cssi/SciSciGPT-SciSciNet huggingface dataset:
Steady Sliding of Two Elastic Half-Spaces With Friction Reduction due to Interface Stick-Slip

The sliding of two perfectly flat elastic half-spaces with a constant interfacial coefficient of friction is investigated. Previous work has demonstrated that this configuration is dynamically unstable due to the destabilization of frictional slip waves. It was speculated that this dynamic instability could lead to stick-slip motion at the sliding interface. It is shown here that stick-slip motion at the interface can exist with a speed-independent interface coefficient of friction. Steady motion persists sufficiently far from the interface and thus gives the impression of uniform sliding. This type of stick-slip motion is due to interfacial slip waves and allows the bodies to slide with an apparent coefficient of friction which is less than the interface coefficient of friction. Furthermore it is shown that the apparent friction coefficient decreases with increasing speed even if the interface friction coefficient is speed-independent. Finally, it is shown that the presence of slip waves may make it possible for two frictional bodies to slide without a resisting shear stress and without any interface separation. No distinction is made between static and kinetic friction.
The aryl hydrocarbon receptor (AhR) pathway as a regulatory pathway for cell adhesion and matrix metabolism

The aryl hydrocarbon receptor (AhR) is an orphan receptor in the basic helix-loop-helix PAS family of transcriptional regulators. Although the endogenous regulator of this pathway has not been identified, the AhR is known to bind and be activated by a variety of compounds ranging from environmental contaminants to flavanoids. The function of this receptor is still unclear; however, animal models indicate that the AhR is important for normal development. One hypothesis is that the AhR senses cellular stress and initiates the cellular response by altering gene expression and inhibiting cell cycle progression and that activation of the AhR by exogenous environmental chemicals results in the dysregulation of this normal function. In this review we will examine the role of the AhR in the regulation of genes and proteins involved in cell adhesion and matrix remodeling, and discuss the implications of these changes in development and disease. In addition, we will discuss evidence suggesting that the AhR pathway is responsive to changes in matrix composition as well as cell-cell and cell-matrix interactions.
Estimating gas permeability and permselectivity of microporous polymers

Abstract Experimental and computational investigations have shown that seemingly minor changes in the chemical structure can have a profound effect on the gas adsorption and separation properties of a polymeric membrane. However, the vast number of possible polymer functionalities makes the evaluation of candidate structures a daunting challenge. This study presents the first systematic screening for multiple series of amorphous porous polymers and elucidates several design principles, which will be useful in the design of new intrinsically microporous polymeric membranes for gas separation applications. Specifically, an efficient method for estimating the gas permeability and permselectivity of a polymeric sample by means of free volume theory, grand canonical Monte Carlo simulations, and the solution diffusion model is presented. This method for calculating permeability is orders of magnitude faster than other techniques involving molecular dynamics simulations and is shown to accurately calculate permeability and permselectivity values when compared to available experimental values. As an example, the method is applied to screen four series of polymers of intrinsic microporosity (PIMs) for CO2, CH4, and N2 permeability and CO2/CH4, and CO2/N2 permselectivity. Outstandingly, the gas separation performance of these PIMs was shown not to move parallel to the upper bound for each gas pair. Several porous polymers with high permeabilities and high solubilities were identified, which highlights the fact that permeable polymers with high solubilities coefficients are feasible and a promising route toward achieving industrially applicable gas separation materials.
Greetings from the General Chair

On behalf of the organizing committee of the 2012 IEEE Canadian Conference on Electrical and Computer Engineering (CCECE), it is my great pleasure to welcome you to the 25th anniversary of this conference. CCECE is the annual flagship of IEEE Canada, and over the past 24 years it has been established as a major forum in various areas of electrical and computer engineering for researchers from Canada and around the world. The silver anniversary of CCECE in Montreal is an important milestone in the history of this conference, and the organizing committee members have been trying hard to make it a memorable one.
LF in LF: mechanizing the metatheories of LF in twelf

We present a mechanized metatheoretic development of two presentations of LF: the Canonical presentation (in which only beta-short, eta-long terms are well-formed) and the original version based on definitional equivalence. We prove the standard metatheory, i.e. that type checking is decidable and canonical forms exist uniquely. We do so by translating structures from the original formulation to the canonical formulation, establishing that definitional equivalence corresponds to syntactic equivalence of canonical forms. This particular approach represents the first syntactic proof of the metatheory of LF, thus the first that can be mechanized in Twelf. It is also the first proof formally addressing the correspondence between hereditary substitution in Canonical LF and definitional equivalence in the traditional version, justifying the body of recent work that takes Canonical LF as primary.
Long-chain and very long-chain methyl-branched alcohols and their acetate esters in pupae of the tobacco hornworm, Manduca sexta

Abstract Four homologous series of very long-chain methyl-branched alcohols (VLMA, C38 to >C44) were found in the internal lipids of developing male pupae of the tobacco hornworm, Manduca sexta, both as free alcohols and as acetate esters. The four major homologous series, with carbon chain backbones of 36–44 carbon atoms, consisted of a monomethyl, two dimethyls and a trimethyl-branched alcohol series. The major alcohol of each homologous series (with the corresponding alkane obtained by reduction in parentheses) was identified as 24-methyltetracontan-1-ol (17-methyltetracontane), 24,28-dimethyltetracontan-1-ol (13,17-dimethyltetracontane), 22,34-dimethyloctatriacontan-1-ol (5,17-dimethyloctatriacontane) and 22,26,34-trimethyloctatriacontan-1-ol (5,13,17-trimethyloctatriacontane). The minor components of the VLMA had backbones with an odd number of carbon atoms (37, 39, 41 and 43). Methyl branches of the minor components were identified on the 18- and 14,18-positions when numbered from the alkyl end of the chain. Also identified were minor amounts of long-chain methyl-branched alcohols (LMA, C25 to C32). The major components in the “wax ester” TLC fraction were acetate esters of the LMA and VLMA.
Turbulence-induced channel crosstalk in an orbital angular momentum-multiplexed free-space optical link

A multichannel free-space optical (FSO) communication system based on orbital angular momentum (OAM)-carrying beams is studied. We numerically analyze the effects of atmospheric turbulence on the system and find that turbulence induces attenuation and crosstalk among channels. Based on a model in which the constituent channels are binary symmetric and crosstalk is a Gaussian noise source, we find optimal sets of OAM states at each turbulence condition studied and determine the aggregate capacity of the multichannel system at those conditions. OAM-multiplexed FSO systems that operate in the weak turbulence regime are found to offer good performance. We verify that the aggregate capacity decreases as the turbulence increases. A per-channel bit-error rate evaluation is presented to show the uneven effects of crosstalk on the constituent channels.
Two polypeptide factors that promote differentiation of insect midgut stem cells in vitro

Isolated stem cells from the midguts of Manduca sexta and Heliothis virescens can be induced to differentiate in vitro by either of two polypeptide factors. One of the peptides was isolated from culture medium conditioned by differentiating mixed midgut cells; we used high performance liquid chromatographic separation and Edman degradation of the most prominent active peak. It is a polypeptide with 30 amino acid residues (3,244 Da), with the sequence HVGKTPIVGQPSIPGGPVRLCPGRIRYFKI, and is identical to the C-terminal peptide of bovine fetuin. A portion of this molecule (HVGKTPIVGQPSIPGGPVRLCPGRIR) was synthesized and was found to be very active in inducing differentiation of H. Virescens midgut stem cells. It was designated Midgut Differentiation Factor 1 (MDF1). Proteolysis of bovine fetuin with chymotrypsin allowed isolation of a pentamer, Midgut Differentiation Factor 2 (MDF2) with the sequence HRAHY corresponding to a portion of the fetuin molecule near MDF1. Synthetic MDF2 was also biologically active in midgut stem cell bioassays. Dose response curves indicate activity in physiological ranges from 10–14 to 10–9 M for MDF1 and 10–15 to 10–5 M for MDF2. Arch. Insect Biochem. Physiol. 40:129–140, 1999. Published 1999 Wiley-Liss, Inc. This article is a US Government work and, as such, is in the public domain in the United States of America.
Luminescence and excitation mechanism of Pr, Eu, Tb and Tm ions implanted into AlN

Abstract We have studied the photoluminescence excitation (PLE) and photoluminescence (PL) spectra of Pr 3+ , Eu 3+ , Tb 3+ and Tm 3+ doped AlN thin film on sapphire at 300 K. PLE spectra obtained under UV excitation (below bandgap of AlN) in the spectral range 200–400 nm, reveal two or three bands. Possible assignments of observed exoitation bands are discussed.
Complexity, Coupling, and the Future of European Integration

Why is there more integration in some areas of the European Union than others? Analyzing the dynamics of the integration process at the “normal politics” level, I specify two conditions, complexity and coupling, that make integration in Europe more likely in specific policy domains. Integration is more likely under conditions of low complexity and tight coupling. Using these two hypotheses, I probe tendencies toward more integration in four areas: competition policy, social policy, agriculture, and foreign and security policy. Integration need not be just a matter of conscious design or bargain, but also the perhaps unintended consequence of interaction between the various actors at the EU level. I conclude that European integration is segmented and that a more integrated Europe is necessarily a more expensive Europe.
Physiology in fractal dimensions: Error tolerance

The natural variability in physiological form and function is herein related to the geometric concept of a fractal. The average dimensions of the branches in the tracheobronchial tree, long thought to be exponential, are shown to be an inverse power law of the generation number modulated by a harmonic variation. A similar functional form is found for the power spectrum of the QRS-complex of the healthy human heart. These results follow from the assumption that the bronchial tree and the cardiac conduction system are fractal forms. The fractal concept provides a mechanism for the morphogenesis of complex structures which are more stable than those generated by classical scaling (i.e., they are more error tolerant).
Using Systematic Feedback and Reflection to Improve Adventure Education Teaching Skills

This study examined how adventure educators could use systematic feedback to improve their teaching skills. Evaluative instruments demonstrated a statistically significant improvement in teaching skills when applied at an outdoor education center in Western Canada. Concurrent focus group interviews enabled instructors to reflect on student feedback to improve teaching in subsequent courses. Instructors had the opportunity to share their experiences, thereby solidifying their learning and validating their practices. The triangulation of quantitative and qualitative data yielded a descriptive model of the reflective process, featuring multiple channels for repeated, systematic feedback to promote continuous reflection. Creating group opportunities for adventure educators to share their teaching experiences is recommended to facilitate instructional improvement, boost staff morale, and instill a sense of professionalism.
Linear and nonlinear optical properties of modified graphene-based materials

The optical properties of graphene-based nanomaterials have attracted much recent attention. This article provides an overview of recent advances in the study of linear and nonlinear optical transitions associated mostly with tailored energy bandgaps. In particular, the optical absorption characteristics and photoluminescence emissions due to various induced bandgaps and, in some cases, the formation of graphene quantum dots are highlighted. Nonlinear optical properties of these materials are reviewed with an emphasis on optical limiting through both nonlinear absorption and scattering mechanisms.
Change in oak abundance in the eastern United States from 1980 to 2008

Although oaks (Quercus spp.) have historically dominated much of the forest land in eastern North America, a great deal of fragmentary and sometimes anecdotal evidence suggests that they have been yielding dominance in recent decades to other, typically more shade-tolerant species. Using FIA data, our work formally quantifies the change in oak abundance in the eastern U.S. during the period of 1980–2008. The results indicate that most areas in the eastern U.S. experienced some decline in oak abundance, but the decrease was not universal either geographically or among species. Declines were especially marked in the Central Hardwood Region, which lost oak abundance on 81% its forested area as measured by importance value (IV). Areas with a high oak abundance were more likely to see a reduction in abundance. Among all 25 species analyzed, eight species decreased significantly in IV while two increased. Both the top two most prevalent white oak species (white oak (Quercus alba) and post oak (Quercus stellata)) and red oak species (northern red oak (Quercus rubra) and black oak (Quercus velutina)) had significant decreases in density and IV. Water oak (Quercus nigra) is one of the red oak species that had a near universal increase of its abundance throughout its native range (83% of area). This study provided a comprehensive quantification of the dynamic of oak species in a regional-wide geographic context, which will provoke forest researchers and managers to revisit the oak decline problem by using knowledge from other regions and other species.
The exponential nature of barrier crossings studied by langevin dynamics

Abstract The Langevin equation is solved numerically for a particle in a potential to study the nature of the barrier crossing dynamics. The barrier crossing process is found to be exponential even for low barriers in a bath with moderate friction. For high barriers, the theory of Mel'nikov and Meshkov is in good agreement with the barrier crossing rate constants of the present study over the whole friction range studied.
Identification of a NovelpelDGene Expressed Uniquely in Planta byFusarium solanif. sp.pisi(Nectria haematococca,Mating Type VI) and Characterization of Its Protein Product as an Endo-Pectate Lyase

Antibodies prepared against a pectin-inducible pectate lyase (PLA) produced by a phytopathogenic fungus Fusarium solani f. sp. pisi (Nectria haematococca, mating type VI) were previously found to protect the host from infection. The gene (pelA) and two of its homologs were cloned and sequenced. Here we report the isolation of a new pectate lyase gene, pelD, from a genomic library of F. solani pisi. A 1.5-kb DNA fragment containing pelD and its flanking regions was sequenced. The nucleotide sequence of pelD would encode a protein of 24.5 kDa which shares 49, 44, and 65% amino acid sequence identity with PLA, PLB, and PLC, respectively, from the same fungus. Because the first 19 amino acid residues appeared to be a signal peptide, the mature enzyme could be a 22.7-kDa protein. pelD transcripts and PLD protein could not be detected in fungus cultured in glucose, pectin, pea epicotyl extract, or a pea cell wall preparation. However, pelD transcripts were readily found by RT-PCR with RNA isolated from infected pea tissues. The cDNA of pelD, thus obtained, was expressed in Pichia pastoris with the putative pelD signal sequence. The secreted PLD was purified and characterized to be an endopectate lyase, and its lyase activity could be inhibited by anti-PLA IgG. Thus, protection of the host observed with the anti-PLA antibodies could reflect inhibition of immunologically related pectate lyases including PLD which is expressed uniquely in planta.
Materiality judgments and audit firm culture: Social-behavioral and political perspectives

Abstract Researchers have traditionally interpreted the formation of auditor judgments as either a technical or a cognitive phenomenon. Their research has, therefore, focused mainly on refining empirical techniques designed to reveal the mental processes used to form judgments interior to the individual. This theoretical and empirical analysis opens this conceptualization on three levels. On the first level, the authors interpret auditor judgment formation as a social-behavioral phenomenon in which the social context of the audit firm vis-a-vis its audit philosophy influences materiality judgments. On the second level, rather than interpreting the firm's philosophy as merely one form of “variable” administrative partners may manipulate to achieve desired ends, the authors treat it as determining of and being determined by the social structure of the audit firm and in turn its culture. Accordingly, they hypothesize that (1) a firm's audit culture, expressed in terms of mechanistic versus organic orientations, systematically influences its members' materiality judgments, which are characterized as “rational comprehensive” or “satisficing”, respectively; and (2) the level of experience of audit firm members, expressed in terms of hierarchical ranks, amplifies the effect of firm culture. On the third level, the authors interpret the formation of materiality judgments vis-a-vis culture as forming an implicit tension with political interests in which the practitioner and administrative components of audit firms contend with one another over the “location” of decision-making discretion and autonomy. Results obtained from an experimental simulation involving the participation of 212 partners, managers and seniors from the former Big 8 firms strongly support both audit firm culture hypotheses. Finally, the authors explore implications using empirical results as well as insights gathered during interviews with firms members directed at probing the political forces influencing the location of decision-making discretion.
Histochemical localization of cysteine-rich proteins by tissue printing on nitrocellulose

Abstract A rapid technique for the histochemical localization of cysteine-rich proteins in plant tissues was developed. It is based on the immediate transfer of proteins to nitrocellulose membranes when a fresh cut organ is pressed against the membrane surface. The print was labeled for cysteine-rich proteins by reduction and alkylation of cysteinyl residues with dansylated iodoacetamide [ N -iodoacetyl- N′ -(-5-sulfo-1-naphthyl)ethylenediamine]. The S-carboxymethylated proteins were visualized by their fluorescence when excited with 360 nm light.
Structuring small firms for rapid growth

Abstract Small firms confront significant dilemmas as they struggle to capitalize on growth opportunities. Surges in demand frequently result in the hiring of additional operating and administrative personnel. Rapid growth in employment, however, creates managerial problems whose resolution requires firms to design collateral systems that both mobilize staff attention toward a shared vision and support the firm's strategic outlook (Hambrick and Crozier 1985; Kotter and Sathe 1978). This article reports on a cross-sectional study of 95 small U.S. firms that experienced a five-year surge in growth. Findings indicate that the internal systems designed by these firms to support their rapid growth varied systematically by strategic orientation and degree of product diversity. Contrary to expectations, the relationship between strategy and structure failed to demonstrate a significant effect on these firms' levels of performance. Indeed, the data suggest that in fashioning these systems, firms' managements may, in fact, be responding to contradictory pulls. 1. Bureaucratization versus Decentralization. Increased hiring stimulates bureaucracy: firms formalize procedures as staffing doubles and triples. Employee participation and autonomy decline and internal labor markets develop. Tied to growth, however, is also an increased diversity in product offerings that favors less formalized decision processes, greater decentralization, and the recognition that the firm's existing human resources lack the necessary skills to manage the broadening portfolio. 2. Environment versus Strategy. High environmental turbulence and competitive conditions favor company cultures that support risk taking, autonomy, and employee participation in decision making. Firms confront competitors, however, through strategies whose implementation depends on the design of formal systems that inhibit risk taking and autonomy. 3. Strategic Emphases on Quality versus Cost versus Innovation. Rapidly growing firms strive to simultaneously control costs, enhance product quality, and improve product offerings. Minimizing costs and undercutting competitors' product prices, however, are best achieved by traditional hierarchical systems of decision making and evaluation that contrast with the kinds of autonomous processes most likely to encourage the pursuit of product quality and innovation. The findings suggest that managing surges in growth involves multiple challenges: resolving the stresses and strains induced by attempts to control costs while simultaneously enhancing quality and creating new products to maintain competitive parity, and centralizing to retain control while simultaneously decentralizing to encourage the contributions of autonomous, self-managed professionals to the embryonic corporate culture. Rapidly growing firms are challenged to strike a balance between these multiple pulls when designing their managerial systems.
Coherence in two-photon down-conversion induced by a laser

We discuss the situation in which idler beams from two parametric down-converter crystals are allowed to interfere. We show that, when two mutually coherent signal beams derived from a common laser are injected into the down-converters, the two idler beams can become mutually coherent also. Moreover, the resulting interference pattern can, in principle, have 100% visibility when the number of injected photons per unit down-converter bandwidth is large. This is just the condition for stimulated down-conversion to dominate over spontaneous down-conversion.
Uptake and transport of horseradish peroxidase by cochlear spiral ganglion neurons.

Abstract Cochlear spiral ganglion neurons in the cat have been classified as type I and type II. The type II neurons are of special interest since they are reported to provide the afferent innervation to three-quarters of the cochlear hair cells, and also because of a recent assertion that they do not project to the brain. In the present study the neuronal marker horseradish peroxidase (HRP) was utilized to re-examine these issues. HRP was injected into the intranuclear cochlear nerve root of adult cats. 18 to 48 h post-injection HRP reaction product was observed in both type I and type II neurons. The majority of labeled cells were characterized by granular reaction product, while a smaller number of cells were also diffusely filled with HRP, resulting in intense staining of the cell soma and its processes. These data indicate that the central axons of type II neurons are constituents of the cochlear nerve root at the level of the brainstem and thus do project centrally. In the organ of Corti HRP-filled fibers to both inner and outer hair cells were observed and demonstrated in electron microscopy to be afferent neurons. This intra-axonal accumulation of the HRP by outer hair cell afferents constitutes direct evidence of the functional projection of these neurons to the cochlear nucleus.
Exploring the Basis of Citizens’ Attitudes Toward the Police:

During the past 20 years, there has been an expanding body of research examining citizens’ attitudes toward the police. Most of this research has been directed at assessing the determinants of thes...
Posttraumatic stress disorder and standardized test-taking ability.

Given the widespread use and high-stakes nature of educational standardized assessments, understanding factors that affect test-taking ability in young adults is vital. Although scholarly attention has often focused on demographic factors (e.g., gender and race), sufficiently prevalent acquired characteristics may also help explain widespread individual differences on standardized tests. In particular, this article focuses on the role that posttraumatic stress symptoms (PSS) potentially play in standardized academic assessments. Using a military sample measured before and after exposure to war-zone stressors, the authors sought to explain test-taking ability differences with respect to symptoms of PTSD on two cognitive tasks that closely match standardized test constructs. The primary method for this analysis is based on an item response theory with covariates approach. Findings suggest that the effect for PSS is significant on both tasks, particularly for those who experience the highest levels of PSS following war-zone exposure. Findings provide potentially valuable information regarding the nature of the relationship between PSS and verbal and logical reasoning test performance.
Peptide inhibition of constitutively activated epithelial Na(+) channels expressed in Xenopus oocytes.

Abstract The hypothesis that 30-amino acid peptides corresponding to the C-terminal portion of the β- and/or γ-rat epithelial sodium channel (rENaC) subunits block constitutively activated ENaC was tested by examining the effects of these peptides on wild-type (wt) rENaC (αβγ-rENaC), truncated Liddle's mutants (αβTγ-, αβγT-, and αβTγT-rENaC), and point mutants (αβYγ-, αβγY-rENaC) expressed inXenopus oocytes. The chord conductances of αβTγ-, αβγT-, and αβTγT-rENaC were 2- or 3-fold greater than for wt αβγ-rENaC. Introduction of peptides into oocytes expressing αβTγ-, αβγT-, and αβTγT-rENaC produced a concentration-dependent inhibition of the amiloride-sensitive Na+ conductances, with apparent dissociation constants (K d) ranging from 1700 to 160 μm, depending upon whether individual peptides or their combination was used. Injection of peptides alone or in combination into oocytes expressing wt αβγ-rENaC or single-point mutants did not affect the amiloride-sensitive whole-cell currents. The single channel conductances of all the mutant ENaCs were the same as that of wild type (αβγ-). The single channel activities (N·P o) of the mutants were ∼2.2–2.6-fold greater than wt αβγ-rENaC (1.08 ± 0.24,n = 7) and were reduced to 1.09 ± 0.17 by 100 μm peptide mixture (n = 9). The peptides were without effect on the single channel properties of either wt or single-point mutants of rENaC. Our data demonstrate that the C-terminal peptides blocked the Liddle's truncation mutant (αβTγT) expressed in Xenopusoocytes but not the single-point mutants (αβYγ or αβγY). Moreover, the blocking effect of both peptides in combination on αβTγT-rENaC was synergistic.
Modeling of aeromagnetic data from the Precambrian Lake Owens mafic complex, Wyoming

Aeromagnetic anomalies overlying the Pre-cambrian Lake Owens layered mafic complex and adjacent bodies in the Medicine Bow Mountains of southeast Wyoming help constrain their geometric and magnetic properties. Modeling of these anomalies shows that the magnetic part of the Lake Owens Complex corresponds well with its surface outcrop and is only about 1 km thick. The remanent magnetization is approximately as strong as the induced magnetization. The total magnetization of the complex is 5.8 x 10-3 emu/cc. Rocks this strongly magnetized, were they located in the deep crust, could account for long-wavelength magnetic anomalies. The anomaly also shows the presence of a small, strongly magnetic body to the northeast of the Lake Owens Complex. This is probably a small, separate mafic body or a piece of the complex broken and disrupted during tectonic activity and/or during later granite intrusion. The Mullin Creek layered mafic complex, to the west of the Lake Owens Complex, has weaker magnetization dominated by induced magnetization or a viscous remanent overprint in the direction of the present Earth's magnetic field. Its surface outcrop corresponds poorly with boundaries of magnetic units. A magnetic unit between the two mafic complexes may be a quartz diorite or a separate, shallow mafic body.
Local structural properties in the terahertz semiconductor Zn1-xCdxTe

Local structural properties of wide-band-gap semiconductors, Zn1-xCdxTe (ZCT) crystals (x=0–0.25), were studied using X-ray absorption fine structure (XAFS) measurements at the Te L1- and Zn K-edges. A previous study by Liu et al. [rf1] reported that ZCT emits or absorbs terahertz (THz) signals with a best efficiency when x0.05. The XAFS studies show that the disorder and the bond length of Te–Zn pairs have maximum values at about x=0.05. We discuss that these structural transitions are relevant to the efficiency of THz emission and absorption in ZCT crystals. We also find that the distance of Te–Cd pairs is at least ~0.2 A longer than that of Te–Zn pairs and that Cd doping causes disorder/distortion in both Te and Zn sites in the crystals.
Two‐dimensional finite element analysis of microwave heating

Transient temperature profiles for long rods of lossy dielectric materials with thermally-dependent dielectric properties exposed to uniform plane waves are obtained. Maxwell's equations and the heal equation are simultaneously solved using the finite element method to predict the power absorbed and the resulting temperalure rise in samples of square and circular cross-section. Following the method introduced recently, we derive an exact radiation boundary condition which is independent of the rod cross-section
Intra-channel chromatic dispersion measurements with live neighboring signals in a long haul DWDM system

A novel four-tone probe signal is used to measure end-to-end residual chromatic dispersion in single 50-GHz DWDM channels of a long-haul ROADM network while transmitting more than 30 live signals in neighboring channels.
Effects of soybean oil and oxidized soybean oil on the stability of β-carotene

Abstract The effects of 1.0%, 2.5%, and 5.0% purified soybean oil and thermally oxidized soybean oil on the stability of 100 ppm β-carotene as a fat-soluble vitamin A and singlet oxygen quencher in isooctane have been studied. The samples were stored under 1000, 2000, or 4000 lx at 20 °C for 2 days and at 50 °C for 16 days in the dark. The β-carotene was determined by high-performance liquid chromatography. The centrifugation and filtration of vegetable mixture, during sample preparation for β-carotene analysis by HPLC, decreased the coefficient of variation from 4.13% to 1.02%. The purified soybean oil and thermally oxidized soybean oil stabilized β-carotene in isooctane under light and in the dark at α = 0.05. The losses of β-carotene, with 1.0% purified oil, 1.0% thermally oxidized oil and without any oil during 48 h under light, were 11.2%, 80%, and 100%, respectively. 100 ppm TBHQ had a protective effect on the stability of β-carotene in isooctane at α = 0.05. The β-carotene stability decreased as the light intensity increased from 1000 to 2000 or 4000 lx at α = 0.05. The stability of vitamins in fruit and vegetable drinks enriched with fat-soluble vitamins and antioxidants during storage can be greatly improved by adding approximately 1.0% high quality non-oxidized soybean oil.
The effects of union membership on absence from work due to illness

A simple model of the effects of unionization on absenteeism due to illness is developed and tested. It is argued that unions lower absenteeism through providing a monopoly wage, but raise it by providing liberal sick-leave benefits. Data from the Michigan Panel Study of Income Dynamics are used to test the model. In regressions which control for human capital and demographic characteristics as well as working conditions, it is found that the net effect of unionization is to encourage absence.
The metastable phase Ni2Mo and the initial stages of ordering in NiMo alloys

The initial stages of ordering in Ni3Mo and Ni4Mo have been investigated by transmission electron microscopy and diffraction. The development of long-range order in Ni3Mo is associated with decomposition into the two metastable phases Ni2Mo and Ni4Mo, which are eventually replaced by the equilibrium Ni3Mo at a later stage of ordering. Evidence for the presence of metastable Ni2Mo phase was also found during the early stages of ordering of Ni4Mo. The presence of the metastable phase Ni2Mo at Ni4Mo composition and that of Ni2Mo and Ni4Mo at Ni3Mo composition can be explained in terms of the recent thermodynamic calculations of the ground states of ordered binary alloys by Cahn and his co-workers.
Theories of Violence: Social Science Perspectives

The articles in this Special Issue provide an overview of some of the major social science perspectives regarding violence in sociology, psychology, anthropology, and political economy. An analysis and a synthesis of these fields of study as they pertain to violence reveal common themes. This paper attempts to examine conceptual commonalities and distinctions across these academic disciplines in an attempt to weave an integrated framework that may elucidate our theoretical understanding of violence. An integrative conceptual framework that highlights shared factors across social science disciplines may further illuminate our understanding of the multidisciplinary correlates of violence and, therefore, assist instructors, practitioners, and researchers in the identification and application of core theoretical concepts that underlie social science explanations of violence; thereby assisting social work students to better understand the interactions between of human behavior and the social environment.
SU‐E‐T‐673: Factors Influencing Normal Brain Dose for Single‐Isocenter Multi‐Target Radiosurgery

Purpose: To evaluate the effects of number of arcs, collimator angle, variable secondary collimator size, and optimization objectives on normal brain dose. Methods: Ten patients treated for multiple cranial metastases were retrospectively planned for single‐isocenter VMAT. All plans were optimized using a standardized objective function and were normalized such that 99% of the total target volume received 18 Gy. Multiple variables were utilized in planning, including numbers of arcs (2 versus 4), collimator angles (45° versus selected per beam to minimize area of normal brain exposed in the beams‐eye‐view), jaw tracking (fixed versus trailing MLC leaf), and a low dose constraint for healthy brain (mean dose 2 Gy versus no constraint). Plan quality was evaluated by conformity index, gradient index, mean absolute volume of normal brain receiving 1.8 Gy (V10), 4.5 Gy (V25), 12 Gy (V12Gy), and normal brain mean dose. Results: Conformity index, gradient index, and V12Gy were not significantly dependent on the factors considered. The low dose constraint reduced the brain mean dose by 56 cGy (13.7% reduction relative to no low dose constraint). Other factors did not have a significant effect on mean dose. The low dose constraint decreased V25 and V10 by 136 cc (28.8% reduction) and 128 cc (12.7% reduction), respectively. Collimator angle and jaw tracking each reduced V25 and V10 by up to 32 cc and 40 cc, respectively. Compared to 2 arcs, 4 arcs decreased V25 by 20 cc and increased V10 by 38 cc. Conclusion: Limiting the normal brain mean dose in the optimization objective function significantly reduces the low dose spill into the normal brain without changing target coverage. Jaw tracking and appropriate selection of collimator also reduces the low dose volume, but to a lesser extent.
Prostaglandin synthesis in different phases of phagocytosis in lung macrophages

Macrophages have a central role in bodily defence and inflammatory responses. Prostaglandins (PGs), mediators of inflammation, are secreted by macrophages during phagocytosis. PGE-like activity was first demonstrated in macrophage-rich peritoneal exudate cell preparations from guinea pigs; later, other kinds of PGs were also found to be released by mouse peritoneal macrophages in response to inflammatory stimuli. We have shown that rabbit alveolar macrophages also produce various PGs in response to phagocytic stimuli like zymosan and heat-killed bacteria; however, it was not known precisely which cellular event is associated with PG production. Traditionally, the phagocytic process is considered in three stages: (1) attachment of the particle to the cell membrane; (2) interiorisation (phagocytosis); and (3) fusion of the phagocytic vesicle with intracellular lysosomes (digestion). We show here that PG secretion in response to phagocytic stimuli by macrophages is independent of the first stage, but dependent on engulfment of the particle. Moreover, PG production does not appear to be associated with the process of engulfment per se, but with some event following internalisation.
High Pressure Liquid Chromatography Assay for Determination of 18-β-Glycyrrhetinic Acid in Plasma

Abstract This report presents a useful high pressure chromatography assay for determination of the proposed chemopreventive agent 18-β-glycerrhetinic acid (GA) in murine and human plasma. Drug was released from plasma proteins through precipitation with a mixture of sodium bisulfate and sodium chloride after which it was extracted with acetonitrile. Standard calibration curves of GA covered the concentration range of 2.5 to 120 μg/ml. The lower limit of detection was 0.5 μg/ml. No endogenous plasma constituents from plasma were found to interfere with the determination of GA. Recover of GA from plasma was greater than 95% over a concentration range of 20 to 100 μg/ml. Linearity of the assay was excellent; within-run precision showed a C.V. of 4.2% at 25 μg/ml, 5.6% at 20 μg/ml and 3.4% at 120 μg/ml. Between-run assay precision and accuracy was also considered to be excellent. The specificity, sensitivity and reproducibility of the procedure are adequate for proposed clinical pharmacology studies of this a...
PARAMETRIC MODEL OF AN INTERMEDIATE TEMPERATURE PEMFC

Proton exchange membrane fuel cells operating with Nafion® membranes have encountered numerous problems associated with water management and CO poisoning because of their low temperature of operation. Higher temperature membranes have been investigated, one such membrane being polybenzimidazole (PBI). This paper presents a parametric model, which predicts the polarization performance of an intermediate temperature proton exchange membrane fuel cell (PEMFC). It also investigates the effects of porous media characteristics on fuel cell performance. Results show that for intermediate temperature fuel cells, mass limitation effects are absent as long as the catalyst regions are sufficiently permeable. It is predicted that the greatest scope for improving PBI PEMFC performance is increasing the membrane conductivity and improving the catalyst performance, as it interfaces with the PBI membrane.
The Impact of High-Frequency Surface Weather Observations on Short-Term Probabilistic Forecasts of Ceiling and Visibility

Abstract The skill of an automated statistical forecasting system that uses only hourly (top of the hour) surface observations is compared with a system that utilizes hourly and high-frequency (interhour) surface observations to forecast low-ceiling and low-visibility events in the New York City, New York, area. Forecasts feature lead times of 1 h and less. Equations to forecast ceiling and visibility conditions 1 h in advance are developed for initialization times at the top of the hour, as well as at 15, 30, and 45 min past the hour. Two forecasting systems are created: a baseline system that utilizes only hourly surface observations and an alternative system that utilizes both hourly surface observations and high-frequency observations. Introduction of the high-frequency observations into the forecasting system produces an additional 1.5%–4.5% reduction in the mean-square error (MSE), as compared with the baseline system for 1-h forecasts made at the top of the hour. By 45 min past the hour, the reduct...
Practices, attitudes, and beliefs associated with complementary and alternative medicine (CAM) use among cancer patients.

Introduction. The high prevalence of complementary and alternative medicine (CAM) use among cancer patients (40%-83%) receiving conventional treatment and the complex relationship between the psych...
Dynamic Earth: Plates, Plumes and Mantle Convection

One might wonder if there is really a need for another book on plate tectonics. Many books exist on this topic already, and the field has reached a stage of maturity where some good books (i.e., books that I have found useful) are already out of print. This is the concern I had when I sat down with this book; however, I was quickly won over by both the content and structure. Davies attempts to separate well-established observations and physical principles things known with a reasonable degree of certainty from interpretation and theory, where the application of these principles is less certain. He walks this fine line well, with a few exceptions.
Phonon Physics and Low Temperature Detectors of Dark Matter

We discuss a number of topics in phonon physics that are relevant to the design of low temperature phonon-based dark matter detectors. These topics include the generation of “primaeval” phonons by the nuclear recoil, the processes by which these phonons decay into lower energy phonons, and the ballistic propagation of these excitations to the sensors on the crystal surface.
Exploring the impact of sleep‐related impairments on the perceived general health and retention intent of an Emergency Medical Services (EMS) sample

Purpose – Little research has been done in studying the impact of sleep‐related impairments on the perceived health and retention intent of Emergency Medical Service (EMS) workers. This paper aims to fill some of the gaps.Design/methodology/approach – This study used a time‐lagged research design to test the impact of three sleep impairments measured in 2005, i.e. sleepiness, relationship difficulty due to sleepiness, and general activity difficulty due to sleepiness, on perceived general health measured in 2006 and 2007, and 2007 intent to leave the EMS profession. Background and work‐related variables, also measured in 2005, were controlled for. A total of 288 complete data EMS repeat‐respondents constituted the study sample across the three years. Although this was only a very small percentage of the total number of respondents, this sample was found to be demographically representative of the incomplete data respondents.Findings – The three‐sleep impairment variable set had a collective significant ad...
An investigation of relationalism across a range of marketing relationships and alliances

Abstract The authors describe four important aspects of the “new” relational environment: (1) the organizational forms of marketing relationships, (2) the governance mechanisms which exist between exchange partners, (3) the perceived effectiveness of the organizational forms, and (4) expectations that the exchange relationship will continue in the future. Two contexts, National Association of Purchasing Management members and Fortune 500 executives, provide a cross-sectional investigation of vertical and horizontal exchange relationships. The results indicate that alliances are more relational than nonalliance exchanges; however, one cannot assume a relational gradation across the organizational forms (i.e., traditional supply agreements, just-in-time relationships, vertical supply alliances, and co-marketing alliances). Further, co-marketing alliances are reported as the exchange relationship with the highest expectation of continuation, but there are no differences in the perceived effectiveness across organizational forms.
Implications for place attachment in coastal Reserve management

This study determined the characteristics of North Carolina Coastal Reserve and North Carolina National Estuarine Research Reserve (jointly referred to as Reserve) visitors, visitor opinions of site conditions, visitor understanding of site management objectives, and patterns of visitation. The latter were investigated to obtain a proxy of place attachment and its effects on knowledge of ownership and perceptions of management. Data were collected on demographics, use patterns, visitor perceptions, and visitor knowledge during the period of 25 May-28 October, 2007. Visitors were educated, wealthy, older, racially homogeneous, and frequent returnees. The majority of respondents supported existing management activities and the implementation of additional use restrictions should site conditions deteriorate. Data indicated that respondents were unaware of which agency manages the Reserve sites or its mission. These findings suggest that management needs to engage in more education of the visiting public. Sensitizing the public to the mission of the Reserve and increasing place attachment could decrease negative visitor impacts.
Disk-Overflow Accretion in GK Persei?

We reanalyze the 1983 European X-ray Observatory Satellite (EXOSAT) observations of GK Per during an outburst to investigate the approximately 5000 s quasiperiodic modulation. We find that the spectral behavior is reminiscent of dipping low-mass X-ray binaries and note that the time scale is characteristic of the radius where an accretion stream overflowing the disk would collide back onto the disk. We suggest that structure caused by such disk-overflow accretion was periodically obscuring the white dwarf, producing the modulation.
Simulation of mammographic x-ray spectra

Attempts to simulate Mo-anode spectra for film mammography by using Mo filters with W-anode tubes have been reported by several workers, and others have generated W-like continua for xeromammographic purposes by heavy Al filtration of Mo-anode tubes. In the present work the success of these simulations was tested by Si(Li) spectrometric methods that measured the spectral shapes and the exposure levels. Comparisons of Mo-anode/Al-filter with W-anode/Al-filter combinations were made, and also of W-anode/Mo-filter with Mo-anode/Mo-filter combinations. In certain circumstances the spectral shape is moderately well simulated but in all cases the useful output is less in the simulations than in the original spectra. The general conclusion is that simulation is always less attractive than direct use of the desired anode.