cssi/SciSciGPT-SciSciNet huggingface dataset:
Migratory patterns of B lymphocytes. I. Fate of cells from central and peripheral lymphoid organs in the rabbit and its selective alteration by anti-immunoglobulin.

Abstract Homing properties of 3H-adenosine-labeled bone marrow (BM), appendix (App), and mesenteric (Mes) and popliteal (Popl) lymph node (LN) cells were studied in the rabbit. While BM cells 24–48 hr after transfer produced equivalent radioactivity (cpm/mg) in App, Mes, and Popl LN of recipients, App and Popl LN cells did not, showing a highly significant preference for their organ of origin. “Homing to antigen” was shown if Popl LN cells were taken from rabbits immunized to the same antigen as was injected in one footpad of recipients 2 weeks earlier. Pretreatment of App cells with sheep anti-rabbit Ig abolished their preferential localization in App as judged in recipients killed 5 hr after transfer, but this was a transient effect and no longer demonstrable by 24 hr. Histological localization of labeled cells showed the corona of follicles in the center of dome-shaped areas of the App to represent “B-influx areas” after transfer of all cell types and this localization was blocked temporarily (5 hr) by prior incubation of App cells with anti-Ig. Thymus-dependent interfollicular areas showed labeled cells after LN cell transfer, and less after App cells, but none after BM. Emphasized in the discussion are (i) the possible effect of antigen on homing of B cells and (ii) the implications of the findings with respect to the appendix as a peripheral lymphoid organ.
Impact of alias resolution on traceroute-based sample network topologies

Most Internet measurement studies utilize traceroute-collected path traces to build Internet maps. In this paper, we measure the impact of alias resolution problem on Internet topology measurement studies. Our analysis shows that the alias resolution process has a significant effect on the observed characteristics of the topology maps.
Studies of Calcification in Plants

It has long been known that insoluble calcium salts in the forms of the carbonate,sulfate, and oxalate occur as optically visible crystals in a wide variety of plants(Solereder, 1908). The deposits are commonly considered to be waste products and occur in a variety of shapes, often seeming to fill a cell. Calcium oxalate crystals are by far the most common, and a single cell may contain from one to many hundreds.Crystal cells have been studied by light and polarization microscopy (see reviews in Guilliermond, 1933; Kuster, 1956) and the crystals have been studied by various techniques including X-ray and infra-red analysis (Pobeguin, 1943; Walter-Levy, 1962).
LASER SPECTROSCOPY OF THE HYDROGEN MOLECULAR ION HD

The hydrogen molecular ion is the simplest bound system that can be called a molecule. Therefore it plays a role in the theory of molecular structure that corresponds to the role of the hydrogen atom in atomic structure theory. The experimental situations, however, little resemble each other, for while the hydrogen atom spectrum is among the most precisely and the earliest studied, that of the hydrogen molecular ion has languished until recently among the “forgotten poor,” spectroscopically speaking. In this talk I will summarize briefly the work [1] several colleagues and I are doing in this area. While by comparison with some of the other spectroscopic experiments reported at this conference it is not yet correct to call our results extremely precise, we have at least been able to uplift the hydrogen molecular ion spectrum to “middle-class respectability,” and have been able to make a significant test of the first-principles theoretical calculations of its spectrum. Our absolute accuracy, as I will show, now is a few parts in 107.
The structure of microtubule ends during the elongation and shortening phases of dynamic instability examined by negative-stain electron microscopy

Microtubules (MTs) are dynamic polymers that can exist in phases of elongation and rapid-shortening at steady-state. These phases have been observed in vitro and in living cells, and this property of MTs has been termed ‘dynamic instability’. The purpose of this study was to use negative-stain electron microscopy (EM) to test if there are structural differences between the ends of MTs in the elongation and shortening phases, which could provide insight into the mechanisms of dynamic instability. MTs in the elongation phase were obtained by seeding either highly purified porcine brain tubulin (PC-tubulin) or tubulin containing microtubule-associated proteins (MTP), from isolated Tetrahymena axonemes. The results are that, in addition to intact cylindrical MTs, a significant fraction of the tubulin polymer in the elongation phase occurred as sheets of parallel protofilaments, as found in previous investigations with self-assembled MTs. Therefore, sheet formation is an intrinsic property of MT assembly that does not depend on the tubulin purity or the method of nucleation. Also, since sheets lack helical symmetry, at least a fraction of tubulin polymers seeded from axonemes did not assemble by helical addition of tubulin dimers to the ends, an assumption often made in mathematical models of dynamic instability. Sheets and intact MTs that were seeded from isolated axonemes, emanated both from the intact MT wall of the axoneme A-subfiber and from the incomplete wall of the B-subfiber. Therefore, axoneme seeds do not provide a homogeneous nucleation site for tubulin growth, or produce a homogeneous population of tubulin polymers under our conditions. Previous evidence has indicated that MT disassembly can occur by a segmental release of tubulin oligomers from the ends and at sites along the length of MTs. However, these studies were performed with MTP, and disassembly was induced by cold depolymerization. We examined MT shortening under conditions that closely represent shortening via dynamic instability, namely isothermal dilution at 37 degrees C of self-assembled MTs. This was compared with the morphology of cold-disassembled MTs. The cold-depolymerization of MTs composed of MTP showed rings and protofilament curls as previously observed using similar methods. Surprisingly, cold-depolymerization of MTs assembled from PC-tubulin induced not only shortening, but also the opening of a large fraction of MTs into sheets, suggesting that the MT lattice contains a cold-labile seam. Under conditions that mimic stochastic shortening, MTs were intact, closed cylinders with ends that were approximately blunt. Therefore, rapid shortening occurs at the ends of the MT, without a long-range disruption of the MT wall. In conclusion, MTs in the elongation phase can have highly irregular ends and need not elongate by a helical assembly process. Conversely, MTs in the shortening phase can have relatively blunt, even ends and can depolymerize in a relatively uniform fashion.
Thinking critically about critical thinking: ability, disposition or both?

Medical Education 2011: 45: 625–635 Objectives The objectives of this study were to determine the extent to which clinician-educators agree on definitions of critical thinking and to determine whether their descriptions of critical thinking in clinical practice are consistent with these definitions. Methods Ninety-seven medical educators at five medical schools were surveyed. Respondents were asked to define critical thinking, to describe a clinical scenario in which critical thinking would be important, and to state the actions of a clinician in that situation who was thinking critically and those of another who was not. Qualitative content analysis was conducted to identify patterns and themes. Results The definitions mostly described critical thinking as a process or an ability; a minority of respondents described it as a personal disposition. In the scenarios, however, the majority of the actions manifesting an absence of critical thinking resulted from heuristic thinking and a lack of cognitive effort, consistent with a dispositional approach, rather than a lack of ability to analyse or synthesise. Conclusions If we are to foster critical thinking among medical students, we must reconcile the way it is defined with the manner in which clinician-educators describe critical thinking – and its absence – in action. Such a reconciliation would include consideration of clinicians’ sensitivity to complexity and their inclination to exert cognitive effort, in addition to their ability to master material and process information.
The effects of lead on otoacoustic emissions and auditory evoked potentials in monkeys

Auditory functioning was assessed in two groups of adult rhesus monkeys (11 years of age). One (n = 11) received modest exposure to lead early in life and the other (n = 8) served as controls and did not receive any lead supplementation. Two lead-exposed monkeys had abnormal distortion product otoacoustic emissions (DPEs) and smaller amplitude or absent evoked potentials. These monkeys had the highest blood levels recorded in their respective groups. For the remaining lead-exposed monkeys there was little difference between their DPEs and the DPEs of the control monkeys with one exception. DPE amplitudes of the control monkeys increased more rapidly as a function of stimulus level than those of the lead-exposed monkeys at most frequencies. There was also a significant but modest effect of lead exposure on the auditory brain stem evoked responses (ABRs) of these lead-exposed monkeys. There was no apparent effect on the middle latency evoked responses (MLRs), although that result could be due to the relatively greater variability of the MLR.
Field size dependence of radiation sensitivity and dose fractionation response in skin.

Four sets of data from the literature were analyzed to assess the effects of field size on dose tolerance and dose fraction size dependence in irradiated skin. The data consisted of combinations of total dose and dose per exposure (or number of fractions) required to yield a given degree of visible damage to the skin, for fields of different sizes. Putative cell survival curves were constructed, under the assumptions that the isoeffect represents a fixed cell survival, and that each exposure during a course of fractionated irradiation has equal effect on cell survival. The analysis showed that 1) overall sensitivity to radiation, and 2) dependence on dose per exposure, both increase with field size. To account for these results we describe a model that can be qualitatively related to the geometric properties of the dermal vascular network. First, vascular function after irradiation should depend on the length of the vessels exposed to the radiation. This directly predicts an increasing sensitivity in large irradiated fields. Furthermore, if vascular function determines radiation response, the shape of the shoulder (low-dose) region of the effective survival curve will depend on the average number of vessels nourishing each cell, with a more pronounced shoulder for a high multiplicity of vessels. The model predicts a greater fractionation sensitivity in large than in small fields, in agreement with our analysis of the isoeffect data. It is therefore possible that the advantages of hyperfractionation in reducing late effects in normal tissues may be related to vascular architecture, and not to inherent differences between late and acutely responding cell populations.
PLANTS OF THE NEW ALBANY SHALE. III: CHAPELIA CAMPBELLII GEN. N.'

A B S T R A C T The single specimen from the Falling Run Member of the Sanderson Formation is interpreted as a segment of a petiole from a region just proximal to a major branching of the frond. The specimen is characterized, basally, by a four-lobed primary xylem strand. Following stelar branching there are two outer papilionoid strands that produce alternate traces bilaterally and two inner clepsydroid strands, oriented at right angles to the plane of the frond. The frond, which appears to be a morphologically flattened and modified lateral branch system, is probably of calamopityean or pteridosperm affinity. IT IS OFTEN DIFFICULT, if not impossible, to distinguish between cauline and foliar axes in primitive plants. Considerable evidence suggests that leaves have evolved by modification of lateral branch systems. If this is true, it is to be expected that primitive leaves will have some stem-like characteristics. The structure of Tetraxylopteris schmidtii (Beck, 1957), a presumed progymnosperm and possible pteridosperm precursor, emphasizes this problem and illustrates a primitive condition in the evolutionary differentiation of leaf and stem. In this plant the cruciform primary xylem strand of axes considered to be the "rachises" is repeated in the primary and secondary "pinna" axes of lateral branch systems which seem functionally to be leaves (fronds). These "fronds" are, however, radially symmetrical with both primary and secondary pinna axes being disposed in an opposite and decussate manner. There are no laminae produced in this system, the terminal branches being small, terete segments produced by one or two dichotomies. These branch systems, interpreted as homologous with leaves, are therefore predominantly stem-like. This problem has again been emphasized by A. G. Long's work on Tristichia ovensi. In Tristichia small laminae are apparently produced only terminally, the large part of the fronds consisting of naked axes. Long (1961) stresses the great difficulty in distinguishing between stems and petioles in compression specimens, but in petrifactions he identifies the axes with internal structure of radial symmetry (reflected externally by a radial arrangement of lateral appendages) as stems, and those with bilateral symmetry as
Measuring profit efficiency with McFadden's gauge function

Abstract Traditional input or output-based technical efficiency measures render composed error stochastic profit frontier estimation intractable for cross-sectional data. An alternative measure based on the gauge function simplifies estimation, permitting econometric techniques commonly used for stochastic cost frontiers.
Devitrification of glass around collapsed babbles in tektites

Abstract Devitrification was first observed around partly collapsed bubbles (vacuoles) in Santa Mesa philippinites heated by the fire which destroyed Manila near the end of World War II. This localization of devitrification furnishes independent evidence that bubbles in normal tektites were formed by water vapor and that the very low pressure in normal tektite bubbles resulted from the absorption in or reaction of the water vapor with the surrounding tektite glass. Although tektites are essentially anhydrous they do contain a trace of water, in fact more than enough to form all the bubbles found in tektites. Experiments show that a similar amount of devitrification and partial collapse of bubbles takes place in philippinites when heated about 4 days at a temperature of 825°C. Under identical conditions of time and temperature australites, indochinites and javanites showed equivalent amounts of change in shorter times. Bediasites showed no change in 7 days. Neither collapse nor devitrification took place around bubbles in Muong Nong-type tektites, indicating that water vapor was not an important constituent of the gas forming these bubbles and that the pressure in the bubbles approaches equilibrium with atmospheric pressure.
Promoting energy strategies on Eco-Certified accommodation websites

The attention on climate change by the international media and the international tourism industry has generated greater interest in issues of energy consumption and greenhouse gas emissions. This study seeks to explore the intersection of these two foci. The purpose of this paper is to examine the type of information about energy use and strategies to reduce energy consumption and greenhouse gas emissions provided by accommodations Eco-Certified by Ecotourism Australia. Specifically, this examination addresses what information is provided, how it is presented, and what the objectives are in promoting this information. Although energy issues are a component in Eco Certification, just under half of the 50 accommodations included provided information about energy on their websites. These accommodations provided information about activities undertaken in each of four strategies previously identified for reducing greenhouse gas emissions in the accommodation sector – reducing energy use, improving energy effic...
Three-dimensional motion analysis by direct matching

We describe a direct-matching approach to determining motion of a rigid body from two time-sequential perspective views. The method does not require finding feature correspondences. It is valid under the following assumptions: (1) Brightness constancy—the brightness of an image point corresponding to a fixed object point does not change after motion. (2) The mathematical form of the object surface is known to within a finite number of parameters. We also show how the computation can be simplified in the case of small motion.
SOLUBILITY OF IRON, CALCIUM AND MAGNESIUM IN AMARANTH AND COLLARD LEAVES

Amaranth(Amaranthus L. cruentus) and collards (Kale) (Brassica oleracea L. var.acephala, (DC.) Alef cv. Vates) were compared for total and soluble contents of iron, calcium and magnesium. Raw and cooked leaf blades were homogenized and subjected toin vitro peptic digestion.
An efficient double-tuned 13C/1H probe circuit for CP/MAS NMR and its importance in linewidths

Abstract A simple double-tuned 13 C 1 H probe for high-field CP/MAS NMR is described. The to 50 ω. Isolation between 1H and 13C channels exceeds 40 dB. The sensitivity ( S N ) of the observation channel (13C) for methyl carbons is close to 47 in a CP/MAS experiment of 10 scans on 70 mg of a sample of hexamethylbenzene for the rotor sample volume of 140 μl. The probe delivers a 2.4 μs 90° proton pulse with only 90 W at 200 MHz and 250 W at 50.3 MHz. Examples are presented of linewidth reduction with higher decoupling power. The effects of anisotropy in the bulk magnetic susceptibility are also discussed.
Solid-state 95Mo NMR study of (aryldiazenido)- and (organohydrazido)polyoxomolybdates. Investigation of model compounds of catalytic molybdenum environments

The {sup 95}Mo static powder and magic angle spinning NMR spectra of the central {plus minus} 1/2 transition of a number of (aryldiazenido)polyoxomolybdates, (organohydrazido)polyoxomolybdates, and unsubstituted polyoxomolybdates were obtained. The spectra clearly demonstrated the existence of octahedral and tetrahedral sites within these compounds by the contrast between the respective line widths and the dependence under MAS conditions of the resonances from these sites. Variation of ligand coordination was also seen to yield a visible chemical shift to the octahedral molybdenum sites in selected complexes. An interactive graphics curve-fitting program was used to estimate the quadrupolar coupling constants, asymmetry parameters of the electric field gradients, the three principal elements of the shielding tensor, and the Euler angles relating the quadrupole and chemical shielding principal axis systems for the molybdenum sites from the static powder spectra. Assignments of the line shape components was made to the different molybdenum sites present in these species. The method of assignment, based on degree of distortion at the site, was vindicated by MO calculations carried out on a simple (MoO{sub 6}){sup 6{minus}} model species. The effectiveness of the {sup 95}Mo NMR technique to obtain these data from Mo(VI) compounds was thus demonstrated and has laid a more » foundation from which future solid-state {sup 95}Mo NMR studies of biological and catalytic molybdenum systems can benefit by comparison of the results obtained with those obtained for these model compounds. « less
Cross-linking of erythrocyte membranes with dimethyl adipimidate.

Abstract Dimethyl adipimidate reacts with lysine residues of proteins to form covalent cross-links. When human erythrocyte membranes are treated with dimethyl adipimidate the percentage of protein which can subsequently be solubilized by treatment with aqueous pyridine is reduced. Evidence is presented that this is due to the formation of cross-links between soluble and insoluble protein molecules. The solubility distribution of protein-bound sialic acid, hexose, and hexosamine is altered in a parallel manner. This effect is not produced by treatment of the membranes with methyl butyroimidate, a monofunctional analogue.
Choropleth Mapping in Secondary Geography: An Application for the Study of Middle America

Abstract Choropleth mapping is one useful cartographic technique that takes geographic instruction beyond the limits of most secondary geography textbooks. It is a simple technique to teach, and it offers the possibility of extending the level of geographic thinking from the description of factual information to interpretation of comparative information and inferences. Choropleth maps of socio economic characteristics for Middle America, for example, raise important questions about Middle American welfare, culture, democracy, and U.S. foreign policies which might otherwise not be discovered or considered by students.
Adult Reading Achievement Comparing Computer-Assisted and Traditional Approaches: A Comprehensive Review of the Experimental Literature

Abstract Since the arrival of personal computers in 1977, several adult basic and secondary education (ABSE) researchers and practitioners have sought to examine the efficacy of computer‐assisted instruction (CAI) to teach reading in the ABSE setting. A much smaller number have utilized quasi‐experimental methods to compare an experimental (CAI) group to a group using more traditional instructional methods. Twenty‐one studies from 1979 to the present examined adult reading achievement or a closely related variable such as language arts by comparing CAI and non‐CAI groups of adults functioning at levels ranging from non‐readers to GED test‐takers. This study attempts to review this literature both to examine the current status of CAI research with this population and to provide program planners with information concerning the use of CAI. Despite considerable variability in design sophistication and clarity of reporting, ten of the 21 studies found no statistically significant differences between the two me...
Ontogeny of visual acuity in two species of deermice (Peromyscus)

Abstract Development of visual acuity in Peromycsus maniculatus and P. leucopus was measured by optokinetic responses. Mice were suspended within a rolating drum lined with black and white stripes of equal width. Stripe width was varied to determine the minimum visual angle which could be seen by each mouse. At 20-cm stimulus distance both species reached a mean visual angle of 21′ of arc by 2 days after eye opening. Development was slower at 40-cm stimulus distace, both species reaching a mean angle of 18′ of arc by 8 days after eye opening. Mean visual angles at three illuminance levels (4·3 lux, 86·1 lux and 861·1 lux) were not diferent. Deermice have better visual acuity and visual range than previously tested rodents and exhibit rapid visual maturation.
Exploring the use and impact of LCA-based information in corporate communications

Background, aim, and scope The effective communication of corporate environmental messages has a history of mixed results and concerns remain around the quality and accurateness of these messages. Life cycle assessment (LCA) information is often presented as a promising informational tool, by which improved communication effectiveness of environmental/sustainable claims may materialize; however, the possibility of information overload has limited its application in marketing communication settings. The overall purpose of this research is to better understand how LCA-based environmental performance information might be effectively communicated in an advertising setting, the impact of such messages on individuals’ attitudes and behavioral intentions, and the mediating roles of informational complexity and credibility.
Managerial efficiency in local government: Implications on jurisdictional consolidation

Using data from Maine, estimates of size economies in the production of public education services are provided under the alternative assumptions of managerial efficiency and inefficiency. While size economies were identified under the traditional assumption of managerial efficiency, limited or no size economies were identified under the more general assumption of managerial inefficiency. These results question the validity of the traditional economies of size literature and the jurisdictional consolidation policy which follows from the traditional literature.
From mechanism to monolith

The stressful nine-month gestation had passed both too quickly and too slowly. Now the wait was finally over and Federico Faggin, father, mother, and midwife, expectantly approached his newborn. Hope tempered with trepidation quickly bubbled over into elation as waveform after waveform happily revealed the lusty cries of a healthy infant: the 4004 was alive and well! It was certainly a promising start for the microprocessor, but not even the other parents of the 4004 - Stan Mazor, Ted Hoff, and Masatoshi Shima - could imagine just how promising. With astonishing speed, its descendants would completely transform human existence.
E-sequences and the Stone–Weierstrass Theorem

Abstract For discrete valuation domain V with finite residue field, we define a variation of the V.W.D.W.O. sequence of Cahen and Chabert in order to construct V-bases for the algebra of even integer-valued polynomials on V and the module of odd integer-valued polynomials on V. Using these bases, we prove a version of the Stone–Weierstrass Theorem for V, namely, that every even (respectively odd) continuous function on the completion V ˆ can be approximated by means of even (respectively odd) integer-valued polynomials on V. Using these approximations, we give series expansions for all even (respectively odd) continuous functions on V ˆ , analogous to results of Mahler for the p-adic integers.
Asymptotic analysis of deterministic and stochastic equations with rapidly varying components

The asymptotic character of deterministic and stochastic equations whose solutions have a rapidly varying component is studied. Of particular interest is the class of problems for which the limiting behavior can be described in a contracted and simplified framework.
Performance and fairness analysis of range control algorithms in cooperative vehicle safety networks at intersections

Cooperative vehicle safety (CVS) systems rely on broadcast of vehicle position to other neighboring vehicles. Scalability is one of the main challenges of CVS, and many congestion control algorithms have been proposed to resolve the issue. These algorithms need to be robust, stable and fair in especially both highways and urban areas. Many of the proposed algorithms have been examined in the past mostly for highway scenarios. In particular, a study of properties such as stability in time and fairness in space for intersection scenarios has not yet been presented in literature for some important scalability solutions. In this paper we study two congestion control algorithms in intersection scenarios and evaluate their fairness and stability properties. We show that the stability and fairness in different typical intersection scenarios can be achieved. The robustness of the algorithms to the high variability of density in intersection scenarios is also verified. While unfairness does not happen in most of the scenarios naturally, a previously proposed method for resolving possible unfairness is evaluated for completeness of the study.
Luminescent properties of Er-doped BaTiO3 thin films for optical waveguides

Erbium doped BaTiO3 thin films for optical waveguide applications were investigated. Characteristic 4f emission at 1560 nm is observed for Er concentrations ranging from 1018 to 1020 cm-3. Factors which determined the luminescence efficiency were investigated and a model for efficiency was developed. The luminescence intensity depended predominantly upon two factors: the concentration of radiative Er centers and the de-excitation efficiency of the excited 4f electron state. At a growth temperature of 725 degree(s)C, the concentration of radiative Er ions was independent of Er dopant concentration. Annealing the thin films in an oxidizing ambient resulted in increased luminescence efficiency whereas annealing under reducing conditions quenched the luminescence.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Adherence of lymphocytes to capillary endothelial basement membrane from rat and mouse brain in vitro.

Abstract An in vitro technique to study the relationship between lymphocytes and brain capillary endothelium is described. Autogenic, allogenic or xenogenic thymic lymphocytes have been found to bind to brain capillary basement membrane.
Competing fatigue mechanisms in BPA-polycarbonate

A change in the mode of fatigue fracture in bisphenol-A-polycarbonate results in a large discontinuity in the fatigue lifetime of notched specimens. This discontinuity is such that the lifetime above the transition is at least an order of magnitudegreater than the lifetime below the transition. In addition, prior creep-loading of the specimens at 7500 psi (52 MPa) for as little as 60 sec or fatiguing at 7500 psi for 500 cycles changes the subsequent fatigue fracture mechanism at 4000 psi (28 MPa) from discontinuous crack growth to plane-strain shear fracture (over most of the notch). The mechanism change also increases the lifetime at 4000 psi by two orders of magnitude. This indicates that the change in mechanism at the notch occurs very early in the fatigue lifetime and is not due to hysteretic heating.
Fidelity: an essential component of evidence-based practice in speech-language pathology.

Purpose To provide a primer regarding treatment fidelity as it affects evidence-based practice (EBP) for speech-language pathologists. Method This tutorial defines treatment fidelity, examines the ...
Epichlorohydrin–triethanolamine reaction in the preparation of quaternary cellulose anion exchangers

The reactions between cotton cellulose and a mixture of triethanolamine and epichlorohydrin in the presence of aqueous NaOH have been studied. It has been shown that cotton fabric pretreated with aqueous base and then reacted with a 3:1 mole ratio of epichlorohydrin to triethanolamine forms a strong base anion exchanger. Resultant properties differed from those of the product made by the conventional method of preparing ECTEOLA cellulose, a commercial product of the same reactants. Titration curves of the strong base cellulose exchangers were similar to that obtained with the product of the reaction between cotton and trimethylglycidylammonium chloride. Substitution of triethylamine for the triethanolamine also resulted in a quaternary base cellulose anion exchanger. A cyclic diquaternary salt, [2,5-p-dioxanylenebismethylene] bis[tris(2-hydroxyethyl)ammonium chloride], has been isolated from the triethanolamine–epichlorohydrin mixture and a mechanism of the reaction has been proposed.
Qualitative Observations of Dense Particle Motion in a Vibration-Excited Granular Bed

The Brazil nut effect is a classic phenomenon in which larger objects typically migrate to the top of a bed of smaller granular media when exposed to vibration. An example of this phenomenon is finding Brazil nuts on the top of a can of mixed nuts. In this study, the Brazil nut problem is simulated by submerging a large particle in a bed of granular media and then subjecting the system to vibration. Stereoscopic X-ray imaging is used to visualize the large particle motion. These images are then compiled into movies where the particle motion may be tracked. Observations of the large particle motion are made under varying conditions of large particle material, vibration frequency, and bed height. Particle percolation, where smaller particles fill small voids beneath the large particles, is the dominate mechanism at higher vibration frequencies. However, as the frequency decreases, or as the disparity between the densities of the large and small particles decrease, the effects of convection become more pronounced.Copyright © 2007 by ASME
Kinetics of tongue projection in Ambystoma tigrinum: Quantitative kinematics, muscle function, and evolutionary hypotheses.

The projectile tongue of caudate amphibians has been studied from many perspectives, yet a quantitative kinetic model of tongue function has not yet been presented for generalized (nonplethodontid) terrestrial salamanders. The purposes of this paper are to describe quantitatively the kinnematics of the feeding mechanism and to present a kinetic model for the function of the tongue in the ambystomatid salamander Ambystoma tigrinum. Six kinematic variables were quantified from high-speed films of adult A. tigrinum feeding on land and in the water. Tongue protrusion reaches its maximum during peak gape, while peak tongue height is reached earlier, 15 ms after the mouth starts to open. Tongue kinematics change considerably during feeding in the water, and the tongue is not protruded past the plane of the gape. Electrical stimulation of the major tongue muscles showed that tongue projection in A. tigrinum is the combined result of activity in four muscles: the geniohyoideus, Subarcualis rectus 1, intermandibularis posterior, and interhyoideus. Stimulation of the Subarcualis rectus 1 alone does not cause tongue projection. The kinetic model produced from the kinematic and stimulation data involves both a dorsal vector (the resultant of the Subarcualis rectus 1, intermandibularis posterior, and interhyoideus) and a ventral vector (the geniohyoideus muscle), which sum to produce a resultant anterior vector that directs tongue motion out of the mouth and toward the prey. This model generates numerous testable predictions about tongue function and provides a mechanistic basis for the hypothesis that tongue projection in salamanders evolved from primitive intraoral manipulative action of the hyobranchial apparatus.
Retardation of autoshaping following pretraining with unpredictable food: Effects of changing the context between pretraining and testing ☆

Abstract In Experiment 1, pigeons exposed to US ONLY pretraining were observed to be retarded in the acquisition of autoshaping relative to naive controls; however, gross changes in contextual stimuli between pretraining and testing alleviated the retardation effect. In Experiment 2, groups of pigeons exposed to CS ONLY, US ONLY, or random CS-US presentations (TRC) were tested for the acquisition of autoshaping. The US ONLY and TRC groups were retarded relative to naive controls. The context change manipulation eliminated the US ONLY retardation effect and attenuated, but did not eliminate, the TRC retardation effect. Context blocking accounts for the US ONLY effect and contributes to the TRC effect; however, context-independent retardation following TRC pretraining suggests the operation of the learned irrelevance cognition.
Nanovision: a new paradigm for enabling fast optical inspection of nanoscale structures

The ability to detect killer defects on the Semiconductor Manufacturing Industry "in line" will require resolution below 30nm by 2005. It has been assumed that optical inspection, which has been the standard tool for such applications for almost two decades and which has enabled inspection throughputs of the order of 60 wafers per hour, cannot meet this challenge. In this paper we show that the limits of optical inspection have not been reached and that therefore existing, cost-effective, mature laser technology can still be exploited to perform fast optical inspection down to the 15nm range. This breakthrough involves the wave interrogated near-field array, a new paradigm in optical inspection that combines the resolution of near-field detection with the efficiency of far-field detection. Full-physics numerical simulations are used to show that: (1) Resonant photonic antennas can amplify the scattered signal from sub-wavelength defects by over three orders of magnitude. (2) Such antennas can also discern the composition of the defect. (3) Holographic filtering of the array's scattered signal easily locates a single defect within the scanning area of the entire array. A scaled-up experiment at microwave frequencies has been performed to prove the feasibility of this technique.
The fish tank model of first-order elimination: An effective pharmacokinetic teaching tool

Abstract Objective This report describes student perceptions of the fish tank model of first-order elimination as a learning aid in a clinical pharmacokinetics course. Fish tank model The model is based on a large rectangular fish tank filled with goldfish that are equally distributed throughout the tank. The elimination of fish results from passing an aquarium net through the water with a consistent motion at a constant rate, such that the number of fish removed per pass of the net consistently declines as the concentration of fish in the tank declines. Volume of distribution is the size of the tank, clearance is the volume of water that passes through the net per unit of time as fish are removed, and the elimination rate constant is the fraction of the volume of the tank compared to the volume of water that has fish cleared from it per unit of time. Assessment Two cohorts of students voluntarily participated in an online survey that called for Likert-type responses to indicate agreement with statements about whether the fish tank model helped them to understand first-order elimination concepts. Survey response rates were 77% and 94%. Both cohorts demonstrated approximately 70–80% agreement that the fish tank model enhanced their learning of clearance, volume of distribution, elimination rate constant, and protein binding. Conclusion The fish tank model appears to be an effective learning aid that helps students to develop a deeper conceptual understanding of basic pharmacokinetic principles.
Increasing Senate Scrutiny of Lower Federal Court Nominees

We argue that the scrutiny of lower federal court nominations in the Senate is not unique to the crisis during the Clinton administration or during the tenure of Orrin Hatch as Judiciary Committee chair. Instead, increased scrutiny of lower court nominees has been a long time in the making. Lower court nominations became more contentious during the Carter administration, increased further late in Reagan's second term, and reached a zenith after the 1994 Republican takeover of Congress. We employ data that examines the delay of nomination from 1969 until 1998. We examine delay pre and post Carter and pre and post the time Senator Orin Hatch served as judiciary chair. We also examine the impact of unified and divided government on these appointments.
Voltammetric characterization and determination of thallium(III,I) at a glassy carbon electrode modified with a film containing iridium oxide

Cyclic voltammetry of a 0.1 mM PdCl2, 0.2 mM Na2IrCl6 0.2 M K2SO4 mixture at a glassy carbon electrode results in the gradual accumulation of a film, which contains Pd(II) and iridium oxide, that promotes the quasi-reversible oxidation of Tl(I). Cyclic voltammetry at 5 mV/s yields a peak potential difference of 35 mV at the modified electrode and about 700 mV at bare glassy carbon. The peak current for the linear scan voltammetric oxidation of 0.2 mM TI(I) in 1.0 M NaCl is directly proportional to the square root of scan rate up to 0.1 V/s. Both cyclic voltammetry and rotating disk voltammetry at modified electrodes provide data consistent with a two-electron oxidation. The modified electrode is suitable for the determination of thallium by differential pulse voltammetry in the micromolar range.
Masked Cyanoacrylates Unveiled by Mechanical Force

Mechanical damage of polymers is often a destructive and irreversible process. However, desirable outcomes may be achieved by controlling the location of chain cleavage events through careful design and incorporation of mechanically active chemical moieties known as mechanophores. It is possible that mechanophores can be used to generate reactive intermediates that can autopolymerize or cross-link, thus healing mechanically induced damage. Herein we report the generation of reactive cyanoacrylate units from a dicyanocyclobutane mechanophore located near the center of a polymer chain. Because cyanoacrylates (which are used as monomers in the preparation of superglue) autopolymerize, the generated cyanoacrylate-terminated polymers may be useful in self-healing polymers. Sonication studies of polymers with the mechanophore incorporated into the chain center have shown that selective cleavage of the mechanophore occurs. Trapping experiments with an amine-based chromophore support cyanoacrylate formation. Addi...
Men's and Women's Reports of Pretending Orgasm

Research shows that many women pretend or “fake” orgasm, but little is known about whether men pretend orgasm. The purpose of this study was to investigate (a) whether, how, and why men pretend orgasm and (b) what men's and women's reports of pretending orgasm reveal about their sexual scripts and the functions of orgasms within these scripts. Participants were 180 male and 101 female college students; 85% of the men and 68% of the women had experienced penile–vaginal intercourse (PVI). Participants completed a qualitative questionnaire anonymously. Both men (25%) and women (50%) reported pretending orgasm (28% and 67%, respectively, for PVI-experienced participants). Most pretended during PVI, but some pretended during oral sex, manual stimulation, and phone sex. Frequently reported reasons were that orgasm was unlikely, they wanted sex to end, and they wanted to avoid negative consequences (e.g., hurting their partner's feelings) and to obtain positive consequences (e.g., pleasing their partner). Result...
Computed tomography perfusion imaging as a potential imaging biomarker of colorectal cancer

Neovascularization was reported to arise early in the adenoma-carcinoma sequence in colorectal cancer (CRC), and the importance of angiogenesis in cancer progression has been established. Computed tomography (CT) perfusion (CTP) based on high temporal resolution CT images enables evaluation of hemodynamics of tissue in vivo by modeling tracer kinetics. CTP has been reported to characterize tumor angiogenesis, and to be a sensitive marker for predicting recurrence or survival in CRC. In this review, we will discuss the biomarker value of CTP in the management of CRC patients.
Generation, sampling and chromatographic analysis of particulate matter in dilute sidestream tobacco smoke

Abstract The sampling and gas chromatographic separation of the particulate matter of sidestream tobacco smoke for high-molecular-weight compounds are described. Four n -alkanes (C 27 , C 29 , C 31 and C 33 ) were identified and their relationship to the particulate levels was established. The sidestream yields of these compounds for several cigarette types, including regular, low- and ultra-low-tar filtered and high-tar unfiltered varieties are reported. Concentrations in diluted smoke at particulate levels similar to ambient tobacco smoke were also determined. Methods for generating test atmospheres of sidestream smoke at low-level, uniform concentrations are described.
Paternal and Household Characteristics Associated With Child Neglect and Child Protective Services Involvement

ABSTRACT This study examined the association of paternal and household characteristics with household-level measures of child neglect and Child Protective Services (CPS) involvement, measured when the index child was 5 years of age. Secondary analyses of the Fragile Families and Child Well-Being Study were conducted using a subsample of 1,089 residential, biological fathers. Logistic regression models indicated that paternal depression was associated with greater than doubled odds of child neglect and CPS involvement. Paternal alcohol use and parenting stress were associated with approximately 50% increased odds for child neglect, and a scale measuring 13 caregiving tasks to reflect positive father involvement with the child was also associated with less risk for child neglect. However, paternal alcohol use, parenting stress, and positive involvement with the child were not associated with CPS involvement. An implication of this study is that paternal psychosocial functioning is important to consider in c...
Clinical assessment instruments in the treatment of child abuse and neglect

Accurate assessment is essential for effective practice #opWodarski, 1981#cp. In child welfare, where assessments must depend on direct as well as indirect evidence, data on parental attitudes toward the victim, problem behaviors within the family constellation, and possible compromising psychopathologies can be obtained through the use of standardized scales. A variety of objective measures pertinent to the assessment of child abuse and neglect are now available that can be used by practitioners with minimal disruption in terms of time, energy, cost, and ease of administration. The purpose of this article is to review a variety of instruments that child welfare workers, specifically, and practitioners involved in children's services, in general, can use in the assessment of child abuse and neglect.
Intestinal obstruction due to schistosomiasis

We have described a patient with intestinal obstruction caused by schistosomiasis but closely resembling colon carcinoma. The cause, demography, pathologic characteristics, and clinical management of the disease caused by Schistosoma mansoni are reviewed.
Protective effects of propranolol on isoproterenol-induced myocardial infarction in arteriosclerotic and non-arteriosclerotic rats

Abstract Arteriosclerotic and non-arteriosclerotic rats were given two s.c. injections of the beta-adrenergic stimulating agent, isoproterenol, (25 and 50 mg/100 g.b.w. respectively) to induce equally massive myocardial infarction. Sub-groups of animals were given the beta-adrenergic blocking agent, propranolol (1.0 mg/100 g b.w., s.c.), three hours prior to isoproterenol. Animals were sacrificed at select time intervals during the acute cardiac necrosis phase and repair phase. Animals pre-treated with propranolol manifested significantly less cardiac necrosis, less excursion of serum GOT, GPT, LDH, glucose, triglycerides, free fatty acids, total cholesterol and corticosterone than isoproterenol-treated animals which showed massive myocardial necrosis, congestive heart failure and marked increase of their serum enzymes, lipids, glucose and corticosterone. The propranolol-treated subjects showed unusual increases in BUN during active cardiac necrosis and persistent hydrothorax during myocardial repair. Histopathologic analyses confirmed the absence of necrosis in propranolol-treated rats but the presence of marked fibroplasia, more severe beta-cell degranulation in isoproterenol-treated subjects and adrenocortical hyperplasia and lipid depletion of the zona glomerulosa commensurate with the severity of congestive heart failure. Arteriosclerotic animals withstood the stress of myocardial infarction better than and responded equally as well as non-arteriosclerotic animals to the necrosis-protecting effects of propranolol.
Ultrafast high repetition rate absorption spectroscopy of polymer shock compression

A dual-beam transient absorption spectrometer for high repetition rate (80 shocks per second) studies of shock compressed materials is described. The apparatus time response is 100 ps, so the time resolution of the shock compression process is generally limited by the shock transit time across the sample. In turn the sample thickness is limited by the sensitivity of the spectrometer. Using 400 nm thick samples of R640 dye aggregates in \textit{poly} methyl methacrylate (PMMA) and a 4.2 GPa laser-driven shock, transient absorption spectra show a shock induced absorption redshift occurring in 500 ps, considerably longer than the 200 ps shock front transit time (round trip) through the sample. This noninstantaneous shock compression is consistent with the $\sim 300$ ps viscoelastic response of PMMA at 4.2 GPa.