cssi/SciSciGPT-SciSciNet huggingface dataset:
Moving-body simulations using overset framework with rigid body dynamics

The simulation of flow past bodies in relative motion is a challenging task due to the presence of complex flow features, moving grids, and rigid body movements under the action of external forces and moments. A generalized grid-based overset framework is presented for the simulation of this class of problems. The equations that govern the fluid flows are cast in an integral form and are solved using a cell-centered finite volume upwind scheme. The rigid body dynamics equations are formulated using quaternion and are solved using fourth-order Runge-Kutta (RK) time integration. The overset framework and the six degree of freedom (6-DOF) rigid body dynamics simulators are developed in a library form for easy incorporation into existing flow solvers. The details of the flow solver, the 6-DOF library, and the overset framework are presented in this paper along with the validation results of the developed system.
Cost analysis of the US spent nuclear fuel reprocessing facility

Abstract The US Department of Energy is actively seeking ways in which to delay or obviate the need for additional nuclear waste repositories beyond Yucca Mountain. All of the realistic approaches require the reprocessing of spent nuclear fuel. However, the US currently lacks the infrastructure to do this and the costs of building and operating the required facilities are poorly established. Recent studies have also suggested that there is a financial advantage to delaying the deployment of such facilities. We consider a system of government owned reprocessing plants, each with a 40 year service life, that would reprocess spent nuclear fuel generated between 2010 and 2100. Using published data for the component costs, and a social discount rate appropriate for intergenerational analyses, we establish the unit cost for reprocessing and show that it increases slightly if deployment of infrastructure is delayed by a decade. The analysis indicates that achieving higher spent fuel discharge burnup is the most important pathway to reducing the overall cost of reprocessing. The analysis also suggests that a nuclear power production fee would be a way for the US government to recover the costs in a manner that is relatively insensitive to discount and nuclear power growth rates.
A model for crystallization of monomolecular layers on contracting surfaces

Abstract A model for early crystallization of monomolecular layers on contracting surfaces is presented which indicates that crystallization may occur at temperatures above the actual crystallization temperatures and in fact irrespective of thermal excitational or vibrational effects of molecules in a monolayer. The mechanism involved in this early crystallization is shown to be mainly due to two-dimensional molecular compaction and rearrangement due to isotropic surface contraction which causes the configurational entropy to play a dominant role in such phase transitions from a liquid to a crystalline state. The critical two-dimensional packing fraction at which such crystallization may occur is shown to be about 0.846.
Hydration of protonated primary amines: effects of intermolecular and intramolecular hydrogen bonds

Abstract Addition of individual water molecules to a number of protonated primary amines, RNH 3 + , was studied experimentally by measuring hydration equilibria in a mass spectrometer equipped with an ion mobility cell and theoretically using molecular mechanics and density functional theory calculations. Water binding sites and energies in RNH 3 + ·(H 2 O) n were examined as a function of n and as a function of the nature of the R-group. R-groups ranged from simple alkyls to amide containing groups potentially able to form hydrogen bonds to the ammonium group. Effects of interest such as location and number of amide CO groups in R and the effect of size of R were investigated on carefully chosen molecules including alkylamines and lysine based systems, such as CH 3 (CH 2 ) x NH 2 ( x = 0 and 9); acetylated lysine; and lysine containing peptides Ac–AAKAA and Ac–A x K (Ac = acetyl, A = alanine, K = lysine; x = 4, 6, 8). For ammonium groups without intramolecular hydrogen bonds it was found that three water molecules form hydrogen bonds to the three hydrogen atoms of the ammonium group filling the first solvation shell. The fourth and fifth water molecules add to water of the first solvation shell (alkylamines) or at a charge-remote site (peptides). Water binding energies in CH 3 NH 3 + ·(H 2 O) n steadily decrease with increasing n (17, 14, 12, and 10 kcal/mol for n = 1, 2, 3, and 4, respectively) due to increasing charge delocalization over the bound n − 1 water molecules, thereby obscuring the start of a new solvation shell at n = 4. A simple electrostatic model, based on natural bond analysis (NBO) derived atomic charges, reproduces this effect quantitatively. Hydration of systems RNH 3 + ·(H 2 O) n with m = 1, 2, or 3 intramolecular hydrogen bonds is analogous to comparable systems R′NH 3 + ·(H 2 O) n + m with no intramolecular hydrogen bonds. For instance, theory indicates that lysine, when N -acetylated on either one of the two amines, exhibits one strong intramolecular hydrogen bond. In these systems the RNH 3 + ·(H 2 O) n ⋯H 2 O binding energies are comparable to those of alkylNH 3 + ·(H 2 O) n +1 ⋯H 2 O and NBO calculations confirm that intramolecular hydrogen bonds remove a similar amount of charge from the ammonium group as intermolecular hydrogen bonds. The pentapeptide (Ac–AAKAA)H + was found to be a system with two intramolecular hydrogen bonds; the polypeptides (Ac–A x K)H + ( x = 4, 6, and 8) are systems with a fully self-solvated ammonium group. The binding energy of either charge-remote water or of water in a second solvation shell is ≤10 kcal/mol. Larger values occur for smaller systems, e.g., for CH 3 NH 3 + ·(H 2 O) 3 + H 2 O Δ H ° = −10 kcal/mol, and smaller values occur for larger systems, e.g., for (Ac–A 8 K)H + + H 2 O Δ H ° = −5 kcal/mol. A strong energy–entropy correlation of Δ S ° n /Δ H ° n =0.0018 K −1 was experimentally found to hold for all hydration processes studied here.
The dynamic interplay between Western medicine and the complementary and alternative medicine movement: how activists perceive a range of responses from physicians and hospitals

Scholars must examine the dynamic relationship between activists and organisational actors, because all social movements interact in some way with the institutions they seek to change, and because activists engage in ongoing attempts to shape these interactions. Using data from the complementary and alternative medicine (CAM) movement in California and hospitals in New York and Massachusetts, I identify how physicians and hospitals respond to the CAM movement, and how activists perceive each response. Using social movement and institutional theories, this study illustrates that social movements can penetrate and reshape formal organisations, because established organisations have permeable boundaries. Organisational responses to activism can take the form of avoidance, compromise, acquiescence, manipulation or defiance. Activists vary in their response to these outcomes, because activists are not unanimous in their goals. These outcomes result from continual negotiation between CAM activists and organisational actors, and within each group. Thus, the outcomes are constantly evolving.
Superiority of selected treadmill exercise protocols predischarge and six weeks postinfarction for detecting ischemic abnormalities

We evaluated 29 uncomplicated post-myocardial infarction patients with heart rate-limited and symptom-limited modified Naughton treadmill exercise tests predischarge and 31 similar patients with symptom-limited modified Naughton and standard Bruce stress tests at 6 weeks following infarction to determine their comparative value for detecting unsuspected ischemic abnormalities. Predischarge, the symptom-limited modified Naughton test identified a significantly greater number of patients with ECG ST segment depression or angina than did the heart rate-limited test (21 vs 13 patients, p less than 0.05). This resulted from a significantly longer average maximal exercise duration (10.5 +/- 4.9 vs 7.9 +/- 4.2 minutes, P less than 0.001) and higher maximal rate-pressure product (21.9 +/- 5.8 vs 19.2 +/- 4.6 X 10(3), p less than 0.001) during the symptom-limited test. At 6 weeks following infarction, the standard Bruce stress test identified a significantly higher frequency of ischemic abnormalities than did the symptom-limited modified Naughton test (20 vs 13 patients, p less than 0.05). This resulted from a higher average maximal rate-pressure product (23.1 +/- 7.3 vs 21.0 +/- 6.2 X 10(3), p less than 0.02), despite a shorter maximal exercise duration (6.9 +/- 1.2 vs 10.7 +/- 4.4 minutes, p less than 0.001) during the Bruce stress test. We conclude that: (1) symptom-limited exercise is superior to heart rate-limited exercise predischarge and (2) the standard Bruce stress test is superior to the symptom-limited modified Naughton exercise test at 6 weeks following infarction for the detection of unsuspected ischemic abnormalities in uncomplicated postinfarction patients.
Integrated Structural Health Monitoring With Guided Waves From Piezoelectric Fibers

Active structural health monitoring of plate-like structures can be performed with ultrasonic guided waves. The activation of ultrasonic guided waves from embedded piezoelectric fibers in carbon fiber reinforced polymer (CFRP) laminated plates is investigated. Finite element analysis simulations of wave propagation from an array of embedded parallel piezoelectric fibers are presented. A quasi-isotropic CFRP having piezoelectric fibers embedded at the midplane is studied. The number and spacing of piezoelectric fibers is varied in order to activate different modes at different frequencies. The simulation results (i) characterize the displacement profile through the thickness of the CFRP plate, (ii) enable visualization of mode excitability, and (iii) demonstrate the source influence. The results indicate that the embedded fibers have a strong potential for either hot spot monitoring or distributed monitoring of large areas. However, due to the size, spacing, and activation of embedded fibers the source influence causes the mode excitability to differ from that of a conventional comb transducer.Copyright © 2008 by ASME and US Government
Awareness: Animal reflections

On traditional measures, many animals appear to have a sense of 'body-ness' or 'mine-ness', but no sense of 'I-ness'.
HELICAL PLASMA CONFINEMENT DEVICES WITH GOOD CONFINEMENT PROPERTIES

The criterion of approximate omnigeneity (i.e., having bounce-averaged drift lying within the magnetic surfaces) is much easier to satisfy than quasihelicity, the condition that $B$, the magnitude of the magnetic field, is a function of only a single linear combination of the toroidal angles. Simple criteria for omnigeneity are presented and used to construct exactly omnigenous forms for $B$ that are far from quasihelical. Though this construction gives a nonanalytic function $B$, close to the constructed systems there exist other systems with analytic $B$. These results indicate that finding helical plasma confinement systems with minimal neoclassical transport is much easier than previously believed.
Side-to-side differences in anterior cruciate ligament volume in healthy control subjects

Examination of anterior cruciate ligament (ACL) anatomy is of great interest both in studying injury mechanisms and surgical reconstruction. However, after a typical acute ACL rupture it is not possible to measure the dimensions of the ACL itself due to concomitant or subsequent degeneration of the remaining ligamentous tissue. The contralateral ACL may be an appropriate surrogate for measuring anatomical dimensions, but it remains unknown whether side-to-side differences preclude using the contralateral as a valid surrogate for the ruptured ACL. This study examined whether the ACL volume is significantly different between the left and right knees of uninjured subjects. ACL volumes were calculated for the left and right sides of 28 individuals using a previously validated MRI-based method. The mean ACL volume was not significantly different (p=0.2331) between the two sides in this population. Side-to-side ACL volume was also well correlated (correlation=0.91, p<0.0001). The results of this study show that the volume of the contralateral ACL is a valid surrogate measure for a missing ACL on the injured side. This non-invasive, in vivo technique for measuring ACL volume may prove useful in future large-scale comprehensive studies of potential risk factors for ACL rupture, in quantifying potential loading effects on ACL size as a prophylactic measure against ACL rupture, and in the use of ACL volume as a screening tool for assessing risk of injury.
Meso-Analysis of a Coastal Snowstorm in New England

Abstract Heavy snow fell on 18 December 1971 in parts of coastal New England, but not in Boston proper, as intense synoptic-scale cyclogenesis occurred over the Gulf Stream to the southeast. Mesoscale analysis of surface data shows that part of the snowfall was attributable to shallow instability in onshore flow, but that a substantial portion was associated with a small and short-lived cyclone which formed at the mouth of Boston Harbor. This analysis, together with consideration of the few pertinent upper-level soundings, indicates a similarity between this cyclone and the “polar low” which produces heavy snow in the United Kingdom. The mechanism of this cyclone appears to be qualitatively similar to that of synoptic-scale baroclinic cyclones. Its small size is attributed to the low hydrostatic stability produced by heat flux from the relatively warm water of Massachusetts Bay and to the restricted vertical depth of the associated atmospheric baroclinic zone. There is a remote possibility that a signific...
A meta-analysis of the utility of C-reactive protein, erythrocyte sedimentation rate, fecal calprotectin, and fecal lactoferrin to exclude inflammatory bowel disease in adults with IBS.

A Meta-Analysis of the Utility of C-Reactive Protein, Erythrocyte Sedimentation Rate, Fecal Calprotectin, and Fecal Lactoferrin to Exclude Inflammatory Bowel Disease in Adults With IBS
Calcium content of mitochondria and endoplasmic reticulum in liver frozen rapidly in vivo

The recognition that the endoplasmic reticulum (ER), rather than the mitochondria, is the main organelle regulating the cytoplasmic Ca2+ concentration in non-muscle cells1,2 supports the notion that an alternative physiological role of mitochondrial Ca transport3–5 is the modulation of Ca-sensitive mitochondrial enzymes through small (micromolar) fluctuations in the concentration of mitochondrial matrix Ca2+ (refs 1,5–7). The latter mechanism could operate only if the mitochondrial Ca concentration were low, as it is in muscle and retinal rods8,9, below the levels saturating the regulated enzymes5. In contrast, if the ER serves as an intracellular Ca store, its Ca content would be expected to be high. In view of the major metabolic function of the liver, the question of whether hepatic mitochondrial matrix Ca2+ regulates metabolism is particularly important, but the range of Ca concentrations reported for isolated liver mitochondria is too wide10–12 to provide a conclusive answer. Therefore, we have used electron probe X-ray microanalysis (EPMA) to measure the subcellular distribution of Ca in liver snap-frozen in vivo, and report here that the endoplasmic reticulum is a major intracellular store of Ca, while the concentration of Ca in mitochondria is low and compatible with the regulation of mitochondrial enzymes.
Evaluation of Serum Prostate-Specific Antigen Levels After Postoperative Radiation Therapy for Pathologic Stage T3, N0 Prostate Cancer

Objective To analyze freedom from progression of serum prostate-specific antigen (PSA) levels in patients who have received radiation therapy after radical prostatectomy for pathologic stage T3, N0 prostate cancer. Design We assessed the freedom from PSA progression after postoperative radiation therapy and its relationship to several potential prognostic factors during a median follow-up of 43 months. Material and Methods Thirty Mayo patients received postoperative radiation therapy for pathologic stage T3, N0 prostate cancer between January 1988 and April 1993. Radiation therapy was initiated within 6 months after prostatectomy Radiation doses ranged from 60 to 67 Gy. Results "Freedom from PSA failure" was defined as the actuarial risk of maintaining a serum PSA level at 0.3 ng/mL or less. The freedom from failure rate was 66% at 3 and 4 years. Prognostic factors significantly associated with an improved freedom from failure were a preradiation PSA level of 1.0 ng/mL or less and no seminal vesicle involvement. A trend toward an improved freedom from failure was noted in patients with low-grade (1 and 2) tumors in comparison with high-grade (3 and 4) tumors. Treatment-related morbidity was minimal. Conclusion Radiation therapy after radical prostatectomy for pathologic stage T3, N0 prostate cancer seems to provide an improved freedom from PSA failure in comparison with that noted in other series of similar patients treated with radical prostatectomy only.
Role of Chest Physicians in Detection and Treatment of Occupational and Environmental Respiratory Disease: A Practice Survey

A survey of American College of Chest Physicians (ACCP) members was conducted to determine their degree of involvement in the diagnosis and prevention of occupational and environmental respiratory disease (OERD). Although the response rate was relatively low, the results are likely to be representative. Calculations based on the data estimate that in the prior year, chest physicians on the average saw 15 patients with OERD caused by work, 13 worsened by work, and 28 affected by the home environment. Asthma appears to be a more common occupational or environmental concern than pulmonary fibrosis. Chest physicians clearly perceived a need for more education in OERD. The survey also demonstrated that although many chest physicians perform routine industrial surveillance testing, it is often done without using standardized methods. Furthermore, chest physicians are actively involved with medical/legal aspects of OERD. Overall, the survey documents the role of chest physicians in the area of OERD and emphasizes significant educational needs.
The insulin-mediated vascular and blood pressure responses are suppressed in CGRP-deficient normal and diabetic rats.

Background Calcitonin gene-related peptide (CGRP) is extensively localized in the perivascular or periadventitia nerves throughout the body. CGRP is a potent vasodilator and its release is associated with dilation of these blood vessels. The present study investigated the contribution of the CGRP-mediated vasodilation to the insulin-induced vasodilatory response. Methods Male Wistar rats were treated with capsaicin (50 mg/kg) at 1–3 days of age to ablate the CGRP-containing neurons. After 8 weeks some animals were made diabetic using streptozotocin. Vehicle-treated animals were used as controls. At 12–13 weeks the animals were fasted, anesthetized with chloralose/urethane and instrumented for recording of cardiovascular dynamics. Results Body weights and basal, insulin, glucose, mean arterial pressure (MAP), heart rate (HR), and vascular flows were not different in CGRP-deficient rats versus controls. Insulin infusion significantly decreased the MAP in vehicle-treated controls but this response was completely attenuated in CGRP-deficient rats. The decreased response to insulin was associated with a diminished vascular dilatatory response in the iliac, renal, and superior mesenteric vessel beds. When insulin was infused in CGRP-deficient diabetic animals there was also a diminished response. Diabetes resulted in an increased renal vascular flow in response to insulin. Conclusions From the present studies we conclude that the insulin-mediated vasodilation was due, in part, to the stimulation of perivascular nerves to release CGRP, and the action of CGRP on vascular smooth muscle enhanced directly or indirectly the vasodilatory response to insulin. Copyright © 2002 John Wiley & Sons, Ltd.
Inhalation transfer factors for air pollution health risk assessment.

To facilitate routine health risk assessments, we develop the concept of an inhalation transfer factor (ITF). The ITF is defined as the pollutant mass inhaled by an exposed individual per unit poll...
Vascular endothelial growth factor administration in chronic myocardial ischemia

Vascular endothelial growth factor (VEGF) is a potent mitogen capable of stimulating angiogenesis. We examined the effect of VEGF administration in a model of chronic porcine myocardial ischemia. N...
Viscoelastic and shrinkage behavior of ultrathin polymeric films

Viscoelastic and shrinkage characteristics of five ultrathin polymeric films are presented. These films include poly(ethylene terephthalate) or PET, poly(ethylene naphthalate) or PEN, an aromatic polyamide (ARAMID), a polyimide (PI), and poly(benzoxazole) or PBO. PET film is currently the standard substrate used for magnetic tapes, and the other four films represent alternative substrates with improved material properties. Thicknesses of the films range from 14.4 μm for PET to 4.4 μm for ARAMID. A creep apparatus is used to measure the viscoelastic and shrinkage characteristics of the films. The largest amount of creep compliance was measured for PET followed by PI, PEN, ARAMID, and PBO. Creep velocity was highest for PET and PI, followed by ARAMID, PEN, and PI. Shrinkage measurements at 50°C for 100 h show that PEN shrinks more than all the other substrates. Time–temperature superposition is used to predict long-term creep behavior, and relationships between polymeric structure and viscoelastic behavior are also discussed. Based on their relative cost and creep behavior, PEN and ARAMID substrates appear to be suitable alternatives to PET. © 1995 John Wiley & Sons, Inc.
RepStore: a self-managing and self-tuning storage backend with smart bricks

With the continuously improving price-performance ratio, building large, smart-brick based distributed storage system becomes increasingly attractive. The challenges, however, include not only reliability, adequate cost-performance ratio, online upgrades and so on, but also the system's ability to achieve these goals in as self-managing and self-adaptive a manner as possible. In this paper, we describe RepStore, a system that fulfills these goals. RepStore unites the self-organizing capability of P2P DHT and the completely autonomous, per-brick tuning mechanism to derive a scalable and cost-effective architecture. RepStore employs replication for active write-intensive data and erasure-coding for the rest, strives to achieve the best cost-performance balance automatically and transparent to application, and does so in a completely distributed manner. Our preliminary evaluations reveal that the system performs much as expected, achieving performance and reliability closer to a 3-way fully replicated system with only 60% of the cost.
Phenotypic analysis of an MgtE magnesium transporter mutation in Bacillus subtilis

Abstract. Magnesium (Mg2+) is the most abundant divalent cation in living cells and plays structural and biochemical roles in many cell processes. Although the importance of Mg2+ as a cellular nutrient has been well established, the process by which organisms obtain Mg2+ from their environment is still unclear. The Gram-positive bacterium Bacillus subtilis is used as a model system to understand Mg2+ uptake and utilization in bacteria. The B. subtilis genome codes for a homolog of the MgtE family of Mg2+ transporters. The protein is 34% identical to the structurally well-characterized MgtE homolog in Thermus thermophilus. This study was designed to characterize phenotypes of a B. subtilis mutant deleted for the mgtE gene. Compared to wild type, the ΔmgtE strain exhibits a Mg2+-dependent growth defect, consistent with a role of MgtE in Mg2+ transport. Additionally, mutant cells are more resistant to manganese, show a decrease in sporulation efficiency, and are more sensitive to hydrogen peroxide than wild ...
Is HIF-1α a Valid Therapeutic Target?

Hypoxia, a reduction in the normal level of tissue oxygen tension, occurs during several pathophysiological processes including tumorigenesis. It may occur during the initial avascular phase or develop in established tumors as a result of new blood vessel formation which is ineffective and provides poor blood flow. Although hypoxia generates a situation unfavorable for cell growth, cancer cells may undergo a series of genetic and metabolic changes that allow them to survive and even proliferate. Tumor hypoxia plays a major role in the induction of the “angiogenic switch” during tumor development. Targeting the critical steps in tumor angiogenesis, including hypoxia-induced pathways, has become a focus for many basic research scientists and clinical investigators. Hypoxia is associated with poor treatment outcome regardless of the modality, suggesting that it should be considered in the development of optimum treatment strategies. One mechanism through which tumor cells respond to reduced oxygen levels is via activation of hypoxia-inducible transcription factors (HIF) (1). HIF-1 is a heterodimer consisting of the hypoxic response factor HIF-1 and the constitutively expressed receptor nuclear activator ARNT or HIF-1 (2) .I n the presence of oxygen, HIF-1 is bound to the tumor suppressor von Hippel–Lindau (VHL) protein that determines the ubiquitination and consequent proteosomal degradation of the transcription factor (3). In the absence of oxygen, HIF-1 degradation is impaired with consequent binding to hypoxia-response genes, such as the proangiogenic vascular endothelial growth factor (VEGF) (4). To date, three members of the HIF family have been cloned: HIF-1 HIF-2 and HIF-3. Whether these components are redundant with overlapping functions or whether they have distinct biological properties remains to be revealed. Of the HIF subunits, the function of HIF-1 has been the most extensively characterized. A growing body of evidence suggests that HIF-1 is an important contributor to tumor progression and metastasis. Remaining questions related to the role of HIFs in general, and HIF-1 in particular, is whether they are in all cases a positive regulator of tumor growth (5,6) and whether HIF-1 is the only member of the HIF family capable of promoting
A Notion of Effectiveness in Arbitrary Structures

The well-developed theory of recursion has been applied to certain algebraic structures with countable universes to obtain interesting and natural results on the question of effective procedures in such structures ([2], [9], [10], [13]). It has also been applied to structures related to the real numbers, via approximations; we cite [3] as but one example. We are interested, however, in the problem of what operations in an arbitrary algebraic structure, possibly quite large and unnatural, can reasonably be considered “effective” in terms of the underlying operations and relations of the structure.
Picosecond 14.7 nm interferometry of high intensity laser-produced plasmas

We have developed a compact, 14.7 nm, sub-5 ps X-ray laser source at Lawrence Livermore National Laboratory ~LLNL! together with a Mach-Zehnder type diffraction grating interferometer built at Colorado State University for probing dense, high intensity laser-produced plasmas. The short wavelength and pulse length of the probe reduces refraction, absorption effects within the plasma and minimizes plasma motion blurring. This unique diagnostic capability gives precise two-dimensional ~2D! density profile snapshots and is generating new data for rapidly evolving laser-heated plasmas. A review of the results from dense, mm-scale line focus plasma experiments will be described with detailed comparisons to hydrodynamic simulations.
PROFILE: Hungry Water: Effects of Dams and Gravel Mining on River Channels

/ Rivers transport sediment from eroding uplands to depositional areas near sea level. If the continuity of sediment transport is interrupted by dams or removal of sediment from the channel by gravel mining, the flow may become sediment-starved (hungry water) and prone to erode the channel bed and banks, producing channel incision (downcutting), coarsening of bed material, and loss of spawning gravels for salmon and trout (as smaller gravels are transported without replacement from upstream). Gravel is artificially added to the River Rhine to prevent further incision and to many other rivers in attempts to restore spawning habitat. It is possible to pass incoming sediment through some small reservoirs, thereby maintaining the continuity of sediment transport through the system. Damming and mining have reduced sediment delivery from rivers to many coastal areas, leading to accelerated beach erosion. Sand and gravel are mined for construction aggregate from river channel and floodplains. In-channel mining commonly causes incision, which may propagate up- and downstream of the mine, undermining bridges, inducing channel instability, and lowering alluvial water tables. Floodplain gravel pits have the potential to become wildlife habitat upon reclamation, but may be captured by the active channel and thereby become instream pits. Management of sand and gravel in rivers must be done on a regional basis, restoring the continuity of sediment transport where possible and encouraging alternatives to river-derived aggregate sources.KEY WORDS: Dams; Aquatic habitat; Sediment transport; Erosion; Sedimentation; Gravel mining
Utility of Perirectal Swab Specimens for Diagnosis of Clostridium difficile Infection

For 139 patients tested for Clostridium difficile infection by polymerase chain reaction, the sensitivity, specificity, positive predictive value, and negative predictive value of testing perirectal swabs vs stool specimens were 95.7%, 100%, 100%, and 99.1%, respectively. For selected patients, perirectal swabs provide an accurate toxigenic C. difficile detection strategy.
Constraint scalable vector graphics, accessibility and the semantic Web

Graphics can represent concepts in a way that is easily understood. Metadata can be utilized to enable users to gain information related to the graphic and its content. For the visually impaired, the ability to access the information depicted in graphics would be an important step towards web usability. Constraint scalable vector graphics (CSVG) is an extension to SVG originally developed to provide increased flexibility in describing diagrams. CSVG provides increased capability in the form of semantic zooming, differential scaling and semantic preservation. A research project is proposed to produce a global ontology for CSVG written in Ontology Web Language (OWL). OWL facilitates a greater degree of machine understanding, greater expressivity and greater reasoning capabilities than many other semantic languages. The CSVG ontology will enable graphics to be annotated in varying levels of abstraction, thereby allowing the graphic to be reused in other contexts.
Wireless tissue palpation: Head characterization to improve tumor detection in soft tissue

For surgeons performing open procedures, the sense of touch is a valuable tool to directly access buried structures and organs, to identify their margins, detect tumors, and prevent undesired cuts. Minimally invasive surgical procedures provide great benefits for patients; however, they hinder the surgeon's ability to directly manipulate the tissue. In our previous work, we developed a Wireless Palpation Probe (WPP) to restore tissue palpation in Minimally Invasive Surgery (MIS) by creating a real-time stiffness distribution map of the target tissue. The WPP takes advantage of a field-based magnetic localization algorithm to measure its position, orientation, and tissue indentation depth, in addition to a barometric sensor measuring indentation tissue pressure. However, deformations of both the tissue and the silicone material used to cover the pressure sensors introduce detrimental nonlinearities in sensor measurements. In this work, we calibrated and characterized different diameter WPP heads with a new design allowing exchangeability and disposability of the probe head. Benchtop trials showed that this method can effectively reduce error in sensor pressure measurements up to 5% with respect to the reference sensor. Furthermore, we studied the effect of the head diameter on the device's spatial resolution in detecting tumor simulators embedded into silicone phantoms. Overall, the results showed a tumor detection rate over 90%, independent of the head diameter, when an indentation depth of 5 mm is applied on the tissue simulator.
On optimal cyclotomic lattices and diagonal-single-layer space-time block codes

An optimization of cyclotomic lattices based diagonal/single-layer space-time block codes is discussed. The concrete full diversity cyclotomic generating matrices are used to generalize the lattices and also studies the optimality in the sense that for a fixed diversity product and thus the transmission signal power is minimized.
Single-unit neural recording with active microelectrode arrays

Discusses the single-unit recording characteristics of microelectrode arrays containing on-chip signal processing circuitry. Probes buffered using on-chip unity-gain operational amplifiers provide an output resistance of 200 /spl Omega/ with an input-referred noise of 11-/spl mu/V root-mean-square (rms) (100 Hz-10 kHz). Simultaneous in vivo recordings from single neurons using buffered and unbuffered (passive) iridium recording sites separated by less than 20 /spl mu/m have shown that the use of on-chip circuitry does not significantly degrade system noise. Single-unit neural activity has also been studied using probes containing closed-loop preamplifiers having a voltage gain of 40 dB and a bandwidth of 13 kHz, and several input de-baseline stabilization techniques have been evaluated. Low-noise in vivo recordings with a multiplexed probe have been demonstrated for the first time using an external asymmetrical clock running at 200 kHz. The multiplexed system adds less than 8-/spl mu/V rms of noise to the recorded signals, suppressing the 5-V clock transitions to less than 2 ppm.
Novel bounds on the capacity of binary channels with deletions and substitutions

We present novel bounds on the capacity of binary channels with independent and identically distributed deletions and substitutions. The proposed bounds are obtained by exploiting an auxiliary system where the channel is the same as in the system of interest, but the receiver is provided with (partial) genie-aided information on the deletion/substitution process. In the case of the deletion channel, that is, when no substitutions occur, the proposed upper bound improves the existing ones for most values of the deletion probability, while the proposed lower bound does not. On the other hand, when the channel model also includes substitution errors, both proposed bounds improve the existing ones, significantly narrowing the region to which the actual capacity can belong.
HLA-G DNA sequence variants and risk of perinatal HIV-1 transmission

HLA-G gene is a non-classical MHC class 1 molecule that is highly expressed in the trophoblast at the maternal-fetal interface. In an attempt to elucidate possible immunological mechanisms facilitating protection of infants born to human immunodeficiency virus type (HIV-1) infected mothers, we have been studying genetic variations in the coding and untranslated regions of HLA-G antigen between HIV-1-infected mothers and their infected or uninfected infants. This study investigated whether HLA-G DNA sequence variants are associated with perinatal HIV-1 transmission. Genomic DNA samples were obtained from a nested case-control study of 34 mother-child pairs co-enrolled in a cohort of the Perinatal AIDS Collaborative Transmission Study in New York. The samples were from two groups predominantly of African-American and Hispanic origin: In the first group, both mother and child were HIV-1-infected; in the second group, only the mother was infected while the child remained uninfected. Genotyping of HLA-G gene were performed on the extracted DNA from peripheral blood mononuclear cells using PCR based sequencing and restriction fragment-length polymorphism analyses. Among the studied HLA-G exons, dissimilarities in HLA-G DNA sequence variants between the HIV-1 non-transmitting mother child pairs were mostly observed in exon 8-3'-untranslated region at nucleotide positions T3742A, C3743T, G3777C (P = 0.001). Non-transmitting HIV-1 mother child pairs exhibited dissimilarities at nucleotide position C3743T allele with decreased risk of perinatal HIV-1 transmission, compared with HIV-1 transmitting mother-child pairs carrying this allele (odds ratio 0.02 [95% confidence interval 0.00–0.15] P = 0.00001). In addition, heterozygous dissimilarities at nucleotide positions C634G and 714 insT/G in the 5'-upstream regulatory region were observed between the mother child pairs of the HIV-1-non-transmitting group while homozygous similarities of C634C, and either 714insG/G or mother-child pairs with similar 714insT/G were observed among the transmitting group in the same region. This study identified new variants in the HLA-G gene and provides further evidence that dissimilarities in the HLA-G DNA sequence variants could influence the transmission of HIV-1 from infected mothers to their infants.
Blockade of the Platelet P2Y12 Receptor by AR-C69931MX Sustains Coronary Artery Recanalization and Improves the Myocardial Tissue Perfusion in a Canine Thrombosis Model

Objective— Reperfusion therapy for myocardial infarction is limited by a significant reocclusion rate and less optimal myocardial tissue perfusion due to excessive platelet accumulation and recruitment at the sites of vascular injury. We assessed the influence of a selective P2Y 12 -receptor antagonist (AR-C69931MX), in conjunction with thrombolytic therapy, on the prevention of platelet aggregation and thrombus formation. Methods and Results— A canine coronary electrolytic injury thrombosis model was used. Tissue-type plasminogen activator (t-PA; 1 mg/kg in phase I, 0.5 mg/kg in phase II in the AR-C69931MX group, and 1 mg/kg in the placebo group in phase I and II) was administered 30 minutes after thrombus formation; either saline or AR-C69931MX (4 μg · kg −1 · min −1 ) was given to all animals intravenously 10 minutes before t-PA administration for a total of 2 hours. All animals received heparin (80 U/kg) as an intravenous bolus followed by a continuous infusion of 17 U · kg −1 · h −1 . Myocardial tissue perfusion was evaluated by use of the colored microsphere technique and real-time myocardial contrast echocardiography. The incidences of reocclusion and cyclic flow variation were significantly decreased in the AR-C69931MX group ( P P Conclusions— The adjunctive administration of AR-C69931MX blocked ADP-mediated platelet aggregation and recruitment and prevented platelet-mediated thrombosis, resulting in prolongation of reperfusion time and a decrease in reocclusion and cyclic flow variations. Importantly, myocardial tissue perfusion was significantly improved in the P2Y 12 antagonist group.
The study of leakage current performance improvement in high voltage technology

The PECVD silicon oxy-nitride film has been widely used as antireflective coating (ARC) and contact etch stop layer (CESL) in IC fabrication. It is typically deposited using SiH4&N2O gas mixtures at temperatures around 400°C, with film properties such as reflective index, wet etch rate, stress and uniformity controlled by varying gas flows, RF powers, temperature and pressures. In addition, the ion bombardment plays a predominant role in controlling the film characteristics, which will influence the electrical properties of device and the yield. The article majorly focuses on the correlation between leakage current performance of high voltage device and the film quality of silicon oxy-nitride, which characterizes as CESL. In this work, a model of leakage current, which caused by the property of CESL oxy-nitride film, has been presented. The higher Si-H bond consisted CESL leads the charge behavior between source and drain, which causes leakage current on Vg < Vt. By reducing the mixture ration of SiH4/N2O to decrease Si-H bond content of silicon oxy-nitride film, a significant yield improvement in HV device is obtained.
On the stability of P-matrices

We establish two sufficient conditions for the stability of a P-matrix. First, we show that a P-matrix is positive stable if its skew-symmetric component is sufficiently smaller (in matrix norm) than its symmetric component. This result generalizes the fact that symmetric P-matrices are positive stable, and is analogous to a result by Carlson which shows that sign symmetric P-matrices are positive stable. Second, we show that a P-matrix is positive stable if it is strictly row (column) square diagonally dominant for every order of minors. This result generalizes the fact that strictly row diagonally dominant P-matrices are stable. We compare our sufficient conditions with the sign symmetric condition and demonstrate that these conditions do not imply each other.
Yeast exosome mutants accumulate 3'-extended polyadenylated forms of U4 small nuclear RNA and small nucleolar RNAs.

The exosome is a protein complex consisting of a variety of 3′-to-5′ exonucleases that functions both in 3′-to-5′ trimming of rRNA precursors and in 3′-to-5′ degradation of mRNA. To determine additional exosome functions, we examined the processing of a variety of RNAs, including tRNAs, small nuclear RNAs (snRNAs), small nucleolar RNAs (snoRNAs), RNase P, RNase MRP, and SRP RNAs, and 5S rRNAs in mutants defective in either the core components of the exosome or in other proteins required for exosome function. These experiments led to three important conclusions. First, exosome mutants accumulate 3′-extended forms of the U4 snRNA and a wide variety of snoRNAs, including snoRNAs that are independently transcribed or intron derived. This finding suggests that the exosome functions in the 3′ end processing of these species. Second, in exosome mutants, transcripts for U4 snRNA and independently transcribed snoRNAs accumulate as 3′-extended polyadenylated species, suggesting that the exosome is required to process these 3′-extended transcripts. Third, processing of 5.8S rRNA, snRNA, and snoRNA by the exosome is affected by mutations of the nuclear proteins Rrp6p and Mtr4p, whereas mRNA degradation by the exosome required Ski2p and was not affected by mutations in RRP6 or MTR4. This finding suggests that the cytoplasmic and nuclear forms of the exosome represent two functionally different complexes involved in distinct 3′-to-5′ processing and degradation reactions.
On the singular values of Gaussian random matrices

This short note is about the singular value distribution of Gaussian random matrices (i.e. Gaussian Ensemble or GE) of size N. We present a new approach for deriving the p.d.f. of the singular values directly from the singular value decomposition (SVD) form, which also takes advantage of the rotational invariance of GE and the Lie algebra of the orthogonal group. Our method is direct and more general than the conventional approach that relies on the Wishart Ensemble and the combination of QR and Cholesky decomposition. Directly based on this p.d.f., and its interpretation by statistical mechanics, we give the physics proof that in the thermodynamic limit (N →∞ ), the singular value distribution satisfies the quadrant law, similar to the celebrated semi-circle lawestablished by Wigner more than 40 years ago for the spectral distribution of Gaussian Orthogonal (or Unitary) Ensembles. This quadrant law was also proved earlier and mathematically more rigorously by some authors based on probabilistic estimations and the moment method, but not directly from the p.d.f. formula. © 2001 Elsevier Science Inc. All rights reserved.
SIMPOL.1: a simple group contribution method for predicting vapor pressures and enthalpies of vaporization of multifunctional organic compounds

Abstract. The SIMPOL.1 group contribution method is developed for predicting the liquid vapor pressure poL (atm) and enthalpy of vaporization Δ Hvap (kJ mol-1) of organic compounds as functions of temperature (T). For each compound i, the method assumes log10poL,i (T)=∑kνk,ibk(T) where νk,i is the number of groups of type k, and bk (T) is the contribution to log10poL,i (T) by each group of type k. A zeroeth group is included that uses b0 (T) with ν0,i=1 for all i. A total of 30 structural groups are considered: molecular carbon, alkyl hydroxyl, aromatic hydroxyl, alkyl ether, alkyl ring ether, aromatic ether, aldehyde, ketone, carboxylic acid, ester, nitrate, nitro, alkyl amine (primary, secondary, and tertiary), aromatic amine, amide (primary, secondary, and tertiary), peroxide, hydroperoxide, peroxy acid, C=C, carbonylperoxynitrate, nitro-phenol, nitro-ester, aromatic rings, non-aromatic rings, C=C–C=O in a non-aromatic ring, and carbon on the acid-side of an amide. The T dependence in each of the bk (T) is assumed to follow b(T)=B1/T+B2+B3T+B4ln T. Values of the B coefficients are fit using an initial basis set of 272 compounds for which experimentally based functions po L,i=fi (T) are available. The range of vapor pressure considered spans fourteen orders of magnitude. The ability of the initially fitted B coefficients to predict poL values is examined using a test set of 184 compounds and a T range that is as wide as 273.15 to 393.15 K for some compounds. σFIT is defined as the average over all points of the absolute value of the difference between experimental and predicted values of log10poL,i (T). After consideration of σFIT for the test set, the initial basis set and test set compounds are combined, and the B coefficients re-optimized. For all compounds and temperatures, σFIT=0.34: on average, poL,i (T) values are predicted to within a factor of 2. Because d(log10 poL,i (T))d(1/T) is related to the enthalpy of vaporization ΔHvap,i, the fitted B provide predictions of ΔHvap,i based on structure.
A Global Perspective on Feeding Assessment in the Neonatal Intensive Care Unit

A comprehensive assessment of feeding performance of infants in the neonatal intensive care unit (NICU) includes not only the traditional approaches of evaluating oral motor control and sensory responses but also evaluation of other factors. Infant feeding is a highly complex and integrated process involving numerous body systems. A global assessment would determine the infant's feeding function in the key areas of state and behavior, tactile responses, motoric control, oral motor function, physiologic control, and coordination of sucking, swallowing, and breathing. Information is obtained through skilled clinical observation as well as from technological monitors or medical tests and procedures. This article provides an overview of a comprehensive assessment that occupational therapists may use when providing service to infants in the NICU.