cssi/SciSciGPT-SciSciNet huggingface dataset:
Further studies with glutarimide antibiotics III. Changes in protein synthesis at the liver microsomal level in rats pretreated with streptimidone

Abstract The administration of streptimidone to rats has a stimulatory effect on ( 14 C)-labeled l -amino acid incorporating activity of a microsomal system in vitro , utilizing materials prepared from the livers of pretreated animals. The stimulatory effect develops maximally after an initial time lag, at 24 hr after administration of the drug at a dose level of 50 mg/kg, and persists for more than 48 hr. There is no sex difference in the response to Streptimidone, but other hormonal factors are involved since adrenalectomized and hypophysectomized rats are more sensitive than intact animals, to the lethal effects of the compound. The stimulation of the in vitro incorporation system is not related to any stabilizing effect that Streptimidone may exert either on the system overall, or on the mRNA-directed activity in particular. Nor is the stimulation related to changes that may occur in the hepatic 105,000 g supernatant fraction following pretreatment, and to changes in the Mg ++ requirement of the in vitro system. The stimulation is compared with stimulatory effects brought about under similar conditions by pretreatiug animals with cycloheximide, Streptovitacin A, or acetoxy-cycloheximide. In experiments testing the influence of Streptimidone pretreatment on protein synthesis at the liver microsomal level in vivo , it becomes evident that streptimidone exerts an initial inhibitory effect on l -( 14 C)-leucine incorporation into protein (at 2 hr) which is no longer observable at 24 hr after pretreatment. The effects of Streptimidone on the loss of radioactivity from prelabeled microsomal fractions incubated in vitro under standard conditions, are discussed. Differences in streptimidone-induced effects on amino acid incorporation in vitro and in vivo are compared with corresponding effects brought about by cycloheximide and other glutarimide antibiotics. It is thought that the differential effects might be partly explained in terms of metabolic factors.
Wavelet and fractal analysis of ground-vehicle images

A large number of terrain images were taken at Aberdeen Proving Grounds, some containing ground vehicles. Is it possible to screen the images for possible targets in a short amount of time using the fractal dimension to detect texture variations. The fractal dimension is determined using the wavelet transform for these visual images. The vehicles are positioned within the grass and in different locations. Since it has been established that natural terrain exhibits a statistical l/f self-similarity property and the psychophysical perception of roughness can be quantified by the same self-similarity, fractal dimensions estimates should vary only at texture boundaries and breaks in the tree and grass patterns. Breaks in the patterns are found using contour plots of the dimension estimates and are considered as perceptual texture variations. Variation in the dimension estimate is considered more important than the accuracy of the actual dimensions number. Accurate variation estimates are found even with low resolution images.
On the hydrolysis and oxidation of glucuronolactone.

Abstract 1. 1.The non-enzymic hydrolysis of glucuronolactone has been studied in distilled water and Tris and phosphate buffer. It proceeds at a faster rate in phosphate than in Tris buffer. 2. 2.Enzymic hydrolysis of glucuronolactone can be demonstrated in liver homogenates while kidney shows little or no activity. In liver, enzymic activity is present in the high speed supernatant primarily. 3. 3.Using kidney homogenates with Tris buffer, it is found that glucuronolactone is more readily oxidized to carbon dioxide than glucuronate.
Pharmacist-led cardiac risk reduction model.

The Cardiovascular Risk Reduction Clinic (CRRC) is a pharmacist-coordinated care model that incorporates the 4 major modifiable risk factors into a single treatment program. The authors aimed to assess the effectiveness of the CRRC model by comparing the Framingham point score before and after CRRC intervention. Retrospective data between 2001 and 2002 were analyzed for 375 veterans (age 65±10 years) with diabetes (88.8%) or coronary artery disease (44%) referred to the CRRC for intensive cardiac risk management. Total Framingham point score decreased from 14.5 at baseline to 13.6 after CRRC intervention (mean change 0.9±0.3). When considering only the patients not at target goals at baseline (n=200), significant improvements in guideline adherence was observed in low-density lipoprotein cholesterol, systolic blood pressure, hemoglobin A1c, and smoking. The CRRC model reduces the risk of cardiovascular events as assessed by Framingham point score in patients with established coronary artery disease and/or diabetes.
Characterization of a recycling nebulization system for inductively coupled plasma spectrometry—I. Stability and humidified argon carrier gas

Abstract A theoretical model for a recycling nebulization system is developed. The time-dependent enhancement of analyte concentration changes with water vapor content, as contributed from the evaporation of large aerosol droplets and initial solution volume. The experimental results over about 60 min for 1 ml of solution are consistent with the theoretical predictions. By the use of argon saturated with water vapor as the carrier gas, the evaporation of aerosol droplets can be reduced, and the long-term drift can be improved significantly.
Holistic Processing of Faces: Perceptual and Decisional Components.

Researchers have used several composite face paradigms to assess holistic processing of faces. In the selective attention paradigm, participants decide whether one face part (e.g., top) is the same as a previously seen face part. Their judgment is affected by whether the irrelevant part of the test face is the same as or different than the relevant part of the study face. This failure of selective attention implies holistic processing. However, the authors show that this task alone cannot distinguish between perceptual and decisional sources of holism. The distinction can be addressed by the complete identification paradigm, in which both face parts are judged to be same or different, combined with analyses based on general recognition theory (F. G. Ashby & J. T. Townsend, 1986). The authors used a different paradigm, sequential responses, to relate these 2 paradigms empirically and theoretically. Sequential responses produced the same results as did selective attention and complete identification. Moreover, disruptions of holistic processing by systematic misalignment of the faces corresponded with systematic and significant changes in the decisional components, but not in the perceptual components, that were extracted using general recognition theory measures. This finding suggests a significant decisional component of holistic face processing in the composite face task.
Low-Temperature Preparation of High-Temperature Nickel Germanides Using Multilayer Reactants

Nickel germanide thin films were prepared using nickel−germanium multilayers as reactive precursors. Over the composition range xNi = 0.24−0.42, high-temperature germanides (δ-Ni5Ge2, e-Ni5Ge3, and...
Hypertrophy and redistribution of astrocytes in the deafferented dentate gyrus

Abstract The response of the astroglial population of the dentate gyrus molecular layer to removal of that region's primary afferent was investigated using Cajal's gold sublimate method. Deafferentation caused the astrocytes to hypertrophy, an effect which was detectable at 24 hr and maximal at 72–96 hr post-lesion. Following this, the astroglia entered a lengthy period of gradual atrophy. Counts of the astrocytes in the various sublayers of the molecular layer led to the conclusion that these cells migrate into denervated dendritic areas from neighboring, nondeafferented zones.
Graph minors. XII: distance on a surface

Abstract Let Γ a graph drawn on a connected surface Σ which is not a sphere. It is " θ -representative" if every non-null-homotopic closed curve meets Γ at least θ times. Also, Γ defines a metric on Σ , discussed in an earlier paper. Our objective here is to study the effect on the metric and on the "representativeness" of making local changes in the drawing or in the surface. We also reformulate more compactly the main theorem of an earlier paper in terms of this metric. These are lemmas to be used later.
Historic primary producer communities linked to water quality and hydrologic changes in the northern Everglades

The northern Everglades Water Conservation Areas have experienced recent ecological shifts in primary producer community structure involving marl periphyton mats and dense Typha-dominated macrophyte stands. Multiple investigations have identified phosphorus (P) as a driver of primary producer community structure, but effects of water impoundment beginning in the 1950s and changes in water hardness [e.g., (CaCO3)] have also been identified as a concern. In an effort to understand pre-1950, primary producer community structure and identify community shifts since 1950, we measured pigment proxies on three sediment cores collected in Water Conservation Area-2A (WCA-2A) along a phosphorus enrichment gradient. Photosynthetic pigments, sediment total phosphorus content (TP), organic matter, total organic carbon and nitrogen were used to infer historic primary producer communities and changes in water quality and hydrology regulating those communities. Excess 210Pb was used to establish historic dates for the sediment cores. Results indicate the northern area of WCA-2A increased marl deposition and increased algal abundance ca. 1920. This increase in (presumably) calcareous periphyton before intensive agriculture and impoundment suggest canal-derived calcium inputs and to some extent early drainage effects played a role in initiating this community shift. The northern area community then shifted to Typha dominance around 1965. The areas to the south in WCA-2A experienced increased marl deposition and algal abundance around or just prior to 1950s impoundment, the precise timing limited by core age resolution. Continued increases in algal abundance were evident after 1950, coinciding with impoundment and deepening of canals draining into WCA-2A, both likely increasing water mineral and nutrient concentrations. The intermediate site developed a Typha-dominated community ca. 1995 while the southern-most core site WCA-2A has yet to develop Typha dominance. Numerous studies link sediment TP >650 mg P/kg to marsh habitat degradation into Typha-dominance. The northern and intermediate cores where Typha is currently support this previous research by showing a distinct shift in the sediment record to Typha dominance corresponding to sediment TP between 600 and 700 mg P/kg. These temporal and spatial differences are consistent with modern evidence showing water-column gradients in mineral inputs (including Ca, carbonates, and phosphorus) altering primary producer community structure in WCA-2A, but also suggest hydroperiod has an effect on the mechanisms regulating periphyton development and Typha dominance.
Dispersion of the Lowest-Order Optical Nonlinearity in InSb

Second-harmonic generation has been studied in InSb. The fundamental source was a ${\mathrm{CO}}_{2}$ laser, and the second-harmonic photon energies were near the band edge. The non-linear susceptibility ${d}_{14}$ is the largest known and shows significant frequency dependence. In a 2.6% range of photon energies, $|{d}_{14}|$ changes by 31% while the linear susceptibility at the second harmonic, ${\ensuremath{\chi}}^{\mathrm{lin}}(2\ensuremath{\omega})$, changes by only 2.8%. In addition ${d}_{14}=|{d}_{14}|{e}^{i\ensuremath{\phi}}$ is complex with $\ensuremath{\phi}\ensuremath{\cong}\ensuremath{-}50\ifmmode^\circ\else\textdegree\fi{}$.
Tribo-Chemistry of Particles Collected During In Situ Gasification of Texas Lignite

Particles collected during in situ gasification of Texas lignite experiments were analyzed for chemical elements. Results obtained by energy dispersive x-ray analysis revealed that the dominating elements in both particles and lignite are Si, S, Al, Fe, and Ca. The concentration of these elements depends on the selected region and varies within the particle size range. Semi-quantitative analysis revealed the same results. This paper presents the scanning electron microscopy (SEM) micrograph and energy dispersive x-ray analysis (EDXA) for particles and Rockdale lignite.Copyright © 1997 by ASME
Analysis of NMR lineshapes of rigid-lattice multispin systems II. Bond length and chemical shielding in CF4

Abstract The 19 F NMR lineshape for the CF 4 molecule enclathrated in the heavy water clathrate hydrate was obtained in magnetic fields of 4 and 14 kG at low temperatures ( T ≤ 4.2K). A fit of the 4-spin lineshape by inclusion of chemical shielding anisotropy in a previously described computer program yielded 1.330 ± 0.005Afor the C F bond length and 138 ± 4 ppm for the difference between chemical shifts parallel and perpendicular to the CF bond. Calculation of the spin-rotation tensor gave C av = − 6.83 ± 0.30 kHz and ( C ∥ − C ⊥ ) = 3.62 ± 0.15 kHz.
Lack of nitric oxide involvement in cholinergic modulation of ovine ciliary beat frequency.

ABSTRACT Ciliary beat frequency (CBF) is regulated, at least in part, by the cytoplasmic calcium concentration ([Ca2+]i). Because Ca2+ can stimulate nitric oxide (NO) production by nitric oxide syn...
VERITAS: a next generation very high energy gamma-ray telescope

VERITAS (the Very Energetic Radiation Imaging Telescope Array System) is one of a new generation of ground-based gamma-ray observatories. It is being built by a collaboration of ten institutions from Canada, Ireland, the U.K. and the U.S.A. VERITAS uses the imaging atmospheric Cherenkov technique (IACT) which was developed by the Whipple collaboration using the Whipple 10m telescope. The 10m was the first ground-based gamma-ray telescope to detect both galactic and extragalactic sources of TeV gamma rays. VERITAS is designed to operate in the range from 50 GeV to 50 TeV with optimal sensitivity near 200 GeV; it will effectively overlap with the next generation of space-based gamma-ray telescopes.
Beta-particle dosimetry of the trabecular skeleton using Monte Carlo transport within 3D digital images

Presently, skeletal dosimetry models utilized in clinical medicine simulate electron path lengths through skeletal regions based upon distributions of linear chords measured across bone trabeculae and marrow cavities. In this work, a human thoracic vertebra has been imaged via nuclear magnetic resonance(NMR)spectroscopy yielding a three-dimensional voxelized representation of this skeletal site. The image was then coupled to the radiation transport code EGS4 allowing for 3D tracing of electron paths within its true 3D structure. The macroscopic boundaries of the trabecular regions, as well as the cortex of cortical bone surrounding the bone site, were explicitly considered in the voxelized transport model. For the case of a thoracic vertebra, energy escape to the cortical bone became significant at source energies exceeding ∼2 MeV. Chord-length distributions were acquired from the same NMRimage, and subsequently used as input for a chord-based dosimetry model. Differences were observed in the absorbed fractions given by the chord-based model and the voxel transport model, suggesting that some of the input chord distributions for the chord-based models may not be accurate. Finally, this work shows that skeletal mass estimates can be made from the same NMRimage in which particle transport is performed. This feature allows one to determine a skeletal S-value using absorbed fraction and mass data taken from the same anatomical tissue sample. The techniques developed in this work may be applied to a variety of skeletal sites, thus allowing for the development of skeletal dosimetry models at all skeletal sites for both males and females and as a function of subject age.
Analysis and comparison of experimental and simulated results for an omnidirectional free space optical receiver architecture

Lasercomm or Free Space Optical (FSO) communication has the potential to provide fiber optic data rates without the need for wired physical connectivity. This paper investigates the feasibility of an Omnidirectional FSO (O-FSO) communications link that utilizes fiber bundles for improved omni-directionality and compares experimental data with modeled results. Current state of the art O-FSO link ranges are limited to 100 meters or so, with data rates of only a few100 kbits/sec. The proposed architecture is formed from commercially available fiber bundle that collects omnidirectional light due to the hemispheric nature of the fiber bundle by exploiting the acceptance cones of the individual fiber exposed to the optical radiation. The experimental transmitter is composed of an LED source that is driven by an On-Off-Keying signal. This paper presents the received optical power while varying the range between the transmitter and receiver. The omni-directionality of this architecture is also verified. The measured results are then compared to the model predictions for omni-directionality and range.
The effect of dimethylsulfoxide on oxygen consumption in cold-exposed rats and hamsters

Summary The O 2 consumption of unrestrained rats and hamsters was measured in an open circuit metabolism system during 3 hrs of exposure to an ambient temperature of 4–7°C. Both rats and hamsters which were treated with 3 or 6 g per kg of DMSO intraperitoneally consumed significantly less O 2 than saline controls during the entire test period. The body temperatures of both rats and hamsters which received 3 g per kg of DMSO fell to below control levels but remained higher than the body temperatures of subjects receiving 6 g per kg of DMSO. O 2 consumption did not manifest this dose dependence. The results are interpreted as indicating that the depression of body temperature which follows DMSO treatment of the type described is at least partially due to an inhibition of the normal thermogenic response required for thermal homeostasis.
Membranes in Balance: Mechanisms of Sphingolipid Homeostasis

Sphingolipids and their metabolites play key cellular roles both as structural components of membranes and as signaling molecules that mediate responses to physiologic cues and stresses. Despite progress during the last two decades in defining the enzymatic machinery responsible for synthesizing and degrading sphingolipids, comparatively little is known about how these enzymes are regulated to ensure sphingolipid homeostasis. Here, we review new insights into how cells sense and control sphingolipid biosynthesis and transport. We also discuss emerging evidence that sphingolipid metabolism is closely coordinated with that of sterols and glycerolipids and with other processes that occur in the secretory pathway. An improved understanding of sphingolipid homeostasis promises to shed light on basic processes in cell biology and disease, including how cells establish and maintain the complex membrane composition and architecture that is a defining feature of eukaryotic cell biology.
Differences in the histogenesis of EDL and diaphragm in rat.

We have examined the histogenesis of the diaphragm and extensor digitorum muscle in rat embryos, with the aim of defining differences in developmental patterns that can be related to the functional requirements of these muscles during and after development. Patterns of interactions between myotubes and other cells, and frequency of gap junctions are quite different in the two muscles. In diaphragm, primary myotubes (at day 16 in utero) are closely associated with each other, forming parallel sheets or palisades and communicating by gap junctions. Secondary myotubes have formed by day 18, but are immature, and the frequency of gap junctions is lower. The arrangement in palisades is maintained even after fibers are separated from each other by their individual basal lamina. In EDL primary fibers at day 16 have fewer gap junctions, and the peak in communication occurs after the appearance of secondary myotubes (day 18 and 21). Secondary myotubes are more mature than in diaphragm at day 18. © 1992 Wiley-Liss, Inc.
MODELING WAVE DAMPING AND SEDIMENT TRANSPORT WITHIN A PATCH OF VEGETATION

Vegetation canopies control mean and turbulent flow structures as well as suspended sediment processes in the coastal wetlands. In this study, a three-dimensional hydrodynamic and sediment transport model is developed for studying flow/wave-vegetation-sediment interactions. The model is based on the non-hydrostatic model NHWAVE. The vege- tation effects on turbulent flow are accounted for by introducing additional formulations associated with vegetation- induced drag and turbulence production in the governing equations. The sediment concentration is obtained by solving the advection-diffusion equation with sediment exchange at the bed. The turbulent flow and suspended sediment are simulated in a coupled manner. The model is validated against the laboratory measurements of partially vegetated open channel flows. It is shown that the model can well predict the vegetation effects on the flow field. The model is then employed to study nearshore sediment suspension influenced by a patch of vegetation, which is located in the surf zone. The turbulence generated by wave breaking is greatly damped by the vegetation patch, resulting in considerably less sediment pickup from the bottom in the surf zone. Within the vegetation patch, most suspended sediments are restricted in a thin layer near the bottom. The net sediment transport is in the shoreward direction, in contrast to the seaward net transport of sediments in the unvegetated surf zone.
Congestion-free routing reconfiguration: Formulation and examples

We consider the network-layer problem of avoiding congestion while reconfiguring the routing paths. We formulate a flow-based and a switch-based model. For the flow-based model, we demonstrate that an optimal sequence of minimum update steps could always be found when the dependency graph is acyclic. For the switch-based model, we find a way to translate a feasible flow-based sequence to a feasible switch-based sequence subject to a tree topology constraint on the routing paths.
A 12-bit 20-Msample/s pipelined analog-to-digital converter with nested digital background calibration

A 12-bit 20-Msample/s pipelined analog-to-digital converter (ADC) is calibrated in the background using an algorithmic ADC, which is itself calibrated in the foreground. The overall calibration architecture is nested. The calibration overcomes the circuit nonidealities caused by capacitor mismatch and finite operational amplifier (opamp) gain both in the pipelined ADC and the algorithmic ADC. With a 58-kHz sinusoidal input, test results show that the pipelined ADC achieves a peak signal-to-noise-and-distortion ratio (SNDR) of 70.8 dB, a peak spurious-free dynamic range (SFDR) of 93.3 dB, a total harmonic distortion (THD) of -92.9 dB, and a peak integral nonlinearity (INL) of 0.47 least significant bit (LSB). The total power dissipation is 254 mW from 3.3 V. The active area is 7.5 mm/sup 2/ in 0.35-/spl mu/m CMOS.
Efficient simulation of large bodies of water by coupling two and three dimensional techniques

We present a new method for the efficient simulation of large bodies of water, especially effective when three-dimensional surface effects are important. Similar to a traditional two-dimensional height field approach, most of the water volume is represented by tall cells which are assumed to have linear pressure profiles. In order to avoid the limitations typically associated with a height field approach, we simulate the entire top surface of the water volume with a state of the art, fully three-dimensional Navier-Stokes free surface solver. Our philosophy is to use the best available method near the interface (in the three-dimensional region) and to coarsen the mesh away from the interface for efficiency. We coarsen with tall, thin cells (as opposed to octrees or AMR), because they maintain good resolution horizontally allowing for accurate representation of bottom topography.
Fundamentals of Magnetorheological Fluid Utilization in High Precision Finishing

Magnetorheological finishing (MRF) is an enabling technology that may produce surface accuracy on the order of 30 nm peak to valley (p-v) and surface micro-roughness less than 10 A rms. In MRF, mec...
Optomechanical considerations for stable lasers

An analysis is presented that indicates the preferred optical arrangement for a stable laser oscillator is to use a hemispherical resonator. Qualitative observations suggest that laser frequency variation is independent of excitation position on the laser box structure. An excitation position that efficiently couples to the end plates on which mirrors are mounted produces substantially higher laser frequency variations.
Nonlinear optical response of granular Y-Ba-Cu-O films.

The nonlinear optical response of a highly granular film of $\mathrm{Y}{\mathrm{Ba}}_{2.1}{\mathrm{Cu}}_{3.4}{\mathrm{O}}_{7\ensuremath{-}x}$ has been interpreted on the basis of the two-dimensional characteristics of the superconducting transition in this film. The behavior of the current-voltage characteristics is consistent with a dissipation mechanism which is dominated by vortex motion as in a Kosterlitz-Thouless transition. The optical response at temperatures near the transition to zero film resistance cannot be interpreted satisfactorily in terms of a realistic thermal model. We believe that nonequilibrium effects contribute to the photoresponse, particularly at low bias currents and low temperatures.
Expression of DNA damage response biomarkers during oral carcinogenesis

Emerging evidence suggests that an intact DNA damage response (DDR) serves as a potent barrier to malignant transformation. Using immunohistochemistry and patient-derived biopsy samples, we investigated whether the same may hold true during oral carcinogenesis. DNA damage accumulates early in the development of oral squamous cell carcinoma (OSCC) as evidenced by the detection of surrogate DDR biomarkers γ-H2A.X and phosphorylated CHK2–threonine-68 (phospho-CHK2 Thr68 ) in epithelial hyperplasias. However, whereas γ-H2A.X expression peaked in dysplastic epithelium, its levels were significantly reduced in OSCCs (χ 2 = 7.655; P = .02). In contrast, there was a trend toward increased phospho-CHK2 Thr68 expression with increasing severity of the pathology. Nonetheless, combined expression of the biomarkers was significantly greater in the nontransformed tissues relative to OSCCs (χ 2 = 6.42; P = .04). Thus, our findings suggest that early therapeutic exploitation of the DDR may be worthy of investigation as a means by which to limit OSCC development.
Scanning electron microscopy of human dental pulp

Abstract Premolar teeth, extracted from 13- and 14-yr-old patients requiring orthodontic treatment, were cleaved longitudinally to expose the entire pulp chamber. Most of the pulp was dissected from the chamber, exposing parts of the odontoblast layer and leaving only a thin portion of pulp tissue covering the dentine. Following fixation and dehydration, the fractured teeth were prepared for scanning electron microscopy (SEM) either by vacuum or critical-point drying. Marked disruption of the odontoblast layer was observed in vaccum-dried preparations. Groups of odontoblasts were scattered over the predentine, the odontoblastic processes displaying either marked stretching or complete separation from the cell body. Critical-point dried specimens showed minimal disturbance of the odontoblast layer and adjacent pulp tissue. Odontoblasts, fibroblasts and collagen fibrils of the pulp and predentine were well preserved by critical point drying, permitting detailed examination by SEM. The pulp dissection and critical-point drying techniques used in this investigation constitute a satisfactory procedure for studying by SEM the morphology and interrelationships of connective tissue elements of the pulp, odontoblasts and predentine.
Microtubule densities and total numbers in selected axons of the crayfish abdominal nerve cord.

The ubiquitous cell organelle, the microtubule, has been assigned a putative role in the phenomenon of axoplasmic transport. In this regard the following question can be posed and subjected to experimental test. Do microtubules extend throughout the length of an axon as single, continuous strands, or are they present in the form of long, but discontinuous lengths? The size of the tubules mandates the use of the electron microscope in an attempt to answer this question. Tubule number and density have been measured in selected single axons of the crayfish abdominal nerve cord in two types of geometry: (1) ‘before’ and ‘after’ an axon splits into two branches; (2) at two macroscopically separated points along unbranched axons which may however undergo large changes in their diameters between the two fiducial points. The results for condition (1) are that a conservation law of tubule number holds across the branch point. For condition (2) the conservation law holds for most of the cases examined, but there are clear violations in the case of several axons. The conclusion is therefore that microtubular continuity is not universally valid. Other results are that microtubule density is uniform across the axonal area, that microtubule density obeys left-right symmetry for corresponding pairs of axons, and that axons with similar functions (e.g. motor axons, interneurons) form groups within which the microtubule densities are similar. A limited number of axons from other species of organisms were measured and the microtubule number and density recorded and included in an overall survey. From this collection, an upper limit to the tubule density is found to be in the neighbourhood of 400 microtubules per μm2.
Reactions of the flavonoid hesperetin with chlorine: a spectroscopic study of the reaction pathways.

The flavonoid hesperetin (Hsp) contains aromatic rings substituted with hydroxyl and methoxyl groups, which activate it toward electrophilic attack and hence make it a potential surrogate for natural organic matter with respect to reactions with chlorine. This paper describes the chlorination pathway of Hsp, based on a combination of electrospray tandem mass spectrometry (MS/MS) and absorbance spectroscopy. When a solution containing Hsp is dosed with NaOCl at pH 7, chlorine substitution into Hsp occurs exclusively into the meta-dihydroxy substituted ring. The first two Cl atoms to enter the ring do so at the highly activated carbons that are each ortho to two oxygenated carbon atoms. These substitutions make the molecule more acidic, but do not change its primary structure or aromaticity. The third Cl atom that substitutes into the molecule does so at one of the previously chlorinated sites, destroying the aromaticity of the ring and altering the molecular properties more dramatically than do the first t...
Synthesis of isoquinuclidine analogs of chloroquine : Antimalarial and antileishmanial activity

The isoquinuclidine (2-azabicyclo[2.2.2]octane) ring system may be viewed as a semi-rigid boat form of the piperidine ring and, when properly substituted, a scaffold for rigid analogs of biologically active ethanolamines and propanolamines. It is present in natural products (such as ibogaine and dioscorine) that display interesting pharmacological properties. In this study, we have expanded our continuing efforts to incorporate this ring system in numerous pharmacophores, by designing and synthesizing semirigid analogs of the antimalarial drug chloroquine. The analogs were tested in vitro against Plasmodium falciparum strains and Leishmania donovani promastigote cultures. Compounds 6 and 13 displayed potent antimalarial activity against both chloroquine-susceptible D6 and the -resistant W2 strains of P. falciparum. All analogs also demonstrated significant antileishmanial activity with compounds 6 and 13 again being the most potent. The fact that these compounds are active against both chloroquine-resistant and chloroquine-sensitive strains as well as leishmanial cells makes them promising candidates for drug development.
Correlation of urinalysis and dipstick results with catheter-associated urinary tract infections in surgical ICU patients

Objective To determine the utility of urinalysis and dipstick results in predicting urinary tract infections in catheterized ICU patients.
Modeling isolation-induced mechanical stress effect on SOI MOS devices

In this paper, the mechanical stress effect of SOI MOS devices was analysed. The width dependence of stress effect and drain current shift were evaluated.
Glycogen Synthase Kinase 3β Phosphorylates Tau at Both Primed and Unprimed Sites DIFFERENTIAL IMPACT ON MICROTUBULE BINDING

Glycogen synthase kinase 3β (GSK3β) phosphorylates substrates, including the microtubule-associated protein tau, at both primed and unprimed epitopes. GSK3β phosphorylation of tau negatively regulates tau-microtubule interactions; however the differential effects of phosphorylation at primed and unprimed epitopes on tau is unknown. To examine the phosphorylation of tau at primed and unprimed epitopes and how this impacts tau function, the R96A mutant of GSK3β was used, a mutation that prevents phosphorylation of substrates at primed sites. Both GSK3β and GSK3β-R96A phosphorylated tau efficiently in situ. However, expression of GSK3β-R96A resulted in significantly less phosphorylation of tau at primed sites compared with GSK3β. Conversely, GSK3β-R96A phosphorylated unprimed tau sites to a significantly greater extent than GSK3β. Prephosphorylating tau with cdk5/p25 impaired the ability of GSK3β-R96A to phosphorylate tau, whereas GSK3β-R96A phosphorylated recombinant tau to a significantly greater extent than GSK3β. Moreover, the amount of tau associated with microtubules was reduced by overexpression of GSK3β but only when tau was phosphorylated at primed sites, as phosphorylation of tau by GSK3β-R96A did not negatively regulate the association of tau with microtubules. These results demonstrate that GSK3β-mediated phosphorylation of tau at primed sites plays a more significant role in regulating the interaction of tau with microtubules than phosphorylation at unprimed epitopes.
Ethnic and Socioeconomic Comparisons of Fitness, Activity Levels, and Barriers to Exercise in High School Females

: The purpose of this study was to determine if high school females differed in individual measures of health-related physical fitness, barriers to exercise, or activity level based on ethnicity or socioeconomic status. A cross-sectional sample consisting of African American (28%), Hispanic (23%), and white (49%) female high school students, 46% from low socioeconomic groups and 54% from moderate or high socioeconomic groups (n = 1314, age = 16.2 ± 0.9) participated in this study. A 15-question survey instrument assessed barriers to exercise and activity level. The FITNESSGRAM fitness test assessed aerobic capacity and body mass index (BMI), and skinfold calipers were used to assess percent body fat. Significant differences between African Americans, Hispanics, and whites were found on the following dependent variables: BMI, percent fat, mile run, perceived barriers to exercise, and activity level. Significant differences between socioeconomic groups were found on the following dependent variables: percent fat, mile run, activity level, and perceived barriers to exercise. These results suggest that students of minority and low socioeconomic groups should be given separate and different interventions regarding health-related fitness. (J Sch Health. 2006;76(1):12-17)
Comparisons of edge state versus bulk conduction in the quantum Hall regime

Abstract We have investigated the nature of current paths in macroscopic two-dimensional samples in the quantum Hall regime using both Si MOSFETs and GaAs heterostructures with island contacts. The Si MOSFETs show a shifting of current paths at the quantum Hall plateau to the side of the sample at the higher chemical potential. This is similar to the behavior expected for edge state conduction in the quantum Hall regime. This is entirely different than the behavior observed in the GaAs heterostructures, where no hint of effects due to edge currents are observed.
Ion Interactions in the High-Affinity Binding Locus of a Voltage-Gated Ca2+ Channel

The selectivity filter of voltage-gated Ca2+ channels is in part composed of four Glu residues, termed the EEEE locus. Ion selectivity in Ca2+ channels is based on interactions between permeant ions and the EEEE locus: in a mixture of ions, all of which can pass through the pore when present alone, those ions that bind weakly are impermeant, those that bind more strongly are permeant, and those that bind more strongly yet act as pore blockers as a consequence of their low rate of unbinding from the EEEE locus. Thus, competition among ion species is a determining feature of selectivity filter function in Ca2+ channels. Previous work has shown that Asp and Ala substitutions in the EEEE locus reduce ion selectivity by weakening ion binding affinity. Here we describe for wild-type and EEEE locus mutants an analysis at the single channel level of competition between Cd2+, which binds very tightly within the EEEE locus, and Ba2+ or Li+, which bind less tightly and hence exhibit high flux rates: Cd2+ binds to the EEEE locus ∼104× more tightly than does Ba2+, and ∼108× more tightly than does Li+. For wild-type channels, Cd2+ entry into the EEEE locus was 400× faster when Li+ rather than Ba2+ was the current carrier, reflecting the large difference between Ba2+ and Li+ in affinity for the EEEE locus. For the substitution mutants, analysis of Cd2+ block kinetics shows that their weakened ion binding affinity can result from either a reduction in blocker on rate or an enhancement of blocker off rate. Which of these rate effects underlay weakened binding was not specified by the nature of the mutation (Asp vs. Ala), but was instead determined by the valence and affinity of the current-carrying ion (Ba2+ vs. Li+). The dependence of Cd2+ block kinetics upon properties of the current-carrying ion can be understood by considering the number of EEEE locus oxygen atoms available to interact with the different ion pairs.
Global Within-Site Variance in Soil Solution Nitrogen and Hydraulic Conductivity Are Correlated with Clay Content

Nutrient fluxes in terrestrial ecosystems are governed by complex biological and physical interactions. Ecologists’ mechanistic understanding of these interactions has focused on biological controls including plant uptake and microbial processing. However, ecologists and hydrologists have recently demonstrated that physical controls are also important. Here, we show that within-site spatial variation in soil solution N concentrations is a function of soil clay content across a globally diverse array of field sites. Clay content explained 35 and 53% of the coefficient of variation (CV) in soil solution nitrate (NO3 −) and dissolved organic nitrogen (DON), respectively. The CV of soil hydraulic conductivity is a similar function of clay content, suggesting that soil hydrology may be a significant mechanism affecting variation in soil solution N. Although vegetation physiognomy and soil C/N ratios are known to affect soil solution N concentrations, neither was significantly related to within-site spatial variation in NO3 − or DON. However, the spatial variation of NO3 − and DON was greater in younger forests than in paired older forests. Our data show that the heterogeneity of an important resource, soil solution N, is a predictable function of clay content. Resource heterogeneity, such as that described here for soil solution N, can affect population, community, and ecosystem processes.
Prolonged transient atrial electrical silence following termination of chronic atrial tachyarrhythmias.

Introduction:Atrial standstill is a rare heterogeneous arrhythmia characterized by electrical and mechanical standstill and electrical inexcitability. A long-lasting progressive form is seen with cardiac and neuromuscular diseases, and a familial or idiopathic form may have a genetic basis. A transient form was described secondary to drug intoxication, electrolyte imbalance, cardiac inflammation, and ischemia. Methods:We investigated three patients with long-standing atrial tachyarrhythmia (AT) (atrial flutter in two, and focal atrial tachycardia in one). All patients underwent a complete electrophysiological study with mapping of right and left atrial activity and radiofrequency ablation (RF Abl) of AT. Results:Following RF Abl of AT, all three patients manifested transient atrial electrical silence in the absence of known reversible causes. Atrial electrical silence was observed when, following AT termination, an escape atrioventricular (AV) junctional rhythm (in two patients) and an escape VVI pacemaker rhythm (in one patient) showed transient ventriculo-atrial (VA) conduction block (up to 30 seconds). A dominant sinus rhythm was observed to return 30 minutes, 90 minutes, and 12 hours, respectively, in the three patients. Two patients received a dual chamber pacemaker and a decision was made not to upgrade the patient with VVI pacemaker. Discussion and Conclusions:The present report expands the spectrum of the syndrome of atrial standstill and raises interesting questions regarding possible electrophysiologic mechanism(s) of prolonged post overdrive atrial standstill. The report suggests that chronic overdrive of sinus and subsidiary atrial pacemakers may result in calcium overloading of cardiac cells, which is known to cause suppression of pacemaker activity as well as increased intracellular resistance. These mechanisms can possibly result in either prolonged suppression of sinus and atrial pacemaker activity and/or pacemaker exit block.
Drought-deciduous behavior reduces nutrient losses from temperate deciduous trees under severe drought

Nutrient resorption from senescing leaves is an important mechanism of nutrient conservation in temperate deciduous forests. Resorption, however, may be curtailed by climatic events that cause rapid leaf death, such as severe drought, which has been projected to double by the year 2100 in the eastern United States. During a record drought in the southeastern US, we studied 18 common temperate winter-deciduous trees and shrubs to understand how extreme drought affects nutrient resorption of the macronutrients N, P, K, and Ca. Four species exhibited drought-induced leaf senescence and maintained higher leaf water potentials than the remaining 14 species (here called drought-evergreen species). This strategy prevented extensive leaf desiccation during the drought and successfully averted large nutrient losses caused by leaf desiccation. These four drought-deciduous species were also able to resorb N, P, and K from drought-senesced leaves, whereas drought-evergreen species did not resorb any nutrients from leaves lost to desiccation during the drought. For Oxydendrum arboreum, the species most severely affected by the drought, our results indicate that trees lost 50% more N and P due to desiccation than would have been lost from fall senescence alone. For all drought-deciduous species, resorption of N and P in fall-senesced leaves was highly proficient, whereas resorption was incomplete for drought-evergreen species. The lower seasonal nutrient losses of drought-deciduous species may give them a competitive advantage over drought-evergreen species in the years following the drought, thereby impacting species composition in temperate deciduous forests in the future.
Vaginal Submucosal Dendritic Cells, but Not Langerhans Cells, Induce Protective Th1 Responses to Herpes Simplex Virus-2

Herpes simplex virus (HSV) type 2 infection occurs primarily at the genital mucosal surfaces and is a leading cause of ulcerative lesions. Despite the availability of animal models for HSV-2 infection, little is known regarding the mechanism of immune induction within the vaginal mucosa. Here, we examined the cell types responsible for the initiation of protective Th1 immunity to HSV-2. Intravaginal inoculation of HSV-2 led to a rapid recruitment of submucosal dendritic cells (DCs) to the infected epithelium. Subsequently, CD11c+ DCs harboring viral peptides in the context of MHC class II molecules emerged in the draining lymph nodes and were found to be responsible for the stimulation of IFNγ secretion from HSV-specific CD4+ T cells. Other antigen-presenting cells including B cells and macrophages did not present viral peptides to T cells in the draining lymph nodes. Next, we assessed the relative contribution to immune generation by the Langerhans cells in the vaginal epithelium, the submucosal CD11b+ DCs, and the CD8α+ lymph node DCs. Analysis of these DC populations from the draining lymph nodes revealed that only the CD11b+ submucosal DCs, but not Langerhans cell–derived or CD8α+ DCs, presented viral antigens to CD4+ T cells and induced IFNγ secretion. These results demonstrate a previously unanticipated role for submucosal DCs in the generation of protective Th1 immune responses to HSV-2 in the vaginal mucosa, and suggest their importance in immunity to other sexually transmitted diseases.
New design approaches to ultra-clean diesel fuels by deep desulfurization and deep dearomatization

Abstract This paper is a selective review on design approaches and associated catalysis and chemistry for deep desulfurization and deep dearomatization (hydrogenation) of hydrocarbon fuels, particularly diesel fuels. The challenge for deep desulfurization of diesel fuels is the difficulty of removing the refractory sulfur compounds, particularly 4,6-dimethyldibenzothiophene, with conventional hydrodesulfurization processes. The problem is exacerbated by the inhibiting effect of polyaromatics and nitrogen compounds, which exist in some diesel blend stocks on deep HDS. With the new Environmental Protection Agency (EPA) Tier II regulations to cut the diesel sulfur from current 500 ppmw down to 15 ppmw by June 2006, refineries are facing major challenges to meet the fuel sulfur specification along with the required reduction of aromatics contents. The principles and problems for the existing hydrodesulfurization processes, and the concepts, advantages and disadvantages of various new approaches will be discussed. Specifically, the following new design approaches for sulfur removal will be discussed: (1) novel catalysts for ultra-deep hydrodesulfurization under conventional HDS process conditions; (2) new design concept for sulfur-tolerant noble metal catalysts for low-temperature hydrogenation; (3) new desulfurization process by sulfur adsorption and capture under H2; (4) new desulfurization process by selective adsorption at ambient temperature without H2 and a related integrated process concept; (5) oxidative desulfurization in liquid-phase; and (6) biodesulfurization.
Sequestration, Phytoreduction, and Phytooxidation of Halogenated Organic Chemicals by Aquatic and Terrestrial Plants

ABSTRACT Laboratory data from plant-mediated transformation of chlorinated and brominated alkanes, alkenes, and chlorinated pesticides, including phytotransformation data from field plants currently used in phytoremediation of trichloroethylene (TCE), were reviewed for the purpose of identifying important phytoprocesses and their respective roles in phytoremediation of halogenated organic compounds (HOCs). The results of the laboratory experiments indicated that the initial very rapid removal of hydrophobic HOCs from water or the gas phase by aquatic and terrestrial plants is primarily due to sequestration. The amount of HOC sequestered is controlled by the plant species and the physicochemical properties (e.g., Kow, aqueous solubility, volatility) of the contaminant. Phytodegradation studies conducted in both the gas and aqueous phases indicated that hexachloroethane (HCA) is dechlorinated to the same metabolites by sterilized and axenically cultivated aquatic plants and an isolated plant dehalogenase fa...