cssi/SciSciGPT-SciSciNet huggingface dataset:
Refinement of Tools for Targeted Gene Expression in Drosophila

A wide variety of biological experiments rely on the ability to express an exogenous gene in a transgenic animal at a defined level and in a spatially and temporally controlled pattern. We describe major improvements of the methods available for achieving this objective in Drosophila melanogaster. We have systematically varied core promoters, UTRs, operator sequences, and transcriptional activating domains used to direct gene expression with the GAL4, LexA, and Split GAL4 transcription factors and the GAL80 transcriptional repressor. The use of site-specific integration allowed us to make quantitative comparisons between different constructs inserted at the same genomic location. We also characterized a set of PhiC31 integration sites for their ability to support transgene expression of both drivers and responders in the nervous system. The increased strength and reliability of these optimized reagents overcome many of the previous limitations of these methods and will facilitate genetic manipulations of greater complexity and sophistication.
The Myth of the Outside Strategy: Mass Media News Coverage of Interest Groups

The ability of interest groups to make their views heard is a central tenet of pluralist views of American politics. Despite consensus about the importance of news coverage to interest groups pursuing “outside strategies,” however, little work has examined the ability of ordinary groups to make news. I argue that the best predictor of an interest group's ability to use the mass media as a political tool is the level of organizational resources (money, members, staff, etc.) it enjoys. Through an investigation of the quantity and quality of news coverage received by a sample of 244 interest groups, I show that uneven distribution of resources leads to heavy concentration of news on the largest and wealthiest groups as well as to important differences in how the media portray group actions. I conclude that the outside strategy is more a romantic myth than an accurate portrayal of the American system.
Virtual simulation and video microscopy for fused deposition methods

Abstract Fused deposition is a layered manufacturing (LM) technology, which is being investigated for fabrication of functional parts. Defects and voids in the build process affect the quality and level of accuracy of components. These occur due to several factors, such as the toolpath contours in a layer, material(s) deposited, and the environmental conditions. For a functional part to be constructed, a perfect green part is critical. To fabricate the highest quality of multi-material parts, a virtual simulation system and experimental real time video microscopy have been developed. In this virtual simulation, we can check or test a variety of the LM process parameters, and make the best selection of toolpath and other parameters. To further understand the LM process and make the simulation program realistic, a visualization of the deposition is necessary. The hardware was constructed and mounted on the existing deposition system (liquefier). Real time deposition of layered manufacturing was recorded. Three materials being investigated were: PZT, silicon nitride, and wax. Using the data from these experiments, virtual simulation was enhanced. The results show that we can make selections of part build parameters and make adjustments to the fabricating environment to obtain high quality parts.
DETERMINATION OF VITAMIN A IN FOOD COMPOSITES BY HIGH SPEED LIQUID CHROMATOGRAPHY

A method is presented for measurement of Vitamin A in food composites by high speed liquid chromatography. Saponification of the sample is necessary, but no purification or separation is required. Neither phytofluene nor other unsaponifiable material in the sample cause interference. Accurate measurement is possible in samples which contain 0.5–4 μg/ml, and recovery of Vitamin A standard in the presence of high levels of carotenoids is 103.5%.
A novel, computationally efficient, approach for Hamilton's law of varying action

Abstract A new technique providing improved computational efficiency in the implementation of Hamilton's Law of Varying Action is presented. Similar to previous methods, this efficient method allows one to construct an approximate solution for an initial value problem in general dynamics without reference to the theory of differential equations associated therewith. Additionally, in the present formulation, the approximating polynomials need not satisfy the initial conditions beforehand. Using orthogonal polynomials, a set of simultaneous equations is obtained that has fewer non-zero entries compared to formulations presented in existing literature. Such a sparse system of equations may result in substantial computational economy. A harmonic oscillator and a two-degrees-of-freedom system with and without damping are studied. The numerical results using present formulations compare well with alternative solutions.
Kinins and Angiotensins Angiotensin I Converting Enzyme (Kininase II) in Edothelial Cells Cultured from Human Pulmonary Arteries and Veins

Human pulmonary endothelial cells were used to study the metabolism of angiotensin I and bradykinin by angiotensin I converting enzyme (kininase II; ACE). The endothelial cells cultured from pulmonary arteries and veins differed with respect to their enzyme activity and their surface structure, as viewed with scanning electron microscopy. Cells from adult pulmonary arteries had greater ACE activity than cells from either adult pulmonary veins or fetal pulmonary arteries. In addition, cells from adult pulmonary arteries exhibited more prominent surface projections than cells from veins or fetal pulmonary arteries. A brief exposure to trypsin decreased the ACE activity in cells from arteries but not in cells from veins. Possibly the differences in ACE activity between these cells are related to their surface structures.
A flow-injection mass spectrometry fingerprinting method for authentication and quality assessment of Scutellaria lateriflora-based dietary supplements

Scutellaria lateriflora, commonly known as skullcap, is used as an ingredient in numerous herbal products. However, it has been occasionally adulterated/contaminated with Teucrium canadense and/or Teucrium chamaedrys, commonly known as germander, due to the morphological similarities between the two genera. The latter contains hepatotoxic diterpenes. Despite the potential hepatotoxicity introduced by germander contamination, analytical methodologies for the authentication and quality assessment of S. lateriflora-based dietary supplements have not been reported. In this study, a flow-injection/mass spectrometry fingerprinting method in combination with principal component analysis was used to survey S. lateriflora-based dietary supplements sold in the USA.
Selective therapeutic hypothermia: A review of invasive and noninvasive techniques

OBJECTIVE: Therapeutic hypothermia is a promising treatment to prevent secondary neurologic injury. Clinical utility is limited by systemic complications of global hypothermia. Selective brain cooling remains a largely uninvestigated application. We review techniques of inducing selective brain cooling. METHOD: Literature review. RESULTS: Strategies of inducing selective brain cooling were divided between non-invasive and invasive techniques. Non-invasive techniques were surface cooling and cooling via the upper airway. Invasive cooling methods include transvascular and compartmental (epidural, subdural, subarachnoid and intraventricular) cooling methods to remove heat from the brain. CONCLUSION: Selective brain cooling may offer the best strategy for achieving hypothermic neuroprotection. Non-invasive strategies have proven disappointing in human trials. There is a paucity of human experiments using invasive methods of selective brain cooling. Further application of invasive cooling strategies is needed.
Molecular docking/dynamics studies of Aurora A kinase inhibitors

Abstract The binding modes of a known 1,4,5,6-tetrahydropyrrolo[3,4-c]pyrazole, quinazoline, pyrimidine and indolinone series of Aurora A kinase inhibitors have been studied using molecular docking and molecular dynamics (MD) simulations. Crystallographic bound compound 8 was precisely predicted by our docking procedure as evident from 0.43 A root mean square (rms) deviations. In addition compound 25 (AZ_68) has been successfully cross-docked within the Aurora A kinase active site, which was pre-organized for inhibitor 8. We found four key sites (A: solvent-exposed front pocket, B: hinge region, C: selectivity pocket and D: solvent-exposed phosphate binding region) of the Aurora A kinase contributing towards the binding of these compounds. We suggest that the small hydrophobic substituents at C-6 position of pyrrolopyrazole nucleus (in compounds 1–8); C-6 and C-7 positions of the quinazoline moiety (in compounds 9–23); C-2 position of the quinazoline and C-4 position of the pyrimidine (in compound 25) could be more effective and selective through increased hydrophobic contacts and selectivity pocket interactions with these modifications of Aurora A kinase inhibitors. Five representative complexes were subjected to 1000 ps of MD simulation to determine the stability of the predicted binding conformations. The low value of the root mean square deviations (ranging from 0.725 to 1.820 A) between the starting complex structure and the energy minimized final average complex structure suggests that the Glide Extra Precision (XP) derived docked complexes are in a state of near equilibrium. The structure-based drug design strategy described in this study will be highly useful for the development of new inhibitors with high potency and selectivity.
High density plasma diagnostics utilizing a neon-like yttrium x-ray laser

Abstract A neon-like yttrium laboratory x-ray laser (XRL) at 155 A has been used to perform radiography, Moire deflectometry and interferometry of plasmas created in various laser-initiated experiments. A system consisting of the XRL, multilayer mirrors, and multilayer beam splitters was assembled to obtain high resolution images of the plasmas. Work is continuing to improve the XRL—higher brightness, shorter pulse length, and enhanced coherence—through a program of simulations and experiments.
Neuronal injury in the motor cortex after chronic stroke and lower limb motor impairment: a voxel-based lesion symptom mapping study

Many studies have examined motor impairments using voxel-based lesion symptom mapping, but few are reported regarding the corresponding relationship between cerebral cortex injury and lower limb motor impairment analyzed using this technique. This study correlated neuronal injury in the cerebral cortex of 16 patients with chronic stroke based on a voxel-based lesion symptom mapping analysis. Neuronal injury in the corona radiata, caudate nucleus and putamen of patients with chronic stroke could predict walking speed. The behavioral measure scores were consistent with motor deficits expected after damage to the cortical motor system due to stroke. These findings suggest that voxel-based lesion symptom mapping may provide a more accurate prognosis of motor recovery from chronic stroke according to neuronal injury in cerebral motor cortex.
Factorial Study of Rain Garden Design for Nitrogen Removal

AbstractNitrate (NO3−-N) removal studies in rain gardens show great variability in removal rates, and in some cases NO3−-N was exported. A three-way factorial design (2×2×4) was devised for eight o...
Controlled release of drugs from hydrogel matrices

A series of polymers with wide ranges of water absorptivity were prepared and utilized as matrices for the controlled release of drugs. The drugs were introduced into the matrices by use of an appropriate organic solvent. Release rates of erythromycin and erythromycin estolate from hydrogel were analyzed kinetically and found to conform to Higuchi's equation, that is, Mt = A(2DtCsC0)1/2, where Mt is the accumulated amount of released drug at time t, A is the surface area, D is the diffusion coefficient, Cs is the solubility of drug in the hydrogel matrix, and Co is the initial drug content of the preparation in the swollen state. The relationship between the water content of hydrogel and the diffusion coefficient of erythromycin in hydrogel is expressed by the equation D = 3.03 × 10−10W3.03 (cm2/sec), where W is the water content (%). The release rate of drug can be controlled quantitatively by adjustment of the water content of the hydrogel matrix. A guide to the design for the preparation is suggested.
The autologous mixed lymphocyte reaction in primary biliary cirrhosis: analysis of activation and blastogenesis of autoreactive T lymphocytes.

Blastogenesis of autoreactive T lymphocytes in the autologous mixed lymphocyte reaction has been shown to be decreased in patients with primary biliary cirrhosis, but the mechanisms underlying this abnormality are not known. To investigate further the abnormal autologous mixed lymphocyte reaction in primary biliary cirrhosis, we measured the activation of autoreactive helper/inducer and suppressor/cytotoxic T lymphocytes concurrently with blastogenesis in 35 patients with primary biliary cirrhosis and 18 healthy controls. Blastogenesis was diminished in autologous mixed lymphocyte reaction cultures from primary biliary cirrhosis patients compared to the control subjects (25,273 ± 20,259 dpm vs. 36,004 ± 14,951 dpm, p < 0.02), but cultures from patients with primary biliary cirrhosis contained significantly increased percentages of activated helper/inducer and suppressor/cytotoxic T lymphocytes: 20.6 ± 7.9 vs. 15.5 ± 5.3%, p < 0.008, and 9.8 ± 7.8 vs. 5.4 ± 3.0%, p < 0.02, respectively. These findings were not related to the histologic stage of liver disease or to the serum bilirubin concentration and were not associated with abnormalities of lymphocyte subsets in fresh peripheral blood specimens. We conclude that the percentage of autoreactive T lymphocytes in autologous mixed lymphocyte reaction cultures from peripheral blood is increased in patients with primary biliary cirrhosis and diminished blastogenesis in autologous mixed lymphocyte reaction cultures is not due to the loss of autoreactive T lymphocytes from peripheral blood. Diminished blastogenesis reflects a diminished proliferative response of activated, autoreactive T lymphocytes in primary biliary cirrhosis. Possible mechanisms that may account for the paradoxical findings of decreased blastogenesis and increased activation of autoreactive T lymphocytes in primary biliary cirrhosis are discussed.
One-way wicking in open micro-channels controlled by channel topography.

One-way wicking (microfluidic diode) behaviors of a range of IPA–water mixtures on internally structured PDMS-based open micro-channels were experimentally demonstrated and quantified. The open microfluidic channels, each internally decorated with an array of angled fin-like-structure pairs, were fabricated using a combined photolithography and soft molding procedure. Propagations of wetting fluids were found to be much more impeded on the fin-tilting direction, or the hard wicking direction, comparing to the opposite direction, or the easy wicking direction. This asymmetric wicking behaviors were attributed to the structure-induced direction-dependent Laplace pressure. Two key parameters – the contact angle of the wicking fluid and the tilting angle of the fin-like structures – were studied. The effects of preferential evaporation and wetting instability were also investigated. The findings of this study are expected to provide a better understanding of how fluids interact with micro-scaled structures and to offer a new way of manipulating fluids at the micron and nanometer scales.
Long-term follow-up of patients on drug holiday from bisphosphonates: real-world setting

Objective: Atypical femoral fractures and osteoporosis of the jaw have been associated with prolonged bisphosphonate therapy for postmenopausal osteoporosis. American Association of Clinical Endocrinologists guidelines suggest a drug holiday after 4 to 5 years of bisphosphonate treatment for moderate-risk patients and 10 years for high-risk patients, but there are minimal data on safe holiday durations. A recent U. S. Food and Drug Administration perspective suggests a treatment duration of 3 to 5 years. Our aim was to describe a group of patients on drug holiday and identify fracture risk.Methods: A retrospective chart review was conducted of 209 patients who started a bisphosphonate drug holiday between 2005 and 2010. Collected data included bone mineral density (BMD), markers of bone turnover, vitamin D status, and clinical and radiographic reports of fractures.Results: Eleven of 209 patients (5.2%) developed a fracture. Their mean age was 69.36 years (±15.58), and the mean lumbar spine and femoral nec...
Impact of Francisella tularensis pilin homologs on pilus formation and virulence.

Francisella tularensis is a facultative intracellular bacterium and the causative agent of tularemia. Virulence factors for this bacterium, particularly those that facilitate host cell interaction, remain largely uncharacterized. However, genes homologous to those involved in type IV pilus structure and assembly, including six genes encoding putative major pilin subunit proteins, are present in the genome of the highly virulent Schu S4 strain. To analyze the roles of three putative pilin genes in pili structure and function we constructed individual pilE4, pilE5, and pilE6 deletion mutants in both the F. tularensis tularensis strain Schu S4 and the Live Vaccine Strain (LVS), an attenuated derivative strain of F. tularensis holarctica. Transmission electron microscopy (TEM) of Schu S4 and LVS wild-type and deletion strains confirmed that pilE4 was essential for the expression of type IV pilus-like fibers by both subspecies. By the same method, pilE5 and pilE6 were dispensable for pilus production. In vitro adherence assays with J774A.1 cells revealed that LVS pilE4, pilE5, and pilE6 deletion mutants displayed increased attachment compared to wild-type LVS. However, in the Schu S4 background, similar deletion mutants displayed adherence levels similar to wild-type. In vivo, LVS pilE5 and pilE6 deletion mutants were significantly attenuated compared to wild-type LVS by intradermal and subcutaneous murine infection, while no Schu S4 deletion mutant was significantly attenuated compared to wild-type Schu S4. While pilE4 was essential for fiber expression on both Schu S4 and LVS, neither its protein product nor the assembled fibers contributed significantly to virulence in mice. Absent a role in pilus formation, we speculate PilE5 and PilE6 are pseudopilin homologs that comprise, or are associated with, a novel type II-related secretion system in Schu S4 and LVS.
X-Ray Isochromats of Molybdenum

Variation of intensity of x-radiation from molybdenum with voltage, for wave-lengths 0.246 to 123 A.---The ordinary x-ray spectrum, intensity as function of wave-length, cannot be interpreted in terms of energy because of the unknown variation of several factors with frequency. In the case of isochromats, intensity per cathode ray for a given wave-length as function of voltage, the problem is simpler. Measurements up to twice the quantum voltage were made in each case except where that would exceed 70 kv. and both voltage and current were determined to 1/10 per cent. The angle between the x-rays and the beam of cathode rays was about 110\ifmmode^\circ\else\textdegree\fi{}. To avoid correcting for the variation of size of focal spot, a single narrow slit was used near the crystal. The correction for crystal scattering was determined from measurements on each side of the reflected beam; it was less than one per cent. except near the quantum voltage. The correction for target absorption was taken to be $\ensuremath{\mu}\overline{x}$ where $\overline{x}$, the mean depth of penetration, was computed from the data reported in the preceding article. After making these corrections, the isochromats were found to be straight lines except for some downward concavity near the feet. The results for 0.41 to 1.23 \AA{} agree within 1 or 2 per cent with an empirical equation for isochromats which is given. The values for the shorter wave-lengths are too unreliable at high voltages to serve as tests. From the above equation, an expression for the radiation from $a$ vanishingly thin target is derived which involves $b$ the coefficient of the Thomson-Whilddington law. If this law and the ${V}^{2}$ law for total intensity are correct, the probability of emission of a quantum with frequency between $\ensuremath{\nu}$ and $\ensuremath{\nu}+d\ensuremath{\nu}$ in distance $\mathrm{ds}$ is $\frac{\mathrm{idsd}\ensuremath{\nu}}{h\ensuremath{\nu}}$, where idsdv is the intensity per cathode ray, with the thin target.
The importance of tissue segmentation for dose calculations for kilovoltage radiation therapy.

Purpose: The aim of this work was to evaluate the effect of tissue segmentation on the accuracy of Monte Carlo(MC)dose calculations for kilovoltage radiation therapy, which are commonly used in preclinical radiotherapy studies and are also being revisited as a clinical treatment modality. The feasibility of tissue segmentation routinely done on the basis of differences in tissue mass densities was studied and a new segmentation scheme based on differences in effective atomic numbers was developed.Methods: MCdose calculations in a cylindrical mouse phantom with small cylindrical inhomogeneities consisting of 34 ICRU-44 tissues were performed using the EGSnrc/BEAMnrc and DOSXYZnrc codes. The dose to tissue was calculated for five different kilovoltage beams currently used in small animal radiotherapy: a microCT 120 kV beam, two 225 kV beams filtered with either 4 mm of Al or 0.5 mm of Cu, a heavily filtered 320 kV beam, and a 192Ir beam. The mean doses to the 34 ICRU-44 tissues as a function of tissue mass density and effective atomic number and beam energy were studied. A treatment plan for an orthotopic lung tumor model was created, and the dose distribution was calculated for three tissue segmentation schemes using 4, 8, and 39 tissue bins to assess the significance of the simulation results for kilovoltage radiotherapy.Results: In our model, incorrect assignment of adipose tissue to muscle caused dose calculation differences of 27%, 13%, and 7% for the 120 kV beam and the 225 kV beams filtered with 4 mm Al and 0.5 mm Cu, respectively. For the heavily filtered 320 kV beam and a 192Ir source, potential dose calculation differences due to tissue mis-assignment were below 4%. There was no clear relationship between the dose to tissue and its mass density for x-ray beams generated by tube potentials equal or less than 225 kV. A second order polynomial fit approximated well the absorbed dose to tissue as a function of effective atomic number for these beams. In the mouse study, the 120 kV beamdose to bone was overestimated by 100% and underestimated by 10% for the 4 and 8-tissue segmentation schemes compared to the 39-tissue segmentation scheme, respectively. Dose to adipose tissue was overestimated by 30% and underestimated by 10%, respectively. In general, organ at risk (OAR) doses were overestimated in the 4-tissue and the 8-tissue segmentation schemes compared to the 39-tissue segmentation.Conclusions: Tissue segmentation was shown to be a key parameter for dose calculations with kilovoltage beams used in small animal radiotherapy when an x-ray tube with a potential ≤225 kV is used as a source. A new tissue segmentation scheme with 39 tissues based on effective number differences derived from mass density differences has been implemented.
A switching system based on microcontroller for successive applying of MGT and CPT on MOSFETs

Abstract A new, low cost switching system based on PIC 18F4550 microcontroller (MCU), called APL-SM v1.0 system, which enables the successive measuring of both the electrical characteristics in midgap-subthreshold technique (MGT) and charge-pumping currents in charge-pumping technique (CPT) of metal–oxide–semiconductor field effect transistor (MOSFET), has been developed. The APL-SM v1.0 system, instead of expensive switching matrix which price is considerably higher, could be used for the switching from MGT to CPT and vice versa. Using the appropriate program, the system allows the monitoring of MOSFETs during long time periods, helping the performing of long lasting experiments. The good agreement in the electrical characteristics, as well as in the charge-pumping currents, obtained using ultra low current, high speed Keithley switching matrix (SM) and APL-SM system, was obtained.
Binder burn out of tape cast ceramics by microwave energy

Microwave power was used to burn out binder from tape-casted barium strontium titanate ceramics. Compared with conventional methods of binder burn out, microwave heating offers some distinctive advantages. The binder burn out process was completed using microwave power at lower temperature and less time. By characterizing the dielectric properties of the tapes at different stages of microwave heating, a better understanding of microwave and conventional binder burn out mechanisms is realized.
Mapping and measuring buildings in the canopy boundary layer in ten U.S. cities

Abstract This study reports on development of a method for inventorying characteristics of urban buildings with special emphasis on their surface construction materials. The work was conducted in response to stated needs from scientists engaged in acid rain damage studies, urban meteorologists interested in the condition of the canopy boundary layer of cities, and others involved in investigations of the physical character of the urban environment. In several instances, these scientists have had little choice but to derive physical (or morphological) characteristics of the city from available spatial data on featuring functional (rather than physical) aspects. The method developed, applicable globally, could support urban meteorological studies. The cities examined were: Boston, Philadelphia, Baltimore, Pittsburgh, Cincinnati, Atlanta, Houston, Denver, Seattle, and Sacramento. All exhibit a wide variety of urban landscapes, building types, and construction materials. High altitude color infrared aerial photographs (at Ames Research Center) were employed to delimit urban terrain zones prior to visiting each city for making direct observations and measurements. Criteria for zone delimitation are morphological and consist of building construction type, venting characteristics, age, density, and related street patterns, items recorded in the field survey were: building dimensions, height, type of roof, venting, and building surface material (e.g., stone, brick, concrete, wood). The data — aggregated by urban terrain zone — reveal, for example, that wall and roof surfaces in areas of tall, densely spaced buildings exceed the ground surface. Conversely, wall and roof areas of low density single-family detached houses form only a small proportion of the ground surface area. These three-dimensional data provide a far more detailed view of the canopy boundary layer in cities than is possible using two-dimensional surface measurements alone. Data analysis also reveals that many of the urban terrain zones (especially those in commercial and industrial areas) are remarkably similar regardless of the city's location. As expected, the dominance of local building materials is more important in houses and other small buildings.
Avian use of early successional habitats: Are regenerating forests, utility right-of-ways and reclaimed surface mines the same?

Abstract The importance of early successional habitats for breeding and post-breeding birds has received recent attention. Common early successional habitats in the eastern United States are regeneration after timber harvests, utility right-of ways and reclaimed surface mines. Few studies, however, have compared the characteristics of these with regard to avian habitat use. We conducted a passive mist-netting study to assess the breeding and post-breeding avian communities associated with these land uses in the Cumberland Mountains of eastern Tennessee. We used analysis of variance to compare the vegetation structure among these habitat types and discriminant function analyses to illustrate differences in vegetation structure and bird abundance among habitats. We banded 1562 individuals of 40 species (1.08 birds/net-hour). The percent cover of saplings, forbs and grass differed among habitat types, but there was no detectable difference in shrub cover. Vegetation structure allowed good discrimination between habitat types (Wilks’ λ = 0.16), specifically in differentiating clearcuts from surface mines and right-of-ways. Although the three habitat types had several avian species in common, the abundance of 12 species differed substantially among habitat types, and their species abundance patterns allowed for excellent discrimination between these habitat types (Wilks’ λ = 0.08). We conclude that these three early successional habitat types are different with regard to vegetation structure and avian community assemblage. These differences are important for local and landscape-scale conservation planning for both early and late successional avian species.
Influence of zinc on copper binding in tissue proteins of steers.

Two experiments were conducted with steers fed diets containing 270 ppm copper either with or without 2050 ppm zinc. Liver biopsies were taken from steers biweekly for 10 wk for analysis. The steers were then killed; tissues were removed, homogenized, and centrifuged, and the pellets were extracted with mercaptoethanol (BME), and selected cytosols and extracts were subjected to gel filtration (Sephadex G-75). Copper and zinc were determined on the BME extracts, pellets after extraction, cytosols, and gel-filtration fractions. Copper accumulated at about the same rate in BME extract and in the extracted pellet, with the smallest amount in the cytosol. In contrast, over 70% of the zinc was present in the hepatic cytosols. Gel filtration of BME extracts revealed the greatest amount of copper in a low-molwt (MW) peak in addition to three minor peaks of copper. Within the hepatic cytosols, the greatest amount of copper accumulated in proteins of MW>75,000, the next greatest amount in 30,000-MW proteins, and the least amount with metallothionein (MT) of steers fed the diet with only copper added. In contrast, the greatest amount of copper was present with MT in hepatic cytosols of the steer fed a diet that included copper plus zinc. Hence the zinc status of steers influences the deposition of copper in the cytosolic proteins (as demonstrated by liver, kidney, and pancreas), but not in the intracellular fractions.
On Finite Sidon Sequences

Abstract A set A of integers is called a Bh-sequence if all sums a1 + · · · + ah, where ai ∈ A, are distinct up to rearrangement of the summands. Let Fh(n) (resp. ƒh(n)) denote the size of a largest Bh-sequence (resp. Bh-sequence for Z/(n)). It is proved that, for every r ≥ 1 as n → ∞, F2r(n) ≤ r1/(2r)(r!)1/rn1/(2r) + O(n1/(4r)). Some open problems concerning Bh-sequences are also discussed in this paper.
Rapid-Injection NMR Study of Iodo- and Cyano-Gilman Reagents with 2-Cyclohexenone: Observation of π-Complexes and Their Rates of Formation1

Rapid-injection is a very useful technique for the preparation of temperature-sensitive and air-sensitive compounds in the cold, nitrogen-filled probe of an NMR spectrometer. We have used this method to prepare solutions of π-complexes from 2-cyclohexenone and prototypical cuprates Me2CuLi·LiI and Me2CuLi·LiCN, and we have assigned structures on the basis of 1H and 13C NMR. In each case two π-complexes were observed, and in the former, their rates of formation were measured by rapid-injection 1H NMR and EXSY spectroscopy. These results provide insights into the normal and anomalous conjugate addition reactions of organocuprates.
An iron-sulfur cluster in the polymerase domain of yeast DNA polymerase ε

DNA polymerase e (Pole) is a multi-subunit polymerase that contributes to genomic stability via its roles in leading strand replication and the repair of damaged DNA. Pole from Saccharomyces cerevisiae is composed of four subunits—Pol2, Dpb2, Dpb3, and Dpb4. Here, we report the presence of a [Fe-S] cluster directly within the active polymerase domain of Pol2 (residues 1–1187). We show that binding of the [Fe-S] cluster is mediated by cysteines in an insertion (Pol2ins) that is conserved in Pol2 orthologs but is absent in the polymerase domains of Polα, Polδ, and Polζ. We also show that the [Fe-S] cluster is required for Pol2 polymerase activity but not for its exonuclease activity. Collectively, our work suggests that Pole is perhaps more sensitive than other DNA polymerases to changes in oxidative stress in eukaryotic cells.
Electrical properties of (Tix V1-x)2O3

The resistivity and thermoelectric properties of single crystals of (TixV1–x)2O3 alloys have been investigated in the range 0 ≦ x ≦ 0.05. It is found that the progressive addition of Ti to V2O3 reduces and ultimately eliminates both the low-temperature metal–insulator transition as well as the high temperature electrical anomaly. The electrical properties are sensitive to annealing processes. The results indicate that in the low temperature region (TixV1–x)2O3 is a band-type intrinsic semiconductor; in the high temperature range it is a narrow-band metal. Der Widerstand und die thermoelektrischen Eigenschaften der (TixV1–x)2O3-Legierungen werden im Bereich 0 ≦ x ≦ 0,05 untersucht. Es wird gefunden, das der fortschreitende Einbau von Ti in V2O3 den Metall–Isolator-Ubergang wie auch die Hochtemperaturanomalien zuerst einschrankt und dann ausschaltet. Die elektrischen Eigenschaften sind vom Gluhverfahren abhangig. Die Untersuchungen zeigen, das (TixV1–x)2O3 im Tieftemperaturregime ein Bandhalbleiter ist, wahrend es im Hochtemperaturbereich einem Schmalbandmetall nahekommt.
The Changing Space of Research: Web 2.0 and the Integration of Research and Writing Environments

Abstract Web 2.0 challenges the artificial compartmentalization of research and writing that often characterizes instruction in composition classes. In Web 2.0, writing and researching activities are increasingly integrated both spatially and conceptually. This article contends that, with this integration, Web 2.0 technologies showcase how research and writing together participate in knowledge production. Through analyzing specific technologies that incorporate Web 2.0 features, including Wikipedia, JSTOR, ARTstor, and del.icio.us, this article argues that including Web 2.0 technologies in composition courses as objects of analysis and as writing and researching resources offers a means to bridge the gap between students’ online proficiencies and academic writing tasks.
Determination of drugs from urine by on-line immunoaffinity chromatography—high-performance liquid chromatography—mass spectrometry

Abstract A method for rapid extraction and identification of drugs in urine is described. The system utilizes a high-performance protein G immunoaffinity column coupled to a reversed-phase analytical column by use of a trapping column and switching valve. A small amount of antibody (5 μg drug-specific) is used for each analysis to extract either propranolol or lysergic acid diethylamide (LSD) from human urine. Urine diluted with phosphate-buffered saline is pumped directly through the protein G column thus eliminating time- and solvent-consuming sample preparation procedures. On-line ultraviolet or mass spectral analysis provides the means of drug detection and identification. With ultraviolet detection propranolol may be detected in spiked urine at the 250 pg/ml level. A Hewlett-Packard mass spectrometer modified for atmospheric pressure ionization and equipped with an ion spray source allows detection of propranolol in urine at 2.5 ng/ml and LSD at 500 pg/ml using single ion monitoring. The potential applicability of the technique for drug confirmations is discussed.
A single amino acid change in the first zinc finger of the DNA binding domain of the glucocorticoid receptor regulates differential promoter selectivity.

Mammalian species are well known to differ in their sensitivity to glucocorticoids, but the molecular basis for this difference remains largely uncharacterized. To address this issue, the transcriptional activity of the mouse and human glucocorticoid receptor (GR) was analyzed on two model glucocorticoid-responsive promoters. Mouse GR (mGR) displayed unique promoter discrimination in response to a range of glucocorticoids, with enhanced activity on a simple glucocorticoid response element (GRE)-based promoter and diminished activity on the complex mouse mammary tumor virus promoter compared with human GR (hGR). Promoter discrimination between mGR and hGR was mapped to a single amino acid change at residue 437 (glycine to valine) of mGR and to sequence differences within individual GREs of the different promoters. Mouse GR displayed higher activation on GREs with a guanine rather than a thymine at the –6 position. Binding studies indicated mGR (mGR437V) displayed a weaker affinity for GREs containing a thymine at the –6 position than a mGR mutant containing a glycine at residue 437 (mGR437G). Despite distinct transcriptional activities, both receptors had similar affinities for response elements that contain a guanine at the –6 position. Our findings support a model by which the presence of a valine residue at position 437 of mGR induces a conformational change that leads to alterations in affinity and/or transcriptional activation in a promoter-dependent context.
Consumption, liquidity constraints and economic development

Abstract The relationship between the severity of borrowing constraints for consumers and the degree of economic development is analyzed for a group of fifty-nine countries. The estimates of the fraction of the consumers who are constrained to borrow in each of the countries in the group are compared with economic indicators and proxies for economic indicators to reveal an inverse relationship between the severity of liquidity constraints and the degree of economic development. Also, an inverse relationship between the severity of borrowing constraints and financial deepening indicates that financial liberalization in developing countries would have interesting macroeconomic implications.
Preincubation with protein synthesis inhibitors protects cortical neurons against oxygen-glucose deprivation-induced death

Twenty-four hour exposure to cycloheximide produced a concentration-dependent reduction in protein synthesis in mouse cortical cell cultures. Unexpectedly, a 24 h pretreatment with cycloheximide exposure also reduced neuronal vulnerability to subsequent oxygen-glucose deprivation-induced injury, measured both acutely (cell swelling) or after one day (cell lysis). This neuroprotective effect was attenuated if the period of cycloheximide pretreatment was shortened to 8 h, and lost if the pretreatment was shortened to 1 h. A comparable neuroprotective effect was also induced by 24 h pretreatment with another protein synthesis inhibitor, emetine. The neuroprotection induced by pretreatment with cycloheximide or emetine was probably not attributable to reduction of apoptosis: (i) neuronal death under these conditions occurs by N-methyl-D-aspartate receptor-mediated excitotoxic necrosis, not apoptosis; (ii) the same cycloheximide pretreatment did not block staurosporine-induced apoptosis. Also unlikely as an explanation is reduction in postsynaptic vulnerability to excitotoxicity, as death induced by exogenous addition of N-methyl-D-aspartate, kainate, or alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate was little affected by cycloheximide pretreatment. Rather, the protective effect of cycloheximide pretreatment was probably explained, at least in part, by marked reduction in the glutamate release induced by oxygen-glucose deprivation.
Gravitational Lensing by Clusters of Galaxies

Gravitational lensing by clusters of galaxies affects the cosmic X-ray background (XRB) by altering the observed density and flux distribution of background X-ray sources. At faint detection flux thresholds, the resolved X-ray sources appear brighter and diluted, while the unresolved component of the XRB appears dimmer and more anisotropic, because of lensing. The diffuse X-ray intensity in the outer halos of clusters might be lower than the sky-averaged XRB, after the subtraction of resolved sources. Detection of the lensing signal with a wide-field X-ray telescope could probe the mass distribution of a cluster out to its virialization boundary. In particular, we show that the lensing signature imprinted on the resolved component of the XRB by the cluster A1689 should be difficult, but possible, to detect out to 8' at the 2-4 σ level, after 106 s of observation with the forthcoming Advanced X-Ray Astrophysics Facility (AXAF) satellite. The lensing signal is fairly insensitive to the lens redshift in the range 0.1 zl 0.6. The amplitude of the lensing signal is, however, sensitive to the faint-end slope of the number-flux relation for unresolved X-ray sources, and it can thus help constrain models of the XRB. A search for X-ray arcs or arclets could identify the fraction of all faint sources that originate from extended emission of distant galaxies. The probability for a 3 σ detection of an arclet that is stretched by a factor of approximately 3 after a 106 s observation of A1689 with AXAF is roughly comparable to the fraction of all background X-ray sources that have an intrinsic size of approximately 1''.
Verification and validation adventures in simulating megagauss-magnetic-field-induced plasma formation on thickwire metallic surfaces

We discuss various verification and validation issues in computational modeling of a series of aluminum “thick-wire,” i.e., rod, experiments that have been conducted on the University of Nevada, Reno (UNR) Zebra generator (2 TW, 1 MA, 100 ns). These conceptually simple experiments involve multi-megagauss surface magnetic fields and have proven to be exceptionally rich in physical phenomena. The experiments also present severe computational challenges. We show that with a proper choice of equation-of-state and resistivity models Eulerian simulations can reproduce many of the observations to a reasonable degree. We also show that Eulerian and Lagrangian computations agree only with serious caveats, leading to the question of whether or not the computations are satisfactorily verified.
Asset allocation decisions in retirement accounts: an all-or-nothing proposition?

Abstract An examination of survey responses about Individual Retirement Account (IRA) holdings reveals that individuals often take all-or-nothing approaches in their decisions to diversify across the asset categories of cash, bonds, and equity. Two thirds of survey respondents put their entire IRA holdings into a single asset category. A surprisingly large proportion of funds is held in cash, while only a minimal amount is invested in bonds. These findings also contrast with those of Bodie and Crane’s (1997) examination of TIAA-CREF participants, which is heavily weighted with individuals holding fixed income annuities. Our results suggest that there is a compelling need for risk education for investors.
Estimation of nuclear DNA content of plants by flow cytometry

A rapid and simple protocol for estimation of nuclear DNA content of plants is described. Suspensions of intact nuclei are prepared either by chopping plant tissues or lysing protoplasts in a MgSO4 buffer, mixed with DNA standards, and stained with propidium iodide in a solution containing DNAase-free RNAase. Fluorescence intensities of the stained nuclei are measured by a flow cytometer. Values for nuclear DNA content are estimated by comparing fluorescence intensities of the nuclei of the test population with those of appropriate internal DNA standards. The same procedure can also be used for rapid determination of ploidy in plant tissues.
Aortic Valve Replacement without Left Heart Decompression

Conventionally, during aortic valve replacement the left ventricle is vented to achieve a dry field, remove air, and prevent ventricular distention. This report demonstrates the feasibility of performing aortic valve replacement without cannulation of either the left ventricle or the left atrium. The technique has been utilized in 54 patients with 1 early death due to pulmonary embolism and 1 late death presumably secondary to ventricular arrhythmias.
The use of diffuse reflectance infrared spectroscopy for studies of molecular sieve catalysis

Diffuse reflectance Fourier transform infrared spectroscopy (DRIFT) in conjunction with gas chromatography has been used to investigate the interaction of light hydrocarbons with the molecular sieve catalyst H-ZSM-5. Experiments were conducted in a controlled-environment (temperature, gas composition) diffuse reflectance cell interfaced with an on-line gas chromatograph. The reactivity of CH3OH, CH3CH2OH, and CH2=CH2 on H-ZSM-5 has been investigated by observing the changes in intensity of the framework hydroxyl stretching vibrations as a function of the type of reactant, temperature, and product mix. C-H stretching vibrations of the organic fragments that form in the molecular sieve channels and pores are also observed in these experiments, and they too are correlated with reactant, temperature, and product mix with the use of spectral subtraction techniques. Important functional features of molecular sieve catalysis detectable by the DRIFT method include (1) the creation of protonated sites during calcining of the synthesis template (the process by which the catalytically active form of the sieve material is produced); (2) the labile nature of these protons as a function of reactant and temperature; and (3) the onset of coking of the molecular sieve as a result of extended use or use at higher temperatures.
Effects of CO2 laser pulse duration in ablation and residual thermal damage: implications for skin resurfacing.

Background and Objectives Resurfacing with the CO2 laser is rapidly gaining acceptance for skin rejuvenation. Advances in CO2 laser and scanning technology allow for precise tissue removal with minimal thermal damage. High energy CO2 laser pulses have been widely used effectively to smooth the surface of facial skin; however, pulse duration effects on ablation and thermal damage have not been systematically studied over the millisecond region (0.25–10 ms). Study Design/Materials and Methods This study characterizes the ablation threshold, heat of ablation, and residual thermal damage in skin resulting from CO2 laser pulses with a Gaussian beam profile. Mass loss from fresh pig skin was measured with an analytical balance, and residual thermal damage was determined through histology. Results Pulse durations >1 ms were associated with higher ablation thresholds and localized increased thermal damage. Conclusions Our results show that although pulse duration is an important determinant in ablation and thermal damage, irradiance is more critical as an independent parameter in predicting the effects of CO2 laser pulses. © 1996 Wiley-Liss, Inc.
Density-of-states and partial-density-of-states functions for the cubic d -band perovskites

The electronic density-of-states and the partial-density-of-states functions for the 14 primary bands of the $\mathrm{AB}{\mathrm{O}}_{3}$ cubic $d$-band perovskites are derived as simple, closed form, analytical formulas with the use of an empirical linear-combinations-of-atomic-orbitals model. Comparisons of the model density functions with those derived from more accurate energy-band calculations presented for SrTi${\mathrm{O}}_{3}$, KTa${\mathrm{O}}_{3}$, and NaW${\mathrm{O}}_{3}$ are shown to be in good agreement.
Doctoral Colloquium -- Open-Source Culture: The Production & Politics of Distributed Creative Peer Production

My research evaluates how the social, legal, and technical elements of distributed creative peer production intersect to produce successful media franchises. I examine two international case studies -- Hatsune Miku and Minecraft -- using a mixed method (ethnographic and computational social scientific) approach to illustrate the politics and processes behind creator, audience, and co-producer relationships.