cssi/SciSciGPT-SciSciNet huggingface dataset:
A vectorized solution for incompressible flow

An algorithm is developed to obtain solutions to the unsteady Reynolds-averaged incompressible Navier-Stokes equations in general curvilinear coordinates on a vector processor. The governing equations are in nonconservative form with the velocity and pressure as dependent variables. Two momentum equations and the Poisson equation for pressure form a set of three governing equations for three flow field unknowns: u, v, and p. The governing equations and boundary conditions are expressed in terms of boundary-conforming curvilinear coordinates, and a checkerboard SOR iteration is used to solve the governing equations. Several possible sequences for a checkerboard SOR iteration are investigated for finding the best overall convergence rate. The efficiency and capability of the present algorithm was assessed using the example of an 18 percent thick NACA 66(3)018 airfoil at zero degree angle of attack for chord Reynolds number range 1000-40,000.
The finO gene of antibiotic resistance plasmid R100

Lambda phages carrying the R100 finO gene have been isolated from an R100::“ cointegrate in which λ was inserted into the R100 traD gene at kb coordinate 72.1. Physical analyses of these phages place the finO gene within R100 SalI fragment D, near kb coordinate 82.0. Analysis of proteins synthesized by the phages did not identify the finO gene product, although a constitutive protein of m.w. 30,100 was encoded by R100 DNA between kb coordinates 78.7 and 81.2.
Life at the hyperarid margin: novel bacterial diversity in arid soils of the Atacama Desert, Chile

Nearly half the earth's surface is occupied by dryland ecosystems, regions susceptible to reduced states of biological productivity caused by climate fluctuations. Of these regions, arid zones located at the interface between vegetated semiarid regions and biologically unproductive hyperarid zones are considered most vulnerable. The objective of this study was to conduct a deep diversity analysis of bacterial communities in unvegetated arid soils of the Atacama Desert, to characterize community structure and infer the functional potential of these communities based on observed phylogenetic associations. A 454-pyrotag analysis was conducted of three unvegetated arid sites located at the hyperarid-arid margin. The analysis revealed communities with unique bacterial diversity marked by high abundances of novel Actinobacteria and Chloroflexi and low levels of Acidobacteria and Proteobacteria, phyla that are dominant in many biomes. A 16S rRNA gene library of one site revealed the presence of clones with phylogenetic associations to chemoautotrophic taxa able to obtain energy through oxidation of nitrite, carbon monoxide, iron, or sulfur. Thus, soils at the hyperarid margin were found to harbor a wealth of novel bacteria and to support potentially viable communities with phylogenetic associations to non-phototrophic primary producers and bacteria capable of biogeochemical cycling.
Evaluation of Titanium Alloys Fabricated Using Rapid Prototyping Technologies—Electron Beam Melting and Laser Beam Melting

This study characterized properties of Ti-6Al-4V ELI (extra low interstitial, ASTM grade 23) specimens fabricated by a laser beam melting (LBM) and an electron beam melting (EBM) system for dental applications. Titanium alloy specimens were made into required size and shape for each standard test using fabrication methods. The LBM specimens were made by an LBM machine utilizing 20 µm of Ti-6Al-4V ELI powder. Ti-6Al-4V ELI specimens were also fabricated by an EBM using 40 µm of Ti-6Al-4V ELI powder (average diameter, 40 µm: Arcam ABO) in a vacuum. As a control, cast Ti-6Al-4V ELI specimens (Cast) were made using a centrifugal casting machine in an MgO-based mold. Also, a wrought form of Ti-6Al-4V ELI (Wrought) was used as a control. The mechanical properties, corrosion properties and grindability (wear properties) were evaluated and data was analyzed using ANOVA and a non-parametric method (α = 0.05). The strength of the LBM and wrought specimens were similar, whereas the EBM specimens were slightly lower than those two specimens. The hardness of both the LBM and EBM specimens was similar and slightly higher than that of the cast and wrought alloys. For the higher grindability speed at 1,250 m/min, the volume loss of Ti64 LBM and EBM showed no significant differences among all the fabrication methods. LBM and EBM exhibited favorable results in fabricating dental appliances with excellent properties as found for specimens made by other fabricating methods.
The status of information systems department: the effects of downsizing

In today’s volatile economy, organizations are constantly exploring avenues to remain competitive. Information systems (IS) downsizing is one of the strategies used by many organizations in continued efforts for survival. There are considerable risks and rewards to the various units within the firm including the IS department associated with downsizing strategy. Empirical studies that evaluate the impact of the process on the IS department are needed to help organizations better manage their information technologies and systems. This study investigates the real impacts of IS downsizing on the IS department as perceived by IS managers of those companies whose IS had been downsized. With a pre‐tested survey instrument, the study compares 12 critical characteristics of 98 IS departments before and after the downsizing process. The gains and drawbacks of IS downsizing are also analysed based on key indicators that are emphasized in the literature. The results indicate that IS downsizing has definite benefits and drawbacks. The findings also show that the net gains on some of the key indicators are not as significant as the IS downsizing proponents may claim.
Tunable phononic crystals with anisotropic inclusions

We present a theoretical study on the tunability of phononic band gaps in two-dimensional phononic crystals consisting of various anisotropic cylinders in an isotropic host. A two-dimensional plane-wave expansion method was used to analyze the band diagrams of the phononic crystals; the anisotropic materials used in this work include cubic, hexagonal, trigonal, and tetragonal crystal systems. By reorienting the anisotropic cylinders, we show that phononic band gaps for bulk acoustic waves propagating in the phononic crystal can be opened, modulated, and closed. The methodology presented here enables enhanced control over acoustic metamaterials which have applications in ultrasonic imaging, acoustic therapy, and nondestructive evaluation.
Horn Flies: Emergence, Survival, and Sterility After 60Co Irradiation of Pupae

Irradiation of colony-reared 30-h-old pupae of Haematobia Irritans (L.) with 2500 rad from 60CO completely inhibited emergence of flies; with irradiation of 54-h-old pupae, some flies emerged, but all died within 3 days. When 78-h-old pupae were irradiated, unusual numbers of adults died within 3 days. However, when pupae were 102 or 126 h old at the time of irradiation, neither emergence nor survival of flies was affected adversely. Also, when this dose was applied after emergence had begun (avg pupal age 120 h), both males and females were sterile. With a dose of 2000 rad, the females were sterile, and fewer than 1.0% of the males were fertile. Male flies eclosing during the initial 24 h of the emergence period accounted for most of this fertility.
Hydrophobic interaction chromatography

Hydrophobic interaction chromatography (HIC) is emerging as a useful technique for the separation of biological compounds. Advances in the past two years in HIC applications, stationary phases, eluents, and theory are reviewed. Recent applications of HIC processes include analytical and semi-preparative separations of a variety of proteins, such as isolectins, hemoglobins, calmodulin, and cardiotoxins. Additionally, HIC is being employed as a tool to investigate protein properties and mechanisms. Advances in HIC stationary phases include development of non-porous, microparticulate supports as well as supports with pore sizes up to 1000 Angstroms. Studies of HIC eluents have further shown the effects of mobile phase pH, water-structuring characterization, and surface tension increments on retention. Various retention mechanisms which have been presented are reviewed; and a correlation relating resolution to column and solute parameters is presented. Protein conformational effects at specific sites have been shown to have a significant impact on retention and specific examples illustrating such effects are discussed.
Fusion or Familialism: A Construct Problem in Studies of Mexican American Adolescents:

This study was an investigation of intergenerational relationships related to the individuation process as reported by Mexican (N = 2,388) and European American (N = 2,907) adolescents. The primary aim was to examine the construct within theories of adolescent development that emotional separation in parent-adolescent relationships is an inherent aspect of the developmental process that occurs across the two ethnic groups. The authors conducted confirmatory factor analyses on a subscale INFUS of an instrument developed to measure family process, the Personal Authority in the Family System Questionnaire (PAFS-Q) developed by Bray, Williamson, and Malone. In sum, findings indicate (a) the need for better measurement testing, (2) the need to revisit the concept of autonomy from the family as a universal task during adolescent development, and (3) caution in the clinical use of concepts such as fusion and independence when delivering mental health services to Mexican adolescents and their families.
Rejoinder to a Postmodernist

This article, a defense of realism and representationalism in history against the postmodernist philosophy of language, is a critical rejoinder to Keith Jenkins's reply to my earlier essay in this journal in 1999 on postmodernism and historiography. 1 Beginning with some remarks on the relationship between philosophy and historiography, this article goes on to note some of the weaknesses in postmodernist Jenkins's discussion of realism, representationalism, Richard Rorty, and Jacques Derrida's well-known dictum that there is nothing outside the text. It also considers Jenkins's talk about emancipation and the end of history and shows why it cannot be taken seriously. The article's conclusion is that postmodernism has nothing to contribute to the understanding of history as a form of thought or a body of knowledge.
Self-Reported versus Observed Classroom Activities in Elementary General Music:

This study compared self-reported music class activity time use and actual time use of general music teachers. Responses from a questionnaire provided self-report data regarding general music instr...
Probit and Logit Model Selection

Monte Carlo experiments are conducted to compare the Bayesian and sample theory model selection criteria in choosing the univariate probit and logit models. We use five criteria: the deviance information criterion (DIC), predictive deviance information criterion (PDIC), Akaike information criterion (AIC), weighted, and unweighted sums of squared errors. The first two criteria are Bayesian while the others are sample theory criteria. The results show that if data are balanced none of the model selection criteria considered in this article can distinguish the probit and logit models. If data are unbalanced and the sample size is large the DIC and AIC choose the correct models better than the other criteria. We show that if unbalanced binary data are generated by a leptokurtic distribution the logit model is preferred over the probit model. The probit model is preferred if unbalanced data are generated by a platykurtic distribution. We apply the model selection criteria to the probit and logit models that li...
Examining the influence of culture on perceived source credibility of asian americans & the mediating role of similarity

Abstract The current study examines some of the cultural influences for Asian Americans on perceived model credibility. Specifically, the effects of racial congruency and ethnic identification are examined between consumers and ad stimuli as well as the role that similarity plays in the process. The findings reveal that model-consumer racial congruency is an important consideration for enhancing source credibility. However, similarity with the model in terms of values and cultural background was found to mediate the relationship. In contrast to other ethnic groups, strength of ethnic identification did not have a significant impact on Asian Americans' perceptions of source credibility.
Characteristics of summer and fall diurnal resting habitat used by American martens in coastal northwestern California.

American martens use resting habitat between periods of activity to provide both thermal refugia and protection from predators. Maintenance or restoration of key elements of marten resting habitat, such as resting structures, requires that managers recognize their characteristics to protect them, or manage for their creation. We measured resting habitat at 4 scales: (1) the resting location— where the marten actually rested; (2) the resting structure—the habitat element that contained the resting location; (3) the resting site—characteristics in the immediate vicinity of each resting structure; and (4) the resting stand—the forest stand containing the resting structure. During the summer and fall of 2001 and 2002 we identified resting structures used by 12 radio-collared martens (7 Male, 5 Female) and 1 uncollared marten. The animals were the members of the only remnant population of martens within the historical range of the Humboldt marten (M. a. humboldtensis). The study area included portions of the Six Rivers National Forest, Smith River National Recreation Area, and adjacent Green Diamond Resource Company lands in coastal northwestern California. We located martens resting on 55 occasions in the following types of structures: snags (37%), logs (23%), live-trees (17%), slash-piles (10%), rock-piles (8%), and shrub clumps (6%). The location in the structure where the marten actually rested was determined on 92% of occasions and included chambers (33%), cavities (33%), broken tops (22%), branch platforms (6%), ground sites (6%), and basal hollows (2%). Woody structures were large, with mean dbh of 93.9 cm for live-trees , 94.9 cm for snags, and 88.2 cm maximum-diameter for logs. The mean age of 24 of the woody resting structures was 339 years (range 131– 666 years). Our results are consistent with results from other studies on resting structure use and highlight the importance of large live and dead woody structures for American martens in coastal forests of northwestern California.
Facile synthesis of one-dimensional peapod-like Sb@C submicron-structures

We demonstrate a novel synthetic route to fabricate a one-dimensional peapod-like Sb@C structure with disperse Sb submicron-particles encapsulated in carbon submicron-tubes. The synthetic route may well serve as a general methodology for fabricating carbon/metallic fine structures by thermally reducing their carbon-coated metal oxide composites.
Differences in Scrapie-Induced Pathology of the Retina and Brain in Transgenic Mice that Express Hamster Prion Protein in Neurons, Astrocytes, or Multiple Cell Types

Prion protein (PrP) is expressed in many tissues and is required for susceptibility to scrapie and other prion diseases. To investigate the role of PrP expression in different cell types on pathology in retina and brain after scrapie infection, we examined transgenic mice expressing hamster PrP from the PrP promoter (tg7), the neuron-specific enolase promoter (tgNSE), or the astrocyte-specific glial fibrillary acidic protein promoter (tgGFAP). After intraocular inoculation with hamster scrapie, clinical disease developed in tg7 and tgNSE mice by 100 days and in tgGFAP mice by 350 days. Astrogliosis and scrapie-associated protease-resistant PrP (PrP-res) were detected in retina and brain before clinical onset. Retinal PrP-res was present in high amounts in both tg7 and tgNSE mice, however only tg7 mice developed retinal degeneration and extensive apoptosis. In contrast, in all three lines of mice high levels of brain PrP-res accompanied by neurodegeneration were observed. Thus, PrP expression on neurons or astrocytes was sufficient for development of scrapie-induced degeneration in brain but not in retina. The combined effects of PrP-res production in multiple cell types was required to produce retinal degeneration, whereas in brain PrP-res production by neurons or astrocytes alone was sufficient to cause neuronal damage via direct or indirect mechanisms.
Aspects of Tubular Reabsorption Revisited

Current concepts as to how reabsorption of filtered fluid occurs in the kidney are discussed. Emphasis is placed on certain unique problems arising from the remarkable covariance of amounts of filtered and reabsorbed. A concept advanced by Carl Ludwig over 100 years ago is exhumed and found to provide a reasonable basis for glomerulotubular balance. Some of the difficulties in accepting this view of the renal modus operandi in the light of the current store of information is discussed. It is proposed that a strong a priori case be made for the proposition that a large or at least significant, fraction of tubular reabsorption may occur in the simple manner suggested by Ludwig. Finally a tentative outline incorporating this concept is offered as a reasonable alternative to the theory which is widely held at the present time.
Zebrafish retinal defects induced by ethanol exposure are rescued by retinoic acid and folic acid supplement.

Abstract Fetal Alcohol Spectrum Disorder (FASD) is caused by prenatal alcohol exposure, producing craniofacial, sensory, motor, and cognitive defects. FASD is highly prevalent in low socioeconomic populations, which are frequently accompanied by malnutrition. FASD-associated ocular pathologies include microphthalmia, optic nerve hypoplasia, and cataracts. The present study characterizes specific retinal tissue defects, identifies ethanol-sensitive stages during retinal development, and dissects the effect of nutrient supplements, such as retinoic acid (RA) and folic acid (FA) on ethanol-induced retinal defects. Exposure to pathophysiological concentrations of ethanol (during midblastula transition through somitogenesis; 2–24 h post fertilization [hpf]) altered critical transcription factor expression involved in retinal cell differentiation, and produced severe retinal ganglion cell, photoreceptor, and Muller glial differentiation defects. Ethanol exposure did not alter retinal cell differentiation induction, but increased retinal cell death and proliferation. RA and FA nutrient co-supplementation rescued retinal photoreceptor and ganglion cell differentiation defects. Ethanol exposure during retinal morphogenesis stages (16–24 hpf) produced retinal defects like those seen with ethanol exposure between 2 and 24 hpf. Significantly, during an ethanol-sensitive time window (16–24 hpf), RA co-supplementation moderately rescued these defects, whereas FA co-supplementation showed significant rescue of optic nerve and photoreceptor differentiation defects. Interestingly, RA, but not FA, supplementation after ethanol exposure could reverse ethanol-induced optic nerve and photoreceptor differentiation defects. Our results indicate that various ethanol-sensitive events underlie FASD-associated retinal defects. Nutrient supplements like retinoids and folate were effective in alleviating ethanol-induced retinal defects.
Sputter-induced pits on {100} nickel surfaces

Nickel (Ni+) ions of 180 keV energy impinging on {100} faces of nickel single crystals produce sputtered surfaces. Examination of these surfaces exposed to fluences up to 8 X 1017 ions/cm2 and at temperatures between 25 °C and 750 °C reveals pits with facets parallel to the {111} and {100} crystallographic planes of the nickel. Subsurface voids also form and, when intersected by the sputtered surface, become small pits which grow with further sputtering. The pits exhibit facets that are direct extensions of facets present on the voids. The voids nucleate and grow during the initial stages of bombardment at temperatures above 600 °C but shrink beyond fluences of ~3.5 X 1017 ions/cm2. Voids are not observed after bombardment at temperatures less than 600 °C. Sputtering at these lower temperatures produces no pits unless the nickel is bombarded first at higher temperatures to produce the requisite voids. Measuring the rate at which the {100} surface recedes due to sputtering provides the sputtering yield. This yield, near 3.8 atoms per Ni+ ion, is independent of temperature from 25 °C to 750 °C. The growth rate of the pits,i.e., the rate at which oppositely inclined {111} faces separate, is also measured. At temperatures below 350 °C, the measured growth rate matches that based on sputtering of these inclined surfaces. The rate increases with increasing temperature above 350 °C, reaching nearly tenfold its low-temperature value by 750 °C. The mechanisms causing this accelerated growth with increasing temperature are discussed and related to the migration of the point defects produced by the bombardment.
Comparison of three recombinant murine leukemia viruses carrying the v-src oncogene of avian sarcoma virus: Differences in in vitro transformation and in vivo pathogenicity

We previously described a recombinant Moloney murine leukemia virus (Mo-MuLV) carrying the v-src oncogene, Mo-MuLV(src). Mo-MuLV(src) encodes a gag-src fusion protein, transforms cells in culture, and induces fibrosarcomas in vivo. To compare transforming properties of the gag-src fusion protein to pp60src encoded by Rous sarcoma virus, we constructed a new recombinant virus, Mo-MuLV(+ src). Mo-MuLV(+ src) encodes pp60src in the context of Mo-MuLV. Cells transformed by Mo-MuLV(+ src) were round and formed colonies in soft agar, whereas Mo-MuLV(src)-infected cells were fusiform and did not grow in suspension. Thus, the extent of transformation induced by Mo-MuLV(+ src) was greater than that induced by Mo-MuLV(src). Subcutaneous inoculation of either virus into neonatal NIH Swiss mice resulted in fibrosarcomas at the site of injection. Further studies indicated that tumors induced by Mo-MuLV(+ src) grew rapidly but rarely metastasized. In contrast, tumors induced by Mo-MuLV(src) grew somewhat more slowly but metastasized with a high frequency (60%). These viruses may provide a useful model system for tumor metastasis. Another src-containing virus was also studied, MRSV (constructed by Anderson and Scolnick). MRSV also encodes pp60src but in the context of amphotropic MuLV. When injected intravenously into six-week-old mice, MRSV induced splenomegaly and spleen foci but no solid tumors, as reported previously. In contrast, Mo-MuLV(src)-induced fibrosarcomas mostly in the spleen under the same inoculation protocol. These results suggest that the v-src oncogene was the major pathogenic determinant in neonatal mice for all three src-containing viruses; however, variations in the nature of the transforming protein modulated the behavior of the induced tumors. In adult mice, greater differences in pathogenicity were observed.
Density of xNa2S.(1 – x)B2S3 (x = 0 to 0.8) Glasses: Correlation with Short‐Range Order

The densities of xNa{sub 2}S + (1 {minus} x)B{sub 2}S{sub 3} glasses have been measured for 0 {le} x {le} 0.80. The variation of the density with x is quite strong and is characterized by a sharp maximum at x {approximately} 0.30. The density increases on the low-alkali side of the maximum from 1.7 g/mL for vitreous B{sub 2}S{sub 3} up to 2.2 g/mL for the x = 0.3 glass and decreases on the high-alkali side to 1.8 g/mL. The increase in the density at low alkali is associated with the increasing fraction of the heavy mass and relatively small volume tetrahedral boron group, Na{sup +}BS{sub 4}{sup {minus}}. The density decrease in the high-alkali range is associated with the decreasing fraction of these groups with the concomitant increase in the fraction of trigonal boron groups with increasing numbers of nonbridging (terminal) sulfurs. To model the density, a weighted fractional mass and volume model was used. The molar volumes of the individual short-range order (SRO) groups were determined from compositions where a particular SRO group was the single group in the glass, by fitting the density data, and by interpolating between groups of known volume. The composition dependence of the fractionsmore » of the individual SRO groups was developed by combining spectroscopic evidence with chemically reasonable hypotheses of the SRO of the glasses. In this way, the density was calculated from first principles with one adjustable parameter, that of the volume of the tetrahedral boron group. The calculated densities were found to agree well with the experimental values.« less
The effect of seawater magnesium on natural fluorescence during estuarine mixing, and implications for tracer applications

Abstract Natural fluorescence, which is thought to result from low molecular weight humic and fulvic compounds, can be used as a tracer to distinguish between individual river waters. Natural fluorescence exhibits conservative mixing with seawater, except for a slight fluorescence increase which is sometimes observed in the low salinity range (0–5‰). This increase is not due to the inner filter effect (internal quenching). Laboratory experiments can reproduce this low-salinity natural fluorescence increase. Of the major seawater ions, only magnesium can cause a similar natural fluorescence increase. Variation in sample pH, ionic strength, or particle content cannot explain the natural fluorescence increase, nor does it appear to be related to the estuarine flocculation of humic material. Addition of seawater magnesium to the fluorescent material with subsequent loss of hydrogen ions could enhance fluorescence by adding crosslinking to the structure. Replacement of a fluorescence-depressing metal like copper or iron by magnesium could also enhance fluorescence, essentially by removing the quenching effect of the metal. Experimental data in this study are consistent with both of these possible mechanisms. Calcium also enhances fluorescence, however the effect of seawater calcium during estuarine mixing is not as apparent as the magnesium effect. The implications of this low-salinity natural fluorescence increase with respect to estuarine and coastal tracer applications depend on whether individual rivers mix in the high or low salinity region of an estuary or coastal area.
Recent Advances in Retinex Theory

It is a cultural commonplace deriving from Newton that the colour of an object we see in the world around us depends on the relative amounts of red light, green light, and blue light coming from that object to our eyes. For a very long time it has been known that the colour of the object when it is part of a general scene will not change markedly with those considerable changes in the relative amounts of red, green, and blue light in the illumination which characterize sunlight versus blue skylight versus grey day versus tungsten light versus fluorescent light. This contradiction was named “colour constancy.” Rather than dwelling on the explanations of colour constancy by Helmholtz and those who have followed him during the last century let us go on to show that the paradox does not really exist because it is not true that the colour of a point on an object is determined by the composition of the light coming from the object.
A multi-institutional retrospective analysis of external radiotherapy for mucosal melanoma of the head and neck in Northern Japan

Abstract Purpose A multi-institutional retrospective study was performed in northern Japan to analyze the outcome of external radiotherapy as the definitive treatment modality for localized mucosal melanoma of the head and neck. Patients and methods Thirty-one patients with localized mucosal melanoma of the head and neck treated by external radiotherapy at nine institutions of the Northern Japan Radiation Therapy Oncology Group between 1980 and 1999 were enrolled in this study. Radiotherapy alone was performed in 21 patients, and the remaining 10 patients received postoperative radiotherapy for gross residual tumors. The fraction size of radiotherapy varied from 1.5–13.8 Gy, with the total dose ranging from 32–64 Gy (median, 50 Gy). The follow-up periods ranged from 1–214 months (median, 16 months). Results Complete or partial responses were observed in 9 patients (29%) and 18 patients (58%), respectively. Local recurrence occurred in 13 patients (41.9%) and distant metastasis occurred in 11 patients (35.5%). Most incidences of local recurrence and distant metastasis developed within 2 years after the initial treatment. Overall cause-specific survival rates of patients at 1 and 3 years were 73% and 33%, respectively. Univariate analysis showed that high dose per fractionated radiotherapy doses (≥3 Gy) was associated with better prognosis for both local control ( p = 0.048) and survival ( p = 0.045). Multivariate analysis indicated that age (better prognosis in younger patients, p = 0.046) was the only significant factor. Radiotherapy for gross residual lesions after surgery did not seem to impact the significant gain of local control and survival. We observed two fatal late complications of mucosal ulcer and bleeding in the high dose per fractionated radiotherapy group. Conclusion Radiotherapy at a dose of 3 Gy or more per fraction was effective in gaining local control in patients with localized mucosal melanoma of the head and neck, and subsequently better survival was possible, especially in younger patients.
Pacemaker activity during aggregation in Dictyostelium discoideum

Abstract This paper reports an investigation of the pacemaker regions which organize cell aggregation in the cellular slime mold Dictyostelium discoideum. Observations are made of time intervals between propagation of successive waves of cell movements from Dd aggregation centers and of the geometries of aggregation waves. The observations are used to deduce cellular properties involved in wave initiation. They show that circular waves are initiated by spontaneous periodic signals (with period 5 minutes) and by spontaneous nonperiodic (continuous) signals, each of which interact with a periodic signal relaying response in the responding cells. Spiral waves can be maintained by signal relaying alone (with no spontaneous signaling). They are initiated in at least one of two ways that were predicted in theory ( Wiener and Rosenblueth, 1946; , Durston, 1973 ) but develop unexpectedly.
Use of radioactivity for determining mechanical properties in surface analysis

The study of mechanical properties of surfaces has been facilitated in recent years by nondestructive radioactive techniques, which monitor the wearing away of γ-emitting species from the surface. Such species can be produced directly by surface-layer activation or indirectly by implanting the products of a nuclear reaction. Each technique has its strengths and weaknesses, and together they allow the study of wear in a complex device such as an engine without having to disassemble it.
Refining switching window by time slots for crosstalk noise calculation

For crosstalk noise calculation, computing switching windows of a net helps us identify noise sources accurately. Traditional approaches use a single continuous switching window for a net. Under this model, signal switching is assumed to happen any time within the window. Although conservative and sound, this model can result in too much pessimism since in reality the exact timing of signal switching is determined by a path delay up to the net, i.e. the underlying circuit structure does not always allow signal switching at arbitrary time within the continuous switching window. To address this inherent inaccuracy of the continuous switching window, we propose a refinement of the traditional approaches, where signal switching is characterized by a set of discontinuous switching windows instead of a single continuous window. Each continuous switching window is divided into multiple windows, called time slots, and the signal switching activity of each slot is analyzed separately to calculate the maximum noise with more accuracy. By controlling the size of a time slot we can trade off accuracy and runtime, which makes this approach highly scalable. We have confirmed by experiments on industrial circuits that up to 90% of the noise violations detected by the traditional approach can be unreal.
Language Performance in Children With Cochlear Implants and Additional Disabilities

Objectives/Hypothesis: Quantify post-cochlear implant (CI) language among children with disabilities and determine the role of nonverbal cognitive quotients (NVCQ) in predicting language. Study Design: Small cohort study in pediatric tertiary care center. Methods: Children (n = 20) with CIs and developmental disabilities were enrolled. Receptive and expressive language was reported as language quotients (LQs). Pre- and post-CI LQs were compared using the signed-rank test. Multiple regression models analyzed language while controlling for possible confounders. Results: Five subjects had symptomatic cytomegalovirus, and four subjects had CHARGE syndrome with hearing loss etiology. Seventy-five percent had cognitive deficits, and 55% had motor delays. Median age of CI was 24 months; median CI duration was 27.7 months. The range of NVCQs for the study cohort was 27 to 115. Fifteen subjects had NVCQs <80. Age at implantation, income, and number of siblings were not correlated with language. Although children had significant increases in language age pre- to post-CI, median LQs did not significantly change after implantation. NVCQ, age at hearing loss diagnosis, implant duration, and number of different therapies attended were significant in models. NVCQ contributed the most unique variance (67%; P = .0003). Pre-CI language performance did not predict post-CI performance. Conclusions: This study is the first step in addressing the effects of CIs on language among children with disabilities. Progress in language skills occurred for all participants, although rates of progress were slow and highly variable. NVCQ was the strongest predictor of language, although cognition is not always sufficient for good language development. Adapting therapeutic strategies may be essential to impact greater language progress in these complex children. Laryngoscope, 2010
On multi-spectral quantitative photoacoustic tomography in diffusive regime

The objective of quantitative photoacoustic tomography (qPAT) is to reconstruct the diffusion, absorption and Gruneisen thermodynamic coefficients of heterogeneous media from knowledge of the interior absorbed radiation. It has been shown in Bal and Ren (2011 Inverse Problems 27 075003), based on diffusion theory, that with data acquired at one given wavelength, all three coefficients cannot be reconstructed uniquely. In this work, we study the multi-spectral qPAT problem and show that when multiple wavelength data are available, all coefficients can be reconstructed simultaneously under minor prior assumptions. Moreover, the reconstructions are shown to be very stable. We present some numerical simulations that support the theoretical results.
A comparative computational study of the homolytic and heterolytic bond dissociation energies involved in the activation step of ATRP and SET‐LRP of vinyl monomers

A quantum-chemical calculation of the homolytic and heterolytic bond dissociation energies of the model compounds of the monomer and dimer is reported. These model compounds include the dormant chloride, bromide, and iodide species for representative activated and nonactivated monomers containing electron-withdrawing groups as well as for a nonactivated monomer containing an electron-donor group. Two examples of sulfonyl and N-halide initiators are also reported. The homolytic inner-sphere electron-transfer bond dissociation is known as atom transfer and is responsible for the activation step in ATRP. The heterolytic outer sphere single electron transfer bond dissociation is responsible for the activation step in single electron transfer mediated living radical polymerization (SET-LRP). The results of this study demonstrated much lower bond dissociation energies for the outer sphere single electron transfer processes. These results explain the higher rate constant of activation, the higher apparent rate constant of propagation, and the lower polymerization temperature for both activated and nonactivated monomers containing electron-withdrawing groups in SET-LRP.
A broadband standing wave RF interferometer for fast and low-cost spectral analysis

A new type of spectrum analyzer (SWIFTS) based on RF interferometry using a low-cost microstrip technology is presented. The acronym SWIFTS was chosen for Stationary Waves Integrated Fourier Transform Spectrometer. The SWIFTS enables both broadband and fast measurements. It consists of a waveguide ended by a short circuit. Power detectors are periodically spaced along the standing wave to sample the signal. The spectrum is obtained with a Fourier transform calculation. A 0.3–5 GHz prototype was built to validate the concept. Measurements on a real cellular phone are presented and discussed.
Frequency-Dependent Viscoelastic Parameters of Mouse Brain Tissue Estimated by MR Elastography

Viscoelastic properties of mouse brain tissue were estimated non-invasively, in vivo, using magnetic resonance elastography (MRE) at 4.7 T to measure the dispersive properties of induced shear waves. Key features of this study include (i) the development and application of a novel MR-compatible actuation system which transmits vibratory motion into the brain through an incisor bar, and (ii) the investigation of the mechanical properties of brain tissue over a 1200 Hz bandwidth from 600-1800 Hz. Displacement fields due to propagating shear waves were measured during continuous, harmonic excitation of the skull. This protocol enabled characterization of the true steady-state patterns of shear wave propagation. Analysis of displacement fields obtained at different frequencies indicates that the viscoelastic properties of mouse brain tissue depend strongly on frequency. The average storage modulus (G') increased from approximately 1.6 to 8 kPa over this range; average loss modulus (G″) increased from approximately 1 to 3 kPa. Both moduli were well approximated by a power-law relationship over this frequency range. MRE may be a valuable addition to studies of disease in murine models, and to pre-clinical evaluations of therapies. Quantitative measurements of the viscoelastic parameters of brain tissue at high frequencies are also valuable for modeling and simulation of traumatic brain injury.
Abnormal Methyl Metabolism in Pancreatic Toxicity and Diabetes

Several experimental studies suggest that disturbed methylation can influence cellular differentiation in the pancreas and contribute to toxic injury in ways that enhance the pathogenesis of pancreatitis and carcinogenesis. In vitro development of fetal rat pancreas requires a basal level of methionine, but full differentiation requires a higher methionine level. Involvement of methylation in normal differentiation is supported by reports of development of hepatocyte-like cells in the pancreas of rats fed a choline-deficient diet. The administration of ethionine by feeding to mice in a choline-sufficient diet caused a lower incidence of acute hemorrhagic pancreatitis than in mice given a choline-deficient diet. Feeding or injections of ethionine in choline-sufficient diets induces low grade pancreatitis and pancreatic atrophy in rats. In the N-nitrosobis(2-oxopropyl)amine-induced model of ductal adenocarcinoma in hamsters, the latent period for induction of carcinomas has been dramatically reduced by the intermittent feeding of a choline-deficient diet combined with ethionine treatment. A recent epidemiologic study in smokers indicates that the risk of pancreatic carcinoma is inverse to serum levels of folate. These studies suggest that compromised methyl metabolism might be associated with pancreatic cancer risk in humans. Finally, it has recently been demonstrated that serum homocysteine and erythrocyte S-adenosylhomocysteine levels are elevated, and erythrocyte S-adenosylmethionine content is reduced in patients with diabetes mellitus and renal failure, likely reflecting disturbed methylation pathways. The latter may contribute to the pathogenesis of complicating lesions in diabetes. These studies suggest that disturbed methyl metabolism may contribute to the pathogenesis of several pancreatic diseases.
Cultural Convergence, Divergence, and Crossvergence

In this monograph, I summarize three theories providing different viewpoints of how attitudes, behaviors, and values of individuals in organizations across cultures change over time. Convergence theory states that the common logic of industrialism has made individuals embrace values, attitudes and behaviors similar to those common in industrialized, capitalist Western countries. The divergence theory suggests that the interpersonal aspects of management will diverge and that individuals from a society will retain their specific value systems, attitudes, and behaviors through time. Lastly, crossvergence theory advocates that the dynamic interaction of sociocultural influences and business ideology can lead to the emergence of a unique value system that is different from the parent cultures and can take form of conforming crossvergence, static crossvergence, or deviating crossvergence. Keywords: convergence; crossvergence; culture; divergence; values
Social Diversity and Economic Development in the Metropolis

Theories of regional economic development are increasingly focused on understanding the reasons for metropolitan economic growth. The “creative capital” perspective argues that such growth is extre...
A pilot study of emollient therapy for the primary prevention of atopic dermatitis

Background Prevention strategies in atopic dermatitis (AD) using allergen avoidance have not been consistently effective. New research reveals the importance of the skin barrier in the development of AD and possibly food allergy and asthma. Correcting skin barrier defects from birth may prevent AD onset or moderate disease severity. Objective We sought to determine the feasibility of skin barrier protection as a novel AD prevention strategy. Methods We enrolled 22 neonates at high risk for developing AD in a feasibility pilot study using emollient therapy from birth. Results No intervention-related adverse events occurred in our cohort followed up for a mean time of 547 days. Of the 20 subjects who remained in the study, 3 (15.0%) developed AD, suggesting a protective effect when compared with historical controls. Skin barrier measurements remained within ranges seen in normal-appearing skin. Limitations No conclusions regarding efficacy can be made without a control group. Conclusions Skin barrier repair from birth represents a novel and feasible approach to AD prevention. Further studies are warranted to determine the efficacy of this approach.
Parallel computing; one opportunity, four challenges

Integration technologies for parallel computing are discussed. Requirements imposed by the need to properly interconnect large numbers of processing elements are emphasized. Four topics discussed as cornerstones in the field of parallel computing are programmability, communication network design, reliable operation, and performance evaluation and benchmarking. >
Formation of the first oxidized iron in the solar system

– For fayalite formation times of several thousand years, and systems enriched in water by a factor of ten relative to solar composition, 1 μm radius olivine grains could reach 2 mole% fayalite and 0.1 μm grains 5 mole% by nebular condensation, well short of the values appropriate for precursors of most chondrules and the values found in the matrices of unequilibrated ordinary chondrites. Even 10 μm olivine crystals could reach 30 mole% fayalite above 1100 K in solar gas if condensation of metallic nickel-iron were delayed sufficiently by supersaturation. Consideration of the surface tensions of several phases with equilibrium condensation temperatures above that of metallic iron shows that, even if they were supersaturated, they would still nucleate homogeneously above the equilibrium condensation temperature of metallic iron. This phenomenon would have provided nuclei for heterogeneous nucleation of metallic nickel-iron, thus preventing the latter from supersaturating significantly and preventing olivine from becoming fayalitic. Unless a way is found to make nebular regions far more oxidizing than in existing models, it is unlikely that chondrule precursors or the matrix olivine grains of unequilibrated ordinary chondrites obtained their fayalite contents by condensation processes. Perhaps stabilization of FeO occurred after condensation of water ice and accretion of icy planetesimals, during heating of the planetesimals and/or in hot, dense, water-rich vapor plumes generated by impacts on them. This would imply that FeO is a relatively young feature of nebular materials.
Factors Influencing the Aging of Rigid Polyurethane Foam

The aging of rigid polyurethane insulation foam is discussed in terms of the basic phenomena involved. Calculated aging curves are presented to illustrate the significance of the FC-11, N2, and O2 diffusion coefficients and initial fluorocarbon pressure on aging behavior. Experimental data are given showing the wide range of aging behavior found with commercial foams, and possible improvements in retarding aging are indicated.
Optical demonstration on Honeywell FLASH program

Flight critical system architects are increasingly integrating aircraft control and management functionality. This functional integration increases performance and cost of ownership requirements on the communication pathways. Optical signal transmission is an attractive approach to satisfying these system requirements. Investigations and demonstrations of optical signaling are needed to validate applicability of fiber based communication systems to the new system architecture performance and cost requirements. Honeywell's activities associated with the Fly-By-Light Advanced System Hardware (FLASH) program have produced a system including key optical interface elements and accomplished preliminary demonstrations needed to validate flexible, optical based aircraft control and avionic systems. The Honeywell Primary Flight Control System (PFCS) included Active Hand Controllers (AHCs), Primary Flight Control Computers (PFCCs) and smart actuation subsystem elements interfaced through various optical implementations and communication protocols. These successful implementations and demonstrations provide an excellent baseline for the processes, tools and materials required to make Fly-by-Light avionic systems marketable.