cssi/SciSciGPT-SciSciNet huggingface dataset:
Simultaneous multipolar radiofrequency ablation in the monopolar mode increases lesion size.

Delivery of radiofrequency (RF) energy from the distal tip of electrophysiology catheters produces lesions that may be too small to ablate arrhythmogenic sites during a single application of RF energy. To produce larger lesions, we delivered RF energy via a quadripolar catheter in which all four electrodes were connected in unipolar fashion. The catheter (Webster Labs) had a 4-mm tip, 2-mm ring electrodes, and 2-mm intereiectrode distance. Lesion size was compared using RF energy delivered in a multipolar configuration with that delivered only to the distal tip using fresh bovine ventricular tissue. In vivo, RF lesions were made in dogs using the distal tip as well as all four poles of the same catheter inserted percutaneously. RF energy was delivered using a constant voltage at a frequency of 400 kHz. Preliminary experiments were conducted to determine the maximum power deliverable without coagulation using each electrode configuration. The use of simultaneous muitipolar RF ablation produced significantly larger lesions both in vitro and in vivo. The length of the lesion was increased by a factor of approximately 2 in both the in vitro and in vivo experiments. There was a trend toward an increasing depth of the lesion by simultaneously applying RF energy to all four electrodes. Lesion width was significantly increased in the in vivo studies. We concluded that simultaneous muitipolar delivery of RF energy produces larger lesions than can be obtained with delivery of RF energy to the distal tip alone. This technique may offer a means of increasing lesion size, leading to a decrease in the number of applications of RF energy necessary for ablation of arrhythmias.
Coupled vertical gratings on silicon for applications in wavelength division multiplexing

An add/drop filter based on coupled vertical gratings is presented on silicon. We analyze the device theoretically and experimentally and show that the concept is easily extended to multi-channel add/drop filters. We demonstrate tunability of the device bandwidth and operation wavelength. The free spectral range of the device exceeds the bandwidth used in wavelength division multiplexing systems, which makes it ideally suited for use in such systems.
The fine structure of a myxopapillary ependymoma of the filum terminale.

A fine structural study of a myxopapillary ependymoma of the filum terminale confirms and emphasizes the distinctive morphological features of this tumor. Electron basement membrane production were identified. It is suggested that they are related to the growth of ependymal tumor cells in juxtaposition to the collagen normally present in the conus medullaris and filum terminale.
Evaluation of Pressurized Fluid Extraction for the Extraction of Environmental Matrix Reference Materials

Pressurized fluid extraction (PFE) has been evaluated for the extraction of selected polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyl (PCB) congeners, and chlorinated pesticides from the following reference materials: SRM 1649a (Urban Dust/Organics), SRM 1650 (Diesel Particulate Matter), SRM 2975 (Diesel Particulate Matter, Industrial Forklift), SRM 1941a (Organics in Marine Sediment), SRM 1944 (New York/New Jersey Waterway Sediment), SRM 2974 (Organics in Freeze-Dried Mussel Tissue), CARP-1 (Ground Whole Carp), and CARP-2 (Ground Whole Carp). Several solvent systems were evaluated for each reference material. PFE showed extraction efficiency comparable to that of Soxhlet extraction for the selected PAHs, PCB congeners, and chlorinated pesticides quantified in the air particulate, sediment, mussel tissue, and fish materials and greater extraction efficiencies for the higher molecular weight PAHs in the diesel particulate materials.
Cosmological constraints on cosmic-string gravitational radiation

The primordial nucleosynthesis and pulsar timing noise constraints on cosmic-string gravitational radiation are computed. The computation consists of a numerical integration of the Friedmann-Robertson-Walker Einstein equations which describe a universe containing radiation, dust, and a one-scale''-model cosmic-string component. The procedure takes into account the effects of the annihilations of massive particle species on the equation of state of the cosmological fluid. An expression for the power emitted per mode of oscillation by a cosmic-string loop, suggested by both analytic calculations and recent numerical simulations, is used. The results of the computation are spectra of the cosmic-string gravitational radiation at nucleosynthesis and at present. Comparison of these spectra with the observed bounds on pulsar timing noise, and the observed bound on the effective number of light neutrino species permitted by the model of nucleosynthesis, allows one to exclude a range of values of {mu}, the cosmic-string linear mass density, for certain values of {alpha}, the size of a newly formed loop as a fraction of the particle horizon radius. We find constraints to {mu} which are more restrictive than any previous limit.
Time-dependent studies in ammonium salts: vibrational properties and hydrogen bonding

Vibrational properties and hydrogen bondingHerbert L. Strauss and Han—Gook ChoUniversity of California, Department of ChemistryBerkeley, California 94720ABSTRACTUsing an FTIR and a diode laser, the dynamics of thereorientation of ammonium salts have been studied. The systemsexamined range from crystalline salts to amorphous polymers. Oneconclusion is that the vibrational bands of hydrogen-bonded H-stretching bands are determined by the lifetimes of the excitedvibrational states and that these depend on frequency and not onnumerous other properties of the system.1. OUTLINE OF RESULTSWe have investigated a series of sulfates, starting wi1h(NH4)2S04, and including the mixed sulfates (NH4)2SO4 -
Analysis of haptic, visual, and verbal presentation mode effects in children’s paired associate learning

The experiment was conducted to assess the relative effectiveness of three different presentation modes on children’s paired associate learning. Thirty- six second- grade children served as subjects. A study- test paired associate recognition procedure was used. The study trial consisted of the presentation of a 20- pair list of common objects in one of three different presentation conditions: haptic object vs. visual object vs. aural label. On the test trial, the children were presented with both original and repaired items in the same mode as study for an old vs. new recognition response. The results indicated that visual- object presentation was superior to both haptic- object and aural- label presentations, which did not differ from each other.
Trauma and Massive Blood Transfusions

Massive hemorrhage in trauma requires a multitude of interventions in order to obtain the best possible outcome. The resuscitative approach of the actively bleeding trauma patient has evolved dramatically over the past decade. Modern strategies deploy an earlier, more aggressive and holistic approach on both the diagnostic and therapeutic side. This review addresses the physiology of hemorrhage and traumatic coagulopathy, current treatment options, including damage control resuscitation, individualized and tailored coagulation management with the application of point-of-care testing, and the use of blood and procoagulant products.
Neutravidin micropatterning by deep UV irradiation

We describe a novel approach for directly patterning neutravidin protein by exposure to deep UV irradiation. Neutravidin is physically absorbed onto the glass or quartz substrate, dehydrated in acetone and air-dried. Dry neutravidin-coated samples are patterned either by top-side or back-side exposure to 185 nm UV. Subsequent introduction of fluorescent biotinylated proteins clearly demonstrates binding to the masked neutravidin regions and no binding to exposed areas. Patterned samples retain their protein affinity for at least three months of storage at room temperature.
Solution structure of [d(GTATATAC)]2 via restrained molecular dynamics simulations with nuclear magnetic resonance constraints derived from relaxation matrix analysis of two-dimensional nuclear Overhauser effect experiments.

Abstract Two-dimensional nuclear Overhauser effect (2D NOE) spectra have been used as the experimental basis for determining the solution structure of the duplex [d(GTATATAC)] 2 employing restrained molecular dynamics (rMD) simulations. The MARDIGRAS algorithm has been employed to construct a set of 233 interproton distance constraints via iterative complete relaxation matrix analysis utilizing the peak intensities from the 2D NOE spectra obtained for different mixing times and model structures. The upper and lower bounds for each of the constraints, defining size of a flat-well potential function term used in the rMD simulations, were conservatively chosen as the largest or smallest value calculated by MARDIGRAS. Three different starting models were utilized in several rMD calculations: energy-minimized A -DNA, B -DNA, and a structure containing wrinkled D -DNA in the interior. Considerable effort was made to define the appropriate force constants to be employed with the NOE terms in the AMBER force field, using as criteria the average constraints deviation, the constraints violation energy and the total energy. Of the 233 constraints, one was generated indirectly, but proved to be crucial in defining the structure: the cross-strand A5-H2 A5-H2 distance. As those two protons resonate isochronously for the self-complementary duplex, the distance cannot be determined directly. However, the general pattern of 2D NOE peak intensities, spin-lattice relaxation time ( T 1 ) values, and 31 P nuclear magnetic resonance spectra lead to use of the A3-H2 A7-H2 distance for A5-H2 A5-H2 as well. Fiver rMD runs, with different random number seeds, were made for each of the three starting structures with the full distance constraint set. The average structure from all 15 runs and the five-structure averages from each starting structure were all quite similar. Two rMD runs for each starting structure were made with the A5-H2 A5-H2 constraint missing. The average of these six rMD runs revealed differences in structure, compared to that with the full set of constraints, primarily for the middle two base-pairs involving the missing cross-strand constraint but global deviations also were found. Conformational analysis of the resulting structures revealed that the inner four to six base-pairs differed in structure from the termini. Furthermore, an alternating structure was suggested with features alternating for the A-T and T-A steps.
Special patient populations: Onychomycosis in the diabetic patient

There are approximately 14 million persons with diabetes in the United States. These patients must cope with the serious complications of this disease, including neuropathy and impaired circulation (leading to the "diabetic foot" and possible amputation), renal disease, cardiovascular disease, and retinopathy (possibly leading to blindness). Although onychomycosis is no more common in diabetics than in the general population, it poses a greater risk because of the possible sequelae. Most notably, impaired sensation can make many diabetics less aware of minor abrasions and ulcerations on their feet that may be caused by trauma from poor nail grooming or by the nail changes characteristic of onychomycosis. These lesions, in turn, may develop into serious bacterial infections and contribute to the severity of the diabetic foot. Thus there is an important clinical rationale for treating diabetic patients with fungal nail infections. A secondary benefit is the improved self-esteem and enhanced quality of life.
Mathematical model for evaluation of the effect of soil erosion on soil productivity

This paper is concerned with the development of a stochastic model for evaluating the long-term effect of soil erosion on soil productivity. Due to random variations in annual crop yield, the effect of erosion on crop production is not easily detectable in the short run, but becomes gradually evident over a sufficiently long time period. Under these circumstances, it seems that an experimental approach to this problem may be very difficult. The long period of time over which such an experiment has to be conducted may result in prohibitively high costs. In addition, it also means that eventual resolution of this problem must be postponed until a distant future time. The stochastic model formulated here provides us with a useful tool to assess the trend in quantitative changes in crop production due to erosion and to project future crop losses. The model is a discrete parameter stochastic process. Its derivation is based on a single assumption that the annual loss rates form a sequence of independent random variables {Zi}1∞ (in this paper, we consider only two particular cases: (a) {Zi}1∞ is a sequence of constants; (b) {Zi}1∞ is a sequence of independent identically distributed random variables). For these particular cases, we obtained its marginal n-dimensional distribution function and correlation function. One of the principal model features is its simple structure and remarkable lack of restrictive and unrealistic assumptions.
Bilateral intraocular foreign bodies simulating crystalline lens

Abstract Purpose To report a case of large bilateral intraocular foreign bodies mistaken for crystalline lens on computed tomography (CT). Design Case report. Methods A 24-year-old man was referred after bilateral open globe repair following a motor vehicle accident. Preoperatively, the CT scan had been read as "Right eye posteriorly dislocated lens . . . No evidence of foreign bodies." Results The patient underwent left eye cataract extraction with removal of a 7 × 5 × 5 mm piece of glass buried in the crystalline lens. The patient subsequently underwent right eye pars plana vitrectomy, removal of another piece of glass measuring 6 × 5 × 5 mm, retinal detachment surgery, and corneal grafting. Conclusions Current safety standards require auto glass to fracture into pieces of a specific size to minimize laceration and missile injury. These pieces of glass may have a shape and size similar to the crystalline lens but have higher radiodensity on CT scan.
The Second Special Issue on Evidence-Based Psychosocial Treatments for Children and Adolescents: A 10-Year Update

This introduction to the Second Special Issue on Evidence-Based Psychosocial Treatments for Children and Adolescents provides background information on the development of this 10-year update and explains how this issue expands on the initial special issue on “empirically supported psychosocial treatments” published in 1998. The introduction also provides a summary of the contents of the present issue and the information covered in the articles contained herein. Also summarized are the criteria used to evaluate the level of evidence for each treatment, as well as the criteria used to evaluate the methodological rigor of the studies that are reviewed. The introduction concludes with comments about the advances that have been made in the past decade, with the hope that this second special issue will serve to stimulate further research and expansion of the evidence base for child and adolescent psychosocial treatments to ameliorate youth clinical problems.
Functional Transplants of Epithelial Hypophysis in Three Species of Amblystoma

SummaryAutoplastic, heterotopic transplants of the pnmordium of the epithelial hypophysis have been made in three species of Amblystoma. These transplants differentiated without contact with the brain, and gave evidence of chromatophorotropic and thyreo-tropic activity.
Study on Drag Coefficients for Two Groups of Bubbles

To apply the two-fluid model to a wide range of flow regimes in gas-liquid two-phase flows, the gas phase is categorized into two groups: small spherical/distorted bubbles as Group 1 and large cap/slug/churn-turbulent bubbles as Group 2 in the modeling of interfacial area transport. The interfacial transfer terms of momentum and energy for the gas phase are then divided into two groups accordingly in the implementation of the two-group interfacial area transport equation to the two-fluid model. Thus, the drag coefficients and the interfacial heat transfer for each group bubbles need to be developed. An approach has been sought for evaluating the drag coefficients of each bubble group based on a comprehensive experimental data base obtained in air-water upward flows in various size round pipes. Comparisons have been made with the theory of the drag coefficients and it was found that the agreement is not very satisfactory although the general trends can be predicted by the current approach.Copyright © 2004 by ASME
Blockade of TSP1-Dependent TGF-β Activity Reduces Renal Injury and Proteinuria in a Murine Model of Diabetic Nephropathy

Transforming growth factor-β (TGF-β) is key in the pathogenesis of diabetic nephropathy. Thrombospondin 1 (TSP1) expression is increased in diabetes, and TSP1 regulates latent TGF-β activation in vitro and in diabetic animal models. Herein, we investigate the effect of blockade of TSP1-dependent TGF-β activation on progression of renal disease in a mouse model of type 1 diabetes (C57BL/6J-Ins2Akita) as a targeted treatment for diabetic nephropathy. Akita and control C57BL/6 mice who underwent uninephrectomy received 15 weeks of thrice-weekly i.p. treatment with 3 or 30 mg/kg LSKL peptide, control SLLK peptide, or saline. The effects of systemic LSKL peptide on dermal wound healing was assessed in type 2 diabetic mice (db/db). Proteinuria (urinary albumin level and albumin/creatinine ratio) was significantly improved in Akita mice treated with 30 mg/kg LSKL peptide. LSKL treatment reduced urinary TGF-β activity and renal phospho-Smad2/3 levels and improved markers of tubulointerstitial injury (fibronectin) and podocytes (nephrin). However, LSKL did not alter glomerulosclerosis or glomerular structure. LSKL did not increase tumor incidence or inflammation or impair diabetic wound healing. These data suggest that selective targeting of excessive TGF-β activity through blockade of TSP1-dependent TGF-β activation represents a therapeutic strategy for treating diabetic nephropathy that preserves the homeostatic functions of TGF-β.
The Politics of Curriculum Change and Stability

and value-free subjects such as mathematics. At the same time, however, the method of teaching abstract skills such as mathematics and reading is sometimes a matter of public controversy, especially in conservative communities.
The case for randomized clinical trials on the treatment of obesity.

Some say that randomized clinical trials on weight loss are unnecessary (“the benefits are ‘obvious’”) and others say that such trials are not feasible because too few participants will succeed in maintaining weight loss. Although the intermediate term benefits of weight loss are beyond dispute (lowering of blood pressure, lipids, blood sugar, etc), there is no proof that these benefits will translate into long term benefits, i.e., lower rates of cardiovascular disease and/or lower overall mortality. While this extrapolation may seem obvious, the clinical trials' literature is full of unexpected, adverse side effects of theoretically appealing therapies (e.g., higher mortality with clofibrate and higher cardiovascular disease rates with estrogen treatment in men). Although there is clearly a voluntary component to food ingestion, there are also powerful physiological forces at work which impact on energy balance. For example, individuals of similar height and weight may nevertheless have widely different daily energy expenditures and hence energy requirements. It has been shown in Pima Indians that those with low energy expenditure (i.e., those who are “fuel efficient”) are more prone to future weight gain than those with high energy expenditure. Also, reduced obese individuals have lower 24-hour energy expenditure than individuals who are spontaneously at the same lean weight It appears that this deficit in energy expenditure may last for several years, if not longer, implying that reduced obese individuals must exercise far greater vigilance over their caloric intake than their spontaneously lean peers. If they allow themselves to ingest the same number of calories as the latter, they are likely to regain weight, thereby exposing themselves to charges of overeating, even though their caloric intake does not exceed that of the spontaneously lean!. Epidemiologic data do not support a benefit of weight loss. Populations such as Mexican Americans, among whom obesity is more common than in the general population, do not have excess mortality past age 45. Life expectancy in the U.S. has improved steadily since the early 1970s, despite a rising prevalence of obesity. Lastly, prospective studies have suggested that people who lose weight die at a higher rate than those who maintain a stable weight. This effect persists even after controlling for latent, subclinical disease and cigarette smoking. Although none of the above considerations prove that voluntary weight loss is bad, they indicate that this treatment should lose its hitherto privileged status and be subjected to the rigors of clinical trials as have been treatments for hypercholesterolemia and hypertension.
Design and numerical simulation of a DNA electrophoretic stretching device

DNA stretching is now a key technology in emerging DNA mapping devices such as direct linear analysis (DLA), though DNA stretching in a high throughput manner is still a challenging problem. In this work, we present a new microfluidic channel design to enhance DNA stretching using kinematic analysis and Brownian dynamics-finite element method (BD-FEM). Our group recently showed in experiments that the extensional electrophoretic field arising from a hyperbolic microcontraction can be utilized to stretch T4-DNA. We demonstrate the reliability of our BD-FEM model for the present problem by showing that the numerical predictions are consistent with the experimental data for the hyperbolic channel. We then investigate DNA stretching for four different funnel shapes. Surprisingly the maximum mean DNA stretch is quite similar in all four designs. Finally, we propose a new design with a side-feeding branch to enhance stretching based on a kinematic analysis along different feeding locations. Our numerical simulation predicted that DNA stretching can be dramatically enhanced using side-feeding.
TiN coatings on M2 steel produced by plasma-assisted chemical vapor deposition

Abstract TiN films were deposited onto M2 steel using plasma-assisted chemical vapor deposition. TiCl 4 , N 2 and H 2 were the reactant gases used at 1 Torr. A plasma was essential for TiN formation at 500 °C and below. At 500 °C, a highly crystalline stoichiometric TiN coating was formed with a (200) surface orientation and having a columnar zone 2 grain structure. At 400 °C, a zone T structure with an additional amorphous component was observed. Both types of films had good adherence with scratch adhesion critical loads comparable with values for sputtered TiN. The zone 2 films failed by cracking and occasional chipping within the coating. The zone T films failed by cracking in the coating and by chipping, within the coating and by the interface. Auger electron spectroscopy depth profiling of thin films indicates that the interface was sharp and no accumulation of chlorine is observed. Auger electron spectroscopy and scanning electron microscopy suggest that distinct TiN islands or nuclei were present in the early stages of growth. The use of an organometallic source, titanium tetrakis-(dimethylamide), resulted in the formation of carbonitride powders.
Respiratory and acoustic signals associated with bolus passage during swallowing.

In order to advance our understanding of the relation between respiration and deglutition, simultaneous videofluoroscopy and respirodeglutometry was performed. Fifteen normal, healthy, young adults (20–29 years of age) were connected to a respirodeglutometer and positioned for simultaneous videofluoroscopic assessment in the lateral plane. Subjects performed three swallows each of a 5-ml and a 10-ml bolus of liquid barium and a 5-ml bolus of paste barium, for a total of nine swallows per subject. Location of the bolus head as identified with videofluoroscopy was associated with eight respirodeglutometric variables. In addition, temporal relations for seven respirodeglutometric variables were calculated as a function of bolus volume and viscosity. Significant temporal differences were found for five of the variables by volume. No significant temporal differences were noted by viscosity. Expiration occurred before 79% and after 96% of the swallows. The number of inspirations preceding a swallow suggested a possible effect resulting from the need to hold a bolus in the mouth before receiving instructions to swallow during videofluoroscopic assessment. This effect may be important during patient evaluation. For a significant number of swallows, respiratory flow ceased before the velum was fully elevated.
The self-consistent cell model equation of state for solids

Abstract An anharmonic equation of state for solids using the Self-Consistent Cell Model (SCCM) is given in a form useful for calculating the usual thermodynamic properties. Following Cowley and Shukla, using the Jaswal-Girifalco potential for copper, calculations are compared with other models and with experiment. The results from the analytic expressions using the SCCM are as good or better than those obtained from far more complicated theories of anharmonicity. Using the Lindemann criterion, the pressure at the melting point was obtained as a function of the melting temperature. A melting line was also obtained for iron and the longitudinal velocity and isothermal bulk modulus along the melting line were calculated. The Hugoniot pressures were calculated and compared with experiment. For both the copper and iron the agreement between theory and experiment is remarkably good considering the empirical nature of the potentials, the simplifying approximations of the SCCM calculations, and the large range of densities and pressures that are compared with experiment.
Emotional Reactivity to Network Stress in Middle and Late Adulthood: The Role of Childhood Parental Emotional Abuse and Support

Purpose: This study examined whether recalled childhood parental emotional abuse and support were associated with emotional reactivity to network stress among middle-aged and older adults. Design and Methods: Hypotheses were tested by performing 2-level multilevel modeling analysis on 787 participants aged 33–83 who participated in the Daily Stress Project (2004–2009). Results: Adult daughters who recalled more childhood emotional abuse from their mother reported a higher average level of daily emotional distress nearly a decade later. The association between network stress and emotional distress was only significant among adult daughters. This emotional reactivity was attenuated by greater childhood emotional support from mothers. Implications: Recalled childhood mother–child relationship continues to influence stress and coping across the lifespan, especially among women.
The Bivariate Normal Distribution and the IQ of Learning Disability Samples

Several studies have indicated that the average IQ score of many learning disability samples is significantly below 100, although above the educable mental retardation range. The bivariate normal probability distribution was used to explain how selecting cases with achievement scores below a given z score cutoff (e.g., scores less than -1.0) and IQ scores above a given cutoff (e.g., IQ scores 80 or greater) can result in an average IQ score significantly below 100. Because of the relationship between achievement and IQ, as the correlation between achievement and IQ increases, the average IQ score of learning disability samples decreases. The bivariate normal probability distribution was illustrated by considering correlations of 0.0, .5, and 1.0.
A table lookup FET model for accurate analog circuit simulation

A table-based approach to the empirical modeling off FETs in circuit simulators addresses the specific requirements of analog circuit design, such as accuracy in reproducing small-signal parameters, large signal nonlinearities, subthreshold characteristics, substrate effects, short-channel effects, and voltage dependent capacitances. Efficiencies in storage and computation brought about by this model in SPICE considerably speed up circuit simulation, compared to an analytical model offering similar accuracy. Methods are described to extract the table entries. The model is not specific to any one type of device or technology, although examples are given of how it may be simplified by using physical insights into device operation. >
Rotaviral and bacterial gastroenteritis in children during winter: an evaluation of physician ordering patterns.

Abstract Background: Identification of the agents of infectious diarrhea may facilitate appropriate therapy and prevent inappropriate antibiotic use. Objectives: To better define the etiology of infectious diarrhea for children
Preliminary Goodness-of-Fit Tests for Normality do not Validate the One-Sample Student t

One of the most basic topics in many introductory statistical methods texts is inference for a population mean, μ. The primary tool for confidence intervals and tests is the Student t sampling distribution. Although the derivation requires independent identically distributed normal random variables with constant variance, σ2, most authors reassure the readers about some robustness to the normality and constant variance assumptions. Some point out that if one is concerned about assumptions, one may statistically test these prior to reliance on the Student t. Most software packages provide optional test results for both (a) the Gaussian assumption and (b) homogeneity of variance. Many textbooks advise only informal graphical assessments, such as certain scatterplots for independence, others for constant variance, and normal quantile–quantile plots for the adequacy of the Gaussian model. We concur with this recommendation. As convincing evidence against formal tests of (a), such as the Shapiro–Wilk, we offer...
Surface Wave Propagation In A Slowly Varying Anisotropic Waveguide

SUMMARY We present a JWKB theory which describes the propagation of seismic surface waves in a laterally heterogeneous, anisotropic waveguide. We introduce a local dispersion relation and local vertical eigenfunctions which depend explicitly on the direction of the local wavevector as a consequence of the anisotropy. the variation of amplitude along a surface wave ray path is determined by a conservation law for the surface wave energy. Apart from the usual dynamical phase, which is the integral of the local wavevector along a ray path, there is an additional variation in phase in a general anisotropic waveguide. This additional phase, which is an analogue of the Berry phase in adiabatic quantum mechanics, vanishes in a waveguide with a local vertical two-fold symmetry axis or a local horizontal mirror plane.
Kenya's Africanization Program: Priorities of Development and Equity

Africa's postindependence leaders are under enormous pressure. They must assume such new functions as the conduct of foreign relations and military defense and must expand developmental activities greatly, all at a time of falling world commodity prices, population explosion, and increasing indifference to foreign aid on the part of the wealthier countries. Local African expectations are rising, even though such requisites for satisfying these aspirations as capital, skills, and initiative remain in short supply. Nationwide linkages and a national identity must be built in the face of quickening ethnic anxieties and inward-lookingness. The functional benefits offered by a continued non-African presence must be secured without causing deep-seated popular frustrations; such frustrations could clearly jeopardize the regime's legitimacy should they become too extreme. The need for schools, hospitals, and welfare activities are juxtaposed against such pressing requirements as the development of power facilities, irrigation schemes, road networks, and industries. The choices are difficult and the demands heavy. No wonder Aristide Zolberg remarks that the “governments with the lowest load capability have assumed the heaviest burdens.” If these restrictions of international environment and resources did not impose sufficient constraints upon governments as they attempt to cope with developmental needs, their flexibility of movement is further constricted by the pulls of ideology. African countries, fresh from an encounter with powerful, privileged European states, carry over a wide range of liberal commitments into the postindependence period. They are naturally determined to continue the struggle against any remaining manifestations of colonialism on the continent—white settler oligarchies, neocolonialist military and economic arrangements, or politically-inspired alignments with powers outside of Africa. Their leaders proclaim both nationalist and pan-Africanist objectives and call simultaneously for a leveling egalitarianism and rapid economic growth. The extent to which they can reconcile these somewhat overlapping, and even conflicting, goals with the compelling claims implicit in nation-building remains a crucial question with broad implications for regime stability.
Physical activity and kidney diseases

Regular physical activity (PA) in the early school years is recommended by several scientific associations for primary prevention of cardiovascular disease. Long-term observational studies have shown that subjects who exercise regularly have significantly less coronary heart disease (CHD) and a reduced risk of cardiovascular disease (CVD). Exercise reduces serum triglycerides, increases serum high density lipoprotein-cholesterol, lowers the blood pressure in patients with primary hypertension [1]. Regular exercise reduces the production of atherogenic cytokines and increases production of atheroprotective cytokines. It should be mentioned, however, that other factors may be associated with physical activity (e.g. a healthy diet, avoiding cigarette smoking, regular medical care) and may contribute to the improved health. No long term studies have been produced on the effects of PA during childhood on CHD and CVD in adult life but indirect evidence suggests that it may produce benefit. Regular exercise, on the other end, is associated with potential adverse effects (eg, musculoskeletal injuries, arrhythmias, myocardial infarction, and rhabdomyolysis); however, the absolute risk of kidney disease during exercise is low [2]. Consensus guidelines for the pre-participation physical evaluation (PPE) suggest a PPE for all children, even those who do not participate in organized sports, as an opportunity to promote health and fitness. PPE includes a medical and family history and a physical examination, with particular emphasis on the musculoskeletal and cardiovascular systems [3]. Exercise induces profound changes in the renal haemodynamics and in electrolyte and protein excretion. Proteinuria, hematuria and changes in serum electrolyte balance have been reported during intense PA; the increase in glomerular filtration may explain these transient alterations but the “nutcracker” compression on the renal vein may have a role. Haemoglobinuria and myoglobinuria may be observed under special exercise conditions [4]. PA does not worse nor reverse kidney disease but may reduce cardiovascular risk in chronic renal disease [5]. Children on dialysis and after a renal transplantation performing aerobic physical exercise show improvements in exercise tolerance, in quality of health and uraemic symptom scores; they gain weight loss, cardiovascular reactivity, avoiding an increase in blood pressure medication [6].
Terahertz Radiation-Band Engineering Through Spatial Beam-Shaping

We propose a terahertz (THz)-band engineering technique based on generation of specifically designed time-domain radiation. The desired time-domain radiation is formed by combining the time-delayed outputs of an array of photoconductive antennas. We have employed this technique to generate tunable narrowband THz radiation. By using an array of identical photoconductive antennas with identical spacings, we have demonstrated a 12.5-mW output peak-power over 0.05-THz bandwidth and a tuning range of 0.65-1.4 THz. Considering the 2.5-THz bandwidth of each individual photoconductive antenna, 50 times higher power efficiency is achieved as a result of radiation-band shaping.
Corticosteroids for the treatment and prevention of chronic lung disease

UNLABELLED Postnatal corticosteroids may prevent chronic lung disease in ventilated very low birthweight infants. However, concern regarding serious neurodevelopmental consequences of therapy has led to strong recommendations to curtail use of this treatment. CONCLUSION Despite the high risk of severe neurological side effects, centers in Europe and North America continue to utilize postnatal corticosteroids, frequently in a fashion that is not supported by the available evidence.
MOLECULAR CHARACTERIZATION OF RIBOSOMAL GENES ON THE Ybb- CHROMOSOME OF DROSOPHILA MELANOGASTER

The question of whether the Ybb- chromosome contains ribosomal genes has been examined by using Southern blot analysis and comparing rDNA hybridization patterns for X/X and X/Ybb- DNA. The results demonstrate that the Ybb- chromosome contains sequences that hybridize to an rDNA probe under stringent conditions. Differential hybridization of some of these sequences with DNAs corresponding to different regions of a complete ribosomal gene repeat provides evidence that some of the genes on the Ybb- chromosome are type 2 repeats. Because data obtained by other workers suggest that type 2 repeats are transcribed only to low levels, these repeats may be classed as "nonfunctional". A further finding is that the ribosomal genes on the Ybb- chromosome do not undergo multiple rounds of DNA replication during polytenization of X/Ybb- cells.
Recent developments in PET detector technology.

Positron emission tomography (PET) is a tool for metabolic imaging that has been utilized since the earliest days of nuclear medicine. A key component of such imaging systems is the detector modules—an area of research and development with a long, rich history. Development of detectors for PET has often seen the migration of technologies, originally developed for high energy physics experiments, into prototype PET detectors. Of the many areas explored, some detector designs go on to be incorporated into prototype scanner systems and a few of these may go on to be seen in commercial scanners. There has been a steady, often very diverse development of prototype detectors, and the pace has accelerated with the increased use of PET in clinical studies (currently driven by PET/CT scanners) and the rapid proliferation of pre-clinical PET scanners for academic and commercial research applications. Most of these efforts are focused on scintillator-based detectors, although various alternatives continue to be considered. For example, wire chambers have been investigated many times over the years and more recently various solid-state devices have appeared in PET detector designs for very high spatial resolution applications. But even with scintillators, there have been a wide variety of designs and solutions investigated as developers search for solutions that offer very high spatial resolution, fast timing, high sensitivity and are yet cost effective. In this review, we will explore some of the recent developments in the quest for better PET detector technology.
Radiation pattern of a biconical antenna with a finite source region

The results of a theoretical study on the radiation pattern of a vertically polarized biconical antenna with a finite source region are presented in this paper. Schelkunoff has formulated the general solution for the radiation pattern of a biconical antenna in terms of spherical harmonics or modes. His formulation is followed in this paper. The dominant mode in a biconical antenna with a zero length source region is a TEM wave and the bicones may be viewed as a transmission line feeding a mismatched load at the antenna aperture. Since the TEM wave is mismatched with free space waves, additional modes are generated inside and outside the antenna to satisfy the boundary conditions.
Model for Predicting Speed Along Horizontal Curves on Two-Lane Highways

This paper describes the development and calibration of a curve speed prediction model. The model includes variables for curve radius, deflection angle, superelevation rate, and tangent speed. The model is based on the hypothesis that drivers modify their side friction demand because of a desire for both safe and efficient travel. One model component reflects a general desire by motorists to have lower side friction demand on higher speed curves. This trend likely reflects the driver's desire to maintain an acceptable margin of safety against sliding out or rolling over. A second model component reflects a willingness by drivers to tolerate slightly higher side friction demand on sharper curves in an effort to minimize the amount of speed reduction. The increase in side friction demand that a driver accepts is found to be proportional to the energy required to slow the vehicle to the curve speed.
Rings of symmetric functions as modules over the Steenrod algebra

We write P s for the polynomial ring on s letters over the field Z=2, equipped with the standard action of Us , the symmetric group on s letters. This paper deals with the problem of determining a minimal set of generators for the invariant ring .P s / Us as a module over the Steenrod algebra A. That is, we would like to determine the graded vector spaces Z=2 A.P s / Us . Our main result is stated in terms of a “bigraded Steenrod algebra” H. The generators of this algebra H, like the generators of the classical Steenrod algebra A, satisfy the Adem relations in their usual form. However, the Adem relations for the bigraded Steenrod algebra are interpreted so that Sq 0 is not the unit of the algebra; but rather, an independent generator. Our main work is to assemble the duals of the vector spaces Z=2 A.P s / Us , for all s 0, into a single bigraded vector space and to show that this bigraded object has the structure of an algebra over H.
Passivity of fit and marginal opening in screw- or cement-retained implant fixed partial denture designs.

The relationship of stress generation upon placement of cement-retained or screw-retained implant restorations has not been thoroughly investigated. Passivity of fit and marginal discrepancies of screw- and cement-retained implant fixed partial denture (FPD) designs were determined using a photoelastic model of a partially edentulous posterior mandibular arch with 3 screw-type implants. Buccal and lingual marginal openings, measured with a traveling microscope before cementation or screw tightening, revealed no statistical difference in adaptation between designs. Screw tightening caused a reduction in marginal opening (changes significant, P < .05). The opening with the cemented FPDs was similar before and after cementation. Photoelastic evaluation of the FPDs showed that cement-retained FPDs exhibited a more equitable stress distribution than did their screw-retained counterparts.
Genetic and molecular analysis of leaf development.

Publisher Summary This chapter discusses the genetic and the molecular analysis of leaf development. The pattern of successive leaves on a meristem, called phyllotaxis, has provided experimental systems for the studies of whole-plant pattern formation. Within the leaf itself, bilateral symmetry, precise and orderly vascular differentiation, and stomata1 patterns within the leaf epidermis all exemplify patterned differentiation. Various hypotheses have been put forward to explain the complex process of pattern generation in plants. The two most prominent hypotheses state: that the genetic mechanisms operate at supracellular levels to generate form and that the patterns are progressively determined in a “differentiation-dependent” manner. Plants often express a heteroblastic variation in leaf shape and size on the axis. It is, therefore, important in developmental studies to have designations for specific leaves. Leaf shape can be studied, by combining the morphological analysis with genetic clonal analysis, utilizing the somatically marked cells and the cellular site of gene action can be elucidated, by combining the clonal analysis with mutational analysis in studies of interactions between mutant and wild-type cells.
Sun-Centered and Hybrid World Views

At the beginning of the 16th Century, the ideas of Aristotle and Ptolemy continued to dominate astronomy, and the predominant world view was geocentric. Ptolemy’s planetary models were reasonably accurate in predicting celestial positions. However, his use of the equant forced planetary epicycles to move with non-uniform speed around their deferent, which was a problem for many Classical Greek traditionalists.
Serum antibodies specific for tumor antigens in colorectal cancer may be useful diagnostic biomarkers

11081 Background: Breast cancer is immunogenic and a number of tumor antigens have been identified using serum from breast cancer patients. We questioned whether humoral immunity to tumor associated antigens (TAA) in breast cancer patients could be used as a biomarker to predict disease. Methods: Serum antibody responses to a panel of TAA were measured in serum from breast cancer patients (n=100–200) and age-matched controls (n=100–200) using ELISA. Results: Breast cancer patients have increased antibody response to p53 (10% vs. 1%, p<0.001), HER2 (13% vs. 5%, p=0.004), MUC1 (20% vs. 3%, p<0.001), topoisomerase II alpha (7% vs. 3%, p=0.001), insulin-like growth factor binding protein 2 (IGFBP2, 14% vs. 1%, p<0.001), cyclin D1 (8% vs. 5%, p=0.04), and cathepsin D (5% vs. 3%, p=0.05). To determine the potential diagnostic value of these serum antibodies, we measured antibody levels to these TAA in an independent sample set which included 184 breast cancer patients and 134 normal donors. Responses were used ...