cssi/SciSciGPT-SciSciNet huggingface dataset:
Thermal stability of the dielectric properties of the low-loss, organic material RT/duroid 6002 from 30 GHz to 70 GHz

For the first time, the thermal stability of the dielectric properties, i.e. the relative permittivity and the loss tangent, are presented for RT/duroid® 6002 from 30 GHz to 70 GHz over the temperature range between 20 °C and 200 °C, using the microstrip ring resonator method at two different microstrip impedances. High-frequency-resolution, Multiline TRL calibrations were performed at each temperature point to increase the accuracy of the measurements. Measurements show a remarkably-stable normalized temperature coefficient of the relative permittivity of −17.6 ppm/°C across the entire bandwidth. Likewise, the normalized loss tangent temperature coefficient had a value of about 0.00118 °C−1, with little variations throughout the measurement bandwidth.
A preliminary discussion of fossil larches (Larix, pinaceae) from the arctic

Abstract Structurally preserved three-dimensional cones of Larix Miller occur in later Tertiary (mid-Pliocene?) beds at Ch'ijee's Bluff, Unit 1 (Twelvemile Bluff) near Old Crow, Yukon, Canada. The morphology of these cones is compared to herbarium material and previously described and illustrated fossil cones, and they are considered part of the extant L. decidua-gmelinii alliance. The systematic relationships of the extant and fossil taxa are reviewed and a new system of classification proposes a partitioning of Larix into two groups on the basis of bract scale morphology. Group I (‘Aristatus’) Larix retain the inferred primitive bract type shared with Pseudotsuga; a relatively long-exserted, tridentate bract in which the costa of the medial fork extends well beyond the lateral forks as a relatively long aristate projection. Group II (‘Laminatus’) Larix includes those forms in which the aristate costa is reduced and all three forks of the tridentate apex are similar in size and shape. In the ‘Laminatus’ group, the overall trend is toward reduction in bract size. Fossil cones from Poland to Greenland, ranging in age from Eocene to Pleistocene, share very similar morphologies which characterize Group II (‘Laminatus’), subgroup IIb. Subgroup IIb includes the forms of Larix with short bracts that are typically hidden beneath the closed, overlapping cone scales. Partitioning the suite of similar Group IIb fossils must await a detailed morphometric-statistical-anatomical analysis. The modern widespread boreal and more restricted European species have their origins in the later Tertiary Group IIb complex.
Challenges in the diagnosis and management of transient ischemic attack.

It is well established that transient ischemic attack (TIA) is a strong predictor of future ischemic stroke [1–3]. The 90 - day stroke risk after TIA is estimated to be 10.5% with, notably, half of the risk occurring within 2 days following TIA [3]. While these data stress the need for urgency in TIA evaluation and accurate risk stratifica tion, real-world clinical decision-making can be very challenging and complex. Indeed, making an accurate diagnosis of TIA, calculating stroke risk and initiating appropriate management are all important steps over which the treating clinician may stumble. Since diagnosis of TIA represents a golden opportunity to prevent sub sequent stroke, it is critical that such errors are minimized. Art of clinical diagnosis
The Design and Implementation of an Antivirus Software Advising System

People use computers for all kind of activities: online gaming, shopping, entertainment, emails, face book, study, research, etc. At the same time, the risk of infection by malicious programs in these computers is rising. The main issue is that general users don't understand what a virus is and how computers get infected. On the other hand, many vendors produce antivirus software with different features to prevent or remove these viruses from people's computers. General users don't understand the concept of each feature in these programs, nor is there a tool to advise users about what the features mean and help them select the right software for personal or business needs. The purpose of this paper is to create an advising system to assist general users to study about computer virus and antivirus, understand the various features of antivirus software products, and select right antivirus software to protect their computers.
Cancer prevention trials in China and Finland

Intervention studies are now viewed as a useful and necessary approach to understanding the relation between nutrition and cancer. Over 20 such studies have been initiated in the past 7 years. Foreign countries may be an attractive site for such investigations, mainly because of desirable population characteristics such as unusually high rates of the cancer being studied, low dietary intake of potential chemopreventive nutrients, stability of the population, and high compliance, and also because of favorable logistical aspects including existing medical, social, or governmental structures that facilitate delivery of the intervention, ongoing cancer registries for endpoint determination, and reduced cost. The three basic elements of an intervention trial, identification and recruitment of a study population, delivery of the intervention and assessment of compliance, and ascertainment of endpoints, are the same in a foreign country as in the United States, but there are a number of special considerations, most notably communication difficulties due to language differences and distance between collaborators, which complicate foreign trials both before and during implementation. The basic elements and status of ongoing trials in China and Finland are presented.
Prediction of proton relaxation rates from measurements of deuterium relaxation in aqueous systems

Abstract Spin-lattice relaxation for deuterium in aqueous solutions of macromolecules is dominated by quadrupolar interactions so that the rotational correlation time for D 2 O and HDO may be determined by measuring the deuteron spin-lattice relaxation time T 1 . This correlation time may then be used to predict the dipole-dipole contribution to proton relaxation from rotational intramolecular water interactions. By subtracting these calculated values from the directly measured proton relaxation rates, the contribution to proton relaxation due to translation and intermolecular dipolar effects may be found. In solutions of polyethylene glycol the translational contribution was estimated to be a constant 40% of the overall relaxation rate when the deuteron relaxation rate varied four-fold, consistent with the view that the translation correlation time varies in direct proportion with the rotational time. It is proposed that deuteron relaxation measurements thus offer a novel method for estimating the hydrodynamic contribution to relaxation due to water-water interactions only in solutions of macromolecules and tissues, separate from the effects of cross relaxation, and these measurements are thus useful for understanding the relative importance of different proton relaxation mechanisms in such media.
Lipoidal membranes stabilize isolated salmon and chicken carbonic anhydrase under conditions of increased temperature and pH.

Abstract 1. 1. Solutions of purified carbonic anhydrase from chicken and salmon erythrocytes were incubated in buffer for 1 hr at 5° or 22°C, at pH 7.3, 7.6, 7.9 or 8.2. 2. 2. At 22°C the enzymes lost up to 25% of their ability to catalyze the CO2 hydration reaction when compared to control solutions maintained in the cold. 3. 3. Loss of enzyme activity (∼50%) also occurred as pH was increased from 7.3 to 8.2. 4. 4. The presence of lecithin vesicles or microsomes completely protected the enzymes from denaturation caused by pH changes and afforded partial protection from changes due to increased temperature.
Optimization of water and air management systems for a passive direct methanol fuel cell

Abstract A multi-phase, multi-component, thermal and transient model is applied to simulate the operation of a passive direct methanol fuel cell and optimize the design. The model takes into consideration the thermal effects and the variation of methanol concentration at the feeding reservoir above the fuel cell. Polarization and constant current cases are numerically simulated and compared with experiments for liquid feed concentration, membrane thickness, water management and air management systems. Parameters considered when determining an optimal design include power density, fuel utilization and energy efficiencies and water balance coefficients. An optimal liquid feed concentration is determined to be 2.0 mol kg−1, which achieved a maximum power density of 21 mW cm−2 and a fuel utilization efficiency of 63.0%. An optimal design of a cell uses a thick membrane (Nafion 117) to reduce methanol crossover and two additional cathode GDLs to improve the water balance coefficient and efficiency of the cell. This combination results in a power density of 23.8 mW cm−2 and a water balance coefficient of −1.71. An air filter may also be added to improve the efficiency and water balance coefficient of the cell, however, a small loss in power density will also occur. Using an Oil Sorbents air filter the water balance coefficient is increased to −0.85, the fuel utilization efficiency is improved by 27.35% and the maximum power density decreased to 21.6 mW cm−2.
The Complex Art of Telling It Simply

If the results of collaborations between experimentalists and computational biologists are hard to understand for those in the collaboration, then reviewers and readers of the paper will also struggle. Thus, authors are encouraged to present the results of these studies as clearly as possible and to avoid obscure, convoluted, jargonistic, or impenetrable descriptions.
A Cell System in Which Rate and Amount of Protein Synthesis Are Separately Controlled

The mean cross-sectional area of Haversian systems in adult human ribs tends to be constant in the face of sevenfold changes in the rates at which these systems are made. This implies that different mechanisms control the total amount of cellular work in making Haversian systems and the rate at which this work is performed.
The Dependence of Secondary Structure in X-Ray Absorption on Crystal Form

An examination of the Ca $K$ absorption edge in the x-ray absorption spectra of different compounds shows clearly that the secondary structure is not the same in different compounds, and is not even the same in the two crystals calcite and aragonite, which are the same chemically, but of different crystalline form. These facts are in accord with Kronig's theory of the secondary structure. In four other crystals, each of which contains two or more metals, the secondary structure was examined to see if it was the same for the two elements in the same crystal. There is a difference for the two elements, which indicates that the crystal form is not the sole factor in determining the secondary structure.
A primer of visual literacy

Responding to the need she so clearly perceives, Ms. Dondis, a designer and teacher of broad experience, has provided a beginning text for art and design students and a basic text for all other students;those who do not intend to become artists or designers but who need to acquire the essential skills of understanding visual communication at a time when so much information is being studied and transmitted in non-verbal modes, especially through photography and film. Understanding through seeing only seems to be an obviously intuitive process. Actually, developing the visual sense is something like learning a language, with its own special alphabet, lexicon, and syntax. People find it necessary to be verbally literate whether they are "writers": or not; they should find it equally necessary to be visually literate, "artists" or not.This primer is designed to teach students the interconnected arts of visual communication. The subject is presented, not as a foreign language, but as a native one that the student "knows" but cannot yet "read." The analogy provides a useful teaching method, in part because it is not overworked or too rigorously applied. This method of learning to see and read visual data has already been proved in practice, in settings ranging from Harlem to suburbia.Appropriately, the book makes some of its most telling points through visual means. Numerous illustrated examples are employed to clarify the basic elements of design (teach an alphabet), to show how they are used in simple syntactic combinations ("See Jane run."), and finally, to present the meaningful synthesis of visual information that is a finished work of art (the apprehension of poetry...).
Purification and some properties of bovine milk lysozyme

Summary Lysozyme (mucopeptide N -acetyhmiramylhydrolase, EC 3.2.1.17) (murami-dase) has been purified from fresh raw bovine milk. The method involved separation of whole milk to obtain skim milk, preparation of the acid whey from the skim milk, adsorption of lysozyme from the whey onto Amberlite IRC-50, fractional precipitation with ammonium sulfate, and then twice chromatographing on Sephadex G-50. The isolated enzyme showed a purification of 36 000-fold on a milk protein basis and a specific activity of 0.35 in comparison with 1.0 for egg-white lysozyme. Starch gel electrophoresis and sedimentation behavior of the enzyme preparation indicated it to be homogeneous. The isolated enzyme protein seemed to have an isoelectric point of pH 9,5 and apparently possessed a molecular weight similar to that of egg-white lysozyme. The purified enzyme in 0.067 M phosphate buffer displayed a pH optimum of 7.9. The enzyme required salts for activity; sodium citrate was the most potent activator of the enzyme activity.
The prognostic significance of Ki-67 labeling indices for oligodendrogliomas.

OBJECTIVE: The prognostic significance of quantitative measurement of tumor proliferative activity was evaluated for oligodendroglial tumors. METHODS: Ki-67/MIB-1 immunochemistry was used to measure proliferative activity in 81 oligodendrogliomas and oligoastrocytomas. The relationships among survival, proliferation, histological features, and clinical variables were evaluated using a Cox proportional hazards analysis. RESULTS: After stratifying by histological grade and adjusting for age at diagnosis, there was a significant association between the Ki-67/MIB-1 labeling index (LI) (percentage of positive cells) and survival (P = 0.04). This association was illustrated further by the significantly different survival of two groups based on LI ranges of less than or equal to 5 and greater than 5 (P < 0.0001). CONCLUSION: The poor correlation between mitotic figures and survival in oligodendrogliomas that has been reported previously emphasizes the need for an accurate method to measure proliferative activity. Our study demonstrated the usefulness of the Ki-67/MIB-1 LI and demonstrated that LI ranges can be defined for clinical application.
Gamma-ray irradiation as a pretreatment for the enzymatic hydrolysis of cellulose

The susceptibility of cellulose to enzymatic hydrolysis can be significantly affected through pretreatment by means of gamma-ray radiation. Experiments were carried out to investigate the effects of this radiation on enzymatic hydrolysis and on the two major structural features of cellulose that most influence hydrolysis, namely, specific surface area and crystallinity.
Raising Safe Villages: Cultural-Ecological Factors That Influence the Emotional Adjustment of Adolescents

The fear of real and imaginary calamity is a detrimental strain on the emotional adjustment of America's urban youth. This study investigated the relationship of African American adolescent perceptions of calamity fears, kinship social support, and neighborhood social capital to various aspects of depression. Findings indicate that adolescents from urban neighborhoods, where they felt safe and were fearful of potential calamity, showed lower levels of global depressive symptoms. Some interesting gender differences were noted, with adolescent girls from high-risk neighborhoods benefiting the mostfrom high levels of neighborhood social capital and high levels of calamity fear Implications for integrating ecological factors into violence prevention and mental health promotion programs are discussed.
Pop Goes the Program: Using Popular Culture Artifacts to Educate Leaders:

The problem and the solution. Creating leaders requires both leadership education and leadership development activities.This article describes an innovative leadership education program that uses the popular culture artifacts described in this issue as a foundation for creating leaders. This program provides a flexibility that makes it applicable to delivery in either educational institutions or organizations.
Clusters of economic freedom

This article uses K-means clustering to group countries using the information from the five areas of the Economic Freedom of the World (EFW) index. The resulting clusters of countries are similar but not identical to quartile groupings found using the overall EFW index. Simple comparisons of socio-economic outcomes along the one-dimensional EFW index yield different results compared with the multidimensional-based country clusters. In particular, social democratic market economies appear to outperform liberal market economies using these simple comparisons.
Foliar Consumption Across a Sudden Oak Death Chronosequence in Laboratory Fires

The recent introduction and spread of sudden oak death (SOD; caused by Phytopthora ramorum) has caused heavy mortality in native tanoak (Notholithocarpus densiflorus [Hook. & Arn.] Manos et al. = Lithocarpus densiflorus [Hook. & Arn.] Rehder) forests in California and Oregon, USA. Following tree death, killed tanoaks retain their dead foliage, resulting in a 1 to 3 year period of extremely low foliar moisture and increased probability of crown ignition. We compared foliage ignition and consumption in a laboratory experiment at simulated crown heights from 0.5 m to 1.5 m across a range of representative foliar moistures (80 %, 70 %, 9 %, and 5 %) found in affected regional forests. Results revealed differences in live and dead foliage consumption. All foliage categories were consumed at the lowest crown base heights; consumption of live foliage declined quickly with increasing height, with minimal consumption occurring above 1 m. Consumption of dead foliage also declined with increasing heights, but some consumption (∼25 %) still occurred up to 1.25 m. These data inform the mechanism for patterns of individual tree torching and firebrand generation reported in wildfires in SOD-infected forests and woodlands.
Liposome microencapsulations without using any organic solvent

ABSTRACT Liposomes are microscopic vesicles composed of phospholipid bilayers surrounding discrete aqueous compartment. Eventhough phospholipid bilayers are formed spontaneously in water, their conventional preparation methods involve either organic solvents or detergent molecules. Organic solvents may create a serious safety problem during liposome manufacturing especially on a large scale and can cause denaturation of proteins and affect the membrane properties. Liposomes are very promising carriers for protein drugs which have aroused great interests in the field of pharmaceutics in these recent years. The objective of this study was to develop a new dispersion process to prepare liposomes without the usage of organic solvents and detergents. The approach involved the usage of a microfludizer for the extrusion and homogenization of aqueous dispersion of phospholipids, and a modified evaporator in order to increase lipid thin film surface area. The properties of the liposomes prepared by the novel metho...
Multilevel Active Storage for big data applications in high performance computing

Given the growing importance of supporting dataintensive sciences and big data applications, an effective HPC I/O solution has become a key issue and has attracted intensive attention in recent years. Active storage has been shown effective in reducing data movement and network traffic as a potential new I/O solution. Existing prototypes and systems, however, are primarily designed for read-intensive applications. In addition, they generally assume that offloaded processing kernels have small computational demands, which makes this solution a poor fit for data-intensive operations that have significant computational demands, including write-intensive operations. In this research, we propose a new Multilevel Active Storage (MAS) solution. The new MAS design can support and handle both read- and write-intensive operations, as well as complex operations that have considerable computational demands. Experimental tests have been carried out and confirmed that the MAS approach is feasible and outperformed existing approaches. The new multilevel active storage design has a potential to deliver a high performance I/O solution for big data applications in HPC.
Dealing with envy

Abstract This paper argues that if envy matters, then it should enter directly into the utility functions. The Pareto sets based on the envious utilities are natural candidates for the socially optimal allocations. Three forms of envious utility functions are considered, and their Pareto sets compared to the usual definition of the fair set where the notion of non-envy is imposed on non-envious utilities. It is shown that very rarely will the fair set coincide with any envious Pareto set, and for certain types of envious utilities, no outcome in the fair set is Pareto optimal.
Telecom-band entanglement generation, storage, and long-distance distribution

We present a source of correlated photon-pairs based on four-photon scattering in silica fiber. With this source we have demonstrated the generation, storage, and long-distance distribution of polarization entanglement in standard optical fiber.
Interrelationships Between Maternal Carotenoid Status and Newborn Infant Macular Pigment Optical Density and Carotenoid Status

Purpose Deposition of the macular pigment carotenoids lutein and zeaxanthin in the human retina occurs early in life. In this study, we examined the interrelationships of maternal carotenoid status and newborn infant macular pigment levels and systemic carotenoid status. As a secondary measure, we also evaluated the effects of intrauterine growth restriction (IUGR) on carotenoid status in term newborn infants. Methods We measured mother and infant skin carotenoids using resonance Raman spectroscopy (RRS), serum carotenoids by HPLC, and mother breast milk carotenoids by HPLC. We measured infant macular pigment levels using noninvasive blue light reflectometry. Results We enrolled 30 healthy term infants, their mothers, and 10 IUGR infants and their mothers. A subset of 16 infants was imaged for macular pigment optical density (MPOD). Infant serum zeaxanthin levels correlated with MPOD (r = 0.68, P = 0.007). Mother serum zeaxanthin levels correlated with infant MPOD (r = 0.59, P = 0.032). Infant and mother serum lutein did not correlate with MPOD. Mother-infant correlations were found for total serum carotenoids (r = 0.42, P = 0.020) and skin carotenoids (r = 0.48, P = 0.001). No difference was seen between IUGR infants and controls in total serum or skin carotenoids. Mothers of IUGR infants had lower total serum carotenoids (P = 0.019) and breast milk carotenoids than controls (P = 0.006). Conclusions Our findings suggest that maternal zeaxanthin status may play a more important role than lutein status in macular pigment deposition in utero. Controlled trials are needed to determine whether maternal zeaxanthin prenatal supplementation can raise infant macular pigment levels and/or improve ocular function.
Adjustable Nanofluidic Channels by Tunnel Cracking of a Constrained Brittle Layer

There is widespread and rapidly increasing interest in adopting nanofluidics as a strategy for developing new capabilities in various scientific areas. A fast, easy, and inexpensive method for creating nanochannels may address technical limitations associated with the limited availability of conventional nanofabrication technologies and contribute to expanding the application of nanofluidics to areas of biological or chemical interest. For example, there is considerable interest in the controlled confinement and manipulation of single polymeric or bio-molecules (e.g., DNA) for analysis. Motivated by this, we present here a cracking-based method for fabrication of adjustable nanofluidic channels.Copyright © 2008 by ASME
Gold catalysis: up to six new bonds by a domino [3+2]/[2+1]/[2+1] cycloaddition

In the presence of the N-heterocyclic carbene gold catalyst (IPrAuNCPhSbF6, 2), propargyl ester 1 undergoes a formal [3+2] cycloaddition reaction with vinyl ethers at room temperature. If the reaction was allowed to continue with excess propargyl ester, one or two sequential cyclopropanations occur on the enolate double bond of the [3+2] reaction product. The one-pot domino cycloaddition reactions created cyclopropanation products with multiple rings, formed multiple new sigma bonds, and new stereocenters. When 2-methoxypropene was allowed to react with excess propargyl ester 1 in the presence of the Au(I) catalyst 2, two tandem cyclopropanations occurred on the initial [3+2] cycloaddition product, which yields a product with a tricyclic carbon frame, six new sigma bonds, and eight new stereocenters. Hence the observation sets a new record for gold-catalyzed domino reactions. The assignment of the product stereochemistry was performed by NMR spectroscopy and confirmed by an X-ray structure analysis.
Persistence and integration of cloned DNA in postembryonic sea urchins

Cloned DNA was injected into the cytoplasm of unfertilized sea urchin eggs which were then fertilized and cultured in the laboratory through metamorphosis. The exogenous DNA replicated manyfold and persisted for weeks in a majority of growing larvae, as shown by hydridizing “dot blots” of the DNA of single individuals with appropriate labeled probes. After metamorphosis 5–15% of the juvenile sea urchins retained the exogenous sequences. Genomic integration of the exogenous sequence was observed in the DNA of a postmetamorphosis juvenile.
Are natural killer cells superior CAR drivers

T lymphocytes engineered to express a chimeric antigen receptor (CAR) are being celebrated as a major breakthrough of anticancer immunotherapy. Natural killer cells have not received similar attention as CAR effectors, although the use of these relatively short-lived cytotoxic cells is associated with several advantages.
Diachroneity of Basin and Range extension and Yellowstone hotspot volcanism in northwestern Nevada

Some of the earliest volcanic rocks attributed to the Yellowstone hotspot erupted from the McDermitt caldera and related volcanic centers in northwestern Nevada at 17–15 Ma. At that time, extensional faulting was ongoing to the south in central Nevada, leading some to suggest that the nascent hotspot caused or facilitated middle Miocene Basin and Range extension. Regional geologic relationships indicate that the total magnitude of extension in northwestern Nevada is low compared to the amount documented in central Nevada and that extension was accommodated almost entirely by the widely spaced, high-angle normal-fault systems that formed the modern ranges. The Santa Rosa Range is the closest major range to the McDermitt caldera. It was tilted ∼15° east and uplifted as an intact crustal block by ∼8 km of slip along a west-dipping normal fault on the west side of the range. Apatite fission-track data from the Santa Rosa footwall block indicate that faulting and extension was ongoing ca. 7.5 Ma and began as early as 10 Ma. Data from the Pine Forest Range to the west indicate a similar 8–10 Ma age for extensional faulting. Basin and Range extension in northwestern Nevada is therefore significantly younger than 17–15 Ma hotspot volcanism. This timing argues against a direct link between the Yellowstone hotspot and the initiation of extension, casting additional doubt on the role of the hotspot in extension across the broader Basin and Range Province.
AN OBSERVATIONAL STUDY OF THE SEA BREEZE

Abstract A series of observations of the sea breeze has been made along a portion of the New England coast near Block Island, Rhode Island. These observations are presented in vertical cross-sections approximately 30 mi long perpendicular to the coast, with wind observations extending upward to an altitude of six thousand feet and temperature observations up to twenty-five hundred feet. The analysis is confined to two days on which the sea breeze was most clearly distinguishable from the over-riding flow and shows the development of the cellular structure of the sea breeze. The expected rotation of the system under the influence of the Coriolis effect is not at first evident, but an analysis of the behavior of the over-riding gradient flow reveals the possible presence of this acceleration of the wind field. In addition, there is evidence toward evening of a speeding up of the flow at low levels which presages the development of a low-level jet in the wind field.
On oscillating dark energy

Abstract Distance–redshift data can impose strong constraints on dark energy models even when the equation of state is oscillatory. Despite the double integral dependence of the distance on the equation of state, precision measurement of the distance–redshift relation for z = 0–2 is more incisive than the linear growth factor, CMB last scattering surface distance, and the age of the universe in distinguishing oscillatory behavior from an average behavior. While oscillating models might help solve the coincidence problem (since acceleration occurs periodically), next generation observations will strongly constrain such possibilities.
Change over Tenure: Voting, Variance, and Decision Making on the U.S. Courts of Appeals

Existing scholarship on the voting behavior of U.S. Courts of Appeals judges finds that their decisions are best understood as a function of law, policy preferences, and factors relating to the institutional context of the circuit court. What previous studies have failed to consider, however, is that the ability to predict circuit judge decisions can vary in substantively important ways and that judges, in different stages of their careers, may behave distinctively. This article develops a theoretical framework which conceptualizes career stage to account for variability in voting by circuit judges and tests hypotheses by modeling the error variance in a vote choice model. The findings indicate that judges are more predictable in their voting during their early and late career stages. Case characteristics and institutional features of the circuit also affect voting consistency.
Role of oxygen in postischemic myocardial injury.

Myocardial function is dependent on a constant supply of oxygen from the coronary circulation. A reduction of oxygen supply due to coronary obstruction results in myocardial ischemia, which leads to cardiac dysfunction. Reperfusion of the ischemic myocardium is required for tissue survival. Thrombolytic therapy, coronary artery bypass surgery and coronary angioplasty are some of the treatments available for the restoration of blood flow to the ischemic myocardium. However, the restoration of blood flow may also lead to reperfusion injury, resulting in myocyte death. Thus, any imbalance between oxygen supply and metabolic demand leads to functional, metabolic, morphologic, and electrophysiologic alterations, causing cell death. Myocardial ischemia reperfusion (IR) injury is a multifactorial process that is mediated by oxygen free radicals, neutrophil activation and infiltration, calcium overload, and apoptosis. Controlled reperfusion of the ischemic myocardium has been advocated to prevent the IR injury. S...
Amplitude modulation and relaxation-oscillation of counterpropagating rolls within a broken-symmetry laser-induced electroconvection strip.

We report a liquid-crystal pattern-formation experiment in which we break the lateral (translational) symmetry of a nematic medium with a laser-induced thermal gradient. The work is motivated by an improved measurement (reported here) of the temperature dependence of the electroconvection threshold voltage in planar-nematic 4-methoxybenzylidene-4-butylaniline. In contrast with other broken-symmetry-pattern studies that report a uniform drift, we observe a strip of counterpropagating rolls that collide at a sink point, and a strong temporally periodic amplitude modulation within a width of 3--4 rolls about the sink point. The time dependence of the amplitude at a fixed position is periodic but displays a nonsinusoidal relaxation-oscillation profile. After reporting experimental results based on spacetime contours and wave number profiles, along with a measurement of the change in the drift frequency with applied voltage at a fixed control parameter, we propose some potential guidelines for a theoretical model based on saddle-point solutions for Eckhaus-unstable states and coupled complex Ginzburg-Landau equations.
Understanding the Threat of Biological Weapons

Biological Weapons: Limiting the Threat, Joshua Lederberg, ed. (Cambridge, Mass.: MIT Press, 1999). 351 pp.. paper (ISBN: 0-262-62128-2), $20.00. Biological Warfare: Modern Offense and Defense, Raymond A. Zilinskas, ed. (Boulder, Colo.: Lynne Rienner. 2000). 307 pp., cloth (ISBN: 1-55587-761-3), $59.95. Books reviewed: Lederberg, Joshua (ed.), Biological Weapons: Limiting the Threat Zilinskas, Raymond A. (ed.), Biological Warfare: Modern Offense and Defense
Fluid shear stress regulates the invasive potential of glioma cells via modulation of migratory activity and matrix metalloproteinase expression.

Background Glioma cells are exposed to elevated interstitial fluid flow during the onset of angiogenesis, at the tumor periphery while invading normal parenchyma, within white matter tracts, and during vascular normalization therapy. Glioma cell lines that have been exposed to fluid flow forces in vivo have much lower invasive potentials than in vitro cell motility assays without flow would indicate.
Pelvic and extremity immobilization after bladder exstrophy closure: complications and impact on success.

Abstract Objectives A successful initial bladder closure is critical to the development of adequate bladder capacity and ultimate continence among patients with bladder exstrophy. Although secure pelvic fixation is essential to success, the various methods of pelvic and extremity immobilization and their impact on surgical outcome have not previously been examined. Methods A review of the approved bladder exstrophy database at our institution identified 194 patients for whom data were available regarding initial bladder closure and the method of pelvic immobilization. The records were reviewed with respect to age at bladder closure, use/type of osteotomy, method of pelvic immobilization, complications related to the immobilization technique, and surgical outcome. Results Of 194 patients identified, initial exstrophy closure failed in 86. Of these 86 patients, the initial closure failed in 80 at another hospital who were referred to our institution for additional treatment. Of the 114 initially closed at this institution, 6 failed. The success rates for initial and second closures were highest after osteotomy (75% versus 38% and 81.5% versus 27%, respectively), and when the patients were immobilized with an external fixator and 6 to 8 weeks of modified Buck's traction with osteotomy (96%) or 4 to 6 weeks of modified Bryant's traction without osteotomy (61%). The spica cast and “mummy wrapping” immobilization techniques were less effective and were associated with significant complications. Conclusions These results demonstrate that a successful exstrophy bladder closure depends on the proper use of the osteotomy and effective postoperative immobilization of the pelvis. Our best outcomes have been achieved using lower extremity traction (with or without external fixation of the pelvis).
Nanocrystalline cobalt oxides for carbon nanotube growth

Thin Films of nanocrystalline cobalt oxide were formed by sol-gel method. Structure, optical properties and surface properties of these films were investigated by numerous characterization techniques. These films were successfully fabricated on glass substrates below 500°C. . Micropatterns of cobalt oxide thin films were also fabricated on glass and silicon substrates by employing a lift-off method. Crystal size of these nanocrystalline cobalt films could be successfully controllable by varying the amount of cobalt precursors and number of layers. These films were used as the seeding layers for carbon nanotube growth in a CVD process By changing the concentration of monomer precursors in the solgel coating solutions, different size nanoclusters hence different size carbon nanotubes could be synthesized in CVD process. This method can be used for controlled growth of carbon nanotubes for many different applications. In this paper, detail of these experimental results will be presented.
Incentive reduction: Increases in postreinforcement detention and subsequent responding1

Three groups of 10 rats each received 64 acquisition and 64 postshift trials in an L-shaped double-alley apparatus. In the postshift period two groups received test trials on which the postreinforcement detention time in the first goal box (Gl) was increased. For one of these groups this increase occurred simultaneously with a reduction in Gl reward magnitude. The results indicated that for neither group did postreinforcement detention increase elevate second-alley speeds relative to those of a group which always received the longer postreinforcement detention.
Determination of alloy content from plume spectral measurements

The mathematical derivation for a method to determine the identities and amounts of alloys present in a flame where numerous alloys may be present is described. This method is applicable if the total number of elemental species from all alloys that may be in the flame is greater than or equal to the total number of alloys. Arranging the atomic spectral line emission equations for the elemental species as a series of simultaneous equations enables solution for identity and amount of the alloy present in the flame. This technique is intended for identification and quantification of alloy content in the plume of a rocket engine. Spectroscopic measurements reveal the atomic species entrained in the plume. Identification of eroding alloys may lead to the identification of the eroding component.
Estimation of steroid hormones by an immunochemical technique.

PREVIOUS studies in this laboratory have established that steroid hormones can be rendered antigenic by coupling them to proteins1. On immunization with the appropriate steroid–protein conjugate, antibodies to testosterone, cortisone, deoxycorticosterone, aldosterone, oestrone and progesterone were produced. Because hapten-inhibition studies were used successfully to elucidate the specificity of these antisera, it was decided to investigate the possibility of developing a procedure sufficiently sensitive for use in the assay of steroids.
HAESA and HAESA-LIKE2 activate organ abscission downstream of NEVERSHED and EVERSHED in Arabidopsis flowers

A ligand-receptor module comprised of the peptide INFLORESCENCE DEFICIENT IN ABSCISSION (IDA) and the receptor-like kinases HAESA (HAE) and HAESA-LIKE2 (HSL2) activates organ abscission in Arabidopsis flowers. Another set of receptor-like kinases, including EVERSHED (EVR), restricts the extent of cell separation in abscission zones by potentially altering HAE/HSL2 localization or activity. The NEVERSHED (NEV) ADP-ribosylation factor GTPase-activating protein facilitates the intracellular movement of molecules required for organ abscission and fruit growth. Here we report further analysis of the relationship between NEV-mediated intracellular traffic, EVR activity and IDA-HAE/HSL2 signaling during flower development. Our results support a model in which cell separation is mediated by HAE/HSL2 signaling downstream of NEV and EVR. We discuss the possibility that conserved circuits control organ abscission and modulate fruit growth.
Limiting behaviour of the occupation of wedges by complex Brownian motion

We prove a theorem which gives the lim inf behaviour ast tends to 0 for the amount of time a complex Brownian motion spends in a wedge with apex at the origin. The result is then shown to hold uniformly for all wedges a.s..
Patterns of resistance to 2-deoxy-D-glucose in pig kidney cells.

Variants resistant to 2-deoxy-D-glucose have been isolated from a clonal line of pig kidney cells by serial cultivation in the presence of inhibitor. Hexokinase activity may be affected directly in this system, since the oxidation of glucose to 6-phosphogluconate by extracts from sensitive and resistant cells is blocked by the addition of 2-deoxy-glucose to the reaction mixture. This blockage was removed by the addition of glucose-6-phosphate to the system, but not by ATP. Resistant cells were found to accumulate significantly less 2-deoxyglucose-6-phosphate than sensitive cells. The rate of phosphorylation of 2-deoxyglucose, however, was higher in extracts from the resistant line. Alkaline phosphatase does not account for the reduced level of 2-deoxyglucose-6-phosphate since this enzyme is not detectable in sensitive or resistant pig kidney cells. Increased acid phosphatase activity was observed in resistant cells, but extracts with high acid phosphatase activity proved incapable of hydrolyzing either 2-deoxyglucose-6-phosphate or glucose-6-phosphate. In comparative growth studies, cells resistant to 2-deoxyglucose proliferated more extensively than sensitive cells in a low glucose nutrient. They removed glucose more effectively from this medium, and were less stimulated by the addition of intermediates from the tricarboxylic acid cycle. The evidence suggests that resistance to 2-deoxyglucose in the cells under study may be based on the ability of the resistant cells to proliferate at concentrations of glucose too low to support the growth of sensitive cells.
Random Phenotypic Variation of Yeast (Saccharomyces cerevisiae) Single-Gene Knockouts Fits a Double Pareto- Lognormal Distribution

Background Distributed robustness is thought to influence the buffering of random phenotypic variation through the scale-free topology of gene regulatory, metabolic, and protein-protein interaction networks. If this hypothesis is true, then the phenotypic response to the perturbation of particular nodes in such a network should be proportional to the number of links those nodes make with neighboring nodes. This suggests a probability distribution approximating an inverse power-law of random phenotypic variation. Zero phenotypic variation, however, is impossible, because random molecular and cellular processes are essential to normal development. Consequently, a more realistic distribution should have a y-intercept close to zero in the lower tail, a mode greater than zero, and a long (fat) upper tail. The double Pareto-lognormal (DPLN) distribution is an ideal candidate distribution. It consists of a mixture of a lognormal body and upper and lower power-law tails. Objective and Methods If our assumptions are true, the DPLN distribution should provide a better fit to random phenotypic variation in a large series of single-gene knockout lines than other skewed or symmetrical distributions. We fit a large published data set of single-gene knockout lines in Saccharomyces cerevisiae to seven different probability distributions: DPLN, right Pareto-lognormal (RPLN), left Pareto-lognormal (LPLN), normal, lognormal, exponential, and Pareto. The best model was judged by the Akaike Information Criterion (AIC). Results Phenotypic variation among gene knockouts in S. cerevisiae fits a double Pareto-lognormal (DPLN) distribution better than any of the alternative distributions, including the right Pareto-lognormal and lognormal distributions. Conclusions and Significance A DPLN distribution is consistent with the hypothesis that developmental stability is mediated, in part, by distributed robustness, the resilience of gene regulatory, metabolic, and protein-protein interaction networks. Alternatively, multiplicative cell growth, and the mixing of lognormal distributions having different variances, may generate a DPLN distribution.
Stages of smoking acquisition versus susceptibility as predictors of smoking initiation in adolescents in primary care

Abstract We evaluated whether susceptibility, the stages of smoking acquisition, and socio-environmental factors can identify adolescents who will become smokers. Our data came from a randomized controlled trial of an intervention to prevent adolescent smoking. Subjects were adolescents ( n =1955) ages 14–17 being seen for routine medical care. The dependent variable was 30-day smoking status at 2-year follow-up (89.6% response rate). Independent variables included susceptibility, the stages of acquisition, and socio-environmental factors. Susceptible adolescents were two to three times more likely to be smokers than non-susceptible adolescents. Compared to acquisition precontemplators, acquisition contemplators were three to five times more likely, and acquisition preparers were five to eight times more likely, to be smokers. When combined into a single measure, susceptible precontemplators were two times, contemplators were six times, and preparers were nine times more likely to be smokers than non-susceptible precontemplators. Our findings suggest that acquisition stage and susceptibility can independently predict smoking onset. They may be used together to target teens for smoking prevention efforts in the clinical setting.
SU‐FF‐T‐17: 3D Monte Carlo‐Based Treatment Planning Evaluation of Intracavitary HDR Balloon Catheter Brachytherapy

Purpose: To evaluate the dosimetric effects of missing tissue and tissue heterogeneities on intracavitary HDR balloon‐catheter brachytherapy using a novel 3D Monte Carlo‐based treatment planning study. Method and Materials: The PTRAN Monte Carlo(MC)photon transport code is used to generate 3D calculations of the doses arising from an HDR 192Ir source in; Anatomy‐based MC simulations modeling the dosimetric effects of missing tissue beyond the skin surface and tissue heterogeneities (such as air pockets) adjacent to the balloon catheter (Mammosite); and in a large water phantom representing those calculations achievable with a conventional 3D brachytherapyRTPS. Each MC simulation employs a track length estimator scoring method in a 3D grid, with 2mm resolution in a 12cm×11cm×8cm volume, scoring 8×106 primary photon histories. The dose matrices from all MC simulation are registered (in the external beam module of a commercial RTPS) to a single, modeled patient CT, which is identical in location, scale, and shape to the patient volume described in the anatomy‐based MC simulations. Several target volumes (e.g. a 1cm margin on the Mammosite balloon) and a skin‐surface contour, are created. Dose‐volume histograms (DVH's) are computed for each volume, per each plan. Comparisons of the resultant DVH's quantify the dosimetric errors expected from routine clinical planning of Mammosite applications. Results: The missing tissue beyond the skin surface reduces target coverage by 1.5–3.5% and skindoses by 8–20%, when compared to calculations achievable with conventional 3D brachytherapytreatment planning systems. A 10cc airpocket neighboring the Mammosite balloon reduces doses to adjacent tissues <0.5%. Conclusion: A detailed 3D Monte Carlo‐based brachytherapyRTP study of the dose prediction errors in balloon catheter HDR applications shows that the missing tissue beyond the skin surface reduces skindoses by as much as 20% and target coverage by as much as 3.5%.
Finite element analysis of composites using chebyshev polynomials

Abstract A finite quasi-prismatic (FQP) element is modified to analyze anisotropic materials. The finite quasi-prismatic element is a three-dimensional finite element which uses conventional interpolating functions in two directions and functions based on Chebyshev polynomials in the third direction. This element is used to solve different anisotropic problems and the results are compared with that of conventional finite elements and analytical solutions.