cssi/SciSciGPT-SciSciNet huggingface dataset:
X-ray scattering investigation of the interfaces in Si/Si1-xGex superlattices on Si(001) grown by MBE and UHV-CVD

Abstract We have used X-ray scattering techniques to compare the interface quality in similar Si/Si 1− x Ge x superlattices on Si(001) grown by either molecular beam epitaxy (MBE) or ultra-high vacuum chemical vapor deposition (UHV-CVD). High-resolution X-ray diffraction revealed that both structures were fully strained. The superlattices grown by chemical vapor deposition showed less thickness fluctuations from period to period, but the interfaces were slightly less chemically abrupt than that of the corresponding molecular beam epitaxy-grown structure. Grazing incidence X-ray specular and diffuse scattering revealed significant differences in the microstructural properties of the interface roughness. Transverse rocking scans of satellite peaks and detector scans showed a very different diffuse component in MBE and UHV-CVD. The structure grown by MBE is characterized by a long auto-correlation length (0.5 μ m) while the UHV-CVD sample possess a shorter correlation length (20–50 nm). In both cases, offset reflectivity scans showed that the diffuse scattering peaks at values of perpendicular wave vector transfer corresponding to the superlattice satellite peaks, indicating a strong cross-correlation of the interface roughness.
Avoided crossings of resonance energy curves of one-electron atoms in an external electric field

A rule is developed which predicts avoided crossings of resonance energy curves of long-lived states of one-electron atoms in an external electric field.
People in the Design of Urban Places

This issue of the Journal of Urban Design focuses on research related to social issues in urban design.2 Concern with social issues in urban design and planning arose in the 1960s in response to mo...
Mission Performance of a Solar-and Microwave-Powered Aircraft

Unmanned aerial vehicles typically have limited flight time due to their reconnaissance payload requirements and their restricted scale. A microwave/solar powered flight vehicle, on the other hand, can remain in-theater continuously by harvesting electromagnetic radiation using on-board antennas and solar panels. A rectifying antenna is used to harvest power and rectify it into a form usable by the on-board electric motors and other electronics, while photovoltaic cells harness incoming solar radiation. Discussed is the design of the fuel-less air vehicle and its sensitivity to several key performance metrics for this class of aircraft. New metrics are presented that are unique to microwave-powered aircraft and are useful in the design of its missions. Of critical importance is the strong coupling among the aircraft's flight performance, power harvesting abilities, and its mission capabilities. Traditional and non-traditional wing shapes are presented in order to motivate a discussion of some of the key parameters in the design of a fuel-less air vehicle.
Recent trends in bilayer formation of synthetic amphiphiles

The property of synthetic dialkyl amphiphiles to form vesicular structures can be exploited in a variety of situations, such as mimicking biological membranes, drug delivery, studies related to artificial photosynthesis, aggregates on solids, etc. The stability and thermotropic behavior of liposomes from natural lipids could be improved by synthetically modifying the alkyl chains of the lipids or by using totally synthetic structures. This article, which highlights the important milestones in the development of vesicular structures from synthetic amphiphiles, encompasses a brief description of investigations reporting the introduction of totally synthetic dialkyl amphiphiles, mixtures of monoalkyl cationic and anionic amphiphiles, hyperextended alkyl amphiphiles, and so on. Furthermore, most of the relevant work in the last decade relating to bilayer formation from synthetic amphiphiles is documented here.
Cell cycle withdrawal without concomitant differentiation: Analysis of a G1-specific temperature-sensitive murine myoblast cell line

Skeletal muscle differentiation is accompanied by the withdrawal of the proliferating myoblasts from the cell cycle in the G1 phase. We showed earlier that the length of G1 and the timing of the differentiative transition could be controlled in large part by the composition of the culture medium. In this study we have asked whether a G1 arrest imposed independently of the culture medium is sufficient to elicit the differentiative response. To examine this possibility we have characterized a new G1-specific ts murine myoblast line. This line, ts-36, was identified as a G1-specific mutant on the basis of four criteria: prolonged viability at the nonpermissive temperature (npt), the kinetics of cell cycle withdrawal and reentry in temperature shift experiments, the ability of the cells to differentiate at the npt in low-growth medium, and, finally, the observation that, by the criterion of flow microfluorometry, the mutant cells block at the G1 landmark in the cell cycle. A ts-imposed G1 arrest of up to 96-hr duration is by itself insufficient to activate the differentiative program in ts-36 cells cultured in complete growth medium. The differentiated phenotype is expressed, however, in temperature-arrested cells cultured either in low-growth (conditioned) medium or in a medium from which mitogens have been removed by ultrafiltration. Differentiation can be reversed by refeeding with complete growth medium. The effects of growth medium can be mimicked by FGF to the extent of inhibiting activation of the differentiative program in temperature-arrested ts-36 cells and in eliciting downregulation of muscle-specific contractile protein synthesis. Extrapolating from these observations suggests that growth factors may have more than one role in myogenesis in vitro. They not only stimulate proliferation, but also inhibit differentiation in the absence of proliferation. Examining the kinetics of withdrawal from the cell cycle indicates that ts-36, cultured in conditioned medium blocks at the npt restriction point rather than the conditioned medium block. Our results suggest that two conditions must be met to trigger myogenic differentiation in vitro. Withdrawal from the cell cycle in G1 alone is not sufficient. Reduction of the mitogen level in the medium below a threshold level is an obligate condition for phenotypic expression.
Effect of molasses on regrowth of E. coli O157:H7 and Salmonella in compost teas

Compost water extracts (compost teas) are gaining popularity among organic growers, largely because of their disease suppressive activity when applied to foliage or soil. Production methods often include addition of supplemental constituents, particularly molasses, to stimulate plant-beneficial microbial populations. We have found that molasses amendments also favor regrowth of human pathogenic bacteria, raising public health concerns about potential contamination of treated crops, particularly produce intended for fresh consumption. Using disease outbreak strains marked with green fluorescent protein (GFP) and spontaneous antibiotic-resistance, we found that regrowth of Salmonella enterica serovar Thompson and Escherichia coli O157:H7 was positively correlated with molasses concentration. For Salmonella, regrowth was also dependent on the type of starter compost material used. Salmonella populations increased from 1 at time 0 to over 1000 CFU ml−1 in dairy manure compost tea with 1% molasses, and from 1 ...
Note on Resonances in Transmutations of Light Nuclei

It is shown that the sharp resonance effects observed in many transmutations involving light nuclei require the existence of fairly strict selection rules to limit the decay rates of the corresponding compound nuclei. Such selection rules in several cases follow from the slowness of the interconversion of spin and orbital angular momentum. Some consequences of this are discussed for the bombardment of B and F by protons.
Endothelial leukocyte adhesion molecule 1: an inducible receptor for neutrophils related to complement regulatory proteins and lectins

Focal adhesion of leukocytes to the blood vessel lining is a key step in inflammation and certain vascular disease processes. Endothelial leukocyte adhesion molecule-1 (ELAM-1), a cell surface glycoprotein expressed by cytokine-activated endothelium, mediates the adhesion of blood neutrophils. A full-length complementary DNA (cDNA) for ELAM-1 has now been isolated by transient expression in COS cells. Cells transfected with the ELAM-1 clone express a surface structure recognized by two ELAM-1 specific monoclonal antibodies (H4/18 and H18/7) and support the adhesion of isolated human neutrophils and the promyelocytic cell line HL-60. Expression of ELAM-1 transcripts in cultured human endothelial cells is induced by cytokines, reaching a maximum at 2 to 4 hours and decaying by 24 hours; cell surface expression of ELAM-1 protein parallels that of the mRNA. The primary sequence of ELAM-1 predicts an amino-terminal lectin-like domain, an EGF domain, and six tandem repetitive motifs (about 60 amino acids each) related to those found in complement regulatory proteins. A similar domain structure is also found in the MEL-14 lymphocyte cell surface homing receptor, and in granule-membrane protein 140, a membrane glycoprotein of platelet and endothelial secretory granules that can be rapidly mobilized (less than 5 minutes) to the cell surface by thrombin and other stimuli. Thus, ELAM-1 may be a member of a nascent gene family of cell surface molecules involved in the regulation of inflammatory and immunological events at the interface of vessel wall and blood.
Studies on compression wood—part VII: Distribution of lignin in normal and compression wood of tamarack [Larix laricina (Du Roi) K. Koch]

The distribution of lignin has been studied in tracheids and ray cells of normal and compression wood of tamarack [Larix laricina (Du Roi) K. Koch]. The three layers in the secondary wall of normal wood tracheids are lignified to approximately the same extent, and previous evidence that the S 3 layer should contain a higher proportion of lignin than the other regions has not been confirmed. The lignin follows closely the orientation of the cellulose microfibrils in all three layers. Compared to the tracheids, the ray cells contain a denser network of lignin in their secondary wall. Only a small proportion of the total lignin in compression wood tracheids is present in the compound middle lamella. The thick S 1 layer is only slightly lignified; the orientation of the lignin in this region is that of the transversely oriented, lamellated microfibrils. The outer portion of S 2 consists largely of lignin but also contains lamellae of cellulose microfibrils which probably have the same helical orientation as the microfibrils in the inner part of S 2. The latter region, which contains the helical cavities, consists of lamellae of cellulose microfibrils which are uniformly encrusted with lignin. The ray cells in compression wood appear to be lignified to the same extent as in normal wood. Transverse sections of the cells reveal a lateral orientation of the lignin. The orientation of the cellulose microfibrils in the S 2 layer of the first-formed springwood tracheids of compression wood is the same as in the cells which are formed later. It is suggested that for ease of reference, the outer, lignin-rich layer in compression wood tracheids be referred to as the S 2(L) layer.
Exhibiting monstrosity: Chang and Eng, the 'original' Siamese twins.

Abstract Chang and Eng, the two young men who would eventually be known around the world as the ‘original’ Siamese twins, arrived in the West in 1829. They were brought to the West to be examined by medical men and to be exhibited to the general public. Throughout the 19th century in Britain and the US, ‘monstrosities’ such as Chang and Eng, as well as a host of other people with unusual anatomies, were considered both spectacles worthy of public display and edifying medical subjects with the potential to build on medical knowledge. The unique case of Chang and Eng illustrates that the boundary between what is of legitimate medical interest and what is considered merely spectacle is often blurred.
Durable Goods Theory for Real World Markets

The early 1970s witnessed three major advances in durable-goods theory--Swan (1970, 1971) and Sieper and Swan (1973) on optimal durability, Coase (1972) on time inconsistency, and Akerlof (1970) on adverse selection. This paper surveys durable goods theory starting with these three contributions, where much of the focus is on recent literature and on models that explain real-world phenomena. In addition to the ideas found in the contributions of Swan, Coase, and Akerlof, topics covered include why producers sometimes practice "planned obsolescence," the role of adverse selection in new-car leasing, and reasons for aftermarket monopolization.
Compleximetric titration of thorium with potentiometric end-point indication

Abstract In this redox-based direct potentiometric method, thorium is titrated with ethylenediaminetetraacetic acid (EDTA) in the presence of the Cu(II)—EDTA complex and ammonium thiocyanate. The indicator electrode is platinum. Solutions of irradiated thorium fuel, with less than 25 μmol in a sample aliquot, can be titrated. Solutions used to dissolve thorium samples contain aluminum, which can be masked kinetically, by pH adjustment, or with oxalate. Metal ions forming EDTA complexes with stability constants similar to or greater than that of copper(II) interfere.
Effect of high pressure carbon dioxide on the solubility and diffusivity of dichloromethane in polyetherimide

The high pressure inverse gas chromatography technique was used to study the effect of carbon dioxide on the solubility and diffusivity of dichloromethane in polyetherimide. CO2 was used as the carrier gas with pressures from 0.7 to 3.5 MPa and temperatures between 100 and 175°C. Similar data were obtained for the dichloromethane-polyetherimide system using helium as the inert carrier gas. As a result of less favorable thermodynamic interactions between the polymer and solvent, the solubility of the dichloromethane was found to be decreased appreciably in the presence of CO2. The increased free volume in the polymer provided by the dissolved CO2 significantly increased the diffusion coefficient. When the temperature was increased the solubility was decreased while the diffusivity was increased. These behaviors have the potential to considerably improve devolatilization processes. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
A Comparison of Landscapes Occupied by Increasing and Decreasing Populations of Grassland Birds

For several decades, many grassland bird species have been declining in abundance throughout the Midwest and Great Plains regions of the United States, possibly due to loss of natural grassland habitat and increasing urbanization. I used 20 years of data from the North American Breeding Bird Survey to identify increasing, decreasing, and stable populations of 36 grassland-nesting bird species. I characterized the immediate landscape (circle with radius = 30 km) surrounding each population based on data from the National Resources Inventory. For each landscape, I calculated the proportion of eight different land-cover types: restored grassland, rangeland, cultivated cropland, pasture, noncultivated cropland, forest, urban land, and water. Using a null model, I compared landscape composition of increasing, decreasing, and stable populations. As predicted on the basis of the habitat preferences of grassland birds, increasing populations inhabited landscapes that contained significantly more restored grassland and rangeland but significantly less forest land and urban land than landscapes inhabited by decreasing populations. There was no significant difference in the proportion of cropland within the landscapes of increasing and decreasing populations, although cropland composed a large proportion (>30%) of many landscapes. In contrast, restored grassland typically composed a very small proportion (<3.5%) of total land cover, yet it was significantly more common in the landscapes of increasing than decreasing populations. These results suggest that grassland birds may benefit from government initiatives, such as the Conservation Reserve Program, that promote the restoration of grassland at a landscape scale.
Robust resource allocation in security games and ensemble modeling of adversary behavior

Game theoretic algorithms have been used to optimize the allocation of security resources to improve the protection of critical infrastructure against threats when limits on security resources prevent full protection of all targets. Past approaches have assumed adversaries will always behave to maximize their expected utility, failing to address real-world adversaries who are not perfectly rational. Instead, adversaries may be boundedly rational, i.e., they generally act to increase their expected value but do not consistently maximize it. A successful approach to addressing bounded adversary rationality has been a robust approach that does not explicitly model adversary behavior. However, these robust algorithms implicitly rely on an efficiently computable weak model of adversary behavior, which does not necessarily match adversary behavior trends. We therefore propose a new robust algorithm that provides a more refined model of adversary behavior that retains the advantage of efficient computation. We also develop an ensemble method used to tune the algorithm's parameters, and compare this method's accuracy in predicting adversary behavior to previous work. We test these contributions in security games against human subjects to show the advantages of our approach.
Real-time detection and classification of objects in flowing water

This paper describes the design of a PC-based real-time machine vision system for detecting and classifying small marine organisms like fish eggs and planktons in flowing water. The system is called the Real-time FLow Imaging and Classification System, or ReFLICS for short, and it will automate the task of visually counting and classifying fish egg samples which is currently performed by trained humans. ReFLICS uses a line-scan image sensor to eliminate double counting and boundary effects. Using a combination of flowmeter and image-based flow error correction algorithm, ReFLICS's line-scan camera can work with changing flow. Design of the complete system from the camera and illumination housing to the machine vision software allows ReFLICS to work in the harsh environments of a ship at sea. Using an industry-standard multi-processor PC with PCI card pipeline image processor and running Microsoft Windows NT, ReFLICS can achieve the high performance required meanwhile maintaining relative low equipment, development, and maintenance costs. This paper provides the ReFLICS system design and presents initial results of the system.
Radiologic Errors and Malpractice: A Blurry Distinction

Medical error: Failure of a planned action to be completed as intended [1]. Medical malpractice: Unreasonable lack of skill. Failure of a physician...to exercise that degree of skill and learning commonly applied under all the circumstances in the community by the average prudent reputable physician with the result of injury...to the [patient] [2].
Mapping a Wind–Modified Urban Heat Island in Tucson, Arizona (with Comments on Integrating Research and Undergraduate Learning)

Tucson, Arizona, is an example of the many cities in the southwestern United States experiencing rapid growth and urban sprawl over the last several decades. The accompanying extensive modification of land use and land cover leads to many environmental impacts, including urban heat islands. The primary aim of this paper is to expand knowledge of the phenomenon for Tucson, by quantifying the amount of urban warming, and by mapping temperature patterns over the city and examining related aspects of the local-scale atmospheric circulation. The secondary aim is to document how an applied empirical research project was integrated into an introductory undergraduate climatology class via active learning. The paper begins and concludes with general and practical comments on combining the research and educational aspects of the project. An analysis of 30-yr temporal trends in urban and nonurban minimum temperatures across the region shows the rate of urban warming to be about three-quarters of the general regional...
The relationship of theory and experiment in the D-region.

Abstract For any physical system, one seeks to monitor its descriptive parameters and construct a model which predicts their temporal and spatial variations. This is a particularly difficult task for the lower ionosphere. In a given situation simultaneous measurements should be conducted of ionization sources, the altitude distribution of all neutral atmospheric constituents, the identification, number density and altitude distribution of different species of positive and negative ions and electrons. These results are compared with theoretical predictions to serve as boundary conditions and guides to modification of the theory. It has not been possible to realize this goal in lower ionosphere research because of the large number of parameters and since certain parameters, as for example, positive ion species distribution and nitric oxide, can only be measured with the aid of sounding rockets. To illustrate the difficulty, recent positive ion composition measurements will be compared with predictions utilizing clustering of ions and neutrals to form hydrated ions.
The A. thaliana disease resistance gene RPS2 encodes a protein containing a nucleotide-binding site and leucine-rich repeats

In plants, resistance to a pathogen is frequently correlated with a genetically defined interaction between a plant resistance gene and a corresponding pathogen avirulence gene. A simple model explains these gene-for-gene interactions: avirulence gene products generate signals (ligands), and resistance genes encode cognate receptors. The A. thaliana RPS2 gene confers resistance to the bacterial pathogen P. syringae carrying the avirulence gene avrRpt2. A map-based positional cloning strategy was used to identify RPS2. The identification of RPS2 was verified using a newly developed transient assay for RPS2 function and by genetic complementation in transgenic plants. RPS2 encodes a novel 105 kDa protein containing a leucine zipper, a nucleotide-binding site, and 14 imperfect leucine-rich repeats.
Selenium bioaccumulation and maternal transfer in the mayfly Centroptilum triangulifer in a life-cycle, periphyton-biofilm trophic assay.

Selenium contamination in aquatic ecosystems provides management challenges because bioaccumulation in animals is largely a function of dietary exposure, whereas regulatory entities have traditiona...
Linguistic Classification in Italy: Problems and Predictions.

SUNTOLo schema in uso generale per descrivere la situazione linguistica italiana comprende due categorie, 'dialetto regionale' e 'italiano regionale', che si adat-tano difficilmente al sistema sociolinguistico generale VARIETA, DIALETTO, LINGUA. Provo di mostrare che queste categorie dovrebbero considerarsi tutt'e due DIALETTI, l'uno un Vecchio' dialetto a base del proto-romanzo, l'altro un 'nuovo' dialetto a base dell'italiano standard (toscano). Se i dialetti italiani si estingueranno fra qualche generazione, non saranno completamente scomparsi: gli 'italiani regionali', continuando dei loro tratti, resteranno e diventeranno i dialetti italiani dell'avvenire.RESUMOLa generale uzata plano, per kiu oni priskribas la italan lingvosituacion, entenas du kategoriojn, "regiona dialekto" kaj "regiona itala lingvo". Tiu en-kategoriigo estas malfacile adaptebla al la kutima socilingvistika sistemo, kiu distingas inter variajo, dialekto kaj lingvo. La aǔtoro provas pruvi, ke ambaǔ kutimaj kategorioj devus esti traktataj kiel dialektoj. Unu el ili estas "malnova" dialekto bazita sur la protolatinida lingvo, la alia estas "nova" dialekto bazita sur la norma itala lingvo (la toska). Se la italaj dialektoj estingigos post kelkaj gene-racioj, ili ne tute malaperos. La "regionaj italaj lingvoj", kiuj daurigos iliajn trajtojn, restos kaj igos la italaj dialektoj de la estonteco.
Publishing perspectives from the editors

After overseeing the review process of almost 1000 manuscripts over the course of 6 years, we, as editors, would like to synthesize some of the factors that we consider to be important to successfully publish in Journal of Retailing or other similar academic publications. Specifically, we discuss choosing an appropriate journal, topic, and the interrelation between the two. Second, we weigh in on one of the most difficult criteria for publication, establishing a contribution. Third, we examine some of the nitty-gritty issues of writing and rewriting a paper. We conclude with the final phase of the first round, submitting the paper and dealing with reviewer feedback.
952-30 Left Ventricular Ejection Performance Improves Late After Aortic Valve Replacement in Patients with Aortic Stenosis and Reduced Ejection Fraction

To assess the time course and magnitude of change in left ventricular (LV) wall stress and ejection performance indices, 24 patients undergoing aortic valve replacement (AVR) for aortic stenosis were prospectively evaluated. Each patient underwent resting radionuclide angiography (RNA), echocardiography, and cardiac catheterization (high fidelity pressure) before AVR, then RNA and echocardiogram at one week and six months after AVR. Patients were stratified by preoperative ejection fraction (EF) into reduced EF (l50%) and normal EF (≥50%) groups. Pre-operatively, peak positive dp/dt was lower in the reduced EF group (1300 vs 1700 mmHg/sec, p = 0.035), and wall stress was elevated similarly in both groups (p = NS). Temporal Relationships of EF and Wall Stress Pre-op 1 Week 6 Mos Normal EF (n = 14) Mean Ejection Fraction (%) 66 64 68 Mean Wall Stress (dyne/cm 2 × 10 3 ) 62 34 44 Reduced EF (n = 10) Mean Ejection Fraction (%) 38 37 57 Mean Wall Stress (dyne/cm 2 × 10 3 ) 78 52 61 Wall stress was reduced at one week post-operatively (p l 0.005) in both groups. Ejection fraction remained depressed in the reduced EF group. By six months, however, EF had dramatically improved in the reduced EF group (p = 0.002). Conclusion In patients with LV dysfunction, EF remains low one week after AVR despite rectification of afterload mismatch. At six months, however, ejection performance improves. Therefore, when measured by ejection phase indices, the surgical benefit from AVR is not evident until late post-operatively.
Activation of guanylate cyclase by α-toxins from krait and cobra venom

Abstract The effects of purified neurotoxins from krait and cobra venom were tested on guanylate cyclase activity in rat tissues. Both α-bungarotoxin and α-cobrotoxin stimulated the activity of the soluble form of this enzyme in lung, spleen and kidney, but were without effect in liver, muscle and brain. Half maximal stimulation of guanylate cyclase occurred at about 1 μM with α-bungarotoxin and at about 0·25 μM with α-cobrotoxin. Reduction and alkylation, or oxidative detoxification of the toxins abolished their ability to stimulate the guanylate cyclase enzyme. Treatment with dithiothreitol also greatly reduced the effect of the toxins. These data suggest that the toxins may act in vitro by altering the redox state of guanylate cyclase. Neither curare nor atropine blocked the stimulatory effect of these toxins on the enzyme.
Huntingtin Regulates RE1-silencing Transcription Factor/Neuron-restrictive Silencer Factor (REST/NRSF) Nuclear Trafficking Indirectly through a Complex with REST/NRSF-interacting LIM Domain Protein (RILP) and Dynactin p150Glued

Huntingtin has been reported to regulate the nuclear translocation of the transcriptional repressor RE1-silencing transcription factor/neuron-restrictive silencer factor (REST/NRSF). The REST/NRSF-interacting LIM domain protein (RILP) has also been shown to regulate REST/NRSF nuclear translocation. Therefore, we were prompted to address the question of how two distinct proteins could have the same function. We initially used a yeast two-hybrid screen to look for an interaction between huntingtin and RILP. This screen identified dynactin p150Glued as an interacting protein. Coimmunoprecipitation of proteins in vitro expressed in a reticulocyte lysate system showed an interaction between REST/NRSF and RILP as well as between RILP and dynactin p150Glued. Coimmunoprecipitation analysis further showed a complex containing RILP, dynactin p150Glued, and huntingtin. Huntingtin did not interact directly with either REST/NRSF or RILP, but did interact with dynactin p150Glued. The N-terminal fragment of wild-type huntingtin did not affect the interaction between dynactin p150Glued and RILP; however, mutant huntingtin weakened this interaction. We further show that HAP1 (huntingtin-associated protein-1) prevents this complex from translocating REST/NRSF to the nucleus. Thus, this study suggests that REST/NRSF, dynactin p150Glued, huntingtin, HAP1, and RILP form a complex involved in the translocation of REST/NRSF into the nucleus and that HAP1 controls REST/NRSF cellular localization in neurons.
The Implications of Joint Cost Standards for Charity Reporting

In 1987, SOP No. 87‐2 permitted charities to report a portion of the joint costs associated with combined public education efforts and fund‐raising appeals as program service expenses. Charities us...
Etch rate studies of base catalyzed hydrolysis of polyimide film. II

The influence of a potassium carbonate (K2CO3) additive on the base catalyzed hydrolysis of polyimide (Kapton†) film in aqueous potassium hydroxide (KOH) was determined experimentally. The etch rate is significantly greater for KOH/K2CO3 solutions compared with solutions composed of KOH only. The experimental order of the reaction with respect to the KOH concentration was found to be 1.5. In addition, the rate was found to increase linearly with respect to the K2CO3 concentration at a fixed KOH concentration. Visual observations of a thinner gel layer on the surface of the film, combined with increased solubility of the etch by-products in KOH/K2CO3 relative to KOH, help to explain the difference in etch rate. It appears the ability of K2CO3 to enhance the solubility of the hydrolyzed polyimide (polyamic acid salt) results in faster etch rates.
Development and Preliminary Reliability of the Functional Upper Extremity Levels (FUEL).

Objective The Functional Upper Extremity Levels (FUEL) is a new classification tool to assess a person's upper-extremity functional and physical performance after sustaining a stroke. The aim of this preliminary study was to develop the tool and determine its content validity and interrater reliability. Method Forty-four licensed occupational therapists ranging in years of experience from 6 mo to 16 yr participated in this study. A two-phase study was conducted: (1) constructing the FUEL and determining its content validity and (2) ascertaining its interrater reliability. Results We found that the FUEL had initial content validity and substantial interrater reliability (Fleiss κ = .754). Conclusion The FUEL can be a useful clinical and research tool in occupational therapy for the assessment and classification of upper-extremity function for people after stroke. Further studies with larger samples and comparison studies with other similar tools are required to support the tool's reliability and validity.
The Magellan UNIX-based SAR processor

Through three cycles of radar data collection at Venus that ended in September 1992, the Magellan mission has collected radar image data covering over 99% of the Venusian planet surface. The data reduction process of deriving image data from radar signal data has been performed primarily on the Primary SAR Processor (PSP) at the Magellan Radar Data Processing Facility (MRDPF). The MRDPF is currently scheduled for de-commissioning in September 1993 after completing its third year of SAR data processing operations. The Magellan UNIX-based SAR Processor (USP) was developed with the objective of preserving Magellan data processing capability. The USP development was a clear departure from utilizing custom-built hardware for SAR processor implementation. It followed the current trend in SAR processor development in utilizing commercial concurrent processing technology and parallel computing machinery. The USP development is presented with discussions focused on algorithm enhancements made possible by the removal of hardware constraints and pertinent implementation considerations that affected throughput and image quality. >
Quantum Mechanics of Black Holes

The popular conception of black holes reflects the behavior of the massive black holes found by astronomers and described by classical general relativity. These objects swallow up whatever comes near and emit nothing. Physicists who have tried to understand the behavior of black holes from a quantum mechanical point of view, however, have arrived at quite a different picture. The difference is analogous to the difference between thermodynamics and statistical mechanics. The thermodynamic description is a good approximation for a macroscopic system, but statistical mechanics describes what one will see if one looks more closely.
Regulation of mTORC1 and mTORC2 Complex Assembly by Phosphatidic Acid: Competition with Rapamycin

mTOR, the mammalian target of rapamycin, is a critical node for control of cell growth and survival and has widely been implicated in cancer survival signals. mTOR exists in two complexes: mTORC1 and mTORC2. Phospholipase D (PLD) and its metabolite phosphatidic acid (PA) have been implicated in the regulation of mTOR; however, their role has been controversial. We report here that suppression of PLD prevents phosphorylation of the mTORC1 substrate S6 kinase (S6K) at Thr389 and the mTORC2 substrate Akt at Ser473. Suppression of PLD also blocked insulin-stimulated Akt phosphorylation at Ser473 and the mTORC2-dependent phosphorylation of PRAS40. Importantly, PA was required for the association of mTOR with Raptor to form mTORC1 and that of mTOR with Rictor to form mTORC2. The effect of PA was competitive with rapamycin-with much higher concentrations of rapamycin needed to compete with the PA-mTORC2 interaction than with PA-mTORC1. Suppressing PA production substantially increased the sensitivity of mTORC2 to rapamycin. Data provided here demonstrate a PA requirement for the stabilization of both mTORC1 and mTORC2 complexes and reveal a mechanism for the inhibitory effect of rapamycin on mTOR. This study also suggests that by suppressing PLD activity, mTORC2 could be targeted therapeutically with rapamycin.
Information-Theoretic Bounds of Evolutionary Processes Modeled as a Protein Communication System

In this paper, we investigate the information theoretic bounds of the channel of evolution introduced in [1]. The channel of evolution is modeled as the iteration of protein communication channels over time, where the transmitted messages are protein sequences and the encoded message is the DNA. We compute the capacity and the rate-distortion functions of the protein communication system for the three domains of life: Achaea, Prokaryotes and Eukaryotes. We analyze the tradeoff between the transmission rate and the distortion in noisy protein communication channels. As expected, comparison of the optimal transmission rate with the channel capacity indicates that the biological fidelity does not reach the Shannon optimal distortion. However, the relationship between the channel capacity and rate distortion achieved for different biological domains provides tremendous insight into the dynamics of the evolutionary processes. We rely on these results to provide a model of protein sequence evolution based on the two major evolutionary processes: mutations and unequal crossover.
Targeting reduction of proteinuria in glomerulonephritis: Maximizing the antifibrotic effect of valsartan by protecting podocytes

Although angiotensin (Ang) II blockade has become a standard antifibrotic therapy in kidney disease, the therapeutic efficacy of Ang II blockade is yet to be optimized. Considering the prognostic impact of proteinuria reduction, we hypothesized that titration of Ang II blockade for optimal anti-proteinuric effect would improve renoprotection. One day after induction of Thy 1.1 glomeruonephritis, rats were treated with increasing doses of the Ang II receptor blocker valsartan in drinking water. Six days after disease induction, the therapeutic effect on proteinuria, podocyte injury and glomerular fibrosis was evaluated. Increasing doses of valsartan resulted in increasing reduction of proteinuria. The maximally effective dose of valsartan was determined to be 1000 mg/l, which reduced proteinuria by 80% and maximally reduced glomerular matrix expansion, fibronectin, collagen I and collagen III staining and glomerular mRNAs for TGFs1, PAI-1, FN and collagen I. Notably, valsartan given at this dose prevented podocyte dysfunction by preserving expression of podocin and nephrin and the counter-regulating molecule B7-1 that is involved in podocyte injury. These results support the hypothesis that higher doses of valsartan are required to optimize proteinuria reduction and glomerulosclerosis amelioration. Further, the optimal dose of valsartan also provides an additional therapeutic effect by preventing podocyte dysfunction.
Identification of Tyrosine Residues in Constitutively Activated Fibroblast Growth Factor Receptor 3 Involved in Mitogenesis, Stat Activation, and Phosphatidylinositol 3-Kinase Activation

Fibroblast growth factor receptor 3 (FGFR3) mutations are frequently involved in human developmental disorders and cancer. Activation of FGFR3, through mutation or ligand stimulation, results in autophosphorylation of multiple tyrosine residues within the intracellular domain. To assess the importance of the six conserved tyrosine residues within the intracellular domain of FGFR3 for signaling, derivatives were constructed containing an N-terminal myristylation signal for plasma membrane localization and a point mutation (K650E) that confers constitutive kinase activation. A derivative containing all conserved tyrosine residues stimulates cellular transformation and activation of several FGFR3 signaling pathways. Substitution of all nonactivation loop tyrosine residues with phenylalanine rendered this FGFR3 construct inactive, despite the presence of the activating K650E mutation. Addition of a single tyrosine residue, Y724, restored its ability to stimulate cellular transformation, phosphatidylinositol 3-kinase activation, and phosphorylation of Shp2, MAPK, Stat1, and Stat3. These results demonstrate a critical role for Y724 in the activation of multiple signaling pathways by constitutively activated mutants of FGFR3.
Asymmetry of visual interference.

This research studies lateral interference among items in the visual field under conditions in which central cognitive factors such as attention and memory limitations are eliminated or controlled for. Under these conditions lateral masking is still found, and it is still asymmetrical (peripheral items interfere with recognition of central items more than central with peripheral). These experiments therefore add to the evidence that both lateral interference and the asymmetry of interference have a component that does not result from cognitive strategies. The experiments also add to the evidence that the asymmetry effect at the sensory level can be attributed to the falloff in acuity from the center to the periphery of the retina, since the mean eccentricity of the target-mask cluster is more peripheral with a peripheral mask than with a central mask. The hypothesis is advanced that the asymmetry effect, as well as lateral interference itself, at the sensory level results from the grouping of target and mask into a single Gestalt-like configuration. The final experiment in the series supports this hypothesis
An update on the natural sources and sinks of atmospheric mercury

Abstract This paper summarizes recent advances in the understanding of the exchange of Hg between the atmosphere and natural terrestrial surfaces including substrates (soil, rocks, litter-covered surfaces and weathered lithological material) and foliage. Terrestrial landscapes may act as new sources of atmospheric Hg, and as repositories or temporary residences for anthropogenically and naturally derived atmospheric Hg. The role of terrestrial surfaces as sources and sinks of atmospheric Hg must be quantified in order to develop regional and global Hg mass balances, and to assess the efficacy of regulatory controls on anthropogenic point sources in reduction of human Hg exposure. Continued field research has allowed for refinement of emission estimates for geothermal and volcanic, and Hg mineralized areas in the western USA to ∼1.2–3.0, and 10–20 Mg/a, respectively. The emission estimate for areas of Hg mineralization in the western USA includes only identified Hg deposits and occurrences, and since other areas of geologic Hg enrichment such as Au and Ag deposits are not considered, the range in values is most likely an underestimate. Laboratory and field measurements have improved understanding of air–surface Hg exchange associated with soils with low or natural background concentrations of Hg (
Magnetization fluctuations in uniformly magnetized thin-film recording media

The noise power spectrum of uniformly magnetized media is measured. The measured spectra are corrected for playback effects (gap loss, spacing loss, head differentiation, and amplifier gain) to yield the spectrum of the medium magnetization fluctuations. The resulting spectral shape approximately fits a simple Lorentzian form. Fluctuation correlation length and variance are easily determined for all states of medium magnetization. Noise power data are compared to the results of in-situ remanence measurements. DC current applied to the recording head produced the uniform magnetization states for which the noise was analyzed. The remanent magnetization corresponding to each current was determined by recording long-wavelength square waves utilizing the same current amplitude that produced the uniformly magnetized state. >
Personalized medicine: The return of the house call?

Personalized medicine is a new mantra evolving in health care. Harnessing each person’s clinical, genetic, genomic, and environmental information drives the concept. The idea is simple. We can maximize a patient’s chances of a better outcome if we base treatments on what we know. However, isn’t this in many ways the way it’s always been? Isn’t this in part the basis for that old-time house call? To see how a disease or condition is being cared for in the home environment? Clinicians have long used personalized medicine, without overt use of single nucleotide polymorphisms, but certainly not totally void of genetic information. Of course, physicians of the past did not have gene chips, but they did have family histories often informing their decisions. Today as we raise the hopes for targeted therapies to break us free from the algorithmic treatments often followed by hit and miss approaches, there is a renewed fervor for personalized medicine. How do we get there and how does the average clinician or researcher understand the burgeoning array of information, talking heads, and latest hype of subgroup benefits? A key aspect is to trust your training, your experience, and your instincts, coupled with a few repeated doses of biostatistics.
Low-cost multi-touch sensing through frustrated total internal reflection

This paper describes a simple, inexpensive, and scalable technique for enabling high-resolution multi-touch sensing on rear-projected interactive surfaces based on frustrated total internal reflection. We review previous applications of this phenomenon to sensing, provide implementation details, discuss results from our initial prototype, and outline future directions.
A near-minimum time controller for two coordinating robots grasping an object

The development of a near-minimum-time control for two coordinating robots manipulating an object in a workspace is addressed. Optimal control theory is used to derive a feedback controller which will enable the two robots to move an object from one place to another in near-minimum time. A dynamic model for the two robots and the load is established and then linearized using the average dynamics method. The model is continuously updated at every control interval, making it suitable for high-speed applications such as minimum-time problems. Bang-bang control theory in conjunction with synchronization of execution time for each joint is used to derive the near-minimum-time controller. The model and the control law are simulated for two distinct schemes. One is a master-slave configuration of the two robots, and the other is based on an optimal controller for both robots. The simulation results indicate that the proposed controller implemented for both schemes behaves favorably. >
Moles: tool-assisted environment isolation with closures

Isolating test cases from environment dependencies is often desirable, as it increases test reliability and reduces test execution time. However, code that calls non-virtual methods or consumes sealed classes is often impossible to test in isolation. Moles is a new lightweight framework which addresses this problem. For any .NET method, Moles allows test-code to provide alternative implementations, given as .NET delegates, for which C# provides very concise syntax while capturing local variables in a closure object. Using code instrumentation, the Moles framework will redirect calls to provided delegates instead of the original methods. The Moles framework is designed to work together with the dynamic symbolic execution tool Pex to enable automated test generation. In a case study, testing code programmed against the Microsoft SharePoint Foundation API, we achieved full code coverage while running tests in isolation without an actual SharePoint server. The Moles framework integrates with .NET and Visual Studio.
Determination of Geometric Farfield for Ducted and Unducted Rotors

In this research, the requirements for microphones to be in the geometric farfield for ducted and unducted rotors have been established. The approach is to acquire acoustic data at various geometric locations relative to the source. This is performed for different rotor configurations and compared with the Inverse Square Law (ISL). This paper produced a measurement requirement that satisfies the ISL. It is presented in terms of rotor diameter and/or duct length. If this requirement is met then data for rotors with different dimensions acquired at any anechoic facility may be compared. Furthermore, the present work defines the shortest distance where farfield microphone should be placed for accurate extrapolation of the data to the rotor noise of a full-scale system by the ISL.
Hepatic Lipase, Lipoprotein Metabolism, and Atherogenesis

The role of hepatic lipase as a multifunctional protein that modulates lipoprotein metabolism and atherosclerosis has been extensively documented over the last decade. Hepatic lipase functions as a lipolytic enzyme that hydrolyzes triglycerides and phospholipids present in circulating plasma lipoproteins. Hepatic lipase also serves as a ligand that facilitates lipoprotein uptake by cell surface receptors and proteoglycans, thereby directly affecting cellular lipid delivery. Recently, another process by which hepatic lipase modulates atherogenic risk has been identified. Bone marrow transplantation studies demonstrate that hepatic lipase present in aortic lesions markedly alters aortic lesion formation even in the absence of changes in plasma lipids. These multiple functions of hepatic lipase, which facilitate not only plasma lipid metabolism but also cellular lipid uptake, can be anticipated to have a major and complex impact on atherogenesis. Consistently, human and animal studies support proatherogenic and antiatherogenic roles for hepatic lipase. The concept of hepatic lipase as mainly a lipolytic enzyme that reduces atherogenic risk has evolved into that of a complex protein with multiple functions that, depending on genetic background and sites of expression, can have a variable effect on atherosclerosis.