cssi/SciSciGPT-SciSciNet huggingface dataset:
Gender, Work Control, and Stress: A Theoretical Discussion and an Empirical Test:

Within the field of occupational stress research the theoretical orientation, the research instruments, and the populations studied have largely been standardized on and restricted to male subjects. This article discusses the threats that single-sex studies pose to the valid assessment of the health effects of working life. Following this critique, an empirical examination of the differential distribution of work control is examined within a random sample (n = 13,203) of Swedish working males and females. Results indicate that even in a socially progressive society the labor force continues to be highly sex-segregated. Males, as a group, were found to have access to a larger and more diverse set of jobs than do females, as a group. Work control was found to be consistently higher among men than among women. The highest level of control was found among white-collar men in male-segregated jobs, while the lowest was found among blue-collar women in male-segregated jobs. It was notable that men had a higher l...
Self-stratified films obtained from poly(methyl methacrylate/n-butyl acrylate) colloidal dispersions containing poly(vinyl alcohol): A spectroscopic study

These studies focus on the role of poly(vinyl alcohol) (pVOH) during colloidal synthesis of poly(methyl methacrylate/n-butyl acrylate) (pMMA/nBA) and its effect on particle coalescence. Using 2D photoacoustic FT-IR spectroscopy and internal reflection IR imaging, we showed that the presence of pVOH creates competing environments between the copolymer particle surfaces, aqueous phases, and dispersing agents which results in migration and self-induced stratification occurring during coalescence. pMMA/nBA/pVOH films stratify to form sodium dodecyl sulfate rich film−air interfaces, and the −SO3- moieties exhibit preferential parallel orientation with respect to the surface. At the same time, the bulk of the film is dominated by intramolecular hydrogen bonding between the pVOH phase and the copolymer matrix. This behavior is attributed to significant interactions between pVOH and pMMA/nBA, resulting in limited mobility of pVOH.
Paroxysmal laryngospasm after laryngeal nerve injury.

Objective: Describe a clinical syndrome of laryngeal hypersensitivity following laryngeal nerve injury. Study Design: Retrospective review of six patients with laryngeal paralysis sustained during neck surgery who presented with paroxysms of coughing and stridor, progressing to brief episodes of complete airway occlusion. Methods: Chart review. Results: Superior laryngeal nerve blockade temporarily improved symptoms in four of five patients. Botulinum toxin relieved spasm in two of three patients and reduced symptoms in the third. Symptoms gradually diminished or resolved in four patients from 1 to 2.5 years later. One patient underwent arytenoidectomy and one patient has a tracheostomy. Conclusions: Patients with laryngeal injury may present with stridor and acute airway obstruction secondary to paroxysmal laryngospasm. The authors have found that superior laryngeal nerve blockade or botulinum toxin may be effective in temporary relief of symptoms.
A parallel connectivity algorithm for de Bruijn graphs in metagenomic applications

Dramatic advances in DNA sequencing technology have made it possible to study microbial environments by direct sequencing of environmental DNA samples. Yet, due to the huge volume and high data complexity, current de novo assemblers cannot handle large metagenomic datasets or fail to perform assembly with acceptable quality. This paper presents the first parallel solution for decomposing the metagenomic assembly problem without compromising the post-assembly quality. We transform this problem into that of finding weakly connected components in the de Bruijn graph. We propose a novel distributed memory algorithm to identify the connected subgraphs, and present strategies to minimize the communication volume. We demonstrate the scalability of our algorithm on a soil metagenome dataset with 1.8 billion reads. Our approach achieves a runtime of 22 minutes using 1280 Intel Xeon cores for a 421 GB uncompressed FASTQ dataset. Moreover, our solution is generalizable to finding connected components in arbitrary undirected graphs.
The Casual Labor Problem in Indian Manufacturing

I. Introduction, 100. — II. Labor supply instability, some Indian-American comparisons, 101; turnover, 101; absenteeism, 103; the casual labor problem, 104; "decasualization" as a possible solution, 106. — III. Eliminating the casual labor market for cotton textile workers in Bombay city, 108; the casual labor problem in the 1920's, 108; the employer's approach: mill decasualization (1930's), 108; the government's scheme for industry decasualization (1950's), 109; the belief in corruption which no longer exists, 112. — IV. A recapitulation, 113. — V. Policy implications of the Bombay approach, 114.
An argument for the genetic simplicity of man and other mammals

Abstract There is a finite upper limit to the number of gene loci which an organism can afford to have. An organism having 3 × 10 6 or so gene loci would exterminate itself from an unbearable mutation load. Yet, the mammalian genome is large enough to accommodate that many gene loci. Natural selection is essentially conservative. A new gene with a hitherto non-existent function can not be created unless a temporary escape from the relentless pressure of natural selection is provided by gene duplication. However, the chance of a redundant copy of an old gene emerging as a new gene is considerably smaller than of that copy becoming degenerate. Perhaps for this reason, evolution from simpler life forms to mammals appears to have been accompanied not only by successive additions of new gene loci, but also by accumulation in the genome of a great deal of degenerate “nonsense” DNA base sequences. At least 90% of the mammalian genomic DNA appears to represent “nonsense” DNA base sequence of various kinds. The creation of additional regulatory systems contributed more to big leaps in evolution than did the creation of new structural genes. Yet, in order not to be burdened with an unbearable mutation load, the necessary increase in the number of regulatory systems had to be compensated by simplification of each regulatory system. It would not be surprising if each mammalian regulatory system is shown to have fewer components than the lac -operon system of Escherichia coli .
Sodium iodide symporter-mediated radioiodide imaging and therapy of ovarian tumor xenografts in mice.

Ovarian cancer represents the fifth leading cause of cancer death among women in the United States, with >16 000 deaths expected this year. This study was carried out to investigate the potential of sodium iodide symporter (NIS)-mediated radioiodide therapy as a novel approach for ovarian cancer treatment. Radioiodide is routinely and effectively used for the treatment of benign and malignant thyroid disease as a result of native thyroidal expression of NIS, which mediates iodide uptake. In vitro gene transfer studies in ovarian cancer cells revealed a 12- and five-fold increase in iodide uptake when transduced with Ad/CMV/NIS or Ad/MUC1/NIS, respectively. Western blot/immunohistochemistry confirmed NIS protein expression. In vivo ovarian tumor xenografts were infected with the adenoviral constructs. 123I imaging revealed a clear image of the CMV/NIS-transduced tumor, with a less intense image apparent following infection with MUC1/NIS. Therapeutic doses of 131I following CMV/NIS infection caused a mean 53% reduction in tumor volume (P<0.0001). MUC1/NIS-transduced tumors did not regress, although at 8 weeks following therapy, tumor volume was significantly less that of control animals (166 versus 332%, respectively, P<0.05). This study represents a promising first step investigating the potential for NIS-mediated radioiodide imaging and therapy of ovarian tumors.
Stability and delay of distributed scheduling algorithms for networks of conflicting queues

This paper explains recent results on distributed algorithms for networks of conflicting queues. At any given time, only specific subsets of queues can be served simultaneously. The challenge is to select the subsets in a distributed way to stabilize the queues whenever the arrival rates are feasible. One key idea is to formulate the subset selection as an optimization problem where the objective function includes the entropy of the distribution of the selected subsets. The dual algorithm for solving this optimization problem provides a distributed scheduling algorithm that requires only local queue-length information. The algorithm is based on the CSMA (Carrier Sense Multiple Access) protocol in wireless networks. We also explain recent results, some of them unpublished so far, on the delay properties of these algorithms. In particular, we present a framework for queuing stability under bounded CSMA parameters, and show how the expected queue lengths depend on the throughput region to be supported. When the arrival rates are within a fraction of the capacity region, queue lengths that are polynomial (or even logarithmic) in the number of queues can be achieved.
An evaluation of Gaussian plume-depletion models with dual-tracer field measurements

Abstract To evaluate atmospheric diffusion-deposition models, airborne tracer concentrations were measured during simultaneous releases of depositing (ZnS) and nondepositing (SF 6 ) tracers. The effective deposition velocity of the ZnS tracer, a polydisperse aerosol, was obtained from the near-surface, crosswind-integrated, dual tracer concentrations, using a method based on the surface depletion model of Horst (1977, Atmospheric Environment 11 , 41–46.). These deposition velocities were in good agreement with predictions based on the particle size distribution of the ZnS tracer and on wind tunnel measurements of the deposition velocities of monodisperse aerosols. Four Gaussian plume-depletion models were evaluated with the dual tracer data. Source depletion and constant eddy-diffusivity models were found to overestimate the depositing/nondepositing concentration ratio near the surface, but the estimates of these models were noticeably improved by a profile correction to the source depletion model and a mass-conservation correction to the K model. Of the four models tested, the corrected source depletion model gave the best agreement with the observations.
The significance of protein disulfide and sulfhydryl groups in prostaglandin action.

Abstract The contraction of the rat uterus and gerbil colon to prostaglandins E 1 , E 2 , F 1α and F 2α and the modification of ADP-induced platelet aggregation by PGE 1 and PGE 2 is inhibited by prior treatment with 1, 4-dithiothreitol (DTT) or with p-hydroxymercuribenzoate (PHMB). The inhibition by both reagents is characterized by an increase in the concentration of prostaglandin needed to elicit half-maximal and maximal responses. The inhibition due to PHMB is reversed by subsequent treatment with thiol compounds whereas, in the case of DTT, oxidising agents are required. N-ethylmaleimide (NEM) prevents the reversal of DTT inhibition by the oxidising agent 5,5′-dithiobis-(2-nitrobenzoate). The effect of DTT is attentuated by the presence of prostaglandin or 7-oxa-13-prostynoic acid, a competitive antagonist for prostaglandins, suggesting protection of those disulfide groups specifically associated with prostaglandin action. It is concluded that dithiothreitol reduces disulfide groups and that PHMB complexes with sulfhydryl groups in the vicinity of one or more components of the prostaglandin receptor.
Measurements in the Transition Vortex Flow Regime of Mixed Convection Above a Horizontal Heated Plate

Experimental results covering the transition vortex flow regime of mixed convection over a heated, horizontal flat plate are presented. A criterion for the onset of vortex instability as a function of critical Reynolds and Grashof numbers was established with the aid of a flow visualization technique. The three-dimensional nature of tis flow regime was documented through both velocity and temperature measurements using laser-Doppler and hot/cold-wire anemometers, respectively. A higher buoyancy force, through a higher plate temperature or a larger downstream distance and/or a lower free-stream velocity, intensifies the strength of the vortices. Velocity and temperature profiles through vortex peaks and valleys are reported to quantify the behavior of these vortices. It has been found from these measurements that the two-dimensional laminar mixed convection flow changes into a transitional three-dimensional vortex flow in a relatively short distance from the leading edge of the plate. The vortex three-dimensional flow continues to intensify as the buoyancy force increases and then develops into a two-dimensional fully turbulent flow at the end of the transition regime. These findings place an upper limit on the applicabilityof the two-dimensional, laminar boundary layer flow analysis for mixed convection a heated horizontal flat plate.
Effects of Submicellar Bile Salt Concentrations on Biological Membrane Permeability to Low Molecular Weight Non-Ionic Solutes†

Bile salts have been hypothesized to mediate cytotoxicity by increasing membrane permeability to aqueous solutes. We examined whether submicellar bile salt concentrations affect model and native membrane permeability to small uncharged molecules such as water, urea, and ammonia. Osmotic water permeability (Pf) and urea permeability were measured in large unilamellar vesicles composed with egg yolk phosphatidylcholine (EYPC) +/- cholesterol (Ch) or rat liver microsomal membranes by monitoring self-quenching of entrapped carboxyfluorescein (CF). Ammonia permeability was determined utilizing the pH dependence of CF fluorescence. Submicellar bile salt concentrations did not significantly alter Pf of EYPC +/- Ch or rat liver microsomal membranes. At taurodeoxycholate (TDC) or tauroursodeoxycholate concentrations approaching those that solubilized membrane lipids, CF leakage occurred from vesicles, but Pf remained unchanged. Higher bile salt concentrations (0.5-2 mM TDC) did not alter Pf of equimolar EYPC/Ch membranes. The activation energy for transmembrane water flux was unchanged (12.1 +/- 1.2 kcal/mol for EYPC) despite the presence of bile salts in one or both membrane hemileaflets, suggesting strongly that bile salts do not form transmembrane pores that facilitate water flux. Furthermore, submicellar bile salt concentrations did not increase membrane permeability to urea or ammonia. We conclude that at submicellar concentrations, bile salts do not form nonselective convective channels that facilitate transmembrane transport of small uncharged molecules. These results suggest that bile salt-mediated transport of specific substrates, rather than nonselective enhancement of membrane permeability, underlies bile salt cytotoxicity for enterocytes and hepatocytes.
A Practical Introduction to Skeletons for the Plant Sciences

Before the availability of digital photography resulting from the invention of charged couple devices in 1969, the measurement of plant architecture was a manual process either on the plant itself or on traditional photographs. The introduction of cheap digital imaging devices for the consumer market enabled the wide use of digital images to capture the shape of plant networks such as roots, tree crowns, or leaf venation. Plant networks contain geometric traits that can establish links to genetic or physiological characteristics, support plant breeding efforts, drive evolutionary studies, or serve as input to plant growth simulations. Typically, traits are encoded in shape descriptors that are computed from imaging data. Skeletons are one class of shape descriptors that are used to describe the hierarchies and extent of branching and looping plant networks. While the mathematical understanding of skeletons is well developed, their application within the plant sciences remains challenging because the quality of the measurement depends partly on the interpretation of the skeleton. This article is meant to bridge the skeletonization literature in the plant sciences and related technical fields by discussing best practices for deriving diameters and approximating branching hierarchies in a plant network.
A Double-Edged Sword: How Oncogenes and Tumor Suppressor Genes Can Contribute to Chromosomal Instability

Most solid tumors are characterized by abnormal chromosome numbers (aneuploidy) and karyotypic profiling has shown that the majority of these tumors are heterogeneous and chromosomally unstable. Chromosomal instability (CIN) is defined as persistent mis-segregation of whole chromosomes and is caused by defects during mitosis. Large-scale genome sequencing has failed to reveal frequent mutations of genes encoding proteins involved in mitosis. On the contrary, sequencing has revealed that most mutated genes in cancer fall into a limited number of core oncogenic signaling pathways that regulate the cell cycle, cell growth, and apoptosis. This led to the notion that the induction of oncogenic signaling is a separate event from the loss of mitotic fidelity, but a growing body of evidence suggests that oncogenic signaling can deregulate cell cycle progression, growth, and differentiation as well as cause CIN. These new results indicate that the induction of CIN can no longer be considered separately from the cancer-associated driver mutations. Here we review the primary causes of CIN in mitosis and discuss how the oncogenic activation of key signal transduction pathways contributes to the induction of CIN.
Exact analytic solution of a mathematical model for chromatographic operations

Abstract An analytic solution to a partial differential equation model describing mass transfer in an adsorption bed is presented. The model includes the effects of pore diffusional resistance within the adsorbent particles as well as resistance to mass transfer in the external film. The solution is developed for systems exhibiting linear equilibrium in the form of an infinite series which allows the calculation of chromatographic response curves for periodic, square-wave changes in concentration at the entrance of the chromatographic column. The series is rapidly convergent for typical chromatographic conditions, and it can be integrated term by term to obtain expressions that allow direct calculation of separation performance parameters such as product cut purity and per cent recovery.
Pathway to understanding AIDS.

The solution structure of HIV-1 Nef and mapping of its binding surface for the SH3 domain of a protein tyrosine kinase illustrates how the primate lentiviruses have tapped into host cell activation pathways.
Induction of Growth Factor Receptors on Cultured Human Melanocytes

Using a sensitive and selective culture system for human epidermal melanocytes, we have demonstrated that the morphologic changes induced by addition of phorbol 12-tetradecanoate 13-acetate (TPA) to proliferating newborn melanocytes are associated with induction of nerve growth factor (NGF) receptors, as measured by messenger RNA (mRNA) levels and protein accumulation and by cell surface immunofluorescent staining. Growth factor deprivation or addition of NGF similarly results in NGF receptor induction. NGF is believed to function in vivo and in vitro as a survival factor for many neural crest-derived cells and has been demonstrated to promote specific neural cell functions ranging from neurite outgrowth to enzyme induction, but to date no role for NGF has been identified with regard to normal human melanocytes. Our data demonstrate that, given appropriate stimulation, cultured human melanocytes may express the NGF receptor gene and therefore suggest that NGF may modulate human melanocyte behavior in vivo. This first demonstration of a growth factor receptor on human melanocytes provides an important opportunity to explore signal transduction relevant to their growth, differentiation, and malignant transformation.
Deviations in food and water consumption and urinary electrolytes with frequency of measurement in rats

Metabolic readings taken 1,2, and 6 times per day from ad lib rats maintained under constant illumination revealed phasic increases in food and water consumption with each change in the number of daily measurements by the E. A temporary dilution in urinary electrolyte concentrations was noted during the first day following the switch from 2 to 6 readings per day. It is recommended that the number of reading periods be fixed from the outset of investigations concerned with metabolism. If this is not possible, then appropriate control groups should be employed to partial out the effect of any changes in the frequency of E presence from those due to the experimental manipulation.
English proficiency and physicians' recommendation of Pap smears among Hispanics

Abstract Background : Hispanics have one of the highest incidence rates of cervical cancer. Physician recommendation is one of the most important cues to cancer screening; however, low English proficiency among Hispanics may hinder health providers' recommendation of Pap smears. Methods : Analysis of data from the 2000 National Health Interview Survey. All Hispanic women, age ≥18, without a Pap smear in the past 3 years or ever and who visited a health care provider in the past year were included. The main outcome was receipt of Pap smear recommendation by a health care provider. Results : A total of 314 Hispanic women were included in the analysis, 44.9% were highly English proficient. Only 7.7% of low English proficient Hispanics not up-to-date in cancer screening reported a recommendation for a Pap smear as compared to 14.3% of highly proficient Hispanics. After adjusting for sociodemographics and health access and utilization factors, highly English proficient Hispanics were more than two times as likely to report receiving a recommendation for a Pap smear as compared to the less proficient (aOR 2.2, 95% CI 1.1–4.5). Conclusions : Low English language proficiency is a barrier to receive a recommendation for Pap smear among Hispanic women not up-to-date with cervical cancer screening. Further research is needed to explore specific mechanisms responsible for the low recommendation rates and to assess the impact of interpreters or Spanish-speaking providers on Pap smear recommendation rates.
Isolation of highly purified glomerular complexes from rabbit cerebellum.

Es wird eine neue Methode zur Praparation der sogenannten «glomerularen Komplexe» aus Kaninchen-Kleinhirn beschrieben, deren komplexe innere Struktur weitgehend intakt bleibt. Mit Hilfe der quantitativen elektronenmikroskopischen Methode wurden uber 90% intakter Glomeruli errechnet.
Influence of soil temperature on niacin and thiamine in honey mesquite

The influence of soil temperature was examined on niacin and thiamine concentration in honey mesquite (Prosopis glandulosa var.glandulosa) seedlings. The seedlings were grown in soil temperature regimes of 21, 27, and 32°C in a controlled environment growth room. Nodulation randomly occurred on the roots of the seedlings, necessitating separate analysis according to the occurrence of nodulation. Roots of nodulated seedlings from the 21°C soil temperature regime contained greater quantities of niacin and thiamine compared to root samples from seedlings grown in either 27 or 32°C regimes. Niacin concentration of non-nodulated seedlings was highest in samples from seedlings grown in the 27°C soil temperature regime and lowest in samples from seedlings grown in the 21°C regime. Thiamine concentration was the greatest from non-nodulated seedlings grown in the 27°C soil temperature regime, while the thiamine concentration of non-nodulated samples from the 32°C regime was the least. Optimal soil temperature for honey mesquite root growth appears to be about 27°C. At sub-optimal soil temperatures niacin might have limited ‘growth’ while at supra-optimal soil temperatures, thiamine might be a limiting factor.
Phase 1 clinical trial of irradiated autologous melanoma cells adenovirally transduced with human GM-CSF gene

The objective of this study was to determine the safety and antitumor activity of an autologous GM-CSF-secreting melanoma cell vaccine that was engineered ex vivo with recombinant replication-incompetent adenovirus harboring a human GM-CSF gene (Adv/hGM-CSF). Melanoma samples were surgically obtained from 30 patients (15 female and 15 male, ages ranging from 23 to 87) and were processed for vaccine preparation. Due to stringent eligibility criteria, 9 out of 30 patients were enrolled in the phase 1 clinical trial (FDA IND7677). Melanoma cell lines established from surgical specimens of 9 patients were transduced with Adv/hGM-CSF (MOI of 100) and subsequently irradiated at 35 Gy. These cell lines secreted human GM-CSF in vitro at an average rate of 80-424 ng/10(6) cells/24 h. All patients were intradermally and subcutaneously injected at several sites with irradiated autologous melanoma cells (2x10(6)-1x10(7) in 300 microl saline), 2-10 times, at intervals of 4-8 weeks. None of the patients vaccinated showed any serious adverse systemic response. Three patients (nos.1, 6 and 7) demonstrated local reaction (erythema) to the vaccination. Tumor-specific CTL assays performed in the absence of K562 cells showed that the levels of CTLs in peripheral blood of 5 patients increased following vaccination, whereas those in one patient declined. Levels of CTLs assayed in the presence of K562 cells were considerably lower than those assayed in the absence of K562 cells, but were also found to increase following vaccination in the peripheral blood of 6 patients. A patient who had been vaccinated 10 times (patient 1) responded to the vaccination by apparent reduction in size of metastatic tumor in the lung. Immunohistochemical examination of the vaccination sites of patient 1, biopsied after the 3rd and 4th vaccination. showed that the vaccination sites responded with infiltration of inflammatory cells, such as T cells (CD3+, CD8+), macrophages and dendritic cells (CD83+), for a period up to about 8 days. These data suggest that repeated vaccinations with irradiated autologous GM-CSF-producing tumor cells were well tolerated by patients and led to the activation of an antitumor immune response in some patients.
In-channel modification of electrochemical detector for the detection of bio-targets on microchip

Abstract The coulometric efficiency (Ceff) of an amperometric detector integrated on PDMS/glass capillary electrophoresis microfluidic device (microchip) has been enhanced by in-channel electrochemical modification. In-channel electrochemical deposition of gold particles was performed in order to vertically increase the surface area of the Au sensing microelectrode. The roughness of the electrodes was characterized using scanning electron microscopy and profilometric analysis. The degree of electrode modification was also characterized by roughness factor determination. Separation processes including detection potential was optimized and the analytical performance of the microchip was tested using a mixture of dopamine (DA) and catechol (CA). The modified electrochemical detector provided well-resolved separation of DA and CA in less than 60 s with enhanced sensitivity; no peak broadening was observed. The limit of detection using in-channel modification of working electrode for DA and CA are 60 and 110 nM, respectively. Thus, in-channel electrochemical deposition of metallic particles should be used to enhance the Ceff of integrated amperometric detection of analytes with good redox properties in order to obtain lower LODs.
Clear plaque mutants of phage P1

Abstract The effect of a shift in temperature on lysogens for temperature-sensitive clear mutants in each of the four P1 clear cistrons is described. Only gene c1 is induced to form phage by such a shift, so it is concluded that this gene is responsible for immunity repressor production. The growth of lysogens carrying a c2, c3, or c4 mutant stops when the temperature is shifted to that at which the clear gene cannot function, indicating that these clear plaque cistrons are also active in the prophage state. Gene c3, in addition to affecting the establishment of lysogeny, appears to be essential for vegetative phage development at early and late times after infection.
Ribavirin pharmacodynamics in high-risk patients for acquired immunodeficiency syndrome

Ribavirin was administered orally in escalating doses for 2 or 4 weeks to 15 symptom-free, human immunodeficiency virus seropositive homosexual men with generalized lymphadenopathy. Reverse transcriptase activity was inhibited during therapy when steady-state plasma concentrations were >6 µmol/L. These concentrations were achieved with 1200 or 2400 mg/day for 2 weeks or a loading dose of 2400 mg/day for 3 days followed by 600 mg/day for 4 weeks. Drug accumulation occurred at all doses. The elimination half-life appeared to be approximately 2 weeks. Reversible adverse reactions, principally resulting in central nervous system symptoms and anemia, correlated with dose and duration of therapy. Immunologic enhancement of T-lymphocyte—mediated mitogen-induced responses was observed in the majority of patients who had reduction in reverse transcriptase activity. However, specific T4 + lymphocyte—mediated antigen-induced responses increased to within the normal range in only three patients. Significant enhancement appeared to correlate with the severity of baseline antigen-induced functional impairment. These data indicate that oral ribavirin can be given for at least 1 month with acceptable toxicity at doses that appear to inhibit human immunodeficiency virus replication. Clinical Pharmacology and Therapeutics (1987) 42, 365–373; doi:10.1038/clpt.1987.165
Frictional and electrical interactions in current collectors

Abstract Numerical results are given for electric current flow through a sliding contact that involves a graphite brush and a copper slip ring. The contact of length 2 l and unit depth moves with velocity c along the brush face. It is found that for a given fixed set of operating conditions (current I , sliding velocity V , contact force F N etc.) many values of c and l may exist; it is also found that c is linear in sliding velocity V .
Steric orientation of hapten groups and the effect on antibody reactivity

Abstract Antibodies to the II isomeric form of the fluorescyl hapten group were elicited in rabbits. IgG antibodes specific for the Fl(II) group were purified by immunoadsorption and their ligand-binding properties measured by fluorescence quenching and equilibrium dialysis. Anti-Fl(II) IgG antibodies were compared to IgG antibodies to the I isomeric form at the protein and active site levels. Comparative H- and L-chain patterns in electrophoresis, using sodium dodecyl sulfate acrylamide gels, indicated small but significant differences. Fluorescence quenching studies with isomeric ligands, in which the side group was small [e.g. FlNH2(I)], suggested that the active sites of the two anti-isomeric populations were quite similar. However, when the fluorescyl group was attached to a large antibodies to discriminate the isomeric forms was affinity dependent. Minor but significant differences in the active sites of the two antibody populations were noted in quantum yield, spectral shift and circular dichroism studies monitoring bound ligand. The studies suggest that steric isomers of large hapten groups may stimulate common anti-fluorescyl clones, and the differences noted in the antibody populations may reflect a differential quantitative enrichment of specific clones.
Proximal tubule structure-function relationships during volume expansion in necturus.

Proximal tubule structure-function relationships during volume expansion in Necturus. Studies were performed in Necturus to determine the relationship of proximal tubular epithelial structure to the physiologic state of net NaCl transport under control experimental conditions and during expansion of the extracellular volume. Although net NaCl transport was depressed during volume expansion in both free flow and stopped flow tubules, morphology was different. Compared to control, epithelial cells of free flow tubules fixed in situ during volume expansion were flattened (reduction in cell height) and intercellular spaces were closed, whereas intercellular spaces were markedly dilated in stopped flow tubules. Dilated intercellular spaces were associated with reversal of the normal hydrostatic pressure gradient. Structural changes in the region of the tight junction were observed during volume expansion. It is proposed that alteration of the tight junction as a diffusion barrier and/or a decrease in effective distance between interstitial and luminal compartments would result in an increase in permeability and flux in the capillary to lumen direction, thus reducing net NaCl transport during volume expansion.
Origin of planetary wrinkle ridges based on the study of terrestrial analogs

Wrinkle ridges (linear, asymmetric topographic highs) are common physiographic features on the Moon, Mars, and Mercury. We describe here some terrestrial features of similar morphology and scale that have formed under compressional stress systems similar to planetary wrinkle ridges. All of the terrestrial analogs are produced by the anticlinal folding of rocks above reverse faults that shallow and typically break the surface. Characteristics common to both terrestrial and planetary ridges include (1) a linear, asymmetric antiformal shape; (2) tension cracks and grabens along the hinges of the antiform; (3) overlapping, en echelon lobes; (4) reversals of the sense of asymmetry along strike; (5) occurrence in compressional environments; and (6) similarity to features produced during compression of various materials in laboratory scale models. These similarities strongly suggest that planetary wrinkle ridges result from deformation associated with shallow thrust faults that either break or come close to the surface. Kinematic models capable of explaining the development of wrinkle ridges include (1) anticlinal folding of rocks over a buried thrust fault that may subsequently propagate to the surface and (2) fault-bend folding of upper-plate rocks over the surface-flattening bend of a thrust fault.
Gas-liquid chromatography-mass spectrometry of methylated and deuteriomethylated per-O-acetyl-aldononitriles from D-mannose

Abstract Peracetylated aldononitriles of the tetra-, tri-, and di-methyl ethers of D-mannopyranose were separated by gas-liquid chromatography, and analyzed by mass spectrometry. Through introduction of deuteriomethyl ether groups, various fragmentions constituting the mass spectra were identified and related to the parent methylated sugar structures. Also identified were several characteristic series of fragment ions that are common to two or more methylated D-mannopyranosides. As expected, mass spectra of the D-mannose derivatives were identical to those previously observed for D-glucose methylated in the same positions. Distinctive mass spectra were also recorded for all additional di- O -methyl-D-mannose derivatives. This information permits use of peracetylated aldononitrite derivatives in methylation-fragmentation analysis of aldohexans.
Apigenin decreases expression of the myofibroblast phenotype

Abstract We investigated the effect of the dietary flavonoid apigenin on myofibroblast function. We report that in myofibroblasts treated with apigenin, proliferation and basal levels of α1(I) collagen and α-smooth muscle actin mRNAs were markedly reduced. Apigenin also attenuated the transforming growth factor-β-stimulated increases of α1(I) collagen and α-smooth muscle actin mRNAs. Characterization of the apigenin effects indicates that apigenin reduces both the stability of the α1(I) collagen mRNA and the rate of transcription of the α1(I) collagen gene through a cycloheximide-sensitive pathway. Western blot analyses indicate that Akt activity is reduced in apigenin-treated myofibroblasts.
Capturing Judgment Policies: A Field Study of Performance Appraisal

Mathematical models of judgment policy are compared in evaluating 625 performance reports during a single rating cycle. Linear and nonlinear analyses are used to describe the cues most important in...
The benefits of early valve replacement in asymptomatic patients with severe aortic stenosis

Objective The prevalence of aortic valve stenosis increases with age, and often the diagnosis is made by echocardiography before symptoms develop. To address the controversies in management of asymptomatic patients with severe aortic stenosis, we assessed the early and late outcomes of aortic valve replacement in these patients. Methods We analyzed data of 622 patients, aged 72 ± 11 years, with isolated asymptomatic severe aortic stenosis. Patients were identified with a peak systolic velocity of greater than 4 m/s by transthoracic echocardiography and monitored for the development of symptoms and need for aortic valve replacement. Results After the initial diagnosis, 166 (27%) patients who were initially asymptomatic experienced the development of chest pain, shortness of breath, or syncope and had aortic valve replacement at Mayo Clinic. Another 97 (16%) patients had aortic valve replacement in the absence of symptoms. Symptomatic patients were more likely to undergo coronary bypass grafting ( P P P = .43). The survival of the 263 patients who underwent aortic valve replacement was not significantly different from an age- and sex-matched population ( P = .99); 10-year survival was 64% (95% confidence interval [CI] 57%–72%) for symptomatic patients and 64% (95% CI 54%–75%) for asymptomatic patients ( P = .92). At 3 years after diagnosis of severe aortic stenosis, 52% (95% CI 48%–56%) of 622 patients had had symptoms develop, undergone aortic valve replacement, or died. Among the entire cohort, older age at diagnosis (hazard ratio [HR] 1.1 per year, P P P = .01), symptoms (HR 2.13, P P Conclusion Among patients with severe aortic stenosis who underwent aortic valve replacement, early and late outcomes were similarly good in patients who had symptoms before the operation compared with those who were asymptomatic. It is important to note that among patients with asymptomatic severe aortic stenosis, the omission of surgical treatment was the most important risk factor for late mortality.
Perceptions of Regional Economic Development: Can Win—Lose Become Win—Win?

This study extends previous research that explored the perceptions of economic development decision makers in Illinois regarding regional economic development competition and cooperation.This research project further contributes to an understanding of the interlocal cooperative interactions that exist between and among local governments.The author uses a qualitative approach using in-depth interviews conducted in 2006-2007 of participants within selected regions of Missouri, Indiana, Kentucky, and Tennessee. In 2002, communities participated in cooperative efforts, understood the benefits of cooperation, and expressed a willingness to cooperate in regional economic development efforts, however, the myriad obstacles to cooperation significantly curtailed cooperative efforts; now, the communities examined in Missouri, Indiana, Kentucky, and Tennessee have moved to actual cooperative action. Interviewees recognize that they must cooperate to be successful in economic development efforts— suggesting perhaps t...
Isolation and partial characterization of a pink pigment from normal human plasma.

DURING our work on the very soluble constituents of normal human plasma a pink pigment was discovered.
Origin and destination entropies of U.S. 1965-70 age-sex-specific intercounty migration flows.

Eight independent pairs of entropy-based rankings of 3140 U.S. county-level units are obtained. The criteria employed are the homogeneities of the distribution of 1965-70 in- and out-migrants of each county--for eight age-sex-specific groups--over the other 3139 counties. The most homogeneous counties for males of ages 19-39 in 1970 consistently have major military facilities. The results show that "for those 65 and over Florida Arizona and Texas counties have the broadest in-migration while Northern metropolitan counties have dispersed out-migration. The cross-correlations of entropies--though all strongly positive--are lowest between those 19-39 and those 65 and over and relatively weak in general between those 65 and over and other groups. In all eight demographic groups destination entropies reach higher values than origin entropies." (EXCERPT)
Efficacy of biliary scintigraphy in suspected sphincter of oddi dysfunction

Sphincter of Oddi dysfunction (SOD) can pose diagnostic challenges for the physician. SOD is classified into types I, II, and III, but clinical outcome after sphincterotomy for suspected types II and III SOD has been unpredictable. Therefore, accurate diagnosis of types II and III SOD is important because of the increased risk of sphincterotomy in patients with SOD. Endoscopic sphincter of Oddi manometry (ESOM) is the gold standard for diagnosis of SOD; however, it is associated with significant morbidity and is not an appropriate screening test. Quantitative hepatobiliary scintigraphy (QHBS) has demonstrated good sensitivity as a screening test for SOD in patients following cholecystectomy; however, studies using this methodology are criticized for poor design and patient selection. Recent publications address these criticisms and provide evidence that QHBS and ESOM are comparable diagnostic tools after exclusion of organic biliary obstruction. QHBS can effectively replace invasive ESOM in the diagnostic algorithm of SOD.
Supramolecular Heterocatemers and Their Role in Cocrystal Design

The cocrystals (4,4‘-biphenol)3·(2-aminopyridine)2 (1), (4,4‘-biphenol)·(caprolactam)2 (2), and (resorcinol)·(caprolactam)2 (3) self-assemble in the form of supramolecular heterocatemers and provide insight into a possibly general approach for the crystal engineering of cocrystals.
Formation of composites comprised of calcium deficient HAp and cross-linked gelatin

Cross-linked gelatin/calcium deficient hydroxyapatite (CDHAp) composites were prepared at or near physiologic temperature. alpha-tricalcium phosphate (alpha-TCP) or a mixture of tetracalcium phosphate and dicalcium phosphate were used as CDHAp precursors. Glutaraldehyde was used to cross-link the gelatin fibers. CDHAp formation reached completion in the presence of cross-linked gelatin fibers. Effects of cross-linking concentrations, proportions of gelatin fiber, molecular weight of gelatin and the temperature of the hydration reaction on the formation of CDHAp were studied. Cross-linked gelatin acts as a nucleating agent for CDHAp formation. The pH variations during CDHAp formation are lower at the onset of the reactions in the presence of cross-linked gelatin fibers. Although cross-linked gelatin fibers enhance CDHAp formation their composites have low mechanical strengths. Swelling of gelatin appears to be a major factor that limits the strengths of the CDHAp/cross-linked gelatin composites.
Time course of increased heme oxygenase activity and expression after experimental intracerebral hemorrhage: correlation with oxidative injury

Heme oxygenase (HO) activity in tissue adjacent to an intracerebral hematoma may modulate cellular vulnerability to heme-mediated oxidative injury. Although HO-1 is induced after experimental intracerebral hemorrhage (ICH), the time course of this induction, its effect on tissue HO activity, and its association with oxidative injury markers has not been defined. We therefore quantified HO activity, HO-1 expression, tissue heme content, and protein carbonylation for 8 days after injection of autologous blood into the mouse striatum. Increased striatal HO-1 protein was observed within 24 h, peaked on day 5 at a level that was 10-fold greater than baseline, and returned to baseline by day 8; HO-2 expression was not altered. HO activity increased by only 1.6-fold at its peak on day 5, and had also returned to baseline by day 8. A significant increase in protein carbonylation was observed at 3-5 days, which also was markedly attenuated by 8 days, concomitant with a return of tissue heme to near-normal levels. These results suggest that the increase in HO activity in tissue surrounding an experimental ICH is considerably less than would be predicted based on an analysis of HO-1 expression per se. As HO-1 expression is temporally associated with increased tissue heme and increased protein carbonylation, it may be more useful as a marker of heme-mediated oxidative stress in ICH models, rather than as an index of HO activity.
Iterating Structures: Teaching Engineering as Design

AbstractWhen structural engineering is taught as a design discipline, engineering and architecture students can understand the open-ended potential of structural engineering solutions and gain a better understanding of the opportunities for structure to shape and reinforce architectural concepts. By formalizing the iterative aspect of design processes common in architecture design studios, structural engineering courses can integrate design without requiring a radical configuration of the conventional lecture class structure. This paper outlines models that include design and analysis iterations in structures lecture courses. Developed for undergraduate and graduate architecture students, this model could be applied to engineering education as well. Student work from these exercises demonstrates integration of architecture and structural engineering. Three examples of iterations are presented to highlight a range of applications, including (1) iteration of method of spanning (e.g., truss, arch, and cable ...
Creep cavitation in iron—I. Sulfides and carbides as nucleation sites

Abstract The nucleation of creep cavities in iron containing controlled additions of C, P and S has been studied using slow strain rate tensile tests ( ϵ = 1.1 × 10 −6 and 4.4 × 10−5s−1) at te and 800°C. The test materials all had the same 100 μm grain size and showed approximately the same UTS at 700°C. When failure occurred by grain boundary cavitation a ductility minimum was found at 700°C and the ductility (% RA) was less than about 40%. The cavitation process depends strongly on the S content: if the S content is above the solubility limit, cavities nucleate easily on grain boundary sulfides and the ductility is very low. In this S regime additions of P can improve the ductility, but the mechanism of this improvement has not been identified. If the S content is well below the solubility limit (about 1 wtppm), the material is always very ductile, even though there are many small (~ 0.1 μm dia.) oxide particles on the grain boundaries that are potential nucleation sites. Carbides were never seen to nucleate cavities, even when the C concentration is as high as 4 times the solubility limit at 700°C. Auger analyses of the grain boundary facets of one of the brittle alloys showed that both S and C segregate to the grain boundaries.
Shoal formation in the Piscataqua River, New Hampshire

The formation of a shoal was investigated in the Piscataqua River, New Hampshire, which is a well-mixed channel with low freshwater flow and tidal currents up to 2.3 m s−1. Observations of sediment characteristics, bathymetry, and bottom current were made, and theory was used to predict bedload transport. Sediment sampling showed the bottom material to be coarse sand and gravel, and sidescan sonar revealed large sand waves directed upriver at the shoal. Bottom current measurements were made along transects upriver and downriver of the shoal and downriver of an adjacent deepwater area that was also studied for comparison. Bedload flux inferred from current measurements using the Brown-Einstein theory indicated that transport is generally directed upriver. Sediment budget calculations showed the shoal area to be depositional before, immediately after, and subsequent to a dredging operation at rates of 0.36 m yr−1, 1.06 m yr−1, and 0.35 m yr−1, respectively. Predredge and subsequent rates were consistent with the historical record of removal by dredging at the shoal.