cssi/SciSciGPT-SciSciNet huggingface dataset:
Prevalence of insomnia symptoms in a general population sample of young children and preadolescents: gender effects

Abstract Objective Our population-based study examined the prevalence of insomnia symptoms and its sociodemographic, subjective, and polysomnographic (PSG) sleep risk factors in young and preadolescent children. Methods We performed a cross-sectional study of 700 children, ages 5–12 years who underwent a 9-h PSG and parent-completed sleep and development questionnaires (Penn State Child Cohort). Insomnia symptoms were defined as parent report of difficulty falling or staying asleep and sleep-disordered breathing (SDB) as an apnea hypopnea index of ⩾1. Results The prevalence of insomnia symptoms was 19.3% and did not significantly change (20.2%) when children with SDB were excluded. A significant interaction between gender and age revealed that the prevalence of insomnia symptoms was highest in girls ages 11 to 12 years (30.6%). This gender difference was not associated with significant differences between girls and boys ages 11–12 years in anxiety and depressive symptoms. In contrast girls ages 11–12 years with insomnia symptoms, but not boys of the same group, demonstrated clinically significant PSG sleep disturbances compared to those without insomnia symptoms. Conclusions These data suggest that one out of five young children and preadolescents of the general population have insomnia symptoms. Importantly, the prevalence of insomnia symptoms peaks in girls ages 11 to 12 years and is associated with objective sleep disturbances which may be related to hormonal changes associated with the onset of puberty rather than anxiety and depression.
Executive summary: Developing objectives, content, and competencies for the training of Emergency Medical Technicians, Emergency Physicians, and Emergency Nurses to care for casualties resulting from Nuclear, Biological, or Chemical (NBC) incidents

Abstract Study objective: The task force assessed the needs, demands, feasibility, and content of training for US civilian emergency medical responders (paramedics, nurses, and physicians) for nuclear/biological/chemical (NBC) terrorism. Methods: A task force representing key professional organizations, stakeholders, and disciplines involved in emergency medical response conducted an iterated instructional-design analysis on the feasibility and content of such training with input from educational professionals. We then analyzed 6 previously developed training courses for their congruence with our recommendations. Results: The task force produced descriptions of learning groups, content and learning objectives, and barriers and challenges to NBC education. Access to training and sustainment of learning (retention of knowledge) represent the significant barriers. The courses analyzed by the task force did not meet all objectives and challenges addressed. Conclusion: The task force recommends training programs and materials need to be developed to overcome the identified barriers and challenges to learning for these audiences. Furthermore, the task force recommends incorporating NBC training into standard training programs for emergency medical professionals. [Waeckerle JF, Seamans S, Whiteside M, Pons PT, White S, Burstein JL, Murray R, on behalf of the Task Force of Health Care and Emergency Services Professionals on Preparedness for Nuclear, Biological, and Chemical Incidents. Executive summary: developing objectives, content, and competencies for the training of emergency medical technicians, emergency physicians, and emergency nurses to care for casualties resulting from nuclear, biological, or chemical (NBC) incidents. Ann Emerg Med. June 2001;37:587-601.]
When the Unexpected Becomes Reality

I always imagined that what I see being portrayed on the news about the situation in Haiti would be enough to prepare me for what I would eventually witness once I would actually be seeing it all for myself. However, I could not fathom what I witnessed when conducting anthropological fieldwork under the direction of Dr. Schuller in 2011. It came as a complete shock to see to what extent the country was destroyed. That was the time when I really took in the atrocity in which people were living.
Magnetic distortions of flowing superfluid 3He

Abstract A marked influence of a magnetic field on superflow in 3He has been observed at saturated vapor pressure. The field distorts and eventually destroys the otherwise isotropic B-phase order parameter, giving rise to another type of state.
Pediatric patient attitudes toward chronic asthma and hospitalization

Abstract Through key cluster analysis techniques, seven attitude clusters, Minimization of Severity, Passive Observance of Illness, Bravado, Expectation of Staff Rejection, Moralistic Authoritarianism, Stigma, and External Control, were delineated in a population of hospitalized pediatric asthmatics. The clusters showed adequate internal consistency, reliability, and generality. Comparison of the pediatric clusters with previously obtained adolescent-adult clusters suggested that basic attitudes toward illness or hospitalization develop in childhood but undergo connotative transformations in the adolescent-adult years. Furthermore, correlational analysis of attitude cluster scores with chronological age revealed that some clusters crystallize early in childhood while others are subject to change over the short run. The possible implications for treatment are discussed.
Local calcium changes regulate the length of growth cone filopodia

Previous studies have demonstrated that the free intracellular calcium concentration ([Ca2+]i) in growth cones can act as an important regulator of growth cone behavior. Here we investigated whether there is a spatial and temporal correlation between [Ca2+]i and one particular aspect of growth cone behavior, namely the regulation of growth cone filopodia. Calcium was released from the caged compound NP–EGTA (o-nitrophenyl EGTA tetrapotassium salt) to simulate a signaling event in the form of a transient increase in [Ca2+]i. In three different experimental paradigms, we released calcium either globally (within an entire growth cone), regionally (within a small area of the lamellipodium), or locally (within a single filopodium). We demonstrate that global photolysis of NP–EGTA in growth cones caused a transient increase in [Ca2+]i throughout the growth cone and elicited subsequent filopodial elongation that was restricted to the stimulated growth cone. Pharmacological blockage of either calmodulin or the Ca2+-dependent phosphatase, calcineurin, inhibited the effect of uncaging calcium, suggesting that these enzymes are acting downstream of calcium. Regional uncaging of calcium in the lamellipodium caused a regional increase in [Ca2+]i, but induced filopodial elongation on the entire growth cone. Elevation of [Ca2+]i locally within an individual filopodium resulted in the elongation of only the stimulated filopodium. These findings suggest that the effect of an elevation of [Ca2+]i on filopodial behavior depends on the spatial distribution of the calcium signal. In particular, calcium signals within filopodia can cause filopodial length changes that are likely a first step towards directed filopodial steering events seen during pathfinding in vivo. © 2002 Wiley Periodicals, Inc. J Neurobiol 50: 263–275, 2002; DOI 10.1002/neu.10027
An antibody exo Diels-Alderase inhibitor complex at 1.95 Angstrom resolution

A highly specific Diels-Alder protein catalyst was made by manipulating the antibody repertoire of the immune system. The catalytic antibody 13G5 catalyzes a disfavored exo Diels-Alder transformation in a reaction for which there is no natural enzyme counterpart and that yields a single regioisomer in high enantiomeric excess. The crystal structure of the antibody Fab in complex with a ferrocenyl inhibitor containing the essential haptenic core that elicited 13G5 was determined at 1.95 angstrom resolution. Three key antibody residues appear to be responsible for the observed catalysis and product control. Tyrosine-L36 acts as a Lewis acid activating the dienophile for nucleophilic attack, and asparagine-L91 and aspartic acid-H50 form hydrogen bonds to the carboxylate side chain that substitutes for the carbamate diene substrate. This hydrogen-bonding scheme leads to rate acceleration and also pronounced stereoselectivity. Docking experiments with the four possible ortho transition states of the reaction explain the specific exo effect and suggest that the (3R,4R)-exo stereoisomer is the preferred product.
Effect of electrodynamic interactions on the translational diffusion of bovine serum albumin at finite concentration

Experimental studies of the translational diffusion coefficient, Dt, of the globular protein bovine serum albumin at very high ionic strength (I > 1.0) are reported. These data and literature values of Dt at moderate ionic strengths (0.1 < I < 1.0) are compared with the predictions of recent hydrodynamic theory. In the theoretical analysis, the combined effects of long-range repulsive (electrostatic) and attractive (electrodynamic) forces are included. The latter may make significant contributions near the isoelectric pH and at moderate ionic strength. At very high ionic strength, all long-range interactions are essentially completely screened, and the diffusion characteristics at finite concentration are dominated by the hard-sphere core repulsion. The experimental diffusion coefficients for bovine serum albumin (BSA) at pH 7.4 and I = 4.0 appear to be in harmony with literature data for Dt measured at the isoelectric pH and I = 0.1, provided an appropriate correction for the electrodynamic interaction is included in the latter.
Use of 234U and 238U isotopes to evaluate contamination of near-surface groundwater with uranium-mill effluent: a case study in south-central Colorado, U.S.A.

The 234U/238U alpha activity ratio (AR) was determined in 47 samples of variably uraniferous groundwater from the vicinity of a uranium mill near Canon City, Colorado. The results illustrate that uranium isotopes can be used to determine the distribution of uranium contamination in groundwater and to indicate processes such as mixing and chemical precipitation that affect uranium concentrations. Highly to moderately contaminated groundwater samples collected from the mill site and land immediately downgradient from the mill site contain more than 100 μg/l of dissolved uranium and typically have AR values in the narrow range of 1.0–1.06. Other samples from the shallow alluvial aquifer farther downgradient from the mill contain 10–100 μg/l uranium and plot along a broad trend of increasing AR (1.06–1.46) with decreasing uranium concentration. The results are consistent with mixing of liquid mill waste (AR≈1.0) with alluvial groundwater of small, but variable, uranium concentrations and AR of 1.3–1.5. In the alluvial aquifer, the spatial distribution of wells with AR values less than 1.3 is consistent with previous estimates of the probable distribution of contamination, based on water chemistry and hydrology. Wells more distant from the area of probable contamination have AR values that are consistently greater than 1.3 and are indicative of little or no contamination. The methodology of this study can be extended usefully to similar sites of uranium mining, milling, or processing provided that local geohydrologic settings promote uranium mobility and that introduced uranium contamination is isotopically distinct from that of local groundwater.
The dopamine response in the nucleus accumbens core-shell border differs from that in the core and shell during operant ethanol self-administration

Background: Ethanol self-administration has been shown to increase dopamine in the nucleus accumbens; however, dopamine levels in the accumbal subregions (core, shell, and core–shell border) have not yet been measured separately in this paradigm. This study was designed to determine if dopamine responses during operant ethanol self-administration are similar in the core, core–shell border, and shell, particularly during transfer from the home cage to the operant chamber and during consumption of the drinking solution. Methods: Six groups of male Long–Evans rats were trained to lever-press for either 10% sucrose (10S) or 10% sucrose + 10% ethanol (10S10E) (with a guide cannula above the core, core–shell border, or shell of the accumbens). On experiment day, 5-minute microdialysis samples were collected from the core, core–shell border, or shell before, during, and after drinking. Dopamine and ethanol concentrations were analyzed in these samples. Results: A significant increase in dopamine occurred during transfer of the rats from the home cage into the operant chamber in all 6 groups, with those trained to drink 10S10E exhibiting a significantly higher increase than those trained to drink 10S in the core and shell. No significant increases were observed during drinking of either solution in the core or shell. A significant increase in dopamine was observed during consumption of ethanol in the core–shell border. Conclusions: We conclude that dopamine responses to operant ethanol self-administration are subregion specific. After operant training, accumbal dopamine responses in the core and shell occur when cues that predict ethanol availability are presented and not when the reinforcer is consumed. However, core–shell border dopamine responses occur at the time of the cue and consumption of the reinforcer.
Chromatographic separation of metal ions on a macroreticular cation-exchange resin with hydrochloric acid in mixed solvents

Abstract Forced-flow chromatography on a cation-exchange resin has been used to obtain separations of metal ions, such as Cu(II), Co(II), Mn(II), V(IV) and Ni(II). The macroreticular resin used provides rapid separations in hydrochloric acid containing organic solvents (tetrahydrofuran, 2-propanol—tetrahydrofuran, dimethyl sulphoxide, dimethylformamide or acetone—dimethylformamide).
Chronic pain management in the surgical patient.

Surgeons are accustomed to treating pain. Surgery plays an integral part in the management of many painful conditions, and treating pain through the perioperative period is a core competency of surgeons; however, managing patients who have chronic pain has not been a high priority in surgical practice. Although a significant number of surgical patients have chronic pain, its management generally has been delegated to others in the health care system. The education of surgeons in the management of chronic pain has been minimal to date. Modern textbooks of surgery discuss the management of chronic pain only briefly. Although surgery does not have a central role in the management of chronic pain, surgeons could have a role in its management. Pain may persist after curative or palliative surgical procedures, and patients often look to their surgeon for help when it does. Armed with some basic knowledge and skills, surgeons could feel more comfortable in continuing to care for their patients who are in chronic pain and strengthening the bond between patient and surgeon as discussed by Lee et al [1]. This article provides some basic information on the management of chronic pain that may improve surgeons’ participation in the care of their patients whose pain persists after surgical procedures have been completed. Although the primary intervention for chronic pain is drug therapy, its optimal management requires a multi-disciplinary approach. Nonpharmacologic and pharmacologic interventions for chronic pain in the surgical patient are discussed.
The use of crystalline visammin in the treatment of angina pectoris.

The high incidence of unpleasant side effects following the use of crude preparations of khellin in the treatment of angina pectoris has limited its clinical use. It was felt that if this vasodilator drug were prepared free of resins, chromones and other plant impurities, it might then be used more extensively in the treatment of coronary insufficiency. Currently, a crystalline preparation of high purity has become available. A series of patients with angina pectoris were studied using this preparation. A Starr ballistocardiograph was interjected into our study in an attempt to obtain objective evidence of any effect this drug might have on the mechanical action of the heart.
Elucidating the Ticking of an In Vitro Circadian Clockwork

A biochemical oscillator can be reconstituted in vitro with three purified proteins, that displays the salient properties of circadian (daily) rhythms, including self-sustained 24-h periodicity that is temperature compensated. We analyze the biochemical basis of this oscillator by quantifying the time-dependent interactions of the three proteins (KaiA, KaiB, and KaiC) by electron microscopy and native gel electrophoresis to elucidate the timing of the formation of complexes among the Kai proteins. The data are used to derive a dynamic model for the in vitro oscillator that accurately reproduces the rhythms of KaiABC complexes and of KaiC phosphorylation, and is consistent with biophysical observations of individual Kai protein interactions. We use fluorescence resonance energy transfer (FRET) to confirm that monomer exchange among KaiC hexamers occurs. The model demonstrates that the function of this monomer exchange may be to maintain synchrony among the KaiC hexamers in the reaction, thereby sustaining a high-amplitude oscillation. Finally, we apply the first perturbation analyses of an in vitro oscillator by using temperature pulses to reset the phase of the KaiABC oscillator, thereby testing the resetting characteristics of this unique circadian oscillator. This study analyzes a circadian clockwork to an unprecedented level of molecular detail.
An enzymic method for determination of the average chain lengths of glycogens and amylopectins.

Abstract A new method for the determination of the average chain lengths of glycogens and amylopectins is described. The method utilizes yeast glucosidase-transferase and sweet-potato β-amylase, and was tested successfully against a number of samples of polysaccharides of known chain lengths. The method has several advantages over previous enzymic methods in that ( 1 ) it is relatively insensitive to the presence of α-amylase, ( 2 ) the enzymes required are readily available—sweet-potato β-amylase is commercially available and we describe a relatively simple method for the isolation of the yeast glucosidase-transferase, ( 3 ) the time required for the assay is short, relative to the method of Lee and Whelan (8).
Magnetic Properties of Superconducting Lead-Base Alloys

Magnetization measurements have been made at 4.2\ifmmode^\circ\else\textdegree\fi{}K on a variety of binary lead-base alloys, with the purpose of determining the effects of solutes, precipitates, and dislocations on superconducting properties. Increasing solute concentration results in increasingly broad magnetic transitions, the results correlating with normal-state electron mean free path in quantitative agreement with "negative surface energy" theories of Abrikosov and others. Magnetic hysteresis and trapped flux are small for annealed single-phase specimens, but are greatly increased by plastic deformation and by cellular precipitation. The maximum magnetic field to which superconductivity persists in these alloys is apparently determined by the electron mean free path, whereas extended defects such as dislocations and precipitates are primarily responsible for magnetic hysteresis and trapped flux.
Radiation-induced recovery processes in cultured marsupial cells.

The ultraviolet sensitivity of Potorous tridactylus male kidney (PtK-2) cells is markedly increased by post irradiation treatment for 24 h with 5 μM emetime (which inhibits protein synthesis by acting on the 40S ribosomal subunit), or with 5 μM cycloheximide (which inhibits by interaction with the 60S subunit), or with the RNA polymerase II inhibitor 5,6,-dichloro-1-s-ribofuranosylbenzimidazole at 50 μM. All 3 treatments give the same sensitivity, while unirradiated cells are little affected. Shortening the time of treatment, or delaying application of the drugs decreases their effect on the same time schedule. Preirradiation of cells, with no drug treatment in the following 8 h, diminishes the sensitivity to a subsequent irradiation with protein synthesis blocked afterwards. Photoreactivation immediately following such preirradiation eliminates its desensitizing effect. Inhibiting protein synthesis after irradiation also markedly reduces the frequency of UV-induced mutants in the surviving population. These facts suggest that gene expression in the period following irradiation facilitates recovery from radiation damage, with an increased probability of mutation, reminiscent of the “SOS response” in Escherichia coli.
Collisional mechanisms for single and double ionization of He by protons and antiprotons

Classical trajectory Monte Carlo calculations have been used to elucidate the collision mechanisms responsible for the differences in the single- and double-ionization cross sections of He atoms by protons and antiprotons in the energy range from 250 to 1000 keV. The calculations employed the Bohr helium-atom model which includes the 1/r/sub 12/ electron-electron interaction. The unexpected large observed difference (Andersen et al., Phys. Rev. Lett. 57, 2149 (1986)) in the ratio R of double to single ionization for proton and antiproton collisions is reproduced by the calculations. The calculations indicate that the antiproton double-ionization cross section is larger than that for protons because of two effects. The first effect is that the antiproton can push one electron into the other from larger impact parameters than for protons which must be between the nucleus and the first electron in order to pull it into a trajectory which collides with the second electron. The most important effect, however, is that at small impact parameters the antiproton screens the helium nucleus causing a Coulomb explosion while the proton increases the binding of the two electrons. The calculations also show a component of the difference in the ratio R at low energies (Eless thanmore » or equal to500 keV) is due to the single-ionization cross sections with protons predicted to have a larger cross section than antiprotons (36% difference at 250 keV).« less
Temperature and field dependences of the generation-recombination noise and the thermal emission rates at the gold acceptor center in silicon☆

Abstract The corner frequencies of the noise power spectra of gold doped silicon MOS field-effect transistors are used to evaluate the fluctuation time constants and the sum of the thermal emission rates of electrons and holes at the gold acceptor center as a function of sample temperature and electric field normal to the silicon-silicon dioxide interface. The sums of the thermal emission rates observed are in good agreement with those obtained more directly from dark and photo current and capacitance transient measurements reported earlier. (8) An attempt to separate the electron and hole emission rates from the noise corner frequency data and from the low frequency noise plateau is not successful due to a number of approximations and uncertainties in the device noise theory which is used to evaluate the observed noise spectra, such as the strong electric field and hence the spatial dependences of the thermal emission rates, the field and temperature dependences of the carrier mobility near the surface, and the depletion approximation assumed in the surface space layer when computing the noise.
Adaptation level and ‘animal spirits’

Abstract In the tradition of physiological psychology dating back to Wilhelm Wundt, an adaptation-level approach is taken to the level of economic certainty, as measured by the psychologically sensitive unemployment series. Unemployment levels ‘low’ relative to the adaptation level are shown to promote confidence — high ‘animal spirits’ — while the converse holds for ‘high’ unemployment rates. The resulting metric is shown to play a major role in confidence level formation and output determination, standing in causal relation to survey measures of consumer and producer confidence as well as industrial production, in a reasonably stable manner. Recessions tend to coincide with periods of low trailing volatility of the unemployment rate as agents become ‘sensitized’ to bad news. The paper also considers the issue of a preference for variety over the business cycle, in the spirit of the spontaneous alternation experiments in psychology which show such a preference in a multitude of settings. It is suggested that attempts to smooth the business cycle may become counterproductive (to the extent that such policy can be considered exogenous) if they produce less than ‘optimal’ levels of ‘variety’, construed in this context as alternation of confidence levels. The literature on subjective novelty surveyed by Scitovsky (1976) suggests that ‘utility maximizing’ and ‘optimal’ or productivity maximizing levels of variety may be different things, as agents tend to do well on a variety of cognitive tasks on the descending outer portion of the Wundt parabola, at levels of arousal beyond utility maximization. A bracing business cycle may be adaptive. Suggestions for further research include relating the current findings to self-organized criticality, and further study of the interworkings of adaptation level and volatility over the business cycle.
External auditory feedback from covert oral behavior during silent reading

Ss were selected for high levels of covert oral behavior during silent reading. High speech-muscle amplitude during silent reading produced a slightly noxious tone, and a reduction in amplitude removed the tone. Feedback reduced amplitude of the controlling and associated speech muscles, but withdrawal of feedback returned the amplitude to about baseline level, indicating that the reduction was not permanent. More effective controlling techniques are required to determine stringently the function of the covert oral response with this approach.
Behavior of relaxor single crystals

The constitutive behavior of relaxor rhombohedral single crystal is discussed in terms of the constitutive behavior of crystal variants. The domain engineered cut gives rise to a stable domain state. Resulting crystal behavior is described. The cut and poled single crystal should display the volume average behavior of single domain crystal variants, but comparison of a crystal variant model with measured properties leads to the identification of inconsistencies. Several possible reasons for these inconsistencies are discussed.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
A factor in quality: information on client satisfaction/dissatisfaction

The interrelation of client satisfaction with quality of service or product produced is brought out in the discussion on the importance to know whether a client (customer) is satisfied or dissatisfied with a company's (contractor's) service or product. Nine factors to be considered in determining client satisfaction or dissatisfaction are discussed. An algorithm is given for determining the client's figure of merit, which gives a means for prioritizing clients to be contacted. The nine factors are types of clients, which includes advantages and disadvantages of clients by class and contact comparisons; criteria for selection of clients to be contacted; the four types of contact and considerations for types to use; those to make the contact; when to contact client; contactor training topics; analysis of results of contact findings; documentation of contacts: and follow-up and follow-through activities. Items concerning the contact plan also are given as well as a sample plan. The paper closes with a set of inferred conclusions. Copyright © 2007 John Wiley & Sons, Ltd.
SECONDARY DEUTERIUM ISOTOPE EFFECTS IN CHEMICAL AND BIOCHEMICAL REACTIONS

Information concerning the secondary isotope rate effect caused by deuterium substitution on the carbon atom next to the reaction center in carbonium ion type reactions is reviewed, and then some other examples of secondary deuterium isotope effects in organic chemistry are summarized. Some new results on isotope effects in some enzyme-catalyzed hydrogen-transfer reactions are also given. (P.C.H.)
The Lossen rearrangement in biological systems. Inactivation of leukocyte elastase and alpha-chymotrypsin by (dl)-3-benzyl-N-(methanesulfonyloxy) succinimide.

Summary (dl)-3-Benzyl-N-(methanesulfonyloxy) succinimide 5 has been found to inactivate human leukocyte elastase and alpha-chymotrypsin efficiently and irreversibly. The kobsd/[i]values were 1170 and 9000 M−1 s−1 respectively. Porcine pancreatic elastase was not inhibited by 5 . Compound 5 may constitute the first example of a mechanism-based inhibitor of a serine proteinase that appears to exert its effect via an unprecedented enzyme-induced Lossen rearrangement.
Cannabinoid Receptor-2 and HIV-Associated Neurocognitive Disorders

Despite the wide spread use of highly active antiretroviral therapy (HAART), mild forms of HIV-associated neuro cognitive disorders (HAND) remain commonplace. HAART treated patients now show low levels of viremia and more subtle yet biologically important signs of brain macrophage and microglial activation. Adjunctive therapeutic strategies are required to eliminate HIV-1 infection and suppress immune activation and its associated neuroinflammation. In this regard, cannabinoid receptor-2(CB2) activation is a promising means to attenuate HAND by inhibiting HIV replication, down regulating inflammation, and suppressing chemokine-like activity of viral neurotoxic proteins (for example, Tat and HIV-1gp120), and thereby prevent neuronal and synaptic loss. Inhibiting even low level HIV replication can attenuate neuronal injury by decreasing the production of neurotoxins. Down regulation of inflammation by CB2 activation is mediated through blunted activation of peri vascular macrophages and microglia; decreased production of tumor necrosis factor-α, chemokines and virotoxins. Down regulated neuroinflammation can decrease blood brain barrier permeability and leukocyte infiltration resulting in reduced neuronal injury. It is suggested that CB2 agonists may further attenuate HAND in HIV-infected patients on HAART. In addition, CB2 activation may also blunt brain injury by attenuating drug addiction.
Does meaning matter? The impact of word knowledge on lateral masking.

BACKGROUND Many older adults have lost the use of their foveae due to disease. Because of this, they must use peripheral retina to do tasks formerly done using the fovea, such as letter identification and reading. Several researchers have recently proposed that reading in the periphery is limited by lateral masking: the reduced perceptibility of a target when it is surrounded by flanking stimuli. None of these studies tested the perceptibility of letters within words, where the semantic relationship between the target letter and the flanking letters is likely to improve perceptibility. This study sought to determine whether the semantic relationship between the flanking stimuli and the target stimulus affects perceptibility of letters in the periphery. METHODS Young, normally-sighted observers identified single letters and the middle letters of three-letter words, trigrams, and letters flanked by x's (xax) presented for 150 ms at 10 degrees eccentricity on each of the primary meridia. In the first experiment, subjects identified letters presented alone and letters flanked by one x on either side. In the second experiment, subjects identified the middle letters of words, trigrams, and xax stimuli, which were either presented in blocks or randomly. In the third experiment, only the words and trigrams were used, and subjects were required to both identify the middle letter and simultaneously indicate whether the stimulus was a word or a trigram. RESULTS The first experiment showed that single letters were identified about 50% more accurately than letters flanked by x's. In the second and third experiments, letter identification was better when the target and flanking letters formed a word than when they formed a trigram and better along the horizontal meridian than along the vertical meridian, which is consistent with previous studies. In the third experiment, the subject's ability to identify the stimulus type had a significant impact on performance. When the stimuli were words, subjects identified the middle letter on 87% of trials when they correctly identified the stimulus and 40% of the trials when they did not; for the trigrams these percentages were 65% and 5%. CONCLUSIONS When the flanking letters and the target letter formed a word, observers were better able to identify the target than when they did not form a word, and this pattern was mediated by the observers' knowledge of stimulus type. These data suggest that to draw conclusions regarding the impact of lateral masking on reading, the stimuli used should be words, not random-letter strings or other target/flanker combinations.
Enhancing the sensitivity of microcantilever-based sensors via geometry modification

Microcantilever based sensors have been being widely used for measuring or detecting various physical conditions, chemical agents and biological species. Researchers are continuing to focus on enhancing the sensitivity of these devices toward improving their performance and applicability. In this paper, a numerical study is performed to assess the influence of microcantilever geometry on sensitivity to improve these devices for better detection of hazardous biological agents in liquid environments. Modal analyses were performed on microcantilevers of different geometries and shapes using ANSYS software and compared to the basic rectangular shaped microcantilever structures employed by most researchers. These structures all possessed a 50 μm length, 0.5 μm thickness and 25 μm width where the cantilever is clamped to the substrate, and were analyzed for their basic resonance frequency as well as the frequency shift for the attachment of a 0.285 picogram of mass attached on their surfaces. These numerical results are compared for the improvement of the sensitivity for MEMS based microcantilever sensor, which is particularly promising for biosensor applications. Of the geometries studied a few were found to possess a significant increase in mass sensitivity over regular rectangular shaped cantilever beam structures of similar dimensions. In particular, it was found that geometries possessing larger clamping widths and/or reduced effective mass at the free end yielded enhanced sensitivity. A triangular shape was found to increase mass sensitivity an order of magnitude over standard rectangular shapes.
Pectus excavatum repair: experience with standard and minimal invasive techniques.

Abstract Background/Purpose: The Nuss procedure is a minimally invasive pectus repair that helps avoid cartilage resection and osteotomy. This report compares outcomes in patients undergoing a standard pectus repair to patients with the Nuss procedure. Methods: One hundred three children (ages 5 to 20 years) with severe pectus excavatum underwent repair. Patients were evaluated for type of repair performed, associated anomalies, cardiopulmonary function, operating time, analgesia requirements, complications, length of hospital stay, hospital and operative charges, and cosmetic result. Statistical analysis was performed using the Mann-Whitney rank sum test. Results: There were 68 patients (average age, 12.6 years) in the standard group and 35, (average age, 9.5 years) in the Nuss group. Associated anomalies were found in 6 standard group and 2 Nuss group patients. Average operating time in Nuss was 3.3 hours and in open procedures, 4.7 hours. Postoperative complications occurred in 13 (20%) standard repair patients and 15 (43%) after the Nuss. In the standard group, 14 patients received intrathecal and 3 received epidural analgesia, while 35 (52%) required an intravenous patient-controlled anesthetic device (PCA; average, 1.8 days). In the Nuss group, 25 patients (71%) received epidural anesthesia (average, 3 days), and 31 (89%) utilized PCA (average 3.8 days). Four (6%) standard patients and 8 Nuss patients (29%) required reoperation. Length of stay averaged 4.0 days (range 2 to 30) in the standard group and 4.8 days (range, 2 to 11) in the Nuss group. Average operating room charge was $8,325 in the standard group and $9,480 in the Nuss group. Average hospital charge was $4,137 for the standard patient and $4,044 for the Nuss group. Analgesic requirements and length of hospital stay were increased ( P Conclusions: Although the Nuss repair is associated with shorter operating time, smaller incisions, and less dissection, early results indicate few other advantages. Drawbacks of the Nuss procedure include high complication and reoperation rates and lack of efficacy in older teenagers and those with connective tissue disorders. Long-term follow-up will be necessary to determine final cosmetic and functional outcomes and define the overall risks and benefits of this procedure as compared with the standard technique. J Pediatr Surg 36:324-328. Copyright © 2001 by W.B. Saunders Company.
Workshop report: 1st INCF Workshop on Mouse and Rat Brain Digital Atlasing Systems

The goal of this workshop was to survey current activities and plans related to development of mouse and rat brain digital atlasing systems. The workshop discussed needs for and types of coordinated action that will ensure rapid progress, compatibility, and dissemination with use of novel technological approaches. The report summarizes the state-of-the-art in the field and provides recommendations for actions.
Zero- and low-magnetic-field transport characterization of AlxGa1-xAs/GaAs lateral dots.

The use of surface gates to define submicrometer-size dots incorporating quantum point contacts (QPC's) is proving profitable in investigating a number of effects including single electron effects and geometry-induced quantum interference. In these studies, characterization of the dots is essential. We report zero- and low-magnetic-field analysis of ballistic transmission through these structures and discuss the trajectories' interaction with the confining potential profiles. We also consider the implications of the component QPC's for reciprocity.
Encountering the expertise reversal effect with a computer-based environment on electrical circuit analysis

Abstract This study examined the effectiveness of a computer-based environment employing three example-based instructional procedures (example–problem, problem–example, and fading) to teach series and parallel electrical circuit analysis to learners classified by two levels of prior knowledge (low and high). Although no differences between the instructional procedures were observed, low prior knowledge learners benefited most from traditional example–problem pairs while their high prior knowledge counterparts benefited most from problem–example pairs. Overall, this study provides empirical support for the expertise reversal effect, which suggests that the effectiveness of certain instruction procedures in example-based learning environments depends upon the learners' level of prior knowledge.
The Advanced Dvorak Technique: Continued Development of an Objective Scheme to Estimate Tropical Cyclone Intensity Using Geostationary Infrared Satellite Imagery

Abstract Tropical cyclones are becoming an increasing menace to society as populations grow in coastal regions. Forecasting the intensity of these often-temperamental weather systems can be a real challenge, especially if the true intensity at the forecast time is not well known. To address this issue, techniques to accurately estimate tropical cyclone intensity from satellites are a natural goal because in situ observations over the vast oceanic basins are scarce. The most widely utilized satellite-based method to estimate tropical cyclone intensity is the Dvorak technique, a partially subjective scheme that has been employed operationally at tropical forecast centers around the world for over 30 yr. With the recent advent of improved satellite sensors, the rapid advances in computing capacity, and accumulated experience with the behavioral characteristics of the Dvorak technique, the development of a fully automated, computer-based objective scheme to derive tropical cyclone intensity has become possibl...
Yields of singlet nitrenes from halogen atom-azide molecule reactions

Chemiluminescence from the a1Δ and b1Σ+ excited electronic states of nitrogen halide diatomics is observed when HN3 is allowed to react with mixtures of halogen atoms in a discharge-flow apparatus. Excited NF (a1Δ) is produced by the F + HN3 reaction, and NCl (a1Δ, b1Σ+) and NBr (a1Δ, b1Σ+) are produced by the F, Cl, + HN3 and F, Br + HN3 reactions, respectively. In the low-density limit, the yield of NF(a1Δ) was found to be near unity. The yields of the b1Σ+ states of NCl and NBr were determined to have a lower limit of ca. 10%. A number of results from these experiments, including direct observation of N3 radicals in the flow, support a hypothetical mechanism in which N3 acts as an intermediate. A second possible mechanism proceeding via an HNF intermediate cannot be ruled out.
Investigation of user selection criteria of airspace design algorithms for the flexible airspace management concept

• Benefits Metrics: Measure of effectiveness in addressing traffic imbalance 1. Number of removed flights [Consistent] 2. Air traffic control resource utilization [Consistent] • Airspace Design Quality Metrics: Measure of “goodness” of the airspace 3. Airspace similarity [Not Consistent] 4. Number of flights with short dwell time [Not Consistent] 5. Distance between traffic crossing points and airspace boundary [Partially Consistent]
Effect of MgAl-layered double hydroxide exchanged with linear alkyl carboxylates on fire-retardancy of PMMA and PS

Alkyl carboxylate-modified layered double hydroxides (LDH) were prepared and used as nanofillers for poly(methyl methacrylate) (PMMA) and polystyrene (PS). The LDH intercalated with long-chain linear alkyl carboxylates (CH3(CH2)nCOO−, n = 8, 10, 12, 14, 16, 20) were prepared via anionic exchange of MgAl–nitrate, showing a systematic increase in basal spacing with longer alkyls. MgAl–undecenoate LDH was prepared by co-precipitation. The MgAl–LDHs were melt blended with poly(methyl methacrylate) and bulk polymerized with styrene to form nanocomposites. The dispersion of the MgAl–LDH in the polymers was investigated by transmission electron microscopy and X-ray diffraction. Thermal and fire properties were studied using cone calorimetry and thermogravimetric analysis; the thermal stability of both polymers was enhanced and a very significant reduction in the peak heat release rate was observed for almost all of the poly(methyl methacrylate) composites and a few of the polystyrene composites.
Precise Relations between the Spectra of Vector and Axial-Vector Mesons

Two sum rules are derived, relating moments of the spectral functions of the vector and axial-vector currents. If it is assumed that the $\ensuremath{\rho}$ and $A1$ mesons dominate these moments, then their masses must be in the ratio $\frac{{m}_{A1}}{{m}_{\ensuremath{\rho}}}=\sqrt{2}$, in very good agreement with experiment.
MAGNETRON INSTABILITY IN THE LOW-SPACE-CHARGE LIMIT

The resonant interaction between practically stable, smooth cavity diocotron modes and empty-magnetron cavity slow waves generates the unstable ``loaded'' magnetron cavity modes. In the low-space-charge, guiding center fluid picture, the most unstable frequency nearly satisfies the Buneman-Hartree resonance with the cathode flow surface, and the growth is symmetric around resonance. A negative density gradient, $dn/drl0$, is necessary for instability. Because the unstable frequencies scale as the diocotron frequency, $\ensuremath{\omega}\ensuremath{\propto}{\ensuremath{\omega}}_{D}$, the relative growth rate, scaling as ${\ensuremath{\omega}}_{D}/\ensuremath{\omega}$, is independent of, and does not go to zero with, ${\ensuremath{\omega}}_{e}^{2}/{\ensuremath{\Omega}}^{2}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}{\ensuremath{\omega}}_{D}/\ensuremath{\Omega}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0$, as it does for diocotron modes.
Effect of docosahexaenoic acid on tissue targeting and metabolism of plasma lipoproteins

We examined the effect of the docosahexaenoic acid (DHA) content of lipoproteins on their metabolism in vivo by a radioisotope labeling and tracking method. Purified HDL and LDL were labeled with (3)H-cholesteryl oleate tracer. To mimic dietary-related changes in fatty acid composition of lipoproteins, we incorporated lipids acylated with either DHA, arachidonic (AA) or oleic (OA) acid to phosphatidylcholine (didocosahexaenoylphosphatidylcholine (di22:6-PC), diarachidonoylphosphatidylcholine (di20:4-PC) and dioleoylphosphatidylcholine (di18:0-PC), respectively) into the purified particles. The lipids, at the amount added, did not cause detectable alterations in the morphology of the lipoproteins. Levels of radiotracers in blood and in several target tissues such as brain, heart, liver, muscle and adipose were determined at 1.5, 3 and 24h after intravenous injection into C57Bl/6J mice. No statistically significant differences were detected in the tissue distribution of tracers introduced into HDL enriched in DHA, compared to particles enriched with OA. In contrast, we found a significantly higher proportion of radiolabel associated with LDL enriched in DHA in heart, brown adipose and brain tissues. The uptake of labels associated with DHA containing LDL nearly doubled for heart and brown adipose tissues at 1.5 and 3h, and it was 30% higher for brain tissues at 24h. The tissue distribution of labels from the same particles enriched in AA or OA did not show a statistically significant difference from unaltered control lipoproteins. These findings point to the possible role of DHA in the regulation of LDL metabolism and involvement of the lipoproteins in transport of n-3 PUFA to target organs.
Vehicle characteristics and emissions: Logit and regression analyses of I/M data from Massachusetts, Maryland, and Illinois

This research extends earlier studies on the relationships between vehicular emissions and characteristics, with a particular focus on the effects of fuel economy, vehicle make and maintenance, and seasonal factors, on emissions of carbon monoxide, hydrocarbons, and nitrogen oxides. Nearly 4 million records of data derived from the 2001 inspection and maintenance (I/M) programs in Illinois, Maryland, and Massachusetts, are used to estimate logit models of test failures and regression models of vehicle emissions. Vehicle age, fuel economy, mileage, engine characteristics, weight, make, general maintenance, and time of year are found to be strong determinants of emissions and test failure rates. The emission models estimated with the Massachusetts data show broad variations in the effects of the independent variables across makes, for both cars and trucks.