cssi/SciSciGPT-SciSciNet huggingface dataset:
LC/MS/MS structure elucidation of reaction intermediates formed during the TiO2 photocatalysis of microcystin-LR

Microcystin-LR (MC-LR), a cyanotoxin and emerging drinking water contaminant, was treated with TiO(2) photocatalysts immobilized on stainless steel plates as an alternative to nanoparticles in slurry. The reaction intermediates of MC-LR were identified with mass spectrometry (MS) at pH of Milli-Q water (pH(sq)=5.7). Eleven new [M+H](+) were observed in the liquid chromatography mass spectrometry (LC/MS) chromatogram with some of them giving multiple peaks. Most of these reaction intermediates have not been reported from previous studies employing TiO(2) nanoparticles at acidic conditions (pH=4.0). Investigating the effects of pH (for 3.0<pH<7.0), toxin adsorption and initial toxin concentration on the degradation efficiency of the TiO(2) photocatalytic films showed that acidic conditions are preferable for the degradation. Combined with the limited surface area of the films and the absence of additional oxidants (i.e., H(2)O(2)) the degradation was slower and more intermediate steps were identified. Possible structures of the intermediates (formed at neutral pH) after analyzing the corresponding MS/MS spectra are reported. The collision-induced dissociation of the [M+H](+) of MC-LR and the intermediates 1011.5 and 1029.5 are discussed and possible fragmentation pathways and mechanisms are also proposed. Analysis of the MS/MS spectra indicates that the fragmentation of some amino acids is less favorable because of internal interaction with free groups of adjacent amino acids. The MS/MS spectra assisted in determining hydroxylation sites, by the formation or alteration of specific product ions such as m/z 599.
Finite element studies of the impact-echo response of plates containing thin layers and voids

Quantitative nondestructive evaluation based on the use of transient stress waves generated by point impact is hindered by the fact that the governing partial differential equations admit closed-form solutions for only the most trivial cases, an infinite half-space and an infinite plate. In previous studies carried out by the authors, the finite element method has been shown to provide useful numerical solutions for a variety of cases involving bounded solids containing flaws. Numerical results have been verified with carefully controlled experiments. Currently, the method is being used to establish the basis for a new nondestructive evaluation technique for civil engineering structures. This technique is called impact-echo, and it is based on the use of low frequency, transient stress waves generated by elastic point impact. In this paper, the impact-echo response of plates containing thin layers is studied using finite element models. The purpose of these studies was to determine the applicability of using the method for detecting voids in layered civil engineering structures. Results of the numerical studies show that it is feasible to use the impact-echo method for this application.
Successfully implementing strategic decisions

Although strategy implementation is viewed as an integral part of the strategic management process, little has been written or researched on it. The overwhelming majority of the literature so far has been on the long-range planning process itself or the actual content of the strategy being formulated. We have so far been giving lip service to the other side of the coin, namely strategy implementation. Consequently, it is not surprising that after a comprehensive strategy or single strategic decision has been formulated, significant difficulties are often encountered during the subsequent implementation process.
Effect and interaction of rainbow trout strain (Oncorhynchus mykiss) and diet type on growth and nutrient retention

Eight strains of rainbow trout were introgressed to develop a single strain (H-ARS) that was selected for faster growth when fed a fishmeal-free, plant-based diet (Selection Diet). For four generations, families from these crosses were fed the Selection Diet and selected for increased weight gain. Growth and nutrient retention were compared among H-ARS and two parental strains, the House Creek (HSC) and Fish Lake (FL) fed either a fish meal or Selection diet for 12 weeks. There was a significant effect of strain (P < 0.01), but not diet on weight gain, and a significant interaction of strain by diet (P < 0.05). The H-ARS trout gained more weight averaged across diet (991% of initial wt.) than the HC (924%) or FL trout (483%). The FL trout fed the fish meal diet gained more weight than FL trout fed the selection diet (510% vs 456%). Conversely, H-ARS trout fed the plant-based diet gained more weight than those fed the fish meal diet (1009% vs 974%). HSC trout had similar weight gain fed either diet (922% vs 926%). A significant effect of strain on protein retention (P < 0.01) was observed, along with a significant strain by diet interaction (P < 0.02). The results demonstrate that rainbow trout can be selectively improved to grow on a plant-based diet.
Simultaneous differential scanning calorimetry and reflected light intensity (DSC–RLI) in the study of inorganic materials

This paper re-examines work on inorganic materials and oxalates, but combines differential scanning calorimetry (DSC) measurements with simultaneous observation and recording of the reflected light intensity to obtain more detailed information about the physical and chemical changes occurring. The method indicates the nature of the changes recorded by the DSC, both physical and chemical and gives additional confirmation of the nature of complex and overlapping DSC peaks for ammonium salts, copper carbonate and the potassium oxalato-complexes of aluminium, copper, iron and chromium.
Equational theories as congruences of enriched monoids

The problem of characterizing the lattices of equational theories is still unsolved. In this paper we describe a class $${\mathcal{K}}$$ of monoids enriched by two unary operations and show that a lattice L is a lattice of equational theories if and only if L is isomorphic to a lattice of congruences of some enriched monoid belonging to $${\mathcal{K}}$$ .
Hematologic abnormalities in adolescents who take oral contraceptive pills.

Sexually active patients (12 to 19 years of age) participated in a study designed to determine if adolescents who take oral contraceptives are susceptible to hematologic abnormalities. This involved individual medical histories recording vitamin ingestin alcohol consumption type of contraceptive used duration of usage and menstrual cycle. Blood samples were drawn for determinations of serum folate B12 ferritin blood count and polymorphonuclear leukocyte lobe count. Results indicate that adolescents with nutritionally poor diets are potentially high risks for developing folic acid deficiency while taking oral contraceptives. The data indicate no significant differences in the mean hemoglobin red blood cell indices or polylobe count in either the patient or control group. The authors stress a need to gather more data on the effects of long term contraceptive pill usage. It is concluded that although contraceptive pill use appears to increase the risk of developing cellular folate deficiency especially in white women the pill appears to offer some protection against iron deficiency and is not associated with anemia.
Successful Treatment of Superior Vena Cava Rupture with Placement of a Covered Stent: A Report of Two Cases

Superior vena cava syndrome (SVCS) is characterized by the development of symptoms, including facial, head, neck, chest, and upper extremity swelling, shortness of breath, and headache, in the setting of superior vena cava (SVC) stenosis or occlusion [1, 2]. SCVS may be caused by a variety of benign and malignant conditions. Since the development of selfand balloon-expandable stents, endovascular repair has become the first-line therapy for the treatment of SVCS [3–5]. The most common complications of stent placement include pulmonary embolus (PE), stent migration, fracture, and misplacement [6]. There are a few case reports describing subclinical rupture after stent placement and death secondary to cardiac tamponade from balloon dilatation of the SVC [7, 8]. Additionally, there is one case report describing the placement of a covered stent for superior vena cava rupture (SVCR) in a non-peer-reviewed journal [9]. We present two cases of SVCR during SVC balloon angioplasty and bare metal stent placement that were successfully treated with placement of a covered stent. Placement of a covered stent may provide a rapid definitive treatment to prevent death from SVCR.
Thermal history and tensile strength determination from fracture surface analysis

Abstract Aluminum alloys are used in various critical aerospace applications that require properties to be obtained from very specific heat treatments. This study shows that the fracture surface can indicate details of the thermal history and strength of the material. This is a novel technique to characterize the material from an analysis of the fracture surface features. This study evaluated the effect of varying the cooling rate and aging time on the fracture surface of an aluminum alloy.
Molecular biological access to the chemistry of unknown soil microbes: a new frontier for natural products

Cultured soil microorganisms have provided a rich source of natural-product chemistry. Because only a tiny fraction of soil microbes from soil are readily cultured, soil might be the greatest untapped resource for novel chemistry. The concept of cloning the metagenome to access the collective genomes and the biosynthetic machinery of soil microflora is explored here.
Bacterial bioluminescence: Absorption and fluorescence characteristics and composition of reaction products of reduced flavin mononucleotide with luciferase and oxygen

Abstract The initial reaction products of FMNH 2 , oxygen and bacterial luciferase are a flavoprotein, free FMN and hydrogen peroxide. This flavoprotein then adds a mole of oxygen to give a product which either reacts with a long-chain aldehyde to give bioluminescence, or in the absence of aldehyde decays to free enzyme, free FMN and hydrogen peroxide.
Bose-Einstein condensation of trapped interacting spin-1 atoms

We investigate Bose-Einstein condensation of trapped spin-1 atoms with ferromagnetic or antiferromagnetic two-body contact interactions. We adopt the mean field theory and develop a Hartree-Fock-Popov type approximation in terms of a semiclassical two-fluid model. For antiferromagnetic interactions, our study reveals double condensations as atoms in the $\ensuremath{\mid}{m}_{F}=0⟩$ state never seem to condense under the constraints of both the conservation of total atom number $N$ and magnetization $M$. For ferromagnetic interactions, however, triple condensations can occur. Our results can be conveniently understood in terms of the interplay of three factors: (anti)ferromagnetic atom-atom interactions, $M$ conservation, and the miscibilities between and among different condensed components.
Report on selected readings on digital computer simulation

The title of this text immediately reveals who it is written for: architects who are interested in computer applications. The author is assuming that the general reader in the field of architecture has absolutely no background in the field of computing and the text is therefore written on a very low level of sophistication, at which the simplicity is exaggerated. Though the text as a whole is probably helpful for an uninformed reader to learn about applications of computers to architecture, a more sophisticated reader will find reading of all but a few sections a waste of time. For a person with specific interests in the field of architecture and computer applications, those few more successful parts are probably quite worth reading, if for nothing else, then just for exposure to what is actually being done in that area. Besides that, an uninformed reader may find it interesting to get exposure to British hardware and ALGOL-based programming practice, as well as British terminology.
Methylmercury affects multiple subtypes of calcium channels in rat cerebellar granule cells

We tested the ability of methylmercury (MeHg) to block calcium channel current in cultures of neonatal cerebellar granule cells using whole-cell patch clamp techniques and Ba(2+) as charge carrier. Low micromolar concentrations of MeHg (0.25-1 microM) reduced the amplitude of whole cell Ba(2+) current in a concentration- and time-dependent fashion; however, this effect was not voltage-dependent and the current-voltage relationship was not altered. Increasing the stimulation frequency hastened the onset and increased the magnitude of block at both 0.25 and 0.5 microM MeHg but not at 1 microM. In the absence of stimulation, all concentrations of MeHg were able to decrease current amplitude. The ability of several Ca(2+) channel antagonists (omega-conotoxin GVIA, omega-conotoxin MVIIC, omega-agatoxin IVA, calcicludine, and nimodipine) to alter the MeHg-induced effect was tested in an effort to determine if MeHg targets a specific subtype of Ca(2+) channel. Each of the antagonists tested was able to decrease a portion of whole cell Ba(2+) current under control conditions. However, none were able to attenuate the MeHg-induced block of whole cell Ba(2+) current, suggesting either that the mechanism of MeHg-induced block involves sites other than those influenced specifically by Ca(2+) channel antagonists or that MeHg was able to "outcompete" these toxins for their binding sites. These results show that acute exposure to submicromolar concentrations of MeHg can block Ba(2+) currents carried through multiple Ca(2+) channel subtypes in primary cultures of cerebellar granule cells. However, it is unlikely that the presence of a specific Ca(2+) channel subtype is able to render granule cells more susceptible to the neurotoxicologic actions of MeHg.
Making light of stress

A nanoparticle that senses reactive oxygen and nitrogen species in the liver should improve in vivo detection of cellular stress.
Margins and Errors

Abstract Timothy Williamson has argued that cases involving fallible measurement show that knowledge comes apart from justified true belief in ways quite distinct from the familiar ‘double luck’ cases. I start by describing some assumptions that are necessary to generate Williamson's conclusion, and arguing that these assumptions are well justified. I then argue that the existence of these cases poses problems for theorists who suppose that knowledge comes apart from justified true belief only in a well defined class of cases. I end with some general discussion of what we can know on the basis of imperfect measuring devices.
Temporal and Spatial Differences in Salinity and Water Chemistry in SW Florida Estuaries: Effects of Human-impacted Watersheds

Three estuaries near Naples, Florida with variably modified watersheds have been investigated to understand the chemical consequences of altering drainage patterns. Blackwater River (near natural drainage, control site), Henderson Creek (moderately modified watershed), and Faka-Union Canal (severe channelization) were sampled for temperature, salinity, δ18O, δ13C of dissolved inorganic carbon (DIC), molality of CO2 (ΣCO2), and Mg:Ca and Sr:Ca ratios between freshwater and marine water end members over a 17-mo period. Carbon isotope composition followed similar seasonal patterns as salinity. Freshwater and seawater end members are more negative than the global average, likely reflecting equilibration with local carbon sources derived from mangrove leaf litter and groundwater. δ13C responds to differences in primary productivity between estuaries. Henderson Creek has higher primary productivity than Blackwater River (probable due to higher sewage input and agricultural runoff) and has more positive δ13C and lower ΣCO2. δ18O is affected by seasonal input of freshwater from atmospheric precipitation, evaporation, and groundwater. Late summer and fall rains lower the δ18O of estuarine water, whereas evaporative conditions in the dry season elevate δ18O to values that can be more positive upstream than those from the Gulf of Mexico (estuarine inversion). Evaporation produces water in the Gulf of Mexico that is >1‰ more positive than the global sea surface average most of the year. The very negative δ18O values in Blackwater River and Henderson Creek likely reflect atmospheric and groundwater contribution. Mg:Ca and Sr:Ca ratios of Gulf water from all three estuaries are similar to global averages at low latitudes. Freshwater end members among estuaries are different in that Blackwater River has higher ratios, suggesting a groundwater contribution. Dolomitic rocks in the subsurface likely provide a source of Mg ions.
CD4+CD45RA+ and CD4+CD45RA− T cell subsets in man maintain distinct function and CD45RA expression persists on a subpopulation of CD45RA+ cells after activation with Con A☆

We have previously shown that Con A-induced suppressor T cells belong to the CD45RA+ subset. After unseparated T cells are activated with Con A, CD45RA expression increases to a maximum (Day 2), and then decreases significantly, but does not disappear entirely (Day 9), while CD29 expression increases steadily. In the present study, we examined the fate of these cell surface molecules on isolated CD4+CD45RA+ and CD4+CD45RA- cells following activation with Con A, and their relationship to the regulatory functions of these subsets. After activation of CD4+CD45RA+ cells with Con A, CD45RO and CD29 antigen expression rapidly increases (greater than 90%). While CD45RA expression is downregulated, approximately 40% of the cells continue to express low-density CD45RA in a stable fashion through Day 21. Despite these phenotypic changes, cells originally CD45RA+ continue to suppress IgG synthesis and provide only minimal B cell help. Furthermore, when cells originally CD45RA+ were sorted on the basis of continued presence, or loss of CD45RA antigen 14 days after activation, both populations demonstrated potent suppression and minimal help. In contrast, after activation with Con A, CD4+CD45A- cells maintain stable phenotype and provide significant help and minimal suppression. Immunoprecipitation of the CD45RA antigen from Day 14 activated CD4+CD45RA+ cells confirms the continued presence of the 205-kDa isoform, but reveals a significant decrease in the 220-kDa isoform. These results suggest that after activation with Con A, cells originally CD45RA+ remain functionally distinct from cells originally CD45RA-, and that CD45RA antigen persists on a subpopulation of CD45RA+ cells after activation with Con A.
Reducing the Overhead of Dynamic Compilation

The execution model for mobile, dynamically-linked, object–oriented programs has evolved from fast interpretation to a mix of interpreted and dynamically compiled execution. The primary motivation for dynamic compilation is that compiled code executes significantly faster than interpreted code. However, dynamic compilation, which is performed while the application is running, introduces execution delay. In this paper we present two dynamic compilation techniques that enable high performance execution while reducing the effect of this compilation overhead. These techniques can be classified as: 1) decreasing the amount of compilation performed ( Compilation), and 2) overlapping compilation with execution (Background Compilation). We first evaluate the effectiveness of lazy compilation. In lazy compilation, individual methods are compiled on demand upon their first invocation. This is in contrast toEager Compilation, in which all methods in a class are compiled when a new class is loaded. Our experimental results (obtained by executing the SpecJVM Java programs on the Jalape ˜ no JVM) show that, compared to eager compilation, lazy compilation results in % fewer methods being compiled and reductions in total time (compilation plus execution time) of %t o %. Next, we present profile-driven, background compilation, a technique that augments lazy compilation by using idle cycles in multiprocessor systems to overlap compilation with application execution. Profile information is used to prioritize methods as candidates for background compilation. Our results show that background compilation can deliver significant reductions in total time ( %t o %), compared to eager compilation.
Power conditioning for high speed ground transportation vehicles

This work discusses the application of power conditioning to high speed ground transportation vehicles propelled by linear induction motors. The vehicle electric power and propulsion system and characteristics of selected vehicles currently under development by the u.S. Department of Transportation are discussed. A Brief review of the linear induction motor is presented. Several classes of power conditioners 3 capable of controlling power to the linear induction motor, are described. These power conditioners include both those which provide variable voltage fixed frequency power control and variable frequency, constant volts per hertz power control.
Soot maturity and absorption cross sections

Abstract We used time-resolved laser-induced incandescence (LII) to compare optical and physical properties of soot at the edge and in the center of two co-flow diffusion flames in common use for soot optical-diagnostics development. We made these measurements over a wide range of laser fluences using a laser wavelength of either 532 or 1064 nm. Our results, combined with the previous results, suggest that the 532:1064 nm absorption cross-section ratio is ≤1.8 for mature soot and increases with increasing hydrogen content and decreasing soot maturity. The absolute absorption cross sections at 532 and 1064 nm, on the other hand, increase with soot maturity. Differences in the signal decay rates between center and edge regions further suggest that the thermal-accommodation coefficient decreases with increasing soot maturity. These results were analyzed using an energy- and mass-balance model that accounts for the effects of soot maturity on the absorption cross section, thermal-accommodation coefficient, and particle density. Given the sensitivity of LII to these parameters, it may be possible to use a combination of in situ measurements of pulsed LII fluence curves and temporal profiles to gain information about soot maturity.
Atomic barium and cesium alignment-to-orientation conversion in external electric and magnetic fields

We present an alternative method for changing atomic alignment to orientation through interactions with orthogonal static electric and magnetic fields. Experimental results demonstrating this effect in the 5d6p $^{1}$P state of atomic barium and the F=4 hyperfine level of the ground state of atomic cesium are presented. The theory of this effect for a j=0 to j=1 electric dipole transition is discussed in detail. The tensor polarizability of the 5d6p $^{1}$P state of Ba is determined to be 1.31(15) MHz/(kV/cm${)}^{2}$, in good agreement with the results of van Leeuwen and Hogervorst [Z. Phys. A 310, 37 (1983)].
Voice source model for continuous control of pitch period

The voiced speech waveform may be synthesized by exciting an LPC vocal tract filter with a pulse waveform patterned after naturally occurring glottal airflow pulses. Such a pulse waveform may be generated by computing samples of a piecewise polynomial curve at equally spaced time intervals. In this type of synthesis, the pitch period is commonly restricted to an integer multiple of the sample interval. A method is presented for removing this restriction, permitting both pulse duration and pitch period to be varied over continuous time. Aliasing distortion is prevented by computing the sample values of pulses that have been low-pass filtered in continuous time prior to sampling. Applications of this technique include modeling glottal pulses by least-squares fit to inverse filter waveforms, the synthesis of calibration waveforms for evaluating measures of speech waveform jitter, the perceptual evaluation of low levels of waveform jitter, and the synthesis of the singing voice.
Preferential initiation of RNA synthesis on repetitious sequences in chromatin.

Abstract RNA synthesized in vitro from human DNA and chromatin with DNA dependent RNA polymerase from Escherichia coli was analyzed by hybridization to human DNA on filters. Comparison of the kinetics of hybridization of a 32 P label on the 5′ terminus of the RNA and a 3 H label throughout the molecule indicated that the RNA transcribed from chromatin was enriched in repetitive sequences at its 5′ end. It is suggested that this may be a reflection of the structure of the chromatin.
Impact of high-κ and SiO2 interfacial layer thickness on low-frequency (1/f) noise in aggressively scaled metal gate/HfO 2 n-MOSFETs: role of high-κ phonons

The effect of high-@k (t"H"f"O"2) and interfacial layer thickness (t"I"L) on the low-frequency (LF) drain current noise is studied in n-MOSFETs with HfO"2 gate oxide and TiN metal gate. While a 1/f type spectrum is observed, the dominant noise mechanism is found to be mobility fluctuations. The variation in Hooge's parameter @a"H is studied and the results are correlated with channel electron mobility (@m). The physical origin of noise fluctuations is then determined from the comparison. The results show that high-@k phonon scattering is likely the dominant source for 1/f noise in aggressively scaled HfO"2-metal gate devices. The devices meet the ITRS specification and the selection of t"I"L becomes significant for use in analog and mixed signal based applications.
Relationship between expression of cell surface hydrophobicity protein 1 (CSH1p) and surface hydrophobicity properties of Candida dubliniensis.

Candida dubliniensis and Candida albicans cause most of the oral candidiasis infections in AIDS patients. Unlike C. albicans, which variably expresses cell surface hydrophobicity (CSH) depending on environmental conditions, C. dubliniensis is hydrophobic under all environmental conditions. C. dubliniensis produces CdCSH1p, a protein related to CaCSH1p that contributes to CSH expression of C. albicans. We investigated whether environmental conditions affect CdCSH1p expression, CSH avidity, and adhesion to fibronectin (Fn). C. dubliniensis CD36 was grown at 23°C and 37°C in four different media. CdCSH1p expression was affected by growth temperature, with cells grown at 37°C expressing the protein, but cells grown at 23°C did not. Hydrophobic avidity for two media was higher in cells grown at 37°C than at 23°C. Cells grown at 23°C were generally less adherent than 37°C-grown cells to Fn. The results suggest CdCSH1p but not hydrophobic avidity may have a role in adhesion of C. dubliniensis to Fn.
Two Novel Type II Restriction-Modification Systems Occupying Genomically Equivalent Locations on the Chromosomes of Listeria monocytogenes Strains

Listeria monocytogenes is responsible for the potentially life-threatening food-borne disease listeriosis. One epidemic-associated clonal group of L. monocytogenes, epidemic clone I (ECI), harbors a Sau3AI-like restriction-modification (RM) system also present in the same genomic region in certain strains of other lineages. In this study, we identified and characterized two other, novel type II RM systems, LmoJ2 and LmoJ3, at this same locus. LmoJ2 and LmoJ3 appeared to recognize GCWGC (W = A or T) and GCNGC, respectively. Both RM systems consisted of genes with GC content below the genome average and were in the same genomic region in strains of different serotypes and lineages, suggesting site-specific horizontal gene transfer. Genomic DNA from the LmoJ2 and LmoJ3 strains grown at various temperatures (4 to 42°C) was resistant to digestion with restriction enzymes recognizing GCWGC or GCNGC, indicating that the methyltransferases were expressed under these conditions. Phages propagated in an LmoJ2-harboring strain exhibited moderately increased infectivity for this strain at 4 and 8°C but not at higher temperatures, while phages propagated in an LmoJ3 strain had dramatically increased infectivity for this strain at all temperatures. Among the sequenced Listeria phages, lytic phages possessed significantly fewer recognition sites for these RM systems than lysogenic phages, suggesting that in lytic phages sequence content evolved toward reduced susceptibility to such RM systems. The ability of LmoJ2 and LmoJ3 to protect against phages may affect the efficiency of phages as biocontrol agents for L. monocytogenes strains harboring these RM systems.
Juror decision making: A case of attitude change mediated by authoritarianism

Abstract For a jury to reach a unanimous decision, certain individuals must change their attitudes with regard to the defendant's guilt during deliberations. Because these changers are the key to the group decision-making process, they were carefully scrutinized to ascertain demographic or personality characteristics which might be mediating their behavior. In three experiments, two using college students as subjects and one using Philadelphia Court of Common Pleas jury pool members, it was found that authoritarians changed their attitude with regard to the defendant's guilt more than equalitarians. Further, most of these “changers” were aware they had changed their attitude. There was no generalizable evidence for the proposition that authoritarians are more likely to favor a guilty verdict.
Differential effects of two hexahydropyrroloindole carbamate-based anticholinesterase drugs on the amyloid beta protein pathway involved in alzheimer disease

One of the main hallmarks of Alzheimer’s disease (AD) is the brain deposition of senile plaques made up of toxic amyloid β-peptide (Aβ), which is derived from a larger protein called the β-amyloid precursor protein (APP). Both APP processing and cholinesterase activity are affected in the AD brain, but, yet, cholinesterase inhibitors (ChEI) remain the primary Food and Drug Administration approved drugs for AD within the United States. Herein, we evaluated the effects of two clinically relevant drugs on the APP pathway, which is presumably involved in AD pathogenesis. Specifically, we compared the actions of the classical ChEI physostigmine (PHY) and its analog phenserine (PHE) on neuronal cell viability, on IC50 and on levels of different amyloid proteins. Interestingly, these drugs share the same chemical backbone, inhibit acetylcholinesterase with similar potency, but differentially affect APP processing. PHE treatment decreased levels of APP in the human neuroblastoma cells (p=0.009) whereas PHY showed a similar but less-pronounced trend, which did not attain statistical significance. PHE treatment significantly decreased levels of Aβ in human neuroblastoma cells (p=0.02) whereas PHY showed no significant change under the same conditions. The divergent actions of these two structurally related drugs on the amyloid pathway indicate that the mechanisms underpinning the cholinergic and the amyloid-lowering properties for this class of drugs are independent of each other.
Minimum Voltage for Threshold Switching in Nanoscale Phase-Change Memory

The size scaling of the threshold voltage required for the amorphous-to-crystalline transition in phase-change memory (PCM) is investigated using planar devices incorporating individual GeTe and Sb2Te3 nanowires. We show that the scaling law governing threshold switching changes from constant field to constant voltage scaling as the amorphous domain length falls below 10 nm. This crossover is a consequence of the energetic requirement for carrier multiplication through inelastic scattering processes and indicates that the size of PCM bits can be miniaturized to the true nanometer scale.
Global Illumination via Density-Estimation

This paper presents a new method for the production of view-independent global illumi-nation solutions of complex static environments. A key innovation of this new approach is its decomposition of the problem into a loosely coupled sequence of simple modules. This approach decouples the global energy transport computation from the construction of the displayable shaded representation of the environment. This decoupling eliminates many constraints of previous global illumination approaches, yielding accurate solutions for environments with non-diffuse surfaces and high geometric complexity.
Electrical isolation design rule for GaAs integrated circuits fabricated on semi-insulating substrates

The characteristics of n-semi-insulating-n (n-si-n) structures that dictate the design rules for electrical isolation between active devices of GaAs integrated circuits fabricated on semi-insulating substrates are studied by one-dimensional and two-dimensional numerical simulations. It is found that the I-V characteristics of these structures are characterized by sharp current-rising regions which result from a potential barrier lowering effect caused by the punchthrough phenomenon. Simplified expressions are derived for quick evaluation of the punchthrough voltages for both one-dimensional and two-dimensional analyses. For a given operating voltage, the one-dimensional calculation gives a larger spacing between n regions in a n-si-n structure for onset of large current flow than does the two-dimensional analysis. Therefore, the spacing obtained from one-dimensional results can be used as a conservative design criterion for device isolation. For more aggressive electrical isolation design, two-dimensional simulation is necessary since it provides more accurate results. >
Identification of Clostridium beijerinckii, Cl. butyricum, Cl. sporogenes, Cl. tyrobutyricum isolated from silage, raw milk and hard cheese by a multiplex PCR assay

Late blowing, caused by the outgrowth of clostridial spores present in raw milk and originating from silage, can create considerable product loss, especially in the production of hard and semi-hard cheeses. The conventional method for the isolation of Clostridium spp. from cheeses with late-blowing symptoms is very complicated and the identification of isolates is problematic. The aim of this work was the development of a multiplex PCR method for the detection of the main dairy-related clostridia such as: Cl. beijerinckii, Cl. butyricum, Cl. sporogenes, Cl. tyrobutyricum. Samples derived from silage, raw milk and hard cheese were analysed by the most probable number (MPN) enumeration. Forty-four bacterial strains isolated from gas positive tubes were used to check the reliability of the multiplex PCR assay. The specificity of the primers was tested by individually analysing each primer pair and the primer pair combined in the multiplex PCR. It was interesting to note that the samples not identified by the multiplex PCR assay were amplified by V2-V3 16S rRNA primer pair and the sequencing revealed the aligned 16S rRNA sequences to be Paenibacillus and Bacillus spp. This new molecular assay provides a simple promising alternative to traditional microbiological methods for a rapid, sensitive detection of clostridia in dairy products.
Starting a hospital dental consultation service: educational and financial considerations.

Summary Most hospital departments of dentistry operate inpatient consultation services, and some information is available in the literature regarding the characteristics of several of these services. To date, however, there have been no published reports analyzing their effectiveness for teaching purposes or the financial impact that consultation services have on dental departments.
A noniterative method for calculating beam position from induced electric signals

The pickup electrodes (PUEs) in the NSLS (National Synchrotron Light Source) storage rings are of the four-button type. Near the center of the PUE, the beam position can be well approximated with a linear function of the sum and the difference signals induced on these electrodes by the bunched beam. The nonlinear response of the PUEs further from the center was measured. An algorithm to compensate for this effect was developed. >
Features versus Context: An Approach for Precise and Detailed Detection and Delineation of Faces and Facial Features

The appearance-based approach to face detection has seen great advances in the last several years. In this approach, we learn the image statistics describing the texture pattern (appearance) of the object class we want to detect, e.g., the face. However, this approach has had limited success in providing an accurate and detailed description of the internal facial features, i.e., eyes, brows, nose, and mouth. In general, this is due to the limited information carried by the learned statistical model. While the face template is relatively rich in texture, facial features (e.g., eyes, nose, and mouth) do not carry enough discriminative information to tell them apart from all possible background images. We resolve this problem by adding the context information of each facial feature in the design of the statistical model. In the proposed approach, the context information defines the image statistics most correlated with the surroundings of each facial component. This means that when we search for a face or facial feature, we look for those locations which most resemble the feature yet are most dissimilar to its context. This dissimilarity with the context features forces the detector to gravitate toward an accurate estimate of the position of the facial feature. Learning to discriminate between feature and context templates is difficult, however, because the context and the texture of the facial features vary widely under changing expression, pose, and illumination, and may even resemble one another. We address this problem with the use of subclass divisions. We derive two algorithms to automatically divide the training samples of each facial feature into a set of subclasses, each representing a distinct construction of the same facial component (e.g., closed versus open eyes) or its context (e.g., different hairstyles). The first algorithm is based on a discriminant analysis formulation. The second algorithm is an extension of the AdaBoost approach. We provide extensive experimental results using still images and video sequences for a total of 3,930 images. We show that the results are almost as good as those obtained with manual detection.
The intramolecular Diels–Alder reaction of tryptamine-derived Zincke aldehydes is a stepwise process

Computational studies show that the base-mediated intramolecular Diels–Alder of tryptamine-derived Zincke aldehydes, used as a key step in the synthesis of the Strychnos alkaloids norfluorocurarine and strychnine, proceeds via a stepwise pathway. The experimentally determined importance of a potassium counterion in the base is explained by its ability to preorganize the Zincke aldehyde diene in an s-cis conformation suitable to bicyclization. Computation also supports the thermodynamic importance of the generation of a stable enolate in the final reaction step. The thermal cycloreversion reaction of the Diels–Alder products is also found to proceed in a stepwise manner.
Targeted Therapy for Human Epidermal Growth Factor Receptor 2–Positive Breast Cancer: Can There Be Too Many Active Drugs?

overall survival in colorectal cancer on the basis of phase II tumor dynamics. J Clin Oncol 27:4103-4108, 2009 12. Frances N, Claret L, Bruno R, et al: Tumor growth modeling from clinical trials reveals synergistic anticancer effect of the capecitabine and docetaxel combination in metastatic breast cancer. Cancer Chemother Pharmacol [epub ahead of print on April 8, 2011] 13. Stein WD, Gulley JL, Schlom J, et al: Tumor regression and growth rates determined in five intramural NCI prostate cancer trials: The growth rate constant as an indicator of therapeutic efficacy. Clin Cancer Res 17:907-917, 2011 14. Tham LS, Wang L, Soo RA, et al: A pharmacodynamic model for the time course of tumor shrinkage by gemcitabine carboplatin in non-small cell lung cancer patients. Clin Cancer Res 14:4213-4218, 2008 15. Maitland ML, Hudoba C, Snider KL, et al: Analysis of the yield of phase II combination therapy trials in medical oncology. Clin Cancer Res 16:5296-5302, 2010 16. Yap TA, Sandhu SK, Workman P, et al: Envisioning the future of early anticancer drug development. Nat Rev Cancer 10:514-523, 2010 17. Bruno R, Lu JF, Sun YN, et al: A modeling and simulation framework to support early clinical drug development decisions in oncology. J Clin Pharmacol 51:6-8, 2010 18. Barrett JS, Mondick JT, Narayan M, et al: Integration of modeling and simulation into hospital-based decision support systems guiding pediatric pharmacotherapy. BMC Med Inform Decis Mak 8:6, 2008
Reactions of the dirhenium(III,III) complex cis-Re2(μ-O2CMe)2Cl4(H2O)2 that lead to the dirhenium(III,II) complexes Re2(μ-O2CMe)Cl4(PR3)2 and tetrarheniumcyclodiyne clusters of the type Re4(μ-O)4Cl4(PR3)4

The reaction of cis-Re2(μ-O2CMe)2Cl4(H2O)2 1 with P(C6H4OMe-p)3 gives the tetranuclear complex Re4(μ-O)4Cl4[P(C6H4OMe-p)3]4 14 along with the salt [(C6H4OMe-p)3PMe]2Re2Cl8 15. Compound 14 is the first symmetrical, neutral, tetrarheniumcyclodiyne type cluster that contains phosphine ligands. Complexes of this same type with PPh3 (16) and PMe2Ph (17) have been prepared by alternative methods but have poor solubility properties. The paramagnetic complex Re2(μ-O2CMe)Cl4(PPh3)2 2, which is prepared from 1 by reaction with PPh3, undergoes phosphine substitution reactions when treated with dichloromethane solutions of other phosphines. Simple non-redox reactions can occur upon reaction of 2 with monodentate and bridging bidentate phosphines to afford complexes of the types Re2(μ-O2CMe)Cl4(PR3)2 [PR3 = PBz3 3, P(C6H4OMe-p)3 4 or PMePh2 5] and trans-Re2(μ-O2CMe)Cl4(μ-PP)2 [PP = dppm 9, Ph2PNHPPh2 10 or (Ph2P)2CCH2 11]. However, reactions that lead either to reduction to dirhenium(II) complexes or Re–Re bond cleavage are encountered in the case of the reactions of 2 with PMePh2, PMe2Ph, PCy3 and dppe; these have led to the isolation of Re2Cl4(PMePh2)4 6, Re2Cl4(PMe2Ph)4 7, mer-trans-ReOCl3(PCy3)2 8, α-Re2Cl4(dppe)2 12, and trans-[ReO2(dppe)2]Cl 13. The structures of compounds 3, 8, 13, 14 and 15 have been determined by X-ray crystallography.
Nucleotide Sequence Analysis of the 5.8S rDNA and Adjacent ITS2 Region of Candida Albicans and Related Species

We have determined the nucleotide sequence for the DNA encoding the 5.8S RNAs and downstream internal transcribed spacer (ITS2) regions for Candida albicans and the taxonomically related species C. parapsilosis, C. tropicalis, C. glabrata and C. krusei. Phylogenetic analysis of all known fungal 5.8S RNA sequences revealed a close relationship between C. tropicalis and C. parapsilosis, and to a lesser extent C. albicans within the yeast-like fungi. This group can itself be delineated from predominantly filamentous species. The more distal relationships between Candida (Torulopsis) glabrata and C. krusei support previous findings based on small (18S) ribosomal RNA sequence analysis, suggesting a greater degree of evolutionary divergence of these species from the C. albicans group. Among strains of C. albicans we observed conservation of the ITS2 region at the nucleotide level. Conservation was also observed for a more limited number of C. parapsilosis strains. Although the 3' region of the ITS spacer was species specific, sequence homology was observed in the 5' end within the albicans/parapsilosis/tropicalis group. Our findings suggest a rapid approach to species identification through the use of non-conserved regions flanked by highly conserved, functional domains.
Dynamic response of intrinsic continua for use in biological and molecular modeling: Explicit finite element formulation

An intrinsic beam formulation has recently appeared (AIAA J. 2003; 41(6):1131–1137), which presents the three-dimensional equations of motion governing spatial and temporal changes in a one-dimensional continua's curvature, strain, rectilinear velocity, and angular velocity. The formulation would suggest several computational advantages over more-traditional displacement-based continua approaches: low-order interpolation functions can describe generally curved and twisted continua configurations; inter-element displacements, slopes, strains, and curvatures can be matched; and finite rotational variables and their complexities are absent. Here, we present a completed intrinsic continua finite element development and critical analysis, which follows from an earlier preliminary treatment as applied to carbon nanotubes (Int. J. Solids Struct. 2007; 44:874–894). Modeling of nodal displacements and rotations are included. Explicit time stepping, with desired high-frequency damping, is accomplished using an implementation of the generalized-α method. Zero-energy modes inherent in the formulation are also identified and rectified. Finally, we document very good agreement between results predicted with the intrinsic continua finite element simulator and results generated using more-traditional finite element simulations. Copyright © 2009 John Wiley & Sons, Ltd.
Space Tug Performance Optimization

I keeping with the concept of reusability the space tug extends the realm of application to near Earth space. Missions which could benefit from the assistance of a tug are now being proposed. From the performance analyst's point of view the trajectories required for these missions are somewhat more complex than those required for missions not employing a reusable assisting vehicle. In order to demonstrate some complexities and indicate one method for analyzing space tug trajectories a particular mission was chosen and is discussed here in some detail. The basic mission profile to be considered is that of the tug-assist-to-escape maneuver. The trajectory is initiated from a circular base orbit. From the base orbit the tug accelerates a spacecraft to an intermediate orbit with energy somewhere between that of the base orbit and escape energy. After separation the spacecraft ignites its engine and accelerates to escape energy. The tug stays in the intermediate orbit for some time and then reignites its engine and returns to the base orbit. Similar results for nonthrusting spacecraft have been obtained by Weyer and Teren.
Direct observation of the effect of autoreceptors on stimulated release of catecholamines from adrenal cells

The direct effect of alpha 2-autoreceptors was studied by measuring the effects of piperoxan, an alpha 2-autoreceptor antagonist, and clonidine, an agonist on catecholamine exocytosis, from single bovine chromaffin cells in culture. Catecholamine release was elicited by stimulation with 100 microM nicotine and was monitored electrochemically with a carbon-fiber microelectrode placed adjacent to the cell. These electrodes allowed the number of exocytotic release events to be monitored and reported as total charge for release following a specific stimulus. Repeated stimulation with 100 microM nicotine showed that total release caused by the second exposure to nicotine was 32% of the first, and release caused by the third exposure to nicotine was 80% of the second. Total release of catecholamine increased significantly after application of 20 microM piperoxan relative to a control application of balanced salt solution. Application of 20 microM piperoxan alone did not cause release. After the cells were incubated in culture medium containing 20 microM clonidine, a significant decrease in nicotine-stimulated catecholamine release was observed. These results confirm that there are autoreceptors on chromaffin cells and, when relatively high levels of catecholamine are released, the catecholamine stimulates the alpha 2-autoreceptors, which inhibits subsequent release through a negative feedback mechanism. In addition to piperoxan, the sympathomimetic drug amphetamine also increases quantal release after application of nicotine. Amphetamine increases the extracellular concentration of catecholamine, and these data appear to indicate that at least part of the pharmacology of amphetamine might involve blocking catecholamine autoreceptors.