cssi/SciSciGPT-SciSciNet huggingface dataset:
Ovarian Sertoli–Leydig cell tumor (androblastoma) with retiform pattern. A clinicopathologic study

The clinicopathologic findings in nine patients with ovarian Sertoli-Leydig cell tumor with retiform pattern are described. The patients ranged in age from 11 months to 23 years; and seven patients were 12 years of age or younger. The most frequent presenting sign was the finding of an abdominal mass. This was associated with pain in five patients. In three patients the pain was severe due to torsion, causing an acute abdominal emergency. Slight virilization was observed in one patient only. Two patients had elevated serum alphafetoprotein (AFP), which correlated well with disease activity. The remaining patients had normal serum AFP. All the tumors were unilateral. At laparotomy the tumor was intact in six patients and ruptured in three. The tumors ranged from 8 to 22 cm, were round or oval, and cystic or solid and cystic. Eight tumors were in FIGO Stage I, and one was associated with abdominal metastases and was Stage III. Histologically, the retiform component varied from moderate to predominant in eight of the nine cases. In two tumors a heterologous component composed of striated muscle was also present. Three patients developed metastases. Two of the patients died 11 months and 2 years after diagnosis and the third patient was lost to follow-up with evidence of disease 2 years after diagnosis. The remaining six patients were well and disease-free for periods of 8 months to 6 years. The majority of these tumors were misinterpreted as serous papillary cystadenocarcinoma or endodermal sinus tumor, which are more malignant neoplasms requiring different therapy. This further underlines the importance of recognizing this histopathologic entity.
Growth rates and elemental composition of Alexandrium monilatum, a red-tide dinoflagellate

Abstract The combined effects of temperature and salinity on growth of Alexandrium monilatum were studied in laboratory cultures. This toxic, red-tide dinoflagellate grew faster with higher temperatures, up to a maximum of approximately 1 division per day at 31 °C. Salinities above 15 psu had a lesser effect on growth rate, as might be expected for an estuarine species. Growth rates of cultures exposed to natural light and temperature fluctuations were comparable to laboratory cultures. The minimum N cell quota suggested that high N flux would be required to support bloom development. A literature survey of documented A. monilatum blooms indicated that within US waters, blooms occur in July–September in nearshore or estuarine regions of the Gulf of Mexico and the Florida Atlantic coast. Temperature and salinity measured during blooms correspond to the optimal growth conditions of the laboratory cultures. Nevertheless, the occurrence of A. monilatum blooms is sporadic compared to the occurrence of seemingly optimal growth conditions. Laboratory growth experiments predict when blooms of this species are unlikely due to low growth rates, but so far cannot predict individual blooms.
A mechanism for computing an efficient system of wastes emission quotas

Abstract Presented is a mechanism that coordinates producers' wastes disposal decisions and consumers' demands for a clean environment. The mechanism imposes emissions' quotas on firms and levies taxes or subsidies on both firms and consumers. It is shown that a competitive equilibrium relative to the mechanism is Pareto optimal, and that the mechanism provides an incentive for each agent to communicate true marginal information in equilibrium.
Beamlet migration on irregular surface with acquisition-aperture correction

Summary Migration with data acquired on surface with irregular topography can be extrapolated from the highest surface based on one-way wavefield propagator. We fill with near surface velocity the area between the highest surface level and the irregular surface. At every depth, the corresponding seismic data are added if receivers or source exist. We use the local-cosine-bases (LCB) beamlet propagator which improves the image quality at the near irregular surface area because of its windowed reference velocity. We apply the local exponential frame (LEF) decomposition to obtain the image and amplitude correction factor in local wavenumber domain and then transform them into local angle domain after all the shot summation. The influence of irregular topography has been eliminated during the continuation process. We test our method with Model94 which has the highest elevation nearly 1800 meters. Compare with the imaging results without aperture correction or with Auto-vertical gain control (AGC), it has significant improvement in image quality, especially, the deep area with weak illumination.
Elastic fields about a perturbed spherical inclusion

Abstract The elastic fields about an inclusion having the shape of a sphere perturbed by a spherical harmonic are calculated by using isotropic linear elasticity theory. This shape is chosen in order to facilitate coupling of this problem with a morphological stability analysis. The components of the displacement field u(r, θ, φ) about the inclusion are found to be proportional to the components of the gradient of the perturbing harmonic. Two alternative boundary conditions are considered, corresponding to 1. (1) a coherent interface, in which forces and displacements are continuous across the interface 2. (2) a “greased” interface, in which forces tangential to the interface vanish at the interface. For a coherent interface, the sign of the dilatation in the matrix depends on the ratio of the shear moduli of the inclusion and matrix; whereas for a greased interface, the sign of the dilatation in the matrix is independent of this ratio. Also, for a greased interface, the perturbation affects the dilatation in the inclusion; this is not the case for a coherent interface.
Comparison of two simple models for high frequency friction: exponential versus Gaussian wings.

Liquid phase vibrational energy relaxation (VER) times T1 typically depend critically on the relaxing mode’s high frequency friction or wing function. The wing function may, in principle, be found ...
Neuropsychological Functioning in Bipolar Disorder and Schizophrenia

Background Some patients with bipolar disorder (BD) demonstrate neuropsychological deficits even when stable. However, it remains unclear whether these differ qualitatively from those seen in schizophrenia (SZ). Methods We compared the nature and severity of cognitive deficits shown by 106 patients with SZ and 66 patients with BD to 316 healthy adults (NC). All participants completed a cognitive battery with 19 individual measures. After adjusting their test performance for age, sex, race, education, and estimated premorbid IQ, we derived regression-based T-scores for each measure and the six cognitive domains. Results Both patient groups performed significantly worse than NCs on most (BD) or all (SZ) cognitive tests and domains. The resulting effect sizes ranged from .37 to 1.32 (mean = .97) across tests for SZ patients and from .23 to .87 (mean = .59) for BD patients. The Pearson correlation of these effect sizes was .71 (p Conclusions Patients with bipolar disorder suffer from cognitive deficits that are milder but qualitatively similar to those of patients with schizophrenia. These findings support the notion that schizophrenia and bipolar disorder show greater phenotypic similarity in terms of the nature than severity of their neuropsychological deficits.
Shock surfing acceleration

Abstract Analytical and numerical analysis identify shock surfing acceleration as an ideal pre-energization mechanism for the slow pick-up ions at quasiperpendicular shocks. After gaining sufficient energy by shock surfing, pick-up ions undergo diffusive acceleration to reach their observed energies. Energetic ions upstream of the cometary bow shock, acceleration of solar energetic particles by magnetosonic waves in corona, ion enhancement in interplanetary shocks, generation of anomalous cosmic rays from interstellar pick-up ions at the termination shock are some of the cases where shock surfing acceleration apply. Inclusion of the lower-hybrid wave turbulence into the laminar model of shock surfing can explain the preferential acceleration of heavier particles as observed by Voyager at the termination shock. At relativistic energies, unlimited acceleration of ions is theoretically possible; because for sufficiently strong shocks main limitation of the mechanism, caused by the escape of accelerated particles downstream of the shock during acceleration no longer exists.
Theoretical modeling of seismic noise propagation in firn at the South Pole, Antarctica

The problem of interfering noise (produced by ground vehicles) on teleseismic arrivals recorded by Global Seismic Network sensors at South Pole Station is addressed. Using the wavenumber integration method, theoretically calculated seismograms show that installing the GSN sensors in a borehole 200 to 300 m deep, 10 km away from the Station, will significantly reduce the vehicle-generated noise and improve signal quality. Because the intrinsic attenuation of seismic waves propagating in the polar firn is low, most of the predicted noise reduction results from wavefront spreading, Rayleigh wave amplitude decay with depth, and from placing the sensors below the refractive waveguide that traps much of the seismic energy in the near surface layers.
Ultrasensitive Electrocatalytic DNA Detection at Two- and Three-Dimensional Nanoelectrodes

Electrochemical DNA detection systems are an attractive approach to the development of multiplexed, high-throughput DNA analysis systems for clinical and research applications. We have engineered a new class of nanoelectrode ensembles (NEEs) that constitute a useful platform for biomolecular electrochemical sensing. High-sensitivity DNA detection was achieved at oligonucleotide-functionalized NEEs using a label-free electrocatalytic assay. Attomole levels of DNA were detected using the NEEs, validating the promise of nanoarchitectures for ultrasensitive biosensing.
The limits of individual control? Perceived officer power and probationer compliance

Abstract Interactions between correctional agents and the offenders they supervise are assumed to be highly contingent upon latent power dynamics. Yet, currently there is little research that differentiates the bases of power used by correctional personnel. The present study drew on a classic typology to examine the role of power in probation supervision. Perceptions of power and their impact on probationers' compliance were examined using data collected from self-report surveys and case files of 376 misdemeanor probationers. Although the results for perceived power were similar to those of prior research, the current study's findings largely did not support the expected relationship between bases of power and compliance with the conditions of probation. The theoretical and practical implications of these results are discussed.
Excitation UNFOLD (XUNFOLD) to improve the temporal resolution of multishot tailored RF pulses.

An extension of the “UNaliasing by Fourier encoding the Overlaps using the temporaL Dimension” (UNFOLD) method to excitation domain (XUNFOLD) is presented that reduces the effective length of small tip angle tailored RF pulses. Multi-shot tailored RF pulses were designed such that each shot could be alternated every TR in a dynamic-imaging application, producing a time series of images with periodic aliased slice profiles. The XUNFOLD method removes the slice-profile aliasing from the complex four-dimensional (xyzt) image data by filtering in the temporal frequency dimension identical to the UNFOLD method. The XUNFOLD technique is demonstrated using 3D tailored RF pulses designed for reducing intravoxel dephasing due to magnetic susceptibility variations in T2*-weighted brain imaging at 3T. The use of XUNFOLD allows for a single-shot implementation of the 3D tailored RF method for reducing susceptibility artifacts.
Some factors in the timing of parent-chick recognition in swallows

Exchanged, sham-exchanged, and untouched clutches of eggs of tree swallows (Iridoprocne bicolor) and of barn swallows (Hirundo rustica) all hatched with equal incubation periods. Exchanged and sham-exchanged broods of tree swallows, exchanged at 3, 7, 12 and 17-days post-hatch showed no differences in overall or day-to-day weight changes, and barn-swallow groups also failed to show a difference. Nestlings exchanged and sham-exchanged on day 17 departed from the nest earlier than did untouched controls in both species, demonstrating a handling effect. Exchanged broods departed earlier than sham-exchanged broods. Observations of parental behaviour in the 30 min before and after exchanges and sham exchanges in the tree and barn swallows showed that handling decreased parental care similarly in both species. When own and alien young were tethered near the nest, alien young begged and struggled more and received more aggressive responses from the parents than did own young. Field observations of colour-marked birds showed that parent barn swallows restrict feeding and protective responses to their own young, and behave aggressively to alien juveniles. Juveniles vocalize to the sight or sound of approaching adults, and are not fed until they vocalize, so that exchange of signals could provide for the post-fledging discrimination. Thus, parent-chick recognition begins at about the time of fledging, after which it is very specific. This timing matches the factors of altricial nesting: parents can restrict parental care to their own eggs or nestlings by merely discriminating their nest from others, whereas after fledging parents must discriminate their own young.
Exploring the backbone dynamics of native spider silk proteins in Black Widow silk glands with solution-state NMR spectroscopy

Abstract Spider dragline silk is an outstanding biopolymer with a strength that exceeds steel by weight and a toughness greater than high-performance fibers like Kevlar. For this reason, understanding how a spider converts the gel-like, aqueous protein spinning dope within the major ampullate (MA) gland into a super fiber is of great importance for developing future biomaterials based on spider silk. In this work, the initial state of the silk proteins within Black Widow MA glands was probed with solution-state NMR spectroscopy. 15 N relaxation parameters, T 1 , T 2 and 15 N-{ 1 H} steady-state NOE were measured for twelve backbone environments at two spectrometer frequencies, 500 and 800 MHz. The NMR relaxation parameters extracted for all twelve environments are consistent with MA silk protein backbone dynamics on the fast sub-nanosecond timescale. Therefore, it is concluded that the repetitive core of spider MA proteins are in an unfolded, highly flexible state in the MA gland.
Prairie-Relict Communities of a Piedmont Monadnock

ABSTRACT A floristic survey of Crowders Mountain State Park, located in Gaston and Cleveland Counties in North Carolina, was conducted from 2010–2011 to document prairie-relict species. In addition, 1-m2 quadrats (n = 200) were sampled from four remnant power line rights-of-way/roadside prairie communities in the park to assess community structure. Cover and frequency values were assessed for species within the quadrats and species were also placed into guild groupings. A total of 143 prairie-relict species from 37 plant families were identified for the entire park, 69 (48%) of which were also found in the sampled quadrats. Eighty-three (58%) species were previously undocumented for the park. Summer forbs represented the largest guild at 66 (46%) with several rare and uncommon species for North Carolina, including the North Carolina Rare Symphyotrichum georgianum (Georgia aster) and Echinacea purpurea (eastern purple coneflower). The communities had a combined Floristic Quality Assessment Index (FQAI) of ...
High-Nuclearity Close-Packed Palladium-Nickel Carbonyl Phosphine Clusters: Heteropalladium [Pd16Ni4(CO)22(PPh3)4]2- and [Pd33Ni9(CO)41(PPh3)6]4- Containing Pseudo-Td ccp Pd16Ni4 and Pseudo-D3h hcp Pd33Ni9 Cores

[Pd16Ni4(CO)22(PPh3)4]2- (1) and [Pd33Ni9(CO)41(PPh3)6]4- (2) were obtained as the two major products from the reduction of PdCl2(PPh3)2 with [Ni6(CO)12]2-. Their crystal structures as [PPh4]+ salts were unambiguously determined from CCD X-ray crystallographic analyses; the resulting stoichiometries were ascertained from elemental analyses. Infrared, multinuclear 1H, 31P{1H} NMR, UV−vis, CV, variable-temperature magnetic susceptibility, and ESI FT/ICR mass spectrometric measurements were performed. The Pd16Ni4 core of 1 ideally conforms to a ccp ν3 tetrahedron of pseudo-Td (43m) symmetry. Its geometry normal to each tetrahedral Pd7Ni3 face (i.e., along each of the four 3-fold axes) may be viewed as a four-layer stacking of 20 metal atoms in a ccp [a(Ni1) b(Pd3) c(Pd6) a(Pd7Ni3)] sequence. A comparative analysis of the different ligand connectivities about the analogous metal-core geometries in 1 and the previously reported [Os20(CO)40]2- has stereochemical implications pertaining to the different possibl...
Reproducibility of renal perfusion MR imaging in native and transplanted kidneys using non-contrast arterial spin labeling.

Purpose: To examine both inter-visit and intra-visit reproducibility of a MR arterial spin labeling (ASL) perfusion technique in native and transplanted kidneys over a broad range of renal function. Materials and Methods: Renal perfusion exams were performed at 1.5 T in a total of 24 subjects: 10 with native and 14 with transplanted kidneys. Using a flow-sensitive alternating inversion recovery (FAIR) ASL scheme, 32 control/tag pairs were acquired and processed using a single-compartment model. Two FAIR-ASL MR exams were performed at least 24 h apart on all the subjects to assess inter-visit reproducibility. ASL perfusion measurements were also repeated back-to-back within one scanning session in 8 native subjects and in 12 transplant subjects to assess intra-visit reproducibility. Intra-class correlations (ICCs) and coefficients of variation (CVs) were calculated as metrics of reproducibility. Results: Intra-visit ICCs ranged from 0.96 to 0.98 while CVs ranged from 4.8 to 6.0%. Inter-visit measurements demonstrated slightly more variation with ICCs from 0.89 to 0.94 and CVs from 7.6 to 13.1%. Medullary perfusion demonstrated greater variability compared with cortical blood flow: intra-visit ICCs from 0.72 to 0.78 and CVs from 16.7 to 26.7%, inter-visit ICCs from 0.13 to 0.63 and CVs from 19.8 to 37%. Conclusion: This study indicates that a FAIR-ASL perfusion technique is reproducible in the cortex of native and transplanted kidneys over a broad range in renal function. In contrast, perfusion measurements in the medulla demonstrated moderate to poor reproducibility for intra-visit and inter-visit measures respectively. J. Magn. Reson. Imaging 2011;33:1414–1421. © 2011 Wiley-Liss, Inc.
Moral Hazard in Federal Farm Lending

In financial markets, moral hazard occurs at both the institutional and borrower level.' It is currently an issue relative to commercial banks and, particularly, savings and loans, where the insurance provided by FDIC and FSLIC has resulted in high-risk activities by institutions under financial stress (Barth, Bartholomew, and Labich). Moral hazard at the individual level results whenever the borrower's economic environment contains incentives which encourage actions that reduce the probability of repaying a loan.
Signals transduced through the CD4 molecule on T lymphocytes activate NF-kappa B.

We have demonstrated that native envelope glycoproteins of HIV-1, gp160 can induce activation of the transcription factor, NF-kappa B. The stimulatory effects of gp160 are mediated through the CD4 molecule, since pretreatment with soluble CD4 abrogates its activity. The gp160-induced NF-kappa B complex consists of p65, p50 and c-rel proteins. The stimulatory effect of gp160 on NF-kappa B activation is protein synthesis independent, is dependent upon protein tyrosine phosphorylation, and abrogated by inhibitors of protein kinase C. The gp160-mediated activation of NF-kappa B in CD4 positive T cells may be involved in biological effects, e.g., enhanced HIV replication, hypergammaglobulinemia, increased cytokine secretion, hypercellularity in bone marrow and apoptosis.
The Replication Initiation Protein Sld2 Regulates Helicase Assembly

Assembly of the Cdc45-Mcm2-7-GINS (CMG) replicative helicase complex must be regulated to ensure that DNA unwinding is coupled with DNA synthesis. Sld2 is required for the initiation of DNA replication in budding yeast. We identified a mutant of Sld2, Sld2-m1,4, that is specifically defective in Mcm2-7 binding. When this sld2-m1,4 mutant is expressed, cells exhibit severe inhibition of DNA replication. Furthermore, the CMG complex assembles prematurely in G1 in mutant cells, but not wild-type cells. These data suggest that Sld2 binding to Mcm2-7 is essential to block the inappropriate formation of a CMG helicase complex in G1. We also study a mutant of Sld2 that is defective in binding DNA, sld2-DNA, and find that sld2-DNA cells exhibit no GINS-Mcm2-7 interaction. These data suggest that Sld2 association with DNA is required for CMG assembly in S phase.
Moisture Effects Including Stiction Resulting From Adsorbed Water Films

Stiction resulting from moisture effects at small elastic contact spots has been identified and studied using bundles of fine, gold-plated copper fibers sliding on a gold-plated copper surface. The relevant measurements were made in the hoop apparatus which permits simultaneous monitoring of the momentary coefficient of friction and electrical contact resistance. Previous studies made with the hoop apparatus have shown that under the action of high local pressure, adsorbed moisture is expelled from between the contact spots leaving only one monomolecular layer of adsorbed water on each of the contacting surfaces. Additional details of the observations are varied and permit a refined analysis. Stiction results during periods of very slow motion or rest through local energy reduction at the spots as excess water is slowly drained in the course of molecular ordering of the two absorbed layers. Complex variations of kinetic friction with humidity and sliding speed are explained through the interplay of excess molecules between the contact spot surfaces, meniscus formation, fluid drag about the spots, and shear thinning in that flow.
Effects of heat release and flame distortion in the transverse fuel jet

An analytical model for a chemically reacting transverse jet is applied to the situation in which effects of compressibility and heat release are important, as in turbulent diffusion flames deflected by an air stream. This model examines the dynamics of the vortex pair structure observed to dominate the flowfield, a structure which causes the combustion process to proceed in a bifurcated flame. Heat release is represented through local source terms coincident with reacted cores of combustion products, and vorticity is represented in terms of a nearfield component of vortex strength (arising from the crossflow) and a farfield component of vortex strength (arising from the fuel jet impulse). Results indicate that the heat release in the reaction acts to reduce the degree of crossflow penetration by the flame, in addition to reducing the strength of the vortices and the magnitude of the vortex spacing. Buoyancy is found to play a lesser role in flame development than that of the jet momentum for the jet-to-crossflow velocity ratios considered. Based on comparisons with experimental results, the amount of entrained oxidizer required for the reaction is found to be lower than that required in an isothermal reaction.
Short‐lived protease–serpin complexes: Partial disruption of the rat trypsin active site

Serpins inhibit serine proteases by mechanically disrupting the protease active site. The protease first reacts with the serpin's reactive center loop (RCL) to form an acylenzyme. Then the RCL inserts into a β-sheet in the body of the serpin, translocating the attached protease ∼70 A and deforming the protease active site, thereby trapping the acylenzyme. Loop insertion (∼1 s−1) is an order of magnitude slower than hydrolysis of a typical substrate acylenzyme (∼50 s−1), indicating that the protease is inhibited during translocation. We have previously trapped a partially translocated covalent complex of rat trypsin and α1-proteinase inhibitor (EpartI*) resulting from attractive interactions between cationic dyes and anionic rat trypsin. Here, using single pair Forster resonance energy transfer, we demonstrate that EpartI* is a metastable complex that can dissociate to free protease and cleaved serpin (I*) as well as convert to the canonical fully translocated complex EfullI*. The partitioning between these two pathways is pH dependent, with conversion favored at low pH and dissociation favored at high pH. The short lifetime of EpartI* (∼3 h at pH 7.4) and the pH dependence of EpartI* dissociation suggest that, unlike in EfullI*, the catalytic triad is intact in EpartI*. These results also demonstrate that interactions between target proteases and the body of the serpin can hinder protease translocation leading to short-lived covalent complexes.
Metabolism of bis(2-methoxyethyl) ether in the adult male rat: evaluation of the principal metabolite as a testicular toxicant.

The metabolism of the reproductive toxicant bis(2-methoxyethyl) ether was studied in male Sprague-Dawley rats, and the principal metabolite (2-methoxyethoxy)acetic acid and its metabolic precursor 2-(2-methoxyethoxy)ethanol were evaluated separately as testicular toxicants. For the metabolism study, rats were given single po doses of (1,2-ethylene-/sup 14/C)bis(2-methoxyethyl) ether at 5.1 or 0.051 mmol/kg body wt. Within 96 hr, approximately 86 to 90% of the radioactivity was excreted in the urine. Urinary metabolites were separated by high-performance liquid chromatography and isolated for characterization by gas chromatography-mass spectrometry. The principal urinary metabolite, accounting for 67.9 +/- 3.3% of the administered high dose and 70.3 +/- 1.3% of the low dose, was identified as (2-methoxyethoxy)acetic acid. A second metabolite, representing 6.2 +/- 0.8% of the high dose and 5.8 +/- 0.8% of the low dose, was identified as methoxyacetic acid, a previously recognized testicular toxicant. In the toxicity study, (2-methoxyethoxy)acetic acid and 2-(2-methoxyethoxy)ethanol were administered to rats at 5.1 mmol/kg body wt by gavage as single daily doses for as many as 20 consecutive days. The testes of rats killed 24 hr after the administration of even numbered doses showed no gross or microscopic abnormalities. These results are in contrast to the previously reported testicular atrophymore » evoked after as few as 8 daily doses of the parent compound, bis(2-methoxyethyl) ether, tested under the same experimental conditions. Thus, the testicular toxicity reported for bis(2-methoxyethyl) ether could be explained by the presence of a minor metabolite, methoxyacetic acid.« less
Intermolecular Hydrogen Transfer in Nitrile Hydrogenation over Transition Metal Catalysts

In the co-hydrogenation of deutero-acetonitrile (CD3CN) and butyronitrile (C3H7CN) over SiO2-supported Pt and Ru catalysts, H atoms are preferentially added to the C atom of the CN groups, but D atoms are added to the N atom. This shows that intermolecular hydrogen transfer from acetonitrile to the nitrogen atom of CN groups takes place. The methyl group of acetonitrile is a more effective donor of hydrons than the propyl group in butyronitrile. Hydrogen transfer is most efficient for breaking the strong N=M chemisorption bond, releasing an amine molecule to the gas phase. The cis-insertion of an alkyl group into an N=M bond leads to a secondary amine.
Genetic correlations between reading performance and IQ in the Colorado Adoption Project

Abstract A multivariate conditional path model was fitted to general cognitive ability and reading performance data obtained from members of 119 adoptive families and 120 nonadoptive families. Measures include Wechsler_R Full-Scale, Verbal, and Performance IQ scores and Peabody Individual Achievement Test (PIAT) Reading Recognition scores for both parents and 7-year-old offspring. Results of model-fitting analyses provide evidence for moderate phenotypic correlations between the PIAT and IQ measures, substantial heritability for IQ and Reading Recognition, and large genetic correlations among the traits, particularly with respect to Verbal IQ and Reading Recognition. Thus, IQ-academic achievement relationships may be largely due to genetic influences.
Improvements in horizontality performance as a function of type of training

90 undergraduates with low spatial perceptual ability were assigned to one of three groups of control, learner-guided instructions, and tutor-guided instructions. The groups differed in amount and ...
Facilitating protein crystal cryoprotection in thick-walled plastic capillaries by high-pressure cryocooling

Many steps in the X-ray crystallographic solution of protein structures have been automated. However, the harvesting and cryocooling of crystals still rely primarily on manual handling, frequently with consequent mechanical damage. An attractive alternative is to grow crystals directly inside robust plastic capillaries that may be cryocooled and mounted on the beamline goniometer. In this case, it is still desirable to devise a way to cryoprotect the crystals, which is difficult owing to the poor thermal conductivity of thick plastic capillary walls and the large thermal mass of the capillary and internal mother liquor. A method is described to circumvent these difficulties. It is shown that high-pressure cryocooling substantially reduced the minimal concentrations of cryoprotectants required to cryocool water inside capillaries without formation of ice crystals. The minimal concentrations of PEG 200, PEG 400 and glycerol necessary for complete vitrification under pressure cryocooling were determined.
Ever-increasing role of mask technology in deep submicron lithography

The role of mask technology is going through a major change as silicon technology moves into the sub 0.5 micrometers regime and optical lithography continues to be the predominant approach. Several possible options are being considered such as DUV, PSM, oblique illumination, optical proximity correction, or some combination of these methods. In addition to tighter mask requirements, a significant challenge by itself, there are unique mask technology development issues to support each lithography option. Practically speaking, masks for the sub 0.50 micrometers lithography regime are becoming less commodity products and more an integral part of the front end silicon technology development. Mask technology is foreseen to have an increasingly important role in the 0.35 micrometers and 0.25 micrometers technology generations and beyond. In this paper, we will first describe the role of mask technology in the sub 0.5 micrometers lithography regime by examining the technology roadmap, specification requirements, and the mask impact on lithographic performance. Secondly, we will describe the major technical challenges facing mask technology and fabrication. Examples will be given. Lastly, we will suggest how to meet these challenges to satisfy the needs of silicon technology.
A quantitative analysis on the thermal properties of phosphate buffered saline with glycerol at subzero temperatures

Abstract This study reports the first comprehensive data on the effects of glycerol, a widely used cryoprotective agent (CPA), on the thermal properties of Phosphate Buffered Saline at subzero and cryogenic (⩽−40 °C) temperatures. A Differential Scanning Calorimeter was used to measure specific and latent heats. Thermal conductivity was determined using a thermistor probe technique. Results differed significantly from known water (ice) or glycerol values, and a simple weight averaging method between water and glycerol was found to over-predict thermal conductivity below −100 °C due to glass formation. This indicates the need for these newly measured thermal properties of CPA solutions particularly below −100 °C.
Plug-in hybrid conversion: As a capstone project and research testbed

An important part of the curriculum in the electrical engineering program at Western Kentucky University (WKU) is the two semester capstone project sequence. During the 2010–2011 academic year, two seniors completed a plug-in hybrid (PHEV) conversion project. The students began by completing the design and system engineering tasks. Secondly, the students designed a set of experiments that evaluated the vehicle's performance, focusing on the vehicles fuel economy of a stock 2007 Toyota Prius. Following the completion of these experiments, the students converted the Prius to a PHEV using a purchased kit. In the stock system, the battery can only be charged when the vehicle is in operation. The PHEV kit adds battery capacity to increase the electrical power capacity and thus decreasing the load for the internal combustion engine. Plugging in the PHEV to a standard utility AC outlet will allow the kit batteries to charge to full capacity for later use. Reported benefits of completing such a project will increase the fuel economy to over 100 miles per gallon. The project ended with re-evaluation of the PHEV system as compared to the stock system. The platform will be used for future projects at WKU and its joint partner, the University of Louisville. This research testbed will be used for numerous undergraduate and graduate research projects.
A note on a flat toroidal crack in an elastic isotropic body

Abstract Betti's reciprocal theorem is used to derive integral equations for problems involving an axisymmetric flat toroidal crack. Numerical estimates for stress intensity factors in fracture mechanics are improved by use of the M-integral conservation law. Stress intensity factors for torsion and uniform tension are given.
A Mycobacterium tuberculosis Sigma Factor Network Responds to Cell-Envelope Damage by the Promising Anti-Mycobacterial Thioridazine

Background Novel therapeutics are urgently needed to control tuberculosis (TB). Thioridazine (THZ) is a candidate for the therapy of multidrug and extensively drug-resistant TB. Methodology/Principal Findings We studied the impact of THZ on Mycobacterium tuberculosis (Mtb) by analyzing gene expression profiles after treatment at the minimal inhibitory (1x MIC) or highly inhibitory (4x MIC) concentrations between 1–6 hours. THZ modulated the expression of genes encoding membrane proteins, efflux pumps, oxido-reductases and enzymes involved in fatty acid metabolism and aerobic respiration. The Rv3160c-Rv3161c operon, a multi-drug transporter and the Rv3614c/3615c/3616c regulon, were highly induced in response to THZ. A significantly high number of Mtb genes co-expressed with σB (the σB regulon) was turned on by THZ treatment. σB has recently been shown to protect Mtb from envelope-damage. We hypothesized that THZ damages the Mtb cell-envelope, turning on the expression of the σB regulon. Consistent with this hypothesis, we present electron-microscopy data which shows that THZ modulates cell-envelope integrity. Moreover, the Mtb mutants in σH and σE, two alternate stress response sigma factors that induce the expression of σB, exhibited higher sensitivity to THZ, indicating that the presence and expression of σB allows Mtb to resist the impact of THZ. Conditional induction of σB levels increased the survival of Mtb in the presence of THZ. Conclusions/Significance THZ targets different pathways and can thus be used as a multi-target inhibitor itself as well as provide strategies for multi-target drug development for combination chemotherapy. Our results show that the Mtb sigma factor network comprising of σH, σE and σB plays a crucial role in protecting the pathogen against cell-envelope damage.
Involvement of the Brewer–Dobson circulation in changes of stratospheric temperature and ozone

Abstract Wintertime temperature and ozone in the Northern Hemisphere stratosphere vary significantly between years. Largely random, those variations are marked by compensating changes at high and low latitudes, a feature that reflects the residual mean circulation of the stratosphere. Interannual changes of temperature and ozone each track anomalous forcing of the residual circulation. This relationship is shown to be obeyed even over the Arctic, where transport is augmented by heterogeneous chemical processes that destroy ozone. Chlorine activation obeys a similar relationship, reflecting feedback between changes of the residual circulation and anomalous photochemistry. Changes of stratospheric dynamical and chemical structure are found be accompanied by coherent changes in the troposphere. Vertically extensive, they reflect inter-dependent changes in the stratosphere and troposphere, which are coupled by the residual circulation through transfers of mass. The corresponding structure is shown to share major features with empirical modes of interannual variability associated with the AO and its cousin, the NAO. A 3D model of dynamics and photochemistry is used to simulate anomalous temperature and ozone. Driven by anomalous wave activity representative of that observed, the model reproduces the salient structure of observed interannual changes. Anomalous temperature and ozone follow in the integrations from anomalous downwelling, which, under disturbed conditions, renders temperature over the Arctic anomalously warm, and from anomalous poleward transport, which renders Arctic ozone anomalously rich. Accompanying random interannual changes in the observed record was a systematic decline of Northern Hemisphere temperature and ozone during the 1980s and early 1990s. Comprising decadal trends, these systematic changes are shown to have the same essential structure and seasonality as random changes, which, in turn, vary coherently with anomalous forcing of the residual circulation. Implications of the findings to the interpretation of stratospheric trends are discussed in light of anomalous residual motion, photochemistry, and feedback between them.
Dichloroacetic acid and trichloroacetic acid-induced DNA strand breaks are independent of peroxisome proliferation

Abstract This study examined whether the induction of single strand breaks in hepatic DNA by dichloroacetic acid (DCA) and trichloroacetic acid (TCA) depends upon peroxisome proliferation. Male B6C3F1 mice were given a single oral dose of either DCA or TCA. At varying times, between 1 and 24 h after administration of the compounds, breaks in DNA were measured using an alkaline unwinding assay. Peroxisome proliferation was monitored at the same time intervals in a parallel experiment by measuring peroxisomal B-oxidation of [ 14 C]palmitoyl-CoA in liver homogenates. Both DCA and TCA significantly increased breaks in DNA at 1, 2, and 4 h post-treatment, with a return to control levels after 8 h. No evidence for an increase in peroxisomal β-oxidation was produced by either chemical up to 24 h after administration. In a separate experiment, mice were treated with DCA or TCA for 10 days and their livers examined for evidence of peroxisome proliferation. An increase in liver weight was observed, particularly with DCA. Both TCA and DCA increased peroxisomal β-oxidation in liver homogenates, with TCA-treated animals showing more activity than those treated with DCA. Electron microscopy revealed that the number of peroxisomes were approximately the same in DCA- and TCA-treated animals. However, peroxisomes induced by DCA treatment frequently lacked nucleoid cores. These data indicate that peroxisomes induced by these compounds differ in their concentration of peroxisomal enzymes. Except for a slight hypertrophy, repeated doses of TCA do not produce significant degenerative changes in the liver of mice. Repeated doses of DCA produce multifocal, subcapsular necrotic regions, and a marked hypertrophic response in the liver. Mice treated with TCA for 10 days and sacrificed 24 h after the last dose did not display increased strand breaks in hepatic DNA. This indicates that peroxisomal proliferation does not contribute to the induction of DNA strand breaks.
Association between pre-pregnancy obesity and the risk of cesarean delivery

Objective To explore the relationship between prepregnancy obesity and the risk for cesarean delivery. Methods The population studied included 20,130 women with live births after 20 weeks' gestation in central New York state between June 1, 1994, and May 31, 1995. Women who were obese before pregnancy were compared with nonobese women with regard to mode of delivery. Obesity was defined as body mass index (BMI) greater than 29. Separate analyses were conducted on the entire sample and on a subset of women with singleton pregnancies and no prior cesarean deliveries, as an estimate of the risk of primary cesarean delivery in obese women. Statistical analyses included χ 2 test, crude odds ratio (OR) with 95% confidence interval (CI), and adjusted OR with 95% CI, using logistic regression to control for confounding variables. Results The adjusted OR was 1.64 (95% CI 1.46, 1.83) for obese women with singleton pregnancies and no prior cesarean deliveries to undergo cesarean delivery. The adjusted OR was 1.66 (95% CI 1.51, 1.82) for obese women in the entire sample to undergo cesarean delivery. In addition, increasing BMI was associated with increased risk for cesarean delivery. Conclusion Compared with nonobese women, women who are obese before pregnancy are at increased risk for cesarean delivery. Preconceptional counseling regarding dietary and life-style modifications may alter this pattern.
Pediculosis and resistance: the perennial problem.

Does resistance really exist among human ectoparasites? Do treatments for pediculosis become less effective over the years? Do the mites or lice actually develop resistance to the insecticides created by humans to do away with these parasitic arthropods? For the past three decades, we have carefully followed the literature and listened to discussions about resistance and human lice.1,2 Periodically, the question of resistance surfaces, but it is never satisfactorily answered nor is it sufficiently dismissed.3,4,5,6,7
Alain badiou, the hebb-event, and materialism split from within

Alain Badiou presents his philosophy as thoroughly and consistently materialist in ways that follow in the footsteps of thinkers ranging from Lucretius to Mao. However, considering Badiou's decisio...
Inhibition of osteogenic differentiation of human mesenchymal stem cells

Mesenchymal stem cells (hMSCs) have been shown to differentiate into osteoblasts that, in turn, are capable of forming tissues analogous to bone. The present study was designed to investigate the inhibition of osteogenesis by hMSCs. Bone marrow-derived hMSCs were treated with transforming growth factor beta-3 (TGFbeta3) at various doses during or after their differentiation into osteogenic cells. TGFbeta3 was encapsulated in poly(DL-lactic-co-glycolic acid) (PLGA) microspheres and released via controlled delivery in the osteogenic culture of hMSCs and hMSC-derived osteoblasts for up to 28 days. Controlled release of TGFbeta3 inhibited the osteogenic differentiation of hMSCs, as evidenced by significantly reduced alkaline phosphatase activity and staining, as well as decreased mineral deposition. After hMSCs had been differentiated into osteoblasts, controlled release of TGFbeta3 further inhibited not only alkaline phosphatase and mineral deposition but also osteocalcin expression. These findings demonstrate the potential for sustained modulation of the behavior of stem cells and/or stem cell-derived lineage-specific cells via controlled release of growth factor(s). The attenuation of osteogenic differentiation of MSCs may facilitate understanding not only the regulation and patterning of osteogenesis in development but also several pathological models such as osteopetrosis, craniosynostosis, and heart valve calcification.
Manipulator motion planning in the presence of obstacles and dynamic constraints

Motion planning algorithms are traditionally restricted to finding spatial or "physical" paths only, while manipulator dynamics is ignored. The attendant low-level problem of timing and velocity along the path is left to the trajectory planner. In this study, these two aspects have been combined. The overall problem has been cast as an optimal control problem. The obstacle avoidance conditions have been for mulated as state-variable inequality constraints. These con straints are shown to be continuously differentiable in our formulation. The continuous-time problem is converted to a discrete-time problem to permit the use of nonlinear pro gramming algorithms for the heavily constrained problem. Computational issues such as discretization effects and al gorithmic efficiency have been addressed. Simulations are performed for the proposed method.
Hepatitis B-associated vasculitis in an infant

from the respiratory tract of heal thy infants. Mucosal damage or disrupt ion of nasocil iary defense mechanisms, as may follow or accompany viral infections of the respiratory tract, p robab ly must occur for the pneumococcus to become invasive. Spontaneous pneumococca l bac te remia in identical twins appears to represent an in f requent occurrence. Experience to date suggests that secondary cases, as may occur with other respiratory pathogens, are not c o m m o n within families or within day care centers in otherwise heal thy infants. The report of Singer and Berger should st imulate fur ther observat ions to define the relative risks to infants o f close exposure to ano ther child with pneumococcal infection. D.S.S.
Differential Scanning Calorimetry (DSC) as a Tool for Probing the Reactivity of Polyynes Relevant to Hexadehydro-Diels–Alder (HDDA) Cascades

The differential scanning calorimetry (DSC) behavior of a number of alkyne-rich compounds is described. The DSC trace for each compound exhibits an exothermic event at a characteristic onset temperature. For the tri- and tetraynes whose [4 + 2] HDDA reactivity in solution has been determined, these onset temperatures show a strong correlation with the cyclization activation energy. The studies reported here exemplify how the data available through this operationally simple analytical technique can give valuable insights into the thermal behavior of small molecules.
Thymocyte Glucocorticoid Resistance Alters Positive Selection and Inhibits Autoimmunity and Lymphoproliferative Disease in MRL-lpr/lprMice

Thymus-derived glucocorticoids antagonize T cell receptor (TCR)-induced thymocyte apoptosis, allowing the survival (positive selection) of cells bearing TCRs that recognize self antigens with low-to-moderate avidity. Here we demonstrate that expression of an antisense glucocorticoid receptor transgene in thymocytes of spontaneously autoimmune MRL-lpr/lpr mice causes the loss of specific TCR Vbeta-bearing T cells that are normally positively selected in this strain. These transgenic mice had lower autoantibody production and milder symptoms of autoimmune disease than MRL-lpr/lpr controls and had markedly reduced accumulation of the TCR+Thy-1+CD4-CD8-B220+ T cells that are the hallmark of the lpr mutation. Thus, decreased glucocorticoid signaling in thymocytes alters the T cell repertoire and greatly diminishes autoimmunity in MRL-lpr/lpr autoimmune mice.