cssi/SciSciGPT-SciSciNet huggingface dataset:
Smart photonics: Optoelectronics integrated onto Si CMOS circuits

Interconnections are a limiting cost and performance factor in present electronic systems, and become even more critical as wiring, processing densities, and speeds increase. Historically, optical interconnections have been most successful in long haul applications where relatively few optoelectronic interfaces are necessary, and costly optoelectronic (OE) interfaces were justified. With the meteoric rise of datacom, which includes medium distance (e.g., "campus" and LAN), short haul (e.g., small office and home), and the ultra-short chip to chip interconnections referenced in the SIA Roadmap, which projects Si ICs facing interconnection bottlenecks before 2010, optical interfaces and interconnections optimized for shorter distances are under intense development. Optoelectronics (OE) can significantly impact the performance of these interconnections, however, the implementation of optoelectronics has, to date, been prohibitively expensive in most cases. To achieve increased OE implementation, cost reduction is critical. Smart photonics, or the integration of OE devices and links with circuitry such as Si CMOS VLSI, can yield both advanced optical links and possibly integrated solutions for optoelectronic interfaces and interconnections to standard electronic systems. Coupled with alignment tolerant designs, these implementations may yield cost effective solutions which are compatible and integrable with electronic systems.
Haploid selection for low temperature tolerance of tomato pollen.

Pollen grains were harvested from an interspecific F1 hybrid between the cultivated tomato, Lycopersicon esculentum Mill., and its wild relative Lycopersicon hirsutum Humb. & Bonpl., a low temperature tolerant accession originating from an altitude of 3200 m in the Peruvian Andes. The two species differ for electrophoretically-detectable loci that mark six (possibly seven) of the 12 tomato chromosomes. Isozyme analysis of the BC1 populations derived from controlled pollinations at normal and low temperatures indicates a significant skewing of allelic frequencies favoring two independent chromosome segments of L. hirsutum at low temperatures. The results demonstrate that gametophytic selection for low temperature tolerance of tomato pollen is determined, at least in part, by genes expressed in the haploid pollen.
A Fluid-Structure Interaction Model of Ciliary Beating

The coupled system of a viscous, incompressible fluid and a single, force-generating organism is difficult to analyze, even when the kinetics of an organism’s waveform is taken as given. In the past decades, the efforts to describe quantitatively the fluid dynamics of spermatozoa and ciliary propulsion have been very successful. Since the Reynolds number is quite small and inertial effects can be neglected, the linear Stokes flow assumption has been used to investigate the hydrodynamic consequences of flagellar undulations [3]. These investigations have been both analytical and computational. Resistive-force theory, initially developed by Gray and Hancock [12], makes use of the linear Stokes flow assumption, and constructs the flow field by means of distributions of fundamental singularities. Lighthill later improved this theory by incorporating slender body approximations [19], since the diameter of a flagellum is much smaller than its length. More detailed hydrodynamic analysis, such as refined slender body theory and boundary element methods, have produced excellent simulations of both two- and three-dimensional flagellar propulsion in an infinite fluid domain or in a domain with a fixed wall [17], [18], [16], [22]. In addition, ciliary motion, where the effect of a single plane surface at the base of the cilia is included, is studied by Gueron and Liron [14], [15], wherein they also present a thorough survey of flagellar hydrodynamics.
Genetic diversity at a single locus under viability selection and facultative apomixis: equilibrium structure and deviations from Hardy-Weinberg frequencies.

We extensively analyze the maintenance of genetic variation and deviations from Hardy-Weinberg frequencies at a diallelic locus under mixed mating with apomixis and constant viability selection. Analytical proofs show that: (1) at most one polymorphic equilibrium exists, (2) polymorphism requires overdominant or underdominant selection, and (3) a simple, modified overdominance condition is sufficient to maintain genetic variation. In numerical analyses, only overdominant polymorphic equilibria are stable, and these are stable whenever they exist, which happens for ~78% of random fitness and mating parameters. The potential for maintaining both alleles increases with increasing apomixis or outcrossing and decreasing selfing. Simulations also indicate that equilibrium levels of heterozygosity will often be statistically indistinguishable from Hardy-Weinberg frequencies and that adults, not seeds, should usually be censused to maximize detecting deviations. Furthermore, although both censuses more often have an excess rather than a deficit of heterozygotes, analytical sign analyses of the fixation indices prove that, overall, adults are more likely to have an excess and seeds a deficit at equilibrium.
Mapping the Pathways of Resistance to Targeted Therapies

Resistance substantially limits the depth and duration of clinical responses to targeted anticancer therapies. Through the use of complementary experimental approaches, investigators have revealed that cancer cells can achieve resistance through adaptation or selection driven by specific genetic, epigenetic, or microenvironmental alterations. Ultimately, these diverse alterations often lead to the activation of signaling pathways that, when co-opted, enable cancer cells to survive drug treatments. Recently developed methods enable the direct and scalable identification of the signaling pathways capable of driving resistance in specific contexts. Using these methods, novel pathways of resistance to clinically approved drugs have been identified and validated. By combining systematic resistance pathway mapping methods with studies revealing biomarkers of specific resistance pathways and pharmacologic approaches to block these pathways, it may be possible to rationally construct drug combinations that yield more penetrant and lasting responses in patients.
Genetic variation in angiotensin-converting enzyme-related pathways associated with sudden cardiac arrest risk

Background Angiotensin-converting enzyme (ACE)–related pathways influence arrhythmias and sudden cardiac arrest (SCA) risk. Objective The purpose of this study was to investigate whether genetic variations in ACE-related pathways are associated with SCA risk. Because these pathways are sex dependent and are influenced by estrogen, we examined these genotype–SCA associations in the full study population and tested for interaction with gender. Methods In a population-based case-control study set in King County, Washington, 211 SCA cases (80% male; mean age 59 years,) and 730 age- and gender-matched controls of European descent were genotyped for 47 single nucleotide polymorphisms (SNPs) in eight genes (ACE, AGT, REN, AGTR1, AGTR2, ACE2, KNG1, BDKRB2). The association of SNPs and haplotypes with SCA risk was examined using logistic regression. Results AGTR1 SNP rs1492099 (allele frequency 15%) was associated with decreased SCA risk (odds ratio [OR] 0.62, 95% confidence interval [CI] 0.4–0.9). Haplotype variation in AGTR2 was associated with SCA risk (global haplotype test P = .001), with haplotype 2 (allele frequency 27%) associated with increased risk (OR 1.26, 95% CI 1.1–1.5). There was interaction with gender on SCA risk for variation in KNG1 (interaction P value range 0.0004–0.017 for 6/8 SNPs). KNG1 SNP rs710448 (allele frequency 42%) was associated with decreased risk (OR 0.44, 95% CI 0.3–0.8) among women but not men. Other SNPs and haplotypes in the eight genes examined were not associated with SCA risk after multiple testing correction. Conclusion Variations in AGTR1 and AGTR2 are associated with SCA risk in a population-based case-control study. There was evidence of interaction with gender on SCA risk for variation in KNG1. These study findings, if replicated, suggest that variation in genes in ACE-related pathways influence SCA risk.
Dyslipidemia in Non-Insulin-Dependent Diabetes Mellitus

IN CONTRAST to other chronic diseases, non-insulindependent diabetes mellitus (NIDDM) is increasing in prevalence in the United States (1). Of the many sequelae of this disease, one of the most significant is accelerated atherosclerotic vascular disease, the leading cause of death among patients with NIDDM (2). One of the most important factors that contribute to cardiovascular disease in NIDDM is the alterations in lipoproteins that accompany NIDDM (3). It is therefore important to understand the etiology of dyslipidemia in NIDDM and strategies for its control. This chapter will summarize the basics of lipoprotein metabolism, review the alterations in lipoprotein composition and metabolism that occur in individuals with NIDDM, and outline potential therapeutic approaches to management of these lipid disorders. II. Lipoprotein Metabolism (Fig. 1) Lipoproteins are spherical particles containing a central core of nonpolar lipids (cholesterol esters, triglycerides) and a surface monolayer of phospholipids an...
An anatomy-based coordinate system for the description of the kinematic displacements in the human knee

The effects and interaction of the anatomical displacements in the human knee are a prerequisite to an accurate assessment and communication of the kinematic data. For the kinematic information to be used to improve diagnosis and treatment, and for better prosthetic design and installation, there must be clear, concise, and universal definitions of the displacements. In general, the displacements are defined as three translations and three rotations. In this paper, anatomic landmarks on the femur and on the tibia are used to define the locations and orientations of the six displacement axes; i.e. three translational and three rotational displacement axes. The most commonly accepted kinematic representation of the knee joint, in the literature, is a special geometry three-cylindric open chain in which the axes of the cylindric joints are defined according to the rotational displacement axes. The sequentially adjacent joint axes are assumed to not only intersect but to intersect at right-angles. The open chain permits a total of six degrees of freedom between a Cartesian reference frame attached to the femur and a Cartesian reference frame attached to the tibia. In this paper, the three rotational axes are shown to be skewed and off-set from each other, therefore, a three-cylindric open chain with skewed joint axes is proposed to measure the six displacements between the two reference frames. The authors believe that the proposed open chain is the most general to date and provides a more realistic representation of the displacements in the knee. To illustrate the significance of the reference frames on the interpretation of measured data, the anterior/posterior drawer is plotted against per cent gait cycle for three existing open chains and the proposed open chain.
Two putative histidine kinases are required for cyst formation in Rhodospirillum Centenum

The photosynthetic bacterium, Rhodospirillum centenum, has a flexible life cycle that permits it to survive starvation as dormant cyst cells. Previous studies have identified some of the key regulators for encystment and demonstrated that the control of development is intricate. This complexity may arise from the need to integrate several environmental signals to mediate a switch from one mode of energy metabolism to another and to ensure that a transition to dormancy is initiated only when necessary. We searched for additional regulators of development by screening for encystment deficient strains after subjecting wild type R. centenum to mini-Tn5 mutagenesis. Analysis of “hypo-cyst” strains led to the identification of two genes that encode putative hybrid histidine kinases (cyd1 and cyd2). Cells with deletions of either gene fail to form cysts under conditions that normally induce development. Furthermore, the deletion strains exhibit altered swarming behavior suggesting that Cyd1 and Cyd2 affect behaviors utilized when the organism is attached to a substrate.
The Flexible Fiberoptic Bronchoscopic Shuttle

The purpose of this paper is to describe a novel and practical technique for endobronchial catheter placement utilizing the flexible fiberoptic bronchoscope. Placement of endobronchial catheters via the flexible bronchoscope is limited by the small dimension of the bronchoscope's internal channel and frequently requires repeated manipulation to verify position endobronchially. We describe preliminary experience with a technique that we call the "bronchoscopic shuttle," which circumvents this limitation. The spectrum of possible clinical uses for this technique is discussed.
Remote sensing of surface solar irradiance: corrections for 3D cloud effects

It has been shown that simple 1-D radiative transfer models can be used with narrow-band satellite radiance observations to estimate the surface radiation budget with a very good overall accuracy. However, as the temporal and spatial resolution increase, large errors may occur in the presence of non-homogeneous cloud fields as comparisons with surface observations indicate. This suggests that 3-D cloud effects become increasingly important for the radiance field observed by the satellite sensor, and that simple 1-D retrieval schemes are not adequate under general cloudy conditions. We used a 3- D Monte Carlo model with simulated cloud liquid water and ice fields to compute radiances at the top of the atmosphere and surface radiation fluxes. Stratiform an deep convective cloud systems are simulated using the PSU/NCAR Mesoscale Model (MM5). The radiance data base thus simulated is analyzed to determine the impact of horizontal resolution and cloud geometry on the relationship between 3-D cloud properties, top of the atmosphere radiance and surface irradiance. The goal is to determine the 3-D cloud characteristics that are responsible for the deterioration of the 1-D surface radiation retrieval scheme and find possible corrections for the cloud 3-D effects.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
The time course of irradiation changes in proton beam-treated uveal melanomas.

Background: Although histopathologic changes in uveal melanomas treated by irradiation have been well characterized, the timing of these effects after irradiation has not been previously evaluated. Methods: The series consisted of a total of 92 eyes with uveal melanoma, enucleated at various intervals after proton irradiation (range, 1 month to 8 years) due to complications (n = 66) or tumor growth (n = 22), or at autopsy (n = 4). Study slides were read, using a standard protocol, by two pathologists masked to the timing of the enucleation after irradiation and the reason for the surgery. Results: The prevalence of inflammation decreased whereas fibrosis increased with time from 15% of cases enucleated within 12 months (early cases) to 61% of those enucleated more than 30 months (late cases) after irradiation ( P for trend=0.0005). Tumor necrosis and blood vessel damage occurred early, and the prevalence of these changes was constant over time. Excluding tumors with evidence of growth after irradiation, mitotic figures became progressively less common as the interval between irradiation and enucleation increased ( P for trend=0.015); no mitotic figures were present in 40 high-power fields more than 30 months after irradiation. Conclusion: Histopathologic changes in irradiated melanomas vary according to the time elapsed since irradiation. Inflammation decreases with time whereas fibrosis becomes more prevalent with time after irradiation. Among controlled tumors, mitotic figures appear only in recently irradiated tumors.
N-Way TEM-Mode Broad-Band Power Dividers

An integrative graphical method of designing a broadband TEM-mode power divider of N output ports is presented. Each branch of the divider's circuit consists of cascaded transmission-line segments, and the corresponding segments of each branch are connected by resistors to a common junction. These resistors absorb the reflected signals due to mismatch at any of the output ports; they are therefore isolated from one another. The symmetry of this circuit permits the use of the method of even- and odd-mode excitations at the output ports. It was found that the even-mode circuit is the same as for a stepped-impedance transformer, which is well known. The odd-mode circuit lends itself to the determination of the isolation resistors using the iterative graphical procedure on a Smith chart. Numerical values of the isolation conductance for dividers of bandwidths up to 10:1, the maximum input VSWR, and the minimum isolation among the output ports are given.
A new iridovirus of two species of terrestrial isopods, Armadillidium vulgare and Porcellio scaber.

A new iridovirus, herein named isopod iridescent virus (IIV), was isolated from two species of terrestrial isopods in Berkeley, Calif. Infected individuals of Armadillidium vulgare
The Style of Advice in Isocrates

Abstract This paper has three goals: (1) to point out a characteristic of Isocrates' style of advice, (2) to use that characteristic to discuss the authenticity of To Demonicus, and (3) to place Isocrates' interest in style in its cultural context.
The helix coil transition of DNA

The design and use of a photometer to detect the transition of DNA from the double helix to random coil form.
The effect of chlorine demand on estimation of the inactivation rate constant

Ct (disinfectant concentration multiplied by exposure time) values for chlorine are used by the US EPA to evaluate the efficacy of disinfection of microorganisms under various drinking water treatment conditions. These Ct values are generally derived from laboratory studies in which chlorine decay is characterized by a first order decay model. The concentration of chlorine is often only measured at the initial and final exposure times. In this study, using bacterial spore inactivation data where residual chlorine was measured at least twice in between initial and final exposure times, chlorine decay models were evaluated to determine the effect on Ct calculations. Traditionally Ct is treated as a constant in estimating the rate constant of the simple Chick-Watson inactivation kinetics model. As Ct is estimated it is subject to estimation error. To account for this error, the parameters of the chlorine decay and the inactivation models were estimated simultaneously.
Southeast asia: The next M&A hotspot?

Many analysts believe Southeast Asia could be the site of an economic boom in the coming years. But what has been happening with M&A activity? And will expansion continue? The authors take a detailed look at several countries in the region, and offer some practical suggestions for potential investors. © 2002 John Wiley & Sons, Inc.
Role of IGF1R in Breast Cancer Subtypes, Stemness, and Lineage Differentiation

Insulin-like growth factor (IGF) signaling is fundamental for growth and survival. A large body of evidence (laboratory, epidemiological, and clinical) implicates the exploitation of this pathway in cancer. Up to 50% of breast tumors express the activated form of the type 1 insulin-like growth factor receptor (IGF1R). Breast cancers are categorized into subtypes based upon hormone and ERRB2 receptor expression and/or gene expression profiling. Even though IGF1R influences tumorigenic phenotypes and drug resistance across all breast cancer subtypes, it has specific expression and function in each. In some subtypes, IGF1R levels correlate with a favorable prognosis, while in others it is associated with recurrence and poor prognosis, suggesting different actions based upon cellular and molecular contexts. In this review, we examine IGF1R expression and function as it relates to breast cancer subtype and therapy-acquired resistance. Additionally, we discuss the role of IGF1R in stem cell maintenance and lineage differentiation and how these cell fate influences may alter the differentiation potential and cellular composition of breast tumors.
Sediment-laden velocity profiles developed in a long boundary-layer wind tunnel

Abstract A sediment-laden fully developed turbulent shear flow, over a plane aerodynamically-smooth, erodible sand surface, was established in a long (30 m) boundary-layer wind tunnel to investigate the influence of a nonuniform sand concentration distribution on velocity profiles. The main flow Reynolds number Umδ/ν covered a range from 3.2×105 to 1.2×106 as the concentration per mass varied between 0.0 and 0.7 which corresponds to a total transport rate per unit width of the tunnel of 0.042 kg/s-m. Velocity profile messurements were made using hot-wire anemometry throughout the entire boundary layer, with emphasis on the wall region. The analysis of mean velocity profiles demonstrates the applicability of the law-of-the-wall in the lower 10% of the boundary layer regardless of the sediment concentration. The upper 90% of the velocity profiles is best described by the law-of-the-wake. The profile parameter π increases with shear velocity from 0.6 for one-phase flow to an asymptotic value of 1.8, reached for main flow Reynolds number larger than 106 and sand concentrations per mass larger than 0.6 near the bed. The velocity measurements display wake distributions which are in excellent agreement with the function proposed by Coles (ref. 7) for one-phase fluids.
The Chlamydomonas MBO2 locus encodes a conserved coiled-coil protein important for flagellar waveform conversion.

Chlamydomonas flagella can undergo a calcium-dependent conversion between an asymmetric ciliary waveform and a symmetric flagellar waveform. Mutations at three MBO loci abolish the predominant ciliary waveform and result in cells that move backward only with the flagellar waveform. We have cloned and characterized the MBO2 gene. It encodes a novel protein with extensive alpha-helical coiled-coils and two leucine zippers. Sequences highly similar to MBO2p were found in a variety of organisms with cilia and flagella, suggesting that the MBO2 gene function may be conserved in many diverse taxa. Antibodies to MBO2p recognized an axonemal protein of 110 kDa, which appeared to be tightly associated with doublet microtubules. The protein was present in flagella of a variety of paralyzed flagellar mutants that lacked different axonemal structures, indicating that MBO2p is a component of a previously uncharacterized flagellar protein complex. In contrast to the earlier suggestion that the MBO2 gene may encode a component of an intramicrotubular beak-like structure present only proximally in flagella, we localized an epitope-tagged MBO2p along the entire length of the flagella. Moreover, the insertion of a hemagglutinin (HA) epitope in the conserved C-terminal domain of MBO2p reduced the swimming velocity of cells transformed with the epitope-tagged gene. These results indicate that MBO2p may play a role both in the assembly of the beak-like structure and the regulation of the force-generation machinery during the ciliary beat.
Acute ventriculoperitoneal shunt malfunction following opening of the spinal subarachnoid space: a case series.

Introduction Malfunction of cerebrospinal shunts is common and due to multiple etiologies. We hypothesize that opening of the spinal dura may prompt shunt failure in select individuals with previously unrecognized tenuous shunt function.
Effect of ionic strength on the interaction of androgen with Sertoli cell nuclei

Abstract Only 35–50% of the label accumulated after incubation of cultured Sertoli cells with 3H-testosterone was readily extractable with 0.4 M KCl during a 1 h exposure. The degree of extractability was relatively constant over the pH range 7.0–8.5 but could be increased by prolonged (15 h) exposure. While 0.1 M KCl extracted a measurable amount of label, 0.4 M KCl was significantly more efficient. Furthermore, a higher proportion of the material extracted with 0.4 M KCl was associated with macromolecular species. After a 45 min exposure to 3H-testosterone, the nuclear fraction contained primarily labeled testosterone and its 5 α-reduced metabolites. The relative distribution of these metabolites between salt-resistant and readily extractable forms varied between experiments. In contrast, 3H-R1881 (17β-hydroxy-17-methylestra-4,9,11-trien-3-one) remained essentially intact int the nuclear fraction but also was only 35% extractable with 0.4 M KCl. In conclusion, although the quantitative aspects of salt extractability appear to depend to some extent upon the extraction conditions, it is apparent that the Sertoli cell nuclear fraction accumulates a significant amount of androgen in a form which is relatively resistant to removal with 0.4 M KCl. The biological significance of this phenomenon reamins to be established.
The Importance of Diagnosing the Polycystic Ovary Syndrome

The polycystic ovary syndrome (PCOS) is an extremely common disorder that occurs in 4% to 7% of women of reproductive age. Although PCOS is known to be associated with reproductive morbidity and increased risk for endometrial cancer, diagnosis is especially important because PCOS is now thought to increase metabolic and cardiovascular risks. These risks are strongly linked to insulin resistance and are compounded by the common occurrence of obesity, although insulin resistance and its associated risks are also present in nonobese women with PCOS. Women with PCOS are at increased risk for impaired glucose tolerance, type 2 diabetes mellitus, and hypertension. Cardiovascular disease is believed to be more prevalent in women with PCOS, and it has been estimated that such women also have a significantly increased risk for myocardial infarction. Many lipid abnormalities (most notably low high-density lipoprotein cholesterol levels and elevated triglyceride levels) and impaired fibrinolysis are seen in women with PCOS. Early diagnosis of the syndrome and close long-term follow-up and screening for diabetes and cardiovascular disease are warranted. An opportunity exists for preventive therapy, which should improve the reproductive, metabolic, and cardiovascular risks.
Reduced Ssy1-Ptr3-Ssy5 (SPS) Signaling Extends Replicative Life Span by Enhancing NAD+ Homeostasis in Saccharomyces cerevisiae

Attenuated nutrient signaling extends the life span in yeast and higher eukaryotes; however, the mechanisms are not completely understood. Here we identify the Ssy1-Ptr3-Ssy5 (SPS) amino acid sensing pathway as a novel longevity factor. A null mutation of SSY5 (ssy5Δ) increases replicative life span (RLS) by ∼50%. Our results demonstrate that several NAD+ homeostasis factors play key roles in this life span extension. First, expression of the putative malate-pyruvate NADH shuttle increases in ssy5Δ cells, and deleting components of this shuttle, MAE1 and OAC1, largely abolishes RLS extension. Next, we show that Stp1, a transcription factor of the SPS pathway, directly binds to the promoter of MAE1 and OAC1 to regulate their expression. Additionally, deletion of SSY5 increases nicotinamide riboside (NR) levels and phosphate-responsive (PHO) signaling activity, suggesting that ssy5Δ increases NR salvaging. This increase contributes to NAD+ homeostasis, partially ameliorating the NAD+ deficiency and rescuing the short life span of the npt1Δ mutant. Moreover, we observed that vacuolar phosphatase, Pho8, is partially required for ssy5Δ-mediated NR increase and RLS extension. Together, our studies present evidence that supports SPS signaling is a novel NAD+ homeostasis factor and ssy5Δ-mediated life span extension is likely due to concomitantly increased mitochondrial and vacuolar function. Our findings may contribute to understanding the molecular basis of NAD+ metabolism, cellular life span, and diseases associated with NAD+ deficiency and aging.
Statistical estimation of feedback models

This paper considers the accuracy of conventional econometric techniques in estimating parameters in a feedback model. Evaluation of the estimation techni ques is accomplished by an experimental procedure in which a nonlinear feedback model generates synthetic data which is then used to estimate the parameters in the data-generating model. Comparison of the estimated and "true" parameter values provides a measure of the accuracy of the estimation technique.Experiments with ordinary and generalized least- squares estimation (OLS and GLS) show that the parameter estimates derived from these methods are highly sensitive to errors in data measurement, especially when a model's feedback structure is not completely known. Further tests of OLS and GLS with different feedback models, as well as experimental evaluations of other estimation techniques, should help to determine the proper role of statistical methods in modeling feedback systems.
Laser Induced Damage Threshold Derived from Chaotic Electron Dynamics

Abstract The small metallic inclusions whose presence is thought to be responsible for the onset of laser induced damage of a dielectric are modeled by one-dimensional square well potentials. The known fact that this system turns chaotic in the presence of a sufficiently strong external field allows for a rather simple estimate of the damage threshold.
Linear quadratic regulation of systems with stochastic parameter uncertainties

In this paper, we develop a theoretical framework for linear quadratic regulator design for linear systems with probabilistic uncertainty in the parameters. The framework is built on the generalized polynomial chaos theory. In this framework, the stochastic dynamics is transformed into deterministic dynamics in higher dimensional state space, and the controller is designed in the expanded state space. The proposed design framework results in a family of controllers, parameterized by the associated random variables. The theoretical results are applied to a controller design problem based on stochastic linear, longitudinal F16 model. The performance of the stochastic design shows excellent consistency, in a statistical sense, with the results obtained from Monte-Carlo based designs.
Determining the density dependence of immigration and emigration of benthic stream invertebrates: theoretical considerations

Simple mathematical models are formulated to describe density independent and density dependent dispersal. These models clarify hypotheses of density dependence and may be manipulated easily to suit particular applications. The models demonstrate that the initial composition of a species aggregate must be controlled before valid conclusions can be drawn about the density dependency of the aggregate's dispersal. Stochastic models of emigration are derived to assess the power of particular experimental designs and statistical techniques to discriminate a known form of density dependent emigration.
Electrically heated tube investigation of cooling channel geometry effects

The results of an experimental investigation on the combined effects of cooling channel aspect ratio and curvature for rocket engines are presented. Symmetrically heated tubes with average heat fluxes up to 1.7 MW/m(exp 2) were used. The coolant was gaseous nitrogen at an inlet temperature of 280 K (500 R) and inlet pressures up to 1.0 x 10(exp 7) N/m(exp 2) (1500 psia). Two different tube geometries were tested: a straight, circular cross-section tube, and an aspect-ratio 10 cross-section tube with a 45 deg bend. The circular tube results are compared to classical models from the literature as validation of the system. The curvature effect data from the curved aspect-ratio 10 tube compare favorably to the empirical equations available in the literature for low aspect ratio tubes. This latter results suggest that thermal stratification of the coolant due to diminished curvature effect mixing may not be an issue for high aspect-ratio cooling channels.
On variational techniques for piezoelectric device analysis

The fact that variational principles are not necessarily unique can be of practical significance when formulating approximation techniques. This result, which is particularly relevant where complicated boundary conditions exist, is pointed out here for the case of piezoelectric media problems.
Outer leaflet-packing defects promote poly(ethylene glycol)-mediated fusion of large unilamellar vesicles

Poly(ethylene glycol)-induced fusion of two different vesicle systems has been examined: dipalmitoylphosphatidylcholine (DPPC) large unilamellar vesicles (LUV) and cardiolipin (CL)/dioleoylphosphatidylcholine (DOPC) (1:10) LUVs. A slight perturbation was established in the outer leaflets of DPPC LUVs by hydrolyzing 0.8% of the outer leaflet lipid with phospholipase A2 to produce lysophosphatidylcholine and palmitate which were then removed by bovine serum albumin. Similarly, 5 mM Ca2+ was added to the external compartment of CL/DOPC LUVs to alter the shape of the CL molecule and thereby create a perturbation in the outer leaflet packing of these vesicles. Contents mixing assays showed that both vesicle systems fused only when the outer leaflets of both contacting vesicles were perturbed as described. Two fluorescent probes (C6-NBD-PC and TMA-DPH) were used to detect changes in outer leaflet molecular packing between nonfusing and fusing systems. The steady-state fluorescence intensity of C6-NBD-PC added externally to either fusing system was enhanced relative to that of nonfusing vesicles. Phase-resolved measurements of probe lifetime showed that this was due mainly to enhanced partitioning of probe from a micellar state into fusing versus nonfusing membranes. Similarly, TMA-DPH was found to undergo more rapid motion when incorporated into fusing as opposed to nonfusing vesicles. The effects of deuterium exchange on probe lifetime also indicated that C6-NBD-PC and TMA-DPH penetrated more deeply into fusing than into nonfusing membranes. These results suggest that the fusogenic perturbations produced in these two very different lipid systems took the form of altered outer leaflet packing. We conclude that, for the two model lipid bilayers examined, small perturbations in lipid packing within contacting bilayer leaflets are necessary and probably sufficient to promote membrane fusion.
Determinants and outcomes of adherence to recommendations from a multidisciplinary tumour conference for hepatocellular carcinoma

Background The multidisciplinary tumour conference (MTC) represents the standard of care in the management of hepatocellular carcinoma (HCC). Clinical outcomes in relation to adherence and non-adherence to MTC recommendations have not been studied.
Creole discourse effects on the speech conjunctive system in expository texts

Abstract The study illustrates how communicative patterns in the speech community and the degree of exposure to registers typical of written genres in home and out of school experiences are reflected in writing development through such pervasive but subconsciously selected language features as conjunctions. The structure of discourse in Creole cultures as well as the ramifications of an oral tradition were shown to have an effect on the Creole-speaking subjects’ tendency to draw on conjunctions and clause-linking strategies typical of registers of spoken discourse in their academic expository writing. On the contrary, the ESL subjects, from a literate tradition, exhibited fewer challenges than their Creole-speaking counterparts with respect to the transfer of the speech conjunctive system into the registers of written academic discourse. The study is guided by the sociocognitive notion that the social and cultural patterns of discourse are linked to the cognitive aspects of academic expository writing. As such, it demonstrates how the communicative patterns of the Creole speech community become pervasive in the development of expository writing. It also emphasizes the fact that the acquisition of these skills is shaped by the social and cultural environments in which they are embedded and are constructively viewed from these environments. Finally, the study provides the context for examining how Creole-speaking students, as opposed to ESL students, grapple with the unfamiliar registers of academic expository prose as they learn to distinguish the conjunctive system typical of registers of spoken discourse from that of registers appropriate for academic expository writing.
Winter Cover and Tillage Influences on Coastal Plain Cotton Production

Winter cover crops and conservation tillage can be used by southeastern Coastal Plain cotton (Gossypium hirsutum L.) growers to meet soil erosion control requirements of the 1985 Food Security Act. Out objective was to determine whether these production practices influence cotton productivity and quality. The study was conducted on a Norfolk loamy sand soil (fine-loamy, siliceous, thermic Typic Kandiudult) near Florence, SC, in 1991 and 1992. Treatments were winter annual cover crops, tillage, and timing of cover crop incorporation or desiccation before cotton planting. Cover crop treatments were crimson clover (Trifolium incarnatum L.), hairy vetch (Vicia villosa Roth.), rye (Secale cereale L.), and winter fallow. Tillage systems were conventional (annual disking and bedding with in-row subsoiling) and conservation (in-row subsoiling only). Soil strength was measured during the spring in the fallow plots in both tillage systems. Incorporation (conventional tillage) or desiccation (conservation tillage) of the winter cover was done 5 or 15 d before cotton planting. Winter legume dry matter production was <1800 Ib/acre per yr. Rye dry matter production was approximately 2200 Ib/acre per year. Soil and crop variables studied were not affected by timing of the cover crop incorporation or desiccation. Soil strength was lower in the top 12 in. with conventional tillage. In conservation tillage, soil strength was the same both years. Conservation tillage had lower lint yield than conventional tillage by 267 Ib/acre following clover and by 259 Ib/acre following vetch [LSD( 0.05 ) = 221 Ib/acre]. Within winter cover treatments following fallow and rye, tillage systems did not differ in yield, but lint yield for conservation tillage following rye was 292 Ib/acre greater than yield for that tillage system following fallow. Fiber properties were not greatly influenced by tillage system or winter cover, but micronaire was 0.1 units lower for cotton following rye than cotton following legumes. Including a rye winter cover crop may better insure successful conversion to conservation tillage cotton production systems on Coastal Plain soils.
Influence of saw fluxes on low-carbon steel weld microstructure

The influence of submergedarc flux composition on the inclusion morphology and weld metal microstructures of low carbon steels is investigated. Systematic weld oxygen variations and changes in inclusion shape and size are obtained by changing the welding flux composition. The influence of inclusion content, morphology, and distribution on achieving specific types of weld metal ferrite is described.
A hybrid tool buy-off decision policy for automotive sheet metal stamping dies

In most cases, manufacturers follow a net build strategy for process development. Functional build represents an integrated approach to product and process development developed by automotive body manufacturers due to the non-rigid nature of sheet metal stampings. This paper proposes a hybrid approach that combines both net build and functional build approaches which results in lower costs than using either method individually. The decision criteria are developed using a Bayesian decision model in the context of purchasing a sheet metal stamping die. The decision rule maps the tool bias to the three actions available to the decision-maker: buy the die, rework the die, and perform a functional evaluation of the panels stamped with the die.
The Role of Physical Activity in Bone Health: A New Hypothesis to Reduce Risk of Vertebral Fracture

Locomotion has always been a major criterion for human survival. Thus, it is no surprise that science supports the dependence of bone health on weight-bearing physical activities. The effect of physical activity on bone is site-specific. Determining how to perform osteogenic exercises, especially in individuals who have osteopenia or osteoporosis, without exceeding the biomechanical competence of bone always poses a dilemma and must occur under medical advice. This article presents the hypothesis that back exercises performed in a prone position, rather than a vertical position, may have a greater effect on decreasing the risk for vertebral fractures without resulting in compression fracture. The risk for vertebral fractures can be reduced through improvement in the horizontal trabecular connection of vertebral bodies.
Erratum: Maximum time delay achievable on propagation through a slow-light medium [Phys. Rev. A 71, 023801 (2005)]

We are grateful to Bruno Macke of the University of Lille for calling to our attention several errors in the equations of our paper 1 . These errors do not appear in the final results of our calculation nor do they influence the conclusions of our work, but they could present a problem for someone attempting to reproduce the details of our calculation. These errors are as follows. The last term of Eq. 4 should read +f 2 / 2 instead of −f 2 / 2. Also Eq. 12 should read
The Effect of Voice Ambulatory Biofeedback on the Daily Performance and Retention of a Modified Vocal Motor Behavior in Participants With Normal Voices.

Purpose Ambulatory biofeedback has potential to improve carryover of newly established vocal motor behaviors into daily life outside of the clinic and warrants systematic research that is lacking in the literature. This proof-of-concept study was designed to establish an empirical basis for future work in this area by formally assessing whether ambulatory biofeedback reduces daily vocal intensity (performance) and the extent to which this change remains after biofeedback removal (retention). Method Six participants with normal voices wore the KayPENTAX Ambulatory Phonation Monitor for 3 baseline days followed by 4 days with biofeedback provided on odd days. Results Compared to baseline days, participants exhibited a statistically significant decrease in mean vocal intensity (4.4 dB) and an increase in compliance (16.8 percentage points) when biofeedback was provided above a participant-specific intensity threshold. After biofeedback removal, mean vocal intensity and compliance reverted back to baseline le...
Hydrocarbon geochemistry of the Puget Sound region—III. Polycyclic aromatic hydrocarbons in sediments

Abstract Polycyclic aromatic hydrocarbon (PAH) distributions and sources are characterized in 96 sediment samples from 24 210 Pb-dated cores collected at locations in the greater Puget Sound. The highest PAH concentrations are found within a few kilometers of several sources including industrial facilities in northern Puget Sound, urban areas in central Puget Sound, and river systems draining coal-bearing strata. Regional patterns of combustion-derived PAH in surficial sediments indicate little atmospheric or waterborne exchange of PAH between different regions of the Sound. Significant subsurface maxima in combustion-derived PAH concentrations ( 210 Pb dated at the 1950s) occur only in sediment cores collected near urban centers. Perylene apparently derives from erosion of a terrestrial source with little or no evidence of in situ production at depth in sediment cores. Coal fragments are carriers of a characteristic suite of alkylated phenanthrene, chrysene, and picene derivatives concentrated near river mouths in central and southern Puget Sound.
Intracellular Association between UDP-glucose:Glycoprotein Glucosyltransferase and an Incompletely Folded Variant of α1-Antitrypsin *

Genetic variants of human alpha1-antitrypsin unable to fold into the native structural conformation are poorly secreted from hepatocytes. The molecular chaperone calnexin coimmunoprecipitates with secretion-incompetent variant null(Hong Kong) retained in stably transfected mouse hepatoma cells (Le, A., Steiner, J. L., Ferrell, G. A., Shaker, J. F., and Sifers, R. N. (1994) J. Biol. Chem. 269, 7514-7519). Mobilization of intracellular Ca2+ stores with metabolic poisons diminished interaction with calnexin and coincided with coimmuoprecipitation of a 150-kDa protein (p150). Mobilization of endoplasmic reticulum lumenal Ca2+ with thapsigargin, an inhibitor of the microsomal Ca2+ATPase, gave a similar result. Coimmunoprecipitation of p150 was specifically disrupted in response to incubation of the cell lysate with exogenous CaCl2. Finally, in ECL Western blotting, p150 was recognized by polyclonal antiserum against UDP-glucose:glycoprotein glucosyltransferase that likely functions in glycoprotein folding and quality control (Sousa, M. C., Ferrero-Garcia, M. A., and Parodi, A. J. (1992) Biochemistry 31, 97-105). The data are consistent with a model in which perturbation of endoplasmic reticulum Ca2+ results in a stable physical association between unfolded human alpha1-antitrypsin and UDP-glucose:glycoprotein glucosyltransferase.
Prospects for dynamic ISR tasking and interpretation based on standing orders to sensor networks

This research is intended to contribute to the development of automated and human-in-the-loop systems for higher level fusion to respond to the information requirements of command decision making. In tactical situations with short time constraints, the analysis of information requirements may take place in advance for certain classes of problems, and provided to commanders and their staff as part of the control and communications systems that come with sensor networks. In particular, it may be possible that certain standing orders can assume the role of Priority Intelligence Requirements. Standing orders to a sensor network are analogous to standing orders to Soldiers. Trained Soldiers presumably don't need to be told to report contact with hostiles, for example, or to report any sighting of civilians with weapons. Such standing orders define design goals and engineering requirements for sensor networks and their control and inference systems. Since such standing orders can be defined in advance for a class of situations, they minimize the need for situation-specific human analysis. Thus, standing orders should be able to drive automatic control of some network functions, automated fusion of sensor reports, and automated dissemination of fused information. We define example standing orders, and outline an algorithm for responding to one of them based on our experience in the field of multisensor fusion.
Impact of vision impairment on intensity of occupational therapy utilization and outcomes in subacute rehabilitation.

OBJECTIVE. To examine whether vision impairment is a predictor of intensity of occupational therapy utilization and outcomes in a sample of older adults ages ≥55 receiving subacute rehabilitation in a long-term care setting. METHOD. Data for this cohort study were collected by means of structured, in-person interviews with 100 older adult rehabilitation patients at admission to a subacute unit in a long-term care facility and by medical chart review after discharge. RESULTS. Regression analyses indicated that after controlling for sociodemographic, health, and social support variables, worse contrast sensitivity was a significant predictor of decreased time in occupational therapy, and worse visual acuity was a significant predictor of higher functional dependency at discharge. CONCLUSION. Vision impairment may prevent full use of occupational therapy and hinder occupational therapy efficacy in subacute care settings. Study findings underscore the importance of developing low vision rehabilitation interventions that can be delivered in conjunction with more traditional subacute rehabilitation