cssi/SciSciGPT-SciSciNet huggingface dataset:
Force/moment constraints for robot compliant motions in the presence of uncertainties

It is shown that by properly choosing the commanded force/moment based on certain force/moment constraints, a compliant translation/rotation can be ensured in the presence of uncertainties if certain design constraints on the sensing, modeling and control uncertainties are satisfied. The term 'design constraints' is used because it is hoped that the constraints imposed on those system parameters can be transformed to constraints on certain intrinsic parameters of some concrete devices, such as the robot arm and the sensors involved. However, the analysis provided is limited to compliant translation on a planar surface and pure compliant rotation constrained by a point, a line or a planar surface. >
SEM localization of cell-surface-associated fibronectin in the cranium of chick embryos utilizing immunolatex microspheres.

Fibronectin has been localized to basement membranes and cell surfaces with the light microscope by fluorescent staining of thick sections, and with the TEM by immunoperoxidase reaction. However, these methods are limited because it is difficult to appreciate the patterned distribution of fibronectin from sectioned material. We have developed a probe for fibronectin that facilitates its identification with the SEM. Our probe consists of two parts; the first component is a derivatized methacrylate microsphere 90 nm in diameter, linked to purified sheep anti-rabbit IgG. The second component is anti-fibronectin IgG raised in rabbits. Stage-3 to -12 chick embryos were fixed and the ectoderm covering the cranial mesoderm was removed. Embryos were treated with testicular hyaluronidase, exposed to rabbit antifibronectin IgG and finally to sheep anti-rabbit IgG conjugated microspheres. As expected, the basal lamina of surface and neural ectoderm as well as the remaining fibrous ECM were heavily decorated with microspheres, whereas control embryos treated with preimmune serum were beadless. Fibronectin was localized on the cell soma and processes of primary mesenchyme as early as stage 3. In addition, it was possible to decorate to various extents, populations of prosencephalic, mesencephalic, and rhombencephalic cranial neural crest cells. Our studies suggest that fibronectin is present in the cranium of chick embryos at earlier times than heretofore realized, and that fibronectin accumulates in a cranial to caudal gradient that reflects the sequential differentiation of the embryonic axis.
NONPARAMETRIC SURVEY RESPONSE ERRORS

I present nonparametric methods to identify and estimate the biases associated with response errors. When applied to survey data, these methods can be used to analyze how observable and unobservable characteristics of the respondent, and characteristics of the design of the survey, affect errors in the responses. This provides a method to correct the biases that those errors generate, by using the estimated response errors to “undo” those biases. The results are useful also to design better surveys, since they point at characteristics of the design and of subpopulations of respondents that can provide identification of response errors. Several models are considered.
Interference by human anti-mouse antibody in two-site immunoassays.

Studies with goat and rabbit anti-mouse antibody, as models of human anti-mouse antibody (HAMA), have shown that several of the commonly used two -site immunoassays (e.g., for CA-125, carcinoembryonic antigen, choriogonadotropin, lutropin, hepatitis B surface antigen, thyrotropin) are susceptible to interference by this type of bridging heterophile antibody. In most cases the interference can be blocked by incubation with mouse IgG. We studied HAMA interference in an assay of hepatitis B surface antigen by using HAMA-positive sera from a transplant patient given OKT3 and from a cancer patient given CYT-103 (modified antibody B72.3). The HAMA interference attributable to the OKT3 could be blocked by incubation with mouse IgG at room temperature. In contrast, the interference caused by the B72.3-induced HAMA could be blocked by prolonged incubation with high concentrations of the B72.3 antibody at 4 degrees C. A limited survey of 50 hospital patients selected without conscious bias revealed two HAMA-positive patients, only one of whom was known to have been exposed to mouse immunoglobulin. HAMA interferences are currently a minor problem in routine laboratory medicine, but the increasing use of diagnostic and therapeutic products involving mouse-origin monoclonal antibodies will make the detection and elimination of HAMA interferences an important part of laboratory practice in the future.
Estimating the Amount of Hydrate And Free Gas From Surface Seismic

Marine seismic data and well log measurements at the Blake Ridge offshore South Carolina show that prominent seismic Bottom Simulating Reflectors (BSRs) are caused by sediment layers with gas hydrate overlying sediments with free gas. We apply a theoretical rock physics model to 2D Blake Ridge marine seismic data to determine gas hydrate and free gas saturation. High-porosity marine sediment is modeled as a granular system where the elastic wave velocities are linked to porosity; effective pressure; mineralogy; elastic properties of the pore-filling material; and water, gas and gas hydrate saturation of the pore space. To apply this model to seismic data, we first obtain interval velocity using stacking velocity analysis. Next, all input parameters to the rock physics model, except porosity and water, gas and gas hydrate saturation, are estimated from geological information. To estimate porosity and saturation from interval velocity, we first assume that the entire sediment does not contain gas hydrate or free gas. Then we use the rock physics model to directly calculate porosity from the interval velocity. Such porosity profiles appear to have anomalies where gas hydrate and free gas are present (as compared to typical profiles expected and obtained in sediment without gas hydrate or gas). Porosity is underestimated in the hydrate region and is overestimated in the free-gas region. We calculate the porosity residuals by subtracting a typical (without gas hydrate and gas) porosity profile from that with anomalies. Next we use the rock physics model to eliminate these anomalies by introducing gas hydrate or gas saturation. As a result, we obtain the desired 2D saturation map. The maximum gas hydrate saturation thus obtained is between 15% and 20% of the pore space (depending on the version of the model used). These saturation values are consistent with those measured in the Blake Ridge wells (away from the seismic line) which are about 12%. Free gas saturation varies between 1% and 2%. The saturation estimates are extremely sensitive to the input velocity values. Therefore, accurate velocity determination is crucial for correct reservoir characterization.
Preoperative saccharine experience and postoperative fluid preference in adrenalectomized rats

Drinking behaviors of adrenalectomized and sham-operated rats were compared under preoperative conditions of saccharine and salt solutions, or only distilled water, available. Saccharine experience did not contribute to a significant change in postoperative drinking behavior; adrenalectomized Ss, regardless of experience, drank less saccharine solution than sham Ss, and all groups consumed similar amounts of NaG. These results contradict other studies in which a sugar solution was the “irrelevant” experience fluid.
Properties of Radio Source Host Galaxies

A brief overview of the current radio source host galaxy state of affairs is given. All the evidence appears to point towards a scenario in which the young radio source expands through the host galaxy on timescales of 105–106 yr, before it ends its life as a large scale FR II radio galaxy. The place and role of the quasars in this evolutionary picture is unclear, however, and remains an issue of debate.
Junctional form of acetylcholinesterase restored at nerve-free endplates.

Abstract Rat soleus muscles were ectopically innervated by implanting a foreign nerve in an endplate-free region of muscle and, 2–3 weeks later, cutting the original nerve. The junctional, 16 S form of acetylcholinesterase (AChE) and focal staining for AChE disappeared from the old endplate region within a few days after denervation. In muscles with an ectopic nerve, but not in paired control muscles, 16 S AChE and focal staining were restored in the old endplate region 1–2 weeks after denervation even though nerve fibers could not be detected in that region. These results suggest that the nerve exerts a local effect, specifying the site at which junctional AChE appears, and a nonlocal effect, perhaps mediated by muscle activity, regulating the amount of junctional AChE.
The fuzzy foreign body fragment: A subtle roentgenographic clue to mediastinal vascular injury

Summary Foreign body injury to mediastinal vascular structures may be present in clinically stable patients who have sustained thoracic trauma. Angiography may occasionally fail to demonstrate such an injury which may lead to delay in surgical management. A subtle roentgenographic finding consisting of a fuzzy metallic fragment contiguous with the mediastinum on admission chest films suggested vascular injury in two patients and prompted surgical exploration. Despite preoperative hemodynamic stability and normal angiograms, major transmural injuries to the pulmonary artery and aorta were encountered in these two patients and were managed successfully.
Numerical investigation of a single-mode chemically reacting Richtmyer-Meshkov instability

We report on high-resolution, numerical simulations of a single-mode, chemically reacting, Richtmyer-Meshkov (RM) instability, at different interface thicknesses. The gases on either side of the diffuse interface were Hydrogen (H $$_2)$$ and Oxygen (O $$_2)$$ , with a pre-shock Atwood number $$(A_t\equiv \frac{\rho _{h}-\rho _{l}}{\rho _{h}+\rho _{l} })$$ of $$\sim $$ 0.5. An incident shock with a Mach number of 1.2 is allowed to traverse from the light (H $$_2)$$ to the heavy (O $$_2)$$ medium in the 2D numerical shock tube. The simulations were performed using the astrophysical FLASH code developed at the University of Chicago, with extensive modifications implemented by the authors to describe detailed H $$_2$$ –O $$_2$$ chemistry, temperature-dependent specific heats, and multi-species equation of state. The interface thickness was systematically varied in the simulations to study the effect of the total mass of fuel burnt and heat added on the hydrodynamic instability growth rates. In the absence of an incident shock, burning results in the formation of so-called combustion waves, which spontaneously trigger RM and Rayleigh-Taylor like instability growth of the interface. We are able to obtain the resulting growth rates of an imposed sinusoidal perturbation, and compare them with the predictions of an impulsive model, with simple modifications to account for the finite thickness of the interface, density changes due to heat addition, and compression of the material line due to the combustion wave. When additionally an incident shock is present, we observe complex interactions between the shock and the aforementioned combustion waves, resulting in significant non-planar distortions of each. When the unstable interface is subjected to a reshock, significant mixing enhancement is observed, accompanied by a dramatic increase in combustion product formation, and combustion efficiency.
Neurogenin 1 Mediates Erythropoietin Enhanced Differentiation of Adult Neural Progenitor Cells

Proneuronal basic helix–loop–helix (bHLH) transcription factor, neurogenin 1 (Ngn1), regulates neuronal differentiation during development of the cerebral cortex. Akt mediates proneuronal bHLH protein function to promote neuronal differentiation. Here, we show that recombinant human erythropoietin (rhEPO) significantly increased Akt activity and Ngn1 mRNA levels in neural progenitor cells derived from the subventricular zone (SVZ) of adult rat, which was coincident with increases of neural progenitor cell proliferation, differentiation, and neurite outgrowth. Inhibition of Akt activity by the phosphatidylinositol 3-kinase/Akt (PI3K/Akt) inhibitor, LY294002, abolished rhEPO-increased Ngn1 mRNA levels and the effects of rhEPO on neural progenitor cells. In addition, reducing expression of endogenous Ngn1 by means of short-interfering RNA (siRNA) blocked rhEPO-enhanced neuronal differentiation and neurite outgrowth but not rhEPO-increased proliferation. Furthermore, treatment of stroke rat with rhEPO signifi...
The relation of nuclear RNA to RNA of other sub-cellular fractions as studied in vitro.

Nuclei containing RNA (labeled in vivo with [6-14C]orotic acid) are combined with a non-radioactive cytoplasmic fraction. During incubation of this reconstituted homogenate, the specific activity of nuclear RNA decreases, and the specific activity of cytoplasmic RNA increases. These phenomena are not due to hydrolysis of nuclear RNA to the level of nucleotides that can be reincorporated into cytoplasmic RNA, nor to a dilution of the nuclear RNA with non-radioactive RNA from other cell fractions. The fraction of highly radioactive nuclear RNA obtained by in vivo labeling is extremely small. After it is released from the nucleus during incubation in vitro, it may be recovered in the final supernatant and post-microsomal fraction (105,000 × g, 2 h. The mitochondria and large microsomes (60,000 × g, 30 in) contain very little of the radioactive RNA released from the nuclei.
Anomalous behavior at the I2/a to Imab phase transition in SiO2-moganite: An analysis using hard-mode Raman spectroscopy

The silica polymorph moganite is commonly intergrown with quartz in microcrystalline silica varieties that are less than ~100 Ma in age. Synchrotron X-ray diffraction suggests that a displacive phase transition occurs when moganite is heated above ~570 K, with an increase in symmetry from I 2/ a to Imab . In the present study, we employed hard-mode Raman spectroscopy to confirm the existence of the α-β moganite transformation and to offer complementary insight into the transition mechanism. Our analysis of the displacement of the 501 Δcm −1 symmetric stretching-bending vibration ( B 3 g mode) with changing temperature strongly supports the existence of a monoclinic-to-orthorhombic phase transition between 570 and 590 K. Between 593 and 723 K, however, the mode remained fixed at 496 Δcm −1 . This behavior was repeated on cooling, but with a hysteresis of over 100 K. We offer three hypotheses that may explain this observation: (1) the intergrowth of nanoscale quartz lamellae within moganite may exert a strain that inhibits the transition; (2) the transition may exhibit a martensitic character marked by the co-existence of α- and β-moganite over a finite temperature interval; and (3) the α- and β-moganite transition may occur via an intermediate phase.
Comparative reproductive success of winter flounder in Long Island Sound: A three-year study (biology, biochemistry, and chemistry)

In a 3-yr study, late prespawning winter flounder were collected from various stations in Long Island Sound (three of them heavily urbanized) and spawned in the laboratory. For comparative purposes, flounder from two sites in the Boston Harbor area were similarly treated in 1987 and 1988. Of the stations in Long Island Sound, New Haven Harbor alone consistently produced low percent viable hatch and small larvae. Boston Harbor produced the smallest larvae of all sites. There were no significant station-to-station differences in lipid utilization during larval development; yolk reserves at stations showing a low percent viable hatch, small larvae, and low embryonic development rate were probably used in part for stress metabolism. No significant differences in concentrations of polychlorinated biphenyls for collections from Long Island Sound were found either in livers of spawned fish, in sediments, or in eggs of winter flounder. The very low metal concentrations in winter flounder eggs showed no relation to the degree of metal contamination found at stations in Long Island Sound and Boston Harbor.
Stability analysis of the Kippenhahn-Schlüter model of solar filaments

In this paper the stability of the Kippenhahn-Schluter model of solar filaments against arbitrary perturbations is investigated. The problem is treated in the MHD approximation and a modification of the energy principle of Bernstein et al. is used. Two necessary and sufficient stability conditions are found: (a) [B z] dB x/dz ≧ 0 and (b) B x d[B z]/dz ≦ 0. Condition (a), in the limit of small currents, leads to the condition already discussed by Kippenhahn and Schluter; condition (b) requires that the current density in the stable filament decreases with height.
The Structural Basis for the Specificity of Epidermal Growth Factor and Heregulin Binding

Abstract Heregulin is a ligand for the erbB3 and erbB4 receptors, with a region of high homology to epidermal growth factor (EGF). Despite this homology, these ligands bind to their corresponding receptors with great specificity. We report here the synthesis of heregulin β 177-241 and show that a region consisting of amino acids 177-226 is sufficient both for binding and stimulation of receptor phosphorylation. Studies of chimeric EGF/heregulin peptides revealed that amino acids 177-181 of heregulin provide the specificity for binding to the heregulin receptor. The substitution of amino acids 177-181 of heregulin for the N terminus of EGF produced a unique bifunctional agonist that binds with high affinity to both the EGF receptor and the heregulin receptor.
Spatial Assessment of a Biocriteria Applied to Texas Tidal Streams

This study reports on a derived multivariate method for assessing ecosystem health within tidally influenced portions of river basins and coastal basins. These tidally influenced areas are highly productive transitional areas which serve as important nursery areas for many fish and shellfish species. Numerous Texas tidal streams under varying degrees of anthropogenic stressors were analyzed jointly with this new, standardized methodology. Physical and chemical constituents of the tidal systems, as well as their resident nekton communities, were compared with nonparametric ordination techniques in order to uncover a biocriteria that might have general applicability over large spatial scales. All of the tidal stream communities were dominated by only a few taxa that each displays tremendous euryhaline/physiological tolerances, and these abilities allow taxa utilizing tidal streams to adapt to a wide variety of environmental stressors. The absence of any clear connections between degraded water-bodies and any impaired nektonic communities should not automatically be viewed as a constraint inherent to the techniques of the methodology presented, but rather a verification that impaired tidal streams are not that common of an occurrence along the Texas coast, at least not when using nekton communities as the degradation indicator.
The mechanism of hypercalciuria in streptozotocin-induced diabetic rats.

Abstract Metabolic studies were performed in streptozotocin-induced diabetic (D) rats and normal control (C) rats to assess the role of hyperphagia in the hypercalciuria of diabetes. Urinary calcium excretion (U Ca V) was significantly higher in D v C rats fed ad libitum. When D rats were pair-fed (calorie and mineral restriction) with C rats, U Ca V declined but remained significantly higher than in C rats. When D rats were allowed their usual increased calorie intake but restricted to C rat mineral consumption, U Ca V remained elevated. These findings suggested a tubular reabsorptive defect. In vivo microinjection studies were then performed to identify the site(s) of the tubular reabsorptive defect. Using 1.0 mmol/L Ca in the injectate, 45 Ca recovery in the urine (CaR%) was significantly higher in D rats after intratubular injections into early and late proximal tubules and late distal but not early distal tubules. An additional load-dependent defect was revealed in the terminal nephron when the Ca concentration of the injectate was increased to 1.8 mmol/L. After early distal injection, CaR% was significantly increased in D v C rats. Infusion of PTH into thyroparathyroidectomized C and D rats enhanced Ca absorption to a similar degree but did not correct the reabsorptive defect in D rats. These results argue against a lack of end-organ responsiveness to PTH in diabetes or a low serum PTH level as the cause of he hypercalciuria. We conclude that hyperphagia contributes to the hypercalciuria of diabetes in the absence of increased Ca intake. Also, two tubular reabsorptive defects exist: one in the loop of Henle; the other, load-dependent in the terminal nephron. PTH does not correct these defects.
Imaging Single Atoms with Z -Contrast Scanning Transmission Electron Microscopy in Two and Three Dimensions

Z-Contrast STEM images of heavily antimony-doped silicon have been acquired which show quantifiable contrast from single impurity atoms inside a crystal. These images are two-dimensional projections of the sample, which makes identifying defects involving clusters of impurities difficult. Spherical aberration-corrected optics allow probes with much larger convergence angles to be used, which makes it possible to localize impurities in three dimensions by optical sectioning. A three dimensional generalization of the standard two-dimensional convolution description of incoherent imaging captures the basics of this new imaging mode, but probe channeling effects introduce important complications for zone-axis crystals.
The end of the information frontier

The possibility now exists of capturing a cradle-to-grave record of everything a person says or does. No longer must a personal history be a partial picture. Technology has made it possible to record, process, store, and retrieve all the text, sounds, and images that are required to paint a complete picture of an individual’s life. The efforts of future historians will be directed more to forgetting than to remembering. By default, society will forget nothing. For almost all of human history, remembering has meant the judicious selection and organization of observations about events and people. There used to be an information frontier beyond which the past was a tabula rasa. That information frontier has gone the way of the dodo. The social memory of events in an individual’s life is not only detailed but permanent. Although physical storage is fallible and changes in technology may make some devices effectively unreadable, these limitations are more than made up for by the negligible cost of duplication and distribution in a network. The record of one’s triumphs and tragedies will haunt one forever. Gone is personal privacy since facts buried in the past can be uncovered at any moment. Gone is personal memory since it is easier to rely on the external social memory of cyberspace. In what follows, we explain these observations and trace their consequences.
Seven Faces in a Crowd: Parallel or Serial Information Processing

Volunteers were given the: task of recognizing a target face buried in a “crowd” of unfamiliar figures. Recognition time increased significantly in proportion to crowd group-size, with a significant difference in times for 7- and 8-member groups. Changing the signal complexity of target stimuli did not affect results. A combined analog-digital processing model is proposed in which information is processed parallelly in batches of limited capacity (<3 bits), which are themselves processed serially.
Absorption coefficient and purine photobleaching rate in colon mucosa during resonance Raman spectroscopy at 251 nm

In contrast to spectroscopy at longer wavelengths, typical attributes of ultraviolet resonance Raman (UVRR) spectroscopy of biologic tissue are higher absorption coefficient, mu, and higher photobleaching rate, kappa. This study was aimed at measuring mu and kappa during UVRR spectroscopy of human colon tissue at 251 nm. mu was used to estimate the penetration depth of the excitation light; kappa was used to predict the rate of signal decrease that was due to photobleaching as a function of laser fluence and tissue thickness. The fitting of the equations through description of a three-state transition model to experimental data that consisted of a purine UVRR signal gave mu = 0.0169 ? 0.0023 mum(-1) and kappa = 0.572 ? 0.168 (mJ/mum(2))(-1). kappa remained independent of power P for P < 1 mW, but higher power values resulted in a higher photobleaching rate. As predicted by the model, signal decrease that was due to photobleaching was slower as sample thickness was increased.
Bootstrapping Direct3D 10

Bootstrapping Direct3D 10 (Chuck Walbourn): A high-level system overview of Direct3D 10 and how it relates to Direct3D 10 and how it relates Direct3D 9 and other graphics APIs. We will run through the basics of setting up and creating a Direct3D 10 device, and demonstrate a few Direct3D 10 code/shader equivalents for existing fixed-function style computations. [40 minutes]
Domain functions of the androgen receptor

Molecular cloning of the androgen receptor cDNA has facilitated analysis of structure/function relationships of this ligand activated transcription factor. Amplification of mutant androgen receptor DNA using the polymerase chain reaction has revealed single base and deletion mutations in the androgen receptor gene that cause the androgen insensitivity syndrome in rats and humans. Site directed mutagenesis of the NH2-terminal and hinge regions indicates specific sequences required for full transcriptional activation and nuclear targeting of the androgen receptor. Finally, transient transfection systems have shown that the antiandrogen cyproterone acetate is both an agonist and antagonist, while hydroxyflutamide acts only as an antagonist and thus is a pure antiandrogen.
Intracranial Hypotension Caused by Anterior Cervical CSF Alleviated by an Epidural Blood Patch

We present a case in which a thoracocervical epidural blood patch was used to treat an anteriorly situated cerebrospinal fluid leak following 2 failed blood patches in the lumbar region. The challenge in identifying the source of the leak, deteriorating health of the patient, and risks from the procedure, contributes to the uniqueness of this case.
Wavelength modulation diode laser absorption spectroscopy for high-pressure gas sensing

A general model for 1f-normalized wavelength modulation absorption spectroscopy with nf detection (i.e., WMS-nf) is presented that considers the performance of injection-current-tuned diode lasers and the reflective interference produced by other optical components on the line-of-sight (LOS) transmission intensity. This model explores the optimization of sensitive detection of optical absorption by species with structured spectra at elevated pressures. Predictions have been validated by comparison with measurements of the 1f-normalized WMS-nf (for n = 2–6) lineshape of the R(11) transition in the 1st overtone band of CO near 2.3 μm at four different pressures ranging from 5 to 20 atm, all at room temperature. The CO mole fractions measured by 1f-normalized WMS-2f, 3f, and 4f techniques agree with calibrated mixtures within 2.0 %. At conditions where absorption features are significantly broadened and large modulation depths are required, uncertainties in the WMS background signals due to reflective interference in the optical path can produce significant error in gas mole fraction measurements by 1f-normalized WMS-2f. However, such potential errors can be greatly reduced by using the higher harmonics, i.e., 1f-normalized WMS-nf with n > 2. In addition, less interference from pressure-broadened neighboring transitions has been observed for WMS with higher harmonics than for WMS-2f.
The design, development, documentation and support of a major finite element system

Abstract The paper discusses various aspects of large general purpose finite element systems which may be of interest both to prospective developers and practising engineers. Although many of the points discussed apply to any field in which the method has been used, attention is concentrated on the static stress analysis problem. The paper considers in detail the initial design decisions concerning program structure, language, usage of available core storage, and methods of accessing backing store. The various facilities which may be of use in such a general system are listed and discussed. The problems which may arise as the development of a system proceeds are considered in three phases; specification, programming and testing. The types of documentation relevant to large engineering systems are described and the importance of an efficient and well organised client support and updating procedure is stressed.
Coupled-channel pseudopotential description of the Feshbach resonance in two dimensions

We derive pseudopotentials that describe the scattering between two particles in two dimensions for any partial wave $m$, whose scattering strength is parametrized in terms of the phase shift ${\ensuremath{\delta}}_{m}$. Using our $m=0$ pseudopotential, we develop a coupled-channel model with two-dimensional (2D) zero-range interactions, which describes the two-body physics across a Feshbach resonance. Our model predicts the scattering length, the binding energy, and the ``closed channel molecular fraction'' of two particles; these observables can be measured in experiments on ultracold quasi-2D atomic Bose and Fermi gases with present-day technology.
Studies of a novel polymerizable amphiphilic dendrimer

Abstract In the present study, we have synthesized a polymerizable amphiphilic dendrimer by attaching 10,12-pentacosadiynoic acid (PDA) to a third generation poly(amidoamine) (PAMAM) dendrimer core (PDA-PAMAM). This dendrimer was characterized by 1H NMR and MALDI-TOF mass spectroscopy. The amphiphilic property of this dendrimer has been studied. Surface pressure and surface dipole moment–area isotherm measurements have shown that PDA-PAMAM forms a stable monolayer at the air–water interface with a limiting molecular area of 460 A2 per molecule. The compressed monolayer can be readily polymerized upon UV irradiation, as like other PDA derivatives. The topography of the monolayer was observed by Brewster angle microscopy (BAM) as well as by the environmental scanning electron microscopy (ESEM). We found a good correlation between the size and shape of monolayer domains observed with the BAM and ESEM techniques. To our knowledge, this is the first time wet mode ESEM has been used to characterize L–B film. The wet mode ensures that L–B films remain intact without being damaged by the high vacuum system of traditional SEM. As a preliminary study, we have found that this new dendrimer forms colloidal particles in chloroform solution and can be readily polymerized by UV irradiation.
The Galactic Centre pulsar population.

The recent discovery of a magnetar in the Galactic centre region has allowed Spitler et al. to characterize the interstellar scattering in that direction. They find that the temporal broadening of the pulse profile of the magnetar is substantially less than that predicted by models of the electron density of that region. This raises the question of what the plausible limits for the number of potentially observable pulsars - i.e., the number of pulsars beaming towards the Earth - in the Galactic centre are. In this paper, using reasonable assumptions - namely, (i) the luminosity function of pulsars in the Galactic centre region is the same as that in the field, (ii) the region has had a constant pulsar formation rate, (iii) the spin and luminosity evolution of magnetars and pulsars are similar, and (iv) the scattering in the direction of the Galactic centre magnetar is representative of the entire inner parsec - we show that the potentially observable population of pulsars in the inner parsec has a conservative upper limit of $\sim$ 200, and that it is premature to conclude that the number of pulsars in this region is small. We also show that the observational results so far are consistent with this number and make predictions for future radio pulsar surveys of the Galactic centre.
Changes in the Theory of Interorganizational Relations in Marketing: Toward a Network Paradigm:

The marketing environment in the 21st century promises to be knowledge rich and very turbulent. The classic, vertically integrated, multidivisional organization, so successful in the 20th century, is unlikely to survive in such an environment. The evidence indicates it will be replaced by new forms of network organization consisting of large numbers of functionally specialized firms tied together in cooperative exchange relationships. This article explores the characteristics of four types of network organization that may represent prototypes of the dominant organizations of the next century. These include the internal market network, the vertical market network, the intermarket network, and the opportunity network. The economic rationale and the types of coordination and control mechanisms driving network organizations are very distinct from those studied under the current exchange or dyadic paradigm. This article analyses the kinds of changes involved in key variables and their meanings in moving from a dyadic view of exchange to a network view.
THE ESSENTIAL ROLE OF CALCIUM ION IN POLLEN GERMINATION AND POLLEN TUBE GROWTH

BREWBAKER, JAMES L., and BEYOUNG H. KWACK. (U. Hawaii, Honolulu.) The essential role of calcium ion in pollen germination and pollen tube growth. Amer. Jour. Bot. 50(9): 859-865. Illus. 1963.-A pollen population effect occurs whenever pollen grains are grown in vitro. Small pollen populations germinate and grow poorly if at all, under conditions which support excellent growth of large pollen populations. The pollen population effect is overcome completely by a growth factor obtained in water extracts of many plant tissues. This factor is shown to be the calcium ion, and its action confirmed in86 species representing 39plant families. Other ions (K+, Mg++, Na+) serve in supporting roles to the uptake or binding of calcium. The high requirement of calcium (300-5000 ppm, as Ca (NO3)2 4H20, for optimum growth) and low calcium content of most pollen may conspire to give calcium a governing role in the growth of pollen tubes both in vitro and in situ. It is suspected that ramifications ofthis role extend to the self-incompatibilities of plants and to the curious types of arrested tube growth distinguishing, for example, the orchids. A culture medium which proved its merit in a wide variety of pollen growth studies included, in distilled water, 10% sucrose, 100 ppm H3BO3, 300 ppm Ca (NO3)2. 4H20, 200 ppm MgSO4. 7H20
“Giving Spirit to our Parents' Stories”

This article illuminates the field trip as an effective pedagogical tool in the undergraduate anthropology classroom. This article emerged from my experiences teaching an undergraduate advanced seminar, African American Anthropology, in which I organized a civil rights field trip to Birmingham, Montgomery, and Selma, Alabama. We went during the 2005 commemorative activities of the fortieth anniversary of “Bloody Sunday” which served as a focal point of the course. Walking tours, museum visits, and other field trips to local and regional sites in the South are discussed as vehicles for engaging student learning in sites that extend beyond traditional course readings, lectures, and films. Memory, identity, and social engagement are discussed as three critical outcomes of the field trip in illuminating American history and African American economic, political, and social experience.
Clinical practice guidelines vs actual clinical practice : the asthma paradigm.

In recent years, a multitude of practice guidelines, statements, position papers, and "best practices" have been promulgated for a number of disease entities by a variety of medical societies and managed care organizations. In the case of asthma, for example, the National Heart, Lung, and Blood Institute of the National Institutes of Health (NIH) initially published guidelines for the diagnosis and management of asthma in 1991; these recommendations were updated in 1997. However, health-care providers have not widely and consistently adhered to these guidelines. Several recent publications suggest that this underutilization of the NIH asthma guidelines may in part be related to a lack of understanding. This lack of understanding appears to span the spectrum of physicians in private practice, physicians working in health maintenance organizations, as well as university-affiliated physicians. Moreover, both primary-care physicians and "asthma specialists" share deficits in their knowledge base. To compound the problem, patients with asthma also demonstrate poor adherence to the guidelines. This poor adherence is evident irrespective of the patient's socioeconomic status. These types of data clearly indicate a need for further educational programs directed to both physicians and patients. However, as with the development and promulgation of any practice guideline, physicians need to be convinced that there exists compelling evidence from well-controlled clinical trials, for example, or from evidence-based medicine, to substantiate implementation of these guidelines.
Application of power hardware-in-the-loop for electric vehicles: A case study utilizing switched reluctance machines

This paper presents the application of Power Hardware-in-the-Loop (PHIL) experiments in electric vehicle development. The switched reluctance machine (SRM) is the subject of PHIL experiments that emulate operational conditions of an electrical vehicle, including battery discharging, mechanical loading cycles, and machine failure for the scenario in which an SRM is employed as the propulsion device. The test bed design is presented along with the experimental data of the test cases. The uniqueness and practicality of PHIL-based experiments in electric vehicles are emphasized and the versatility is demonstrated through several potential operational scenarios of SR.
Public Relations in Media Center Administration

The article discusses why public relations are needed in media center operations. It says public relations is inevitable whether it is planned or not, therefore planning is important. Public relations programs should bring faculty and media personnel together in a spirit of cooperation to implement the many facets of educational technology. The article lists 1) the purposes and needs of a public relations program, 2) steps for organizing, 3) principles to follow, 4) some “don'ts” and, 5) ways to combat the “don'ts.”
Multilayer Self-Assembly of Amphiphilic Cyclodextrin Hosts on Bare and Modified Gold Substrates: Controlling Aggregation via Surface Modification

Self-assembled multilayers of the three modified cyclodextrins (hexakis(2,3-O-hexyl-6-deoxy-6-amino)-α-cyclodextrin (1), heptakis(2,3-O-hexyl-6-deoxy-6-amino)-β-cyclodextrin (2), and octakis(2,3-O-hexyl-6-deoxy-6-amino)-γ-cyclodextrin (3)) on bare gold, as well as on gold surfaces modified with mercaptopropionic (4) and mercaptooctanoic (5) acid, were investigated by cyclic voltammetric, contact angle, FT-IR, and quartz crystal microbalance measurements in neutral aqueous media. The level of organization of the aggregates formed by the three CD derivatives (1−3) on the negatively charged surface of the mercaptopropionic and mercaptooctanoic acid modified gold electrodes proved to be substantially better than that on bare gold electrodes. This finding suggests that although the amphiphilic character of compounds 1−3 can induce aggregation on a gold surface, the electrostatic interaction between the carboxylic acid groups and the positively charged cyclodextrins is the primary force leading to the formation...
Treating the Patient With Digital Hypersensitivity

Digital hypersensitivity is a functionally disabling condition, which often responds to conservative treatment with structured sequential desensitization. This case study describes the treatment hierarchy as the patient responds with objective improvement at each stage.
Fluorescence dequenching kinetics of single cell-cell fusion complexes

In an earlier paper which models the cell-cell (or virus-cell) fusion complex as two partial spherical vesicles joined at a narrow neck (Rubin, R. J., and Yi-der Chen. 1990. Biophys. J. 58:1157–1167), the redistribution by diffusion of lipid-like molecules through the neck between the two fused cell surfaces was studied. In this paper, we extend the study to the calculation of the kinetics of fluorescence increase in a single fusion complex when the lipid-like molecules are fluorescent and self-quenching. The formalism developed in this paper is useful in deducing fusion activation mechanisms from cuvette fluorescence measurements in cell-cell fusion systems. Two different procedures are presented: 1) an exact one which is based on the exact local density functions obtained from diffusion equations in our earlier study; and 2) an approximate one which is based on treating the kinetics of transfer of probes between the two fused cells as a two-state chemical reaction. For typical cell-cell fusion complexes, the fluorescence dequencing curves calculated from the exact and approximate procedures are very similar. Due to its simplicity, the approximate method should be very useful in future applications. The formalism is applied to a typical cell-cell fusion complex to study the sensitivity of dequenching curves to changes in various fusion parameters, such as the radii of the cells, the radius of the pore at the fusion junction, and the number of probes initially loaded to the complex.
Effect of isolating cold aisles on rack inlet temperature

Data center facilities house large number of computer servers that dissipate high power. With rapid increase in the heat flux of such systems, their thermal management has become a challenge that needs to be addressed. In this paper effect of isolating cold aisle on rack inlet temperature is studied computationally. Two raised floor data center configurations with alternating hot and cold aisle arrangement are considered to present this study. Cold aisles are isolated in three ways viz. roofs, doors and roofs & doors. Significant reduction in rack inlet temperature is seen by isolating the cold aisles. Based on the study, recommendations are presented on the ways to isolate the cold aisle and achieve better thermal management without changing the room layout or cold air supply.
Essay on the Contributors to the Elastic Stability Theory

This paper revisits the historical aspects of the contributions made into the elastic stability theory from the structural engineering point of view.Extensive quotations are brought in order to substantiate the claims made. It is hoped that the review constitutes a contribution to the identification of the main ideas pertinent to engineering mechanics.
Effect of hyperglycemia independent of changes in insulin or glucagon on lipolysis in the conscious dog.

Abstract In the face of fixed basal levels of insulin (9 μU/ml) and glucagon (63 pg/ml) maintained by the infusion of somatostatin and replacement amounts of the two pancreatic hormones, the mean arterial plasma glucose concentration was elevated from 102 to 217 mg/dl by continous glucose infusion. Hyperglycemia resulted in a significant decrease in the arterial blood glycerol (35%) and plasma free fatty acid concentrations (46%). The drop in the blood glycerol level was paralleled by a decline in hepatic glycerol uptake indicating thathyperglycemia did not alter the fractional extraction of glycerol by the liver. These results support the view that glucose has a direct antilipolytic effect in vivo.
User-generated analogies of the world wide web: implications for design

The purpose of the present study was to gain insight into the mental representations (e.g., mental models, analogies, user models) that people generate of the World Wide Web. There were three groups of participants included in this study: younger adults with web experience, older adults with web experience, and older adults without web experience. All three groups of participants most frequently described the web as a source of information. There is an apparent mismatch between the models recommended by designers and the models given by our participants. Most users' models consisted of multiple idea units. However, most user models recommended by designers consist of one general idea. Differences were also found between the models offered by our two groups of older adults.
Formation control of multiple vehicles using dynamic surface control and hybrid systems

This paper deals with the formation control of multiple vehicles, using a combination of dynamic surface sliding control and hybrid systems. Each vehicle must perform several manoeuvres, either independently, or in a coordinated fashion as part of a vehicle formation. A dynamic surface controller is designed for each manoeuvre. Switches between manoeuvres and communication protocols between vehicles are represented using hybrid systems formalisms. Here, we present the design of both independent and coordinated dynamic positioning (DP) controllers for ocean vehicles using dynamic surface control. Independent and coordinated dynamic positioning are manoeuvres that the modules forming a floating runway at sea must perform. Experimental results using scaled modules are shown.
Analysis of filter-paper-absorbed, finger-stick blood samples for chloroquine and its major metabolite using high-performance liquid chromatography with fluorescence detection

Abstract Methodology has been developed to facilitate the collection, transport, and analysis of blood samples in studies of chloroquine absorption and metabolism. The method utilizes high-performance liquid chromatography (HPLC) with fluorescence detection to quantify chloroquine and its major metabolite, desethylchloroquine, in 100-μl quantities of blood collected on filter paper. Detection limits are 5 ng/ml for both analytes. No loss of either analyte occurred from filter-paper-collected blood spots stored over a twelve-weeks' period at room temperature. Filter-paper-collected, finger-stick blood spots give values for each analyte comparable to corresponding determinations on venous, whole-blood samples. The HPLC mobile phase selected has general applicability to the separation of antimalarial drugs. The methodology permits effective assessment of chloroquine prophylaxis compliance and parasite drug resistance in remote, malaria-endemic regions.
Endoscopy-assisted surgery of the petrous apex

Abstract Objective Five large petrous apex lesions, 4 cholesterol granulomas and 1 cholesteatoma, were managed with a combination of microsurgical and endoscopic techniques. Study design and setting Retrospective review of clinical experience in an academic medical center. Traditional microsurgical approaches, infracochlear and/or retrofacial, were used in all cases, followed by endoscopic examination and debridement of the interior of the cysts. In all cases residual disease or fibrous septae within the cysts were found endoscopically that were not evident through use of the operating microscope. Results In all cases, the lesions were successfully managed without operative complications. Conclusions The addition of endoscopic visualization to traditional microsurgical approaches allowed exposure of recesses within the lesions, removal of debris and inspissated secretions, and identification and removal of septae and fibrous bands within the petrous apex lesions that would not have been identified with the operating microscope alone. No surgical or postsurgical complications occurred in any of the cases, including facial weakness, hearing loss, or cerebrospinal fluid (CSF) leak.
Speed-of-light effects in high-resolution long-cavity fiber Fabry - Perot scanning interferometers.

High-resolution fiber Fabry–Perot scanning interferometers demonstrate bandwidths from 20 MHz to 4 kHz with corresponding cavity lengths from 26 mm to 500 m. Finite speed-of-light effects are observed for cavity lengths as short as 5 m. Analytical and experimental results show an inverse square-root dependence of bandwidth on cavity length in the speed-of-light-limited regime.