cssi/SciSciGPT-SciSciNet huggingface dataset:
Mathieu instability of a spar platform with mooring and risers

Abstract Mathieu instability for a spar platform arises when there is a harmonic variation in the pitch restoring coefficients caused by large heave motion and the period of the heave motion is half of the pitch natural period. The pitch restoring coefficient can be represented by a function of the displaced volume and the metacentric height of spar hull. Due to heave motion, the displaced volume and the metacentric height of the spar platform change in time and this heave/pitch coupling can be represented by Mathieu’s equation. The objective of this study is to evaluate damping effects and hull/mooring/riser coupled effects on the principal instability. In the simulation, the heave/pitch coupling of the spar platform is considered using the modified Mathieu equation. The wave elevation effect on Mathieu instability is also investigated. The Mathieu instability of a practical spar platform is carefully checked by a series of systematic simulations and comparisons of many different scenarios. When heave resonance occurs at the heave natural period equal to half of the pitch natural period, Mathieu instability, a kind of lock-in phenomenon, actually arises to increase the pitch motion significantly. The available damping is found to be important in suppressing the instability. The results also show that the additional pitch restoring force from buoyancy-cans plays an important role in the spar Mathieu instability.
Testosterone treatment of human foreskin in a novel transplant model.

Abstract Objectives To determine whether testosterone would increase angiogenesis in human foreskin, because of the known effects of testosterone on endothelial cells and vascular endothelial growth factor expression. Surgical management of complex hypospadias in a patient who has undergone multiple procedures is technically very challenging. It is possible that therapy to increase the blood supply to this tissue could be beneficial. Methods We used a newly developed model of human skin transplantation, in which full-thickness human foreskin is transplanted subcutaneously onto the dorsum of a nude rat. At 10 days after transplantation, tissue was treated with either testosterone gel or vehicle control. After an additional 7 days, the tissue was harvested, embedded in paraffin, stained for factor VIII to assess vascularity, and examined histologically. Results The testosterone-treated tissue demonstrated increased factor VIII staining (31.14 ± 1.53 vessels per high-power field) compared with the control group (18.25 ± 2.3 vessels per high-power field; P Conclusions Treatment of human foreskin with testosterone, in a transplant model, increased vascularity and decreased early fibrosis. Testosterone treatment may improve the surgical management of complex hypospadias repair.
Butorphanol and nalbuphine in opioid-dependent humans under a naloxone discrimination procedure.

Abstract Opioid-maintained volunteers were trained to distinguish between a low dose of the opioid antagonist naloxone (0.15 mg/70 kg, im; i.e., Drug A) and placebo (i.e., Drug B) under an instructed novel-response drug-discrimination procedure in which subjects identify the drug condition as “A,” “B,” or “N” (neither A nor B—‘novel’). Once the discrimination was acquired, doses of naloxone (0–0.15 mg/70 kg, im) and the mixed-action opioid agonist/antagonists butorphanol (0–1.5 mg/70 kg, im) and nalbuphine (0–3.0 mg/70 kg, im) were tested. Naloxone produced dose-related increases in naloxone-appropriate responding with little or no ‘novel’-appropriate responding. Butorphanol produced a dose-related increase in naloxone- and ‘novel’-appropriate responding, occasioning approximately 70% and 29%, respectively, at the highest dose tested. Nalbuphine produced 40–65% naloxone-appropriate responding at all doses tested and 33% ‘novel’-appropriate responding at the highest doses. Self-reported effects produced by each agent differed only slightly. These results suggest that mixed-action opioid agonist/antagonists may be distinguished from the opioid antagonist naloxone based on their discriminative-stimulus effects under a novel-response naloxone discrimination procedure.
A description of Caudospora pennsylvanica sp. n. (Caudosporidae, Microsporidia), a parasite of the larvae of the black fly, Prosimulium magnum Dyar and Shannon

Abstract Caudospora pennsylvanica sp. n. (Caudosporidae, Microsporidia) is described. C. pennsylvanica is a parasite of larvae of the black fly, Prosimulium magnum Dyar and Shannon, in north central Pennsylvania. An account of stages in the life cycle of C. pennsylvanica as well as a comparison of this species with C. simulii Weiser are presented.
Management of Aortic Valve Insufficiency in Patients Supported By Long-Term Continuous Flow Left Ventricular Assist Devices

Continuous flow (CF) left ventricular assist devices (LVADs) have yielded improved outcomes in patient survival and quality of life compared with first-generation pulsatile pumps; however, they have been associated with an increased incidence of postimplant aortic valve insufficiency (AI), which can have can have serious clinical consequences if not diagnosed and treated expeditiously. We reviewed our experience with AI after LVAD since the start of our CF LVAD program. From March 2006 through July 2011, 94 patients with chronic heart failure underwent implantation of a HeartMate II (HM II) LVAD. Severe AI developed in three patients after CF LVAD implantation. The clinical records of these patients were reviewed to analyze the presenting signs and symptoms of AI, identify the duration of LVAD support when the AI occurred, how the AI was treated, and the outcomes.
Studies of DNA dumbbells. III. Theoretical analysis of optical melting curves of dumbbells with a 16 base-pair duplex stem and Tn end loops (n = 2, 3, 4, 6, 8, 10, 14).

Optical melting curves of seven DNA dumbbells with the 16 base-pair duplex sequence 5′G-C-A-T-A-G-A-T-G-A-G-A-A-T-G-C3′ linked on both ends by Tn (n = 2, 3, 4, 6, 8, 10, and 14) loops measured in 30, 70, and 120 mM Na+ are analyzed in terms of the numerically exact statistical thermodynamic model of DNA melting. The construction and characterization of these molecules were described in the previous paper (Amaratunga et al., 1992). As was recently reported for hairpins (T. M. Paner, M. Amaratunga, M. J. Doktycz, and A. S. Benight, 1990, Biopolymers, Vol. 29, pp. 1715-1734) theoretically calculated melting curves were fitted to experimental curves by simultaneously adjusting the parameters representing loop and circle formation to optimize the fits. The systematically determined empirical parameters provide evaluations of the free energies of hairpin loop formation ΔGloop(n) and single-strand circles ΔGcircle(N), as a function of end loop size, n = 2–14, and circle size, N = 32 + 2n. The dependence of these quantities on solvent ionic strength over the range from 30 to 120 mM Na+ was evaluated. An approximately analytical expression for the partition function Q(T) of the dumbbells was formulated that allowed a means for determining the transition enthalpy ΔH° and entropy ΔS° for every dumbbell, revealing the dependence of these quantities on loop size. In this multistate approach a manifold of partially melted intermediate microstates are considered and therefore no assumptions regarding the nature of the melting transitions (that they are two-state) are required. The transition thermodynamic parameters were also determined from a van't Hoff analysis of the melting curves. Comparisons between the results of the multistate analysis and the two-state van't Hoff analysis revealed significant differences for the dumbbells with larger end loops, indicating that the melting transitions of the larger looped dumbbells deviate considerably from two-state behavior. Results are then compared with published melting studies of much larger DNA dumbbells (D. B. Naritsin and Y. L. Lyubchenko, 1990, Journal of Biomolecular Structure and Dynamics, Vol. 8, pp. 1–13), of small hairpins (Paner et al., 1990; M. J. Doktycz, T. M. Paner, M. Amaratunga and A. S. Benight, 1990, Biopolymers, Vol. 30, pp. 829–845) and another dumbbell (A. S. Benight, J. M. Schurr, P. F. Flynn, B. R. Reid, and D. E. Wemmer, 1988) Journal of Molecular Biology, Vol. 200, (pp. 377–399). ΔGloop (n = 4) and ΔGcircle (40) were also evaluated from analysis of the melting curves of the 15 DNA dumbbells with 16 base-pair stems presented in the first paper (Doktycz et al., 1992). With the exception of the dumbbell with the central sequence 5′-T-T-A-A-3′, these quantities were found to be virtually independent of the sequence identity of the central 4 base pairs of the stem.
TEACHING THE STANDARD DEVIATIONS OF LINEAR COMBINATIONS OF RANDOM VARIABLES USING GRAPHICS

ABSTRACT This article gives a geometric interpretation that views the standard deviation of a linear combination of random variables in terms of the length of the hypotenuse of a triangle and its calculation as equivalent to the theorem of Pythagoras. This illustration shows students why the coefficients are squared and the variances are added even when one or more of the coefficients are negative. Linear combinations of two variables are discussed for both the independent and the dependent situations, and the extension to three variables is illustrated for the independent case.
The effect of topical treatment on esophageal pH during acid reflux in dogs

Abstract Objective To determine the effect of suction, lavage and instillation of sodium bicarbonate solution on esophageal pH during acidic gastro-esophageal reflux (GER) in anesthetized dogs. Study design Prospective, clinical trial. Animals Ten healthy dogs, 4.8 ± 2.4 years old, and weighing 37.1 ± 7.9 kg. Methods Dogs were admitted to the study if they were under general anesthesia and regurgitation occurred. A sensor-tipped catheter was used to measure esophageal pH. On study entry the esophagus was suctioned. After an interval of at least 5 minutes, if the esophageal pH was still less than 4 the esophagus was lavaged with tap water and again suctioned. In 6 dogs 20 mL of dilute bicarbonate solution was instilled into the esophageal lumen. Results Suctioning fluid from the esophagus did not change the pH significantly. Lavage with tap water caused the pH to increase above 4 in four dogs, with the average pH increasing from 1.2 ± 0.5 to 3.5 ± 4.9. In all dogs where dilute bicarbonate solution was instilled, esophageal pH increased to above 6 for up to 180 (mean ± SD, 89 ± 81) minutes. Conclusions and Clinical relevance Suctioning refluxate from the esophagus does not change the pH of the esophageal lumen. Instillation of a small volume of bicarbonate solution predictably increased the pH above 4 following an episode of acidic GER. Care must be taken that fluid is instilled into the lumen of the esophagus, and not into the trachea.
Changes in Spring Snowpack for Selected Basins in the United States for Different Climate-Change Scenarios

AbstractSpring snowpack is an important water resource in many river basins in the United States in areas where snowmelt comprises a large part of the annual runoff. Increasing temperatures will likely reduce snowpacks in the future, resulting in more winter runoff and less available water during the summer low-flow season. As part of the National Climate Change Modeling Project by the U.S. Geological Survey, distributed watershed-model output was analyzed to characterize areal extent and water-equivalent volumes of spring snowpack for a warming climate. The output from seven selected watershed models from the mountainous western United States and one model from coastal Maine in the northeastern United States shows a future of declining spring snowpack. Snow-cover area (SCA) and snow-water equivalent (SWE) were used to compare the spring snowpack for current conditions (2006) with three time periods in the future (2030, 2060, and 2090) using three Intergovernmental Panel on Climate Change (IPCC) emission ...
A Dicer-2-Dependent 80S Complex Cleaves Targeted mRNAs during RNAi in Drosophila

Abstract We use native gel electrophoresis to characterize complexes that mediate RNA interference (RNAi) in Drosophila . Our data reveal three distinct complexes (R1, R2, and R3) that assemble on short interfering RNAs (siRNAs) in vitro. To form, all three complexes require Dicer-2 (Dcr-2), which directly contacts siRNAs in the ATP-independent R1 complex. R1 serves as a precursor to both the R2 and R3 complexes. R3 is a large (80S), ATP-enhanced complex that contains unwound siRNAs, cofractionates with known RNAi factors, and binds and cleaves targeted mRNAs in a cognate-siRNA-dependent manner. Our results establish an ordered biochemical pathway for RISC assembly and indicate that siRNAs must first interact with Dcr-2 to reach the R3 "holo-RISC" complex. Dcr-2 does not simply transfer siRNAs to a distinct effector complex, but rather assembles into RISC along with the siRNAs, indicating that its role extends beyond the initiation phase of RNAi.
Small heat exchanger using silver powder

Abstract A simple heat exchanger using silver powder for cooling pure liquid 3He is described. The temperature difference across the heat exchanger was less than 5μK at the superfluid transition of 3He with a thermal flux of 0.06 nW.
Self-calibration of large phased-array antennas for radar

Self-calibration of a phased antenna array is required when distortions in the array are not known a priori and cannot be measured, or when turbulence in the propagation medium perturbs the radiation field. Two types of self-calibration procedures are discussed that have proved successful in experimental high-resolution two-dimensional microwave radar imaging. Each extracts information from the backscattered reradiation field to deduce a compensating weight vector for the phased array antenna. The first depends upon the presence of a strong reflector in the field of view of the transmitter. The second calibrates the array from correlation estimates of wavefront samples in the array. The basic algorithm in each group is described, along with two more sophisticated algorithms in the latter class. Two-dimensional radar images of airplanes are shown with resolution comparable to human vision. The performance of each algorithm and comparisons between them are illustrated by these images of targets and by simulation experiments.©1993 John Wiley & Sons Inc
Effect of soy protein on intestinal absorptive ability of calves by the xylose absorption test.

Abstract Five calves per group were fed whole milk (control) or one of three milk replacers with one-third of the total protein provided by a soy product. Soy products were Promocaf (a commercial soy protein concentrate), an experimental soy protein concentrate, and an experimental soy flour. After a 24-h fast, calves were fed xylose solution. Urine was collected for 5h. Jugular blood was sampled at 0, .5, 1, 1.5, 2, 2.5, 3, 4, and 5h after xylose administration. Xylose tests were weekly on each calf through 5 wk of age. Urinary xylose excretion, as a percentage of xylose fed, was higher in the control group during the last 4 wk than in groups fed milk replacers. Mean urinary xylose excretions during 5 wk from calves sampled 5h after xylose administration were 12.4, 4.2, 4.2, and 4.3% of xylose administered for calves fed milk, soy flour, soy protein concentrate, and Promocaf, respectively. Mean increases in peak of xylose concentration in plasma were 55.7, 44.4, 42.8, and 45.3 mg/100ml. Peak values for control calves were higher than those for calves fed soy products at wk 4 and 5. Times required to reach peak value did not differ significantly. Neither xylose concentration of plasma nor urinary xylose excretion differed among the groups fed soy products.
Infrared Measurements of Stratospheric Composition

The observational techniques and results of i.r. measurements of the minor and trace molecular composition of the lower stratosphere are reviewed. Emphasis is given to those theoretical aspects of ...
FTIR method for VLE measurements of acid‐gas–alkanolamine systems

The standard industrial process for the purification of natural gas is to remove acid gases, mainly hydrogen sulfide and carbon dioxide, by the absorption and reaction of these gases with alkanolamines, but the lack of reliable and accurate vapor-liquid equilibrium (VLE) data impedes the commercial application of more efficient alkanolamine systems. The objective of this research was to develop an FTIR apparatus and an in-situ technique capable of making VLE measurements of acid-gas-aqueous alkanolamine systems and to improve the accuracy of vapor-liquid equilibrium measurements at low hydrogen sulfide and carbon dioxide concentrations. The new FTIR apparatus and technique were tested in VLE measurements of low concentrations of carbon dioxide and hydrogen sulfide in aqueous mixtures of diethanolamine.
Compositionally modulated phase in crystalline n-alkane mixtures.

We report an x-ray scattering study of the compositionally modulated microphase separated state (\ensuremath{\mu}PSS) of binary n-alkane $({\mathrm{C}}_{23}{\mathrm{H}}_{48}{:\mathrm{C}}_{28}{\mathrm{H}}_{58})$ mixtures. By employing a quenching technique, we obtained many orders of sharp lamellar and superlattice reflections. The \ensuremath{\mu}PSS is a regular superstructure consisting of pure ${\mathrm{C}}_{23}$ layers, and layers rich in ${\mathrm{C}}_{28}$ but containing up to $\ensuremath{\sim}14%{\mathrm{C}}_{23}$ plus voids. A monolayer of the minority component regularly alternates with one or more layers of the majority. The mechanism for thermodynamic stability of the \ensuremath{\mu}PSS may be related to the entropy associated with longitudinal displacements of the molecules.
Analysis of the electrocardiographic waveforms produced by right ventricular pacing: relation to the nonpaced patterns.

Background: Ventricular aberrant conduction has a confounding effect on the known relationships between the electrocardiogram (ECG) and left ventricular (LV) mass. By relating the ECG of right ventricular pacing to LV mass and to nonpaced recordings, clarification of these effects might emerge. Methods and Results: In 30 patients (age, 81 ± 7 years; 13 women) who had right ventricular paced ECGs and echocardiograms, 24 of who also had nonpaced ECGs, comparative analyses were performed. Although the nonpaced ECGs had strong correlations with various echocardiographic measurements, for paced ECGs, only QRS complex voltage and interventricular septal thickness (IVS) were significantly related. However, paced QRS complex voltage relationships correlated with those of nonpaced QRS complexes, ranging from an r = 0.54, P < 0.006, for the sum of the R in aVL and the S in V-3 to r = 0.78, P < 0.001, for the sum of the R in I and the S in III. Paced ECGs had a QRS complex with a greater spatial amplitude, a longer duration, and a more superior position, and had more deeply inverted T waves than nonpaced ECGs. The differences between the voltages of paced and nonpaced QRS complexes, moreover, diminished as LV mass and/or IVS increased. When compared with nonpaced ECGs, paced ECGs showed the most similarity to nonpaced ECGs having a left bundle branch block (LBBB) pattern. Except for the presence of more superiorly directed QRS complexes, paced impulses were not significantly different (P < 0.008) from nonpaced impulses having a LBBB pattern. Also, the nonpaced ECG pattern had no discernable effect on ECG produced by right ventricular (RV) pacing. Conclusions: Despite having weak relations with echocardiographic measurements, the QRS complex voltage of the paced ECG correlated with those of nonpaced ECGs, and the voltage differences between them were smaller as LV mass increased.
Self-normalized linear tests

Making decisions based on a linear combination L of features is of course very common in pattern recognition. For distinguishing between two hypotheses or classes, the test is of the form sign (L - /spl tau/) for some threshold /spl tau/. Due mainly to fixing /spl tau/, such tests are sensitive to changes in illumination and other variations in imaging conditions. We propose a special case, a "self-normalized linear test" (SNLT), hard-wired to be of the form sign (L/sub 1/ - L/sub 2/) with unit weights. The basic idea is to "normalize" L/sub 1/, which involves the usual discriminating features, by L/sub 2/, which is composed of non-discriminating features. For a rich variety of features (e.g., based directly on intensity differences), SNLTs are largely invariant to illumination and robust to unexpected background variations. Experiments in face detection are promising: they confirm the expected invariances and out-perform some previous results in a hierarchical framework.
Effect of digitonin on the binding of opiate agonists and antagonists to membrane-bound and soluble opioid binding sites

Abstract Treatment of rat or toad brain membranes with low concentrations of digitonin (0.01–0.1%) inhibits the binding of opioids to their receptors. Moreover, the binding of agonists is inhibited to a greater extent than that of antagonists. Inhibition of antagonist binding is completely and specifically reversed by sodium ions (200 mM) while agonist binding is not. The binding of opiates to toad brain membrane is significantly less sensitive to digitonin than the binding to rat brain membranes. The present results furnish an explanation for our previous findings, i.e. good yield of binding to (digitonin/NaCl) solubilized binding sites from rat brain can only be obtained with labeled opiate antagonists. Furthermore, they also explain why good yields of binding to the soluble opioid binding sites from toad brain can be obtained in the absence of sodium, while high concentrations of NaCl are required for mammalian brain, such as rat.
The growth of interventional pain management in the new millennium: a critical analysis of utilization in the medicare population.

Interventional pain management has been growing by leaps and bounds with the introduction of an array of new CPT codes, the expansion of interventional techniques, and utilization. Interventional pain manage- ment dates back to the origin of neural block- ade and regional analgesia, in 1884. Over the years, pain medicine and interventional pain management have taken many approaches, including biological, biopsychosocial, and psychosocial. In the late 1990s and early 2000s, a new philosophy of precision diagnosis and high- tech management has evolved. An interven- tional pain physician may be either a reduc- tionist, a monotherapist or a combination of the two. Interventionalists have been criti- cized for excessive undisciplined application of needle procedures. Interventional techniques are per- formed by many primary specialists (anes- thesiology, physiatry, neurology, etc.) and physicians designated by CMS in interven- tional pain management (-09) and pain man- agement or pain medicine (-72) which went into effect in 2003 and 2002. Overall, the frequency of utilization of interventional procedures has increased substantially since 1998. It is estimated that among Medicare recipients, the frequency of interventional procedures, which includes epidural, spinal neurolysis, and adhesiolysis procedures; facet joint interventions and sac- roiliac joint blocks; and other types of nerve blocks, excluding continuous epidurals, im- plantables, disc procedures, intraarticular injections, trigger point and ligament injec- tions, had increased by 95% from 1998 to 2003. In the Medicare population, facet joint interventions and sacroiliac joint blocks have increased by 222% from 1998 to 2003. Over- all, the utilization ofvarious nerve blocks (ex- cluding epidurals, disc injections, and fac- et joint blocks) in Medicare recipients from 1998 to 2003 were performed approximately 50% of the time by non-pain physicians. Interventional pain management is growing rapidly, under the watchful eye of the government, and third party payors. Estab- lishing an algorithmic approach and following guidelines may improve compliance and qual- ity of care without implications of abuse.
Computationally efficient mutual information estimation for non-rigid image registration

The accuracy and computational complexity of mutual information (MI) estimation are critical factors in multi-modality non-rigid image registration. This paper discusses the accuracy and complexity of MI estimation approaches based on non-rigid registration functions. General formulations have been derived for Shannon's and Renyi's definitions of MI, as well as Cauchy- Schwartz quadratic MI. The results obtained indicate that a fuzzy histogram binning estimation approach is significantly faster and more accurate than the conventional non-parametric Parzen window estimation approach. The analytical formulations obtained for various MI definitions are continuously differentiable and are shown to be computationally efficient for high-dimensional optimization problems particularly for non-rigid image registration.
High-rate, short length, (3,3s)-regular LDPC of girth 6 and 8

This paper presents a simple construction of a class of LDPC codes generalizing [BHS01] and gives necessary and sufficient, easy to implement, conditions for avoiding 2m cycles, m/spl ges/2. The parity check matrix is formed by square blocks, with each block a sum of three permutation matrices, chosen such that the block is (3,3) regular. The resulting codes have rate (s-1)/s.
Investigating the readability of state-based formal requirements specification languages

The readability of formal requirements specification languages is hypothesized as a limiting factor in the acceptance of formal methods by the industrial community. An empirical study was conducted to determine how various factors of state-based requirements specification language design affect readability using aerospace applications. Six factors were tested in all, including the representation of the overall state machine structure, the expression of triggering conditions, the use of macros, the use of internal broadcast events, the use of hierarchies, and transition perspective (going-to or coming-from). Subjects included computer scientists as well as aerospace engineers in an effort to determine whether background affects notational preferences. Because so little previous experimentation on this topic exists on which to build hypotheses, the study was designed as a preliminary exploration of what factors are most important with respect to readability. It can serve as a starting point for more thorough and carefully controlled experimentation in specification language readability.
Corruption and Municipal Finance

I examine the effect that state-level public corruption has on municipal financing activities in the United States. Corruption has a strong adverse impact on total bond issuance costs and state debt ratings, but not on individual bonds' ratings. This is because corrupt states are more likely to use institutional means to partially mitigate the negative effects of corruption. Strikingly, the impact that corruption has on issuance costs vanishes for credit-enhanced bonds and for locally underwritten bonds, but not for bonds underwritten by high reputation investment banks. These results are useful for understanding the costs of corruption and how institutions can attenuate corruption's negative effects.
5.8-GHz circularly polarized dual-diode rectenna and rectenna array for microwave power transmission

This paper reports a new circularly polarized rectenna whose rectifying circuit includes two diodes. The rectenna consists of a coplanar stripline (CPS) truncated patch antenna and CPS bandpass filter, which can block harmonic signals up to the third order reradiating from the rectifying circuit. The rectenna is printed on Rogers Duroid 5880 substrate with /spl epsiv//sub r/=2.2 and a thickness of 20 mil. The new dual-diode rectenna can provide at least twice the dc output voltage than the traditional rectenna with only a single diode, which has the same layout dimension as the single-diode rectenna. The dual-diode rectenna achieves an RF-to-dc conversion efficiency of 76% at 5.8 GHz. The proposed rectennas can be interconnected to form the rectenna arrays by series, parallel, and cascaded connections. It is found that a cascade connected rectenna array can provide the highest output voltage. The antenna element can be easily extended to become a traveling-wave antenna or array suitable for high output voltage or current in wireless power transmission applications.
Smart Interface Materials Integrated with Microfluidics for On-Demand Local Capture and Release of Cells

In nature, cells adhere and detach selectively in circulation with sophisticated signaling mechanisms.[1–4] Selective capture of cells and biological materials using microfluidics has been a rapidly growing field with multiple applications in diagnostics (e.g., CD4 cell count for HIV monitoring,[5–9] capture of circulating tumor cells,[10] pathogen detection,[11–13] isolation of neutrophils from blood,[14] isolation of mixed leucocytes,[15] and separation of T-lymphocytes[16]) and regenerative medicine for stem cell isolation.[17,18] Microfluidic devices offer advantages such as handling small samples volumes, low consumption of expensive reagents, and shorter assay times, enabling portable automated devices.[7,9,17] Although capturing cells in micro-channels has been studied, spatial control of capture and on-demand release of cells in microfluidic channels remains as an unaddressed challenge.
A Cell's Perspective of its Culture Surface

Atomic Force Microscopy (AFM) was employed to probe the internal structure of living HepG2/C3A cells grown on various commercially-available substrates. In order to understand the driving mechanisms behind the different cell morphologies, the surface properties of these substrates was characterized with AFM and related techniques. The roughness of a 10μm×10μm region of a series of substrates was determined and found to be independent of both coating and culture media, with the exception of thick hydrogel-like coatings. Probing with functionalized tips could not distinguish relative degrees of hydrophobicity under cell culture media, presumably because Debye shielding masks the substrate surfaces. Force spectroscopy was performed on the surfaces to determine exposed surface proteins/polymers intrinsic to the substrate and adsorbed from culture media. Preliminary investigation of cell-mediated substrate reconstruction suggests that the cells secrete large (1000kDa) polymeric molecules at the substrate interface.
Managing Contention with Medley

As WLANs achieve gigabit per second speeds, they will need to support users with a wide range of workloads, ranging from VoIP and Web clients to data backup, file transfers, and streaming high-definition video. Unfortunately, channel efficiency degrades severely in these scenarios under existing MAC protocols due to contention and back-off overheads. Moreover, small yet latency-sensitive flows suffer disproportionally as load increases. We present Medley, a system that leverages frequency-based contention to allocate subchannels in an OFDMA-based link layer in a delay-fair manner. In contrast to traditional CSMA schemes in which each node competes uniformly for the channel, Medley ensures that nodes with smaller service rates are served before those with heavier demand; the more bandwidth a node consumes, the larger its packet average delay will become. An initial implementation of Medley on a software defined radio platform demonstrates its feasibility in a small network, while more comprehensive simulation results show its benefits under a wider range of conditions. Medley delivers delay fairness while remaining over $94$ percent efficient in the face of massive over-subscription.
Factors Associated With Cervical Spine Injury in Children After Blunt Trauma

Study objective Cervical spine injuries in children are rare. However, immobilization and imaging for potential cervical spine injury after trauma are common and are associated with adverse effects. Risk factors for cervical spine injury have been developed to safely limit immobilization and radiography in adults, but not in children. The purpose of our study is to identify risk factors associated with cervical spine injury in children after blunt trauma. Methods We conducted a case-control study of children younger than 16 years, presenting after blunt trauma, and who received cervical spine radiographs at 17 hospitals in the Pediatric Emergency Care Applied Research Network (PECARN) between January 2000 and December 2004. Cases were children with cervical spine injury. We created 3 control groups of children free of cervical spine injury: (1) random controls, (2) age and mechanism of injury-matched controls, and (3) for cases receiving out-of-hospital emergency medical services (EMS), age-matched controls who also received EMS care. We abstracted data from 3 sources: PECARN hospital, referring hospital, and out-of-hospital patient records. We performed multiple logistic regression analyses to identify predictors of cervical spine injury and calculated the model's sensitivity and specificity. Results We reviewed 540 records of children with cervical spine injury and 1,060, 1,012, and 702 random, mechanism of injury, and EMS controls, respectively. In the analysis using random controls, we identified 8 factors associated with cervical spine injury: altered mental status, focal neurologic findings, neck pain, torticollis, substantial torso injury, conditions predisposing to cervical spine injury, diving, and high-risk motor vehicle crash. Having 1 or more factors was 98% (95% confidence interval 96% to 99%) sensitive and 26% (95% confidence interval 23% to 29%) specific for cervical spine injury. We identified similar risk factors in the other analyses. Conclusion We identified an 8-variable model for cervical spine injury in children after blunt trauma that warrants prospective refinement and validation.
Eye Symbolism in Flannery O’Connor's REVELATION

Flannery O’Connor's “Revelation” includes concrete details invested with symbolic meaning that move the story forward. An examination of eyes as symbols reveals the gradual unfolding that leads Rub...
Measurement of body composition in burned children: is there a gold standard?

Background: Maintaining lean body mass (LBM) after a severe burn is an essential goal of modern burn treatment. An accurate determination of LBM is necessary for short- and long-term therapeutic decisions. The aim of this study was to compare 2 measurement methods for body composition, whole-body potassium counting (K count) and dual x-ray absorptiometry (DEXA), in a large prospective clinical trial in severely burned pediatric patients. Methods: Two-hundred seventy-nine patients admitted with burns covering 40% of total body surface area (TBSA) were enrolled in the study. Patients enrolled were controls or received long-term treatment with recombinant human growth hormone (rhGH). Near-simultaneous measurements of LBM with DEXA and fat-free mass (FFM) with K count were performed at hospital discharge and at 6, 9, 12, 18, and 24 months post injury. Results were correlated using Pearson's regression analysis. Agreement between the 2 methods was analyzed with the Bland-Altman method. Results: Age, gender dis...
Constrained stochastic control with probabilistic criteria and search optimization

The dynamic programming approach is applied to both fully and partially observed constrained Markov process control problems with both probabilistic and total cost criteria that are motivated by the optimal search problem. For the fully observed case, point-wise convergence of the optimal cost function for the finite horizon problem to that of the infinite horizon problem is shown. For the partially observed case, a constrained finite horizon problem with both probabilistic and expected total cost criteria is formulated that is demonstrated to be applicable to the radar search problem. This formulation allows the explicit inclusion of certain probability of detection and probability of false alarm criteria, and consequently it allows integration of control and detection objectives. This is illustrated by formulating an optimal truncated sequential detection problem involving minimization of resources required to achieve specified levels of probability of detection and probability of false alarm. A simple example of optimal truncated sequential detection that represents the optimization of a radar detection process is given.
Architectural Mechanisms for Explicit Communication in Shared Memory Multiprocessors

The goal of this work is to explore architectural mechanisms for supporting explicit communication in cache-coherent shared memory multiprocessors. The motivation stems from the observation that applications display wide diversity in terms of sharing characteristics and hence impose different communication requirements on the system. Explicit communication mechanisms would allow tailoring the coherence management under software control to match these differing needs and strive to provide a close approximation to a zero overhead machine from the application perspective. Toward achieving these goals, we first analyze the characteristics of sharing observed in certain specific applications. We then use these characteristics to synthesize explicit communication primitives. The proposed primitives allow selectively updating a set of processors, or requesting a stream of data ahead of its intended use. These primitives are essentially generalizations of prefetch and poststore, with the ability to specify the sharer set for poststore either statically or dynamically. The proposed primitives are to be used in conjunction with an underlying invalidation based protocol. Used in this manner, the resulting memory system can dynamically adapt itself to performing either invalidations or updates to match the communication needs. Through application driven performance study we show the utility of these mechanisms in being able to reduce and tolerate communication latencies.
Hospital Inpatient Costs for Adults with Multiple Chronic Conditions

This article offers national estimates of the proportions of hospital inpatient cases and cost for adult, nonmaternal patients who have multiple chronic conditions. The authors employ a refined classification of chronic versus acute conditions, collapsed to no more than one condition per distinct category of condition. The number of different chronic conditions provides a simple measure of complexity, differing from measures of severity of illness that pertain to a particular episode of treatment. A multivariate regression finds that the number of chronic conditions is an independent influence on hospital cost per case, controlling for other key determinants. Patients with complex illness (e.g., 3+ or 5+ chronic conditions) have a disproportionately large effect on hospital cost per year. The identification of patients in the hospital with complex illness can help in targeting new covered services in a health plan or in risk adjusting health plan premiums. Current policies and demonstrations for the Medicare program may not be sufficient to address complex illness.
Shifting Boundaries on the Professional Knowledge Landscape: When Teacher Communications Become Less Safe.

AbstractResearched in the narrative-inquiry tradition, this article continues to map the terrain of teachers’ professional knowledge landscapes by distinguishing knowledge communities from other teacher groups. It brings to light a bridging space in which the boundaries of teachers’ landscapes may shift, and their transactions may become less safe, particularly when hotly contested matters reach narrative plateaus that are difficult to surmount. This personal experience study conducted in relationship with African-American teachers, Hope and Lorne, makes these distinctions known amid the unexamined narrative freight that pervaded their school contexts and against the backdrop of the historical African-American neighborhood within which their campuses were located.
Motion Estimation in Gated Cardiac Emission Tomography by Optical Flow Techniques

The purpose of this work was to develop and test a new motion estimation algorithm for gated cardiac emission tomography that is designed to be more accurate than conventional methods particularly for relatively large frame-to-frame displacements. The proposed method consists of a sequential application of the conventional Horn-Schunck algorithm to quadratic approximations of the standard, non-rigid frame registration model (with a quadratic smoothing term). The method was tested on frames reconstructed from noisy and noise-free data generated from the 4D cardiac phantom. Our simulations indicated that the method improved motion estimation accuracy relative to the Horn-Schunck method, with increased improvement at lower noise levels.
Chain dynamics in entangled polymers: Diffusion versus rheology and their comparison

This review article scrutinizes and reanalyzes the extensively available literature data on the tracer and self chain diffusion coefficients Dtr and Ds along with the corresponding zero-shear viscosity η0 to show that Ds ∝ M−ν starts with ν > 2.0 and converges to the asymptotic scaling exhibited by Dtr ∝ M−2.0 as the molecular weight M increases beyond M/Me = 10–20, in contrast to the onset of the asymptotic scaling M3 for η0 taking place typically for M/Me ≫ 10–20. A coherent analysis of these observations leads to the suggestion that the observed crossover in Ds is due to the constraint release effect, which diminishes around M/Me = 10–20 and is negligible in measurements of Dtr when the matrix molecular weight P is much greater than M. The contour length fluctuation (CLF) effect, which is believed to cause the molecular weight scaling of η0 to deviate significantly from its limiting behavior of M3, has little direct influence on the chain diffusion. The absence of the CLF effect on Ds leads to a much stronger than linear dependence of the product η0Ds on M, which has been observed previously. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 1589–1604, 2003
Knowledge Structure Measures of Reader's Situation Models across Languages: Translation Engenders Richer Structure.

In order to further validate and extend the application of recent knowledge structure (KS) measures to second language settings, this investigation explores how second language (L2, English) situation models are influenced by first language (L1, Korean) translation tasks. Fifty Korean low proficient English language learners were asked to read an L2 story and then complete L2 concept map and summary writing tasks, with or without an intervening L1 production tasks (Translated versus Directed conditions). Posttest comprehension was measured using the TOEFL multiple-choice items associated with the story (both in L2). KS elicited as concept maps and as text summaries were used to represent the situation models before, during, and after writing. For analysis, all of the participants’ maps and writing artifacts were converted into Pathfinder Networks (PFNets) that were analyzed using two distinctly different approaches, correlation of the raw proximity data and also degree centrality of the PFNets, in order to analyze the PFNets statistically and to visually describe KS cognitive state changes over time. The correlation results showed that the Translated Writing participants’ L2 KS relative to the Directed Writing condition are more similar to that of an expert and are significantly correlated with comprehension posttest scores. Including L1 tasks substantially improved the qualities of the L2 KS artifacts and underlying mental structures related to reading comprehension. In addition, the average centrality results showed that the KS ‘form’ of the participants’ PFNets who translated were relational network structures relative to the Directed Writing group’s (English only) PFNets that had a more linear structure that matched the text surface structure, suggesting a fundamental way that L1 and L2 cognitive processing differs.
The controversy in clinical results among men and women after coronary bypass operation.

In 1974, disturbed by slightly higher operative mortality in women than in men after coronary artery bypass graft (CABG) operation, we set out to review our experience with this subject. The overall results of operative mortality, infarction rate, number of grafts, graft patency, and postoperative
Uniform Stabilization of a Thin Cylindrical Shell with Rotational Inertia Terms

We consider a well-known model of a thin cylindrical shell with rotational inertia terms. We introduce suitable dissipative feedback controls on the boundary in the form of forces, shears, and moments and show that the resulting closed loop feedback problem generates a s.c. semigroup of contractions in the energy space and that the corresponding energy of the system decays exponentially in the uniform topology. Consequently, we obtain the exact controllability of the cylinder by explicit boundary controls.
Application of Alternative ODE in Finance and Economics Research

This chapter introduces ordinary differential equation (ODE) and its applications in finance and economics research. There are various approaches to solve an ordinary differential equation. Among them, the most commonly used approaches are the classical approach for a linear ODE and the Laplace transform approach. We demonstrate the applications of ODE in both deterministic and stochastic systems. As an application in deterministic systems, we apply ODE to solve a simple gross domestic product (GDP) model and an investment model of a firm, which is well studied in Gould (The Review of Economic Studies 1, 47–55, 1968). As an application in stochastic systems, we employ ODE in a jump-diffusion model and derive the expected discounted penalty given the asset value follows a phase-type jump diffusion process. In particular, we study capital structure management model and derive the optimal default-triggering level. For related results, please see Chen et al. (Finance and Stochastics 11, 323–355, 2007).
Mineral and Bone Disorders in Chronic Kidney Disease

A 64-year-old woman with a history of chronic kidney disease (CKD) Stage 4 [estimated glomerular filtration rate (eGFR) of 17 cc/min/1.73 mm2] is referred for evaluation of “poor kidney function.” Over the last month she has complained of itching, skin eruptions on her arms and back, and nonspecific bone pain. She has been unable to sleep at night and denies changes in soap, laundry detergent, or perfume. She has never been prescribed a phosphate binder or vitamin D, has no dietary restrictions, and dines out a few times per week. She usually consumes bacon and eggs for breakfast, a sandwich with cheese and cold cuts for lunch, and beans and chicken or fish for dinner. She has never been to see a nutritionist but feels her dietary intake is adequate. Physical exam is remarkable for diffuse areas of excoriation on her arms and back with raised hard central pustules. Pertinent laboratory values: phosphorous—7.5 mg/dL, calcium—7.9 g/dL, albumin—4 g/dL, creatinine—3.5 mg/dL, urea—50 mg/dL, alkaline phosphatase—180 mg/dL, bicarbonate—20 mEq/L. Intact PTH and vitamin D 25 are pending at the end of her visit.