cssi/SciSciGPT-SciSciNet huggingface dataset:
Bulk rheology of dilute suspensions in viscoelastic liquids

A theoretical relation is derived for the bulk stress in dilute suspensions of neutrally buoyant, uniform size, spherical drops in a viscoelastic liquid medium. This is achieved by the classic volume-averaging procedure of Landau and Lifschitz which excludes Brownian motion. The disturbance velocity and pressure fields interior and exterior to a second-order fluid drop suspended in a simple shear flow of another second-order fluid were derived by Peery [9] for small Weissenberg number (We), omitting inertia. The results of the averaging procedure include terms up to orderWe2. The shear viscosity of a suspension of Newtonian droplets in a viscoelastic liquid is derived as $$\eta _{susp} = \eta _0 \left[ {1 + \frac{{5k + 2}}{{2(k + 1)}}\varphi - \frac{{\psi _{10}^2 \dot \gamma ^2 }}{{\eta _0^2 }}\varphi f_1 (k, \varepsilon _0 )} \right],$$ whereη0, andω10 are the viscosity and primary normal stress coefficient of the medium,e0 is a ratio typically between −0.5 and −0.86,k is the ratio of viscosities of disperse and continuous phases, and\(\dot \gamma \) is the bulk rate of shear strain. This relation includes, in addition to the Taylor result, a shear-thinning factor (f1 > 0) which is associated with the elasticity of the medium. This explains observed trends in relative shear viscosity of suspensions with rigid particles reported by Highgate and Whorlow [6] and with drops reported by Han and King [8]. The expressions (atO (We2)) for normal-stress coefficients do not include any strain rate dependence; the calculated values of primary normal-stress difference match values observed at very low strain rates.
Temperature Effect of Interfacial Fracture Toughness on Underfill for Pb-Free Flip Chip Packages

In this study, the interfacial fracture toughness between passivation layer and underfill was investigated at elevated temperatures by performing conventional four-point bending test and finite element simulation. Since the board level reflow temperature for Pb-free flip chip packaging is reaching as high as 260degC, the concern about delamination at the interfaces between underfill and its surrounding components becomes a more serious reliability issue. To estimate the interfacial strength, interfacial fracture toughness at a specific mixed mode loading condition is calculated. As temperature is increased, the interracial toughness was also increased up to the glass transition temperature. Beyond the glass transition temperature, however, interfacial fracture toughness is decreased.
Teaching groupwork at a distance using an asynchronous online role-play

Given the proliferation of online groups and growth in distance learning, there is a pressing need to develop best practices for teaching group work online. The following paper explores the implementation of an asynchronous role-play exercise conducted in online undergraduate classes about group work. The overall purposes were to help students learn about group stages and dynamics through participating in an experiential exercise and further develop their knowledge about online groups. Thematic analyses of students’ reflections on their online role-play experience are discussed, considerations regarding the complex role of the instructor are explored, educational benefits and related challenges are analyzed, and guidelines are presented to facilitate best practices when implementing an online role-play exercise.
Cavity Flow Assessment Using Advanced Turbulence Methods

The vortex shedding generated by compressible subsonic flow interacting with a wall cavity has been investigated using large-eddy-simulation-based turbulence techniques embedded within a legacy Reynolds-averaged Navier– Stokes solver. Cavity simulations using hybrid turbulence approaches seek the accuracy of large-eddy simulation by providing filtering andmodeling of subgrid-scale turbulence with the cost of traditional Reynolds-averaged Navier– Stokes. Simulations applying differing techniques of hybridization of the Menter k-! shear stress transport Reynolds-averaged Navier–Stokes approach include detached eddy simulation (DES-SST), blended subgrid-scale turbulencemodels (GT-HRLES), and a self-adjusting large-eddy-simulation–very-large-eddy-simulation technique (KES) provide an understanding of differing hybrid approaches. Cavity flow results from Reynolds-averaged Navier–Stokes and hybrid simulations are compared with experiment and large-eddy simulation predictions. Evaluation of important flow characteristics illustrates the abilities of these advanced turbulence modeling techniques comparedwith traditional Reynolds-averagedNavier–Stokesmodels. Examination of the influence of the grid, time step, and simulation period demonstrates the sensitivity of the aerodynamic and aeroacoustic predictions to these parameters. In particular the subgrid-scale blended model, GT-HRLES, shows significant improvement in the ability to capture the acoustic signatures and flowfield features on a Reynolds-averaged Navier–Stokes or very-large-eddy-simulation grid compared with the other models.
Nonlinear Adaptive Attitude Control of Spacecraft

A model reference adaptive control law is presented for largeangle rotational maneuvers of spacecraft using reaction jets. It isassumed that the various parameters of the spacecraft arecompletely unknown, and unknown but bounded disturbancetorques are acting on the spacecraft. The controller includes adynamic system in the feedback path. Simulation results arepresented to show that fast, large angle rotational maneuvers can beperformed using the adaptive controller in spite of uncertainty inthe system.
Type I interferon response and innate immune sensing of cancer

Unexpectedly, many cancers appear to induce a spontaneous adaptive T cell response. The presence of a T cell infiltrate has been linked to favorable clinical outcome in multiple cancer types. However, the innate immune pathways that bridge to an adaptive immune response under sterile conditions are poorly understood. Recent data have indicated that tumors can induce type I interferon (IFN) production by host antigen-presenting cells (APCs), which is required for a spontaneous T cell response in vivo. The innate immune sensing pathways that trigger type I IFN production are being elucidated. Host type I IFNs are also required for optimal therapeutic efficacy with radiation. This recently uncovered role for host type I IFNs for antitumor immunity has important fundamental and clinical implications.
Is the quantum of transmitter release composed of subunits

THE quantal theory of transmitter release proposed by del Castillo and Katz1 states that the endplate potential is built up of unit potentials (quanta), each of which is the size of the spontaneously occurring miniature endplate potentials (m.e.p.ps). It has recently been proposed that unit potentials and m.e.p.ps are built up of 2–15 still smaller subunits2–4. The basis for this proposal has been drawn in part from two observations. First, some preparations show a distinct class of small-mode m.e.p.ps of amplitude typically about 1/7 that of the average m.e.p.p. Second, amplitude histograms of m.e.p.ps display multiple peaks whose amplitudes sometimes appear to be integer multiples of the small-mode m.e.p.p. amplitude2–4. We now present evidence suggesting that the peaks on histograms of m.e.p.p. amplitudes may arise from random variation in the data due to a limited sample size. The data do not support the proposal that m.e.p.ps and unit potentials are composed of 2–15 subunits.
Extensibility Characteristics of Human Cheek-Visco-elastic Properties

Using a hydraulic bellows system mounted on a maxillary partial denture, continuous force-displacement data were taken in an edentulous area in the maxillary bicuspid-molar region on ten adults. Both loading and unloading force-displacement curves showed three segments. Two visco-elastic properties - hysteresis and relaxation - were consistently evident. The maximum difference in force-magnitude of the hysteresis loop was 1.02 g. A pre-conditioning phenomenon of the cheek tissue, evidenced by a reduction of the area of the hysteresis loop, was observed in a series of repeated runs.The significance of the study was that: (1) in some individuals, the cheek could be displaced, by expansion of the molars, up to 1 mm into a second stable position; and (2) the relaxation phenomenon suggests a limited adjustive capacity in cheek stiffness.
Cash incentives and turnover in center-based child care staff

Abstract The current study evaluates the Workforce INcentive Project (WIN), a programmatic effort to increase child care workforce stability in center- and home-based child care providers via the provision of bi-annual cash incentives based on educational attainment. Five hundred and thirteen center-based teaching staff (304 WIN and 209 comparison) and 167 center directors (93 WIN and 74 comparison) from 179 state-licensed child care centers (99 WIN and 80 comparison) participated in the study reported. Survival analyses were conducted to compare turnover rates between the WIN group and the comparison group over a 20-month period. All analyses controlled for participant satisfaction with employment, location (i.e., urban, suburban, and rural), and, where appropriate, hourly wages. Although WIN participation was generally associated with lower rates of turnover in center-based staff, when position type, educational attainment, experience in the field, and hourly wages were considered (separately and together), WIN's relationship with turnover varied widely for directors and teaching staff. Findings are discussed in terms of past research and future cash incentive programs.
Explicit Bounds for the Return Probability of Simple Random Walks

We give an exact computation of the second order term in the asymptotic expansion of the return probability, P 2 (0,0), of a simple random walk on the d-dimensional cubic lattice. We also give an explicit bound on the remainder. In particular, we show that P 2 (0,0) < 2 (d/4πn) d/2 where n ≥ M=M(d) is explicitly given.
Frequency and predictors of obstructive sleep apnea among individuals with major depressive disorder and insomnia

Abstract Objective Disturbances in sleep continuity are common among individuals with major depressive disorder (MDD) and can impact the course of depression and response to treatment. Several studies have examined depressive symptom severity among sleep-disordered patients with obstructive sleep apnea (OSA). In contrast, little is known about OSA in patients with MDD. The goal of this study was to examine the frequency and predictors of OSA in a sample of individuals with comorbid MDD and insomnia. Methods Participants were 51 individuals who enrolled in a treatment study on insomnia and depression, met criteria for MDD and comorbid insomnia, and underwent an overnight polysomnography evaluation. An apnea–hypopnea index ≥15 events per hour was used as a cutoff score for OSA. Regression analyses were conducted to examine clinical and demographic predictors of OSA severity as measured by the apnea–hypopnea index. Results The results revealed that 39% of the sample met criteria for OSA. The OSA group had significantly higher body mass index (BMI) scores and a significantly greater proportion of men. Regression analysis revealed that male sex, older age, and higher BMI were significant predictors of OSA severity. Neither depression severity nor insomnia severity was a significant predictor. Conclusions These findings indicate that the frequency of OSA is higher among individuals with comorbid MDD and insomnia than was previously found among people with either MDD or insomnia alone. In addition, previously identified predictors of OSA (male sex, older age, and high BMI) also apply to this population.
Correlation of aromatase activity with histological differentiation of breast cancer--a morphometric analysis.

Differentiation is a term that indicates the degree to which a tumor resembles histologically the tissue or cell of origin. A system to quantitate the proportion of breast cancer cells participating in glandular differentiation or remaining within ducts was employed. The degree of tumor differentiation of 58 primary breast cancers was correlated with estrogen (ER) and progesterone receptors (PR) and tumor aromatase activity. There was a significant association between tumor differentiation (≥2% cancer cells exhibiting glandular differentiation) and the presence of ER or PR in tumors. Conversely, there was no correlation between tumor differentiation and measurable tumor aromatase activity.
Competruism: Ideology with a sustainable future

Abstract Unless the advanced nations adopt a new socioeconomic order compatible with the technological milieu of the information age, they could face catastrophe in the years just ahead. Free societies should consider shifting from capitalism, with its perilous obsession with consumption, to the competruistic ideology which provides a sustainable future through its focus on conservation. This emerging ideology employs ‘productive efficiency’ as the criterion of success in its mission to maximize the value its free societies add to the global economy.
Gasoline taxes and revenue volatility: An application to California

This paper examines how applying different combinations of excise and sales taxes on motor fuels impact the volatility of retail fuel prices and tax revenues. Two features of gasoline and diesel markets make the choice of tax mechanism a unique problem. First, prices are very volatile. Second, demand for motor fuels is extremely inelastic. As a result, fuel expenditures vary substantially over time. Tying state revenues to these expenditures, as is the case with a sales tax, results in a volatile stream of revenue which imposes real costs on agents in an economy. On July 1, 2010, California enacted Assembly Bill x8-6, the “Gas Tax Swap”, increasing the excise tax and decreasing the sales tax on gasoline purchases. While the initial motivation behind the revenue neutral swap was to provide the state with greater flexibility within its budget, we highlight that this change has two potentially overlooked benefits; it reduces retail fuel price volatility and tax revenue volatility. Simulating the monthly fuel prices and tax revenues under alternative tax policies, we quantify the potential reductions in revenue volatility. The results reveal that greater benefits can be achieved by going beyond the tax swap and eliminating the gasoline sales tax entirely.
Development of curved helical micro-drill point technology for micro-hole drilling

At the present time micro-drills with planar point geometry are prevalent in industrial practice. Unfortunately, they possess a number of undesired characteristics and limitations that influence their performance in terms of hole quality and tool life. To resolve the problems of planar micro-drills, this paper focuses on issues related to micro-drill point geometry (including the flank and flute) and presents a framework for a technology, built around a computer integrated system, for the design, manufacture, and evaluation of drills in general and of a new generation of micro-drills with curved helical point and flute geometry in particular. It is expected that this technology will support the rapid development of new customized micro-drills to meet specific manufacturing requirements.
a look at friendships between preschool-aged children with and without disabilities in two inclusive classrooms:

A naturalistic study of six naturally occurring friendships among preschool-aged children with and without disabilities in inclusive settings was conducted with the children, their parents, and teachers. Data were collected through participant observations and interviews. Descriptive field notes, a fieldwork journal, and transcribed interviews were inductively analysed. Analysis uncovered descriptions, meanings, and revealed various perspectives regarding the friendships studied including those of the children, parents, and teachers. The friendships are described as typical and portray characteristics that are common among friendships during the preschool-age period. The friendships were dynamic and changed throughout the course of the study. Several factors influenced the formation of the friendships including: similarity in play styles; the opportunity to engage in similar activities; similar knowledge and interests; proximity; and parental factors. Implications for further research are discussed.
Field desorption collision activation linked scanning mass spectrometry of underivatized oligopeptides

Field desorption production of protonated molecular ions from nanomole amounts of chemically underivatized penta-, tetra- and dipeptides, coupled with collision induced decomposition of [M + H]+ ions, yielded partial amino acid sequence information. Linked scanning of two of the three fields detected ions produced in the first field free region of a double focusing mass spectrometer.
In vitro degradation characteristics of poly(anhydride imides) containing pyromellitylimidoalanine

The in vitro degradation characteristics of poly(anhydride-imides) containing pyromellitylimidoalanine, with either 1,6-bis(carboxyphenoxy)hexane (CPH) or sebacic acid (SA) were assessed. The copolymers contained up to 50 mol % of the imide monomer, pyromellitylimidoalanine (PMA-ala). Degradation was pH sensitive, being enhanced under basic conditions. Control of degradation times from 2 days to 2 months was achieved by the selection of appropriate monomer units in the polymer backbone. Monomers were chosen based on their solubility in aqueous media, as well as how they influenced the hydrophobicity and crystallinity of the polymer matrices. Polymer degradation was followed by ultraviolet spectroscopy and high-pressure liquid chromatography. Increasing the amount of imide monomer, PMA-ala, and the use of SA (rather than CPH) as the comonomer increased the degradation rate of the polymer matrices.
Information is critical for cellular life

Functional Organization of CellsThe ability to receive, process and respond to information is critical for cellular life. This ability arises from the cell signaling network that processes information from external and internal sources. There are at least three sources of information: chemical signals, cell shape and mechanical forces. Integrating and processing information from all of these sources to coordinately control multiple cellular machines is essential for both homeostasis and regulated change in cell state. A key feature of signaling networks is the topology of regulatory motifs. Determining regulatory motif topology and the resultant information processing capability requires an integrated computational approach that blends graph theory-based analyses to identify and characterize regulatory motifs with differential equation-based models to determine functional capabilities of these motifs and how information processing changes with time and specific locations within the cell. Graph theory analyses indicate that large networks have a head-to-head topology that results in a depletion of long loops and such systems appear to be more dynamically stable. Interactions between motifs such as feedfoward loops and bifans indicate that multi-motif organization may be critical for biological processes. Differential equation models show that a set of three stacked and nested feedforward loops that is spatially specified is required for the β-adrenergic receptor triggering of the differentiated state in podocytes. These predictions have been experimentally verified. Thus the size of regulatory motifs and how the motifs are juxtaposed with respect to each other give rise to functional organization. There is partial overlap between the structural organization that arises from the presence and location of intracellular organelles and functional organization. Together the functional and structural organization of the cell determines how information is integrated, and how this integrated information is used to co-ordinate and regulate biological processes.
Extravascular optical coherence tomography: evaluation of carotid atherosclerosis and pravastatin therapy.

Background and Purpose—Extravascular optical coherence tomography (OCT), as a noninvasive imaging methodology with micrometer resolution, was evaluated in a murine model of carotid atherosclerosis by way of assessing the efficacy of pravastatin therapy. Methods—An OCT device was engineered for extravascular plaque imaging. Wild-type mice and apolipoprotein E–deficient (ApoE−/−) mice were randomized to 3 treatment groups: (1) wild-type on a diet of standard rodent chow (n=13); (2) ApoE−/− on a high-fat, atherosclerotic diet (HFD; n=13); and (3) ApoE−/− on a HFD given daily pravastatin (n=13). Mice were anesthetized and the left common carotid was surgically exposed. Three-dimensional (3D; 2 spatial dimensions+time) and 4D (3 spatial dimensions+time) OCT images of the vessel lumen patency were evaluated. After perfusion, in situ OCT imaging was performed for statistical comparison with the in vivo results and final histology. Results—Intraoperative OCT imaging positively identified carotid plaque in 100% of...
Three-Dimensional Motion of Sliders Contacting Media

Characterization of slider motion induced by contact is becoming a critical aspect of developing advanced head-disk interfaces. While vertical motion induced by contact has been studied, very little is known about off- and down-track motions. We have applied three separate laser Doppler vibrometers to measure slider movement in three orthogonal directions simultaneously. We have measured the position of a slider as it undergoes a transition from flying to making full contact with the media surface. We find that slider motion varies considerably with varying levels of contact and that motion in all three directions is considerable. Spectral decomposition is used to identify the vibration modes that are excited in each direction, and we find that for most of the test velocities, modes excited in the vertical direction give rise to motion in the two orthogonal directions. In addition, we present a depiction of the vertical, down-track, and off-track position changes by plotting the position of the slider in real space coordinates to help visualize more completely how the slider moves in space. These trajectories depict the periodic, elliptical path the slider takes and identify how the paths change with contact. Analysis of motion identifies that at some levels of contact, a majority of motion is repeatable, but that nonrepeatable components increase with the amount of contact. Additionally, down-track motion is the only component whose magnitude increases monotonically with increasing contact.
A scanning and stereographic ultrastructural analysis of the isolated inner mitochondrial membrane during change in metabolic activity.

Abstract Current studies of the molecular mapping of the respiratory cytochromes on the surface of the inner mitochondrial membrane have required a three-dimensional surface analysis of the purified intact inner mitochondrial membrane (mitoplast membrane). Thus scanning electron microscopy and stereographic transmission electron microscopy were used to investigate the details of surface topography of the inner membrane prior to initiation of oxidative phosphorylation and the surface transformation which occurs during oxidative phosphorylation. Stabilization of the delicate, complex surface configurations of the intact inner membrane, as well as the surface of the intact mitochondrion, was accomplished by glutaraldehyde fixation followed by criticalpoint drying. The non-phosphorylating mitoplast surface is composed of many finger-like membrane extensions which are variably branched. The cristal membrane borders enlarged intracristal spaces at the periphery of the mitoplast between these extensions. Surface extensions can exceed 100 in number and may account for the similar number of inner membrane sites of contact made with the outer membrane in the intact mitochondrion. The distal ends of the surface extensions correspond to the inner boundary membrane of the intact mitochondrion. With the initiation of oxidative phosphorylation, surface analysis shows a retraction and folding over of the surface extensions of the active membrane. This results in a transition to bridge-like short extensions compactly arranged on the mitoplast surface while the cristal membrane becomes deeply invaginated. These arrangements are best demonstrated by stereographic analysis. Although the resolution of the scanning electron microscope for molecular details of the surface of isolated intracellular organelles is somewhat limiting, we have found critical-point drying combined with scanning and stereographic electron microscopy to be of unlimited use in the rapid analysis of a suborganelle membrane surface with unusually complex topography.
Optimizing short-term production schedules in surface mining: Integrating mine modeling software with AMPL/CPLEX

Abstract Short-term production scheduling is the operational basis for mine production over time spans of days, weeks and months. Short-term schedules concentrate on making long-term mine plans operationally feasible and ensuring a steady flow of product for both meeting gross production targets and blending ore. Mathematical programming techniques have been applied to optimize short- and long-term production schedules, but widespread application of these techniques has been limited by the use of routines that are opaque to the end user or difficult to implement. Several examples are provided to illustrate the advantages of using the math modeling language AMPL in conjunction with Techbase, a popular mine modeling package. The strengths of MIP methods as applied to production scheduling are discussed, as are techniques for coping with the limitations of these algorithms.
Effects of Flock Size, Age at Housing, and Mating Experience on Two Strains of Egg-type Chickens in Colony Cages

Abstract We compared effects of four variables on fertility, feathering, and production of 2 experimental strains of naturally mated W.L. chickens: (1) housing at 12 vs. 20 wk. of age, (2) small flock (1♂:10♀female; ) vs. large flock (2♂♂:20♀♀), (3) restricted vs. nonrestricted movement of males, and (4) inexperienced vs. experienced replacement males. Flock size significantly affected average fertility from 20—44 wk., 39.4% for 1♂: 10♀♀ compared with 55.5% for 2♂♂: 20♀♀. Fertility of individual flocks varied from 0 to 100%. Neither restriction of male movement by a partition nor age when housed significantly affected fertility. Flocks with experienced replacement males had higher fertility than flocks with inexperienced replacement males (57.0 vs. 49.9%), approaching significance at P Early housing, large flock size, and absence of partitions increased feather damage. Birds with the most feather damage were the most fearful. Hens in small flocks laid more eggs than those in large flocks.
Some behavioural observations on wild and captive sand monitors, Varanus gouldii (Sauria: Varanidae)

Behavioural observations were made on wild and captive sand monitors in Australia. Threat and defensive postures are described for V. gouldii and reference is made to V. varius and V. spenceri; such behaviour is compared to other species within the family Varanidae. With captive V. gouldii, one case of cannibalism occurred when space was restricted.
“An Amazing Specimen”: NFL Draft Experts’ Evaluations of Black Quarterbacks

This paper, by way of examining two reputable sports publication, uses quantitative methods to study how NFL draft experts evaluate Black college quarterbacks. We find that draft experts buy into and perpetuate racial stereotypes about Blacks that adversely impact Black college quarterbacks’ chances of matriculating to the National Football League.
A Novel Low-Complexity HMM Similarity Measure

In this letter, we propose a novel similarity measure for comparing Hidden Markov models (HMMs) and an efficient scheme for its computation. In the proposed approach, we probabilistically evaluate the correspondence, or goodness of match, between every pair of states in the respective HMMs, based on the concept of semi-Markov random walk. We show that this correspondence score reflects the contribution of a given state pair to the overall similarity between the two HMMs. For similar HMMs, each state in one HMM is expected to have only a few matching states in the other HMM, resulting in a sparse state correspondence score matrix. This allows us to measure the similarity between HMMs by evaluating the sparsity of the state correspondence matrix. Estimation of the proposed similarity score does not require time-consuming Monte-Carlo simulations, hence it can be computed much more efficiently compared to the Kullback-Leibler divergence (KLD) thas has been widely used. We demonstrate the effectiveness of the proposed measure through several examples.
Gab2 regulates the migratory behaviors and E-cadherin expression via activation of the PI3K pathway in ovarian cancer cells

Ovarian cancer, the most deadly gynecologic malignancy, is often diagnosed late and at the advanced stage when the cancer cells have already migrated and invaded into other tissues and organs. Better understanding of the mechanism of metastasis in ovarian cancer cells is essential to the design of effective therapy. In this study, we investigated the function of scaffolding adaptor protein Gab2 in ovarian cancer cells. Gab2 is found to be overexpressed in a subset of ovarian tumors and cancer cell lines. Gab2 expression mainly regulates the migratory behaviors of ovarian cancer cells. Overexpression of Gab2 promotes the migration and invasion, and downregulates E-cadherin expression in ovarian cancer cells with low-Gab2 expression. Conversely, knockdown of Gab2 expression inhibits the migration and invasion, and promotes E-cadherin expression in ovarian cancer cells with high-Gab2 expression. By expressing Gab2 wild-type and Gab2 mutants that are defective in activation of the PI3K and Shp2-Erk pathways, we find that Gab2 inhibits E-cadherin expression and enhances the expression of Zeb1, a transcription factor involved in epithelial-to-mesenchymal transition (EMT), and cell migration and invasion through the activation of the PI3K pathway. Knockdown of Zeb1 expression blocks Gab2-induced suppression of E-cadherin expression and increase in cell invasion. LY294002 and GDC-0941, inhibitors of PI3K, or Rapamycin, an inhibitor of PI3K downstream target mTOR, can reverse the effects of Gab2 on migration and invasion. Overall, our studies reveal that Gab2 overexpression, via activation of the PI3K-Zeb1 pathway, promotes characteristics of EMT in ovarian cancer cells.
Relative contribution of cytosine deamination and error-prone replication to the induction of propanodeoxyguanosine-->deoxyadenosine mutations in Escherichia coli.

The role of cytosine deamination as a possible mechanism for PdG-->A transitions induced by propanodeoxyguanosine (PdG) was investigated by site-specific mutagenesis techniques. PdG was placed at position 6256 in the (-)-strand of M13MB102 by ligating the oligodeoxynucleotide 5'-GGT(PdG)TCCG-3' into a gapped-duplex derivative of the vector. Unmodified and PdG-modified M13MB102 genomes containing either uracil or thymine in the (+)-strand were transformed into Escherichia coli strains differing in their ability to excise uracil bases from DNA. After replication of the site specifically modified M13MB102, base-pair substitutions were detected by in situ hybridization using [32P]-labeled probes containing each of the possible mismatched bases opposite position 6256 in the (+)-strand. The ratio of PdG-->A and PdG-->T was unchanged in strains defective in the repair of uracil residues, which suggests that uracil is not an intermediate in the generation of PdG-->A mutations. Similar results were obtained when PdG-M13MB102 was incubated for 14 days prior to transformation in an attempt to increase the extent of deamination. As a control experiment to test the sensitivity of the assay to detect deaminations opposite PdG, uracil-containing M13MB102 with a PdG.T mismatch at position 6256 was transformed into E. coli JM105. Hybridization analysis indicated that approximately 80% of the phage plaques generated after genome replication contained T in the (+)-strand at position 6256. Thus, any deamination of cytosine to uracil would have been easily detected. Adducted and unadducted genomes were also transformed into E. coli LM114 or LM113, which carry a mutant umuD or umuC gene, respectively. Significant and comparable reductions in PdG-->A and PdG-->T were observed, suggesting that both mutations require the active participation of the UmuD and the UmuC proteins in the replication complex. The results of our experiments suggest that the PdG-->A mutations induced by PdG are not caused by cytosine deamination, but arise coincident with PdG-->T mutations during replication of the PdG-containing genomes. Also, the uracil-containing (+)-strand does not appear to be degraded, as is commonly assumed in site-specific mutagenesis experiments, and serves as a template for DNA synthesis when replication of the (-)-strand is blocked by an adduct such as PdG.
A Sociological Analysis of Commitment Generation in Alcoholics Anonymous

SUMMARY This paper utilizes a conceptual framework of commitment generation in voluntary organizations formulated by ,Rosabeth Moss Kanter in order to provide a sociological explanation for the success of Alcoholics Anonymous in the treatment of alcohol abuse. This paper demonstrates that Alcoholics Anonymous is systematically organized around the processes of sacrifice, investment, renunciation, communion, mortification and transcendence. An examination will be made of how those processes function to generate and sustain a strong commitment to sobriety among its members. In addition, consideration will be given to how those processes function to submit to social control salient aspects of collective life that have implications for commitment, including identity, interpersonal intimacy, work, recruitment, sanctions, extra-group ties and ideology. Alcoholics Anonymous (A.A.) is purportedly an effective means of treating alcoholism among intellectuals as well as among blue-collar workers [e.g. 1, ch. 4; 21. It is the purpose of this paper to provide a sociological explanation for the success of Alcoholics Anonymous in the treatment of alcohol abuse. Why does this not particularly genteel or fashionable, lay organizations that inveighs no financial charges on its members enjoy success in restoring many alcohol abusers to sobriety? The nineteenth-century social theorist Emile Durkheim has given us a clue to the solution of this question. In such classic works of sociological analysis as
A theory for the ablation of non-newtonian liquids near the stagnation point

Many liquids of practical importance for ablation have non-Newtonian flow characteristics that may be caused by flow-induced structural changes or by gas bubble concentrations in the liquid. The liquid-layer equations for viscous flow are integrated with a viscosity parameter that is a function of temperature and shear force. Near the stagnation point, non-Newtonian deviations are caused by shear as well as the pressure gradient. If the parameter responsible for non-Newtonian behavior approaches zero, the result of Adams and Bethe is obtained. Non-Newtonian flow may cause substantial changes of surface temperature and ablation effectiveness. Numerical results for an ablating model substance with the physical properties of Pyrex glass, but varying shear rate dependency, are given at several altitudes.
Contextual pathways to Latino child welfare involvement: A theoretical model located in the intersections of place, culture, and socio-structural factors

Abstract Latino children and families represent the fastest growing group in the child welfare system. However, research that explores Latinos experiences in the child welfare system is limited. By drawing upon several bodies of literature, this paper introduces a Latino Child Welfare Research and Practice Model that incorporates the physical, individual and social, institutional, socio-political, and subjective environments. The theoretical model posits that the lack of attention to these multiple and interlocking contextual dimensions of environment increases risk for Latino children to enter the child welfare system. Taken together, the five dimensions of environment incorporate contextual pathways to Latino child welfare that are historically situated in time and place, rooted in culture, and ideologically driven by socio-structural institutions. The model is used as a guiding framework to inform effective Latino child welfare practice, research, and policy recommendations.
Probing Protein Folding with Substitution-Inert Metal Ions. Folding Kinetics of Cobalt(III)-Cytochrome c

Ligand-substitution processes at the heme strongly influence peptide backbone dynamics during the folding of cytochrome c (cyt c). When cyt c is unfolded with guanidine hydrochloride (GuHCl) at pH 7, one of the axial ligands (Met 80) is replaced by a nitrogenous base from an amino acid residue; this misligation introduces an energy barrier with an associated folding time of several hundred milliseconds. A great deal of evidence points to His 26 or His 33 as the ligand in unfolded horse heart cyt c. Nevertheless, recent studies indicate that other bases (Lys or N-terminus in yeast cyt c) can act as ligands as well. We have found that the substitution-inert heme in the Co(III) derivative of cyt c (Co-cyt c) allows a closer look at the folding kinetics and the ligands in the unfolded form of this protein.
Analysis of white layers formed in hard turning of AISI 52100 steel

The formation mechanisms and properties of white layers produced in machining of hardened steels are not clearly understood to date. In particular, detailed analysis of their structure and mechanical properties is lacking. This paper investigates the differences in structure and properties of white layers formed during machining of hardened AISI 52100 steel (62 HRC) at different cutting speeds. A combination of experimental techniques including transmission electron microscopy (TEM), X-ray diffraction (XRD), and nano-indentation are used to analyze the white layers formed. TEM results suggest that white layers produced at low-to-moderate cutting speeds are in large part due to grain refinement induced by severe plastic deformation, whereas white layer formation at high cutting speeds is mainly due to thermally-driven phase transformation. The white layers at all speeds are found to be comprised of very fine (nano-scale) grains compared to the bulk material. XRD-based residual stress and retained austenite measurements, and hardness data support these findings.
Effects of methylation and ring size on mutagenicity of cyclic nitrosamines in Drosophila melanogaster

Abstract The mutagenic activity of 7 nitrosopiperazines, 2 nitropyrrolidines, and 3 nitrosomorpholines was examined in the X-linked recessive-lethal assay of Drosophila melanogaster . Mutagenicity is also reported for a series of cyclic nitrosamines that differ in structure only in the number of carbon atoms in the ring. Of the 18 compounds tested, 6 (nitrosopiperazine; 2,3,5,6-tetramethyl-dinitrosopiperazine; nitrosoproline; 2,5-dimethylnitrosopyrrolidine; nitrosothiomorpholine; and nitrosooctamethyleneimine) were nonmutagenic. As we reported earlier in investigations with the nitrosopiperidines, substitutions with methyl groups at all of the α-carbon atoms reduce or eliminate the mutagenic activity of dinitrosopiperazine and nitrosopyrrolidine.
Integers, without large prime factors, in arithmetic progressions. II

We show that, for any fixed e > 0, there are asymptotically the same number of integers up to x , that are composed only of primes ⩽ y, in each arithmetic progression (mod q ), provided that y ⩾ q 1+e and log x /log q →∞ as y →∞: this improves on previous estimates.
The synthesis, characterization and X-ray crystal structures of the fac-cis and mer-trans isomers of Re(NEt)Cl3(PMe3)2

Abstract The reaction of mer-trans-ReOCl3(PPh3)2 with PMe3 in benzene/THF affords an approximately equimolar mixture of the previously unreported fac-cis-ReOCl3)2 (1) and mer-trans-ReOCl3(PMe3)2 (2) as blue and green crystals, respectively. These isomers, which can easily be separated, have been structurally characterized by X-ray crystallography. In the structure of 1, the ReO distance is 1.670(5) A, while the axial ReCl bond (trans to ReO) is longer (2.453(2) A) than the two equatorial ReCl bonds (2.381(2) and 2.386(2) A). The structure of 2 is complicated by an orientation disorder in which the OReCl unit is arranged in two opposite orientations such that the half atoms Re and Re′ are well resolved but the O/Cl half atoms coalesce.
Modeling the Benchmark Active Control Technology Wind-Tunnel Model for Application to Flutter Suppression

This paper describes the formulation of a model of the dynamic behavior of the Benchmark Active Controls Technology (BACT) wind-tunnel model for application to design and analysis of flutter suppression controllers. The model is formed by combining the equations of motion for the BACT wind-tunnel model with actuator models and a model of wind-tunnel turbulence. The primary focus of this paper is the development of the equations of motion from first principles using Lagrange''s equations and the principle of virtual work. A numerical form of the model is generated using values for parameters obtained from both experiment and analysis. A unique aspect of the BACT wind-tunnel model is that it has upper- and lower-surface spoilers for active control. Comparisons with experimental frequency responses and other data show excellent agreement and suggest that simple coefficient-based aerodynamics are sufficient to accurately characterize the aeroelastic response of the BACT wind-tunnel model. The equations of motion developed herein have been used to assist the design and analysis of a number of flutter suppression controllers that have been successfully implemented.
The fit of certain dental casting alloys using different investing materials and techniques.

Abstract The relative fit of castings for normal tooth preparations and the Bureau of Standards MOD die were investigated. As used, the phosphate investments gave a degree of fit comparable with the thermal expansion gypsum types followed in order by ethyl silicate and hygroscopic materials. The information presented does not indicate clinical unacceptability of any of the materials or techniques, but it merely points out areas in which problems may exist.
Strategy for increasing drug solubility and efficacy through covalent attachment to polyvalent DNA-nanoparticle conjugates.

Paclitaxel, a potent chemotherapeutic utilized in a variety of cancers, can be limited in its effectiveness due to inherent insolubility in aqueous media and acquired chemoresistance within certain cells. An approach has been developed for increasing Paclitaxel solubility and effectiveness by covalent attachment to gold nanoparticles via DNA linkers. The resulting conjugates are highly soluble in aqueous buffer, exhibiting greater than a 50-fold increase in solubility over the unconjugated drug. DNA linkers are labeled with a fluorophore, which affords a convenient means of visualizing resultant conjugates within cells. Internalized conjugates demonstrate increased activity as compared with free drug across a variety of cell types, including a Paclitaxel-resistant cell line. Attachment to DNA–nanoparticle conjugates may become a general strategy for solubilizing and enhancing a wide variety of therapeutic agents in aqueous media.
Unusual nonprotein imino acid and its relationship to phenolic and nitrogenous compounds in Copaifera

Abstract The unusual imino acid, N -methyl- trans -4-hydroxy- L proline has been isolated from leaves of five species of the leguminous tropical tree Copaifera , and for the first time characterized by 1 H and 13 C NMR and mass spectrometry. This imino acid can constitute up to 3% of the mature leaf dry weight and 10% of the nitrogen; it also constitutes 2–3 % of the dry weight of the seed. Preliminary feeding trials have shown it to be a very effective inhibitor of larval development of the seed-feeding bruchid beetle Callosobruchus maculatus and to have significant feeding deterrence of the leaf-feeding lepidopteran Spodoptera littoralis . Phenolic compounds, also known to affect herbivores adversely, comprise 6–10% leaf dry weight. However, the imino acid displayed a mean of 50% reactivity compared to standards commonly used in analysis of total phenolics by the Folin-Denis (F-D) assay [gallic acid, tannic acid and (+) catechin], thus resulting in a significant overestimate of phenolics by this assay. It is concluded that assessment of leaf food quality for herbivores of Copaifera by assays widely used for this purpose in ecological studies, such as F-D for phenolics and Kjeldahl for total nitrogen content, give some misleading results.
Adversarial Collective Bargaining: An Anachronism

While our adversarial free (meaning minimal governmental interference) collective bargaining has been praised as a positive attribute of our labor‐management relations, it is hardly free and probably no longer even a positive attribute. This paper examines the process and explains how it has become limited to the point where the most crucial employment issues often no longer need to be bargained at all. Though the purpose of our labor laws was to resolve industrial strife through collective bargaining by balancing the power between employers and unions, our contemporary system can now often be characterized as limited, imbalanced, adversarial gamesmanship. Current research demonstrates the need for a more open and expanded bargaining agenda to meet the needs of both the changed workplace and the changed marketplace of today ‐ something the present process seems incapable of doing. Specific recommendations are offered to both management and labor which are derived from recent research.
Patterns of pelvic recurrence following definitive resections of rectal cancer.

Patterns of local and distant recurrences following resections for rectal cancer provide clinical perspective for multidisciplinary prevention and follow-up programs. From 1968 to 1976 at Memorial Hospital, 412 patients with potentially curable rectal cancer were treated by anterior (AR) or abdominoperineal (APR) resections. First sites of recurrences were categorized as pelvis, liver, distant viscera, and intraabdominal/ retroperitoneal sites. Pelvic recurrences were further evaluated according to the location of the tumor, type of resection, and stage of disease. Among the 412 cases, 182 (44.2%) patients developed recurrence, of which 105 (57.6%) were pelvic. Pelvic recurrence was the predominating site either alone (55 of 103) or with concomitant extra-pelvic sites (50/79). In instances of single-site first recurrence, pelvic failure was recognized earliest at 19.1 months, which was significantly earlier than single-distant visceral sites at 34.9 months. Pelvic recurrence was selectively related to various categories of the Dukes and modified Dukes staging systems. Dukes stage significantly predicted pelvic recurrence rates for Dukes A versus B. Astler-Coller stages of B2 and C1 were associated with significantly lower rates of pelvic recurrence (29.7% and 22.1%, respectively) than C2 cancers. The incidence of pelvic recurrence was significantly increased for low and mid rectal cancers as compared with cancers at or above 12 cm. The type of resection utilized (APR versus AR) was associated with no difference in the rate of pelvic recurrence, except for the few patients in whom AR was performed for low rectal Dukes C cancers. Patients with pelvic recurrence had an ultimate disease-free survival of only 3.8% as compared with patients with no pelvic recurrence of whom 77% remained alive without disease or went on to die of other causes. The timing and predominance of pelvic failure in rectal cancer with its own treatment-related morbidity and overall dismal survival outcome justifies organized multidisciplinary efforts to prevent such failure and prospective trials of comprehensive follow-up programs to evaluate improved cure rates or palliation. Cancer 53:1354-1362, 1984.