cssi/SciSciGPT-SciSciNet huggingface dataset:
Influence of pitting corrosion on structural integrity of aluminum alloys

In recent years, the US Air Force has focused attention on extending the life of its aging fleet. Consequently, the Air Force is concerned about a growing number of aging aircraft that require extensive maintenance. One of the main causes of aging aircraft failure is due to corrosion damage and fatigue of its aluminum alloy parts. Many parts of corrosion damage can affect the aluminum structures of an aircraft. In this paper, result on controlled pitting corrosion will be discussed. Pitting corrosion triggers serious damage in aircraft structures because pits act as one of the nucleation sites for fatigue crack formation. To study the role of pits in fatigue crack initiation, pits were created on high strength aluminum alloy 2024-T3 samples by an accelerated electrochemical method. These pits have a variety of diameters and depths. The scanning electronic microscopy. The pitted surface was examined, and parameters such as average roughness and pit depth were determined. In addition, 3D images of the pitted surface were recorded. These result provide the details of the critical pit size that can lead to fatigue crack initiation in Al 2024-T3. The understanding of the role of pitting in crack initiation aids in extending the fatigue life of the aging aircraft.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Massive natural occurrence of unusually large bacteria ( Beggiatoa sp.) at a hydrothermal deep-sea vent site

WHITE web-like 'mats' of the filamentous sulphur-oxidizing bacterium Beggiatoa are commonly observed on the surface of anoxic sediments1–3. As a typical interface organism Beggiatoa requires a source of inorganic reduced sulphur and dissolved free oxygen. The first pure cultures of marine strains of Beggiatoa were recently obtained by artificially reconstructing an O2–H2S interface in a semi-solid medium that supports the gliding mobility of the filaments4,5. The maximal thickness of these Beggiatoa mats in culture was 1.0 mm. We now report the discovery of dense layers of filamentous sulphur-oxidizing bacteria up to 3 cm thick on the sediment surface, and up to 30 cm thick between stands of vestimen-tiferan tube worms at the Guaymas Basin hydrothermal vent site in the Gulf of California at a depth of 2,010 m. The mats are essentially monocultures of Beggiatoa-type organisms containing filaments of three width classes, the largest filaments being 116-122 μm in diameter. Freshly collected filaments showed chemoautotrophic metabolism and active gliding motility. The phenomenon of a natural mass growth of a bacterium is of great physiological and ecological interest, and could also be of biotechnical importance considering the difficulties of mass cultivation of interface organisms such as Beggiatoa and the other 'large' sulphur-oxidizing bacteria such as Thiovulum6 and Thioploca7.
Thermoplastic polyheterocycles. II: Polyalkylene-imides†

Polyalkylene-imides (i.e., aliphatic-aromatic polyimides) were prepared smoothly in N-methyl pyrollidone from straight chain aliphatic diamines and pyrromellitic dianhydride. Melting points of the polymers ranged from about 300 to 450°C, depending of the length of the alkylene chains. An odd/even effect related to the alkylene chain was noted for melting points and glass transition temperatures (Tg) of the polymers. The Tgs were relatively high, especially when compared to similarly structured polyalkylene-heterocycles, e.g., polyakylenebenzoxazoles.
Solar Collection Grid Sizing for Absorption Air Conditioning: A Design for El Salvador

To decrease high levels of energy consumption associated with air conditioning in tropical regions the usefulness of a chiller, powered by solar energy and utilizing a lithium bromide absorption cycle was analyzed. In conjunction with officials at the University of Central America (UCA) in El Salvador, a solar heat collection system has been designed which will be implemented at UCA and used to power a 10 ton absorption chiller. The unit will be installed to provide air conditioning to an auditorium, which is currently under construction. Using climate data from the region, an analysis was performed to determine the cooling load and resulting solar collection grid size needed. The system was designed to provide air conditioning 80% of the year. A simulation tool was created to predict the performance of the heat collection system based on the collector grid and storage tank size. To prove the efficacy of the theoretical calculations, a scaled down model of the heat collection system for the solar powered chiller was built and tested at Santa Clara University (SCU).Copyright © 2006 by ASME
Optimizing etch uniformity for alternating aperture phase shift masks on Etec Systems' Tetra photomask etch system

A simple method for minimizing the glass etch non-uniformity in the Etec Systems' Tetra etch tool will be presented along with etch rate performance stability results. In this triple etch process, the final phase uniformity was improved from ± 5 ° to ± 1.3 ° phase shift at 248 nm without changing either processing chemistry or any other process parameters. The procedure used to obtain this improved uniformity as well as maps illustrating the depth distribution over the plate after each step will be given.
Dust Emission Features in NGC 7023 between 0.35 and 2.5 Microns: Extended Red Emission (0.7 Microns) and Two New Emission Features (1.15 and 1.5 Microns)

We present 0.35-2.5 μm spectra of the south and northwest filaments in the reflection nebula NGC 7023. These spectra were used to test the theory of Seahra & Duley that carbon nanoparticles are responsible for extended red emission (ERE). Our spectra fail to show their predicted second emission band at 1.0 μm even though both filaments exhibit strong emission in the familiar 0.7 μm ERE band. The northwest filament spectrum does show one, and possibly two, new dust emission features in the near-infrared. We clearly detect a strong emission band at 1.5 μm which we tentatively attribute to β-FeSi2 grains. We tentatively detect a weaker emission band at 1.15 μm which coincides with the location expected for transitions from the conduction band to midgap defect states of silicon nanoparticles. This is added evidence that silicon nanoparticles are responsible for ERE as they already can explain the observed behavior of the main visible ERE band.
Physical Basis for Quasi-Universal Relationships Describing Bankfull Hydraulic Geometry of Sand-Bed Rivers

Empirical data indicate that hydraulic geometry relationships for single-thread sand-bed rivers (i.e., rivers with median bed-material size between 0.062 and 0.50 mm) can be delineated such that bankfull width, bankfull depth, and channel slope are related in consistent ways to bankfull discharge. Such relationships ought to be the external expression of physical relationships intrinsic to sand-bed river dynamics. In this study, a back-calculation is performed to identify parameters (exponents and coefficients) for three relationships taken to be intrinsic to sand-bed rivers: (1) a generalized Manning-Strickler resistance relationship; (2) a relationship for channel-forming Shields number; and (3) a relationship for sand yield at bankfull flow. To back-calculate parameters for the physical relationships, first the hydraulic geometry relationships are expressed in suitable dimensionless form. Second, the physical relationships are expressed with coefficients and exponents that are analytically related to p...
The Impact of Different Kinds of Neighborhood Involvement on Residents' Overall Evaluations of Their Neighborhoods

Abstract This paper focuses on the relative impact of different kinds of social participation on an individual's sentiment toward his or her neighborhood. Three kinds of neighborhood participation are considered: (1) informal social participation; (2) involvement in formal neighborhood voluntary associations; and (3) use of neighborhood services. Survey data on nine moderate income neighborhoods with various racial mixes are employed in the analysis. The results of the regression analysis indicate that informal social participation and use of neighborhood services are positively associated with overall sentiment toward the neighborhood, whereas involvement in formal neighborhood voluntary associations has no relationship to the dependent variable. The implications of these findings for policy-making concerned with neighborhood maintenance and revitalization are discussed.
Feeding probiotic Lactobacillus paracasei to Ossabaw pigs on a high-fat diet prevents cholesteryl-ester accumulation and LPS modulation of the Liver X receptor and inflammatory axis in alveolar macrophages

Liver X receptors (LXR) play an integral role in cholesterol metabolism and the inflammatory response. High-fat (HF) diets and microbial infection can antagonize the LXR pathway leading to accumulation of cholesteryl-esters (CE) and increased expression of pro-inflammatory mediators in macrophages. The probiotic bacteria Lactobacillus paracasei possesses cholesterol lowering and immune modulating properties. Therefore, the present study sought to model whether daily feeding of L. paracasei to juvenile Ossabaw pigs fed a HF diet could modulate cholesterol metabolism and the LXR/inflammatory axis in lipopolysacharide (LPS)-stimulated alveolar macrophages (AM). The results showed that AM from pigs fed a HF diet had significantly higher concentrations of CE compared to AM from pigs fed a control (C) diet, but not in pigs fed a HF diet with L. paracasei (HFPB). Ex vivo LPS stimulation of AM opposed LXR agonist-mediated transcription of cholesterol metabolism related genes: ABCA1, CH25H and PPARγ in pigs on the C diet, and LXRα, ABCA1, ABCG1, CH25H and PPARγ in pigs on the HF diet. This effect was abrogated for all these genes except LXRα in AM from pigs given L. paracasei. Protein analysis of culture supernatants revealed that AM from HFPB-fed pigs had significantly lower LPS-induced protein expression of IL-1β than AM from HF-fed pigs. Moreover, AM from pigs fed the C diet and given L. paracasei, had significantly higher mRNA levels of IL-8, and IL-6, in response to LPS. These data demonstrated a role for L. paracasei in modulating AM cholesterol metabolism and the response to LPS.
The central nervous system in animal models of hyperhomocysteinemia

Growing epidemiological evidence of associations between mildly elevated plasma homocysteine with age-related cognitive impairment, neurodegenerative and cerebrovascular disease has stimulated interest in the role of homocysteine in neurological and neuropsychiatric disorders. Homocysteine is an intermediate in the folate, vitamin B12 and B6 dependent pathways of one-carbon and sulfur amino acid metabolism. Impairments of these pathways may cause CNS dysfunction by promoting the intracellular generation of homocysteine, which is postulated to have vasotoxic and neurotoxic properties. It might also inhibit the methylation of myelin basic protein and membrane phospholipids, or disrupt biogenic amine metabolism and many other vital CNS reactions. However, it is unclear which, if any, of these putative mechanisms underlies the epidemiological associations. Genetic mouse models of hyperhomocysteinemia suggest that the primary metabolic disturbances rather than homocysteine per se may be important in determining neurological outcomes. However, severe and early developmental abnormalities in these mice limit their usefulness for understanding the relation of hyperhomocysteinemia to adult CNS disorders. Pharmacologic and dietary studies on homocysteine in rodents have reported heightened neuronal sensitivity to neurotoxic insults, neurochemical abnormalities and cerebrovascular dysfunction. Such studies are consistent with a causal relationship, but they fail to distinguish between effects that might result from a dietary imbalance and those that might be caused by homocysteine per se. Future work should be directed towards refining these models in order to distinguish between the effects of homocysteine and its determinants on neurological and behavioral outcomes that represent different CNS disorders.
Big black delta - "huggin & kissin" official video

Loosely inspired by the stories of Ray Bradbury, this intentionally ambiguous narrative features an astronaut traversing Mars, a strange cat, a beautiful woman, decades of memories, and an undersea battle.
Unfolding and configuring two decades of research and publications on place marketing and place branding

In the past few decades, a growing number of communities, cities, states/provinces, nations and regions have adopted marketing and branding concepts and tools to attract investors, visitors, residents, events and so on. The prolific body of literature on ‘place marketing’ and ‘place branding’ produced and the vast number of venues for publication of articles on these subjects corroborate the growing importance of the area for both scholars and practitioners. This article unfolds and configures 212 articles on ‘place marketing’ and ‘place branding’ produced by 280 authors and published by 43 periodicals over a two-decade period. It concludes that, in spite of the fact that ‘place marketing’ and ‘place branding’ research have steadily intensified, the assessment of the articles published between 1990 and 2009 on these topics, conducted for this investigation, gives rise to some questions about the future of the field.
η6-Hydroquinone and catechol complexes of manganese tricarbonyl. 0olecular structure of [(η6-hydroquinone) Mn(CO)3]2SiF6☆

Abstract The reaction of ( η 6 -acenaphthene)Mn(CO) 3 + with hydroquinone and catechol affords the stable π-bonded complexes ( η 6 -hydroquinone)Mn(CO) 3 + ( 1 ) and ( η 6 -catechol)Mn(CO) 3 + ( 2 ). The X-ray structure of [ 1 ] 2 SiF 6 shows an approximately planar arene ligand with the -OH substituents strongly hydrogen bonded to fluorine atoms in the SiF 6 2− anion. Deprotonation of 1 and 2 by NEt 3 yields the corresponding π-bonded semiquinone complexes.
Macrophage Migration Inhibitory Factor is Increased in the Urine of Patients With Urinary Tract Infection: Macrophage Migration Inhibitory Factor-Protein Complexes in Human Urine

Purpose: MIF is a proinflammatory cytokine present in preformed stores in human urothelium. In animal models of bladder inflammation, including bacterial cystitis, MIF is up-regulated in the bladder and released from the bladder as a high molecular weight complex. We compared urine MIF amounts in patients with UTI to that in patients without UTI, and we examined and identified MIF-protein complexes in urine.Materials and Methods: Using enzyme-linked immunosorbent assay we compared MIF levels in the urine of 14 patients with UTI to levels in 16 controls with no UTI. Western blotting under native, denaturing and reducing conditions was done to examine MIF complexes found in urine. Mass spectrometry identified MIF associated proteins in urine, while co-immunoprecipitation confirmed the associations.Results: Mean urine MIF amounts ± SEM determined by enzyme-linked immunosorbent assay were significantly greater in 14 patients with UTI compared to that in 16 controls (1.96 ± 0.40 vs 0.59 ± 0.09 ng/mg creatinine...
2‐Arachidonoyl‐glycerol suppresses interferon‐γ production in phorbol ester/ionomycin‐activated mouse splenocytes independent of CB1 or CB2

Arachidonoyl-glycerol (2-AG), an endogenous ligand for cannabinoid receptor types 1 and 2 (CB1 and CB2), has previously been demonstrated to modulate immune func- tions including suppression of interleukin-2 ex- pression and nuclear factor of activated T cells (NFAT) activity. The objective of the present studies was to investigate the effect of 2-AG on interferon- (IFN-) expression and associated upstream signaling events. Pretreatment of splenocytes with 2-AG markedly suppressed phorbol 12-myristate 13-acetate plus calcium ionophore (PMA/Io)-induced IFN- secretion. In addition, 2-AG suppressed IFN- steady-state mRNA expression in a concentration-dependent manner. To unequivocally determine the puta- tive involvement of CB1 and CB2, splenocytes derived from CB1 / /CB2 / knockout mice were used. No difference in the magnitude of IFN- suppression by 2-AG in wild-type versus CB1/CB2 null mice was observed. Time-of-addi- tion studies revealed that 2-AG treatment up to 12 h post-cellular activation resulted in suppres- sion of IFN-, which was consistent with a time course conducted with cyclosporin A, an inhibi- tor of NFAT activity. Coincidentally, 2-AG per- turbed the nuclear translocation of NFAT pro- tein and blocked thapsigargin-induced elevation in intracellular calcium, suggesting that altered calcium regulation might partly explain the sup- pression of NFAT nuclear translocation and sub- sequent IFN- production. Indeed, Io partially attenuated the 2-AG-induced suppression of PMA/Io-stimulated IFN- production. Taken to- gether, these data demonstrate that 2-AG sup- presses IFN- expression in murine splenocytes in a CB-independent manner and that the mech- anism partially involves suppression of intracel- lular calcium signaling and perturbation of NFAT nuclear translocation. J. Leukoc. Biol. 77: 000-000; 2005.
Levels of analysis issues relevant in the assessment of information systems service quality

To date, researchers in Information Systems (IS) and other disciplines have exhausted a considerable amount of effort devising measures of service quality. Given this extensive work, it is interesting to note that levels of analysis issues have not been discussed. To address this deficiency, this paper defines levels of analysis and applies the concept to the assessment of service quality. Issues related to specifying the level of analysis are discussed, including the level of theory, data collection, and statistical analysis. Additionally, the use of service quality in unit-level models is discussed, with special emphasis given to issues of data aggregation.
Pharmacokinetics of oxaliplatin (NSC 266046) alone and in combination with paclitaxel in cancer patients.

Oxaliplatin (OPT), a third-generation platinating agent, is currently being evaluated in a phase II clinical trial in head and neck cancer patients and in a phase I clinical trial in combination with paclitaxel (TXL). Purpose: The aim of this study was to investigate the pharmacokinetics and biological correlates of OPT alone as well as the potential pharmacokinetic interaction between OPT and TXL. Methods: In the phase II study, OPT was given alone as a 2-h i.v. infusion at 60 mg/m2 weekly for 4 weeks with the cycle repeated after a 2-week rest. In the concurrent phase I combination trial OPT was also given as a 2-h i.v. infusion, but followed by a 1-h i.v. infusion of TXL, weekly for 4 weeks with the cycle repeated after a 2-week rest. The clinical pharmacokinetics of OPT alone and in combination with TXL were investigated in the first cycle of each treatment protocol. The platinum levels in plasma, plasma ultrafiltrate (PUF) and urine were measured by a fully validated inductively coupled plasma mass spectrometry (ICPMS) method. Results: In the ten patients receiving OPT alone, the concentration-time profiles of total platinum exhibited a biexponential decline both in plasma and in PUF. The peak levels of platinum were 2.72±0.41 µg/ml in plasma and 1.36±0.42 µg/ml in PUF at the end of the OPT infusion, and the platinum levels were still detectable at >10 ng/ml 94 h after the OPT infusion. The mean terminal t1/2 values of total platinum in plasma and in PUF were 58.9 h and 22.8 h, respectively. The AUC of ultrafilterable platinum represented about 10% of that of the total plasma platinum. The platinum levels in the DNA fraction of peripheral white blood cells (WBC) correlated with the platinum levels in PUF (r=0.77, P<0.01). In the phase I combination study, the dose level of OPT was escalated from 35 mg/m2 to 60 mg/m2. The concentration-time profiles of platinum in the combination trial also showed biexponential decay in plasma and in PUF as exhibited by OPT alone. However, the terminal elimination rate constant (β) of total plasma platinum increased at all dose levels of OPT when combined with TXL at 45 mg/m2 (P<0.05). A concomitant increase in clearance (CL) of total plasma platinum was observed at the OPT dose level of 45 mg/m2 in combination with TXL at 45 mg/m2. No statistically significant difference in the 24-h urinary elimination of total platinum was detected between the combination groups and the single-agent group. The AUC values of total platinum in PUF were proportional to OPT doses ranging from 35 to 60 mg/m2, whether OPT was given alone or in combination with TXL. Conclusions: OPT clearance may be enhanced by TXL when the two agents are used in combination in patients. The Pt-DNA adduct level in peripheral WBC was found to be a good indicator for oxaliplatin exposure in patients, and should be further exploited for potential tumor drug exposure.
Teacher Training Matters The Results of a Multistate Survey of Secondary Special Educators Regarding Transition From School to Adulthood

This study examined critical features of secondary special educator’s experiences with transition professional development to predict variables most likely to influence performance of transition pl...
Domestic and Export Demand for U.S. Agricultural Products

Current financial conditions within the agricultural sector focus our attention on the imbalances between quantities supplied, quantities demanded, and price levels which are sufficient to cover the production costs for a significant number of producers. While the discussion often centers on the importance of the export market, the domestic market remains the major or sole outlet for many agricultural subsectors. Thus, to assess realistically future resource needs for agricultural production, it is important to evaluate both foreign and domestic demand potential. In this paper we first draw on recent research to evaluate the potential for domestic market growth to the year 2000. We then provide an assessment of the growth potential in export markets. Finally, we draw some conclusions regarding resource needs, assuming historical trend yields.
Can severe language disability be identified in three-year-olds?Evaluation of a routine screening procedure.

This study evaluates the predictability of a new language screening procedure in 3-y-olds. It is used in several Child Health Centres (CHC) in Sweden and has the character of a field study involving more than 60 CHC nurses. The main questions concern the (i) development in 3-y-olds assessed as severely language delayed and (ii) whether there are any earlier unknown severely disabled children identified at 4 y of age. Ninety-six percent of the original study population participated in the follow-up. The calculations are based on results from 2237 children. A well-established screening routine, which has been shown capable of predicting the risk of not being able to follow expected schooling, and case records were used as an acceptable proxy outcome measure, pending a better gold standard. In the group of severely disabled 3-y-olds, sensitivity, specificity and positive predictive values were 86, 99 and 43%, respectively. Finally, three false-negatives were identified. In light of the present results, continued application of the 3-y screening is discussed.
Nodal-related signals induce axial mesoderm and dorsalize mesoderm during gastrulation

Mouse embryos homozygous for a null mutation in nodal arrest development at early gastrulation and contain little or no embryonic mesoderm. Here, two Xenopus nodal-related genes (Xnr-1 and Xnr-2) are identified and shown to be expressed transiently during embryogenesis, first within the vegetal region of late blastulae and later in the marginal zone during gastrulation, with enrichment in the dorsal lip. Xnrs and mouse nodal function as dose-dependent dorsoanterior and ventral mesoderm inducers in whole embryos and explanted animal caps. Using a plasmid vector to produce Xnr proteins during gastrulation, we show that, in contrast to activin and other TGF beta-like molecules, Xnr-1 and Xnr-2 can dorsalize ventral marginal zone explants and induce muscle differentiation. Xnr signalling also rescues a complete embryonic axis in UV-ventralized embryos. The patterns of Xnr expression, the activities of the proteins and the phenotype of mouse nodal mutants, all argue strongly that a signaling pathway involving nodal, or nodal-related peptides, is an essential conserved element in mesoderm differentiation associated with vertebrate gastrulation and axial patterning.
Study of the constrained LQG problem using homotopy

Optimal linear quadratic Gaussian (LQG) compensators with constrained structures are a sensible way to generate good multivariable feedback systems meeting strict implementation requirements. The optimality conditions obtained for the constrained LQG compensator are a set of highly coupled matrix equations that cannot be solved algebraically except when the compensator is centralized and full order. An alternative to the use of general optimization methods for solving the problem is to use homotopy. The benefit of the method is that it uses the solution to a simplified problem as a starting point and the final solution is then obtained by solving a simple differential equation. The author investigates the convergence properties and the limitation of such an approach and sheds some light on the nature and the number of solutions to the constrained LQG problem. >
A NaCl‐regulated plant gene encoding a brain protein homolog that activates ADP ribosyltransferase and inhibits protein kinase C

Summary A cDNA clone pCZ1, with a 1.1 kb insert, was isolated from a NaCI-adapted tobacco cell cDNA library that encodes an apparently full-length 29 kDa protein (251 amino acids) with a calculated pl of 5.7. The encoded peptide had a high amino acid sequence identity with bovine 14-3-3 protein which was originally found as an abundant protein in the animal central nervous system. Recently, proteins with sequence identity to 14-3-3 protein have also been found in plants, insects and yeast, and appear to have diverse physiological functions. Similar to the bovine brain 14-3-3 protein, the recombinant pCZ1 protein stimulated ADP-ribosylation of protein substrate by ADP-ribosyl-transferase from the plant and animal pathogenic bacterium Pseudomonas aeruginosa. This recombinant protein also inhibited protein kinase C activity in vitro. Southern blot analyses indicated that most likely five genes encoding 14-3-3-like proteins are present in tobacco. The pCZ1 cDNA insert hybridized to a single mRNA of 1.1 kb from cultured tobacco cells. The level of this mRNA transcript in tobacco cells was downregulated upon adaptation to NaCl but was unaffected by short-term treatment with NaCl, ABA or ethylene. In tobacco plants, expression of transcript that hybridized to pCZ1 was tissue specific, and was most abundant in roots and flower parts. Monoclonal antibody raised against GF14 protein, a maize protein with substantial sequence identity with 14-3-3 protein detected two bands on SDS-PAGE of total proteins from unadapted tobacco cells and only a single band from cells adapted to NaCl. The GF14 antibody was also used to illustrate that the G-box element of a salt-induced gene is associated with a 14-3-3-type protein.
Electromyography in Biomechanics

The purpose of this paper is to discuss the use of EMG as related to biomechanical function and dysfunction. The uses and limitations of this technique are described and instrumentation features and methods of data collection and interpretation are presented. We also discuss factors that influence the relationship of EMG to biomechanical measurements and cite as examples studies that have used EMG. Emphasis is placed on improving the ability of the physical therapist to use and interpret EMG data in kinesiology and biomechanics.
Diodes as pseudo active elements in high frequency DC/DC converters

A novel approach to realizing zero-voltage switching in high-frequency DC/DC converters is presented. Utilizing the parasitic associated with the diode stored charge, it is shown that the diode reverse current established for charge removal can be used advantageously to accomplish soft switching. The entire family of single-transistor DC/DC converters can be realized using the technique. The converter topologies are seen to differ from their hard-switched counterparts only by the presence of a resonant capacitor. It is also shown that device and component stresses are moderate as compared to existing quasi-resonant and resonant techniques. Converter analysis is rather complex as a result of the dominant diode nonlinearities, and no closed-form expressions are possible. Converter transfer characteristics are obtained through simulation, and operating limits are analytically obtained. The concept is validated by experimental results using buck-type converters rated at approximately 100 W and operating at frequencies around 1 MHz. >
Fundamentals of silicon material properties for successful exploitation of strain engineering in modern CMOS manufacturing

Semiconductor industry has increasingly resorted to strain as a means of realizing the required node-to-node transistor performance improvements. Straining silicon fundamentally changes the mechanical, electrical (band structure and mobility), and chemical (diffusion and activation) properties. As silicon is strained and subjected to high-temperature thermal processing, it undergoes mechanical deformations that create defects, which may significantly limit yield. Engineers have to manipulate these properties of silicon to balance the performance gains against defect generation. This paper will elucidate the current understanding and ongoing published efforts on all these critical properties in bulk strained silicon. The manifestation of these properties in CMOS transistor performance and designs that successfully harness strain is reviewed in the last section. Current manufacturable strained-silicon technologies are reviewed with particular emphasis on scalability. A detailed case study on recessed silicon germanium transistors illustrates the application of the fundamentals to optimal transistor design.
Long-term Perfusion of Isolated Rats Islets in Vitro

A perfusion system is described for long-term maintenance of isolated rat islets in vitro. This system permits the monitoring of the pattern, rate, and amount of insulin secretion following repeated, acute stimulations with glucose during the period of culture. Fibroblastic proliferation did not occur, thus making is possible to reclaim the islets for biochemical and morphologic studies at the conclusion of the experiments. Maintenance of the islets with a low concentration of glucose (1.0 mg./ml.) resulted in a marked decline in insulin secretion following acute stimulations with glucose (5.0 mg./ml.) during an eight-day interval. Stimulation with 10 mM theophylline and 5.0 mg./ml. glucose on day 9 resulted in enhanced insulin release. The decline in glucose sensitivity occurred even more rapidly when the islets were maintained in the presence of a lower concentration of glucose (0.5 mg./ml.). The pattern of insulin release was altered with an absence of a first phase of secretion. Adenylate cyclase activity of islets maintained with 0.5 mg./ml. glucose for four days was significantly decreased in comparison with islets from fed rats and islets maintained with 2.5 mg./ml. glucose. A means of maintaining the same biphasic pattern and amount of glucose-induced insulin release was achieved by using alternating levels of glucose (1.5 and 2.5 mg./ml) for maintenance of the islets during a 36-day interval.
Commercial Sex-Pheromone Lures Facilitate Collection of Skin and Carpet Beetles (Coleoptera: Dermestidae) in Natural and Urban Environments

ABSTRACT The pheromone (Z)- and/or (E)-14-methyl-8-hexadecenal (Trogodermal) is the main sex attractant for pest carpet beetles, Trogoderma granarium Everts, 1898, Trogoderma inclusum LeConte, 1854, Trogoderma glabrum (Herbst, 1783) and Trogoderma variable Ballion, 1878. This pheromone is often used to detect these pests within granaries, but it has not been reported to have been used to trap beetles in outside environments. We used Trogodermal-baited traps to collect over 3,000 dermestids in 43 dispersed locations in North and Central America; only 85 dermestids were collected in unbaited traps. Nine species of Trogoderma Dejean and individuals of Megatoma Herbst, Orphilus Erichson, Orphinus Motschulsky, and Thaumaglossa Redtenbacher were collected. This study is the first documentation of intergeneric dermestid response to Trogodermal.
Photonic filtering for high-frequency optoelectronic oscillator operation

A Fabry-Perot etalon with 1.498 GHz free spectral range is used for photonic filtering in an optoelectronic oscillator. Oscillations at multiples of its FSR are produced at 10.49 GHz, 36.0 GHz, and 53.9 GHz.
The Molecular Mechanisms of Allosteric Mutations Impairing MepR Repressor Function in Multidrug-Resistant Strains of Staphylococcus aureus

Overexpression of the Staphylococcus aureus multidrug efflux pump MepA confers resistance to a wide variety of antimicrobials.mepAexpression is controlled by MarR family member MepR, which represses mepAand autorepresses its own production. Mutations in mepR are a primary cause of mepA overexpression in clinical isolates of multidrug-resistant S. aureus. Here, we report crystal structures of three multidrug-resistant MepR variants, which contain the single-amino-acid substitution A103V, F27L, or Q18P, and wild-type MepR in its DNA-bound conformation. Although each mutation impairs MepR function by decreasing its DNA binding affinity, none is located in the DNA binding domain. Rather, all are found in the linker region connecting the dimerization and DNA binding domains. Specifically, the A103V substitution impinges on F27, which resolves potential steric clashes via displacement of the DNA binding winged-helix-turn-helix motifs that lead to a 27-fold reduction in DNA binding affinity. The F27L substitution forces F104 into an alternative rotamer, which kinks helix 5, thereby interfering with the positioning of the DNA binding domains and decreasing mepRoperator affinity by 35-fold. The Q18P mutation affects the MepR structure and function most significantly by either creating kinks in the middle of helix 1 or completely unfolding its C terminus. In addition, helix 5 of Q18P is either bent or completely dissected into two smaller helices. Consequently, DNA binding is diminished by 2,000-fold. Our structural studies reveal heretofore-unobserved allosteric mechanisms that affect re- pressor function of a MarR family member and result in multidrug-resistant Staphylococcus aureus. IMPORTANCE Staphylococcus aureus is a major health threat to immunocompromised patients. S. aureus multidrug-resistant variants that overexpress the multidrug efflux pump mepAemerge frequently due to point mutations in MarR family member MepR, the mepA transcription repressor. Significantly, the majority of MepR mutations identified in these S. aureus clinical iso- lates are found not in the DNA binding domain but rather in a linker region, connecting the dimerization and DNA binding do- mains. The location of these mutants underscores the critical importance of a properly functioning allosteric mechanism that regulates MepR function. Understanding the dysregulation of such allosteric MepR mutants underlies this study. The high- resolution structures of three such allosteric MepR mutants reveal unpredictable conformational consequences, all of which pre- clude cognate DNA binding, while biochemical studies emphasize their debilitating effects on DNA binding affinity. Hence, mu- tations in the linker region of MepR and their structural consequences are key generators of multidrug-resistant Staphylococcus aureus.
Modelling the negative Poisson's ratio of compressed fused fibre networks

Examples of auxetic fused fibrous assemblies can be found among both natural and synthetic materials. In theory, fibrous network materials can exhibit negative Poisson's ratios, yet the deformation mechanisms and parameters which give rise to a negative Poisson's ratio in disordered fibrous materials are not well understood, and this class of auxetic materials remains largely under-explored. The potential applications of auxetic fibre networks include their use as reinforcement in composites. The process of embedding auxetic random fibrous networks in a polymer matrix is an attractive alternate route to the manufacture of auxetic composites; however, before such an approach can be developed, a methodology for designing fibrous networks with the desired negative Poisson's ratios must first be established. This requires an understanding of the factors which bring about negative Poisson's ratios in these materials. In this work, we present a modelling approach to study the auxetic behaviour of compressed fused fibrous networks. Finite element analyses of three-dimensional stochastic fibre networks were performed to gain insight into the effects of parameters such as network anisotropy, network density and degree of network compression on the out-of-plane Poisson's ratio. The simulation results suggest that compression and anisotropy are the critical parameters that give rise to auxetic behaviour in these materials. We comment on the use of this model to inform the design of fibrous auxetic materials across different length scales, and on the feasibility of developing auxetic composites by using auxetic fibrous networks as the reinforcing phase. Preliminary experimental results indicate that this approach is a promising route in the pursuit of negative Poisson's ratio composites.
Bacterial transformations of inorganic nitrogen in the oxygen-deficient waters of the Eastern Tropical South Pacific Ocean

Abstract Rates of transformations of inorganic nitrogen were measured in the low oxygen, subsurface waters (50–450 m) of the Eastern Tropical South Pacific during February 1985, using 15N tracer techniques. Oxygen concentrations over the entire region were in a range (O2 Measured rates of nitrate reduction and estimated rates of denitrification were sufficient to respire nearly all of the surface primary production that might be transported into the oxygen deficient zone. These results imply that the supply of labile organic material, especially from the surface, was more important than oxygen concentration in modulating the rates of nitrogen transformations within the low oxygen water mass of the Eastern Tropical South Pacific. The pattern of nitrite oxidation and nitrite reduction activities in the oxygen minimum zone supports the hypothesis ( Anderson et al., 1982, Deep-Sea Research, 29, 1113–1140) that nitrite, produced from nitrate reduction, can be recycled by oxidation at the interface between low and high oxygen waters. Rates for denitrification, estimated from nitrate reduction rates, were in harmony with previous estimates based on electron transport system (ETS) measurements and analysis of the nitrate deficit and water residence times. Assimilation rates of NH4+ were substantial, providing evidence for heterotrophic bacterial growth in low oxygen waters. Ambient concentrations of ammonium were maintained at low values primarily by assimilation; ammonium oxidation was an important mechanism at the surface boundary of the low oxygen zone.
After Consensus, What? Performance Criteria for the UN in the Post-Cold War Era*

Not since 1945 has the UN enjoyed such support across the East-West divide as today. Cold War standards to evaluate UN performance are now of little value, but there is little general and theoretical discussion of alternative criteria. In an effort to clarify the issues at stake in what is sure to be a lively debate, the authors derive four distinct performance criteria extant in the literature on UN performance. These criteria include (1) declarations found in organic documents (charter-based), (2) medium and short-term objectives established by agency officials (operational), (3) past performance (trend-based), and (4) a scenario following elimination of the agency (absence-based). The strengths and weaknesses of each criteria are discussed theoretically and concretely through use of the four criteria to assess UN peace-keeping operations. The authors conclude that a blending of the operational and trend-based approach offers the most promising avenue for UN evaluation.
Falsely elevated bispectral index during deep hypothermic circulatory arrest

A 2-month-old infant underwent repair of a ventricular septal defect under deep hypothermic circulatory arrest. Bispectral index and EEG suppression ratio were evaluated using an Aspect BIS monitor. Erroneous readings from the monitor could have led to a potentially dangerous alteration in surgical and anaesthetic management.
Sensing Deforming and Moving Objects with Commercial Off the Shelf Hardware

In many application areas, there exists a crucial need for capturing 3D videos of fast moving and/or deforming objects. A 3D video is a sequence of 3D representations at high time and space resolution. Although many 3D sensing techniques are available, most cannot deal with dynamic scenes (e.g. laser scanning), can only deal with textured surfaces (e.g. stereo vision) and/or require expensive specialized hardware. This paper presents a technique to compute high-resolution range maps from single images of moving and deformable objects. A camera observes the deformation of a projected light pattern that combines a set of parallel colored stripes and a perpendicular set of sinusoidal intensity stripes. While the colored stripes allow recovering absolute depths at coarse resolution, the sinusoidal intensity stripes give dense relative depths. This twofold pattern makes it possible to extract a high-resolution range map from each image captured by the camera. This approach is based on sound mathematical principles, but its implementation requires giving great care to a number of low-level details. In particular, the sensor has been implemented using commercial off the shelf hardware, which distorts sensed and transmitted signals in many ways. A novel method was developed to characterize and compensate for distortions due to chromatic aberrations. The sensor has been tested on several moving and deforming objects.
The Kinetics of HCO3− Synthesis Related to Fluid Secretion, pH Control, and CO2 Elimination

In 1928 Henriques (20) deduced from the rates of HC03 � CO2 reactions published by Faurholt (14), that the conversion process was too slow to account for the loss of respiratory CO2 across the lung. Henriques sought for an enzyme in blood to catalyze the process; for reasons I have reviewed elsewhere (32) he concluded that there was none, but that the rapid reaction was mediated by carbaminohemoglobin (20). Meldrum & Roughton, five years later, discovered carbonic anhydrase (CA) in red cells (38). It is now clear that the interconversion of CO2 � HC03 has physiological implications far greater than the carriage and excretion of metabolic CO2 in red cells. This process occurs in other sites, and the reaction is also central to the formation of H+ and HC03 in secretory organs (reviewed in 30). In the present chapter I consider anew HC03 formation in certain secre­ tory processes, in generation of an alkaline milieu, and in subserving the excretion or removal of CO2 from certain special tissues. Chemically, these are analogous to the interconversion in red cells; the latter is considered by Klocke elsewhere (this volume). An earlier review (34) covers other aspects of HC03 or COjsynthesis, i.e. in shell formation and salivary secretion. The purpose of this review is to try to coordinate this subject by weaving
The Role of Information and Order in the Origin of Life

Living systems exist as dynamically ordered structures even despite limitations on order set by the 2nd law of thermodynamics and coarse graining. These famously state that, globally, disorder must increase. By comparison, living systems only exist locally and so can instead achieve states of increased order and information. This emergent property of spontaneous ordering is shared with other systems, such as crystals, that likewise overcome the 2nd law on a local basis. However, living systems obey certain properties that set them apart from these and which lead to their underlying biological function. Among these are the central roles played by the cell membrane, spatially local variability of order, information feedback, quorum sensing, and quantum-like behavior. Nevertheless, there is (at least) one distinct convergence between living and nonliving systems. This is a direct mathematical parallel between the forms of the Lotka-Volterra equations of biology and the Hartree scattering equations of physics. These indicate that particle-particle interaction potentials of physics have direct analogs to species-species fitness functions of biology. This correspondence is derived, explored, and used as a point of departure for finding further quantum-like mathematical properties of living systems by use of the principle of extreme physical information (EPI). The possibility of life’s origin as an inorganic polymer and/or micelles is discussed, as well as the possible central role played by the acquisition of our moon. Finally, a possible “aim” for life is discussed.
Optical Logic and Optically Accessed Digital Storage

A computer system can be divided according to its three principal functions: 1. The Processor Unit in which information streams interact. This is where the logic is implemented. Modern computer systems often utilize a number of processors [1]. 2. The Storage and/or Memory which acts as a repository for information. Typically this consists of a hierarchy [2] of subunits. The members of the hierarchy correspond to different trade-offs for access speed vs. capacity. Thus small amounts of information can be stored with a very rapid access capability. (There is unfortunately no universally accepted distinction between “Storage” and “Memory.” Most frequently, however, Memory refers to the faster portions of the hierarchy, where access can be highly selective, and where information is typically stored in physically distinguishable devices.) 3. The Input-Output Devices which act as transducers to the external world.
Educational Specialization of Southern Sociologists with the Doctorate

sets of data and may be due to the evaluating procedures themselves, they indicate a need to explore further the effects on findings of different ranking techniques,23 of the status of the ranker, and of the nature of the objects being ranked. Finally, the findings suggest that it would be theoretically fruitful to re-examine results of previous studies of values in relation to socioeconomic status in the broader context of consenlsus, which allows for a consideration of the extent to which value agreements and differences are commonly understood within and among social class groupings.
What May We Expect from Biological Control

Biological control work has been subject to extremes of popular approval and disapproval. This is due to a lack of understanding, on the part of the general public, of just what results may reasonably be expected from this method. Success IS dependent upon biological principles with which the grower is not always familiar. Some insect pests are favorable subjects for attack by this method and others are not. It is pointed out that the proper co-relation between host and parasite and freedom from secondary parasites, are important factors in this type of control. The future is bright for this branch of economic entomology.