cssi/SciSciGPT-SciSciNet huggingface dataset:
Accessibility control of V(D)J recombination.

Abstract Mammals contend with a universe of evolving pathogens by generating an enormous diversity of antigen receptors during lymphocyte development. Precursor B and T cells assemble functional immunoglobulin (Ig) and T cell receptor (TCR) genes via recombination of numerous variable (V), diversity (D), and joining (J) gene segments. Although this combinatorial process generates significant diversity, genetic reorganization is inherently dangerous. Thus, V(D)J recombination must be tightly regulated to ensure proper lymphocyte development and avoid chromosomal translocations that cause lymphoid tumors. Each genomic rearrangement is mediated by a common V(D)J recombinase that recognizes sequences flanking all antigen receptor gene segments. The specificity of V(D)J recombination is due, in large part, to changes in the accessibility of chromatin at target gene segments, which either permits or restricts access to recombinase. The chromatin configuration of antigen receptor loci is governed by the concerted action of enhancers and promoters, which function as accessibility control elements (ACEs). In general, ACEs act as conduits for transcription factors, which in turn recruit enzymes that covalently modify or remodel nucleosomes. These ACE‐mediated alterations are critical for activation of gene segment transcription and for opening chromatin associated with recombinase target sequences. In this chapter, we describe advances in understanding the mechanisms that control V(D)J recombination at the level of chromatin accessibility. The discussion will focus on cis‐acting regulation by ACEs, the nuclear factors that control ACE function, and the epigenetic modifications that establish recombinase accessibility.
Stereotypes in Four Current AOUM Sexuality Education Curricula: Good Girls, Good Boys, and the New Gender Equality.

It has long been noted that sexuality education curricula contain gender stereotypes and heterosexism that may be harmful to people of all genders. Many of the stereotypes and sources of heterosexism that have been discussed in the literature have to do with old-fashioned and restrictive roles for men and women and focus on heterosexual sex and marriage. In this article, we analyzed four currently used Abstinence Only Until Marriage (AOUM) curricula in order to examine to what extent these curricula reproduce these stereotypes. We found only a few instances of older stereotypes of boys as pursuers and girls as passive recipients. There were instead more modern ideals of choice and equality that were represented; however, we found that the language of choice and equality was often used to support new stereotypes of female sexuality. For example, in treating boys and girls as equal in terms of pressuring each other to have sex or objectifying each other, they introduce some problematic new images and stereo...
Immunologic sensitization prior to birth.

Abstract A series of clinical and experimental reports have been presented in which there is evidence to indicate that prenatal sensitization of the fetus to specific antigens can occur during apparently normal pregnancies. It appears that the mechanism involved in the alteration of the immune response may be the prenatal passage of antigen and/or maternal cells to the developing fetus and the production of specific immunologic reactivity. If future clinical and experimental investigations define more clearly the mechanism by which this event occurs, methods of specifically altering the immune response of the offspring could be developed. This type of “immunologic engineering” could afford the offspring an enhanced immune response against infectious agents and vertically transmitted oncogenic agents or could induce specific tolerance to selected tissue antigens.
Negotiating task interruptions with virtual agents for health behavior change

Virtual health counseling agents on mobile devices need to be able to interrupt their users when it is time for them to engage in healthy behaviors, such as scheduled medication taking or exercise. However, these real-time reminders often represent task interruptions for individuals who are engaged in work activities. This paper presents the results of a study which compares four strategies used by a virtual agent on a PDA for interrupting users at work to perform a healthy behavior. We find that, among several interruption coordination strategies previously explored in the HCI literature, empathic interruptions are superior overall in gaining both short-term compliance and self-reported desire to continue working with the agent.
Separation and reconstruction of BCG and EEG signals during continuous EEG and fMRI recordings

Despite considerable effort to remove it, the ballistocardiogram (BCG) remains a major artifact in electroencephalographic data (EEG) acquired inside magnetic resonance imaging (MRI) scanners, particularly in continuous (as opposed to event-related) recordings. In this study, we have developed a new Direct Recording – Prior Encoding (DRPE) method to extract and separate the BCG and EEG components from contaminated signals, and have demonstrated its performance by comparing it quantitatively to the popular Optimal Basis Set (OBS) method. Our modified recording configuration allows us to obtain representative bases of the BCG- and EEG-only signals. Further, we have developed an optimization-based reconstruction approach to maximally incorporate prior knowledge of the BCG/EEG subspaces, and of the signal characteristics within them. Both OBS and DRPE methods were tested with experimental data, and compared quantitatively using cross-validation. In the challenging continuous EEG studies, DRPE outperforms the OBS method by nearly 7 fold in separating the continuous BCG and EEG signals.
Birth weight threshold for postponing preterm birth.

Abstract OBJECTIVE : The study was designed to determine the birth weight threshold at which obstetric efforts intended to delay delivery might potentially improve rates of neonatal morbidity and mortality among pregnancies delivered after spontaneous preterm labor or rupture of the membranes. STUDY DESIGN : We studied 1147 singleton infants with birth weights between 1000 and 2499 gm and whose only complication was spontaneous preterm labor or preterm rupture of the membranes. The Mantel-Haenszel χ 2 statistic was used to evaluate trends for neonatal mortality and several indexes of morbidity. RESULTS : The birth weight threshold for neonatal mortality was 1600 gm ( p p CONCLUSION : Aggressive obstetric attempts to prevent preterm birth for infants whose weights exceed 1900 gm offers few apparent potential benefits. (Am J Obstet Gynecol 1992;167:1145–9).
Agree to disagree.

In the previous Accidental Note, Bangdiwala (2012) presented methods for exact and approximate calculations of p-values in cross-tabulations of two categorical variables, when the research question...
The Utility of Annual Reports: An International Study

This article reports on a major study which is part of ongoing international research into the use and usefulness of financial statements for investment decisions. The survey reported covered 4,000 individual investors, 900 institutional investors and 900 financial analysts, in 3 countries. It was found that the 3 groups in all 3 countries revealed a strong belief in the importance of financial statements for investment decisions whether “buy” or “hold/sell.” It was also found that the individual investor group was far less homogeneous than previous research has assumed, and that cultural or social differences between countries do exist in this field.
The Disordered Monologue: A Classroom Demonstration of the Symptoms of Schizophrenia

This article describes a demonstration that simulates a verbal encounter with a person experiencing symptoms of schizophrenia. Unannounced, the instructor launches into a monologue that illustrates...
The measurement of inequality and poverty: A policy maker's guide to the literature

Abstract Mathematical measures of poverty and inequality embody values that reflect the historical, political, social, intellectual and ethical forces prevalent at the time of their formulation. So that policy makers may select measures of poverty and inequality that are consistent with their values, it is important to make explicit the value judgements implicit in the measures. Models designed to measure poverty and inequality fall into four categories: absolute poverty measures; absolute income measures; relative poverty measures; and relative inequality measures. This article examines the principal models within each category and discusses the assumptions, limitations and values implicit in the models.
An improved algorithm for computing logarithms over GF(p) and its cryptographic significance (Corresp.)

A cryptographic system is described which is secure if and only if computing logarithms over GF(p) is infeasible. Previously published algorithms for computing this function require O(p^{1/2}) complexity in both time and space. An improved algorithm is derived which requires O =(\log^{2} p) complexity if p - 1 has only small prime factors. Such values of p must be avoided in the cryptosystem. Constructive uses for the new algorithm are also described.
Size effect on mechanical behavior of random fiber networks

Abstract Bonded random fiber networks are heterogeneous on multiple scales. This leads to a pronounced size effect on their mechanical behavior. In this study we quantify the size effect and determine the minimum model size required to eliminate the size effect for given set of system parameters. These include the network density, the fiber length and the fiber bending and axial stiffness. The results may guide the definition of models and the selection of the size of representative volume elements in sequential multiscale models of fiber networks. To underline the origins of the size effect, we characterize the network heterogeneity by analyzing the geometry of the network (density distribution), the strain field and the strain energy distribution. The dependence of the heterogeneity on the scale of observation and system parameters is discussed.
Parity breakdown and induced fermion number in the O(3) nonlinear σ model

Abstract We study the fermion number induced by solitons in the O(3) nonlinear σ model in (2+1)-dimensions, in the presence of a parity breaking fermion mass term. The appearance of zero energy modes during the adiabatic evolution of a background of winding number unity is analysed as a function of the relative magnitudes of the explicit, odd parity, fermion mass, m odd , the fermion mass induced by the Yukawa coupling, m Y , and the inverse soliton width, 1 ϱ s . We find ϱ c , the maximum value of ϱ = ϱ s m Y for which a fermion zero energy level crossing occurs. For M f = m odd / m Y ϱ > ϱ c ( M f ) the ground state charge of the soliton is wholly topological. Otherwise, it vanishes.
A predictive extended corresponding states model for pure and mixed refrigerants including an equation of state for R134a

Abstract We have developed a predictive corresponding states model for the thermophysical properties of pure refrigerants and refrigerant mixtures. The bulk phase properties such as the density, enthalpy and entropy are predicted using the principle of extended corresponding states, incorporating a recent 32-term modified Benedict-Webb-Rubin correlation for the R134a (1,1,1,2-tetrafluoroethane) reference fluid. This theoretically based model uses shape factors to ensure conformality among the various components. A correlation for the shape factors was found by mapping saturation boundaries of the fluids of interest onto the reference fluid and then fitting the results to an empirical correlation. In this work we present the coefficients for density-independent shape-factor correlations for 21 refrigerants, and a set of universal coefficients that can be used with any refrigerant given only the critical parameters and the acentric factor. We show comparisons with experimental density data for each of the 21 refrigerants. We also demonstrate the use of generalized coefficients for shape factors where only the critical parameters and acentric factors are known. In addition, we present comparisons of the volume prediction for two binary refrigerant mixtures and one ternary refrigerant mixture.
Peer victimization and self-efficacy in coping with conflict as predictors of depressive feelings among females in early adolescence

This studied explored the extent to which peer victimization (being bullied) and efficacy in coping with conflict explained recent depressive feelings among 135 girls enrolled in grades 5 through 8 of six Catholic schools that serve the inner-city neighborhoods of one Midwestern metropolitan area. The results of bivariate analyses show that the school setting and ethnicity significantly influence peer victimization and depressive feelings among females in early adolescence. Results of stepwise regression analysis show that peer victimization and ethnicity explain more of the variance in depressive feelings than the ability to cope with conflict. Findings suggest that, in order to mediate depressive feelings among females who are victimized by peers, school personnel may need to develop and implement programs that focus on helping those females who are most likely to initiate relational aggression as a means of victimizing peers.
Mast Cells and Immunological Skin Diseases

Mast cells play an important role in both adaptive and innate immunity, and a large body of literature demonstrates their functions in skin immunity. This article reviews the literature on the role of this cell type in the pathogenesis of a number of immunological skin diseases, including contact dermatitis, atopic dermatitis, immunobullous disease, scleroderma, and chronic graft-vs.-host disease. In all these diseases, mast cells are noted to increase in number and undergo degranulation in the affected skin, and in some cases, their specific mediators are detected. Elucidation of the contribution of mast cells to the pathogenesis of these diseases has been aided significantly by the use of animal models, especially mouse models. The studies of mast cell-deficient mice in conjunction with normal congenic mice have been particularly fruitful, although in some cases, such as contact dermatitis, a definitive conclusion has not been achieved despite extensive efforts. The role of mast cells in atopic dermatitis has also been suggested by studies of gene polymorphism, which have linked some of the mast cell-related genes to the disease. In the case of scleroderma and chronic graft-vs.-host disease, the function of mast cells in fibrosis is further supported by the ability of these cells and their mediators to induce activation and proliferation of fibroblasts. Therapies targeting mast cells may prove beneficial for treatment of these inflammatory and autoimmune diseases.
Elastic cracks and screw dislocation pile-ups crossing a bimaterial interface

Elastic cracks and screw dislocation pile-ups crossing bimaterial interface, deriving dual singular integral equations
Stimulus control and the growth of the infant’s effective visual field*

The size of the infant’s effective visual field was studied weekly in infants starting at 2 weeks of age until they were 10 weeks old, The field was initially quite small, 15 deg to either side of their line of regard. Over the 2-month period of the study, it more than doubled for stimulus conditions in which the peripheral event was in motion and the fixation object static, and it remained approximately the same size when motion was present in the fixation event and the peripheral object was static. As with adults, the infant’s effective visual field is directly related to the stimuli available.
A better scalar Preisach algorithm

A Preisach hysteresis model for the case in which Everett's function, E(H/sub 1/, H/sub 2/), has been defined from measurements of the magnetization change from a turning point H/sub 1/ to the field H/sub 2/. E(H/sub 1/, H/sub 2/) is the integral of the Preisach density function, whose symmetry imposes the relation E(H/sub 1/, H/sub 2/)=E(-H/sub 1/, -H/sub 2/). This is inconsistent with measured first-order curves. The source of the inconsistency is that magnetization changes depend on the state of the medium, not just the most recent turning point as Preisach assumes. A Preisach-like algorithm is proposed that is consistently defined by first-order curves and that predicts magnetization changes based on the state of the medium. The algorithm maintains a turning-point history and predicts closed minor loops, like the traditional model, but also predicts noncongruent minor loops and nonzero initial susceptibility. >
Spatial Analysis of Income Disparities in Pedestrian Safety in Northern New Jersey: Is There an Environmental Justice Issue?

Environmental justice regulations have proliferated in the past two decades as a method for community activists to challenge federally funded projects if they perceive that they may have a disproportionate impact on low-income communities of color. Recently, arguments have surfaced suggesting that disparities in traffic safety investments be included under the umbrella of environmental justice. This study reviewed the literature on transit-related environmental justice arguments and examined the relationship between pedestrian crashes and low-income communities of color (as well as a series of other factors). A negative binomial regression was estimated to determine whether these associations existed in a three-county area of northern New Jersey. Low median income and high black and Latino populations are two of several parameters associated with high numbers of pedestrian crashes. An innovative use was made of Street View data in recording road safety features (such as buffers, medians, and pedestrian co...
852 BONEMINERAL TURNOVER IN OSTEOGENESIS IMPERFECTA

A young boy with the severe form of osteogenesis imperfecta was treated with NaF for 8 years (1 mg F/kg/d). The frequency of fractures decreased somewhat, but we could detect no gross improvement in bone density. Based on F balance studies and analysis of a bone biopsy, his body F burden was estimated to be about 5 gm at the end of the treatment period (age 14 yr). NaF treatment was abruptly stopped, and during the next 4 1/2 years a number of 24hr urine samples were analyzed for F. After the first few days, during which only 28 mg F were excreted, fluoride excretion declined exponentially: 10% of the body F burden was lost with a half-time of 5 months, 90% with one of 9 years. This latter value is within the range observed by others for the elimination of F and other “bone-seekers” (Sr, Pb, Ra) in normal subjects. Since approximately 99% of body F is located in the mineral phase of bone this element can serve as a tracer for bone mineral. Based on the extended observations on our patient, it would appear that bone mineral turnover is normal in this disease.
Adapting speaking after evidence of misrecognition: Local and global hyperarticulation

In this paper we examine the two-way relationship between hyperarticulation and evidence of misrecognition of computer-directed speech. We report the results of an experiment in which speakers spoke to a simulated speech recognizer and received text feedback about what had been ''recognized''. At pre-determined points in the dialog, recognition errors were staged, and speakers made repairs. Each repair utterance was paired with the utterance preceding the staged recognition error and coded for adaptations associated with hyperarticulate speech: speaking rate and phonetically clear speech. Our results demonstrate that hyperarticulation is a targeted and flexible adaptation rather than a generalized and stable mode of speaking. Hyperarticulation increases after evidence of misrecognition and then decays gradually over several turns in the absence of further misrecognitions. When repairing misrecognized speech, speakers are more likely to clearly articulate constituents that were apparently misrecognized than those either before or after the troublesome constituents, and more likely to clearly articulate content words than function words. Finally, we found no negative impact of hyperarticulation on speech recognition performance.
Simultaneous-successive factor structure of the WISC―R: a validation study

Sr~mma~y.-It has been suggested that the Wechsler Intelligence Scale for Children-Revised (WISC-R) may usefully be interpreted in terms of a Simultaneous-Successive factor structure. A previous attempt to validate this hypothesis via factor analysis of 8 of the 12 WISC-R subtests was later shown to be an unreliable test of this model. The present study, performed upon 36 children, aged 645 to 12% yr., 45% female, 83% black, tested the validity of the two-factor model vis-6-vis the Kaufman Assessment Battery for Children (K-ABC), which is reported to have an unambiguous SimultaneousSequential (Successive) factor structure. Present results do not support a salient Simultaneous-Successive structure for the WISC-R, and clinicians should be wary of using the proposed two-factor model of the WISC-R for diagnostic or remedial purposes. Kaufman ( 1979) proposed that the Wechsler Intelligence Scale for Children-Revised (WISC-R) (Wechsler, 1974) could, in some cases, usefully be interpreted in terms of the Luria-Das simultaneous-successive model of information processing. Das, Kirby, and Jarman ( 1979) describe simultaneous processing as involving stimuli which require consideration of more than one e!ement at the same time and describe successive processing as involving stimuli whose temporal or sequential order is most essential. Although Kaufman ( 1979) clearly did not recommend a processing interpretation of the WISC-R in the absence of support from other test data or behavioral observations, his suggestion of such an underlying factor structure has led to attempts to test empirically this hypothesis. Naglieri, Karnphaus, and Kaufrnan (1983) performed a factor analysis involving the origina! standardization sample (N = 2,200) of the WISC-R, a mentally retarded sample (n = 80) and a learning and behavior-disordered sample (n = 100) to test empirically the claim of Kaufrnan. The analysis was performed on only 8 of the 12 WISC-R subtests (Arithmetic, Information, Vocabulary, and Comprehension were excluded), and the results were interpreted by the authors as support for the simultaneous-successive model. Matheson ( 1983), however, criticized the study as a statistically unreliable test of the factor structures involved 1;ecause the number of WISC-R subtests
Chemical form and distribution of mercury and selenium in canned tuna

The content, chemical form and distribution of mercury and selenium were determined for several samples of canned tuna. Samples represented albacore, bluefin, skipjack and yellowfin species, and were packed in either water or vegetable oil. Recently-processed samples (less than one year old) and much older samples (8-29 years old) were examined. Methylmercury was the predominant mercury form in all samples, comprising 57.4-94.7% of the total mercury content. For these samples, 7.6-44.8% of the total selenium content was present as selenate. There was no apparent effect of packing medium, species or sample age on the methylmercury and selenate percentages. Although the total selenium content exceeded that of total mercury, there was no apparent correlation between the total levels of both elements. Sample age influenced the level of water-extractable mercury and selenium in canned tuna. For recently canned samples, an average of 27.0% of the total mercury and 55.6% of the total selenium content were water-extractable. However, for the older samples, the corresponding respective average extractable levels were 46.4 and 48.2%. For both categories, inorganic mercury and selenate were more extractable, on an average percentage basis. In addition, an average of 7.2% of the total mercury content was benzene-extractable.
Reactive processing with difunctional oligomers to compatibilize polymer blends

The addition of telechelic reactive oligomers to a polymer blend as a compatibilization process is investigated. The results presented in this paper suggest that this process provides a mechanism by which blocky copolymeric compatibilizers can be formed during processing, as demonstrated by the changes in the mechanical and optical properties of the phase separated polymer blends. The results also show, however, that the presence of unreacted smaller oligomers can act as a plasticizer in the blend and can thus detrimentally affect the mechanical properties of the blend if any remains after processing. Careful control of the mixing conditions or post processing thermal annealing may be required to minimize this potentially deleterious effect. However, the data suggest that this optimization is possible.
Equine spermatozoal motility and fertility associated with the incorporation of d-(+)-mannose into semen extender.

Abstract Mannose is capable of decreasing bacterial attachment to the uterine mucosa in mares. Bacteria gain entry into the mare's uterus during breeding; therefore, a practical method to deliver mannose to the uterus is to incorporate it into semen extenders. The effect of mannose on spermatozoal motility and subsequent sperm fertilizing capability is unknown. The present study evaluated progressive spermatozoal motility in semen extender formulations incorporating mannose and assessed the fertility of mares inseminated with a mannose-containing semen extender. In Experiment 1, progressive spermatozoal motility in extender mixtures containing 0 mannose (control), 25, 37 or 49 mg/mL mannose was evaluated at 20 °C or 5 °C holding temperatures for 0, 12, 24 and 48 h post-dilution. Measures were repeated three times using five stallions of proven fertility. High concentrations of mannose in the extender affected progressive motility beyond the time and temperature effects noted in the controls. Extender containing only mannose sugar (49 mg/mL) displayed an immediate depression in progressive motility compared with controls (45.5% versus 62.9%, respectively; P
Cymbal and BB underwater transducers and arrays

The cymbal is a miniaturized class V flextensional transducer that was developed for use as a shallow water sound projector and receiver. Single elements are characterized by high Q, low efficiency, and medium power output capability. Its low cost and thin profile allow the transducer to be assembled into large flexible arrays. Efforts were made to model both single elements and arrays using the ATILA code and the integral equation formulation (EQI). Millimeter size microprobe hydrophones (BBs) have been designed and fabricated from miniature piezoelectric hollow ceramic spheres for underwater applications such as mapping acoustic fields of projectors, and flow noise sensors for complex underwater structures. Green spheres are prepared from soft lead zirconate titanate powders using a coaxial nozzle slurry process. A compact hydrophone with a radially-poled sphere is investigated using inside and outside electrodes. Characterization of these hydrophones is done through measurement of hydrostatic piezoelectric charge coefficients, free field voltage sensitivities and directivity beam patterns.
Effects of mycorrhizal roots and extraradical hyphae on 15N uptake from vineyard cover crop litter and the soil microbial community

The objectives of this study were to evaluate the contribution of arbuscular mycorrhizal (AM) fungal hyphae to 15N uptake from vineyard cover crop litter (Medicago polymorpha), and to examine the soil microbial community under the influence of mycorrhizal roots and extraradical hyphae. Mycorrhizal grapevines (Vitis vinifera) were grown in specially designed containers, within which a polyvinyl chloride (PVC) mesh core was inserted. Different sizes of mesh allowed mycorrhizal roots (mycorrhizosphere treatment) or extraradical hyphae (hyphosphere treatment) to access dual labeled 15N and 13C cover crop litter that was placed inside the cores after 4 months of grapevine growth. Mesh cores in the bulk soil treatment, which served as a negative control, had the same mesh size as the hyphosphere treatment, but frequent rotation prevented extraradical hyphae from accessing the litter. Grapevines and soils were harvested 0, 7, 14, and 28 days after addition of the cover crop litter and examined for the presence of 15N. Soil microbial biomass and the soil microbial community inside the mesh cores were examined using phospholipid fatty acid analysis. 15N concentrations in grapevines in the hyphosphere treatment were twice that of grapevines in the bulk soil treatment, suggesting that extraradical hyphae extending from mycorrhizal grapevine roots may have a role in nutrient utilization from decomposing vineyard cover crops in the field. Nonetheless, grapevines in the mycorrhizosphere treatment had the highest 15N concentrations, thus highlighting the importance of a healthy grapevine root system in nutrient uptake. We detected similar peaks in soil microbial biomass in the mycorrhizosphere and hyphosphere treatments after addition of the litter, despite significantly lower microbial biomass in the hyphosphere treatment initially. Our results suggest that although grapevine roots play a dominant role in the uptake of nutrients from a decomposing cover crop, AM hyphae may have a more important role in maintaining soil microbial communities associated with nutrient cycling.
Computed tomography assisted repair of a central tarsal bone slab fracture in a horse

Summary A 13-year-old Quarter Horse gelding was presented for repair of a central tarsal bone fracture. Radiographs showed a single large nondisplaced sagittal slab fracture; however, computed tomography (CT) revealed an additional small, displaced central tarsal bone fragment. The complex fracture was repaired, under the same anaesthetic period as the CT examination, using the CT hard copies images, intraoperative fluoroscopy and radiographs. The horse recovered well and after rehabilitation showed no residual lameness at work. Computed tomography was instrumental in achieving precise screw placement and successful fracture repair.
Proton and metal adsorption onto bacterial consortia: Stability constants for metal-bacterial surface complexes

Abstract In this study, we conduct potentiometric titrations and metal adsorption experiments (Cd, Ca, Cu, Pb, Sr, and Zn) using bacterial consortia grown from three representative locations and sampled over the course of a year in order to determine whether bacterial diversity affects proton and metal uptake behaviors. We observe significant changes in bacterial diversity from one site to another, and from month to month during the study period. Despite these changes in diversity, all of the bacterial consortia studied exhibit similar proton and metal uptake, strongly suggesting universal adsorption behavior for the bacterial species present in these samples. We demonstrate that a single, metal-specific, averaged surface complexation model can be used to reasonably account for the acid/base and metal adsorption behaviors of each consortium. We use a four discrete site non-electrostatic model to describe the protonation of the consortia functional groups, with averaged pKa values of 3.2 + 0.2 / − 0.4, 4.8 + 0.2 / − 0.3, 6.5 + 0.3 / − 0.8, and 9.2 + 0.1 / − 0.3, and site concentrations of (1.0 ± 0.28) × 10− 4, (1.2 ± 0.23) × 10− 4, (6.12 ± 1.1) × 10− 5, and (9.7 ± 2.0) × 10− 5 moles of sites per gram wet mass of bacteria, respectively. The metal adsorption data are used to constrain site-specific bacterial surface complexation models, and we determine the stability constants for the important metal–bacterial surface complexes. These calculated stability constants correlate well to known stability constants for metal–acetate complexes, yielding predictive relationships that enable the estimation of the extent of adsorption of other metals onto bacterial consortia. This study demonstrates that a wide range of bacteria exhibit similar proton and metal adsorption behaviors, and that a single set of averaged acidity constants, site concentrations, and stability constants for metal–bacterial surface complexes can be used to model the adsorption behavior.
Selective or routine axillary disease staging for patients with clinically lymph node–negative breast cancer?

Background. Although sentinel lymph node biopsy (SLNB) has become the standard for patients with clinically lymph node-negative breast cancer, less than one third of patients who undergo SLNB will have lymph node metastases. Therefore, we hypothesized that a subset of patients in whom SLNB can be avoided can be identified before operation. Methods. We prospectively studied 220 patients with early stage breast cancer who underwent SLNB. We analyzed primary tumor features, biologic markers, and demographic data. Results. Overall, 31 % of the patients had lymph node metastases. Although patients with lymph node metastases had larger neoplasms than patients who were lymph node negative (mean, 2.3 ± 0.1 cm versus 1.5 ± 0.1 cm; P <.0001), 10% of patients with T1a tumors, 19% of patients with T1b tumors, and 30% of patients with Tic tumors had lymph node metastases. Palpable tumors were lymph node positive in 41% of patients versus 17% for nonpalpable tumors (P =.0001). Lymph node metastases were seen in 71 % of patients with tumor angio or lymphatic invasion versus 17% of patients without (P <.0001). Seventy-five percent of patients with an increased preoperative serum CA 27.29 had lymph node metastases, and the mean levels were greater among patients who were lymph node positive (27 U/ml ± 2 versus 20 ± 1; P =.0002). There was no significant association between any other demographic, histologic, or molecular feature that was investigated and lymph node metastases. Conclusion. We did not identify histologic, demographic, or molecular variables that can exclude the risk of associated lymphatic metastases reliably. Furthermore, not all predictive factors are known before the operation (eg, whether the tumor is T1a or T1b). Therefore, we recommend that SLNB be performed in all patients with clinically lymph node-negative invasive breast cancer.
A hybrid approach for teaching introduction to Operations Management

The purpose of this paper is to describe a new design for the Operations Management course taught in many large business schools. A hybrid approach is developed and has been successfully implemented at our university. The course provides an alternative to the standard, large section lecture model of content delivery that has been popular for years on large college campuses. In particular, the course design blends lecture, small class attention and practical hands-on problem solving to provide a more effective learning environment.
Stabilization of perceived echo amplitudes in echolocating bats. I. Echo detection and automatic gain control in the big brown bat, Eptesicus fuscus, and the fishing bat, Noctilio leporinus.

Previous research on echo detection in bats has suggested that the effective threshold is a function of the acoustic clutter in the experimental environment, as might be expected given the low ambient noise levels typical of such psychophysical research. This paper demonstrates that theory of signal detectability (TSD) methodology is applicable to bats and uses it to show that an important element of clutter limiting in Eptesicus fuscus and Noctilio leporinus is backward masking of phantom targets by the real echo from the loudspeakers used to generate them. This information suggests that a previous estimate of the magnitude of automatic gain control (AGC) is too high, due to variable backward masking inherent in the experimental method used. A re‐examination of gain control using a masking‐free method shows that it reduces auditory sensitivity by 6 to 7 dB per halving of target range, rather than 11 dB as previously thought.
Primary hyperparathyroidism with a history of head and neck irradiation: The consequences of associated thyroid tumors

Background Information on thyroid tumors is scant in patients with primary hyperparathyroidism (HPT) and history of head and neck irradiation. The study objective was to investigate thyroid pathology in primary HPT patients with irradiation history presenting for parathyroidectomy. Methods A prospective database of 1,020 parathyroidectomy patients was analyzed. 916 consecutive HPT patients were identified. History of radiation, neck ultrasound results, thyroid operations, and pathology was assessed. Patients with radiation history were compared to those with no radiation. Results Of the 916 HPT patients, 49 (5%) had a history of radiation and were more likely to have nodular thyroid disease (95% vs 52%), undergone a prior thyroidectomy (29% vs 4%), or had concurrent thyroidectomy (49% vs 26%). Nine of 49 (24%) had thyroid cancer. Of the 867 patients with no history of radiation, 259 underwent thyroid resection (32 prior and 227 concurrent) and 32 (12%) had thyroid cancer. Conclusion Primary HPT patients with head and neck irradiation presenting for parathyroidectomy had marked increase in nodular thyroid disease: nearly 1 in 2 had concurrent thyroidectomy, and nearly 1 in 4 had thyroid carcinoma. High resolution ultrasound prior to parathyroidectomy detects associated thyroid pathology and allows the surgeon to plan the extent of thyroid resection.
The Digital Age and the Future of Social Network Science and Engineering

The articles in this special issue focus on social network services in digital environments.
Ensemble Controllability of the Bloch Equations

Finding control fields (pulse sequences) that can compensate for the dispersion in the parameters governing the evolution of a quantum system is an important problem in coherent spectroscopy and quantum information processing. The use of composite pulses for compensating dispersions in system dynamics is widely known and applied. In this paper, we make explicit the key aspects of the dynamics that make such a compensation possible. We highlight the role of Lie algebras and non-commutativity in the design of a compensating pulse sequence. Finally, we investigate three common dispersions in NMR spectroscopy, the Larmor dispersion, rf inhomogeneity and the strength of couplings between the spins.
Normal development of the ipsilateral retinocollicular pathway and its disruption in double endothelial and neuronal nitric oxide synthase gene knockout mice.

The development of the ipsilateral retinocollicular pathway involves activity-dependent refinement in which misdirected axons retract to form a precise retinotopic map in adults. This refinement is altered by disruption of genes for the endothelial and neuronal isoforms of nitric oxide synthase (e,nNOS), but the extent of disruption during early development is not known. Therefore, we studied the refinement of this pathway in normal C57/BL6 and e,nNOS double knockouts from P4 to P21 and in adults. Anterograde tracers were injected into one eye to localize the ipsilateral retinal projection (IRP) within the superior colliculus (SC). At P4, the IRP in normal mice was distributed throughout the dorsoventral extent of the superficial gray layer (SGL) across most of the rostrocaudal axis of SC. Between P4 and P9, the pathway retracted to the rostromedial SC, and retracted further between P15 and P21, such that multiple patches of label were seen only in the rostral 200–300 μm. Refinement also began to occur between P4 and P9 in e,nNOS double knockout mice, but labeling was more extensive in P9, P15, and P21 knockout animals. This delay in refinement was confirmed quantitatively at P15 where differences in the area occupied by the pathway were statistically significant. The refinement process is therefore in progress in both normal and e,nNOS knockout mice before eye opening but is significantly delayed in the double knockouts. The IRP in normal mice is also more exuberant at early ages, and the process of refinement more protracted than has been previously reported, suggesting that there is a prolonged critical period of synaptic plasticity. J. Comp. Neurol. 426:651–665, 2000. © 2000 Wiley-Liss, Inc.
Cancer-specific beliefs and survival: A population-based study of African-American and White breast cancer patients

Objective: Beliefs about cancer and its treatment have been shown to influence cancer stage at diagnosis and, thus, prognosis. The association between these beliefs and survival is understudied, especially among racially/ethnically diverse populations. We investigated the relationship between cancer-specific beliefs and survival in a cohort of African-American and White women with newly diagnosed breast cancer followed for up to 15 years. Methods: We examined beliefs about cancer detection, treatment, and curability in a population-based cohort of 145 African-American and 177 White women diagnosed with breast cancer in Connecticut, US, between 1987 and 1989. Cox proportional-hazards models were adjusted for stage at diagnosis, other biomedical variables, socio-demographic and lifestyle factors. Results: In multivariate models, perceived cancer incurability was associated with a higher risk of death from any cause (hazards ratio (HR)=1.67, 95 confidence interval (CI)=1.11, 2.51). Further control for tumor characteristics, genetic alterations, access to care, and additional psychosocial factors did not alter these findings. Other cancer-specific beliefs examined here were not related to survival. Conclusions: Perceived cancer incurability is independently associated with survival among breast cancer patients in fully adjusted models. The identification of the underlying mechanisms of this association has potential for translation into intervention strategies for cancer patients.
Transient phase-induced nucleation

A transient metastable rotator phase occurring on crystallization of hexadecane into its triclinic phase from the supercooled melt was directly observed with time-resolved synchrotron x-ray scattering. In this system, the limit of supercooling (the crystallization temperature) is determined by the thermodynamic stability of the transient phase with respect to the liquid. The crystallization kinetics of the homologous series of n -alkanes was measured and explained in terms of a crossover from stability to “long-lived” metastability to transient metastability. This crossover allowed further confirmation of the nature of the transient phase.
Phosphatase Inhibitors Potentiate 4-Hydroxynonenal-induced Phospholipase D Activation in Vascular Endothelial Cells

We have previously reported that endothelial cell phospholipase D (PLD), activated by 4-hydroxynonenal (4-HNE), was independent of protein kinase C activation. To determine whether PLD stimulation by 4-HNE is related to protein tyrosine phosphorylation, the effects of tyrosine kinase (Tyrk) and protein tyrosine phosphatase (PTPase) inhibitors on PLD activation were investigated. Pretreatment of bovine pulmonary artery endothelial cells (BPAEC) with Tyrk inhibitors, such as genistein, erbstatin, and herbimycin attenuated 4-HNE-induced PLD activation. Furthermore, vanadate, phenylarsine oxide, and diamide, inhibitors of PTPases, markedly increased the 4-HNE-induced PLD activation. The effects of Tyrk and PTPase inhibitors were specific towards the 4-HNE, as these agents had no effect on the agonist- or TPA- induced PLD activation. In addition to PLD activation, treatment of BPAEC with 4-HNE increased tyrosine phosphorylation of proteins including bands of molecular weights 40,000–60,000, 70,000–90,000, and ...
Interaction energies, structure, and dynamics at functionalized graphitic structure–liquid phase interfaces in an aqueous calcium sulfate solution by molecular dynamics simulation

Abstract Molecular dynamics simulations were performed to study the effect of surface functionalization of graphitic structures on the molecular-scale energetic, structure, and dynamics of water and ions at graphite surface–liquid phase interfaces. Three types of carbon surface structures were investigated: a pristine graphite plane and two graphite planes functionalized with hydroxyl (–OH) and carboxylate (–COO−, deprotonated carboxyl) groups. A divalent salt, calcium sulfate, was combined with water to simulate an electrolyte liquid phase. Results highlighted the ordering of H2O molecules that occurs near graphite surfaces and revealed a subtle effect on the position of the H2O layers associated with ions and functional group type. Surface functionalization of the graphitic structures affected the H-bond network and the orientation of near-surface H2O molecules, decreased the ion hydration, and significantly restrained the mobility of near-surface H2O molecules and bulk Ca2+ and SO 4 2 - ions.
Clinical dosimetry during the angiographic examination. Comments on coronary arteriography.

Data are given on the radiation exposure occurring in high volume angiographic suites to physicians and technical personnel. Emphasis is directed to coronary artery examinations since multiple recording modalities are utilized in these examinations and consequently personnel exposures are greater than in other angiographic studies. A comparison of dose exposures when these examinations are done via the brachial versus the femoral method and an explanation of the higher doses recorded by the brachial method are discussed. A clear health hazard is identified. In those departments with a large volume of angiographic examinations, a periodic rotation of personnel should be instituted. With the availability of inexpensive dose-rate meters, the directors of cardiovascular laboratories should individually monitor and evaluate exposure to their physicians and the technical personnel involved in their examinations.
The role of drift orbit bifurcations in energization and loss of electrons in the outer radiation belt

[1] Radiation levels in Earth's outer electron belt (L ≳ 2.5) vary by orders of magnitude on the time scales ranging from minutes to days. Multiple acceleration and loss processes operate across the belt and compete in defining its global variability. One such process is the drift orbit bifurcation effect. Caused by coupling of the drift and bounce motions, it breaks the second adiabatic invariant of radiation belt electrons producing their transport in radius and pitch angle. In this paper we investigate implications of drift orbit bifurcations to the global state and variability of the outer electron belt. For this purpose we use three-dimensional test particle simulations of electron guiding center motion in a realistic magnetic field model. We show that even at most quiet solar wind conditions bifurcations affect a broad range of the belt penetrating inside the geosynchronous orbit. This has an important practical implication for the analysis of experimental particle data: since the third adiabatic invariant is undefined for bifurcating orbit, the electron phase space density cannot be expressed in terms of three adiabatic invariants. We show that long-term transport of electrons due to drift orbit bifurcations is a complex combination of large ballistic jumps and small-amplitude diffusion in the second invariant and radial location. To model long-term transport, we derive an empirical map of the second invariant and radial jumps at bifurcations. The map can also be implemented by other radiation belt models, which cannot directly account for the physics of drift orbit bifurcations. Drift orbit bifurcations can produce electron losses through the magnetopause escape and through pitch angle scattering into the atmospheric loss cone. Most electrons, however, can stay quasi-trapped in the bifurcation regions for very long time periods. The pitch angle and radial transport due to drift orbit bifurcations lead to their meandering back and forth across the region producing mixing and recirculation of particle populations with different initial conditions. We show that this recirculation can greatly amplify electron energization by radial diffusion. Compared to the diffusion alone, the combined action of radial diffusion and drift orbit bifurcations can double electron energization at each recirculation cycle. Our results suggest that drift orbit bifurcations can play an important role in the buildup of increased electron fluxes in the storm recovery phase.