cssi/SciSciGPT-SciSciNet huggingface dataset:
Exploratory investigation of solid freeform construction

A radical departure from generally accepted concepts in construction robotics is proposed in this paper. A new process derived from the emerging field of additive manufacturing processes is investigated for its potential effectiveness in construction automation. In essence, complex assemblies of large construction components are substituted with a large number of elemental component assemblies. The massive complexity of information processing required in construction is replaced with a large number of simple elemental operations which lend themselves easily to computer control. This exploratory work is illustrated with sample masonry structures that cannot be obtained by casting. They are manufactured by an incremental deposition of sand and Portland cement akin to Navajo sand painting. A thin layer of sand is deposited, followed by the deposition of a patterned layer of cement. Steam is then applied to the layer to obtain rapid curing. A characterization of the resulting material properties shows rather novel anisotropic properties for mortar. Finally, the potential of this approach for solid freeform fabrication of large structures is assessed.
Estimation of the diurnal variation of potential evaporation from a wet bare soil surface

Note: 132: 71-89 Reference EFLUM-ARTICLE-1992-006doi:10.1016/0022-1694(92)90173-S Record created on 2005-09-08, modified on 2017-02-23
The Molecular Basis of the Action of Chloroquine in Porphyria Cutanea Tarda

A single therapeutic dose of chloroquine, a 4 aminoquinoline, administered to patients with porphyria cutanea tarda (PCT) results in a massive porphvrinuria with subsequent remission at the disease. In the present investigation, an experimental animal model of porphyria was utilized to elucidate the initial biochemical events involved in the therapeutic response of patients with PCT to chloroquine. Rats were made chemically porphyria by treatment with 3.5 dicarbethoxy 1.4 dihydro 2,4,6, trimethyl pyridine (DDC) and subsequently treated with chloroquine. As in patients with PCT, chloroquine caused a massive porphyrinuria in the experimental animals. The increased excretion of porphyrin was associated with a marked decrease in hepatic porphyrin content without changing the activity of δ-aminoleyulinic acid synthetase. The rate controlling enzyme of porphyrin biosynthesis. In addition, there was no biochemical evidence of hepatotoxicity in the experimentally porphyric animals during chloroquine treatment. The validity of the present model system for the study of the effects of chloroquine in PCT is supported by the similarity of the response of the chemically porphyric animals and PCT patients to primaquine, an 8-aminoquinoline. In both instances, primaquine has no effect on porphyrin excretion. In vitro data based on spectrophotometric and gel filtration studies demonstrated that porphyrins form a unique molecular complex with chloroquine. Further equilibrium dialysis studies demonstrate that chloroquine causes the release of tissue-bound prophyrins. The in vitro studies, in association with the results from the animal model, suggest that the initial event following chloroquine administration to patients with PCT is a release of bound hepatic porphyrin and its rapid elimination.
D s spectrum and leptonic decays with Fermilab heavy quarks and improved staggered light quarks

We present preliminary results for the D{sub s} meson spectrum and decay constants in unquenched lattice QCD. Simulations are carried out with 2 + 1 dynamical quarks using gauge configurations generated by the MILC collaboration. We use the ''asqtad'' a{sup 2} improved staggered action for the light quarks, and the clover heavy quark action with the Fermilab interpretation. We compare our spectrum results with the newly discovered 0{sup +} and 1{sup +} states in the D{sub s} system.
Reaction of alloxan with thiol groups of proteins blockage of the reactivation of reduced ribonuclease

Abstract 1. 1.|The reactivation of reduced ribonuclease was used as a tool to study the reaction of alloxan with thiol groups of an enzyme with an established structure. 2. 2.|Unlike the structurally related compound dehydroascorbic acid, alloxan (0.1 mM) blocked the reactivation of reduced ribonuclease by a rat liver microsomal fraction or by autooxidation. All thiol groups of the reduced enzyme disappeared upon treatment with the reagent. 3. 3.|When followed spectrophotometrically, the reaction of alloxan with reduced ribonuclease resulted in the appearance of peak in the 295–350-mμ region with a maximum at 312 mμ and a slight hyperchromicity in the tyrosine region. Under the same conditions, alloxan did not affect the enzymatic activity or the spectrum of native ribonuclease. 4. 4.|It is concluded that alloxan exerts its effect in this system by binding the thiol groups of reduced ribonuclease. Oxidation of these residues by the reagent, if it occurs to any appreciable extent, seems to be secondary to the addition reaction under the experimental conditions used.
Potential role of dual-polarization X-band radar in hydrological applications

Summary form only given. Compared with the National Weather Service (NWS) Weather Surveillance Radar-1988 Doppler (WSR-88D) network, the X-band weather radar network developed by National Science Foundation Engineering Research Center (NSF-ERC) for Collaborative Adaptive Sensing of the Atmosphere (CASA) has greatly improved the remote sensing of weather in the lower atmosphere. Quantitative Precipitation Estimation (QPE) is one of the important goals of this meteorological radar network and it is also serving as an important tool to monitor rainfall intensity and total rainfall amount. A Kdp-based rainfall algorithm was developed using the measurements of Kdp values from the dual-polarization radars in CASA network to provide high spatial and temporal resolution rainfall estimates. In addition, a Fourier-space, linear system-based nowcasting method was implemented to use these rainfall estimates as input to generate short-term forecasts of rainfall. Incorporating distributed hydrological models, the high resolution precipitation estimation and nowcasting results in CASA can lead to signicant improvement in urban flood warnings and advisories resulting in substantial savings of life and property. This paper first presents a brief overview of the CASA QPE and nowcasting systems. Then, potentials of the CASA dual-polarization X-band radar network in hydrological applications are focused on by analyzing the QPE and nowcasting products using the networked radar data collected in IP-1 test bed in southwestern Oklahoma. The great performance of CASA QPE and short-term QPF system in Oklahoma test bed encourages this networked radar rainfall methodology to be implemented in the populous Dallas-Fort Worth (DFW) metropolitan area for urban flash flood monitoring and mitigation. A brief description about the DFW urban demonstration network will also be given in this talk.
The oscillator strength of extended exciton states and possibility for very fast scintillators

Abstract Streak camera measurements of luminescence from ZnO single crystals as a function of temperature show that the spontaneous radiative lifetime of the “free exciton” band at 380 nm is 440 ps at room temperature, decreasing to 290 ps at 85 K. The donor-bound exciton lifetime is 50 ps from 85 K down to 16 K, the lowest temperature we measured. This is significantly faster than is consistent with the dipole matrix element of any single atom transition scaled to the same wavelength. We discuss the oscillator strength of extended exciton states based on the theory of defect-bound excitons, and examine its limit for free excitons. In that regard, we ask what physically limits the coherent dipole size and how a material might be engineered for “giant” exciton oscillator strength. The phenomenon applies to single excitons, not just coherently produced multiple excitations.
Ecological zonation during the carbonate transgression of a late Ordovician rocky shore (Northeastern Manitoba, Hudson Bay, Canada)

Abstract Late Ordovician (Ashgillian) carbonates belonging to the Port Nelson Formation transgress a resistant rocky shore near Churchill, Manitoba on the southwest flank of the Hudson Bay Basin in Canada. Examples of ancient rocky shores are very rare and this locality offers the first opportunity to document extensive offshore biological zonation with spatial reference to a well defined shoreline. Five biofacies zones are parallel to a 350 m-long shoreface carved into the Precambrian Churchill Quartzite. Eroded boulders of the dark quartzite blanket the shoreface and clast size is observed to decrease dramatically up section through 4.5 m of tan-colored carbonates. From an onshore to offshore position, the ecological zones include (1) boulder-encrusting favositid corals and a related high-energy fauna, (2) a shell pavement dominated by the inarticulate brahciopod Monomerella, (3) large, free-standing tabulate corals including Palaeophyllum, Calapoecia, and Catenipora, (4) tunneled trace fossils including chondritid, thalassinoid, and less common vertical “volcano” burrows, and (5) surface Cruziana burrows associated with rare, large isotelid (asaphacean) trilobites. Siphuncular debris from aminocerid cephalopods abundantly scattered through zones 2–3, provides data on current orientation consistent with long-shore drift. A wide field of ripple marks preserved near the top of the stratigraphic sequence confirms that wave trains advanced shoreward at an indirect angle of about 45°. Although currents deflected by natural groin fields may have swept coarse clastics more seaward at some spots than others, the biological zones are remarkably linear and persistent. The Churchill site is a comparatively simple case of landward migration by shore-parallel biofacies primarily controlled by factors related to water depth and distance from shore. This interpretation does not preclude the possibility that more random facies patterns may have existed in protected embayments or along more irregularly cliffed sectors of the ancient Churchill coast.
Evaluation of Process Uncertainty in Activated Sludge Treatment by Probabilistic Modeling

AbstractSimulation-based design and analysis of biotreatment systems depends to a great extent on the accuracy of the model parameters used. In many cases, site-specific parameter estimates are not available and parameter values recommended in the literature are adopted along with a measure of judgment to account for bioprocess uncertainty. To better quantify process certitude associated with this approach and thus provide guidance to process designers lacking site-specific parameter values, stochastic simulations were conducted and the empirical frequency distributions derived from the simulation results were interpreted in terms of process certitude. In general, the simulation results confirmed field experience and current practice in biotreatment from a probabilistic standpoint and provided context in terms of process certitude. The certitude of achieving specific treatment levels increased with sludge age, validating the application of a design safety factor on the minimum solids retention time. The i...
Understanding complex perturbative effective potentials

We examine the situation where the perturbatively calculated effective potential develops an imaginary part. We show that his imaginary part has a natural interpretation as a decay rate per unit volume of a well-defined state and that it agrees quantitatively with an independent calculation of this rate. We examine in some detail the nature of this decay process.
Nonuniformity of chain-length distributions in photopolymerized layers

For free-radical photopolymerization with a photobleaching initiator, constant chain propagation and termination rate constants kp and kt, and termination occurring only by recombination, we account for Beer−Lambert attenuation and initiator consumption to predict how spatial variation of the final chain length distribution (CLD) depends on kp, kt, incident light intensity Io, layer thickness L, photoinitiator absorption coefficient αA and initial concentration CA,0, and quantum yield of photoinitiator consumption φ, for a typical value (10-4) of the initial ratio of initiator and monomer concentrations CA,0/CM,0. We show how spatial variation of the final CLD depends on initial absorbance γ = αACA,0L and a parameter β = kp[fCA,0/(φαAIokt)]1/2, where f primary radicals are produced per photoinitiator molecule consumed. For small γ, the number-averaged mean chain length increases with depth at each β and with β at each depth. The chain length at which the CLD achieves its maximum value, along with a measur...
EFFECT OF PITUITARY HORMONES UPON SERUM FREE FATTY ACID CONCENTRATION OF THE RABBIT1

A previous study showed that the injection of a crude extract of hog pituitarjr glands in the rabbit causes a 10- to 15-fold increase in the serum free fatty acid (FFA) concentration within 2 hours. In the present investigation the effect of purified preparations of 9 pituitary hormones, including the recently described pituitary component “Fraction H” (which has previously been shown to be different from the recognized pituitary hormones), upon the rabbit’s serum FFA level was studied. The following hormone preparations were found to have no effect upon the serum FFA concentration: bovine GH (10 mg.), TSH (8.3 mg.), prolactin (10 mg.), FSH (10 mg.), and oxytocin (30 units). The following hormone preparations caused a modest increase in the rabbit’s serum FFA level 2 hours after the injection: porcine GH (Raben-Westermeyer preparation) (5 mg.), ICSH (10 mg.), and vasopressin (40 units). Purified ACTH and Fraction H were highly active in increasing the rabbit’s serum FFA concentration. After the injection ...
Thermodynamic characterization of NiAl

Abstract Thermodynamic properties of the high-stability intermetallic compound nickel aluminide, NiAl, have been determined from mass-spectrometric, weight-loss effusion, and calorimetric measurements, using samples from a single preparation with a composition determined to be Ni0.986Al1.014. Per mole of NiAl molecules, the specific heat capacity at room temperature of 298 K is 48.54 J · K−1 · mol−1, with a linear temperature dependence of +0.0104 J · K−2 · mol−1. At the same temperature, the enthalpy of formation is −133.7 kJ · mol−1, the entropy is about 53.8 J · K−1 · mol−1 and the enthalpy difference between room temperature and absolute zero is 7.97 kJ · mol−1. The Gibbs free-energy is −130.2 kJ · mol−1 at T = 298 K, with a linear temperature dependence of +5.04 J · K−1 · mol−1. The Debye temperature is 452 K, while the electronic density-of-states at the Fermi-level is about 0.29 states per eV-atom. The NiAl+ ions were observed in the high-temperature mass spectra. Pressures for the gas at these temperatures were estimated and used with the results of quantum-mechanical calculations of total energy, specific heat, and entropy to calculate free-energy functions for the gas. These and additional results are compared with other measurements and discussed in terms of current theories of the electronic and structural properties of the compound.
Innovation Prospects in US — Mexico Border Water Management: The IBWC and the BECC in Theoretical Perspective:

Binational water management along the US—Mexican border is changing as a result of new institutions and approaches growing out of the North American Free Trade Agreement (NAFTA). In this study we examine the two leading border water-management agencies today, the venerable International Boundary and Water Commission (IBWC) and the new Border Environment Cooperation Commission (BECC), to understand better the post-NAFTA prospects for policy innovation in this issue area. The two agencies, IBWC and BECC, are analyzed from the perspective of two prominent theoretical explanations for agency behavior, structural choice politics and interorganizational implementation, to identify their political and institutional limitations as binational water-management agencies. We then chart the prospects for further innovation in binational water management along the US—Mexico border.
The incorporation of labeled methionine by typhus rickettsiae

Abstract Typhus rickettsiae incubated with [ 35 S]methionine under suitable conditions show a small but highly significant uptake of methionine. Heat-inactivated rickettsiae and particles from normal yolk sac show no uptake under the same conditions. The substances required for optimum uptake are: ATP or ADP, the other nucleoside-5′-monophosphates, DPN, glutamine, the naturally occurring amino acids, and either a protein fraction from yolk sac or a suitable preparation of bovine serum albumin. The maximum uptake observed in different experiments amounts to 7 to 20 mμg methionine per 100 μg rickettsial protein in 24 h.
Percolation Properties of Random Ellipses

We compute the percolation concentration for identical ellipses with aspect ratio b/a in a two-dimensional plane where both the centers and orientations are random. We have obtained a comprehensive set of results ranging from circles to needles which can be well fit by the interpolation formula p/sub c/ = (1+4y)/(19+4y), where y = b/a+a/b. We also obtain results for random centers and random orientations along the two principal directions which are virtually indistinguishable from the previous case. These results are used to critique the various effective-medium theories that have been developed for the electrical conductance and elastic moduli of sheets containing random elliptical inclusions. An interpolation formula is developed that appears superior to all these effective-medium theories.
Influence of Agricultural Extension Contact on Control of Farmland Degradation among Yam Farmers in Delta North Agricultural Zone of Delta State, Nigeria

The main objective of the study was to investigate the influence of extension contact on control of farm land degradation among yam farmers. Eight rural communities were randomly selected for the study. From the eight communities one hundred and twenty (120) yam farmers were randomly drawn to compose the sample. Data were collected by use of structured interview schedule and analysed by mean, Chi square test and Pearson r. It was found that majority of the farmers were old (M =47.77) and below secondary education (M = 9.41). The mean number of extension contact had by the farmers was 3.93. The yam farmers agreed that land degradation could cause famine (M= 2.78), low yam yield (M= 2.71), low quality of yam (M= 3.14), and tussle and pressure on available land M= 2.51). There was a positive and significant relationship between extension contact and perception of the effects of farm land degradation on yam production (r = 0.87). There were significant relationships between number of extension contacts, and mulching (X2 =60.25, r= 0.71); organic manure application (X2 = 55.03, r = 0.68); and avoidance of bush burning (X2 = 86.40, r = 0.85). There was no significant relationship between extension contacts and terracing (X2 =15.95, r= 0.37). The study established that education campaign I the control of farm land degradation through avoidance of bush burning, use of mulching and organic manure. The education campaigns to control farm land degradation was effective in the study area. DOI: 10.5901/mjss.2014.v5n2p33
Calibration of Disease Simulation Model Using an Engineering Approach

Abstract Objectives Calibrating a disease simulation model's outputs to existing clinical data is vital to generate confidence in the model's predictive ability. Calibration involves two challenges: 1) defining a total goodness-of-fit ( GOF ) score for multiple targets if simultaneous fitting is required, and 2) searching for the optimal parameter set that minimizes the total GOF score (i.e., yields the best fit). To address these two prominent challenges, we have applied an engineering approach to calibrate a microsimulation model, the Lung Cancer Policy Model (LCPM). Methods First, 11 targets derived from clinical and epidemiologic data were combined into a total GOF score by a weighted-sum approach, accounting for the user-defined relative importance of the calibration targets. Second, two automated parameter search algorithms, simulated annealing (SA) and genetic algorithm (GA), were independently applied to a simultaneous search of 28 natural history parameters to minimize the total GOF score. Algorithm performance metrics were defined for speed and model fit. Results Both search algorithms obtained total GOF scores below 95 within 1000 search iterations. Our results show that SA outperformed GA in locating a lower GOF . After calibrating our LCPM, the predicted natural history of lung cancer was consistent with other mathematical models of lung cancer development. Conclusion An engineering-based calibration method was able to simultaneously fit LCPM output to multiple calibration targets, with the benefits of fast computational speed and reduced the need for human input and its potential bias.
Sex- and age-related differences in bone microarchitecture in men relative to women assessed by high-resolution peripheral quantitative computed tomography

The trabecular and cortical compartments of bone each contributes to bone strength. Until recently, assessment of trabecular and cortical microstructure has required a bone biopsy. Now, trabecular and cortical microstructure of peripheral bone sites can be determined noninvasively using high-resolution peripheral quantitative computed tomography (HR-pQCT). Studies that have used HR-pQCT to evaluate cohorts of both men and women have provided novel insights into the changes in bone microarchitecture that occur with age between the sexes, which may help to explain the lower fracture incidence in older men relative to women. This review will highlight observations from these studies on both the sex- and age-related differences in trabecular and cortical microstructure that may underlie the differences in bone strength, and thereby fracture risk, between men and women.
Influence of atherosclerosis on the composition, synthesis, and esterification of lipids in aortas of squirrel monkeys (Saimiri sciureus).

Summary The composition and synthesis of lipids from aortas of squirrel monkeys were studied following perfusion with [1- 14 C]acetate or [2- 14 C]mevalonate. Twenty-nine cholesterol-fed and 6 control monkeys were used. After 1 year on diet, the cholesterol-fed group had only slightly more aortic atherosclerosis than controls. In both groups fatty streaks and raised plaques were seen. Fatty acid composition of phospholipids and triglycerides was similar in both groups. Substantial differences were noted in the cholesteryl esters; the principal change was an increase in cholesteryl oleate in aortas from cholesterol-fed monkeys. In control aortas perfused with [l- 14 C]acetate phospholipid and triglyceride comprised approximately 90 % of lipid radioactivity. Among cholesterol-fed monkeys there was a slight increase in incorporation of newly synthesized fatty acids into aortic phospholipids with a slight decrease into triglycerides. Cholesteryl ester synthesis was increased approximately 6 times; oleic acid showed the greatest relative increase in synthesis. [2- 14 C]Mevalonate incorporation into aortic lipids was similar for both groups. More than 95 % of the total lipid radioactivity was recovered in two fractions, one has been identified as squalene. Perhaps most significant in these studies is the demonstration of metabolic changes (primarily an increase in cholesteryl ester synthesis) occurring in arteries only slightly more diseased than controls.
Accuracy of land surface elevation from CALIPSO mission data

We assess the accuracy of land surface elevation retrieved from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) mission through comparisons with the U.S. Geological Survey National Elevation Dataset (NED), Shuttle Radar Topography Mission (SRTM), and the altimetry product from the Geoscience Laser Altimeter System onboard the Ice, Cloud, and Land Elevation Satellite (ICESat). The vertical accuracy of the CALIPSO-derived land surface elevation was tested against these three datasets for about 16 million lidar shots over the continental United States. The results show that the CALIPSO-derived elevation was highly correlated with the elevation result from the NED, SRTM, and ICESat datasets. The overall absolute vertical accuracies of the CALIPSO-derived land surface elevation expressed as the root mean square error (RMSE) are 5.58 and 5.90 m when compared with the SRTM and NED results, respectively. Lower accuracy of the CALIPSO-derived land surface elevation was achieved by comparison with the ICESat results (8.35-m RMSE), primarily due to the several kilometers distance between the CALIPSO and ICESat ground footprints. The results show that the variability in terrain, vegetation, canopy, and footprint size can all influence comparisons between the CALIPSO-derived elevation and the results obtained from NED, SRTM, and ICESat datasets.
SCAFFOLD ATTACHMENT REGIONS IN CENTROMERE-ASSOCIATED DNA

Due to indications that kinetochore proteins are an integral part of the protein scaffold component of the chromosome (Earnshaw et al. 1984), we chose to map the distribution of scaffold attachment regions (SARs) at centromeres. Using the SAR mapping assay of Mirkovitch et al., Southern blots were prepared and probed with32P-labeled fragments from the human 1.9 kb centromeric α-satellite repeat unit of chromosome 1 or the 1.7 kb centromeric α-satellite repeat unit of chromosome 16. Our results demonstrated the presence of one SAR site per 1.9 kb repeat unit in chromosome 1, and every 1.7 kb repeat unit in chromosome 16, separated by regions of small DNA loops over the length of the α-satellite regions. We also identified several in vitro vertebrate topoisomerase II and cenP-B consensus sequences throughout the chromosome 1 α-satellite region using computer and base ratio analysis, to address the question as to why some α-satellite regions are SAR related and others are not. To provide in situ indications of SAR localization in the human genome, SAR DNA and non-SAR DNA were prepared following lithium 3,5-diiodosalicylate extraction. Sequences protected from DNAse I digestion by SAR proteins, as compared with unprotected DNA that was digested by the enzyme, was labeled with biotin-UTP, hybridized to chromosomal DNA in situ, and then detected with fluorescein-avidin-DCS. Both SAR and non-SAR DNA selectively labeled virtually all centromeric regions of the human metaphase karyotype. Chromosomal arms were less strongly bound by SAR DNA, with a pattern that followed the chromosomal axis. In the more condensed chromosomes an R-banding pattern was evident. In general, labeling patterns produced by both SAR and non-SAR fractions were similar, as expected from the indications that SAR DNAs are heterogenous in sequence and do not form a specific class of sequences. We conclude that centromeric regions of several, possibly all, human metaphase chromosomes are also regions where the chromosomal axis contains loops, smaller in size than in the arms and where attachment sites are concentrated. This clustering of SARs may be responsible in part for the tight chromatin packing associated with the primary constriction of the centromeric region.
Theranostic Magnetic Core–Plasmonic Shell Star Shape Nanoparticle for the Isolation of Targeted Rare Tumor Cells from Whole Blood, Fluorescence Imaging and Photothermal Destruction of Cancer

Cancer is one of the most life-threatening diseases, which causes 7.6 million deaths and around 1 trillion dollars economic loss every year. Theranostic materials are expected to improve early detection and safe treatment through personalized medicine. Driven by the needs, we report the development of a theranostic plasmonic shell–magnetic core star shape nanomaterial based approach for the targeted isolation of rare tumor cells from the whole blood sample, followed by diagnosis and photothermal destruction. Experimental data with whole blood sample spiked with SK-BR-3 cancer cell shows that Cy3 attached S6 aptamer conjugated theranostic plasmonic/magnetic nanoparticles can be used for fluorescence imaging and magnetic separation even in 0.001% mixtures. A targeted photothermal experiment using 1064 nm near-IR light at 2–3 W/cm2 for 10 min resulted in selective irreparable cellular damage to most of the SK-BR-3 cancer cells. We discuss the possible mechanism and operating principle for the targeted imagin...
Altered transcriptional regulation of human interstitial collagenase in cultured skin fibroblasts from older donors.

Abstract Primary human dermal fibroblasts isolated from the medial aspect of the proximal forearm of young and old donors were compared for the expression of interstitial collagenase, 72 kDa type IV collagenase, the tissue inhibitor of metalloproteinase type 1, and pro-α2 (I) collagen mRNA at basal levels and after stimulation with the tumor promotor 12- O -tetradecanoyl-phorbol-13-acetate. Higher basal and induced steady-state mRNA levels of interstitial collagenase were found in the cells from older donors. Ratios of basal and induced steady-state mRNA levels of interstitial collagenase to pro-α2 (I) collagen, and interstitial collagenase to the tissue inhibitor of metalloproteinases type 1 were also higher in the cells from older donors. Seventy-two kiloDalton type IV collagenase and pro-α2 (I) collagen mRNA showed similar levels of expression in the cells from young and old donors and were not altered by treatment with 12- O -tetradecanoyl-phorbol-13-acetate. Transient transfection assays with the interstitial collagenase promoter linked to a reporter gene showed increased activity of the reporter in cell strains with high interstitial collagenase mRNA levels. Mobility shift assays demonstrated increased binding activity to the specific 12- O -tetradecanoyl-phorbol-13-acetate response element in nuclear extracts from the cell strains with higher induced collagenase mRNA levels and higher reporter gene activity. These findings are consistent with the observed phenotype of interstitial collagenase and its specific tissue inhibitor in the senescent fibroblast aging model.
Effects of decellularization on the mechanical and structural properties of the porcine aortic valve leaflet

Abstract The potential for decellularized aortic heart valves (AVs) as heart valve replacements is based on the assumption that the major cellular immunogenic components have been removed, and that the remaining extracellular matrix (ECM) should retain the necessary mechanical properties and functional design. However, decellularization processes likely alter the ECM mechanical and structural properties, potentially affecting long-term durability. In the present study, we explored the effects of an anionic detergent (sodium dodecyl sulfate (SDS)), enzymatic agent (Trypsin), and a non-ionic detergent (Triton X-100) on the mechanical and structural properties of AV leaflets (AVLs) to provide greater insight into the initial functional state of the decellularized AVL. The overall extensibility represented by the areal strain under 60 N/m increased from 68.85% for the native AV to 139.95%, 137.51%, and 177.69% for SDS, Trypsin, and Triton X-100, respectively, after decellularization. In flexure, decellularized AVLs demonstrated a profound loss of stiffness overall, and also produced a nonlinear moment–curvature relation compared to the linear response of the native AVL. Effective flexural moduli decreased from 156.0±24.6 kPa for the native AV to 23.5±5.8, 15.6±4.8, and 19.4±8.9 kPa for SDS, Trypsin, and Triton X-100 treated leaflets, respectively. While the overall leaflet fiber architecture remained relatively unchanged, decellularization resulted in substantial microscopic disruption. In conclusion, changes in mechanical and structural properties of decellularized leaflets were likely associated with disruption of the ECM, which may impact the durability of the leaflets.
On the mechanism for the reduction of nitrogen monoxide on Rh(111) single-crystal surfaces

Isothermal kinetic experiments were carried out with isotopically-labeled molecular beams in order to characterize the surface reactions involved in the reduction of nitrogen monoxide with carbon monoxide on Rh(111) single-crystal surfaces. The new data reported here offers support for the basic model advanced previously where N2 production takes place via the formation of N–NO intermediates at the periphery of atomic nitrogen surface islands. However, they also highlight a few additional subtle complications. In particular, the rapid desorption of a small amount of 14N14N upon switching from 14NO + CO to 15NO + CO mixtures points to the role of additional adsorbates nearby the reaction surface site in facilitating the dissociation of the N–NO intermediates. In addition, the results from experiments with mixed 14NO + 15NO + CO indicate a combination of reactions at the edges of previously deposited 14N islands and the growth of new mixed 14N + 15N surface clusters.
Surgical management of Skene’s gland abscess/infection: a contemporary series

Introduction and hypothesis We report our experience with surgical excision for treatment of Skene’s gland abscess/infection after conservative measures have failed.
Numerical simulation of granular materials in a rotating tumbler

Using a simple numerical model based on particle dynamics, we perform two-dimensional simulations of granular materials inside a rotating tumbler. Still in its first stages of development, the model can quantitatively reproduce some of the general behavior observed in these systems, both for monodisperse and binary mixtures. Work is currently being done to validate the model and obtain results that are directly comparable to experiments.
Burn depth determination in human skin using polarization-sensitive optical coherence tomography

Accurate evaluation of the depth of injury in burn victims is of considerable practical value to the surgeon, both for initial determination of resuscitation fluid requirements, and in deciding whether excision and closure of the wound is necessary. Currently, burn depth is most accurately evaluated by visual inspection, though decisions concerning treatment may not be possible for a number of days post-injury. As part of our ongoing efforts to provide an objective, quantitative method for burn depth determination, we present here the results of a study using polarization-sensitive optical coherence tomography (PS-OCT) to detect and measure thermally induced changes in collagen birefringence in skin excised from burn patients. We find that PS-OCT is capable of imaging and quantifying significantly reduced birefringence in burned human skin.
Ultrasonic Characterization of SOL/GEL Processing

The sol/gel process has recently received attention because it enables the production of pure and homogeneous glass without external heating, eliminating the high processing temperatures needed in conventional methods. A disadvantage of the process is that if the rate of evaporation during syneresis is too high, cracking due to mechanical shrinkage can be extensive. A slower evaporation rate produces less cracking, but results in a longer processing time. The key to decreasing processing time while simultaneously eliminating shrinkage cracks lies in monitoring the change of the mechanical properties during the evaporation process. Ultrasonic techniques are ideal for this purpose. To monitor the process, an ultrasonic signal was passed through the material. Spectrum changes were measured and then converted to changes in modulus and viscosity, while shrinkage and density changes were monitored using an air-type transducer and an electronic balance. The results show no observable change up to the beginning of the gelation process, followed by rapid increase in the modulus and viscosity after the onset of shrinkage. This finding was confirmed using a viscometer and laser light scattering measurements. Because of the effectiveness of this ultrasonic technique in detecting changes in the material, such as the onset of cracking, it may be used in controlling and improving the process.
Commensurate defect superstructures in a Langmuir-Blodgett film.

Molecular-resolution atomic force microscope images of Ba arachidate Langmuir-Blodgett multilayers show two previously unknown structures, a tilted (26 o ) triclinic packing with a 3×1 sawtooth height modulation, and a tilted (19 o ) rectangular herringbone packing with an alternating vertical offset, along with untilted disordered regions, all within the same molecular layer. The submicron extent of each region, the extent of twinning and defects, and the complexity of the molecular packing make the determination of the lattice structure of these materials impossible by any other technique
Plant temperature stress detection with machine vision

Spectral and morphological features were used to detect temperature induced stress on tomato plants. Top projected canopy area (TPCA) and profile were selected as morphological features and the reflectance of plant under side canopy (USC) and its average gray level were chosen as spectral features. Temperature regimes (day/night, 18/6 hours) 24/21 degrees Celsius, 21/18 degrees Celsius, and 19.5/16.5 degrees Celsius were used. Both spectral and morphological features were capable of detecting temperature stresses. Reflectance and gray level of plant USC correlated with average environment temperatures. The stress was detected after one week from occurrence based on both morphological and spectral features. However, stress was detected more clearly based on spectral features.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Reviving partial order planning

This paper challenges the prevailing pessimism about the scalability of partial order planning (POP) algorithms by presenting several novel heuristic control techniques that make them competitive with the state of the art plan synthesis algorithms. Our key insight is that the techniques responsible for the efficiency of the currently successful planners–viz., distance based heuristics, reachability analysis and disjunctive constraint handling–can also be adapted to dramatically improve the efficiency of the POP algorithm. We implement our ideas in a variant of UCPOP called REPOP. Our empirical results show that in addition to dominating UCPOP, REPOP also convincingly outperforms Graphplan in several “parallel” domains. The plans generated by REPOP also tend to be better than those generated by Graphplan and state search planners in terms of execution flexibility.
Commerce geophysical lineament—Its source, geometry, and relation to the Reelfoot rift and New Madrid seismic zone

The Commerce geophysical lineament is a northeast-trending magnetic and gravity feature that extends from central Arkansas to southern Illinois over a distance of ≈400 km. It is parallel to the trend of the Reelfoot graben, but offset ≈40 km to the northwest of the western margin of the rift floor. Modeling indicates that the source of the aeromagnetic and gravity anomalies is probably a mafic dike swarm. The age of the source of the Commerce geophysical lineament is not known, but the linearity and trend of the anomalies suggest a relationship with the Reelfoot rift, which has undergone episodic igneous activity. The Commerce geophysical lineament coincides with several topographic lineaments, movement on associated faults at least as young as Quaternary, and intrusions of various ages. Several earthquakes (M b > 3) coincide with the Commerce geophysical lineament, but the diversity of associated focal mechanisms and the variety of surface structural features along the length of the Commerce geophysical lineament obscure its relation to the release of present-day strain. With the available seismicity data, it is difficult to attribute individual earthquakes to a specific structural lineament such as the Commerce geophysical lineament. However, the close correspondence between Quaternary faulting and present-day seismicity along the Commerce geophysical lineament is intriguing and warrants further study.
Heterogeneous electron transfer at designed semiconductor/liquid interfaces. Rate of reduction of surface-confined ferricenium centers by solution reagents

Reduction of surface-confined ferricenium by solution reductants iodide, diindenyliron, (eta/sup 5/-C/sub 5/H/sub 5/)/sub 4/Fe/sub 4/(CO)/sub 4/, 1,1'-dimethylferrocene, ferrocene, and phenylferrocene has been studied in EtOH-0.1 M (n-Bu/sub 4/N)ClO/sub 4/ and also in H/sub 2/O-NaClO/sub 4/ for iodide. The surface-confined ferricenium can be generated on n-type Si by illumination of the electrode at some potential more positive than approx. -0.2 V vs. SCE. Linear sweep voltammetry was used to directly measure the time dependence of the surface ferricenium concentration in the dark and in the presence of the various reducing agents. The rate constant for the reaction with iodide was measured in both solvents, and the value in EtOH is somewhat lower than would be estimated from homogeneous solution reaction of ferricenium with iodide under the same conditions. Values of reaction rate constants for reaction with all other reductants indicate that the reduction rate is mass transport, not charge transfer, limited under the conditions employed. The relative ordering of the fast reductants has been determined to be diindenyliron > (eta/sup 5/-C/sub 5/H/sub 5/)/sub 4/Fe/sub 4/(CO)/sub 4/ approx. 1,1'-dimethylferrocene > ferrocene approx. phenylferrocene. Most of the derivatized surfaces have been prepared from (1,1'-ferrocenediyl)dichlorosilane, but preliminary results with polyvinylferrocene modified and (1,1'-ferrocenediyl)dimethylsilane derivatizedmore » surfaces are similar. Very high coverage surfaces from (1,1'-ferrocenediyl)dichlorosilane show some evidence for selective reduction of the more accessible ferricenium centers when a fast reductant is used. Steady-state photoanodic current at a given concentration of reductant generally accords well with the measured k/sub et/ values, and for the iodide experiments the steady-state photocurrent is directly proportional to surface coverage of electroactive ferrocene.« less
Pulmonary function in diseases of the chest.

An accurate evaluation of the degree of pulmonary function impairment may be made from the following physiological tests: (1) Ventilation measurements from spirogram tracings (total vital capacity, three second timed vital capacity, maximal breathing capacity and the shape of the exhalation curve following a deep breath), (2) the degree of bronchospasm present, (3) the residual air capacity and alveolar nitrogen per cent after seven minutes oxygen breathing, (4) the arterial blood oxygen saturation at rest and immediately after step-up exercise, (5) the oxygen uptake during step-up exercise, (6) the per cent of oxygen extracted from the inspired air breathed and (7) the character and duration of dyspnea after step-up exercise.
Phonon modes in carbon nanotubules

Abstract The relationship between the phonon modes in carbon nanotubules and those in a graphene sheet is studied by use of the zone-folding method. The modes identified with pure translations and rotations are identified. General results relating to the symmetry properties of the Raman and infrared activity of the phonon modes are deduced. It is shown that as the diameter of a tubule increases, the number of Raman and infrared active modes is essentially unchanged despite the increase in the number of atoms per unit cell. Explicit phonon dispersion curves are presented for a small diameter armchair carbon tubule.
Race, Socio-Economic Status, and Perceived Similarity as Determinants of Judgements by Simulated Jurors.

Eighty-four simulated jurors judged a defendant on trial for armed robbery after reading trial transcripts and other background information in a 2 × 2 factorial design which varied the defendant’s race and socioeconomic status (SES). Higher SES (middle class) defendants were judged less guilty and assigned fewer years in prison than low SES defendants regardless of race. A race x SES interaction on attributed blameworthiness of the defendant, which was inversely related to the jurors’ judgments of the defendant’s similarity to them, was also found. Theoretical and methodological implications of these findings for jury simulation studies are discussed.
Internally Consistent Approach for Modeling Solid-State Aggregation: I. Atomistic Calculations of Vacancy Clustering in Silicon

A computational framework is presented for describing the nucleation and growth of vacancy clusters in crystalline silicon. The overall approach is based on a parametrically consistent comparison between two representations of the process in order to provide a systematic method for probing the details of atomic mechanisms responsible for aggregation. In this paper, the atomistic component of the overall framework is presented. First, a detailed set of targeted atomistic simulations are described that characterize fully the thermodynamic and transport properties of vacancy clusters over a wide range of sizes. It is shown that cluster diffusion is surprisingly favorable because of the availability of multiple, almost degenerate configurations. A single large-scale parallel molecular dynamics simulation is then used to compute directly the evolution of the vacancy cluster size distribution in a supersaturated system initially containing 1000 uniformly distributed vacancies in a host lattice of 216 000 Si atoms at 1600 K. The results of this simulation are interpreted in the context of mean-field scaling theory based on the observed power-law evolution of the size distribution moments. It is shown that the molecular dynamics results for aggregation of vacancy clusters, particularly the evolution of the average cluster size, can be very well represented by a highly simplified mean-field model. A direct comparison to a detailed continuum model is made in a subsequent article.
Anti-Colonialism and Social Science: Georges Balandier, Madeira Keita, and “the Colonial Situation” in French Africa

Two young men met on a quay at the port in Conakry, Guinea in 1946. One, waiting dockside, was Mamadou Madeira Keita, a low-level civil servant and archivist. Years later, when he was a political prisoner in the Malian Sahara, some would argue that he was “the first francophone African ethnographer.” The other, descending the gangplank, was the Frenchman Keita had come to meet. Georges Balandier was unknown then, but would soon become a leading figure in the fields of sociology and anthropology. The encounter between Keita and Balandier was foundational for both men. Conakry incubated a canonical intervention—Balandier's 1951 article “La Situation Coloniale”—that some attribute an ancestral role in a particular francophone tradition of postcolonial thought. Conakry, and Guinea at large, was also the crucible in which a powerful anti-colonial politics were forged by Madeira Keita and his allies. In this particular corner of West Africa, anti-colonial politics and an emergent, politically engaged social science conditioned each other, like the two strands of a double helix, each a necessary yet ultimately contingent element of the other's structure. Though these links did not last long, they had important effects. This article, by emphasizing the contingencies of the two men's intertwined biographies, seeks to carry out Balandier's dictate to emphasize the “concrete” nature of this particular situation in order to understand how and why anti-colonial politics and an innovative sociology converged and ultimately diverged.
Multiflavor QCD in two dimensions: Breakdown of local color symmetry and liberation of massive quarks

Abstract It is shown that in two-dimensional, multiflavor QCD with one massless flavor, local color symmetry is broken spontaneously and the gluons rendered massive by means of the Schwinger mechanism. The massive quarks are thereby liberated.