cssi/SciSciGPT-SciSciNet huggingface dataset:
Chemical attraction of hermit crabs and other attendants to simulated gastropod predation sites

Simulated gastropod predation sites were observed in the gulf intertidal near the Edward Ball Marine Laboratory, Sopchoppy, Florida,Fundulus similis, Callinectes sapidus, Melongena corona, Clibanarius vittatus, andPagurus longicarpus were attracted to the sites by small molecules released passively from the flesh of wounded or dead animals. Flesh consumers (F. similis, C. sapidus, andM. corona) were attracted to molecules released from the flesh of bivalves, gastropods, and crabs. Shell users (C. vittatus andP. longicarpus) were attracted only to small molecules from gastropod flesh, withP. longicarpus attendingP. duplicatas sites whileC. vittatus preferentially attendedM. corona, Busycon contrarium, andBusycon spiratum sites. Flesh consumers and shell users may be attracted to the sites by different sets of small molecules. The addition of proteolytic enzymes to the flesh increased the attendants at a site, indicating that the attractant molecules might be amino acids or small peptides. Flesh consumers were attracted to the sites primarily in the first 12 hr while the shell users were attracted from 2 hr to several days postinitiation. New shells were attractive to hermit crabs up to 12 hr after entry by a hermit crab. The shell species of the attendantC. vittatus were in different proportions than the generalC. vittatus population, and the shell fit of theP. longicarpus attendants was not as good as the general population ofP. longicarpus. Significantly moreC. vittatus attended than P. longicarpus, and it was speculated that there were moreC. vittatus in the area with a poor shell fit thanP. longicarpus.
On the formation of the solar system.

THE object of this article is to point out the significance of some properties of Jupiter (the most massive planet in the solar system) for the problem of the origin of the solar system. The mass of Jupiter is 0.001 solar masses, and its orbital eccentricity is 0.05. The following discussion shows that these properties of Jupiter are primaeval, and that they have not been affected by the evolution of the solar system.
High-speed imaging of supercavitating underwater projectiles

High-speed images of supercavitating underwater projectiles traveling up to and exceeding the speed of sound in water were captured using a variety of methods. These images reveal information on projectile flight behavior, stability mechanisms, cavity shape, and in-barrel launch characteristics. This information was used to understand the physics of supercavitating bodies, verify computer models, aid failure analysis, and produce projectile launch package design modifications. In the supersonic tests, projectile shock waves were revealed. Imaging consisted of standard video, 16-mm high-speed, laser illuminated motion pictures, high-speed gated intensified video, and stroboscope illuminated 35-mm still photography. Both front-lit and shadowgraph configurations were used.
Investigation of fracture flow paths using alterant geophysical tomography

The mapping of fractures is a problem of major importance to many geotechnical projects. It is a three dimensional problem requiring the use of measurement methods with sufficient resolution and probing range to map fractures at a distance from exposed surfaces. The National Research C6uncil's report on Rock Mechanics Research Requirements [1] identified a need for major improvements in the methods used for mapping remote fractures. This article discusses a new geophysical method (Alterant Geophysical Tomography, AGT) in which tracers are forced into the in situ rock fractures to change the transmission properties of electromagnetic waves propagated between boreholes or tunnels. The theoretical advantages of the method and the results of the first experiment where it was used are also presented. This technique is analogous to the medical diagnostics technique known as X-ray fluoroscopy wherein a tracer is used to attenuate X-rays. The movement of the tracer within the digestive tract or circulatory system of the human body is monitored by measuring the attenuation of X-rays. AGT involves the transmission of an electromagnetic energy field through fractured rock before, during, and/or after a tracer is forced into the fractures. By using alterant geophysical tomography, changes induced by these tracers are mapped in the plane defined by the two boreholes. This approach is intended for geologic environments where fracture flow dominates such that the tracer penetrates the fractures but not the rock matrix.
Cloning, expression, crystallization and preliminary crystallographic analysis of a pentapeptide-repeat protein (Rfr23) from the bacterium Cyanothece 51142

A unique feature of cyanobacteria genomes is the abundance of genes that code for hypothetical proteins containing tandem pentapeptide repeats approximately described by the consensus motif A(N/D)LXX. To date, the structures of two pentapeptide-repeat proteins (PRPs) have been determined, with the tandem pentapeptide-repeat sequences observed to adopt a novel type of right-handed quadrilateral beta-helix, or Rfr-fold, in both structures. One structure, Mycobacterium tuberculosis MfpA, is a 183-residue protein that contains 30 consecutive pentapeptide repeats and appears to offer antibiotic resistance by acting as a DNA mimic. The other structure, Cyanothece 51142 Rfr32, is a 167-residue protein that contains 21 consecutive pentapeptide repeats. The function of Rfr32, like the other 35 hypothetical PRPs identified in the genome of Cyanothece, is unknown. In an effort to understand the role of PRPs in cyanobacteria and to better characterize the structural properties of Rfr-folds with different amino-acid sequences, a second PRP from Cyanothece 51142, Rfr23, has been cloned, expressed and purified. Selenomethione-substituted protein was crystallized by vapor diffusion in hanging drops. Nearly complete SAD and native diffraction data sets were collected from these crystals to 2.5 and 2.1 A resolution, respectively, using synchrotron radiation. The crystals belonged to space group I4(1), with unit-cell parameters a = b = 106.61, c = 53.37 A, and one molecule per asymmetric unit. Preliminary analysis of the electron-density map from the SAD data shows that Rfr23 contains an Rfr-fold.
Acknowledgment of Reviewers

On behalf of the editors of mBio , I gratefully acknowledge the following individuals who served as reviewers for the journal from 2010 to 2013, and they will be recognized annually moving forward. Their time and effort in reviewing articles have been essential in ensuring the high quality of our publications, and their help is greatly appreciated.
Magnetic moment of Dirac neutrinos.

The neutrino magnetic moment in the SU(2)/sub L/ x U(1)/sub Y/ model, in the N = 1 broken supergravity model, and in the SU(2)/sub L/ x SU(2)/sub R/ x U(1)/sub B//sub -//sub L/ left-right model is examined. We find that in all these models the magnetic moment is always directly proportional to the neutrino mass. It is emphasized that although in the left-right model the magnetic moment is proportional to the charged-lepton mass the combination of this mass and the left-right mixing effectively gives a neutrino mass. Given a small value of the neutrino mass its magnetic moment is too small to be of experimental interest.
The MITRE Tactical Channel Emulation System

We present a robust solution to the problem of predicting and evaluating the performance of fielded tactical radios. The MITRE Tactical Channel Emulation System (TCES) enables the evaluation of networked radios in a laboratory environment using digital baseband emulation of RF propagation conditions. The digital emulation approach offers significant advantages (e.g., cost, logistics, repeatability, etc.) over field testing. Furthermore, digital emulation is preferable to a purely software-based simulation approach in that it offers a high degree of accuracy and precision in radio behavior and can operate in real time. This approach also offers improvements in fidelity and scale over existing analog-based radio testing systems. With the TCES, a scenario encompassing multiple radios that are either stationary or are placed on some arbitrary combination of mobile platforms in a chosen geographical area can be readily constructed using an appropriate front-end modeling tool. The propagation information (e.g., time-varying and position-dependent path loss and carrier phase rotation) is extracted from the front-end tool and is used to control a matrix of Field-Programmable Gate Array- (FPGA-) based digital baseband channels. Each radio transmitter output is captured in real time, converted to a digital baseband signal, and passed through a digital baseband channel. The signal for each radio receiver is comprised of a linear combination of these digital baseband channel outputs. Each linear combination of channel outputs is converted to an analog RF signal and forms the input signal for a given radio receiver. An initial 16-by-16 node prototype of the system has already been used successfully by a DoD customer, and a 32-by-32 node prototype is currently under construction. We present an overview of the system, describe its implementation, and discuss future extensions, such as increasing scale to 64-by-64 and beyond, along with enhancements such as Doppler and multipath channels.
Infrared study of the adsorption and reaction of methyl chloride and methyl iodide on silica-supported Pt catalysts

The low-temperature adsorption of methyl chloride andmethyl iodide on silica-supported Pt catalysts has beeninvestigated by transmission Fourier transform infraredspectroscopy. The IR data show that methyl chloride and methyliodide dissociate at low temperatures (near 200 K) to form anadsorbed hydrocarbon fragment on the surface, identified asmethyl groups. Methyl groups are characterized by a singleinfrared absorption band near 2965 cm−1. Methyl groups reactwith hydrogen to form gas-phase methane as the sample is warmedbetween 200 and 473 K. Reaction of approximately 10 Torr ofmethyl chloride at 473 K over a Pt/SiO2catalyst shows that only20% of the methyl chloride decomposes to form gas-phase methaneand hydrogen chloride in the absence of hydrogen. However, inthe presence of an equal amount of hydrogen, all of the methylchloride is converted to methane and hydrogen chloride. Incontrast to the quantitative conversion of methyl chloride, lessthan 10% of the initial 10 Torr of methyl iodide forms methaneat 473 K and no hydrogen iodide forms in the presence or absenceof hydrogen gas. Although the activation barrier for C–Cl bonddissociation in adsorbed methyl chloride is higher than thebarrier for C–I bond dissociation in adsorbed methyl iodide, thelower energy barrier for removal of adsorbed chlorine comparedto adsorbed iodine is the cause of the higher catalytic activityof Pt/SiO2toward methyl chloride decomposition. In addition tothe thermal decomposition of CH3Cl, we have investigated thepossibility of using solar radiation for the decomposition ofCH3Cl on Pt/SiO2. The results for the photo-assisteddecomposition of CH3Cl adsorbed on Pt/SiO2are presented and discussed.
An endoscopic-assisted technique for retrosellar access during the extended retrosigmoid approach: a cadaveric feasibility study and quantitative analysis of retrosellar working area

The retrosigmoid approach has been advocated for certain petroclival tumors but provides limited access to any retrosellar extension of tumor, necessitating a two-stage operation. Our purpose was to demonstrate preliminary feasibility of an endoscopic-assisted technique to provide retrosellar access during the extended retrosigmoid approach and compare microscopic and endoscopic retrosellar working area. Standard retrosigmoid craniectomy and partial petrosectomy respecting inner ear structures were performed on six embalmed cadaveric heads. Two balloons were inflated to simulate a 15 mm petroclival tumor. Retrosellar clival and brainstem working area and ipsilateral oculomotor nerve and posterior cerebral artery (PCA) working distance were measured using the endoscope and microscope. Artificial tumors were implanted and resected using the endoscopic-assisted technique to assess feasibility. The endoscope provided significantly greater mean working area/distance on the clivus (201.6 vs 114.8 mm2, p < 0.01), brainstem (223.5 vs 121.2 mm2, p < 0.01), ipsilateral oculomotor nerve (10.8 vs 6.4 mm, p < 0.01), and ipsilateral PCA (13.7 vs 8.9 mm, p = 0.01). Petrous dissection to create a 10 × 10 mm working channel and artificial tumor resection was feasible in all dissections. The superior petrosal vein required ligation in 9 (75 %) cases. Air cells were exposed in 1 (8 %) case. The described endoscopic-assisted technique can provide retrosellar access during the extended retrosigmoid approach to access petroclival tumors with retrosellar extension. Risks include superior petrosal vein sacrifice, bleeding that can impair visualization, injury to the trigeminal nerve during endoscopic insertion/manipulation or injury to the brainstem while working in the medial limits of exposure. Further work is necessary to determine clinical feasibility, safety, and efficacy.
Effects of HA 1077, a novel calciumantagonistic spasmolytic agent on intracerebral arterioles of rats

The effects of the new spasmolytic agent HA 1077, which belongs to the calciumantagonists but acts by mechanisms different from those of conventional calcium channel blockers, on the cerebral microcirculation were studied in rats using isolated and cannulated intracerebral (parenchymal) arterioles of 50 μm average diameter. After the vessels had developed spontaneous tone, increasing concentrations of HA 1077 were applied extraluminally. HA 1077 induced vasodilation in a dose-dependent manner with a maximal increase of vessel diameter of 73.9±5.1% (Mean±SEM, n=5) at 10−4M and with half-maximal responses (ED50) of 1.00×10−6M. The extent of maximal vasodilation achieved by HA 1077 was significantly greater than that induced by such conventional calcium channel blockers as diltiazem, verapamil, nifedipine and nimodipine (about 50% each in a previous report from our laboratory). Vasoconstriction induced by synthetic thromboxane A2 (10−9M to 10−5M) which is throught to be highly dependent on intracellular calcium, was completely inhibited by 10−4 M HA 1077, whereas both verapamil and nimodipine at a concentration at maximal vasodilation effects (10−5M and 10−7M respectively) only partially inhibited such vasoconstriction. These results suggest that HA 1077 may exert a more potent vasodilator effect on the cerebral microcirculation than do conventional calcium channel blockers.
Hybrid intermediacy between pollination syndromes in Penstemon, and the role of nectar in affecting hummingbird visitation

Flower size dimensions, colour, and nectar quantities potentially account for differences in pollinator species between Penstemon centranthifolius (Benth.) Benth. (tubular, red, nectar-rich, hummingbird pollinated) and Penstemon spectabilis Thurber (wide, purple, nectar-poor, hymenopteran pollinated). For this study, floral characters and pollinator attraction were measured for the two species, F1 hybrids, and backcrosses. Floral dimensions, nectar characters, and color spectra combined in the hybrids in a largely linear fashion, consistent with an interpretation of net additive gene expression. In other words, the changes from one pollination syndrome to another appeared to be quantitative. There were some deviations from linearity, but not so much as to obscure the linear effect. Generally, backcrosses were not more variable than F1 hybrids or pure parents. Hummingbirds preferred P. centranthifolius over P. spectabilis. The strength of this preference varied by year, and the birds did not respond to hyb...
Tetradecameric chaperonin 60 can be assembled in vitro from monomers in a process that is ATP independent

Abstract The present work shows that monomers of cpn60 (groEL) formed at 2.5 M urea could be assembled to tetradecamers in a process that was independent of ATP. Reassembled cpn60 was able to assist the folding of urea unfolded rhodanese. When cpn60 was incubated at urea concentrations higher than 2.75 M, assembly of tetradecameric cpn60 did not occur after dialysis, and the presence of ATP did not stimulate the assembly process. The cpn60 used here did not display the previously reported ATP-dependent self-assembly of cpn60 monomers that required a higher urea concentration (4 M) for formation (Lissen et al. (1990) Nature 348, 339–342). Assembly and disassembly of cpn60 tetradecamers were followed as a function of the urea concentration by ultracentrifugation and gel electrophoresis in the presence of urea. The electrophoresis results demonstrate that there is rapid assembly of tetradecamers following preincubation and rapid removal of urea at concentrations lower than 2.5 M. Thus, previous methods monitored irreversible dissociation of cpn60, and the present results indicate that the cpn60 assembly requirements for ATP are dependent on pretreatment conditions.
Acceptability of the Schedule for the Evaluation of Individual Quality of Life-Direct Weight (SEIQoL-DW) in youth with type 1 diabetes

The purpose of this study was to assess the acceptability of the Schedule for the Evaluation of Individual Quality of Life-Direct Weight (SEIQoL-DW) in youth with diabetes. This measure asks respondents to assess the importance and satisfaction of domains that they nominate as being important to their own quality of life. Seventy-seven young people (age 8–17 years, M = 12.4) with type 1 diabetes were given the SEIQoL-DW. Data from 10 participants were deemed invalid due to respondents' inability to understand the task. Respondents whose data were deemed invalid were all under 12 years of age, M = 9.3. For participants with valid data, interviewers' ratings of participant boredom and fatigue were low. Time to complete the interview was reasonably short, M = 14.9 min. Of the 335 total QOL domains nominated by participants with valid data, only 19 domains (6%) were nominated with the assistance of a standard list. Forty-five participants nominated ‘diabetes’ as a life domain. Results indicate the SEIQoL-DW performed well with respondents over 12 years of age, is appropriate for samples with diabetes, and taps into diabetes-relevant domains. Further research with more diverse samples is needed before firm age cut-offs can be established for its use.
Flowers for Algernon: steroid dysgenesis, epigenetics and brain disorders

While a recent study has reported that early citalopram exposure alters cortical network function and produces autistic-like behaviors in male rats, when evaluating antidepressant animal models of autism spectrum disorder (ASD) it is important to note that some selective serotonin (5-HT) reuptake inhibitors alter 3α-hydroxysteroid dehydrogenase activity, and thus steroidogenesis. At least one study has examined the effect of repeated citalopram administration on the serum and brain concentration of testosterone (T) and its metabolites and shown that citalopram increases serum T. Several in vitro studies also suggest that sex steroid can alter 5-HT homeostasis. While research efforts have demonstrated that transgenic mice expressing the most common of multiple gain-of-function 5-HT reuptake transporter (SERT) coding variants, SERT Ala56, previously identified in children with ASD, exhibit autistic-like behaviors, elevated p38 MAPK-dependent transporter phosphorylation, enhanced 5-HT clearance rates and hyperserotonemia, a few studies provide some evidence that 5-HT may alter gonadal steroidogenesis. T, 17β-estradiol and synthetic estrogens are known inhibitors of AKR1C21 (BRENDA, E.C. 1.1.1.209), the epitestosterone (epiT) producing enzyme in rodents. EpiT is a naturally occurring steroid in mammals, including man. An analysis of the literature suggests that epiT may be the central mediator in the epigenetic regulation of gene expression. Over thirty years ago, it was shown that rat brain epiT production is higher in females than in males. Asimilar finding in humans could explain the sex differences in the incidence of autism and other brain disorders. Despite this, the role of epiT in brain development remains a long neglected area of research.
Cysteine oxidase in brain.

Summary Cysteine oxidase, which catalyzes the oxidation of cysteine to the neuroexcitatory and neurotoxic compounds cysteine sulfinic and sulfonic acids, previously has not been studied successfully in brain. Here we report optimal conditions for measuring cysteine oxidase activity in rat brain, describe its regional and subcellular distribution and compare activity during several stages of development. Employing NAD+ as cofactor, substantial activity was measurable in whole brain homogenate 70% of which was localized to the microsomal fraction. Appreciable activity was present throughout brain with a 3-fold difference being detected between ponsmedulla and cerebral cortex, the regions with the highest and lowest levels respectively. Cysteine oxidase activity in adult rat brain was approximately 5 times higher than that measured at birth. For the first 6 days of life there was very little change in activity; thereafter, a steady increase occurred with adult levels being reached between the 25th and 50th days.
Lactate and base deficit in trauma: does alcohol or drug use impair their predictive accuracy?

Background: Abnormal blood lactate and base deficit (BD) reflect hypoperfusion and have been documented to predict outcome in trauma. Alcohol and drug use may also induce metabolic acidosis in trauma victims, potentially diminishing the predictive accuracy of lactate and BD. We, therefore, sought to examine the effect of alcohol and drug use on the predictive accuracy of admission blood lactate and BD in trauma. Methods: Prospective data were collected on 15,179 patients admitted to the R Adams Cowley Shock Trauma Center over a 3-year period from 1998 to 2000. Patients were stratified by age, gender, race, injury severity score (ISS), Glasgow coma score (GCS), alcohol concentration and illicit drug use. Multiple regression analyses were used to assess admission blood lactate and BD as independent risk factors for mortality, intensive care unit (ICU) admission, and ICU and hospital length of stay (LOS) controlling for alcohol and drug use [cocaine, phencyclidine and methamphetamines] by measured serum concentrations. Results: The mean age of the study cohort was 37 ± 19 years, mean ISS was 9 ± 10, mean GCS 14.1 ± 2.7, 71% were male and 77% sustained blunt trauma. Alcohol testing was completed in 13,102 of 15,179 (86.3%) of patients. Alcohol screen was positive in 27% (n = 3536) of the total cohort tested (n = 13,102) with a mean blood alcohol concentration of 141 ± 95 mg/dL; 7% (n = 992) had positive drug screens. Increasing injury severity was associated with significantly increased admission blood lactate and BD (p < 0.001). Patients with positive alcohol and drug screens had significantly increased admission blood lactate, BD and injury severity compared with patients with negative alcohol and drug screens (p < 0.01). Patients with positive alcohol and drug screens had a significant increase in admission to the ICU (p < 0.05), but no significant increase in mortality, ICU or hospital LOS compared with patients with negative screens. Multiple logistic and linear regression analyses confirmed admission lactate and BD as significant independent predictors of mortality, ICU and hospital LOS (p < 0.01). These results were unchanged after controlling for alcohol and drug use as covariates in the logistic and linear regression analyses. Conclusion: Alcohol and drug use are common in trauma, but do not impair the predictive accuracy of admission lactate and BD in trauma outcome. Admission lactate and BD are therefore confirmed as significant independent predictors of trauma outcome in patients with acute alcohol and drug use in this largest clinical study to date.
Growth of acetotrophic, methane-producing bacteria in a pH auxostat

Three acetotrophicMethanosarcina species, which included marine, nonmarine, and thermophilic strains, were grown on acetate in a 10-liter pH auxostat. Specific growth rates and molar growth yields were constant throughout growth. Cell yields were up to 18-fold greater than previously reported. These properties of the pH auxostat indicate that it is a preferred culture method for the biochemical study of methanogenesis from acetate.
Human Shadow Removal with Unknown Light Source

In this paper, we present a shadow removal technique which effectively eliminates a human shadow cast from an unknown direction of light source. A multi-cue shadow descriptor is proposed to characterize the distinctive properties of shadows. We employ a 3-stage process to detect then remove shadows. Our algorithm improves the shadow detection accuracy by imposing the spatial constraint between the foreground subregions of human and shadow. We collect a dataset containing 81 human-shadow images for evaluation. Both descriptor ROC curves and qualitative results demonstrate the superior performance of our method.
Unilateral, but not bilateral, locus coeruleus lesions facilitate recovery from sensorimotor cortex injury

This study investigates the role of the locus coeruleus in recovery from sensorimotor cortex injury. Unilateral locus coeruleus lesions given 2 weeks prior to unilateral sensorimotor cortex injury facilitate subsequent motor recovery compared to animals with only a sensorimotor cortex injury, while bilateral locus coeruleus lesions severely retard motor recovery. The results suggest that recovery of function from the cortical injury is facilitated as long as a sufficient amount of the noradrenergic system remains intact, perhaps to provide a basis for compensatory sprouting. The results also suggest that recovery does occur in the absence of the locus coeruleus, indicating that the noradrenergic system is not necessary for recovery to occur after the cortical injury.
Luminescence properties of erbium in III–V compound semiconductors

Abstract Optoelectronic materials doped with Er atoms are receiving widespread attentions due to their impact on optical communication systems operating at 1.54 μm. Optical amplifiers based on Er-doped fibers have demonstrated major improvements in link distance, data rates and reduced needs for signal regeneration. III–V semiconductors doped with Er offer the prospect of very stable, temperature-insensitive, laser diodes emitting at 1.54 μm. This paper provides a review of the luminescence characteristics of III–V semiconductors doped with Er atoms. Aspects of Er incorporation in the III–V crystal host, photoluminescence properties, and prototype electroluminescent devices are addressed. Details of some of the first observations of photoluminescence of Er atoms in III–V nitride semiconductors, in particular GaN epilayers, are discussed. The GaN epilayers were optically excited using an argon-ion laser and spectra, centered at 1.54 μm, were observed at 6, 77 and 300 K. The spectra display many of the allowed transitions typical of the Er 3+ configuration and are nearly as intense at room temperature as at 77K. This result indicates that the wide bandgap III–V semiconductors may be ideal host materials for Er-doped electroluminescent devices.
How Physicians View Caregivers: Simmel in the Examination Room

The presence of caregivers in medical encounters changes the doctor-patient relationship. Although there is extensive literature on how caregivers affect medical encounters, there is little research on how physicians view such caregivers. We explore that issue by conducting structured, in-depth interviews with eighteen pediatricians and eighteen geriatricians. The interviews were recorded and transcribed, content analysis was performed, and conceptual codes were developed based on material in the interviews. Findings support Simmel's theory about the changes occurring when dyads become triads. Adding caregivers to medical encounters leads to a loss of intimacy between patients and physicians, decreased patient participation, and the formation of coalitions between physicians and caregivers. We conclude by urging medical schools to sensitize physicians to how caregivers affect medical encounters.
INTERPRETATION OF SCREEN FACTOR MEASUREMENTS.

Screen-factor (SF) measurements are widely used in the petroleum industry to characterize polymer solutions. The measurements are easy to perform and provide information that is different from solution-viscosity measurements. However, there has been no quantitative explanation of what solution property is being measured by SF. The authors show that SF measures the elongational viscosity of a polymer solution. Experiments on a modified commercial screen viscometer show the relationship between SF measurements and elongational-flow measurements performed by Durst and coworkers. Durst has shown that the elongational flow field in a packed bed of spheres triggers a transition in the conformation of a flexible polymer molecule, such as polyacrylamide, from a coiled to a stretched state. This transition in conformation is accompanied by a jump in the resistance to flow by an order of magnitude. They show that conventional screen viscometers operate in the regime where the molecules are in the highly stretched state. On the basis of Durst's work, it is calculated that the SF measurement is sensitive to high-molecular-weight tails in the polymer molecular-weight distribution.
A general method for the computer simulation of biological systems interacting with fluids.

At this Symposium on Biological Fluid Dynamics, it is appropriate to ask whether there is any common theme that unites the diverse problems that arise in the study of living systems interacting with fluids. The answer that immediately comes to mind is this: biological fluid dynamics invariably involves the interaction of elastic flexible tissue with viscous incompressible fluid. (In many cases the tissue is not only elastic, it is also active, i.e. capable of doing work on the fluid). This paper describes the immersed boundary method, which is a general framework for the computer simulation of biofluid dynamic systems. This method has already been applied to blood flow in the heart (including the computer-assisted design of prosthetic cardiac valves), platelet aggregation during blood clotting, aquatic animal locomotion, wave propagation along the basilar membrane of the inner ear, and flow in collapsible tubes. In the immersed boundary method, the elastic (and possibly active) biological tissue is treated as a part of the fluid in which additional forces (derived from the tissue stresses) are applied. Because the tissue is represented in terms of its force field, the method remains straightforward, even when the geometry of the biological tissue is complicated, dynamic and not known in advance.
COMPARISON OF RETURN PROCEDURES INVOLVING MAILED VERSUS STUDENT-DELIVERED PARENTAL CONSENT FORMS

Significantly more parental consent forms were returned by mail than delivered to the school by the children. This result suggests that to improve the rate of return for parental consent forms permitting research with children, students' handling of such forms be kept to a minimum.
In-group rationalizations of risk and indoor tanning: A textual analysis of an online forum

Unlike other health behaviors, there does not appear to be a strong relationship between perceived skin cancer risk and reduction or cessation of indoor tanning bed use. This study seeks to address this inconsistency by determining how indoor tanning bed users rationalize skin cancer risk with their tanning behavior. Qualitative textual analysis of indoor tanning message board posts (N = 330) revealed varied perceptions of risk, including acknowledging the risk of indoor tanning; denying or downplaying risk, often citing perceived health benefits associated with tanning; blaming outside forces for cancer, such as lotion or genetics; and fatalistic beliefs about cancer. These results highlight the nuanced relationship between perceived skin cancer risk and indoor tanning bed use.
Integration regions for vernier acuity in the cat: comparative aspects of cortical scaling.

The spatial region involved in vernier acuity (integration region) was behaviorally determined in cats and compared with published human data and cortical scaling parameters for the two species. Integration region was estimated from vernier thresholds obtained with: (1) gaps of various sizes between the contiguous ends of the offset contours (gap effects); and (2) irrelevant contours placed at various distances from the vernier offset (interference effects). The gap studies showed that thresholds decreased as the gap grew from 0 to 4–7 min but then increased progressively with separations greater than 7 min. In the interference studies, thresholds were increased 2–6 times when the irrelevant contours were located within 40 min of the offset. Comparing these data with available human measures showed large species differences. Converting the interference distances for both species into cortical distances using published estimates of cortical magnification factor did not resolve the discrepancy. However, a comparison of the cat data with published human data, taken at an eccentricity at which the estimated human cortical magnification factor equals that of the cat, i.e. 7 deg, showed the effects of gap size and interference distance on vernier thresholds to be remarkably similar between the two species. This similarity supports the hypothesis that positional acuity depends upon mechanisms in striate cortex, and also suggests that such acuity may be mediated by a generic neural mechanism common to mammals.
Biomarkers in Overactive Bladder

Overactive bladder (OAB) remains a remarkably common urologic condition and results in significant clinical and economic sequelae. Although likely underestimated, the overall prevalence of OAB is projected to be between 15% and 38%. The diverse etiologies of this symptom complex have limited attempts to develop reproducible biological markers of disease. Recent advances in bladder and urothelial physiology have dramatically expanded our repertoire of potential markers for use in diagnosis and to monitor treatment. Herein we present an overview of several emerging options for OAB diagnosis and review the available literature regarding these prospective biomarkers. Despite intensive awareness into OAB diagnostics, we are witness to the genesis of exploration on detrusor function and urothelial biology that will guide interventions in the coming decades. Immense opportunity exists for future evaluation of OAB pathophysiology to advance our knowledge regarding management of this multifactorial urologic disorder and define biomarkers of the disease process.
Prototyping Execution Models for HTMT Petaflop Machine in Java

The Hybrid Technology MultiThreaded (HTMT) project is an attempt to design a machine with radically new hardware technologies that will scale to a petaflop by the 2004 time frame. These technologies range from multi-hundred GHz CPUs built from superconductive RSFQ devices through active optical networks and 3D holographic memories to Processing-In-Memory (PIM) for active memories. The resulting architecture resembles a three level hierarchy of “networks of processing nodes” of different technologies and functionality. All this new technology, however, has a huge and unknown effect on software execution models for applications. This paper discusses several potential HTMT models and how they can be prototyped and demonstrated using a combination of multithreaded Java and LAN-connected workstations.
Effects of walking velocity on vertical head and body movements during locomotion

Trunk and head movements were characterized over a wide range of walking speeds to determine the relationship between stride length, stepping frequency, vertical head translation, pitch rotation of the head, and pitch trunk rotation as a function of gait velocity. Subjects (26-44 years old) walked on a linear treadmill at velocities of 0.6-2.2 m/s. The head and trunk were modeled as rigid bodies, and rotation and translation were determined using a video-based motion analysis system. At walking speeds up to 1.2 m/s there was little head pitch movement in space, and the head pitch relative to the trunk was compensatory for trunk pitch. As walking velocity increased, trunk pitch remained approximately invariant, but a significant head translation developed. This head translation induced compensatory head pitch in space, which tended to point the head at a fixed point in front of the subject that remained approximately invariant with regard to walking speed. The predominant frequency of head translation and rotation was restricted to a narrow range from 1.4 Hz at 0.6 m/s to 2.5 Hz at 2.2 m/s. Within the range of 0.8-1.8 m/s, subjects tended to increase their stride length rather than step frequency to walk faster, maintaining the predominant frequency of head movement at close to 2.0 Hz. At walking speeds above 1.2 m/s, head pitch in space was highly coherent with, and compensatory for, vertical head translation. In the range 1.2-1.8 m/s, the power spectrum of vertical head translation was the most highly tuned, and the relationship between walking speed and head and trunk movements was the most linear. We define this as an optimal range of walking velocity with regard to head-trunk coordination. The coordination of head and trunk movement was less coherent at walking velocities below 1.2 m/s and above 1.8 m/s. These results suggest that two mechanisms are utilized to maintain a stable head fixation distance over the optimal range of walking velocities. The relative contribution of each mechanism to head orientation depends on the frequency of head movement and consequently on walking velocity. From consideration of the frequency characteristics of the compensatory head pitch, we infer that compensatory head pitch movements may be produced predominantly by the angular vestibulocollic reflex (aVCR) at low walking speeds and by the linear vestibulocollic reflex (1VCR) at the higher speeds.
The role of individual and community normative factors: a multilevel analysis of contraceptive use among women in union in Mali.

Unlike in other African countries the fertility rate in Mali has remained at a relatively high rate of 6.8 births per woman. Little research exists on the role that community norms play in use of family planning particularly in low-prevalence countries. Data on 7671 women in union from the 2001 Mali Demographic and Health Survey were analyzed using multilevel modeling techniques to assess the effects of individual and community factors on the adoption of modern contraceptive methods. Only 5% of women in union were using a modern contraceptive method in 2001. The odds of contraceptive use were elevated among women in the highest wealth quintile women who approved and whose partner approved of family planning those who had had recent discussions on family planning with their partner or others and those exposed to family planning messages (odds ratios 1.4-2.7). At the community level the odds of modern contraceptive use rose with the proportion of women who were exposed to family planning messages (5.5) and decreased as the mean number of births per woman rose (0.7). In the final model which included both individual- and community-level factors the community factors were no longer significant. Because approval of family planning and discussion of family planning with partners were shown to be the factors most strongly associated with modern contraceptive use in the multilevel model programs that seek to increase individual approval and those that teach communication between partners could be particularly helpful to increasing contraceptive use in Mali. (authors)
Disturbance-utilizing controllers for noisy measurements and disturbances II. The discrete-time case

Abstract This paper considers the discrete-time counterpart, of the ‘ noisy ’ disturbance-utilizing control problem treated in the preceding paper. The results are applicable to the design of high-performance digital control systems for plants with both waveform-type and noise-type disturbances.
Flexible Consumer Demand Systems and Linear Estimation: Food in India

Demand equations in real income and nominal prices can be obtained directly by differentiating a cost function in which output is replaced by real income. This derivation is possible because recent advances show that certain index numbers provide close approximation to real income without knowledge of the utility function parameters. Three flexible functional forms corresponding to well-known flexible cost functions were used to estimate food demand elasticities. Time-series and cross-sectional data from ten Indian states for twenty years were used. The estimates provide a complete set of expenditure, price, and cross-price elasticities for four commodities, some close substitutes.
Formal verification: is it real enough?

While formal verification (FV) of logic designs has been described in an industrial context, it has not yet become a mainstream methodology. The purpose of this report is to summarize a body of experience in the application of industrial-scale FV. FV is a realistic means to successfully address the growing complexities of contemporary design. Introducing FV into the design flow is a strategic decision that requires investment in engineering resources (training and methodology adjustment) as well as support and commitment from management. When appropriately applied, FV is a powerful verification vehicle which contributes to increasing design quality and shortening time to market, with a notable return on the investment in engineering resources.
Role of Cj1211 in Natural Transformation and Transfer of Antibiotic Resistance Determinants in Campylobacter jejuni

Campylobacter jejuni, an important food-borne human pathogen, is increasingly resistant to antimicrobials. Natural transformation is considered to be a main mechanism for mediating the transfer of genetic materials encoding antibiotic resistance determinants in C. jejuni, but direct evidence for this notion is still lacking. In this study, we determined the role of Cj1211 in natural transformation and in the development of antibiotic resistance in C. jejuni. Insertional mutagenesis of Cj1211, a Helicobacter pylori ComH3 homolog, abolished natural transformation in C. jejuni. In vitro coculture of C. jejuni strains carrying either kanamycin or tetracycline resistance markers demonstrated the development of progenies that were resistant to both antibiotics, indicating that the horizontal transfer of antibiotic resistance determinants actively occurs in mixed Campylobacter populations. A mutation of Cj1211 or the addition of DNase I in culture media completely inhibited the formation of progenies that were resistant to both antibiotics, indicating that the horizontal transfer of the resistance determinants is mediated by natural transformation. Interestingly, the mutation of Cj1211 also reduced the frequency of emergence of spontaneous mutants that were resistant to fluoroquinolone (FQ) and streptomycin but did not affect the outcome of FQ resistance development under FQ treatment, suggesting that natural transformation does not play a major role in the emergence of FQ-resistant Campylobacter strains during treatment with FQ antimicrobials. These results define Cj1211 as a competence factor in Campylobacter, prove the role of natural transformation in the horizontal transfer of antibiotic resistance determinants in Campylobacter, and provide new insights into the mechanism underlying the development of FQ-resistant Campylobacter strains.
Haptic editing of decoration and material properties

We explore haptic editing as a powerful way to enhance haptic realism. Building upon the framework of a previous implicit-based haptic technique, our haptic decoration technique allows the user to first paint directly on 3D models, and then to sense the thickness variation due to the added paint. Meanwhile, material editing permits the user to edit and feel local material properties such as friction and stiffness in a natural way. In addition, we extended the initial haptic model to support some novel features including a magnetic surface attraction that forces the tool tip to stick to the surface of complex models.
The Homeodomain Proteins PBX and MEIS1 Are Accessory Factors That Enhance Thyroid Hormone Regulation of the Malic Enzyme Gene in Hepatocytes

Triiodothyronine (T3) stimulates a robust increase (>40-fold) in transcription of the malic enzyme gene in chick embryo hepatocytes. Previous work has shown that optimal T3 regulation of malic enzyme transcription is dependent on the presence of an accessory element (designated as region E) that immediately flanks a cluster of five T3 response elements in the malic enzyme gene. Here, we have analyzed the binding of nuclear proteins to region E and investigated the mechanism by which region E enhances T3 responsiveness. In nuclear extracts from hepatocytes, region E binds heterodimeric complexes consisting of the homeodomain proteins PBX and MEIS1. Region E contains four consecutive PBX/MEIS1 half-sites. PBX-MEIS1 heterodimers bind the first and second half-sites, the third and fourth half-sites, and the first and fourth half-sites. The configuration conferring the greatest increase in T3 responsiveness consists of the first and fourth half-sites that are separated by 7 nucleotides. Stimulation of T3 response element functions by region E does not require the presence of additional malic enzyme sequences. In pull-down experiments, PBX1a and PBX1b specifically bind the nuclear T3 receptor-alpha, and this interaction is enhanced by the presence of T3. A T3 receptor-alpha region containing the DNA binding domain plus flanking sequences (amino acids 21-157) is necessary and sufficient for binding to PBX1a and PBX1b. These results indicate that PBX-MEIS1 complexes interact with nuclear T3 receptors to enhance T3 regulation of malic enzyme transcription in hepatocytes.
The political dynamics of regulatory change: Speculation and regulation in the real estate sector

China's real estate sector has experienced dramatic changes since the late 1980s. This article explores the political economy of China's recent ‘real estate fever’ and examines the government's efforts to deal with rampant speculation and foster the growth of a real estate industry. It suggests that the political dynamics of regulatory changes in the real estate sector illustrate the problems of Chinese policy making in the reform era.
Motivation rulers for smoking cessation: a prospective observational examination of construct and predictive validity

Background Although popular clinically, the psychometric properties of motivation rulers for tobacco cessation are unknown. This study examined the psychometric properties of rulers assessing importance, readiness, and confidence in tobacco cessation.