cssi/SciSciGPT-SciSciNet huggingface dataset:
Shedding of the immunodominant P20 surface antigen of Eimeria bovis sporozoites.

Abstract P20 is an immunodominant surface antigen of Eimeria bovis sporozoites. As parasites underwent merogony within cultured bovine monocytes and Madin-Darby bovine kidney (MDBK) cells, P20 appeared to be shed gradually by meronts and was absent in type 1 and 2 first-generation merozoites. Meronts of E. bovis appeared to shed P20 into the parasitophorous vacuole of bovine monocytes, whereas MDBK cells evidently released P20 into the culture medium or destroyed its antigenic determinant.
Modeling of flexible elements in robotic systems for modular environments

Recently, modularity in robotics has received considerable attention. For successful implementation of such an architecture, development of user-friendly, modular software becomes crucial. In order to address this problem, a model of the modular system is needed that can: (1) represent the system with an acceptable accuracy; and (2) be easily restructured for different robot configurations. In this study, the authors develop a dynamic model for modular robots that may have flexible components. They consider that the flexible components are distributed throughout the system such that they can induce either link or joint deflections. The system model is derived in a format that readily lends itself to controller design.
Increasing risk with state-dependent preferences

Abstract A definition of increasing risk for state-dependent preferences is introduced and its usefulness for the analysis of concrete economic problems is illustrated. For classes of individuals with the same reference set the notion of increasing risk has three equivalent characterizations analogous to those obtained in the case of state-independent preferences. The definition is used to conduct a comparative statics analysis of a portfolio problem with state-dependent preferences.
Antagonistic effect of magnesium chloride on the nickel chloride–induced inhibition of DNA replication in chinese hamster ovary cells

The degree of inhibition of semiconservative DNA replication induced by nickel chloride (NiCl2) was analyzed by radiolabeled-thymidine incorporation alone or with cesium chloride (CsCl) density gradient centrifugation. The onset and duration of this Ni2+-induced inhibition was time- and concentration- dependent, but the degree of inhibition was not. A maximal reduction in the rate of DNA synthesis was observed within the first hour of treatment with 2.5 mM NiCl2, which was the highest noncytotoxic concentration utilized. After six hours, 500 μM and 1 mM as well as 2.5 mM NiCl2 all produced the same 50% to 60% reduction in [3H]-thymidine incorporation into DNA. The inhibitory effect of nickel ions on DNA synthesis was reversible. The rate of DNA synthesis following a 500 μM or 1 mM NiCl2 treatment began to increase after washout of nickel, but a six-hour exposure of cells to 2.5 mM NiCl2 produced a sustained 50% to 60% suppression of DNA synthetic activity for at least 36 hours. At all concentrations of NiCl2 used in this study, some inhibition of DNA synthesis persisted for at least 48 hours, but by 72 hours after treatment, the rate of [3H]-thymidine incorporation was actually 10% above the control. Examination of autoradiographic slides of cells treated with 2.5 mM NiCl2 for six hours demonstrated a 60% reduction of silver grains, but there was no preferential reduction in the quantity of grains in the nucleolus or any other region. Cesium chloride density gradient analysis of the replication of nucleolar DNA in cells treated with 2.5 mM nickel supported the autoradiographic findings. The inhibitory effect of NiCl2 on DNA replication was prevented by the addition of magnesium chloride (MgCl2) to cells maintained in a simple salts/glucose medium (SGM). This effect did not appear to be due to an antagonism of the cellular uptake of nickel by Mg2+, since the maximally effective dose of Mg2+ reduced 63Ni2+ uptake by no more than 25% while the inhibition of replication was completely reversed.
Specific blue-green algal carotenoids in sediments of Esthwaite Water

Two cores from Esthwaite Water have been analyzed for oscillaxanthin, derived from Oscillatoria alone, and myxoxanthophyll found only in blue-green algae. Myxoxanthophyll profiles are similar for the two cores with maxima at 6-7 cm and 14-16 cm and low values in the top 5 cm and below 17-19 cm. Oscillaxanthin follows the same general pattern but without pronounced maxima. Such profiles can be used to indicate the appearance of Oscilhtoria and other blue-green algae in a lake, and indirectly, the onset of eutrophication. Raw data for the blue-green algae present in the lake between 1948 and 1976 have been analyzed. When the years of maximal algal counts in the lake are correlated with the depths of myxoxanthophyll maxima in the sediment, an annual sedimentation rate for the top 15 cm e well with results by other methods.
Intra- and intermolecular interactions in the solid state structure of 2-iodylbenzenesulfonamides: a heptacoordinated organic iodine(V) compound

Single crystal X-ray structures of two 2-iodylbenzenesulfonamides reveal a combination of intra- and intermolecular I⋯O interactions leading to a typical hexacoordinated and a unique heptacoordinated iodine(V) center.
Biological effects of microwave radiation on the testes of Swiss mice.

Nachweis histologischer Veranderungen am Hodengewebe 2 Monate alter Schweizer Mause nach Mikrowellenbestrahlung. Es ergab sich, dass eine nichtionisierende Bestrahlung bei 1,7 GHz und einer Intensitat von 50 mW/cm2 wahrend 30–40 min die Samenbildung verandert.
A novel method for the introduction of an aliphatic primary amino group at the 5' terminus of synthetic oligonucleotides

Abstract Reaction of the 5′ hydroxyl group of a support bound synthetic oligonucleotide with the new reagent N-trifluoroacetyl-2-aminoethyl-(2-cyanoethyl)-N,N-diisopropylaminophosphor-amidite yields, upon deprotection, an oligonucleotide having a 5′ primary amino terminus. The amino derivatized oligomer can then be specifically reacted with the N-hydroxysuccinimide ester of d -biotin to give a stable oligonucleotide-biotin adduct.
Tantalum Pentoxide Gate Dielectrics Formed by Tantalum Oxidation

Tantalum pentoxide (Ta2O5) films were formed by oxidizing thin tantalum (Ta) films on bare and NO-nitrided silicon substrates. The 43-400 A thick Ta films were deposited using physical vapor deposition (PVD) and oxidized using O2 for 2-60 min at 550-800 C in a furnace or single wafer tool. Uniform and stoichiometric Ta2O5 films were successfully produced as determined from XRD, AES depth profiling, XTEM, and ellipsometric analysis. The nitridation pretreatment was found to minimize the interfacial Ta-Si reactions which occur during the oxidation. Well-behaved CV and IV curves were obtained from mercury probe measurements. No CV hysteresis was observed. An equivalent oxide thickness of 38 A and a leakage current of 7×10−9 A/cm2 at +1V were obtained for a 120 A thick Ta2O5 film on a 15 A interfacial SiO2 layer.
Claude Bernard: On the origin of carbon monoxide poisoning

Although it was Claude Bernard who first published an accurate description of the physiology of carbon monoxide poisoning, [1] this is not the work for which he is best known. The nineteenth century French physician and scientist is renowned for a wide variety of physiological and biological discoveries, the most important of which pertain to the glycogenic function of the liver, the role of the pancreas in digestion, muscle physiology and vasomotor nerve function [2]. He is recognized as establishing physiology as an important area of medical study, and his magnum opus, Introduction to the Study of Experimental Medicine is considered a classic in scientific literature [3]. Born in 1813 in the village of Saint-Julien in the Beaujolais region, Bernard began his career as an apprentice in a pharmacy. He was an indifferent trainee, and a year and a half of service managed mainly to induce in him a distrust of the haphazard empirical methods then prevalent in medicine. Years later, a testimonial from the pharmacist indicated that he had ‘‘conducted himself honorably and faithfully’’ but excluded to mention that he showed any special talent for pharmacy [4]. Among his tasks was the compounding of ‘‘theriaque’’, a widely-used panacea composed of opium, squills, spikenard and myrrh dissolved in honey and wine. Bernard soon discovered that any available excess medicinal powders were also often appended to the mixture. His real interest lay in becoming a playwright. Having had a play produced in the provinces, Bernard proceeded to Paris to have his literary work reviewed by Saint-Marc Girardin, an influential critic and professor of literature at the Sorbonne. The latter was unimpressed, allegedly advising Bernard, ‘‘You have done some pharmacy, study medicine. You have not the temperament of a dramatist’’ [4]. Following this advice, Bernard entered the Medical College of France, from where he graduated in 1843. While at medical school, he became a disciple of Francois Magendie, a vigorous proponent of the experimental method. Bernard never practiced clinical medicine, turning instead to laboratory investigation and teaching. His wife and daughters eventually abandoned him when he refused to give up experimental medicine in order to pursue a more lucrative clinical practice [5]. Upon Magendie’s death in 1855, Bernard replaced him as lecturer at the College of France. He began to compile his lectures beginning in that year, and by 1879, this comprised a body of work of fourteen volumes. In 1857, Bernard published a volume entitled Lecons sur les Effets des Substances Toxiques et Medicamenteuses (Lectures on the effects of toxic and medicinal substances), this constituting the series of lectures he had * Corresponding author. Present address. 2219 Dorrington, Houston, TX 77030, USA. Tel.: /1-713-839-1170; fax: /1-713-8391467. E-mail address: jvaron@roamer.net (J. Varon).
Updated Software Reliability Metrics

The Institute of Electrical and Electronics Engineers’ Standard Dictionary of Measures of the Software Aspects of Dependability (982.1) has been scheduled for updating. This standard was issued several years ago. Since then new software reliability metrics have been developed and evaluated. In addition, modifications of metrics in the standard have developed and evaluated. The objective of this paper is to describe, evaluate, and apply the new and modified metrics, using failure data from several releases of the NASA Space Shuttle flight software. Recognizing that users of standards have other applications, the methodology, equations, and prediction plots are explained so that reliability engineers can apply the metrics to their applications. The metrics are assessed from two standpoints: 1) identify metrics that support a specified purpose (e.g., demonstrate reliability growth) and 2) use these metrics to identify software releases that, based on reliability predictions, are ready to deploy and identify which software requires additional testing. Prediction accuracy is computed for all metrics and the metrics are compared based on the results.
Cloning of the human and mouse type X collagen genes and mapping of the mouse type X collagen gene to chromosome 10.

Type X collagen, a homotrimer of α1(X) polypeptide chains, is specifically expressed by hypertrophic chondrocytes in regions of cartilage undergoing endochondral ossification. We have previously described the isolation of a small fragment of the human type X collagen gene (COL10A1) and its localization to the q21–q22 region of human chromosome 6 [Apte, S., Mattei, M.-G. & Olsen, B. R. (1991) FEBS Lett. 282, 393–396]. Using this fragment as a probe to screen genomic libraries, we report here the isolation of human and mouse genomic clones which contain the major part of the human and mouse type X collagen genes. In both species, the 14-kb genomic clones which were isolated contain a long open reading frame (>2000 bp in length) which codes for the entire C-terminal non-collagenous (NC1) domain, the entire collagenous (COL) domain and part of the N-terminal non-collagenous (NC1) domain, the entire collagenous (COL) domain and part of the N-terminal non-collagenous (NC2) domain of the α1(X) collagen chain. The human genomic clone contains the major part of the COL10A1 gene, in addition to the region we have previously cloned, and is highly similar to the corresponding portions of the mouse genomic clone (84.5% similarity at the nucleotide level, and 86.1% at the level of the conceptual translation product). The identification of the mouse genomic clone as the α1(X) collagen gene (Col10a1) was confirmed by in situ hybridization of a fragment of the mouse genomic clone to sections from newborn mic. Hybridization was restricted to the hypertrophic chondrocytes of developing chondroepiphyses, being absent in small chondrocytes and in other tissues. Using interspecific backcross analysis, the locus for the mouse α1(X) collagen gene was assigned to chromosome 10. The cloning and chromosomal mapping of the human and mouse α1(X) collagen genes now permit the investigation of the possible role of type X collagen gene defects in the genesis of chondrodysplasias in both species and provide data essential for the generation of transgenic mice deficient in type X collagen.
Measuring hydrogen by cold-neutron prompt-gamma activation analysis

By irradiating with cold neutrons and avoiding hydrogenous materials of construction, we have developed a PGAA instrument at the Cold Neutron Research Facility at NIST with hydrogen detection limits in the microgram range in many materials. Quantities of 5–10 μg H/g are presently measurable in gram-sized samples of silicon or quartz, and of order 0.01 wt % can be quantitatively measured in complex silicate rocks.
Chip-scale electrodynamic synthetic jet actuators

We report a chip-scale electrodynamic synthetic jet actuator that integrates both a coil and a wax-bonded NdFeB permanent magnet using standard silicon micromachining processes. A copper micro-coil and a poly-dimethyl-siloxane (PDMS) diaphragm with the magnet are fabricated onto two different dies. An orifice, through which the jet is synthesized, is laser cut on the coil die. The dies are then assembled together to create a device with the dimensions 7.5 mm × 7.5 mm × 1 mm. Operating at 180 Hz and 20 mW input power, the device generates a fluidic jet with a peak velocity of 2.1 m/s.
Ebselen Attenuates Lung Injury in Experimental Model of Carrageenan-Induced Pleurisy in Rats

The study evaluates the role of Ebselen (Eb), an organoselenium compound in animal model of acute lung injury induced by carrageenan (CG). Wistar rats received saline or 2 % λ-carrageenan in the pleural cavity, and treatment with Eb (50 mg/kg intragastrically) or dexamethasone (Dx) (0.5 mg/kg intraperitoneal) after CG administration. After 4 h, rats were euthanized and the pleural exudate removed for analysis of the total cell count, total protein, lactate dehydrogenase, and nitrite/nitrate. Moreover, lung tissue were removed to verify the myeloperoxidase activity and oxidative damage. Eb showed anti-inflammatory activity by inhibiting leukocyte influx, myeloperoxidase activity, and nitrite/nitrate concentration. Eb presented with an anti-inflammatory activity similar to Dx and an antioxidant activity better than Dx. This study suggests that Eb plays an important role against the oxidative damage associated with anti-inflammatory activity in animal model of acute lung injury, proving to be similar or potentially more effective than Dx.
Hepatic artery aneurysms: The management of 22 patients

Hepatic artery aneurysms (HAAs) are being encountered with increasing frequency. A retrospective study of the management of HAAs at a single institution over an 18-year period is presented. The medical records of all patients diagnosed with HAA were reviewed. There were 22 patients who collectively had 23 HAAs. They were of equal gender distribution with a mean age of 53 +/- 16 years. Sixteen patients were symptomatic. Angiography was definitive in all cases and was necessary for determining therapy. There were 16 true aneurysms and 7 pseudoaneurysms. The method of treatment depended on the anatomic location of the aneurysm and the status of the patient. Treatment was by surgery (n = 10 patients), embolization (n = 8 patients), or by observation (n = 3 patients). There were two acute deaths; one patient died on admission without therapy, and one patient died following surgery. Two patients had surgical complications. Three of seven patients required repeat embolization, and one had open surgery after failed embolization. Three patients died of unrelated causes. The follow-up period was 2 months to 8 years. Thus, early HAA mortality and morbidity rates were 9.1 and 22.7%, respectively. Unless precluded by significant comorbidities, active treatment is advocated in the management of patients with HAAs. Surgery is the preferred treatment for extrahepatic lesions, while embolization is appropriate for intrahepatic aneurysms, the majority of which are pseudoaneurysms. Increased clinical awareness and aggressive, definitive management are necessary in obtaining optimal outcomes.
The role of topotecan for extending the platinum-free interval in recurrent ovarian cancer: an in vitro model.

Abstract Objective . Topotecan, a novel topoisomerase-I inhibitor, is an active agent of second-line chemotherapy for extending the platinum-free interval (PFI) and improving the chances of a response to platinum in recurrent ovarian cancer patients. The aim of this study was to understand the molecular mechanism of topotecan-based second-line chemotherapy through an in vitro cell culture model and to gain clinical insight into sequencing issues for second-line treatment with novel agents versus retreatment with platinum. Study design . The human ovarian cancer cell line A2780 and the cisplatin resistance cell line A2780-CR were separately seeded in 6-well cell culture plates and then exposed to multiple concentrations of cisplatin plus paclitaxel or topotecan for 7 days. Surviving cells were recovered and cultured in drug-free media for 3 weeks and then replated in a 96-well microtiter plate. The LD 50 for these cells was determined by a cytotoxic MTT assay after exposure to multiple clinically relevant concentrations of cisplatin or topotecan. Surviving cells were cultured in drug-free media for an additional 4 weeks at which time the LD 50 was reassessed for each cell population by a second MTT assay. Using RT-PCR and Northern blot hybridization to measure mRNA expression, the molecular profile of these cells in terms of resistance was evaluated for the multidrug-resistant gene (MDR-1), multidrug-resistant protein (MRP), Topoisomerase-I, and β-Actin. Results . The LD 50 to cisplatin was unchanged in A2780-CR cells treated by topotecan. Those A2780-CR cells originally exposed to higher concentrations of cisplatin became more resistant to cisplatin in the MTT assays, while those A2780-CR cell lines treated with a combination of lower cisplatin concentrations and paclitaxel became more sensitive to cisplatin in the MTT assay ( P 50 for cisplatin in every cell line decreased significantly after a 4-week drug-free interval ( P P Conclusions . The acquired resistance to cisplatin in A2780 is potentially due to P-glycoprotein-mediated multidrug resistance. This acquired resistance to cisplatin is an unstable phenotype in that some cell populations become sensitive after a drug-free interval and topotecan treatment. This reversal of resistance, however, does not appear to be simply due to loss of MDR-1 expression. While in vivo confirmation is required, agents with novel mechanisms of action offer a strategy to extend the platinum-free interval and thereby improve survival in patients with recurrent ovarian cancer.
How Different are VA Nursing Home Residents

Objective: To identify similarities and differences between VA nursing home residents and other nursing home residents. Design: Comparison of cross-sectional data from three sources. Participants: Residents of VA nursing homes nationwide in early October 1986 (n = 10,117); participants in the 1985 National Nursing Home Survey (NNHS) (n = 5,243); residents assessed in New York State nursing homes in 1988 (n = 94,840). Measures: Age-stratified comparisons were made between the VA and the NNHS for gender, marital status, race, ethnicity, length of stay, activities of daily living (ADL) status, and selected diagnoses and conditions. Additionally, case-mix data were compared between the VA and the New York State populations. Main Results: The population of VA nursing homes is over-whelmingly men (96.1% versus 28.4% in the NNHS), and 31.2% of the VA population is under 65 years of age compared with 11.6% in the NNHS. Young (<65) VA residents are considerably more impaired in ADL than young residents in the NNHS; differences are less pronounced in those over 65 years old. VA case mix is slightly higher than the overall New York State population though the distribution of residents into categories in the Resource Utilization Groups, Version II system is somewhat different. Conclusions: VA nursing homes contain a substantial distinctive population of seriously impaired residents under 65 years of age. Though differences exist, older VA residents have many similarities to residents of non-VA nursing homes and constitute a functionally impaired population that can provide insights into the status of nursing home residents generally.
Twisted magnetization states near the compensation temperature of Fe ∕ Gd multilayers: Anisotropy and surface-termination effects

Inhomogeneous magnetization depth profiles in antiferromagnetically coupled Fe/Gd multilayers are investigated using x-ray magnetic circular dichroism (XMCD) measurements. Spin configurations are studied as a function of temperature and applied field on two multilayers with different termination layers. We place particular emphasis on the vicinity of the ferrimagnetic compensation temperature (T{sub Comp}), where the Gd and Fe magnetizations are equal but opposite. While away from T{sub Comp} the spin configurations are dictated by the presence of surface- and bulk-twisted states, unusual field dependence is observed near T{sub Comp}. We used micromagnetic simulations to show that the unusual observed phenomena near T{sub Comp} are due to a small uniaxial anisotropy in the Fe layers, whose influence on the spin configurations becomes apparent only near T{sub Comp}. The simulations also show the onset of the surface- and bulk-twisted phases at temperatures below and above T{sub Comp} in agreement with the experimental XMCD data.
Renal Angioplasty and Stent Placement with Distal Protection: Preliminary Experience with the FilterWire EX

Percutaneous transluminal renal angioplasty and stent placement with use of a coronary protection device was performed in a total of four patients with hypertension ( n = 4) and/or renal insufficiency ( n = 3) referred for revascularization of five renal arteries. Renal revascularization was successful in all five renal arteries (100%), but renal revascularization under protection by the FilterWire EX was achieved in only three of five renal arteries (60%). In one of these three, only a suboptimal seal was achieved between the vessel wall and the filter basket. Nevertheless, use of the device was safe and fibrin and/or cholesterol fragments were retrieved from three renal arteries. The FilterWire EX needs to be modified for the renal circulation to achieve the full theoretical advantages of these systems in this vascular bed.
Cytosine methylation does not affect binding of transcription factor Sp1

DNA methylation may be a component of a multilevel control mechanism that regulates eukaryotic gene expression. We used synthetic oligonucleotides to investigate the effect of cytosine methylation on the binding of the transcription factor Sp1 to its target sequence (a G + C-rich sequence known as a "GC box"). Concatemers of double-stranded 14-mers containing a GC box successfully competed with the human metallothionein IIA promoter for binding to Sp1 in DNase I protection experiments. The presence of 5-methylcytosine in the CpG sequence of the GC box did not influence Sp1 binding. The result was confirmed using double-stranded 20-mers containing 16 base pairs of complementary sequence. Electrophoretic gel retardation analysis of annealed 28-mers containing a GC box incubated with an Sp1-containing HeLa cell nuclear extract demonstrated the formation of DNA-protein complexes; formation of these complexes was not inhibited when an oligomer without a GC box was used as a competitor. Once again, the presence of a 5-methylcytosine residue in the GC box did not influence the binding of the protein to DNA. The results therefore preclude a direct effect of cytosine methylation on Sp1-DNA interactions.
Monoclonal antibody analysis of common surface protein(s) of Renibacterium salmoninarum.

We are reporting the development of two monoclonal antibodies which recognize ten separate isolates of Renibacterium salmoninarum. Both monoclonal antibodies recognize a 57 kDa protein doublet and several lower molecular weight antigens present in bacterial lysates. The 57 kDa antigen appears to correlate with a 57 kDa surface protein named Antigen F by GETCHELL et al. (1985).Antibody capture ELISA analysis indicates that the antibodies recognize different epitopes of the same protein (s). Cross-reactions were not observed with control bacteria or with normal chinook salmon serum proteins.
The Physical Oceanography of Two Rings Observed by the Cyclonic Ring Experiment. Part I: Physical Structures

Abstract Eight cruises over a 10-month period in the North Atlantic have provided the Cyclonic Ring Experiment with observations of two rings. Life histories, structure and structural changes have been studied with emphasis on the effects of Stream interaction and spindown processes. Ring AL was generated in September 1976 with a central water mass composed of Slope and anticyclonic ring waters. Ring BOB separated from the Stream in March 1977 with a Shelf and Slope Water core. Both rings had a 7-month lifetime, interacted with the Gulf Stream and were regenerated. The Stream interaction altered the core structures, and in the case of BOB, cruise observations show significant changes in ring size and shape. BOB's spatial extent decreased with interaction and increased during spindown while eccentricity of the ring behaved in an opposite manner.
Feeding the cities and feeding the peasants: What role for Africa's women farmers?

Abstract Arguing that increased attention to the problems of women farmers in Africa can help solve both urban and rural food supply problems, this paper builds its case on a close examination of the extensive farming system of the Beti peoples of southern Cameroon and the intensive farming practices of the Haya of northwestern Tanzania. The first part of the paper addresses technological and socio-economic problems constraining the expansion of food production and marketing; the second describes two situations in which the removal of specific constraints allowed women farmers to demonstrate their capacity and willingness to expand their output and improve their welfare.
Influence of methylation on the properties of uracil and its noncovalent interactions with alkali metal ions: Threshold collision-induced dissociation and theoretical studies

Abstract The influence of methylation on the properties of uracil and its noncovalent interactions with alkali metal ions is investigated both experimentally and theoretically. Threshold collision-induced dissociation (CID) of M+(xMeU) with Xe is studied in a guided ion beam mass spectrometer. M+ include the following alkali metal ions: Li+, Na+, and K+. Five methylated uracils are examined, xMeU = 1-methyluracil, 3-methyluracil, 6-methyluracil, 1,3-dimethyluracil, and 5,6-dimethyluracil. In all cases endothermic loss of the intact nucleobase is the dominant reaction pathway, while ligand exchange to produce MXe+ is observed as a minor reaction pathway. The threshold regions of the cross sections are interpreted to extract 0 and 298 K bond dissociation energies (BDEs) for M+ xMeU after accounting for the effects of multiple ion-neutral collisions, kinetic and internal energies of the reactants, and dissociation lifetimes. Ab initio calculations at the MP2(full)/6–31G* level of theory are used to determine the structures of these complexes and provide molecular constants required for the thermochemical analysis of the experimental data. Theoretical bond dissociation energies are determined from single point energy calculations at the MP2(full)/6–311 + G(2d,2p) level using the MP2(full)/6–31G* geometries. Excellent agreement between theory and experiment is found for the Na+ and K+ systems, while theory systematically underestimates the strength of binding in the Li+ systems. Theoretical calculations are also performed to examine the influence of methylation on the acidities, proton affinities, and Watson–Crick base pairing energies. The present results are compared to earlier studies of uracil and 5-methyluracil to more fully elucidate the influence of methylation on the properties of uracil, its noncovalent interactions with alkali metal ions, and nucleic acid stability.
Perturbation analysis of an undulating free surface in a multi-layered structure

This paper presents an analysis of the effect of an undulating free surface on the stress state in a multi-layered structure with an arbitrary number of layers. We present a simple procedure to derive in terms of stress functions the first-order perturbation solution for a multi-layered structure subjected to residual stresses and to external edge loads. The solution is valid for undulation amplitudes that are small compared to undulation wavelength, and it reproduces results reported earlier for homogeneous materials and bi-layers. Using this perturbation solution, the stability of a stressed undulating surface with a given surface energy is evaluated. This analysis leads naturally to the definition of a critical undulation wavelength above which undulations are preferred energetically over a flat surface. The results obtained in the perturbation analysis can be applied to surface diffusion/etching problems in multi-layered structures and to a range of other engineering problems related to undulating surfaces and surface stability.
Spatially-resolved analysis of nanoparticle nucleation and growth in a microfluidic reactor

Microfluidic systems provide a unique platform for investigation of fundamental reaction processes, which is critical to understanding how to control nanostructure synthesis on a production scale. We have examined the synthesis of cysteine-capped CdS quantum dot nanocrystals (CdS-Cys) between two interdiffusing reagent streams in a continuous-flow microfluidic reactor. Using spatially resolved photoluminescence imaging and spectroscopy of the microreactor, we have acquired kinetic and mechanistic data on the CdS-Cys nanoparticle nucleation and growth, and observed a binary shift in the particle emission spectrum from a higher (2.9 eV) to lower (2.5 eV) energy emission peak within the first second of residence time. Several reactor models have been tested against the spatially and spectrally resolved signals, which suggest that homogeneous reaction and particle nucleation are diffusion-limited and occur only at the boundary between the two laminar streams, while a slower activation process occurs on a longer (seconds) time scale. The results provide direct insight into the rapid processes that occur during crystallization in microfluidic mixing channels, and demonstrate the potential of using controlled microfluidic environments with spatially resolved monitoring to conduct fundamental studies of nanocrystal nucleation and growth.
Radha Jalan and ElectroChem, Inc.: Energy for a Clean Planet

ElectroChem, Inc. was a global supplier of fuel cell technology for government and commercial applications. When the founder unexpectedly died in 1992, the firm had not yet achieved profitability a...
Actions of lithium ions and insulin on glucose utilization, glycogen synthesis and glycogen synthase in the isolated rat diaphragm.

Abstract The effects of lithium ions and insulin on carbohydrate metabolism of the isolated rat diaphragm were studied and compared. Like insulin, lithium ions caused a conversion of glycogen synthase D to the more active I form of the enzyme. Maximal activation of the enzyme was produced by about 5 mM LiCl. Lithium ions markedly increased glucose utilization and glycogen synthesis by the diaphragm, but the action of this ion appears to be exerted by a mechanism different from that of insulin, since the effects of maximal concentrations of the two agents are additive. In their action on glucose metabolism, lithium ions had a unique ability to direct the glucose taken up by the cell toward glycogen. Insulin and lithium ions had opposite effects on the tissue content of glucose 6-phosphate; insulin increased the tissue level of this metabolite, whereas lithium ions decreased it. ATP and creatine phosphate concentrations were not affected by insulin or lithium ions. The effects of lithium ions on carbohydrate metabolism are exerted at relatively low concentrations of Li, and our results indicate that significant alterations of carbohydrate metabolism may occur when therapeutic or toxic amounts of lithium salts are ingested by man.
Operation bolster: Canada and the European community monitor mission in former Yugoslavia, 1991–92

The European Community Monitor Mission (ECMM) was the first peacekeeping operation which attempted to limit the conflict in the Balkans and pre‐dated the UN deployment by ten months. Originally an ad hoc organization, the ECMM developed permanence in the region as the conflict spread by adapting its roles and missions to new situations, particularly after the UN deployed in 1992. Its permanence was due in part to Canadian participation in the Mission. This provided significant operational professionalism and continuity, despite the fact that Canadian policymakers viewed this contribution merely in symbolic terms vis‐a‐vis Canadian‐European relations. The ECMM's flexible, and sometimes convoluted, modus operandi provides peacekeeping specialists with a case study on the limits of coalition peacekeeping operations and with a model for a future preventive conflict monitoring organization.
IRD Digital Background Calibration of SAR ADC With Coarse Reference ADC Acceleration

A coarse analog-to-digital converter (ADC) is used as the reference path to resolve the input interference problem in correlation-based background calibration of multistep ADCs. A 16-bit successive-approximation-register (SAR) ADC employing a subbinary architecture is calibrated with an 8-bit reference path, achieving a nearly 20 × reduction in convergence time and greatly improved steady-state linearity performance in simulation. The SAR ADC bit-weight calibration is based on the principle of internal redundancy dithering (IRD), a technique in which the bit decision thresholds are dithered by a pseudorandom bit sequence (PRBS) within the redundancy region. Aided by the coarse reference ADC, behavioral simulation shows that 89-dB signal-to-noise plus distortion ratio and the 115-dB spurious-free dynamic range (SFDR) are achievable with the proposed calibration for a SAR ADC with 1% digital-to-analog converter mismatch errors.
Overexpression of post-translationally modified peptides in Escherichia coli by co-expression with modifying enzymes

Post-translational modification plays crucial roles in signal transduction in eukaryotic cells. To elucidate the biological function of a protein with a specific post-translational modification, it is necessary to isolate the modified protein. However, it is difficult to incorporate a modified amino acid into a specific position of a protein, in particular, in a large-scale preparation. In order to prepare post-translationally modified proteins in Escherichia coli (E. coli), we have constructed co-expression vectors that contain protein and corresponding enzyme genes. The protein and enzyme are co-expressed in the same E. coli cells and the protein is post-translationally modified in vivo. By using this system, the transcriptional activator cyclic-AMP-response-element-binding protein (CREB) was phosphorylated at Ser-133 and the hypoxia-inducible factor-1alpha (HIF-1alpha) was hydroxylated at Asn-803 in E. coli. Although the constructs of the proteins we used are very flexible and susceptible to degradation by proteases in E. coli when they are expressed alone, the B1 domain of streptococcal protein G (GB1) fused to the N-terminus of the proteins increased the yields dramatically. Site-specific phosphorylation of CREB and hydroxylation of HIF-1alpha were confirmed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) and NMR. Our GB1-fusion co-expression system can be used in the same way as conventional protein expression in E. coli, making it a flexible and economical method to produce a large amount of a post-translationally modified protein.
In situ x-ray-scattering study of the Au(001) reconstruction in alkaline and acidic electrolytes.

X-ray scattering from the solid/liquid interface of a Au(001) single crystal in 0.1 M potassium hydroxide and 0.1 M perchloric acid electrolytes has been measured. In both solutions the Au surface reconstruction consists of an incommensurate-hexagonal monolayer with a structure similar to the clean annealed vacuum surface at room temperature. In KOH electrolyte the reconstruction is aligned along the [110] direction, unlike the vacuum and perchloric acid interfaces, where the reconstruction is rotated [plus minus](0.5--0.8)[degree] from the [110] direction. In KOH solution the reconstruction forms rapidly at electrode potentials below [minus]0.25 V (versus the saturated calomel electrode) and is lifted in a narrow potential region (40 mV) above [minus]0.10 V, very close to the estimated potential of zero charge (PZC) for the reconstructed surface. In perchloric acid solution the reconstruction forms much more slowly at potentials just below the PZC of the unreconstructed surface, and is stable up to approximately 0.30 V, which is just positive of the PZC. In KOH solution the stability of the reconstruction is controlled primarily by the interaction of the surface with hydroxyl anions. The controlling mechanism in perchloric acid is unclear.
Rapid Finite-source Analysis and Near-fault Strong Ground Motions: Application to the 2003 Mw 6.5 San Simeon and 2004 Mw 6.0 Parkfield Earthquakes

Rapid characterization of near-fault strong ground shaking is essential for assessment of an earthquake's impact, including the scale of damage and loss. ShakeMap (Wald et al. , 1999a) was developed as a tool for this purpose. To generate a ShakeMap, observed peak and spectral ground motion, as well as estimated instrumental intensity (Wald et al. , 1999b), are interpolated with a model of ground-motion attenuation to produce contour maps of the various parameters. In California, the California Integrated Seismic Network (CISN) automatically produces ShakeMaps for moderate to large events within several minutes of their occurrence. ShakeMaps have proven to be a valuable information resource for seismologists, emergency responders, and the general public. The ShakeMap approach works best in regions with dense station coverage. In such cases, the observed ground motions control the contouring of the maps. In poorly instrumented regions or in cases where data telemetry is lost (possibly due to strong shaking), ShakeMap relies on an assumed ground-motion attenuation model to estimate the motions based on the magnitude of the earthquake and the distance of a site to the source. This model is based on published ground-motion attenuation relationships and the distance from site to epicenter in the absence of information regarding the fault orientation and length. Once additional information is available, such as aftershock distribution and surface faulting reports, ShakeMaps are updated to account for rupture finiteness by computing the distance from the site to the closest surface projection of the fault. Rapid finite-source models can also provide the information needed to update ShakeMaps in this manner (Dreger and Kaverina, 2000). For large regions of California, station coverage in outlying areas is insufficient to obtain detailed data-based ShakeMaps. To address the coverage issue, and to have a back-up system should telemetry fail at key near-fault strong-motion stations, we …
Cargo- and adaptor-specific mechanisms regulate clathrin-mediated endocytosis

Clathrin-mediated endocytosis of surface receptors and their bound ligands (i.e., cargo) is highly regulated, including by the cargo itself. One of the possible sources of the observed heterogeneous dynamics of clathrin-coated pits (CCPs) might be the different cargo content. Consistent with this, we show that CCP size and dynamic behavior varies with low density lipoprotein receptor (LDLR) expression levels in a manner dependent on the LDLR-specific adaptors, Dab2 and ARH. In Dab2-mCherry–expressing cells, varying LDLR expression leads to a progressive increase in CCP size and to the appearance of nonterminal endocytic events. In LDLR and ARH-mCherry–expressing cells in addition to an increase in CCP size, turnover of abortive CCPs increases, and the rate of CCP maturation decreases. Altogether, our results underscore the highly dynamic and cargo-responsive nature of CCP assembly and suggest that the observed heterogeneity is, in part, related to compositional differences (e.g., cargo and adaptors) between CCPs.
Conformational Role of Xanthan Gum in its Interaction with Guar Gum

: : Ubbelohde viscometry, texture analysis, and centrifugation were used to investigate the effects of chain conformational changes of xanthan or deacetylated xanthan gum on its interaction with guar gum. Guar gum was not effective in denaturing xanthan gum when the xanthan helical structure was stabilized by salt. The intrinsic viscosities of deacetylated xanthan and guar blends were higher than those calculated from the weight averages of the 2. Conformational change was not observed for deacetylated xanthan, presuming deacetylated xanthan was in the exact conformation for guar to bind so that the most stable heterotypic structure between deacetylated xanthan and guar was formed directly, thus the strongest interaction was observed between deacetylated xanthan and guar.
Scaling and universality in avalanches.

We have studied various one- and two-dimensional models in order to simulate the behavior of avalanches. The models are based on cellular automata and were intended to have the property of ``self-organized criticality'' proposed by Bak, Tang, and Wiesenfeld [Phys. Rev. Lett. 59, 381 (1987); Phys. Rev. A 38, 384 (1988)]. By varying the sizes of the systems, we have investigated the scaling properties of these models. In particular, we have addressed the question as to whether simple finite-size scaling or multifractal analysis is more suited to fitting the data on the distribution of avalanche sizes. By varying the underlying microscopic rules that describe how an avalanche is generated, we have also studied whether different models have the same, universal properties. In our one-dimensional models we find that the multifractal analysis is much better than the analysis based on simple finite-size scaling. We also find that there are several different universality classes. Nevertheless, certain models with similar rules appear to belong to the same class. In two dimensions, we find that the simple finite-size scaling works quite well and that the distribution functions can be fit over wide ranges by a simple power law. The multifractal analysis also works well and it is difficult to tell which form is a better fit to the data. Again, as in one dimension, there are several different universality classes and different models with similar rules belong to the same class.
Efficient transitive closure reasoning in a combined class/part/containment hierarchy

Class hierarchies form the backbone of many implemented knowledge representation and reasoning systems. They are used for inheritance, classification and transitive closure reasoning. Part hierarchies are also important in artificial intelligence. Other hierarchies, e.g. containment hierarchies, have received less attention in artificial intelligence. This paper presents an architecture and an implementation of a hierarchy reasoner that integrates a class hierarchy, a part hierarchy, and a containment hierarchy into one structure. In order to make an implemented reasoner useful, it needs to operate at least at speeds comparable to human reasoning. As real-world hierarchies are always large, special techniques need to be used to achieve this. We have developed a set of parallel algorithms and a data representation called maximally reduced tree cover for that purpose. The maximally reduced tree cover is an improvement of a materialized transitive closure representation which has appeared in the literature. Our experiments with a medical vocabulary show that transitive closure reasoning for combined class/part/containment hierarchies in near constant time is possible for a fixed hardware configuration.
Relations between fermion masses from effective potentials in internal space

The assumption of approximately similar effective potentials in internal space acting on «scale particles» leads to relations among the quark and lepton masses and their weak-interaction mixing angles. The mass of the t-quark is predicted to be 27 GeV. The model also implies that the (νμ,e) and (s, d) mixing angles are of comparable magnitude, siding against the high-mass solutions for neutrino oscillation accelerator experiments involving νμ→e.
The Crystal Structures of 6-N-Heptylmercaptopurine at 123 K and 6-N-Hexylaminopurine at 295 K

Abstract 6-N-Heptylmercaptopurine, C12H18N4S, (I), is monoclinic, P21c, Z = 4, with cell dimensions at 123 K [295 K] of a = 15.527(7) [15.219(7)], b = 7.140(3) [7.275(3)], c = 11.979(6) [12.414(7)] A, β = 101.21(4) [100.15(4)]° 6-N-Hexylaminopurine, C11H17 N5, (11), is triclinic, P1, Z = 2, with cell dimensions a = 5.210(10), b = 8.466(13), c = 13.932(10) A, α = 97.03(16), β = 92.03(7), γ = 104.43(17)°. In the crystal structure of I the molecular packing is head-to-head bilayer with double stacks of purine moieties and interdigitating alkyl chains. This structure is isostructural with the long-chain alkyl pyranosides. In II, the hydrogen-bonded purine residues are packed in imbricated layer structure with antiparallel twisted alkyl chains which are not intercalated. Only structure II shows evidence of thermotropic crystal-to-crystal phase transitions in both heating and cooling cycles; neither crystal forms a liquid crystal phase and both melt directly to an isotropic liquid.
A new paradigm for Human-Building Interaction: the use of CFD and Augmented Reality

Abstract This paper presents an interactive speech and gesture recognition-based, immersive Augmented Reality (AR) model designed to visualize and interact with buildings and their thermal environments. The paper introduces a Human–Building Interaction (HBI) model that allows for the efficient exploration of Computational Fluid Dynamics (CFD) data sets in real time. This model includes four components: wireless sensor data, CFD analysis, Human–Computer Interaction (HCI), and AR visualization. The sensor data component tracks temperature and velocity changes that occur within a room and updates the boundary conditions for simulation. The CFD analysis component performs simulation with the new boundary conditions, and the post-processed data are exported as Virtual Reality Modeling Language (VRML) models. The HCI component consists of a library of gesture recognition tasks. These tasks update and process data for the AR visualization component. The AR visualization component aids in tracking the user's movement in real time and poses graphical information onto the Head-Mounted Device (HMD), allowing the user to visualize CFD data sets that are superimposed on to the actual scene.