cssi/SciSciGPT-SciSciNet huggingface dataset:
Challenges in drug delivery to tumors of the central nervous system: An overview of pharmacological and surgical considerations

The majority of newly diagnosed brain tumors are treated with surgery, radiation, and the chemotherapeutic temozolomide. Development of additional therapeutics to improve treatment outcomes is complicated by the blood-brain barrier (BBB), which acts to protect healthy tissue from chemical insults. The high pressure found within brain tumors adds a challenge to local delivery of therapy by limiting the distribution of bolus injections. Here we discuss various drug delivery strategies, including convection-enhanced delivery, intranasal delivery, and intrathecal delivery, as well as pharmacological strategies for improving therapeutic efficacy, such as blood-brain barrier disruption.
Understanding models of the geomagnetic field by Fourier analysis.

Fourier spectra of X, Y, and Z components for both latitudinal and longitudinal circular profiles are deduced analytically from a n*=64 spherical harmonic model of the internal geomagnetic field. Expressions and numerical results demonstrate that the spectra behave differently for different field components and different profiles. Simplified anomaly model studies indicate that, despite being much less in amplitude with respect to the spectra of the core field, the spectra with long wavelengths of crustal field are generally more significant than those with short wavelengths of the same source. Wavelength should not be used as a criterion to discuss the depth of the field sources. The crustal field may be seriously distorted by high-pass filtering, whereas truncation at the commonly accepted level of spherical harmonic model of the core field has little effect on localized patterns of the anomalies.
Hydrodynamic slip: Polymer adsorption and desorption at melt/solid interfaces.

Hydrodynamic slip due to lack of molecular interfacial interactions is demonstrated rheologically as a function of molecular weight and temperature, by comparing poly(dimethyl siloxane) (PDMS) suspensions of bare and silane-treated glass spheres. The magnitude of interfacial slip between treated spheres and PDMS matrix increases with the applied stress and with the molecular weight of PDMS matrices. The onset stress for slip drops sharply with temperature and PDMS molecular weight.
HIV infection is not associated with Reiter's syndrome: data from the Johns Hopkins Multicenter AIDS Cohort Study

Reiter's syndrome has been reported to occur in up to 10% of patients with HIV infection. However, no properly controlled epidemiological studies have been conducted to determine whether HIV infection is an independent risk factor or whether the immunodeficiency induced by HIV infection is permissive for infection with other arthritogenic organisms. The prevalence and incidence of Reiter's syndrome were determined in 1133 homosexual/bisexual men enrolled in the Johns Hopkins Multicenter AIDS Cohort Study. There was no difference in the prevalence of Reiter's syndrome at entry into the study in 1984 between 357 HIV-positive and 776 HIV-negative men: five per 1000 in both groups. During 5 years' follow-up, one case of Reiter's syndrome developed among each group of HIV-positive and HIV-negative men. These data fail to support a direct etiological role for HIV infection in the development of Reiter's syndrome.
Convex Polytopes and Enumeration

This is an expository paper on connections between enumerative combinatorics and convex polytopes. It aims to give an essentially self-contained overview of five specific instances when enumerative combinatorics and convex polytopes arise jointly in problems whose initial formulation lies in only one of these two subjects. These examples constitute only a sample of such instances occurring in the work of several authors. On the enumerative side, they involved ordered graphical sequences, combinatorial statistics on the symmetric and hyperoctahedral groups, lattice paths, Baxter, Andre, and simsun permutations,q-Catalan andq-Schroder numbers. From the subject of polytopes, the examples involve the Ehrhart polynomial, the permutohedron, the associahedron, polytopes arising as intersections of cubes and simplices with half-spaces, and thecd-index of a polytope.
Patterns of intraspecific agonistic interactions involved in nest defense of a primitively eusocial halictine bee

Intraspecific nest defense inLasioglossum zephyrum involves specific agonistic action patterns by guard bees released by non-resident intruders. When guards are not highly motivated, intention movements are exhibited which also occur in the context of more aggressive interactions. Antennation, either mutual or by one bee, usually occurs prior to aggressive movements. Two main action patterns occur when a non-resident bee attempts to enter a nest: (1) the guard blocks the nest entrance with the abdomen, which often leads to backing movements and abdominal thrusts to eject the intruder, (2) the guard assumes a fight posture with head and abdomen extended toward the intruder; from the fighting posture, lunging often results in which the guard moves forward, alternating between head (mandibular) and abdomen (sting) thrusts. Most interactions are one-sided, with the intruder retreating from the guard, but mutual more intense fighting does occur.
Novel TP53 gene mutation and correlation with p53 immunohistochemistry in a mixed epithelial carcinoma of the endometrium

► We examine the correlation between p53 immunohistochemistry and TP53 gene mutation status in a mixed epithelial endometrial carcinoma. ► We describe a novel R306* (c.916C > T) mutation in exon 8 of the TP53 gene. ► We propose that the distinction between Type I and Type II endometrial carcinomas may be more fluid than previously believed.
Current Perspectives on the Diagnosis and Treatment of Double Depression.

In recent years, the frequency with which patients present with 'double depression', i.e. coexisting chronic depression (dysthymia) and acute major depression, has become increasingly evident. A growing research literature demonstrates that patients with double depression are at increased risk for poor outcome, including poor psychosocial functioning, high usage of medical services, high rates of suicide attempts, and increased recurrence of major depression. Furthermore, naturalistic studies have shown that when these patients are treated in the community, they often do not receive adequate antidepressant medication to treat their acute or chronic depressive disorders.In this article, we introduce a typology that is designed to assist clinicians in determining useful strategies in the short and long term treatment of double depression. This differentiates between those patients with double depression who present primarily with acute depression; those presenting primarily with chronic depression (where treatment can focus on the single, more severe disorder, and may be time-limited or episodic); and those presenting with severe acute depression and severe chronic depression, in whom lifelong medication is often required. Aggressive treatment is recommended for all patients with double depression, but refined treatment strategies based on depressive typology may help to increase compliance, consolidate therapeutic gains and forestall relapse.A growing psychopharmacology literature shows that several different classes of medication [tricyclic antidepressants, monamine oxidase inhibitors, selective serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitors and others] are effective in the treatment of double depression, although perhaps somewhat less effective than in the treatment of acute major depression.
Survival of algal cultures after freezing by controlled and uncontrolled cooling.

Abstract A comparison of the effect of controlled and uncontrolled cooling during the freezing of algal cells was made. With the controlled cooling procedure, the temperature drop from room temperature to −30 °C occurred at the rate of about 1 °C per min. With the uncontrolled cooling procedure, freezing of a 0.2-ml sample to −30 °C required about 25 sec. Viability determinations were made after the specimens had remained at −79 °C for 1 to 2 hr for both procedures. The number of intact cells, the number of cells retaining their viability, and the mitotic activity of the viable cells were higher in samples frozen by controlled cooling than in those frozen by uncontrolled cooling. When cells suspended in 10% glycerol were frozen by controlled cooling, the rate of survival was comparable to untreated samples. These evidences were unanimously true for the 16 strains (six genera) tested. The degree of susceptibility to uncontrolled cooling varied with each strain, however. Of 23 strains (five genera) tested, all were frozen successfully by controlled cooling. No detectable deterioration of the cultures was observed after 19 to 36 months of storage in the liquid nitrogen refrigerator (−160 ° to −196 °C). Two strains of Euglena were included in these tests. Their response to the cooling procedures and storage temperatures demonstrated no deviation from other algal strains. However, a delay in motility of cells in the recovered cultures was observed.
Analysis of histamine and Nτ-methylhistamine in plasma by gas chromatography-negative ion-chemical ionization mass spectrometry

Abstract Current methods of quantitation of histamine and its major metabolite N τ -methylhistamine are inaccurate and insensitive to the very low concentrations that exist in plasma samples. Therefore, an accurate and sensitive method for quantification in plasma has been developed using the stable isotope dilution assay with negative ion-chemical ionization mass spectrometry. For histamine, after the addition of [ 2 H 4 ]histamine to 2 ml of plasma, the plasma sample is deproteinized, extracted into butanol, back extracted into HCl, derivatized to the pentafluorobenzyl derivative (CH 2 C 6 F 5 ) 3 -histamine, purified on silica gel columns, and then quantified with negative ion-chemical ionization mass spectrometry by selected ion monitoring of the ratio of ions m z 430 434 . For N τ -methylhistamine, after the addition of N τ -[ 2 H 3 ]methylhistamine to 2 ml of plasma, the plasma sample is deproteinized, extracted into butanol, back extracted into HCl, derivatized to the heptafluorobutyryl derivative (C 3 F 7 CO 2 ) 2 - N τ -methylhistamine, purified on silica gel columns, and then quantified with negative ion-chemical ionization mass spectrometry by selected ion monitoring of the ratio of ions m z 497 500 . The precision of the histamine assay is 3.1% and the accuracy is 95.5 ± 2.5% while the precision of the N τ -methylhistamine assay is 1.9% and the accuracy is 106.8 ± 1.9%. The lower limits of sensitivity are 1 pg for histamine and 6 pg for N τ -methylhistamine injected on column. Using the assay in three normal human volunteers, plasma concentrations of histamine were 130, 92, and 85 pg/ml, and of N τ -methylhistamine were 229, 228, and 216 pg/ml. This assay provides a very sensitive and accurate method of quantitation of histamine and N τ -methylhistamine in plasma samples.
Pen-based interaction techniques for organizing material on an electronic whiteboard

This paper presents a scheme for extending an informal, penbased whiteboard system (the Tivoli application onthe Xerox LiveBoard) to provide interaction techniques that enable groups of users in informal meetings to easily organize and.rearrange material and to manage the space on the board. The techniques are based on the direct manipulation of boundaries and the implicit recognition of regions. The techniques include operations for shrinking and rearranging, structured borders that tessellate the board, freeform enclosures that can be split, fused, and linked, and collapsible annotations. Experience with using these techniques, the results of a user test, some design trade-offs and lessons, and future directions are discussed.
Unrelated Cord Blood Transplantation in Adult and Pediatric Acute Lymphoblastic Leukemia: Effect of Minimal Residual Disease on Relapse and Survival

Data on pretransplantation minimal residual disease (MRD) and outcomes of umbilical cord blood transplantation (UCBT) are limited. Out of the 143 patients with acute lymphoblastic leukemia (ALL) who underwent UCBT at the University of Minnesota between 2004 and 2010, we evaluated 86 patients with available MRD assessment data by 4- and 8-color flow cytometry analysis immediately before transplantation. Ten patients (11.6%) were MRD-positive, and 76 were MRD-negative (88.4%). Most of the patients (82%) received myeloablative conditioning. GVHD prophylaxis consisted of cyclosporine and mycophenolate mofetil. In multivariate analysis, age, disease status (complete remission [CR] 1 versus CR2/CR3), disease group (precursor B cell ALL versus Philadelphia chromosome–positive ALL versus T cell ALL), and time to transplantation had no impact on relapse. Patients with MRD before UCBT had a greater incidence of relapse at 2 years (relapse rate, 30%; 95% confidence interval [CI], 4%-56%) and lower 3-year disease-free survival (30%; 95% CI, 7%-58%) compared with those without MRD (relapse rate, 16%; 95% CI, 8%-25%; P = .05; disease-free survival, 55%; 95% CI, 43%-66%; P = .02). Our data suggest that in patients with ALL, achieving an MRD-negative state before UCBT improves outcomes.
Confronting Entrenched Insurgents

During counterinsurgency operations, government forces with superior firepower confront weaker low-signature insurgents. Under what conditions should government (Blue) forces attack insurgent (Red) strongholds? How should the government allocate its force across different strongholds when the insurgents' threat to the Blue civilian population must be taken into account? How should the government respond to “smart” insurgents who anticipate the government's optimal plan of attack and prepare accordingly? How do the results change when the government takes Red civilian casualties resulting from attacks on insurgent strongholds into account? This article addresses these questions. Using Lanchester models modified to account for imperfect intelligence, we formulate an optimal force allocation problem for the government and develop a knapsack approximation that has tight error bounds. We also model a sequential force allocation game between the insurgents and the government and solve for its equilibrium. When the government has perfect intelligence, in equilibrium the insurgents concentrate their force in a single stronghold that the government either attacks or not depending upon the resulting casualty count. Otherwise, under reasonable assumptions regarding the government's behavior and intelligence capabilities, it is optimal for the insurgents to “spread out” in a way that maximizes the number of soldiers required to win all battles. If the government worries about Red civilian casualties, the insurgents have a strong incentive to blend in with the Red civilian population, because this can prevent government attacks while allowing the insurgents to inflict casualties on Blue civilians. Such strategic behavior makes it harder for the government to protect its citizens from insurgent attacks.
A note on fuzzy sets

Fuzzy sets are defined as mappings from sets into Boolean lattices. The basic set theory type results for Zadeh's fuzzy sets are shown to carry over. Some results on convex fuzzy sets, star-shaped fuzzy sets, and arcwise connected fuzzy sets are given. Fuzzy sets with “holes,” bounded fuzzy sets, and connected fuzzy sets are also discussed.
Behavior of shear studs subjected to fully reversed cyclic loading

A series of experimental and analytical tests on modified composite push-out specimens and bare steel shear studs were performed to investigate the behavior of shear studs subjected to fully reversed cyclic load. Of specific interest was the behavior under low-cycle fatigue. Such load would be applicable to composite or hybrid structures subjected to seismic events. An overview of previous research in the area of shear stud behavior is included. Reversed cyclic loading resulted in an almost 40% reduction in shear stud capacity compared to static capacities. This reduction occurs due to low-cycle fatigue of the stud/weld materials as well as concrete degradation. Existing relationships for concrete strength predicted the change in capacity under static and low-cycle fatigue loads. Initial bending of studs did not affect the shear stud load capacity. While shielded metal arc welding of shear studs provides a very different stud base condition, the percentage reduction in capacity was similar. Boundary conditions in push-out specimens did not significantly affect the initial bending and shear stresses, which appear to control failure modes.
A multidimensional scaling study of visual memory of 5-year olds and adults

Abstract Nonmetric multidimensional scaling is expounded as a methodology for investigating memory development. Judgements of similarities between complex objects were obtained from 5-year-olds and adults under two conditions: (1) when objects were simultaneously present at the time of comparison, and (2) when the objects were not simultaneously present and had to be compared on the basis of short-term memory. Scaling solutions for similarity judgments by each age group in the two conditions were obtained. Comparison within each age group of the configurations from the memory condition with the simultaneous condition indicated that the internal representations of both children and adults contained much of the information the subjects extracted from the stimuli during “direct” perception. The scaling techniques, which could be widely applied in developmental studies of memory and perception, are explained and critically discussed.
Cardiovascular instability after patent ductus arteriosus ligation in preterm infants: the role of hydrocortisone.

Following patent ductus arteriosus (PDA) ligation, preterm infants may develop profound hypotension and respiratory failure. Prophylactic stress hydrocortisone (HC) has emerged as a therapy to prevent complications, postulating these infants do not synthesize steroids because of an immature hypothalamic–pituitary–adrenal axis. The purpose of this study was to compare outcomes in infants who received stress HC before their PDA ligations to those who did not. A retrospective chart review was performed of infants who underwent PDA ligations at our institution's neonatal intensive care unit. Data were collected on treatment with HC, and respiratory and cardiovascular support. Gestational age (GA) and birth weight were lower in the HC group (24 vs 25 weeks, 632 vs 790 g), but age at time of surgery was similar (26 vs 21 days). Cardiorespiratory support was comparable between the groups pre- and post-operatively. In regression models that adjusted for GA, HC treatment was not independently related to respiratory support postoperatively, but was associated with a decrease in postoperative dopamine (2.2 mcg kg−1 min−1; P=0.03). Respiratory support postoperatively was predicted by preoperative respiratory support. GA and age at surgery were not independently associated with outcome. Preoperative stress HC was not associated with improved cardiorespiratory stability, regardless of GA. Further investigation is needed to identify infants who may benefit from this therapy.
Thermodynamics of mucopolysaccharide-dye binding. II. Binding constant and cooperativity parameters of acridine orange-dermatan sulfate system.

In the acridine orange–dermatan sulfate system, free and bound dye can be distinguished from each other spectroscopically. This permits the use of fluorometric methods to study the binding of acridine orange to the acid mucopolysaccharide dermatan sulfate. Experiments were conducted at 24°C in 10−3M citrate/phosphate buffer at pH = 7.0. The binding of the dye is highly cooperative, as evidenced by considerable interaction between adjacent bound dye molecules. Analysis of the data indicates that dermatan sulfate binds 2.3 ± 0.3 mol of acridine orange per dermatan sulfate uronic acid residue with a cooperative binding constant, Kq ranging from 4.9 to 6.0 × 105M−1 which corresponds to a free energy of 7.74 ⩽ ΔG° ⩽ 7.86. The cooperativity parameter q apparently increases with increasing polymer-to-dye ratio.
Nanochemistry: Synthesis and Characterization of Multifunctional Nanoclinics for Biological Applications

This paper presents the use of nanoscale chemistry to synthesize a multilevel, hierarchically built nanoparticle, which we define as a nanoclinic, for targeted diagnostics and therapy. This nanoclinic, produced by multistep chemistry in a nanosize micelle, consists of a thin silica shell encapsulating magnetic (Fe2O3) nanoparticles and fluorescent dyes for enhanced contrast magnetic resonance and optical imaging and magnetic-induced cancer therapy. Furthermore, the surface of these prototype nanoclinics is functionalized with a biotargeting group, luteinizing hormone-releasing hormone (LH−RH). In the work reported here, the LH−RH targets receptor-specific cancer cells for utilization in imaging and investigation of biological effects. The structure and function of these nanoclinics have been characterized using electron and X-ray diffractions, transmission electron microscopy, atomic force and scanning electron microscopy and two-photon laser scanning microscopy. Targeting of the receptor-specific cells h...
Paracrystallites found in evaporated amorphous tetrahedral semiconductors

Variable coherence microscopy shows that as-deposited amorphous germanium and silicon contain medium-range order. The ordering can be explained by a fine-grained paracrystallite material in which intergranular stress has been relaxed by deformation. On annealing, the paracrystallite structure transforms towards the lower-energy continuous random network (CRN). We present data on a variety of vacuum-evaporated samples, and on molecular dynamics simulations of candidate structures.
Church Membership, Consanguineous Marriage, and Migration in a Scotch-Irish Frontier Population

This article discusses the persistence of a pattern of close consanguineous marriages among a group of Scotch-Irish American families that migrated in almost every generation from the early 1700s to the mid-1800s These migrations involved not separate nuclear families, but small networks of families already related by marriage and common descent. Such kin-structured migration created a small set of kin at each new destination who became the focus of spouse selection for the next generation of marriages. The histories of these families suggest that ethnic and denominational separateness from other frontier populations may have contributed both to the pattern of kin-structured migration and, through endogamy, to the associated consanguineous marriages.
Fuchs-Kliewer phonon structure and surface integrity of NiO(100)

Abstract Defects have been deliberately introduced into NiO(100) single-crystal surfaces by Ar + bombardment and by slow H 2 reduction, and the resulting surfaces have been studied by changes in their Fuchs-Kliewer phonon spectrum. Both treatments produce near-surface reduction, as measured by Auger electron spectroscopy. The phonon spectra are obtained by high-resolution electron energy loss spectroscopy (HREELS) using 2.8 eV electrons, with the electron loss data collected in the specular direction. Sputtered surfaces show great decreases in specularly diffracted intensity, but result in little change in the fundamental properties of the phonons. H 2 -reduced surfaces show a more gradual decrease in total spectral intensity but yield an equally rapid decrease in phonon spectral intensity relative to that of the elastically scattered peak. At large reduction values, the phonon mode shifts to lower frequency. The changes in the phonon spectra are discussed in terms of current understanding of the nature of the defects created in Ar + bombardment and in the H 2 reduction process.
Dramatic irony in mourning becomes electra

(1965). Dramatic irony in mourning becomes electra. The Southern Speech Journal: Vol. 31, No. 1, pp. 42-55.
Environment, migration and health in Southern Peru

Abstract A health questionnaire was given to three populations of Peruvians: low-altitude sedentes, low-altitude migrants and high-altitude migrants, all of whom resided in the same low-altitude valley. Estimates of health were computed for each individual by summing the number of symptoms reported in the questionnaire. In general, male and female high-altitude migrants reported more symptoms than low-altitude sedentes. Female low-altitude migrants also reported more symptoms than did female sedentes, while there were virtually no differences between male low-altitude migrants and sedentes. Differences in numbers of days ill and the inability to work due to illness paralleled the differences in reported symptoms. It is suggested that the population differences are primarily the result of changes in the physical and cultural environments which are related to migration: high-altitude migrants being more affected than low-altitude migrants because of the greater degree of change they experience in migrating from high to low altitude. Specifically male high-altitude migrants reported significantly more gastrointestinal symptoms while both males and females reported significantly greater numbers of respiratory symptoms. Although the source of the former difference is unclear, it is felt that the increase in respiratory symptoms is a result of biological adaptations to high altitude which are no longer functional at low altitude.
Design of disturbance-rejection controllers for linear multivariable discrete-time systems using entire eigenstructure assignment

The method of entire eigenstructure assignment constitutes a powerful new method for the design of on-board digital flight controllers. This fact is demonstrated by the presentation of a technique for the design of finite settling time disturbance-rejection controllers for linear multivariable discrete-time systems incorporating digital integrators. The computational attractiveness of the method of entire eigenstructure assignment is illustrated by designing a time-optimal disturbance-rejection controller for the lateral dynamics of the F-4 aircraft. The transient-response characteristics of the controlled aircraft are illustrated by the presentation of the results of simulation studies for a number of sampling periods when the aircraft is subjected to a very severe yawtorque disturbance.
Secondary organic aerosol formation from aromatic precursors. 2. Mechanisms for lumped aromatic hydrocarbons

Quantitative kinetic and physical phase partitioning models of secondary organic aerosol (SOA) formation resulting from the reactions of lumped aromatic species were integrated into a state of the art mechanism for gas-phase reactions (SAPRC). Aromatic and aerosol precursor species were aggregated based on their rate of reaction with OH radicals. Model parameters for the lumped model species were estimated based on the properties of individual compounds making up the lumped parameters. The model was applied to estimate the contribution of aromatic precursors to the formation of SOA in Houston, TX.
Central connections of the hepatic branch of the vagus nerve: a horseradish peroxidase histochemical study

Abstract The hepatic branch of the vagus nerve has been implicated as an important source of afferent input controlling both physiological and behavioral homeostasis. In addition, it is clear that parasympathetic efferents to the liver can significantly alter hepatic functions. In order to begin physiological studies on the nature of hepatic afferent and efferent relations, it will be necessary to understand the central anatomical organization of the components of this small visceral nerve. By carefully exposing and dissecting the hepatic branch of the vagus and applying crystalline horseradish peroxidase (HRP) to it, we were able to elucidate a predominant pattern of afferent terminations within the left subnucleus gelatinosus, the medial division of the left solitary nucleus and the left lateral edge of the area postrema. Efferent nuclei were concentrated in the left dorsal motor nucleus of the vagus (DMN) with a few scattered neurons located in the right DMN as well as the left anterior nucleus ambiguus.
Motor unit recruitment patterns during reflex compensation of muscle yield investigated by computer simulations

An important function of the stretch reflex in the soleus muscle in the decerebrate cat preparation is to compensate for the tendency of muscle suddenly to yield during ramp increases in length. As the level of background (i.e. pre-stretch) force increases, there is a systematic change in the curvature of the force trajectory during this reflex compensation, from concave to convex with respect to increasing force. The hypothesis that this change in curvature was due to background force-dependent changes in the recruitment pattern of motor units was investigated with a combined computer simulation/ experimental technique. The simulation consisted of 20 model motor units for the soleus muscle, each based on a distributed moment muscle model. The timing of recruitment of the motor units was optimized to allow the simulation outputs to fit a set of experimental data records on the reflex response to stretch initiated at five different levels of pre-stretch force. The resulting recruitment patterns showed that a tendency for recruitment to be concentrated progressively in the early portion of the stretch as pre-stretch force increased could account for the changes in reflex force curvature. These results are consistent with the skewed distribution of intrinsic electrical thresholds of motoneurons, in which low-threshold units are much more frequent than high-threshold ones. Therefore the changes in recruitment pattern and reflex force curvature may be due primarily to the intrinsic properties of motoneurons.
EVALUATION OF GRAMM LOW-RESOLUTION DOCKING METHODOLOGY ON THE HEMAGGLUTININ-ANTIBODY COMPLEX

A single protein-protein pair, the complex of the influenza virus hemagglutinin with an antibody (Fab BH151), was suggested for prediction at the second experiment on the Critical Assessment of Techniques for Protein Structure Prediction. To predict the structure of the complex, we applied our docking program GRAMM at a decreased resolution (to accommodate the conformational inaccuracies). The lowest-energy match showed a remarkable "low-resolution" surface complementarity between the molecular structures. After receiving the experimental structure of the complex we had a chance to verify our assumptions and results. The analysis of the hemagglutinin-antibody interface revealed several significant conformational changes in the side chains, which resulted in deep interpenetrations of the hemagglutinin and the antibody structures. This confirmed our initial assumption that the structural changes will be beyond the tolerance of high-resolution rigid-body docking. The comparison of the predicted low-resolution match, submitted as the solution, and the experimentally determined complex showed significant structural discrepancies in the orientation of the antibody, due to the low-resolution character of the docking. Because of the severe structural errors, no residue-residue contacts were predicted correctly. However, a significant part of the antigenic site was determined. This illustrates the practical value of the present methodology for the initial prediction of the binding site, as well as points out the problem of transition from the low-resolution predictions of protein-protein complexes to the accurate structure.
The Non-approximability of Non-Boolean Predicates

Constraint satisfaction programs where each constraint depends on a constant number of variables have the following property: The randomized algorithm that guesses an assignment uniformly at random satisfies an expected constant fraction of the constraints. By combining constructions from interactive proof systems with harmonic analysis over finite groups, Hastad showed that for several constraint satisfaction programs this naive algorithm is essentially the best possible unless P = NP. While most of the predicates analyzed by Hastad depend on a small number of variables, Samorodnitsky and Trevisan recently extended Hastad's result to predicates depending on an arbitrarily large, but still constant, number of Boolean variables. We combine ideas from these two constructions and prove that there exists a large class of predicates on finite non-Boolean domains such that for predicates in the class, the naive randomized algorithm that guesses a solution uniformly is essentially the best possible unless P = NP. As a corollary, we show that the k-CSP problem over domains with size D cannot be approximated within Dk-O(√k) - Ɛ, for any constant Ɛ > 0, unless P = NP. This lower bound matches well with the best known upper bound, Dk-1, of Serna, Trevisan and Xhafa.
Calamovilfa, a misplaced genus of Gramineae

Calamovilfa, generally considered to be a member of the tribe Agrostideae and most closely allied to such genera asCalamagrostis andAmmophila, was investigated, using as criteria the embryo structure, lodicules, leaf epidermis and anatomy, and chromosome size and number. These studies revealed thatCalamovilfa belongs with the chloridoid-eragrostoid group, whereasAgrostis,Calamagrostis, andAmmophila, with which it was compared, are truly festucoid. All evidence indicates strongly thatCalamovilfa is most closely related toSporobolus. These two genera are not only very similar with respect to criteria mentioned above, but also on the basis of a number of gross morphological features, particularly those of the spikelet and the fruit.
Does ending affirmative action in college admissions lower the percent of minority students applying to college

Abstract The purpose of this study is to determine how ending affirmative action in public colleges in Texas affected the percent of minority high school graduates applying to college. I find the end of affirmative action significantly lowered the percent of Hispanic students applying to college by 1.6 percentage points and significantly lowered the percent of black students applying to college by 2.1 percentage points. The end of affirmative action in public colleges in Texas did not significantly affect the percent of white students applying to college. A year after the end of affirmative action in Texas. The Texas State Legislature passed a percent plan that guarantees students who graduate in the top ten percent of their high school class admission to any public college in Texas. The percent of minority students applying to college increased significantly when the percent plan was accompanied by changes in financial aid.
Space-time foam as the universal regulator

A distribution of virtual black holes in the vacuum will induce modifications in the density of states for small perturbations of gravitational and matter fields. If the virtual black holes fill the volume of a typical spacelike surface then perturbation theory becomes more convergent and may even be finite, depending on how fast the number of virtual black holes increases as their size decreases. For distributions of virtual black holes which are scale invariant the effective dimension of space-time is lowered to a noninteger value less than 4, leading to an interpretation in terms of fractal geometry. In this case general relativity is renormalizable in the 1/N expansion without higher derivative terms. As the Hamiltonian is not modified the theory is stable.
Microwave oscillations of a nanomagnet driven by a spin-polarized current

The recent discovery that a spin-polarized electrical current can apply a large torque to a ferromagnet, through direct transfer of spin angular momentum, offers the possibility of manipulating magnetic-device elements without applying cumbersome magnetic fields. However, a central question remains unresolved: what type of magnetic motions can be generated by this torque? Theory predicts that spin transfer may be able to drive a nanomagnet into types of oscillatory magnetic modes not attainable with magnetic fields alone, but existing measurement techniques have provided only indirect evidence for dynamical states. The nature of the possible motions has not been determined. Here we demonstrate a technique that allows direct electrical measurements of microwave-frequency dynamics in individual nanomagnets, propelled by a d.c. spin-polarized current. We show that spin transfer can produce several different types of magnetic excitation. Although there is no mechanical motion, a simple magnetic-multilayer structure acts like a nanoscale motor; it converts energy from a d.c. electrical current into high-frequency magnetic rotations that might be applied in new devices including microwave sources and resonators.
Zebrafish CaV2.1 Calcium Channels Are Tailored for Fast Synchronous Neuromuscular Transmission

The CaV2.2 (N-type) and CaV2.1 (P/Q-type) voltage-dependent calcium channels are prevalent throughout the nervous system where they mediate synaptic transmission, but the basis for the selective presence at individual synapses still remains an open question. The CaV2.1 channels have been proposed to respond more effectively to brief action potentials (APs), an idea supported by computational modeling. However, the side-by-side comparison of CaV2.1 and CaV2.2 kinetics in intact neurons failed to reveal differences. As an alternative means for direct functional comparison we expressed zebrafish CaV2.1 and CaV2.2 α-subunits, along with their accessory subunits, in HEK293 cells. HEK cells lack calcium currents, thereby circumventing the need for pharmacological inhibition of mixed calcium channel isoforms present in neurons. HEK cells also have a simplified morphology compared to neurons, which improves voltage control. Our measurements revealed faster kinetics and shallower voltage-dependence of activation and deactivation for CaV2.1. Additionally, recordings of calcium current in response to a command waveform based on the motorneuron AP show, directly, more effective activation of CaV2.1. Analysis of calcium currents associated with the AP waveform indicate an approximately fourfold greater open probability (PO) for CaV2.1. The efficient activation of CaV2.1 channels during APs may contribute to the highly reliable transmission at zebrafish neuromuscular junctions.
Generation of hydrogen peroxide by incidental metal ion-catalyzed autooxidation of glutathione

Autooxidation of reduced glutathione in 50 mM buffer at pH 7.9 is indetectably slow in the presence of 1 mM DETAPAC, EDTA, TET, or tripyridine, but passing buffer through Chelex resin was insufficient to remove traces of catalytically active metals. Production of hydrogen peroxide during glutathione autooxidation was catalyzed by traces of Fe+2 or Cu+2, and to a much lesser extent by Cu+1 and Ni+2, but not to a detectable extent by Na+1, K+1, Fe+3, Al+3, Cd+2, Zn+2, Ca+2, Mg+2, Mn+2, or Hg+2. Cysteine was a much better precursor for hydrogen peroxide production than were cysteine sulfinic or sulfonic acids. The chelators EGTA, NTA, bipyridine, dimethyl glyoxime, salicylate, and Desferal were ineffective at preventing autooxidation. EDDA and 8-hydroxyquinoline were partially effective. Catalase could completely prevent the accumulation of detectable H2O2, but superoxide dismutase was only slightly inhibitory. Hydroxyl radical and singlet oxygen quenching agents (mannitol and histidine) stimulated. A mechanism for the production of H2O2 during trace metal catalyzed oxidation of glutathione is proposed, involving glutathione-complexed metal and dissolved oxygen. Although a radical intermediate can not be ruled out, no radical initiated chain reaction is necessary.
Surface segregation and adsorption effects of iron–technetium alloys from first-principles

Abstract Surface properties of Tc-rich and Fe-rich portions of the Tc–Fe binary alloy phase diagram were computed in this work on the basis of density functional theory. Tc and Fe were found to have minimal degrees of mixing in the parent phases, consistent with the experimentally derived phase diagram. The influence of oxygen on surface phase stability was also studied, with no significant impact on surface segregation or degree of surface mixing. Oxygen adsorption was shown to change the ordering of surface facets in Tc, such that the pyramidal phase becomes lower in energy than the prismatic phase, even with low coverage of oxygen. No evidence for increased surface segregation upon oxidation was found for the solid-solution phases. A potential–pH surface Pourbaix diagram was derived for Tc and H, OH and O adsorbed sub-monolayers were shown to be precursors to oxide formation. While Tc and Fe have similar reactivities and properties in their parent phases, and hence, also in solid-solution, the properties of the intermetallic are expected to be significantly different due to the size-mismatch between the elements.
Quality assessment of perinatal regionalization by multivariate analysis: Illinois, 1991–1993

Objective To identify (1) those elements in the infrastructure of a regionalized perinatal network that have independent effects on the variation in perinatal mortality among nontertiary units (member level I and II hospitals) and (2) shortcomings, if any, in a traditional perinatal data base that impede quality assessment of contemporary regionalized care. Methods We analyzed perinatal surveillance data for 3 years, from 1991 to 1993, in the state of Illinois, representing more than 190,000 annual births. Fetal death and neonatal mortality rates for the 97 nontertiary hospitals studied were the dependent variables of interest. Two sets of independent variables were studied, those assessing the maternal sociobehavioral risk of populations served and those assessing the network infrastructure (defined as the facilities of member hospitals and their function within the regionalized network). We used multivariate analysis to partition the variation in hospital rates of perinatal mortality into two components, one attributable to maternal sociobehavioral risk and the other to the network infrastructure. Results Maternal sociobehavioral risk alone explained 73% of the variation in hospital fetal death rates and 38% of that in hospital neonatal mortality rates. When controlling for maternal sociobehavioral risk, rates of inborn very low birth weight (VLBW) deliveries ( P P = .01) had independent effects on the variation in hospital fetal death rate; rates of inborn VLBW deliveries ( P P P = .029) had independent effects on the variation in hospital neonatal mortality rate. Conclusions In this mature statewide network, the rate of inborn VLBW deliveries exerted the strongest independent effect on variation in level I and II hospital rates of both fetal death and neonatal mortality. However, that there was such a large effect from maternal sociobehavioral risk alone has important public health implications. Additions and modifications to traditional perinatal surveillance are suggested better to assess the quality of regionalization in a contemporary health care environment.
Quiver Matrix Mechanics for IIB String Theory (I): Wrapping Membranes and Emergent Dimension

Abstract In this paper we present a discrete, nonperturbative formulation for type IIB string theory. Being a supersymmetric quiver matrix mechanics model in the framework of M(atrix) theory, it is a generalization of our previous proposal of compactification via orbifolding for deconstructed IIA strings. In the continuum limit, our matrix mechanics becomes a (2+1)-dimensional Yang–Mills theory with 16 supercharges. At the discrete level, we are able to construct explicitly the solitonic states that correspond to membranes wrapping on the compactified torus in target space. These states have a manifestly SL(2, Z ) -invariant spectrum with correct membrane tension, and give rise to an emergent flat dimension when the compactified torus shrinks to vanishing size.
Characterization of proopiocortin converting activity in rat anterior pituitary secretory granules.

Lysates from purified secretory granules of ratanterior pituitary glands were incubated with [3H]phenylalanine or [3H]arginine-labeled toad proopiocortin. The processed products formed were identified by immunoprecipitation with ACTH and β-endorphin antisera, and by comigration with known markers on acid-urea polyacrylamide gels. Proopiocortin was cleaved by the secretory granule lysate primarily to 21,000 mol wt ACTH, 13,000 mol wt ACTH, 16,000 mol wt NH2-terminal glycopeptide, β-lipotropin, a β-endorphin-like peptide, and β-endorphin. Characterization of the anterior pituitary proopiocortin-converting activity shows that it: (1) cleaves specifically at the peptide bond on the carboxy side of the lysine-arginine residues of proopiocortin, (2) has a pH optimum in the acidic range, (3) is present in membrane and soluble fractions of the granule lysate, and (4) is inhibited by leupeptin, pepstatin A, and 2,2' dithiodipyridine, but not by p-chloromercuribenzoate, diisopropyl, fluorophosphate, phateNα-p-tosyl...
The Relationship between Energy Literacy and Environmental Sustainability

Sustainability, first identified as a characteristic of eco-systems, is the capacity to maintain a process indefinitely. Environmental sustainability receives significant public and government attention, triggered by concerns about climate change, decreasing energy supplies, and increasing food costs. Colleges and universities receive positive notice for their greening efforts, and the academy is expected to be a leader in efforts to improve sustainability. Therefore coursework and curricula must be developed to train students about sustainable resource consumption processes. This paper describes curricula materials related to energy literacy, defined as conceptual fluency with the economic and social components of energy use. These materials were developed and piloted over a three year period, and were tested with a pre- and post-course survey administered with questions based on the New Environmental Paradigm (NEP) and Environmentally Responsible Behavior (ERB). The findings of this study suggest that discussion of sustainability with disaster themes triggers anxiety that interferes with the development of ERB. In contrast, materials emphasizing the pragmatic necessity and benefits derived from sustainable practices relate to improvements in ERB. This suggests sustainability curricula should mitigate anxiety aroused by the topic, and instead emphasize pragmatic motivations for changing energy consumption patterns.
HealthSouth, Inc.: An Instructional Case Examining Auditors' Legal Liability

ABSTRACT: This instructional case explores auditors' legal liability under the Securities Exchange Act of 1934 by asking students to assume the role of either the plaintiffs' (investors') or defendants' (Ernst & Young's) legal counsel. By using publicly available documents and testimony (provided on a dedicated website for this instructional case) in their arguments, students not only explore in depth one of the more egregious accounting scandals of the new millennium, but also are exposed to the plaintiff's burden of proof and the defendant's defenses in a Rule 10b-5 action. Additionally, by understanding the root causes of the fraud and why it took so long to uncover, students can better understand a number of the provisions set forth by the Sarbanes-Oxley Act of 2002. Results of a student survey after completion of the case indicate that case objectives were met. Students also report enjoying the case materials and welcoming other cases using similar types of materials.
Shaping Academic Task Engagement with Percentile Schedules.

The purpose of this study was to examine the use of percentile schedules as a method of quantifying the shaping procedure in an educational setting. We compared duration of task engagement during baseline measurements for 4 students to duration of task engagement during a percentile schedule. As a secondary purpose, we examined the influence on shaping of manipulations of the number of observations used to determine the criterion for reinforcement (the m parameter of the percentile formula). Results showed that the percentile formula was most effective when a relatively large m value (20 observations) was used.