cssi/SciSciGPT-SciSciNet huggingface dataset:
A single prenatal lipopolysaccharide injection has acute, but not long-lasting, effects on cerebral kynurenine pathway metabolism in mice.

In rodents, a single injection of lipopolysaccharide (LPS) during gestation causes chemical and functional abnormalities in the offspring. These effects may involve changes in the kynurenine pathway (KP) of tryptophan degradation and may provide insights into the pathophysiology of psychiatric diseases. Using CD1 mice, we examined acute and long-term effects of prenatal LPS treatment on the levels of kynurenine and its neuroactive downstream products kynurenic acid (KYNA), 3-hydroxykynurenine (3-HK) and quinolinic acid. To this end, LPS (100 μg/kg, i.p.) was administered on gestational day 15, and KP metabolites were measured 4 and 24 h later or in adulthood. After 4 h, kynurenine, KYNA and 3-HK levels were elevated in the fetal brain, 3-HK and KYNA levels were increased in the maternal plasma, and kynurenine was increased in the maternal brain, whereas no changes were seen in the placenta. These effects were less prominent after 24 h, and prenatal LPS did not affect the basal levels of KP metabolites in the forebrain of adult animals. In addition, a second LPS injection (1 mg/kg) in adulthood in the offspring of prenatally saline- and LPS-treated mice caused a similar elevation in 3-HK levels in both groups after 24 h, but the effect was significantly more pronounced in male mice. Thus, acute immune activation during pregnancy has only short-lasting effects on KP metabolism and does not cause cerebral KP metabolites to be disproportionally affected by a second immune challenge in adulthood. However, prenatal KYNA elevations still contribute to functional abnormalities in the offspring.
Empowering Women as Leaders in Pediatric Anesthesiology: Methodology, Lessons, and Early Outcomes of a National Initiative.

Research has shown that women have leadership ability equal to or better than that of their male counterparts, yet proportionally fewer women than men achieve leadership positions and promotion in medicine. The Women's Empowerment and Leadership Initiative (WELI) was founded within the Society for Pediatric Anesthesia (SPA) in 2018 as a multidimensional program to help address the significant career development, leadership, and promotion gender gap between men and women in anesthesiology. Herein, we describe WELI's development and implementation with an early assessment of effectiveness at 2 years. Members received an anonymous, voluntary survey by e-mail to assess whether they believed WELI was beneficial in several broad domains: career development, networking, project implementation and completion, goal setting, mentorship, well-being, and promotion and leadership. The response rate was 60.5% (92 of 152). The majority ranked several aspects of WELI to be very or extremely valuable, including the protege-advisor dyads, workshops, nomination to join WELI, and virtual facilitated networking. For most members, WELI helped to improve optimism about their professional future. Most also reported that WELI somewhat or absolutely contributed to project improvement or completion, finding new collaborators, and obtaining invitations to be visiting speakers. Among those who applied for promotion or leadership positions, 51% found WELI to be somewhat or absolutely valuable to their application process, and 42% found the same in applying for leadership positions. Qualitative analysis of free-text survey responses identified 5 main themes: (1) feelings of empowerment and confidence, (2) acquisition of new skills in mentoring, coaching, career development, and project implementation, (3) clarification and focus on goal setting, (4) creating meaningful connections through networking, and (5) challenges from coronavirus disease 2019 (COVID-19) and the inability to sustain the advisor-protege connection. We conclude that after 2 years, the WELI program has successfully supported career development for the majority of proteges and advisors. Continued assessment of whether WELI can meaningfully contribute to attainment of promotion and leadership positions will require study across a longer period. WELI could serve as a programmatic example to support women's career development in other subspecialties.
Getting More Out of Two Asset Portfolios

Two-asset portfolio mathematics is a fixture in many introductory finance and investment courses. However, the actual development of the efficient frontier and capital market line are generally left to a heuristic discussion with diagrams. In this article, the mathematics for calculating these attributes of two-asset portfolios are introduced in a framework intended for the undergraduate classroom. [G10, G11]
Early operative morbidity in 184 cases of anterior vertebral body tethering.

Fusion is the current standard of care for AIS. Anterior vertebral body tethering (AVBT) is a motion-sparing alternative gaining interest. As a novel procedure, there is a paucity of literature on safety. Here, we report 90-day complication rates in 184 patients who underwent AVBT by a single surgeon. Patients were retrospectively reviewed. Approaches included 71 thoracic, 45 thoracolumbar, 68 double. Major complications were those requiring readmittance or reoperation, prolonged use of invasive materials such as chest tubes, or resulted in spinal cord or nerve root injury. Minor complications resolved without invasive intervention. Mean operative time and blood loss were 186.5 ± 60.3 min and 167.2 ± 105.0 ml, respectively. No patient required allogenic blood transfusion. 6 patients experienced major (3.3%), and 6 had minor complications (3.3%). Major complications included 3 chylothoracies, 2 hemothoracies, and 1 lumbar radiculopathy secondary to screw placement requiring re-operation. Minor complications included 1 patient with respiratory distress requiring supplementary oxygen, 1 superficial wound infection, 2 cases of prolonged nausea, and 1 Raynaud phenomenon. In 184 patients who underwent AVBT for AIS, major and minor complication rates were both 3.3%.
Enzymes of phospholipid synthesis in Bacillus Calmette-Guerin induced rabbit alveolar macrophage. Characterization and localization of cytidine diphosphocholine phosphotransferase and monoacylphospholipid acyltransferase.

Abstract The rabbit alveolar macrophage is capable of renewing its plasma membrane by at least two metabolic pathways. It contains (1) a monoacylphospholipid acyltransferase, which catalyzes the synthesis of diacylphospholipids by recycling monoacylphospholipids produced by the action of phospholipases and (2) a cytidine diphosphocholine phosphotransferase (CDPcholine phosphotransferase), which catalyzes the last step in the synthesis de novo of diacylglycerophosphocholine. These activities have been characterized in the cell homogenate with respect to time, protein, pH optimum (for CDPcholine phosphotransferase), substrate specificity (for monoacylphospholipid acyltransferase) and cation requirement (for CDPcholine phosphotransferase). Monoacylphospholipid acyltransferase activity is localized solely in the endoplasmic reticulum. On the other hand, the CDPcholine phosphotransferase activity can be measured in the endoplasmic reticulum and in the plasma membrane, characterized by both differential and gradient sedimentation techniques. In addition to the normal route of phospholipid synthesis in the endoplasmic reticulum, the rabbit alveolar macrophage may thus possess the capacity for in situ synthesis of phospholipids of plasma membrane as a mechanism for membrane renewal following phagocytosis.
Control of space robots in uncertain environments using neural networks

Many space robotic systems would be required to operate in uncertain or even unknown environments. In this paper, the problem of identifying such environments for compliance control is considered. In particular, neural networks are used for identifying environments that a robot establishes contact with, with fixed nonlinear structure and unknown parameters. Compliant motion experiments have been performed with a robotic arm, where desired contact forces are computed using a neural network. >
The design, construction and testing of the X-ray laser project krypton-fluoride laser amplifier

A large, UV preionized excimer krypton-fluoride (KrF) laser amplifier was designed and fabricated. This laser amplifier produced an on-target laser power density of 2*10/sup 18/ W/cm/sup 2/. Maximum output energy was determined to be 5 J in a 20-ns-long pulse, and maximum instantaneous power was achieved in a 250-350-mJ, 300-fs pulse with an injection (seed) pulse of approximately=3-4 mJ in a triple pass configuration. The output wavelength is 248 nm. The amplifier has a volume of approximately 5 liters. UV preionization was accomplished with a traveling spark board. Fast, low inductance switching of the high voltage was accomplished through the use of an electrically triggered rail-gap. Some of the design and tradeoffs of the electrical pulse discharge circuitry, considerations related to the materials used, the optics, gas handling, timing requirements, and some experimental results are discussed. >
Human immunodeficiency virus type 1 reverse transcriptase. 3'-Azidodeoxythymidine 5'-triphosphate inhibition indicates two-step binding for template-primer.

Abstract Human immunodeficiency virus type-1 (HIV-1) reverse transcriptase (RT) catalyzes DNA synthesis by an ordered sequential mechanism. After template-primer (T·P) binds to free enzyme, the deoxynucleoside triphosphate to be incorporated binds to the RT and T·P binary complex (RTT·P). After incorporation of the bound nucleotide, catalytic cycling is limited either by a conformational change (for processive synthesis) or release of the enzyme from the extended T·P (for single-nucleotide incorporation). To explore cycling through these alternate rate-limiting steps, we determined kinetic parameters for single-nucleotide incorporation by HXB2R HIV-1 RT with chain-terminating nucleotide substrates 3′-azido-3′-deoxythymidine triphosphate (AZTTP) and dideoxythymidine triphosphate on a homopolymeric T·P system, poly(rA)-oligo(dT)16. Inhibition of processive deoxythymidine monophosphate incorporation by these chain-terminating substrates was also examined. Because AZTTP is a substrate, its Kmshould be equivalent to Ki, and since Kmfor AZTTP should be influenced by the dissociation rate constant for RTT·P, we examined the effect of altering RTT·Pdissociation on AZTTP kinetic parameters. The dissociation rate constant was modulated by making use of different T·P substrates, viral sources of RT, and a mutant RT altered at a residue that perturbs T·P binding. As expected from earlier work, the time course of AZTMP incorporation on poly(rA)-oligo(dT)16was biphasic, with a burst followed by a slower steady-state phase representing kcat(0.42 min−1) which was similar to the rate constant for RTT·Pdissociation. Additionally, Kmfor AZTTP (110 nM) was lower than its equilibrium dissociation constant (1200 nM). AZTTP inhibition (KiAZTTP) of processive dTMP incorporation and incorporation of a single nucleotide were similar. However, a simple correlation between the RTT·Pdissociation rate constant and KiAZTTPwas not observed. These results indicate that a simple ordered model for single-nucleotide incorporation is inadequate and that different forms of RTT·Pexist which can limit catalysis. The results are discussed in the context of a two-step binding reaction for T·P where the binary RTT·Pcomplex undergoes an isomerization before binding of the deoxynucleotide substrate.
Evaluating the Impact of Guessing and Its Interactions With Other Test Characteristics on Confidence Interval Procedures for Coefficient Alpha.

The effect of guessing on the point estimate of coefficient alpha has been studied in the literature, but the impact of guessing and its interactions with other test characteristics on the interval estimators for coefficient alpha has not been fully investigated. This study examined the impact of guessing and its interactions with other test characteristics on four confidence interval (CI) procedures for coefficient alpha in terms of coverage rate (CR), length, and the degree of asymmetry of CI estimates. In addition, interval estimates of coefficient alpha when data follow the essentially tau-equivalent condition were investigated as a supplement to the case of dichotomous data with examinee guessing. For dichotomous data with guessing, the results did not reveal salient negative effects of guessing and its interactions with other test characteristics (sample size, test length, coefficient alpha levels) on CR and the degree of asymmetry, but the effect of guessing was salient as a main effect and an inte...
De sillas y almohadones o de la naturaleza ritual del poder en la Nueva España de los siglos XVI y XVII

This article examines the relationship between public ritual and colonial authority in sixteenth and seventeenth-century New Spain. In colonial society, the establishment of authority depended more on such things as prestige, reputation and/or public appearance than on the use of force. This helps explain the great transcendence attributed by contemporaries to all kinds of public rituals. Their effects were far from negligible: they were much more than a disguise with which to make the rulers’ power more palatable. Royal officials constituted their power and identities through public ceremony, and therefore placed crucial importance on maintaining an authoritative public image.
A Short Review of Magnetospheric Substorms

Due to the great number of papers on magnetospheric substorms published in the recent years I will give only a short account of the main progress realized since the publication of Akasofu’s (1968) book. The purpose of Figure 1 is to place the sub-storm phenomena in the general frame of the solar wind magnetosphere interaction. When this interaction increases as a consequence of a southward interplanetary field, energy is stored in the magnetosphere (substorm growth phase). Beyond a certain limit the resultant configuration is unstable and the energy stored is suddenly released producing the substorm expansion phase. A recovery phase ends this explosive part of the substorm; the process repeats as long as the strong interaction is maintained. A reversal of the interplanetary magnetic field northward switches off the strong interaction.
Mechanisms of adhesion enhancement using reactive ion mixing

Abstract Reactive ( 28 Si + and 27 Al + ) and nonreactive ( 40 Ar + and 84 Kr + ) ion mixing was performed on Ni, Cu, and Ni/Si films on polymeric and ceramic substrates. Nonreactive ion mixing gave little or no adhesion enhancement despite substantial interfacial mixing and substrate hardening. Reactive ion mixing produced significant adhesion enhancements (2–45 ×). These adhesion enhancements were attributed to the formation of ion-induced chemical complexes that chemically attach the films and substrates. These interfacial complexes are formed most readily by reactive ions that are thermodynamically reactive with both film and substrate species and that are capable of forming mixed chemical bonds. Reactive intermediate layers and nonreactive ion mixing can also produce interfacial complexes and adhesion enhancement, but care must be taken to avoid selective reaction and the formation of inert interfacial compounds.
Detection of Free Peritoneal Cancer Cells in Gastric Cancer Using Cancer-Specific Newcastle Disease Virus

Cytologic detection of peritoneal gastric cancer cells by Papanicolaou staining offers important prognostic information but has low sensitivity. We evaluated a novel detection technique using Newcastle disease virus expressing the enhanced green fluorescent protein (NDV-GFP) gene. NDV-GFP was tested on MKN-1 human gastric adenocarcinoma cells plated upon rat hepatocytes to determine tumor-specific infection and GFP expression. Malignant ascites infected with increasing doses of virus was evaluated for NDV-GFP dose determination. Peritoneal lavage samples from 30 patients with gastric adenocarcinoma undergoing staging laparoscopy were evaluated with NDV-GFP. NDV-GFP can specifically detect one MKN-1 cell among one million benign rat hepatocytes. NDV-GFP at 5 × 106 plaque-forming units (PFU) produced optimal GFP expression in malignant ascites. Noncancerous cells were non-GFP expressing. GFP-expressing cells counterstained positive for carcinoembryonic antigen expression, confirming their cancerous origin. Furthermore, in patients with advanced gastric cancer, GFP expression was markedly enhanced over cytology. Of six patients with M1 disease discovered during laparoscopy, only 50% were cytology positive. All six, however, were NDV-GFP positive. Cytology was positive in 9% of patients with T3 disease, 8% with N1 disease, and 50% with N2 disease. In contrast, NDV-GFP was positive in 95% of T3 patients and 100% of patients with N1 or N2 disease. NDV-GFP can specifically infect and detect peritoneal gastric cancer cells and offers a more sensitive method compared with conventional cytology. This novel modality may offer enhanced detection of intraperitoneal cancer spread and provide important prognostic information.
Innocent Murmurs and Pediatric Patients: When Should the Primary Care Provider Refer?

IN THE PEDIATRIC population, heart murmurs are extremely common and most children will have a detectable murmur at some point during their childhood. Approximately 80% of children ages 3 to 4 may have a murmur (Burns, Dunn, Brady, Starr, & Blosser, 2013). Providers may notice these murmurs at one visit and not at the next, which is normal. Due to this large number of murmurs in childhood, primary care physicians often detect murmurs during well child examinations or sick visits and refer patients to a pediatric cardiologist for assessment. However, less than 1% of all murmurs in the pediatric age group are a result of congenital heart defects (Etoom & Ratnapalan, 2013), and 61% of patients referred for murmurs to a cardiology subspecialist were found to have functional or innocent murmurs (Etoom & Ratnapalan, 2013). Unnecessary referral and diagnostic tests escalate parental anxiety; however, if referral is necessary then further evaluation is warranted. A thorough history and physical examination (focusing on vital signs, age-appropriate exercise capacity, respiratory or gastrointestinal manifestations of congestive heart failure and a thorough cardiac examination including features of the murmur) are necessary to make a decision (Frank & Jacobe, 2011). The goal of this article is to demonstrate how pediatricians and other providers can distinguish between an innocent versus pathologic murmur and determine when and why a pediatric patient should be referred to a pediatric cardiologist for further evaluation of a new cardiac murmur. What is a Murmur?
Evidence for the direct role of acetylcholinesterase in neurite outgrowth in primary dorsal root ganglion neurons.

Dorsal root ganglion (DRG) neurons show a transient peak expression of acetylcholinesterase (AChE) during periods of axonal outgrowth prior to synaptogenesis, suggesting that AChE has a non-enzymatic role during development. We have previously shown that perturbation of cell surface AChE in cultured embryonic rat DRG neurons results in decreased neurite outgrowth and neurite detachment. In this report, we demonstrate a direct correlation between endogenous AChE content and neurite outgrowth in primary DRG neurons. Adenoviral vectors were constructed using full-length rat AChE T cDNA in either the sense or antisense orientations to overexpress or knock down AChE expression, respectively. Treatment with the sense-expressing vector produced a 2.5-fold increase in AChE expression and a 2-fold increase in neurite length compared with either untreated or null virus-treated control cells. Conversely, treatment with the antisense-expressing vector reduced AChE expression by 40% and resulted in a reduction in neurite length of similar magnitude. We also observed that overexpression of AChE resulted in greater branching at the distal tips of each primary neurite as well as an increase in cell body size. These findings further indicate that AChE expressed on the axonal surface of developing DRG neurons may modulate their adhesive properties and thereby support axonal development.
Biological and phytochemical evaluation of plants V: Isolation of two cytotoxic alkaloids from Chelidonium majus

A routine screening of randomly selected native plants for biological activity revealed that an extract from Chelidonium majus elicited significant cytotoxicity, but was devoid of antitumor properties. A subsequent investigation of the alkaloids from this plant resulted in the isolation of coptisine as the chloride. Coptisine chloride and a second new alkaloid have been shown to be two of the cytotoxic principles of Chelidonium majus.
Characterization of phenolic polymers synthesized by enzyme-mediated reactions in bulk solvents and at oil-water interfaces

Phenolic polymers are synthesized from horseradish peroxidase-catalyzed reactions in the presence of hydrogen peroxide. The reactions are carried out in homogeneous mixtures of water and polar solvents such as DMF as well as at the oil-water interface of AOT/isooctane reversed micelles and isooctane-water biphasic systems. Polymer characteristics are analyzed using thermal, spectroscopic and chromatographic techniques. Polymer molecular weight dependence on the reaction medium composition is demonstrated for poly (p-ethylphenol) and poly (m-cresol). It is shown that thermal curing of polymers leads to cross-linking, and as a result, there is a significant increase in molecular weight. Cross-linking appears to be directly to the aromatic rings, and not via ether links, as inferred from infrared spectra. A process scheme for the production, under controlled conditions, of phenolic polymers in ethanol-water mixtures is presented. The process allows enhanced monomer conversions and ability to tailor polymer molecular weight. Possible applications for phenolic polymers are discussed.
A Conserved Region of c-Ha-Ras Is Required for Efficient GTPase Stimulation by GTPase Activating Protein but Not Neurofibromin

Abstract The effector binding domain and the switch II region of c-Ha-Ras are necessary for p120GAP-stimulated GTP hydrolysis. We report a third region of c-Ha-Ras located within the α3 helix (amino acids 101-103) which is also required for efficient p120GAP, but not neurofibromin-mediated hydrolysis. This highly conserved region of the Ras protein was investigated using an insertion-deletion mutant (Ras-100LIR104) originally characterized by Willumsen et al. (Willumsen, B. M., Adari, H., Zhang, K., Papageorge, A. G., Stone, J. C., McCormick, F., and Lowy, D. R(1989) in The Guanine Nucleotide Binding Proteins; Common Structural and Functional Properties (Bosch, L., Kraal, B., and Parmeggiani, A., eds) pp. 165-178, Plenum Press, New York). The 100LIR104 substitution did not alter the intrinsic hydrolytic rate of the protein. The p120GAP-stimulated hydrolysis of Ras-100LIR104, however, was decreased by 2-3-fold compared to wild type Ras. This decrease in p120GAP-stimulated hydrolysis was not due to its inability to physically associate with Ras-100LIR104•GTP (as determined by competitive binding assays). Surprisingly, neurofibromin-stimulated GTP hydrolysis was unaltered by the mutation. Finally, no differences were observed in the ability of either the p120GAP catalytic domain or the neurofibromin GRD to accelerate Ras-100LIR104 GTPase activity, indicating that the amino-terminal noncatalytic GAP region is critical for p120GAP-stimulated GTP hydrolysis. This is the first report of a Ras mutation which differentiates between p120GAP and neurofibromin activity.
Thalamic Ablations and Neocortical Development: Alterations of Cortical Cytoarchitecture and Cell Number

The diversity of neocortical cytoarchitecture could arise from genetic prespecification of cell types and numbers in the ventricular zone, by interaction of cells with their immediate environment, efferent targets, or afferent inputs. Here, we examine the role of the thalamus as efferent target or afferent source in the early control of cell number and type in the developing neocortex. Electrolytic lesions of the thalamus were made in hamsters at birth prior to the thalamic innervation of layer IV. By postnatal day 7, when migration to the cortex is complete, there were no differences in cell number between the cortical plate contralateral and ipsilateral to the thalamic lesion, showing that the absence of thalamic input does not influence the last phases of neocortical cell generation or migration. However, the incidence of pyknotic cells was elevated in the upper half of the cortical plate at this time. By adulthood, the number of cells per unit column of cortex was reduced, due to the apparent absence of small, nonpyramidal cells of layer IV, as determined from Nissl-stained material. Therefore, some of the cytoarchitectonic variability of the neocortex could arise epigenetically by the interaction of neocortical cells with their afferent connections.
Reported challenges for socio‐cultural curricula in instructional design

Purpose – The purpose of this paper is to examine the perceived challenges of attempting to integrate topics related to social and cultural issues into the coursework in graduate programs in Instructional Design and Technology (IDT).Design/methodology/approach – An open‐ended online survey instrument was developed for this study for three reasons. First, the study aimed at investigating what is actually happening in IDT programs in terms of integration of social and cultural issues into coursework. Using an online questionnaire, data were collected from IDT instructors and instructional designers.Findings – Findings of the study indicated that while there is a general agreement and interest in infusing content that addresses socio‐cultural perspectives challenges into courses, the challenges include the existence of a common framework for defining and prioritizing socio‐cultural issues, and difficulties in identifying the most important issues to address, and appropriate instructional approaches to addres...
SU‐E‐J‐158: A Phantom Study Based Simulation to Quantify the Motion and Tumor Volume Affected 18F‐FDG PET Uptake Distribution Within the Tumor

Purpose: Molecular imaging studies reveal tumor heterogeneity which may explain therapeutic resistance. Alternatively, variations observed in the SUV uptake may not be due to intrinsic heterogeneity of the tumor, but due to effects of position resolution (volume dependence) or tumor motion . The objective of this study is to evaluate motion artifacts on PET SUV uptake within tumors for different volumes. Methods: We conducted a phantom study: spheres of homogeneous18F‐FDG activity of motion amplitudes (0, 5, 10, 15, 20, 25, 30 mm) and volumes (internal diameter 10, 13, 17, 22, 28, 37 mm). Any variation observed in SUV uptake distribution with homogeneous activity spheres must be due to motion and volume effects. Therefore, we used this data to quantify uptake variations as a function of motion and volume. PET SUV uptake values for each tumor were fit with a Woods‐Saxon model with 2 parameters: radius and skin depth. When the ratio of radius to skin depth becomes small, this simplifies to a Gaussian. By using this parameterization for stationary phantoms, using the probability density function for motion, and using an image convolution technique we were able to simulate the SUV uptake distribution of moving tumor in the central 2D plane. Taking voxel by voxel SUV uptake distribution in 2D we quantified the accuracy of our simulation for motion affected, tumor volume affected SUV uptake heterogeneity within the phantom. Results: Phantom study for stationary spheres show motion has a high impact on SUV uptake distributions. Maximum percentage uptake variation across the phantoms was 22%. Convolution results confirm that motion is the largest contributor to the SUV heterogeneity of the tumors. Average difference between convolution and measurement is 6.7%. Conclusion: These results will impact the studies that utilize tumor heterogeneity such as tumor detection, planning with dose painting, and treatment response. UVA Radiation Oncology george Amarino Grant ‐ 2012
Distributed Receive Beamforming: A Scalable Architecture and Its Proof of Concept

We propose and demonstrate a scalable architecture for distributed receive beamforming. In a receive cluster of N + 1 nodes receiving a message from a distant transmitter, N nodes are designated as amplify-and-forward relays and one node is designated as the receiver. The relay nodes apply a phase shift to their received signal and forward it such that their forwarded signals add up constructively at the receiver, with received SNR scaling linearly with N. This approach transforms a distributed receive beamforming problem on the "long link" from transmitter to receive cluster into a distributed transmit beamforming problem on the "short link" from relays to receiver, so that the number of degrees of freedom on the short link need not scale with N. A key simplification relative to distributed transmit beamforming is that, for stable oscillators, relay frequency synchronization is not required. For oscillators with drift, we provide a simple rule of thumb for when explicit frequency synchronization can be avoided. Explicit timing alignment can also be avoided by exploiting the timing of the message received on the long link. That leaves the problem of phase adjustment at the relays, and we employ an algorithm originally invented for distributed transmit beamforming for this purpose, using one bit (per iteration) feedback from the receiver. Experimental results with software-defined radios (whose oscillators have significant drift) demonstrate that the expected gains in received signal strength are obtained with the proposed architecture.
Averaged equations for inviscid disperse two-phase flow

Averaged equations governing the motion of equal rigid spheres suspended in a potential flow are derived from the equation for the probability distribution. A distinctive feature of this work is the derivation of the disperse-phase momentum equation by averaging the particle equation of motion directly, rather than the microscopic equation for the particle material. This approach is more flexible than the usual one and leads to a simpler and more fundamental description of the particle phase. The model is closed in a systematic way (i.e. with no ad hoc assumptions) in the dilute limit and in the linear limit. One of the closure quantities is related to the difference between the gradient of the average pressure and the average pressure gradient, a well-known problem in the widely used two-fluid engineering models. The present result for this quantity leads to the introduction of a modified added mass coefficient (related to Wallis's ‘exertia’) that remains very nearly constant with changes in the volume fraction and densities of the phases. Statistics of this coefficient are provided and exhibit a rather strong variability of up to 20% among different numerical simulations. A detailed comparison of the present results with those of other investigators is given in § 10.As a further illustration of the flexibility of the techniques developed in the paper, in Appendix C they are applied to the calculation of the so-called ‘particle stress’ tensor. This derivation is considerably simpler than others available in the literature.
Reconsidering the “Palin Effect” in the 2008 U.S. Presidential Election

“The ‘Palin Effect’ in the U.S. 2008 Presidential Election” analyzes the effect of Sarah Palin on presidential vote choice. Two of the substantive conclusions are (1) Palin cost McCain votes among ...
Measures and predictors of educational growth with four years of college

The potential utility of a college admissions test as a measure of the cognitive learning outcomes of general education is investigated. A residual form of the ACT Assessment was administered to a stratified random sample of 112 seniors at Tennessee Technological University. Detailed comparisons of gain scores are made with those of a previous study which focused upon educational growth with two years of college. Although the results show substantial gains in performance on the ACT Assessment for the seniors, the absence of demonstrable relationships with institutional experience or “exposure” variables together with the presence of “ceiling” effects warrant the recommendation that admissions tests are not appropriate as indicators of cognitive learning outcomes.
Crystal and Molecular Structure of Pyrrole-2-carboxylic Acid; π-Electron Delocalization of Its Dimers−DFT and MP2 Calculations

The crystal and molecular structure of pyrrole-2-carboxylic acid (PCA) determined by single-crystal X-ray diffraction is presented. Intermolecular H-bonds for this structure are analyzed. The DFT calculations at the B3LYP/6-311++G(d,p) level of theory and ab initio calculations at the MP2/6-311++G(d,p) level are performed for dimers of pyrrole-2-carboxylic acid and for similar model species. The X-ray data and calculations show that the pyrrole moiety within pyrrole-2-carboxylic acid influences the π-electron delocalization and hence the strength of the hydrogen bonds. The geometrical and energetic features of H-bonds of PCA dimers and of model complexes are analyzed. Additionally, the Bader theory is applied, and the characteristics of the bond critical points and ring critical points confirm the influence of the pyrrole moiety on the strength of H-bond interactions.
Angle-resolved Auger electron emission from LaB6(001) with and without chemisorbed oxygen

Abstract The angular intensity distributions of La(M 5 N 4.5 N 4.5 ) and B(KL 1 L 1 ) Auger electrons have been measured as a function of polar and azimuthal angles for clean and oxygen-covered LaBg 6 (001). The method used employs a dispersive cylindrical mirror energy analyzer and a two-axis rotation sample manipulator. Significant structure is observed in both polar and azimuthal profiles and, at least in the case of La Auger emission, can be partially accounted for using a simple scattering model. Polar profiles obtained by this method and those obtained using angle-resolved X-ray photoemission show many similarities. The angular intensity profiles are consistent with a model of the surface in which the La layer is outermost on the polar LaB 6 (001) plane and the adsorption of oxygen occurs at both La and B sites.
Exploratory backdraft experiments

This study is a qualitative exploration of backdraft phenomena. Backdraft is defined as a rapid deflagration following the introduction of oxygen into a compartment filled with accumulated excess pyrolyzates. A scenario describing the physical and chemical fundamentals underlying backdraft phenomena is presented. A half-scale apparatus, designed to avoid dangerous overpressures, was used to obtain data from backdraft experiments. A gas burner supplied a 150 kW natural gas fire in a 1.2 m high, 1.2 m wide, 2.4 m long compartment with a small, 25 mm high, 0.3 m wide vent to ambient at floor level. Significant unburnt fuel accumulates in 180 seconds, when a hatch covering a 0.4 m high, 1.2 m wide vent, centered on a short wall, is opened, simulating a window breaking due to thermal stresses. The propagation across the compartment of the cold density-driven flow, which enters through the new opening, is called a “gravity current.” This gravity current carries a flammable mixed layer to a spark located near the burner on the opposite wall. The rapid deflagration that results upon ignition of the mixed layer is the backdraft. A compartment fire model is used to calculate conditions in the compartment before the vent opens. The hypothesized scenario appears to be confirmed by the deflagrations and exterior fire balls observed in these preliminary experiments.
Effects of vortex pairing on particle dispersion in turbulent shear flows

Abstract Particle dispersion in large-scale dominated turbulent shear flow is investigated numerically with special emphasis on the effects of the vortex-pairing phenomenon. The particle dispersion is visualized numerically by following the particle trajectories in a flow consisting of large vortices which are undergoing pairing interaction. The flow field is generated by a discrete vortex method. Important global and local fiow quantities from the numerical simulation compare reasonably well with experimental measurements. For both cases of point sources with continuous particle release and an initially distributed line source, the particle dispersion results demonstrate that the extent of particle dispersion depends strongly on the Stokes number, the ratio of the particle aerodynamic response time to the characteristic time of the vortex-pairing flow field. Particles with relatively small Stokes numbers disperse laterally at approximately the saine rate as that of the fluid particles and particles with large Stokes numbers disperse much less than the fluid particles. Particles with intermediate Stokes numbers (0.5-5) may be dispersed laterally farther than the fiuid particles and may actually be flung out of the vortex structures. Due to the strong particie entrainment power, the flow during the vortex-pairing process seems to produce higher particle lateral dispersion than the pre-pairing and post-pairing flows.
COUPLING PROTEIN DYNAMICS TO REACTION CENTER ELECTRON DENSITY IN ENZYMES: AN ELECTRONIC PROTEIN PROMOTING VIBRATION IN HUMAN PURINE NUCLEOSIDE PHOSPHORYLASE

The notable three oxygen stacking that occurs upon binding of ribonucleoside substrate and phosphate nucleophile by human purine nucleoside phosphorylase (hPNP) enables the coupling of protein dynamic modes to compress this stack, squeezing the ribosyl O4' between ribosyl O5' and the nuclophilic OP. Created primarily by the motion of active site residue H257, this compression dynamically lowers the barrier height for N9–C1' ribosidic bond cleavage by as much as 20%. As such, this compression constitutes a protein promoting vibration (PPV) (S. Nunez et al.). Presently, we demonstrate charge fluctuations in the ribose and purine components of the ribonucleoside substrate, as well as specifically across the N9–C1' ribosidic bond, that are correlated with the PPV and can explain the decrease in reaction barrier height due to their facilitating cleavage of the ribosidic bond. hPNP apparently employs protein dynamics to push electrons, a finding that suggests that this coupling may be found more generally in enzymes that catalyze substitution and elimination reactions.
Some thoughts on the reported results of TREC

The periodic TRECs - Text REtrieval Conferences - have reported the results of a variety of recall studies in large-scale document retrieval. While the efforts of TREC are noteworthy and laudable, there are reasons why its results, especially the recall values which are central to its conclusions, should be accepted with some caution.
Replicating an established open skills curriculum: are the same results obtained in a different setting?

Introduction The aim of this study was to ascertain whether the University of Texas, Southwestern (UTSW) open skills curriculum (Goova et al. 13 ) could be successfully implemented in the University of Minnesota (UMN) multisite training program. We posed 4 questions: (1) Is the curriculum feasible? (2) Did residents' skills improve? (3) Did UMN residents achieve the same level as UTSW residents? (4) What factors were associated with posttest success? Methods Postgraduate year-1 residents ( n = 22) were enrolled in the curriculum, which included orientation, access to video instruction, 3 months of independent practice using portable kits and practice logbooks, presurveys and postsurveys, and pretesting and posttesting. Evaluation was based on UTSW proficiency measures (time, errors, and total proficiency score). Descriptive statistics, paired sample t tests, analysis of variance, and bivariate correlations were calculated. Results were compared with Goova. Results Startup costs at UMN were $9804 vs $776 at UTSW. Our curriculum required 51 direct faculty hours vs 376 at UTSW. UMN trainees' skills improved significantly (mean score=973 [standard deviation=267] at baseline vs 1325 [standard deviation=215] at posttest), but they achieved proficiency in only 38.6% of tasks at posttest, compared with 88.7% by UTSW trainees. Best predictors of UMN posttest proficiency score were (1) categorical vs preliminary resident status (p r = 0.510, p=0.008), and (3) self-assessed baseline proficiency ( r = 0.415, p=0.027). Participation in skills laboratories during clerkship or fourth year medical school, estimated number of cases (surgeon or first assistant), and number of practice repetitions recorded in booklets were not predictive of the posttest score. Conclusions The UTSW open skills curriculum is feasible and effective in a new setting. Differences from UTSW-published success rates may be related to their superior onsite monitoring of practice and a policy requiring residents to achieve proficiency for each task before posttesting.
Association Between Waiting Times for Kidney Transplantation and Rates of Live Donation

A deceased donor (DD) allocation system incorporating net life survival benefit has been proposed. In this system, many kidneys will be shifted to younger recipients, thereby decreasing their waiting times. The goal of this study was to determine the potential effects of altering waiting times on the likelihood of live donor kidney transplantation (LDKT). We analyzed 93727 waiting list candidates to determine the association of various patient factors with likelihood of LDKT. The proportion of patients receiving LDKT was compared by the median DD waiting time at that patient's transplant center for someone of that patient's age category and race. LDKT was consistently higher as waiting times became longer. After adjusting for all other factors associated with likelihood of LDKT, waiting time remained a significant, independent predictor. Patients with the longest DD waiting times had 2.3-fold higher odds of LDKT (95% CI 2.11–2.58, p < 0.001). In planning the new DD allocation policy, we must account for resulting alterations in LDKT. It is possible that shifting DD kidneys to younger recipients may decrease LDKT or shift it to older recipients, net effects not consistent with the goal of net life survival benefit.
Fulminant onset of acute leukemia from normal hematopoiesis within 3 months of follow up for multiple myeloma treated with total therapy protocols

Assiduous surveillance for genetic aberrations is necessary in patients on cytotoxic therapies to detect therapy-related myeloid neoplasms (t-MN). Current modalities include metaphase cytogenetics and FISH. Since t-MN may develop abruptly in cytogenetically normal patients, a discussion exploring additional methods such as SNP-array and targeted-deep-sequencing to detect subchromosomal abnormalities is needed.
Endocrine and anatomical correlations in human ovarian pathology.

Knowledge of normal gonadal hormone production and function provides the basis for understanding the ovarian pathologic effects resulting from perturbations in endocrine balance and feedback. A pre...
The Chilean pension reform: 25 years later

A quarter of a century ago, Chileans embarked on a course of reform to modernise their economy. As part of these reforms, the Chilean government replaced the traditional pension system with one based on private retirement accounts. The radical reform, which brought dynamism to the Chilean economy, was a solution to the chaotic nature of the old system. The pension reform replaced the old pay-as-you-go-system with one pre-funded with personal retirement accounts. The Chilean experience illustrates that, when needed, extreme and fiscally sound pension reforms can bring dynamism to the capital markets. The system is, however, not perfect. Various measures of pension coverage suggest that the system is far from universal; commissions, although declining, still eat a significant piece of the retirees’ accounts; the amount of workers projected to depend on the minimum pension guarantee or the assistance pension raises concerns about the fiscal consequences of the system.
Idiopathic short stature: conundrums of definition and treatment.

Children with idiopathic short stature (ISS) are statistically defined by height SDS for their bone age and should be distinguished from children with familial short stature for whom height SDS corresponds to mean parental SDS and from the most common explanation for short stature referred to pediatric endocrinologists, constitutional delay in growth and maturation (CDGM), in which there is normal height for bone age and predicted normal adult stature. Low IGF-I levels reported in ISS may be the result of subtle undernutrition or reference to standards appropriate for chronologic age but not osseous maturation in CDGM inappropriately labeled as ISS. While growth hormone (GH) treatment of ISS may add 4-5 cm to adult height, meta-analysis indicates that there is no documented evidence that such treatment improves health related quality of life or psychological adaptation. Thus, the estimated cost of US$52 000/inch gained is difficult to justify. Absence of data regarding efficacy of the use of IGF-I for treatment of ISS has been noted in a recent consensus statement from the North American and European pediatric endocrinology societies. This report further emphasizes the importance of discouraging the expectation that taller stature from GH treatment will improve quality of life.
L-threonine administration increases glycine concentrations in the rat central nervous system

Abstract Intraperitoneal administration of L-threonine increased the glycine and threonine concentrations in rat spinal cord. Glycine contents also increased in synaptosomes prepared from spinal cords from threonine-pretreated animals. These findings suggest that plasma threonine concentrations normally might affect production of glycine by central nervous system neurons, and also that exogenous threonine might be useful in modifying glycinergic transmission.
Are cobaltates conventional? An ARPES viewpoint

Abstract Recently discovered class of cobaltate superconductors (Na 0.3 CoO 2 · n H 2 O) is a novel realization of interacting quantum electron system in a triangular network with low-energy degrees of freedom. We employ angle-resolved photoemission spectroscopy to study the quasiparticle parameters in the parent superconductors. Results reveal a large hole-like Fermi surface generated by the crossing of heavy quasiparticles. The measured quasiparticle parameters collectively suggest two orders of magnitude departure from the conventional weak coupling (such as Al) Bardeen–Cooper–Schrieffer electron dynamics paradigm and unveils cobaltates as a rather hidden class of relatively high temperature superconductors. These parameters also form the basis for a microscopic Hamiltonian of the system.
Self-assembling bipyridinium multilayers

The identification of strategies to assemble nanostructured films with engineered properties on solid supports can lead to the development of innovative functional materials. In particular, the self-assembly of electroactive multilayers from simple molecular building blocks on metallic electrodes can offer the opportunity to regulate the exchange of electrons between the underlying substrate and solution species. In this context, we designed an experimental protocol to prepare electroactive films from bipyridinium bisthiols. Specifically, we found that a compound incorporating two bipyridinium dications at its core and terminal thiol groups self-assembles into remarkably stable multilayers on polycrystalline gold. The surface coverage of the resulting films can be regulated by adjusting the exposure time of the gold substrate to the bipyridinium solution. Control experiments with appropriate model compounds demonstrate that both bipyridinium dications as well as both thiol groups must be present in the mo...
Correlated Proton and Heavy Ion Upset Measurements on IDT Static RAMs

Upset measurements on four types of CMOS/NMOS RAMs by IDT have been performed using both protons and heavy ions.