cssi/SciSciGPT-SciSciNet huggingface dataset:
Neuropsychological assessment of African children: evidence for a universal brain/behavior omnibus within a coconstructivist paradigm.

Abstract Cross-cultural neuropsychology with African and American children provides evidence of consistent deficit patterns in attention, working memory, and learning in children at risk from disease affecting brain function by means of similar pathophysiologic mechanisms (e.g., cerebral malaria (CM) and sickle-cell disease (SCD); HIV in African and American children). These brain–behavior disease processes are also modified in a consistent manner cross-culturally by quality of developmental milieu and caregiving. We then present findings from the pioneering use of computerized cognitive rehabilitation therapy (CCRT) with Ugandan children surviving CM and with HIV. This neuropsychological evidence that CCRT enhances positive brain plasticity in a consistent manner across cultures supports the “coconstructive” paradigm (Li, 2003), since plasticity across the life span is the hallmark of this approach. Coconstructivism is a holistic multi-dimensional approach that emphasizes reciprocal biocultural influences across the life span. It also emphasizes the reciprocal interaction of culture and the genome in shaping brain/mind at multiple levels: neurobiological, cognitively, behavioral, and sociocultural (Li, 2003). Cross-cultural neuropsychology in healthy and diseased brains, brain imaging technologies, and genomic research can triangulate the manner in which a universal brain/behavior omnibus drives plasticity across the life span. As such, the further scientific characterization of the brain/behavior omnibus can provide the vital lynchpin between biology and culture in Li's coconstructive paradigm, revolutionizing our understanding of intelligence and culture.
Solving Markov Random Fields with Spectral Relaxation

Markov Random Fields (MRFs) are used in a large array of computer vision and maching learning applications. Finding the Maximum Aposteriori (MAP) solution of an MRF is in general intractable, and one has to resort to approximate solutions, such as Belief Propagation, Graph Cuts, or more recently, approaches based on quadratic programming. We propose a novel type of approximation, Spectral relaxation to Quadratic Programming (SQP). We show our method offers tighter bounds than recently published work, while at the same time being computationally efficient. We compare our method to other algorithms on random MRFs in various settings.
The effect of placental chorionicity on estimated fetal weight discordancy in twin gestations

551 THE EFFECT OF PLACENTAL CHORIONICITY ON ESTIMATED FETAL WEIGHT DISCORDANCY IN TWIN GESTATIONS LAMI YEO, CANDE ANANTH, MARTIN CHAVEZ, JOHN SMULIAN, ANTHONY VINTZILEOS, UMDNJ-RobertWood JohnsonMedical School/RobertWood JohnsonUniversityHospital, Obstetrics, Gynecology and Reproductive Sciences, New Brunswick, New Jersey OBJECTIVE: To determine the effect of placental chorionicity on estimated fetal weight (EFW) discordancy in twin gestations. STUDY DESIGN: Over the last 9 years, all twin gestations with EFW assessment performed from 12-38 weeks were retrospectively identified. Chorionicity was determined at the initial sonographic exam. Gestational age-specific differences in EFW discordancy between dichorionic/diamniotic (DD) and monochorionic/diamniotic (MD) twins was determined, and are expressed as percent of discordancy per week in gestation. EFW discordancy for each set of twins was defined as (large twin-small twin)/large twin. RESULTS: There were 1,429 twin gestations (1,163 DD and 266 MD fetuses). Starting at 18 weeks, the percent EFW discordancy between DD and MD twins becomes statistically significant (P!0.05) (Figure). For DD twins, at R28 weeks, the percent EFW discordancy begins to increase at an accelerated rate and continues to increase with advancing gestational age. On the other hand, for MD twins, at R22 weeks, the percent EFW discordancy begins to increase at an accelerated rate; however, at R32 weeks, it decreases. The ‘‘traditional 20%’’ EFW discordancy is not seen in MD twins until after 25 weeks, and not seen in DD twins until after 30 weeks.
In vitro characterization of leukocyte mimetic for targeting therapeutics to the endothelium using two receptors.

Abstract Selectins (E- and P-selectin) and other endothelial expressed leukocyte adhesion molecules (ELAMs) are potential targets for site-specific delivery of therapeutics to the vascular endothelium due to their specific and highly regulated expression in vascular disease. It was recently shown that degradable microspheres coated with antibodies against E-selectin or other ELAMs can target inflammation in vivo. However, targeting ELAMs alone cannot differentiate between normal and diseased state, as a basal level of these LAMs are expressed on endothelium in healthy tissues. Furthermore, leukocytes usually employ two separate adhesion molecules in parallel to home to diseased tissues, and we recently quantified the advantages of a two-receptor display for the targeting of leukocyte mimetics (Eniola AO, Willcox PJ, Hammer DA. Interplay between rolling and firm adhesion elucidated with a cell-free system engineered with two distinct receptor–ligand pairs. Biophys J 2003;85:2720–31). Here, we describe a leukocyte mimetic for targeting therapeutics to the vasculature in inflammatory diseases via two receptors, selectin and intercellular cell adhesion molecule-1 (ICAM-1), where biodegradable, polymer microspheres were co-functionalized with the selectin ligand, sialyl Lewis X (sLe X ), and an antibody against ICAM-1, anti-ICAM-1 (aICAM-1). These two-receptor targeted particles, at given ratios of sLe X /aICAM-1, firmly adhere to substrate surface in flow only when both targeting ligands can interact with their respective receptors, mimicking the multi-step in vivo leukocyte adhesion in inflammation. Thus, we have faithfully recreated the specificity and extent of leukocyte adhesion in a platform that can allow for local delivery of therapeutics.
Spatial Characterization of Water Quality in Seven Eastern Kentucky Reservoirs Using Multivariate Analyses

We conducted water quality surveys along seven eastern Kentucky reservoirs three times during the 1994 growing season in order to understand the spatial variability within and between impoundments from a common geological setting. Sixteen parameters were measured at sites along the reservoirs representing each zone (riverine, transition, or lacustrine), and eight of these parameters displayed a statistically significant site/zone effect. Most of these were particle-associated parameters (total Fe, NH 4 + , total suspended solids, and total phosphorus) that decreased significantly down-reservoir. Water transparency increased significantly down-reservoir, in accordance with this pattern. Temperature and dissolved oxygen also showed a significant spatial effect, as temperature was highest towards the riverine end and dissolved oxygen was highest at the lacustrine end. Six parameters showed significant variability among these reservoirs, including ammonium and chlorophyll a . The remaining four (conductivity,...
Effects of major-road vehicle speed and driver age and gender on left-turn gap acceptance

Because the driver's gap-acceptance maneuver is a complex and risky driving behavior, it is a highly concerned topic for traffic safety and operation. Previous studies have mainly focused on the driver's gap acceptance decision itself but did not pay attention to the maneuver process and driving behaviors. Using a driving simulator experiment for left-turn gap acceptance at a stop-controlled intersection, this study evaluated the effects of major traffic speed and driver age and gender on gap acceptance behaviors. The experiment results illustrate relationships among drivers' left-turn gap decision, driver's acceleration rate, steering action, and the influence of the gap-acceptance maneuver on the vehicles in the major traffic stream. The experiment results identified an association between high crash risk and high traffic speed at stop-controlled intersections. The older drivers, especially older female drivers, displayed a conservative driving attitude as a compensation for reduced driving ability, but also showed to be the most vulnerable group for the relatively complex driving maneuvers.
What You Think You Know Can Hurt You: Perceptual Biases About HIV Risk in Intimate Relationships

The use of heuristic biases and the false consensus effect can lead individuals to misperceive risk of HIV infection. The current paper presents the results of two studies which sought to examine whether individuals, (a) weigh risk relevant information accurately in their assessments of HIV risk, and (b) are susceptible to the false consensus effect in their assessments of actual intimate partner risk behaviors. The results of the first study support the hypothesis that individuals do not use objective risk information based on probability statistics in their assessments of HIV risk. In addition, the results of the second study find that female partners exhibit the false consensus effect regarding sexual risk behaviors, whereas male partners did not. Discussion centers on the role of perceptual biases in HIV risk behaviors among individuals in intimate relationships.
Tracheal and Airway Neoplasms

Neoplasms of the trachea are uncommon, accounting for only 0.2% of all respiratory malignancies in the United States. 1 The incidence of primary tracheal cancer is estimated to be 1 in every 1,000,000 persons per year. Cancers of the bronchi occur approximately 400 times more frequently than tracheal cancer. The majority, 90%, of tracheal tumors in adults are malignant with squamous cell carcinoma (SCC) and adenoid cystic carcinoma (ACC) being the most common. Most of the airway tumors in children are benign. 2,3 Given the rarity of these neoplasms and their nonspecific clinical presentations, the diagnosis is often delayed by months or even years. Increased awareness and detection of airway neoplasms by radiologists is, therefore, of paramount importance in the care of these patients.
High power femtosecond laser system for intracavity high harmonic generation

We report on a high power (>6.5 Watts) Ti:sapphire based frequency comb producing ∼25 µJ pulses at 50MHz inside a fs enhancement cavity. The system is used to generate intracavity high harmonics below 62 nm.
Cultural narratives in TESOL classrooms: a collaborative reflective team analysis

Due to increasing globalization and immigration, there has been an increase in the culturally and linguistically diverse student population in the public school system. Educating teacher candidates to become culturally aware, sensitive and competent in order to meet the needs of this diverse population has been a concern of teacher education programs. The purpose of this study was to explore the potential usefulness of cultural narratives in teacher education classrooms and determine how they could be used as an instructional strategy to positively influence the pre- and in-service teachers’ growing knowledge and application of teaching culturally and linguistically diverse students with the views of the three TESOL (Teaching English to Speakers of Other Languages) teacher educators. Using the collaborative narrative inquiry, three TESOL educators, who are from linguistically, racially and culturally different backgrounds, academic settings and locations, analyzed the personal cultural narratives of one T...
Prediction of extraprostatic extension in the neurovascular bundle based on prostate needle biopsy pathology, serum prostate specific antigen and digital rectal examination.

ABSTRACT Purpose: There are few studies on predictors of extraprostatic extension (EPE) in the region of the neurovascular bundle (NVB). We investigated whether clinical information and prostate biopsy data could predict EPE of clinical localized prostate cancer. Materials and Methods: Through a retrospective analysis of the pathology database we identified 2,660 cases of clinically localized prostate cancer treated with radical retropubic prostatectomy without preoperative adjuvant therapy at The Johns Hopkins Hospital. The study sample involved a total of 3,006 lobes with prostate cancer including 2,070 with organ confined disease, 620 with EPE in the NVB at the posterolateral edge of the prostate and 316 with EPE in a region other than the NVB (EPE elsewhere). Through univariate and multivariate logistic regression analysis we determined whether patient age, year of surgery, serum prostate specific antigen, digital rectal examination, biopsy highest Gleason score, perineural invasion, percent of side specific biopsy cores with cancer, percent of each core involved with cancer and the maximum percent of a core involved with cancer was predictive of EPE in the NVB. Results: Prostate specific antigen (10 or greater vs less than 10), biopsy Gleason score (7 or greater vs 6 or less), digital rectal examination (abnormal vs normal), percent of side specific cores with tumor (greater than 33.3% vs 33.3% or less) and average percent involvement of each positive core (greater than 20% vs 20% or less) were all found to be statistically significant independent predictors of NVB penetration in multivariate analysis. The generated model stratifies each of these variables into high and low risk. The probability of EPE in the NVB was less than 10% in cases with 1 or fewer of the higher risk variables and was 10% or greater in cases with more than 1 of the higher risk variables. Conclusions: The model generated in this study allows for the preoperative identification of patients with 10% or greater probability of EPE in the NVB. Our algorithm will help provide objective parameters that aid in the decision to spare the NVB safely.
On Locally Adaptive Density Estimation

Abstract Theoretical and practical aspects of the sample-point adaptive positive kernel density estimator are examined. A closed-form expression for the mean integrated squared error is obtained through the device of preprocessing the data by binning. With this expression, the exact behavior of the optimally adaptive smoothing parameter function is studied for the first time. The approach differs from most earlier techniques in that bias of the adaptive estimator remains O(h 2) and is not “improved” to the rate O(h 4). A practical algorithm is constructed using a modification of least squares cross-validation. Simulated and real examples are presented, including comparisons with a fixed bandwidth estimator and a fully automatic version of Abramson's adaptive estimator. The results are very promising.
On the Mechanism of Pd(O) Catalyzed Formation of Oxazolidin-2-ones from Vinyl Epoxides

Abstract The reaction of vinyl epoxides with isocyanates proceeded with overall retention of configuration.
Enhanced neutrophil function in children on bromide therapy.

The final step in neutrophil bacterial killing is formation of a toxic halide complex. For this reason, we studied neutrophil function in children receiving bromide anticonvulsant therapy. Whole blood and serum were obtained from 7 patients with seizure disorders treated orally with triple bromide elixir to examine neutrophil function as measured by lu- minol enhanced chemiluminescence (CL). Serum bromide concentrations [Br−] were determined concomitantly. There was a direct correlation between [Br−] and CL activity of neutrophils (r = 0.87) with peak CL responses significantly higher than controls when [Br−] were in the therapeutic range (10–20 mM). With [Br−] above 25 mM, CL activity was reduced. Serum from patients also enhanced CL of control neutrophils with a similar relationship to measured [Br−]. To confirm that enhanced neutrophil activity was attributable to [Br−] use, [Br−] ranging from 0–50 mM were added to control neutrophils in otherwise normal physiologic conditions and the CL assay was performed. Results expressed as percent of control values were as follows: [Br−] 5 mM, 110%; 10 mM, 158%.; 15 mM, 194%.; 20 mM, 252%; 25 mM, 136%.; 30 mM, 364%.; and 50 mM, 205%>. These data demonstrate that Br− enhances phagocytic and bactericidal activity of neutrophils and suggest that Br− therapy may augment host defense capabilities.
Intensive care after fresh water immersion accidents in children.

Six children who remained in deep coma after immersion accidents in fresh water received therapy to maintain normal intracranial pressure (ICP). This involved controlled ventilation to ensure hypocapnia and hyperoxaemia, maintenance of low normothermia, fluid restriction, dexamethasone (1-1.5 mg/kg initially, 1-1.5 mg/kg/day as maintenance) and barbiturates (phenobarbitone and thiopentone). The latter were given in a wide range of dosage. Increased ICP was common to all patients, but could always be kept at acceptable levels. All patients suffered from pulmonary oedema; three developed broncho-pneumonia and two developed adult respiratory distress syndrome. All children survived with good recovery, two needed active rehabilitation for several months. Language: en
Time reversal symmetry or the reciprocity theorem in low-energy electron diffraction

Abstract Two letters on the subject of the title have appeared recently with experimental evidence. It is noted that similar evidence for this effect was first presented in 1936. These results are reproduced here.
P2P M-commerce in pervasive environments

Pervasive environments are characterized by the presence of wireless devices ranging from sensors to mobile PDA-phones to laptops. Peer-to-Peer (P2P) information sharing in such environments presents a tremendous opportunity for people and devices to exchange information such as music, pictures, documents and stock tickers with peers. Information that has a monetary value introduces a whole new set of problems for P2P interaction in pervasive environments. In this work, we present the design of a middleware that attempts to solve these problems using concepts of the Contract Net Protocol, Semantic Service Discovery and secure transaction protocols.
Wavelets and wave propagation modeling

This paper discusses several current attempts to use acoustic and electromagnetic wave propagation for modeling physical phenomena and the role that wavelet analysis is playing in these efforts. The first problem involves geophysical modeling of the ocean floor using acoustic waves, and wavelets have recently been shown to play an important role. The second problem involves modeling of SAR radar images in the context of automatic target recognition efforts. The third problem is global illumination in computer graphics, i.e., simulation of reflected and absorbed light for everyday environments. The role of wavelets is more embryonic in these latter two areas, but there are some common principles in all of these modeling efforts, and the methodology of wavelets seems well suited to certain aspects of these problems.
Catalytic antibody model and mutagenesis implicate arginine in transition-state stabilization

To probe the mechanism of the catalytic antibody NPN43C9, we have constructed a three-dimensional model of the NPN43C9 variable region using our antibody structural database (ASD), which takes maximal advantage of immunoglobulin sequence and structural information. The ASD contains separately superimposed variable light and variable heavy chains, which reveal not only conserved backbone structure, but also structurally conserved side-chain conformations. The NPN43C9 model revealed that the guanidinium group of light chain Arg L96 was positioned at the bottom of the antigen-binding site and formed a salt bridge with the antigen's phosphonamidate group, which mimics the negatively charged, tetrahedral transition states in the hydrolysis reaction. Thus, the model predicts both binding and catalytic functions for Arg L96, which previously had not been implicated in either. First, Arg L96 should enhance antigen binding by electrostatically complementing the negative charge of the antigen, which is buried upon complex formation. Second, Arg L96 should promote catalysis by electrostatically stabilizing the negatively charged transition states formed during catalysis. These hypotheses were tested experimentally by design and characterization of the R-L96-Q mutant, in which Arg L96 was replaced with Gln by site-directed mutagenesis. As predicted, antigen binding in the R-L96-Q mutant was decreased relative to that in the parent NPN43C9 antibody, but binding of antigen fragments lacking the phosphonamidate group was retained. In addition, the R-L96-Q mutant had no detectable esterase activity. Thus, the computational model and experimental results together suggest a mechanism by which the catalytic antibody NPN43C9 stabilizes high-energy transition states during catalysis.
The virus-specific RNA species in free and membrane-bound polyribosomes of transformed cells replicating murine sarcoma-leukemia viruses.

Abstract Ribonucleic acids extracted from polyribosomes of cells replicating murine sarcoma-leukemia viruses (M-MSV(MLV)) were resolved by electrophoresis on 2.5% polyacrylamide gels. Virus-specific RNA was detected by hybridization of RNA in the gel fractions with the 3H-DNA product of the viral RNA-directed DNA polymerase. The postmicrosomal supernatant and the free polyribosomes contained one peak of virus-specific RNA with a molecular weight of about 2.9 × 106 (35S). In contrast, the microsomes and the membrane-bound polyribosomes contained two peaks of virus-specific RNA in approximately equal amounts with molecular weights of 2.9 × 106 (35S) and 1.5 × 106 (approximately 20S). The high molecular weight viral RNA species might serve as polycistronic mRNA for the synthesis of large polypeptides that are cleaved to form the smaller viral proteins.
Trends in triplet excitation delocalization in highly conjugated (porphinato)zinc(II) arrays probed by EPR spectroscopy

Abstract The lowest photoexcited metastable triplet state of a family of highly conjugated (porphinato)zinc(II) arrays in which ethyne, butadiyne, and octatetrayne units bridge the macrocycle carbon frameworks were studied by EPR spectroscopy at low temperature in solution. One series of meso -to- meso ethyne -bridged (porphinato)zinc(II) structures probes how the length of the conjugated bridge separating two (porphinato)zinc(II) units effects the nature of the triplet excited state, while a second set of compounds assesses the impact that oligomer size has upon triplet state spin distribution and orientation. Although the magnitude of the EPR | D | values decrease with increasing number of porphyrin units, the data do not suggest that the lowest triplet excitation extends beyond a single porphyrin unit. With augmented conjugation, these systems show a progressive oblate-to-prolate spin distribution transition that causes the direction of largest dipolar interaction to align along a vector defined by the highly conjugated axes of these molecules. Temperature EPR line shape studies of these Zn porphyrin arrays reveal that (1) the triplet spectrum evinces no changes up to 100 K, indicating the absence of Jahn–Teller-induced dynamics, and (2) the EPR spectra of the triplet states for all dimers, trimers, and pentamers exhibit electron spin polarization up to temperatures surpassing 100 K, suggesting spin lattice relaxation times that do not decrease significantly with temperature.
Probing the accuracy of the isomerization energy of the 3-D morphed potential of Ar–HBr

Abstract Investigations of the lowest Σ-bending vibrations of Ar–DBr ( v = 0) and Ar–HBr ( v = 1) are reported using a co-axially configured submillimeter supersonic jet spectrometer. The v = 1 spectra were obtained using glow discharge excitation. Analyses of hyperfine substructure in these spectra provide accurate molecular parameters for Ar–DBr and Ar–BrD isomeric states, direct determination of their corresponding isomerization energies, and respective parameters in the v = 1 HBr stretching vibration of the Ar–HBr isotopomer. This experimental data provides a sensitive probe of the relative energies of potential minima for previously determined 3-D Ar–HBr morphed potential and compared with results from extrapolations to the CCSD(T)/CBS limit.
A case study of excessive subtropical transport in the stratosphere of a data assimilation system

[1] Assessments of transport show that results derived from assimilated (or analyzed) winds exhibit significantly larger mixing and entrainment rates compared to those derived from general circulation model (GCM) winds, where the GCM transport is somewhat closer (statistically) to values inferred from observations. This discrepancy presents a challenge to our ability to understand and model the global distributions of long-lived trace gases. We use the Goddard Earth Observation System's Finite Volume Data Assimilation System to explore this issue by examining how the data assimilation process alters the dynamics of the underlying GCM and how this leads to greater lower stratospheric mixing and transport in the subtropics. We show that the excessive subtropical transport is related to the proliferation of eddy features in the subtropics, and we examine various possibilities that may cause this. These include the generation of upward propagating features, equatorward propagating features, and meridionally confined features in the process of data assimilation. In particular, it is argued that unstable regions forced directly by the analysis increments play an important role in generating the excess subtropical transport.
A Syndrome of Methylmalonic Aciduria, Homocystinuria, Megaloblastic Anemia and Neurologic Abnormalities in a Vitamin B12-Deficient Breast-Fed Infant of a Strict Vegetarian

We studied a six-month-old infant with severe megaloblastic anemia, coma and hyperpigmentation of the extremities. He was found to have methylmalonic aciduria (79 mumol per milligram of creatinine) and homocystinuria (0.85 mumol per milligram of creatinine). Additional biochemical abnormalities included cystathioninuria, glycinuria, methylcitric aciduria, 3-hydroxypropionic aciduria and formic aciduria. The concentration of vitamin B12 in the serum was 20 pg per milliliter. This severe nutritional deficiency was a consequence of inadequate intake, for the infant was exclusively breast-fed by a strictly vegetarian mother who manifested methylmalonic aciduria. Our observations emphasize the importance of educating strict vegetarians about the deficiency of vitamin B12 in their diets and the importance of vitamin B12 supplementation.
An ab initio molecular orbital study of the reduction of carbonyls by alkylaluminum complexes

Semi-empirical and ab initio MO methods were used to explore mechanisms for the reduction of carbonyls by alkylaluminum reagents. Two distinct pathways have been observed experimentally, depending on the stoichiometric amounts of the reagents present. The corresponding intermediates and transition structures have been characterized. Alkylaluminum alkoxides are generally less reactive than the analogous alkylaluminum complexes. We suggest that the controlling factor here is not binding of the substrate, but the higher barrier to reaction of the alkoxide.
Multitemporal spectroradiometry-guided object-oriented classification of salt marsh vegetation

ABSTRACT This study addresses the use of multitemporal field spectral data, satellite imagery, and LiDAR top of canopy data to classify and map common salt marsh plant communities. Visible to near-infrared (VNIR) reflectance spectra were measured in the field to assess the phenological variability of the dominant species i Spartina patens, Phragmites australis and Typha spp. The field spectra and single date LiDAR canopy height data were used to define an object-oriented classification methodology for the plant communities in multitemporal QuickBird imagery. The classification was validated using an extensive field inventory of marsh species. Overall classification accuracies were 97% for Phragmites , 63% for Typha spp. and 80% for S. patens meadows. Using a fuzzy assessment analysis, these accuracies were 97%, 76%, and 92%, respectiv ely, for the three major species. Keywords: salt marsh; vegetation monitoring; image classification; Phragmites australis; QuickBird; LiDAR; spectroradiometer, image se gmentation, Connecticut
Workshop report: Evolutionary life history analysis of human behavior

On 21 May 1983 a workshop was held at the University of California at Los Angeles on the application of evolutionary life history models to the study of human behavior. There were 24 attendees, representing primarily the academic disciplines of anthropology, biology. and psychology. The major purpose of this workshop was to discuss the applicability of evolutionary life history models to the study of human reproduction and development, with a major emphasis on developing research methodology. There were nine presentations. [Abstracts of the papers presented at the workshop have been published previously in the HI/~~c~H Etholog\ Nm.s/rttcr. (vol. 3. no. IO: 1983). and are available from the authors upon request.] In his introductory comments. Konald Weigel addressed
Design and optimization of polymer electrolyte membrane (PEM) fuel cells

The performance of polymer electrolyte membrane (PEM) fuel cells is studied using a single-phase two-dimensional electrochemical model. The model is coupled with a nonlinear constrained optimization algorithm to determine an optimum design of the fuel cell with respect to the operation and the geometrical parameters of cathode such as the air inlet pressure, the cathode thickness and length and the width of shoulders in the interdigitated air distributor. In addition, the robustness of the optimum design of the fuel cell with respect to uncertainties in several electrochemical reaction and species transport parameters (e.g., gas diffusivity, agglomerate particle size, etc.) is tested using a statistical sensitivity analysis. The results of the optimization analysis show that higher current densities at a constant cell voltage are obtained as the inlet air pressure and the fraction of the cathode length associated with a shoulder of the interdigitated air distributor are increased, and as the cathode thickness and the length of the cathode per one interdigitated gas distributor shoulder are decreased. The statistical sensitivity analysis results, on the other hand, show that the equilibrium cathode/membrane potential difference has the largest effect on the predicted polarization curve of the fuel cell. However, the optimal design of the cathode side of the fuel cell is found not to be affected by the uncertainties in the model parameters such as the equilibrium cathode/membrane potential difference. The results obtained are rationalized in terms of the effect of the fuel-cell design on the air flow fields and the competition between the rates of species transport to and from the cathode active layer and the kinetics of the oxygen reduction half-reaction.
Multi-scale reinforcement of CFRPs using carbon nanofibers

In this paper, stacked-cup carbon nanofibers (CNF) were dispersed in the matrix phase of carbon-fiber-reinforced composites based on a high-performance epoxy system with and without modification by an elastomeric triblock copolymer (TCP) for increased toughness. The addition of the TCP provided an enhancement in toughness at the cost of a slight degradation in modulus and strength. The CNFs, on the other hand, provided significantly enhanced strength and stiffness in matrix-dominated configurations, including tension of quasi-isotropic composites and short beam shear strength of both quasi-isotropic and unidirectional composites. Scanning electron microscopy revealed enhanced adhesion between the matrix and carbon fibers with the addition of either TCP or CNFs. However, CNF agglomeration in the studied systems partially offset the energy dissipation processes brought about by the nanofibers, thereby limiting interlaminar fracture toughness enhancements by CNF addition. These results show good promise for CNFs as low-cost reinforcement for composites while offering insight into the codependent morphologies of multi-scale phases and their influence over bulk properties.
Appendicitis over forty

Charts of 616 patients over the age of 40 presenting to a community hospital emergency department with lower abdominal pain were reviewed to estimate the incidence and establish the profile of appendicitis in older patients. Appendicitis remains the commonest cause of undiagnosed lower abdominal pain, and retains a common presentation at all ages. Much of the pre-operative delay in patients who perforated appendices occurred in the hospital. Barium enema was a useful and safe diagnostic procedure used in 22 cases.
Orolaryngeal Reflex Responses to Changes in Affective State

Previous research has shown that the eye-blink startle reflex can be modulated by changes in affective state. The purpose of the present study was to determine whether human perioral and trigemino-...
Double inversion black-blood fast spin-echo imaging of the human heart: a comparison between 1.5T and 3.0T.

Purpose To evaluate the effectiveness of blood suppression and the quality of black-blood cardiac images acquired at 3.0 Tesla using a double-inversion recovery fast spin-echo sequence by comparing data acquired at 3.0T to data acquired at 1.5T. Materials and Methods Black-blood T2-weighted fast spin-echo images of the heart were acquired from five normal volunteers at 1.5T and five normal volunteers at 3.0T. Region-of-interest signal intensity measurements were performed at several locations in the suppressed blood regions of the left and right ventricles and around the left ventricle walls to assess the effectiveness and uniformity of the blood suppression, the myocardial signal-to-noise ratio (SNR), and the signal uniformity at both field strengths. B1 field maps were produced in phantoms and in subjects at both field strengths. Results Blood suppression performance is equivalent at 1.5T and 3.0T. The improvement in SNR at 3.0T compared with 1.5T is less than has been predicted in previous studies. The signal uniformity is significantly poorer at 3.0T than at 1.5T due to dielectric effects and shorter radio frequency wavelengths (P < 0.005). Conclusion Spin-echo and spin-echo echo-train sequences that perform well at 1.5T will produce large signal variations in the chest cavity at 3.0T without modifications. B1 insensitive methods must be explored and implemented for spin-echo sequences to fully realize the advantages of using these sequences for high-field MRI. J. Magn. Reson. Imaging 2003;17:648–655. © 2003 Wiley-Liss, Inc.
Theory of collision effects on atomic and molecular line shapes

A review of recent developments in the theory of the effects of binary collisions on the spectral profiles associated with atomic and molecular systems is presented. To consistently account for collisional perturbations of both the internal energy levels and the velocity of active (emitting or absorbing) atoms or molecules, one must use a theory in which the center-of-mass motion of the active atoms has been quantized. Following this procedure general equations for absorption or emission line shapes are obtained. The line shapes may exhibit narrowing or broadening with increasing perturber pressure, depending upon the nature of the collision interaction. The physical significance of the collision mechanisms giving rise to such behavior is discussed, as is the experimental evidence in support of the theory. Various applications of the theory are presented.
Some aspects of viscous stress relaxation and intraplate seismicity

Abstract Considerable evidence suggests that the lithosphere has a Maxwellian rheology with an effective viscosity of 1026 poise or less. In a Maxwellian lithosphere viscous stress dissipation limits the maximum attainable stresses (due to mechanisms providing a constant stress buildup) to a value σmax given by the product of stress buildup rate ( C ) and viscous relaxation time τ : σ max = C · τ where τ is the ratio of viscosity to rigidity. The effectiveness of several intraplate stress building mechanisms in a Maxwellian lithosphere was analysed with the following results: 1. (1) The maximum stress produced by the latitudinal drift of lithospheric plates is 27 bars or less 2. (2) The maximum stress produced by the cooling of uplifted, eroded regions is 90 bars or less 3. (3) Lithospheric flexure due to isostatic rebound causes maximum stresses of 68 bars or less for the Appalachian rebound and approximately 150 bars for the Laurentide rebound. It is concluded that none of the mechanisms considered are likely to cause earthquakes if the mechanical strength of the lithosphere is on the order of 1 kb. If the strength of the lithosphere is on the order of 100 bars, then intraplate earthquakes may result from the Laurentide deglaciation as well as from the cooling of uplifted, eroded regions; but if the lithospheric viscosity is on the order of 1025 poise, then only the Laurentide deglaciation may produce adequate stresses. The fact that a stress buildup rate of 74 bars/ 200 yrs along the San Andreas fault generates earthquakes requires a minimum lithospheric viscosity on the order of 1022 poise.
Conformational Change Induced In A Random Coil Peptide By Prion Peptide Aggregates

The in vivo aggregation of many different polypeptides into β-sheet-rich amyloid fibers is associated with a range of diseases. The mechanism of aggregation for many of these proteins is still unknown; small polypeptides are useful models for exploring this process by both physical and computational methods. H1, a peptide derived from residues 109-122 of the Syrian hamster prion peptide (Ac-MKHMAGAAAAGAVV-NH2) forms antiparallel β-sheet aggregates in solution. As determined by isotope-edited infrared (IR) spectroscopy, the H1 β-sheets have three overhanging residues at the N-terminus, with residue 117 aligned in all strands (1). The A117G mutant, however, exists nearly entirely as monomer as a result of backbone flexibility and the inability to align across residue 117 (2). In this study, the results of mixing wild-type H1 and A117G were monitored by Fourier Transform infrared spectroscopy (FTIR). Regardless of their relative concentrations, combining H1 and A117G resulted in the spontaneous, irreversible conversion of A117G from its unordered form to β-sheet by a mechanism in which the H1 peptides are proposed to serve as a nucleating template. Isotope-edited IR studies suggest that the β-sheet formed after mixing H1 and A117G is composed of alternating strands from each peptide variant. This process occurs spontaneously over time, and its rate is accelerated with increasing temperature. This work suggests a model for the templating of an unordered polypeptide into a β-sheet fibril.(1) Silva, R.A.G.D., W. Barber-Armstrong and Decatur, S.M. (2003) J. Am. Chem. Soc. 125: 13674.(2) Petty, S.A., Adalsteinsson, T., and Decatur, S.M. (2005) Biochemistry 44: 4720.
Electronic and Nuclear Magnetic Relaxation in Crystals with Fluorite Structure Containing Eu 2 + or Mn 2 +

The spin-lattice relaxation time ${T}_{1}$ was measured for ${\mathrm{Eu}}^{2+}$ in Ba${\mathrm{F}}_{2}$ and for ${\mathrm{Mn}}^{2+}$ in Ba${\mathrm{F}}_{2}$ and Sr${\mathrm{F}}_{2}$ at about 9 GHz. The nuclear relaxation time of the ${\mathrm{F}}^{19}$ nucleus was also measured at 29 MHz at temperatures below 77\ifmmode^\circ\else\textdegree\fi{}K. Each impurity ion shows a one-phonon relaxation with ${T}_{1}\ensuremath{\propto}{T}^{\ensuremath{-}1}$ in the liquid-helium region, and a Raman relaxation with ${T}_{1}\ensuremath{\propto}{T}^{\ensuremath{-}5}$ at higher temperatures. In the Raman region, the matrix element of the dynamic crystalline field for ${\mathrm{Eu}}^{2+}$ in Ba${\mathrm{F}}_{2}$ is smaller than for ${\mathrm{Eu}}^{2+}$ in Ca${\mathrm{F}}_{2}$, in accordance with simple crystal-field theory. The opposite effect is observed for the case of the smaller ${\mathrm{Mn}}^{2+}$ ion; the matrix element decreases as the host lattice size decreases. A minimum in the ${T}_{1}$ vs $T$ curve for the ${\mathrm{F}}^{19}$ nucleus occurs near 30\ifmmode^\circ\else\textdegree\fi{}K for Ba${\mathrm{F}}_{2}$ containing ${\mathrm{Mn}}^{2+}$ and near 50\ifmmode^\circ\else\textdegree\fi{}K for Sr${\mathrm{F}}_{2}$ containing ${\mathrm{Mn}}^{2+}$, in approximate agreement with theory. For temperatures below the minima, the relaxation rate is attributed predominantly to the effect of ${\mathrm{Mn}}^{2+}$ pairs or clusters and to iron, which was found by spectroscopic analysis.
A new paradigm for implementing ecologically - based participatory IPM in a global context: the IPM CRSP model

Integrated Pest Management (IPM) is a key component in the development of sustainable agro ecosystems. The Integrated Pest Management Collaborative Research Support Program (IPM CRSP) is a USAID funded project that is a consortium of U.S. universities working with host country national programs and other stakeholders to promote IPM globally. The IPM CRSP model is based on a Participatory Integrated Pest Management (PIPM) process that has as its goals to help reduce: agricultural losses due to pests, damage to natural eco-systems including loss of biodiversity, and pollution and contamination of food and water supplies. The IPM CRSP participatory model is based on networking, institution building, private sector interaction, research-technology development and technology transfer. The new IPM CRSP beginning in 2005 will build on the experience of the previous IPM CRSP (1992-2004). The technical approach of the New IPM CRSP is to implement an ecologically-based, participatory IPM (EP-IPM) program with a carefully-conceived strategy for local, national, regional, and global diffusion of IPM capacity and knowledge. Broad participation and communication are critical components of the strategy, along with a competitive process and a management plan designed to ensure high quality research and accountability. The approach is based on a competitive process open to U.S. universities who are expected to partner with host country national programs and other stakeholders in the development of Regional IPM Centers and on five Global IPM Themes including invasive species, insect transmitted viruses, regional diagnostic laboratories, information technologies and databases, and impact assessment.
The mechanics of phase transformations

Abstract We outline a program to phase transformations by utilizing only the traditional concepts of mechanics together with the new notion of “normal” and “excited” atoms. The meaning of phase transformations is used here in a broad sense to cover phenomena ranging from liquid-vapor transitions and spinodal decomposition to the formation of slip and shear bands, plastic zones and necks, liquid crystal transitions, damage localization, and crack nucleation. In principle, all these phenomena are interpreted within the same theoretical framework by identifying the “excited” atoms and their motion with the predominant microstructure which is responsible for the transformation. For simplicity, we present the basic ideas in one dimension and assess only qualitatively the appropriateness of the model. Roughly speaking, transformations are occurences of a certain instability in the variables defining the body before the transformation. In our approach we retain the same variables but we introduce non-local interactions, usually in the form of gradients, in order to stabilize the behavior and trace the evolution of the system during the transformation.
Effect of Long Term Treatment with Calcitriol on Calcium Absorption and Mineral Metabolism in Postmenopausal Osteoporosis

The mechanism of impaired calcium absorption in postmenopausal osteoporosis is controversial. If it is caused by calcitriol deficiency, it should be corrected by long term administration of physiological doses of this metabolite, whereas if it is caused by either a primary defect in calcium absorption or intestinal resistance to calcitriol action, it should not be. In 56 osteoporotic women, mean (+/- SE) fractional calcium absorption (0.52 +/- 0.02) was lower (P less than 0.001) than that in 20 age-matched normal women (0.61 +/- 0.02). Treatment with calcitriol (0.5-0.75 micrograms/day) increased calcium absorption after 6-12 months to 0.67 +/- 0.02 (P less than 0.001) and, in 29 patients, to 0.66 +/- 0.02 (P less than 0.001) after 24 months. After treatment, only 1 patient still had subnormal calcium absorption. In 26 patients treated with placebo for 6-12 months, there was no significant change in calcium absorption. For all studies, total calcium absorption (fractional absorption X estimated dietary intake) correlated directly with urinary calcium excretion (r = 0.61; P less than 0.001). Urinary hydroxyproline excretion, an index of bone resorption, was 31.0 +/- 1.5 mg/dl glomerular filtration rate (GFR) initially and decreased during treatment to 24.6 +/- 1.1 mg/dl GFR (P less than 0.001) after 6-12 months and to 27.9 +/- 1.3 mg/dl GFR (P less than 0.01) after 24 months. The finding that calcium absorption can be normalized by small doses of calcitriol supports the hypothesis that insufficient endogenous production of calcitriol is the major cause of decreased calcium absorption in postmenopausal osteoporosis.
A Child-Centered Approach to High-Conflict and Domestic-Violence Families: Differential Assessment and Interventions

This paper discusses the extent of violence in high-conflict litigating families, differentiating between abusive relationships and high-conflict divorce, and describing the numerous ways that parenting is deficient and compromised. Guidelines for making access plans that minimise adverse effects on children, restrains further abuse, and protects parents who have been victimised is followed by a discussion of the specialised services needed, and the challenges in coordinating the efforts of family court and community agencies on behalf of these families.
Investigating Dynamics of Dark Focus of the Human Eye in Young Adults

Although the static behavior of accommodation in foveal vision has been well documented, the dynamic aspect of the resting state (dark focus) of accommodation is still unknown. In the present study, the accommodative dynamics of dark focus at the fovea is assessed objectively from a total of ten participants (five males and five females, aged 21–38 years) using the modified Shin-Nippon SRW-5000 autorefractor, a newly developed method to continuously monitor the accommodation process. Actual and potential applications of this study including specifications for designs are also discussed.