cssi/SciSciGPT-SciSciNet huggingface dataset:
The number of existing functional somatic syndromes (FSSs) is an important risk factor for new, different FSSs.

Abstract Objective The objective of this study is to test the hypothesis that the number of functional somatic syndromes (FSSs) predicts new, additional FSSs. Methods In a recent case–control study of interstitial cystitis/painful bladder syndrome (IC/PBS), we used symptom-based consensus definitions to identify these FSSs: fibromyalgia (FM), chronic fatigue syndrome (CFS), irritable bowel syndrome (IBS), chronic pelvic pain, migraine, sicca syndrome and panic disorder. Those present before the incidence year were called antecedent FSSs; those with onset during the incidence year were called incident FSSs. In each of two groups, 312 IC/PBS cases and 313 controls, rates of incident FSSs were compared among those with 0, 1, 2, or ≥ 3 antecedent FSSs. Confounding was assessed using logistic regression analyses that included the individual antecedent FSSs, published correlates of these FSSs, and demographic variables. Results The incidence of a new FSS increased with the number of antecedent FSSs, as did that of incident FM, CFS and IBS studied separately. These findings were not confounded by other variables. The presence of multiple antecedent FSSs generally had the highest odds ratio for new, different, incident FSSs. Conclusions This study revealed that the number of antecedent FSSs was among the strongest risk factors for other FSSs, especially incident FM, CFS and IBS. This suggests that the FSSs are linked through a polysyndromic phenotype. If each FSS is heterogeneous, to seek a pathogenesis common to all FSSs, individuals with multiple FSSs should be sought; to seek a pathogenesis unique to a specific FSS, mature persons who have only that FSS should be studied.
Estrogen increases intracellular p26Bcl-2 to p21Bax ratios and inhibits taxol-induced apoptosis of human breast cancer MCF-7 cells

Recent studies have demonstrated that following estrogen ablation, estrogen responsive breast cancer cells undergo apoptosis. In addition, estrogen receptor (ER) expression has been strongly correlated with the expression of the bcl-2 gene product, p26Bcl-2 protein, which is known to inhibit apoptosis. In the present studies, we investigated whether estrogen affects the intracellular levels of p26Bcl-2 and thereby modulates taxol-induced apoptosis of estrogen responsive human breast cancer MCF-7 cells. Transfer of MCF-7 cells to a culture-medium without estrogens reduced their intracellular p26Bcl-2 levels by 50%. Inclusion of 0.1 μM estradiol in the medium produced approximately a four-fold increase in p26Bcl-2, but not p29Bcl-xL or p21Bax levels; the expression of the c-myc and mdr-1 genes remained unchanged. Estradiol-induced four-fold increase in the ratio of the p26Bcl-2 to p21Bax levels caused a significant decline in the lethal, kilobase size DNA fragments of apoptosis, which had resulted when MCF-7 cells were cultured in a medium without estrogen. In addition, in MCF-7 cells, estradiol-induced increase in the intracellular p26Bcl-2 to p21Bax ratios was associated with a significant reduction in the large-sized DNA fragmentation induced by treatment with taxol. The increased ratios also protected MCF-7 cells against taxol-mediated cytotoxicity as assessed by the MTT assay. These results suggest that by modulating p26Bcl-2 levels, estrogens may affect the antitumor activity of taxol and potentially of other anti-breast cancer drugs against estrogen responsive human breast cancer cells.
Observations on survival curve analysis with particular reference to breast cancer treatment

The proper analysis of survival curves of patients treated for cancer is critical to advances in clinical investigation. In this article, the presentation of such survival curves is reviewed and the various possible effects of treatment on these curves are discussed. The results of breast cancer treatment are used as examples. It is argued that the use of a semilogarithmic presentation is preferred in displaying the long-term force of mortality of the disease. In many human cancers, such as carcinoma of the breast, the demonstration of a "cured" subgroup requires follow-up of greater than 10 years and cannot be inferred from data evaluated earlier. Beneficial effects noted on the initial portion of the survival curve are not necessarily associated with an improvement in the likelihood of long-term survival, but are rather a reflection of delay or reduction on the initial force of mortality. Since both hosts and tumors are heterogeneous, it is also possible that there are different effects on various subgroups, making curve interpretation complex. In some cases, an early detrimental effect may obscure a benefit in the long-term outcome. These considerations emphasize that effects seen on the early portion of survival curves may not only be premature, but may also be misleading.
Induced waveguiding in a two-dimensional Λ-configuration atomic medium

We show that induced waveguiding of a cw probe by a spatial soliton pump in a two-dimensional (one longitudinal and one transverse spatial dimension) Λ-configuration atomic medium can be achieved. The effects of probe-pump detuning and the initial probe transverse momentum on waveguiding are also examined.
An analysis of the relationship of teachers' reported use of classroom management strategies on types of classroom interactions

The results of an investigation to determine teachers' reported use of classroom management strategies and their relationship to teacher and student interactions are presented. We interviewed 20 teachers to determine how they developed and used classroom management strategies, and then observed the interactions of these teachers with children with serious behavior disorders (SBD). Results identified two groups of teachers: one that scored high on planned use of the strategies, and one that scored low. Comparisons between the two groups of the interaction patterns revealed small, but statistically significant differences in the mean length and total percent time involved in positive interactions. The group reporting higher use of the management strategies engaged in positive interactions which were longer in duration than the interactions of the group reporting lower use. The results are discussed in terms of further research needs and implications for teacher training programs.
Soil Nitrogen Status as Affected by Tillage, Crops, and Crop Sequences

Conservation tillage practices, including no-till (NT), reduce soil erosion and increase precipitation storage efficiency, but many decrease available soil N. We conducted studies at two sites to determine the comparative effects of NT and stubble mulch (SM) on the N supplying capacity of Pullman clay loam (fine, mixed, thermic torrertic Paleustolls) cropped to continuous wheat (Triticum aestivum L.) (CW), continuous grain sorghum [Sorghum bicolor (L.) Moench] (CS), wheat-sorghum-fallow (WSF), and wheat-fallow (WF) sequences (...)
Avatar creation in virtual worlds: Behaviors and motivations

Abstract Avatar creation has become common for people to participate and interact in virtual worlds. Using an online survey (N = 244), we investigated both the behavioral characteristics and major motivations for avatar creation in virtual worlds. Our results suggest that a majority of the participants had multiple avatars; these avatars’ appearance did not merely resemble the human players; and their personality did not necessarily mirror the player’s real personality. Furthermore, participants on average spent over 20 h per week and often interacting with others in the virtual worlds. Our exploratory factor analysis yielded four major motivations: virtual exploration, social navigation, contextual adaptation, and identity representation.
Quantification of damage parameters using X-ray tomography images

Damage in materials can be represented in many forms such as specific void or crack surfaces, the spacing between cracks, scalar representation of damage and general tensorial representation of damage. This paper presents methods to quantify the specific damaged surface area, the specific damaged surface area tensor, the damage tensor, the mean solid path among the damaged surfaces and the mean solid path tensor. The methods are general and use the reconstructed three-dimensional structure from tomography images and a virtual sectioning technique to obtain cross-sectional images needed for the quantification. The paper also presents the relation between the quantified damage parameters and their applications in mechanical modeling. This work is applied in particular to quantify the damage parameters of asphalt concrete specimens of the WesTrack project.
White matter lesions in children and adolescents with migraine.

Abstract Background The etiology and clinical importance of white matter lesions in migraine remain poorly understood. To understand these issues more fully, we reviewed the brain magnetic resonance imaging scans of pediatric patients and assessed the relationships between white matter lesions, migraine type, patent foramen ovale, and right-to-left shunting. Methods The magnetic resonance imaging scans of a cohort of children (n = 89) and adolescents, ages 6 to 18 years, who participated in a study of migraine and patent foramen ovale were reviewed. All children in the cohort had undergone saline contrast transthoracic echocardiography and transcranial Doppler studies. Results White matter lesions were detected in 15 of the 89 patients (17%). White matter lesions were small ( P = 1.0); (2) patent foramen ovale (five with white matter lesions among 35 with patent foramen ovale [14%] vs. 10 with white matter lesions among 54 without patent foramen ovale [19%]; P = 0.77); or (3) shunt size (two large shunts in 15 with white matter lesions [13%] vs. nine large shunts among 72 without white matter lesions [13%]; P = 1.0). Conclusions These results indicate that small white matter lesions are not infrequent in children and adolescents with migraine. However, no relationships between white matter lesions and migraine type, patent foramen ovale, or degree of right-to-left shunting were observed.
The influence of brief episodes of aerobic exercise activity, soothing music-nature scenes condition, and suggestion on coping with test-taking anxiety

This study examines the influence of aerobic exercise activity, soothing musicnature scenes condition, and suggestion on coping with test-taking anxiety. Sixty test anxious subjects were randomly assigned to four treatment groups consisting of 15-min episodes of exercise or soothing music-nature scenes condition with or without verbal suggestion that the treatment task in which they were engaged would be helpful to them. A videotaped “intelligence test” used to stimulate test-taking anxiety was given to the subjects after the soothing music-nature scenes condition or exercise tasks. The Multiple Affect Adjective Checklist (MAACL) was used to appraise anxiety during the laboratory procedures. Results indicate that exercise, soothing music-nature scenes condition, and suggestion play a role in reducing anxiety. While relaxation activity proved to be superior to exercise in reducing anxiety immediately following the “treatment” episode, these differences disappear following exposure to a stressful “IQ test” and exercise (as well as suggestion) had a better stress inoculation effect than soothing music-nature scenes condition or no suggestion.
Ventricular ectopy associated with peroral colonic lavage

Peroral colonic lavage solutions are widely used to prepare patients for colonoscopy. The effects of peroral colonic lavage on cardiac rhythm have not been evaluated previously. Using continuous electrocardiographic monitoring, the authors evaluated cardiac rhythm in 22 patients undergoing 24 colonoscopic examinations. Monitored periods included a control phase, the period of preparation with the lavage solution, and the period of colonoscopy. In 12 of 24 evaluations, patients demonstrated an increase in ventricular ectopy during the preparation phase compared to the control period (p = 0.01). Two patients demonstrated ventricular tachycardia, four patients manifested complex ventricular ectopy without ventricular tachycardia, and six patients demonstrated an increase in simple premature ventricular contractions. The authors conclude that peroral colonic lavage is associated with increased ventricular ectopy.
K0L → π0e+e− experiments; BNL E791

Abstract The K 0 L → π 0 e + e − process has recently been the subject of renewed consideration by both experimentalists and theoreticians. The basic ideas that motivate this search are described, together with the characteristic features of high sensitivity experiments. In particular we detail the K 0 L → π 0 e + e − branch of the BNL-791 experiment. We also discuss the sensitivity of the currently running experiments as well as of the newly proposed ones.
901-36 Computer-based Interpretation of Intracardiac Electrograms: Identifying Rhythm Mechanisms from Ventricular Extrastimulus Tests

Introduction A computer-based system for analyzing complex cardiac rhythms is being developed in our laboratory. The system analyzes rhythms by adapting and simulating one or more semi-quantitative electrophysiologic models based on a sequence of events (P waves, QRS complexes, His bundle potential, etc.) on an event-by-event basis. The electrophysiologic model developed for the system can represent anatomies consisting of up to 4 accessory pathways, up to 3 AV nodal slow pathways, and 1 Mahaim pathway. We hypothesized that this system can (1) generate the correct electrophysiologic model(s) based on the observed events, (2) correctly differentiate between AV Nodal Reentrant Tachycardia (AVNRT), AV Reentrant Tachycardia (AVRT), and Atrial Tachycardia (ATACH) based on intracardiac electrogram data obtained during ventricular extrastimulus pacing protocols, and (3) generate ladder diagrams describing the identified rhythm mechanisms. Methods Typical cases were identified for each of the desired rhythms (AVNRT, AVRT, and ATACH). Using software written in our lab, the cases were annotated to extract wave timing and morphology from the body-surface electrocardiogram and wave timing of the high right atrial. His bundle, and right ventricular intracardiac electrograms. Due to the anatomic complexity underlying reentrant tachyarrhythmias, we developed novel algorithms for enumerating the complete set of conduction paths through complex electrophysiologic models. We also developed the logic necessary for reasoning with multiple model paths and simultaneous activation of anatomically distinct model regions. The system was developed in C on a UNIX workstation and runs on UNIX workstations or IBM PC-compatible computers. Results In all cases, the system (1) generated the correct set of electrophysiologic models, (2) eliminated or supported the appropriate models (i.e. rhythm mechanisms) based on the ventricular extrastimulus, and (3) generated ladder diagrams describing the rhythm mechanisms. Conclusions This is the first report of a computer-based system capable of deriving differential diagnoses with supporting ladder diagrams from intracardiac electrogram recordings. This demonstrates the potential for automatic analysis of complex rhythms by computer-assisted analysis of intracardiac electrograms. This system may be useful in the clinical electrophysiology laboratory by assisting physicians with the enormous amount of data generated during the typical electrophysiology study.
Temporal specificity in serial feature-positive discrimination learning

Two experiments examined the temporal specificity of learning in operant serial feature-positive discriminations (feature-->target+/target-). Test performance was better when the target cues were presented at their customary times after the features than when they were presented at earlier or later times. When features trained with one feature-target interval were combined with targets trained with another interval, performance was best when the test interval was the same as the interval associated with the feature, suggesting that the temporal information was coded with the feature cue. Finally, the temporal specificity of the responding controlled by occasion setters was unaffected by feature extinction. Implications for the nature of learning in occasion setting are discussed.
A versatile synthesis of β-amino acids using the Nicholas reaction. I: Application to β-lactams of the carbapenem class

Abstract Homochiral acetylenic acids of general structure 10 , prepared using the Schreiber modification of the Nicholas reaction, have been converted to β-amino acid derivatives of type 11 by a two steps sequence involving Curtius rearrangement followed by oxidative cleavage of the acetylenic bond. Amino acid derivatives 11 are excellent precursors for β-lactams of the carbapenem class.
Lewis number effects on flame spreading over thin solid fuels

Abstract The propagation rates and thermal characteristics of flames spreading downward over thin solid fuel samples are measured. Effects of diluent type, oxygen concentration, pressure, and fuel bed thickness are examined. Pressure and fuel bed thickness effects showed the trends expected based on existing flame spread theory. However, comparison of observed and predicted spread rates in various O2diluent atmospheres indicate a Lewis number (Le) effect which has not been considered previously. An approximate extension of previous flame spread theory to include Le effects is proposed and found to compare favorably with the experimental results. A new phenomenon is observed in O2SF6 and O2CO2 atmospheres near the limit: cellular flame front propagation. An explanation based on Le effects and finite-rate chemistry is proposed. Application of these results to the assessment of fire hazards and fire suppression in air and nonstandard atmospheres is discussed.
Nonproductive, cell-associated virus exists before the appearance of antiviral antibodies in experimental measles encephalitis

The ability of measles virus to induce a cell-associated state of infection in the central nervous system (CNS) plays an important role in the pathogenesis of subacute sclerosing panencephalitis (SSPE), a fatal disease of children and young adults. The mechanism by which such an infection state is established is unknown, but several hypotheses have been proposed. One of these suggests that antiviral antibodies induce the nonproductive infection state by a process termed antigenic modulation. Results presented here demonstrate that antigenic modulation is not involved in the induction of a cell-associated CNS infection in newborn hamsters by the LEC strain of SSPE derived measles virus. This follows from the finding that nonproductive, cell-associated virus can be isolated from infected CNS tissues prior to the appearance of antiviral antibodies.
Isolation of CYP2L2 and two other cytochrome P450 sequences from a spiny lobster, Panulirus argus, hepatopancreas cDNA library

Abstract Cytochrome P450 monooxygenases constitute an enzyme superfamily, with at least 74 known families. Members of CYP families 1–4 are important in the phase 1 metabolism of lipophilic xenobiotics, such as those found in contaminated marine environments. Previous studies (James et al. Arch. Biochem. Biophys. (1996) 329, 31–38) showed that a major form of P450 in spiny lobster, Panulirus argus, hepatopancreas was CYP2L1, a new sub-family, and that there was evidence for other P450 forms in hepatopancreas. We now report the sequence of a second member of this subfamily, named CYP2L2, present in P. Argus hepatopancreas. The deduced amino acid sequences of CYP2L1 and CYP2L2 share 54.7% sequence identity and an additional 13.6% of the sequences show conservative substitutions. Analysis of the sequences of CYP2L1, CYP2L2 and other representative CYP2 family members (from rat and mouse sub-families 2A, 2B, 2D and 2E) showed that the crustacean sequences clustered together. In addition to CYP2L2, cDNA clones of 66 to 117 base pairs from the 5′ coding region of two more P450 isoforms were isolated from the spiny lobster cDNA library. The deduced amino acid sequence of one of these additional cDNA clones was identical to the first 22 amino acids of the N-terminal sequence of a P450 protein previously isolated from hepatopancreas microsomes. These studies confirm earlier biochemical evidence that the hepatopancreas contains multiple forms of cytochrome P450.
Environment-dealing with the data deluge

The problem of making a flood of remote sensing data readily accessible to a growing international community of global-change researchers and policy makers is discussed. The ambitious data and information system being built by the US National Aeronautics and Space Administration (NASA), with assistance from other agencies, is described. Called the Earth Observing System Data and Information System (EOSDIS), it will manage the mountains of EOS and Earth-science satellite data and will also handle the harvesting and sharing of information, the dissemination of ideas, and the establishment of a community of collaborators that will be professionally close-knit but geographically dispersed both in the United States and elsewhere. >
Sinistrality and reduced longevity: reply to Coren and Halpern's replay.

Summary.-Coren and Halpern's response to Fudin, Renninger, Lembessis, and Hirshon's 1993 report of a nonsignificant difference in longevity between left-handed and right-handed baseball players contained errors of fact, theory, and omission. Especially disturbing is that they ignored the fact that our negative findings were found not only with parametric tests but with the same nonparametric tests that they had used. We defend our use of parametric tests given the particular data we analyzed, and we comment on the databases that we and Halpern and Coren considered and the results of studies of handedness and longevity. Fudin, Renninger, Lembessis, and Hirshon (1993) set out to analyze the longevity data for sinistral and dextral baseball players that Halpern and Coren (1988, 1990) reported to have analyzed, using their definition of handedness and their statistical procedures. We could not replicate their controversial finding of a significant longevity advantage for dextrals, finding instead a nonsignificant 38.57-day advantage for dextrals. Coren and Halpern's (1993) response to our analysis contained several statements we wish to address.
LEED study of the stepped surface of vicinal Si (100)

Abstract Periodic stepped surfaces prepared on vicinal silicon (100) by ion bombardment and annealing have been studied by LEED. An unusual aspect of the diffraction patterns from [011] zone samples was the presence of fractional order multiplets with half the splitting of the integral order doublets. An explanation is given, based on the superposition of diffraction from three distinct domain types. These differ in the orientations of their dangling bonds and the arrangements of successive terraces. The simpler patterns from [001] zone samples evidenced just two reconstruction domains. All non-integral order beams disappeared when samples were exposed to ionized hydrogen. This facilitated both the identification of certain lattice distortions, and the determination of step heights, which were found to be two atomic layers in all cases.
Thermochemical water-splitting for H2 generation using sol-gel derived Mn-ferrite in a packed bed reactor

Abstract This paper reports synthesis of Mn-ferrite using sol-gel technique, which involved the addition of Mn and Fe salts in ethanol followed by gelation using propylene oxide (PO). As-prepared gels were aged, dried and calcined rapidly upto different temperatures of 600 °C–900 °C and quenched in air. Calcined powders obtained were analyzed using x-ray diffraction, BET surface area analyzer, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The gels calcined rapidly upto 600 °C and quenched in air resulted into a phase pure Mn-ferrite with porous/nanoparticle morphology and higher SSA. The H 2 generation ability of the calcined powder was investigated by performing multiple thermochemical cycles in the Inconel packed bed reactor. In addition, the effects of several process parameters such as water-splitting temperature (T ws ), regeneration temperature (T reg ), regeneration time (t reg ) and volumetric flow rate of water (v o ) on H 2 generation ability of Mn-ferrite were investigated in detail.
DYNAMICAL PARTON MODEL FOR HADRONS.

Assuming that hadrons are bound states of large numbers of partons and antipartons, we argue that the hadronic medium is characterized by a tension which is independent of the amount by which it has been stretched. The dynamically stable configurations of such a medium are spinning loops, where the tension is balanced against the centrifugal force. The corresponding Regge trajectories are in excellent agreement with experiment, but rise only like ${s}^{\frac{2}{3}}$ for large $s$.
Mean profile depth analysis of field and laboratory traffic-loaded chip seal surface treatments

This paper presents a laboratory and field study to evaluate the mean profile depth (MPD) parameter that represents the surface texture of chip seal pavements. A three-dimensional laser profiler is used to determine the MPD values from both field pavement sections and field samples that have been tested in the laboratory using the third-scale model mobile loading simulator (MMLS3). Data obtained from five different field-constructed chip seal sections are used to evaluate the effects of different factors on the MPD of chip seal pavements. These factors include aggregate type, emulsion application rate, field versus MMLS3 traffic loading and traffic volume. The results presented in this paper suggest that: (1) chip seal pavements constructed using lightweight aggregate have larger initial MPD values and faster reduction in MPD as a function of the number of wheel passes than those constructed using granite 78M aggregate; (2) MPD values obtained from a drier section (with drier indicating a lower emulsion-t...
Unifying Theory of Quantitative Atomic Force Microscopy Using Piezo Excitation in Liquids

Base-excitation of microcantilevers using a dither piezoelectric element, also known as acoustic excitation, is one of the most popular methods for dynamic atomic force microscopy (AFM) because it is inexpensive, easy to use and does not require special cantilevers. However, in liquid environments there are problems using this method for quantitative force spectroscopy. The problems arise due spurious peaks in the driving spectrum (also known as “forest of peaks”) caused by piezo and fluid cell resonances, as well as a large base motion, which make it very hard to quantify the exciting forces. Although some groups have tried to overcome these limitations, it is has generally been accepted that acoustic excitation is unsuitable for quantitative force spectroscopy in liquids. In this work the authors show that a thorough understanding of the excitation forces and base motions reveals a method by which quantitative analysis is in fact possible with acoustic excitation in liquid environments, thus opening this popular method for quantitative dynamic AFM in liquids. This method is validated by experiments using a scanning laser Doppler vibrometer, which can measure the actual base motion. Finally, the method is demonstrated by performing force spectroscopy on solvation shells of octamethylcyclotetrasiloxane (OMCTS) molecules on mica.Copyright © 2011 by ASME
Salivary Glucose Oxidase: Multifunctional Roles for Helicoverpa zea?

Labial glands of Helicoverpa zea produced a glucose oxidase (GOX), which was present in the saliva and midgut lumen. We purified GOX 23-fold by isoelectric focusing of labial gland homogenates and investigated physical and kinetic properties of the enzyme. D-glucose and 6-deoxy-D-glucose were the optimal substrates of 22 carbohydrates tested with GOX. The enzyme was not inhibited by several inhibitors of fungal GOX but was sensitive to HgCl(2). Labial gland GOX activities varied daily during larval development with highest activities found when larvae were actively feeding. Based on pH optimum, pI, molecular weight estimate and K(m(glucose)), the insect enzyme is not derived from fungal GOXs but appears to have similar kinetic and physical attributes to other insect GOXs. Some possible functions are discussed, including antimicrobial properties, manipulating midgut O(2) levels, altering host plant defense responses, and metabolizing carbohydrates. Arch. Copyright 1999 Wiley-Liss, Inc.
Can Precolposcopy Education Increase Knowledge and Decrease Anxiety

Objective: To investigate the impact of an educational intervention on knowledge and anxiety level of women scheduled for colposcopy after an abnormal Papanicolaou (Pap) test. Design: Experimental, randomized controlled study. Setting: An inner-city medical school. Participants: The final sample consisted of 58 women in the intervention group and 55 women in the control group. Exclusion criteria included any previous colposcopy. Interventions: The women in the intervention group received in the mail, approximately 1 week before their appointment, a one-page handout about colposcopy. The control group received no mailed handout. After arriving for the visit, women were asked to participate in the study and then were interviewed. Main Outcome Measures: Knowledge of reason for visit and knowledge of colposcopy as measured by content analysis of interview; and anxiety as measured by the Spielberger State/Trait Anxiety Inventory. Results: Women in the intervention group demonstrated significantly more knowledge about the reason for their visit and about colposcopy than did the other women. No significant difference in mean anxiety score was found between the groups. Conclusions: The intervention increased knowledge about colposcopy for this population. Because patient education is an essential nursing function, these results are encouraging. This intervention can be replicated by nurses in other settings. Further research is necessary to understand how nurses can best help women alleviate anxiety before colposcopy.
Anion Binding Properties of Reduced and Oxidized Iron-Containing Superoxide Dismutase Reveal No Requirement for Tyrosine 34†

We report the first spectroscopic observation of substrate analogue binding to the reduced state of iron superoxide dismutase from Escherichia coli (Fe(2+)SOD) and demonstrate that the pH dependence reflects inhibition of anion binding by ionized Tyr34, not loss of a positive contribution on the part of Tyr34's labile proton. This can also explain the pH dependence of the K(M) of Fe(2+)SOD. Thus, it appears that substrate binding to Fe(2+)SOD occurs in the second sphere and is not strongly coupled to hydrogen bond donation. Parallel investigations of substrate analogue binding to the oxidized state (Fe(3+)SOD) confirm formation of a six-coordinate complex and resolve the apparent conflict with earlier nuclear magnetic relaxation dispersion (NMRD) results. Thus, we propose that two F(-) ions can bind to the oxidized Fe(3+)SOD active site, either displacing the coordinated solvent or lowering its exchange rate with bulk solvent. We show that neutral Tyr34's unfavorable effect on binding of the substrate analogue N(3)(-) can be ascribed to steric interference, as it does not apply to the smaller substrate analogues F(-) and OH(-). Finally, we report the first demonstration that HS(-) can act as a substrate analogue with regard both to redox reactivity with FeSOD and to ability to coordinate to the active site Fe(3+). Indeed, it forms a novel green complex. Thus, we have begun to evaluate the relative importance of different contributions that Tyr34 may make to substrate binding, and we have identified a novel, redox active substrate analogue that offers new possibilities for elucidating the mechanism of FeSOD.
Reducing Multiplexing Artifacts in Multi-Pinhole SPECT With a Stacked Silicon-Germanium System: A Simulation Study

In pinhole single photon emission computed tomography (SPECT), multi-pinhole collimators can increase sensitivity but may lead to projection overlap, or multiplexing, which can cause image artifacts. In this work, we explore whether a stacked-detector configuration with a germanium and a silicon detector, used with $^{123}{\rm I}$ (27–32, 159 keV), where little multiplexing occurs in the Si projections, can reduce image artifacts caused by highly-multiplexed Ge projections. Simulations are first used to determine a reconstruction method that combines the Si and Ge projections to maximize image quality. Next, simulations of different pinhole configurations (varying projection multiplexing) in conjunction with digital phantoms are used to examine whether additional Si projections mitigate artifacts from the multiplexing in the Ge projections. Reconstructed images using both Si and Ge data are compared to those using Ge data alone. Normalized mean-square error and normalized standard deviation provide a quantitative evaluation of reconstructed images' error and noise, respectively, and are used to evaluate the impact of the additional nonmultiplexed data on image quality. For a qualitative comparison, the differential point response function is used to examine multiplexing artifacts. Results show that in cases of highly-multiplexed Ge projections, the addition of low-multiplexed Si projections helps to reduce image artifacts both quantitatively and qualitatively.
Mechanical stress (shaking) and reticuloendothelial function in the chick embryo

Abstract Stage 34 (8 day) and 41 (15 day) chick embryos were exposed (3 min) to two separate amounts of mechanical (shaking) stress. Eggs were shaken in the horizontal plane through their long axes. A laboratory shaker (Eberbach) was used to produce the stress and one complete excursion defined as carriage movement through 7.92 cm (3.96 cm in opposite directions). Reticuloendothelial system (RES) activity, as measured by colloidal carbon clearance (CCC), was evaluated following administration via an allantoic vein. Shaking stage 34 or 41 embryos at 100 excursions per minute (EPM) did not affect CCC; shaking them at 300 EPM resulted in an immediate and significant depression of CCC. Stage 41 embryos exposed to 300 EPM and reincubated for either 1, 2 or 4 hours prior to CCC determination reverted to control CCC values sooner than stage 34 embryos subjected to the same regimen. Functional RES response to mechanically induced stress has now been shown for the first time in an embryonic system (at two distinct developmental stages). The response appears to parallel that reported for various adult organisms. Furthermore, we suggest a temporal relationship regarding functional development of the embryonic RES.
Probing cilia-driven flow in living embryos using femtosecond laser ablation and fast imaging

Embryonic development strictly depends on fluid dynamics. As a consequence, understanding biological fluid dynamic is essential since it is unclear how flow affects development. For example, the specification of the left-right axis in vertebrates depends on fluid flow where beating cilia generate a directional flow necessary for breaking the embryonic symmetry in the so-called left-right organizer. To investigate flow dynamics in vivo proper labeling methods necessitate approaches that are compatible with both normal biology and in vivo imaging. In this study, we describe a strategy for labeling and analyzing microscopic fluid flows in vivo that meets this challenge. We developed an all-optical approach based on three steps. First we used sub-cellular femtosecond laser ablation to generate fluorescent micro-debris to label the flow. The non-linear effect used in this technique allows a high spatial confinement and a low invasiveness, thus permitting the targeting of sub-cellular regions deep inside the embryo. Then, we used fast confocal imaging and 3Dparticle tracking were used to image and quantify the seeded flow. This approach was used to investigate the flow generated within zebrafish left-right organizer, a micrometer scale ciliated vesicle located deep inside the embryo and involved in breaking left-right embryonic symmetry. We mapped the velocity field within the vesicle and surrounding a single beating cilium, and showed that this method can address the dynamics of cilia-driven flows at multiple length scales. We could validate the flow features as predicted from previous simulations. Such detailed descriptions of fluid movements will be valuable in unraveling the relationships between cilia-driven flow and signal transduction. More generally, this all-optical approach opens new opportunities for investigating microscopic flow in living tissues.
Predictive factors of hospital length of stay in patients with operatively treated ankle fractures

Background Operative fixation of ankle fractures is common. However, as reimbursement plans evolve with the potential for bundled payments, it is critical that orthopedic surgeons better understand factors influencing the postoperative length of stay (LOS) in patients undergoing these procedures to negotiate appropriate reimbursement. We sought to identify factors influencing the postoperative LOS in patients with operatively treated ankle fractures.
A witness account of solar microscope projections : collective acts integrating across personal and historical memory

The paper describes the author's witnessing of images projected from an eighteenth- century solar microscope made by John Dollond, now at the Deutsches Museum in Munich. Peter Heering facilitated this session as part of his research on the solar microscope. A rectangular mirror, the length of a hand, mounted outside a museum window caught the sunlight and directed it indoors into the microscope's optical tube with its specimen. Astonishing detail was displayed in the resulting image projected onto a screen at human height. Crisply delineated scales patterned the image cast by a historical specimen of a but- terfly wing. Observers interacted fluidly with these images in the very dark room. In sharing what we noticed, questioned and conjectured, we contributed to a temporary community. These participant interactions relate to Steven Shapin and Simon Schaffer's notion that, in the seventeenth century, Robert Boyle used witnessing as a ' collective act'. Here, the 'collective act' spanned participation across history. For example, Robert Hooke's 1665 Micrographia inspired Philip and Phylis Morrison's workshop during my college years and their collabor- ation with the Eames Office on a film depicting travel through 'powers of ten', based on Kees Boeke's 1957 picture book. Personal memories were extended and informed by historical experiences, both for Robert Hooke's subsequent interpreters and for Peter Heering's parti- cipants. Three or four times during two days, at a prearranged time, I would meet a few others by the Goethe statue in the foyer of the Library at the Deutsches Museum in Munich, only to disperse and resume our continuing studies. Overcast skies frustrated our
A model of the influence of false-positive mammography screening results on subsequent screening

Decades of empirical research have demonstrated psychological and behavioural consequences of false-positive medical tests. To organise this literature and offer novel predictions, we propose a model of how false-positive mammography results affect return for subsequent mammography screening. We propose that false-positive mammography results alter how women think about themselves (e.g., increasing their perceived likelihood of getting breast cancer) and the screening test (e.g., believing mammography test results are less accurate). We further hypothesise that thoughts elicited by the false-positive experience will, in turn, affect future use of screening mammography. In addition, we discuss methodological considerations for statistical analyses of these mediational pathways and propose two classes of potential moderators. While our model focuses on mammography screening, it may be applicable to psychological and behavioural responses to other screening tests. The model is especially timely as false-positive medical test results are increasingly common, due to efforts to increase uptake of cancer screening, new technologies that improve existing tests' ability to detect disease at the cost of increased false alarms, and growing numbers of new medical tests.
A concept for energy harvesting from quasi-static structural deformations through axially loaded bilaterally constrained columns with multiple bifurcation points

A major obstacle limiting the development of deployable sensing and actuation solutions is the scarcity of power. Converted energy from ambient loading using piezoelectric scavengers is a possible solution. Most of the previously developed research focused on vibration-based piezoelectric harvesters which are typically characterized by a response with a narrow natural frequency range. Several techniques were used to improve their effectiveness. These methods focus only on the transducer?s properties and configurations, but do little to improve the stimuli from the source. In contrast, this work proposes to focus on the input deformations generated within the structure, and the induction of an amplified amplitude and up-converted frequency toward the harvesters? natural spectrum. This paper introduces the concept of using mechanically-equivalent energy converters and frequency modulators that can transform low-amplitude and low-rate service deformations into an amplified vibration input to the piezoelectric transducer. The introduced concept allows energy conversion within the unexplored quasi-static frequency range (?1?Hz). The post-buckling behavior of bilaterally constrained columns is used as the mechanism for frequency up-conversion. A bimorph cantilever polyvinylidene fluoride (PVDF) piezoelectric beam is used for energy conversion. Experimental prototypes were built and tested to validate the introduced concept and the levels of extractable power were evaluated for different cases under varying input frequencies. Finally, finite element simulations are reported to provide insight into the scalability and performance of the developed concept.
Vasodilation in black Americans: Attenuated nitric oxide-mediated responses

Background Attenuated vasodilation in response to the intra-arterial administration of the β-adrenergic agonist isoproterenol (INN, isoprenaline), an endothelium-independent vasodilator, has previously been observed in normotensive black Americans. To determine whether this reflected a more generalized attenuation of responses to vasodilators, we compared forearm blood flow responses to the endothelium-dependent vasodilator methacholine and the endothelium-independent vasodilator sodium nitroprusside in young normotensive black men and white men. Methods Forearm blood flow responses to the intra-arterial administration of isoproterenol (10 to 400 ng/min), methacholine (0.25 to 8 μg/min), and sodium nitroprusside (0.25 to 8 μg/min) were measured with use of venous occlusion plethysmography in 11 normotensive black men (mean ± SE age, 30.5 ± 2.2 years) and nine normotensive white men (mean age, 28.0 ± 3.2 years). Results Baseline characteristics, including baseline forearm blood flow, were similar in the black and the white subjects. Vasodilation in response to isoproterenol, sodium nitroprusside, and methacholine was significantly attenuated in black subjects, resulting respectively in a 3.7-fold, 3.6-fold, and 5.0-fold increase in forearm blood flow in black subjects and a 7.5-fold, 5.2-fold, and 6.9-fold increase in forearm blood flow in white subjects (ANOVA; isoproterenol, p < 0.0001; sodium nitroprusside, p < 0.0001; methacholine, p = 0.01). Conclusions Our finding of attenuated nitric oxide-mediated vasodilation in response to methacholine and sodium nitroprusside in healthy black American men suggests that attenuated vasodilation in black subjects is a relatively generalized phenomenon, resulting in attenuated responses to multiple vasodilators that act through different receptor- and nonreceptor-mediated mechanisms. Clinical Pharmacology & Therapeutics (1997) 62, 436–443; doi:
TCDD reduces rat hepatic epidermal growth factor receptor: comparison of binding, immunodetection, and autophosphorylation

Administration of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a potent tumor promoter, to rats resulted in a dose-dependent decrease in hepatic plasma membrane epidermal growth factor receptor (EGFR). The present study is the first to quantify and compare alterations in hepatic EGFR levels in female Sprague-Dawley rats 7 days after a single oral gavage dose of TCDD (0, 1, 5, 25, and 50 micrograms/kg) using three different techniques: (1) equilibrium receptor binding, (2) EGF induced receptor autophosphorylation, and (3) Western blot detection with a rabbit anti-rat EGFR polyclonal antibody. All three methods similarly demonstrated that the level of hepatic EGFR is significantly decreased at a dose of TCDD as low as 1 micrograms/kg. We showed that the immunoblot technique is a sensitive and quantitative alternative to radioligand binding assays. It is concluded that TCDD decreased total EGFR protein and maximum binding capacity without altering ligand binding affinity (Kd). The results demonstrated that ligand-induced autophosphorylation capacity and basal phosphotyrosine residues of plasma membrane EGFR were both decreased parallel with the decrease in EGFR protein, suggesting no TCDD-related alteration in the inherent functional ability of the receptor to undergo activation. Furthermore, it was found that the dose-response curve for EGFR protein level determined by Western blot analysis was similar for both male and female Sprague-Dawley rats.
THE LYMPHATIC STATUS OF HAMSTER CHEEK POUCH TISSUE IN RELATION TO ITS PROPERTIES AS A GRAFT AND AS A GRAFT SITE

Hamster cheek pouch skin, transplanted to the side of an isogenic host's chest wall, retains its immunologically privileged status as evidenced by the prolonged survival of inlaid homografts of ordinary skin. Various findings sustain the premise that exemption from rejection by otherwise susceptible homografts in both intact pouch tissue and in established pouch skin isografts is due to an impediment in the afferent pathway of the immunologic reflex, i.e., to deficient lymphatic drainage. Although lymphatics were not apparent when dye was injected into pouch skin grafts or into grafts of ordinary skin sustained by them, lymph vessels were readily and consistently revealed by dye injected into intact trunk skin or established isografts of trunk skin. When suspensions of viable lymph node cells from specifically sensitized parental strain donors were injected superficially into either the intact skin or established grafts of normal skin on F(1) hybrid hamsters, a striking hypertrophy of the regional lymph nodes occurred, due to graft-versus-host reactivity. However, similar cell suspensions inoculated into intact pouch tissue or into pouch skin grafts on F(1) hamsters incited no regional lymphadenopathy, indicating the lack of appropriate pathways to the nodes. When skin homografts were inlaid eccentrically into pouch skin isografts, so that they were in contact with host skin at one edge, rejection occurred. Furthermore, rejection of long-established intrapouch skin homografts resulted if the hosts received: (a) small homografts of ordinary skin transplanted to conventional beds; (b) suspensions of donor strain pouch skin epidermal cells, injected intracutaneously; (c) lymph node cells from specifically sensitized donors of the same strain, i.e. adoptive immunization; or, (d) if a portion of the target homograft's perimeter was surgically approximated to body skin. Treatment of normal hamsters with two closely spaced pulses of ALS, although only marginally effective in prolonging the lives of homografts of trunk skin, enabled pouch skin homografts to survive for very long periods. The influence of this brief treatment with immunosuppressant was still demonstrable if challenge of hosts with the weakly immunogenic pouch skin homografts was delayed for 100 days.