cssi/SciSciGPT-SciSciNet huggingface dataset:
The effect of wild radish floral morphology on pollination efficiency by four taxa of pollinators.

The effects of floral morphology on rates of pollen removal and deposition by different pollinators in generalist plant species are not well known. We studied pollination dynamics in wild radish, Raphanus raphanistrum, a plant visited by four groups of pollinators: honey bees, small native bees, butterflies, and syrphyd flies. The effects of anther position and other factors on pollen removal during single visits by all four pollinator taxa were measured. Flowers with high anther exsertion (i.e., anthers placed higher above the opening of the corolla tube) tended to have the highest numbers of pollen grains removed, but this effect was strongest for honey bees and butterflies. For all pollinator taxa, pollen removal increased with the number of pollen grains available on a flower and whowed a positive, decelerating relationship with the duration of the visit. The effects of stigma position and other factors on pollen deposition during single visits by honey bees and butterflies were also studied. The nectar-feeding butterflies had a higher pollination efficiency (percentage of pollen grains removed from anthers that were subsequently deposited on a stigma) than the nectar- and pollen-feeding honey bees. Flowers with intermediate stigma exsertion had the highest numbers of pollen grains deposited on their stigmas by butterflies, but stigma exsertion had no effect on deposition by honey bees. For both butterflies and honey bees, pollen deposition on the recipient flower increased with the amount of pollen removed from the donor flower, and there was a positive, decelerating relationship between deposition and time spent at the flower; these results are analogous to those for pollen removal. The effects of anther and stigma exsertion on pollen removal and denosition did not fit predictions based on patterns of floral correlations, but results for morphology, pollen availability, time spent per visit, and pollinator efficiency are in broad agreement with previous studies, suggesting the possible emergence of some general rules of pollen transfer.
The effects of high-frequency amplification on the objective and subjective performance of hearing instrument users with varying degrees of high-frequency hearing loss.

Purpose The purpose of the present study was to determine if amplifying beyond 2 kHz affected the objective and subjective performance of hearing instrument users with varying degrees of mild-to-se...
General network equilibrium analysis

Network equilibrium problems, such as electric, hydraulic, traffic and economic equilibrium problems, are very common topics in real world situations. Equilibrium solutions can be characterized by various flow laws which govern the feasible flows on the underlying network, the dependent index quantity which is resulted by feasible flows, and the equilibrium principles which put the network system in a stable state. In this paper, a generalized complementary model is established for the general network equilibrium problems. Due to the nature of conical duality and complementary characterization of equilibrium solutions, under some monotonicity assumptions, the equilibrium problem is equivalent to the extremality conditions of a generalized geometric programming problem. Hence geometric programming methods can be applied to the network equilibrium analysis. Furthermore, the recent studies of Fang and Peterson (1982) in generalized variational inequalities can be adopted to handle more complicated cases. In ...
Basaltic injections into floored silicic magma chambers

Recent studies have provided compelling evidence that many large accumulations of silicic volcanic rocks erupted from long-lasting, floored chambers of silicic magma that were repeatedly injected by basaltic magma. These basaltic infusions are commonly thought to play an important role in the evolution of the silicic systems: they have been proposed as a cause for explosive silicic eruptions [Sparks and Sigurdsson, 1977], compositional variation in ash-flow sheets [Smith, 1979], mafic magmatic inclusions in silicic volcanic rocks [Bacon, 1986], and mixing of mafic and silicic magmas [Anderson, 1976; Eichelberger, 1978]. If, as seems likely, floored silicic magma chambers have frequently been invaded by basalt, then plutonic bodies should provide records of these events. Although plutonic evidence for mixing and commingling of mafic and silicic magmas has been recognized for many years, it has been established only recently that some intrusive complex originated through multiple basaltic injections into floored chambers of silicic magma [e.g., Wiebe, 1974; Michael, 1991; Chapman and Rhodes, 1992].
Molecular Weight and Polydispersity Effects on Interdiffusion at the Interface Between Polystyrene and Poly(vinyl methyl ether)

Time dependence and the effect of polystyrene (PS) and poly(vinyl methyl ether) (PVME) molecular weight and polydispersity on interdiffusion at the interface of PS and PVME were investigated with attenuated total reflection infrared spectroscopy (ATR-FTIR). The time dependence of interdiffusion was studied by varying the thickness of the slow-diffusing component, PS, and the results were analysed using a combination of Fickian and Case II models. PS samples with molecular weights ranging from 1.0 × 105 to 3.0 × 106, above the entanglement molecular weight, were used to study the effect of molecular weight on interdiffusion. PS samples with controlled polydispersity ranging from 1.1–3.0 were prepared using a trimodal distribution constructed from monodisperse PS samples. The polydispersity of the PS samples was controlled by varying the number average molecular weight of the distributions while keeping the weight average molecular weight constant. To study the effect of PVME molecular weight and molecular weight distribution on interdiffusion, PVME was fractionated three times from an aqueous solution to increase its molecular weight from 9.9 × 104 to 1.7 × 105 and reduce its polydispersity index from 2.1 to 1.4, respectivley.
Mechanisms of stress-related mucosal damage

During the last 15 years, there has been a dramatic decline in the incidence of bleeding from stress-related mucosal damage. This decrease probably relates to an increased understanding of those mechanisms responsible for the pathogenesis of stress-related mucosal damage and the application of this knowledge to prophylaxis and treatment. Stress-related bleeding has become less of a clinical problem, in part, because of the development of improved techniques for the treatment of shock and its accompanying gastric mucosal hypoperfusion. The nearly routine use of prophylactic antacid and/or histamine (H2)-receptor antagonist therapy to adequately buffer intragastric acidity is another factor that has minimized the development of stress-related damage. As continued understanding of the mechanisms responsible for stress damage is obtained and therapy applied appropriately, this disease should become a disorder of only historical interest in years to come.
Early Time Dynamics in Heavy Ion Collisions from CGC and from AdS/CFT

Abstract We review two different theoretical approaches to the strong interaction dynamics at the early times immediately following heavy ion collisions. One approach is based on small-coupling physics of the Color Glass Condensate (CGC). The other approach is based on Anti-de Sitter space/Conformal Field Theory (AdS/CFT) correspondence and may be applicable to describing large-coupling QCD interactions. We point out that in terms of theoretical tools the two approaches are somewhat similar: in CGC one deals with classical gluon fields produced in a nuclear shock wave collision, while in AdS/CFT one studies classical gravity in a gravitational shock wave collision. We stress, however, that the resulting physics is different: the classical gluon fields in CGC lead to a free-streaming medium produced in heavy ion collisions, while the classical gravity in the 5-dimensional AdS bulk is likely to lead to ideal hydrodynamics description of the produced medium. Also, the valence quarks in colliding nuclei in CGC continue along their light cone trajectories after the collision with very little recoil, while we show that in AdS the colliding nuclei are likely to lose most of their energy in the collision and stop.
Differential Epigenetic Regulation of TOX Subfamily High Mobility Group Box Genes in Lung and Breast Cancers

Aberrant cytosine methylation affects regulation of hundreds of genes during cancer development. In this study, a novel aberrantly hypermethylated CpG island in cancer was discovered within the TOX2 promoter. TOX2 was unmethylated in normal cells but 28% lung (n = 190) and 23% breast (n = 80) tumors were methylated. Expression of two novel TOX2 transcripts identified was significantly reduced in primary lung tumors than distant normal lung (p<0.05). These transcripts were silenced in methylated lung and breast cancer cells and 5-Aza-2-deoxycytidine treatment re-expressed both. Extension of these assays to TOX, TOX3, and TOX4 genes that share similar genomic structure and protein homology with TOX2 revealed distinct methylation profiles by smoking status, histology, and cancer type. TOX was almost exclusively methylated in breast (43%) than lung (5%) cancer, whereas TOX3 was frequently methylated in lung (58%) than breast (30%) tumors. TOX4 was unmethylated in all samples and showed the highest expression in normal lung. Compared to TOX4, expression of TOX, TOX2 and TOX3 in normal lung was 25, 44, and 88% lower, respectively, supporting the premise that reduced promoter activity confers increased susceptibility to methylation during lung carcinogenesis. Genome-wide assays revealed that siRNA-mediated TOX2 knockdown modulated multiple pathways while TOX3 inactivation targeted neuronal development and function. Although these knockdowns did not result in further phenotypic changes of lung cancer cells in vitro, the impact on tissue remodeling, inflammatory response, and cell differentiation pathways suggest a potential role for TOX2 in modulating tumor microenvironment.
College Students' Choices of Study Strategies

For a closed-book examination, study strategies that could promote deep processing correlated positively with scores but were not likely to be used by the 46 students. For an open-book, open-note examination, strategies that might have led to confusion regarding the locations of material in the textbook and lecture notes correlated negatively with scores, although they were not likely to be used by the 58 students.
The taste of fat elevates postprandial triacylglycerol.

To explore the contributions of taste and smell stimulation by dietary fat on the postprandial rise of serum triacylglycerol (TAG), 19 healthy, overnight-fasted adults received lipid loads (50 g safflower oil in capsules) followed by oral (i.e., taste and smell) or odor-only stimulation with cream cheese on crackers or no load with odor or no stimulation. In eight participants, lipid loading was followed by taste-only stimulation. Stimulation was provided (where applicable) at 3-min intervals for 60 min and 15-min intervals for an additional 60 min. Blood was drawn at stipulated times. Fat loading with oral stimulation led to serum TAG concentrations that were significantly elevated over baseline at 2, 4, and 6 h. Fat loading with odor stimulation led to a significant rise only at 4 h. No significant elevation was observed with either no-load treatment. Taste-only treatment led to a significantly higher TAG response than all other treatments except loading with oral stimulation. These data provide additional evidence supporting a taste component for human fat perception.
Reduced conservatism in stability robustness bounds by state transformation

This note addresses the issue of "conservatism" in the time domain stability robustness bounds obtained by the Lyapunov approach. A state transformation is employed to improve the upper bounds on the linear time-varying perturbation of an asymptotically stable linear time-invariant system for robust stability. This improvement is due to the variance of the conservatism of the Lyapunov approach with respect to the basis of the vector space in which the Lyapunov function is constructed. Improved bounds are obtained, using a transformation, on elemental and vector norms of perturbations (i.e., structured perturbations) as well as on a matrix norm of perturbations (i.e., unstructured perturbations). For the case of a diagonal transformation, an algorithm is proposed to find the "optimal" transformation. Several examples are presented to illustrate the proposed analysis.
INDIVIDUAL-BASED COMPUTATIONAL MODEL USED TO EXPLAIN 2009 PANDEMIC H1N1 IN RURAL CAMPUS COMMUNITY

In the beginning of fall semester 2009, over 2,000 students contacted the student health service at Washington State University to report symptoms of influenza. The epidemic in Pullman, WA made national news, and many speculated on the severity and extent of the disease spread. Analysis of data from the influenza A(H1N1)pdm09 epidemic in Pullman, WA offers an opportunity to gain insights into characteristics of this rural campus community outbreak. In this study, an individual-based stochastic epidemic simulation model was used with the data to estimate infection parameters and make projections of the number of symptomatic individuals that would result given a variety of plausible scenarios. The parameters that were estimated include the number of individuals initially infected and the basic reproductive ratio (R0). The model was then used to predict the magnitude of infection with vaccination, isolation and quarantine. The results show that the best single intervention strategy is vaccination, and the reduction in infection is greatest when vaccination, isolation and quarantine are used simultaneously.
Analysis of hydrodynamic petroleum entrapment in Sage Creek field, Big Horn Basin, Wyoming

Abstract The mathematical procedure for locating hydrodynamic traps can be combined into a single computer program that will draw new oil potential contours for a variety of postulated water flow conditions. A mapping program call SURFER is used in this case to calculate oil potentials using Hubbert's equation directly from known structural and water potential data, and to draw the contours automatically. The method is applied to Sage Creek field, a known hydrodynamic trap in the Big Horn Basin in northwest Wyoming and it is shown that hydrodynamics alone can not trap the oil accumulation in this structure. It is suggested that the trapping mechanism in this field is a function of reservoir heterogeneities associated with a strong hydrodynamic gradient.
Elastography Methods Applicable to the Eye

Elastography is the mapping of tissues and cells by their respective mechanical properties, such as elasticity and viscosity. Our interest primarily lies in the human eye. Combining Scanning Laser Doppler Vibrometry (SLDV) with geometrically focused mechanical vibratory excitations of the cornea, it is possible to reconstruct these mechanical properties of the cornea. Experiments were conducted on phantom corneas as well as excised donor human corneas to test feasibility and derive a method of modeling. Finite element analysis was used to recreate the phantom studies and corroborate with the experimental data. Results are in close agreement. To further expand the study, lamb eyes were used in MR Elastography studies. 3D wave reconstruction was created and elastography maps were obtained. With MR Elastography, it would be possible to noninvasively measure mechanical properties of anatomical features not visible to SLDV, such as the lens and retina. Future plans include creating a more robust finite element model, improving the SLDV method for in-vivo application, and continuing experiments with MR Elastography.
Effect of body tilt on receptive field orientation of simple visual cortical neurons in unanesthetized cats

The receptive field (RF) orientation of 53 simple visual cortical neurons was determined by recording the activity of single cells during presentation of stationary bars of light. An RF tuning curve was constructed for each cell by averaging the neural discharge resulting from the repeated presentation of a number of slit orientations. RF curves were then determined again, following a 45 degrees roll tilt of the entire head and body, and subsequently after the return of the animal to the original horizontal position. RF tuning curves were typical of what others have found to characterize simple cells, and were highly replicable on the return to the starting position. In 73% of the cells studied, the RF orientation after tilt remained unaltered relative to the head axis (+/- 15 degrees); in the remaining 27% of the cells RF orientations either under- or over-shot the retinal tilt by more than 15 degrees, and in some cases by as much as 45 degrees. These results support the hypothesis that the well documented vestibular inputs to visual cortex play a role in modifying the RF orientation selectively of visual cortical neurons, and suggest that such information may be an important neurophysiological substrate underlying visual spatial constancy mechanisms.
Water sorption of poly(methyl methacrylate): 1. Effects of molecular weight

Abstract A sample of poly(methyl methacrylate), PMMA, of low molecular weight (10 4 D) took up less water (1.2%) than samples of high molecular weight (10 6 D: 2.0%). In contrast, the uptake of water was only slightly dependent on molecular weight for samples made by radiolysis in the glassy state. It is concluded that uptake of water depends on the closer molecular packing possible in polymers of lower molecular weight. However during radiolysis in the glassy state, this potential is not fully realized because of limited mobility. In more detail, the small changes in the diffusion coefficient and uptake of water in irradiated samples were consistent with closer packing in samples with M n ⩽ 10 000. It is concluded that molecular packing proceeds more readily below the critical molecular weight for formation of an entangled network.
Interspecific variation for thermal dependence of glutathione reductase in sainfoin.

Understanding the biochemical and physiological consequences of species variation would expedite improvement in agronomically useful genotypes of sainfoin (Onobrychis spp.) Information on variation among sainfoin species is lacking on thermal dependence of glutathione reductase (B.C. 1.6.4.2.), which plays an important role in the protection of plants from both high and low temperature stresses by preventing harmful oxidation of enzymes and membranes. Our objective was to investigate the interspecific variation for thermal dependency of glutathione reductase in sainfoin. Large variation among species was found for: (i) the minimum apparent Km (0.4–2.5 μM NADPH), (ii) the temperature at which the minimum apparent Km was observed (15°–5°C), and (iii) the thermal kinetic windows (2°–30°C width) over a 15°–45°C temperature gradient. In general, tetraploid species had narrower (≤17°C) thermal kinetic windows than did diploid species (∼30°C), with one exception among the diploids. Within the tetraploid species, the cultivars of O. viciifolia had a broader thermal kinetic window (≥7°C) than the plant introduction (PI 212241, >2 °C) itself.
Estimation of material parameters in a dynamic nonlinear plate model

Abstract The output-least-square estimation of flexural rigidity with observation of deformations is considered for a dynamic von Karman system. Since such equations may have multiple solutions, we develop a theory for the estimation of coefficients in systems with solution sets that are compact in suitable spaces. We provide a convergence theory based on Galerkin approximations and regularity of optimal estimators of the Galerkin systems. We also obtain stability results for the dependence of the optimal estimator upon the data. A numerical estimation algorithm is developed and the results of numerical experiments are reported.
An evaluation of the relationship between kinetic data collection of DTG curves and its corresponding R-square and activation energy values for kinetic plots

In this study the significance of data point collection on R-square values and activation energy values of resulting kinetic plots is explored. Several data collection sets were examined to observe this phenomena. These data sets were taken from DTG plots of benzophenone. Benzophenone undergoes a zero-order kinetics process as it evaporates. The maximum number of data points, which may be utilized to give an optimum R-square value of 0.9999, is established. This number is the optimum number of data points that should be collected to ensure a resulting linear kinetic plot. This is also the number of data points which will provide a more accurate activation energy value determination.
Establishing the validity of recovery from stuttering without formal treatment

There is no empirical basis for determining goals for stuttering treatment. One approach that might resolve this issue is to systematically investigate persons who claim to have recovered from stuttering without the assistance of treatment. However, critical methodological and conceptual issues must be overcome first in order to assure these persons had a valid stuttering problem and that their recovery was independent of treatment. This study examined a validation procedure for solving these issues based on the combination of two methods: independent verification and self-reports. Forty-two subjects participated: 14 adults who recovered from stuttering without assistance, 14 adults with persistent stuttering, and 14 adults who were normally fluent speakers. For the independent verification, a Speech Behavior Checklist was administered to 42 individuals familiar with the recovered subjects' past speech and the other subjects' current speech. Results indicated that persons who knew the recovered subjects w...
Identifying the Intermediate in the Dioxygen Transfer from 4a-Hydroperoxyflavin Anion to Phenolate and Indole Anions☆

Abstract Semiempirical andab initiomolecular orbital methods are used to identify the plausible intermediate involved in dioxygen transfer from 4a-hydroperoxyflavin anion to phenolate and indole anions. According to the present study, both 4,4a-dioxetane and 4a,10-dioxetane derived from 4a-hydroperoxyflavin anion are the likely candidates.
Should you upgrade to Mac OS X in your computing labs

This portion of the lab management panel will discuss the issues involved in upgrading to Mac OS X in public computing labs.Issues discussed will include:Hardware: Despite Apple's recommendations, what is the minimum reasonable hardware configuration for a Mac OS X lab computer? Do you need all new peripherals?Initial setup: How to install and configure Mac OS X for a public computing lab environment.Maintenance: How to keep the computers in a clean and usable state using security tools and automated refreshing or imaging software.Mac OS Classic: Issues involved in running Classic under OS X in a computing lab.Authentication: Using LDAP and other authentication methods, roaming profiles, and other issues related to having multiple logins on the same Mac.Should you do it?: How to decide when it is time to upgrade your labs to OS X.
Visualization and Interpretation of 3D Seismic in the Carboniferous of the UK Southern North Sea

Abstract Examples from the Carboniferous of the UK Southern North Sea are used to illustrate the application of visualization tools to increase the effectiveness of 3D seismic interpretation. Maintaining the seismic data to the fore throughout the interpretation workflow and decision-making process is vital for well planning in field development and trap validation in prospect evaluation. Scaling of the seismic into the 9true-depth9 domain and the automatic generation and visualization of layers using isochores derived from well data are the key elements in this interpretation workflow. Together these allow full integration of the seismic with various well data and interpreted elements. The main example is from Murdoch K, one of ConocoPhillips9s most recent UK discoveries, part of a pre-Permian extensional graben inverted during the Early Tertiary tectonic phase. Other examples from the McAdam Field and an exploration prospect are used to highlight additional aspects of the method.
Copper metallization for on-chip interconnects

Continued dimensional scaling of the elements of integrated circuits places significant restrictions on the width, density and current carrying capability of metallic interconnects. It is expected that, by the year 2000, the transistor channel length will be at 0.l8piri [1], while microprocessors will pack more than 15 million transistors over an area of '-700mm2. To conserve area, interconnects will continue to be stacked at an increasing number of levels (6 by the year 2000, vs 4 in todays leading microprocessors) and the minimum spacing and width within an interconnect layer will shrink to 0.3.tm. In addition, it is expected that future interconnects will need to sustain increasingly higher current densities without electromigration failures [2]. Aluminum alloys are the conductors of choice in present-day interconnects, and much effort is focused n means to extend the usefulness of aluminum through improvements in reliability, either by new alloy formulations [3], or by the development of complicated multimetal stacks [4. A more radical approach, which is gaining increased attention, is the replacement of aluminum altogether by copper. The bulk resistivity of copper is significantly lower than that of aluminum (1.7.tW-cm for Cu vs. 3.0iW-cm for Al-Cu), which is expected to translate to interconnects of higher performance because of reduction in signal propagation delay. In addition, the significantly higher melting temperature of copper (.-1100°C vs. -600°C for Al-Cu alloys) and its higher atomic weight are expected to translate to improved resistance to electromigration [5]. However, as with any new process trying to break into the mainstream, significant improvement in reliability and performance over that achievable with aluminum alloys must be demonstrated first. Towards this purpose, processes need to be developed that deposit conformal copper films of high purity with acceptable throughput, and integration schemes need to be developed which produce interconnects and multilevel metal structures with reliability significantly better than that of aluminum. This article describes our efforts to integrate copper in the backend of integrated circuits. The first part deals with the chemical vapor deposition (CVD) of copper films. The second describes the integration of copper into the last metal level of a 2-level metal 0.5um BiCMOS SRAM circuit.
Confusion, Cost, and Emotion Research

The inferences that can be drawn from Izard’s article are unclear. Izard (2010) suggests that his data raise questions concerning inconsistencies, confusion, and costs in emotion research. I suggest that his data do not speak to the issues of confusion and costs, and that the choice of distinguished scientists may have been inappropriate to meet the goals of Izard’s study. Of course, questions concerning the efficiency of research in emotion studies are interesting. I describe more appropriate ways of addressing such issues.
How officers spend their time with the community

Using data from field observation of police patrol officers at work in two American cities, we explore similarities and differences between the tasks undertaken by generalist patrol officers and community policing specialists. As expected, community policing specialists are much more able to choose the work they do and the people they encounter. Specialists use their discretion to spend less “face time” with the public and more time “behind the scenes” than do patrol generalists, and to engage a higher-status and less problem-ridden clientele. Implications for adoption of community policing are discussed.
Supernovae: New explosions of old stars?

Examples of stellar explosions have emerged that fall outside the traditional types of supernova. The nature of the stars that produce them and the mechanism by which they explode is far from clear. The novel properties of the faint supernova SN 2005E mean that it does not fit readily into the established supernova categories. Types Ib, Ic and II, core-collapse supernovae, are thought to form when a massive star explodes at the end of its life, and type Ia as a result of the thermonuclear explosion of an accreting white dwarf. From spectroscopic data, Perets et al. conclude that SN 2005E is helium rich, like a type Ib, and lacks the hydrogen, silicon and sulphur spectral lines typical of type Ia. But based on its presence in an 'old' stellar environment, and with a low derived ejected mass, they argue against a core-collapse origin and for an origin from a low-mass, old progenitor, probably a helium-accreting white dwarf in a binary system. Kawabata et al. see it differently. SN 2005E resembles SN 2005cz, they say, a type Ib supernova that is unusual in being found in an elliptical galaxy. Both SN 2005E and SN 2005cz, they suggest, are best explained as products of the core collapse of massive stars at the low (6–12 solar mass) end of massiveness. In the accompanying News & Views, David Branch discusses these two models in the context of the latest thinking on how stars explode.
Kinematic corrections to the Coulomb potential in multiple scattering theory

A previous study of the Coulomb interaction in nonrelativistic multiple-scattering theory is extended to account for relativistic effects. The projectile-nucleus Coulomb potential is computed from the relativistic M\o{}ller amplitude for projectile-nucleon scattering at low momentum transfer. The resulting Coulomb potential is reasonably approximated by folding $\frac{{e}^{2}}{|\stackrel{\ensuremath{\rightarrow}}{\mathrm{r}}\ensuremath{-}{\stackrel{\ensuremath{\rightarrow}}{\mathrm{r}}}^{\ensuremath{'}}|}$ with the nuclear charge density, but must be multiplied by an additional kinematic factor to bring the corresponding projectile-nucleus Coulomb-scattering amplitude into agreement with relativistic results.
Palladium- and platinum-catalyzed coupling reactions of allyloxy aromatics with hydridosilanes and hydridosiloxanes: Novel liquid crystalline/organosilane materials

Pt-and Pd-catalyzed reactions of a set of allyloxyaromatic mono-and diesters with selected silanes were examined to develop simple, mild methods of forming liquid crystal (LC)/ siloxane and LC/silsesquioxane polymers. Pt complexes catalyze hydrosilylation to give primarily (≤ 80% selectivity at 100% conversion) terminal silylation of the allyloxys. The catalyst, platinum-1,3-divinyltetramethyldisiloxane [Pt (dvs), gives the cleanest reactions, fewest side products, under the mildest conditions. Model studies of Pt(dvs) catalyzed hydrosilylation of 4-allyloxy methylbenzoate gave relative reactivities (HSiO1.5)8 ≫ Et3SiH > HMe2SiOSiMe2H > Ph2SiH2. The cubic silsesquioxane, (HSiO1.5)8, is so reactive hydrosilylation is over in 1–3 h at 0°C. All other reactions required > 40°C and longer reaction times. Initial efforts to form high polymers by Pt-catalyzed reactions of bis-allyloxy aromatics with Ph2SiH2 provide polymers with bimodal MW distributions (polystyrene), Mws ≈ 30 kDa, and PDIs ≈ 5. Pd catalysis gives quite different products resulting from loss of propene with coincident formation of SiO bonds, “oxysilylation.” The same products appear (10–15%) in some Pt catalyzed reactions. Palladium dibenzylideneacetone/ Ph3P[Pd(dba)2/Ph3P], gives the cleanest oxysilylation reactions. Relative oxysilylation activities are: Ph2SiH2 > HMe2SiOSiMe2H > Et3SiH. Polymerization with Pd catalysts provides polymers with Mws ≈ 11 kDa, and PDIs ≈ 2. Reaction of 1 equiv. of (HSiO1.5)8 with 4 equiv. of 4-(4-allyloxy-benzoyloxy) biphenyl gives relatively pure tetrasubstituted LC/silsesquioxane [Mn ≈ 1860 Da, PDI ≈ 1.09 (styrene equiv.) vs. 1746 Da caled.] A detailed analysis of the products formed, the catalytic reactivity patterns of the his (allyloxy) aromatic diesters and their LC transitions is presented. © 1994 John Wiley & Sons, Inc.
Plasmonic light trapping in ultrathin single crystal silicon membrane for solar cells application

We report the experimental characterization of a promising light trapping scheme, in ultrathin, mechanically flexible, single crystal silicon membranes that included front surface nanotexturization and a back-sruface array of plasmonic metallic nanoparticles for solar cell applications. Sub-ten micrometer free standing silicon membranes were produced by the chemical etching of silicon wafers. The produced membranes were observed to be mechanically flexible, yet sufficiently sturdy to tolerate the different processing steps during solar cell fabrication. We studied the plasmonic effects of different metallic nanoparticles for optical absorption enhancement on the nanotexturized ultrathin silicon membranes by incorporating them on the back surface of the samples. A promising short circuit current density as high as 36.43 mA/cm2 was calculated from the measured optical absorption spectra in a 7.85 µm thick single crystal silicon membrane with front surface nanotexturization along with a back surface array of random mixture of gold and silver nanoparticles. The extracted current density value compares favorably well with the value of 15.68 mA/cm2 associated with a flat silicon membrane of the same thickness. The described light trapping scheme may enable the possibility for demonstrating high-efficiency, mechanically flexible photovoltaic devices in the near future.
Active Aeroelastic Tailoring of High-Aspect-Ratio Composite Wings

Abstract : The objective of the proposed work is to study the fundamental mechanisms of active aeroelastic tailoring of high-aspect-ratio composite wings. The emphasis will be on actively exploring structural flexibility to enhance flight performance and reduce structural weight, while controlling aeroelastic instabilities. To investigate the effects of distributed anisotropic strain actuation and their synergism with the passive aeroelastic tailored composite structure, a suitable nonlinear active aeroelastic framework is required. Therefore, an analysis and design tool is being developed for high aspect ratio active flexible wings. The formulation is capable of modeling the nonlinear large deflection behavior of the wings, deformation due to applied voltages on the active plies in the skin of the wing, and the unsteady subsonic aerodynamic forces acting on the wing. Because the wing is long and slender, it can be reasonably well modeled as a beam undergoing three dimensional displacements and rotations. The cross sectional stiffness, inertia, and actuation properties of the wing are calculated along the span, and then a 1-d nonlinear beam model is constructed. This is a novel beam representation that is based on the beam curvatures, resulting in a computationally efficient low-order model suitable for preliminary structural design and control synthesis. Preliminary numerical results are presented in this report.
HALOS: fast, autonomous, holographic adaptive optics

We present progress on our holographic adaptive laser optics system (HALOS): a compact, closed-loop aberration correction system that uses a multiplexed hologram to deconvolve the phase aberrations in an input beam. The wavefront characterization is based on simple, parallel measurements of the intensity of fixed focal spots and does not require any complex calculations. As such, the system does not require a computer and is thus much cheaper, less complex than conventional approaches. We present details of a fully functional, closed-loop prototype incorporating a 32-element MEMS mirror, operating at a bandwidth of over 10kHz. Additionally, since the all-optical sensing is made in parallel, the speed is independent of actuator number - running at the same bandwidth for one actuator as for a million.
Science of computing suite (SOCS): resources for a breadth-first introduction

Over the last ten years, our department's breadth-first introductory course has evolved independently of other survey courses in computer science. Due to its success, we duplicated the ideas into our course for non-majors, and this has also proven successful. None of the published resources match our vision for these courses, and so the department has developed its own. In this paper, we describe the design of the majors course, and we introduce a variety of resources developed for both courses. These resources, which could be useful in many other courses also, are freely available through the Web.
Three-phase cyanate ester composites with fumed silica and negative-CTE reinforcements

Three-phase cyanate ester adhesives have been developed using a bisphenol E cyanate ester resin, fumed silica, and negative-CTE (coefficient of thermal expansion) reinforcements: short carbon fiber or zirconium tungstate (ZrW2O 8 ). Fumed silica was used to impart thixotropic behavior on the resin and decrease settling in the adhesives. The cured composites were evaluated using various thermal analysis techniques for their thermal-mechanical properties. Composites with short carbon fiber showed enhanced modulus and decreased thermal expansion (70% reduction for 20 vol%) and showed little phase separation. While settling of the dense ceramic particles could not be completely eliminated for the zirconium tungstate composites through rheological modification of the adhesive with added fumed silica, a reduction in CTE of 84% was achieved in the composite (58 vol%) compared to the neat resin. In addition, the effect of thermal history on the cure and temperature induced ZrW2O8 phase transitions, and their corresponding influence on thermal strains vs. temperature, are examined by thermomechanical analysis.
The daytime behaviour of domestic cats in a free-roaming population

Abstract The cats ( Felis catus ) of this study were found to fluctuate daily between solitary and group living. These temporal changes in behaviour were interpreted as reflecting adjustments made by the cats for maximum use of different food sources available at these times. The dependence on both a solitary and communal life style for food procurement prevented any intricacy of either pattern from evolving. The structure of each behavioural pattern is discussed.
Observation of a novel transient ferryl complex with reduced CuB in cytochrome c oxidase.

The reaction between mixed-valence (MV) cytochrome c oxidase from beef heart with H2O2 was investigated using the flow-flash technique with a high concentration of H2O2 (1 M) to ensure a fast bimolecular interaction with the enzyme. Under anaerobic conditions the reaction exhibits 3 apparent phases. The first phase (τ ≅ 25 μs) results from the binding of one molecule of H2O2 to reduced heme a3 and the formation of an intermediate which is heme a3 oxoferryl (Fe4+O2-) with reduced CuB (plus water). During the second phase (τ ≅ 90 μs), the electron transfer from CuB+ to the heme oxoferryl takes place, yielding the oxidized form of cytochrome oxidase (heme a3 Fe3+ and CuB2+, plus hydroxide). During the third phase (τ ≅ 4 ms), an additional molecule of H2O2 binds to the oxidized form of the enzyme and forms compound P, similar to the product observed upon the reaction of the mixed-valence (i.e., two-electron reduced) form of the enzyme with dioxygen. Thus, within about 30 ms the reaction of the mixed-valence f...
Further evidence for the “piano stool” transition state in η6-cyclooctatetraenemetal fluxional molecules

The fluxional behavior of the molecule (η6-C8H8)(η4-norbornadiene)Ru has been studied by carbon-13 NMR spectroscopy in the temperature range −72 to +60°C and by proton NMR in the range −90 to +95°C. The spectrum in the slow exchange limit is in accord with the presumed structure provided rapid rotation (or accidentally equivalent chemical shifts) is assumed for the norbornadiene ligand. In the slow exchange limit the C8H8 ligand has four 13C signals at 127.3, 93.5, 92.3, and 66.8 ppm (vs. TMS). As the temperature is raised these all broaden and collapse at the same rate. This behavior rigorously rules out the occurrence of 1,2 shifts and is consistent only with the occurrence of a symmetrical, “piano stool” transition state or with a series of 1,3 shifts. It is argued that the former is the correct choice. Proton spectra are also reported and shown to be consistent with the mechanistic conclusion. The norbornadiene ligand rotates rapidly in such a way as to average environments of the olefinic carbon atoms (and the attached protons) though the 13 C spectrum shows evidence for slowing of this motion at −72°C.
Subunit organization and Rab interactions of Vps-C protein complexes that control endolysosomal membrane traffic

Traffic through late endolysosomal compartments is regulated by sequential signaling of small G proteins of the Rab5 and Rab7 families. The Saccharomyces cerevisiae Vps-C protein complexes CORVET (class C core vacuole/endosome tethering complex) and HOPS (homotypic fusion and protein transport) interact with endolysosomal Rabs to coordinate their signaling activities. To better understand these large and intricate complexes, we performed interaction surveys to assemble domain-level interaction topologies for the eight Vps-C subunits. We identified numerous intersubunit interactions and up to six Rab-binding sites. Functional modules coordinate the major Rab interactions within CORVET and HOPS. The CORVET-specific subunits, Vps3 and Vps8, form a subcomplex and physically and genetically interact with the Rab5 orthologue Vps21. The HOPS-specific subunits, Vps39 and Vps41, also form a subcomplex. Both subunits bind the Rab7 orthologue Ypt7, but with distinct nucleotide specificities. The in vivo functions of four RING-like domains within Vps-C subunits were analyzed and shown to have distinct functions in endolysosomal transport. Finally, we show that the CORVET- and HOPS-specific subunits Vps3 and Vps39 bind the Vps-C core through a common region within the Vps11 C-terminal domain (CTD). Biochemical and genetic experiments demonstrate the importance of these regions, revealing the Vps11 CTD as a key integrator of Vps-C complex assembly, Rab signaling, and endosomal and lysosomal traffic.
Monoclonal Antibodies to Hyphal Exoantigens Derived from the Opportunistic Pathogen Aspergillus terreus

Aspergillus terreus has been difficult to identify in cases of aspergillosis, and clinical identification has been restricted to the broad identification of aspergillosis lesions in affected organs or the detection of fungal carbohydrates. As a result, there is a clinical need to identify species-specific biomarkers that can be used to detect invasive A. terreus disease. Monoclonal antibodies (MAbs) were developed to a partially purified preparation of cytolytic hyphal exoantigens (HEA) derived from A. terreus culture supernatant (CSN). Twenty-three IgG1 isotype murine MAbs were developed and tested for cross-reactivity against hyphal extracts of 54 fungal species. Sixteen MAbs were shown to be specific for A. terreus. HEA were detected in conidia, hyphae, and in CSN of A. terreus. HEA were expressed in high levels in the hyphae during early stages of A. terreus growth at 37°C, whereas at room temperature the expression of HEA peaked by days 4 to 5. Expression kinetics of HEA in CSN showed a lag, with peak levels at later time points at room temperature and 37°C than in hyphal extracts. Serum spiking experiments demonstrated that human serum components do not inhibit detection of the HEA epitopes by MAb enzyme-linked immunosorbent assay (ELISA). Immunoprecipitation and proteomic analysis demonstrated that MAbs 13E11 and 12C4 immunoprecipitated a putative uncharacterized leucine aminopeptidase (Q0CAZ7), while MAb 19B2 recognized a putative dipeptidyl-peptidase V (DPP5). Studies using confocal laser scanning microscopy showed that the uncharacterized leucine aminopeptidase mostly localized to extracellular matrix structures while dipeptidyl-peptidase V was mostly confined to the cytoplasm.
Flight results of the ring laser gyro based inertial navigation system for Atlas/Centaur

The authors describe the Centaur modern avionics suite and discuss the inertial navigation flight performance. The integration of modern ring laser gyro and microprocessor technology into the Atlas/Centaur launch vehicle resulted in an order-of-magnitude improvement in orbital insertion accuracy over the previous gimbaled platform guidance system. The improved positioning accuracy minimizes the orbital correction burns required by the payload, which conserves valuable propellant required for station keeping. The upgrading of the avionics resulted in a factor-of-five reduction in recurring hardware cost and close to 200 lbs in weight reductions. >
A simple method for tracking vertebrate-dispersed seeds.

Tracking vertebrate-dispersed seeds from parent plant to deposition site remains a primary obstacle to understanding the ecological and evolutionary consequences of seed dispersal. We evaluate a new and simple technique for tracking seeds. Fluorescent microspheres (15 μm diameter) are applied to fruits and later recovered in fecal material associated with the fruits’ seeds. Trials with captive Cedar Waxwings (Bombycilla cedrorum) demonstrated that (1) percentage recovery of microspheres is high, (2) all defecations containing seeds also contain microspheres, (3) relatively few microspheres are recovered in defecations not containing seeds, and (4) presence of microspheres on fruits does not affect fruit choice. Field trials with five species of fruits demonstrated that, after ∼30 d under full sun and high temperatures, photodegradation limits one’s ability to detect microspheres. The field trials also showed that an anti-transpirant applied with the microspheres allows them to adhere to fruits without det...
NATO, Rational Escalation and Flexible Response

A multi-stage escalation model is developed in which each stage is taken as a psychologically distinct and empirically feasible mode of conflict available to two states in a hostile, deterrent relationship. Each stage is defined by a generic, extensive-form game of mutual deterrence in which the credibility of each player's threat is allowed to vary. In the multi-stage model these games are linked to one another by way of a common outcome, creating a new game with a distinct dynamic. The results of previous research on one- and two-stage games are summarized and the model extended to games with three stages. A three-stage escalation game composed solely of one of the three possible one-stage deterrence games has strategic characteristics identical to those of its component parts: mutual credibility at each stage implies stable deterrence; mutually incredible threats at every stage result in an unstable deterrence relationship, as does an asymmetry of credibility at all three stages of the game. In other w...
Nuclear choreography: interpretations from living cells

The advent of green fluorescent protein technology, its use in photobleaching experiments and the development of methods to rapidly acquire images and analyze complex datasets have opened the door to unraveling the mechanisms of nuclear functions in living cells. Studies over the past few years have characterized the movement of chromatin, nuclear proteins and nuclear bodies and, in some cases, correlated their dynamics with energy dependence, cell cycle progression, developmental changes, factor targeting and nuclear position. The mechanisms by which nuclear components move or are restrained have important implications for understanding not only the efficacy of nuclear functions but also the regulation of developmental programs and cellular growth.
Book Review Essays

Book reviewed in this article: Building housing theory: notes on some recent work: Headey, B. Building housing theory: notes on some recent work: Political Economy of Housing Workshop of the Conference of Socialist Economists. Building housing theory: notes on some recent work: Pugh, C. Building housing theory: notes on some recent work: Foster, J. Building housing theory: notes on some recent work: Marcuse, P.