cssi/SciSciGPT-SciSciNet huggingface dataset:
Involvement of nitroreductase and O-acetyltransferase on the mutagenicity of plant-activated benzidine and 4-aminobiphenyl

Benzidine and 4-aminobiphenyl (4-ABP) are activated by intact plant cells and cell free TX1MX into mutagenic metabolites that induce frameshift and base pair substitution mutations in Salmonella typhimurium. The plant activation of these agents is plant peroxidase-mediated and bacterial O-acetyltransferase (OAT) dependent. TX1MX-activated benzidine and 4-ABP were analyzed with S. typhimurium frameshift tester strains, YG1021, YG1024, TA98, TA98NR, TA98/1,8-DNP6, MP219, and base pair substitution tester strains, YG1026, YG1029, TA100, TA100NR, TA100TN:OAT, and MP208. Concentration ranges for benzidine and 4-ABP were 1-50 microM and 0.1-1 mM, respectively. This study was conducted to determine if the plant-activation of benzidine and 4-ABP follows the prostaglandin H synthase-mediated activation pathway in mammals [Smith et al. (1992): Chem Res Toxicol 5;431-439]. In this model, benzidine is N-acetylated by S. typhimurium OAT. This acetylated product is a substrate for PHS and is converted into a 4-nitro product which is catalyzed by nitroreductase into a N-hydroxy intermediate. The pathway assigns a specific role for nitroreductase in the activation of benzidine. By employing S. typhimurium strains that express different levels of OAT and/or nitroreductase, we determined that the plant-activation of benzidine and 4-ABP has an absolute requirement of bacterial OAT activity for the induction of frameshift mutations at hisD3052 and is required for the optimal mutagenic response at hisG46. Nitroreductase also plays a role in the plant activation of these agents. The data suggest that the plant-activation of benzidine and 4-ABP generates at least two classes of proximal mutagenic intermediates. One class requires S. typhimurium OAT alone to be transformed into the ultimate mutagen and a second class requires both OAT and nitroreductase.
Targeting and clustering citron to synapses

Citron-N (citron) binds activated Rho and concentrates at excitatory postsynaptic densities on the smooth dendritic shafts of hippocampal GABAergic neurons. Since little is known about how cytoplasmic proteins become targeted and retained at synapses, we asked how citron attains this discrete distribution. We first sought to determine whether the synaptic localization machinery is unique to GABAergic interneurons, but in neurons cultured from either cerebral cortex or hippocampus, low levels of citron are found in a small population of glutamatergic neurons concentrated at the tips of dendritic spines in addition to shaft synapses. These data suggest that the targeting domains in citron can be utilized appropriately by any neuron, and consistent with this idea, tagged, exogenous, full-length citron becomes concentrated at postsynaptic sites in all hippocampal neurons in which it is introduced. Citron contains multiple sites for protein-protein interaction, including coiled-coil, pleckstrin homology, cysteine-rich zinc binding and CMG domains, as well as a proline-rich region and a PDZ binding tail that is known to interact with PSD-95/SAP90. Using citron deletion mutants, we find that the coiled-coil (CC) domain, located in the N-terminal half of the protein, mediates somatodendritic targeting, self-oligomerization and puncta formation independent of the Rho binding domain, while regions in the C-terminal half of citron are responsible for precise alignment of postsynaptic citron clusters at sites apposing presynaptic boutons. Rho binding and activation regulate membrane targeting and the number of synapses containing citron. Thus, citron's clustering at postsynaptic membranes is mediated by multiple domains, and its synaptic distribution is modified in response to Rho activation.
Designing executive reporting and decision support systems for colleges and universities

THIS ARTICLE presents a design concept, alternative hardware and software environments, and application development strategies for building executive reporting and decision support systems for colleges and universities. It is based on seven years of application development experience in a planning and institutional research office that provides information center support to senior officers and middle managers in a private, comprehensive university. The author recommends design and implementation strategies gained from case study experience from a NERComP consortium project — Decision Support Systems for Higher Education Management.
Lariat ether receptor systems show experimental evidence for alkali metal cation-pi interactions.

Cation−π interactions occur between cations and electron-rich species such as double bonds, triple bonds, and arenes. The π-electron system may be neutral or anionic, but the latter are less relevant to biology, at least so far as is currently known. Among the 20 essential amino acids, there are four aromatic residues. These are benzene, phenol, indole, and imidazole, on the side chains of phenylalanine, tyrosine, tryptophan, and histidine, respectively. Of these, imidazole is expected to be a σ-donor, and benzene, phenol, and indole are antipicated to serve as π-donors. Sodium and potassium are the most abundant cations in living systems. This Account describes an experimental system that has been developed to probe, especially by X-ray crystallography, the interactions that occur between Na+ or K+ and the neutral arenes of particular biological significance.
Evaluating the Usability of E-Voting Technologies

Voting has been an accepted means for electing candidates, receiving public approval for referendums and budgets, and for many other tasks where the will of the people, whether a broad population or a select group, can be recorded and measured in a tangible way. Because of advances in technology, together with problems inherent in manual forms of voting, the concepts and issues relating to electronic voting (e-voting) and various other technology-based forms, are been proposed, discussed, and examined. The goal of all such systems is the casting and recording of the votes from eligible voters as they intended to be cast, with adequate security. This security requires that there be no identifiable connection between the voter and the vote that is cast, while providing an audit trail that can be used to validate that every vote was counted and tallied, as cast. The focus of this paper is to examine electronic voting technologies from the perspective of usability in controlled environments. Current research has shown that such systems form the majority of the nascent e-voting technologies, primarily because they have come closest to solving the usability and security issues inherent in technology—based voting systems.
Analysis of Ductile Bursting in Pressure Vessels of Texture-Hardening and Filament-Wrapped Materials

Analyses are presented for predicting the strength governed by the plastic tensile instability (PTI) phenomenon in thin-walled cylindrical and spherical pressure vessels constructed of texture- hardening alloys and with or without over-wrapped filaments. These analyses are important in predicting ductile bursting of pressure vessels used in such high-performance applications as high-pressure storage bottles, liquid-propellant tankage, and solid rocket casings. The analyses cover cylindrical pressure vessels subject to any ratio of biaxial stresses. Also means of estimating the effect of finite length is presented. Spherical vessels of texture- hardening material and cylindrical vessels with filaments over wrapped on a texture-hardening metallic substrate are treated as special cases. The analytical results are compared with available experimental results with good success.
The gonadotropin-releasing hormone pituitary receptor interacts with a guanosine triphosphate-binding protein: differential effects of guanyl nucleotides on agonist and antagonist binding.

Binding of the GnRH agonist [DAla6,NMe-Leu7,Pro9Net]GnRH to bovine anterior pituitary membranes is inhibited by guanyl nucleotides. The effect of guanyl nucleotides is temperature dependent, in that significant binding inhibition is observed when the receptor-hormone interaction is measured at 37 C, and no inhibition is seen at 4 C. Micromolar concentrations of the nonhydrolyzable GTP analog 5′-guanylylimidodiphosphate [Gpp(NH)p] displace the bound agonist in a dosedependent manner, with half-maximal displacement occurring in a concentration range of 0.1–0.5 μM, and maximum displacement occurring at a concentration of 50 fiM Gpp(NH)p. At a concentration of 50 nM, the other nucleotides GTP and GDP inhibit binding to a lesser extent, while GMP, cGMP, 5′- adenylylimidodiphosphate [App(NH)p], ATP, and cAMP have no effect on the binding. At 37 C, Gpp(NH)p reduces the affinity of the agonist by a factor of 6 and increases its dissociation rate. In the presence of Gpp(NH)p at 37 C, there is also a 2-fold increas...
On the Inertial Stability f the Equatorial Middle Atmosphere

Abstract A theory of inertial instability on the equatorial beta-plane is developed with application to the inertial stability of the equatorial middle atmosphere at the solstices. It is shown that the stability of this region depends primarily on two unknowns. First, there is the question of whether eddy diffusion can be regarded as stabilizing, or whether this diffusion actually arises from the instability itself. Second, because the diabatic circulation would appear to induce a cross-equatorial shear much greater than that observed, or than that modeled in Holton and Wehrbein (1980), it appears that the gravity wave-induced decelerations would he crucial to the stability of this flow. Unfortunately, the parameterization scheme of Leovy (1964) designed to mimic this effect obscures the issue, since this “frictional drag” concept is invalid on a local basis (Lindzen, 1981). The expected structure and vertical wavelength of the equatorial inertial instability is discussed in the context of this simple mod...
Towards quantifying tropical tree species richness in tropical forests

This letter reports tests of whether the normalized difference vegetation index (NDVI) from Landsat Enhanced Thematic Mapper Plus (ETM+) and radar backscatter (C-, L-and P-bands) from Airborne Synthetic Aperture Radar (AIRSAR) imagery can be used to estimate tree species richness from 25 1-ha plots within continuous lowland forest types (dry, moist, wet) in the Panama Canal Zone Watershed. Species richness for trees ranged from 49 to 98 species per ha. There was no evidence that density, basal area, above-ground biomass or P-backscatter was correlated with tree species richness. Mean and standard deviations (SDs) of the NDVI could explain 39% and 37% of the variance in tree species richness, respectively (41% when combined), while mean radar backscatter in the shorter wavelength C-and L-bands could explain 44% and 33% of the variance in tree species richness, respectively (50% when combined).
GROWTH OF TWO FACULTATIVELY HETEROTROPHIC MARINE CENTRIC DIATOMS1,2

SUMMARY The facultative, heterotrophs Cyclotella cryptica (sclone WT-1-8) and Coscinodiscus sp. were selectively isolated from coastal waters by dark incubation of organically enriched solid medium. C. cryptica grows in the dark with glucose and galactose, and Coscinodiscus sp. with glucose. Clone WT-1-8 of C. cryptica grows about twice as fast with glucose as a previously studied clone (0-3A). In the dark with, 5 × 10−6 M glucose C. cryptica divides every 3 days, while with 5 × 10−5 M glucose Coscinodiscus sp. divides every 10 days. Heterotrophic growth of either diatom for 1 year does not cause a major reduction in carbon, nitrogen, chlorophyll a, and chlorophyll c contents, or in photosynthetic ability, compared to light-grown cells. It is possible that facultative heterotrophy is of ecological benefit to these diatoms, probably for slow growth and survival during extended periods of dim light or darkness.
The effectiveness of two oral contraceptives in suppressing plasma androstenedione, testosterone, LH, and FSH, and in stimulating plasma testosterone-binding capacity in hirsute women☆☆☆

Abstract The effectiveness of two oral contraceptives in suppressing plasma androstenedione (A), testosterone (T), LH, and FSH and in stimulating testosterone-estradiol-binding globulin TeBG) was evaluated in 39 hirsute women. Twenty-seven hirsute women received norethindrone 2 mg.-mestranol 0.1 mg. (Group I) and 12 received norgestrel 0.5 mg.-ethinyl estradiol 0.05 mg. (Group II). Hormone assays were performed before treatment and at the end of 3 weeks of therapy. Ninety per cent of the women in both groups had an elevated plasma A and/or T. During treatment, plasma A, T, LH, and FSH were significantly reduced in both groups ( p p
Exact At-speed Delay Fault Grading in Sequential Circuits

This paper examines the problem of exact delay fault grading in non-scan sequential circuits using a sequence of test patterns that are applied with a rated clock. Delay faults ending at flip-flops are latched as uncorrelated errors. The errors latched on flip-flops by previous tests may enhance the at-speed delay fault coverage for each pattern in the sequence. In addition, the propagation of errors (and the faults they represent) may be facilitated by other latched errors as well as potential delayed transitions activated by each at-speed test application. An exact grading method is presented and its impact over existing methods is demonstrated experimentally.
Presynaptic regulation of dendrodendritic dopamine transmission

The amount of dopamine release from terminals in the forebrain following an electrical stimulus is variable. This dynamic regulation, both between and within trains of electrical stimuli, has fostered the notion that burst firing of dopamine neurons in vivo may be a determinant of dopamine release in projection areas. In the present study dendritic dopamine release was examined in the substantia nigra and ventral tegmental area in mouse brain slices using whole-cell recording of a dopamine-mediated inhibitory postsynaptic current (IPSC). Paired stimuli produced a depression of the IPSC that was not observed with paired pulses of exogenously applied dopamine. Increasing the number of electrical stimuli from one to five produced an increase in the amplitude the dopamine IPSC but the increase was less than additive, indicating a depression of transmission with each successive stimulus. Analysis with fast-scan cyclic voltammetry demonstrated that presynaptic D2-autoreceptors did not contribute to the depression. Facilitation of the IPSC was observed only after the probability of release was reduced. Thus the regulation of dopamine release in the cell body region was dependent on dopamine neuron impulse activity. Under circumstance where there was initially little activity the probability of dopamine release was high and repetitive activation resulted in depression of further release. With increased activity, the release probability decreased and a burst of activity caused a relative facilitation of dopamine release. This form of regulation would be expected to limit activity within the cell body region.
Left-sided appendicitis in a patient with congenital gastrointestinal malrotation: a case report.

Background While appendicitis is the most common abdominal disease requiring surgical intervention seen in the emergency room setting, intestinal malrotation is relatively uncommon. When patients with asymptomatic undiagnosed gastrointestinal malrotation clinically present with abdominal pain, accurate diagnosis and definitive therapy may be delayed, possibly increasing the risk of morbidity and mortality. We present a case where CT was crucial diagnostically and helpful for pre-surgical planning in a patient presenting with an acute abdomen superimposed on complete congenital gastrointestinal malrotation.
Multidecadal otolith growth histories for red and gray snapper (Lutjanus spp.) in the northern Gulf of Mexico, USA

Dendrochronology (tree-ring analysis) techniques were applied to develop chronologies from the annual growth-increment widths of red snapper (Lutjanus campechanus) and gray snapper (Lutjanus griseus) otoliths sampled from the northern Gulf of Mexico, USA. Growth increment widths showed considerable synchrony within and across species, indicating that some component of environmental variability influenced growth. The final, exactly dated red snapper chronology continuously spanned 1975 through 2003, while the gray snapper chronology continuously spanned 1975 through 2006. To determine baseline climategrowth relationships, chronologies were compared to monthly averages of sea surface temperatures, U winds (west to east), V winds (south to north), and Mississippi River discharge. The gray snapper chronology significantly (P < 0.01) correlated with winds and temperature in March and April, while the red snapper chronology correlated with winds in March. Principal components regression including springtime winds and temperature accounted for 28 and 52% of the variance in the red and gray snapper chronologies, respectively. These results indicate that snapper growth was favored by warm sea surface temperatures and onshore winds from the southeast to the northwest in March and April. Overall, this study provides preliminary, baseline information regarding the association between climate and growth for these commercially important snapper species.
Learning from the value of your mistakes: evidence for a risk-sensitive process in movement adaptation.

Risk frames nearly every decision we make. Yet, remarkably little is known about whether risk influences how we learn new movements. Risk-sensitivity can emerge when there is a distortion between the absolute magnitude (actual value) and how much an individual values (subjective value) a given outcome. In movement, this translates to the difference between a given movement error and its consequences. Surprisingly, how movement learning can be influenced by the consequences associated with an error is not well understood. It is traditionally assumed that all errors are created equal, i.e., that adaptation is proportional to an error experienced. However, not all movement errors of a given magnitude have the same subjective value. Here we examined whether the subjective value of error influenced how participants adapted their control from movement to movement. Seated human participants grasped the handle of a force-generating robotic arm and made horizontal reaching movements in two novel dynamic environments that penalized errors of the same magnitude differently, changing the subjective value of the errors. We expected that adaptation in response to errors of the same magnitude would differ between these environments. In the first environment, Stable, errors were not penalized. In the second environment, Unstable, rightward errors were penalized with the threat of unstable, cliff-like forces. We found that adaptation indeed differed. Specifically, in the Unstable environment, we observed reduced adaptation to leftward errors, an appropriate strategy that reduced the chance of a penalizing rightward error. These results demonstrate that adaptation is influenced by the subjective value of error, rather than solely the magnitude of error, and therefore is risk-sensitive. In other words, we may not simply learn from our mistakes, we may also learn from the value of our mistakes.
The role of resting state networks in focal neocortical seizures.

Objective: The role of resting state functional networks in epilepsy is incompletely understood. While some pathologic diagnoses have been shown to have maintained but altered resting state connectivity, others have implicated resting state connectivity in disease progression. However little is known about how these resting state networks influence the behavior of a focal neocortical seizure. Methods: Using data taken from invasively monitored patients with intractable focal neocortical epilepsy, we evaluated network connectivity (as determined by oscillatory covariance of the slow cortical potential (,0.5 Hz)) as it relates to neocortical seizure foci both in the interictal and ictal states. Results: Similar to what has been shown in the past for sleep and anesthesia, electophysiologic resting state networks that are defined by this slow cortical potential covariance maintain their topographic correlation structure throughout an ictal event. Moreover, in the context of focal epilepsy in which the seizure has a specific site of onset, seizure propagation is not chaotic or random. Rather, the seizure (reflected by an elevation of high frequency power) preferentially propagates along the network that contains the seizure onset zone. Significance: Taken together, these findings further undergird the fundamental role of resting state networks, provide novel insights into the network-influenced behavior of seizures, and potentially identify additional targets for surgical disconnection including informing the location for the completion of multiple subpial transections (MSPTs).
Characterization of hepatocellular carcinoma (HCC) in non-alcoholic fatty liver disease (NAFLD) patients without cirrhosis

The incidence of hepatocellular carcinoma (HCC) has increased significantly in United States over the last few decades in parallel with the epidemic of nonalcoholic fatty liver disease (NAFLD). Limited data suggests that HCC could arise in steatotic liver without the presence of cirrhosis. The present study was conducted to characterize patients with NAFLD presenting with HCC in non-cirrhotic liver (NCL) compared to the NAFLD- HCC patients in association with cirrhotic liver (CL). A retrospective analysis of all patients diagnosed with HCC and NAFLD diagnosis seen at our institution between 2003 and 2012 was done. The patients were characterized based on demographic and clinical variables as well as histological and tumor features. Comparisons between the NCL and CL groups were done using analysis of variance (ANOVA) or the non-parametric Kruskal–Wallis tests and Pearson's chi-square tests or Fisher's Exact tests as appropriate. P value of 5 cm) (77.8 % vs. 10.6 %), and receive hepatic resection as the modality of HCC treatment (66.7 % vs. 17 %); and were less likely to receive loco-regional therapy (22.3 % vs. 61.7 %) or orthotopic liver transplantation (OLT) (0 % vs. 72.3 %), with p value 0.05). Patients with HCC in the absence of liver cirrhosis are more likely to present at an older age with larger tumor and have higher rates of tumor recurrence. Studies to assess the cost-effectiveness of HCC surveillance in this group should be conducted.
Macroscopic, Histologic, and Ultrastructural Lesions Associated With Avian Keratin Disorder in Black-Capped Chickadees (Poecile atricapillus)

An epizootic of beak abnormalities (avian keratin disorder) was recently detected among wild birds in Alaska. Here we describe the gross, histologic, and ultrastructural features of the disease in 30 affected adult black-capped chickadees (Poecile atricapillus). Grossly, there was elongation of the rhamphotheca, with varying degrees of lateral deviation, crossing, and gapping between the upper and lower beak. Not uncommonly, the claws were overgrown, and there was alopecia, scaling, and crusting of the skin. The most prominent histopathologic features in the beak included epidermal hyperplasia, hyperkeratosis, and core-like intrusions of necrotic debris. In affected birds, particularly those with moderate to severe beak overgrowth, there was remodeling of premaxillary and mandibular bones and various dermal lesions. Lesions analogous to those found in beaks were present in affected claws, indicating that this disorder may target both of these similar tissues. Mild to moderate hyperkeratosis occurred in other keratinized tissues, including skin, feather follicles, and, occasionally, sinus epithelium, but typically only in the presence of microbes. We did not find consistent evidence of a bacterial, fungal, or viral etiology for the beak lesions. The changes observed in affected birds did not correspond with any known avian diseases, suggesting a potentially novel hyperkeratotic disorder in wild birds.
Coaxial microwave neutron interrogation source

A compact neutron generator is being developed based on a novel coaxial dipole permanent magnet electron cyclotron resonance (ECR) ion source. The ion source is capable of generating a high fraction of atomic ion species and can operate at low pressure. Multiple deuterium ion (D + ) beamlets are extracted from the plasma ion source and accelerated to a beam-loaded titanium target creating 2.4 MeV neutrons as a result of the D-D fusion reaction at the target surface. This paper describes the design of the ECR-based neutron generator as well as reports on preliminary simulation and experimental results of the ion source performance.
Localization using ambiguous bearings from radio signal strength

In this paper, we consider the problem of localizing a mobile robot team capable of measuring ambiguous bearing estimates using received signal strength indicators (RSSI) from radio transceivers (e.g., ZigBee). More precisely, we formulate a robust bearing estimator that leverages anisotropic but symmetric radiation profiles to identify π-periodic bearing estimates between pairs of communicating agents. Utilizing these ambiguous bearing estimates along with compass and odometric measurements, we present a Multi-hypothesis Extended Kalman Filter-based framework that exploits agent motion to resolve the resulting state ambiguity and achieve localization up to translation. Despite the combinatoric nature of our problem, for teams exhibiting certain topological properties, we show that only two initial hypotheses need consideration to recover state. Experimental results from a small team of differential drive robots are presented to demonstrate the utility of our approach. Simulation results are also presented that explore our framework's convergence properties for larger team sizes.
Elevated 12- and 20-hydroxyeicosatetraenoic acid in urine of patients with prostatic diseases

The role of eicosanoids (metabolites of arachidonic acid) in prostate diseases is receiving increased attention. We investigated the relationship between the concentrations of urinary free acids of 12- and 20-hydroxyeicosatetraenoic acids (12- and 20-HETE) and the benign prostatic hypertrophy (BPH) and prostate cancer (Pca). Urinary concentrations of 12-HETE and 20-HETE of BPH and Pca patients were significantly higher than normal subjects. After removal of the prostate gland, the urinary concentrations of these eicosanoids decreased to concentrations similar to the normal subjects. These results suggest that urinary free acids of 12-HETE and 20-HETE indicate an abnormality of the prostate gland.
Spectra of recursive models of disintegrated strongly minimal theories

This paper gives an overview of results about the spectra of computable (or recursive) models of strongly minimal disintegrated theories. Spectra of strongly minimal disintegrated theories in finite languages and in languages consisting of binary relation symbols will be described.
Comparison of myocardial contrast echocardiography derived myocardial perfusion reserve with invasive determination of coronary flow reserve.

Aims Invasive measurements of coronary flow reserve (CFR) by Doppler flow wire are an established method for determining coronary blood flow physiology. Myocardial contrast echocardiography (MCE) is a potential non-invasive method for quantifying myocardial blood flow (MBF). However, few studies have compared MCE-derived myocardial perfusion reserve (MPR) with Doppler flow wire-derived CFR, measured simultaneously in human subjects. This study aimed to correlate MCE-derived MPR with Doppler flow wire-derived CFR. Methods and results Ten patients with at least two angiographically normal coronary arteries underwent simultaneous invasive Doppler flow wire measurements and MCE imaging at rest and at peak hyperaemia. Hyperaemia was induced by intravenous adenosine infusion. Doppler-derived CFR was calculated as the ratio of hyperaemic to baseline average peak red blood cell velocity. MPR was calculated as the hyperaemic to baseline ratio of the following parameters: myocardial blood volume (MBV), myocardial microbubble velocity (MMV), and MBF. MCE was performed using real-time and triggered imaging with contrast infused intravenously by bolus and continuous methods. Regardless of whether the contrast was infused by bolus or continuous methods, Doppler flow wire-derived CFR had a stronger correlation with MPR derived by MBV ( r = 0.8, P = 0.05) than with MPR derived by microbubble velocity ( r = 0.3, P > 0.05) or MBF ( r = 0.4, P > 0.05). Real-time imaging with continuous infusion provided better correlation with CFR than triggered imaging methods or bolus administration. Conclusion Myocardial perfusion reserve derived by real-time infusion MBV measurements correlates with Doppler flow wire-derived CFR. Therefore, MPR may be a potential surrogate for Doppler flow wire-derived CFR in patients with angiographically normal coronary arteries.
The Engaged Dissertation: Exploring Trends in Doctoral Student Research.

This study explored the extent to which doctoral students are conducting community-engaged scholarship and investigated the characteristics of their degree-granting institutions. The research utilized the most immediate work of doctoral students by examining completed dissertations. Analysis showed which graduate students are pursuing community engagement through their scholarship, whether they are increasing in number, and the fields of study and institution types with which they are affiliated. By identifying who is producing engaged scholars, best practices can be identified in the future. In addition, the findings revealed which disciplines and institution types have room to increase their output of community-engaged research.
Effects of La2O3/ZnO Additives on Microstructure And Microwave Dielectric Properties of Zr0.8Sn0.2TiO4 Ceramics

Dielectric ceramics of Zr[sub 0.8]Sn[sub 0.2]TiO[sub 4] containing La[sub 2]O[sub 3] and ZnO as sintering aids were prepared and investigating for microstructure and microwave dielectric properties. Low-level doping with La[sub 2]O[sub 3] and ZnO (up to 0.30 wt%) is good for densification and dielectric properties. These additives do not affect the dielectric constant and the temperature coefficient. Dielectric losses increase significantly at additive levels higher than 0.15 wt%. The combined additives La[sub 2]O[sub 3] and ZnO act as grain growth enhancers. With 0.15 wt% additives, a ceramic having a dielectric constant, a quality factor, and a temperature coefficient of frequency at 4.2 GHz of 37.6, 12,800 and [minus]2.9 ppm/C, respectively, was obtained. The quality factor was considerably improved by prolonged sintering.
An empirical study of collaborative acoustic source localization

Field biologists use animal sounds to discover the presence of individuals and to study their behavior. Collecting bio- acoustic data has traditionally been a difficult and time- consuming process in which researchers use portable microphones to record sounds while taking notes of their own detailed observations. The recent development of new deploy- able acoustic sensor platforms presents opportunities to develop automated tools for bio-acoustic field research. In this work, we implement an AML-based source localization algorithm, and use it to localize marmot alarm-calls. We assess the performance of these techniques based on results from two field experiments: (1) a controlled test of direction-of- arrival (DOA) accuracy using a pre-recorded source signal, and (2) an experiment to detect and localize actual animals in their habitat, with a comparison to ground truth gathered from human observations. Although small arrays yield ambiguities from spatial aliasing of high frequency signals, we show that these ambiguities are readily eliminated by proper bearing crossings of the DOAs from several arrays. These results show that the AML source localization algorithm can be used to localize actual animals in their natural habitat, using a platform that is practical to deploy.
Blue-green-red LEDs based on InGaN Quantum Dots by Plasma-assisted MBE using GaN QDs for Dislocation Filtering

In this paper, we report the development of blue-green-red LEDs based on InGaN quantum dots (QDs) and quantum wells in the active region, and GaN QDs in the nucleation layer for dislocation filtering, by plasma assisted molecular beam epitaxy. Self-assembled InGaN QDs and GaN QDs were grown in the Stranski-Krastanov mode. For the GaN QDs grown at 770 °C, the height distribution of the dots shows a bimodal distribution, which can be attributed to the interaction of the GaN QDs with the threading dislocations. TEM and XRD studies indicate that GaN QDs in the nucleation region help threading dislocations to deviate and annihilate. The average dot height, diameter and density of the InGaN QDs were estimated to be 3 nm, 30 nm and 7×1010 cm−2, respectively. The cathodoluminescence emission peak of the InGaN/GaN multiple layer quantum dots (MQDs) was found to red shift 330 meV with respect to the emission peak of the uncapped single layer of InGaN QDs due to Quantum Confined Stark effect. Blue LEDs based on InGaN/GaN multiple quantum wells (MQWs) as well as green and red LEDs based on InGaN MQDs emitting at 440 nm, 560 nm and 640 nm with FWHM of 30 nm, 87 nm and 97 nm, respectively, were grown and fabricated. The electroluminescence peak positions of both the green and red InGaN MQD LEDs are shown to be more blue-shifted with increasing injection current than that of the blue InGaN/GaN MQW LEDs.
Measurements of phase velocity and group velocity in human calcaneus.

Abstract Ultrasonic velocity in calcaneus correlates highly with bone mineral density, which is a good predictor of osteoporotic fracture risk. Several commercial bone sonometers perform a velocity measurement based on the transit time of a broadband pulse to assess skeletal status. This approach is somewhat problematic, however, because several authors have reported ambiguities in measurements in calcaneus. Phase velocity is an alternative that may be less dependent on device spectral characteristics. In addition, dispersion (the frequency-dependence of phase velocity) is a fundamental property worth investigating to increase understanding of interaction between ultrasound and bone. To compare two group-velocity measurement methods and one phase-velocity measurement method, a polycarbonate sample (for method validation) and 24 human calcanei were investigated in vitro . Phase velocity in calcaneus at 500 kHz was 1511 m/s ± 30 m/s (mean ± standard deviation). Average phase velocity decreased approximately linearly with frequency (−18 m/s MHz). The two group velocity measurements were comparable and tended to be slightly lower than phase velocity. The magnitude of dispersion showed little correlation with bone mineral density.
Auditor independence: a review of literature

Independence is one of the most important attributes of the accounting profession. The auditor independence is measured by how honest an auditor is in reporting the material misstatements found in the financial statements by managers. The auditor maintains his/her independence by not having any conflicts of interest with the client (managers). The auditor is encouraged to appear independent in the sight of investors, but only to the extent that the audit fees cover the cost of the actual audit. This research is expected to serve as a guide in understanding the importance of auditor independence and the challenges auditors face. The major purpose of this research is to survey the auditor independence related research literature published during the period from 1992 to 2010. This survey suggests that a wide range of topic areas has been discussed and this learning can be incorporated in revising auditor independence related curricula.
Television's Model of the Quest for African Consciousness: A Comparison with Cross' Empirical Model of Psychological Nigrescence:

Using Cross' four-stage empirical model of Nigrescence (the development of African consciousness), this paper examines what appears to be television's highly formularized presentation of the context, content, and process of the search for African identity among African American children. Situation comedies from the late 1970s and early 1980s that featured Black children in predominately White environments are the central focus of this analysis because (a) television appears to have restricted the quest for African consciousness to situation comedy, and (b) television appears to have confined the racial consciousness quest to the domain of children, and primarily to Black children in White environments. Using examples from "Fish," "Diff'rent Strokes," "Facts of Life," and "Webster," the authors contend that Black children characters are presented as progressing through the Pre-encounter, Encounter, and Immersion phase of the Immersion-Emersion stages of Cross's model, but are reverted before they reach the...
Inducible HSP70 Is Critical in Preventing the Aggregation and Enhancing the Processing of PMP22

Chaperones, also called heat shock proteins (HSPs), transiently interact with proteins to aid their folding, trafficking, and degradation, thereby directly influencing the transport of newly synthesized molecules. Induction of chaperones provides a potential therapeutic approach for protein misfolding disorders, such as peripheral myelin protein 22 (PMP22)-associated peripheral neuropathies. Cytosolic aggregates of PMP22, linked with a demyelinating Schwann cell phenotype, result in suppression of proteasome activity and activation of proteostatic mechanisms, including the heat shock pathway. Although the beneficial effects of chaperones in preventing the aggregation and improving the trafficking of PMP22 have been repeatedly observed, the requirement for HSP70 in events remains elusive. In this study, we show that activation of the chaperone pathway in fibroblasts from PMP22 duplication-associated Charcot-Marie-Tooth disease type 1A patient with an FDA-approved small molecule increases HSP70 expression and attenuates proteasome dysfunction. Using cells from an HSP70.1/3(-/-) (inducible HSP70) mouse model, we demonstrate that under proteotoxic stress, this chaperone is critical in preventing the aggregation of PMP22, and this effect is aided by macroautophagy. When examined at steady-state, HSP70 appears to play a minor role in the trafficking of wild-type-PMP22, while it is crucial for preventing the buildup of the aggregation-prone Trembler-J-PMP22. HSP70 aids the processing of Trembler-J-PMP22 through the Golgi and its delivery to lysosomes via Rab7-positive vesicles. Together, these results demonstrate a key role for inducible HSP70 in aiding the processing and hindering the accumulation of misfolded PMP22, which in turn alleviates proteotoxicity within the cells.
Penetration of Antibiotics into Respiratory Secretions

Successful treatment of intrabronchial infection depends upon adequate transport of antibiotics across the blood-bronchus barrier. This paper discusses the various influences on antibiotic concentrations in the lung and describes a canine model for detailed pharmacologic studies of antibiotics in bronchial secretion. A number of factors influence antibiotic penetration into bronchial secretions, including physicochemical characteristics of the drug and such host factors as bronchial inflammation and injury. The method of antibiotic administration also influences bronchial drug levels; the highest local concentrations are associated with the highest peak values in serum. In addition, each antibiotic has a characteristic pattern of penetration into bronchial secretions. Optimal methods of antibiotic therapy for lung infection may depend on the specific minimal inhibitory concentration for the infecting organism.
Communities of Practice in Sociolinguistic Description: Analyzing Language and Identity Practices among Black Women in Appalachia

In this paper, we examine the identities of eight women who share similar demographic profiles but exhibit different language practices. These middle-aged and older women belong to two social groups, which, we argue, constitute two communities of practice within a small black Appalachian community in the Southern United States. From interview data, we analyze six diagnostic sociolinguistic variables (third singular -s absence, copula absence, rhoticity, consonant cluster reduction, habitual be) and also examine productions of /u/ and /o/. The groups differ significantly in their use of the morphosyntactic and syntactic variables and in their vowel productions, but not the consonantal features. Combining our quantitative findings with qualitative data, we suggest language is one of several vehicles the women use to transmit symbolic messages to others and thereby construct identities for themselves and their groups, whose members adhere to different language ideologies, religious norms, notions of feminine decorum, and educational standards.
Specificity and structure of obsessive-compulsive disorder symptoms.

Research in obsessive-compulsive disorder (OCD) shows heterogeneous symptoms. No longer satisfied with categorizations of obsessions or compulsions, contemporary symptom measures are multidimensional and assess specific symptoms (e.g., checking, washing) as well as experiences bearing a putative relation to OCD (e.g., hoarding). This two-study correlational design examined three OCD measures in student samples (total N=805). Objectives were to evaluate (a) the measures' joint factor structure; (b) specificity of relations between OCD and symptoms of general distress, panic, and depression; and (c) the pattern of convergent and discriminant relations among OCD scales after accounting for general distress. Results were that both exploratory and confirmatory factor analyses supported a five-factor structure: checking, contamination, rituals, impulses, and hoarding. Scales showed meaningful patterns of relations with general distress, panic, and depression. That is, OCD symptoms correlated moderately with general distress and panic, but related more weakly to depression. Parallel scales measuring the five domains were reliable and showed strong convergence across instruments. After accounting for general distress, discriminant validity was found: Mono-trait correlations between instruments were the highest correlations overall and were substantially higher than hetero-trait values either within or between instruments. We discuss the importance of understanding relations among OCD measures, between OCD and other symptoms, and implications of this type of analysis for defining OCD. Depression and Anxiety 0:1–12, 2007. © 2007 Wiley-Liss, Inc.
Computing material-selective projection images in MR.

We detail a robust, general method for computing projection images of individual materials in a volume as linear combinations of MR projection images with different material-dependent weightings. Signal per unit volume for each material in each raw image is acquired directly for accurate cancellation of undesired, overlapping materials. The weighted sum of the input images is determined to maximize the signal-to-noise ratio (SNR) and minimize inhomogeneity effects in the material-selective images. We tested the implementation experimentally in both phantom and human studies, producing selective images with reasonable SNRs and material isolation. With further develop ment of sequences to rapidly acquire input images having greater material differentiability, we envision the application of the selective projection imaging format to screening studies searching over large volumes for diseased tissues. © 1989 Academic Press, Inc.
Modeling Rater Disagreement for ADHD: Are Parents or Teachers Biased?.

The present study is the first to utilize twin modeling to examine whether parent-teacher disagreement for ADHD ratings is due to parent or teacher bias, or due to raters observing different but valid ADHD behaviors. A joint analysis was conducted with 106 twin pairs, including twins selected for ADHD and control twin pairs. Total ADHD scores were analyzed using multiple rater models that estimate genetic and environmental contributions common to both raters and unique to each rater. Results suggest that 1) disagreement in ADHD ratings is strongly due to parents and teachers observing different ADHD behaviors, some of which is valid and some of which is due to bias, and 2) parents may be more biased than teachers in their ADHD ratings.
Examining Relations Between Negative Life Events, Time Spent in the United States, Language Use, and Mental Health Outcomes in Latino Adolescents

Despite the growing number of Latino youth in the US, little research has examined factors that influence the development of mental health symptoms among this population, including factors related to immigration. This study examined the link between negative life events (NLEs) and two outcomes, symptoms of anxiety and engagement in delinquency, among Latino adolescents. Time spent in the US and use of language with family and friends were examined as moderators. Study measures were completed by 144 Latino adolescents (N = 78 males; ages 14–19 years) attending a school in a large, Midwestern city. Multiple regression analyses indicated that exposure to NLEs was the only significant unique predictor of anxiety symptoms, and exposure to NLEs and male gender were significant predictors of engagement in delinquency. Further, an interaction was found between NLEs and language use with friends, indicating that exposure to NLEs is significantly related to engagement in delinquent acts at both high and low use of English with their friends; the magnitude of this association was stronger for low use of English. No other significant interactions were found. Findings indicate that exposure to NLEs are important to consider for understanding the development of problem behavior among Latino adolescents. Further, the language that Latino youth speak with their friends is important to consider when monitoring these youth for mental and behavioral health symptoms. Interventions geared toward Latino youth should consider both exposure to NLEs and cultural factors to improve the cultural sensitivity of intervention efforts.