cssi/SciSciGPT-SciSciNet huggingface dataset:
Exponential supermartingales for evaluating end-to-end backlog bounds

A common problem arising in network performance analysis with the stochastic network calculus is the evaluation of (min, +) convolutions. This paper presents a method to solve this problem by applying a maximal inequality to a suitable constructed supermartingale. For a network with D/M input, end-to-end backlog bounds obtained with this method improve existing results at low utilizations. For the same network, it is shown that at utilizations smaller than a certain threshold, fluid-flow models may lead to inaccurate approximations of packetized models.
Correspondence principles: the relationship between classical trajectories and quantum spectral

The general correspondence principle specifies a relationship between wave functions and families of trajectories. For bounded systems with regular trajectories, this general correspondence principle leads to the principle of quantization of action. The general principle also leads to a correspondence principle for finite-resolution spectra: oscillation in the average density of states, or in the average oscillator strength as a function of energy, are connected to periodic or to closed orbits. This principle holds independently or whether classical trajectories are orderly or chaotic. >
Modeling nonlinear optical mixing processes in droplets

We have recently modeled third-order sum-frequency generation (TSFG) in droplets. The basic approach is similar to the model developed by Cooney and Gross for coherent anti- Stokes Raman scattering (CARS) from droplets. In this model, three generating waves interact to generate a third-order nonlinear polarization, which then radiates inside the sphere as described by the model of H. Chew et al. The intensity of the output waves at the sum frequency is proportional to the spatial overlap (amplitude and phase) of the nonlinear polarization with the output resonance of the droplet cavity mode, and to the integral of the products of the frequency dependence of the nonlinear polarization and the output resonance mode. Here we review our approach to modeling TSFG in droplets, discuss second-order sum frequency generation (SSFG) and CARS in droplets, stressing the similarities and differences among TSFG, SSFG, and CARS in droplets, and discuss the possible application of these mixing processes for fuel droplet characterization. We not that TSFG and SSFG from droplets are too weak to be useful for fuel droplet characterization, but that CARS is readily detectable from droplets and may be useful for determining the concentrations of chemical species in fuel droplets.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
The Future of Astronomy in Space

This talk will address a science-driven technology roadmap for space optical astronomy in the coming decades including a 2005 Advanced Telescopes and Observatories NASA roadmap and more recent progress in this area.
Coronins: the return of the crown

Coronins are highly conserved regulators of the actin cytoskeleton whose structure and biological function have remained mysterious until recently. They were originally identified in Dictyostelium, where they localize to actin-rich crown-like structures on the dorsal surface of cells. Coronins bind filamentous actin and the Arp2/3 complex and are involved in modulating actin dynamics. Unlike other known Arp2/3-binding proteins, coronins inhibit Arp2/3 nucleating activity. Genetic data from Dictyostelium, yeast and Drosophila indicate that coronins are important regulators of several actin-dependent physiological processes. Here, we review recent insights into mammalian coronin structure, function and regulation and identify key questions that remain unanswered in this field.
Thin route tropo: A new approach to long range communications

This new system of communications makes use of tropospheric scatter for the transmission of digital information over long distances more reliably than high frequency radio; more economically than wire; less vulnerably than microwave or VHF and cheaper than conventional tropospheric scatter systems. Using only a narrow-band width, it can be used for transmission of data (teletype, telemetry, canned messages, facimile, etc.) over distances of upwards to 500 miles, using relatively low power transmitters and simple antenna systems. It will provide a useful link in the radio communication systems for many government agencies, both military and non-defense. While limited to these under the present regulations, it has potential for use for commercial applications in the future.
Investigation of Protein/Lipid Interactions via Scanning Probe Acceleration Microscopy: Theory and Experiment

There is great interest in the application of proximal probe techniques to simultaneously image and measure mechancial properties of surfaces with nanoscale spatial resolution. There have been several innovations in generating time-resolved force interaction between the tip and surface while acquiring a tapping mode AFM image. These tip/sample forces contain information regarding mechanical properties of surfaces in an analogous fashion to a force curve experiment. Here, we demonstrate, via simulation, that the maximum and minimum tapping forces change with respect to the Young’s modulus and adhesiveness of a surface, but the roughness of the surfaces has no effect on the tapping forces. Using these changes in tapping forces, we determine the mechanical changes of a lipid membrane after exposure to a huntingtin exon1 (htt exon1) protein with an expanded polyglutamine (polyQ) domain. Expanded polyQ domains in htt is associated with Huntington’s disease, a genetic neurodegenerative disorder. The htt exon1 protein caused regions of increased surface roughness to appear in the lipid membrane, and these areas were associated with decreased elasticity and adhesion to the AFM probe.© 2012 ASME
Differential expression of genes in elastase-induced saccular aneurysms with high and low aspect ratios

BACKGROUND: Morphologic features are thought to play a critical role in the rupture of intracranial, saccular aneurysms. OBJECTIVE: The objective of this study was to investigate the gene expression pattern of saccular aneurysms with distinct morphologic patterns. METHODS: Elastase-induced saccular aneurysms with high (≥ 2.4) and low (≤ 1.6) aspect ratios (ARs) (height to neck width) were created in 15 rabbits (n = 9 for high AR and n = 6 for low AR). RNA was isolated from the aneurysms and analyzed using a microarray containing 294 rabbit genes of interest. Genes with a statistically significant difference between low and high AR (P < .05) and a fold change of ≥ 1.5 and ≤ 0.75 to represent up- and down-regulation in high AR compared with low AR were used to identify pathways for further investigation. RESULTS: Fourteen genes (4.8%) were differentially expressed in high-AR aneurysms compared with low-AR aneurysms. The expression of osteopontin, tissue inhibitor of matrix metalloproteinase, haptoglobin, cathepsin L, collagen VIII, fibronectin, galectin 3, secreted frizzled-related protein 2, CD14, decorin, and annexin I were up-regulated, whereas the expression of myosin light chain kinase, Fas antigen, and CD34 were down-regulated in high-AR aneurysms. CONCLUSION: In a rabbit model of saccular aneurysm, high AR was associated with differential expression of inflammatory/immunomodulatory genes, structural genes, genes related to proteolytic enzymes and extracellular matrix-related genes. These findings may focus efforts on targets aimed at avoiding spontaneous rupture of intracranial, saccular aneurysms.
A numerical method for two phase flow with an unstable interface

Abstract The random choice method is used to compute the oil-water interface for two dimensional porous media equations. The equations used are a pair of coupled equations: the (elliptic) pressure equation and the (hyperbolic) saturation equation. The equations do not include the dispersive capillary pressure term and the computation does not introduce numerical diffusion. The method resolves saturation discontinuities sharply. The main conclusion of this paper is that the random choice is a correct numerical procedure for this problem even in the highly fingered case. Two methods of inducing fingers are considered: deterministically, through choice of Cauchy data and heterogeneity, through maximizing the randomness of, the random choice method.
Consumer language, patient language, and thesauri: a review of the literature.

Objective: Online social networking sites are web services in which users create public or semipublic profiles and connect to build online communities, finding likeminded people through self-labeled personal attributes including ethnicity, leisure interests, political beliefs, and, increasingly, health status. Thirty-nine percent of patients in the United States identified themselves as users of social networks in a recent survey. “Tags,” user-generated descriptors functioning as labels for user-generated content, are increasingly important to social networking, and the language used by patients is thus becoming important for knowledge representation in these systems. However, patient language poses considerable challenges for health communication and networking. How have information systems traditionally incorporated these languages in their controlled vocabularies and thesauri? How do system builders know what consumers and patients say?
Investigating Marketing Students’ Perceptions of Active Learning and Social Collaboration in Blogs

Web 2.0 technology has found a niche in education. In response to students’ comfort level in using social media, many business educators have explored the use of Web 2.0 applications in courses. Research on the use of Web 2.0 tools to determine effectiveness for learning is still in its infancy. The authors describe one such experiment in which students used blogs in several courses. Application of blogs in courses, and assessment of this technology in regard to affecting learning behavior, as well as perceptions of students toward blogs were studied. Recommendations, challenges, opportunities, and strategies for use of blogs in courses are provided in this research.
Intercalary regeneration in imaginal wing disk of Drosophila melanogaster

IN this paper we show for the first time that the developmental capacity of imaginal disk cells from Drosophila can be altered by appropriate grafting operations. The appendages of amphibians and immature arthropods, and the imaginal disks of holometabolous insects, are capable of undergoing pattern regulation when parts are removed. (Pattern regulation is used here to describe the alteration of cell fates in response to an abnormal situation in a developing system; we include under this term both regeneration and duplication.) Regulation then occurs during growth of the tissue by cell division, a process termed epimorphosis1. A characteristic feature of epimorphic regulation which has recently been recognised, is the different regulative responses shown by complementary pieces. For example when an imaginal disk of Drosophila is bisected and allowed to grow for some time, one of the two fragments usually regenerates the missing parts, while the other undergoes duplication of the presumptive pattern already present2. Similarly, whereas the stump of an amputated amphibian or cockroach limb can regenerate distally, the amputated distal part, if kept alive by grafting to a host animal, can also undergo pattern regulation by forming the distal pattern elements, thereby duplicating itself3–6.
Genomic organization and expression of 23 new genes from MATα locus of Cryptococcus neoformans var. gattii

The pathogenic yeast Cryptococcus neoformans (Cn) causes cryptococcosis, a life-threatening disease of the brain. Molecular studies of Cn variety gattii have lagged behind other two varieties (var. grubii and var. neoformans) although they have distinct biology and disease patterns. We focused on gene discovery in MATalpha locus because it predominates in clinical strains. A var. gattii cosmid library was screened with DNA probes from other two varieties. Two positive clones were sequenced to identify ORFs based on similarities to known proteins, and to ESTs using bioinformatics, and manually by a curator. Approximately 76kb sequenced DNA revealed 23 genes and ORFs. The existence of predicted genes was verified by RT-PCR analyses designed to amplify spliced sequences. The results confirmed that the transcripts were expressed both at 30 and 37 degrees C. The var. gattii MATalpha locus genes showed rearrangements in order and orientation vis-a-vis other two varieties. Mating-specific genes showed higher nonsynonymous mutation rates, and gene trees showed var. gattii strains in a distinct clade. The identification of the largest number, thus far, of var. gattii structural genes should set the stage for future molecular pathogenesis studies.
On the use of asymptotic approximations of Green's type when the coefficient has zeros

Allowance is made for the error terms in the cases where χ has a simple zero at x = 0, or two simple zeros at a; = ± 1 (with χ either positive or negative for − 1 x
Nonvolatile components produced in triolein during deep-fat frying

Triolein was heated at 190°C (375°F) in a deep-fat fryer for 12 h/day until high-performance size-exclusion chromatography indicated polymer formation had exceeded 20%. Increases in the free fatty acid, total acid value, food oil sensor andp-anisidine values upon heating indicated that thermal oxidation and degradation of triolein had occurred. After the initial sample (day 0), the peroxide values decreased to very low values. The amount of polymeric triacylglycerol material increased during heating. Linear regression analysis of percent polymer vs. heating time indicated that the sample would contain ≥20% polymers after 51.1 h of heating. Capillary supercritical fluid chromatography (SFC) was used to determine the percentage of triolein remaining after 12, 24, 36, 48 and 60 h of heating, which was 68.6, 53.9, 35.9, 33.0 and 19.0%, respectively. The average reaction rate constant (apparent first-order) for the change in triolein concentration, SFC, during heating was 0.0256±0.0011 h−1.
Imagining the near and far future: The role of location familiarity

Plausible personal events envisioned as occurring in the near future tend to be reported as more vivid than those set in the far future. Why is this? The present set of three experiments identified one’s familiarity with the location in which the event is placed as critical in this regard. Specifically, Experiment 1 demonstrated that amongst a wide range of phenomenological characteristics, clarity of location appears to drive the overall difference in vividness between events imagined to take place in the near and the far future. Experiments 2 and 3 were designed to further elucidate this finding. Experiment 2 demonstrated that near future events are more likely than far future events to be imagined in familiar locations. Experiment 3 showed that future events set in familiar locations tend to be imagined with greater clarity than those set in unfamiliar locations. The results of all three experiments converge on the conclusion that the difference in vividness of events imagined as occurring in the near and far future is mediated by one’s familiarity with the location in which the event is imagined to occur.
A fracture mechanics-based model for assessing the mechanical failure of nuclear fuel rods due to rock fall

Abstract One of the potential failure mechanisms of nuclear fuel rods that will be disposed in the proposed Yucca Mountain repository is mechanical failure of the degraded cladding tubes caused by rock fall impacting on waste packages. In this paper, the development of a fracture mechanics-based model for treating rock fall-induced failure of nuclear fuel cladding tubes is described. The rock fall model has been developed by treating the forces acting on the fuel-rod cladding due to an impacting rock in terms of either a point or distributed load. The stress intensity factors of cracks in the cladding rods assembled in a 17×17 array are analyzed by performing appropriate elastic bending analyses. The critical stress at the onset of cladding failure is predicted on the basis of a fracture criterion that is applicable for both large and small cracks. The proposed model is used to assess the critical size and weight of rock fall required to cause cladding failure as a function of the impact location, loading condition, and the geometry of rock fall, as well as the initial defect size, hydrogen content, and fracture toughness of the cladding at the time of rock fall. The result indicates that the critical rock radii for cladding failure are well within the size range of potential rock falls estimated based on the joint spacings of rocks at the repository site. These theoretical predictions remain to be verified by laboratory and field data.
Cross-layer resource allocation for wireless distributed computing networks

The allocation of communication power consumption and computing rate is inherently one of the cross-layer problems in wireless distributed computing networks (WDCNs). This paper exploits a subgradient approach to choose the optimal power-rate pair for maximizing the network computing capability and minimizing the power consumption. The impact of heterogeneous channel conditions for different nodes are modeled as a penalty term in the objective function to balance the performance and power consumption, and increase the amount of the power for the computing task. Simulation results show that both energy efficiency and the distributed computing power ratio (DCPR) can be increased by considering the wireless channel conditions. These results provide some guidelines for designing the protocol dedicated to WDCNs.
Cation and Anion Transport in a Dicationic Imidazolium-Based Plastic Crystal Ion Conductor

Here we investigate the organic ionic plastic crystal 1,2- bis(N-(N'-hexylimidazolium-d2(4,5)))ethane 2PF6 − in one of its solid plastic crystal phases by means of multinuclear solid-state (SS) NMR and pulsed-field-gradient NMR diffusometry. We quantify distinct cation and anion diffusion coefficients as well as the Arrhenius diffusion activation energies (Ea) in this dicationic imidazolium-based plastic crystal. Our studies suggest a change in transport mechanism for the cation upon varying thermal and magnetic treatment (9.4 T), evidenced by differences in cation and anion Ea. Moreover, variable temperature 2 H SSNMR line shapes support a change in local molecular environment upon slow cooling in B0. We quantify the percentage of mobile anions as a function of temperature with 19 F SSNMR, wherein two distinct spectral features are present. We also comment on the Arrhenius pre-exponential factor for diffusion (D0), giving insight into the number of degrees of freedom for transport for both cation and anion as a function of thermal treatment. Given the breadth and depth of our measurements, we propose that bulk ion transport is dominated by anion diffusion in ionic-liquid-like domain boundaries separating crystallites. This study elucidates fundamental properties of this plastic crystal, and allows for a more general and deeper understanding of ion transport within such materials.
Thermal expansion of metal-matrix composites

Abstract The thermal expansion of various fiber- and particle-reinforced metal-matrix composites has been measured and the experimentally obtained values compared with the predictions of various theoretical models. The particulate composites exhibited some residual strain when cooled down from the peak temperature to room temperature. The magnitude of this strain was a function of the peak temperature and number of thermal cycles. The thermal expansion response of the fiber-reinforced composites was significantly different from that of the particulate composites. These composites exhibited very small residual strains when cooled down from the peak temperature to room temperature. In addition, the thermal expansion response was not linear over the test temperature range but exhibited regions of distinctly different slopes. The observed behavior of these particulate and fibrous composites is described on the basis of the thermal stresses developed in such composites as a result of the differences in the coefficient of thermal expansion between the reinforcement and the matrix.
Dynamic Mechanical Analysis and Dielectric Relaxation for Second Order Nonlinear Optical Applications

Relaxation dynamics of poly(methyl methacrylate) (PMMA) and doped PMMA systems are investigated as a function of processing temperature and frequency. Polymer relaxations and changes in local mobility are responsible for chromophore reorientation and lead to a loss in second-order nonlinear optical (NLO) properties. Studying polymer relaxations enables the temporal and thermal stability of the NLO polymer systems to be more accurately and readily predicted. The polymer dynamics are studied by correlating mechanical and dielectric relaxations to polymer and chromophore relaxations that occur during chromophore reorientation in second harmonic generation experiments. Dielectric and mechanical relaxation techniques enable polymer relaxation dynamics to be observed over a broad frequency range. The plasticization effect of the NLO chromophores on the polymer relaxation dynamics is also investigated.
A method to determine 18O kinetic isotope effects in the hydrolysis of nucleotide triphosphates

A method to determine 18O kinetic isotope effects (KIEs) in the hydrolysis of GTP that is generally applicable to reactions involving other nucleotide triphosphates is described. Internal competition, where the substrate of the reaction is a mixture of 18O-labeled and unlabeled nucleotides, is employed, and the change in relative abundance of the two species in the course of the reaction is used to calculate KIE. The nucleotide labeled with 18O at sites of mechanistic interest also contains 13C at all carbon positions, whereas the 16O-labeled nucleotide is depleted of 13C. The relative abundance of the labeled and unlabeled substrates or products is reflected in the carbon isotope ratio (13C/12C) in GTP or GDP, which is determined by the use of a liquid chromatography-coupled isotope ratio mass spectrometer (LC-coupled IRMS). The LC is coupled to the IRMS by an Isolink interface. Carbon isotope ratios can be determined with accuracy and precision greater than 0.04% and are consistent over an order of magnitude in sample amount. KIE values for Ras/NF1333-catalyzed hydrolysis of [β18O3,13C]GTP were determined by change in the isotope ratio of GTP or GDP or the ratio of the isotope ratio of GDP to that of GTP. KIE values computed in the three ways agree within 0.1%, although the method using the ratio of isotope ratios of GDP and GTP gives superior precision (<0.1%). A single KIE measurement can be conducted in 25 min with less than 5 μg nucleotide reaction product.
Predisposition and Nonpreference of Greenbug for Certain Host Cultivars

The cultivars “Reno” barley, Hordeum vulgare L.; “Arkwin” oats, Avena sativa L.; “Balbo” rye, Secale cereale L.; and “Ponca” wheat, Triticum aestivum L., which served for culturing greenbugs, Schizaphis graminum (Rondani) (biotype C) prior to testing did not predispose the greenbugs to different preferences for cultivar host species. However, greenbugs reared on “RS 671” sorghum, Sorghum bicolor (L.) Moench, showed a definite preference for sorghum compared with greenbugs cultured on oats, rye and wheat. Overall rye was least preferred and barley most preferred. The culture host cultivar did not influence days to reproduction or nymphs produced per day, but the host on which the greenbug was living had a decided influence on these factors. Nonpreference for resistant “KS 30” sorghum vs. susceptible “RS 671” sorghum was not influenced by the host cultivar on which the greenbug was cultured but decreased with a decrease in temperature.
Using Case Studies in Supervision: No Simple Stories

(1994). Using Case Studies in Supervision: No Simple Stories. Teaching Education: Vol. 6, No. 1, pp. 133-141.
Aphasia in Hebrew speakers

Abstract This paper presents a review of studies reporting aphasia and related language deficits in Hebrew speakers First, a brief introduction to the main characteristics of Hebrew is provided. Then, studies that address Hebrew features are described, presented based on the language deficits at their focus. The contribution of each study is reviewed, specific participant and lesion information is included when available, as are specific examples of the impaired language skills. A summary of the characteristics of aphasia in Hebrew is then provided.
Private equity and corporate governance in India

Purpose – Developing economies that are subject to global influences, such as through exposure to global product, labor and capital markets, may be expected to practice higher standards of corporate governance (CG) than less globalized developing economies. This paper seeks to understand the relationship between CG and firm ownership by private equity investors in India, and to understand whether CG practices in particular national institutional contexts change when the firm is exposed to investors with a background in other countries' institutional contexts. Taking India as a test case, the paper aims to explore how CG standards are affected by private equity investment that originates from developed countries.Design/methodology/approach – A primary survey on Indian firms' CG practices for firms that receive private equity and for comparable firms that do not was used to determine differences in CG. Private equity investors were surveyed to determine their national institutional contexts. The CG practice...
Inter-Model Comparison of the Landscape Determinants of Vector-Borne Disease: Implications for Epidemiological and Entomological Risk Modeling

Extrapolating landscape regression models for use in assessing vector-borne disease risk and other applications requires thoughtful evaluation of fundamental model choice issues. To examine implications of such choices, an analysis was conducted to explore the extent to which disparate landscape models agree in their epidemiological and entomological risk predictions when extrapolated to new regions. Agreement between six literature-drawn landscape models was examined by comparing predicted county-level distributions of either Lyme disease or Ixodes scapularis vector using Spearman ranked correlation. AUC analyses and multinomial logistic regression were used to assess the ability of these extrapolated landscape models to predict observed national data. Three models based on measures of vegetation, habitat patch characteristics, and herbaceous landcover emerged as effective predictors of observed disease and vector distribution. An ensemble model containing these three models improved precision and predictive ability over individual models. A priori assessment of qualitative model characteristics effectively identified models that subsequently emerged as better predictors in quantitative analysis. Both a methodology for quantitative model comparison and a checklist for qualitative assessment of candidate models for extrapolation are provided; both tools aim to improve collaboration between those producing models and those interested in applying them to new areas and research questions.
Separator reconnection at Earth's dayside magnetopause under generic northward interplanetary magnetic field conditions

[1] We investigate the global properties of magnetic reconnection at the dayside terrestrial magnetopause under generic northward interplanetary magnetic field (IMF) conditions. In particular, we consider a zero dipole tilt case where the y and z components of the IMF (in GSM coordinates) are equal in magnitude, using three-dimensional resistive magnetohydrodynamics (MHD) simulations to address the following questions: (1) What is the geometry of the dayside X line? (2) How is current density distributed over the magnetopause surface? Using a technique described by Geene (1992) to track the magnetic nulls in the system, we identify the dayside X line as a magnetic separator line, a segment of a magnetic field line which extends across the dayside magnetopause, terminating in the cusps. We demonstrate that the separator line is the intersection of two separatrix surfaces which define volumes containing topologically distinct field lines. Parallel current density, proportional to the parallel electric field in our resistive MHD simulations, is distributed in a broad, thin sheet which extends across the separator line and terminates in the cusps. Thus separator reconnection at the dayside magnetopause displays features of both antiparallel (near the cusp nulls) and component (near the subsolar separator line) reconnection. We discuss some implications of our results for spacecraft observations of reconnection signatures.
Mitochondrial associations with specific components of the cortex of Tetrahymena thermophila Nanney & McCoy, 1976: microtubules and the epiplasm

Ultrastructural observations of the cortically-located mitochondria of Tetrahymena thermophila revealed associations not only between the mitochondria and certain of the cortical microtubule bands, but also between the mitochondria and the epiplasm of the cortex. Most of the distal mitochondrial surface is close and parallel to the epiplasm; favorable views show bridge-like structures spanning the 20–10 nm gap between the mitochondrion and the epiplasm. Previous studies have shown that the placement of mitochondria in the cortex appears to be determined by certain of the cortical microtubule bands. This study, however, shows that mitochondrion-microtubule interactions account for only a small proportion of the total mitochondrial area associated with the cortex; the rest is accounted for by the epiplasm. A possible analogue of the spectrin layer of erythrocyte membranes, the epiplasm may be important in helping to arrange the intricately organized components of the ciliate cortex. Its involvement in apparently helping to “moor” mitochondria to their cortical sites is the first suggestion of any role in cell patterning played by the epiplasm.
The choroid plexus and the paradox of interferons in the aging brain.

The choroid plexus (CP) function is largely viewed as the source of cerebrospinal fluid (CSF) and as a barrier between the blood and the CSF. Other functions of the CP are becoming increasingly recognized as in the recent publication by Baruch et. al. who demonstrate increased expression of interferon type I mRNA signature (irf7, ifns and ifit1) in CP of aged brains compared to younger brains, whereas interferon type II dependent genes (icam1, cxcl10, and ccl17) are reduced in the aging CP. The authors speculate an IFN-dependent mechanism that plays a role in the aging process and cognitive decline. This short communication summarizes the findings by the authors and highlights the seemingly paradoxical roles of IFN type I and type II in neuroinflammation.
A numerical mixing zone model for water quality assessment in natural streams: Conceptual development

Abstract A mixing zone is an area of a water body contiguous to wastewater disposal site in which the water quality does not comply with the water quality standards. The zone has been considered as one of the water quality characteristics for the protection of indigenous aquatic biota and regulated by the in-zone quality and the volumetric configuration. This paper presents the conceptual development of a numerical model which can predict the in-zone quality and volumetric configuration in natural streams. The model is based on the transformed advection-dispersion equation where transverse distance is replaced by dimensionless cumulative discharge.
Engineering Persistence: Past, Present, and Future Factors and Gender Differences.

This research examined past, present, and future factors that might be related to persistence in engineering for women and men. Students currently or formerly enrolled in an undergraduate engineering program completed the Engineering Carrer Survey which assessed factors included in general models of college student change (e.g., background characteristics, interactions with socializing agents). Results indicated that: (1) present factors were more important than past or future factors in distinguishing between engineering persisters and nonpersisters, (2) few factors distinguished between women and men who persisted, or between women and men who did not, and (3) the best predictor of engineering persistence for both sexes was grade point average, although subsequent predictors depended on gender. Limitations and implications for future research are discussed.
Phosphorylation of paxillin by p38MAPK is involved in the neurite extension of PC-12 cells

Cell adhesions play an important role in neurite extension. Paxillin, a focal adhesion adaptor protein involved in focal adhesion dynamics, has been demonstrated to be required for neurite outgrowth. However, the molecular mechanism by which paxillin regulates neurite outgrowth is unknown. Here, we show that paxillin is phosphorylated by p38MAPK in vitro and in nerve growth factor (NGF)–induced PC-12 cells. Ser 85 (Ser 83 for endogenous paxillin) is identified as one of major phosphorylation sites by phosphopeptide mapping and mass spectrometry. Moreover, expression of the Ser 85 → Ala mutant of paxillin (paxS85A) significantly inhibits NGF-induced neurite extension of PC-12 cells, whereas expression of wild-type (wt) paxillin does not influence neurite outgrowth. Further experiments indicate that cells expressing paxS85A exhibit small, clustered focal adhesions which are not normally seen in cells expressing wt paxillin. Although wt paxillin and paxS85A have the same ability to bind vinculin and focal adhesion kinase, wt paxillin more efficiently associates with Pyk2 than paxS85A. Thus, phosphorylation of paxillin is involved in NGF-induced neurite extension of PC-12 cells, probably through regulating focal adhesion organization.
Charge-coupled-device analogue matched filters

Charge-coupled-device shift registers are used to construct filters matched to both a 13-chip Barker-coded p-n sequence and a chirp signal with a time-bandwidth product of 10. The letter describes the design and fabrication of the devices, and presents preliminary operational characteristics of the filters. A 5 MHz chip rate for the Barker code filter is demonstrated
New angle on myosin

Motion and force in biological systems are produced by motor proteins, which reach out from one set of filaments or organelles and translate these relative to a second set of filaments. These motor proteins take the chemical energy of ATP and convert it into mechanical energy. The laws of physics dictate that the production of mechanical energy must involve the exertion of a force through a displacement. Recent work has shown that forces are of the order of 5–10 pN and displacements are between 5–10 nm (1, 2). Basically, there are two simple ways in which a motor protein could produce a force through a distance. In one model the motor protein could produce relative translation by attaching to one of the filaments followed by a shortening of some element, most likely the element tethering it to the first set of filaments, thereby effecting a translation. In the second model the motor protein could attach to the second set of filaments and then undergo a rotation, thus acting as a “rowing oar” propelling one set of filaments past the other. Studies of both the structure and function of myosin have suggested that it functions by the second of the two above hypotheses. Electron microscopy showed that myosin could assume different orientations in the filament lattice of the muscle, a conclusion that was supported by x-ray diffraction patterns (3, 4). In addition, it was shown that the head region of myosin interacting with actin could generate force and displacement, eliminating any structural element that could reasonably shorten (5). Thus the current paradigm for explaining the action of myosin is that at least a portion of the myosin head must rotate during the power stroke. The goal of the field for many years has been to identify which portions rotate …
Gas sensors for improved air quality in transportation

There is increasing concern about the quality of the air breathed by passengers in the cabins of various different forms of transport. In the case of motor vehicles, the concentration of air pollutants in passenger cabins, particularly in the urban environment, is significantly higher (by two to three times) than the nominal value outside the cabin. Aircraft draw in fresh air from outside the cabin. On the ground the same concentration mechanism as motor vehicles applies. At altitude the major problem is the relatively high concentration of ozone. In cruise liners the problem is analogous to large hotels and casinos: efficient air‐conditioning requires re‐circulation of the air and pollutant concentrations build up over time. Strategies are being developed to mitigate these effects, and for optimal operation most require the use of low cost gas sensors for monitoring and/or control. This article describes what can be achieved with mixed‐metal oxide semiconductor gas sensors.
Multimerization of Surfactant Protein D, but Not Its Collagen Domain, Is Required for Antiviral and Opsonic Activities Related to Influenza Virus

Surfactant protein D (SP-D) plays important roles in the initial innate defense against influenza A virus (IAV). The collagen domain of SP-D is probably critical for its homeostatic functions in vivo and has been implicated in the modulation of macrophage responses to SP-D-ligand complexes. For the current studies, we used a panel of rat SP-D mutants lacking all or part of the collagen domain to more specifically evaluate the contributions of this domain to viral interactions. SP-D multimers lacking the collagenous sequence efficiently neutralized Phil82 IAV, promoted neutrophil uptake of IAV, and also potentiated the IAV-induced neutrophil respiratory burst response. A dodecameric mutant with shortened collagenous arms showed enhanced viral aggregation and neuraminidase inhibition, and an increased capacity to inhibit a partially collectin-resistant strain of IAV. By contrast, truncated molecules lacking an N-terminal and collagen domain showed no detectable antiviral and opsonizing activity, despite preservation of lectin activity and detectable viral binding. Thus, multimerization, which is mediated by the N-peptide, is more important than the collagen domain for efficient viral neutralization and opsonization. However, the structure of the collagen domain significantly influences the anti-viral activity of multimerized forms of SP-D.
Shapes, surfaces and saccades

Saccadic localization of spatially extended objects requires the computation of a single saccadic landing position. What representation of the target guides saccades? Saccades were examined for various targets composed of dots to determine whether landing position corresponded to the center-of-gravity (average location) of the dots, the center-of-area of the shape, or the symmetric axis. Targets were composed of dots configured as outline drawings of circles, ellipses, cardioids, wiggly lines, or amorphous blobs. In some cases, dot spacing was varied, extraneous dot clusters were superimposed, or different distributions of dots inside the boundary were added. Quasi-random dot clusters without a well-defined contour were also studied. Instructions were to look at the target as a whole, and keep latency long enough to avoid compromising accuracy. Saccades landed with a high level of precision (S.D.s 7-10% of target eccentricity) near the center-of-area of the target shape, rather than at the center-of-gravity of the dots or on the symmetric axis. Landing position was unaffected by the spacing of dots along the boundary, the addition of dots within the boundary, or the addition of the extraneous dot clusters. When the target was a cluster of quasi-random dots, saccades landed closer to the center-of-area of the implied surface than to the average location of the dots. Overall, the positions of individual dots were important only insofar as the dots affected overall target shape. The results show that a representation of target shape guides saccades, rather than a more primitive representation of individual elements within the attended region.
An isoelectric focusing study of seasonal variation in rattlesnake venom proteins

Adult specimens of seven southern Pacific rattlesnakes (Crotalus viridis helleri), four northern black-tailed rattlesnakes (Crotalus molossus molossus), and six western diamondback rattlesnakes (Crotalus atrox) were housed under controlled light and temperature and milked of venom monthly for 20 months. Ambient conditions were modelled to simulate seasonal change. Weighed amounts of lyophilized venom from each snake were compared chronologically for variation in isoelectric focusing patterns, using natural and immobilized gradients. No variation in patterns was evident over this time period for any individual snake. However, intraspecific differences were obvious in the venom samples. The pattern seems indicative of a species, however, concentration of various protein constituents seems individual and genetically "fingerprinted'. Unlike other physiological functions that demonstrate cyclicity in response to temperature and photoperiod, concentration ratios of venom components appear to be constant regardless of external cues. These findings may further emphasize the medical importance of treating snakebite victims symptomatically as individuals. A variation exists in the components of venoms of any given species, as well as in the physiological sensitivities of humans to a venom.
Fracture Criterion for Notched Thin Composite Laminates

Fracture behavior of fiber-dominated center-notched AS4/3501-6 graphite-epoxy laminates is investigated in this study. Nine laminate configurations are studied to examine flaw size effects, crack tip damage mechanisms, and failure modes under uniaxial tensile loading. Results indicate that a constant value of fracture toughness K Q is a laminate material property. A layup independent failure criterion is proposed, which relates laminate fracture toughness to the fracture toughness K Q 0 of the principal load bearing ply. K Q 0 characterizes the in situ fracture toughness of a notched 0-deg layer in the event of fiber breakage along the plane of the notch. Once its value is estimated from preliminary tests, this parameter can be used to predict fracture toughness, and hence residual strength, of other fiber-dominated laminates of the same material system. The model predictions agree well with current experimental results, as well as with data published by other researchers. The model is further extended to predict residual strength of laminates with inclined cracks (mixed-mode loading). It is demonstrated that the normal projection of the crack to the applied load can be considered as the equivalent crack and governs laminate residual strength.
A realm of caveat emptor

Consumerism has progressed rapidly in some areas, not at all in others. The struggle to have products accurately and openly labeled as to price, quantity, and quality, continues to be urged on many fronts. Strategies pursued include consumer education, as well as surveillance of provider of goods and services. An exceedingly costly product consumed each year by various private and public employers is the college graduate. A premium price must be paid to fill vacancies with college graduates, but it is virtually impossible to obtain reliable information about skills and qualities of available graduates. Probably no group is deceived more often regarding the qualities of a product than those who must hire on the basis of degrees and transcripts provided by our colleges and universities. In this market the buyer must surely beware. Honest labeling regarding the achievements of the student to whom a degree has been granted is virtually unknown. The acquisition of a bachelor's degree carries nothing in the way of assurance regarding a minimum level of knowledge or intellectual skills. Likewise, the listing of a course on a student's transcript guarantees the employer nothing concerning the student's competence in the subject. In this realm the consumer is not assured "satisfaction guaranteed, or your money back." One can anticipate objections to the viewpoint that college graduates are "products" created or refined for employers. Although obviously all concerned fondly hope that the college experience does much more than render an individual employable, this outcome still looms large in the eyes of many students, their parents, and employers. Studies of motivations for college attendance indicate the prominence of occupational objectives, especially in the case of first generation collegians. And the frequency with which a college degree-often in a specific field-is part of job specifications strongly suggests a belief that something useful (from an employer's perspective) is occurring during a four year sojourn at college. Those persons presumably in the best position to provide useful information regarding the output of our colleges and universities are our faculty members. As one responsibility the faculty always has observed the students' performance in their courses, and appraised the quality of their work. Those students failing to meet a minimum level of competence were to be failed with no credit. Thus, the
Acoustic Characteristics of a Gas Turbine Exhaust Model

To investigate the sources of acoustic radiation from a gas turbine exhaust, a one-seventh scale model has been constructed. The model geometrically scales the flow path downstream of the rotating parts including support struts and turning vanes. A discussion and comparison of different kinds of aerodynamic and acoustic scaling techniques are given. The effect of the temperature ratio between model and prototype is found to be an important parameter in comparing acoustical data.
The reverse Warburg effect: Aerobic glycolysis in cancer associated fibroblasts and the tumor stroma

Here, we propose a new model for understanding the Warburg effect in tumor metabolism. Our hypothesis is that epithelial cancer cells induce the Warburg effect (aerobic glycolysis) in neighboring stromal fibroblasts. These cancer-associated fibroblasts, then undergo myo-fibroblastic differentiation, and secrete lactate and pyruvate (energy metabolites resulting from aerobic glycolysis). Epithelial cancer cells could then take up these energy-rich metabolites and use them in the mitochondrial TCA cycle, thereby promoting efficient energy production (ATP generation via oxidative phosphorylation), resulting in a higher proliferative capacity. In this alternative model of tumorigenesis, the epithelial cancer cells instruct the normal stroma to transform into a wound-healing stroma, providing the necessary energy-rich micro-environment for facilitating tumor growth and angiogenesis. In essence, the fibroblastic tumor stroma would directly feed the epithelial cancer cells, in a type of host-parasite relationship. We have termed this new idea the "Reverse Warburg Effect." In this scenario, the epithelial tumor cells "corrupt" the normal stroma, turning it into a factory for the production of energy-rich metabolites. This alternative model is still consistent with Warburg's original observation that tumors show a metabolic shift towards aerobic glycolysis. In support of this idea, unbiased proteomic analysis and transcriptional profiling of a new model of cancer-associated fibroblasts (caveolin-1 (Cav-1) deficient stromal cells), shows the upregulation of both (1) myo-fibroblast markers and (2) glycolytic enzymes, under normoxic conditions. We validated the expression of these proteins in the fibroblastic stroma of human breast cancer tissues that lack stromal Cav-1. Importantly, a loss of stromal Cav-1 in human breast cancers is associated with tumor recurrence, metastasis, and poor clinical outcome. Thus, an absence of stromal Cav-1 may be a biomarker for the "Reverse Warburg Effect," explaining its powerful predictive value.