cssi/SciSciGPT-SciSciNet huggingface dataset:
Interaction of insulin-like growth factor II with rat chondrocytes: receptor binding, internalization, and degradation.

We have characterized the interaction of insulin- like growth factor II (IGF-II) with its plasma membrane receptor(s) on cultured rat chondrocytes. Our studies, paralleling those already reported for IGF-I, demonstrate that [125I]IGF-II binds to these receptors with a high degree of affinity and that this process is reversible, specific, and time, temperature, and concentration dependent. At 4 C, unlabeled IGF-II causes halfmaximal displacement of the labeled ligand at a concentration of 22 ng/ml, whereas IGF-I is approximately l/200th as potent, and insulin does not displace [125I]IGF-II even at a concentration of 10 μg/ml. Maximum binding to chondrocytes (44% of added radioactivity) occurred after 4–5 h of incubation at 15 C. Compared to [125I]IGF-I binding, this value is 7-fold higher and is consistent with an affinity constant (Ka = 3.8 × 108 M-1) approximately 1 order of magnitude greater. Photoaffinity labeling studies disclose that IGF-II binds primarily to the type II IGF receptor, which has an ap...
Numerical analysis of multi-mechanistic flow effects in naturally fractured gas-condensate systems

Abstract The study of depletion performance of naturally fractured reservoirs has gained wide interest in the petroleum industry during the last few decades and poses a challenge for the reservoir modeler. The presence of a retrograde gas-condensate fluid incorporates an additional layer of complexity to the performance of this class of reservoirs. Upon depletion, reservoir pressure may fall below the dew-point of the hydrocarbon mixture which results in liquid condensation at reservoir conditions. In the case of fractured gas-condensate reservoirs, condensate will first appear in the high-conductivity channels supplied by the fracture network and around the external edges of the matrix blocks which are the zones prone to faster depletion. Since the bulk of hydrocarbon storage resides inside the matrix, it is critical to answer the question whether the condensate formed in the matrix edges would irreversibly trap the gas found in the inner-most portions of the matrix. It is believed that the interplay of Darcian-type flow and Fickian-type flow (multi-mechanistic flow) is the key to answering the questions about depletion performance and ultimate recovery in these reservoirs. This study investigates the recovery mechanisms from a single matrix block surrounded by an orthogonal matrix network, as the fundamental building block for the full-scale system. In this work, we show the dominant flow processes and recovery mechanisms taking place in naturally fractured gas-condensate reservoirs and describe the depletion performance of these systems, which provides guidance for the development and analysis of this class of reservoirs.
Digital imaging of reaction zones in hydrocarbon - air flames using planar laser-induced fluorescence of CH and C2

A method for instantaneously imaging the position of the reaction zone in hydrocarbon–air flames is described. The technique is based on planar laser-induced fluorescence of the combustion radicals CH and C2. Using a Nd:YAG-pumped dye-laser illumination source, fluorescence images were recorded with an image-intensified 100 × 100 photodiode array camera. Results are presented for acetylene–air and ethylene–air gaseous flames as well as for a heptane–air spray flame. Details of excitation–detection strategies and fluorescence yields are discussed.
Prediction of forming limit curves using an anisotropic yield function with prestrain induced backstress

Abstract The Forming Limit Diagram (FLD), a plot of the maximum major principal strains that can be sustained by sheet materials prior to the onset of localized necking, is a useful concept for characterizing the formability of sheet metal. Both experimental and numerical results in the literature have shown that the level of the FLD is strongly strain path dependent and the prediction of FLD depends on the shape of the initial yield function and its evolution. In this work, to improve the accuracy of FLD prediction under nonlinear strain paths for a given material, the evolution of the yield function is proposed in terms of the changes of its center and its curvature. The center of the subsequent yield surface after preloading and unloading will be determined via a backstress tensor, and the curvature change will be reflected by changing the exponent in the yield function. Both parameters are functions of the effective plastic strain and will be determined using the forming limit strains obtained from two nonlinear tests. Using this approach, a combination of Marciniak–Kuczynski (M–K) analysis (Marciniak, Z., Kuczynski, K. 1967. Limit strains in the processes of stretch-forming sheet metal. Int. J. Mech. Sci. 9, 609.) and a general anisotropic yield criterion developed by Karafillis and Boyce (Karafillis, A.P., Boyce, M.C. 1993. A general anisotropic yield criterion using bounds and transformation weighting tensor, J. Mech. Phys. Solids, 41, 1859) is used to predict nonlinear FLDs of both Al2008-T4 and Al6111-T4. Excellent agreements were obtained between computed FLDs with the experimental data of Graf and Hosford (Graf, A., Hosford, W.F. 1993a. Calculations of forming limit diagrams for changing strain paths. Metall. Trans. A. 24, 2497; Graf, A., Hosford, W.F. 1993b. Effect of changing strain paths on forming limit diagrams of Al 2008-T4. Metall. Trans. A. 24, 2503; Graf, A., Hosford, W.F. 1994. The influence of strain path changes on forming limit diagrams of Al 6111-T4. Int. J. Mech. Sci. 36, 897). This prediction capability provides a powerful tool in the design and optimization process of 3D sheet metal forming where strain path changes are inevitable.
lacZ translation initiation mutations

Sixteen single point mutations near the beginning of the lacZ gene have been isolated and their effect on lacZ expression has been measured. Five mutations were obtained that alter a potential stem-and-loop structure in the messenger RNA that masks the initiation codons. Formation of this stem-and-loop is a result of transcription of DNA sequences introduced during the cloning of the lac regulatory region. The mutations isolated were then moved into a background that deleted this structure. Analysis of these mutations indicated that the secondary structure inhibited lacZ expression 5.8-fold and that either single point mutations or a 9 base-pair deletion could relieve this inhibition completely. In addition, it was found that an A to C transversion in the first base following the initiation codon (in the absence of the inhibitory secondary structure) decreases lacZ expression almost twofold, whereas C to U transitions in the next two positions have negligible effects. Mutations were also obtained that either increase or decrease the length of the Shine-Dalgarno sequence. The effects of these mutations were studied in the presence or absence of the secondary structure that involves the two initiation codons. It was found that when translation initiation was inhibited by the secondary structure, increasing the length of the Shine-Dalgarno sequence increased lacZ expression 2.8-fold and decreasing the length of this sequence reduced lacZ expression 12-fold. When translation initiation was not inhibited by the secondary structure, increasing the length of the Shine-Dalgarno sequence had no effect and decreasing the length of this sequence only reduced lacZ expression sixfold. The mechanistic implications of these results are discussed. Two initiation codons are located in the beginning of the lacZ gene, 7 and 13 bases from the Shine-Dalgarno sequence. NH2-terminal sequence analysis indicated that the majority of the protein synthesized initiate at the first initiation codon in the wild-type lacZ gene (in agreement with results reported previously by J. L. Brown and his colleagues). Upon introduction of sequences that result in a change in the mRNA secondary structure, both initiation codons are used in almost equal amounts. Three mutations and two pseudorevertants were obtained, which are located in the first initiation codon. It was found that when the first initiation codon is changed from AUG to GUG, translation initiation is decreased tenfold at that codon.(ABSTRACT TRUNCATED AT 400 WORDS)
Effects of acute, moderate ethanol consumption on human platelet aggregation in platelet-rich plasma and whole blood.

Background: Platelet-inhibitory effects of alcohol potentially contribute to the reduced risk of coronary heart disease associated with moderate drinking. However, few studies have directly examined the effects of acute consumption of a moderate dose of alcohol on aggregation of platelets from healthy human subjects. In the present study, we examined those effects, with the use of multiple platelet agonists and two aggregation measurement techniques, as part of an ongoing series of studies that evaluate the actions of ethanol on platelet function. Methods: Human subjects consumed alcohol at a dose equivalent to one drink (0.25 ml/kg) or two drinks (0.5 ml/kg). One hour after ingestion, anticoagulated blood was collected and agonist-induced aggregation of platelets was measured in both whole blood and in platelet-rich plasma. Results: Inhibition of aggregation by ethanol consumption was observed in whole blood (measured as maximum change in impedance) and reached statistical significance (p < 0.05) in the 0.5 ml/kg alcohol group for two collagen concentrations (0.625 and 1.25 μg/ml) as well as for the highest concentration of adenosine diphosphate tested (p < 0.05). Inhibition was 15.4%, 22.6%, and 10.5%, respectively, for these three situations. In platelet-rich plasma, after consumption of 0.5 ml/kg ethanol, aggregation (measured as maximum change in optical density) in response to 1.25 μg/ml collagen was significantly inhibited (p < 0.05); no other significant inhibition was observed at either dose of alcohol in any other cases with platelet-rich plasma. In comparison of male and female subjects, there was a statistically significant difference (p < 0.05) in the degree of inhibition by ethanol consumption (0.5 ml/kg) of whole-blood platelet aggregation induced by collagen, whereby female aggregation was inhibited to a greater extent than male. Conclusions: This study shows that alcohol, at physiologically relevant doses, below those investigated in most previous human studies, has a dose-dependent inhibitory effect on platelet aggregation. Such an effect could potentially contribute to the beneficial effects of alcohol consumption against coronary artery disease. The inhibitory action is most readily measured with whole-blood platelet aggregometry, with the use of collagen as the agonist. This observation is consistent with the view that alcohol reduces platelet sensitivity to thrombotic stimuli by inhibition of arachidonic acid release and, therefore, subsequent thromboxane synthesis.
A Certain Class of Binocularly Equivalent Configurations

Originating in a mathematical study of a series of binocular visual phenomena experienced in certain demonstrations developed by The Hanover Institute (formerly Dartmouth Eye Institute), the following analysis shows that even binocular vision does not provide absolute localization of objects. On the contrary, a series of vertical targets may furnish binocularly the same angular clues, if their location, their inclination, and their shape are suitably chosen. Although the straight lines where the possible equivalent vertical targets intersect the horizontal plane represent only a special, so to speak degenerated subset of the whole set of equivalent conic sections, their mathematical analysis reveals that two theorems of projective geometry dealing with projective properties of conic sections find an interesting application in the field of binocular vision. In the introduction, two actual experiments are described. The geometrical construction and the computations on which these experiments are based are discussed in the last section where two additional theoretically possible experiments are suggested.
Geodesic curvature flow on surfaces for automatic sulcal delineation

Sulcal folds (sulci) on the cortical surface are important landmarks of interest for investigating brain development and disease. Accurate and automatic delineation of the sulci is a challenging problem due to substantial variability in their shapes across populations. We present a geodesic curvature flow method for an automatic and accurate delineation of sulcal curves. We assume as input an atlas brain surface mesh on which a set of sulcal curves have been delineated. The sulcal curves are transferred to approximate corresponding locations on the subject brain using a transformation defined by an automatic surface based registration method. The locations of these curves are then refined to follow the true sulcal fundi more closely using geodesic curvature flow on the cortical surface. We present a level set based formulation of this flow on non-flat surfaces which represents the sulcal curves as zero level sets. We also incorporate a curvature based weighting that drives the sulcal curves to the bottoms of the sulcal valleys in the cortical folds. The resulting PDE is discretized on a triangulated mesh using finite elements. Finally, we present a validation by comparing sets of automatically delineated sul-cal curves with sets of manually delineated sulcal curves and show that the proposed method is able to find them accurately.
Preliminary studies on degradation products of quercetin in the rat's gastrointestinal tract.

Abstract Paper chromatographic studies of the ether extracts of the lyophilized rat stomach and its contents were made following the feeding of randomly labeled quercetin-C 14 . Radioactive phloroglucinol carboxylic acid, phloroglucinol, and protocatechuic acid were identified. A fourth radioactive compound still not identified plus a radioactive “quercetin-like” compound were also noted. Protocatechuic acid, phloroglucinol carboxylic acid, and phloroglucinol were also found following incubation of quercetin with a porcine gastric mucin preparation.
The Compressive Failure of Aluminum Nitride Considered as a Model Advanced Ceramic

Abstract Uniaxial quasi-static compression, uniaxial dynamic compression and confined dynamic compression experiments were performed to characterize the failure of Aluminum Nitride (AlN) using a servo hydraulic machine and a modified Kolsky bar set-up respectively. High-speed digital cameras are used to visualize the failure processes. A summary of the available experimental results, including that in the literature, shows that the compressive strength of the AlN is sensitive to strain rate in the range from 10 −3 to 10 3 s −1 , and that the deviatoric strength of AlN is linearly dependent on pressure at low pressures and nearly independent of pressure above a transitional pressure (about 2 GPa). TEM characterization of fragments obtained after dynamic loading is used to characterize the deformation mechanisms in the AlN for varying confinement. The transition in the pressure dependent behavior is shown to be the result of a change of deformation mechanism. Classical wing crack micromechanics is used to predict the transition in the deformation mechanism, and to explain the observed behavior at low pressure.
Yield of stress single-photon emission computed tomography in asymptomatic patients with diabetes.

Abstract Background Patients with diabetes without clinically apparent coronary artery disease are at increased risk of cardiac death. The value of screening stress testing in these patients remains controversial. The goal of this study was to examine the yield of stress single-photon emission computed tomography (SPECT) in asymptomatic diabetic patients. Methods The results of stress SPECT in patients without prior myocardial infarction or coronary revascularization were compared in asymptomatic diabetics (n = 1738) versus symptomatic diabetic patients (n = 2998), asymptomatic nondiabetic patients (n = 6215), and symptomatic nondiabetic patients (n = 16,214). Results Abnormal scans were present in 58.6% of asymptomatic diabetic patients, approximately equal to the percentage in symptomatic diabetic (59.5%) ( P = not significant) and higher than in asymptomatic nondiabetic (46.2%) ( P P P = .051); asymptomatic nondiabetic, 11.1% ( P P Conclusions Asymptomatic diabetic patients have a high prevalence of both abnormal and high-risk SPECT scans. The finding that approximately 1 in 5 of these individuals has a high-risk scan suggests a potentially more widespread application of screening stress SPECT in asymptomatic diabetic patients to identify those with severe coronary artery disease.
Macroscopic limits for stochastic partial differential equations of McKean–Vlasov type

A class of quasilinear stochastic partial differential equations (SPDEs), driven by spatially correlated Brownian noise, is shown to become macroscopic (i.e., deterministic), as the length of the correlations tends to 0. The limit is the solution of a quasilinear partial differential equation. The quasilinear SPDEs are obtained as a continuum limit from the empirical distribution of a large number of stochastic ordinary differential equations (SODEs), coupled though a mean-field interaction and driven by correlated Brownian noise. The limit theorems are obtained by application of a general result on the convergence of exchangeable systems of processes. We also compare our approach to SODEs with the one introduced by Kunita.
ACM HotMobile 2013 poster: RazorCam: a prototyping environment for video communication

Design verification takes 80 % of times in the flow design of hardware/software applications. To reduce this duration, subsequent transformations are performed across different levels of abstraction until the final implementation. We propose a rapid prototyping camera system based on FPGAs, which allows designs to be explored and evaluated in realistic environments. Our focus is on the design of a generic embedded hardware/software architecture with a symbolic representation of the input application to allow a programmability at a very high abstraction level. The hardware/software partitioning is facilitated through the integration of OpenCV and SystemC in the same environment for rapid simulation and OpenCV and Linux in the run-time environment.
Study of neutron closed-shell nuclei

Abstract Neutron closed-shell nuclei have been studied in the framework of the BCS approximation. The residual interaction is of Gaussian type with a Serber mixture. The calculation is limited to the diagonalization in the two-quasi-particle subspace. The closed-shell particles are considered as inert. Low-energy spectra, E0 transitions and magnetic moments are discussed. The results are in qualitative agreement with experiment.
Urticaria and Angioedema

Although acute urticaria and angioedema are common in children, they are usually self-limited and cause only transient discomfort. However, when chronic, they can significantly affect quality of life and can be life threatening if the airway is affected. The causes of urticaria and angioedema are many, and a thorough medical history is the most important diagnostic tool. Nevertheless, the cause often remains idiopathic. Both immunoglobulin E– and non-immunoglobulin E–mediated immunologic mechanisms may be involved. Many nonallergic medical conditions, including various infections, autoimmune diseases, and malignancies, may present with urticaria and angioedema, sometimes before other manifestations of the disease become evident. The possibility of an underlying systemic disease should be considered in patients with chronic or atypical symptoms. Treatment involves identification and avoidance of the trigger if possible and chronic suppressive therapy if the cause cannot be identified or eliminated. Patients at risk for airway involvement should receive additional education and a supply of autoinjectable epinephrine.
Characterization of the abnormal pancreatic development, reduced growth and infertility in Cdk4 mutant mice.

Characterization of the abnormal pancreatic development, reduced growth and infertility in Cdk4 mutant mice
Introduction to Chemistry and Applications in Nature of Mass Independent Isotope Effects Special Feature

Stable isotope ratio variations are regulated by physical and chemical laws. These rules depend on a relation with mass differences between isotopes. New classes of isotope variation effects that deviate from mass dependent laws, termed mass independent isotope effects, were discovered in 1983 and have a wide range of applications in basic chemistry and nature. In this special edition, new applications of these effects to physical chemistry, solar system origin models, terrestrial atmospheric and biogenic evolution, polar paleo climatology, snowball earth geology, and present day atmospheric sciences are presented.
CONFORMATIONAL ENERGY CALCULATIONS OF ENZYME‐SUBSTRATE INTERACTIONS. II. Computation of the Binding Energy for Substrates in the Active Site of α‐Chymotrypsin

Empirical energy calculations are carried out to study the binding of the substrates N-acetyl-L-phenylalanine amide, N-acetyl-L-tyrosine amide, N-formyl-L-tyrosine α-mide, and N-acetyl-L-tryptophan amide to the enzyme molecule α-chymotrypsin. As an initial probe of the active-site surface, the low-energy conformations of the phenylalanine substrate (see Part I) are allowed to approach the enzyme by overall rotational and translational motion until a minimum is achieved in the enzyme-substrate interaction energy. Four regions of good binding are found near the active site, the one of lowest energy being that in which the ring is oriented in the cleft of the enzyme. This cleft binding site is the same as the binding position found by X-ray diffraction for the virtual substrate N-formyl-L-tryptophan; the other three favorable binding regions might not be detected by X-ray analysis, possibly because they are blocked in the dimer structure of the crystalline enzyme. Further investigation of the most favorable (cleft) binding site indicates that left-handed α-helical backbone conformations of the substrate do not form stable enzyme-substrate complexes, while the equatorial seven-membered ring, as well as the right-handed α-helical and β and γ backbone conformations (the latter three of which commonly occur in proteins) bind well. The calculated binding energies of all four substrates correlate with experimental binding constants.
New Results for an Approximate Method for Calculating Two-Dimensional Furrow Infiltration

AbstractThis study expands the analysis of a proposed furrow infiltration formulation based on an approximate solution to the two-dimensional Richards equation. The approach calculates two-dimensional infiltration flux as the sum of one-dimensional infiltration and a second term labeled the edge effect. The edge effect varies linearly with time when the applied water pressure is constant. It is a function of sorptivity, soil water content, and the empirical parameters γ and W* that require calibration for the specific soil and furrow geometry. The primary objectives of the analysis were to better understand how furrow geometry affects the edge effect and the resulting empirical parameter values and to provide additional guidance for calibration. For a given flow depth, furrow geometry defines the wetted perimeter and the water pressure applied along that wetted perimeter. A subobjective was to evaluate the effect of the assumed soil water retention model on the calibration results. The results show that t...
Comparison of Stress Corrosion Cracking and Corrosion Fatigue (Anodized and Non-Anodized Grade 4 CP Ti)

In light of the possible effects of anodization on stress corrosion cracking (SCC) and corrosion fatigue (CF) of CP titanium, a research project has been completed recently in our laboratories to evaluate and compare SCC and CF of anodized versus non-anodized samples from a single lot of Grade 4 CPTi. Initial evaluation of alloy composition, microstructure, Vickers microhardness, and mechanical properties including the tensile and yield strength, % elongation and reduction of area was performed. After these tests ensured the material met the standards of ASTM Standard Specification for Unalloyed Titanium for Surgical Implant Applications (F 67), samples were prepared using low stress grinding techniques. Samples were divided into two groups, and the non-anodized SCC and CF testing was initiated. The surface of the second group of samples was anodized by Synthes to provide a green/gold surface consistent with standard production processing and then tested using the identical methodology as used for the non-anodized samples. Results of the slow strain rate SCC testing on both smooth and notched anodized and non-anodized samples in both distilled de-ionized water and Ringers solution at 37°C showed no effect of anodization. Results of corrosion fatigue testing indicated that, while there was no effect of anodization on corrosion fatigue, there was a significant effect of the notch on the fatigue characteristics regardless of the two different surface conditions.
Functional magnetic resonance imaging of regional brain activity in patients with intracerebral gliomas: findings and implications for clinical management.

Abstract Functional magnetic resonance imaging (fMRI) was performed in seven patients harboring intracerebral gliomas proven by histological analysis using a noninvasive blood oxygen level-dependent technique based on the documented discrepancy between regional increases in blood flow and oxygen use in response to regional brain activation. We combined fMRI with conventional magnetic resonance imaging (MRI) during motor or language task activation experiments to investigate the potential usefulness of mapping regional brain activity as part of treatment planning in patients with intracerebral gliomas, in whom preservation of areas of functioning brain tissue is critical. Statistical fMRI maps were generated and directly mapped onto conventional MRI scans obtained at the same session. Of the five patients cooperative enough to remain motionless for the study and perform the task, the location of activation in the primary sensorimotor cortex on the side of the tumor was clearly displaced compared with that in the normal contralateral hemisphere in four patients. Four of the five tumors in these patients showed fMRI activation within the periphery of (or immediately adjacent to) areas of presumed tumor based on spin-echo MRI. In some patients with neurological deficit, the extent of activation was reduced on the side of the tumor as compared with the normal hemisphere. The supplemental motor area and the ipsilateral primary motor cortex were also reproducibly activated during motor tasks. We conclude that blood oxygen level-dependent fMRI can localize areas of cortical function in patients undergoing treatment planning for gliomas so that therapy can be directed away from regions of residual function. Our preliminary data suggest that functioning cortex within or adjacent to tumor margins can be demonstrated, which may correspond to partial preservation of clinical function. Our preliminary data also suggest that there may be a quantifiable difference on fMRI between activation in tumor-bearing cortex and activation in corresponding normal cortex in the contralateral hemisphere. We postulate that the magnitude of this difference may relate to the severity of patient deficit.
Measuring information provided by language model and acoustic model in probabilistic speech recognition: theory and experimental results

Abstract In probabilistic speech recognition it is often interesting to evaluate the contribution of the language model and that of the acoustic model. We propose an information theoretical approach which takes into account the interaction between the two sources of information. Experimental results are presented concerning the IBM prototype real-time recognizer of the Italian language based on a 20,000-word vocabulary.
Sexual function in women with urodynamic stress incontinence, detrusor overactivity, and mixed urinary incontinence.

Objective This study was undertaken to compare sexual function in sexually active women with urodynamic stress incontinence (USI), detrusor overactivity (DO), and mixed urinary incontinence (MUI). Study design We reviewed the medical records of all women evaluated for urinary incontinence (UI) at our institution between March 2003 and August 2004. At the time of initial evaluation, all women completed the short form of the Pelvic Organ Prolapse/Urinary Incontinence Sexual Function Questionnaire (PISQ-12). PISQ-12 scores of age-matched women with urodynamic diagnoses of USI, DO, and MUI were compared. Statistical analysis was performed with 1-way analysis of variance and χ 2 contingency table analysis. Results Fifty women with USI, 50 with DO, and 48 with MUI were included in this study. Subject demographics were similar among the 3 groups. Mean PISQ-12 scores did not differ significantly among the 3 groups. Conclusion Among sexually active women with urinary incontinence, sexual function as assessed by the PISQ-12 does not differ according to type of incontinence.
Persistence of lpr/lpr-derived lgG2a secreting B cells in normal → lpr/lpr adult radiation chimeras or lpr/lpr → normal kidney capsule chimeras

Lethally irradiated MRL/lpr mice reconstituted with bone marrow stem cells from a normal mouse strain develop a state of split hematopoietic chimerism; erythrocytes, granulocytes, and macrophages are derived from the normal stem cell inoculum while the peripheral T lymphocytes are derived from radioresistant lpr host cells. Moreover, these mice have normal levels of serum IgM and IgG2a produced by radioresistant host B cells, even though they have relatively few sIgM+ B cells. In order to better understand the differentiation and regulation of B cells present in these chimeric mice, the current study was undertaken to localize and to assess the functional capacity of the lpr B cells producing the serum antibodies. Surface IgG2a+ cells could not be found in the spleen or lymph nodes of these mice, but large lymphocytes containing cytoplasmic IgG2 of host (lpr) allotype could be readily detected, even though they constituted less than 1% of the total spleen population. The host-derived serum IgG2 and IgG2+ cells were even present in the spleens of "leaky" mice that had relatively normal numbers of donor-derived sIgM+ B cells. These lpr B cells secreted IgG2a antibody that bound ssDNA, but they could not respond to immunization with SRBC. These results indicate that the lpr-derived radioresistant B cells have a limited capacity for proliferation and are already committed to the memory lineage. The presence of similar B cells in normal mice transplanted with neonatal lpr/lpr spleen fragments suggests that lpr/lpr B cell development is inherently abnormal.
Even If You Build It, We May Not Come: Correlates of Non-attendance at a Sexual Risk Reduction Workshop for STD Clinic Patients

Sexual risk reduction interventions have been shown to reduce sexual risk behavior; however, attendance at these interventions is sometimes disappointingly low. To improve recruitment efforts, we investigated whether patient characteristics were associated with non-attendance at a single-session, sexual risk reduction intervention. Patients from an STD clinic (N = 990; 48% female; 64% African American) who were eligible and who agreed to participate in a randomized, clinical trial were invited to a 4-h, sexual risk reduction workshop. Fifty-six percent of those who were invited attended the workshop. Those who did not attend were more likely to be younger, male, Caucasian, and employed. Attendance did not differ as a function of sexual behavior or infection status. These findings identify the population sub-groups who are likely to require special effort to attract to a workshop. We encourage more effective marketing and recruitment approaches for sexual risk reduction programs.
Self-assembly of Collagen Peptides into Microflorettes via Metal Coordination

The self-assembly of synthetic biomaterials, such as collagen peptides, can be harnessed for a range of biomedical applications. In an effort to obtain collagen-based macromolecular assemblies with temporal control, we designed a system that assembled only in the presence of external stimuli. We report a collagen triple helical peptide that is modified with a His(2) moiety on its C-terminus and a nitrilotriacetic acid unit on its N-terminus that rapidly and reversibly assembles in the presence of metal ions. Dynamic light scattering and turbidity experiments confirmed the presence of higher order aggregates in solution upon the introduction of Zn(2+), Cu(2+), Ni(2+), and Co(2+). This assembly process was found to be fully reversible using EDTA as a metal ion chelator. Control peptides that contain only a single ligand-modified terminus were not responsive to the same metal ions, thus demonstrating the requirement of both ligand modifications for peptide assembly. Scanning electron microscopy imaging of the peptide-metal assemblies revealed micrometer-sized florettes in addition to curved, stacked sheets. More detailed analysis of the Zn(2+)-generated microflorettes showed that the surface of these particles contains ruffled structures with a highly dense surface area. Potential folding intermediates in the formation of the microflorettes were observed at lower temperatures and at early time points in the assembly that are composed of curved layered sheets. Significantly, the assembly process proceeded under mild conditions using neutrally buffered aqueous solution at room temperature. These microscopic structures offer opportunities in many areas, including drug delivery, tissue engineering, and regenerative medicine.
Nitric oxide modulates respiratory-related neural activity in the isolated brainstem of the bullfrog

The effects of nitric oxide (NO) on respiratory-related neural activity were investigated using the isolated brainstem preparation from bullfrogs (Rana catesbeiana). Addition of the NO donor, sodium nitroprusside (SNP), or the amino acid precursor for NO synthesis, L-arginine (L-Arg), produced significant increases in respiratory-related burst frequency. Inhibition of nitric oxide synthase (NOS) with N q -nitro-L-arginine (L-NA), a non-selective NOS inhibitor, 7-nitro indazole (7-NI), reversibly abolished burst activity. These results suggest that production of NO, probably via neuronal NOS (nNOS), provides a facilitatory input to the respiratory central pattern generator (CPG) in the amphibian brainstem. Endogenous production of NO may be a necessary inter- or intracellular messenger for neurotransmission and/or neuromodulation of central respiratory drive to motor effecters in the bullfrog. © 1998 Published by Elsevier Science Ireland Ltd. All rights reserved
Tetraphenylene ring flip revisited.

The ring flip barrier of a series of benzannulated cyclooctatetraenes is investigated at B3LYP and MP2. The ring flip of tetraphenylene proceeds through a nonplanar transition state, contrary to a previous study, with a large barrier of 78.6 kcal mol−1.
Parental and Child Health Beliefs and Behavior

Personal interviews concerning health beliefs and behav iors were conducted with a parent and child in each of 250 households. Index scores were constructed for parental and child health beliefs, and these scores were entered, along with demographic variables, in a series of multiple regression analyses predicting child health beliefs and behaviors. The age of the child was the variable most highly associated with three of four child health behaviors and four of six child health beliefs. The children's snacking between meals and cigarette smoking were related to several parental behaviors and, to a lesser extent, parental health beliefs. The children's health beliefs were less predictable than were their health behaviors, and the observed significant relationships were with parental health beliefs and demographics. The implications for the design of health education programs are discussed.
SOURCE AND SINK HABITATS OF RED-WINGED BLACKBIRDS IN A RURAL/SUBURBAN LANDSCAPE

The objectives of this study were to distinguish demographic source and sink habitats of Red-winged Blackbirds (Agelaius phoeniceus) and to determine the factors influencing source–sink status prior to fledging. In Boulder County, Colorado, I monitored 591 nests between 1995 and 1997 in breeding habitats that were either natural (wetlands, tallgrass prairie) or anthropogenic (hayfields, roadside ditches). To determine source–sink status, I calculated the productivity necessary to offset mortality. Predation was the main determinant of source–sink status, while brood parasitism had virtually no impact on this population. Anthropogenic habitats consistently functioned as sinks throughout the three-year study. Sources occurred only in natural habitats, and source sites had fewer buildings nearby than did sinks. In addition, climate variability may have influenced reproduction by influencing egg-laying dates. In 1995, possible source habitats included tallgrass prairie and wetlands. In 1996, tallgrass prairie...
Rat precision-cut lung slices as a model for deformation-induced lung injury studies

Rat precision-cut lung slices (PCLS) were characterized as a novel ex vivo model for lung injury studies. PCLS of 250 μm in thickness were sutured onto silastic well membranes and stretched. Change in membrane surface area (%AMSA) was not significantly different from change in alveolar surface area (%AASA) throughout three cycles of stretch. At a stretch of 38%AMSA, circumferential strain and radial strain did not differ significantly, confirming that the PCLS stretched in an equi-biaxial manner. Phenotype characteristics were examined by fluorescently staining fixed PCLS for alveolar type I (ATI) and type II (ATII) cells markers; both cell types were present up to three days in culture. In summary, our testing of the new preparation shows that this is a reproducible and effective method for studying deformation-induced injury.
Effect of semolina and absorption level on extrusion of spaghetti containing non-traditional ingredients

Specific mechanical energy (SME), mechanical energy, extrusion rate and temperature of extruded spaghetti were monitored to determine the effects of semolina, hydration level and non-traditional ingredients on pasta extrusion using a semi-commercial pasta press with a fixed screw speed of 25 rpm. SME transferred to the dough during extrusion and the temperature of extruded spaghetti were greater with strong than with weak gluten semolina and at low than at high absorption levels. When compared with semolina hydrated to 300 g kg−1 absorption, SME transferred to the dough was 13 kJ kg−1 lower for semolina mixed with buckwheat (Fagopyrum esculentum Moench.) bran flour, 47 kJ kg−1 lower for semolina mixed with flaxseed (Linum usitativissimum L.) flour and 7 kJ kg−1 lower for semolina mixed with wheat (Triticum turgidum var. durum L.) bran. Weak gluten semolina, high absorption levels and non-traditional ingredients reduced the mechanical energy required for extrusion more than they reduced extrusion rate. The target temperature for extruded spaghetti was 45 °C. The temperature of extruded spaghetti containing flaxseed flour was below 45 °C whereas the temperature of spaghetti containing wheat bran was above 45 °C, regardless of semolina type or absorption level. Copyright © 2006 Society of Chemical Industry
Predicting asthma morbidity in Harlem emergency department patients.

Objectives: To determine predictors of asthma morbidity in African American patients with asthma. Proxies for asthma morbidity were emergency department (ED) visits for asthma and hospitalizations for asthma. Methods: This was a prospective observational study that evaluated baseline predictors of asthma morbidity in adults in an urban, predominantly African American community in New York City. Potential predictors of asthma morbidity evaluated were education, gender, employment status, current smoking status, asthma severity, duration of asthma, daily use of a peak flow meter, presence or absence of pets at home, presence or absence of a significant other, presence or absence of medical insurance, and previous hospitalization for asthma in the past year. Follow-up consisted of a repeat questionnaire obtained between nine and 15 months after the baseline questionnaire. Follow-up data collection was limited to the last three-month history of ED visits or hospitalizations before the follow-up visit. At follow-up, the baseline predictors were related to the presence or absence of ED visits for asthma or hospitalizations for asthma. All predictors were evaluated individually (crude odds ratio [OR]) and simultaneously (adjusted OR) in a logistic regression model with the dichotomous outcome variable ED visits or hospitalization. Results: Return ED visits on follow-up were more likely to occur in asthma patients hospitalized in the previous year (adjusted OR, 3.9; 95% confidence interval [CI] = 1.7 to 9.0) and were less likely to occur in asthma patients with pets (OR, 0.4; 95% CI = 0.2 to 0.9). Patients with moderate/severe asthma, relative to patients with mild asthma, were more likely to be seen in the ED on follow-up on initial analysis (crude OR, 2.4; 95% CI = 1.1 to 1.5), but the adjusted OR was not significant. Follow-up hospitalizations were significantly more likely to occur only in subjects reporting daily use of a peak flow meter (OR, 6.8; 95% CI = 1.3 to 34.5). Subjects hospitalized for asthma in the previous year were more likely to be hospitalized subsequently on initial analysis (crude OR, 2.9; 95% CI = 1.0 to 8.1), but the adjusted OR was not significant. Conclusions: It appears that African American patients with asthma who had previous hospitalizations for asthma within the past year or use a peak flow meter daily (a marker for more severe asthma) are more likely to visit the ED in the future or to be hospitalized for asthma, respectively. These patients need to be targeted and treated more aggressively to improve asthma care and decrease morbidity. The apparent protective effect of the presence of pets on reducing ED visits is unclear at this time, and the
Oxygen-induced lung injury in the newborn piglet.

Abstract Oxygen-induced lung toxicity was studied in artificially fed newborn miniature piglets. Paired littermates of newborn piglets were exposed to either 96–98% oxygen or air for 2, 4, 7 or 10 days. Development of pulmonary edema, as monitored by both the lung wet weight to dry weight ratio and the lung wet weight to body weight ratio, was evident 4 days after the start of oxygen exposure. Examination of light and electron micrographs showed that pulmonary edema was located mainly in the perivascular and interstitial spaces. Endothelial and type I cells were normal in appearance throughout the oxygeh exposure. After exposure to 10 days of oxygen, type II cells appeared to show a decrease in the size of lamellar bodies and an increase in the number and size of mitochondria. The activity of pulmonary antioxidant defenses, as measured by the activity of superoxide dismutase (SOD), glutathione peroxidase (GP) and glutathione reductase (GR), and the level of reduced glutathione (GSH), showed a progressive increase in activity with duration of oxygen exposure, culminating in a significantly higher SOD, GP and GSH level in 7-day oxygen-exposed piglets. It is concluded that the newborn piglet is less susceptible to oxygen-induced lung injury compared to adults of other species, and the increase in the lung complement of SOD, GR, GP and GSH may contribute to the apparent resistance to oxygen toxicity.
Enhancing Quality of Trainee-written Consultation Notes

Inpatient consultations between generalists and specialty care providers represent a specific situation where poor information exchange between physicians could result in delayed diagnoses, inadequate follow up, or duplication of services.1, 2 Unfortunately, subspecialty trainees do not receive formal instruction in how to provide an effective consultation.3 As a result, consultation notes are variable in quality and often do not meet the needs of the referring provider or the patient.4
A Novel Immunocompetent Rat Model of HCV Infection and Hepatitis

Background & Aims: Hepatitis C virus (HCV) infects millions of people worldwide. Therapy is limited, and treatment does not produce a sustained response in the majority of patients. Development of new agents has been hampered by the lack of a convenient animal model. The aim of this study was to determine whether an immunocompetent rat, tolerized and transplanted with a human hepatoma cell line (Huh 7 cells), could be used to sustain an HCV infection. Methods: Fetal rats were tolerized in utero with 10 5 Huh 7 cells. One day after birth, rats were transplanted with 5 × 10 6 Huh 7 cells and, a week later, inoculated with HCV, genotype 1. Results: In tolerized, transplanted, and HCV-infected rats, Huh 7 cells were found in the liver, and HCV viral replication was detected by the presence of negative strand HCV RNA. HCV levels in serum were measured at 11,000 copies/mL at week 4, peaked at 22,500 copies/mL by week 12. In tolerized, transplanted, inoculated rats, but not controls, serum alanine aminotransferase (ALT) values increased to 60 IU/L by week 4 and reached a peak of approximately 120 IU/L by week 13. Histology showed foci of mononuclear infiltrates in portal and central regions. Conclusions: HCV-inoculated immunocompetent rats tolerized and transplanted with Huh 7 cells support HCV gene expression, viral replication, and develop biochemical and histologic evidence of hepatitis.
How Culture Can Guide Evolution: An Inquiry into Gene/Meme Enhancement and Opposition

We study the relationship between genetic evolution, learning, and culture. We start with the sim ulation environment of Hinton and Nowlan in which individual learning was shown to guide genetic evolution towards a difficult adaptive goal. We then consider, in lieu of individual learn ing, culture in the form of social learning by imitation. Our results demonstrate that when genes and culture cooperate, or enhance one another, culture too is able to guide genetic evolution towards an adaptive goal. Further, we show that social learning is superior to individual learning insofar as it with genetic evolution converges more quickly to the goal. However, the social learn ing algorithm results in slower genetic assimilation of adaptive alleles than with individual learn ing. It is as if, we argue, the adaptive values are stored in the culture rather than in the genes. Finally, we consider what happens when culture and genes pursue diametrically opposed goals. Here we show that culture, in the form of social le...
Topology, stability, sequence, and length: Defining the determinants of two-state protein folding kinetics

The fastest simple, single domain proteins fold a million times more rapidly than the slowest. Ultimately this broad kinetic spectrum is determined by the amino acid sequences that define these proteins, suggesting that the mechanisms that underlie folding may be almost as complex as the sequences that encode them. Here, however, we summarize recent experimental results which suggest that (1) despite a vast diversity of structures and functions, there are fundamental similarities in the folding mechanisms of single domain proteins and (2) rather than being highly sensitive to the finest details of sequence, their folding kinetics are determined primarily by the large-scale, redundant features of sequence that determine a protein's gross structural properties. That folding kinetics can be predicted using simple, empirical, structure-based rules suggests that the fundamental physics underlying folding may be quite straightforward and that a general and quantitative theory of protein folding rates and mechanisms (as opposed to unfolding rates and thus protein stability) may be near on the horizon.