seen in early stages of CKD, and risk is compounded in more advanced stages. Bariatric surgical candidates should be counseled on their increased risk of surgical complications even with mild CKD, and the benefits of bariatric surgery should be carefully weighed against significantly increased risks of complications in severe CKD.
Tree Topologies along a Tropical Line Segment

Tropical geometry with the max-plus algebra has been applied to statistical learning models over tree spaces because geometry with the tropical metric over tree spaces have some nice properties such as convexity in terms of the tropical metric. One of the challenges in applications of tropical geometry to tree spaces is the difficulty interpreting outcomes of statistical models with the tropical metric. This paper focuses on combinatorics of tree topologies along a tropical line segment, an intrinsic geodesic with the tropical metric, between two phylogenetic trees over the tree space and we show some properties of a tropical line segment between two trees. Specifically we show that a probability of a tropical line segment of two randomly chosen trees going thorough the origin (the star tree) is zero and we also show that if two given trees differ only one nearest neighbor interchange (NNI) move, then the tree topology of a tree in the tropical line segment between them is the same tree topology of one of these given two trees with possible zero branch lengths.
James Murray Templeton (1860–1892)

This chapter explores the tragic life of James Murray Templeton and his marriage to Rosamond Dale Owen after Oliphant’s demise. New sources are reprinted in this chapter that reveal the issues he had with Oliphant’s teachings and ideology.
An interferometric velocity calibrator for73Ge Mössbauer spectrometer

A velocity calibrator based on a laser driven Michelson interferometer was designed for a73Ge Mossbauer spectrometer in the range of 100 to 500 μm/sec. The conventional method of counting the interference fringes cannot be used in this case because the displacement only spans about 3 to 15 μm and only a few fringes can be observed during one velocity sweep. The velocity calibration obtained this way was compared with the calibration obtained from57Fe measurement, and excellent agreement was found between the two methods.
On the innovations problem for a finite additive white noise approach to nonlinear filtering

Consider an observed process which consists of a stochastic signal process with additive Gaussian white noise in the sense of Balakrishnan. Under the assumption that E exp δ∥s∥T/2 0, where St is the signal process, and St is independent of the noise, it is shown that there exists a bijective causal mapping from the observation space to the innovations space. This shows that the innovations equivalence conjecture of Kailath holds for the finitely additive white noise non-linear filtering problem in this case.
An experimental study on combining the auto-context model with corrective learning for canine LEG muscle segmentation

Corrective learning is a technique that applies classification methods for automatically detecting and correcting systematic segmentation errors produced by existing segmentation methods with respect to some gold standard (manual) segmentation. To allow corrective learning more effectively correct errors that require non-local contextual information to capture, we extend the corrective learning technique by combining it with auto-context learning and conduct experimental study to verify its effectiveness. In our experiment, we take multi-atlas joint label fusion as the host segmentation method, for which we apply our corrective learning technique to improve, and apply it on a canine leg muscle segmentation application. We show that the auto-context enhanced corrective learning produces prominent improvement over the original corrective learning method.
Supplementing Neural Reinforcement Learning with Symbolic Methods

Several different ways of using symbolic methods to enhance reinforcement learning are identified and discussed in some detail. Each demonstrates to some extent the potential advantages of combining RL and symbolic methods. Different from existing work, in combining RL and symbolic methods, we focus on autonomous learning from scratch without a priori domain-specific knowledge. Thus the role of symbolic methods lies truly in enhancing learning, not in providing a priori domain-specific knowledge. These discussed methods point to the possibilities and the challenges in this line of research.
Empiricism at Bay

At the risk of being regarded a ‘square’ and ‘reactionary’ I wish to defend, explicate, reformulate and ‘salvage’ whatever seems valuable to me in the empiricist tradition in the philosophy of science. I am fully aware of the almost hostile vogue of ‘beating-up’ on the empiricists, a fashion that is still in full swing. My only consolation is the remark of a well-known British philosopher. When he visited us at the University of Minnesota a few years ago, he said to me: “Don’t worry Feigl, if you don’t catch the bus of philosophy the first time, just wait a while, it’ll come ‘round again!” Since I was lucky enough to catch the bus of philosophical fashion some forty years ago, I hope to be lucky once again during the rest of my ‘natural life’.
Analysis of protein-protein interaction using proteinchip array-based SELDI-TOF mass spectrometry.

Protein–protein interactions are key elements in the assembly of cellular regulatory and signaling protein complexes that integrate and transmit signals and information in controlling and regulating various cellular processes and functions. Many conventional methods of studying protein–protein interaction, such as the immuno-precipitation and immuno-blotting assay and the affinity-column pull-down and chromatographic analysis, are very time-consuming and labor intensive and lack accuracy and sensitivity. We have developed a simple, rapid, and sensitive assay using a ProteinChip array and SELDI-TOF mass spectrometry to analyze protein–protein interactions and map the crucial elements that are directly involved in these interactions. First, a purified “bait” protein or a synthetic peptide of interest is immobilized onto the pre-activated surface of a PS10 or PS20 ProteinChip and the unoccupied surfaces on the chip are protected by application of a layer ethanolamine to prevent them from binding to other non-interactive proteins. Then, the target-containing cellular protein lysate or synthetic peptide containing the predicted amino acid sequence of protein-interaction motif is applied to the protected array with immobilized bait protein/ peptide. The nonspecific proteins/peptides are washed off under various stringent conditions and only the proteins specifically interacting with the bait protein/peptide remain on the chip. Last, the captured interacting protein/peptide complexes are then analyzed by SELDI-TOF mass spectrometry and their identities are confirmed by their predicted distinctive masses. This method can be used to unambiguously detect the specific protein–protein interaction of known proteins/peptides, to easily identify potential cellular targets of proteins of interest, and to accurately analyze and map the structural elements of a given protein and its target proteins using synthetic peptides with the predicted potential protein interaction motifs.
On estimating rate of change of pitch

Spectra formed from adjacent speech segments are likely to be similar particularly if the pitch is constant. If the pitch is going up, the peaks in the later spectrum will be farther apart; the second peak will be very like a stretched version of the first. An algorithm is given for estimating this stretch and converting it to rate of change of pitch. Results are presented showing the accuracy of the method. >
Replication Pattern of Sertoli Cells in Maturing Rat Testis in Vivo and in Organ Culture

The pattern of Sertoli cell replication in maturing rat testes was investigated in vivo and in organ culture, using pulse labeling with ‘H-thymidine and radioautography. The labeling index of Sertoli cells was found to be related to the age of the animals. It was highest in testes of newborn animals and decreased with age, most drastically on day 11. No labeled Sertoli cells were found after postnatal day 15. This pattern appeared to be independent of extragonadal in vivo influences since it was retained in isolated testes grown in organ culture.
Assisting democrats or resisting dictators? The nature and impact of democracy support by the United States National Endowment for Democracy, 1990–99

With the advance of the ‘third wave’ of democratization, developed countries such as the United States have implemented explicit strategies of democracy promotion by providing assistance to governments, political parties, and other non-governmental groups and organizations through a variety of channels. This article examines one facet of US democratization and democracy assistance in the 1990s: National Endowment for Democracy aid. It draws on a dataset composed of democratization data for the developing world, assistance provided by the NED, and other control variables including growth in wealth, progress in education, and the impact of culture. The article first discusses the nature of NED assistance and then investigates the relationship between NED support and democratization in the developing world in multiple regression analyses controlling for other economic and political factors. The findings cast doubt on the effectiveness of NED grants as an instrument of democracy promotion or consolidation. At...
Highly Efficient Copper-Mediated Atom-Transfer Radical Addition (ATRA) in the Presence of Reducing Agent

The synthesis, characterization and exceptional activity of Cu I (TPMA)Br [TPMA = tris(2-pyridylmethyl)amine] and [Cu II (TPMA)Br][Br] complexes in ATRA reactions of polybrominated compounds to alkenes in the presence of reducing agent (AIBN) was reported. [Cu II (TPMA)Br][Br], in conjunction with AIBN, effectively catalyzed ATRA reactions of CBr 4 and CHBr 3 to alkenes with concentrations between 5 and 100 ppm, which is the lowest number achieved in copper-mediated ATRA. The molecular structure of Cu I (TPMA)Br indicated that the complex was pseudo-pentacoordinate in the solid state due to the coordination of TPMA [Cu I -N: 2.1024(15), 2.0753(15), 2.0709(15) and 2.4397(14) A] and bromide anion to the copper(I) center [CU I -Br 2.5088(3) A]. Variable temperature 1 H NMR and cyclic voltammetry studies confirmed the equilibrium between Cu I (TPMA)Br and [Cu I -(TPMA)(CH 3 CN)][Br], indicating some degree of halide anion dissociation in solution. The coordination of the bromide anion to the [Cu I (TPMA)] + cation resulted in a formation of much more reducing Cu I (TPMA)Br complex (E 1/2 = -720 mV vs. Fc/Fc + ) than the corresponding ClO 4 - (E 1/2 = -422 mV vs. Fc/Fc + ) and PF 6 - (E 1/2 = -421 mV vs. Fc/Fc + ) analogues. In [Cu II (TPMA)Br][Br], the Cu II atom was coordinated by four nitrogen atoms [Cu II -N eq 2.073(2) A and Cu II -N ax 2.040(3) A] from TPMA ligand and a bromine atom [Cu II -Br 2.3836(6) A]. The overall geometry of the complex was distorted trigonal bipyramidal. Cu I (TPMA)Br and [Cu II (TPMA)-Br][Br] complexes showed similar structural features from the point of view of TPMA coordination. The only more pronounced difference in the TPMA coordination to the copper center was observed in the shortening of Cu-N ax bond length by approximately 0.400 A on going from Cu I (TPMA)Br to [Cu II (TPMA)Br][Br].
The origin of syphilis

Abstract A popular misconception often places the blame for syphilis on the American Indian. In truth, no one race or subspecies of Man is responsible for this venereal malady. Syphilis has been a part of Man's cultural heritage and physical past since early prehistoric times but scientists are just beginning to realize the past record of the disease. Three theories are discussed.
Threshold for Optically Induced Dislocation Glide in GaAs-AlGaAs Double Heterostructures: Degradation via a New Cooperative Phenomenon?

We have observed a sharp threshold for the process of optically induced glide at which the velocity changes by more than a factor of ${10}^{3}$ when the excitation intensity changes only 20%. This threshold is insensitive to doping and to the presence of a $p\ensuremath{-}n$ junction. The effect is shown not to be related to recombination-enhanced motion or to local heating. An explanation in terms of the reduction of frictional forces by interaction with unrecombined carriers is offered.
Monetary Policy Under Imperfect Capital Markets in a Small Open Economy

Following the financial crises of the late 1990's an increasing number of emergingmarket countries have adopted a flexible exchange-rate regime and an inflation-targeting monetary-policy framework. This trend has generated a growing debate on the appropriate monetary-policy rule for "financially fragile" economies with thin and incomplete financial markets that are subject to highly volatile capital flows. Within this context, I examine the implications of alternative monetary-policy rules and the choice of instruments and targets in a small open economy with imperfect capital markets. I compare a benchmark efficient-markets model with a monetary-targeting regime and three different inflation-targeting rules: the Taylor rule, a CPI inflation-target rule, and a non-tradable inflation-target rule. Furthermore, I study how sensitive the results are to varying degrees of capital-market integration.
Development of an Enzyme-Linked Immunosorbent Assay for the Detection of the Pyrethroid Insecticide Fenpropathrin

A competitive enzyme-linked immunosorbent assay (ELISA) was developed for the quantitative detection of fenpropathrin [(RS)-R-cyano-3-phenoxybenzyl-2,2,3,3-tetramethylcyclopropanecarboxylate]. Polyclonal antisera were isolated from rabbits immunized with two different fenpropathrin hapten conjugates. One hapten contained an amino function; the other contained a carboxyl group for conjugation to carrier proteins. Mollusk hemocyanins, thyroglobulin, and fetuin were used as carrier proteins. The antisera varied greatly in their affinities for fenpropathrin. A homologous assay system using the coating antigen format was the most sensitive. The IC50 for fenpropathrin was 20 Ig/L, and the lower detection limit was 2.5 Ig/L. Pyrethroids, such as phenothrin, permethrin, resmethrin, fenvalerate, deltamethrin, cyfluthrin, and cypermethrin, and the pyrethroid metabolites, 3-phenoxybenzoic acid and fenpropathrin acid, did not cross-react significantly in this assay. Ten percent acetone or methanol and a pH of 4 were determined to be optimum assay conditions. Various cationic, anionic, and nonionic detergents had no significant effect on the assay.
Full length article: Asymptotics of polynomials orthogonal over the unit disk with respect to a polynomial weight without zeros on the unit circle

We establish asymptotic formulas for polynomials that are orthogonal over the unit disk with respect to a weight of the form |w(z)|^2, where w(z) is a polynomial without zeros on the unit circle |z|=1. The formulas put in evidence a strong connection between the behavior of the polynomials and the reproducing kernel of an associated weighted Bergman space, which produces interesting new features in the presence of a weight w with interior zeros.
Effect of continuous low dose gamma irradiation on bactericidal activity of phagocytic cells of mice.

Mice were subjected to continuous gamma radiation (128 r/22 hours) for 3 weeks, and bactericidal activity of their phagocytes determined at weekly intervals. Bactericidal activity declined gradually through 2 weeks exposure (1800 r) then fell off rapidly in the third week (2695 r). These results are compared to those obtained with mice exposed top single doses of x irradiation. (auth)
Effects of intraventricular injection of gastrin on release of LH, prolactin, TSH and GH in conscious ovariectomized rats

Abstract Conscious ovariectomized (OVX) rats bearing a cannula implanted in the 3rd ventricle were injected with 2 μl of 0.9% NaCl containing varying doses of synthetic gastrin and plasma gonadotropin, GH and TSH levels were measured by RIA in jugular blood samples drawn through an indwelling silastic catheter. Control injections of saline iv or into the 3rd ventricle did not modify plasma hormone levels. Intraventricular injection of 1 or 5 μg gastrin produced significant suppression of plasma LH and prolactin (Prl) levels within 5 min of injection. Injection of 1 μg gastrin had no effect on plasma GH, but increasing the dose to 5 μg induced a progressive elevation, which reached peak levels at 60 min. By contrast, TSH levels were lowered by both doses of gastrin within 5 min of injection and the lowering persisted for 60 min. Intravenous injection of gastrin had no effect on plasma gonadotropin, GH and TSH, but induced an elevation in Prl levels. In vitro incubation of hemipituitaries with gastrin failed to modify gonadotropin, GH or Prl but slightly inhibited TSH release at the highest dose of 5 μg gastrin. The results indicate that synthetic gastrin can alter pituitary hormone release in unrestrained OVX rats and implicate a hypothalamic site of action for the peptide to alter release of a gonadotropin, Prl and GH. Its effect on TSH release may be mediated both via hypothalamic neurons and by a direct action on pituitary thyrotrophs.
New insights into critical events of avian gastrulation.

The formation and progression of the primitive streak are key events of avian gastrulation. We examine these processes in detail, using various morphological approaches. We show that formation of the primitive streak occurs locally at the caudal midline of the area pellucida, as cells in the caudal midline undergo an epithelial-to-mesenchymal transformation, and that extensive migration of delaminated cells arising from more rostral or peripheral areas of the blastoderm is not involved in streak formation. Instead, such delamination occurs earlier and is restricted to the process of hypoblast formation. Moreover, we provide evidence that progression of the primitive streak involves two processes: convergent-extension movements within the streak per se, and progressive delamination of midline epiblast cells in a caudal-to-rostral sequence. We have identified a subpopulation of primitive-streak cells located at its dorsal midline surface that undergoes extensive rostral displacement concomitant with streak progression. The fact that these cells are located only dorsally and do not elongate ventrally as do adjacent ingressing cells, suggests that these cells retain their residency within the primitive streak, at least until regression of the primitive streak occurs. Finally, by following labeled cells over time we establish the timing of movement of epiblast cells toward and into the primitive streak, providing direct evidence that cell–cell intercalation occurs within the primitive streak during its progression. Collectively, our results provide new insight into complex and central events of avian gastrulation. Anat Rec 262:238–252, 2001. © 2001 Wiley-Liss, Inc.
Diagnostic difficulties of foreign body aspiration in children

A case of a 4-year-old child who aspirated a 22-caliber bullet is presented to illustrate the variability of signs and symptoms of foreign body aspiration. Despite the large size of the bullet, cough, dyspnea, and wheezing were absent on presentation. Chest roentgenogram confirmed the diagnosis of a radiopaque bronchial foreign body. A retrospective review of 42 additional children with foreign body aspiration showed 8 (19%) were unwitnessed, 24 (57%) were asymptomatic at presentation, 8 (19%) had normal physical examinations, and 10 (24%) had normal inspiratory/expiratory chest roentgenograms. This demonstrates the importance of considering bronchoscopy for any child who presents with a history of possible foreign body aspiration, but is asymptomatic and has normal roentgenographic findings.
An Evidence Base for Group Work with Older Adults Living in the Community

There is a small but illuminating body of research related to group work with older adults living in the community. A broad range of interventions with diverse elderly participants have been studied internationally using qualitative and quantitative methodologies. Although scanty, the published literature informs group work practitioners on the strengths and limitations of different interventions. This article presents a critical review of 13 studies published between 1990 and 2007 to guide group work practitioners in organizing and facilitating groups for older adults in the community. Each review notes the characteristics of the participants, type of group intervention, methodology, and findings of the study. It examines the rigor, impact, and applicability of the findings to practice with this population. Much needs to be done to develop an evidence base for group work with older adults living in the community. Recommendations for practice and future research are offered.
Quasiparticle interference, quasiparticle interactions, and the origin of the charge density wave in 2H-NbSe2

We show that a small number of intentionally introduced defects can be used as a spectroscopic tool to amplify quasiparticle interference in 2H-NbSe2 that we measure by scanning tunneling spectroscopic imaging. We show, from the momentum and energy dependence of the quasiparticle interference, that Fermi surface nesting is inconsequential to charge density wave formation in 2H-NbSe2. We demonstrate that, by combining quasiparticle interference data with additional knowledge of the quasiparticle band structure from angle resolved photoemission measurements, one can extract the wave vector and energy dependence of the important electronic scattering processes thereby obtaining direct information both about the fermiology and the interactions. In 2H-NbSe2, we use this combination to confirm that the important near-Fermi-surface electronic physics is dominated by the coupling of the quasiparticles to soft mode phonons at a wave vector different from the charge density wave ordering wave vector.
Energy-Efficient Clocking Based on Resonant Switching for Low-Power Computation

A mechanism for the reduction of dynamic energy dissipation based on energy recovery resonant switching in a computing circuit is described. The resonant circuit with controlled switches conserves energy by recovering 90% of energy that would be otherwise lost during logic state transitions. The new approach of incorporating an energy recovery storage capacitor in the resonant circuit helps to initialize the logic operation and moves the energy back and forth to the load capacitance. This energy-conserving approach preserves thermodynamic entropy, ideally preventing heat generation in the system. This proposed method is used for generating an energy-efficient “flat-topped” (quasi-trapezoidal) waveform, which is required to perform the low power digital logic computation, especially for clocking in the system applications.
Health Disparities in Procreation: Unequal Access to Assisted Reproductive Technologies

There is a significant increase in the use of assisted reproductive technology to treat infertility, yet access to services is not equal for all women in the United States. Some marginalized groups face significant barriers accessing assisted reproductive technology. The authors review obstacles preventing marginalized populations from procreating, based on class, race and ethnicity, age, marital status, sexual orientation, and disability. The sociopolitical climate in the United States that maintains these obstacles is evaluated by the authors in this article. Finally, suggestions are provided for structural changes to decrease disparities in access to assisted reproductive technology and recommendations for family therapists working with clients who are unable to access assisted reproductive technology.
Acute Cardiopulmonary and Echocardiographic Responses to Inhaled Nitric Oxide (INO) in Infants with Persistent Pulmonary Hypertension of the Newborn (PPHN)

Acute Cardiopulmonary and Echocardiographic Responses to Inhaled Nitric Oxide (INO) in Infants with Persistent Pulmonary Hypertension of the Newborn (PPHN)
JFK and the future of global leadership.

On 10 June 1963 President John F. Kennedy gave a speech that changed the world. His commencement speech at American University helped to spur the signing of a world-changing agreement between the Soviet Union and the United States-the Partial Nuclear Test Ban Treaty. This episode of peacemaking is remarkable for two reasons. First, it arguably helped to save the world, since the nuclear confrontation at that stage of the Cold War was not a 'stable balance of terror', as sometimes described, but rather a highly unstable situation that was prone to accidents, misjudgements and potential disasters. Second, this was an episode of statesmanship in which presidential leadership played a crucial role. Following the Cuban Missile Crisis, Kennedy understood that he bore sole responsibility on the US side to find a way back from the brink of nuclear war. He used the 'peace speech' to create a novel kind of peace diplomacy, and worked together with his counterpart, Soviet leader Nikita Khrushchev, to pull the superpowers back from this precarious brink.
Decentralized computation for robust stability of large-scale systems with parameters on the hypercube

In this paper, we propose a parallel algorithm to solve the problem of robust stability of systems with large state-space and with large number of uncertain parameters. The dependence of the system on the parameters is polynomial and the parameters are assumed to lie in a hypercube. Although the parameters are assumed to be static, the method can also be applied to systems with time-varying parameters. The algorithm relies on a variant of Polya's theorem which is applicable to polynomials with variables inside a multi-simplex. The algorithm is divided into formulation and solution subroutines. In the formulation phase, we construct a large-scale semidefinite programming problem with structured elements. In the solution phase, we use a structured primal-dual approach to solve the structured semidefinite programming problem. In both subroutines, computation, memory and communication are efficiently distributed over hundreds and potentially thousands of processors. Numerical tests confirm the accuracy and scalability of the proposed algorithm.
Preparation of alkoxides for the synthesis of ceramics

Abstract The literature is reviewed to summarize methodologies for synthesizing metal alkoxides applicable as organic precursors to high-purity, well-characterized ceramic powders. Typical examples of preparation techniques, patents, and commercial manufacturing methods are provided, and special precautions noted. Basically, metal alkoxide synthesis is determined by the electronegativity of the metal concerned; synthetic routes may lead directly from the metal or a metal halide, or may be indirect, involving alcoholysis.
Review of physics and applications of relativistic plasmas driven by ultra-intense lasers

As tabletop lasers continue to reach record levels of peak power, the interaction of light with matter has crossed a new threshold, in which plasma electrons at the laser focus oscillate at relativistic velocities. The highest forces ever exerted by light have been used to accelerate beams of electrons and protons to energies of a million volts in distances of only microns. Not only is this acceleration gradient up to a thousand times greater than in radio-frequency-based sources, but the transverse emittance of the particle beams is comparable or lower. Additionally, laser-based accelerators have been demonstrated to work at a repetition rate of 10 Hz, an improvement of a factor of 1000 over their best performance of just a couple of years ago. Anticipated improvements in energy spread may allow these novel compact laser-based radiation sources to be useful someday for cancer radiotherapy and as injectors into conventional accelerators, which are critical tools for x-ray and nuclear physics research. They might also be used as a spark to ignite controlled thermonuclear fusion. The ultrashort pulse duration of these particle bursts and the x rays they can produce, hold great promise as well to resolve chemical, biological or physical reactions on ultrafast (femtosecond) time scales and on the spatial scale of atoms. Even laser-accelerated protons are soon expected to become relativistic. The dense electron–positron plasmas and vast array of nuclear reactions predicted to occur in this case might even help bring astrophysical phenomena down to Earth, into university laboratories. This paper reviews the many recent advances in this emerging discipline, called high-field science.
Properties ( V) and ( w V) on C(Ω X)

A formal series Σxn in a Banach space X is said to be weakly unconditionally converging, or alternatively weakly unconditionally Cauchy (wuc) if Σ|x*(xn)| < ∞ for every continuous linear functional x* ∈ X*. A subset K of X* is called a V-subset of X* iffor each wuc series Σxn in X. Further, the Banach space X is said to have property (V) if the V-subsets of X* coincide with the relatively weakly compact subsets of X*. In a fundamental paper in 1962, Pelczynski [10] showed that the Banach space X has property (V) if and only if every unconditionally converging operator with domain X is weakly compact. In this same paper, Pelczynski also showed that all C(Ω) spaces have property (V), and asked if the abstract continuous function space C(Ω, X) has property (F) whenever X has property (F).
Reliability and validity of the clinical instructor survey tool.

To assess the perceived importance of clinical instructors' techniques, the Clinical Instructor Survey Tool was developed and administered to 13 subjects to assess internal consistency. Cronbach alpha was .82.
Using classifier ensembles to label spatially disjoint data

We describe an ensemble approach to learning from arbitrarily partitioned data. The partitioning comes from the distributed processing requirements of a large scale simulation. The volume of the data is such that classifiers can train only on data local to a given partition. As a result of the partition reflecting the needs of the simulation, the class statistics can vary from partition to partition. Some classes will likely be missing from some partitions. We combine a fast ensemble learning algorithm with probabilistic majority voting in order to learn an accurate classifier from such data. Results from simulations of an impactor bar crushing a storage canister and from facial feature recognition show that regions of interest are successfully identified in spite of the class imbalance in the individual training sets.
IDENTIFICATION OF THE COMPLEMENTARY DNA STRANDS OF THE COLIPHAGE DELETION MUTANT λdgA_J BY DNA-DNA HYBRIDIZATION

Both complementary strands of coliphage mutant λdgA_J DNA, in which almost the entire left arm (genes A to J) is deleted (Fig. 2)., react with guanine-rich ribopolymers and show only marginal separation during centrifugation in the CsCl density gradient. The preparatively isolated "heavy" and "light" fractions of λdgA_J DNA were shown to correspond respectively to the "heavy" (C) strand and the "light" (W) strand of the wild-type λ or λcb2 DNA. This was ascertained by DNA-DNA hybridization between nonlabeled λdgA_J DNA fractions bound on nitrocellulose filters and 3H-thymidine-labeled, preparatively separated strands ofλcb2 DNA. This study shows that both strands of λdgA_J DNA have rather similar affinities for guanine-rich ribopolymers, but nevertheless the C strands of λdgA_J DNA contain somewhat more poly G-binding, dC-rich clusters than the W strands. It also provides a general method for identifying the separated strands derived from DNA fragments, obtained either by shearing or by isolation of DNA from appropriate deletion mutants of the phage.
Meta-Analysis: Chronic Disease Self-Management Programs for Older Adults

The authors examined studies of the effectiveness of self-management programs for osteoarthritis, hypertension, and diabetes mellitus. Self-management programs appear to produce clinically importan...
Reported Variation in the Evaluation of Antenatal Hydronephrosis: Results of A Web-Based Survey of Pediatric Urologists

Purpose The evaluation and management of prenatally diagnosed hydronephrosis is variable. This study identifies variability in the current practice of pediatric urology in dealing with the commonly identified prenatal ultrasound finding of hydronephrosis. We examine the role of radiographic testing and antibiotic prophylaxis in evaluation and treatment of this condition. Moreover we report results based on practitioner demographics such as location and length of practice. Material and Methods A web-based survey link was sent to pediatric urologists on the American Academy of Pediatrics and European Society of Pediatric Urology mailing list. Respondents answered questions concerning demographics and practice patterns/influences concerning their use of radiographic tests and prophylactic antibiotics in the evaluation and treatment of antenatal hydronephrosis. Results One-hundred-fifty-six respondents completed the survey representing mostly pediatric urologists in academic and private practice in North America (50%) and Europe (40%). Respondents were split nearly evenly when asked whether radiographic factors influenced their decisions to obtain further imaging or to place infants on prophylactic antibiotics. Even among those reporting that radiographic findings influenced their decision for prophylaxis the parameters that triggered intervention demonstrated variability. Radiographic studies reportedly used to further evaluate infants with postnatal hydronephrosis also varied markedly. North American physicians were more likely to prescribe antibiotics for any prenatal hydronephrosis (72% vs. 37%, p Conclusions There is considerable variation in resource utilization in the evaluation and treatment of antenatal hydronephrosis among pediatric urologists. This variability is most likely due to the absence of meaningful clinical data and guidelines. This should prompt pediatric urologists to collaborate, design and carry out prospective, controlled trials to help guide evaluation of this common pathology.
The influence of “inert” diluent gases on the rate of carbon gasification

Abstract The effect of diluent gases on gasification rates of the C-O2 and C-CO2 reactions has been studied. At equal starting pressures of reactant and diluent, rates for both reactions are: N2 > Ar > He. For the C-CO2 reaction, the presence of a diluent results in higher gasification rates than when no diluent is present in the order: Xe > N2 > Ar. Possible reasons for the diluent effects are discussed.
Optimization of Port Design for Layered Core Heat Exchanger

This paper presents a design study of the geometry of the ports on a layered core heat exchanger, which is used in automotive engines. Using fluid dynamics, and fluid computational programs, the performance characteristics of a double boss port design was obtained as well as a single boss port design. The two designs were compared, and an optimized design shall be proposed. This optimization study compares the fluid flow and overall heat transfer of the layered core heat exchanger.Copyright © 2009 by ASME