cssi/SciSciGPT-SciSciNet huggingface dataset:
Geographic distribution of co-dominant DNA stemlines in breast carcinoma.

Breast carcinomas often contain multiple DNA stemlines in flow cytometric DNA histograms. However, due to mixing during tissue disaggregation the microanatomical relationship between the cells which comprise distinct stemlines is unclear. We performed image cytophotometric DNA analysis (IA) on two separate areas of intact tissue sections of 19 breast carcinomas which were selected on the basis of flow cytometric (FCM) DNA content heterogeneity (i.e., multiple stemlines). For comparison, similar analyses were performed on seven tumors with unimodal FCM DNA histograms. Six of the 7 tumors (86%) with unimodal FCM histograms were also unimodal in both IA DNA histograms. Among tumors with heterogeneous FCM DNA histograms, the presence of multiple stemlines was confirmed in IA DNA histograms in 16/19. In nine of these 16 cases, multiple DNA stemlines having similar DNA indices were present in both areas of neoplasm examined with IA. The remaining seven cases displayed unimodal IA histograms in both areas, however DNA indices differed between the two histograms. These findings imply that cell populations corresponding to flow cytometrically detected DNA stemlines are often intimately admixed, even within geographically separated portions of breast tumors. This pattern suggests that productive interactions between genetically distinct tumor populations may lead to stable co-dominance of ancestral clones during progression of some breast carcinomas.
Black Population Concentration and Black-White Inequality: Expanding the Consideration of Place and Space Effects

For over 40 years, sociologists have investigated the relationship between the concentration of black population in a geographic area and the relative economic standing of blacks in that area. These tests of what has come to be called the "visibility-discrimination hypothesis" have established that concentration of black population in an area is positively related to black-white inequality in that area. In this article, we extend the consideration of the place effects and consider space effects by (1) tapping effects of normative structures in the spatial context of a local area on black-white inequality in the local area, (2) measuring the effects of the concentration of black population in adjacent areas on black-white inequality in the focal area, (3) controllingfor spatial dependence in inequality when examining these processes, and (4) examining the effects of these place and space factors on both occupational and wage inequality, so that their effects can be compared between the two outcomes and effects on wage inequality can be assessed net of occupation effects. After testing our model with data on local labor market areas, we conclude by examining the implications of our analysis for future studies of the visibilitydiscrimination hypothesis and for the general use of models that examine the effects of local place. For over 40 years, sociologists have investigated the relationship between the concentration of black population in a geographic area and the relative economic standing of blacks in that area. The roots of this tradition lie in Blalockls (1956) formulation of the "visibility-discrimination" hypothesis: the contention that where
Serum vitamin B12, C and folate concentrations in the New Mexico elder health survey: correlations with cognitive and affective functions.

Objectives: 1) To compare serum vitamin B12, C and folate concentrations in a randomly selected sample of elderly (age 65 years or older) male and female Hispanics and nonHispanic whites (NHW) and 2) to examine associations between serum B12, C and folate concentrations compared to measures of cognitive and affective (depression) functions.Methods: Equal numbers of male and female Hispanics and NHW were randomly sampled from the Health Care Financing Administration (Medicare) registrant list for Bernalillo County, New Mexico, and asked to volunteer for a paid home interview followed by a paid comprehensive interview/examination covering health and health-related issues. In addition to serum determinations of B12, C and folate, associations were examined between these vitamins and measures of cognitive and affective functions.Results: Males and Hispanics had lower serum vitamin B12, C and folate concentrations than females and NHW respectively. Participants taking a multivitamin supplement (MVI) had higher...
Relationship between crystallinity and electronic properties of silicon-on-sapphire

Abstract A comparative study of electronic properties (determined by photovoltage spectroscopy) and of the crystalline perfection (determined by UV reflection technique) was carried out on a series of silicon-on-sapphire wafers of different crystallinity. It was found that the improvement of crystallinity led to a significant reduction of the concentration of deep levels in the middle of the energy gap. Differences in the as-deposited crystalline quality can be related to differences in the electronic properties even after the deposits were ion implanted, oxidized and annealed. Recently discovered slight amorphization of silicon-on-sapphire was quantitatively analyzed in terms of the amorphization factor, η. It was found that η decreases with improvement of crystallinity and its value for SOS films was one to two orders of magnitude smaller than in a typical a-Si.
Positioning the Potato as a Primary Food Source of Vitamin C

Ascorbic acid, better known as vitamin C, is a crucial nutrient in the human diet. It performs many physiological functions in its primary roles as an electron donor and antioxidant. Vitamin C has been directly linked to collagen formation, iron absorption, cancer prevention, immunomodulation, and maintenance of normal nerve function. It is suspected to decrease the likelihood of strokes, cataracts, hypertension, and lead toxicity. Vitamin C deficiency leads to a condition called scurvy, accompanied by a weakening of blood vessels, bones and connective tissues, hair and tooth loss, joint swelling, and eventually death. Intake of vitamin C is considered inadequate, even among some parts of the population in developed countries where diet is not restricted, but more especially for at-risk populations in developing countries. Potatoes are an important worldwide source of vitamin C, contributing about 20% of the dietary intake in Europe. They are a vital source of vitamin C not only because of relatively high content, but because they can be stored, leading to consistent availability. Any improvement in the vitamin C content of potato products will have a beneficial impact on human nutrition. A three-pronged approach can be used to increase the vitamin C content of potatoes involving breeding, improved crop management, and modification of cooking processes. Breeding has tremendous potential for increasing vitamin C content in tubers as evidenced by research results in studies documenting germplasm variability and inheritance patterns. Management research may define practices that will slow the natural decline that occurs near the end of field growth and storage, a response partially conditioned by plant stress. Research into cooking procedures may help reduce the oxidative and enzymatic degradation of vitamin C that results from exposure to moisture, heat, and air.
Epidemic models with spatial spread due to population migration.

A spatial diffusion operator that governs the migration of polymorphic populations is derived and some specific epidemic models are analyzed in the presence of this type of diffusion. Threshold criteria and asymptotic behavior of solutions are derived, and it is shown that spatially heterogeneous steady states can occur in these models.
Wave Propagation and a Secular Theory of Calculation Based on Hamilton-Jacobi Theory

Summary A Hamilton-Jacobi method, often used in Astronomy, is outlined. It allows one to suppress secular terms in perturbation calculations. Noting the correspondence between classical mechanics and wave propagation, we use the method to treat the effect of small lateral variations in structure on the propagation of elastic surface waves. The basic result is that the horizontal wave vector is conserved, but the change in position, at which a particular spectral density is found, depends linearly on time. The purpose of this note is to outline a Hamilton-Jacobi method for the solution of wave propagation with perturbations acting (Osgood 1965; Smart 1953). This method has been used in astronomical calculations but has not yet received notice from the geophysical community. The basic result is the following. For a physical system with Hamiltonian Ho-H,, it is possible to obtain a set of variables (a, B) which satisfy Hamiltonian equations in which the new Hamiltonian is HI. When HI is zero, these variables become constants of the motion for the system with Hamiltonian H,. Several examples using this method will be shown (Bogoliubov & Mitropolsky 1961; Backus 1962a, b). For a physical system with Hamiltonian H,, the Hamiltonian equations of motion are with q and p the co-ordinates and momenta respectively
A review of the linear term in the low-temperature specific heat of La2CuO4 and La2−xMxCuO4 (M = Ba, Ca, Sr)

In this report I will summarize the results of an extensive review of the low-temperature specific heat of the La-based high-temperature superconductors, withT c between 30 and 40 K, and the related nonsuperconducting compound La2CuO4. There have been two previous studies by Fisheret al. [1] and Fischeret al. [2] which also reviewed the low-temperature specific heat of these materials. This work was undertaken to extend a similar study of the 90 K superconductor YBa2Cu3O7−δ which we recently completed [3]. This review will focus exclusively on the low-temperature specific heat and will update the previous studies by including recent results.
Learning by Collaborating: Convergent Conceptual Change

The goal of this article is to construct an integrated approach to collaboration and conceptual change. To this end, a case of conceptual change is analyzed from the point of view of conversational interaction. It is proposed that the crux of collaboration is the problem of convergence: How can two (or more) people construct shared meanings for conversations, concepts, and experiences? Collaboration is analyzed as a process that gradually can lead to convergence of meaning. The epistemological basis of the framework of analysis is a relational, situated view of meaning: Meanings are taken to be relations among situations and verbal or gestural actions. The central claim is that a process described by four primary features can account for students' incremental achievement of convergent conceptual change. The process is characterized by (a) the production of a deep-featured situation, in relation to (b) the interplay of physical metaphors, through the constructive use of (c) interactive cycles of conversati...
Adjunct faculty and the continuing quest for quality

This chapter addresses the use of adjunct faculty in community colleges. It examines issues of finding, hiring, orienting, evaluating, and developing adjuncts and stresses critical areas of ensuring quality and maintaining institutional standards.
Comparative antiestrogenic activities of 2,3,7,8-tetrachlorodibenzo-p-dioxin and 6-methyl-1,3,8-trichlorodibenzofuran in the female rat

The ED50s for the dose-response induction of hepatic microsomal aryl hydrocarbon hydroxylase (AHH) and ethoxyresorufin O-deethylase (EROD) by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in the female Sprague-Dawley rat were 3.3 and 2.7 nmol/kg, respectively. In contrast, the corresponding ED50 values for induction by the nontoxic 6-methyl-1,3,8-trichlorodibenzofuran (MCDF) were 524 and 578 mumol/kg for AHH and EROD, respectively, and TCDD was greater than 1.5 X 10(5) more potent than MCDF as an agonist for this response. Cotreatment of the female rats with MCDF (20, 50, or 100 mumol/kg) and TCDD (6.4 nmol/kg) showed that MCDF partially antagonized the induction of AHH and EROD by TCDD and this corresponded with results previously reported in the male rat. Like TCDD, MCDF also caused a dose-response decrease in uterine and hepatic cytosolic and nuclear estrogen (ERc and ERn) and progesterone (PRc and PRn) receptor levels. The relative TCDD/MCDF potencies for the reduction of uterine ERc, ERn, PRc, and PRn levels were 293, 569, 560, and 459, respectively, and comparable potency ratios (693, 409, 405, and 424, respectively) were observed in the liver. Since MCDF was active as an antiestrogen at dose levels which caused only minimal induction of hepatic monooxygenases, it is unlikely that induction of these enzymes and the subsequent increased metabolism of estradiol play a role in the antiestrogenic effects of MCDF (or TCDD). The reasons for the differences in the relative potency of MCDF for the "traditional" Ah receptor-mediated response (i.e., AHH induction) and the modulation of steroid hormone receptor binding levels are unknown. MCDF, a compound which exhibits relatively high TCDD receptor binding activity and low toxicity, represents a new class of nontoxic halogenated aromatic antiestrogens that can be utilized to further probe the mechanism of this response in model systems.
Carcinoembryonic antigen (CEA) levels and tumor histology in colon cancer

The demonstration of a tumor specific antigen (carcinoembryonic antigen) in 1965 raised the hope that the long-sought after “blood test for cancer” had been found [ 11, 121. Early optimistic reports suggested that the serum carcinoembryonic antigen (CEA) would be elevated or positive in as high as 90% of patients with colon cancer [9,24,27]. This original promise of CEA has not been fulfilled due to (1) a high incidence of false negatives in early lesions, (2) positive titers associated with malignancies outside the G.I. tract, (3) a significant number of false positives in patients with benign inflammatory disease [6, 9, 16, 20, 231. Despite these shortcomings, the CEA titer is elevated in over 70% of patients with carcinoma of the colon [5, 20, 251. During the past 5 years many investigators have tried to assess the role of CEA in cancer diagnosis, management and prognosis [2,20,21]. A number of studies have shown the plasma CEA may not be directly related to the size and extent of the colon cancer [ 1, 16,261. Recently we posed the question: Is the tumor associated with a high CEA titer histologically different from the tumor associated with a low CEA titer? In this study an attempt is made to answer that question by examining independently tumor
Performance changes during the sustained operation of a complex psychomotor task.

Fifteen male subjects were exposed to a primary tracking task and a variety of subsidiary tasks for a total of 15 hours. Tracking performance was assessed through the use of two error measures, amount of time off the target track, and number of times off target. Subsidiary performance tasks included: a vigilance task requiring subjects to respond to the deflection of the noodle of a small meter; two reaction time tasks requiring response to the onset of one or the other of two lights; mental multiplication, which required the solution of simple multiplication problems; and digit span, in which the subject was required to repeat as rapidly and as accurately as possible a sot of digits of either five, six or seven numbers in length. In addition, three physiological measures were obtained. A significant decrement in trucking performance was obtained for both measures utilized. This decrement was not particularly abrupt in its occurrence but rather took place cumulatively over the entire course of the experim...
Role of Lorentz–Stark broadening of hydrogen spectral lines in magnetized plasmas: Applications to magnetic fusion and solar physics

Abstract Broadening of hydrogen spectral lines in plasmas is an important diagnostic tool for many applications (here and below by “hydrogen atoms” and “hydrogen spectral lines” we mean atoms and spectral lines of hydrogen, deuterium, and tritium). In magnetized plasmas radiating hydrogen atoms moving with the velocity v across the magnetic field B experience a Lorentz electric field EL=v×B/c in addition to other electric fields. Since the velocity v has a distribution, so does the Lorentz field, thus making an additional contribution to the broadening of spectral lines. Compared to previous studies of this contribution, we cover the following new aspects. First, we consider the Lorentz–Doppler broadening of highly-excited hydrogen lines and produce new analytical results for arbitrary strength of the magnetic field B. We show for the first time that in the high-B case, the π-components of hydrogen lines are significantly suppressed compared to the σ-components. Second, we derive analytically Lorentz-broadened profiles of highly-excited hydrogen lines. We obtain expressions for the principal quantum number nmax of the last observable hydrogen line in the spectral series. These expressions differ very significantly from the corresponding Inglis–Teller result and constitute a new diagnostic method allowing to measure the product T1/2B, where T is the atomic temperature. Third, we consider magnetized plasmas containing a low-frequency electrostatic turbulence. This kind of turbulence causes anomalous transport phenomena (e.g., the anomalous resistivity) and is therefore very important to be diagnosed. We derive analytically distributions of the total electric field and the corresponding Stark profiles of hydrogen lines. We demonstrate that our findings lead to a significantly revised interpretation of the previous and future experimental data in magnetic fusion and the observational data in solar physics.
FAILURE OF INTEGRATED CARDIAC ACTION AT SUPERNORMAL HEART RATES.

SummaryHearts of anesthetized dogs were driven at slowly accelerating rates from atrial or ventricular electrodes. The rate thresholds for various abnormalities and failures were determined for both types of drive. Pulsus alternans occurs at a slower rate during atrial than during direct ventricular drive. Conduction from ventricle to atrium fails at slower rates than does A-V conduction. Alternation in electrical response voltage and ultimately 2:1 stimulus-electrical response ratios develop at high rates of drive in both atrium and ventricle much more commonly than do fibrillation or other irregularities of response. Sudden changes in rate and irregularities of stimulus pulse spacing are more apt to disorganize cardiac function than are progressive rate changes.
Isozyme variability in species of the genus Drosophila. VI. Frequency-property-environment relationships of allelic alcohol dehydrogenases in D. melanogaster.

Adult Drosophila melanogaster from naturally occurring populations in the Eastern United States were examined by gel electrophoresis for their alcohol dehydrogenase (ADH) phenotype. The ADH enzymes were partially purified and characterized. Frequencies of the controlling alleles, Adh4 and Adh6, were discovered to vary in a clinal pattern. Adh6 reaches a maximum frequency of about 0.90 in the South and minimum of about 0.50 in the North. Partially purified enzymes from the three Adh genotypes varied according to specific activity, substrate specificity, and heat stability. A differential influence of pH was indicated. There was little variation in Km values for ethanol and DPN+ among the enzymes.
Simulation-based LQR-trees with input and state constraints

We present an algorithm that probabilistically covers a bounded region of the state space of a nonlinear system with a sparse tree of feedback stabilized trajectories leading to a goal state. The generated tree serves as a lookup table control policy to get any reachable initial condition within that region to the goal. The approach combines motion planning with reasoning about the set of states around a trajectory for which the feedback policy of the trajectory is able to stabilize the system. The key idea is to use a random sample from the bounded region for both motion planning and approximation of the stabilizable sets by falsification; this keeps the number of samples and simulations needed to generate covering policies reasonably low. We simulate the nonlinear system to falsify the stabilizable sets, which allows enforcing input and state constraints. Compared to the algebraic verification using sums of squares optimization in our previous work, the simulation-based approximation of the stabilizable set is less exact, but considerably easier to implement and can be applied to a broader range of nonlinear systems. We show simulation results obtained with model systems and study the performance and robustness of the generated policies.
Two-component model for the associated multiplicity in inclusive reactions

A simple, two-component model for the charged multiplicity associated is presented with the observed particle in an inclusive reaction. At small p/subT/ the scattering is ascribed to a coherent or ''soft'' component, whereas at large p/subT/ the production mechanism is assumed to be incoherent or ''hard.'' At fixed incident energy and missing mass, the p/subT/ dependence of n/subc/ is given by the relative weights of hard and soft scattering, so that the multiplicity is a sensitive probe of the transition region between the two components. The model is applied to recent multiplicity data for pp $Yields$ pX and pp $Yields$ $pi$$sup +$X at 28.5 GeV/c, as well as to data at Fermilab and CERN-ISR energies.
Fused Deposition Modeling BioPrinter

Scaffolds with three-dimensional, customizable architectures will be fabricated and populated with fibroblasts via automated processes of a Fused Deposition Modeling BioPrinter. The success of the design will be dependent on the accuracy of fabrication and adhesion/proliferation of the seeded fibroblasts.
Effect of light and visual deprivation on the retina

Abstract The effect of light and unilateral visual deprivation (achieved by lid-suturing) on the retina of albino rats has been studied. Lid-sutured and unoperated animals were illuminated daily for 8, 11, or 16 hrs. With increasing time of illumination a progressive decrease in thickness of the outer retinal layers was observed in undeprived animals and in the open eye of the monocularly deprived rats. The shrinkage was greater in the outer plexiform than in the outer nuclear layer. In the lid-sutured eye considerably less change was found in the outer nuclear layer. The difference in thickness of the outer retinal layers of the sutured and companion open eye was 2.5 times greater after 16 than after after 8 hr of light exposure. The loss of receptors seems to be a function of the length of illumination. The decrease in thickness of the outer retinal layers in the open eye of the deprived animals was greater than in the undeprived ones suggesting that more light enters the former eye. It was assumed that an animal which has only one eye available keeps it open for longer periods of time than when both eyes are used.
Dopamine transporter levels in cocaine dependent subjects

Cocaine use is a significant problem in the US and it is well established that cocaine binds to the dopamine transporter (DAT) in the brain. This study was designed to determine if the DAT levels measured by 99m Tc TRODAT SPECT (single photon emission computed tomography) brain scans are altered in cocaine dependent subjects and to explore clinical correlates of such alterations. SPECT brain scans were acquired on 21 cocaine dependent subjects and 21 healthy matched controls. There were significantly higher DAT levels in cocaine dependent subjects compared to controls for the anterior putamen (p = 0.003; Cohen’s d effect size = 0.98), posterior putamen (p < 0.001; effect size = 1.32), and caudate (p = 0.003; effect size = 0.97). DAT levels in these regions were 10%, 17%, and 8% higher in the cocaine dependent subjects compared to controls. DAT levels were unrelated to craving, severity of cocaine use, or duration of cocaine use, but DAT levels in the caudate and anterior putamen were significantly (p < 0.05) negatively correlated with days since last use of cocaine. © 2008 Elsevier Ireland Ltd. All rights reserved.
Antibody isotype-specific engagement of Fcγ receptors regulates B lymphocyte depletion during CD20 immunotherapy

CD20 monoclonal antibody (mAb) immunotherapy is effective for lymphoma and autoimmune disease. In a mouse model of immunotherapy using mouse anti–mouse CD20 mAbs, the innate monocyte network depletes B cells through immunoglobulin (Ig)G Fc receptor (FcγR)-dependent pathways with a hierarchy of IgG2a/c>IgG1/IgG2b>IgG3. To understand the molecular basis for these CD20 mAb subclass differences, B cell depletion was assessed in mice deficient or blocked for stimulatory FcγRI, FcγRIII, FcγRIV, or FcR common γ chain, or inhibitory FcγRIIB. IgG1 CD20 mAbs induced B cell depletion through preferential, if not exclusive, interactions with low-affinity FcγRIII. IgG2b CD20 mAbs interacted preferentially with intermediate affinity FcγRIV. The potency of IgG2a/c CD20 mAbs resulted from FcγRIV interactions, with potential contributions from high-affinity FcγRI. Regardless, FcγRIV could mediate IgG2a/b/c CD20 mAb–induced depletion in the absence of FcγRI and FcγRIII. In contrast, inhibitory FcγRIIB deficiency significantly increased CD20 mAb–induced B cell depletion by enhancing monocyte function. Although FcγR-dependent pathways regulated B cell depletion from lymphoid tissues, both FcγR-dependent and -independent pathways contributed to mature bone marrow and circulating B cell clearance by CD20 mAbs. Thus, isotype-specific mAb interactions with distinct FcγRs contribute significantly to the effectiveness of CD20 mAbs in vivo, which may have important clinical implications for CD20 and other mAb-based therapies.
Evaluating the effectiveness of poverty alleviation programs

This chapter discusses the necessary ingredients for rigorous evaluation of poverty alleviation programs in developing countries. It confronts such poverty-specific issues as empowerment of the poor, beneficiary participation in design and implementation of programs, and beneficiary assessments.
Fragmenting the platelet to reduce metastasis

In this issue of Blood , Zhang et al describe an antiplatelet reagent attacking metastasis, the most deadly aspect of cancer. 1 Their experiments outline an early-stage preclinical approach providing proof-of-principle for antiplatelet strategies that may ultimately lead to an improved prognosis for the cancer patient.
Label-free integrative pharmacology on-target of opioid ligands at the opioid receptor family

In vitro pharmacology of ligands is typically assessed using a variety of molecular assays based on predetermined molecular events in living cells. Many ligands including opioid ligands pose the ability to bind more than one receptor, and can also provide distinct operational bias to activate a specific receptor. Generating an integrative overview of the binding and functional selectivity of ligands for a receptor family is a critical but difficult step in drug discovery and development. Here we applied a newly developed label-free integrative pharmacology on-target (iPOT) approach to systematically survey the selectivity of a library of fifty-five opioid ligands against the opioid receptor family. All ligands were interrogated using dynamic mass redistribution (DMR) assays in both recombinant and native cell lines that express specific opioid receptor(s). The cells were modified with a set of probe molecules to manifest the binding and functional selectivity of ligands. DMR profiles were collected and translated to numerical coordinates that was subject to similarity analysis. A specific set of opioid ligands were then selected for quantitative pharmacology determination. Results showed that among fifty-five opioid ligands examined most ligands displayed agonist activity in at least one opioid receptor expressing cell line under different conditions. Further, many ligands exhibited pathway biased agonism. We demonstrate that the iPOT effectively sorts the ligands into distinct clusters based on their binding and functional selectivity at the opioid receptor family.
Consequentialism, rights, and the new social welfare theory

Abstract Traditional consequentialist social welfare theory [SWT] is intendedly value-free and institutionless. It follows that, while unattenuated exchange and property rights are assigned an implicit, instrumental role in the achievement of first-best Paretian optima, little attention has focused on alternative rights construals, on their associated, correlative duties, and on the implications for SWT. This is true, even among economists who regard “freedom” as morally exigent. This paper argues that the rights which social welfare theorists regard as instrumentally important—and, therefore, legally sanctioned—need not, in consequentialist theory, be respected: The duties which are correlative to social welfare theorists' implicitly sanctioned rights may, in consequentialist terms, be overcome by purely utilitarian considerations. It follows, pari passu, that reliance on a goal-based efficiency standard is irreconcilable with respect for the rights which most economists either take to be intrinsically important or seek to justify. Granting this, normative analysis must take account of the logical and other tensions among consequences, rights, duties, and other dimensions of moral evaluation.
FMSI: a FORTRAN program for inverting fault/slickenside and earthquake focal mechanism data to obtain the regional stress tensor

Program FMSI inverts observations of slip directions on fault planes of known orientation in order to determine the best-fitting four-parameter stress tensor, defined by three principal stress directions and R=(σ2 − σ1)/(σ3 − σ1), and the associated uncertainty. Special effort is applied to two important aspects of this analysis: how to define the best-fitting model, and how to identify it. The misfit between a fault observation and a stress model is defined as a rotation of the combined fault plane/slip vector that achieves an orientation for which the observed and predicted slip directions on the fault plane are aligned. The best model is the one that minimizes the sum of these values for all data. Many different misfit rotations are possible; program FMSI allows the user to select from among a number of possible measures of rotation misfit, differing in solution quality and computational efficiency. The optimum stress model and estimates of confidence limits are determined by a systematic search over ranges of one stress magnitude and three stress orientation parameters.
Guanosine 3′,5′-bispyrophosphate coordinates global gene expression during glucose-lactose diauxie in Escherichia coli

Guanosine 3′,5′-bispyrophosphate (ppGpp), also known as “magic spot,” has been shown to bind prokaryotic RNA polymerase to down-regulate ribosome production and increase transcription of amino acid biosynthesis genes during the stringent response to amino acid starvation. Because many environmental growth perturbations cause ppGpp to accumulate, we hypothesize ppGpp to have an overarching role in regulating the genetic program that coordinates transitions between logarithmic growth (feast) and growth arrest (famine). We used the classic glucose-lactose diauxie as an experimental system to investigate the temporal changes in transcription that accompany growth arrest and recovery in wild-type Escherichia coli and in mutants that lack RelA (ppGpp synthetase) and other global regulators, i.e., RpoS and Crp. In particular, diauxie was delayed in the relA mutant and was accompanied by a 15% decrease in the number of carbon sources used and a 3-fold overall decrease in the induction of RpoS and Crp regulon genes. Thus the data significantly expand the previously known role of ppGpp and support a model wherein the ppGpp-dependent redistribution of RNA polymerase across the genome is the driving force behind control of the stringent response, general stress response, and starvation-induced carbon scavenging. Our conceptual model of diauxie describes these global control circuits as dynamic, interconnected, and dependent upon ppGpp for the efficient temporal coordination of gene expression that programs the cell for transitions between feast and famine.
Research training for residents.

I have been given the almost impossible task of assessing the status of research in otolaryngology residency programs across the country. How best to do this is elusive to me. However, three methods seem appropriate for the task. The first is to sample the philosophical opinions of program directors representing widely varied sized and geographically situated programs. The second is to review the pertinent results of the Society of University Ophthalmologists (SUO) survey, performed in 1981, regarding research and residency programs. The third is the presentation of an example of a program with a mandatory research rotation, specifically, that of the University of Washington, Seattle. Prior to composing this article, I thought it best to sample the opinions of directors of representative otolaryngology training programs. What follows are excerpts from letters composed by seven program directors in response to the question, What roles do researchers play in their training programs
A natural history of human tree climbing

Walking and running have dominated the literature on human locomotor evolution at the expense of other behaviors with positive and negative fitness consequences. For example, although modern hunter-gatherers frequently climb trees to obtain important food resources in the canopy, these behaviors are seldom considered within the existing framework of primate positional behavior. As a result, inferences about the arboreal performance capabilities of fossil hominins based on a resemblance to humans may be more complicated than previously assumed. Here we use ethnographic reports of human tree climbing to critically evaluate hypotheses about the performance capabilities of humans in trees compared with other primates. We do so by reviewing the ecological basis of tree climbing behavior among hunter-gatherers and the diversity of human climbing techniques and styles. Results suggest that the biological and adaptive significance of human climbing has been underestimated, and that some humans are surprisingly competent in trees, particularly during vertical climbing and activities in the central core of trees. We conclude that while hominins evolved enhanced terrestrial locomotor performance through time, such shifts may have imposed only minor costs on vertical climbing abilities. The diversity of the locomotor repertoire of modern humans must therefore be taken into account when making form-function inferences during the behavioral reconstruction of fossil hominins.
Toward "pain-free" statin prescribing: clinical algorithm for diagnosis and management of myalgia.

Myalgia, which often manifests as pain or soreness in skeletal muscles, is among the most salient adverse events associated with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins). Clinical issues related to statin-associated myotoxicity include (1) incidence in randomized controlled trials and occurrence in postmarketing surveillance databases; (2) potential differences between statins in their associations with such adverse events; and (3) diagnostic and treatment strategies to prevent, recognize, and manage these events. Data from systematic reviews, meta-analyses, clinical and observational trials, and postmarketing surveillance indicate that statin-associated myalgia typically affects approximately 5.0% of patients, as myopathy in 0.1% and as rhabdomyolysis in 0.01%. However, studies also suggest that myalgia is among the leading reasons patients discontinue statins (particularly high-dose statin monotherapy) and that treatment with certain statins (eg, fluvastatin) is unlikely to result in such adverse events. This review presents a clinical algorithm for monitoring and managing statin-associated myotoxicity. The algorithm highlights risk factors for muscle toxicity and provides recommendations for (1) creatine kinase measurements and monitoring; (2) statin dosage reduction, discontinuation, and rechallenge; and (3) treatment alternatives, such as extended-release fluvastatin with or without ezetimibe, low-dose or alternate-day rosuvastatin, or ezetimibe with or without colesevelam. The algorithm should help to inform and enhance patient care and reduce the risk of myalgia and other potentially treatment-limiting muscle effects that might undermine patient adherence and compromise the overall cardioprotective benefits of statins.
Comparison of interviewed and non-interviewed non-Hodgkin's lymphoma (NHL) patients in the San Francisco Bay Area.

Abstract PURPOSE: To determine whether interviewed non-Hodgkin's lymphoma (NHL) patients differed from non-interviewed NHL patients and to revise the population-based risk estimate for NHL associated with HIV infection in homosexual men in the San Francisco Bay Area. Differences between study participants and non-participants are a concern in epidemiologic studies. Recruitment techniques can be modified when nonparticipation is a result of subject refusal. However, the solutions for nonparticipation due to death are less clear, especially when rapid case ascertainment (RCA) is used to identify newly diagnosed patients. METHODS: A large population-based case-control study was conducted in the San Francisco Bay Area between 1988 and 1995 to investigate risk factors for NHL. Nearly 1600 patients were interviewed and included in this study. A total of 1047 NHL patients were not interviewed because they had died prior to contact (602 patients) or we had received their RCA information after the study had ended (445 patients). We compared available demographic, clinical, and histologic profiles of the interviewed and non-interviewed NHL patients. RESULTS: Compared with the interviewed group, the non-interviewed group was younger, had more single HIV-infected homosexual men and a higher incidence of high-grade and “not-otherwise-specified” lymphoma. When categorized by sex and sexual preference, median age at diagnosis of NHL was the same for the interviewed and non-interviewed homosexual men. Combining interviewed and non-interviewed patients, the estimated risk for NHL associated with HIV infection in homosexual men [odds ratio (OR) = 50] is substantially higher than we had estimated in our earlier publications (OR = 20). CONCLUSIONS: High-grade lymphomas associated with poor survival in homosexual men are likely to be under-represented in case-control studies of NHL.
Human Fetal Heart Rate Dishabituation between Thirty and Thirty-Two Weeks Gestation

Few studies of human fetal habituation have included dishabituation procedures (i.e., assessment of the reemergence of a habituated response) to determine if response decrements are the result of reevaluation of information (a brain process) or fatigue of peripheral receptors. The purpose of this study is to describe the ability of the human fetus to learn and recall information with procedures to assess the central nervous system. Fetal heart rate (FHR) of 84 fetuses between 30 and 32 weeks gestational age was examined in response to 3 series of vibroacoustic (VA) stimuli presented at pseudorandom intervals of 25-45 s over the head of the fetus. Responses to the first series of 15 stimuli (S1) were compared with an identical second series of 15 stimuli (S1) presented over the head of the fetus. Between the 2 series, a novel (dishabituating) VA stimulus (S2) was presented, differing from S1 in intensity and frequency. The third series of S1s was applied to the mother's thigh as a control for possible maternal responses to the stimulus. Prestimulus FHR was computed during a 5 s interval before each stimulus, and mean FHR was computed during the intertrial interval (average FHR). The response to S1 during the first series of trials (1-15) produced a sustained rise in both prestimulus and average FHR, r(83) = .90, p < .001. After the novel S2 (trial 16) the rate of change was attenuated for average FHR, r(83) = .12, ns, to S1 for trials 17-31 but not prestimulus FHR, r(83) = .50, p < .001. The decrease in FHR response was reestablished when stimulation was applied to mother's thigh, trials 32-41, r(83) = .92, p < .001. A significant habituation pattern across trials was observed for the first series of S1s when prestimulus HR was subtracted from each preceding average FHR value (delta FHR). After the single novel stimulus (S2), the FHR response to S1 reemerged. All combinations of beginning and ending series slopes were compared, and only the rate of change during the last 4 trials of the initial presentation of S1 and the first 4 trials after the novel stimulus was significant, F(1, 82) = 9.21, p < .003. Uterine contractions collected from the continuous record were not related to the presentation of the novel stimulus, chi 2(1, N = 84) = 0.59, p < .50, ns, or delta FHR slope after the novel stimulus, chi 2(9, N = 84) = 10.52, p < .50, ns. These results established that the 32 week human fetus is capable of detecting, habituating, and dishabituating to an external stimulus and support the premise that areas of the human fetal central nervous system critical for detecting and discriminating information and for learning and memory have developed by the early third trimester.
Convected transient analysis for large space structures maneuver and deployment

Convected-transient analysis techniques in the finite-element method are used to investigate the deployment and maneuver of large spacecraft structures with multiple-member flexible trusses and frames. Numerical results are presented for several sample problems.
Van Deemter-type relationship for determining the optimum initial flow-rate and optimum pressure programming rate in temperature/pressure-programmed capillary column gas chromatography utilizing separation numbers

Accurate prediction of the optimum conditions for a double-programmed gas chromatographic separation (simultaneous temperature and pressure programming) has been accomplished for the first time using a new relationship analogous to that established by the Van Deemter equation. Separation numbers (TZ values) for CH, the homologous pair average [e.g., (C12 + C13)/2 = C12.5], were determined for a C12–C17 series of n-alkanes and related to the average of the elution flow-rate, Fe, of the two homologues used to calculate TZ. Fe is defined as the flow-rate at the time of solute elution. Conditions for analysis involved the selection of a low temperature programming rate (TPR) and four different initial flow-rates (0.677, 1.10, 1.49 and 1.89 ml/min) upon which was super-imposed a series of positive and negative pressure programming rates, PPr. Graphs of TZ versus Fe were parabolic curves which could be described in terms of longitudinal diffusion and resistance to mass transfer. Higher Fes of 1.49 and 1.89 ml/min resulted in straight lines with negative slopes as only resistance to mass transfer was operating. This effect is discussed in terms of laminar and turbulent flow (as predicted by Reynold's number, Re). All plots could be modeled by the quadratic expression TZ = x(Fe)2 + y(Fe) + z. By differentiation, the optimum Fe and maximum TZ for each CH was determined, and, from this, the optimum initial flow-rate PPR could be derived. The example cited is for the data obtained using an initial flow-rate of 0.677 ml/min, a TPR of 0.90°C/min starting at 40°C and nine different PRRs. The optimum initial flow-rate determined under these conditions was found to be 0.80 ml/min with an optimum PPR of 0.12 kPa/min.
109 Use of EPR Spectroscopy to Measure Tissue Oxygen in an Ischemic Flap Model

Methods to reliably measure tissue oxygenation in situ are currently lacking. We have developed a vertically oriented, dorsal, bipedicle flap model that is easy to perform, reliably reproduces tissue ischemia, eliminates craniocaudal variation, and is amenable to studying therapeutic modalities. The effect of narrowing this flap on tissue oxygenation measured with Licox electrodes has previously been presented. In this study we utilize in situ EPR spectroscopy to demonstrate the oxygen gradient in the flap as a function of flap width and placement of a silicone sheet directly under the flap. The effect of wound healing over a 2 week period is demonstrated. Twenty four, 300 gm male Sprague-Dawley rats underwent creation of the bipedicle flap according to the following groups: 2.5 cm flap with silicone, 2.0 cm flap without silicone, 2.0 cm flap with silicone. Each group of 6 animals was injected with EMS char at 2 cm intervals along the flap and one injection in the control, non-ischemic tissue. A 4th group underwent 2.0 cm flaps with silicone and use of lithium phthalocyanin as the paramagnetic material. Wound measurements and EPR spectroscopy were performed on days 3, 7, 10 and 14. On day 14, after EPR measurements, the animals were sacrificed and their wounds excised. One flap and one control wound were preserved for histologic analysis, the other flap and control wounds were prepared for lactate measurements. EPR spectroscopy demonstrated a gradient of oxygen that was lowest in the center of the flap and greatest at either end. Changes in the oxygen gradient correlated with narrowing and placement of the intervening silicone sheet. This new technology has never been utilized in an animal model of impaired wound healing. Comparison of recently developed paramagnetic materials for optimal tissue oxygen and free radical measurements will be presented.
New source of evidence: explosive traces in hair

This study examines the sorption of explosives [TNT, RDX, PETN, TATP] to hair during exposure to their vapors. In each test, three colors of hair were simultaneously exposed to explosive vapor. Washing, extracting, and gas chromatographic quantification protocols were developed, and replication of quantitative data was confirmed. Results show that sorption of explosives, via vapor diffusion, to black hair is significantly greater than to blond, brown or bleached hair. Furthermore, the rate of sorption is directly related to the vapor density of the explosive: TATP >>> TNT >> PETN > RDX. Using TNT as the prototype, persistence of the explosive upon standing in air and upon repeated washing with sodium dodecyl sulfate was demonstrated. This study indicates that hair can be a useful indicator of explosive exposure/handling. Work is in progress to develop this technique into an effective forensic tool.
Effects of the ultimobranchial and parathyroid glands and vitamins D2, D3 and dihydrotachysterol2 on blood calcium and intestinal calcium transport in the frog.

Administration of 500 μg vitamin D2 or D3 with ingestion of calcium to ultimobranchialectomized (UBX) or UBX-parathyroidectomized (PTX) frogs (Rana pipiens) induced hyerpcalcemia and hypercalciuria not apparent in control or PTX frogs. Calcium transport in isolated everted gut sacs was significantly elevated in UBX and UBX-PTX frogs but not in controls or PTX animals. Further, with Vitamin D3 in UBX frogs the duodenal segment had a greater capacity to transport calcium than the jejunal-ileal segment when compared to control, PTX or UBX-PTX frogs. Dihydrotachysterol2 and calcium ingestion also induced hypercalcemia, hypercalciuria and increased calcium transport in gut of UBX and UBX-PTX frogs, with no change seen in PTX or controls after 5 days. The inhibitory influence of the ultimobranchial glands on intestinal calcium transport apparently does not require the presence of the parathyroids and exhibits an inhibitory influence against a high calcium gradient across the duodenal segment. (Endocrinology 96:...
Impact of undergraduate science course innovations on learning.

play active role This attributed mounting lectures, recitations, and laboratory sessions do not guarantee that students deep standing of critical concepts ( 1 5). Since the National Science Foundation (NSF) to research projects that science instruction. The resulting increase of student-centered innovations studies raises for How innovations red in undergraduate science courses have a positive on student learning? types of questions motivated a 3-year, NSF-funded