cssi/SciSciGPT-SciSciNet huggingface dataset:
Autophagy at the gut interface: Mucosal responses to stress and the consequences for inflammatory bowel diseases

Autophagy is a conserved homeostatic process by which cells degrade and recycle cytoplasmic contents and organelles. Recently, autophagy has come to prominence as a factor in many disease states, including inflammatory bowel diseases. In this review we explore the recent discoveries in autophagy and how these relate to the special conditions experienced by the gut mucosa. We will pay particular attention to autophagy as an innate immune process and its role in the development and education of the adaptive immune system.
Fluxes of metals to a manganese nodule radiochemical, chemical, structural, and mineralogical studies

Fluxes of metals to the top and bottom surfaces of a manganese nodule were determined by combining radiochemical (230Th,231Pa,232Th,238U,234U) and detailed chemical data. The top of the nodule had been growing in its collected orientation at 4.7 mm Myr−1 for at least 0.5 Myr and accreting Mn at 200 μg cm−2 kyr−1. The bottom of the nodule had been growing in its collected orientation at about 12 mm Myr−1 for at least 0.3 Myr and accreting Mn at about 700 μg cm−2 yr−1. Although the top of the nodule was enriched in iron relative to the bottom, the nodule had been accreting Fe 50% faster on the bottom.232Th was also accumulating more rapidly in the bottom despite a 20-fold enrichment of230Th on the top. The distribution of alpha-emitting nuclides calculated from detailed radiochemical measurements matched closely the pattern revealed by 109-day exposures of alpha-sensitive film to the nodule. However, the shape and slope of the total alpha profile with depth into the nodule was affected strongly by226Ra and222Rn migrations making the alpha-track technique alone an inadequate method of measuring nodule growth rates. Diffusion of radium in the nodule may have been affected by diagenetic reactions which produce barite, phillipsite and todorokite within 1 mm of the nodule surface; however, our sampling interval was too broad to document the effect. We have not been able to resolve the importance of nodule diagenesis on the gross chemistry of the nodule.
Infrared and optical absorption of hydrogenated boron nitride thin films

Abstract By the careful analysis of the infrared absorption lines around 1400 cm −1 of various boron nitride thin films grown by chemical vapor deposition, we present evidence that this region contains three different lines. These three lines are due to three different boron-containing icosahedra, and we associate two different amorphous phases with these three lines. One of these lines at 1371 cm −1 is also present in large band gap amorphous hydrogenated boron, suggesting that our boron nitride thin films contain amorphous hydrogenated boron-like material. The other two lines at 1263 cm −1 and 1505 cm −1 are roughly correlated and we associate them with a low band gap amorphous boron nitride material. We can then understand that changing either the substrate temperature of the growing film or the ammonia to diborane ratios in the feedstock gives rise to differing amounts of these two amorphous phases. Finally, we associate the larger bandgap boron nitride thin films with larger amorphous hydrogenated boron concentrations.
Continuous centrifugation in virus processing

Ambler's Q/Σ relationship between the throughput of a centrifuge and its mechanical characteristics has been translated from batch data in order to predict operating conditions for continuous centrifugation in virus processing. A Sharples Laboratory Supercentrifuge was converted from batch to continuous operation and a slurry feed device was developed. A correlation between operating conditions for continuous centrifugation and amount of test virus recovered from the feed showed that the Q/Σ values at which high concentrations of the virus were recovered were almost identical to the Q/Σ values for significant virus recovery in batch centrifugation. Titration and gravimetric determinations of the sediments recovered from continuous centrifugation operations indicate that product purity might be influenced by operating conditions.
Electrical measurements of AC losses in high temperature superconducting coils at variable temperatures

Measurements of AC losses in high temperature superconducting (HTS) coils wound from two different types of YBa2Cu3O7 (YBCO) coated conductors are reported. AC loss measurements by different arrangements of voltage loops and pick-up coils were investigated to propose accurate and convenient techniques to measure the AC losses in HTS coils, especially for large coils with the measurement signals significantly higher than the input range of typical lock-in amplifiers. A new and simple sub-cooling technique with an open liquid nitrogen bath was developed to measure AC losses in the sample coils at variable temperatures between 65 and 77 K. The temperature dependence of the losses in these coils was qualitatively explained based on the data on transport and magnetization AC losses in isolated tapes at variable temperatures.
On the Zeros of the Successive Derivatives of Integral Functions.

In 1936 the author proved [2] the following: Theorem 1. If f(z) (≢ 0) is entire of exponential type δ such that each f(v)(x) (v=0, 1, …) vanishes somewhere in the interval I1=[0,½] of the real axis, then $$\delta \geqslant \pi ,$$ (1) and the function $$f(z) = CoS \pi z$$ (2) shows that π is the best constant, because cos πz satisfies all conditions.
Optimizing the coating process of organic actinide extractants on magnetically assisted chemical separation particles

Abstract The coatings of ferromagnetic-charcoal-polymer microparticles (1–25 gm) with organic extractants specific for actinides were optimized for use in the magnetically assisted chemical separation (MACS) process. The organic extractants, octyl (phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) dissolved in tributyl phosphate (TBP), coated the particles when a carrier organic solvent was evaporated. Coated particles were heated in an oven overnight to drive off any remaining carrier solvent and fix the extractants on the particles. Partitioning coefficients for americium obtained with the coated particles routinely reached 3000–4000 ml g−1, approximately 10 times the separation efficiency observed with the conventional solvent extraction system using CMPO and TBP.
The Emerging Role of the Hematopoietic Stem Cell Niche in MyeloproliferativeNeoplasms

Myeloproliferative neoplasms (MPN) are chronic hematological neoplasms arising from the accumulation of genetic mutations in hematopoietic stem cells (HSCs). This notion is supported by genomic studies on MPN patients, in which recurrent mutations on genes such as JAK2, CALR, and MPL have been identified. Interestingly, recent studies using MPN mouse models have demonstrated that the HSC niche, where HSCs are located and maintained in the bone marrow (BM), plays an important role in MPN initiation and progression. Changes in the BM microenvironment alone can serve as a driver for altered hematopoiesis and hematological malignancies. Additionally, during MPN progression mutant HSCs remodel the HSC niche into a hospitable microenvironment for themselves that accelerates disease progression, creating a positive feedback loop where mutant HSCs thrive, and continue to alter the BM microenvironment to their advantage. In an attempt to provide a fresh perspective in understanding MPN pathogenesis, this review highlights the studies conducted that explore the role of the HSC niche in MPN pathogenesis and progression.
Positron annihilation spectroscopy for chemical analysis: A novel probe for microstructural analysis of polymers☆

Abstract Positron annihilation spectroscopy for chemical analysis (PASCA) has been developed to analyze the microstructure of polymers. Positron annihilation lifetime measurements give direct information about the dimension and contents of free-volume holes in amorphous materials. The angular correlation measurements of positron annihilation radiation give additional information about the shape of the free-volume holes in oriented polymeric materials. The unique capability of PASCA to probe free-volume properties is from the fact that positronium atom is trapped in the atomic-scale holes which have a size ranging from 1 to 10 A. Theoretical aspects, experimental developments of PASCA, and examples in analyzing the microstructures of epoxy, PEEK, and PMMA polymers are presented.
Rate of climbing fiber degeneration in rabbit cerebellum following parafloccular stalk and medullopontine lesions

To resolve inconsistencies in experimental studies which use reduced silver methods to detect cerebellar climbing fiber sources within the brain stem, an evaluation of the temporal course of degeneration was undertaken. The paraflocculus of the rabbit is uniquely situated within the temporal bone and connects with the corpus cerebelli via a stalk passing through a bony foramen. A unilateral electrolytic lesion deafferented the paraflocculus without disturbing blood supply or causing damage (18 animals). Comparatively, another group of unilateral lesions was placed at the dorsolateral pontomedullary junction, adding significantly to the cortical area deafferented (12 animals). Animals of each group were killed at successively longer intervals commencing at 18 hours, and a modified Fink-Heimer impregnation process was applied to the cerebellar cortex and opposite-sided controls. In parafloccular lesions, degeneration was detected at 24 hours in the climbing fibers of the molecular layer. At successively longer intervals, degeneration became increasingly evident in granule layer and white matter. Subsequent to dorsolateral pontomedullary lesions, climbing fiber degeneration was first observed in the molecular layer at 24 hours and was clearly evident there at 36 hours. By 72 hours degeneration had reached the white matter, meanwhile disappearing in the molecular layer where it was first seen. Using techniques of Nauta-Fink-Heimer to display secondary climbing fiber degeneration in cerebellar cortex, it was found that too long post-operative intervals could preclude its detection, since in both groups of animals it commenced earlier and disappeared sooner in the molecular layer.
Thyroid bed fine needle aspiration in patients after thyroidectomy--a useful follow-up tool with proposed diagnostic categories.

After thyroidectomy for primary thyroid malignancies, patients are closely monitored for recurrence or metastasis. Fine needle aspiration (FNA) has been used as the appropriate diagnostic modality for occult masses identified radiographically in the thyroid bed. In this study, we report our institutional experience with FNA of the thyroid bed and propose practical diagnostic categories. A retrospective chart review of all thyroid bed FNAs between April 2008 and January 2013 was performed, and a cohort of 39 patients was retrieved. The cytology diagnoses were divided into 5 categories including nondiagnostic, inflammatory/reactive, bland follicular cells, suspicious for neoplasm/malignancy, and malignant. The follow-up histologic and/or clinical findings were collected for each category. The 39 patients included 9 males and 30 females (ages 15-79 years). Prior thyroidectomies were due to papillary thyroid carcinoma (31 cases), follicular carcinoma (3 cases), medullary carcinoma (1 case), Hurthle cell carcinoma (1 case), malignancy unspecified (1 case), follicular adenoma (1 case), and multinodular goiter (1 case). Overall, 33% (13 cases) of thyroid bed FNAs were nondiagnostic, and 10% (4 cases) were categorized as "inflammatory/reactive." None of the patients in these 2 categories demonstrated evidence of clinical recurrence. One patient with a "bland follicular cells" thyroid bed FNA diagnosis had metastatic papillary thyroid carcinoma on follow-up histology. Of 14 patients in the "suspicious" and "malignant" categories, 10 had malignant follow-up diagnosis on histology. In conclusion, thyroid bed FNA with standardized diagnostic categories is a useful modality for follow-up in patients who have undergone thyroidectomy.
Characterization of organic compounds in simulated rainfall runoffs from model coal piles

Model coal piles were constructed and leached with distilled water under simulated rainfall conditions. The piles were composed of one of four coals: two of high sulfur content (Illinois #6 and Western Kentucky), one of low sulfur content (Montana Nerco), and one of variable sulfur content (Texas lignite). There were nine rainfall simulations spaced 15 days apart. The runoffs were collected, extracted at acid and base pH, and analyzed by capillary column gas chromatography/mass spectrometry (GC/MS). Also, an extreme case was simulated by stir-extracting a coal with three different organic solvents in an acid and base medium, and the extracts were analyzed by GC/MS. The most common organic compound identified in any extract was phenanthrene. Aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs), and methyl and ethyl substituted PAHs were also identified. The concentration of most of the compounds did not exceed 50 μg/L. The concentrations of compounds in the extreme case simulations ranged from below detection (< 1 μ/L) up to 107 μ/L. The data demonstrated that runoffs from coal piles may contain numerous organic compounds including many PAHs.
On the application of Liapunov's direct method to discrete dynamic systems with stochastic parameters

A Liapunov function specially suitable for the study of the almost sure asymptotic stability of a class of linear discrete systems, described by a set of second order differential equations with stochastic parameters, is presented. A theorem and related corollaries, applicable to systems involving general types of forces, are obtained. The proposed technique is shown to be useful in minimizing the computational efforts associated with relatively large dynamic systems. Several examples, including systems involving follower forces, are included to demonstrate the effectiveness of the method.
Striatal outcome processing in healthy aging

Functional MRI of young adults has implicated the striatum in the processing of rewarding and punishing events. To date, only two published experiments (Samanez-Larkin et al., 2007; Schott et al., 2007) have explored similar phenomena in older adults, with both studies emphasizing the anticipation of monetary outcomes. To better understand older participants' striatal responses to delivered outcomes, we engaged 20 older adults and 13 younger adults in a card-guessing task that rewarded correct guesses with monetary gain and punished incorrect guesses with monetary loss. Overall, the older adults retained most of the typical features of the striatal response, so that activity in the caudate head showed reliable differentiation between rewards and punishments during the 6- to 9-sec postoutcome window. Comparison of the older and younger adults also pointed to some potential aging effects on outcome activity, including reductions in the magnitude and extent of striatal activation, and a trend for the older adults to show a decreased early punishment response. In sum, our data suggest that the signaling of outcome valence remains relatively stable into late adulthood, although more research is needed to understand some subtle changes that might occur across the life span.
Experimental test of coherent betatron resonance excitations

Sustained coherent betatron oscillations have been produced in the Brookhaven National Laboratory Alternating Gradient Synchrotron (AGS) using a high-frequency oscillating dipole field operating very near a subharmonic of the betatron tune. The betatron oscillations were adiabatically induced and manipulated in a controlled fashion so that the transverse emittance of the particle beam was preserved. This procedure will be used to induce spin flip in the AGS during the crossing of depolarizing resonances during polarized beam operation. It may also find applications toward measuring nonlinear parameters of transverse motion in synchrotrons and storage rings.
Little Firms and Big Patents: A Model of Small-Firm Patent Signaling

Patent strategies of small technology-intensive firms are difficult to explain with standard incentive arguments based on intellectual property rights. This paper develops a rationale for patent filing as a disclosure strategy. We develop a two-sender signaling game to study patenting incentives of two technology start-ups to file in a large-scale patent system with the goal to attract a user firm. Both start-ups may decide to invest in costly modification of their patent application before filing. The paper identifies a separating equilibrium in which the high-quality inventor files and so separates from its technology competitor. Of particular interest is the study of pooling and semi-separating equilibria, as well as the impact of subsidies. We find that a higher quality of a country's inventions, reflected in the possible innovative steps and thus in higher expected profits for foreign user firms, may increase the chance of the relatively lower-quality inventor to enter international technology markets.
Pulse stretching and spectroscopy of subnanosecond optical pulses using a Fabry-Perot interferometer

Abstract A Fabry-Perot interferometer has been used to produce optical pulses of variable width from a short gaussian input pulse. Pulse stretching of two to five or more times the original pulse width is possible provided a longer tail on the output pulse is acceptable. Calculations and measurements of pulse shape and interferometer finesse are presented, along with a discussion of short-pulse spectroscopy using a Fabry-Perot interferometer.
Presence of the Evening bat (Nycticeius humeralis) in westernmost Kansas

The evening bat, Nycticeius humeralis, is an austral species (Armstrong, Choate, and Jones 1986) that ranges from the southeastern United States north to the southern Great Lakes region and west to the central Great Plains (Watkins 1972). In Kansas, the species was known from just four counties (Clay, Douglas, Jewell, and Johnson) in the northeast when Jones, Fleharty, and Dunnigan (1967) reviewed the distributional status of bats in the state. Birney and Rising (1968) subsequently reported specimens of the evening bat from Franklin and Ford counties, the latter in southwestern Kansas, and Kunz, Choate, and George (1980) reported specimens from Barber and Comanche counties in south-central Kansas. Sparks and Choate (2000) added more than a dozen counties, most in north-central Kansas, to the known range of the species in the state and opined that this tree-dwelling species, which previously was rare at the western limit of its range, was becoming increasingly common in riparian corridors. They concluded that the lack of forested habitats in much of western Kansas in the past possibly restricted the range of the evening bat to the eastern twothirds of the state (Sparks and Choate 2000), but that growth of forested habitats along watercourses was enabling this species to expand westward.
GROWTH FAILURE WITH NORMAL SERUM RIA-GH AND LOW SOMATOMEDIN ACTIVITY: SOMATOMEDIN RESTORATION AND GROWTH ACCELERATION AFTER EXOGENOUS GH

Two three-year-old boys with dwarfism (height ages 1–4/12 and 1–11/12 years) and delayed bone ages (1–4/12 and 1–9/12 years) had normal growth hormone (GH) responses after stimulation and low levels of somatomedin. Unlike patients with Laron Syndrome, the two patients generated normal levels of somatomedin after administration of exogenous hGH. Treatment with hGH (2 IU every other day) brought about a significant increase in the growth rate of both patients. The growth rate of the first patient increased from 2 cm/year before treatment to 12 cm/year on therapy. The growth rate of the second patient was 4.5 cm/year before treatment, and 8.3 cm/year while on treatment. The two cases represent a new syndrome of dwarfism which may be caused by secretion of a biologically inactive but immunoreactive GH.
Heat transfer from rotating annular fins

Abstract Experiments have been performed to determine the heat transfer coefficients for arrays of shaft-attached, rotating annular fins. The experiments encompassed a wide range of rotational speeds and interfin spacings (including the limiting case of the single annular fin). The efficiency of the fins was equal to one. It was found that the fin heat transfer coefficient decreased with decreasing interfin spacing, the extent of the decrease being of major proportions at low rotational speeds but being quite moderate at high speeds. Thus, closely spaced fins can be used at high rotational speeds without a significant spacing-related decrease in the transfer coefficient, but at low speeds the fins must be farther apart to avoid overly low values of the coefficient. The heat transfer coefficient also decreased as the rotational speed decreased, with a particularly rapid dropoff at low speeds when the interfin spacing was small. For the most part, the fin heat transfer coefficients substantially exceeded those for an unfinned rotating shaft, thereby providing an incentive for finning. It was also found that at high rotational speeds, the heat transfer coefficient for a rotating disk served as a lower bound for the annular-fin heat transfer coefficients. To facilitate the use of the results for design, a correlation was developed which represents the fin heat transfer coefficient as a continuous function of the investigated independent parameters.
Norway's offshore petroleum industry

Abstract During the past decade, Norway has become an important oil and gas producer. Annual production is six times national consumption. Development policies of the national government have been cautious, and future policies will probably follow a similar pattern. The government recently opened offshore areas poleward of 62°N latitude, a decision likely to have a significant impact on Norway's future as an oil producer. Norway maintains a tight reign on foreign oil company participation, domestic downstream processing of crude, oil company taxation and oil revenue investment within the national economy. Norway's large inflow of oil-related capital investments and production revenues have contributed to significant inflation and to changes in local labour supplies. Norway has always used its petroleum industry to further the country's overall development goals, a policy that will continue in the years ahead.
Design of a Novel Mechanical Syringe Pump for Neonatal Care in Low-Resource Settings

Hospitals in the developing world lack access to an affordable means of administering intravenous therapy at the accuracy required for neonates. This paper presents the design and performance of a mechanical syringe pump for delivering IV therapy in low-resource settings. Current available syringe pumps are limited to electronic pumps and disposable mechanical pumps. Commercially available electronic syringe pumps, frequently used in the developed world, are expensive, require highly trained technical personnel, and rely on an electricity source, so they are unfeasible for developing world clinics. Disposable mechanical pumps, on the other hand, require specialized one-time-use equipment and can produce only one flow rate per syringe size. We introduce a novel mechanical syringe pump specifically designed to make proper neonatal IV therapy accessible to low-resource hospitals. The device consists of a gravity-based driver that operates independent of electrical power and a metronome-inspired clockwork mechanism for regulation of flow rate. It features a simple user interface for quick and easy setup before operation and costs less than $100. A prototype of the design was constructed and tested using water in 20 cc, 30 cc, and 60 cc syringes at room temperature (25 deg.C). Results show that the device is capable of producing a variety of flow rates between 5 cc/hr and 40 cc/hr for standard syringe sizes with errors within 15%. Based on these results, the system has been shown to be a feasible option for low-resource hospitals requiring a safe, inexpensive, and easy-to-use method of neonatal IV therapy.
Modeling of imaging processes in the low-vacuum SEM

The presence of a gas in the specimen chamber of low-vacuum scanning electron microscopes (SEMs) gives rise to a number of interactions that are not found in their high-vacuum counterparts. Many of these interactions are integral to the specimen charge neutralizing capabilities of these instruments. However, these interactions, and the electronic charge state of the specimen, give rise to a number of processes that influence, and sometimes even dominate, secondary electron contrast. As many of the processes are stochastic in nature, and depend on discrete interactions between electrons, gaseous ions, neutral molecules, and the specimen surface, modeling can offer important insights for contrast interpretation. This paper discusses these interactions and the mechanisms through which contrast is influenced. Copyright © 2005 John Wiley & Sons, Ltd.
Thermodynamics and kinetics of a folded-folded' transition at valine-9 of a GCN4-like leucine zipper

Spin inversion transfer (SIT) NMR experiments are reported probing the thermodynamics and kinetics of interconversion of two folded forms of a GCN4-like leucine zipper near room temperature. The peptide is 13Calpha-labeled at position V9(a) and results are compared with prior findings for position L13(e). The SIT data are interpreted via a Bayesian analysis, yielding local values of T1a, T1b, kab, kba, and Keq as functions of temperature for the transition FaV9 right arrow over left arrow FbV9 between locally folded dimeric forms. Equilibrium constants, determined from relative spin counts at spin equilibrium, agree well with the ratios kab/kba from the dynamic SIT experiments. Thermodynamic and kinetic parameters are similar for V9(a) and L13(e), but not the same, confirming that the molecular conformational population is not two-state. The energetic parameters determined for both sites are examined, yielding conclusions that apply to both and are robust to uncertainties in the preexponential factor (kT/h) of the Eyring equation. These conclusions are 1) the activation free energy is substantial, requiring a sparsely populated transition state; 2) the transition state's enthalpy far exceeds that of either Fa or Fb; 3) the transition state's entropy far exceeds that of Fa, but is comparable to that of Fb; 4) "Arrhenius kinetics" characterize the temperature dependence of both kab and kba, indicating that the temperatures of slow interconversion are not below that of the glass transition. Any postulated free energy surface for these coiled coils must satisfy these constraints.
Voltage‐Gated Sodium Channels: Therapeutic Targets for Pain

Objective. To provide an overview of the role of voltage-gated sodium channels in pathophysiology of acquired and inherited pain states, and of recent developments that validate these channels as therapeutic targets for treating chronic pain. Background. Neuropathic and inflammatory pain conditions are major medical needs worldwide with only partial or low efficacy treatment options currently available. An important role of voltage-gated sodium channels in many different pain states has been established in animal models and, empirically, in humans, where sodium channel blockers partially ameliorate pain. Animal studies have causally linked changes in sodium channel expression and modulation that alter channel gating properties or current density in nociceptor neurons to different pain states. Biophysical and pharmacological studies have identified the sodium channel isoforms Nav1.3, Nav1.7, Nav1.8, and Nav1.9 as particularly important in the pathophysiology of different pain syndromes. Recently, gain-of-function mutations in SCN9A , the gene which encodes Nav1.7, have been linked to two human-inherited pain syndromes, inherited erythromelalgia and paroxysmal extreme pain disorder, while loss-of-function mutations in SCN9A have been linked to complete insensitivity to pain. Studies on firing properties of sensory neurons of dorsal root ganglia demonstrate that the effects of gain-of-function mutations in Nav1.7 on the excitability of these neurons depend on the presence of Nav1.8, which suggests a similar physiological interaction of these two channels in humans carrying the Nav1.7 pain mutation. Conclusions. These studies suggest that isoform-specific blockers of these channels or targeting of their modulators may provide novel approaches to treatment of pain.
Wold decomposition, prediction and parameterization of stationary processes with infinite variance

A discrete time stochastic process {Χt} is said to be a p-stationary process (1<p≦2)if $$E\left| {\sum\limits_{k = 1}^n {b_k X_{tk + h} } } \right|^p = E\left| {\sum\limits_{k = 1}^n {b_k X_{tk} } } \right|^p $$ , for all integers n≧1, t 1,...t n,h and scalars b 1,...b n.The class of p-stationary processes includes the class of second-order weakly stationary stochastic processes, harmonizable stable processes of order α (1<α≦2), and p thorder strictly stationary processes. For any nondeterministic process in this class a finite Wold decomposition (moving average representation) and a finite predictive decomposition (autoregressive representation) are given without alluding to any notion of “covariance” or “spectrum”. These decompositions produce two unique (interrelated) sequences of scalar which are used as parameters of the process {Χt}. It is shown that the finite Wold and predictive decomposition are all that one needs in developing a Kolmogorov-Wiener type prediction theory for such processes.
Origins of binding specificity of the A1 heterogeneous nuclear ribonucleoprotein.

The A1 heterogeneous nuclear ribonucleoprotein (hnRNP) is the best studied of the "core" hnRNP proteins that are tightly associated with heterogeneous nuclear RNA (hnRNA) within eukaryotic nuclei. Previous studies suggested that hnRNP A1 preferentially binds (under nonequilibrium conditions) to the pyrimidine-rich span of sequence at the 3'splice site of most introns [Swanson, M.S., & Dreyfuss, G. (1988) EMBO J. 11, 3519-3529; Buvoli et al. (1990) Nucleic Acids Res. 18, 6595-6600; Ishikawa et al. (1993) Mol. Cell. Biol. 13, 4301-4310]. Recently, Burd and Dreyfuss [(1994) EMBO J. 13, 1197-1204] used selection/amplification from pools of random sequence RNA to uncover an even higher-affinity A1 oligo that contained two copies of a high-affinity consensus sequence, UAGGGU/A. We have extended these studies by using a fluorescence assay to characterize the equilibrium binding properties of A1 to each of these oligonucleotides. By also characterizing the binding of A1 to sequence-randomized control oligonucleotides, we have been able to better evaluate the inherent "sequence-specific" binding properties of A1. Although these studies indicate that under equilibrium conditions A1 cannot specifically recognize the beta-globin, 3'-splice site DNA oligo analogue studied by Buvoli et al. (1990), they confirmed the high-affinity binding to the "winner" 20-mer RNA that was uncovered via selection/amplification and that has the sequence UAUGAUAGGGACUUAGGGUG (Burd & Dreyfuss, 1994). In 0.1 M NaCl, we found that A1 has approximately 100-fold higher affinity for this winner sequence sequence than it does for either a randomized version of this sequence or a 20-mer oligo corresponding to an unrelated beta-globin intron sequence. This winner RNA oligo aggregates in solution to form an apparent dimer that may represent a G-quartet resulting from dimerization of two Hoogsteen base-paired hairpins. On the basis of salt sensitivity studies carried out with various fragments of A1, the ability of A1 to discriminate the winner sequence from its randomized control results primarily from increased ionic interactions with the glycine-rich, COOH terminal domain of A1 that extends from residue 196 to 319. Nonetheless, most of the overall energy of binding for the A1 winner complex results from determinants that are resident within the first 195 residues of A1. The unique ability of the winner sequence (but not its sequence-randomized control) to form a higher-order aggregate, which may correspond to a G-tetrad, appears to facilitate the additional ionic interactions with the COOH terminal domain. Taken together, these data suggest the need to reevaluate possible and probable functions of A1 in vivo.
Iterative TIN-based automatic filtering of sparse LiDAR data

In this letter, a novel method for automatic separation of terrain points and object points using sparse Light Detection And Ranging (LiDAR) data is developed. The proposed method is based on iterative elimination of step edges connecting terrain points to object points. The first stage is to detect these edges. Using a triangulated irregular network (TIN) interpolation of the LiDAR raw points, each triangle is assigned to one of two classes: edge triangle or non-edge triangle, using the slope as the discriminative function. Edge triangles are located at the boundary between terrain and non-terrain points; therefore, the vertices of each triangle consist of terrain points and object points. Initially the lower points are considered as terrain points and the higher points as object points. The elevation of object points is adjusted using an interpolation method based on the estimated local slope. The local slope is calculated using non-edge adjacent triangles to the step triangle. The slopes of modified tr...
Distribution and biomass of an estuarine ctenophore population,Mnemiopis leidyi (A. Agassiz)

For an estuarine population of the ctenophoreMnemiopsis leidyi (A. Agassiz), density of small individuals, indicative of recent spawning, and total biomass were measured on 32 dates over 20 months. These observations were related to the environmental parameters of temperature, salinity, daylight, and presence of a predator.
Thermoregulatory responses to cycling with and without a helmet

This study examined the effects of wearing a helmet on selected body temperatures and perceived heat sensation of the head and body while cycling in a hot-dry (D) (35 degrees C, 20% relative humidity (RH) and hot-humid (H) (35 degrees C, 70% RH) environment. Ten male and four female cyclists (mean +/- SD: males = age 27 +/- 7 yr, peak O2 uptake (VO2) 4.10 +/- 0.54 L.min-1; females = age 26 +/- 3 yr, peak O2 uptake (VO2) 3.08 +/- 0.49 L.min-1) performed four randomized 90-min cycling trials at 60% of peak VO2 both with (HE) and without (NH) a commercially available cycling helmet in both D and H environments. VO2, core (Te), skin (Tsk), and head skin temperatures, heart rate (HR), rating of perceived exertion (RPE), and perceived thermal sensation of head (TSH) and body (TSB) were measured throughout exercise. For all measured variables, no significant difference was evident between HE and NH. However, Tc, Tsk, and mean head skin temperatures were higher (P
Physical and biological controls of nitrate concentrations in the upper subtropical North Pacific Ocean

Abstract Vertical profiles of nitrate down to 1000 m depth were obtained about every 5 days and over several years by four profiling floats deployed near Station ALOHA in the North Pacific subtropical gyre. As a first step, we study the episodic and rapid (10–30 days) changes in the depth of constant-nitrate surfaces observed in the float records. These changes are in general correlated with similar changes in the depth of isopycnal surfaces and have a small horizontal scale (horizontal wavelength less than 2°). They are furthermore observed over the whole water column sampled by the floats and throughout the year, with no apparent seasonal cycle. Using these characteristics as well as a 7-year high-resolution time series of potential density at Station ALOHA and a high-resolution numerical simulation of the circulation around the station, we conclude that these episodic changes correspond to the depth anomalies associated with the rapid changes and/or small-scale features of the eddy field. Large vertical velocities associated with submesoscale frontal processes are confined to the surface mixed layer (SML) and play no role in the episodic nitrate events except, perhaps, in late winter to early spring when the SML reaches the top of the nutricline. As a second step, we study the variations of nitrate concentration along isopycnal surfaces, which enables us to isolate the effects of biological processes. In the lower euphotic zone (125–200 m), the nitrate variations reflect the response of the ecosystem to the eddy variability: the shallower the isopycnal surface, the lower the nitrate concentration, and conversely, with nitrate varying in Redfield stoichiometric proportions with oxygen anomaly (defined here as dissolved oxygen minus oxygen saturation). In the upper euphotic zone (0–125 m), in contrast, eddy-induced variations in along-isopycnal oxygen anomaly do not conform with current knowledge about supply and variability of nitrate, ammonium and dissolved organic matter; some other nitrogen source that remains to be identified is required for mass balance.
A new reformulation-linearization technique for bilinear programming problems

This paper is concerned with the development of an algorithm for general bilinear programming problems. Such problems find numerous applications in economics and game theory, location theory, nonlinear multi-commodity network flows, dynamic assignment and production, and various risk management problems. The proposed approach develops a new Reformulation-Linearization Technique (RLT) for this problem, and imbeds it within a provably convergent branch-and-bound algorithm. The method first reformulates the problem by constructing a set of nonnegative variable factors using the problem constraints, and suitably multiplies combinations of these factors with the original problem constraints to generate additional valid nonlinear constraints. The resulting nonlinear program is subsequently linearized by defining a new set of variables, one for each nonlinear term. This “RLT” process yields a linear programming problem whose optimal value provides a tight lower bound on the optimal value to the bilinear programming problem. Various implementation schemes and constraint generation procedures are investigated for the purpose of further tightening the resulting linearization. The lower bound thus produced theoretically dominates, and practically is far tighter, than that obtained by using convex envelopes over hyper-rectangles. In fact, for some special cases, this process is shown to yield an exact linear programming representation. For the associated branch-and-bound algorithm, various admissible branching schemes are discussed, including one in which branching is performed by partitioning the intervals for only one set of variables x or y, whichever are fewer in number. Computational experience is provided to demonstrate the viability of the algorithm. For a large number of test problems from the literature, the initial bounding linear program itself solves the underlying bilinear programming problem.
Delayed chronic type A dissection following CABG: implications for evolving techniques of revascularization.

Background: Postoperative dissection in some patients is related to manipulation of the aorta and accounts for 3% to 5% of deaths after cardiac surgery. Methods: Between 1987 and 1999, 109 patients with previous cardiac operations were treated for chronic type A dissection. In 31 of the patients, the etiology was related to aortic manipulation. Twenty-one patients (17 men, 4 women; 67 ± 13 years of age) had isolated coronary artery bypass grafting (CABG) as their first operation and were reviewed. The interval between operations was 52.9 ± 47.3 months. Results: Reoperation was elective in 11 patients, urgent in 10 patients. Median maximal aortic diameter was 6.8 ± 2.1 cm; 9 patients had major aortic insufficiency. The intimal tear was at the partial occlusion clamp site in 12 patients (57.1%), at the cross-clamping site in 4 patients (19.1%), and at the proximal anastomosis in 1 patient (4.8%); 4 patients (19.1%) had multiple tears at several sites. Cystic media necrosis was present in 9.5% of the patients, severe atherosclerosis in 47.6% of the patients, and 42.9% of the patients had both. Nine patients (42.9%) underwent a modified Bentall procedure, 12 patients (57.1%) underwent a supracoronary anastomosis, and all had open distal anastomosis. There were two (9.5%) hospital deaths and three (14.3%) postoperative strokes. Freedom from cardiac or aorta-related mortality was 85.7% at a mean follow-up of 49.3 months. Conclusions: In patients who develop type A dissection of the aorta after previous CABG, the intimal tear most often is at partial occlusion clamp site. This complication is associated with morbidity and mortality. It remains to be seen whether the use of partial occlusion clamps on the pulsating and often diseased aorta during off-pump coronary artery bypass (OPCAB) will increase the risk of delayed iatrogenic dissections.
Dual closed-loop, optoelectronic, auto-oscillatory detection circuit for monitoring fluorescence lifetime-based chemical sensors and biosensors.

We present a new detection instrument for sensor measurements based on excited-state fluorescence lifetimes. This system consists of a primary optoelectronic loop containing a resonance-type rf amplifier, a modulatable fluorescence-excitation light source, a fiber optic feedback loop (with a gap for a fluorescent sensor), and a photomultiplier tube. A secondary, phase-feedback optoelectronic circuit consists of a long-wavelength-pass optical filter, a second photomultiplier tube, a photodiode, an electronic phase detector, a dc amplifier, and an electronic phase shifter (inserted into the main loop). This phase-feedback circuit is new with respect to our previous work. Under the appropriate conditions, the main loop exhibits self-oscillations, manifesting themselves as sinusoidal rf modulation of light intensity. The phase-feedback circuit detects the modulation phase shift resulting from the finite excited-state lifetimes of a fluorophore. As the excited state lifetime changes, the phase shift from the electronic phase shifter also changes, which results in a shift in self-oscillation frequency. The detection system uses self-oscillation frequency as the detection parameter and has excellent resolution with respect to changes in excited-state lifetime (~1 ps).
Outcome of narrowing related side branches after high-speed rotational atherectomy

High-speed rotational atherectomy (HSRA) is advocated for calcified and diffusely narrowed coronary arteries. There are often side branches involving these kinds of lesions. The presence of significant lesion-related side branches has been considered a relative contraindication to rotational atherectomy. This study was performed to determine the rate, predictors, and outcome of side branch occlusion after HSRA. The angiograms of 418 patients were examined with 320 side branches in 240 target vessels of > or = 1 mm in diameter being identified. Vessels were scored as either perfused (Thrombolysis In Myocardial Infarction 2 or 3 flow) or occluded (Thrombolysis In Myocardial Infarction 0 or 1 flow before and after the procedure. A detailed quantitative angiographic analysis was performed on a total of 108 side branches including all cases of branch occlusion. Clinical outcomes were determined in all cases with side branch loss. There were 24 occlusions in 21 patients after the procedure, giving a rate of branch loss of 7.5%. Follow-up angiography of > or = 24 hours was available for 13 of the occluded branches and 12 were found to be patent. In the 21 patients with branch occlusion, 6 sustained a myocardial infarct (of which 5 were non-Q-wave), 2 underwent coronary artery bypass grafting, and 2 died. There are frequently lesion-associated side branches in the types of vessels to undergo HSRA. These branches remained patent 92.5% of the time, with occlusion occurring infrequently and usually being transient. When occlusion did occur, there was a 29% incidence of myocardial infarction.
Tendon-Bone Interface Motion in Transosseous Suture and Suture Anchor Rotator Cuff Repair Techniques:

BackgroundAlthough many studies involving rotator cuff repair fixation have focused on ultimate fixation strength and ability to restore the tendon's native footprint, no studies have characterized the stability of the repair with regard to motion between the tendon and repair site footprint.HypothesisSuture anchor fixation for rotator cuff repair has greater interface motion between tendon and bone than does transosseous suture fixation.Study DesignControlled laboratory study.MethodsTwelve fresh-frozen human cadaveric shoulders were tested in a custom device to position the shoulder in internal and external rotations with simulated supraspinatus muscle loading. Tendon motion relative to the insertional footprint on the greater tuberosity was determined optically using a digital camera rigidly connected to the humerus, with the humerus positioned at 60° of internal rotation and 60° of external rotation. Testing was performed for the intact tendon, a complete supraspinatus tear, a suture anchor repair, and...
A performance comparison of RIPPLE and LMS for high dimensional piecewise linear functions

The method of ordinary least squares approximation is not resistant to data points that cause a disproportionate influence in the fit. When outliers are known to exist in the data, robust estimation algorithms are preferred. However, the performance of most robust estimation algorithms degrades in higher dimensions due to factorial complexity and sparse data. A new polynomial time algorithm RIPPLE has been developed to produce robust estimations of data obtained from piecewise linear functions. This paper presents a comparison between the new algorithm RIPPLE and a standard robust estimation algorithm LMS.
Management of Transgenderism

Gender identity disorder (transgenderism) is poorly understood from both mechanistic and clinical standpoints. Awareness of the condition appears to be increasing, probably because of greater societal acceptance and available hormonal treatment. Therapeutic options include hormone and surgical treatments but may be limited by insurance coverage because costs are high. For patients seeking male-to-female (MTF) change, hormone treatment includes estrogens, finasteride, spironolactone, and gonadotropin-releasing hormone (GnRH) analogs. Surgical options include feminizing genital and facial surgery, breast augmentation, and various fat transplantations. For patients seeking a female-to-male (FTM) gender change, medical therapy includes testosterone and GnRH analogs and surgical therapy includes mammoplasty and phalloplasty. Medical therapy for both FTM and MTF can be started in early puberty, although long-term effects are not known. All patients considering treatment need counseling and medical monitoring.
Composite Hydroxylapatite/Plaster Implants for Complex Endodontic Periapical Defects and Lesions

Implantation of a malleable composite hydroxylapatite/plaster of Paris mixture moistened with calcium hydroxide solution was performed in periapical defects which could not be treated successfully by nonsurgical procedures. A 1.5:1 mixture of sintered hydroxylapatite particles (OrthoMatrix HA-500) and plaster of Paris (USC Medical Grade Calcium Sulfate Hemihydrate B) containing 0.85% K2 SO4 is moistened with Calcium Hydroxide Topical Solution, USP and formed into a malleable mass. This is placed into the surgical defect, shaped and covered with resorbable polyester mesh. The flap is replaced and pressure applied for 5 minutes before suturing. Sutures are removed in I week and x-rays are taken immediately after surgery and at six month intervals. In all types of defects in which the material was employed, the prognosis for postsurgical tooth retention was improved and short term success was 91%. The success achieved suggests that this implantation procedure should receive wider application for complex endodontic periapical osseous defects.
Turnpikes or Freeways

Editor in Chief Fred Douglis discusses the online media dilemma of free versus paid content and services.