cssi/SciSciGPT-SciSciNet huggingface dataset:
Benchmark problems in structural control : Part II : Active tendon system

In a companion paper (Spencer et al.), an overview and problem definition was presented for a well-defined benchmark structural control problem for a model building configured with an Active Mass Driver (AMD). A second benchmark problem is posed here based on a high-fidelity analytical model of a three-storey, tendon-controlled structure at the National Center for Earthquake Engineering Research (NCEER). The purpose of formulating this problem is to provide another setting in which to evaluate the relative effectiveness and implementability of various structural control algorithms. To achieve a high level of realism, an evaluation model is presented in the problem definition which is derived directly from experimental data obtained for the structure. This model accurately represents the behaviour of the laboratory structure and fully incorporates actuator/sensor dynamics. As in the companion paper, the evaluation model will be considered as the real structural system. In general, controllers that are successfully implemented on the evaluation model can be expected to perform similarly in the laboratory setting. Several evaluation criteria are given, along with the associated control design constraints. © 1998 John Wiley & Sons, Ltd.
Chemical inducers of differentiation in Friend leukaemia cells inhibit lymphocyte mitogenesis

Several phorbol esters, the potent tumour-promoting agents1 isolated from croton oil, induce proliferation of human lymphoctyes2,3 and enhance the mitogenic effect of lectins on bovine lymphocytes4. While studying the mitogenic properties of one of these agents, phorbol myristate acetate (PMA), we found that dimethyl sulphoxide (DMSO), frequently used as a solvent for PMA, markedly inhibits PMA-induced mitogenesis at DMSO concentrations that have little effect on phyto-haemagglutinin (PHA)-induced responses. DMSO, as well as a variety of other organic compounds, induce erythroid differentiation in Friend leukaemia (FL) cells5–9. Phorbol esters, on the other hand, are potent inhibitors of both spontaneous and induced cellular differentiation10–13. We therefore investigated the relationship between the potency of compounds to induce erythroid differentiation in FL cells and their potency to inhibit lymphocyte proliferation induced by PMA and other mitogens. We report here that many of the compounds that induce erythroid differentiation in FL cells are similar to DMSO hi selectively suppressing PMA-induced lymphocyte mitogenesis.
Sampling of orbital sinus blood closely reflects brain ethanol content in rats

It was demonstrated that the aerial righting reflex can be used as an index of acute ethanol-induced impairment of motor coordination in rats, and was found to directly correlate with blood ethanol content from the infraorbital plexus. A study of ethanol within the blood and its distribution in brain regions showed that the ethanol content of orbital sinus blood closely reflected that in the cerebral cortex, midbrain, and cerebellum. Ethanol administration by intraperitoneal (IP) injection (2, 3 or 4 g/kg) produced the same distribution as 24 hr ethanol vapor inhalation (28 mg/l). Blood ethanol concentrations were slightly higher than brain ethanol concentrations when measured at 10, 30, and 60 min after IP injection and immediately following ethanol vapor administration. Also, in rats 48 hr following ethanol vapor inhalation when tolerance to ethanol is exhibited, the distribution and concentrations of ethanol in blood and brain from acute ethanol (2 g/kg, IP) were unaltered when compared with controls. These data suggest that ethanol distribution within the brain does not play a role in the phenomenon of tolerance to ethanol.
Confidence intervals using orthonormally weighted standardized time series

We extend the standardized time series area method for constructing confidence intervals for the mean of a stationary stochastic process. The proposed intervals are based on orthonormally weighted standardized time series area variance estimators. The underlying area estimators possess two important properties: they are first-order unbiased, and they are asymptotically independent of each other. These properties are largely the result of a careful choice of weighting functions, which we explicitly describe. The asymptotic independence of the area estimators yields more degrees of freedom than various predecessors; this, in turn, produces smaller mean and variance of the length of the resulting confidence intervals. We illustrate the efficacy of the new procedure via exact and Monte Carlo examples. We also provide suggestions for efficient implementation of the method.
USE OF SCENARIO-BUILDING TRANSPORTATION MODEL FOR DEVELOPING COUNTRIES

Scenario building is a technique used to evaluate a set of alternatives and give policy makers a quick tool for identifying which are politically viable. The transportation system hierarchy prevailing in a large metropolitan area in a developing country is examined using a scenario-building model. The model is bidimensional with two parameters: distance traveled and the value of time of persons using the transportation system. It is applied to metropolitan Madras (population 6 million) in India. Two scenarios are developed: first, using the perceived costs of various modes available in Madras, and second, using costs reflecting the changes that could arise as a result of policy changes. Results suggest that policy needs to be oriented toward promoting the use of nonmotorized modes, motorized two-wheelers, and public transit instead of emulating that of developed countries. This model and its results will be useful to decision makers in examining scenarios of their choice.
Isolation and identification of a plasmatocyte-spreading peptide from the hemolymph of the lepidopteran insect Pseudoplusia includens.

Abstract Insect blood cells (hemocytes) play an essential role in defense against parasites and other pathogenic organisms that infect insects. A key class of hemocytes involved in insect cellular immunity is plasmatocytes. Here we describe the isolation and identification of a peptide from the moth Pseudoplusia includens that mediates the spreading of plasmatocytes to foreign surfaces. This peptide, designated plasmatocyte-spreading peptide (PSP1), contains 23 amino acid residues in the following sequence: H-ENFNGGCLAGYMRTADGRCKPTF-OH. In vitro assays using the synthetic peptide at concentrations ≥2 nm induced plasmatocytes from P. includens to spread on the surface of culture dishes. Injection of this peptide into P. includenslarvae caused a transient depletion of plasmatocytes from circulation. Labeling studies indicated that this peptide induced 75% of plasmatocytes that were double-labeled by the monoclonal antibodies 49G3A3 and 43E9A8 to spread, whereas plasma induced significantly more plasmatocytes to spread. This suggests that only a certain subpopulation of plasmatocytes responds to the peptide and that other peptidyl factors mediate plasmatocyte adhesion responses.
Photoproduction of hydrogen by dye-sensitized systems

Abstract Visible light-induced production of hydrogen has been investigated in five different systems. These are: safranine O/EDTA, safranine T/EDTA, proflavine/EDTA, acridine orange/EDTA, and acridine yellow/EDTA, with and without added K2PtCl6. In the two safranine systems photoproduction of hydrogen was observed even in the absence of a Pt catalyst. Also, the addition of an electron mediator such as methyl viologen was found not necessary. Acridine yellow/EDTA/K2PtCl6 has been shown to be the best system examined, which upon addition of Triton X-100, showed further enhancement of the rate of hydrogen evolution.
Characterization of an Acid-Dependent Arginine Decarboxylase Enzyme from Chlamydophila pneumoniae

Genome sequences from members of the Chlamydiales encode diverged homologs of a pyruvoyl-dependent arginine decarboxylase enzyme that nonpathogenic euryarchaea use in polyamine biosynthesis. The Chlamydiales lack subsequent genes required for polyamine biosynthesis and probably obtain polyamines from their host cells. To identify the function of this protein, the CPn1032 homolog from the respiratory pathogen Chlamydophila pneumoniae was heterologously expressed and purified. This protein self-cleaved to form a reactive pyruvoyl group, and the subunits assembled into a thermostable (αβ)3 complex. The mature enzyme specifically catalyzed the decarboxylation of l-arginine, with an unusually low pH optimum of 3.4. The CPn1032 gene complemented a mutation in the Escherichia coli adiA gene, which encodes a pyridoxal 5′-phosphate-dependent arginine decarboxylase, restoring arginine-dependent acid resistance. Acting together with a putative arginine-agmatine antiporter, the CPn1032 homologs may have evolved convergently to form an arginine-dependent acid resistance system. These genes are the first evidence that obligately intracellular chlamydiae may encounter acidic conditions. Alternatively, this system could reduce the host cell arginine concentration and produce inhibitors of nitric oxide synthase.
Transcriptional Regulation of the Mouse Gene Encoding the α-4 Subunit of the GABAA Receptor

The γ-aminobutyric acid type A receptors (GABAA-Rs) mediate fast inhibitory synaptic transmission in the brain. The α4 subunit of the GABAA-R confers distinct pharmacological properties on the receptor and its expression pattern exhibits plasticity in response to physiological and pharmacological stimuli, including withdrawal from progesterone and alcohol. We have analyzed the promoter region of the mouse GABRA4 gene that encodes the α4 subunit and found that the promoter has multiple transcriptional initiation sites and lacks a TATA box. The minimal promoter for GABRA4 spans the region between –444 to –19 bp relative to the coding ATG and shows high activity in cultured mouse cortical neurons. Both Sp3 and Sp4 transcription factors can interact with the two Sp1 binding sites within the minimal promoter and are critical for maximal activity of the promoter in neurons.
GABAergic supersensitivity within the pars reticulata of the rat substantia nigra following chronic haloperidol administration

These studies were performed to evaluate the effects of chronic haloperidol administration on the responsiveness of the pars reticulata neurons of the substantia nigra (SNR) to microiontophoretically applied gamma-aminobutyric acid (GABA) and glycine. Rats were administered haloperidol in their feed (CHAL treatment) for 30 days in increasing concentrations. All experiments were conducted two days after termination of the CHAL treatment. GABA receptor binding and neuronal responsiveness to GABA were significantly increased within the SNR following CHAL treatment. The mean EC50 value for GABA was significantly decreased for SNR neurons in CHAL-treated rats, but there was no change in the EC50 for glycine. Specific [3H]GABA binding (4 nM) was elevated by more than 50% within the SNR. Scatchard analysis of [3H]muscimol binding data revealed that the binding capacities (Bmax) of both high and low affinity GABA binding sites within the SNR were significantly increased without a change in the apparent dissociation constants (Kd) of either site. Although no regional difference in responsiveness to GABA was detected within the SNR of CHAL-treated rats, the spontaneous activity of neurons located within the rostral two-thirds of the nucleus was reduced; however, there was no change in spontaneous activity of neurons located within the caudal one-third. These data provide direct physiological evidence to support the conclusion that the increase in GABA binding within the SNR following CHAL treatment reflects a neuronal supersensitivity to GABA.
Heeding the Sirens: The Politics of IMF Program Participation

Given similar economic distress indicators, why do some states enter into International Monetary Fund (IMF) programs while others do not? Building on extant studies of IMF program participation that highlight the importance of various economic and political determinants, this article proposes an argument focusing on the political incentives of the IMF and a borrowing country when they engage in IMF program negotiations. Specifically, the study develops a domestic politics argument to highlight the interactions among sovereignty costs, competence costs, economic conditions and domestic regime types, and tests the argument using a cross-national time-series dataset of all IMF agreements between 1970 and 2006. It finds that when the economic crisis is mild, democracies are less likely than non-democracies to enter IMF programs, but that when the economic crisis is severe, democracies are more likely to do so than their autocratic counterparts. The article attributes this tendency to democratic leaders’ electoral vulnerability and shows that these patterns become more pronounced as elections draw near.
Can we dramatically reduce the incidence of coronary heart disease

Thrombotic events caused by atherosclerosis are by far the most common cause of death in the world. Advances in treatment have prolonged the life of patients with atherosclerotic disease, but treating individuals with clinically manifest disease will not result in a cure, and will not prevent the majority of such events. This paper explores the possibility that early implementation of a drug-based approach to the prevention of atherosclerosis and atherothrombotic events could dramatically reduce the footprint of this disease. Specifically, we consider the potential impact on atherothrombotic events of a population-based, pharmacological approach to lowering serum LDL-cholesterol levels in asymptomatic adults aged 35-50 years. We also consider the feasibility and basic design considerations for a clinical trial to assess the validity of this public health and primary prevention approach.
On the Anomalous Properties of the h 1-Cyclopentadienyltin(IV) Halides

Abstract h 1-Cyclopentadienyltin(IV) halides exhibit low Mossbauer Quadrupole Splittings reflecting the similarity of the C5H5 and halide ligands at tin, and leading to the expectation of strong Lewis acid character; however, Lewis bases form the expected adducts only if bidentate, or in the case of (h 1-C5H5)2SnCl2 and pyridine, only in petroleum ether, while in benzene for X[sbnd]Cl and in all solvents used for X[dbnd]Br and I, SnX4.2py and (h 1-C5H5)3SnX form from (h 1-C5H6)2SnX2 through redistribution; and h 5-C5H5SnCl likewise forms tin(II) chloride adducts only.
Combined Environments versus Consecutive Exposures for Insulation Life Studies

The service life of an insulating material which will be used in a nuclear radiation environment cannot be predicted by the usual thermal-aging methods; neither can it be predicted from experiments in which thermal aging follows a pre-exposure to radiation at room temperature. To have any reliable significance, the experiment must be conducted in a combined environment of both thermal and nuclear radiation. At the Naval Research Laboratory an apparatus has been designed and used to achieve this exposure condition. Results show that by combining radiation with heat the normal thermal life of several materials is increased by as much as 800 percent, and for one of these materials the increase was over 3500 percent in one combination of radiation and heat. This is probably due to a balancing of the chain-scission and cross-linking mechanisms which occur in polymer reactions. Increased life is not universal for all materials, for in some of these experiments less than normal thermal life was observed.
Intradomain distances in the regulatory domain of the myosin head in prepower and postpower stroke states: fluorescence energy transfer.

The relative movement of the catalytic and regulatory domains of the myosin head (S1) is likely to be the force generating conformational change in the energy transduction of muscle (Rayment, I., Holden, H. M., Whittaker, M., Yohn, C. B., Lorenz, M., Holmes, K. C., and Milligan, R. A. (1993) Science 261 ,5 8-65). To test this model we have measured, using frequency-modulated FRET, three distances between the catalytic domain and regulatory domains and within the regulatory domain of myosin. The donor/acceptor pairs included MHC cys707 and ELC cys177; ELC cys177 and RLC cys154; and ELC cys177 and gizzard RLC cys108. The IAEDANS (donor) or acceptor (DABMI or IAF) labeled light chains (ELC and RLC) were exchanged into monomeric myosin and the distances were measured in the putative prepower stroke states (in the presence of MgATP or ADP/AlF4 - ) and the postpower stroke states (ADP and the absence of nucleotides). For each of the three distances, the donor/acceptor pairs were reversed to minimize uncertainty in the distance measured, arising from probe orientational factors. The distances obtained from FRET were in close agreement with the distances in the crystal structure. Importantly, none of the measured distances varied by more than 2 A, putting a strong constraint on the extent of conformational changes within S1. The maximum axial movement of the distal part of myosin head was modeled using FRET distance changes within the myosin head reported here and previously. These models revealed an upper bound of 85 A for a swing of the regulatory domain with respect to the catalytic domain during the power stroke. Additionally, an upper bound of 22 A could be contributed to the power stroke by a reorientation of RLC with respect to the ELC during the power stroke.
Pavlov and the Pavlovians in the laboratory

The general character of the Pavlovians and their role in the experimental investigation of conditioned reflexes is discussed. From 1897 to 1936, Ivan P. Pavlov had at least 146 co-workers and he was closely involved in their experimental work. The social background, nationality, and gender of the Pavlovians are described together with the daily routine in the laboratories. It is pointed out that, despite Pavlov's authoritarian style, the Pavlovians characterized him as the epitome of a scholar and an admirable human being. It is concluded that the work in the laboratories was truly a cooperative effort between Pavlov and his co-workers.
Improving investment performance for pension plans

Over the past half-decade, pension plans in the US have seen their ample surpluses turn into massive deficits. Many pension trusts in early 2006 possess funding ratios below 75 per cent. This paper suggests that multi-period investment models can increase performance for long-term investors including pension plans, family offices and university endowments. The framework improves the investor's understanding of risks and rewards in a temporal setting. Contribution and saving strategies can be integrated with asset allocation decisions to enhance the sponsoring company's shareholder value via the pension trust. Applying an overlay strategy further improves performance. Advantages are illustrated via several examples, including the slow-growing telecommunication sector and the under-funded pension plan of a car company.
Analysis of Potassium Titanyl Phosphate Laser Settings and Voice Outcomes in the Treatment of Reinke’s Edema

Objective:Despite increased clinical utility of the 532-nm potassium titanyl phosphate (KTP) laser, no studies have examined outcomes for Reinke’s edema (RE) as a function of laser parameters and initial treatment effects. Variability in delivery parameters, fiber-to-tissue distance, and immediate end-tissue effects limits universal application of existing study outcomes. We examine voice outcomes using standardized treatment classification, providing justification for laser parameter selection and immediate tissue effect in clinical use.Methods:Retrospective review of 9 patients who underwent KTP laser treatment for RE. Demographics, RE severity, laser settings, total laser energy, and immediate tissue effects were correlated with quantified voice outcomes.Results:An average of 157 joules (6-640 J) was delivered over a 0.369-second exposure time (0.1-0.9 seconds). Immediate tissue effects varied from nonablative treatment (type I and type II) to ablation without tissue removal (type III). Overall, Voice ...
The Effect of the Contact Model on the Design of Mechanical Systems.

Impact is a wide-spread phenomenon in mechanical systems that can have a significant effect on the system’s dynamics, stability, wear, and damage. The simulation of impact in complex, mechanical systems, however, is often too computationally intensive for high fidelity finite element analyses to be useful as design tools. As a result, rigid body dynamics and reduced order model simulations are often used, with the impact events modeled by ad hoc methods such as a constant coefficient of restitution or a penalty stiffness. The consequences of the choice of contact model are studied in this paper for a representative multiple-degrees of freedom mechanical system. Four contact models are considered in the analysis: a constant coefficient of restitution model, two similar elastic-plastic constitutive models, and one dissimilar elastic-plastic constitutive model. The predictions of wear, mechanical failure, and stability are assessed for each of the contact models, and the subsequent effect on the system design is investigated. These results emphasize the importance of choosing a realistic contact model when simulations are being used to drive the design of a system.Copyright © 2012 by ASME
The dual sustainability of wind energy

Abstract Academics, practitioners, and policy makers continue to debate the benefits and costs of alternative sources of energy. Environmental and economic concerns have yet to be fully reconciled. One view is that decisions that incorporate both society's concern with the environment and investors’ desire for shareholder value maximization are more likely to be truly sustainable. We coin the term dual sustainability to mean the achievement of environmental and financial sustainability simultaneously. Many experts believe that wind energy can help to meet society's needs without harming future generations. It is clean and renewable. Because the fuel is free it provides the ultimate in energy independence. Wind energy has emerged as a leading prospect, in part, because it is considered by many to be environmentally sustainable. However, a key question that remains is whether wind energy is financially sustainable without the extensive government support that has helped to create and nurture this growth industry. Using reliable, proprietary data from field research, our analysis employs a capital budgeting framework to evaluate the financial economics of investments in wind energy. We find that because of the convergence of improved technology, greater efficiency, and with the increasing cost of traditional, competing sources such as oil and natural gas, wind energy is close to becoming self-sustaining financially without the extensive federal government support that exists today. Wind energy can provide the best of both worlds. It is sustainable from an environmental perspective and it is becoming sustainable financially. In short, those companies investing in wind energy will be able to do well by doing good. Perhaps the achievement of dual sustainability is true sustainability. Our research findings and dual sustainability have several interesting and important implications for public policy towards wind energy. All imply that public policy can now be executed in a more effective and efficient manner. In the paper we outline and offer these better and cheaper public policy alternatives for consideration.
Classical Raman spectroscopic studies of NADH and NAD+ bound to liver alcohol dehydrogenase by difference techniques

We report the Raman spectra of reduced and oxidized nicotinamide adenine dinucleotide (NADH and NAD+, respectively) and adenosine 5'-diphosphate ribose (ADPR) when bound to the coenzyme site of liver alcohol dehydrogenase (LADH). The bound NADH spectrum is calculated by taking the classical Raman difference spectrum of the binary complex, LADH/NADH, with that of LADH. We have investigated how the bound NADH spectrum is affected when the ternary complexes with inhibitors are formed with dimethyl sulfoxide (Me2SO) or isobutyramide (IBA), i.e., LADH/NADH/Me2SO or LADH/NADH/IBA. Similarly, the difference spectra of LADH/NAD+/pyrazole or LADH/ADPR with LADH are calculated. The magnitude of these difference spectra is on the order of a few percent of the protein Raman spectrum. We report and discuss the experimental configuration and control procedures we use in reliably calculating such small difference signals. These sensitive difference techniques could be applied to a large number of problems where the classical Raman spectrum of a "small" molecule, like adenine, bound to the active site of a protein is of interest. The spectrum of bound ADPR allows an assignment of the bands of the bound NADH and NAD+ spectra to normal coordinates located primarily on either the nicotinamide or the adenine moiety. By comparing the spectra of the bound coenzymes with model compound data and through the use of deuterated compounds, we confirm and characterize how the adenine moiety is involved in coenzyme binding and discuss the validity of the suggestion that the adenine ring is protonated upon binding. The nicotinamide moiety of NADH shows significant molecular changes upon binding.(ABSTRACT TRUNCATED AT 250 WORDS)
High-power operation of highly reliable narrow stripe pseudomorphic single quantum well lasers emitting at 980 nm

Ridge waveguide pseudomorphic InGaAs/GaAs/AlGaAs single-quantum-well lasers exhibiting record high quantum efficiencies and high output power densities (105 mW per facet from a 6 mu m wide stripe) at a lasing wavelength of 980 nm are discussed that were fabricated from a graded index separate confinement heterostructure grown by molecular beam epitaxy. Life testing at an output power of 30 mW per uncoated facet reveals a slow gradual degradation during the initial 500 h of operation after which the operating characteristics of the lasers become stable. The emission wavelength, the high output power, and the fundamental lateral mode operation render these lasers suitable for pumping Er/sup 3+/-doped fiber amplifiers. >
Testing for Nonstationarity Using Maximum Entropy Resampling: A Misspecification Testing Perspective

One of the most important assumptions in empirical modeling is the constancy of the statistical model parameters which usually reflects the stationarity of the underlying stochastic process. In the 1980s and 1990s, the issue of nonstationarity in economic time series has been discussed in the context of unit roots vs. mean trends in AR(p) models. This perspective was subsequently extended to include structural breaks. In this article we take a much broader perspective by allowing for more general forms of nonstationarity. The focus of the article is primarily on misspecification testing. The proposed test relies on Maximum Entropy (ME) resampling techniques to enhance the information in the data in an attempt to capture heterogeneity “locally” using rolling window estimators. The t-heterogeneity of the primary moments of the process is generically captured using orthogonal Bernstein polynomials. The effectiveness of the testing procedure is assessed using Monte Carlo simulations.
An efficient procedure for the study of inhomogeneous liquids

A complete description of an inhomogeneous fluid requires knowing not only its density ρ( r ) at any point r in space, but also its pair distribution function g( r 1, r 2). These can be found from coupled integral equations, but even in cases with homogeneity in two of the three dimensions, such solutions in direct space are cumbersome enough to have earned the task a reputation as ‘computationally intensive’. Here we propose using purpose-built basis functions that are orthogonal with weight function ρ( r ) to expedite the work. We find that these not only produce a satisfying simplification of the formalism, but also reduce the computing effort needed to something on the order of 1% of that of the earlier calculations in direct space.
Reevaluation of vesicle distributions in basaltic lava flows

A fundamental dichotomy in the study of basaltic lava flows is that observations of active flows are restricted to flow surfaces, yet older flows are often exposed only in vertical cross section. Cross-sectional exposures of an inflated basaltic sheet flow emplaced in Kalapana, Hawaii, from 1990 to 1991 provide an unusual opportunity to merge these two viewpoints, permitting the development of the internal structure of the flow to be viewed in the context of its known emplacement history. We demonstrate that fundamental features of the flow structure—a thick upper vesicular crust that diminishes downward in overall vesicularity, a dense flow interior, and a thin lower vesicular zone—are generated through syn-emplacement cooling of upper and lower flow crusts. Both the inverse correlation of overall vesicularity and vesicle size and the constant relative thickness of the upper vesicular zone are unique to inflated flows and permit a reinterpretation of flows previously interpreted to be ponded (rapidly emplaced). Identification of inflation, in turn, implies near-horizontal paleoslopes and permits estimates of flow duration based on upper flow crust thickness.
Mineralogy, Petrology, and Classification of Types 3 and 4 Carbonaceous Chondrites

Petrographic studies and microprobe analyses on Type 3 and 4 carbonaceous chondrites reveal two distinct sub-types, provisionally called the Vigarano sub-type and the Ornans sub-type. The most obvious diagnostic distinction between the sub-types is textural. The chondrites belonging to the Vigarano sub-type may be characterized as having large (1–2 mm dia.) ‘spongy’ chondrules embedded in an abundant, fine-grained, opaque matrix; ‘spongy’ chondrules contain numerous spheroidal droplets of nickel-iron or sulfide dispersed throughout the silicate chondrule. The chon-drites belonging to the Ornans sub-type may be characterized as a close-packed aggregate of small (0.2–0.5 mm dia.) metal-poor chondrules with fine-grained, opaque matrix packed between the chondrules.
Actin polymerization promotes the reversal of streaming in the apex of pollen tubes

Actin polymerization is important in the control of pollen tube growth. Thus, treatment of pollen tubes with low concentrations of latrunculin B (Lat-B), which inhibits actin polymerization, permits streaming but reversibly blocks oscillatory growth. In the current study, we employ Jasplakinolide (Jas), a sponge cyclodepsipeptide that stabilizes actin microfilaments and promotes polymerization. Uniquely, Jas (2 microM) blocks streaming in the shank of the tube, but induces the formation of a toroidal-shaped domain in the swollen apex, of which longitudinal optical sections exhibit circles of motion. The polarity of this rotary motion is identical to that of reverse fountain motility in control pollen tubes, with the forward direction occurring at the edge of the cell and the rearward direction in the cell interior. Support for the idea that actin polymerization in the apical domain contributes to the formation of this rotary motility activity derives from the appearance therein of aggregates and flared cables of F-actin, using immunofluorescence, and by the reduction in G-actin as indicated with fluorescent DNAse. In addition, Jas reduces the tip-focused Ca2+ gradient. However, the alkaline band appears in the swollen apex and is spatially localized with the reverse fountain streaming activity. Taken together, our results support the idea that actin polymerization promotes reversal of streaming in the apex of the lily pollen tube.
Letter to the Editor-Remarks on Finite Queuing Tables

Formulas are given for a quantity, D, tabled in Peck and Hazelwood's Finite Queuing Tables 1958, Wiley. D is the equilibrium probability of delay of an arriving customer in a finite queuing system. Formulas involving D are given for the cumulative distribution of the system's state.
Obesity, hyperphagia and increased metabolic efficiency in Pc1 mutant mice

Prohormone convertase 1 (PC1) mutations lead to obesity in humans. However, Pc1 knockout mice do not become obese; in fact, they are runted due to a defect in growth-hormone releasing hormone processing, leading to the speculation that PC1 subserves different functions between mouse and human. Here, we report a novel allele of mouse Pc1 (N222D) that leads to obesity, abnormal proinsulin processing and multiple endocrinological defects. Increased energy intake and a more efficient metabolism contribute to the obesity in Pc1(N222D/N222D) mice. Defective proinsulin processing leads to glucose intolerance, but neither insulin resistance nor diabetes develop despite obesity. The obesity is associated with impaired autocatalytic activation of mature PC1 and reduced hypothalamic alpha-MSH. This is the first characterization of Pc1 mutation in a model organism that mimics human PC1 deficiency.
DNA Demethylation in Zebrafish Involves the Coupling of a Deaminase, a Glycosylase, and Gadd45

Evidence for active DNA demethylation in vertebrates is accumulating, but the mechanisms and enzymes remain unclear. Using zebrafish embryos we provide evidence for 5-methylcytosine (5-meC) removal in vivo via the coupling of a 5-meC deaminase (AID, which converts 5-meC to thymine) and a G:T mismatch-specific thymine glycosylase (Mbd4). The injection of methylated DNA into embryos induced a potent DNA demethylation activity, which was attenuated by depletion of AID or the non enzymatic factor Gadd45. Remarkably, overexpression of the deaminase/glycosylase pair AID/Mbd4 in vivo caused demethylation of the bulk genome and injected methylated DNA fragments, likely involving a G:T intermediate. Furthermore, AID or Mbd4 knockdown caused the remethylation of a set of common genes. Finally, Gadd45 promoted demethylation and enhanced functional interactions between deaminase/glycosylase pairs. Our results provide evidence for a coupled mechanism of 5-meC demethylation, whereby AID deaminates 5-meC, followed by thymine base excision by Mbd4, promoted by Gadd45.
Hepatosplenic and Hepatocytotropic T-Cell Lymphoma Two Distinct Types of T-Cell Lymphoma in Dogs

The clinical, clinicopathologic, and pathological findings of 9 dogs with T-cell lymphoma that involved the liver in the absence of peripheral lymphadenopathy were assessed. Seven dogs had hepatosplenic T-cell lymphoma (HS-TCL). Dogs with HS-TCL presented with hepato- and/or splenomegaly, regenerative anemia, thrombocytopenia, and hypoproteinemia. The clinical course was rapidly progressive with all dogs but 1 dead within 24 days of initial presentation. Neoplastic lymphocytes were centered on hepatic and splenic sinusoids and had a CD3+ (5/7), TCRαβ- (5/5), TCRγδ+ (3/5), CD11d+ (6/7), granzyme B+ (5/7) immunophenotype. Bone marrow and lungs were consistently but variably involved. These findings closely resemble the human disease and support the classification of HS-TCL as a distinct World Health Organization entity in dogs. The remaining 2 dogs markedly differed in the pattern of hepatic involvement by neoplastic lymphocytes, which were not confined to hepatic sinusoids but invaded hepatic cords. In addition, neoplastic cells had a CD11d- immunophenotype, and clinicopathologic data indicated marked cholestasis and mild to absent anemia. Based on the distinct tropism of neoplastic lymphocytes for hepatocytes, the name hepatocytotropic T-cell lymphoma (HC-TCL) is proposed. Given the histomorphologic, clinicopathologic, and immunophenotypic differences, HC-TCL likely represents a separate biological entity rather than a histomorphologic variant of HS-TCL.
Prenatal Brain Malformations following Acute Ethanol Exposure in the Rat

Morphology of the cerebral cortex was studied in fetuses on gestational Day 21 following oral administration of several doses of ethanol (for total doses of 10, 15, or 18 g/kg) to pregnant rats on gestational Days 14 and 15, a critical period for the development of the cerebral cortex. All doses of ethanol were associated with a reduction in maternal weight gain, fetal body weight, and placental weight. Only the high dose of ethanol (total dose 18 g/kg) caused significant fetal cortical thinning. Acute exposure of pregnant rats to ethanol produced dose-dependent malformations of the cerebral cortex and hippocampus in fetuses. On gestational Day 21, the 18 g/kg group contained fetuses with severely disorganized cortical architecture, heterotopias of the cerebral cortex, pia and choroid plexus, and status verrucosus deformis. Fetuses from the 10 g/kg group had less severe malformations, such as disorganization of layers of cortical neurons and dentate granule cells while fetuses from the 15 g/kg group had a mixture of severe and minor malformations. This study demonstrates that acute ethanol exposure during a critical period of development in rats can result in brain malformations similar to those reported in human fetuses and neonates from alcoholic mothers.
Issues in Education: Tiger Moms: Five Questions That Need to be Answered

Recently, we have been hearing about a parenting style identified as being a “tiger mom,” a term popularized with the publication of Amy Chua's Battle Hymn of the Tiger Mother (2011). Chua points t...
Global stabilization and restricted tracking for linear systems subject to input and measurement saturation-a chain of integrators case

The problems of global stabilization and restricted tracking via state feedback for a chain of integrators of arbitrary length subject to input saturation were solved by Teel (1992). In this paper, the authors show by explicit construction of controllers that these same two problems can also be solved even when all the state measurements are also subject to magnitude saturation.
Investigating the Influence of Interconnection Parasitic Inductance on the Performance of SiC Based DC-DC Converters in Hybrid Vehicles

Silicon carbide (SiC) based devices are known to outperform Si devices in many aspects, such as lower power dissipation, higher operating temperatures, and higher switching frequencies. SiC devices will benefit hybrid vehicles when applied into the DC-DC converters and inverters as part of the electrical power conversion needed to drive the powertrain. Nevertheless, SiC devices can suffer from oscillations as a result of the underdamped response to an RLC circuit composed of device output capacitance, parasitic inductance, and on-state resistance. This paper aims at investigating the influence of the interconnection parasitic inductance on the performance of SiC-based DC-DC converter in hybrid vehicles.
Clinical hyperthermia with a new device: the current sheet applicator.

Abstract Purpose: The current sheet applicator (CSA) is a newly developed microwave hyperthermia device. Advantages over commercial microwave applicators include its small size and high ratio of heating area to physical aperture area. These physical characteristics make the CSA excellent for heating constricted areas and allow the use of arrays of CSAs over large surfaces. This study examines the clinical efficacy of the CSA for heating superficial malignant tumors. Methods and Materials: From December 1989 through October 1991, 19 patients with recurrent or metastatic superficial malignant tumors were treated once or twice weekly to 30 hyperthermia fields using one to four CSAs. Each field received from one to four hyperthermia treatments for a total of 74 treatments. The treatment objective was to elevate the tumor temperature to a minimum of 42.5°C for 30 min (2 patients) or 60 min (17 patients). Intratumor temperatures were measured with percutaneous fiberoptic thermometry probes. All patients received concurrent fractionated radiation therapy with total dose ranging from 20 to 65 Gy (median 46 Gy). Seventeen of the 30 fields had been previously irradiated to a median dose of 50 Gy. Results: Mean values for the maximum temperature, average temperature, and minimum temperature were 43.6°C ± 1.0, 42.2°C ± 1.4, and 41.0°C ± 1.5, respectively. Mean values for T 50 and T 90 were 42.2°C ± 1.1 and 41.0°C ± 1.3, respectively. The overall response rate for all assessable fields was 96%. Only three responding tumors have progressed with a median follow-up period of 6 months. Treatment related morbidity was generally mild and self-limited. Conclusion: The CSA is a promising new microwave hyperthermia device capable of heating superficial tumors to therapeutic temperatures. When used in combination with radiotherapy, response rates are excellent without excessive toxicity.
Structure of Si(1 1 4) determined by global optimization methods

In this article we report the results of global structural optimization of the Si(1 1 4) surface, which is a stable highindex orientation of silicon. We use two independent procedures recently developed for the determination of surface reconstructions, the parallel-tempering Monte Carlo method and the genetic algorithm. These procedures, coupled with the use of a highly optimized interatomic potential for silicon, lead to finding a set of possible models for Si(1 1 4), whose energies are recalculated with ab initio density functional methods. The most stable structure obtained here without experimental input coincides with the structure determined from scanning tunneling microscopy experiments and density functional calculations by S.C. Erwin, A.A. Baski, L.J. Whitman [Phys. Rev. Lett. 77 (1996) 687]. � 2005 Elsevier B.V. All rights reserved.
Elucidating the Relationship Between Obesity and Depression: Recommendations for Future Research

The obese population is heterogeneous in its experiences of psychosocial disturbances, yet many obese individuals do experience such problems as body image disturbance, low self-esteem, diminished self-efficacy, and binge eating. Furthermore, recent research has repeatedly found obesity to correlate with negative affect, depressed mood, and clinical depression. In their comprehensive review, Markowitz, Friedman, and Arent (2008) identify numerous psychosocial and biological processes that they hypothesize to act as mediating factors in the relationship between obesity and depression. This commentary extends Markowitz and colleagues’ review and proposed causal pathway model by (a) evaluating the specificity of the relationship between obesity and depression, and (b) providing recommendations for the empirical evaluation of causal hypotheses.
Self-reported cigarette smoking vs. serum cotinine among U.S. adolescents

No national data have been used to compare self-reported and biochemically assessed cigarette smoking status among adolescents. We investigated discrepancies between self-reported smoking and measurement of serum cotinine concentration among adolescents aged 12-17 years in a representative sample (n=2,107) of the U.S. population. Smoking prevalence was 12.9% among teens who reported in a private interview whether they smoked during the previous 5 days (95% CI=10.9%-14.9%) and 12.5% (95% CI=10.3%-14.7%) according to serum cotinine concentration greater than 11.40 ng/ml (the cutpoint). Among teens who reported being a nonsmoker (i.e., that they did not smoke during the previous 5 days), 2.7% (95% CI=1.6%-3.8%) had a serum cotinine concentration of greater than 11.40 ng/ml. Discrepancies among self-reported nonsmokers were less likely among Mexican Americans than among Whites. Among self-reported smokers, 21.1% (95% CI=13.7%-28.5%) had a serum cotinine concentration of 11.40 ng/ml or less. This discrepancy is explained primarily by the high proportion (37.0%) of teen smokers who reported smoking, on average, less than 1 cigarette per day. We believe that social stigma or fear that their parents would find out about their survey responses may be the main explanation for the 2.7% discrepancy among self-reported nonsmokers, and that smoking patterns (including the extent of nicotine dosing) and a lack of measurement of recency of cigarette smoking are the main explanations for the 21.1% discrepancy among self-reported smokers. Efforts to improve the validity of self-reported cigarette smoking will benefit tobacco-related surveillance, evaluation, and research activities for adolescents.
Isolation and partial characterization of amphibian tyrosine oxidase polysomes

A population of polysomes isolated from frogskinis capable of supporting protein synthesis in a cell-free system containing an energy generating system, ‘soluble components’, and amino acids. These polysomes catalyse the oxidation of DOPA after gentle trypsinization, and they also have antigenic determinants attributable to tyrosine oxidase. Skin polysomes sedimented in 10–30 % sucrose gradients contain tyrosine oxidase peaks of enzymic activity at the bottom and top of the tube and in the 250 S regions. A peak of tyrosine oxidase antigenic acitvity is found in the 250–350S region of the gradient. Polysomes resolved on the gradient retain the ability to support protein synthesis in a cellfree system. All 250–350S particles capable of supporting the incorporation of [ 14 C]amino acid into tyrosine oxidase are precipitable with tyrosine oxidase antibodies. It is probable that 250–350S tyrosine oxidase antibody precipitates contain only polysomes for this protein.
Effects of Very Fine Particle Size on Reflectance Spectra of Smectite and Palagonitic Soil

Abstract A montmorillonite clay and a palagonitic soil sample were sieved to produce a series of size fractions in order to investigate the role that extremely fine particle sizes play on absorption strengths in martian analog materials. Significant decreases in band strength for both samples were observed as particle size decreased. The less than 5-μm fractions had 1.4-, 1.9-, and 2.2-μm bands that were approximately half the strength of the absorptions from the 45- to 75-μm size fractions. X-ray diffraction and loss on ignition measurements indicate that there are no significant changes in crystallinity, composition, or water content with particle size. Thus the reduction in spectral contrast is dominated by changes in the ratio of scattering to absorption with particle size. Furthermore, larger particles of montmorillonite clay are not individual crystals but are aggregates of much smaller particles. Nevertheless, the aggregate particles exhibit spectral properties consistent with the size of the aggregate, not the individual particles in the aggregate. This has important implications for the spectroscopic determination of the composition of the extremely fine martian dust. The abundance of very fine grained mineral phases such as phyllosilicates will be underestimated if comparisons to coarser or clumped laboratory samples are made.
Temporal cues in the antiphonal long-calling behaviour of cottontop tamarins

In primates, long-range communication is often mediated by the use of ‘long’ (or ‘loud’) calls. Beyond the acoustic classification of these calls and descriptions of the behavioural context in which they are produced, few experimental studies have examined how species-typical information is encoded in the structure of these signals. We present the results of eight experimental conditions designed to isolate the mechanisms underlying the perception of long calls in cottontop tamarins, Saguinus oedipus .O ur procedure involved presenting a combination of naturally produced and experimentally manipulated long calls to individuals isolated from their group, and then recording the relationship between signal design and the production of antiphonal long calls by the test subject. Tamarins did not distinguish between normal calls and time-reversed or pitch-shifted long calls, but normal response rates did require the species-typical amplitude envelope. Furthermore, there was suggestive evidence that the number of syllables and the syllable rate may also influence antiphonal calling responses. We discuss these results in terms of the mechanisms of vocal recognition in primates and other taxa.