cssi/SciSciGPT-SciSciNet huggingface dataset:
Localization of epidermal sphingolipid synthesis and serine palmitoyl transferase activity: alterations imposed by permeability barrier requirements.

Sphingolipids, the predominant lipid species in mammalian stratum corneum play, a central role in permeability barrier homeostatis. Prior studies have shown that the epidermis synthesizes abundant sphingolipids, a process regulated by barrier requirements, and that inhibition of sphingolipid synthesis interferes with barrier homeostasis. To investigate further the relationship between epidermal sphingolipid metabolism and barrier function, we localized sphingolipid synthetic activity in murine epidermis under basal conditions, and following acute (acetone treatment) or chronic (essential fatty acid deficiency, EFAD) barrier perturbation, using dithiothreitol and/or the staphylococcal epidermolytic toxin to isolate the lower from the outer epidermis. Under basal conditions, both the activity of serine palmitoyl transferase (SPT), the rate-limiting enzyme of sphingolipid synthesis, and the rates of3H-H2O incorporation into sphingolipids were nearly equivalent in the lower and the outer epidermis. Following acute barrier perturbation, SPT activity increased significantly in both the lower (35%;P < 0.05) and the outer epidermal layers (60%;P < 0.01). The rates of3H-H2O incorporation into each major sphingolipid family, including ceramides, glucosylceramides and sphingomyelin, increased significantly in both the lower and the outer epidermis of treated flanks after acute barrier disruption. Finally, SPT activity was modestly elevated (20%;P < 0.01) in the lower but not in the outer epidermis of EFAD animals. These studies demonstrate the ability of both lower and outer epidermal cells to generate sphingolipids, and that permeability barrier homeostatic mechanisms appear to differentially regulate SPT acitivity and sphingolipid synthesis in the lower and the outer epidermis in response to acute and chronic barrier perturbation. Moreover, intraepidermal sites of sphingolipid synthesis displayed distinctive differences in the localization and alterations of cholesterologenesis in response to equivalent barrier perturbations.
Pattern driven lazy reduction: A unifying evaluation mechanism for functional and logic programs

A novel lazy evaluation mechanism, pattern-driven lazy reduction, is developed that serves as a unifying evaluation mechanism for both functional and logic programs. The reduction of a function call can be viewed as “semantically” unifying the function call with the left hand side of a defining equation, and applying the unifier to the right hand side. Lazy reduction is achieved by the pattern which the function call matches against. Function reductions are actually “driven” by patterns in this sense. It is shown that this evaluation mechanism works well for both functional programs and logic programs that involve “executable” functions. As a result, logic programs can be enhanced with (1) the availability of a functional computing environment where there is no notion of backtracking, thus alleviating the degree of control difficulties typically encountered in logic programs, and (2) the ability to terminate “infinite computations” without the introduction of complex control issues at the user-level. On the other hand, functional programs can be equipped with the power of logic programming languages, e.g., Prolog.
Protecting God from Science and Technology: How Religious Criticisms of Biotechnologies Backfire

Many religious critics argue that biotechnology (such as cloning and genetic engineering) intrudes on God's domain, or plays God, or revolts against God. While some of these criticisms are standard complaints about human hubris, I argue that some of the recent criticism represents a “Promethean” concern, in which believers unreflectively seem to fear that science and technology are actually replicating or stealing God's special deity–defining powers. These criticisms backfire theologically, because they diminish God, portraying God as an anthropomorphic superbeing whose relevance and special nature are increasingly rivaled by human power.
Stability of Plane Poiseuille Flow with Heat Transfer

The influence of heat transfer on the stability of a plane Poiseuille flow in a channel is under investigation. The liquid flow is affected by the heat transfer through the variation in viscosity with temperature. Additional viscosity gradient terms are included in a modified Orr‐Sommerfeld equation, and it is the presence of these terms which leads to a prediction of more unstable flows, for without the inclusion of these extra terms, the flow is stabilized. The results show that a temperature difference between the walls is always destabilizing and, in particular, a temperature difference between the walls of 100°F leads to a reduction in the critical Reynolds number from 7800 to 4600.
1519 ROLE OF THE ANION IN VOLUME EXPANSION NATRIURESIS IN NEWBORN DOGS

Neonatal dogs 2 to 18 days had volume expansion (VE) with either NaCl (n=7) or NaHC03 (n=8) to determine the role of the anion in VE natriuresis. In VE with NaCl, Fractional Excretion (FE) of sodium, FENa, = 1.1%, FEK = 41.8%, FECl = 3.0%, FEHCO3 = .03%. In VE with NaHCO3, plasma HCO3 was elevated (37.3 mM) and FENa = 2.8% (p<.05), FEK = 84.7% (p<.01), FECl = 0.6% (p<.01), FEHCO3 = 7.3% (p<.01). When plasma HCO3 was elevated (32.7 mM) without VE by exchange transfusion with high HCO3, low Cl blood in 15 puppies, FENa = .4%, FEHCO3 = .7%, FEK = 47.1%. Without VE in 14 puppies with normal plasma HCO3, receiving ethacrynic acid and amiloride to block Henle's Loop (HL) and distal tubular function, FENa = 27%, FEHCO3 = 2%, FEK = 30%, FECl = 37%, but with saline VE and these diuretics FENa = 55% (p<.01), FECl = 64.2% (p<.01), FEHCO3 = 2.4% (N.S.), FEK = 68% (p<.01). We conclude that without VE almost all HCO3 is reabsorbed in the proximal tubule (PT) even with high plasma HCO3. VE, due either to NaCl or NaHCO3, inhibits PT Na reabsorption, resulting in increased loads of Na, HCO3 and Cl to HL. However, with VE due to NaCl relatively more Cl and less HCO3 is delivered to HL than during VE with NaHCO3. Thus, in the saline group HL reabsorbs more Na (as Cl) than in the HCO3 group so that in the latter group, more Na is presented to the distal tubule (as HCO3), resulting in greater distal K secretion. The net effect is greater Na, K and HCO3 and less Cl excretion during VE with NaHCO3 than with NaCl.
EFFECTS OF POSITIVE-ION RESONANCES IN PHOTOIONIZATION OF NEUTRAL ATOMS

Single photoionization of neutral atoms is examined theoretically for a situation in which the photoionizing laser is tuned close to the resonant frequency for transitions between the ground and first-excited states of the positive ion. The resonant coupling in the positive ion is shown to have a dramatic peak-splitting effect on the kinetic-energy spectrum of the ionized electron. An essential-states analysis of the photoionization process is presented, and a comparison is made with numerical results for one-dimensional helium. The agreement between the results establishes the validity of the essential-states approach. The possibility of superposing this core-coherence effect with laser-induced autoionization effects is considered.
Physiological effects of emotional odors

Advances in neuromaging have provided new and exciting knowledge concerning how odors come to activate emotional systems in the brain. Often neglected are the concomitant changes that follow this activation throughout the body. Odor-induced emotional changes in peripheral physiological systems will be critically discussed including changes in respiration, muscle tone, skin conductance and heart rate. Multidimensional patterning of these responses may prove especially valuable in identifying subtle emotional response. Research to date, however, contains few examples of successful response patterning related to odors.
The role of tumor-associated macrophages in breast cancer progression (Review)

It is well established that the tumor microenvironment plays a major role in the aggressive behavior of malignant solid tumors. Among cell types associated with tumor microenvironment, tumor-associated macrophages (TAMs) are the most influential for tumor progression. Breast cancer is characterized by having a large population of TAMs, and experimental models have exposed multiple mechanisms by which TAMs interact with and influence the surrounding tumor cells. The process of metastasis involves tumor cells gaining access to the tissue outside the immediate tumor environment and invading the confining extracellular matrix (ECM). Supporting this process, TAMs secrete proangiogenic factors such as VEGF to build a network of vessels that provide nutrition for tumor cells, but also function as channels of transport into the ECM. Additionally, TAMs release factors to decrease the local pro-inflammatory antitumor response, suppressing it and providing a means of escape of the tumor cells. Similarly, hypoxia in the tumor microenvironment stimulates macrophages to further produce VEGF and suppress the T-cell immune responses, thus, enhancing the evasion of tumor cells and ultimately metastasis. Given the multiple roles of TAMS in breast cancer progression and metastasis, therapies targeting these cells are in development and demonstrate promising results.
Time after apple pressing and insoluble solids influence the efficiency of the UV treatment of cloudy apple juice

Abstract The effects of suspended insoluble solids (SIS) concentration and particle size, and the time after apple pressing on the efficiency of UV treatment of cloudy apple juice were evaluated. Clear model solutions (formulated to resemble physicochemical characteristics of apple juice) and commercial apple juice, containing different solids concentrations, were treated using a CiderSure reactor at 14 mJ cm −2 UV dose. Particle size effect was assessed on model solutions treated at 7 mJ cm −2 UV dose. The juice flow rate through the UV machine was determined. All samples were inoculated with Escherichia coli ATCC 25922 (10 6 –10 7 CFU ml −1 ) and UV treated at 214.5 ml s −1 fixed flow rate. Log reductions were calculated. Increasing SIS concentrations did not significantly affect the juice flow rate (P > 0.05) but adversely affected the inactivation of E. coli (P −2 , a negative linear relationship between SIS and flow rate was observed and particle size significantly affected the flow rate (P
Error prediction for adaptive modulation and coding in multiple-antenna OFDM systems

In this paper, the problem of packet error rate (PER) prediction is addressed in the multiple-antenna broadband OFDM context, and its impact on adaptive modulation and coding (AMC) is quantified. The analysis is based on a physical layer comprising various modulation and coding schemes, ranging from robust space-time block coding (STBC) modes to high bit rate spatial division multiplexing (SDM) modes, and also hybrid SDM-STBC schemes. For each mode the expression of several link quality metrics (LQM) enabling PER prediction in the broadband OFDM channel, such as instantaneous signal-to-noise ratio (SNR), capacity, or exponential effective SNR metrics are provided. Their advantages and limitations are investigated. Finally, their performance is benchmarked in the IEEE 802.11a/g/n context. It is shown that the choice of the LQM has a significant impact on the throughput performance of the AMC algorithm.
The Debye-Waller factor: From villain to hero in protein crystallography†

A personal and partially anecdotal account is given of the role of the Debye–Waller factor in protein crystallography and protein dynamics.
Four novel U RNAs are encoded by a herpesvirus

Summary Marmoset T lymphocytes transformed by herpesvirus saimiri contain the first virally encoded U RNAs (called HSURs) to be identified. HSURs assemble into small nuclear ribonucleoproteins of low abundance (⩽ 2 × 10 4 copies/cell). They bind proteins with Sm determinants and acquire a 5′ trimethylguanosine cap structure. The sequences of HSUR 1 (143 nucleotides), HSUR 2 (115 nucleotides), HSUR 3 (76 nucleotides), and HSUR 4 (106 nucleotides) are related to each other but are distinct from any previously characterized cellular U RNA. The viral genes encoding the HSURs possess conserved enhancer, promoter, and 3′ end formation signals unique to U RNA genes. HSUR 1 and HSUR 2 have a similar 5′ end sequence that exhibits perfect complementarity to the highly conserved AAUAAA polyadenylation signal. Oligonucleotide directed RNAase H degradation indicates that this 5′ end region is available for base pairing interactions within the HSUR 1 and HSUR 2 snRNP particles.
Effects of applied sewage sludge compost and fluidized bed material on apple seedling growth.

Abstract Two waste products, composted sewage sludge and fluidized bed material (FBM, a coal/limestone combustion byproduct) were used as soil amendments for apple seedlings (Malus domestica) grown in the greenhouse. Compost was applied at rates equivalent to 0, 25 and 50 dry metric tons/ha and FBM was applied at levels of 1 and 2 times the soil lime requirement on a weight basis (12.5 and 25.0 metric tons/ha). Plant growth was significantly increased by compost or FBM additions. Tissue Ca was increased by both wastes, reflecting the high Ca inputs to the low fertility Arendtsville soil. Potentially high soil Mn levels were reduced by both wastes due to their neutralizing effect on soil pH. Root Cd levels were increased by compost additions even though soil pH was maintained above 6.3. Tissue Zn, Cu and Ni were not consistently affected by waste additions.
Sealing pond bottoms with muddy water

Abstract Seepage losses from constructed wetlands, wildlife refuges, wastewater lagoons, runoff collection ponds, and other engineered surface impoundments of water or aquatic ecosystems in areas with deep groundwater levels can be minimized with artificial liners (plastic, compacted earth, etc.) or with natural processes like sediment accumulation and microbiological and chemical processes. Sediment accumulation can be increased by deliberately adding soil slurries or muddy (turbid) water. When these are applied to the water surface, settling of the particles to the bottom then creates a graded sediment layer with the coarsest particles on the bottom and the finest particles on top. Column studies in the laboratory showed that, for a given amount of soil added, such a graded layer gives more seepage control than a compacted earth liner. Also, split slurry applications to create a layered lining gave more seepage control than when the same total amount of soil was given in one single slurry application. Subsequent addition of sodium carbonate to the water reduced seepage even more, giving a total seepage reduction in the columns from 1000 to 0.2 cm/day. The study also indicates the importance of avoiding turbid inflows into infiltration basins for groundwater recharge, as well as soil erosion within the basins themselves, if infiltration rates need to be maximized.
Academic software: vision and perspective

Note: In pages that follow, "computer software," "academic software," etc. refer only to microcomputer software. Minicomputer software and mainframe computer software are subject to different constraints from those associated with the smaller machines. We recognize the continuing significance and impact of PLATO, authoring systems, and other large-scale CAI projects; however, dealing with them explicitly is beyond the scope of this paper. As the networking of microcomputers on campuses (and between campuses) continues, the economics associated with software for micros will have even more in common with that of the larger systems now in place.
Effects of Genes, Sex, Age, and Activity on BMC, Bone Size, and Areal and Volumetric BMD

Quantitative genetic analyses of bone data for 710 inter-related individuals 8-85 yr of age found high heritability estimates for BMC, bone area, and areal and volumetric BMD that varied across bone sites. Activity levels, especially time in moderate plus vigorous activity, had notable effects on bone. In some cases, these effects were age and sex specific. Introduction: Genetic and environmental factors play a complex role in determining BMC, bone size, and BMD. This study assessed the heritability of bone measures; characterized the effects of age, sex, and physical activity on bone; and tested for age- and sex-specific bone effects of activity. Materials and Methods: Measures of bone size and areal and volumetric density (aBMD and vBMD, respec- tively) were obtained by DXA and pQCT on 710 related individuals (466 women) 8-85 yr of age. Measures of activity included percent time in moderate + vigorous activity (%ModVig), stair flights climbed per day, and miles walked per day. Quantitative genetic analyses were conducted to model the effects of activity and covariates on bone outcomes. Results: Accounting for effects of age, sex, and activity levels, genes explained 40-62% of the residual variation in BMC and BMD and 27-75% in bone size (all p < 0.001). Decline in femoral neck (FN), hip, and spine aBMD with advancing age was greater among women than men (age-by-sex interaction; all p 0.05). %ModVig had the most notable effect on bone; high activity was associated with higher aBMD at all sites, but the magnitude of this effect varied. Activity among men was associated with higher FN BMC and cross- sectional area (CSA) at the 4% radius, but this was not observed among women (sex-by-activity interaction, both p 0.05). Younger women had greater cortical vBMD (Cort-vBMD) than younger men, with minimal difference between low and high activity levels. Influence of activity was greater in older women: older women with low activity had lower Cort-vBMD than older men, but older women with high activity had higher Cort-vBMD than older men (age-by-sex-by-activity interaction, p � 0.04). Conclusions: High heritability estimates for DXA and pQCT measures varied across bone sites. Percent time spent in moderate to vigorous activity had the most notable effect on bone, and in some cases, this effect was age or sex specific. J Bone Miner Res 2007;22:737-746. Published online on February 19, 2007; doi: 10.1359/JBMR.070213
Investigation of relations between porosity, pore structure, and C1− diffusion of fly ash and blended cement pastes

By-product fly ash from coal combustion influences the properties of cement pastes significantly. A study has been carried out to contribute to understanding the behavior and function of fly ash and other substituents in cement pastes. Comparisons are made with the properties of pastes of as-received portland cement and preliminary comparisons made with granulated blast furnace slag cement and silica fume-cement. Relations between the median pore size, porosity and Cl− diffusion of fly ash-cement pastes, and the implications of observations for diffusion mechanisms and the probable pore structure of the blended cement pastes are discussed. Measurements include non-evaporable water (Wn), porosity and pore structure by mercury porosimetry, Cl− transport by a rapid method under the influence of an applied electric field, and the permeability to water. X-ray diffraction phase characterization has been made before and after Cl− diffusion.
On the Statistical Properties of Two-Dimensional Decaying Turbulence

By high-resolution numerical integration of two-dimensional Navier-Stokes equations we show that the turbulent flow at high Reynolds number is dominated by a simple and weakly unstable Hamiltonian system of pointlike vortices. The large instabilities, typical of the turbulent flow, are found uniquely outside vortices, in the wide dissipative region which results to be only a small perturbation of the vortex system. Moreover, the statistical distribution of vortex sizes determines the slope of the energy spectrum, which is steeper than that predicted by phenomenological theories.
Role of topical fluoroquinolones on the pathogenesis of diffuse lamellar keratitis in experimental in vivo studies

Purpose To investigate the potential role of commercially available topical fluoroquinolones in diffuse lamellar keratitis (DLK) using New Zealand White rabbit models. Setting Campbell Ophthalmic Microbiology Laboratory at the University of Pittsburgh, Pittsburgh, Pennsylvania, USA. Methods In a DLK challenge model, laser in situ keratomileusis flaps were created by a microkeratome in rabbit eyes (n = 10 per group) and the stromal beds were treated with 1 drop of Ciloxan (ciprofloxacin 0.3%), Ocuflox (ofloxacin 0.3%), balanced salt solution (BSS), or Pseudomonas aeruginosa endotoxin before flap closure. After the procedure, eyes were treated with the same drugs 4 times daily. On postoperative day 1, the eyes were examined by slitlamp and graded (modified Linebarger DLK grading scale) in a masked fashion. In a DLK exacerbation model, all eyes received 1 drop of endotoxin on the stromal interface followed by flap closure. After the procedure, the rabbit eyes (10 per group) were treated 4 times daily with Ciloxan, Ocuflox, or BSS and graded for DLK on postoperative day 1 as before. Results In the challenge model, Ciloxan, Ocuflox, and endotoxin all produced higher median DLK scores than the BSS control (P = .02). Ciloxan produced significant DLK in more eyes and had higher median scores (70%, 1.0) than Ocuflox (40%, 0.5) or endotoxin (45%, 0.5) (P = .05). In the endotoxin-induced model, Ciloxan produced significantly higher DLK scores than Ocuflox or BSS (P = .05). Conclusions Topical fluoroquinolones caused and exacerbated DLK in rabbit models. Ocuflox was associated with less DLK than Ciloxan. The clinical significance of these findings can only be assessed in clinical trials.
Strategies for disease modification in Alzheimer's disease

Treating Alzheimer's disease (AD) is the biggest unmet medical need in neurology. Current drugs improve symptoms, but do not have profound disease-modifying effects. Three main classes of disease-modification approaches can be defined: one that is broadly neurotrophic or neuroprotective, one that targets specific aspects of AD pathology, and one that is based on epidemiological observation. This review discusses all three approaches, with particular emphasis on anti-amyloid strategies - currently the most active area of investigation. The approaches that are reviewed include secretase inhibition, amyloid-beta aggregation inhibition, immunotherapy and strategies that might indirectly affect the amyloid pathway.
Synthesis and characterization of cyano-substituted disilacyclobutane rings and poly(silylenemethylene) polymers

Abstract The synthesis, and characterization by nuclear magnetic resonance (NMR) spectroscopy, of two cyano-substituted 1,3-disilacyclobutanes, 1,3-dicyano-1,3-dimethyl-1,3-disilacyclobutane, [Si(CN)(Me)CH 2 ] 2 , and 1,1,3,3-tetracyano-1,3-disilacyclobutane, [Si(CN) 2 CH 2 ] 2 , are reported. Evidence for a trans / cis exchange process in solution was obtained in the case of [Si(CN)(Me)CH 2 ] 2 , where the initially obtained all- trans isomer was observed, by NMR spectroscopy, to rearrange to a mixture of the cis and trans isomers. The corresponding poly(silylenemethylene) (PSM) polymers, [Si(CN)(Me)CH 2 ] n and [Si(CN) 2 CH 2 ] n , were obtained in, respectively, fully and partially substituted form by means of exchange reactions carried out on the corresponding chloro-PSMs with trimethylsilyl cyanide. The [Si(CN)(Me)CH 2 ] n polymer, which is a silicon analog of poly(methacrylonitrile), was found to exhibit a glass transition at 33 °C.
Overcoming the barriers: A concerted effort to prevent ventilator-associated pneumonia

Evidence-based strategies to prevent ventilator-associated pneumonia (VAP) and other complications of critical illness have been published during the past few years 1–3 . Despite the availability of guidelines and practice recommendations, many nurses do not implement known strategies for preventing VAP in the critical care setting. What are some of the reasons for lack of evidence-based practice?
Multinozzle Emitter Arrays for Nanoelectrospray Mass Spectrometry

Mass spectrometry (MS) is the enabling technology for proteomics and metabolomics. However, dramatic improvements in both sensitivity and throughput are still required to achieve routine MS-based single cell proteomics and metabolomics. Here, we report the silicon-based monolithic multinozzle emitter array (MEA) and demonstrate its proof-of-principle applications in high-sensitivity and high-throughput nanoelectrospray mass spectrometry. Our MEA consists of 96 identical 10-nozzle emitters in a circular array on a 3 in. silicon chip. The geometry and configuration of the emitters, the dimension and number of the nozzles, and the micropillar arrays embedded in the main channel can be systematically and precisely controlled during the microfabrication process. Combining electrostatic simulation and experimental testing, we demonstrated that sharpened-end geometry at the stem of the individual multinozzle emitter significantly enhanced the electric fields at its protruding nozzle tips, enabling sequential nan...
Physical and kinetic properties of sheep liver pyridoxine kinase.

Abstract Pyridoxine kinase purified from sheep liver was found to consist of a single polypeptide chain with a molecular weight of 60,000 as determined by gel filtration, sedimentation equilibrium ultracentrifugation, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The isoelectric pH of the enzyme was 5.1, and the pH optimum was between 5.5 and 6.0. The enzyme required divalent cations for activity. At cation concentrations of 80 μ m , the enzyme activity with each cation was in the order of Zn 2+ > Mn 2+ > Mg 2+ . At cation concentrations of 400 μ m , the enzyme activity with each cation was in the order of Mn 2+ > Zn 2+ > Mg 2+ . Excess free divalent cation inhibited the enzyme. Pyridoxine kinase also required monovalent cations. The enzyme activation was greatest with K + , then Rb + and NH 4 + , whereas the enzyme had very little activity with Na + , Li + , or Cs + . Na + did not interfere with the activation by K + . The activation of the kinase by K + , NH 4 + , and Rb + followed Michaelis-Menten kinetics, and the apparent K m values for the cations were 8.9, 3.7, and 5.3 m m , respectively. Increasing the potassium concentration lowered the apparent K m value of the enzyme for pyridoxine and had little or no effect on the K m for ZnATP 2− or the V of the kinase-catalyzed reaction.
Metabotropic glutamate receptors (mGlus) and cellular transformation.

Abstract Although the glutamatergic system usually functions in the CNS, expression has been observed in non-neuronal tissues and a subset of cancers. Metabotropic glutamate receptors (mGlus) are highly “druggable” GPCRs and thus a priority for validation as therapeutic targets. We have previously reported that the aberrant expression of mGlu1 is sufficient to induce spontaneous melanoma development in vivo. We isolated and characterized several stable mGlu1-mouse melanocytic clones and demonstrated that these clones are transformed and tumorigenic. We hypothesize that expression of mGlus may not be uncommon in the pathogenesis of tumors other than melanoma, and that activity of an otherwise normal glutamate receptor in an ectopic cellular environment involves signaling pathways which dysregulate cell growth, ultimately leading to tumorigenesis. As most human cancers are of epithelial origin (carcinomas), in this review, the possibility that mGlu1 could function as a complete oncogene and transform epithelial cells is also discussed.
Evaluation of video sequence indexing and hierarchical video indexing

As a first step to creating a video database, a video sequence has to be segmented into several subsequences based on significant changes in the scene. This enables the media user to identify the whole or a part of the sequence and to retrieve scenes of interest from a large video database. Researchers in the past have used a histogram based inter-frame difference approach to identify significant scene changes. To determine which is the best color coordinate system for video indexing, we have evaluated the histogram based indexing method using different color coordinate systems -- RGB, HSV, YIQ, L*a*b*, L*u*v* & Munsell -- and compared the results for accuracy of indexing with reference to subjective indexing. Since it is difficult to determine the exact threshold value to obtain reasonably good results, we also propose a vide segmenting method called hierarchical histogram based indexing that segments a video sequence into several levels of subsequences using different levels of threshold.
Impacts of settlement, damming, and hydromanagement in two boreal lakes: a comparative paleolimnological study

Namakan Lake, located in shared border waters in northeastern Minnesota and northwestern Ontario, was subjected to several anthropogenic impacts including logging, damming, water-level manipulations, and perhaps climate change. We used paleolimnology to determine how these stressors impacted Namakan Lake in comparison to a control lake (Lac La Croix) that was not subject to damming and hydromanagement. One core was retrieved from each lake for 210Pb dating and analysis of loss-on-ignition and diatom composition. 210Pb-derived chronologies from the cores indicated that sediment accumulation increased after logging and damming in Namakan Lake; Lac La Croix showed no significant change. Loss-on-ignition analysis also showed an increase in concentration and accumulation of inorganic material after damming in Namakan Lake; again, minimal changes were observed in Lac La Croix. Diatom communities in both lakes displayed community shifts at the peak of logging. Simultaneous, post-1970s diatom community changes may reflect regional climate warming. Taxonomic richness in Namakan Lake decreased sharply after damming and the peak of logging, and was followed by a slow recovery to taxonomic richness similar to that prior to damming. Ecological variability among post-damming diatom communities, however, was greater in Namakan Lake than in Lac La Croix. A diatom calibration set was used to reconstruct historical conductivity and total phosphorus (TP). Lac La Croix showed little historical change in conductivity and TP. In contrast, conductivity increased for several decades in Namakan Lake after damming, possibly in relation to several large fires and flooding. Total phosphorus also increased in Namakan Lake after damming, with a possible decrease in the last decade to pre-damming TP levels.
The Oshima–Sekiguchi and Liouville theorems on Heintze groups

Abstract Let L be an elliptic operator on a Riemannian manifold M. A function F annihilated by L is said to be L -harmonic. F is said to have moderate growth if and only if F grows at most exponentially in the Riemannian distance. If M is a rank-one symmetric space and L is the Laplace–Beltrami operator for M, the Oshima–Sekiguchi theorem [T. Oshima, J. Sekiguchi, Eigenspaces of invariant differential operators on an affine symmetric space, Invent. Math. 57 (1980) 1–81] states that a L -harmonic function F has moderate growth if and only if F is the Poisson integral of a distribution on the Furstenberg boundary. In this work we prove that this result generalizes to a very large class of homogeneous Riemannian manifolds of negative curvature. We also (i) prove a Liouville type theorem that characterizes the “polynomial-like” harmonic functions which vanish on the boundary in terms of their growth properties, (ii) describe all “polynomial-like” harmonic functions, and (iii) give asymptotic expansions for the Poisson kernel. One consequence of this work is that every Schwartz distribution on the boundary is the boundary value for a L -harmonic function F which is uniquely determined modulo “polynomial-like” harmonic functions.
The Comparability of Equal Raw Scores Obtained from In-Level and Out-Of-Level Testing: One Source of the Discrepancy between In-Level and Out-of-Level Grade Equivalent Scores.

individualized testing in terms of grade equivalent scores depressed performance indices. Long, Schraffran, and Kellogg (1977), using the Gates-MacGinitie Test, found evidence that grade-equivalent scores from out-of-level testing and grade level testing were not comparable. There are three possible reasons for these differences in grade equivalent scores found with grade-level and instructional level testing. 1. The student being tested out-of-level has had an alternative curriculum to that of the child being tested in-level. The questions on the test may be systematically relatively easier or harder for the child being tested out-of-level. 2. If the test selected to match the child's instructional level is inappropriately too difficult in level, the child's score may be largely a function of guessing. The grade equivalent values assigned to chance scores increase with the increase in grade levels. The developmental curves for each test level move sequentially up the grade level score scale. Therefore "chance" performance results in increasing grade equivalent values. 3. The test levels and derived scores may not be well articulated at chance score levels of achievement tests. The first possible cause for the discrepancy in grade equivalent results is the one addressed in this research. Since the assignment of grade equivalent scores is based on
Ball-on-flat reciprocating sliding wear of single-crystal, semiconductor silicon at room temperature

Abstract This paper describes the reciprocating linear sliding friction and wear experiments of a polycrystalline silicon ball on a single-crystal, silicon flat at room temperature in an argon environment. The normal loads used were 2.65, 3.59, 4.73 and 5.80 N, and the sliding velocity was 1.3 cm s −1 . The coefficient of friction at a normal load of 2.65 N initially decreased from 0.45 and stabilized at 0.23 after 400 cycles. At higher normal loads, the coefficients of friction were initially 0.45 but later fluctuated between 0.2 and 0.4. The degree of frictional fluctuation as well as the wear volume increased with load. The fluctuation of the coefficient of friction is related to the geometry of the wear debris which form into a cylindrical shape (‘rolls’). A mechanism for roll formation is described.
Long-term in vitro analysis of limb cartilage development: involvement of Wnt signaling.

Endochondral skeletal development involves the condensation of mesenchymal cells, their differentiation into chondrocytes, followed by chondrocyte maturation, hypertrophy, and matrix mineralization, and replacement by osteoblasts. The Wnt family of secreted proteins have been shown to play important roles in vertebrate limb formation. To examine the role(s) of Wnt members and their transmembrane-spanning receptor(s), Frizzled (fz), we retrovirally misexpressed Wnt-5a, Wnt-7a, chicken frizzled-1 (Chfz-1), and frizzled-7 (Chfz-7) in long-term (21 day) high density, micromass cultures of stage 23/24 chick embryonic limb mesenchyme. This culture system recapitulates in vitro the entire differentiation (days 1–10), growth (days 5–12), and maturation and hypertrophy (from day 12 on) program of cartilage development. Wnt-7a misexpression severely inhibited chondrogenesis from day 7 onward. Wnt-5a misexpression resulted in a poor hypertrophic phenotype by day 14. Chfz-7 misexpression caused a slight delay of chondrocyte maturation based on histology, whereas Chfz-1 misexpression did not affect the chondrogenic phenotype. Misexpression of all Wnt members decreased collagen type X expression and alkaline phosphatase activity at day 21. Our findings implicate functional role(s) for Wnt signaling throughout embryonic cartilage development, and show the utility of the long-term in vitro limb mesenchyme culture system for such studies. © 2004 Wiley-Liss, Inc.
A pilot study of concomitant boost accelerated superfractionated radiotherapy for stage III cancer of the uterine cervix

Purpose Retrospective studies suggest that prolonged treatment time adversely affects control rates of squamous carcinomas managed by radiotherapy. From 1989 to 1994 a prospective clinical trial was conducted to assess the feasibility and efficacy of concomitant boost accelerated superfractionated (CBASF) radiotherapy for advanced uterine cervical carcinoma. Methods and materials Twenty newly diagnosed patients with FIGO stage III squamous cell carcinoma of the cervix were irradiated using a CBASF regimen. Patients received 45 Gy administered to the whole pelvis in 25 fractions in 5 weeks. On Monday, Wednesday, and Friday of the last 3 weeks, an additional 1.6 Gy boost was given 6 hours after the whole pelvis treatment. The 9 boost treatments, totaling 14.4 Gy, were given via lateral fields encompassing the parametria and primary tumor for a cumulative tumor dose of 59.4 Gy. A single low-dose rate brachytherapy procedure was performed within 1 week after the external beam radiotherapy to raise the point A dose to 85-90 Gy in 42 days. Primary endpoints of analysis were local control, complications, and patterns of failure. Results are compared with the outcomes of 21 patients treated with conventionally fractionated (CF) radiotherapy during the same years. Results Median total treatment time was 46 days in the CBASF group (range 37-62). Median follow-up interval among surviving CBASF patients is 3.8 years. The four-year actuarial local control rates are 78% and 70% in the CBASF and CF groups, respectively (p = ns). Only 2 CBASF patients required a treatment break because of acute toxicity, but severe late complications occurred in 8/20 CBASF patients for a crude rate of 40%. Distant failure was more common than local failure in the CBASF group, and para-aortic node failure occurred in six of the eight CBASF patients with distant failure. Conclusions In the management of stage III cervix cancer, the CBASF regimen produced a trend toward improved local control when compared with the CF regimen, shifting the patterns of failure toward a higher rate of isolated distant failures. The high frequency of para-aortic node failure warrants consideration of elective treatment to this region in stage III patients treated with curative intent. Although the high local control rate of the CBASF regimen supports further investigation of accelerated treatment regimens for locally advanced cervix cancer, the unacceptable risk of late complications necessitates refinement in technique and scheduling to improve the therapeutic ratio.
Predicted Reaction Rates of HxNyOz Intermediates in the Oxidation of Hydroxylamine by Aqueous Nitric Acid

This work reports computed rate coefficients of 90 reactions important in the autocatalytic oxidation of hydroxylamine in aqueous nitric acid. Rate coefficients were calculated using four approaches: Smoluchowski (Stokes-Einstein) diffusion, a solution-phase incarnation of transition state theory based on quantum chemistry calculations, simple Marcus theory for electron-transfer reactions, and a variational TST approach for dissociative isomerization reactions that occur in the solvent cage. Available experimental data were used to test the accuracy of the computations. There were significant discrepancies between the computed and experimental values for some key parameters, indicating a need for improvements in computational methodology. Nonetheless, the 90-reaction mechanism showed the ability to reproduce many of the trends seen in experimental studies of this very complicated kinetic system. This work highlights reactions that may govern the system evolution and branching behavior critical to the stability of the system. We hope that this analysis will guide experimental investigations to reduce the uncertainties in the critical rate coefficients and thermochemistry, allowing an unambiguous determination of the dominant reaction pathways in the system. Advances in efficient and accurate solvation models that effectively separate entropic and enthalpic contributions will most directly benefit solution-phase modeling efforts. Methods for more accurately estimating activity coefficients, including at infinite dilution in multicomponent mixtures, are needed for modeling high ionic strength aqueous systems. A detailed derivation of the solution-phase equilibrium and transition state theory rate expressions in solution is included in the Supporting Information.
Evanescent-wave tracking: new approach to the analysis of large reflector and aperture antennas

A new method based on local evanescent-wave tracking is proposed for the analysis of large reflector and aperture antennas.
Applications Of A Two-Wavelength Laser Scanner For Material/Device Characterization

Applications of a two-wavelength laser scanner for evaluating spatial variations in several material/device parameters WI semiconductors are described. Use of two-wavelength scanning (λ = 1.15 pm and λ = 6328 A) permits excitation and collection of carriers from different depths below the surface of a semiconductor, thereby allowing separation of bulk and near surface (such as a surface junction) characteristics. These characteristics include minority carrier diffusion length, junction recombination, and local variations in photovoltaic effects caused by localized defects, twins and grain boundaries. Laser scanning may be done in two different modes. 1. Carrier generation and collection along the same direction -- in this mode the signal is related to carrier recombination effects. It is shown that the signal due to long wavelength excitation is proportional to the bulk diffusion length. Measurements may be done either on unprocessed substrates using a transparent electrode and capacitive coupling, or following P-N junction formation at the surface. 2. Carrier excitation and collection normal to each other -- this mode is used in unprocessed substrates (single or polycrystalline) to determine lateral variations in the internal fields arising from such effects as impurity inhomogeneities and grain boundaries.
Transport by a Kinesin in the Presence of Magnetic Nanoparticles

Superparamagnetic nanoparticles are used to influence the medium in which kinesin nanotransport occurs. Simulation results show that nanoparticles form chain-like structures aligned with the direction of applied external magnetic field. The strength of the links in these chains depends on the properties of the particles and on the intensity of the applied magnetic field. Therefore, altering the magnetic field can be used to dynamically control the loads kinesins have to overcome - analogous to modifying properties of the medium in which the transport takes place.The components of the motor protein, namely its two heads, two neck linkers and a neck and a cargo linker, are considered to be linear elastic elements. The chemical reaction of ATP/ADP and the heads is modeled using Michaelis-Menten kinetics and the Arrhenius equation. The overall model is shown to successfully capture the hand-over-hand motion of kinesin. By simulating the transport of a cargo by kinesin through obstacles created by the magnetic nanoparticles, it is shown that the resisting force created by chains of magnetic nanoparticles affects the speed of kinesin transport.However, characterizing the motion of a kinesin in the presence of many magnetic nanoparticles requires stochastic simulations at a variety of conditions. The required computational time is prohibitive. Hence, a generalized model is developed to estimate the force on the cargo without solving the full-order system dynamics every time. Finally, the motion of cargo under varying magnetic fields is studied. These results can be used to detect possible deficiencies in kinesin - microtubule interactions.
Interaction of capillary wetting and fringing magnetic field in ferrofluid systems

Abstract Where a ferrofluid contacts a nonmagnetic material, an externally imposed magnetic field is ordinarly distorted by the discontinuity in permeability. Where a ferrofuid free surface contacts a solid wall, the free surface is usually distorted by the contact angle it must make with the wall. We have analyzed the interaction of the fringing effect and the wetting effect in two representative case studies: the capillary rise of free surfaces of ferrofluid pools and the evolution of magnetohydrostatic equilibrium shapes of ferrofluid drops captive between parallel plates as the strength of an externally imposed magnetic field was varied. In both, the experimental measurements of ferrofluid meniscus shape agree well with predictions computed from theory, indicating that the wetting properties of the solid/liquid/gas system are adequately accounted for in the theory. In the first case the capillary rise is found to increase steadily with applied field strength until onset of the normal field instability. In the second case the captive drop deforms asymmetrically, forming a neck closer to the upper plate than the lower, and finally becomes unstable and breaks.
Pharmacological Inhibition of KIT Activates MET Signaling in Gastrointestinal Stromal Tumors

Gastrointestinal stromal tumors (GIST) are the most common adult sarcomas and the oncogenic driver is usually a KIT or PDGFRA mutation. Although GISTs are often initially sensitive to imatinib or other tyrosine kinase inhibitors, resistance generally develops, necessitating backup strategies for therapy. In this study, we determined that a subset of human GIST specimens that acquired imatinib resistance acquired expression of activated forms of the MET oncogene. MET activation also developed after imatinib therapy in a mouse model of GIST (KitV558del/+ mice), where it was associated with increased tumor hypoxia. MET activation also occurred in imatinib-sensitive human GIST cell lines after imatinib treatment in vitro. MET inhibition by crizotinib or RNA interference was cytotoxic to an imatinib-resistant human GIST cell population. Moreover, combining crizotinib and imatinib was more effective than imatinib alone in imatinib-sensitive GIST models. Finally, cabozantinib, a dual MET and KIT small-molecule inhibitor, was markedly more effective than imatinib in multiple preclinical models of imatinib-sensitive and imatinib-resistant GIST. Collectively, our findings showed that activation of compensatory MET signaling by KIT inhibition may contribute to tumor resistance. Furthermore, our work offered a preclinical proof of concept for MET inhibition by cabozantinib as an effective strategy for GIST treatment.
A stability analysis of a mobile base robot with an energy function

In this paper, a stability analysis coordinating with a computed force/torque control for a mobile base robot (MBR) is introduced. A stability envelope based on the relations between the system's mechanical energy and the stability relation is derived. A computed force/torque control algorithm is applied to the MBR that accounts for the dynamics of the composite system. The above tool is necessary for a mobile robot to perform complex assembly or manufacturing tasks in an unstructured environment.
Learning Disabled Students' Spontaneous Use of Test-Taking Skills on Reading Achievement Tests

The present investigation was undertaken to identify the type of strategies learning disabled (LD) students employ on standardized, group-administered achievement test items. Of particular interest was level of strategy effectiveness and possible differences in strategy use between LD and nondisabled students. Students attending resource rooms and regular third-grade classes were administered items from reading achievement tests and interviewed concerning the strategies they had employed in answering the questions and their level of confidence in each answer. Results indicated that (a) LD students were less likely to report use of appropriate strategies on inferential questions, (b) LD students were less likely to attend carefully to specific format demands, and (c) LD students reported inappropriately high levels of confidence.