cssi/SciSciGPT-SciSciNet huggingface dataset:
Utility of Once-Daily Dose of Low-Molecular-Weight Heparin to Prevent Venous Thromboembolism in Multisystem Trauma Patients

Venous thromboembolism is a preventable cause of death in the severely injured patient. Low-molecular-weight heparins (LMWHs) have been recommended as effective, safe prophylactic agents. However, LMWH use remains controversial in patients at risk for bleeding, those with traumatic brain injury, and those undergoing multiple invasive or operative procedures. We hypothesized that a protocol utilizing once-daily LMWH prophylaxis in high-risk trauma patients, regardless of the need for invasive procedures, is feasible, safe, and effective. From August 1998 to August 2000, all patients admitted to our American College of Surgeons-verified Level I trauma facility following injury were evaluated for deep venous thrombosis (DVT) risk and prospectively followed. Patients at high risk for DVT, including those with stable intracranial injuries, were placed on our institutional protocol and prospectively followed. Patients on the protocol received daily injections of the LMWH, dalteparin; DVT screening was performed with duplex ultrasonography within 48 hours of admission and after 7 to 10 days after injury. Regimen compliance, bleeding complications, DVT rates, and pulmonary embolus (PE) rates were analyzed. During the 2-year study period, 6247 trauma patients were admitted; 743 were considered at high risk for DVT. Most of the patients were men (72%), with a mean age of 38.7 years (range 15–89 years) and a mean injury severity score (ISS) of 19.5. Compliance with the daily regimen was maintained in 74% of patients. DVT was detected in 3.9% and PE in 0.8%. The wound complications rate was 2.7%, and the need for unexplained transfusions was 3%. There were no exacerbations of head injury following dalteparin initiation due to bleeding. There were 16 patient deaths; none was caused by PE or late hemorrhage. Once-daily dosing of prophylactic LMWH dalteparin is feasible, safe, and effective in high-risk trauma patients. Our protocol allows one to “operate through” systemic prophylaxis and ensures timely prophylaxis for brain-injured and multisystem trauma patients.
Antigen receptor-initiated signals for B cell development and selection

The B cell antigen receptor or signaling components of this receptor play varying roles in determining the fate of the B cell at different stages of B cell development. Signals generated through this receptor complex or its various components determine the survival, progression, expansion, and activation of the B cell. Factors that determine the fate of the B cell following antigen receptor engagement include the developmental stage, coreceptor expression, degree and stability of ligand-receptor engagement, and the availability of T cell-derived secondary signals. The author's laboratory is interested in defining the molecular processes linking B cell antigen receptor signaling to these specific cellular responses in the context of antigen-independent and dependent B cell development. Here our current progress and thinking with regard to the determination between negative selection and activation as it pertains to the transition from the immature- to the mature-stage B cell will be discussed.
Multilayer microfluidic devices created from a single photomask

The time and expense associated with high quality photomask production can discourage the creation of multilayer microfluidic devices, as each layer currently requires a separate photomask. Here we describe an approach in which multilayer microfabricated devices can be made from a single photomask. The separate layers and their corresponding alignment marks are arranged in separate halves of the mask for two layer devices or quadrants for four layer devices. Selective exposure of the photomask features and rotation of the device substrate between exposures result in multiple copies of the devices on each wafer. Subsequent layers are aligned to patterned features on the substrate with the same alignment accuracy that is achieved using separate photomasks. We demonstrate this approach by fabricating devices employing multilayer soft lithography (MSL) for pneumatic valving. MSL devices containing as many as 5 layers (4 aligned fluidic layers plus a manually aligned control layer) were successfully created using this approach. Device design is also modularized, enabling the presence or absence of features as well as channel heights to be selected independently from one another. The use of a single photomask to create multilayer devices results in a dramatic savings of time and/or money required to advance from device design to completed prototype.
Effect of nonparabolicity in GaAs/Ga1-xAlxAs semiconductor quantum wells.

We investigate the effect of nonparabolicity in various bands of bulk semiconductors on the electronic-subband-edge energies in quantum wells. We compare the results from different versions of the model originally proposed by Bastard. We show that their efficacy in yielding the correct quantum-well energy levels for the conduction band can be characterized in terms of two parameters, namely, the effective mass ${m}^{\mathrm{*}}$ and the nonparabolicity parameter \ensuremath{\gamma}. We have performed this comparison of the models for a number of well widths for GaAs/${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$${\mathrm{Al}}_{\mathrm{x}}$As quantum-well structures using the results from an eight-band second-order k\ensuremath{\cdot}p Hamiltonian, in a transfer-matrix method derived earlier, as the benchmark. We confirm the observation made earlier that band nonparabolicity actually raises the lowest conduction-band energy level of the quantum well by a small amount while lowering the higher energy levels.
Environmental influences on masculine sexual behavior in mice.

Abstract Retention of masculine copulatory behaviors following castration varies among B6D2F1 male mice. In the present study, we examined the effect of test environment and the amount of behavioral testing after castration, on retention of copulatory responses in castrated B6D2F1mmale mice. Results showed that weekly behavioral testing after castration was not necessary for the retention of ejaculatory reflexes. However, the test environment had a major effect. Following castration, 26% of the males completely stopped showing ejaculatory responses when tested in the test arenas. When these males were tested in their home cages, 75% achieved at least one ejaculatory response in four home cage tests. Castrated males that continued to copulate in the test arena situation also achieved ejaculatory reflexes in their home cages. These results indicate that for some B6D2F1 males, the retention of sexual behaviors after castration is influenced by environmental factors.
Factors Influencing Mobile Source Particulate Matter Emissions-to-Exposure Relationships in the Boston Urban Area

Benefit-cost and regulatory impact analyses often use atmospheric dispersion models with coarse resolution to estimate the benefits of proposed mobile source emission control regulations. This approach may bias health estimates or miss important intra-urban variability for primary air pollutants. In this study, we estimate primary fine particulate matter (PM2.5) intake fractions (iF; the fraction of a pollutant emitted from a source that is inhaled by the population) for each of 23 398 road segments in the Boston Metro Core area to evaluate the potential for intra-urban variability in the emissions-to-exposure relationship. We estimate iFs using the CAL3QHCR line source model combined with residential populations within 5000 m of each road segment. The annual average values for the road segments range from 0.8 to 53 per million, with a mean of 12 per million. On average, 46% of the total exposure is realized within 200 m of the road segment, though this varies from 0 to 93% largely due to variable population patterns. Our findings indicate the likelihood of substantial intra-urban variability in mobile source primary PM2.5 iF that accounting for population movement with time, localized meteorological conditions, and street-canyon configurations would likely increase.
Improvement of the backpropagation algorithm for training neural networks

Abstract The application of artificial neural networks (ANNs) to chemical engineering problems, notably malfunction diagnosis, has recently been discussed (Hoskins and Himmelblau, Comput. chem. Engng 12, 881–890, 1988). ANNs “learn”, from examples, a certain set of input-output mappings by optimizing weights on the branches that link the nodes of the ANN. Once the structure of the input-output space is learned, novel input patterns can be classified. The backpropagation (BP) algorithm using the generalized delta rule (GDR) for gradient calculation (Werbos, Ph.D. Thesis, Harvard University, 1974), has been popularized as a method of training ANNs. This method has the advantage of being readily adaptable to highly parallel hardware architectures. However, most current studies of ANNs are conducted primarily on serial rather than parallel processing machines. On serial machines, backpropagation is very inefficient and converges poorly. Some simple improvements, however, can render the algorithm much more robust and efficient.
The lost rhetorics of Aristotle

Our understanding of Aristotle's theory of rhetoric is incomplete as little is known of the content or philosophy of his lost rhetorics. Although ancient testimonia alludes to as many as nine Aristotelian rhetorics, modern scholarship recognizes four (including the extant Rhetoric). This article examines Aristotle's lost rhetorics and their influence upon his philosophy of rhetorical discourse.
Anomalous Variability in Antarctic Sea Ice Extents During the 1960s With the Use of Nimbus Data

The Nimbus I, II, and III satellites provide a new opportunity for climate studies in the 1960s. The rescue of the visible and infrared imager data resulted in the utilization of the early Nimbus data to determine sea ice extent. A qualitative analysis of the early NASA Nimbus missions has revealed Antarctic sea ice extents that are significant larger and smaller than the historic 1979-2012 passive microwave record. The September 1964 ice mean area is 19.7 × 106 km2± 0.3 × 106 km2. This is more the 250,000 km2 greater than the 19.44 × 106 km2 seen in the new 2012 historic maximum. However, in August 1966 the maximum sea ice extent fell to 15.9 × 106 km2 ± 0.3 × 106 km2. This is more than 1.5 × 106 km2 below the passive microwave record of 17.5 × 10 6 km2 set in September of 1986. This variation between 1964 and 1966 represents a change of maximum sea ice of over 3 × 106 km2 in just two years. These inter-annual variations while large, are small when compared to the Antarctic seasonal cycle.
Cardiac effects of oxyfedrine in the cat

Abstract Oxyfedrine, a new aminoketone of the phenylethylamine series, was studied in three cardiac preparations in the cat. Oxyfedrine (0.5 × 10 −6 g/ml) exerted a positive inotropic effect while 5.0 × 10 −5 g/ml exerted a negative inotropic effect in the cat papillary muscle preparation. Positive inotropic, and coronary vasodilator effects were elicited by oxyfedrine in the cat Langendorff preparation. However, premature ventricular systoles and first degree heart blocks appeared with the two highest concentrations (10 −7 g/ml and 10 −6 g/ml). In the intact cat, oxyfedrine initiated positive inotropic and chronotropic effects as well as as marked decline in mean arterial blood pressure due to systematic arterial vasodilation. Oxyfedrine could not be demonstrated to be an independent coronary vasodilator. These findings indicate that oxyfedrine may not be of significance in the therapeutics of shock.
Development of Maladaptive Coping: A Functional Adaptation to Chronic, Uncontrollable Stress

Health disparities are rooted in childhood and stem from adverse early environments that damage physiologic stress-response systems. Developmental psychobiological models of the effects of chronic stress account for both the negative effects of a stress-response system calibrated to a dangerous and unpredictable environment from a health perspective, and the positive effects of such an adaptively calibrated stress response from a functional perspective. Our research suggests that contexts that produce functionally adapted physiologic responses to stress also encourage a functionally adapted coping response-coping that can result in maladjustment in physical and mental health, but enables children to grow and develop within those contexts. In this article, I highlight the value of reframing maladaptive coping as functional adaptation to understand more completely the development of children's coping in different contexts, and the value of such a conceptual shift for coping-based theory, research, and intervention.
Electrostatic interactions in aromatic oligopeptides contribute to protein stability

Abstract Recent X-ray crystallographic studies of aromatic oligopeptides have shown that aromatic amino acid side chains participate in enthalpically-favorable, weakly polar interactions that stabilize oligopeptide folds. These interactions are important in peptides used as model therapeutic agents for sickle-cell disease, in vasopressin (antidiuretic hormone) and in [Leu]-enkephalin. The aromatic groups of globular proteins display similar behavior and thereby contribute to the stability of the three-dimensional structure of proteins.
Electron intersubband relaxation in doped quantum wells.

The intersubband relaxation time of an electron is calculated by considering electron-electron and electron-phonon (bulk LO phonon) scattering in a GaAs quantum well. The relaxation time is derived and numerically evaluated within the random-phase approximation with full multiple subband and frequency-dependent screening. The electron scattering due to the coupled system of electrons and phonons is compared with the decoupled scattering where both electron-electron and unscreened electron-phonon scattering are considered separately. It is shown that the intersubband relaxation time is heavily influenced by the electron density in the well. It is also shown that at room temperature it is necessary to use the finite-temperature dielectric function to accurately determine the intersubband relaxation time.
A 180nm CMOS image sensor with on-chip optoelectronic image compression

We demonstrate an image sensor which directly acquires images in a compressed format. The sensor uses diffractive optical structures integrated in the CMOS back-end layer stack to compute a low-order 2D spatial Gabor transform on visual scenes. As this computation occurs in the optical domain, the readout back-end uses the transform outputs to implement the subsequent image digitization and compression simultaneously. Implemented in a 180nm logic CMOS process, the image sensor uses a 384×384 array of complementary angle-sensitive pixel pairs, consumes 2mW at a frame rate of 15fps, and achieves a 10:1 compression ratio on test images.
An Area-of-Review Variance Study of the East Texas Field

The East Texas oil field, discovered in 1930 and located principally in Gregg and Rusk Counties, is the largest oil field in the conterminous United States. Nearly 33,000 wells are known to have been drilled in the field. The field has been undergoing water injection for pressure maintenance since 1938. As of today, 104 Class II salt-water disposal wells, operated by the East Texas Salt Water Disposal Company, are returning all produced water to the Woodbine producing reservoir. About 69 of the presently existing wells have not been subjected to US Environmental Protection Agency Area-of-Review (AOR) requirements. A study has been carried out of opportunities for variance from AORs for these existing wells and for new wells that will be constructed in the future. The study has been based upon a variance methodology developed at the University of Missouri-Rolla under sponsorship of the American Petroleum Institute and in coordination with the Ground Water Protection Council. The principal technical objective of the study was to determine if reservoir pressure in the Woodbine producing reservoir is sufficiently low so that flow of salt-water from the Woodbine into the Carrizo-Wilcox ground water aquifer is precluded. The study has shown that the Woodbine reservoirmore » is currently underpressured relative to the Carrizo-Wilcox and will remain so over the next 20 years. This information provides a logical basis for a variance for the field from performing AORs.« less
Folate pathway and nonsyndromic cleft lip and palate

Nonsyndromic cleft lip with or without cleft palate (NSCLP) is a common birth malformation caused by genetic, environmental and gene-environment interactions. Periconceptional supplementation with folic acid, a key component in DNA synthesis and cell division, has reduced the birth prevalence of neural tube defects (NTDs) and may similarly reduce the birth prevalence of other complex birth defects including NSCLP. Past studies investigating the role of two common methylenetetrahydrofolate reductase (MTHFR) SNP polymorphisms, C677T (rs1801133) and A1298C (rs1801131), in NSCLP have produced conflicting results. Most studies of folate pathway genes have been limited in scope, as few genes/SNPs have been interrogated. In this study, we asked whether variations in a more comprehensive group of folate pathway genes were associated with NSCLP and, if so, were there detectable interactions between these genes and environmental exposures. In addition, we evaluated the data for a sex effect. Fourteen folate metabolism related genes were interrogated using eighty-nine SNPs in multiplex and simplex non-Hispanic White (NHW) (317) and Hispanic (128) NSCLP families. Evidence for a risk association between NSCLP and SNPs in nitrous oxide 3 (NOS3) and thymidylate synthetase (TYMS) was detected in the NHW group, whereas associations with methionine synthase (MTR), betaine-homocysteine methyltransferase (BHMT2), MTHFS and SLC19A1 were detected in the Hispanic group. Evidence for over-transmission of haplotypes and gene interactions in the methionine arm was detected. These results suggest that perturbations of the genes in the folate pathway may contribute to NSCLP. There was evidence for an interaction between several SNPs and maternal smoking, and for one SNP with sex of the offspring. These results provide support for other studies that suggest that high maternal homocysteine levels may contribute to NSCLP and should be further investigated.
Impact of (Z)-7-dodecenol and turbulence on pheromone-mediated flight manoeuvres of male Trichoplusia ni

. Turbulence and chemical noise are two factors which may influence pheromone-mediated flight manoeuvres of a moth in natural habitats. In this study, the effects of turbulence and the behavioural antagonist (Z)-7-dodecenol on flight manoeuvres of male Trichoplusia ni (Hubner) were evaluated in a wind tunnel. Male moths increase airspeed and course angles when turbulence is increased. This leads to significant increases in the length of flight tracks, but significant reductions in the time taken to reach a pheromone source. In less disturbed pheromone plumes, distributions of course angles and track angles of male T.ni show a prominent peak centred about 0° relative to the upwind direction, indicating that moths can temporarily steer directly upwind toward a pheromone source. When (Z)-7-dodecenol is released 10 cm upwind of a pheromone source to form an overlapping plume downwind, course angles, airspeeds and ground-speeds of male T.ni are reduced significantly compared with those in uncon-taminated pheromone plumes. This results in a longer flight time to reach a pheromone source. The decrease in flight speed would decrease the rate of contact with filaments, and thereby perhaps allow the moth to detect uncon-taminated pheromone filaments independently from filaments containing the behavioural antagonist.
A method for scheduling in parallel manufacturing systems with flexible resources

We address the Parallel-Machine Flexible-Resource Scheduling (PMFRS) problem of simultaneously allocating flexible resources, and sequencing jobs, in cellular manufacturing systems where the cells are configured in parallel. We present a new solution methodology for the PMFRS problem called the Nested Partitions (NP) method. This method combines global sampling of the feasible region and local search heuristics. To efficiently apply the NP method we reformulate the PMFRS problem, develop a new sampling algorithm that can be used to obtain good feasible schedules, and suggest a new improvement heuristic. Numerical examples are also presented to illustrate the new method.
Induced states of anxiety and depression: Effects on self-reported affect and tonic psychophysiological response

The present investigation was designed to measure the self-report and tonic psychophysiological response to induced mood states of anxiety and depression. Sixty female participants were randomly assigned to one of three conditions: anxiety, depression, or neutral. Anxiety-inducing self-statements led to significant increases in tonic heart rate and to significantly greater increases in state anxiety than did depression or neutral self-statements. The methodological advantages of this experimental paradigm are discussed, as well as the clinical implications for the conceptualization and treatment of disorders resulting from maladaptive physiological arousal.
Bilateral Subdural Hematomas after Lumboperitoneal Shunt Placement

Abstract Background Lumboperitoneal shunts are commonly placed as treatment for a variety of conditions, and complications can be significant. Objectives We discuss a rare complication of these shunts, namely bilateral non-traumatic subdural hematoma formation. Case Report A patient with a normal neurologic examination but severe nausea, weight loss, and dehydration presented 2 weeks after lumboperitoneal shunt placement for cryptococcal meningitis, and was found to have bilateral subdural hematomas. Conclusions Physicians should be aware of this potentially devastating complication of shunt placement so that prompt and appropriate treatment can be initiated.
Vapor shielding and erosion of surfaces exposed to a high heat load in an electrothermal accelerator

The experimental and theoretical verification of the vapour shield concept in an electrothermal accelerator is reported. Measurements of the ablation mass loss of the insulator material (Lexan) demonstrate that the energy transmission factor through the vapor shield is of the order of 10%. If enough vapor is produced under high heat flux, the vapor shield mechanism will help limit the surface erosion in electromechanical devices. The erosion of the barrel material (aluminum) has a strong axial dependence, and the erosion depth increases with input energy. >
Near-infrared spectrometric determination of blood pH.

Abstract Background. Reflectance near-infrared spectroscopy (600–2200 nm) can noninvasively probe deep into tissues. Blood is the predominant absorber of near-infrared light in biological tissues. We investigated the feasibility of using reflectance near-infrared spectroscopy to measure blood pH in vitro . Methods. Reflectance near-infrared spectra (600–2200 nm) were obtained with a fiberoptic probe immersed in diluted human packed red blood cells maintained at 37°C. Changes in pH (6.800–7.600) were induced by: (1) varying the partial pressure of carbon dioxide by the bubbling of mixtures of humidified carbon dioxide and nitrogen gas through the blood; and (2) adding 1 N HCl/NaOH. Humidified oxygen gas was bubbled through the blood to generate variations in oxygen saturation. After each titration of pH, the spectrum was recorded and blood was sampled for the measurement of: pH, pCO 2 , and pO 2 using blood gas analysis; and hemoglobin concentration and oxygen saturation using co-oximetry. Samples from three separate pH titrations were combined (120 total samples) and analyzed using partial least-squares analysis to generate a mathematical model relating spectral changes to pH (calibration set). This model was then used to predict the pH of a set of 36 pH titrations (prediction set). Results. Quantitative and qualitiative analyses of the spectra in the calibration set found that spectral changes in the wavelength range, 650–1050 nm, were directly related to changes in pH. First-derivative-treated spectra from the calibration set, analyzed using partial least-squares analysis, generated a mathematical model with a cross-validated r 2 of 0.939 and a standard error of calibration of 0.046 pH unit. When this model was applied to the prediction set, with an offset correction, the r 2 was 0.936 with a standard error of prediction of 0.050 pH unit. Conclusion. Blood pH can be predicted in vitro with clinical significance using reflectance near-infrared spectroscopy (650–1050 nm) within a standard error of 0.050 pH unit.
On the Question of Protein Binding and the Diffusibility of Circulating Antidiuretic Hormone in the Dog

The question whether antidiuretic hormone (ADH) in plasma exists as the free octapeptide or is bound to some large molecule was investigated by circulating the blood of an anesthetized dog through a dialysis chamber, and assaying the dialysate and plasma for ADH. The rate of dialysis of endogenous ADH was compared with the rate of the in vitro dialysis of highly purified arginine vasopressin. In both cases the diffusion rate was dependent on the concentration gradient of ADH across the membrane. The percentage of equilibrium attained after 1 hr of dialysis was found to be the same in vivo and in vitro. Information on the diffusibility of ADH across capillaries was obtained by introducing a physiological salt solution containing 6% dextran into the thoracic and peritoneal cavities. Subsequently, samples from these sites were assayed for ADH. Lymph was collected from the thoracic duct and from the cervical lymphatic ducts, and assayed for ADH. ADH was present in lymph and in fluid withdrawn from the thoraci...
The design of dwell-rise-dwell cams with reduced sensitivity to parameter variation

Abstract This paper presents a new approach to designing dwell-rise-dwell profiles for cam follower systems. The cam profiles are designed such that perturbations in the system parameters have a reduced influence on the dynamic response. This is accomplished by minimizing the parameter sensitivity of output mass motion. The system parameters considered are those that appear in the equation of motion, namely, the mass, spring stiffness, damping coefficient, and the speed of cam rotation. The design optimization problem is formulated as a linear quadratic optimal control problem that is easy to solve. Comparisons with a polydyne cam design shows that the approach developed here yields a cam design that has superior performance in terms of residual vibration, peak contact stress, energy loss and the required preload force. The new design also exhibits better attributes despite possible variations in the system parameters.
Active vibration control of a three-stage tensegrity structure

This experimental study demonstrates the efficiency of simple control strategies to damp a 3-stage tensegrity tower structure. The tower is mounted on a moving support which is excited with a limited bandwidth random signal (filtered white noise) by a shaker. Our goal is to minimize the tansmissibility between base acceleration and top plate acceleration using piezoelectric displacement actuators and force sensors collocated at the bottom stage of vertical strings. Two types of controllers have been designed, namely, it local integral force feedback control and acceleration feedback control. It can be shown that both controllers can effectively damp the first 2 bending modes by about 20 dB, and the acceleration feedback controller performs even better as it can also reduce the amplitude of the next 2 bending modes by about 5-10 dB.
Age Specific Behavioral Responses of Odonate Larvae to Chemical and Visual Cues from Predators

ABSTRACT Many aquatic organisms possess the ability to detect and respond to visual and chemical cues from predators and injured conspecifics, but relatively few studies have investigated if those responses change during development in odonates. In a laboratory experiment, I exposed 8th and 12th instar larvae of the dragonfly Anax junius to (1) the presence of a free-swimming fish predator (Lepomis macrochirus); (2) water that recently contained L. macrochirus; (3) water that contained crushed conspecifics; (4) water that recently contained living conspecifics; and (5) charcoal filtered tap water that contained no visual or chemical stimuli. The 12th instar A. junius moved more often, spent more time moving and spent less time perched on artificial aquatic vegetation than did 8th instar A. junius. A. junius moved less in the presence offish chemical cues relative to the control. Although 8th and 12th instar A. junius differed in their responses to stimuli from predators, the overall response of A. junius ...
Shell Mounds and Mounded Landscapes in the San Francisco Bay Area: An Integrated Approach

ABSTRACT Current understanding of the shell mounds of the San Francisco Bay Area, now almost completely destroyed due to urban expansion, is summarized. After interpretations of how and why coastal hunter-gatherers created these sites are discussed, salient characteristics of shell mounds from the area are outlined. Because core questions concerning the meaning and function of these sites remain unresolved, a new project that integrates the results of re-analyses of older museum collections with archival records and CRM work is discussed, an approach that may have applicability in other developed coastal areas. Results of a regional analysis that relies on an assessment of site type drawn from many site records are then presented. First-time discovery of site type throughout the past 100 years is then analyzed across 20 topographic quadrangles; we conclude that the region's earliest archaeologists captured a surprising range of site type diversity, especially with respect to shell-bearing sites. A north-s...
Photochemistry from highly excited triplet states of substituted anthracenes in thin polymer films

Abstract Photobleaching of distributed (methyl and phenyl) anthracenes in thin polymer films has been observed under inert atmosphere with both direct and triplet sensitized excitation, exhibiting both wavelength and intensity dependence of quantum yields (which are in the range ≈ 10−2–10−5). The data consistent with a reaction between a highly excited anthracene triplet and the polymer.
Surface-Mediated Segregation and Transport Processes in Mixed Hydrocarbon Multilayer Assemblies

The transport and structural phase dynamics exhibited by multilayer assemblies comprised of cyclic and linear alkanes are analyzed with reflection absorption infrared (RAIR) and temperature-programmed desorption spectroscopies. Infrared spectroscopy reveals that methyl group substitutions have a significant effect on the nature of the mode softening seen in the C-H stretching region for surface-bound cyclohexanes. The magnitude of the red-shifts seen increases with the degree of methyl substitution. The energetics of the surface binding do not correlate in a simple way with the magnitude of red-shifts seen in the RAIR spectra, however. We find instead that the strengths of the surface interactions are more directly correlated with both the size and shape of the molecule (with the latter presumably reflecting its ability to form a densely packed structure). We also find that the diffusion of molecules in a mixed hydrocarbon multilayer assembly is weakly activated, with substantial interlayer mixing being seen at temperatures significantly below the threshold for the desorption of the multilayer. The mixing, while driven by mass action, shows a pronounced bias for the surface binding of n-alkanes over cycloalkanes of similar molecular weight (e.g., n-octane is more strongly bound on Pt(111) than is cis-1,3-dimethylcyclohexane). The data strongly suggest that attractive lateral interactions in the adsorbed layers lead to the biases seen in this surface-induced segregation. Thermal desorption spectra confirm this sensitivity and interestingly show multiple monolayer desorption features for cyclic alkane adsorbates when mixed in a monolayer assembly with an appropriate linear n-alkane. We suggest that the attractive lateral interactions in the monolayer lead to the formation of island domains and that the desorption kinetics appear to sensitively reflect this underlying rate/structure sensitivity.
Observation of a second-sound-like mode in superfluid-filled aerogel

Superfluid $^{4}\mathrm{He}$ is interesting acoustically because it can support more than one mode of sound propagation, and these can be used to study critical properties. Recently, there has been interest in superfluid-filled aerogels, but for such compressible materials one does not observe the ordinary (fourth) sound; instead there is a mode intermediate between first and fourth sound and a second-sound-like mode. We present a theory for the modes and the first observation of the aerogel second-sound-like mode, which is important because it propagates near the critical temperature.
Efficient synthesis of achiral seco-cyclopropylbenz[2,3-e]indoline analogues: [4-amino-2-(5,6,7-trimethoxyindole-2-carboxamido)naphthalen-1-yl]ethyl chloride and [4-hydroxy-2-(5,6,7-trimethoxyindole-2-carboxamido)naphthalen-1-yl]ethyl chloride.

Achiral seco-aminocyclopropylbenz[2,3-e]indoline and seco-hydroxycyclopropylbenz[2,3-e]indoline (seco-CBI) analogues of the duocarmycins and CC-1065, e.g., 7 and 8, are potent anticancer agents. This paper describes significantly improved synthetic strategies for preparing these compounds. Starting from Martius acid (9), the new strategy gave a 13-fold increase in the overall yield of 7, and the use of di-tert-butyl malonate was economically beneficial. For compound 8, the new strategy employed an Emmons−Horner reaction, followed by a Stobbe condensation, and the overall yield was improved 15-fold.
Marginal donors for patients on regular waiting lists for liver transplantation

The use of marginal donors is well accepted by most centers for emergency situations, but there is debate on their use for patients on regular waiting lists. We report our experience of the 1-year survival for patients on waiting lists (n = 147, 1-year survival = 32%), patients transplanted from good donors (n = 60, 1-year survival = 84%), and patients transplanted from marginal donors (n = 15, 1-year survival = 56%). We concluded that liver transplantation from marginal donors (a) is a safe procedure (b) has a 1-year survival that is significantly better than that on a waiting list (c) is ethically justified especially in countries with donor shortages, and (d) may allow transplantation of “special” high risk and poor longterm outcome patients.
Experimental Study of a Membrane Antenna Surface Adaptive Control System

Due to their ultra lightweight and high packaging efficiency, membrane reflectors are getting more and more attention for mission architectures that need extremely large in-space deployable antennas. However, maintaining the surface shape of a membrane reflector to the instrument precision requirements is a very challenging problem. This experimental study investigated using PVDF membrane piezoelectric material as actuators to control the surface figures of membrane reflectors. The feasibility of this approach is demonstrated by several sets of test results.
Tarsal Tunnel Syndrome

Tarsal tunnel syndrome, unlike its similar sounding counterpart in the hand, is a significantly misunderstood clinical entity. Confusion concerning the anatomy involved, the presenting symptomatology, the appropriateness and significance of various diagnostic tests, conservative and surgical management, and, finally, the variability of reported results of surgical intervention attests to the lack of consensus surrounding this condition. The terminology involved in various diagnoses for chronic heel pain is also a hodgepodge of poorly understood entities.
Polyarticular inflammatory arthritis in a pre‐Columbian skeleton from Kodiak Island, Alaska, U.S.A.

A human skeleton of a 30–35-year-old female from Kodiak Island, Alaska, U.S.A. exhibits skeletal lesions which strongly suggest polyarticular inflammatory arthritis. Skeletal lesions associated with the joints include porosity and destruction of joint surfaces, periarticular cystic erosion, and hypertrophic bone formation. Severe manifestations occur in the knee, ankle, and elbow. Hand and foot bones are also involved. However there is minimal involvement of the spine. The age and sex of the skeleton and the pattern of arthritic change are compatible with a diagnosis of juvenile rheumatoid arthritis. Since the specimen is probably dated to before A.D. 1200 it represents an important case in trying to clarify the history of polyarticular inflammatory arthritis.
Student use of personal digital assistants in a computer engineering course

Penn State Abington has integrated the student use of personal digital assistant (PDA) technology to foster active and collaborative learning experiences in the classroom and laboratory. Palm/sup TM/ PDA technology was introduced into a sophomore-level digital systems course in the fall of 2000. The students have investigated handheld software tools for enhancing learning and instruction in both the lecture and laboratory components of the course. Handheld databases, simple CAD tools, C programming, image capture, web-based tools, and robotics applications have been explored.
Changed southwest forests: resource effects and management remedies

Over 150 years of occupancy by northern Europeans has markedly changed vegetative conditions in the Southwest. Less fire due to grazing and fire suppression triggered a shift to forests with very high tree densities, which in turn contributed to destructive forest tires. Options to deal with these changes include prescribed fire, thinning and timber harvest to mimic natural disturbances and conditions. However, there are barriers to implementing these activities on a scale large enough to have a significant benefit.
Nonlinear multigrid algorithms for Bayesian optical diffusion tomography

Optical diffusion tomography is a technique for imaging a highly scattering medium using measurements of transmitted modulated light. Reconstruction of the spatial distribution of the optical properties of the medium from such data is a difficult nonlinear inverse problem. Bayesian approaches are effective, but are computationally expensive, especially for three-dimensional (3-D) imaging. This paper presents a general nonlinear multigrid optimization technique suitable for reducing the computational burden in a range of nonquadratic optimization problems. This multigrid method is applied to compute the maximum a posteriori (MAP) estimate of the reconstructed image in the optical diffusion tomography problem. The proposed multigrid approach both dramatically reduces the required computation and improves the reconstructed image quality.
Spatial uncertainty analysis of population models

Abstract This paper describes an approach for conducting spatial uncertainty analysis of spatial population models, and illustrates the ecological consequences of spatial uncertainty for landscapes with different properties. Spatial population models typically simulate birth, death, and migration on an input map that describes habitat. Typically, only a single “reference” map is available, but we can imagine that a collection of other, slightly different, maps could be drawn to represent a particular species’ habitat. As a first approximation, our approach assumes that spatial uncertainty (i.e., the variation among values assigned to a location by such a collection of maps) is constrained by characteristics of the reference map, regardless of how the map was produced. Our approach produces lower levels of uncertainty than alternative methods used in landscape ecology because we condition our alternative landscapes on local properties of the reference map. Simulated spatial uncertainty was higher near the borders of patches. Consequently, average uncertainty was highest for reference maps with equal proportions of suitable and unsuitable habitat, and no spatial autocorrelation. We used two population viability models to evaluate the ecological consequences of spatial uncertainty for landscapes with different properties. Spatial uncertainty produced larger variation among predictions of a spatially explicit model than those of a spatially implicit model. Spatially explicit model predictions of final female population size varied most among landscapes with enough clustered habitat to allow persistence. In contrast, predictions of population growth rate varied most among landscapes with only enough clustered habitat to support a small population, i.e., near a spatially mediated extinction threshold. We conclude that spatial uncertainty has the greatest effect on persistence when the amount and arrangement of suitable habitat are such that habitat capacity is near the minimum required for persistence.
Laser alignment system for helical pinhole SPECT

Pinhole single photon emission computed tomography (SPECT) is very sensitive to mechanical alignment because it is a magnifying geometry. Because of magnification, small mechanical shifts of the aperture result in a large change in the projection data. Helical orbits may be used for pinhole SPECT to improve the completeness of the projection data. This has been done by using a research scanner to provide rotation while a linear stage produces axial movement. The combined effect is a helical orbit. However, reconstruction quality may be limited by the alignment of the linear stage with the axis of rotation of the scanner. We have developed a laser system for aligning the linear stage. We present the system design and estimate the accuracy of its alignment. Experimental helical pinhole SPECT data are presented.
A new method for estimating dimensions and 3-D reconstruction of coronary arterial trees from biplane angiograms

The coronary arteries may be represented and visualized efficiently by a generalized cylinder (GC) model with elliptical cross-sections. By using this model and utilizing quadratic expression of an ellipse, the intensity distribution of an ellipse in any image plane, which is perpendicular to the plane of the arterial cross-section, is computed. A nonlinear parametric model for observed intensity distribution of an arterial cross-section is applied to estimate not only cross-sectional areas but also parameters of the ellipse which are essential in 3-D reconstruction of an arterial segment. This model takes into account background intensity, noise and blurring. Performance of this model has been tested on computer-generated and actual data for various background types and noise values and compared to those of other methods for estimating arterial dimensions. The computed cross-sectional areas from our model for computer-generated as well as actual data demonstrate much less variability than those reported in recent literature. 3-D reconstruction of arterial segments from actual biplane angiograms is presented. >
Voodoo Multipliers Revisited: Public Policy For Recessions and Boomtimes

This paper makes the argument that certain public goods (those lacking special interest backing) are likely to be under-provided by governments. Moreover, some such goods are complementary with private goods (e.g. roads and automobiles), while other such goods are substitutes for private goods (e.g. mass transit and automobiles). A case is made for providing the latter class of goods during boom times, and providing the former as stimulus during recessions.
Racial Disparity in Administrative Autism Identification Across the United States During 2000 and 2007

Evidence of disparate identification of autism at national and local levels is accumulating, but there is little understanding about disparate identification of autism at the state level. This study examined trends in state-level administrative identification of autism under the Individuals with Disabilities Education Act. Prevalence rates and odds ratios were calculated for each state using enrollment counts for years 2000 and 2007. Results indicated increases in administrative prevalence of autism for all racial groups from 2000 to 2007, but increasing underidentification of Black and Hispanic students in 2007 compared with White students. Variability existed in the identification of autism among Black and Hispanic students across states over time. Implications for the findings are discussed in the context of the field’s need to establish rigorous policies and practices for eligibility determinations due to autism and equitable access to evidence-based intervention practices.
Evolution of Drug-Resistant Viral Populations during Interruption of Antiretroviral Therapy

ABSTRACT Analysis of a large number of HIV-1 genomes at multiple time points after antiretroviral treatment (ART) interruption allows determination of the evolution of drug-resistant viruses and viral fitness in vivo in the absence of drug selection pressure. Using a parallel allele-specific sequencing (PASS) assay, potential primary drug-resistant mutations in five individual patients were studied by analyzing over 18,000 viral genomes. A three-phase evolution of drug-resistant viruses was observed after termination of ART. In the first phase, viruses carrying various combinations of multiple-drug-resistant (MDR) mutations predominated with each mutation persisting in relatively stable proportions while the overall number of resistant viruses gradually increased. In the second phase, viruses with linked MDR mutations rapidly became undetectable and single-drug-resistant (SDR) viruses emerged as minority populations while wild-type viruses quickly predominated. In the third phase, low-frequency SDR viruses remained detectable as long as 59 weeks after treatment interruption. Mathematical modeling showed that the loss in relative fitness increased with the number of mutations in each viral genome and that viruses with MDR mutations had lower fitness than viruses with SDR mutations. No single viral genome had seven or more drug resistance mutations, suggesting that such severely mutated viruses were too unfit to be detected or that the resistance gain offered by the seventh mutation did not outweigh its contribution to the overall fitness loss of the virus. These data provide a more comprehensive understanding of evolution and fitness of drug-resistant viruses in vivo and may lead to improved treatment strategies for ART-experienced patients.
Characterization of intracellular accumulation of poly-β-hydroxybutyrate (PHB) in individual cells of Alcaligenes eutrophus H16 by flow cytometry

Poly-beta-hydroxybutyrate (PHB) accumulates in individual cells of Alcaligenes eutrophus in the form of refractile bodies which alter the light-scattering properties of individual cells. Flow cytometry has been applied to measure the distributions of single-cell light-scattering intensity in Alc. eutrophus populations during batch cultivation of the organism. These measurements clearly identify heterogeneities in the inoculum which influence the lag interval prior to beginning of exponential growth. Light-scattering distributions show greater homogeneity and are extremely similar during balanced, exponential growth. After exhaustion of the nitrogen source and with carbon source still available, significant PHB accumulations occur and the flow cytometry measurements reveal extreme heterogeneity in single-cell light-scattering properties. These measurements clearly demonstrate the potential advantages of single-cell light-scattering measurements by flow cytometry for analysis and control of certain fermentation processes. Single-cell light-scat light-scattering measurements in conjunction with flow sorting instrumentation have been applied to demonstrate enrichment of PHB-producing cells, initially present in a number concentration of 0.01%by a factor of 300 in a single pass. Flow cytometry-cell sorting technology should find significant application in strain improvement and mutant selection.