cssi/SciSciGPT-SciSciNet huggingface dataset:
Studies on the process of mouse meiosis and ovulation with daunomycin.

Der Effekt von Daunomycin auf weibliche Keimzellen wurde untersucht und mit bereits bekannten Befunden an somatischen Zellen verglichen. Es finden sich Unterschiede, die fur das Wissen uber die Effekte chemischer Mutagene auf den Sauger von Interesse sind.
Preferential oxidation of carbon monoxide with iron-promoted platinum catalysts supported on metal foams

Abstract A series of 5 wt% Pt/0.5 wt% Fe/γ-Al2O3 catalysts supported on metal foams of different geometries were synthesized and tested for preferential oxidation of a low CO concentration in the presence of a high H2 concentration. The catalysts were tested in a fixed bed adiabatic reactor at a total pressure of 0.2 MPa (absolute) to simulate fuel processor operating pressure. The inlet temperature was varied from 80 °C to 170 °C, and the gas hourly space velocity ranged from 5000 h−1 to 45,000 h−1. The inlet gas composition to the reactor reproduced that of the effluent stream from the water-gas-shift reactor in a typical fuel processor: H2 42%, CO2 9%, H2O 12%, CO 1.0%, O2 0.5–1.0%, and N2 35–35.5%. The geometry of a foam is characterized by the volume fraction of solid material (cell density) and by the number of pores per inch. The catalysts with lower cell densities generally exhibited higher CO conversions and selectivities. Under most operating conditions, the CO conversion and selectivity of the best metal foam catalysts were comparable to those of a 400 cells per square inch, ceramic straight-channel monolith with the same nominal catalyst loading. Both the reverse water-gas-shift (r-WGS) reaction and transport resistances affected the performance of these catalysts. Under adiabatic conditions, the r-WGS reaction made it impossible to achieve low outlet CO concentrations. The effects of space velocity and linear velocity were studied independently using various catalyst lengths and volumetric gas flow rates. At a constant space velocity, the CO conversion increased with higher linear velocities, suggesting a significant mass transfer resistance between the bulk gas and the catalyst surface.
U-Pb geochronologic constraints on the age of thrusting, crustal extension, and peraluminous plutonism in the Little Rincon Mountains, southern Arizona

The Little Rincon thrust fault is a mylonitic shear zone that juxtaposes Middle Proterozoic Continental Granodiorite over metasedimentary rocks of Proterozoic and early Paleozoic age. This fault is structurally beneath the San Pedro detachment fault and associated ductile deformational fabrics, which formed during early Oligocene to early Miocene time. A syntectonic leucogranite sill within the Little Rincon shear zone yields a U-Pb concordia-intercept age 66{plus minus}10 Ma for zircon and a concordant age 51{plus minus}2 Ma for fractions composed of monazite and xenotime. This demonstrates that compressional deformation in the Catalina and Rincon mountains is generally coeval with Laramide thrust faults that extend at least from southeastern California to southeastern Arizona. A peraluminous granite pluton that truncates the shear zone but displays extension-related fabrics yields a lower-intercept age 24{plus minus}12 Ma for zircon and an age of 30{plus minus}6 Ma for monazite. This indicates that some peraluminous plutons in the region were emplaced during regional crustal extension.
A Prospective Study of Obesity, and the Incidence and Progression of Lower Urinary Tract Symptoms

Purpose: We prospectively evaluated the association between adiposity and the risk of lower urinary tract symptoms incidence and progression in the Health Professionals Followup Study (HPFS).Materials and Methods: At baseline participants reported current height and weight, and weight at age 21 years. A year later they reported waist and hip circumferences, and every 2 years thereafter they reported weight. Participants periodically completed the International Prostate Symptom Score (I-PSS) and reported surgery or medication use for lower urinary tract symptoms. We used Cox proportional hazards regression to estimate the multivariable adjusted association between adiposity and lower urinary tract symptoms incidence and progression. The incidence analytical cohort of 18,055 men had no lower urinary tract symptoms at baseline. A total of 6,461 men entered the progression analytical cohort when they first experienced lower urinary tract symptoms.Results: The risk of lower urinary tract symptoms in 4,088 case...
The behavioral correlates of overall and distinctive life history strategy.

Life history (LH) theory provides an evolutionary theoretical framework for understanding individual differences in maturation, mating, reproduction, parenting, and social interaction. However, the psychometric assessment of human life history has been largely limited to generalized self-reports. Using template matching, this article examines the relationship between personality differences associated with slow-life history (slow-LH) and social behavior in 3 archival datasets. Two of these datasets include direct observations of behavior in the laboratory, and the 3rd provides self-reports of behavior in real life situations experienced within the preceding 24 hr. The results paint a consistent picture of the slow-LH individual as engaging in numerous adaptive social behaviors. However, when “normativeness” (the tendency for most people to be normal in both the statistical and evaluative sense) is statistically removed from the LH scores, a slightly different picture emerges. Both slow-LH and fast-LH persons display a number of behaviors that may be either adaptive or maladaptive in different contexts. Specifically, slow-LH individuals tended to behave in a manner that was considerate, kind, hard-working, and reliable but also socially awkward, insecure, and overcontrolling. Fast-LH individuals came across as talkative, socially skilled, dominant, and charming but also unpredictable, hostile, manipulative, and impulsive. These results are consistent with the evolutionary interpretation of LH strategies as being adapted to systematically different environments rather than better or worse approaches to reproductive fitness overall.
Classification of Adults for Family Studies of Developmental Language Disorders

A variety of approaches has been used to classify the status of adult subjects in familial studies of developmental language disorders. In this report, we directly compare the results of four diffe...
Linear and non-linear impacts of a non-native plant invasion on soil microbial community structure and function

Biological invasions can alter ecosystem functions such as litter decomposition and nutrient cycling, but little is known about how invader abundance influences the impact on the ecosystem. It is often assumed that impacts are proportional to invasion density, but this assumption has never been tested and has little justification. We tested the hypothesis that the microbial community structure and function of a mixed hardwood forest soil changed after invasion by Japanese barberry (Berberis thunbergii), an invasive shrub commonly found in eastern hardwood forests, and that changes were proportional to the density of invasion. We constructed microcosms with mixtures of native and invasive leaf litter, and measured microbial community structure (phospholipid fatty acids) and function (litter decomposition). Decomposition was linearly related to the degree of invasion (R 2 = 0.945), but the ratio of bacteria to fungi exhibited a strongly non-linear, threshold response (R 2 = 0.513). These results indicate that impacts of Japanese barberry invasion are not always proportional to invasion density. This finding has implications for the study of biological invasions as well as practical implications for the management of exotic invasive species.
The use of graphic design in an interactive computer teaching program.

The widespread diffusion of affordable computers into the scientific and educational community has provided the opportunity to design medical and scientific teaching programs illustrated either by hand or by utilizing commercially available software and manipulating existing computer generated images. The medical illustrator can provide the ideal aesthetic link between text format information and the visual representation of such knowledge in a concise presentation format. The availability of interactive multimedia programs has given the medical illustrator an environment to create and enhance Hypermedia designed specifically for the parpose of medical education. This paper will focus on the incorporation of illustration and screen design into “CT The Came,” an experimental medical teaching program currently being developed in the Johns Hopkins Body CT Imaging Laboratory. The program is designed to provide an enjoyable approach to learning Computed Tomography (CT), and is directed toward an audience of medical students, residents, and fellows.
E258K HCM-causing mutation in cardiac MyBP-C reduces contractile force and accelerates twitch kinetics by disrupting the cMyBP-C and myosin S2 interaction.

Mutations in cardiac myosin binding protein C (cMyBP-C) are prevalent causes of hypertrophic cardiomyopathy (HCM). Although HCM-causing truncation mutations in cMyBP-C are well studied, the growing number of disease-related cMyBP-C missense mutations remain poorly understood. Our objective was to define the primary contractile effect and molecular disease mechanisms of the prevalent cMyBP-C E258K HCM-causing mutation in nonremodeled murine engineered cardiac tissue (mECT). Wild-type and human E258K cMyBP-C were expressed in mECT lacking endogenous mouse cMyBP-C through adenoviral-mediated gene transfer. Expression of E258K cMyBP-C did not affect cardiac cell survival and was appropriately incorporated into the cardiac sarcomere. Functionally, expression of E258K cMyBP-C caused accelerated contractile kinetics and severely compromised twitch force amplitude in mECT. Yeast two-hybrid analysis revealed that E258K cMyBP-C abolished interaction between the N terminal of cMyBP-C and myosin heavy chain sub-fragment 2 (S2). Furthermore, this mutation increased the affinity between the N terminal of cMyBP-C and actin. Assessment of phosphorylation of three serine residues in cMyBP-C showed that aberrant phosphorylation of cMyBP-C is unlikely to be responsible for altering these interactions. We show that the E258K mutation in cMyBP-C abolishes interaction between N-terminal cMyBP-C and myosin S2 by directly disrupting the cMyBP-C–S2 interface, independent of cMyBP-C phosphorylation. Similar to cMyBP-C ablation or phosphorylation, abolition of this inhibitory interaction accelerates contractile kinetics. Additionally, the E258K mutation impaired force production of mECT, which suggests that in addition to the loss of physiological function, this mutation disrupts contractility possibly by tethering the thick and thin filament or acting as an internal load.
COMPOUND STIMULUS CONTROL BY DISCRIMINATIVE STIMULI ASSOCIATED WITH HIGH AND MODERATE RESPONSE RATES1

Four rats received water on a fixed-ratio schedule for lever pressing in the presence of a tone (or light) stimulus and on a variable-interval schedule in the presence of a light (or tone) stimulus. Following stabilization of a high response rate during the fixed-ratio component and a moderate response rate during the variable-interval component, brief periods with the light and tone presented simultaneously but with no responses reinforced were inserted into the regular training schedule. Response rates during the compound stimuli were intermediate between the response rates controlled by the individual fixed-ratio and variable-interval associated stimuli.
Impact of continuous EEG monitoring on clinical management in critically ill children.

Background Continuous EEG (cEEG) monitoring is being used with increasing frequency in critically ill patients, most often to detect non-convulsive seizures. While cEEG is non-invasive and feasible in the critical care setting, it is also expensive and labor intensive, and there has been little study of its impact on clinical care. We aimed to determine prospectively the impact of cEEG on clinical management in critically ill children.
Cellular mechanisms governing synaptic development in Drosophila melanogaster.

The neuromuscular connections of Drosophila are ideally suited for studying synaptic function and development. Hypotheses about cell recognition can be tested in a simple array of pre-and postsynaptic elements. Drosophila muscle fibers are multiply innervated by individually identifiable motoneurons. The neurons express several synaptic cotransmitters, including glutamate, proctolin, and octopamine, and are specialized by their synaptic morphology, neurotransmitters, and connectivity. During larval development the initial motoneuron endings grow extensively over the surface of the muscle fibers, and differentiate synaptic boutons of characteristic morphology. While considerable growth occurs postembryonically, the initial wiring of motoneurons to muscle fibers is accomplished during mid-to-late embryogenesis (stages 15–17). Efferent growth cones sample multiple muscle fibers with rapidly moving filopodia. Upon reaching their target muscle fibers, the growth cones rapidly differentiate into synaptic contacts whose morphology prefigures that of the larval junction. Mismatch experiments show that growth cones recognize specific muscle fibers, and can do so when the surrounding musculature is radically altered. However, when denied their normal targets, motoneurons can establish functional synapses on alternate muscle fibers. Blocking synaptic activity with either injected toxins or ion channel mutants does not derange synaptogenesis, but may influence the number of motor ending processes. The molecular mechanisms governing cellular recognition during synaptogenesis remain to be identified. However, several cell surface glycoproteins known to mediate cellular adhesion events in vitro are expressed by the developing synapses. Furthermore, enhancer detector lines have identified genes with expression restricted to small subsets of muscle fibers and /or motoneurons during the period of synaptogenesis. These observations suggest that in Drosophila a mechanism of target chemoaffinity may be involved in the genesis of stereotypic synaptic wiring. © 1993 John Wiley & Sons, Inc.
Labor-dependent capital income taxation

Abstract Capital taxation which is negatively correlated with labor supply is proposed. This paper uses a life-cycle model of heterogeneous agents that face idiosyncratic productivity shocks and shows that the tax scheme provides a strong work incentive when households possess large assets and high productivity later in the life-cycle, when they otherwise would work less. The system also adds to the saving motive of prime-age households and raises aggregate capital. The increased economic activities expand the tax base and the revenue neutral reform results in a lower average tax rate. The negative cross-dependence generates a sizable welfare gain in the long-run relative to the tax system that treats labor and capital income separately as a tax base. The reform, however, can hurt the elderly during the transition with a high marginal tax on their capital income.
Pilot prospective evaluation of 99mTc-MDP scintigraphy, 18F NaF PET/CT, 18F FDG PET/CT and whole-body MRI for detection of skeletal metastases.

ObjectiveThe aim of this study was to compare 99mTc-MDP bone scanning, 18F NaF PET/CT, 18F FDG PET/CT, and whole-body MRI (WBMRI) for detection of known osseous metastases.Patients and MethodsThis prospective pilot trial (September 2007-April 2009) enrolled 10 participants (5 men, 5 women, 47–81 yea
Association of HLA-DQB1 alleles with risk of follicular lymphoma.

In a recent genome-wide association study of follicular lymphoma (FL), we identified novel risk alleles on chromosome 6p21.33 that appeared to be part of an extended haplotype including HLA-DRB1*0101, DQA1*0101, and DQB1*0501. To follow up on these findings, we obtained 2–4 digit HLA-DQB1 allelotypes on a subset of 265 cases of FL and 757 controls using a novel assay that applies multiplexed ligation-dependent probe amplification (MLPA). We confirmed a positive association between FL and the HLA-DQB1*05 allele group (OR = 1.70, 95% CI 1.28–2.27; adjusted p-value = 0.013) and also identified an allele group inversely associated with FL risk, HLA-DQB1*06 (OR = 0.51, 95% CI 0.38–0.69; adjusted p-value = 4.46 × 10−5). Although these findings require verification, the role of HLA class II proteins in B-cell survival and proliferation makes this a biologically plausible association.
Direct identification of protein epitopes by mass spectrometry without immobilization of antibody and isolation of antibody-peptide complexes.

A rapid new approach is described that combines the selectivity and sensitivity of immunoaffinity and mass spectrometric based techniques for mapping protein epitopes. The approach alleviates the n...
The mobility of [14C]3‐chloro‐P‐toluidine hydrochloride in a loam soil profile

The movement of radiolabeled 3-chloro-p-toluidine hydrochloride (CPTH) in a loam soil was evaluated in a column leaching study. Twenty-five-gram portions of the soil were treated with about 30 μg/g of uniformly labeled [14C]CPTH, and then incubated (aged) for 24 h under aerobic conditions; this soil was applied to untreated soil columns, which were then leached with dilute aqueous calcium sulfate for a total leachate volume equal to or greater than 50.8 times the cross-sectional area, or about 450 to 600 ml. Results indicated that about 2% of the initial radiolabeled compound leached through the soil profile, with the mean apparent partition coefficient calculated to be 65 ml/g. The soil columns were separated into 6-cm sections and extracted with dilute aqueous calcium sulfate, followed by 80% aqueous acetonitrile. About 90% of the [14C]CPTH was sorbed to the uppermost 6 cm of soil. Following extraction, the residual soil was combusted, with these results indicating that an average 77% of the parent compound and products present in the upper 6 cm were bound to the soil colloids. Approximately 1% of the applied radiolabeled compound volatilized during the soil aging and leaching processes. The mean mass balance based upon [14C] analyses was 102%. One major metabolite was detected in leachate fractions and soil extracts, which was tentatively identified as N-acetyl-3-chloro-p -toluidine, based upon HPLC retention times. This same degradation product was previously identified and confirmed using mass spectroscopy in CPTH aerobic soil biodegradation and fish accumulation studies. The extent to which CPTH was bound to the loam soil colloids, with only minimal movement through the soil profile, suggests a low potential for mobility of this pesticide in the soil environment.
The significance of recurrent lung opacities in neonates on surfactant treatment for respiratory distress syndrome.

Purpose. To determine the significance of recurrent opacities in chest radiographs of neonates on surfactant therapy for respiratory distress syndrome (RDS) after an initial period of improvement.¶Materials and methods. Serial pre- and post-surfactant chest radiographs on 94 preterm infants with RDS were analyzed and the pattern of chest radiographic response was classified as (a) clear, (b) recurrent opacities, and (c) no response. Their clinical characteristics were also recorded.¶Results. In 34 infants the RDS changes cleared within 3 days. 31 infants developed lung opacities within 10 days after an initial period of improvement. Twenty-nine infants failed to respond to the surfactant. The corresponding mean birth weights for the three groups were 1.74, 1.19, and 0.76 kg and the mean gestation ages 32.6, 27.7, and 25.4 weeks. The incidence of bronchopulmonary dysplasia (BPD) was highest among the slumping infants (72. % vs 50 % in no responders, P < 0.001)¶Conclusions. The pattern of chest radiographic response is primarily affected by gestation age and birth weight. Recurrent lung opacity after an initial positive response to surfactant therapy may be caused by such factors as edema from barotrauma and patent ductus arteriosus. Infants with intraventricular hemorrhage may demonstrate neurogenic edema. Other contributory factors include pneumonia and abnormal consumption of surfactant. Recurrent lung opacities after surfactant may be a predictor of chronic lung disease in the preterm infant.
SU-GG-T-241: Patient Specific QA Using EBT2 Films for VMAT

Purpose: To report on EBT2 film based patient specific QA scheme for evaluation of the in‐house volumetric modulated arc therapy (VMAT) planning algorithm applied to the new rotational delivery technique. Methods: Planning CTimages of selected prostate patients were transferred to the in‐house developed treatment planning (TP) system. Deliverable VMAT plans were optimized by a dose‐volume‐histogram based objective function and a conjugate gradient search. Two approaches of VMAT patient specific QA using EBT2 films at 100 cm SAD with 15MV photons on Varian Trilogy™ were developed: 1) through a phantom mounted on an isocentric mounting fixture, and 2) through a rectangular phantom (25×25×20 cm3) positioned on the treatment couch. Calibration films were irradiated at dmax (3 cm) for doses up to 10 Gy. All films were scanned using an Epson 10000XL flatbed scanner with 72 dpi (0.035 mm) pixel resolution. Pixel values were converted to doses using the established calibration curve. The 2D dose distributions were generated from the film data analysis. In‐house software was utilized to compare the measured doses from films with the associated TP data for each methodology. Results and Discussion: Both testing techniques reported less than 2% discrepancy of the absolute doses at the isocenter. First approach showed better passing rates than the second method. In both cases that the measured planar dose distributions achieved more than 90% passing rates with a set of 3% /3 mm dose and DTA criteria. EBT2 film dosimetry in phantom was in good agreement with TP results, and all film results in our study have created an acceptable passing rate with fine spatial resolution compared to other detector‐arrays QA methods. Conclusions: The patient specific EBT2 film QA for VMAT prostate patients showed extremely satisfactory results. EBT2 film analysis with either setup approach here was useful for VMAT patient QA.
Risk management for water and energy pipelines

Pipelines are linear systems usually serving a vital community function such as transport of water, fuel or industrial products. In case of utility pipelines a necessary design requirement is the maintenance of serviceability. Disruptions should be kept to minimum and safe operation is expected to be maintained at minimum maintenance effort. In case of energy pipelines such as oil or gas it can also be a public health and safety issue. Certain materials such as cast iron are susceptible to sudden breaks. Occasionally these breaks present a public hazard when escaping gas enters a building and causes an explosion. For example, the frequency of incidents reported to the Office of Pipeline Safety involving cast iron pipe is 1.5 incidents per 1,000 miles versus 0.7 for plastic and 0.5 for steel (Gideon and Smith, 1979). Also, the maintenance costs per mile of cast iron pipe are significantly higher than for steel or plastic pipe. In this paper, we present a methodology which uses economic and risk exposure evaluations to make repair versus replace decisions, i.e., should a particular pipe segment be replaced in the planning year, or should it be maintained and repaired, as necessary, for at least one more year? The methodology provides an efficient screening tool to rapidly analyze an entire network of piping segments and identify the critical segments for replacement during the planning year based on probabilities of breaks and leaks, replacement and repair costs, and possible consequences of pipe failure. Although most of the
Overview of signal processing by the immune system in systemic lupus erythematosus.

Systemic lupus erythematosus SLE is considered a chronic inflammatory disease, with periods of waxing and waning, where the disease pathogenesis is attributed to circulating antinuclear autoantibodies (1;2) and the dysfunction of T and B lymphocytes (3-5) and dendritic cells (6; 7). Although the pathogenesis is believed to lie in the dysregulation of the immune system, the involvement of various organ systems often leads to secondary morbidities resulting from renal failure, hypertension, and atherosclerosis (8). The cause of SLE is incompletely understood and current therapies have limited efficacy. A rational approach for therapeutic design requires a detailed understanding of disease pathogenesis. Independent lines of evidence have implicated environmental factors and genetic determinants of the host in the causation of the disease (9). Concordance rates for SLE are approximately 25% in monozygotic twins (10). Alternatively, the discordance rate may be as high as 70% among monozygotic twins (11), suggesting a significant role for exogenous agents (12;13). Genome-wide association studies have identified numerous chromosomal loci that may harbor lupus susceptibility genes (14), however, the functional significance of these lupus-associated polymorphisms is presently unknown. Therefore, further characterization of the molecular and cellular basis of signaling abnormalities within the immune system that lead to autoreactivity and inflammation and their relationship to regulation of gene expression remain critical for understanding of disease pathogenesis (15). In the first paper of the special issue of Autoimmunity Reviews dedicated to the signaling abnormalities in lupus, Stanford Peng provides an authoritative review of T and B cell dysfunction and their genetic bases. Fernandez et al demonstrate that mitochondrial dysfunction characterized by elevated transmembrane potential and increased mitochondrial mass causes accumulation of Ca 2+ in mitochondria and enhanced Ca 2+ fluxing upon T cells activation as well as predisposition to death by necrosis; the latter of which is pro-inflammatory stimulating B cells and dendritic cells by releasing oxidized DNA and high mobility group B1 protein. Rapamycin treatment that inactivates the mammalian target of rapamycin (mTOR), a protein of the outer mitochondrial membrane sensing changes in the transmembrane potential normalizes Ca 2+ fluxing in SLE patients. Next, Jose Crispin and George Tsokos focus on the regulation of IL-2 expression of T cells which they view as a fundamental defect of T cell dysfunction. They discuss the newly discovered role of chromatin re-organization through through acetylation of histones and the influence of Foxp3 in “non-regulatory” T cells. Gabriela
Free-energy determinants of alpha-helix insertion into lipid bilayers

A detailed treatment is provided of the various free-energy terms that contribute to the transfer of a polyalanine alpha-helix from the aqueous phase into lipid bilayers. In agreement with previous work, the hydrophobic effect is found to provide the major driving force for helix insertion. However, an opposing effect of comparable magnitude is also identified and is attributed to the large free-energy penalty associated with the desolvation of peptide hydrogen bonds on transfer to the low dielectric environment of the bilayer. Lipid perturbation effects as well as the entropy loss associated with helix immobilization in the bilayer are also evaluated. Two configurations of a membrane-bound 25mer polyalanine helix were found to be lower in free energy than the isolated helix in the aqueous phase. The first corresponds to the case of vertical insertion, in which a helix terminus protrudes from each side of the bilayer. The second minimum is for the case of horizontal insertion, for which the helix is adsorbed upon the surface of the bilayer. The calculated free-energy minima are found to be in good agreement with recent measurements of related systems. Large free-energy barriers resulting from desolvation of unsatisfied hydrogen-bonding groups at the helix termini are obtained for both insertion processes. The barriers for insertion are significantly reduced if the helix termini are assumed to be "capped" through the formation of hydrogen bonds with polar sidechains. For uncapped helices, our results support recently proposed models in which helices are inserted by first adsorbing on the membrane surface and then having one terminus "swing around" so as to penetrate the bilayer.
Radical Misinterpretation: A Reply to Stoutland

Frederick Stoutland’s critical notice of Donald Davidson: Meaning, Truth, Language, and Reality appeared in the December 2006 issue of this journal (Vol. 14, no. 4). It would be fair to say that it...
Plant-Animal Mutualism: Coevolution with Dodo Leads to Near Extinction of Plant

An endemic sapotaceous tree Calvaria major found on the island of Mauritius is nearly extinct because its seeds apparently required passage through the digestive tract of the now-extinct dodo Raphus cucullatus to overcome persistent seed coat dormancy caused by a specially thickened endocarp.
Fracture toughness of monolithic nickel aluminide intermetallics

Abstract The fructure toughness of several nickel aluminide intermetallics have been determined in accordance with standard testing techniques. The intermetallics tested, Ni3Al (24 at.% Al), Ni3Al + 0.2 at.% B and NiAl (45 at.% Al), were produced by conventional vacuum hot-pressing techniques while processing conditions were varied to produce systematic changes in grain size. The toughness obtained and details of the fracture behavior were distinctly different for the materials studied. Ni3Al exhibited an initiation toughness of MPa m 1 2 , whire the boron-doped material had a toughness exceeding 30 MPa m 1 2 . NiAl, on the contrary, demonstrated toughness values of about 5 MPa m 1 2 . This differences are discussed in the light of deformation and fracture mechanisms operating at the crack tip in the cases described. In situ fracture monitoring and post-failure analyses are utilized in support of the discussion.
Is estimation of Floquet multipliers of human walking valid

The Floquet multiplier has been widely used to assess orbital stability of human walking. Floquet introduced it to quantify the stability of periodic motion of deterministic linear systems, but human walking involves highly nonlinear dynamics and inevitable noise. This preliminary study addresses the validity of Floquet multiplier estimation of a nonlinear system with stochastic noise. Noise was added to a simplified but nonlinear model of human walking so that the variability of model walking was comparable to that of human walking. Results show that linear regression yields a biased measure of the Floquet multiplier though its accuracy improves with a sufficient number of strides.
Mitochondrial phylogeny of the endemic Hawaiian craneflies (Diptera, Limoniidae, Dicranomyia): implications for biogeography and species formation.

Situated in the middle of the Pacific Ocean, over 3000 km from the nearest continental land mass, the Hawaiian Archipelago is the most remote island group on earth. The Hawaiian Islands are often referred to as a ‘‘conveyor belt” archipelago (Carson and Clague, 1995); as the Pacific plate moves to the northwest over a stationary hotspot, islands are formed, carried with the plate, and gradually subside at a more-or-less constant rate (Price and Clague, 2002; Ziegler, 2002). This hotspot has been active for over 40 million years (Carson and Clague, 1995) and has resulted in a chain of successively older islands, seamounts, and atolls stretching northwest across the Pacific. Currently, there are eight ‘‘high islands” in the southeast of the chain that, at over 1000 m in elevation, are able to support a diverse flora and fauna. The youngest island, dated at less than 600,000 years old, is the Big Island of Hawai‘i. Kaua‘i, at about 5 million years old, is the oldest high island (Price and Clague, 2002). Extreme isolation, coupled with the unique geology and environmental conditions of the islands, has made Hawai‘i a ‘‘natural laboratory” where the effects of evolution are readily observable (Kaneshiro, 1995). Over 850 endemic flowering plant (Wagner et al., 1990) and 4000 endemic insect species (Liebherr, 2001) are each thought to have been derived from about 200 colonization events. Colonist species can rapidly fill open ecological niches and diversify in situ, resulting in an amazing array of endemic fauna and flora. Newly emerging islands are then colonized from
Pressure indicators for removable prosthodontics

P.I.P. and Coltene pressure spot indicator were tested on the same 30 sets of complete maxillary and mandibular dentures and on two maxillary dentures against natural dentition. They were tested at delivery for pressure spots, but adjustments were not made. They were tested again after 24 hours to visualize and compare actual pressure spots. Half the dentures were adjusted according to P.I.P. and half according to Coltene pressure spot indicator. The patients were recalled after 1 week to determine if they were free from discomfort. The P.I.P. showed a greater clinical correlation of predictable to actual pressure spots and enabled the investigators to spare more patients from post-delivery discomfort.
Barotropic Vortex Stability to Perturbations from Axisymmetry

Abstract Tropical cyclones and dynamically similar model vortices robustly maintain a near-axisymmetric horizontal structure where the vortex flow is strongly nonlinear in spite of persistent asymmetric forcing represented by horizontal variations in the environmental winds and the Coriolis parameter. Since tropical cyclone motion relative to environmental “steering” has been associated with vortex asymmetries in even the simplest numerical models, identification of a barotropic mechanism that stabilizes vortices to dispersive influences is important. A nondivergent, barotropic analytical model is used to identify the asymmetry-damping influence of symmetric angular windshear as the mechanism by which a barotropic vortex resists asymmetric forcing. Solutions are obtained for the evolution of linear asymmetric perturbations imposed as initial conditions on a steady, Rankine vortical flow. Perturbations combining various radial and azimuthal structures that might be expected from environmental and convectiv...
Masked hypertension is prevalent in children with sickle cell disease: a Midwest Pediatric Nephrology Consortium study

Background The prevalence of hypertension and abnormal blood pressure (BP) patterns on 24-h ambulatory BP monitoring (ABPM) remains unknown in children with sickle cell disease (SCD).
Substrate-induced changes in reactivity of sulfhydryl groups of carbamyl phosphate synthetase

Summary 1. The influence of various sulfhydryl-group reagents on the activity of frog-liver carbamyl phosphate synthetase (ATP:carbamate phosphotransferase(dephos-phorylating), EC 2.7.2.5) has been examined. 2. Acetylglutamate, a cofactor for the enzyme, will accelerate inactivation by some reagents (the disulfide, 5,5′-dithio-bis(2-nitrobenzoic acid); N-ethylmaleimide), but will protect against the action of other reagents (mercuribenzoate; silver). Inactivation by some reagents is only slightly affected by acetylglutamate. 3. ATP and Mg2+ will prevent acetylglutamate-induced inactivation by the disulfide, but will not reverse cofactor protection against mercuribenzoate. In the absence of acetylglutamate, ATP and Mg2+ have no effect on inactivation by sulfhydryl reagents. 4. Urea and 0·5 M KCl increase the rate of reaction of 5,5′-ditliio-bis(2-nitro-benzoate) with the sulfhydryl groups of the enzyme. Acetylglutamate will do so only in the presence of 0·5 M KCl, or if very low levels of disulfide are used. ATP and Mg21 greatly reduce the rate of reaction of sulfhydryl groups, whether or not cofactor is present. The kinetics are first order in disulfide concentration. 5. The present findings strengthen previous findings which suggest that the tertiary protein structure, about the active site of the enzyme, may be modified by cofactor or substrate. It is proposed that mercuribenzoate is highly reactive to one or more sulfhydryl groups which are exposed on the enzyme, but masked by acetylglutamate activation. The cofactor activation, however, exposes other sulfhydryl groups which are preferentially reactive to reagents such as disulfides. Addition of substrate will mask the sulfhydryl groups exposed by activation. The addition of co-factor will fail to influence inactivation by some reagents, because they are equally reactive with both types of sulfhydryl groups.
Lymphotoxin-beta and TNF regulation in T cell subsets: differential effects of PGE2.

The effects of prostaglandin E2(PGE2) on lymphotoxin β (LT-β) and tumour necrosis factor alpha (TNF) were assessed in murine CD4+Th1and Th2T cell clones. LT-β mRNA was constitutively expressed by both T cell subsets. However, PGE2inhibited its accumulation only in Th1, but not Th2clones. PGE2inhibited TNF mRNA accumulation and production and release of bioactive material by both Th1and Th2T cells. The effects of PGE2were also evaluated on production of IL-3, another cytokine produced by both T cell subsets, and interleukin 4 (IL-4), which is produced only by Th2cells. Though IL-3 was produced by both T cell subsets it was only inhibited in Th1cells, a pattern similar to that observed for LT-β. Accumulation of IL-4 mRNA in Th2cells was not inhibited by PGE2. These results demonstrate that PGE2does not affect LT-β, IL-4, or IL-3 in Th2cells, but inhibits TNF mRNA accumulation and production in this T cell subset. Thus, TNF appears to be the only cytokine susceptible to inhibition by PGE2in Th2cells. The fact that PGE2inhibits LT-β and IL-3 in Th1but not Th2cells points to a different mechanism of regulation of the same cytokine in different subsets. The mechanisms that contribute to TNF mRNA accumulation also may differ in the two CD4+T cell subsets, because cycloheximide superinduced TNF mRNA in Th2cells, but not in Th1cells. The inhibitory effects of PGE2on TNF mRNA accumulation by either T cell subset did not requirede novoprotein synthesis since preincubation with the protein synthesis inhibitor, cycloheximide, did not alter the PGE2-mediated effects. Cross-regulation of cytokine production and function has been demonstrated for both T cell subsets, and PGE2may modulate the outcome of an immune response via differential regulation of cytokine production.
Implementing TQM for library services: the issues

TQM is defined as managing the entire organization so that it excels in all dimensions of products and services which are important to the customers. Excellence in a TQM organization is defined by customer requirements and needs.
Statistical studies of protein sequences: Pair and triplet analysis in helical conformations

Abstract Nearest neighbor pair and triplet associations in helical conformations of protein chains were compared with the same associations in Monte Carlo sequences generated from equivalent populations of suborns. The analysis was performed with different groupings of amino acids: on the basis of chemical similarities, side-chain volume and side-chain orientation in crystals. The results of the tests with chemical similarity groupings of residues give evidence of specific associations of amino acids in the proteins analyzed, but the basis of this association is unknown.
Neurochemical correlates of behavior: Levels of amino acids in four areas of the brain of the rat during drug-induced behavioral excitation

The levels of GABA, aspartate, glutamate, glycine and alanine were determined in 4 specific brain areas (telencephalon, diencephalon-mesencephalon, cerebellum and pons-medulla oblongata) of rats killed during a period of drug-induced behavioral excitation. Behavioral excitation was obtained in adult, male Wistar rats working on a Sidman shock-avoidance schedule following administration of 2 mg/kg tetrabenazine (TBZ) 18 hr after iproniazid (50 mg/kg) pretreatment. When compared to trained animals (working on the avoidance schedule but receiving no drugs), the excited rats had increased levels of GABA in the telencephalon and diencephalon-mesencephalon, decreased levels of aspartate in all 4 brain areas, and a lower content of glycine in the pons-medulla region. The changes in the levels of aspartate in all areas of the brain, GABA in the diencephalon-mesencephalon, and glycine in the pons-medulla were significantly correlated (p<0.01) with the degree of excitation. It was observed that avoidance training alone produced increases in the levels of four amino acids: aspartate in telencephalon and cerebellum, GABA in cerebellum, and glycine and glutamate in the pons-medulla. The injection of iproniazid alone or iproniazid followed by TBZ into naive animals had little effect on the levels of the five amino acids. The data are discussed in terms of aspartate and GABA interacting as neurotransmitters with cholinergic and catecholaminergic and/or serotonergic neurons to produce the behavioral excitation.
Site-selective electron transfer from purines to electrocatalysts: voltammetric detection of a biologically relevant deletion in hybridized DNA duplexes.

Background The one-electron oxidation of guanine nucleobases is of interest for understanding the mechanisms of mutagenesis, probing electron-transfer reactions in DNA, and developing sensing schemes for nucleic acids. The electron-transfer rates for oxidation of guanine by exogenous redox catalysts depend on the base paired to the guanine. An important goal in developing the mismatch sensitivity is to identify a means for monitoring the current resulting from electron transfer at a single base in the presence of native oligonucleotides that contain all four bases. Results The nucleobase 8-oxo-guanine (8G) is selectively oxidized by the redox catalyst Os(bpy) 3 3+/2+ (bpy = 2,2′-bipyridine) in the presence of native guanine. Cyclic voltammograms of Os(bpy) 3 + show current enhancements indicative of nucleobase oxidation upon addition of oligonucleotides that contain 8G, but not in the presence of native guanine. As expected, similar experiments with Ru(bpy) 3 + show enhancement with both guanine and 8G. The current enhancements for the 8G/Os(III) reaction increase in the order 8G-C ~ 8G·T Conclusions The base 8G can be effectively used in conjunction with a lowpotential redox catalyst as a probe for selective electron transfer at a single site. Because of the high selectivity for 8G, rate constants can be obtained that reflect the oxidation of only one base. The mismatch sensitivity can be used to detect biologically relevant abnormalities in DNA.
Glycogen synthase in the rat tapeworm, Hymenolepis diminuta—I. enzyme activity during development and with crowding

Abstract 1. 1. Activity of glycogen synthase (E.C. 2.4.1.11) in Hymenolepis diminuta (Cestoda: Cyclophyllidea) was investigated as a function of development and with crowding. 2. 2. Synthase activity was low in the anterior and posterior ends of the worms and highest in the pregravid proglottids in the mid-portion of the strobila. 3. 3. The enzyme activity increased during development of the cestode at least up to 15 days postinfection, but the increase in activity apparently was not due to conversion of the inactive to the active form. 4. 4. Mature oncospheres also contained glycogen synthase, but the activity was lower than in strobilar tissues. 5. 5. Synthase I activities and the proportion of total activity in the I form were generally higher in worms from high density (100 worm) infections than in those from low density (10 worm) infections.
Repair of a disconnected stent-graft limb facilitated by in situ fenestration.

PurposeTo describe the use of in situ fenestration to facilitate management of a disconnected iliac stent-graft limb that could not be repaired by conventional endovascular techniques.TechniqueAn 85-year-old man who had a Zenith endovascular graft deployed 3 years earlier for a 10-cm infrarenal abdominal aortic aneurysm presented with separation of the right iliac stent-graft limb from the main body, resulting in type III endoleak and sac enlargement. The disconnected limb occluded the ostium of the main stent-graft body, blocking all conventional endovascular techniques to traverse the graft limb–main body intersection. To overcome the problem, the cephalad portion of the proximal disconnected limb overlying the main body gate was successfully fenestrated with an endoscopic FNA needle and continuity restored with a Viabahn stent-graft across the balloon-modeled fenestration.ConclusionIn situ fenestration of endovascular stent-grafts may be a useful adjunct in performing rescues of late complications in p...
Experienced Teachers’ Strategies for Assessing Nature of Science Conceptions in the Elementary Classroom

This study explored the nature of science (NOS) assessments K-4 classroom teachers developed for measuring students’ understandings of NOS elements. We used the Views of Nature of Science Questionnaire-Form VNOS-D2 (Views of Nature of Science Elementary School Version 2) and interviews to verify that teachers’ conceptions of NOS were sufficient to enable them to teach and assess NOS. We collected copies of teachers’ action research designs, lesson plans, and assessment tools, conducted classroom observations and made field notes of their science instruction and assessments. We videotaped conversations at monthly workshops to note discussion surrounding teaching and assessing NOS in K-4 classrooms. We found that experienced teachers designed a variety of strategies for assessing NOS conceptions that differed by grade level.
HIV-1 Gp120 protein modulates corticotropin releasing factor synthesis and release via the stimulation of its mRNA from the rat hypothalamus in vitro: involvement of inducible nitric oxide synthase

In the present study, we examined whether the human immunodeficiency virus type I (HIV-I) gp120 coat protein can modulate corticotropin releasing factor (CRF) secretion by using the incubation of rat hypothalamic explants as an in vitro model. Treatment of the hypothalamic fragments with recombinant gp120 resulted in a time- and concentration-dependent increase in CRF release. The maximal dose of 10 nM gp120 increased CRF release by 56.4% after 1 h, and 78.4% after 3 h, as compared with their respective controls. The intra-hypothalamic amount of CRF was also increased by 54.7% and 77.3% vs. controls after 1 and 3 h, respectively. Moreover, the action of gp120 was blocked by pretreatment with cycloheximide, suggesting that the viral protein modulates CRF secretion via an increase in its synthesis. We also investigated the effects of gp120 on CRF gene expression. RNase protection analyses of total RNA isolated from the explants indicated that 10 nM gp120 significantly increases CRF mRNA in a time-dependent manner. Furthermore, gp120 did not modify CRF mRNA stability, suggesting that the viral protein modulates CRF gene expression at the transcriptional level. Analysis of the mechanisms that mediate gp120-induced CRF synthesis was conducted. The incubation of the explants with recombinant interleukin-1 (IL-1) type I receptor antagonist (hrIL-1 ra) did not antagonize the actions of gp120 at 1 and 3 h, indicating that the effect of the latter is independent of IL-1 mediated mechanisms. The involvement of some second messenger pathways was also investigated. Specific inhibitors of cAMP-PKA, cyclo-oxygenase or heme oxygenase pathways failed to antagonize the gp120-induced increase in CRF production. By contrast, incubation with nonselective inhibitors of nitric oxide synthase (NOS), L-NAME and L-NNA, or aminoguanidine (AG), a selective inhibitor of inducible NOS (iNOS), blocked CRF release and, AG, its mRNA accumulation, stimulated by gp120, whereas selective inhibitors of endothelial and neuronal NOS had no effect. In addition, only L-NAME, L-NNA and AG were able to inhibit the gp120-stimulated production of nitrites. These results indicate that gp120 directly stimulates CRF gene expression and peptide synthesis from the rat hypothalamus in vitro via the activation of iNOS. Therefore, the actions of this viral protein on the HPA axis may, in part, reflect its ability to modulate CRF synthesis.