cssi/SciSciGPT-SciSciNet huggingface dataset:
Optimal static load balancing in distributed computer systems

A distributed computer system that consists of a set of heterogeneous host computers connected in an arbitrary fashion by a communications network is considered. A general model is developed for such a distributed computer system, in which the host computers and the communications network are represented by product-form queuing networks. In this model, a job may be either processed at the host to which it arrives or transferred to another host. In the latter case, a transferred job incurs a communication delay in addition to the queuing delay at the host on which the job is processed. It is assumed that the decision of transferring a job does not depend on the system state, and hence is static in nature. Performance is optimized by determining the load on each host that minimizes the mean job response time. A nonlinear optimization problem is formulated, and the properties of the optimal solution in the special case where the communication delay does not depend on the source-destination pair is shown.Two efficient algorithms that determine the optimal load on each host computer are presented. The first algorithm, called the parametric-study algorithm, generates the optimal solution as a function of the communication time. This algorithm is suited for the study of the effect of the speed of the communications network on the optimal solution. The second algorithm is a single-point algorithm; it yields the optimal solution for given system parameters. Queuing models of host computers, communications networks, and a numerical example are illustrated.
Organizational Characteristics and Information Systems Planning: An Empirical Study

Information Systems IS planning has gained considerable interest among researchers and practitioners in recent years because of the large investments that firms have made in IS and the increasingly strategic nature of the impact of information systems on organizational performance. Since IS planning is performed in an organizational context, characteristics of the organization may have a significant influence on the quality and effectiveness of the IS planning process. A research model is developed that links two major dimensions of IS planning-the quality of the planning process and planning effectiveness-with a set of eight organizational factors derived from contingency research in IS planning, strategic business planning, organizational studies, and technology innovation. The model is validated using data collected from a field survey of 249 senior IS executives. Canonical correlation analysis is used to test the research hypotheses and validate the model. The results of the study indicate that the two planning dimensions respectively reflecting the "means" and "ends" of IS planning are equally important. The results also indicate that planning resources, the intended strategic impact of IS on future business operations, the quality of facilitation mechanisms, the quality of implementation mechanisms, and the quality of strategic business planning are significantly associated with the quality and effectiveness of IS planning. The implications of the results to further research and to managerial practice are highlighted.
Convective heat transfer in an electrically conducting fluid at a stretching surface with uniform free stream

Abstract An analysis is carried out to study the flow and heat transfer characteristics in an electrically conducting fluid near an isothermal sheet. The sheet is linearly stretched in the presence of a uniform free stream of constant velocity and temperature. The effects of free convection and internal heat generation or absorption are also considered. The resulting coupled nonlinear differential equations are integrated numerically and the flow and heat transfer characteristics are discussed. Although the velocity profiles are similar in the absence of free stream, it is shown that the differential system gives rise to nonsimilar velocity profiles in the boundary layer.
Role of bilateral chemosensory input in food discrimination by Manduca sexta larvae

The function of bilateral chemosensory input in food discrimination was examined using larvae of the tobacco hornworm, Manduca sexta (Johan.) (Lepidoptera: Sphingidae), in 2-choice preference tests. Larvae having three different complements of chemosensory organs remaining after microsurgery were tested: unoperated, unilaterally-ablated, and bilaterally-ablated. Discrimination between Solanum pseudocapsicum (L.) and Pelargonium hortorum (Bailey) was reduced after unilateral removal of chemosensory organs. A similar effect was found in tests offering larvae a choice between one plant species or an ethanolic extract of S. pseudocapsicum and wetted filter paper, indicating an impaired food detection. These results demonstrate that both sets of chemosensory organs are required for normal feeding decisions about these plants. Six additional plant species were each tested against wetted filter paper. The function of bilateral chemosensory input in food discrimination varies with the plant species tested. Bilateral chemosensory input is required for discrimination of Vigna sinensis (Savi) and Raphanus sativus (L.), but not for that of Lycopersicon esculentum (Mill.), Datura innoxia (L.), Brassica napus (L.), and Canna generalis (Bailey). Discrimination of V. sinensis, S. pseudocapsicum, and P. hortorum by unoperated larvae is twice as strong as that by unilaterally-ablated larvae, suggesting algebraic addition of unilateral sensory inputs. For R. sativus unilateral input does not mediate discrimination, but bilateral input does, indicating sensory processing which may be more than additive. These results show that information mediated by bilateral chemosensory organs of M. sexta is not redundant in mediating feeding decisions, but provide the necessary sensory input for normal discrimination. This suggests that, for some plant species, feeding decisions are based on both qualitative and quantitative aspects of chemosensory input. No difference in preferences between left-sided and right-sided operated larvae were observed which suggests functional duplication of each set of unilateral chemosensory organs. Possible neural mechanisms underlying feeding decisions mediated by bilateral versus unilateral chemosensory inputs are discussed.
Monomeric lithium triazapentadienyl complexes.

Treatment of 1,3,5-triazapentadienes [N{(C3F7)C(Mes)N}2]H and [N{(C3F7)C(Dipp)N}2]H (where Mes = 2,4,6-Me3C6H2; Dipp = 2,6-Pri2C6H3) with n-BuLi in hexane, followed by the crystallization from hexane–THF mixture afforded the corresponding lithium 1,3,5-triazapentadienyl complexes as their THF solvates. X-Ray crystallographic analyses revealed that [N{(C3F7)C(Mes)N}2]Li(THF)2 and [N{(C3F7)C(Dipp)N}2]Li(THF) are monomeric in the solid state. [N{(C3F7)C(Mes)N}2]Li(THF)2 has a four-coordinate lithium center with a distorted tetrahedral geometry, and features a boat-shaped C2N3Li metallacycle. [N{(C3F7)C(Dipp)N}2]Li(THF) has a three-coordinate lithium atom and a planar, U-shaped C2N3 ligand backbone. The synthesis, solid-state structure, and 1H and 19F NMR spectroscopic details of [N{(C3F7)C(Mes)N}2]H are also reported.
An ultra-sensitive wearable accelerometer for continuous heart and lung sound monitoring

This paper presents a chest-worn accelerometer with high sensitivity for continuous cardio-respiratory sound monitoring. The accelerometer is based on an asymmetrical gapped cantilever which is composed of a bottom mechanical layer and a top piezoelectric layer separated by a gap. This novel structure helps to increase the sensitivity by orders of magnitude compared with conventional cantilever based accelerometers. The prototype with a resonant frequency of 1100Hz and a total weight of 5 gram is designed, constructed and characterized. The size of the prototype sensor is 35mm×18mm×7.8mm (l×w×t). A built-in charge amplifier is used to amplify the output voltage of the sensor. A sensitivity of 86V/g and a noise floor of 40ng/√Hz are obtained. Preliminary tests for recording both cardiac and respiratory signals are carried out on human body and the new sensor exhibits better performance compared with a high-end electronic stethoscope.
Effects of Reduction in Drugs or Dosage after Long-Term Control of Systemic Hypertension

In this article, the Veterans Administration Cooperative Study Group reported on the effects of reducing dosage or discontinuing drug therapy altogether in hypertensive patients. They determined that while stopping therapy may be effective in some patients, patients often returned to a hypertensive state. The group recommended a reduction of dosage as a more effective alternative in instances where it was desirous to minimize side effects or reduce drug costs.
Should China Implement Congestion Pricing

Over the past two decades, China has experienced a dramatic increase in auto ownership and use, with the number of privately owned vehicles increasing more than 70 folds in twenty years, from 0.82 million in 1990 to 59.39 million in 2010. Urban roads in major Chinese cities have, thus, become much more congested. Congestion pricing, theoretically, helps to internalize traffic externalities and reduce congestion. Practically, it has been implemented in a number of countries. This article presents the economic theory of congestion pricing and discusses international practices of congestion pricing. Based on the theory and practices, the article proposes implications for China and argues that China should consider implementing congestion pricing to combat traffic congestion in major cities.
Vibrational spectroscopic studies of triethoxy(4-(trifluoromethyl)-phenyl) silane and its sol–gel coating

We have prepared a silica sol-gel using triethoxy (4-(trifluoromethyl)-phenyl) silane (TETFMPS) as a precursor in ethanol solution under acidic condition. The prepared sol-gel was applied to the surface treatment of aluminum for corrosion prevention. Infrared and Raman spectra of the silane coupling agent, sol-gel and sol-gel films on metal have been collected. Infrared spectroscopy has been used to study the thermal effect on the chemical composition of xerogel. Results suggested that TETFMPS molecule has a C(s) point group symmetry with the plane of reflection orthogonal to the phenyl ring and the organic part of the sol-gel film remains essentially unchanged at or below 450 °C but decomposes at or above 550 °C. After the decomposition of the organic branch, the remaining film is composed of silica. Vibrational assignments were suggested by using the collected spectroscopic data in different states along with the group vibrational frequencies and other related references.
Free C+-actions on C3 are translations

Let X be a smooth contractible three-dimensional affine algebraic variety with a free algebraic C+-action on it such that S=X//C+ is smooth. We prove that X is isomorphic to S×C and the action is induced by a translation on the second factor. As a consequence we show that any free algebraic C+-action on C3 is a translation in a suitable coordinate system.
UDP-d-glucuronic acid-5-epimerase and UDP-N-acetylglucosamine-4-epimerase of rabbit skin

Abstract UDP-GNAc-4-epimerase has been isolated from rabbit-skin extracts which had previously been found to contain UDP-GA-5-epimerase. Both enzymes fractionate similarly with ammonium sulphate, require catalytic NAD+ and are inhibited by NADH. NADP is not active in either case while thionicotinamide-AD+ and AP-AD+ are less active than NAD+. The inhibition of each epimerase by the others substrate as well as by UDPG, uracil, uridine, and UDP may be explained by a non-specific binding of the base and/or sugar moiety to the enzymes.
Quantum control of dispersion in electromagnetically induced transparency via interacting dressed ground states

We offer a general treatment of electromagnetically induced transparency (EIT) in a five level system consisting of four metastable ground states. Two additional rf-microwave fields coherently couple the two ground states of the standard EIT $\ensuremath{\Lambda}$ atom to a pair of additional hyperfine states in the ground state manifold, generating two sets of dressed states that interact via the probe and control lasers, which couple to the electronic excited state. These new hyperfine dressed states manifest themselves in the linear optical susceptibility of the probe as new resonances in addition to the Autler-Townes doublet characteristic of EIT. In particular, we show that the existence of two new narrow resonances, whose width are limited only by ground state decoherence, appear inside the normal EIT transparency window. We show that by controlling the intensity of these rf-microwave fields, one can engineer both the position and width of these narrow resonances and thereby exercise additional control over both the dispersion and group velocity of the probe.
Three-dimensional endothelial-tumor epithelial cell interactions in human cervical cancers

The purpose of this study is to understand the multicellular interaction between tumor epithelial (TEC) and human umbilical vein endothelial cells (HUVEC). The development of in vitro systems in which to coculture these cells as multicellular aggregates is very critical. Cell lines were established from cervical tumor cells (n = 6) and two from HUVEC (n = 2) and they were cultured as three-dimensional (3-D) multicellular-cultures using Cytodex-3 microcarrier beads in the rotating wall vessel (RWV). After a 240-h incubation, TEC and HUVEC proliferated exponentially to 4.2 x 10(7) and 2.2 x 10(7) cells/ml, respectively, without requiring a feeder layer; in contrast to the two-dimensional (2-D) cultures that average about 8 x 10(5) cells/ml. Phase contrast microscopy indicated formation of 3-D aggregates that varied in size from 0.5 to 5 mm. The size of the aggregates (1-5 mm, 6-14 microcarriers) increased over time; however, the number of aggregates (0.5-1 mm, 2-5 microcarriers) decreased over a long-term incubation (240 h) because the cells merged to form large clumps. Maximum aggregation was observed with TEC at 120 h and HUVEC at 96 h. The culture of TEC in the absence of HUVEC produced minimal differentiation in contrast to cocultures. The TEC and HUVEC as cocultures in RWV proliferated at an accelerated rate (1.3 x 10(7) cells/ml, 96 h). The TEC-HUVEC coculture presented tubular structures penetrating the tumor cell masses, forming aggregates larger in size than the monocultures and typically with greater cell mass and number. The cells were viable (trypan blue exclusion) and metabolically active (glucose utilization) until 240 h. These data suggest that RWV provides a new model that allows us to investigate the regulatory factors that govern tumor angiogenesis.
Progesterone synthesis and histology of postpartum bovine corpora lutea.

Abstract In vitro progesterone (P4) synthesis by corpora lutea (CL) from the first, second or third ovulation after calving was compared and correlated with their histology and cytology. The CL were removed 7 to 12 days after ovulation, and luteal cells isolated by digestion with collagenase. The response of isolated cells to luteinizing hormone (LH) was determined. Hematoxylin-eosin stained tissues were used to study histology, and the distribution of cell types was estimated by stereological methods. Ovulation occurred within 25 days of calving and interovulatory intervals were short, 12.1 ± 3.9 days and 12.6 ± 4.8 days, respectively. The CL removed after first ovulation were smaller and contained fewer live cells than those obtained after subsequent ovulations. Stimulation by LH in vitro was independent of cycle number or day of cycle but was related to the histology of the tissue. The CL composed of large cells (> 24 μm) with vacuolated cytoplasm contained high amounts of P4 but were not stimulated by LH. Conversely, CL composed of small and medium- sized cells (10 to 20 μm) and/or intact larger cells contained little P4 but were stimulated by LH. These observations indicate that the response of postpartum CL to LH in vitro is dependent upon the structural integrity of the tissue at the time of removal. Furthermore, these observations suggest that the short life of CL during the postpartum period may not be due to the absence of luteotrophic support, but to the action of a luteolytic mechanism.
Task and social orientation: a study of field dependence, "arousal," and memory for incidental material.

A conceptualization of field dependence-independence as a motivational orientation reflected in attentional selectivity and autonomic activity was tested using an incidental learning paradigm. 60 Ss assigned to a structured or unstructured condition were exposed to social and neutral incidental material; basal skin resistance was recorded. Results indicated that field-dependent Ss reflect social motivation by high non-specific “arousal” and by learning incidental material of a social nature. Field-independent Ss reflect task motivation by becoming “aroused” in response to specific task requirements and by learning task-relevant incidental material.
Constructing NAFTA: Myth, Representation, and the Discursive Construction of U.S. Foreign Policy

The passage of the North American Free Trade Agreement in November 1993 signified the acceptance of Mexico as an equal trading partner with the United States and Canada. However, accepting Mexico as an equal partner challenged a deeply ingrained U.S. image of Mexico as inferior, childlike, dependent, and suspicious. How was it possible for the U.S. public and its congressional representatives to accept equal economic integration with a country that embodied such a negative image? Addressing this dilemma through a constructivist approach, this article argues that the existing image of Mexico remained intact. The passage of NAFTA instead resulted from a discursive construction of NAFTA that emphasized a positive U.S. self-image through American myths thereby allowing the simultaneous acceptance of Mexico as inferior and as an equal trading partner. American myths and other representational elements constructed NAFTA for the American public and created a policy success for President Clinton. This article relies on an empirical investigation of newspaper advertisements to demonstrate how myths contributed to the discursive construction of NAFTA.
Everyday Practice and Ritual Space: the Organization of Domestic Ritual in Pre-Aztec Xaltocan, Mexico

This article offers new understanding to commoner ritual in central Mexico before the rise of the Aztec Empire through an examination of domestic ritual and everyday practice in Early to Middle Postclassic (AD 900–1350) households in Xaltocan. It also seeks to better understand the ways in which elites negotiate and reinvent ritual traditions to gain and maintain power. In this study, I integrate multiple lines of evidence including ethnohistory, household archaeology and burials to understand the organization, practice and meaning of ritual among commoners before the rise of the Aztec Empire. I argue that pre-Aztec commoner ritual worked to foster solidarity, social continuity and collective memory and was intimately concerned with the protection of household members and the maintenance of household and universal equilibrium. While some of the symbolism and rituals documented in pre-Aztec domestic contexts appear similar to those depicted in Aztec contexts, I argue that state rituals held different meanings as Aztec elites adopted and transformed widely-held commoner rituals and symbols to craft an ideology that promoted their own political agenda. Ultimately, domestic- and state-level ritual should be seen as part of an ever-changing, but necessarily intertwined, historical and political process.
Two clusters of genes for major chorion proteins of Drosophila melanogaster

Abstract cDNA clones complementary to poly(A)-containing RNA from ovarian follicle cells of Drosophila have been prepared. On the basis of restriction mapping and cross hybridization tests, 22 such clones were found to comprise four classes (group I–group IV). Filter-bound DNA from clones in each group hybridized, under stringent conditions, with a single size class of ovarian poly(A)-containing RNA. The mobilities of these RNAs on gels corresponded to those of putative chorion messenger RNAs (Spradling and Mahowald 1979). Translation of the RNAs in vitro yielded proteins with apparent molecular weights 1000–3000 daltons greater than those of mature chorion proteins isolated from purified eggshells. When a membrane fraction from dog pancreas was included in the in vitro translation reaction, the mobilities of the products were indistinguishable from those of major chorion proteins in three cases: c38 (group I), c36 (group II) and c18 (group III). The 16K product of hybrid-selected RNA from group IV clones could not be associated unambiguously with a specific chorion protein. Hybridization of cloned cDNAs to restriction digests of DNA prepared from embryonic nuclei was consistent with the presence of one (c38 and c36) or several (c18) copies of these genes per haploid genome. Hybridization in situ of RNA transcripts from the clones to polytene chromosomes demonstrated that the genes for these four proteins are clustered at two sites. In agreement with previous results (Spradling, Waring and Mahowald 1979), both c36 and c38 are coded at 7E11-7F1-2 on the X chromosome. Group III and group IV clones were both localized at a site on the third chromosome (66D15).
Potassium ferrate(VI): an environmentally friendly oxidant

Abstract The iron(VI) derivative, potassium ferrate(VI) (Fe(VI)) has properties such as high stability, oxidizing power, selectivity, and a non-toxic by-product Fe(III), that make potassium ferrate(VI) an environmentally friendly oxidant for natural waters. This paper presents a review of its properties and its role in environmental and industrial removal of contaminants. Fe(VI) is a powerful oxidizing agent throughout the entire pH range with a reduction potential varying from +2.2 V to +0.7 V in acidic and basic solutions, respectively. Fe(VI) ion reduces rapidly and exothermally to Fe(III) and oxygen in strong acids, while the oxygen ligands of Fe(VI) exchange very slowly with water at pH 10. In dilute solutions, the lowest rate of reduction of Fe(VI) by water occurs between pH 9.4 and 9.7. Fe(VI) is also a selective oxidant for a large number of organic compounds with Fe(III) as a by-product. Fe(VI) therefore has a role in cleaner (‘greener’) technology for organic synthesis. Other applications of Fe(VI) include production of ferrate(V) by pulse radiolysis, ‘super-iron’ batteries, and wastewater treatment processes. Many of the contaminants in wastewater can be removed by Fe(VI) in seconds to minutes with formation of non-hazardous products. Fe(VI) is also a disinfectant, antifoulant, and coagulant, and therefore a promising multi-purpose wastewater treatment chemical.
Independence, Dominance, and Power: (Re)Examining the Impact of School Policies On the Academic Development of Indigenous Youth

This article explores how school policies framed by Western knowledge systems legitimize assimilationist socialization and learning practices that distance school leaders and teachers from American Indian students and their educational process. By deconstructing school rules, microaggressions are revealed, illuminating the inherent tension between academic knowledge and Indigenous knowledge systems (IKS) in schools. When IKS are validated and incorporated into academic knowledge systems, Indigenous youth are constructed as knowledge producers and active agents in schools. Likewise, educational processes are informed by social and cultural contexts, and educators are encouraged to rethink educational policies and school learning.
Distinguishing organizational from strategy commitment: Linking officers' commitment to community policing to job behaviors and satisfaction

Previous research has highlighted the important role of officers' attitudes and receptivity to the change to community policing. We identified two levels of commitment—commitment to the police organization as a whole and commitment to the strategic direction of the police department toward community policing and found evidence that the two levels of commitment are distinct. Organizational commitment was directly related to job satisfaction but only indirectly related to officers' behaviors consistent with those expected with a community-policing orientation. Conversely, the level of commitment to a community-policing strategy was unrelated to job satisfaction but directly related to the frequency of community policing-type behaviors. Strategy commitment also mediated the effects of managerial support and organizational commitment and partially mediated the effects of job experience on officers' behavior. Implications of this multiple-level perspective to commitment for future research are discussed.
Cell/cell channel formation involves disulfide exchange

The oocyte cell/cell-channel assay was used to identify amino acids involved in the process of cell/cell-channel formation. The expression of the rat liver gap-junction protein, connexin 32, in single oocytes, results in the accumulation of a pool of channel precursors. Upon pairing of such oocytes, cell/cell channels form rapidly from this pool. The rate of formation is affected by thiol-specific reagents and the pH. This suggests the involvement of extracellular cysteine residues in the channel formation process. Two connexin-32 mutants were generated by site-directed mutagenesis in which cysteine residues were replaced by serine. Both mutant connexins were unable to form cell/cell channels. Thus, the cysteine residues appear to play an important role in the channel formation process.
Transcriptional regulation of mammalian cytochrome c oxidase genes

The cytochrome c oxidase (COX) holoenzyme is a 13-subunit complex that carries out the terminal step in the electron transport chain. Three of the subunits, which contain the electron transfer function, are coded by mitochondrial DNA and the other ten subunits by nuclear DNA. Since the holoenzyme contains equivalent amounts of each subunit, we and others have examined transcriptional regulation of COX nuclear subunits to explore whether there is a common basis for co-regulation. Each gene is seen to have a unique pattern of recognition by regulatory factors; although some factors bind to more than one gene, not all COX genes seem to be regulated by the same set of factors. Current information about the COX promoters that have been examined is summarized, and the relation of promoter regulation to coordinate gene expression is discussed.
Inhibition of s-nitrosation of reduced glutathione in aerobic solutions of nitric oxide by phosphate and other inorganic anions

Reduced glutathione is nitrosated in aerobic solutions of nitric oxide under physiological conditions; however, the extent of S-nitrosation was found to be dependent on the inorganic anions present. Of nine anions tested, the bifunctional anions, arsenate, phosphate, and pyrophosphate (40 mM), inhibited the S-nitrosation reaction from 20 to 40%, whereas SO4(2-), H3BO3, SCN-, NO3-, Cl-, and acetate inhibited this reaction < or = 15%. A mechanism of inhibition is presented that involves the catalytic hydrolysis of N2O3 by the bifunctional anions; however, using [18O]phosphate as inhibitor, only 10% of the theoretically produced N2O3 was found to be hydrolyzed to nitrite via this mechanism as calculated from the loss of 18O from phosphate. We conclude that this mechanism accounts for only a minor part of the increased inhibition of S-nitrosation by these bifunctional anions.
Spatial Econometric Models of Cross-Sectional Interdependence in Political Science Panel and Time-Series-Cross-Section Data

In this paper, we demonstrate the econometric consequences of different specification and estimation choices in the analysis of spatially interdependent data and show how to calculate and present spatial effect estimates substantively. We consider four common estimators—nonspatial OLS, spatial OLS, spatial 2SLS, and spatial ML. We examine analytically the respective omitted-variable and simultaneity biases of nonspatial OLS and spatial OLS in the simplest case and then evaluate the performance of all four estimators in bias, efficiency, and SE accuracy terms under more realistic conditions using Monte Carlo experiments. We provide empirical illustration, showing how to calculate and present spatial effect estimates effectively, using data on European governments' active labor market expenditures. Our main conclusions are that spatial OLS, despite its simultaneity, performs acceptably under low-to-moderate interdependence strength and reasonable sample dimensions. Spatial 2SLS or spatial ML may be advised for other conditions, but, unless interdependence is truly absent or minuscule, any of the spatial estimators unambiguously, and often dramatically, dominates on all three criteria the nonspatial OLS commonly used currently in empirical work in political science.
Scanning probe microscopy study of dynamic adhesion behavior of polymer adhesive blends

Abstract Scanning Probe Microscopy (SPM) has been utilized to study the adhesive behavior of a blend of poly(ethylene propylene) (PEP) and the n-butyl ester of abietic acid. This blend is a model for a pressure sensitive adhesive (PSA). Force–distance measurements with simultaneous X-modulation gave information on both lateral and normal force during loading and unloading. This was a key advantage of the approach. The mechanism of adhesive failure has been elucidated by comparing the dependence of pull-off force (Fpull-off) and oscillating lateral force (Flateral) on velocity of loading/unloading and by studying the change with velocity in the loss of effective contact area during debonding. Change in contact area with time was inferred from change in the rms lateral force. The velocity dependence of Flateral indicates that its magnitude is strongly influenced by both contact time and the presence of tackifier. In contrast, the velocity dependence of Fpull-off is controlled by both the loading and unloading processes. While the adhesive behavior of the polymer (PEP) was mainly controlled by chain stretching during the unloading process, the adhesive performance of the tackifier enriched surface (PEP/60) was determined by the loading process at 10–50 nm/s loading velocity and by the unloading process at 100–1000 nm/s velocity.
Dietary supplements and other alternative medicines for erectile dysfunction What do I tell my patients

Dietary supplements and other alternative medicines have enjoyed a tremendous amount of popularity and use over the past decade. Although, the prevalence of these therapies for erectile dysfunction (ED) is unknown at this time, numerous media outlets and alternative medicine publications seem to support the utilization of these therapies for ED. The placebo effect is approximately 25% (1 out of 4 benefit) from past randomized trials of FDA approved medications for ED. Adequate clinical trials are needed for dietary supplements for ED to access whether or not a benefit beyond a placebo effect exists. Clinicians should become aware of these supplements and the current research espousing or discouraging their use, and they should understand the adverse effects associated with them in order to effectively discuss these products with any patient inquiring about them.
Ultralow-Background Large-Format Bolometer Arrays

In the coming decade, work will commence in earnest on large cryogenic far-infrared telescopes and interferometers. All such observatories - for example, SAFIR, SPIRIT, and SPECS - require large format, two dimensional arrays of close-packed detectors capable of reaching the fundamental limits imposed by the very low photon backgrounds present in deep space. In the near term, bolometer array architectures which permit 1000 pixels - perhaps sufficient for the next generation of space-based instruments - can be arrayed efficiently. Demonstrating the necessary performance, with Noise Equivalent Powers (NEPs) of less than 10 -20 W/√Hz, will be a hurdle in the coming years. Superconducting bolometer arrays are a promising technology for providing both the performance and the array size necessary. We discuss the requirements for future detector arrays in the far-infrared and submillimeter, describe the parameters of superconducting bolometer arrays able to meet these requirements, and detail the present and near future technology of superconducting bolometer arrays. Of particular note is the coming development of large format planar arrays with absorber-coupled and antenna-coupled bolometers.
Instructional and Curricular Requisites of Mainstreamed Students with Learning Disabilities

The successful integration of students with learning disabilities into mainstream reading classes may require teachers to adapt instruction and curricula in major ways. In this article, we discuss the relation between the instruction prescribed by standardized commercial curricula and the reading achievement of mainstreamed students with learning disabilities and other low-performing nonhandicapped students. An instructional template designed to complement commercially published reading lessons is described and its effects on the reading achievement of mainstreamed students with learning disabilities examined. Next, the limitations of generic instructional procedures to rectify the deficiencies of mainstream curricular programs for students with greater-than-average instructional needs are reviewed. We conclude with a discussion of the complexity of educating instructionally needy learners in mainstream settings and the significance of well-designed instruction.
Index support for rule activation

Integrated rule and database systems are quickly moving from the research laboratory into commercial systems. However, the current generation of prototypes are designed to work with small rule sets involving limited inferencing. The problem of supporting large complex rule programs within database management systems still presents significant challenges. The basis for many of these challenges is providing support for rule activation. Rule activation is defined as the process of determining which rules are satisfied and what data satisfies them. In this paper we present performance results for the DATEX database rule system and its novel indexing technique for supporting rule activation. Our approach assumes that both the rule program and the database must be optimized synergistically. However, as an experimental result we have determined that DATEX requires very few changes to a standard DBMS environment, and we argue that these changes are reasonable for the problems being solved. Based on the performance of DATEX we believe we have demonstrated a satisfactory solution to the rule activation problem for complex rule programs operating within a database system.
Robust differential co-expression discovery: an insight into pharmacodynamics of tyrosine kinase inhibitor

Studies of gene expression in drug sensitive and resistant cell lines can help us understand mechanisms of drug resistance, side effects and uncover new potential drug targets. Such analyzes require methods that move beyond uni-variate tests of differential expression. Here we propose a new differential co-expression analysis framework to detect molecular mechanism of drug sensitivity. We started with the Fisher's Z transformation to measure the co-expression difference. Then we developed a novel method to conquer the common problems Fisher's Z transformation cannot handle -- heterogeneity of cell line tissue types, outlying samples or clusters and relatively small number of samples. We generated a tightly inter-linked network of dasatinib related genes, connected by differential co-expression and significant inter-correlation. We observed three main types of differential co-expression. We did literature survey of result gene pairs and confirmed that genes in the detected pairs are related to dasatinib, or related to each other. Such discoveries bring new insights on this second generation tyrosine kinase inhibitor.
Atomic multipolar contributions to electronic polarization in organic molecular crystals

The self-consistent computation of electronic polarization in organic molecular crystals is extended to include, in first order, corrections in the continuous gas-phase charge distribution ρG(r). The potential ΔΦa(ra) at molecule a in the crystal is due to the difference between ρG(r) and a point-charge approximation. ΔΦa(ra), which represents atomic multipolar contributions, is evaluated for crystals of anthracene and perylenetetracarboxylic dianhydride (PTCDA). The corrections to the polarization energies of molecular cations are P+(1) = -0.25 and -0.14 eV for anthracene and PTCDA, respectively, while P−(1) = 0.25 and 0.18 eV for the anions. The leading term of atomic multipoles is the ΔΦa(ra)-charge interaction that corresponds to the charge-quadrupole term in the submolecular approach. There are also new contributions in ΔΦa(ra)-redistributed charge and coupling of induced dipoles to gradients of ΔΦa(ra). First-order correction to electronic polarization is a general approach that combines the advantages of discrete charges for self-consistent treatment of crystals with accurate electrostatic potentials based on the best available molecular charge distribution.
A zebrafish SKIV2L2-enhancer trap line provides a useful tool for the study of peripheral sensory circuit development

The zebrafish is an ideal model for elucidating the cellular and molecular mechanisms that underlie development of the peripheral nervous system. A transgenic line that selectively labels all the sensory circuits would be a valuable tool for such investigations. In this study, we describe such a line: the enhancer trap zebrafish line Tg(SKIV2L2:gfp)(j1775) which expresses green fluorescent protein (gfp) in the peripheral sensory ganglia. We show that this transgene marks all peripheral ganglia and sensory nerves, beginning at the time when the neurons are first extending their processes, but does not label the efferent nerves. The trapped reporter is inserted just upstream of a previously poorly described gene: lhfpl4 on LG6. The expression pattern of this gene by in situ hybridization reveals a different, but overlapping, pattern of expression compared to that of the transgene. This pattern also does not mimic that of the gene (skiv2l2), which provided the promoter element in the construct. These findings indicate that reporter expression is not dictated by an endogenous enhancer element, but instead arises through an unknown mechanism. Regardless, this reporter line should prove to be a valuable tool in the investigation of peripheral nervous system formation in the zebrafish.
Citizen virtues in a technological order

Contemporary philosophical discussions about technology mirror a profound distance between technical practice and moral thought. I consider the origins of this gap as reflected in both ancient and modern writings. The philosopher's version of technocracy ‐ rushing forward with the analysis of moral categories in the hope that policy‐makers or the public will find them decisive ‐ does nothing to bridge this gap and is, therefore, a forlorn strategy. The trouble is not that we lack good arguments and theories, but rather that modern politics does not provide appropriate roles and institutions in which the activity of defining the common good in technology policy is a legitimate project. I find glimmerings of an alternative practice in the ‘Scandinavian approach’ to democratic participation in technological design.
Composition and Biomass Productivity of Bryophyte Assemblages in Natural and Restored Marshes in the Prairie Pothole Region of Northern Minnesota

Cattail (Typha angustifolia)-dominated temperate marshes have high productivity and are valuable resources in the prairie pothole region of the northern USA. Whereas bryophytes of peatlands have been studied extensively, bryophytes in marsh assemblages in wetlands without peat accumulation have been largely overlooked, and bryophyte contribution to productivity in these systems has not been assessed. We studied bryophyte assemblage composition and biomass productivity in restored and natural marshes in northwestern Minnesota. Bryophyte species richness was low in all marshes but increased from submerged toward upland marsh vegetation zones. Under the cattail canopy, a dense carpet of Leptodictyum riparium dominated the bryophyte assemblage. Unlike marshes in the northern prairie pothole region and eastern Great Lakes region that are dominated by species of Drepanocladus, prairie wetlands in western Minnesota were dominated by L. riparium with D. aduncus relatively uncommon. Bryophyte biomass in natural marshes was comparable to that of bryophyte-dominated peatlands and increased over time in restored marshes. Natural wetlands had higher species richness, bryophyte cover and bryophyte biomass than restored wetlands and even after 34 years, the bryophyte assemblage in restored wetlands was not comparable to natural wetlands.
Design challenges for hemoproteins: the solution structure of apocytochrome b5.

In order to characterize the structural and dynamic factors that determine the assembly in b hemoproteins, the solution structure of the 98-residue protein apocytochrome b5 was determined by NMR methods. Over 800 experimental restraints derived from a series of two- and three-dimensional experiments were used. Holocytochrome b5, the protein with iron protoporphyrin-IX liganded to His-39 and His-63, contains in sequence the following elements of secondary structure: beta 1-alpha 1-beta 4-beta 3-alpha 2-alpha 3-beta 5-alpha 4-alpha 5-beta 2-alpha 6 [Mathews, F.S., Czerwinski, E. W., & Argos, P. (1979) The Porphyrins, Vol. 7, pp. 107-147, Academic Press, New York]. The folded holoprotein possesses two hydrophobic cores: an extensive, functional core around the heme (core 1), and a smaller, structural core remote from the heme (core 2). The apoprotein was found to contain a stable four-stranded beta-sheet encompassing beta 1, beta 2, beta 3, and beta 4 and three alpha-helices, corresponding to alpha 1, alpha 2, and alpha 6. Two short alpha-helices (alpha 3 and alpha 5) appear to form partially, and alpha 4 is not detected. These three helices and beta 5 border the heme binding pocket and are disordered in the apoprotein NMR structure. According to backbone 1H-15N NOE results, the most flexible region of the apoprotein, except for the termini, extends from Ala-50 (in beta 5) to Glu-69 (in alpha 5). The polypeptide segment bearing His-63 (located immediately prior to alpha 5) exhibits faster internal motions than that bearing His-39 (at the C-terminal end of alpha 2). The latter imidazole samples a restricted region of space, whereas the former can adopt many orientations with respect to the stable core. It was concluded that heme removal affects the structure and dynamics of most of core 1 whereas it leaves core 2 largely intact. The results provide guidelines for the rational design of b hemoproteins: a modular structure including a packed, stable core and a partially folded binding site is anticipated to present strong kinetic and thermodynamic advantages compared to approaches relying on the complete formation of secondary structure prior to heme binding.
Improved energy compensation for time-of-flight mass spectrometry.

A model for improved energy compensation in time-of-flight (TOF) mass spectrometry has been developed and tested. This model includes effects of both the acceleration and drift region on mass resolution for surface desorption TOP mass spectrometers that employ ion mirrors to improve mass resolution. Appropriate placement of an additional stage onto the conventional one- and two-stage mirrors provides compensation for flight time spreads, caused by initial ion kinetic energy distributions, in both regions. Experimental results that validate the model calculations are presented for a modified commercial two-stage ion mirror. For example, m/†m for Na+ was improved from ∼ 100 to ∼ 200 using only a 200-eV drift energy and a 58-cm drift path.
Portal Motor Velocity and Internal Force Resisting Viral DNA Packaging in Bacteriophage ϕ29

Abstract During the assembly of many viruses, a powerful molecular motor compacts the genome into a preassembled capsid. Here, we present measurements of viral DNA packaging in bacteriophage ϕ 29 using an improved optical tweezers method that allows DNA translocation to be measured from initiation to completion. This method allowed us to study the previously uncharacterized early stages of packaging and facilitated more accurate measurement of the length of DNA packaged. We measured the motor velocity versus load at near-zero filling and developed a ramped DNA stretching technique that allowed us to measure the velocity versus capsid filling at near-zero load. These measurements reveal that the motor can generate significantly higher velocities and forces than detected previously. Toward the end of packaging, the internal force resisting DNA confinement rises steeply, consistent with the trend predicted by many theoretical models. However, the force rises to a higher magnitude, particularly during the early stages of packaging, than predicted by models that assume coaxial inverse spooling of the DNA. This finding suggests that the DNA is not arranged in that conformation during the early stages of packaging and indicates that internal force is available to drive complete genome ejection in vitro. The maximum force exceeds 100pN, which is about one-half that predicted to rupture the capsid shell.
Why does Escherichia coli have two primary pathways for synthesis of glutamate

Escherichia coli has two primary pathways for glutamate synthetase-glutamate synthase pathway is known to be essential for synthesis at low ammonium concentrations and for regulation of the glutamine pool, but the necessity for glutamate dehydrogenase (GDH) has been uncertain. The results of competition experiments between the wild type and a GDH-deficient mutant during nutrient-limited growth and of direct enzyme measurements suggest that GDH is used in glutamate synthesis when the cell is limited for energy (and carbon) but ammonium and phosphate are present in excess, while the glutamine synthetase-glutamate synthase pathway is used when the cell is not under energy limitation. The use of alternative routes for glutamate synthesis implies that the energy cost of biosynthesis may be less when energy is limited than when energy is unlimited.
Statistical mechanics of the travelling salesman on the Sierpinski gasket

We study the statistical mechanics of the travelling salesman on a Sierpinski gasket in which the bond lengths {λ i } are quenched random variables. The problem of finding the shortest closed path which visits all N sites is tractable if all the |λ i ― 1| are less than (2N + 1) ―1 . For a particular choice of the bond-length probability distribution and at low temperatures, the system behaves like a set of non-interacting Ising spins in a quenched random magnetic field. The relevance of one of our results to collapsed polymer chains in random media is also discussed Nous etudions la mecanique statistique du probleme du voyageur de commerce sur un tamis de Sierpinski dans lequel les longueurs des liaisons (λ i ) sont des variables aleatoires et gelees. Le probleme de trouver le plus court chemin ferme qui visite tous les N sites est traitable si tous les |λ i ― 1| sont inferieurs a (2N + 1) ―1 . Pour un choix particulier d'une distribution de probabilite pour les longueurs des liaisons et aux basses temperatures, le systeme se comporte comme des spins d'Ising sans interactions dans un champ magnetique aleatoire. La pertinence d'un de nos resultats aux chaines polymeriques compactes en milieux aleatoires est aussi discutee