cssi/SciSciGPT-SciSciNet huggingface dataset:
Cholangiography of mucin‐hypersecreting intrahepatic biliary neoplasms

Bile duct obstruction caused by profuse mucin secretion in a major bile duct is rare. Such cases are often incorrectly identified as choledocholithiasis before being histologically proven. The goal of this study was to analyze the cholangiograms of mucin-hypersecreting intrahepatic biliary neoplasms and to try to identify the characteristic cholangiographic features of this rare disease. A retrospective analysis of 20 cholangiograms (from 6 men and 14 women) of mucin-hypersecreting intrahepatic biliary neoplasms over a 13-year period was carried out. Sixty percent of the patients had associated biliary tract stones. A mucinous substance drained out during biliary catheterization (endoscopic retrograde cholangiography [ERC]; percutaneous transhepatic cholangiography [PTC] in 4 patients. The cholangiographic findings included: (1) The appearance of diffuse “ground-glass” filling defects of extrahepatic duct and non-visualization of the tumor-bearing intrahepatic duct in 9 patients (45%), (2) multiple amorphous filling defects of the extrahepatic duct and tumor-bearing intrahepatic duct in 5 patients (25%), (3) multiple filling defects of the extrahepatic duct and non-visualization of the tumor-bearing intrahepatic duct in 4 patients (20%), and (4) single amorphous filling defect of the extrahepatic duct in 2 patients (10%). Mucin-hypersecreting intrahepatic tumors with mucobilia should be highly suspected when the following cholangiographic characteristic are shown: (1) mucinous substance draining out during catheterization (ERC or PTC); (2) diffuse “ground-glass” appearance filling defects; and (3) multiple amorphous filling defects of the bile duct associated with a cystic mass density within the liver on sonography or computed tomographic scan.
Effects of Hen Egg Shell and Other Calcium Sources Upon Egg Shell Strength and Ultrastructure

Abstract The suitability of egg shell as a calcium source in layer diets was examined by comparing pulverized and crushed sterilized egg shells against oyster shell, limestone grit, and pulverized limestone, as calcium supplements. These calcium sources were fed in appropriate amounts to obtain diets with 3% total calcium. Breaking strength of the eggs, determined at 90 and 150 days of feeding, showed that eggs from the hens fed the diets containing oyster shell, pulverized egg shell and limestone grit were significantly stronger (P Scanning electron micrographs revealed that most of the changes responsible for differences in shell breaking strength apparently take place in the palisade layer, while the mammillary layer remains approximately constant. It appeared that the palisade layer contributes most of the strength in the shell. As the palisade layer decreased in thickness and in concentration, there was a closely predictable decrease in breaking strength of the eggs. Evidence was obtained indicating a poor correlation between breaking strength and total shell thickness. Breaking strength is a superior measure of egg shell quality because it takes into consideration both the thickness and the concentration of the palisade layer around the crystalline mammillary portion of the egg shell.
Misalignment induced shear deformation in 3D chip stacking: A parametric numerical assessment

The misalignment effect in three dimensional (3D) chip packages is studied numerically using the finite element method (FEM). The model features a through-silicon-via (TSV)/micro-bump bonding structure connecting two adjacent silicon (Si) chips, with and without surrounding underfill. Misalignment is implemented through a prescribed shear deformation, and we seek to parametrically explore the trend of stress and deformation fields as affected by the geometry and material. Different solder thicknesses in the micro-bump, as well as a special case where the entire solder region is transformed into the intermetallic compound, are considered in this study. The effects of shear deformation are also compared with those due to thermal expansion mismatch. A thinner solder region in the micro-bump is found to have a higher propensity of damage initiation. The existence of underfill enhances the resistance to overall shear deformation, although with a much greater buildup of local stresses. With an intermetallic layer in place of the soft solder alloy in the micro-bump, the overall shear strength of the structure increases but with a concomitant increase in the risk of local brittle failure.
Injectable hydrogels for bone and cartilage repair

Injectable in situ crosslinkable gels are highly desirable clinically as they can be introduced into a body via a minimally invasive manner using endoscopic or percutaneous procedures. Several hydrophilic polymeric systems that respond to stimuli such as light, temperature, pH, ionic concentration as well as those that can undergo chemical reactions to form crosslinked matrices are currently under development. This paper discusses the applications of hydrogels as scaffolds to mimic the native extracellular matrix of bone and cartilage. A comprehensive description of various gelation methods used in hydrogel preparation and their application as injectable cell and protein delivery vehicle for bone and cartilage regeneration is also presented.
The significance of trisomy 7 mosaicism in chorionic villus cultures.

Two cases of mosaic trisomy 7 confined to the cultured cells and not found in direct preparation were detected from 200 consecutive first-trimester chorionic villus samples (CVS) analysed. The mosaicism was similar in the two cases, but the pregnancy outcome was different. In both cases, the direct metaphases from the CVS were 46, XY. Culture metaphases were mos46,XY/47,XY, + 7; the trisomy 7 was seen in 34 per cent of cells from case 1 and 53 per cent from case 2. A sonogram at 151/2 weeks revealed fetal death in utero in case 1, and the patient declined amniocentesis. The fetal tissue failed to grow in culture, but the placental cultured cells were 47,XY, + 7 in 28 (100 per cent) cells analysed. In the second case, all the amniotic fluid cells were 46,XY and the pregnancy resulted in a normal male with a 46,XY karyotype in the cord blood and foreskin fibroblast cultures. The term placenta was mosaic with 13/163 (8 per cent) trisomy 7 cells. Extensive cytogenetic studies on the placenta for the first time confirmed trisomy 7 mosaicism confined to the villus cultures.
A survey of web caching schemes for the Internet

The World Wide Web can be considered as a large distributed information system that provides access to shared data objects. As one of the most popular applications currently running on the Internet, the World Wide Web is of an exponential growth in size, which results in network congestion and server overloading. Web caching has been recognized as one of the effective schemes to alleviate the service bottleneck and reduce the network traffic, thereby minimize the user access latency. In this paper, we first describe the elements of a Web caching system and its desirable properties. Then, we survey the state-of-art techniques which have been used in Web caching systems. Finally, we discuss the research frontier in Web caching.
Modeling the nonlinear viscoelastic behavior of polyurea using a distortion modified free volume approach

The pressure-dependent behavior of polyurea was examined under monotonic loading in the confined compression configuration. Additional data from Arcan shear and uniaxial compression was used to respectively complete parameter selection for the linear and nonlinear behavior and then validate it. The bulk and shear relaxation behavior were both pressure dependent. Under ramp loadings, the shear and tensile responses were quite nonlinearly viscoelastic.
Ensemble Monte Carlo simulation of a 0.35- mu m pseudomorphic HEMT

Theoretical analysis and precise comparison to experiment of the performance of a 0.35- mu m pseudomorphic Al/sub 0.15/Ga/sub 0.85/As/In/sub 0.15/Ga/sub 0.85/As high-electron-mobility transistor (HEMT) are presented. The calculations are made using an ensemble Monte Carlo simulation with the unique inclusion of real space transfer as well as the full details of the two-dimensional electron gas, velocity overshoot, and ballistic transport, and the effects of the two-dimensional electric field profile. The calculated current-voltage characteristic is compared to recent experimental measurements showing excellent agreement to within approximately 10% over a full range of gate and drain biases. It is found that near the source, the two-dimensional system dominates the transport physics, while near the pinch-off point, the effects of real space transfer become apparent. It is further determined that the high-speed performance of the pseudomorphic HEMT stems predominantly from the high electron confinement within the two-dimensional system, and the high electron mobility and confinement within the gamma valley in the bulk InGaAs. >
An end-to-end domain-driven software development framework

This paper presents a comprehensive, domain-driven framework for software development. It consists of a meta-programmable domain-specific modeling environment and a model transformation generator toolset based on graph transformations. The framework allows the creation of custom, domain-oriented programming environments that support end-user programmability. In addition, the framework could be considered an early, end-to-end implementation of the concepts advocated by the OMG's Model Driven Architecture initiative.
Fostering informed empathy through patient-centred education about persons with disabilities

Introduction Having a disability can negatively affect provider-patient communication. Persons with disabilities report the need for better communication with their health care providers and argue that education regarding disabilities is lacking for health care professionals. We sought to determine if a patient-centred curriculum focused on individuals with disabilities could foster the development of informed empathy.
A Test of the Effect of Satellite Spin on Two-Way Doppler Range-Rate Measurements

Analysis indicates that the rotation of a satellite can cause an error in the range-rate measurements of a two-way Doppler tracking system. The error is proportional to the rotation rate, and the constant of proportionality depends on the polarization of the satellite transponder antennas. Measurements made by ground-based simulation confirmed the analytical prediction.
Mechanisms Through Which Adolescents Attend and Respond to Antismoking Media Campaigns

Based on H. Markus and R. B. Zajonc’s (1985) O-S-O-R model, this study explores which pre- and postorientations are associated with antismoking campaign effectiveness. Analyzing nationally representative survey data, this study finds that sensation seeking as an internal orientation and antismoking education as a learned orientation play critical roles in adolescents’ level of awareness to both antismoking campaigns (i.e., “truth”) and prosmoking media messages. In turn, exposure to both kinds of smoking-related media messages seems significantly related to adolescents’ smoking intention rather indirectly through negative attitudes toward tobacco companies and through peer smoking norms, respectively. A comparative analysis between younger and older adolescents seems to suggest that school-based antismoking education may be more effective for younger adolescents, whereas antismoking media campaigns may be more effective for older adolescents.
The Influence of Various Preparations of Lactic Acid and Sugars on the Growth of Transplanted Tumors: II. Mouse Sarcoma 180

In a previous paper (1) we discussed the effect of injections of sodium lactate and ethyl lactate on rat sarcoma 39, a tumor which tends to retrogress spontaneously in a certain percentage of cases. In this paper we report on experiments with mouse sarcoma 180, a very stable tumor with only a slight tendency toward retrogression. The effect was tested of injections not only of various preparations of lactic acid but also of different sugars. The following is a list of the preparations examined and of the number of mice which were used in the various experiments. The experimental procedure in this work was the same as that applied in the experiments with rat sarcoma 39. In all cases except those in which lactic acid was given orally the lactic acid preparations and sugars were injected subcutaneously at a distance from the tumor.
Experimental tests of open-loop maximum-power-point tracking techniques for photovoltaic arrays

Abstract Two open-loop maximum-power-point tracking techniques for photovoltaic arrays are described and evaluated experimentally for the first time. These techniques both slave the operating point of a photovoltaic array to the state of a pilot cell. Experiments were performed to compare these open-loop methods with well-known array operating point control methods. For 25 days, array and pilot cell current-voltage data were recorded at 3 min intervals from a working photovoltaic string to compare the different tracking techniques. During this winter experimental period, minimal (about 1%) energy losses resulted from slaving the array voltage to a fixed multiple of the pilot cell open-circuit voltage. Larger energy losses (about 7%) resulted from slaving the array current to a fixed multiple of the pilot cell short-circuit current. At least 2.2% of the energy would be lost through array operation at a fixed voltage during this period. A method of setting the multiplying factors which determine the details of the slaving algorithm is described. Because of its small energy losses, the voltage-slaved pilot cell method is found to be a viable alternative for the control of photovoltaic arrays.
Ramping Up to Meet NCLB Mandates by Creating an ESL Program Reflecting Effective Schools Research

This case study describes how a high school in a mid-sized interior city of the United States with a rapidly growing population of English Language Learners (ELLs) ramped up its English as a Second Language (ESL) program to better meet the educational needs of its students, as well as to prepare them to meet the accountability requirements of the No Child Left Behind Act (NCLB) of 2001. This school's ESL program, which reflects the findings of effective schools research (e.g., Reynolds & Teddlie, 2000a), provides a model for high schools with similar populations.
Nuclear multifragmentation: models and observables☆

Abstract First two major classes of models for nuclear dynamics are considered, namely onebody (mean-field) models and A -body (molecular-dynamics) models, and some areas in need of further progress are identified; a brief description is also given of a recently developed quasi-classical molecular-dynamics model that incorporates a Pauli potential and mimics nuclear systems well. Then the attention is turned towards statistical models of multifragmentation, and recent work on contrasting sequential binary breakup with prompt multifragmentation is described.
Noise in a Driven Josephson Oscillator

The effect of noise on the microwave-induced steps in the current-voltage characteristic of a Josephson junction is investigated theoretically. The dynamic resistance of a step is obtained in the limit that the capacitance of the junction is small. The phase fluctuations of the junction are greatly reduced in the presence of the microwave signal, and the dynamic resistance can be extremely small.
Cytomegalovirus infection of trophoblast cells elicits an inflammatory response: a possible mechanism of placental dysfunction.

Objective We sought to determine whether cytomegalovirus infection of extravillous trophoblast cells induces inflammatory changes that lead to cell death. Study design Extravillous trophoblast (HTR-8/SVneo) cells were infected with cytomegalovirus. Cell death assays were performed 8 to 48 hours after infection. The expression and secretion of cytokines (interleukin-6 and -8) preceding cell death was measured by polymerase chain reaction and enzyme-linked immunosorbent assay. Results Cell viability (lactate dehydrogenase assay) was reduced approximately 20%, and rates of apoptosis (measured by TdT-mediated dUTP-X nick end labeling [TUNEL] assay) were increased approximately 40% at 16 to 48 hours after infection. Significantly elevated levels of caspase-3 mRNA levels were observed before increased cell death. Interleukin-6 and -8 mRNA expression and protein secretion were up-regulated 8 to 16 hours after cytomegalovirus infection. Conclusion Placental exposure to cytomegalovirus induces an inflammatory response that precedes invasive trophoblast cell death. Cytomegalovirus may prevent normal placental invasion, which results in adverse reproductive outcomes that are associated with placental dysfunction.
Bioequivalence of Liquid and Reconstituted Lyophilized Etanercept Subcutaneous Injections

The objective of this study was to compare the pharmacokinetics of liquid and reconstituted lyophilized etanercept. This single-center, open-label study had a 2-period crossover design in which 36 healthy subjects were randomly assigned in a 1:1 ratio to etanercept (liquid/lyo or lyo/liquid). The treatments were separated by 28 days. Blood samples were obtained predose and at 10 predetermined time points postdose. Serum concentrations were determined by enzyme-linked immunosorbent assay. Noncompartmental pharmacokinetic parameters were analyzed using a standard crossover analysis of variance model. Thirty-three subjects completed both treatment periods. Geometric mean values (adjusted) of area under the serum drug concentration-time curve from time zero to the time of the final quantifiable sample, area under the serum drug concentration-time curve from time zero to infinity, and maximum concentration obtained with the 50-mg/mL liquid etanercept injection were 93.0%, 90.7%, and 98.5% of the respective parameters for 2 injections of 25 mg/mL reconstituted formulation. All associated confidence intervals were within the predefined equivalence interval of 80% to 125%. No differences in safety profiles of the 2 formulations were apparent. Liquid etanercept was bioequivalent to the reconstituted lyophilized etanercept formulation.
Drop Retention Force as a Function of Drop Size

The force, f, required to slide a drop past a surface is often considered in the literature as linear with the drop width, w, so that f/w = const. Furthermore, according to the Dussan equation for the case that the advancing and receding contact angles are constant with drop size, one can further simplify the above proportionality to f/V(1/3) = const where V is the drop volume. We show, however, that experimentally f/V(1/3) is usually a decaying function of V (rather than constant). The retention force increases with the time the drop rested on the surface prior to sliding. We show that this rested-time effect is similar for different drop sizes, and thus the change of f/V(1/3) with V occurs irrespective of the rested-time effect which suggests that the two effects are induced by different physical phenomena. The time effect is induced by the unsatisfied normal component of the Young equation which slowly deforms the surface with time, while the size effect is induced by time independent properties. According to the Dussan equation, the change of f/V(1/3) with V is also expressed in contact angle variation. Our results, however, show that contact angle variation that is within the scatter suffices to explain the significant force variation. Thus, it is easier to predict contact angle variation based on force variation rather than predicting force variation based on contact angle variation. A decrease of f/V(1/3) with V appears more common in the system studied compared to an increase.
The computational complexity of abduction

Abstract The problem of abduction can be characterized as finding the best explanation of a set of data. In this paper we focus on one type of abduction in which the best explanation is the most plausible combination of hypotheses that explains all the data. We then present several computational complexity results demonstrating that this type of abduction is intractable (NP-hard) in general. In particular, choosing between incompatible hypotheses, reasoning about cancellation effects among hypotheses, and satisfying the maximum plausibility requirement are major factors leading to intractability. We also identify a tractable, but restricted, class of abduction problems.
Approximate orthogonal distance regression method for fitting quadric surfaces to range data

Abstract Fitting surfaces to 3-D data is one of the basic methods of surface description for 3-D vision. Most techniques of surface fitting proposed in the literature are “least-squares”-based that rarely produce satisfactory results if noise level is very high or if the data points are sampled from a small area. A new approach is presented in this paper that minimizes the mean squared approximate orthogonal distances with linearization using Newton's iteration method. This approach usually yields a good fit and the algorithm is reliable and efficient for real applications. Results are reported for synthetic data and several examples of real range data. Experimental results demonstrate that the approximate orthogonal distance performs better than the least squares based methods.
Temperature-sensitive tree-ring width chronologies of pink pine (Halocarpus biformis) from Stewart Island, New Zealand

Abstract Long instrumental or proxy climatic records are scarce for the Southern Hemisphere relative to many northern regions, but are essential for a global perspective of past climate variability. In this paper we describe two tree-ring width chronologies of pink pine which are the first published for Stewart Island, New Zealand (47°S, 168°E), one of the southernmost forested land masses on the globe. A chronology for western-central Stewart Island (Doughboy-Rakeahua) extends from 1682 to 1990; the other, for southern Stewart Island (Pegasus) from 1690 to 1991. Both series are positively correlated with warm-season surface air temperatures for southern New Zealand and vicinity. Although there are shorter intervals of comparable warmth, the highest 20-year periods of growth during the past 300 years occurred during the middle 1950s–1970s, coinciding with record warming since around 1950 in New Zealand. Chronologies developed from two related species: silver pine ( Lagarostrobus colensoi ) from Ahaura, western South Island, New Zealand, and huon pine ( Lagarostrobus franklinii ) from Tasmania also indicate recent warming which is unusual, although not statistically unprecedented, within the contexts of the past 642 and 2290 years of record, respectively.
The effects of time-compressed audio and verbal redundancy on learner performance and satisfaction

Digital audio is becoming increasingly popular in higher education with faculty digitally recording and broadcasting lectures for students to learn-on-demand. Students have discovered accelerated playback features in popular computer software and use it to reduce the amount of time spent listening to audio-enhanced instruction. In the current study, 183 undergraduates were randomly assigned to one of three audio-enhanced multimedia presentations that were recorded at three speeds (1.0, 1.4, and 1.8). Results show no significant difference on performance across treatments and a significant difference on satisfaction in favor of 1.4 times the normal audio speed. The results also indicate statistical differences in favor of verbal redundancy, in which the same verbal information was presented on both an auditory and visual channel.
The changing look in dental education.

Widespread significant changes in curriculum planning are being made in dental schools throughout the country. The distinctive new curriculum of the Pittsburgh School of Dental Medicine, based on an educational philosophy and the application of learning theory, is an example of what is being done.
Characterization of friction and speed effects and methods for detection of cochlear implant electrode tip fold-over

Perimodiolar electrode arrays for cochlear implant surgery present surgeons with challenges during their insertion into the cochlea. These challenges stem from the inherent flexibility of these arrays and the fragile intracochlear anatomy and has opened opportunities for high precision robotic systems. This paper investigates effects of insertion speed on insertion forces using perimodiolar electrode arrays in human temporal bones and complements previously published results on insertion force and speed relationships when using straight outer-wall electrode arrays. The paper presents a custom-made parallel robot equipped with a high resolution force/moment sensor as an insertion platform. Experimental results using 42 insertions in 8 temporal bones are analyzed and grouped by insertion speed. Our results show a reduction in insertion forces up to insertion speeds of 1 mm/s. The second aspect of this paper is the investigation of the feasibility of using insertion force and speed data to sense conditions predicting the onset of electrode tip fold over, a complication resulting in poor placement of electrode contacts. It is shown that tip folding can be detected by features taken from insertion force data when employing a support vector machine classifier. The capability to detect such errors in a procedure is a critical component to the development of a practical surgical tool.
On some results of Takács in ballot problems

Suppose that in a ballot candidate A scores a votes and candidate B scores b votes and that all the possible voting records are equally probable. Let @a"r and @b"r denote the number of votes registered for A and B among the first r votes recorded. Let @D(@D*) denote the number of subscripts r for which the inequalitt (strict inequality) @a"r>[email protected]@b"r+v(@a"r>@[email protected]"r+v holds where @m>=0 and v are arbitrary real numbers. Simple combinatorial proofs are given for the following theorems of which the first two are due to Takacs [4,5] and the third is new. (1) If a and b are relatively prime, @m = ab and v=0, then P(@D=j)=1(a+b), j=1,2,...,a+b, (2) If @m= (a-1)b and v=0, then P(@D^*=j)=1(a+b), j=1,2,...,a+b. (3) If @m=(a+1)b and v=0 then P(@D=j)=1(a+b), j=0,...,a+b-1. Also, closed form expressions for the probabilities P(@D=a+b) and P(@D^*=a+b are given without any restrictions on @m and v special cases of which have been derived by Takacs [6] among others.
On Fluctuations and the General Distribution Problem in Electron Cascades

Recent developments of Bhabha, Friedman, and J\'anossy are applied to the general probability distribution problem of electron cascades (cosmic-ray showers). In particular, it is shown that the master function giving the probability of any number of particles with any given energy distribution at a depth $t$ in a shower is determined, in principle, by the average energy spectrum. Certain theorems connecting the various functions are derived, and a discussion is given of the as yet unsolved problem of getting satisfactory analytic or numerical results from the formalism. Only the simplified model originated by Furry has been discussed, but the theorems embody many properties of the actual electron-photon multiplication process.
Growth and development of mice offspring after irradiation in utero with 2,450-MHz microwaves

Mice offspring irradiated in utero with 2,450-MHz radio-frequency (RF) radiation at 0 or 28 mW/cm2 (whole-body averaged specific absorption rate = 0 or 16.5 W/kg) for 100 minutes daily on days 6 through 17 of gestation were evaluated for maturation and development on days 1, 5, 10, 12, 15, and 17 of age. The tests used to determine differences in developmental age in the two treatment groups were body weight, urine concentrating ability, brain weight, tolerance to ouabain, and bone lengths. Fifteen sham-irradiated and 26 RF-irradiated litters, normalized to eight pups/litter, were used in this study. Mean body weight of the microwave-irradiated offspring were significantly (p = .0003) decreased only on day 1 of age. Brain weight on days 10, 12, and 17 were significantly lower in microwave-irradiated pups (p = .01). There were no significant differences in the two groups in urine concentrating ability on day 5, ouabain tolerance on day 15, or bone length on days 5, 10, 12, and 17. It is concluded that there is a persistent delay in postnatal development of the brain after RF irradiation with 16.5 W/kg during gestation.
Westergaard-Type Solution for Edge Load Transfer Problem:

On the prominent issue of edge load transfer in portland cement concrete pavements, common understanding has been that Westergaard's last contribution was the very cursory treatment contained in his 1948 paper. A recent examination of the archives at the U.S. Army Engineer Waterways Experiment Station, however, has brought to light a consulting report that Westergaard submitted to the Corps of Engineers in 1949 containing a detailed examination of the edge load transfer problem, prepared by his associate M. S. Skarlatos. To expedite dissemination of this information, the results of an investigation that sought to extend and refine the edge load transfer solution by Skarlatos using modern computational tools are presented. A comparison of this solution to earlier finite element solutions is also presented. Following the same approach as Skarlatos and Westergaard, closed-form equations are derived for the maximum deflection and maximum bending stress occurring on the unloaded side of an edge capable of load...
Role of the Russell–McPherron effect in the acceleration of relativistic electrons

While it is well known that high fluxes of relativistic electrons in the Earth's radiation belts are associated with high-speed solar wind and its heightened geoeffectiveness,less known is the fact that the Russell McPherron(R M) effect strongly controls whether or not a given high-speed stream is geoffective. To test whether it then follows that the R M effect also strongly controls fluxes of relativistic electrons, we perform a superposed epoch analysis across corotating interaction regions (CIR) keyed on the interfaces between slow and fast wind. A total of 394 stream interfaces were identified in the years 1994-2006. Equinoctial interfaces were separated into four classes based on the R-M effect,that is, whether the solar wind on either side of the interface was either(geo)effective (E) or ineffective (I) depending on season and the polarity of the interplanetary magnetic field (IMF). Four classes of interface identified as II, IE, EI,and EE are possible. The classes IE and EI correspond to CIRs with polarity changes indicating passage through the heliospheric current sheet. To characterize the behavior of solar wind and magnetospheric variables, we produced maps of dynamic cumulative probability distribution functions (cdfs) as a function of time over 10-day intervals centered on the interfaces. These reveal that effective high-speed streams have geomagnetic activity nearly twice as strong as ineffective streams and electron fluxes a factor of 12 higher. In addition they show that an effective low-speed stream increases the flux of relativistic electrons before the interface so that an effective to ineffective transition results in lower fluxes after the interface.We conclude that the R-M effect plays a major role in organizing and sustaining a sequence of physical processes responsible for the acceleration of relativistic electrons.
Photometry of Dione, Tethys, and Enceladus on the UBV system

UBV measurements of Dione, Tethys, and Enceladus were made with an area-scanning photometer on several nights during the 1972/73 and 1973/74 apparitions of Saturn. The observed brightness variations have been separated into two components - one a function of orbital position, the other a function of solar phase angle. Dione and Tethys are brightest near greatest eastern elongation and faintest near greatest western elongation. The reverse is true of Enceladus. Opposition surges are observed for Dione and Tethys.
Gravity waves over a permeable bed

Abstract The attenuation of Waves on the free surface of a viscous fluid which is bounded below by a porous bed of finite depth, is studied. It is assumed that the viscosity, permeability of the porous bed and the bottom friction, according to the quadratic law, contribute to the dissipation of the wave energy. By linearizing the nonlinear frictional force, the complete linear problem is solved for the damping coefficients and the results are compared with the case when the turbulence is absent.
Healthy Smiles: A Multidisciplinary Baby Bottle Tooth Decay Prevention Program

Abstract Baby bottle tooth decay (BBTD) is a serious and preventable disease which continues to afflict many children each year. This type of decay has been associated with increased infections, impaired nutrition, sleeplessness, low self-esteem, lethargy, and poor concentration in children. Despite the knowledge of effective techniques that can reduce its incidence, approximately one percent to 50 percent of children continue to suffer from it in the United States. The strategies to prevent its occurrence are basic and straightforward; however, the methodology with which to reach individuals at highest risk is more complex. Therefore, BBTD educational campaigns are called upon. This article, in turn, describes one such campaign, Healthy Smiles, which was developed and implemented as a means to combat this problem. Perhaps the strategies utilized in this project can be examined by health educators and program developers as to whether they would be applicable in other such projects throughout the U.S.
Hormonal control of the tail fin and of the nuptial pads in the male red-spotted newt

Abstract Seasonal variation in tail fin height and in display of nuptial pads has been followed in the red-spotted newt ( Notophthalmus viridescens viridescens ), and various experiments have been conducted to elucidate the hormonal control of those structures. The height of the tail is constant in the female, but in the autumn that of the male increases to maximal proportions and black, keratinized nuptial pads form on the hind legs. At the end of the spring breeding season these nuptial pads are lost and the tail fin is markedly reduced in height. A similar loss of pads and decline in tail height takes place whenever pad-bearing males are brought into the laboratory and kept at room temperature with long day lengths. Loss of tail height was apparently unaffected by thyroidectomy or by the administration of testosterone on alternate days, but its decline was slowed by autografting the pituitary gland and was halted by the administration of prolactin on alternate days. Tail height of laboratory-conditioned male newts was restored over a period of 2–3 wk by the administration of prolactin. In hypophysectomized, conditioned males the response of the tail fin to prolactin was greatly reduced but was restored to a considerable extent by the additional administration of thyroid hormone or thyroid stimulating hormone. In intact animals the loss of nuptial pads was delayed by autografting of the pituitary gland, by thyroidectomy, and by the administration of prolactin. It was unaffected by testosterone, but was prevented by prolactin and testosterone given in combination. The combined dose also induced restoration of pads after their regression in laboratory-conditioned males. In hypophysectomized, laboratory-conditioned males thyroxine or thyroid stimulating hormone was required in addition to prolactin and testosterone for the restoration of nuptial pads. Luteinizing hormone, but not progesterone, was an effective substitute for testosterone.
Sediment oxygen profiles in a super-oxygenated antarctic lake

Perennially ice-covered lakes are found in the McMurdo Dry Valleys of southern Victoria Land, Antarctica. In contrast to temperate lakes that have diurnal photic periods, antarctic (and arctic) lakes have a yearly photic period. An unusual feature of the antarctic lakes is the occurrence of O2 at supersaturated levels in certain portions of the water column. Here we report the first sediment O2 profiles obtained using a microelectrode from a perennially ice-covered antarctic lake. Sediment cores collected in January and October 1987 from Lake Hoare in Taylor Valley show oxygenation down to 15, and in some cases, 25 cm. The oxygenation of sediments several centimeters below the sediment-water interface is atypical for lake sediments and may be characteristic of perennially ice-covered lakes. There is a significant difference between the observed January and October sediment O2 profiles. Several explanations may account for the difference, including seasonality. A time-dependent model is presented which tests the feasibility of a seasonal cycle resulting from the long photoperiod and benthic primary production in sediments overlain by a highly oxygenated water column.
Next-generation space telescope: a large UV-IR successor to HST

Attention is given to the science goals of the Next Generation Space Telescope (NGST), namely, detection and spectroscopy of gas giant planets to earthlike planets around nearby stars, study of nearby star-forming complexes with resolutions of 5-50 AU in the visible and IR, measurement of stellar populations in a variety of environments, spatial resolution and mapping of complex structures in the inner narrow line regions for AGN and QSOs, and investigation of the structure and evolution of galaxies at redshifts greater than 1. The NGST characteristics, milestones, long-term strategy, and launch capability are also discussed.
Auctions and bidding: A guide for computer scientists

There is a veritable menagerie of auctions—single-dimensional, multi-dimensional, single-sided, double-sided, first-price, second-price, English, Dutch, Japanese, sealed-bid—and these have been extensively discussed and analyzed in the economics literature. The main purpose of this article is to survey this literature from a computer science perspective, primarily from the viewpoint of computer scientists who are interested in learning about auction theory, and to provide pointers into the economics literature for those who want a deeper technical understanding. In addition, since auctions are an increasingly important topic in computer science, we also look at work on auctions from the computer science literature. Overall, our aim is to identifying what both these bodies of work these tell us about creating electronic auctions.
Convergence Properties of the Perturbative Expansion in Scalar Wave Scattering on Random Media

Scalar wave propagation in an isotropic randomly fluctuating medium is analyzed in terms of the multiple-scattering expansion, i.e., expansion of the scattering coefficient in powers of the fluctuation strength. It is shown that, in the limit of small absorption and sufficiently weak fluctuations, the leading terms in the multiple-scattering series can be summed exactly, and represented in terms of the radiative transfer equation (or its modification, taking into account back-scattering enhancement). On the other hand, the full series, including non-leading terms, is only asymptotic (non-convergent). For a weakly absorbing medium, and a typical shape of the correlation function, the first, the next-to-leading, correction to the cross-section is of the order π δ (2,πα/λ0)3 , δ being the variance of two-point correlations, α the correlation length, and λ0 the wavelength. The main effect of this correction is to modify the interaction kernel of the radiative-transfer equation in the way that favors individua...
Virtual medical geographies: conceptualizing telemedicine and regionalization

Telemedicine is an innovation that is changing the geography of medical care provision. Regionalization of care is one important type of geographical change resulting from the implementation of telemedicine technology. This paper introduces a range of issues bound up with telemedicine and medical care regionalization and offers a geographical conceptualization of those issues through a synthesis of ideas from several literatures. It begins by providing a background for regionalization and telemedicine. The paper continues by examining the formation of ‘virtual’ regions and the problem of their internal integration and integration with ‘material’ regions of care. A penultimate section argues for the use of regional economic geography and territoriality as contexts for understanding the continued growth and development of telemedicine networks. As part of an overall critical challenge to the protelemedicine bias in the medical care literature, the paper ends by suggesting the development of a normative ethi...
Dentin dysplasia, Type II: A rare autosomal dominant disorder

Dentin dysplasia, Type II, is a rare autosomal dominant disorder. The primary teeth are amber and translucent and the pulp chambers are obliterated. The permanent teeth have a normal to brown-gray coloration and a thistle-tube pulp configuration with multiple true denticles. To date, only five families with this disorder have been reported. This article presents two additional families. Light and scanning electron microscopy of an affected primary incisor showed the dentin, including the mantle layer, to be highly disorganized throughout. Possible pathogenic events associated with the phenotype are discussed.
A radio frequency measurement technique utilizing audio distortion to access the instantaneous sensitivity of a security systems receiver

A receiver measurement technique has been demonstrated to assess the instantaneous sensitivity of a security system's radio frequency (RF) receiver. Application of this measurement technique to a security systems wireless link can be used as warning to a system attack, identification of an interference source(s), changes in propagation conditions, or equipment failure. The interference sources may be unintentional or intentional, both of which can affect the performance of the receiver. An RF receiver used in a security system may be used to receive voice, video, telemetry, etc., which most likely is of high importance and/or consequence since it is used to gather information as part of a security system. In most cases, the receivers used in security systems have no indication of instantaneous receiver sensitivity. The measurement technique utilizes an RF audio distortion measurement to characterize the degradation to the communications receiver by providing a quantitative measure to the quality of the receiver's audio signal. This technique provides a way to quantify the performance of an RF receiver under a variety of conditions. The distortion to the audio signal can be the result of conducted, radiated, and/or coupled interference from active components that are within the receiver's passband.
Percutaneous transhepatic cholangiography and biliary decompression. Invasive, diagnostic, and therapeutic procedures with too high a price?

• To investigate and/or treat the causes of jaundice, 221 patients underwent the following procedures over 7 years: percutaneous transhepatic cholangiography (PTC) alone (104 patients), PTC with external biliary drainage (69 patients), or PTC with external/internal biliary drainage (48 patients). Forty-nine procedure-related complications occurred in 39 patients (18%). Three patients (1.5%) required an emergency operation for hepatic hemorrhage (2 patients) and a perforated gallbladder (1 patient). Two patients (1%) died as a direct result of the procedure secondary to hemorrhage (1 patient) and sepsis (1 patient). Preoperative biliary decompression, although technically (95%) and physiologically (82%) successful in the majority of patients, had no therapeutic benefit when compared (nonrandomized) with those patients without alleviation of jaundice prior to surgical intervention. ( Arch Surg . 1989;124:885-888)
Tightly-bound ATP and ADP in reconstituted submitochondrial particles.

Abstract Soluble beef-heart mitochondrial ATPase (F1) which was depleted of tightly bound nucleotide was reconstituted with depleted submitochondrial particles and oligomycin-sensitivity conferring protein. A correlation was noted between the recovery of energy-transduction capability and the reloading of tightly bound nucleotide. Reconstituted membrane-bound F1 contained both ATP and ADP tightly bound; the total (ATP and ADP) was tentatively calculated to be around 3.6 moles per mole membrane-bound F1.
Synaptic NMDA receptor-mediated currents in anterior piriform cortex are reduced in the adult fragile X mouse

Abstract Fragile X syndrome is a neurodevelopmental condition caused by the transcriptional silencing of the fragile X mental retardation 1 ( FMR1 ) gene. The Fmr1 knockout (KO) mouse exhibits age-dependent deficits in long term potentiation (LTP) at association (ASSN) synapses in anterior piriform cortex (APC). To investigate the mechanisms for this, whole-cell voltage-clamp recordings of ASSN stimulation-evoked synaptic currents were made in APC of slices from adult Fmr1 -KO and wild-type (WT) mice, using the competitive N-methyl- d -aspartate (NMDA) receptor antagonist, CPP, to distinguish currents mediated by NMDA and AMPA receptors. NMDA/AMPA current ratios were lower in Fmr1 -KO mice than in WT mice, at ages ranging from 3–18 months. Since amplitude and frequency of miniature excitatory postsynaptic currents (mEPSCs) mediated by AMPA receptors were no different in Fmr1 -KO and WT mice at these ages, the results suggest that NMDA receptor-mediated currents are selectively reduced in Fmr1 -KO mice. Analyses of voltage-dependence and decay kinetics of NMDA receptor-mediated currents did not reveal differences between Fmr1 -KO and WT mice, suggesting that reduced NMDA currents in Fmr1 -KO mice are due to fewer synaptic receptors rather than differences in receptor subunit composition. Reduced NMDA receptor signaling may help to explain the LTP deficit seen at APC ASSN synapses in Fmr1 -KO mice at 6–18 months of age, but does not explain normal LTP at these synapses in mice 3–6 months old. Evoked currents and mEPSCs were also examined in senescent Fmr1 -KO and WT mice at 24–28 months of age. NMDA/AMPA ratios were similar in senescent WT and Fmr1 -KO mice, due to a decrease in the ratio in the WT mice, without significant change in AMPA receptor-mediated mEPSCs.
Trauma in pregnancy.

Objective To determine whether the severity of maternal injury or other maternal and fetal variables will predict the outcome of pregnancy in the injured pregnant patient. Patients and Methods In this retrospective review of pregnant patients hospitalized at a level 1 trauma center from 1986 to 1996, we analyzed the maternal Injury Severity Score, maternal mortality, fetal-neonatal mortality, maternal hypotension, and fetal heart rate . Results Sixty-one pregnant women were identified who were hospitalized after trauma. The mean ± SD maternal age was 26.6±6.6 years. The distribution of trauma per gestational age was 21%, 20%, and 59% for the first, second, and third trimester, respectively. The most common mechanism of injury was motor vehicle crashes. Long-term pregnancy outcome was available in 53 patients (87%). There was 1 maternal death. Fetal-neonatal death occurred in 8 (15%) of 53 pregnancies. Most maternal physiologic variables were not predictors of pregnancy outcome. We were unable to detect a difference in the distribution of Injury Severity Scores between viable and nonviable pregnancies. However, maternal hypotension and low fetal heart rate were common in nonviable pregnancies (P=.02). Conclusions Maternal hypotension and fetal heart rate are potential predictors of pregnancy outcome after trauma. Other maternal and fetal physiologic variables are poor measures of fetal well-being and are unable to predict fetal outcome. Fetal-neonatal death does not necessarily correlate with severity of maternal injury.