cssi/SciSciGPT-SciSciNet huggingface dataset:
Effect on glycemic control of the addition of 2.5 mg glipizide GITS to metformin in patients with T2DM.

Abstract Aims: This study evaluated the effects on glycemic control of the addition of 2.5 mg glipizide GITS to metformin in patients with mild-to-moderate, but suboptimally controlled type 2 diabetes. Methods: In this multicenter, double-blind, placebo-controlled study, 122 patients with type 2 diabetes inadequately controlled ( A 1c 7–8.5%) on metformin (≥1000 mg/day for ≥3 months) were randomized to 16 weeks treatment with 2.5 mg/day glipizide GITS ( n = 61) or placebo ( n = 61), in addition to their current metformin dose. The primary efficacy variable was the change in A 1c from baseline to endpoint. Changes in fasting plasma glucose (FPG), insulin concentrations, lipid profile and safety variables were also measured. Results: The addition of glipizide GITS to metformin gave significantly greater improvements in mean A 1c and FPG from baseline to endpoint than placebo addition ( p A 1c level of A 1c p A 1c p Conclusions: This study showed that the addition of 2.5 mg glipizide GITS to metformin significantly improved glucose control in patients with type 2 diabetes inadequately controlled by metformin monotherapy.
Modeling Gold Price Movements and Forecasts

Factors which have contributed to gold price fluctuation include the interaction between gold demand and supply, government intervention, uncertainty of the world political environment and global economic stability. Previously researchers looked at modeling the variation in gold price movements. Williams (1972) used a pure descriptive way to review the activities of the gold market during the period from 1968 to 1972, a time when great changes in gold prices occurred. He asserted that the private gold markets are relatively unstable, and that gold prices may show a rapid rise under conditions of crisis or acute uncertainty. In Williams' study, no precise relationship or functional forms were employed to explain the fluctuation of gold prices.
Modernity in material form? Mobile phones in the careers of Ghanaian market women

Recent research on mobile phones in market exchange activities in the Global South has tended to dematerialise the phone, narrowing its application to accord with disciplinary concerns rather than to its full range of material possibilities. This article seeks to expand the model of the mobile phone in socio-economic development by examining its uptake and adaptation among Ghanaian market women. The analysis considers development in terms of market women's own self-defined notion of progress. Rather than leading to more impersonal and calculative trade relationships, their uses reflected deepening relations with trade partners and opportunities for enhanced affiliation at all levels.
PARÆSTHESIÆ FROM ECTOPIC IMPULSE GENERATION IN HUMAN SENSORY NERVES

Intraneural microelectrode recordings were obtained from sensory nerve fascicles in awake normal subjects experiencing post-ischaemic paraesthesiae. Spontaneous activity in afferent fibres started about half a minute after re-establishment of circulation; it peaked by the second minute and slowly waned thereafter. This parallelled the time course and intensity of the perceived paraesthesiae. During the most intense stage of paraesthesiae, single unit discharges consisted of prolonged bursts of high-frequency impulses (200-300 imp/s) lasting for 1 to 7 seconds. Repeated bursts became progressively shorter and often exhibited marked rhythmicity as paraesthesiae became weaker. Hyperventilation increased paroxysmal firing and paraesthesiae, whereas ischaemic periods repeated at short intervals exhausted the impulse generating mechanism. The outcome of local anaesthetic blocks indicated that the impulses were generated ectopically along the nerve fibres previously subjected to ischaemia and not primarily from the receptors in the skin. The high frequency of the discharge and the quality and distribution of various paraesthesiae suggest that sensory units with myelinated fibres participated in the paroxysmal discharge; normal activity, but no ectopic discharges were recorded in unmyelinated fibres. It is proposed that the perverted quality of paraesthesiae is due to an abnormal spatio-temporal pattern of ectopic impulses from different types of sensory units. creating a chaotic percept consisting of an assortment of sensations referred in irregular succession to multiple areas.
Adaphostin and bortezomib induce oxidative injury and apoptosis in imatinib mesylate-resistant hematopoietic cells expressing mutant forms of Bcr/Abl

Effects of the tyrphostin adaphostin and bortezomib were examined in Bcr/Abl+ leukemia cell resistant to imatinib mesylate secondary to Bcr/Abl point mutations. Adaphostin was equally effective in inducing mitochondrial damage, caspase activation, JNK activation, and Raf-1, phospho-Stat3 and -Stat5 inactivation in mutant and wild-type cells, but differentially down-regulated phospho-Bcr/Abl. Adaphostin and bortezomib synergistically induced apoptosis in wild-type and mutant cells, including T315I mutants. Notably, adaphostin+/-bortezomib potently induced ROS and lethality in mutant cells, effects attenuated by the antioxidant NAC. These findings indicate that adaphostin+/-bortezomib circumvent imatinib resistance due to Bcr/Abl point mutations most likely through ROS generation.
A numerical study of combustion stability in emergency oxygen generators

Combustion in sodium chlorate based emergency oxygen generators is accompanied by significant oscillations of the product oxygen flow rate, which decrease the efficiency of these devices. Reactant melting and convective heat transfer from the generated gas are key steps in the process. In this work, the effect of reactant melting on filtration combustion front propagation stability in gas generating mixtures is investigated numerically. The formation of melting regions is demonstrated in cases with significant convective gas-to-core heat transfer. Numerical simulations exhibit the oscillatory behavior of oxygen generation. By decreasing the effective heat of reaction, reactant melting is detrimental to combustion front stability. The simulations show growth of pulsations with increasing reaction activation energy and decreasing convective heat transfer. A strong stabilization of front propagation is observed when combustion temperature reaches the melting point of reaction product. These results identify the important factors responsible for pulsating behavior of chemical oxygen generators. © 2005 American Institute of Chemical Engineers AIChE J, 2006
Ranging and target detection performance through lossy media using an ultrawideband S-band through-wall sensing noise radar

An S-band noise radar has been developed for through-wall ranging and tracking of targets. Ranging to target is achieved by the cross-correlation between the time-delayed reflected return signal and the replica of the transmit signal; both are bandlimited ultrawideband (UWB) noise signals. Furthermore, successive scene subtraction allows for target tracking using the range profiles created by the cross-correlation technique. In this paper, we explore the performance of the radar system for target detection through varied, lossy media (e.g. a 4-inch thick brick wall and an 8-inch thick cinder-block wall) via correlation measurements using the S-band radar system. Moreover, we present a qualitative analysis of the S-band noise radar as operated under disparate testing configurations (i.e. different walls, targets, and distances.) with different antennas (e.g. dual polarized horns, helical antennas with different ground planes, etc.). In addition, we discuss key concepts of the noise radar design, considerations for an antenna choice, as well as experimental results for a few scenarios.
Buckling delamination in compressed multilayers on curved substrates with accompanying ridge cracks

Residually compressed films and coatings are susceptible to buckle delamination. The buckles often have linear or telephone cord morphology. When the films are brittle, such buckles are susceptible to the formation of ridge cracks that extend along their length, terminating close to the propagating front. The ridge-cracked buckles are invariably straight-sided (not telephone cord) and differ in width. Buckle delaminations of this type occur on flat and curved substrates: having greatest technological relevance in the latter. They occur not only in single layer films but also in multilayers, such as thermal barrier systems. Establishing the mechanics of ridge-cracked buckle delaminations for multilayers on curved substrates serves two purposes. (a) It allows the prediction of buckle delamination and spalling for technologically important systems. (b) It provides a test protocol for measuring properties such as the delamination toughness of the interface and the stresses in the layers. Both objectives are addressed in the article: the latter by devising an inverse algorithm. Implementation of the algorithm is demonstrated for diamond-like carbon films on planar glass substrates and a thermal barrier multilayer on a curved superalloy substrate.
Uranus and the shape of elliptical rings

It is reported that when the star SAO158687 passed behind the Uranus system, its light was occulted twice by the epsilon (fifth) ring of the planet. The first part of the ring to occult was about 100 km wide and the second part was about 40 km wide. The variable width of the ring is accounted for by differences in the orbital eccentricities of the individual particles composing the ring.
Observations of Seasonal Variations in Atmospheric Greenhouse Trapping and Its Enhancement at High Sea Surface Temperature

Greenhouse trapping is examined theoretically using a version of the radiative transfer equations that demonstrates how atmospheric greenhouse trapping can vary. Satellite observations of atmospheric greenhouse trapping are examined for four months representing the various seasons. The cause of the super greenhouse effect at the highest SSTs is examined, and four processes are found to contribute. The middle and upper troposphere must be particularly moist and the temperature lapse rate must be increasingly unstable over the warmest regions to explain the observed distribution of atmospheric greenhouse trapping. Since the highest SSTs are generally associated with deep convection, this suggests that deep convection acts to moisten the middle and upper troposphere in regions of the highest SSTs relative to other regions. The tropical atmospheric circulation acts to both increase the temperature lapse rate and greatly increase the atmospheric water vapor concentration with spatially increasing SST.
Remaking the House and Senate: Personal Power, Ideology, and the 1970s Reforms

Although much has been written on the critical congressional reforms of the 1970s, few studies have analyzed support for reform systematically. In this article, we draw upon previously untapped sources of information that make an individual-level, quantitative analysis possible. We analyze 20 indicators that measure support for a wide variety of reforms in both chambers. Our results reveal a remarkably consistent pattern: in virtually every case, junior members and liberals were more pro-reform than were senior members and conservatives. Also, Republicans were often more likely than Democrats to back reform. Our findings challenge the view that the reform movement was essentially a Democratic party phenomenon; liberals and junior members in both parties�not just Democrats�supported reform.
Numerical and modeling issues in application of CFD to flow in a simplified plenum relevant to a prismatic VHTR

Abstract Computational Fluid Dynamics (CFD) calculations have been performed for turbulent flow inside a plenum model that resembles a section of the lower plenum of a typical helium-cooled prismatic Very High Temperature Reactor (VHTR). Different Reynolds Averaged Navier–Stokes (RANS) based turbulence models are employed to investigate the capability in capturing unsteady large scale coherent structures due to vortex shedding at two different Reynolds numbers. A grid convergence study is conducted with those models which were able to capture unsteady vortex shedding. The non-linear interaction of mesh quality, turbulence model and numerical scheme lead to flow regime changes with significantly different unsteady behaviors. This makes it difficult to assess numerical and modeling uncertainty using the procedures available in the literature. Some remedies to overcome this difficulty are recommended. The numerical uncertainty in the local values of velocity components at selected locations inside the plenum, as well as the uncertainty associated with derived quantities such as wall shear stress at critical locations are calculated and reported. Since there are no experiments corresponding to the present cases simulated, the current analysis can be considered as a blind application of the proposed uncertainty estimation procedures.
Surface tension driven instability of a liquid film flow down a heated incline

Abstract The onset of surface tension driven stationary circulation in a thin film flow down a heated incline is studied by use of linear theory. In the limiting case of a horizontal liquid film, the onset of circulation takes place at finite critical wave numbers and Marangoni numbers for a large range of relevant flow parameters if the stabilizing effect of gravity neglected by previous workers is taken into account. If the angle of inclination Φ of the incline is so small that sin Φ ⪡ 1 and if the Rayleigh number is of order sin 3 Φ , then the flow structure corresponding to the neutrally stable state is that of stream-wise oriented vorticies. The critical Marangoni number of the film on a heated incline is smaller than that of the corresponding horizontal film by an amount sin 2 Φ F where F depends on relevant flow parameters.
Synthesis and pharmacological evaluation of novel 9- and 10-substituted cytisine derivatives. Nicotinic ligands of enhanced subtype selectivity.

We report the synthesis and pharmacological properties of several cytisine derivatives. Among them, two 10-substituted derivatives showed much higher selectivities for the α4β2 nAChR subtype in binding assays than cytisine. The 9-vinyl derivative was found to have a very similar agonist activity profile to that of cytisine.
Contrast Sensitivity Predicts Target Detection Field Performance of Pilots

Our recent research has shown that contrast sensitivity, not visual acuity, can predict a pilot's ability to detect an air-to-ground target in a flight simulator. Here we report a further study that shows a similar predictive power under actual field conditions. Eighty-four Air Force pilots, seated at the end of a runway, typically in groups of ten per week, reported the detection of an approaching T-39 jet aircraft under visibility conditions varying from 0.5 to over 15 miles for 10 field trials. The pilots' detection ranges were correlated with their individual contrast sensitivities and standard visual acuities. Contrast sensitivity, not visual acuity, was found to be a good predictor of detection range. These results have strong implications for the creation of performance-related vision standards.
Androgen receptor immunoreactivity in somatostatin neurons of the periventricular nucleus but not in the bed nucleus of the stria terminalis in male rats.

Abstract Somatostatin (SS) is a neuropeptide responsible for the inhibition of growth hormone (GH) release from the anterior pituitary. The existence of sexual dimorphism in the pattern of GH secretion in several mammalian species strongly suggests a role of sex steroids in the regulation of GH release. It has been recently demonstrated that SS mRNA levels are decreased by gonadectomy in male rats while administration of testosterone reversed the postgonadectomy decrease in hypothalamic SS mRNA levels. The mechanism(s) by which androgens regulate somatostatin neurons are unknown at this time. Both direct and indirect pathways have been suggested. In this study, double-labeling immunocytochemistry was used to address the question of whether SS neurons have androgen receptors in adult male rats. About 70–75% of SS-immunoreactive (-ir) neurons in the periventricular hypothalamic nucleus possess androgen receptors and this co-localization persists throughout the rostrocaudal extent of this nucleus. In the bed nucleus of the stria terminalis, no SS-ir neurons were shown to have androgen receptors. These results suggest that androgens may directly exert their effect upon SS neurons in the periventricular nucleus.
The High Temperature Behaviour of TiAl Containing Carbide Reinforcements

The mechanical behaviour of γ-TiAl reinforced with Ti2AIC platelets is investigated in the temperature range between 293K and 1255K. Comparison with the particle-free material of same matrix composition reveals a pronounced strengthening effect of the platelike reinforcements up to about 1000K. However, under creep loading the composite is remarkably weak. It is shown that this weakness is caused by diffusional creep along the particle/matrix interface. Modelling of this process indicates that the dimensions of the Ti2AlC particles (thickness d≈1μm, length 1≈20μm) are too small to avoid this unwanted deformation mechanism. It is concluded that thicknesses well above 10±m are needed to maintain reinforcement strengthening at high temperature in this system.
Concurrent DTA, electrothermal analysis and TG using DuPont thermal analysis equipment

Abstract Concurrent TG—DTA and TG—EC measurements were performed using a modified DuPont thermobalance and control console. The DTA and EC sample probes, which were inserted into the furnace tube, permitted DTA and EC measurements to be made in conjunction with TG data. The TG curve was recorded on the DuPont control console plotter while the DTA or EC curves were recorded on an outboard X—Y plotter. The use of the combined techniques is illustrated by TG—DTA and TG—EC curves of CuSO 4 - 5H 2 O, (NH 4 ) 2 C 2 O 4 ) - H 2 O, and NH 4 NO 3 .
Robot reliability using fuzzy fault trees and Markov models

Robot reliability has become an increasingly important issue in the last few years, in part due to the increased application of robots in hazardous and unstructured environments. However, much of this work leads to complex and nonintuitive analysis, which results in many techniques being impractical due to computational complexity or lack of appropriately complex models for the manipulator. In this paper, we consider the application of notions and techniques from fuzzy logic, fault trees, and Markov modeling to robot fault tolerance. Fuzzy logic lends itself to quantitative reliability calculations in robotics. The crisp failure rates which are usually used are not actually known, while fuzzy logic, due to its ability to work with the actual approximate (fuzzy) failure rates available during the design process, avoids making too many unwarranted assumptions. Fault trees are a standard reliability tool that can easily assimilate fuzzy logic. Markov modeling allows evaluation of multiple failure modes simultaneously, and is thus an appropriate method of modeling failures in redundant robotic systems. However, no method of applying fuzzy logic to Markov models was known to the authors. This opens up the possibility of new techniques for reliability using Markov modeling and fuzzy logic techniques, which are developed in this paper.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Analysis of a hybrid zone between subspecies of the tiger salamander (Ambystoma tigrinum) in central New Mexico, USA

We analyzed patterns of variation in polymorphic loci across a contact zone between two subspecies of tiger salamander, Ambystoma tigrinum nebulosum and A. t. mavortium, in west-central New Mexico. We found no fixed differences between A. t. mavortium and A. t. nebulosum. Allele frequencies across the contact zone did not vary concordantly among loci, but frequencies at two loci varied with elevation. Gene flow extends through the contact zone from A. t. mavortium into A. t. nebulosum, but not conversely. A. t. mavortium and A. t. nebulosum have no obvious impediments to gene flow within this contact zone, but some populations differ in time of reproduction. The contact zone comprises a variety of habitats, approximating typical A. t. mavortium or A. t. nebulosum habitats. There is an irregular pattern of differences in allelic frequencies among populations that covaries with habitats and is consistent with a model of a mosaic contact zone. Our results contrast with those of a study along the Front Range in Colorado, where allelic composition at some loci changed abruptly across a narrow zone of contact. These contrasting results suggest that the dynamics shaping the contact zone between the same taxa may differ. Absence of a similar pattern of genetic differentiation between A. t. mavortium and A. t. nebulosum in New Mexico and in Colorado suggests a complex set of evolutionary interactions along the eastern front of the Rocky Mountain axis.
Studies of isolated adult rat heart cells: the surface morphology and the influence of extracellular calcium ion concentration on cellular viability.

Abstract Rat cardiac muscle was dissociated into single cells by a coronary perfusion technique with collagenase and hyaluronidase in a Ca-free medium. Retention of the cylindrical shape of isolated muscle cells could be achieved by regulation of [Ca2+]0 and temperature. Cells kept at 4 °C, and 0.01 mM CaCl2 remained cylindrical for more than a week and contracted spontaneously upon warming at 37 °C. At [Ca2+]0 between 0.1–2 mM and 37 °C, cells underwent contracture and rounded up. Scanning (SEM) and transmission electron microscopy were used to analyze the structure of cylindrical and rounded muscle cells. The extracellular aspect of the sarcolemma at lateral cell surfaces and intercalated disc regions were clearly revealed for SEM analysis. Both the distribution and number of T-tubule openings on the surfaces can be estimated and a three-dimensional description of the intercalated disc obtained. This study reveals that isolated adult heart cells are extremely sensitive to [Ca2+]0, but with careful control of this cation, this preparation should be helpful in the analysis of both sarcolemmal structure and the pathological changes which accompany myocardial injury.
Pen harvester for powering a pulse rate sensor

Rapid developments in the area of micro-sensors for various applications such as structural health monitoring, bio-chemical sensors and pressure sensors have increased the demand for portable, low cost, high efficiency energy harvesting devices. In this paper, we describe the scheme for powering a pulse rate sensor with a vibration energy harvester integrated inside a pen commonly carried by humans in the pocket close to the heart. Electromagnetic energy harvesting was selected in order to achieve high power at lower frequencies. The prototype pen harvester was found to generate 3 mW at 5 Hz and 1 mW at 3.5 Hz operating under displacement amplitude of 16 mm (corresponding to an acceleration of approximately 1.14 grms at 5 Hz and 0.56 grms at 3.5 Hz, respectively). A comprehensive mathematical modelling and simulations were performed in order to optimize the performance of the vibration energy harvester. The integrated pen harvester prototype was found to generate continuous power of 0.46–0.66 mW under normal human actions such as jogging and jumping which is enough for a small scale pulse rate sensor.
Stress factor assessment for microsystems-enabled photovoltaics

Microsystems-enabled photovoltaics (MEPV) utilizes microfabrication techniques to achieve various scaling advantages and attain high power density and efficiency. This paper describes accelerated test results for silicon MEPV that were used for development of a reliability model. MEPV has previously demonstrated good resilience to high reverse bias voltages. We further study this performance parameter by examining the degradation effects of prolonged reverse bias stress at voltage levels below breakdown. Light-induced degradation is examined through extended exposure to the output of a 405 nm laser diode. Samples are also subjected to moderate temperature cycling. The post-stress samples are evaluated through electrical tests and defect localization techniques. The results can be used to generate lifetime predictions and provide insights into design improvements for more reliable MEPV.
Structural, spectroscopic and redox characterization of the soluble complexes [M(SC6H4NR2)4]2− and the effects of N-H … S hydrogen bonds

Abstract The complex [(C2H5)4N]Na[Fe(SC6H4NH2-2)4] (1) has been synthesized in order to study the influence of ligand hydrogen bonding on the redox potential of monomeric iron-sulfur complexes. Compound 1 crystallizes in space group P 2 1 c , with a = 11.747(4), b = 25.058(5), c = 12.301(3) A , β = 106.22(2)° and Z = 4 . The related cobalt complex [(C2H5)4N]2[Co(SC6H4NH2−2)4] (2) was also synthesized and found to crystallize in space group Pccn with a = 12.544(3), b = 13.920(3), c = 24.646(15) A and Z = 4 . The average MS bond length is 2.341(1) A in 1 and 2.295(2) A in 2. The electronic absorption spectrum of 2 is consistent with an equilibrium between the respective tetrahedral and pseudo-octahedral complexes [Co(SC6H4NH2-2)4]2− and [Co(SC6H4NH2-2)3]−. The proton NMR spectra of 1 and 2 in saturated CD3CN solutions show unusually broad, isotropically shifted ligand proton signals, indicative of exchange broadening. This result is consistent with the occurrence of [M(SC6H4NH2−2)4]2− complex anions in equilibrium with species that could not be identified by 1H NMR. The cyclic voltammetry data for 1, 12.0 mM in CH3CN, show two irreversible redox waves with Eox at −0.50 and −0.25 V, respectively, relative to SCE. The peak at −0.50 V is a likely candidate for the redox couple of the complex [Fe(SC6H4NH2-2)4]2−. The peak at −0.25 V probably belongs to a pseudo-octahedral iron complex.
Work in progress — The iCollaborate MSE project

The overall objectives of the research work in the iCollaborate MSE (Materials Science and Engineering) project are to measure if improvements in student learning outcomes, student engagement, and successful course completion are possible if the structure in basic materials engineering courses is transformed from primarily deductive practice to an Information Communication Technology (ICT) enabled inductive teaching and learning environment. The specific innovations that are proposed in the project are the development of MSE education applications for the iPod Touch, which facilitate and support collaborative learning opportunities, by targeting specific student learning objectives that are known to be challenging for many students in basic MSE courses. We are studying whether the combination of specific learning objective targets, completed in collaborative groups, and supported by conceptually contained data, visuals, audio, and information from the iPod Touch, will lead to specific improvements in learning outcomes for students. The purpose of this work-in-progress paper is to describe the initial suite of iPod applications that have been created, the challenges faced in the development of them, and the observable differences in collaborative experiences of the students with and without the devices. This work is supported by the National Science Foundation, CCLI, grant, # 0941012.
Helping or Hurting: Are Adolescent Intervention Programs Minimizing Racial Inequality?:

In 1965, appalled by the racial disparity with respect to access to higher education, the federal government implemented the Higher Education Act. After more than 40 years of programmatic intervention, gaps persist. As such, this study analyzes two of the three original HEA programs—Upward Bound and Talent Search—focusing on race/ethnicity and socioeconomic status, examining program effectiveness on a national scale. Based on deformed choices ideology and using a nationally representative data set, the National Education Longitudinal Study, event history analysis is employed to determine the effect of Upward Bound and Talent Search with respect to college attendance rates. Both hazard and risk ratios are used to determine the interaction between program participation and race/ethnicity. Program participation significantly benefits low-SES African American and impoverished Hispanic students, providing college attendance opportunities equivalent to that of average-SES White students. Once the school effect ...
Adsorption of aminopyridines to phosphatidylserine membranes

Abstract Aminopyridines belong to the class of compounds which facilitate synaptic transmission at low calcium concentration, an effect associated with the block of K+ channels, enhanced entry of calcium into presynaptic terminals and greater release of transmitter. We have measured the zeta-potential of phosphatidylserine vesicles in the presence of aminopyridines and some related compounds in order to relate the strength of association of the aminopyridines with their biological effectiveness. The dependence of zeta-potential on the concentration of aminopyridines was analyzed in terms of the Langmuir-Stern-Grahame adsorption model. The rank order of the association constants (in M−1) obtained in the study was as follows: 3,4-diaminopyridine (6.5), 4,5-diaminopyrimidine (3.8), 4-aminopyridine (2.6), 3-aminopyridine (1.8), 2-aminopyridine (1.6), 4-dimethylaminopyridine (0.5), 4-aminopyridine methiodide (0.2), and, as control, calcium (12.1). The comparison of association constants with published results of the electric potential maps obtained by the CNDO / 2 method suggests that binding to phosphatidylserine membrane increases with the density of excess charge on the protonated aminopyridine ring. We find that the sequence of potencies of aminopyridines in blocking K+ channels, in releasing transmitter, and in the shifts of calcium concentration dependence of synaptic transmission are about the same as the sequence of association constants with the phosphatidylserine membrane. Assuming that the binding domain for aminopyridines in the presynaptic terminal has similar adsorption properties as the phosphatidylserine membrane, we estimate the electric potential difference between the domain and the external solution to be between —300 and —340 mV.
Graduate Teaching Assistants and Inquiry-Based Instruction: Implications for Graduate Teaching Assistant Training

This article examines the teaching environment and training program experienced by chemistry graduate teaching assistants (GTAs) at a large research–doctoral university through interviews and observations of the GTAs. Details of the chemistry training program and GTA evaluations of the training are discussed. The teaching styles of the introductory laboratory GTAs are discussed, particularly in light of inquiry-based instruction currently being introduced into undergraduate laboratory classes. The findings from this study suggest directions for chemistry GTA training programs. Specifically, training programs must meet the needs of chemistry GTAs, assisting them with instruction and assessment. In addition, chemistry GTAs need specific training to successfully implement reform-based instruction, such as scientific inquiry-based instruction, in their laboratory classes.
Effect of Albumin Binding on Extraction of Sulfobromophthalein by Perfused Elasmobranch Liver: Evidence for Dissociation‐Limited Uptake

We investigated the role of serum albumin in the hepatic uptake of organic anions by determining the effect of added bovine albumin on sulfobromophthalein (BSP) uptake in skates, an animal which naturally lacks this protein. A single-pass perfused liver model was used to determine steady-state net uptake rates as the BSP or BSP and albumin concentrations were systematically varied. Results indicated that two different steps in the uptake process are capable of limiting the uptake rate depending on the albumin and BSP concentrations selected. At higher rates of uptake corresponding to higher BSP concentrations (up to 112 μM), saturation kinetics were observed as the BSP concentration was varied, with apparent Kra and Vmax values which were independent of the albumin concentration (0.05 to 0.75%). These data suggest that under these conditions uptake is limited by a saturable step intrinsic to the liver. In contrast, for lower BSP concentrations and albumin concentrations below about 0.5%, a different kinetic pattern was seen which suggested that the rate-limiting step in uptake was transfer of BSP from albumin to the liver. The latter data were found to be consistent with a model in which the limiting step in the transfer process is spontaneous dissociation of the BSP from binding sites on albumin within the sinusoid. These results suggest that skate liver clears BSP from albumin solutions by a two-step mechanism in which dissociation from albumin is followed by a saturable process consistent with carrier-mediated transport. The albumin concentration and uptake velocity are important factors in determining which of these steps limits the uptake rate. Clearance is efficient and irreversible even though elasmobranch liver lacks high-affinity cytosolic binding proteins for BSP, and elasmobranch plasma does not normally contain albumin.
Theoretical studies of reaction chromatograms by the fast fourier transform technique

Abstract The theoretical treatment of the elution profile in chromatographic reactors by the Fast Fourier Transform technique is presented. The mass balance equations describing linear reaction chromatography with multiple components under equilibrium and non-equilibrium conditions are solved by means of the Laplace transformation. The Fast Fourier Transform algorithm can invert these transfer functions from Laplace domain into time domain solutions in a simple and rapid manner. From the time domain solutions the relevant reaction kinetic parameters in reaction chromatography may be isolated and evaluated.
Effects of latanoprost on tyrosinase activity and mitotic index of cultured melanoma lines

The intraocular pressure-lowering drug latanoprost, a phenyl-substituted analogue of prostaglandin F2 alpha (PGF2 alpha), increases iris pigmentation in a small number of patients. In theory, this could be due to increased melanogenesis or melanocyte proliferation. To distinguish these two possibilities, the present study examined the effects of latanoprost on tyrosinase activity (the rate-limiting step for melanin synthesis) and mitotic index of cultured melanoma lines. Murine cutaneous melanoma lines (S91 and B16), and human uveal (OCM1, OCM3, and OM431) and cutaneous (SK-MEL5 and M21) melanoma lines were cultured with PGE1, PGE2, PGF2 alpha, latanoprost, or the adenylate cyclase stimulating agent forskolin. After treatment, tyrosinase was assayed with respect to its dopa oxidase activity using a colorimetric assay. PGE1, PGE2, PGF2 alpha, and latanoprost greatly increased tyrosinase activity in murine melanoma lines and caused small increases in tyrosinase activity in human uveal and cutaneous melanoma lines. Similar results were obtained with the cAMP-elevating compound forskolin. Cyclic AMP content, as determined by an enzyme-linked immunoassay, was similarly increased by all treatments, with forskolin being the most potent stimulator. Since the species difference in tyrosinase activity was observed without an apparent difference in induction of cAMP, latanoprost would appear to induce tyrosinase activity through a non-cAMP-dependent pathway. Finally, latanoprost and PGF2 alpha did not enhance the mitotic index of human uveal or cutaneous melanoma lines, measured by [6-3H] thymidine uptake, although they increased the mitotic index of one murine cutaneous line. Given that latanoprost induced tyrosinase activity, but did not increase the mitotic index in any of the human melanoma lines studied, this suggests that the in vivo iris pigmentation side effect of latanoprost may not result from increased cell division, but from elevated tyrosinase activity.
Ambiguity and Organizational Analysis The Consequences of Micro versus Macro Conceptualization

This article marks out the contrasting assumptions and implications of two prevalent yet implicit approaches to organizational analysis: the micro and macro perspectives. It traces ambiguities in the concepts of organizational power, politics, change, and policymaking to the dual meanings possible for such terms given alternate micro and macro perspectives. Practitioner styles, mirroring micro and macro scholarly orientations are also described.
DFS70/LEDGFp75: An Enigmatic Autoantigen at the Interface between Autoimmunity, AIDS, and Cancer

Clinical and diagnostic laboratories often encounter patient sera containing antinuclear antibodies (ANAs) that produce a nuclear dense fine speckled immunofluorescence pattern on HEp-2 cells. These autoantibodies usually target the dense fine speckled protein of 70 kD (DFS70), commonly known as lens epithelium-derived growth factor p75 (LEDGFp75). Anti-DFS70/LEDGFp75 autoantibodies have recently attracted much interest because of their relatively common occurrence in sera from patients with positive ANA tests with no clinical evidence of systemic autoimmune rheumatic disease (SARD). Their presence has been documented primarily in patients with diverse non-SARD inflammatory conditions and “apparently healthy” individuals. While there is circumstantial evidence that depending on the context these autoantibodies could play protective, pathogenic, or sensor roles, their significance remains elusive. DFS70/LEDGFp75 has emerged during the past decade as a stress transcription co-activator relevant to HIV integration, cancer, and inflammation. It is not clear, however, what makes this protein the target of such a common autoantibody response. We suggest that a better understanding of DFS70/LEDGFp75 biology is key to elucidating the
Process Technology Variation

Moore's law technology scaling has improved performance by five orders of magnitude in the last four decades. As advanced technologies continue the pursuit of Moore's law, a variety of challenges will need to be overcome. One of these challenges is the management of process variation. This paper discusses the importance of process variation in modern transistor technology, reviews front-end variation sources, presents device and circuit variation measurement techniques, including circuit and memory data from the 32-nm node, and compares recent intrinsic transistor variation performance from the literature.
Aluminum and chronic renal failure: sources, absorption, transport, and toxicity

In normal subjects the gastrointestinal tract is a relatively impermeable barrier to aluminum with a low fractional absorption rate for this metal ion. Aluminum absorbed from the gastrointestinal tract is normally excreted by the kidneys; in the presence of impaired renal function aluminum is retained and accumulates in body tissues. Aluminum-containing medications are given, by mouth, to patients with chronic renal failure as phosphate-binding agents for the therapeutic control of hyperphosphatemia. Patients with chronic renal failure are also exposed to aluminum in domestic tap-water supplies used either for drinking or, in those on dialysis treatment, in the preparation of their dialysate. In patients with end-stage chronic renal failure, particularly in those on treatment by hemodialysis, the accumulation of aluminum in bone, brain, and other tissues is associated with toxic sequelae. An increased brain content of aluminum appears to be the major etiological factor in the development of a neurological syndrome called either "dialysis encephalopathy" or "dialysis dementia"; an increased bone content causes a specific form of osteomalacia. An excess of aluminum also appears to be an etiological factor in a microcytic, hypochromic anemia that occurs in some patients with chronic renal failure on long-term treatment with hemodialysis. The various mechanisms involved in the toxic phenomena associated with the accumulation of aluminum in body tissues have not been clearly defined but are the subject of extensive investigations.
Expanding Policy Options for Educating Teenagers

David Stern argues that some basic features of the American high school must be modified if it is to serve all students successfully. He notes, for example, that only three-quarters of U.S. high school students graduate four years after beginning ninth grade and that the National Assessment of Educational Progress found no improvement in reading or mathematics for seventeen-year-olds between 1971 and 2004. The nation's system for educating teenagers, says Stern, seems to be stuck, despite the constant efforts of teachers and repeated waves of reform. Citing two widely accepted public purposes of educating teenagers-preparation for civic participation and for economic self-sufficiency-Stern proposes four new strategies to achieve those goals. He draws on empirical evidence suggesting that these are promising directions for research and policy, but acknowledges that existing studies provide only limited guidance. First, he says, schools should continue the current trend toward integrating educational options to provide young people with skills and experiences that pave the way to both college and careers. Second, states and districts should tie education funding not simply to the number of students attending school, but also to what young people learn, whether they graduate, and whether they find jobs or enroll in postsecondary education. Such a move, he argues, would encourage teaching and learning formats that use students' time more effectively. Third, more adults in addition to classroom teachers should be involved in educating teenagers. Other adults acting as academic advisers, learning coaches, student advocates, internship supervisors, mentors, and college counselors could help guide the education of teenagers inside and outside of school and provide some relief for the chronic shortage of teachers. Fourth, schools should expand the options for educating teenagers outside of geographically fixed schools. Combining improved Internet-based curriculum with internships and civic engagement projects, for example, may produce better results for many young people and also may promote academic achievement for teenagers who do not thrive in conventional classrooms and for those who face academic and social challenges when they move from one place to another. Stern argues that the limited success of today's high schools makes such new initiatives well worth trying and evaluating. www.futureofchildren.org
Robust curve detection by temporal geodesics

The formation of temporal geodesics (i.e., fast routes) in a velocity field seems to offer a means of detecting curves by parallel hardware in a wide range of images with little prior design information. This hypothesis was tested by devising and constructing a dotted-curve detector based on it, and applying the detector to several synthetic dotted images covering a wide range of dotted curves and dotted partially coherent noise. The results are encouraging. The dotted-curve detector searches for fast routes in a velocity field determined locally by the approximate collinearity or cocircularity of clusters of dots, and globally by the tortuousness of the route and the uniformity of the spacing of dots along the route. The routes are found by a parallel adaptive classification of the dots into curve dots and noise dots, followed by a parallel merging and splitting of graphs spanning temporal close dots or subgraphs at successively higher levels of abstraction. >
Filtering features for a composite event definition language

This research has enhanced a distributed, rule-based application integration environment with a composite event definition language (CEDL) and detection system. CEDL builds on existing composite event operators and selection modes, adding features to support the filtering of primitive and composite events. The filtering features include basic parameter filtering on primitive and composite events, aggregate and quantifier filters on cumulative event parameters, and time filters for defining the lifetime of the composite event detection process. This paper presents examples of CEDL, illustrating the expression of application-oriented events through the aggregation and correlation of distributed events.
Optimal control and performance of variable stiffness devices for structural control

This paper addresses control of structural vibrations using semi-active actuators that are capable of producing variable stiffness. Usually vibration suppression is achieved using damping devices rather than variable stiffness ones. However, variable stillness devices have significant advantages for shock isolation purposes. In this work we use a passivity approach to establish the requirements for the control law for a structure equipped with semi-active variable stiffness devices. We also solve a minimum-time, optimal control problem that demonstrates that our, passive, resetting feedback control law approximates the optimal control. An example simulation is given that shows favorable damping qualities are achieved for a three story building subject to the El Centro earthquake.
Distance Education: What Do Our Students Tell Us?

Objective: Given the rapid growth of distance education in social work, there is need to evaluate contemporary efforts in schools of social work, including multisite assessments of distance learning. This article reports multisite data addressing the question of how students enrolled in distance learning courses at two urban campuses (one using Interactive TV (ITV) and the other videotape) perceive their learning experiences. Method: 142 students' responses were received from voluntarily submitted survey questionnaires querying students regarding their experiences with the technology used in their course, their learning environment, the instructor's teaching skills, and perceived resource availability. Results: Respondents at both sites were pleased with their learning experience, with 100% of ITV students and 75% of the students who viewed video - taped courses indicating they would enroll in distance learning again. Conclusions: The opin- ions of remote student respondents suggest positive learning experiences are had by students in schools of social work, particularly as they experienced these two delivery formats. Distance education includes all types of formal instruction conducted when teachers and students are located a geographic distance from one another. Historically, distance learning evolved from the field of correspondence edu- cation. Today, telecommunication technology is the likely connector between the instructor and his or her remote students (Gilbert, 1995). These new technologies provide us with opportunities to expand access to educa- tion and information at a favorable economic cost. As a result, interest in dis - tance education has grown significantly in recent years among social work educators. In fact, a recent survey of accredited schools of social work in the United States found a 5% rise in the use of distance education over a 2-year period, with 16% of all accredited programs now employing technologies to deliver social work courses (Siegel, Jennings, Conklin, & Flynn, 1998).