cssi/SciSciGPT-SciSciNet huggingface dataset:
Collapsing glomerulopathy in a renal transplant recipient: potential molecular mechanisms.

BACKGROUND In this case report, we describe a predisposed renal transplant patient who developed FSGS with cellular and collapsing features after sirolimus exposure and discuss the potential molecular mechanisms. CASE REPORT A 35-year old African American female with end stage renal disease due to lupus nephritis received a living related renal transplant from a brother. She had immediate function achieved serum creatinine level of 1.7 mg/dl post day 4. Following a slow rise in the creatinine, first renal allograft biopsy performed on post op day 14 that showed thrombotic microangiopathy (TMA) involving arterioles and glomerular capillaries without any sign of rejection. The serological work up was negative for donor specific and antiphospholipid antibodies. The TMA was attributed to tacrolimus which was subsequently discontinued. It was replaced with sirolimus with loading dose of 10mg once and then 5 mg daily maintenance dose at day 21. At day 35, the patient was noted to have nephrotic range proteinuria, 12 gm/24 hrs. A second renal biopsy performed that revealed de novo focal segmental glomerulosclerosis with cellular and collapsing features, mild mesangial proliferative glomerulonephritis with immunoflourescence consistent with early recurrence of lupus nephritis ISN/RPS class 2. The etiology of cellular and collapsing FSGS was thought to be related to sirolimus based on timing of exposure and negative work up for secondary causes of collapsing FSGS. Sirolimus was switched to cyclosporine. At day 105, proteinuria decreased to 1.6 grams/day and serum creatinine leveled off 1.6 mg/dL. CONCLUSIONS We report a case of possible sirolimus-induced collapsing FSGS in a renal transplant recipient who may have been predisposed to develop a podocytopathy possibly due to TMA and altered WT1 expression resulting from m-TOR exposure.
Variable phosphorus uptake rates and allocation across microbial groups in the oligotrophic Gulf of Mexico

Microbial uptake of dissolved phosphorus (P) is an important lever in controlling both microbial production and the fate and cycling of marine P. We investigated the relative role of heterotrophic bacteria and phytoplankton in P cycling by measuring the P uptake rates of individual microbial groups (heterotrophic bacteria and the phytoplankton groups Synechococcus, Prochlorococcus and picoeukaryotic phytoplankton) in the P-depleted Gulf of Mexico. Phosphorus uptake rates were measured using incubations with radiolabelled phosphate and adenosine triphosphate coupled with cell sorting flow cytometry. We found that heterotrophic bacteria were the dominant consumers of P on both a biomass basis and a population basis. Biovolume normalized heterotrophic bacteria P uptake rate per cell (amol P μm(-3) h(-1)) was roughly an order of magnitude greater than phytoplankton uptake rates, and heterotrophic bacteria were responsible for generally greater than 50% of total picoplankton P uptake. We hypothesized that this variation in uptake rates reflects variation in cellular P allocation strategies, and found that, indeed, the fraction of cellular P uptake utilized for phospholipid production was significantly higher in heterotrophic bacteria compared with cyanobacterial phytoplankton. These findings indicate that heterotrophic bacteria have a uniquely P-oriented physiology and play a dominant role in cycling dissolved P.
The cardiovascular response to digoxin in conscious dogs with left atrial obstruction.

In addition to positive inotropic and atrioventricular conduction-blocking properties, digoxin is capable of producing systemic and pulmonary vasoconstriction. However, whether chronic digoxin treatment exacerbates the pulmonary hypertension that results from left atrial (LA) outflow obstruction has not been specifically examined. This study assessed the vascular and inotropic responses to 5 days of digoxin treatment in six conscious dogs before and after filling a permanently implanted LA balloon. Dogs were also instrumented to measure left ventricular (LV) pressure, LV dP/dt, mean systemic arterial (MAP), right atrial (RAP), pulmonary arterial, and pulmonary capillary wedge pressures, as well as cardiac output (CO). Under normal conditions with the balloon empty, digoxin treatment (40 μ g/kg loading dose and 12 μ g/kg/d for 5 days) reduced CO (−17%) and increased systemic (SVR) and pulmonary (PVR) vascular resistances 27% and 37%, respectively; heart rate (HR) and LV dP/dt were not changed. Filling the balloon with enough saline to double PVR also increased SVR (52%), HR (42%), and RAP (92%), and reduced CO (−24%). During LA outflow obstruction, 5 days of digoxin reduced HR (−17%). SVR (−29%), and RAP (−23%), but did not alter PVR, CO, or LV dP/dt. This study demonstrates that although systemic and pulmonary vasoconstriction result from chronic digoxin treatment under normal conditions, the drug produces systemic vasodilation and no change in PVR during LA outflow obstruction.
Vibrational relaxation of highly excited molecules: VV transfer from SF6 to N2O

Abstract Vibrational energy transfer from SF 6 to N 2 O was studied as a function of SF 6 vibrational energy. The intensity, rise time and decay time of N 2 O fluorescence increased monotonically with the level of donor excitation. The observations are consistent with a mechanism that is not mode specific, with donor VT relaxation faster than intermolecular VV transfer.
Temperature-dependent viscosity correlations of vegetable oils and biofuel–diesel mixtures

Viscosity correlations of peanut, soy, sunflower, waste vegetable oil and its biofuel mixtures with diesel are presented based on three suggested equations. Calibrated capillary viscometers are used for measurements. Temperature is changed between the range of 20 °C and 120 °C. Correlations show small standard errors based on the method of curve fitting.
Dispersion corrections to the electron-nucleus scattering

Abstract The nonstatic second-order corrections to the elastic electron scattering off nuclei have been calculated with a model that can reproduce the whole inelastic excitation spectrum. Both the Coulomb and transverse current interaction are included; intermediate states are summed without using closure. The dispersion correction, expressed relative to the first Born result, is dependent on the nuclear Fermi momentum only. Numerical results for 40 Ca are presented and are shown to be small (about 3%). This justifies the present practice of omitting the dispersion effect in analyzing data; however, it should be included when better experimental accuracy can be obtained in the future.
THE EFFECT OF ACTIVATION OF WILD-TYPE P53 FUNCTION ON FLUOROPYRIMIDINE-MEDIATED RADIOSENSITIZATION

Abstract Purpose: We have hypothesized that fluoropyrimidine-mediated (FdUrd) radiosensitization occurs in cells that inappropriately enter S phase in the presence of drug, resulting in defective repair of radiation-induced DNA damage (14) . This model would predict that prevention of entry into S phase would abrogate sensitization produced by FdUrd. We wished to test this prediction by blocking S phase entry of HT29 human colon cancer cells. Methods: We used HT29 cells that had been transduced with a murine temperature-sensitive p53 (ts29G) and, as a control, HT29 cells transduced with a neomycin plasmid (HT29neo). The murine temperature-sensitive p53 demonstrates wild-type p53 function when cells are incubated at the permissive temperature (32°C) and mutant p53 function at the nonpermissive temperature (38°C). We determined the effect of wt p53 function on FdUrd-mediated radiosensitization and cell cycle progression. Results: Incubation of ts29G cells at the permissive temperature (32°C) activated p21 and blocked entry of cells into S phase. Whereas FdUrd greatly increased the radiosensitivity of HT29neo cells and ts29G cells incubated at 38°C, FdUrd had no effect on the radiation sensitivity of ts29G cells incubated at the permissive temperature (32°C). Conclusions: These findings are consistent with our hypothesis that FdUrd-mediated radiosensitization requires progression into S phase. It is possible that the heterogeneity of clinical responses seen after combined therapy with fluoropyrimidines and radiation is explained, in part, by differences among tumor cells in the control of S phase progression.
Spatiotemporal Differentiation of Myocardial Infarctions

Myocardial infarction (MI), also known as a heart attack, is the leading cause of death in the U.S. It often occurs due to the occlusion of coronary arteries, thereby leading to insufficient blood and oxygen supply that damage cardiac muscle cells. Because blood vessels are branching throughout the heart, MI occurs at different spatial locations (e.g., anterior and inferior portions) of the heart. The spatial location of the diseased is rupts normal excitation and propagation of cardiac electrical activity in space and time. Most previous studies focused on the relationships between disease and time-domain biomarkers from 12-lead ECG signals (e.g., Q wave, QT interval, ST elevation/depression, T wave). Few, if any, previous approaches investigated how the spatial location of diseases will alter cardiac vectorcardiogram (VCG) signals in both space and time. This paper presents a novel spatiotemporal warping approach to quantify the dissimilarity of disease-altered patterns in 3-lead spatiotemporal VCG signals. The hypothesis testing shows that there are significant spatiotemporal differences between healthy control, MI-anterior, MI-anterior-septal, MI-anterior-lateral, MI-inferior, and MI-inferior-lateral. Furthermore, we optimize the embedding of each functional recording as a feature vector in the high-dimensional space that preserves the dissimilarity distance matrix. This novel spatial embedding approach facilitates the construction of classification models and yields an averaged accuracy of 95.1% for separating MIs and Healthy Controls (HCs) and an averaged accuracy of 95.8% in identifying anterior-related MIs and inferior-related MIs.
Effects of intermetallic formation at the interface between copper and lead-tin solder

An investigation was undertaken of the role of intermetallics in determining the strength of soldered joints, using copper and a lead-tin solder as the materials of interest. Joints formed at various times and temperatures were tested in shear, and measurements of the thickness of the two intervening intermetallic layers formed were taken. The temperature of formation was found to have the greatest effect on the strength, with the strength decreasing as the temperature increased. Failure at the interface occurred in two stages. In all cases, the first stage consisted of fracture within the intermetallic layer, accounting for partial separation of the interface only. The area of the interface showing this kind of behaviour increased with both time and temperature. Final stages of failure involved shear within the solder immediately above the intermetallic layers. The two intermetallic phases found at the interface were determined by X-ray diffraction to be Cu6Sn5 and Cu3Sn. Both intermetallics were found for all joint-forming conditions investigated. The growth of Cu6Sn5 reached a limiting value for times longer than 30min, but increased in thickness with temperature. Cu3Sn also increased in thickness with temperature, but showed linear increases with time; the rate of increase was greater for the higher temperatures.
Trends in Stomatal Density and 13C/12C Ratios of Pinus flexilis Needles During Last Glacial-Interglacial Cycle.

Measurements of stomatal density and δ13C of limber pine (Pinus flexilis) needles (leaves) preserved in pack rat middens from the Great Basin reveal shifts in plant physiology and leaf morphology during the last 30,000 years. Sites were selected so as to offset glacial to Holocene climatic differences and thus to isolate the effects of changing atmospheric CO2 levels. Stomatal density decreased ∼17 percent and δ13C decreased ∼1.5 per mil during deglaciation from 15,000 to 12,000 years ago, concomitant with a 30 percent increase in atmospheric CO2. Water-use efficiency increased ∼15 percent during deglaciation, if temperature and humidity were held constant and the proxy values for CO2 and δ13C of past atmospheres are accurate. The δ13C variations may help constrain hypotheses about the redistribution of carbon between the atmosphere and biosphere during the last glacial-interglacial cycle.
Suppression of in vivo immune responses in the guinea pig by phytohemagglutinin

The effect of phytohemagglutinin-P (PHA) on in vivo immune responses was assessed in guinea pigs. PHA was administered daily, commencing 2 days prior to antigen. This regimen depressed the humoral antibody response to bovine gamma globulin (BGG) (p < 0.005) and abolished the delayed cutaneous hypersensitivity (DCH) response to tuberculin (BCG) (p < 0.005) after primary immunization with BGG and BCG. In guinea pigs immunized to BCG, PHA inhibited the DCH response to secondary challenge with the antigen. It prolonged the survival of skin allografts exchanged between inbred guinea pigs (NIH strains 2 and 13) from a mean of 10.6 days to 13.1 days(p < 0.01).
Scan-independent slot arrays with parasitic wire arrays in a stratified medium

The effect of a parasitic wire array on the scan admittance of a slot array has been investigated. Structures considered can consist of an infinite slot array and an arbitrary number of parasitic infinite arrays of piecewise linear wires, all arrays being embedded in a stratified medium. These include, as particular cases, phased arrays of Clavin elements. Expressing the fields from the arrays as plane waves, a procedure similar to the periodic moment method for infinite periodic structures is set up to obtain the scan admittance of the slot array. Scan admittances are presented for a slot array with monopole arrays in free space, and a slot array with a tilted dipole array in a stratified medium. Blind spots at which the incident energy is mainly reflected rather than transmitted were found. Results obtained indicate the possibility of using parasitic wire arrays for scan compensation of active slot arrays. >
From hybrid energy systems to microgrids: Hybridization techniques, configuration, and control

This paper reviews the hybridization techniques and system configurations for hybrid alternative energy systems. The topic is extended to the control and energy management of microgrids, the cornerstones of smart grids. A framework of distributed, hierarchical control for microgrids is also discussed in the paper.
Multicriterion Decision Merging: Competitive Development of an Aboriginal Whaling Management Procedure

Abstract International Whaling Commission management of aboriginal subsistence whaling will eventually use an aboriginal whaling management procedure (AWMP) chosen from a collection of candidate procedures after grueling simulation testing. An AWMP is a fully automatic algorithm designed to operate on the results of an assessment (i.e., a statistical estimation problem relying on sparse series of whale abundance data) to produce a catch limit in each year of real or simulated management. An AWMP should, as much as possible, meet the conflicting objectives of low population risk, high satisfaction of needed catch, and high rate of population recovery. The choice of the best procedure falls naturally in the multicriterion decision making framework, because one of several candidates must be chosen on the basis of high-dimensional simulated performance summaries over a wide range of assumptions about whales and whaling. However, standard multicriterion decision making methods are impractical and unsatisfying ...
Data mining in predicting survival of kidney dialysis patients

The number of dialysis patients due to end stage kidney disease is increasing. Finding ways to improve patient outcomes and reduce the cost of dialysis is a challenging task. Dialysis care is complex and multiple factors may influence patient survival. More than 50 parameters may be monitored while providing a kidney dialysis treatment. Understanding the collective role of these parameters in determining outcomes for an individual patient and administering individualized treatments is of importance. Individual patient survival may depend on a complex interrelationship between multiple demographic and clinical variables, medications, and medical interventions. In this research, a data mining approach is used to elicit knowledge about the interaction between these variables and patient survival. Two different data mining algorithms are employed for extracting knowledge in the form of decision rules. Data mining is performed on the individual visits of the " most invariant " patients as they form " signatures " for their decision categories. The concepts introduced in this research have been applied and tested using a data collected at four dialysis sites. The computational results are reported.
Understanding General Distrust of Corporations

Organizational research on trust and distrust has focused mainly on interpersonal relationships within organizations or impressions people have about specific companies. Less is known about people's attitudes toward all corporations (ie, as institutions). This article describes a theory of distrust toward corporations, how this attitude forms and how its study can contribute to organizational research. A corporate distrust scale was developed and shown to have favorable psychometric properties and nomological validity. People who scored higher on corporate distrust were higher on general cynicism, organization-specific cynicism, negative affectivity and liberal political attitudes. Corporate distrust correlated negatively with interpersonal trust, positive attitudes toward human nature and belief in a just world. The article suggests that the construct can be used in future research on beliefs about the corporate world.
Integrating psychotherapy and pharmacotherapy in the treatment of depression

Depression is a common, often incapacitating, disorder characterized by emotional, cognitive, behavioral, and physiological symptoms. Psychotherapy and pharmacotherapy are both effective, but limited, treatments for depression. Integration of these modalities has the potential to combine the benefits and compensate for the limitations of each approach, thereby significantly enhancing positive therapeutic outcomes. Integrated treatment for depression may be conducted by a single therapist or by two therapists, one providing psychotherapy and one pharmacotherapy. In either form of integration, it is essential for the therapist or therapists to be mindful of potential complications and to deal with them in constructive ways. © 1997 John Wiley & Sons, Inc.
The effect of shoulder immobilization on driving performance

Background The purpose of this study was to evaluate the effect of sling immobilization on driving performance with use of a driving simulator. Methods This is a prospective trial with a cohort of 21 healthy volunteers comparing their driving ability with and without sling immobilization on their dominant (driving) extremity. Multiple variables, including number of collisions, off-road excursions, and centerline crossings, were measured with a validated driving simulator. Trials were separated by 2 weeks to control for “adaptations” to the simulator. Statistical significance was found in collisions between sling and no-sling tests. Results The total number of collisions for trial 1 (no sling) was 36 (mean, 1.7 ± 1.2) compared with 73 (3.7 ± 1.6) (P Conclusion Sling immobilization of the dominant driving arm results in a decrease in driving performance and safety with respect to the number of collisions in a simulated driving circuit (P
Distributed Data Query in Intermittently Connected Passive RFID Networks

This paper focuses on distributed data query in intermittently connected passive RFID networks, which are characterized by extraordinarily limited communication capacity and asynchronous and opportunistic communication links. To address such unique challenges, we propose a distributed data query framework that clusters RFID readers and establishes a 0-1 Knapsack model based on dynamic packet appraisal to enable highly efficient data transmission. We implement a prototype by using Alien RFID gears and carry out experiments that involve 52 volunteers for 14 days to evaluate the proposed data query framework.
Kirkpatrick Baez spectrograph concepts for future space missions

We discuss and analyze a two reflection grazing incidence spectrograph concept based on the Kirkpatrick-Baez telescope. The classical Kirkpatrick-Baez telescope uses two banks of crossed, cylindrical mirrors to achieve focus. Performance of a two reflection design is discussed for single mirror set and multiple mirror bank configurations.
Low Altitude Signatures of the Plasma Sheet: Model Predictions of Local Time Dependence

We combine two theoretical models of plasma sheet particle transport to trace plasma sheet particles from the nightside magnetospheric equatorial plane to low altitudes. We predict that the low-altitude signature of the plasma sheet is manifestly different at different local times. The Guiding Center Transport Model (GCTM) (Onsager et al., 1993) uses a given particle energy, position, and an assumed magnetic and electric field to trace the low-altitude particle's trajectory to the plasma sheet. The Finite Tail Width Convection Model (FTWCM) (Spence and Kivelson, 1993) uses two Maxwellian plasma sources, one downtail and one on the dawnside boundary layer, to generate distribution functions across the tail plasma sheet. Using Liouville's theorem, the distribution functions at the equatorial level are projected to low altitudes. When this signature of the plasma sheet is projected to low altitudes near the Earth, the spatial variation in the equatorial plasma properties produce a latitudinal variation in the isoflux contours. Isoflux contours at high latitudes at dawn extend to lower latitudes at dusk, reflecting a larger plasma sheet plasma pressure at dusk than at dawn. This prediction is based solely on a projection of spatial variations in equatorial plasma properties.
Heavy metal Muslims: the rise of a post-Islamist public sphere

This article explores the emergence of new, youth-oriented public spheres in the Middle East and North Africa through the lens of the burgeoning extreme music scenes across the region. I argue that the seeming incongruity of genres such as extreme heavy metal or gangsta rap becoming popular in the Muslim world is a reminder of the diversity of contemporary Islam; more deeply, it reveals that the borders between religious belief and seemingly secular practices in Muslim societies are increasingly porous, with politically marginalized young metalheads and their more activist religious peers sharing many of the same societal goals. These are greater autonomy and even democracy, the right for tolerance of divergent views, and the rejection of the hypocrisy, corruption and authoritarianism of their leaders. I conclude with an analysis of the political implications of a still tentative rapprochement between ostensibly secular artists and the religious forces who less than a decade ago were spearheading their persecution, and in some cases prosecution, across the region.
Double Diaphragm Forming of a Discontinuous Advanced Composite Prepreg Material: Process Development and Material Modeling

Due to their superior strength-to-weight ratios, advanced composite parts are increasingly being used by the aircraft industry. This industry is constantly looking for less costly, faster, and more reliable methods to produce advanced composite parts, while still maintaining the very high safety and reliability standards required. This paper describes a new SBCF (Stretch Broken Carbon Fiber) material being developed by Hexcel Corporation for use in forming of aerospace parts. The SBCF material is a discontinuous aligned fiber prepreg material that comes in unidirectional and woven forms. If commercialized, the SBCF material will expand the range of parts that can be formed using a double diaphragm forming (DDF) process. This paper also discusses the FEM modeling of the DDF process for the purposes of predicting part defects. Having defect prediction capabilities will reduce the time and money required to determine if a part can be formed using the SBCF material and DDF. A rudimentary orthotropic-viscoelastic model is developed for the SBCF material to be used in forming simulations being developed concurrently. Model parameters are derived from force-to-stretch (i.e. tensile tests run at a constant displacement rate) and relaxation experiments. A simple model for the diaphragm is developed and preliminary forming simulations are built. Early simulations include forming over hemi-ellipsoid and curved c-channel shapes.© 2005 ASME
Small angle X-ray diffraction studies of (−)-Δ8-tetrahydrocannabinol and its O-methyl analog in membranes

Small angle X-ray diffraction was used to study the topography of (-)-delta 8-tetrahydrocannabinol (delta 8-THC) and its pharmacologically inactive methoxy analog (-)-O-methyl-delta 8-tetrahydrocannabinol (Me-delta 8-THC) in a membrane. The membrane preparations were partially hydrated dimyristoylphosphatidylcholine (DMPC) bilayers. Comparisons between electron density profiles from the drug-containing and drug-free membranes showed that the amphipathic delta 8-THC residues near the interface of the bilayer where the polar phenolic OH of the drug molecule is oriented towards the corresponding polar side of the phospholipid bilayer. Conversely, the highly hydrophobic Me-delta 8-THC distributes deeper in the bilayer away from the interface. Our results point out these two structurally-related, but pharmacologically very different, cannabinoids interact with membranes in strikingly different manners. This observation may, in part, explain the different pharmacological properties of the two cannabinoids.
Numerical investigation of the thermal stratification in cryogenic tanks subjected to wall heat flux

The flow pattern and thermal stratification of a cryogenic cylindrical tank are numerically studied. The tank sidewall is subjected to either a uniform heat-flux or two discrete levels of uniform heat-flux at the upper and lower halves of the tank wall. The tank bottom is kept at a constant temperature controlled by the heat exchanger of a thermodynamic vent system. The tank pressure is also assumed constant resulting in a constant saturation temperature at the interface which is higher than the tank bottom temperature. The effects of vapor motion and vapor superheat on the mass and heat transfer processes at the interface are assumed negligible such that the calculations of liquid region can be decoupled from the vapor region. Dimensionless steady-state conservation equations are solved by a finite-difference method. The effects of modified Rayleigh number, Prandtl number, tank aspect ratio, wall heat-flux parameter, and wall heat-flux distribution on the liquid velocity and temperature fields are investigated. Also, their effects on the rate of heat transfer through the interface and the tank bottom are examined.
Who's Afraid of the Hill Boundary?

The Jacobi{Maupertuis metric allows one to reformulate Newton's equations as geodesic equations for a Riemannian metric which degenerates at the Hill boundary. We prove that a JM geodesic which comes sufficiently close to a regular point of the boundary contains pairs of conjugate points close to the boundary. We prove the conjugate locus of any point near enough to the boundary is a hypersurface tangent to the boundary. Our method of proof is to reduce analysis of geodesics near the boundary to that of solutions to Newton's equations in the simplest model case: a constant force. This model case is equivalent to the beginning physics problem of throwing balls upward from a fixed point at fixed speeds and describing the resulting arcs, see Fig. 2.
Explosives detection and identification using surface plasmon-coupled emission

To fight against the explosives-related threats in defense and homeland security applications, a smarter sensing device that not only detects but differentiates multiple true threats from false positives caused by environmental interferents is essential. A new optical detection system is proposed to address these issues by using the temporal and spectroscopic information generated by the surface plasmon coupling emission (SPCE) effect. Innovative SPCE optics have been designed using Zemax software to project the fluorescence signal into clear "rainbow rings" on a CCD with subnanometer wavelength resolution. The spectroscopic change of the fluorescence signal and the time history of such changes due to the presence of a certain explosive analyte are unique and can be used to identify explosives. Thanks to high optical efficiency, reporter depositions as small as 160-μm in diameter can generate a sufficient signal, allowing a dense array of different reporters to be interrogated with wavelength multiplexing and detect a wide range of explosives. We have demonstrated detection and classification of explosives, such as TNT, NT, NM, RDX, PETN, and AN, with two sensing materials in a prototype.
The U.S. national library of medicine and international medlars cooperation

Abstract The U.S. National Library of Medicine (NLM) initiated its computer-based bibliographic information storage and retrieval system, MEDLARS, in 1964. Currently, the NLM has eight international MEDLARS quid-pro-quo arrangements with the United Kingdom, Sweden, France, West Germany, Japan, Australia, Canada and the World Health Organization. The policy aspects of these arrangements are discussed as well as the organizational and operational characteristics of these non-U.S. Medlars Centers.
Electron dose calculation using multiple-scattering theory: A new theory of multiple scattering

Starting from the Boltzmann–Fokker–Planck transport equation, we have developed a new theory of multiple scattering which incorporates the advances already made with our Gaussian multiple‐scattering theory for electron dose calculation. This incorporation has been accomplished in a natural way, by modifying the scattering power T and by adding a convolution term to the distribution‐function equation of the Gaussian theory. Our previous results concerning increasing the accuracy of the small‐angle approximation used and dealing with localized tissue inhomogeneities have thus been maintained, and we have arrived at a complete distribution function in both transverse spatial and angular variables. When integrated over the transverse angular variables, for a first‐order small‐angle approximation this distribution function for a pencil beam is essentially the same as the Moliere multiple‐scattering distribution, which includes large‐angle single scattering. For a water phantom, we have used comparisons with EGS4 Monte Carlo calculations to demonstrate the greatly increased accuracy of our new multiple‐scattering theory over the Gaussian theory, which includes the usual Fermi–Eyges theory. We have also presented a fairly accurate Gaussian approximation to the pencil‐beam dose profiles given by our new theory, which can be used in order to maintain the mathematical simplicity of the predictions of the Fermi–Eyges theory.
Educational debt of physicians-in-training: determining the level of interest in a loan repayment program for service in a medically underserved area.

Purpose The amount of financial debt incurred by Texas medical students and residents during training was examined as well as the impact of this debt on these trainees' career choices. Method An invitation to participate was sent in a Web-based survey to medical students and residents at 6 university programs in Texas during the 2005–2006 academic year. Results Overall, 818 students (20%) and 529 residents (14%) responded to the survey. Of these, 96% of students and 85% of residents had taken out educational loans, and approximately 62% of students and residents expected their debt to exceed $100,000. More than half of students and residents expected educational debt to influence their choice of practice type and practice area and to affect important personal decisions. Approximately 52% of students and 38% of residents indicated an interest in participating in a loan repayment program that involved service in a medically underserved area. In general, women and members of minority groups were more likely to express such an interedst. Conclusions Medical students and residents incur considerable financial debt, which seems to affect their career choices. Approximately half of the students and one third of the residents surveyed indicated that they would consider participating in a loan repayment program that required practice in an underserved area.
Research and Application of Auger-air Drilling and Sieve Tube Borehole Protection in Soft Outburst-prone Coal Seams

Abstract Hole accidents during drilling and borehole collapse during extracting are bottlenecks restricting gas drainage efficiency in soft outburst-prone coal seams in China. The auger-air combined drilling technique and sieve tube mounting method are an alternative solution to these technology bottlenecks. The auger-air drilling technique combines the advantages of “dry style” auger drilling and air drilling. Specially designed blade in drill rod can stir up large particles of coal so that large particles can be brought to ground smoothly using compressed air and is efficient to prevent borehole accidents. After drilling is completed, the sieve tube is tripped in through the inner hole of drilling pipes, and then lifting up drilling pipes, the tube sieve will provide a complete tunnel for gas extraction. Field application proves that with proper drilling parameter selection and appropriate tube install control, it is more promising to double drilling depth and raise gas drainage efficiency.
Trends in Instrument Development for Reactor Tn-Core Flux Monitoring

Some significant developments have taken place relative to power reactor fixed in-core flux instrumentation during the past five years, both from the standpoint of sensor development and assembly design. This has resulted in improved sensor lifetimes and operational reliability. A comparative analysis of the main characteristics of three in-core monitors, namely miniature fission chambers, self-powered flux detectors and gamma thermometers will be given.
A novel pulsed-plasma approach for protein immobilization by grafting reactive amine groups on polyurethane-coated biosensors

Abstract Reliable surface chemistry is necessary for immobilization of biological recognition molecules on sensor surfaces. A dry and rapid method of pulsed-plasma assisted grafting of amine surface functional groups, using ammonia gas on polyurethane surfaces is successfully demonstrated by using pulse cycle times of 1–180 s (on–off). One cycle of plasma treatment was found to generate higher amine groups as they tend to degrade upon longer exposure to the high-energy radicals. Successful amination of the polyurethane surfaces was demonstrated by Fourier transform infrared spectroscopy (FTIR). To establish the availability of the surface amine groups for reaction, 1 μm carboxylated polybeads were reacted to polyurethane-coated piezoelectric excited millimeter-sized cantilever (PEMC) sensors before and after plasma treatment. Scanning electron microscope micrographs of PEMC sensors exposed to the same concentration of beads show more than four-fold increase in the presence of beads post pulsed-plasma treatment. Application of this method for protein immobilization was established by BSA chemisorption on plasma treated PEMC sensors.
Synchronization of Multiple Optomechanical Oscillators

We design and fabricate a 2 × 2 optomechanical oscillator array. We show the onset of synchronized mechanical oscillations when the array is excited by a single continuous wave laser.
Evidence against a systemic humoral factor controlling the intestinal compensatory response following X-irradiation.

The investigation was devised to determine whether changes noted in the unirradiated duodenum and colon of single rats after X-irradiation of only the exteriorized rat jejunum and ileum are mediated by a systemic humoral factor. Littermate Holtzman male rats were joined in parabiosis and one month later, the temporarily exteriorized jejunum and ileum of one member was exposed to 1,000 R of 250 kVp X-irradiation. Two days after X-irradiation, and 1, 12 and 24 h after 1 μCi/g body weight tritiated thymidine (6 Ci/mMi) was injected intraperitoneally, rats were sacrificed and appropriate tissues removed. Single rats which had the exteriorized jejunum and ileum irradiated were studied from 1–3 days after irradiation. At autopsy, samples of colon and duodenum were taken for determination of dpm/crypt and dpm/mg of intestine. Crypt cell migration rates were determined employing autoradiography. Tritium content and columnar cell migration rate in duodenum and colon of unirradiated rats compared to irradiated rats indicated that irradiation of one member of the pair had no effect on tritium incorporation or epithelial cell migration in the duodenum or colon of the unirradiated partner. Epithelial cell proliferation and crypt cell migration were increased in unirradiated duodenum and colon of single intestine-irradiated rats. Essentially the same changes were seen in the irradiated member of a parabiotic pair, but none of these changes were noted in the unirradiated member. The absence of stimulation in the unirradiated parabiont suggests that either a systemic humoral factor is not present after X-irradiation or is not present in sufficient concentration to be detected by these methods.
Donnan dialysis preconcentration coupled with ion chromatography and electrocatalytic oxidation for the determination of cyanide.

Abstract An electrocatalytic amperometric detector for the ion chromatographic determination of CN− is described. A conducting composite that is based on a graphite-loaded sol–gel material comprises the working electrode. The composite is doped with a RuII metallodendrimer which is demonstrated to promote the electrochemical oxidation of CN− at potentials positive of 0.5 V vs. Ag/AgCl. In 6 mM NaOH, 0.05 M NaCl flowed at 1.0 ml min−1, a 5-point calibration curve with the following linear least squares parameters is obtained over the range, 1.0–30 M CN−: slope, 24.2±0.1 nA M−1; intercept, −6±2 nA; and r, 0.9997. The detection limit, 0.7 μM CN−, compares favorably to that obtained by amperometry at a silver electrode, 0.5 μM CN−, under comparable experimental conditions. A 60-min preconcentration by Donnan dialysis increases the sensitivity by a factor of 23.6.
Acoustooptic Phase and Frequency Shifters for Single Mode Fibers

The design of in-line phase and frequency shifters for single mode fibers is discussed. The basic configuration consists of a cylindrically symmetric piezoelectric transducer fabricated on the fiber surface. For the phase shifter the fiber core is concentric and no polarization coupling occurs. The frequency shifter utilizes a birefringent fiber with a non-concentric core and transducer pairs driven 90° out of phase. Factors affecting the performance of both devices are discussed.
The AP Chemistry Course Audit: A Fertile Ground for Identifying and Addressing Misconceptions about the Course and Process

The advanced placement course audit was implemented to standardize the college-level curricular and resource requirements for AP courses. While the process has had this effect, it has brought with it misconceptions about how much the College Board intends to control what happens within the classroom, what information is required to be included in a syllabus submission, and how far the audit requirements extend. Each of these misconceptions will be addressed in the context of a historical view of the process, and some advice for teachers in preparing their AP chemistry syllabus for review will be provided. This contribution is part of a special issue on teaching introductory chemistry in the context of the advanced placement (AP) chemistry course redesign.
Pre dialysis of blood prime in continuous hemodialysis normalizes pH and electrolytes

In critically ill children weighing 20 mEq/l were normalized to below 5 mEq/l within 7.5 min of dialysis in all cases. Blood bank-derived blood can be "conditioned" quickly to physiological pH and electrolyte concentrations using these simple pre-dialysis regimens. Unlike some blood preparation regimens that have been published, the technique used in this trial requires no special equipment or added medications that are not already used in CRRT.
The coherent potential approximation is a realizable effective medium scheme

The effective electrical conductivity of an aggregate, composed of grains of various conductivities, is frequently estimated by the coherent potential approximation, which embodies a local effective medium concept. It is proved rigorously that this approximation is exact for a wide class of hierarchical model composites made of spherical grains: the starting material 0 in the hierarchy is chosen arbitrarily, otherwise, materialj=1, 2, ... consists of equisized spheres, sayj-spheres, of arbitrary conductivities embedded in materialj — 1. The spatial distribution of thej-spheres must satisfy a mild homogeneity condition and their radiusr j must, asymptotically, increase faster than exponentially withj. Furthermore, the minimum spacing, 2s j , between thej-spheres is such that the ratios j /r j diverges. On the basis of these and some further ancillary conditions it is established that the coherent potential approximation becomes asymptotically exact for the effective conductivity of materialj→∞. The results extend to other effective parameters of the composites, including the thermal conductivity, dielectric constant and magnetic permeability. In addition, the model composites and the proof of realizability may be generalized to allow non-spherical grains.
Erosion and Sedimentation

According to legend, a conversation that took place more than 70 years ago between Albert Einstein and his eldest son, Hans Albert Einstein, gives rise to the favorite anecdote of every scientist or engineer working in the field of sediment transport. During this conversation, Hans told his father of his intent to carry out research on the mechanics of sediment transport. Albert had done some work in this area, notably on hindered settling in sediment suspensions, and he advised his son not to pursue study in this field, as he felt sediment transport was so difficult that it was intractable. Like many good sons before him, Hans ignored this advice, and went on to be one of a handful of prominent scientists that shaped modern sediment-transport theory and practice.
SPERMATOPHORES AND SPERMATOZOA OF THE SQUID LOLIGO PEALII.

In the squid, spermatozoa are encased in spermatophores formed from male accessory secretions. Spermatophores about 1 cm in length were found to contain between seven and ten million densely packed spermatozoa. The substance of the sphermatophore itself was identified chiefly as a protein-polysaccharide complex, the precise composition differing among the various tunics and membranes; outer layers were classed as mucopolysaccharides, and the inner as mucoproteins. Of special morphological interest is the spiral filament consisting of tightly packed stellate particles in a gelatinous matrix, and of chemical interest the ‘cement’ which appears to be a strongly alkaline substance. A photomicrographic record was made of the spermatophoric reaction, which results in the release of the spermatozoa. Metabolic studies carried out with suspensions of squid spermatozoa have shown that the motility of such spermatozoa can be extended significantly by the addition of glycolys-able sugars. The ability of squid spermatozoa to convert glucose and fructose into lactic acid contrasts markedly with the lack of glycolytic ability which characterizes the spermatozoa of invertebrates with fully external fertilization. The spermatophore fluid of the squid contains a substance which, when added to a suspension of washed spermatozoa, causes a distinct inhibition of sperm motility and respiration; the nature of the factor responsible for this effect is still unknown.
Nonlinear six-degree-of-freedom aircraft trim

Whencomputingnumerical trimsolutions,it is dif cult to knowifallpossible trimsolutionshavebeen found.This paper presents closed-form formulas for computing all possible trim values for six-degree-of-freedom nonlinear aircraft models. The models include gravity, nonlinear angular-rate terms, and tabular aero functions. However, the models are linear in four functions of the four inputs (thrust, aileron, elevator, rudder). The four independent control inputs lead to a four-dimensional trim set. In the subsonic case where the Mach dependence of the aero functions can be ignored, the four-dimensional trim set is parameterized by (pitch angle, roll angle, angle of attack, sideslip angle) giving at most two real trim values for each set of  xed values of these four parameters. When the Mach dependence of the aero functions needs to be considered, the four-dimensional trim set is parameterized by (speed, angle of attack, sideslip angle, and heading angular rate) giving up to eight trim values for each  xed set of values of these four parameters. The advantageof these closed-form computations,over more numerical methods, is that they give all possible solutions values.
The Coronary Circulation

Dramatic advances have been made in the last two decades in the diagnosis and treatment of coronary artery disease. The development of open heart surgical techniques for bypassing occluded arteries made quantitative diagnostic techniques more important. Computer enhanced angiographic methods, together with measurements using tomography, ultrasound and magnetic resonance imaging have greatly improved the precision of the diagnosis. A more complete understanding of coronary mechanics and control has enabled physicians to better interpret the significance of geometric information and to supplement this information with functional assessment of stenosed arteries. Finally, traditional bypass surgery is now supplemented with closed-chest techniques such as balloon angioplasty. Biomedical engineers have been involved in all of these developments. This paper will review these developments and attempt to identify remaining questions.
The effects of simple compression and wetting on the thermal conductivity of rocks

Measured thermal gradients in the Earth run from about 6° per km to 150° per km. Some of the differences may be due to differences in the rate at which heat is flowing toward the surface, but many of them result, doubtless, from differences in conductivity of the rocks through which the heat flows. Out of hundreds of gradient-measurements, only about a dozen have been correlated with conductivity, and it is significant that in these cases the values obtained for the rate of heat-flow differ from their mean value by only about 25 per cent, although the gradients themselves vary by a factor of four or five.