cssi/SciSciGPT-SciSciNet huggingface dataset:
Third Annual Brown Lecture in Education Research—The Flat Earth and Education: How America’s Commitment to Equity Will Determine Our Future

In the knowledge-based economy that characterizes the 21st century, most previously industrialized countries are making massive investments in education. The United States ranks poorly on many leading indicators, however, primarily because of the great inequality in educational inputs and outcomes between White students and non-Asian “minority” students, who comprise a growing share of the U.S. public school population. Standards-based reforms have been launched throughout the United States with promises of greater equity, but while students are held to common standards—and increasingly experience serious sanctions if they fail to meet them—most states have not equalized funding and access to the key educational resources needed for learning. The result of this collision of new standards with old inequities is less access to education for many students of color, rather than more. This article outlines current disparities in educational access; illustrates the relationships between race, educational resour...
Thermal properties of particulate TIMs in squeeze flow

Abstract Direct numerical simulations based on a thermal Lattice–Boltzmann method are utilized to compute the effective thermal conductivity of particulate thermal interface materials (TIMs). By simulating the squeezing process, we obtain the particle distribution in a situation similar to application. Therefore, there is no need to calculate the average thermal characteristics from several pre-defined random distributions. The effects of particle volume fraction, particle size, and particle to matrix thermal conductivity ratio on the thermal performance are investigated. The results for the effective thermal conductivity are in agreement with the existing semi-analytical and experimental results reported in the literature.
A phosphatidylinositol 3-kinase phosphodiesterase 3B-cyclic AMP pathway in hypothalamic action of leptin on feeding.

Using male Sprague-Dawley rats implanted with third intracerebroventricular (ICV) cannulae, we found that cilostamide, a phosphodiesterase 3 (PDE3) inhibitor, (i) reversed the established effects of leptin on food intake and body weight, (ii) blocked, at the hypothalamic level, the leptin-induced tyrosine phosphorylation of signal transducer and activator of transcription 3 (Stat3) and (iii) blocked the DNA binding of p-Stat3. Additionally, ICV administration of leptin increased hypothalamic phosphatidylinositol 3-kinase (PI3K) and PDE3B activities and decreased cyclic AMP (cAMP) concentration. These results indicate that a PI3K–PDE3B–cAMP pathway interacting with the Janus kinase 2 (Jak2)–Stat3 pathway constitutes a critical component of leptin signaling in the hypothalamus.
Probing the interaction of solvents with the stationary phase of C18 high-performance liquid chromatographic column material by variable-temperature dependent 129Xe nuclear magnetic resonance spectroscopy.

Abstract VT 129Xe NMR was applied to probe the interactions of solvents having different polarity indices with the stationary phase of a RP-C18 HPLC column material. It was observed that the highly polar ethylene glycol molecules do not mix with the alkyl chains of the RP-C18 stationary phase and the solvent is unable to enter the pores and the spaces between the particles. Three phases in this sample are defined as stationary/xenon phase, xenon gas phase (in the pores and the spaces between the particles) and ethylene glycol/xenon phase. In contrast to ethylene glycol, the nonpolar solvent cyclohexane was observed to be well mixed with the RP-C18 stationary phase. The capillary rise effect allows the solvent to enter the pores and the spaces between the particles. Two phases in this sample are defined as stationary/cyclohexane/xenon phase and cyclohexane/xenon phases. The properties of ethyl acetate are between those of ethylene glycol and cyclohexane. The 129Xe NMR results show that the rational reversed phases should be conditioned from highly solvating to more polar solvents to remove the trapped air. The 129Xe NMR results also show that pure stationary phase exists only when a highly polar solvent is used in reversed-phase chromatography. For a solvent with lower polarity, a stationary/solvent phase actually forms. This, together with the mobile phase, determines the selective factor for separating mixtures.
Neuropharmacology of earthworm giant fibers

Abstract The effects of a variety of neurotropic drugs on excitability and action potential form of the giant nerve fibers of the earthworm ventral cord were studied with external electrodes. Earthworm giant fibers were like frog sciatic myelinated fibers in the types of changes induced by most drugs tested, the worm fibers being generally more sensitive. Many centrally active drugs, such as chlordiazepoxide, LSD and methamphetamine, resembled local anesthetics in causing conduction block by increased threshold; unlike procaine, the threshold elevation caused by the above drugs could not be restored transiently toward normal by repetitive maximal stimulation. With most imipraminics, phenothiazines and related agents the mechanism of conduction block did not seem to depend on threshold increase. Earthworm fibers differed from frog sciatic in several respects: they were not made hyper-excitable by calcium depletion; they showed repetitive firing with high concentration of calcium (the repetitive firing could be antagonized by barbital and trimethadione, not by bromide or diphenylhydantoin); they showed transient lowering of threshold by cholinesterase inhibitors; catelectrotonic repetitive firing could be blocked byd-tubocurarine. Some of the above findings suggest that N-cholinergic receptors may function in earthworm but not in frog myelinated fibers. The following relationships held true over a wide range of variation of nerve properties by drugs and physiological maneuvers. The ratio of spike voltage when at maximum rate of activation to the maximum spike voltage itself remained relatively constant (0·7 approximately): spike amplitude was modifiable independently of threshold or maximum rate of activation; usually there was an inverse relation between threshold and maximum rate of activation, the only notable exception being initial threshold-lowering action of typical depolarizing monovalent cations (K, Rb, Cs).
Factors Affecting Abundance of Lake Herring (Coregonus artedii Lesueur) in Western Lake Superior

Abstract A field and laboratory study was conducted in 1965–1968 to investigate factors affecting lake herring (Coregonus artedii Lesueur) abundance in western Lake Superior. Commercial landings in November-December in the Duluth-Superior area dropped from 1,117,000 pounds in 1954 to 2000 pounds in 1966. Wisconsin catches also declined markedly. Abundance and fishing intensity indices decreased with landings. Commercial catches and abundance of chubs (Coregonus spp.) and smelt (Osmerus mordax) increased simultaneously with the herring reduction. Biological characteristics of Duluth-Superior and Apostle Islands (Wisconsin) herring stocks were examined and compared. Herring eggs were more abundant and viable in the latter area, and laboratory hatching success was significantly greater for Apostle Islands eggs. Herring larvae were generally more abundant and smaller in the Apostle Islands; distribution and growth did not differ between areas. Abundance of larvae in both areas declined sharply in June-July. A...
Can visual perception be used to estimate body part angles

For two decades, observational methods have been used to measure postural loads in industry. These methods depend on the analyst's judgment to characterize correctly the working postures. The errors associated with estimating the body part's angular deviation from the neutral position are not known. Recently, videotaping of a work situation, followed by examination of the tape to assess postural position has become more commonly practised. This study was conducted to determine the error which accompanies the judging (without tools) of postural angles. In the present study, a method was used whereby 20 subjects were asked to report the perceived angles which closely matched the actual shoulder flexion angle displayed on the TV screen. The results showed no significant differences among the three angular ranges (‘low’, 1–60°; ‘medium’, 61–120°; and ‘high’, 121–180°) of shoulder flexion, in terms of algebraic and absolute errors. Subjects tended to slightly overestimate the true angle in the low range and to...
Lesbians With Physical Disabilities: A Qualitative Study of Their Experiences With Counseling

The authors interviewed 25 lesbians with physical disabilities about their counseling experiences. Using a phenomenological qualitative approach, the authors identified 9 themes. Five themes addressed participants' perceptions of their counselors: general satisfaction or dissatisfaction, counselors' general effectiveness, counselors' awareness and education regarding sexual orientation and/or disability, discrimination and bias, and counselor identity. Three themes related to the participants' attempts to negotiate the counseling process: coming out or self-disclosure, self-advocacy, and accessibility/accommodations. The final theme related to depression.
A dynamic factor model framework for forecast combination

A panel of ex-ante forecasts of a single time series is modeled as a dynamic factor model, where the conditional expectation is the single unobserved factor. When applied to out-of-sample forecasting, this leads to combination forecasts that are based on methods other than OLS. These methods perform well in a Monte Carlo experiment. These methods are evaluated empirically in a panel of simulated real-time computer-generated univariate forecasts of U.S. macroeconomic time series.
One-loop gap equations for the magnetic mass in d = 3 gauge theory

Recently several workers have attempted determinations of the so-called magnetic mass of $d=3$ non-Abelian gauge theories through a one-loop gap equation, using a free massive propagator as input. Self-consistency is attained only on-shell, because the usual Feynman-graph construction is gauge-dependent off-shell. We examine two previous studies of the pinch technique proper self-energy, which is gauge-invariant at all momenta, using a free propagator as input, and show that it leads to inconsistent and unphysical results. In one case the residue of the pole has the wrong sign (necessarily implying the presence of a tachyonic pole); in the second case the residue is positive, but two orders of magnitude larger than the input residue, which shows that the residue is on the verge of becoming ghost-like. This happens because of the infrared instability of $d=3$ gauge theory. A possible alternative one-loop determination via the effective action also fails. The lesson is that gap equations must be considered at least at the two-loop level.
Friction and Wear of Pyrophyllite on the Atomic Scale

Pyrophyllite, Al2Si4O10(OH)2, a layered aluminosilicate material, has several properties which suggest that it might exhibit desirable frictional properties for solid-state lubrication. These include a lamellar structure and a low-energy basal plane. Here, we utilize atomic force microscopy to investigate the tribological performance of mineralogical pyrophyllite samples and compare the results to those of other minerals and solid lubricants. The results indicate that pyrophyllite exhibits low friction forces and shear stresses, on the same order of other commonly used solid lubricant materials, and a high resistance to deformation within a single layer. These fundamental findings highlight the potential use of pyrophyllite as a possible tribological material and alternative solid lubricant.
Effects of NO on the ignition of hydrogen and hydrocarbons by heated counterflowing air

Abstract Experiments were carried out to study the influence of NO in air on the ignition temperature of hydrogen and hydrocarbons in a nonpremixed counterflowing system. These experiments were performed from 0.5 to 6 atm, with the NO concentration varying from 100 ppm to 15,000 ppm. It is shown that addition of a small amount of NO in air significantly reduces the ignition temperature of all fuels. For hydrogen, under certain pressures, NO eventually becomes an inhibitor at higher levels of addition. Thus there appears to exist an optimal NO concentration at which the catalytic effect is the most pronounced, and this optimal concentration was found to also depend on the system pressure. Numerical simulation was performed in the hydrogen case to better understand the kinetics of the observed phenomenon. It was found that at low NO concentrations, the ignition temperature was determined by the interaction of the H 2 -O 2 -NO subsystem, whereas at high NO concentrations the ignition temperature was mostly affected by the NO x chemistry. For hydrocarbons, the minimum temperature was much less pronounced and in most cases nonexistent. Furthermore, the extent of temperature decrease depended on the nature of the fuel.
Planned Radical Change in Organizations: Unintended Consequences on Roles and Continuity

This study employed a case study design to examine the planned radical change in the New Jersey Department of Transportation (NJDOT) from a vertically integrated hierarchical organization with a typical pyramid structure to a more horizontal organization that operated in a project management environment. As part of the planned radical change, the role of engineers changed as project managers were trained to manage engineering and construction projects for the entire lifecycle of the projects. To implement the change in a timely manner, a small pilot group of project managers was established to manage some 60 projects largely unencumbered by the existing constraints within the organization. This included changing the oversight authority of licensed professional engineers and middle managers, in addition to changing the job specifications of a majority of NJDOT employees. The successful transition to a horizontal organization with a project management discipline achieved its goals. However, the organization...
A dynamic eddy-viscosity closure model for large eddy simulations of two-dimensional decaying turbulence

This paper puts forth a simplified dynamic eddy-viscosity subgrid-scale model for the vorticity transport equation which is employed in a large eddy simulation study of freely evolving isotropic two-dimensional turbulent flows. The dynamic parameter is averaged in space, thereby retrieving a spatially constant value which only varies in time. The proposed dynamic model is applied to a two-dimensional decaying turbulence problem in a square periodic box, which is a standard prototype of more realistic turbulent flows in the atmosphere and oceans, in order to eliminate any possible errors associated with the boundary conditions or mesh non-uniformities. Compared with high-resolution direct numerical simulations, the performance of the dynamic model is systematically investigated considering various filtering strategies by means of test filters. The effects of the computational resolution and the filtering ratio between the test and the grid filters are also studied by using a huge set of parameters.
Differences in risk factors for lower extremity arterial occlusive disease.

Background Patients undergoing lower extremity revascularization have associated cardiovascular risks: smoking, hypertension, dyslipidemia, and diabetes. This study evaluated the impact of cardiovascular risk factors on proximal versus distal arterial occlusive disease in patients undergoing lower extremity revascularization as adjusted to a control group without vascular disease. Study design We performed a retrospective, case-control study that included 151 patients undergoing lower extremity revascularization and 229 patients undergoing knee and hip replacement (controls). Risk factors were determined for each of three separate groups undergoing revascularization for different levels of occlusive disease: aortoiliac, superficial femoral, and popliteal-tibial. Comparisons to controls were tested using t-tests or chi-square tests and multiple logistic regression. Results Dyslipidemia was associated with a significant risk of aortoiliac (odds ratio [OR]=3.4; p=0.0006) and superficial femoral occlusion (OR=2.8; p=0.01) but was less strongly associated with popliteal-tibial occlusion (OR=2.1; p=0.09). Smoking was strongly associated with aortoiliac (OR=4.5; p=0.004) and superficial femoral disease (OR=4.6; p=0.0007) but not popliteal-tibial disease (OR=1.3; p=0.53). In contrast, diabetes mellitus and chronic renal insufficiency were strong risk factors for popliteal-tibial occlusion (OR=5.4, p=0.0002; OR=3.9, p=0.01, respectively), but were not significant risk factors for aortoiliac or superficial femoral occlusion. Conclusions These data, which use revascularization level as a surrogate marker for lower extremity arterial disease, suggest that the risk factor profile for proximal disease differs from that of distal disease. These findings may reflect differences in the biology of disease and indicate that different risk factors have various anatomic influences on arterial disease formation.
Reactions of thermal-energy electrons with organic compounds

Abstract The products resulting from the reaction between electrons of thermal energy and several electron-absorbing organic compounds have been studied. Thermal electrons were generated by maintaining a glow discharge between a stainless-steel electrode and a silver-silver chloride electrode in a nitrogen atmospher. The organic compounds investigated fell into two principal classes whose structures contained either simple or conjugated electrophores. The identification of the reaction products by gas chromatography-mass spectrometry showed that simple electrophores, such as nitrobenzene and o -dichlorobenzene, react predominantly by a dissociative mechanism while conjugated electrophores, such as benzaldehyde and trans -cinnamaldehyde, react predominantly by a non-dissociative mechanism. m -Chlorobenzaldehyde, containing both a simple electrophore (chlorine subsituent) and a conjugated electrophore (carboxaldehyde moiety), was found to react primarily by a non-dissociative mechanism. trans -Cinnamaldehyde, even though possessing a more extensive system of conjugation than benzaldehyde, was found to be less reactive than the latter. Reaction mechanisms consistent with possible pathways of the major products of representative compounds studied are also presented.
Clinical case presentation: therapeutic challenges in adolescent-onset bipolar disorder.

CONTROVERSY HAS FLOURISHED in the past several years regarding the diagnosis of bipolar disorder in children and adolescents. In an attempt to address the issues in June 2002, the American Academy of Child and Adolescent Psychiatry convened a working conference entitled “Methodological Issues and Controversies in Clinical Trials with Child and Adolescent Patients with Bipolar Disorder” (Carlson et al. 2003). Conference participants agreed on several broad methodological questions to be addressed, so as to foster investigation and a better understanding of the clinical presentation, diagnostic criteria, natural history, and treatment of early-onset bipolar disorder. Although a work in progress, an important conclusion of the proceedings was the recommendation for methodologically rigorous, large-scale trials of treatment of acute mania in youth. One of the areas of greatest controversy has been the clinical presentation and diagnostic criteria for bipolar disorder in young patients (Geller and Luby 1997; Kafantaris 1995). Although young patients may present with classic “gold standard” symptomatology consistent with adult mania (e.g., elevated mood, grandiosity, and flight of ideas), younger patients may also present with less florid though no less challenging symptoms (e.g., unrelenting irritability, aggressive dyscontrol, and “mixed states”) (Steele and Fisman 1997; Wozniak et al. 1995). To complicate differential diagnosis further, many investigators have reported high levels of comorbidity with disruptive behavior disorders in association with early-onset bipolar disorder (Biederman et al. 1999). Unfortunately, to date, there has been a paucity of rigorous, well-controlled pharmacological studies, perhaps related to the difficulty of diagnosis, symptom severity, and limited response to agents used in adults. Thus, the evidence base for treatment remains quite limited. This case presentation illustrates some of these diagnostic and therapeutic challenges in an adolescent with bipolar disorder.
Multiple current spiking in long Gunn oscillators

Abstract The application of a single voltage bias pip superimposed on the voltage of a long Gunn oscillator has been seen to trigger multiple current spikes having the period of the normal Gunn oscillations. An explanation is provided in terms of localized impact ionization.
Background adaptation in developing rat retina: an electroretinographic study.

Abstract ERG stimulus/response curves were obtained from developing rat retina. For dark adapted eyes and those adapted to background lights, the stimulus/response relations were fit as well as possible by H 2 curves. Apex points of H 2 curves represent compactly variations of maximum response size and sensitivity of response with age and adaptation. The range of variation of maximum response size is the same for a- and b-waves at each age. Sensitivity of the dark adapted b-wave increases to adult levels by age 18 days; after this, the variation of b-wave sensitivity by background lights becomes mature. The relation of ERG development to anatomical development is discussed.
Altered peptide ligand modulation of experimental allergic encephalomyelitis: immune responses within the CNS

An altered peptide ligand (analog) of the encephalitogenic epitope of proteolipid protein residues 139-151 (p139-151) in which residues 144 and 147 are substituted with leucine and arginine, respectively (LR), protects from clinical but not histological experimental allergic encephalomyelitis (EAE). To understand in situ events associated with this protection, T cells from brains of mice immunized with either native p139-151, the analog LR or a combination of the two were isolated and characterized. High proportions of cells from co-immunized mice (38%) and LR-immunized mice (58%) reacted to both p139-151 and LR, whereas fewer cells from p139-151 immunized mice (7%) were cross-reactive. T cell clones derived from brains of LR- and co-immunized mice were also cross-reactive in vitro. By reverse transcriptase-based polymerase chain reaction, higher levels of TGF-beta mRNA, and lower levels of TNF-alpha and IFN-gamma mRNA were found in the central nervous system (CNS) tissue of LR and co-immunized mice. Immunohistochemistry demonstrated greater TGF-beta immunoreactivity in CNS inflammatory foci in co-immunized and LR-immunized mice. There were no significant differences in CD4+ or CD8+ cell infiltrates among the groups and differences in other cytokines were not identified by immunocytochemistry. Protection from clinical EAE in LR and co-immunized mice was partially abolished by anti-TGF-beta antibody treatment. Thus, protection from clinical disease following immunization with the analog LR is associated with infiltration into the CNS of a T cell population that could potentially recognize the native PLP peptide and with enhanced TGF-beta production by cells within CNS inflammatory foci.
Diagnostics for heteroscedasticity in regression

SUMMARY For the usual regression model without replication, we provide a diagnostic test for heteroscedasticity based on the score statistic. A graphical procedure to complement the score test is also presented. Some key u'ords: Influence; Linear model; Residual; Score test. Diagnostic methods in linear regression are used to examine the appropriateness of assumptions underlying the modelling process and to locate unusual characteristics of the data that may influence conclusions. The recent literature on diagnostics is dominated by studies of methods for the detection of influential observations. Cook & Weisberg (1982) provide a review. Diagnostics for the relevance of specific assumptions, however, have not received the same degree of attention, even though these may be of equal importance. Our purpose here is to provide appropriate diagnostic techniques to aid in an assessment of the validity of the usual assumption of homoscedasticity when little or no replication is present. Available methods for studying this assumption include both graphical and nongraphical procedures. The usual graphical procedure consists of plotting the ordinary least squares residuals against fitted values or an explanatory variable. A megaphone shaped pattern is taken as evidence that the variance depends on the quantity plotted on tlle abscissa (Weisberg, 1980, Chapter 6). In ? 3 we suggest several ways in which this
Ordering of alkylcyanobiphenyl molecules at MoS2 and graphite surfaces studied by tunneling microscopy

Abstract The interfacial ordering of the alkylcyanobiphenyl family of liquid crystal molecules is studied on the MoS 2 and graphite surfaces and found in both cases to arise from registry with the substrate. Aromatic and aliphatic groups are observed to have different contrasts in tunneling microscope images, with the aromatic/aliphatic contrast difference being much higher on graphite than on MoS 2 .
Shape and size effects in nanostructured 2D magnetic systems

Abstract The magnetization process of magnetic particles, including 2D arrays of nanosize patterns, strongly depends on the shape and size of elements. For a finite size body in the shape of an ellipsoid of rotation the magnetization M and the demagnetizing field H Di =− N ij M j can be considered uniform all over the body. For non-ellipsoidal shapes the demagnetizing “factor” becomes a local tensor N ij =N ij (r) and the magnetization is no more uniform M=M(r). Results of numerical modeling of the shape and size dependence of the demagnetizing tensor elements are presented for particles having a width-to-height ratio range from 0.01 to 10, calculated using the finite-difference method. This effect becomes increasingly important for arrays of nanosize particles with an aspect ratio in this range. The demagnetizing effects are the most pronounced at the corners and edges. As a result, it prevents full saturation of particles in applied fields even in Hz⩾4πMs, and contributes to substantial in-plane components acting on the neighboring particles.
Frequency representation in the dorsal medullary nucleus of the leopard frog,Rana p. pipiens

The anuran auditory periphery has two papillae sensitive to different frequency ranges. The projections of fibers from these individual organs were traced to their termination sites in the dorsal medullary nucleus (DMN) by injecting HRP into their nerve roots. Fibers from the amphibian papilla (AP), sensitive to low and intermediate frequencies, were found to terminate throughout most of the DMN. Fibers from the high frequency-sensitive basilar papilla (BP) had terminal fields restricted to the extreme dorsomedial region of the nucleus. Multiunit recordings from the DMN revealed that high frequency neurons are restricted to the dorsomedial DMN, while low and intermediate frequency neurons are present across the width of the nucleus, thus corroborating anatomical results. Physiological results further suggest an orderly representation of frequency along the dorsoventral axis of the DMN, with low frequencies represented ventrally, high frequencies dorsally.
Robust communication connectivity for multi-robot path coordination using Mixed Integer Nonlinear Programming: Formulation and feasibility analysis

Mixed Integer Nonlinear Programming (MINLP) techniques are increasingly used to address challenging problems in robotics, especially Multi-Vehicle Motion Planning (MVMP). A particular challenge in using this framework is encoding stochastic phenomena such as communication connectivity in the form of MINLP constraints. The main contribution of this paper is an analytical formulation of communication connectivity constraints using stochastic physical layer communication models. These constraints account for the log-normal channel shadowing in noisy communication environments and specify inter-vehicle connectivity in terms of the outage probability of communication. A method is developed to provably accord robustness to communication failure by specifying an upper bound on the outage probability in terms of the inter-vehicle communication range. Finally, we demonstrate the utility of this formulation in the context of a realistic decentralized Multi-Vehicle Path Coordination (MVPC) scenario in which multiple robotic vehicles travel along predetermined fixed paths and are required to maintain communication connectivity during their transit. Conditions that affect the feasibility of the MVPC problem are formalized. Examples that assist in visualizing these conditions are provided.
Abschätzung von Bruchzähigkeitskennwerten aus der Bruch- oder Kerbschlagarbeit

Mittels eines einfachen mechanischen Modells wurde ein Zusammenhang zwischen der gesamten Brucharbeit eines angerissenen Balkens unter Biegung und der Bruchzahigkeit hergeleitet. Erganzt durch eine Korrektur fur die relativ kurze und ausgerundete Kerbe lasst sich daraus eine Formel zur Berechnung des kritischen J-Integrals aus der Kerbschlagarbeit erhalten. Diese Formel gilt, anders als die bekannten empirischen Korrelationsformeln, allgemein fur alle elastisch-plastischen Werkstoffe und darf, da bei der Herleitung auf Konservativitat der Annahmen geachtet wurde, in allen Fallen als konservativ betrachtet werden. Obschon sie nur fur die Hochlage hergeleitet wurde, lasst sie sich auch im zah-sprod-Ubergangsbereich als untere Grenze anwenden. Will man in diesem Bereich Uberkonservativitat vermeiden, ist die bekannte Verschiebung der Ubergangstemperatur zusatzlich zu berucksichtigen. Vergleiche mit experimentellen Daten aus eigenen Versuchen und der Literatur bestatigen die Zuverlassigkeit der vorgeschlagenen Berechnungsformel. Estimation of Fracture Toughness from the Charpy Fracture Energy By means of a simplistic mechanical model a mathematical relation between the total fracture energy of an edge-cracked beam under bending and the fracture toughness was derived. Inserting the parameters of the standard Charpy specimens and accounting for the finite root radius and the shallowness of the notch, an equation to calculate fracture toughness from the Charpy fracture energy was obtained. Unlike the commonly used empirical correlation formulas, the presented equation is applicable to any elastic-plastic material. From its theoretical basis and the underlying assumptions it is expected to be conservative in any case. Although the derivation only holds for the upper-shelf regime, it also is applicable to the brittle-to-ductile transition regime as a lower bound. In this range, the degree of conservatism can be reduced by accounting for the well-known shift of the transition temperature. Comparison with experimental data confirm these features of the presented formula.
Quantifying bacterial population dynamics in compost using 16S rRNA gene probes

Composting provides a dynamic setting for studying ecological topics such as succession, competition, and community stability in a relatively short period of time. This study used hierarchical small sub-unit-based rRNA gene probes to quantify the change in the relative abundance of phylogenetic groups common to compost in laboratory scale reactors. Bacterial 16S rRNA gene targets accounted for only 37% of all small subunit (SSU) rRNA genes initially, but increased to a maximum of 83% of the total at 84 h. The sum of rRNA genes detected using probes specific to Pseudomonas and low-G+C Gram-positive rRNA genes represented between 16% and 87% of the total. The lack of hybridization to the taxon-specific probes was most pronounced between 36 h and 60 h, when the pH was between 4.6 and 4.8. During this period the relative abundance of taxon-specific gene targets accounted for only 17–33% of the total bacterial rRNA gene targets. Pseudomonas-type 16S rRNA genes were the most abundant of the groups measured until 72 h. Those genes had their highest relative abundance at 12 h (78% of bacterial rRNA genes; 30% of all rRNA genes), after which time their relative abundance began to decline as the temperature increased. Prior to 72 h, 16S rRNA genes from low-G+C Gram-positive bacteria (LGC-GPB) represented less than 7% of the bacterial rRNA genes. However, by 84 h the relative abundance of LGC-GPB and Bacillus rRNA genes had increased to 60% and 18% of the bacterial rRNA gene targets, respectively (50% and 15% of all rRNA genes, respectively).
Rethinking Student Services: Assessing and Improving Service Quality

ABSTRACT Recruitment and retention of students are critical challenges facing university administrators. Similar problems related to attracting and retaining customers plague other service industries as well. While the benefits of enhanced service quality have helped many service industries address recruitment and retention problems, limited attention has been given to exploring opportunities provided by the service quality concept within the educational field. This manuscript describes a methodology which may be used to identify service quality improvement opportunities within an educational environment. Results of an investigation of the quality of services provided by four student enrollment services administrative subunits are presented. Specific changes relevant to improving the service delivery system are identified and implementation issues critical to successful management of needed transitions are discussed.
Modeling electronegative discharges at low pressure

Summary form only given, as follows. In a previous study, a macroscopic analytic model was developed for a plasma discharge with a three component (electronegative) core and an electropositive edge region. Both regions were treated in the high pressure approximation of constant mobility for the positive ions. We extend the treatment to low pressures for which the ion thermal velocity within the electropositive region is much less than the ion flow velocity by using a variable mobility model with constant mean free path for the positive ions. The density at the interface between the electropositive region and the sheath is determined by generalizing the low pressure electropositive solutions to a finite flow boundary condition at the interface with the electronegative plasma. The results are also extended to a wider parameter range in which the electropositive region disappears and a more general Bohm loss condition holds at the plasma-sheath interface. It is also possible to have an additional transition region in which the flow at the edge of the electronegative region is required to be sonic. The resulting algebraic equations are solved numerically over all parameter ranges and compared to analytical approximations. It is shown that the formalism can be extended to two positive ion species (four plasma components), and explicit equations for oxygen are presented.
Understanding STEM-focused high school students’ perceptions of task importance: The role of “standing out” and “fitting in” in mathematics class

Abstract One theoretical extension of Optimal Distinctiveness Theory (ODT; Brewer, 1991 , Leonardelli et al., 2010 ) is that individuals will work toward the satisfaction of their own social identity needs for differentiation (standing out) and assimilation (fitting in). Because these needs serve as driving forces behind the attitudes people adopt, and the behaviors they enact, the motivational properties of these needs are likely to be manifest in achievement contexts. Bridging ODT and Expectancy-Value Theory, this article examines the prediction that academic tasks are seen by students as more important when they contribute to students’ ability to stand out (task differentiation) from and fit in (task assimilation) with their classmates. This prediction was supported among an ethnically diverse sample of STEM-focused high school students who rated the importance of 18 mathematics-related academic tasks. Additional analyses demonstrated that the association between task assimilation and task importance was stronger for students who perceived their academic learning environment to be performance-focused (performance goal structure). There also was a significant interaction between task differentiation and task assimilation, such that the association between task assimilation and task importance attenuated at higher levels of task differentiation. The present study is one of the few investigations to assess how students’ valuing within a single academic domain might fluctuate from one academic task to the next (e.g., taking notes versus working out problems on the board). The Discussion addresses the theoretical and practical significance of acknowledging differentiation and assimilation as vehicles for motivating students in the classroom.
Characterization of a massive transformation by microstructural analysis

Quantitative metallography was employed to investigate experimentally the nucleation behavior and growth rates in a quenched Ag + 50 at. pct Cd alloy undergoing an isothermal massive transformation at 373 K (100 °C). The experimental characterization of the massively transforming microstructure as a function of time was accomplished by the stereological measurement of the microstructural variables, Vv, the volume fraction transformed, Sv, the parent/daughter interfacial area density, and λmax, the largest intercept-free nodule length of the newly forming daughter phase. These data were compared to statistically derived geometrical models of the microstructure formulated on various nucleation and growth premises and expressed in terms of these same variables. A model was found which matched the data in all respects, and this allowed certain nucleation characteristics, the interface migration rates, and the nodule shapes of the daughter phase to be deduced.
Management systems as technology: Japanese, US and national firms in the Brazilian electronic sector

Abstract This paper recognizes that technological change is an endogenous factor in many dynamic Japanese firms and that the change is promoted by unique soft technologies of organizational design and management systems. Certain key soft technologies are identified and attempts to transfer them to the Brazilian electronics sector are analyzed. Although the attempts have been incomplete, it is noteworthy that US multinationals and Brazilian national firms appear to have been more successful than subsidiaries of Japanese firms. Factors impeding full assimilation are identified for each of the three groups studied. It is also argued that successful transfer of these soft technologies would increase Brazil's domestic technological capacity.
Laryngeal and Manual Reaction Times of Stuttering and Nonstuttering Adults

This investigation compared the reaction times of thirteen stuttering and thirteen nonstuttering adults for forefinger button pressing, nonspeeeh vocal initiation, and speech-mode vocal initiation....
The Intra-uterine Growth-cycles of the Guinea-pig

Nach den in dieser Arbeit vorgebrachten und erorterten Figuren und Tatsachen und nach dem Aussehen der aus diesen Tatsachen konstruierten Kurve scheinen mir nachstehende Schlusfolgerungen erlaubt: 1) Es ist moglich, eine Kurve zu erhalten, welche das intrauterine Wachstum von Embryonen durch indirekte Mittel veranschaulicht, so durch regelmasig wiederholte Wagung der Mutter in regelmasigen Zwischenraumen wahrend der Schwangerschaft. 2) Fur das Meerschweinchen beginnt ein Zyklus bei der Befruchtung der Eier und endet ungefahr 60 Tage spater. Ein andrer Zyklus beginnt eine kleine Weile vor dem Ablauf des ersten Zyklus und dauert noch nach der Geburt an. 3) Sowohl beim Meerschweinchen wie beim Menschen fallt die Geburt in den Verlauf eines Zyklus und nicht in oder nahe an die gemeinsame Ablaufszeit zweier Zyklen. 4) Die Jungen des Menschen werden noch vor der Vollendung des ersten Zyklus geboren, wahrend das Meerschweinchen noch im Uterus einen Zyklus vollendet und einen zweiten anfangt. Es ist durchaus wahrscheinlich, das dieser Umstand die Ursache fur das vorgeruckte Entwicklungsstadium des letzteren Tieres bei der Geburt abgibt.
Role for mouse macrophage IgG Fc receptor as ligand-dependent ion channel

The interaction of ligands with the mouse macrophage Fc receptor which binds IgG2b and IgG1 immune complexes (FcR gamma 2b/gamma 1) triggers phagocytosis and secretion of various mediators of inflammation. FcR gamma 2b/gamma 1 has been purified using a monoclonal anti-FcR antibody, 2.4G2, and seems to be an integral membrane glycoprotein of molecular weight (Mr) 47,000-60,000 (ref. 6). Monoclonal antibody 2.4G2 is suitable as a tool for functional studies of FcR because it binds to a functional site of the receptor and induces cellular responses that are normally associated with the occupied receptor. We reported previously that binding of ligands to the macrophage FcR resulted in Na+/K+ ion fluxes through the plasma membrane, and that similar ion fluxes were observed in proteoliposomes containing reconstituted FcR. We have now incorporated FcR into planar lipid bilayers and report here that FcR gamma 2b/gamma 1 forms ligand-dependent cation-selective ion channels, with a conductance of 60 pS in 1 M KCl and an average open channel lifetime of 250 ms. The conductance decays to baseline levels within a few minutes. These results suggest a receptor-ionophore model for the signalling of phagocytosis and inflammatory responses.
Evolution of proton order during ice-film growth: An analysis of island shapes

Scanning tunneling microscopy reveals that two-dimensional islands equilibrated on the surface of ice multilayers change their shape with increasing film thickness from triangular to hexagonal. We propose that this shape change is caused by a transition from polarized ice at the Pt substrate toward proton disorder (i.e., vanishing net polarization) at larger film thicknesses. A kinetic model estimates how quickly the substrate-induced proton order decays via introduction of protonic defects during growth.
Trajectories of change in emotion regulation and social anxiety during cognitive-behavioral therapy for social anxiety disorder

Cognitive-behavioral therapy (CBT) for social anxiety disorder (SAD) may decrease social anxiety by training emotion regulation skills. This randomized controlled trial of CBT for SAD examined changes in weekly frequency and success of cognitive reappraisal and expressive suppression, as well as weekly intensity of social anxiety among patients receiving 16 weekly sessions of individual CBT. We expected these variables to (1) differ from pre-to-post-CBT vs. Waitlist, (2) have differential trajectories during CBT, and (3) covary during CBT. We also expected that weekly changes in emotion regulation would predict (4) subsequent weekly changes in social anxiety, and (5) changes in social anxiety both during and post-CBT. Compared to Waitlist, CBT increased cognitive reappraisal frequency and success, decreased social anxiety, but had no impact on expressive suppression. During CBT, weekly cognitive reappraisal frequency and success increased, whereas weekly expressive suppression frequency and social anxiety decreased. Weekly decreases in social anxiety were associated with concurrent increases in reappraisal success and decreases in suppression frequency. Granger causality analysis showed that only reappraisal success increases predicted decreases in subsequent social anxiety during CBT. Reappraisal success increases pre-to-post-CBT predicted reductions in social anxiety symptom severity post-CBT. The trajectory of weekly changes in emotion regulation strategies may help clinicians understand whether CBT is effective and predict decreases in social anxiety.
Influence of spironolactone on cadmium-induced changes in hepatic and renal gluconeogenic enzymes in rats.

Serum glucose, serum protein, serum glutamic oxalacetic transminase (SGOT), serum glutamic pyruvic transaminase (SGPT), and hepatic and renal gluconeogenic enzymes [pyruvate carboxylase (PC), phosphoenolpyruvate carboxykinase (PEPCK), fructose‐1,6‐diphosphatase (F‐1, 6‐DPase), and glucose‐6‐phosphatose (G‐6‐Pase)] were determined in rats treated daily with cadmium alone (0.25 mg/kg·d, injected ip) and in rats pretreated with spironolactone (50 mg/kg·d and 100 mg/kg·d, injected sc) prior to cadmium administration. Rats receiving no treatment, propylene glycol, or spironolactone (100 mg/kg·d, injected sc) were used as controls. The daily treatments were continued for an extended period of 90 d, and the rats were sacrificed at 30‐, 60‐, and 90‐d intervals during the continuous daily treatment schedule. Cadmium treatment significantly increased the amount of serum protein, glucose, serum enzymes, and all the four key gluconeogenic enzymes as compared to controls. Pretreatment of rats with spironolactone 6 h p...
Nonlocal Response in Transition Metamaterials

We investigate resonant enhancement of light in transition metamaterialsunder the local and nonlocal response function approximations, and analyze the influence of nonlocality on the field distribution in the near-zero region.
Chemotaxis of eosinophils and neutrophils by aggregated immunoglobulins

Abstract Human myeloma proteins of all recognized immunoglobulin classes, including IgE, were purified and chemically aggregated. The chemotactic properties of these aggregated immunoglobulins for enriched preparations of human eosinophils and neutrophils were studied in vitro with the use of a modification of the Boyden chamber. Significant chemotactic effects were exerted on eosinophils and neutrophils by IgG and IgM in the presence of fresh human serum. IgE did not attract eosinophils either alone or in the presence of fresh serum. Inhibition of chemotaxis was observed when fresh human serum was heated at 56 °C. for 30 minutes and when the same concentration of chemotactic agents was placed in both compartments of the chambers. The results indicate that aggregated IgG and IgM, in the presence of fresh human serum, generate chemotactic factor(s) for eosinophils and neutrophils and that heatlabile serum factors are essential for chemotaxis of these cells. These results are discussed in terms of the eosinophil and neutrophil chemotactic factors derived from the complement system, ECF-C and NCF-C, and the eosinophil chemotactic factor of anaphylaxis, ECF-A, associated with immediate-type hypersensitivity reactions.
Control of behavioral circadian rhythms for nesting and wheel running in mice.

Abstract In Experiment 1 a circadian rhythm for nest-building behavior is demonstrated in 10 males from a genetically heterogeneous stock of Mus musculus . In Experiment 2, this circadian rhythm in nesting and that for wheel running activity were monitored simultaneously in an additional sample of five males from the same stock. Under a 16:8 LD photoperiod, mice displayed a 24-hr periodicity for both behaviors but a phase difference in peak behavioral intensities of approximately two and one-half hours. After ten days of exposure to constant light both rhythms persisted, but with no detectable difference in phase. The altered phase relationship under constant light suggests a difference in control of the circadian periodicities of these two behaviors. In Experiment 3, 5 additional males were subjected to a 10-hr shift in photoperiod to further examine control of these rhythms as well as those in food and water consumption. All four circadian rhythms re-entrained within four days. Thus, their entrainment mechanisms are functionally similar in spite of the differences in control suggested in Experiment 2.