cssi/SciSciGPT-SciSciNet huggingface dataset:
A note on dc crowding effects in the small-signal distributed transistor model

A distributed transistor model including linear dc crowding is analyzed. An expression for the short-circuit input impedance is derived for the cases of "very small" crowding and "large" crowding. It is found that in both cases the impedance is approximately equal to that of a transistor with no dc crowding and a shorter active base region. The effective length of the base region depends on the degree of crowding.
AS08-04 - Nonverbal coordination: a neglected change factor

Introduction Past research has shown that nonverbal behavior plays an important role in the development and maintenance of a therapeutic relationship. However, the exact nature of specific nonverbal behaviors that help promoting a therapeutic relationship have remained elusive. Objectives Nonverbal synchrony - the coordination of patient's and therapist's body movement - was analyzed in a sample of N = 104 therapy sessions randomly drawn from an archive of routinely recorded ambulatory psychotherapies. Methods Motion energy analysis (MEA) was used to automatically and objectively quantify nonverbal synchrony in video-recorded therapy sessions. Using a bootstrap approach, it was first ascertained that the phenomenon actually exists: Nonverbal synchrony was compared to the amount of synchrony one would expect to occur by chance. Subsequently, patient's post-session questionnaires and post-therapy outcome assessments were associated with the amount of nonverbal synchrony. Results Nonverbal synchrony occurs at a level that is significantly higher than expected by chance. Patient-therapist dyads that showed higher synchrony also reported higher relationship quality and better outcome at the end of therapy. Conclusions The coordination of nonverbal behavior is a hitherto neglected facet of the therapeutic relationship. Nonverbal synchrony embodies relevant aspects of both short-term outcome (post-session reports) as well as long-term outcome (post-therapy assessments). Given the fact that the therapeutic relationship is an important change factor, these data indicate that paying more attention to nonverbal aspects of the therapeutic relationship may maintaining the therapeutic relationship and thus increase the chance of patient's improvement.
Arrival Times of Satellite-Broadened Laser Pulses

A method for measuring the time of arrival of very narrow laser pulses which have been reflected and randomly broadened by a target is examined. It is known that these return pulses from the target have very small rise times. A threshold detection algorithm that detects the rising edge of the pulse is used for obtaining the pulse arrival times. The errors of the scheme are evaluated numerically for different pulse shapes, and a loose bound on the errors of detecting a typical pulse is obtained. Finally, a gamma-density model is used to characterize the random gain processes of the optical receiver, and the effect of such random gains on the errors of threshold detection is analyzed.
A novel analytical model for switches with shared buffer

Switches with a shared buffer have lower packet loss probabilities than other types of switches when the sizes of the buffers are the same. In the past, the performance of shared buffer switches has been studied extensively. However, due to the strong dependencies of the output queues in the buffer, it is very difficult to find a good analytical model. Existing models are either accurate but have exponential complexities or not very accurate. In this paper, we propose a novel analytical model called the Aggregation model for switches with shared buffer. The model is based on the idea of induction: first find the behavior of two queues, then aggregate them into one block; then find the behavior of three queues while regarding two of the queues as one block, then aggregate the three queues into one block; then aggregate four queues, and so on. When all queues have been aggregated, the behavior of the entire switch will be found. This model has perfect accuracies under all tested conditions and has polynomial complexity.
New concepts in biological evaluation of novel protein foods

Technology has advanced to where it is now possible to fabricate new foods having high acceptability and providing better nutrient balance than the traditional foods they replace. If such products ultimately represent a major portion of the diet, then a new approach to toxicology and nutritional evaluation has to evolve to allow proper estimation of the safety and adequacy of the products. Traditional approaches to these problems are based upon the elucidation of major changes in the test organism, i.e., evaluation of substances of high biological potency. For food analogs, any deleterious effect will probably be at levels just above the natural noise level of the system. To compensate for this, most traditional evaluations of analogs have been made by feeding the test substances at extremely high, nonphysiological levels with the hope that this will reveal any toxic response. With this approach, however, many traditional foods would appear to be inadequate. A better technique may be designed to explore the functional consequences of feeding the test analog over several generations, using stress as a modifier to increase sensitivity of the system. Other sensitive measures such as behavior and resistance to disease should be included. The conceptual basis of this approach was used to test a vegetable protein analog (VPA). The feeding of VPA to animals as a significant part of the diet resulted in no change in the capacity of the animal to grow and reproduce and to function under stress conditions. Preliminary results of feeding this material through three generations also produced no changes in the parameters studies.
The Effects of Differential Goalbox Reward and Reward Shifts on the Frustration Effect

Summary To determine whether incomplete reward reduction and reward increment would influence the “frustration effect” (FE) in the double alleyway, female hooded rats (N = 103) were given 105 trials with 50% partial reward in Goalbox 1, with four or 12 pellets in Goalbox 1 and four or 12 pellets in Goalbox 2. On trials 106–153, the postshift phase, half of the rats in each group were shifted to a reward magnitude opposite to that previously received in Goalbox 1. During preshift, the magnitude of the FE was directly related to Goalbox 1 and Goalbox 2 reward magnitudes. During postshift, the magnitude of the FE was directly related to Goalbox 1 and Goalbox 2 reward magnitudes and was not significantly related to either increase or decrease of Goalbox 1 reward. The results were discussed in terms of a frustration/competing response framework.
Influence of nonnative earthworms on mycorrhizal colonization of sugar maple (Acer saccharum).

Summary • Exotic earthworms can modify or eliminate surface organic (Oe/Oa) horizons in cold-temperate forest ecosystems and have profound effects on the forest soil environment, especially the rooting zone. • We examined the effects of earthworm colonization of northern hardwood forest soils on the abundance and morphology of mycorrhizal fungi associated with sugar maple ( Acer saccharum ). We compared mycorrhizal associations of areas of earthworm invasion with those of reference (no-worm) areas in Arnot Forest, central New York, USA. • The organic horizon in reference areas had higher mycorrhizal colonization rates and higher colonized root length than did surface layers in areas with active earthworm populations. Hyphal coils were more abundant and also formed a greater proportion of total fungal colonization in reference plots. Vesicles were more abundant and were a higher contribution to total colonization in earthworm plots, indicating a possible stress response to the presence of earthworms. • By affecting mycorrhizal colonization and morphology, earthworms may influence nutrient uptake capacity of dominant forest species. Our results suggest that a profound change in the mycorrhizal system will be one component of the potential ecosystem effects of invasion of new forest habitat by nonnative earthworms.
Nanolitre liquid patterning in aqueous environments for spatially defined reagent delivery to mammalian cells

Microscale biopatterning enables regulation of cell-material interactions and cell shape, and enables multiplexed high-throughput studies in a cell- and reagent-efficient manner. The majority of available techniques rely on physical contact of a stamp, pin, or mask with mainly a dry surface. Inkjet and piezoelectric printing is carried out in a non-contact manner but still requires a substantially dry substrate to ensure fidelity of printed patterns. These existing methods, therefore, are limited for patterning onto delicate surfaces of living cells because physical contact or substantially dry conditions are damaging to them. Microfluidic patterning with laminar streams does enable non-contact patterning in fully aqueous environments but with limited throughput and reagent diffusion across interfacial flows. Here, we describe a polymeric aqueous two-phase system that enables patterning nanolitres of a reagent-containing aqueous phase, in arbitrary shapes, within a second aqueous phase covering a cell monolayer. With the appropriate medium formulation, reagents of interest remain confined to the patterned phase without significant diffusion. The fully aqueous environment ensures high reagent activity and cell viability. The utility of this strategy is demonstrated with patterned delivery of genetic materials to mammalian cells for phenotypic screening of gene expression and gene silencing.
Reperfusion with ATP-MgCl2 following prolonged ischemia improves myocardial performance.

This study was designed to test the hypothesis that infusion of ATP-MgCl2 during reperfusion following a prolonged period of hypothermic global ischemia would result in enhanced functional recovery of cardiac function. Two groups of dogs (n = 6 each) were placed on cardiopulmonary bypass (CP) with systemic hypothermia to 28°C and subjected to 150 min of aortic cross-clamping. Crystalloid cardioplegia was infused every 20 min during ischemia. Reperfusion and rewarming were carried out for 20 min before discontinuation of CP bypass. During reperfusion, the experimental group received ATP-MgCl2 (1.0 mg/kg/min ATP, 0.33 mg/kg/min magnesium). At 15 and 45 min following bypass, hemodynamic assessment was carried out for each animal by constructing Starling curves over a range of filling pressures at constant heart rate and comparing each animal to its own prebypass control level. The results indicated that ATP-treated animals exhibited complete functional recovery whereas control animals showed marked reduction in hemodynamic performance and myocardial compliance and had a higher myocardial water content (P < 0.05). We conclude that infusion of ATP-MgCl2 during reperfusion following hypothermic ischemia may help ameliorate reperfusion injury.
A parallel boundary fitted dynamic mesh solver for applications to flapping flight

Abstract A parallel numerical solution procedure for unsteady incompressible flow is developed for simulating the dynamics of flapping flight. A collocated finite volume multiblock approach in a general curvilinear coordinate is used with Cartesian velocities and pressure as dependent variables. The Navier–Stokes equations are solved using a fractional-step algorithm. The dynamic grid algorithm is implemented by satisfying the space conservation law by computing the grid velocities in terms of the volume swept by the faces. The dynamic movement of grid in a multiblock approach is achieved by using a combination of spring analogy and Trans-Finite Interpolation. The spring analogy is used to compute the displacement of block corners, after which Trans-Finite Interpolation is applied independently on each computational block. The performance of the code is validated in forced transverse oscillations of a cylinder in cross-flow, a heaving airfoil, and hovering of a fruitfly. Finally, the unsteady aerodynamics of flapping flight at Re = 10,000 relevant to the development of Micro Air Vehicles is analyzed for forward flight. The results show the capability of the solver in predicting unsteady aerodynamics characterized by complex boundary movements.
Counselors Under Fire: Youth Opportunity Centers.

Intensive interviewing of counselors, supervisors, clients, and community workers associated with a sample of Youth Opportunity Centers led to the conclusion that assumptions of client-centered therapy are untenable in such settings. The assumptions not found tenable are: (a) client comes voluntarily; (b) client wants help; (c) client accepts counselor's authority; (d) client comes as individual; (e) counselor accepts client. Because of bureaucratic conditions of government programs, because of poverty and demoralization of clients, and because of race and other differences, counseling (except of a highly directive sort) is not possible. A group approach which takes into account the organized nature of the client population is personally recommended and described.
A comparison of thin film microrefrigerators based on Si/SiGe superlattice and bulk SiGe

Most of the conventional thermal management techniques can be used to cool the whole chip. Since thermal design requirements are mostly driven by the peak temperatures, reducing or eliminating hot spots could alleviate the design requirements for the whole package. Monolithic solid-state microcoolers offer an attractive way to eliminate hot spots. In this paper, we review theoretical and experimental cooling performance of silicon-based microrefrigerators on a chip. Both Si/SiGe superlattice and also bulk SiGe thin film devices have been fabricated and characterized. Direct measurement of the cooling along with material characterization allows us to extract the key factors limiting the performance of these microrefrigerators. Although Si/SiGe superlattice has larger thermoelectric power factor, the maximum cooling of thin film refrigerators based on SiGe alloys are comparable to that of superlattices. This is due to the fact that the superlattice thermal conductivity is larger than bulk SiGe alloy by about 30%.
d0/fn-mediated ring-opening Ziegler polymerization (ROZP) and copolymerization with mono- and disubstituted methylenecyclopropanes. Diverse mechanisms and a new chain-capping termination process

The mono- and disubstituted methylenecyclopropane derivatives 2-phenyl-1-methylenecyclopropane (A) and 7-methylenebicyclo[4.1.0]heptane (B) have been successfully implemented in ring-opening Ziegler polymerization. Homogeneous ethylene + 2-phenyl-1-methylenecyclopropane (A) random copolymerizations are mediated efficiently by the single-site catalysts Cp*2ZrMe+B(C6F5)4-, [Cp*2LuH]2, [Cp*2SmH]2, and [Cp*2YH]2 (Cp* = C5Me5) to produce a copolymer (C) with A enchained in a ring-opened fashion. Single-site coordinative polymerization of 7-methylenebicyclo[4.1.0]heptane (B) proceeds via either ring-opened or ring-unopened pathways. In the presence of Cp*2ZrMe+ MeB(C6F5)3- at 0 °C, B undergoes polymerization to afford the insoluble, ring-unopened homopolymer D, which was characterized by CPMAS NMR, DSC, elemental analysis, FTIR, TGA, and XRD. The melting point of polymer D lies above its decomposition temperature (>300 °C). Random copolymerizations of B and ethylene mediated by Cp*2ZrMe+MeB(C6F5)3- at room temp...
The role of verbal and nonverbal communication in a two-person, cooperative manipulation task

Motivated by the differences between human and robot teams, we investigated the role of verbal communication between human teammates as they work together to move a large object to a series of target locations. Only one member of the group was told the target sequence by the experimenters, while the second teammate had no target knowledge. The two experimental conditions we compared were haptic-verbal (teammates are allowed to talk) and haptic only (no talking allowed). The team's trajectory was recorded and evaluated. In addition, participants completed a NASA TLX-style postexperimental survey which gauges workload along 6 different dimensions. In our initial experiment we found no significant difference in performance when verbal communication was added. In a follow-up experiment, using a different manipulation task, we did find that the addition of verbal communication significantly improved performance and reduced the perceived workload. In both experiments, for the haptic-only condition, we found that a remarkable number of groups independently improvised common haptic communication protocols (CHIPs). We speculate that such protocols can be substituted for verbal communication and that the performance difference between verbal and nonverbal communication may be related to how easy it is to distinguish the CHIPs from motions required for task completion.
Functions and Cognitive Bases for the Concept of Actual Causation

Our concept of actual causation plays a deep, ever-present role in our experiences. I first argue that traditional philosophical methods for understanding this concept are unlikely to be successful. I contend that we should instead use functional analyses and an understanding of the cognitive bases of causal cognition to gain insight into the concept of actual causation. I additionally provide initial, programmatic steps towards carrying out such analyses. The characterization of the concept of actual causation that results is quite different from many standard views: it is graded, context-sensitive, and extrinsic.
Thermal expansion of a PRD-166 fibre-reinforced glass-matrix composite

Abstract Coefficients of thermal expansion ( ctes ) of PRD-166/glass and SnO2-coated PRD-166/glass composites were measured as a function of fibre volume fraction, and these experimental values of cte compared with those predicted using various models. Schapery's model was found to predict the cte values of the SnO2-coated fibre composites more accurately. None of the models were successful in predicting the cte of the uncoated fibre composites because of the chemical reactivity between the fibre and matrix. The effect of fibre misorientation and fibre breakage on the cte of the composites was also investigated. Fibre breakage induced during composite fabrication was found to affect the cte more significantly than the processing-induced fibre misorientation in these composite systems. This was because the constraint on expansion exerted by short (broken) fibres is less than that due to long continuous fibres.
A Unified Creep-Plasticity Model for Halite

There are two national energy programs which are considering caverns in geological salt (NaCl) as a storage repository. One is the disposal of nuclear wastes and the other is the storage of oil. Both short-time and long-time structural deformations and stresses must be predictable for these applications. At 300K, the nominal initial temperature for both applications, the salt is at 0.28 of the melting temperature and exhibits a significant time dependent behavior. A constitutive model has been developed which describes the behavior observed in an extensive set of triaxial creep tests. Analysis of these tests showed that a single deformation mechanism seems to be operative over the stress and temperature range of interest so that the secondary creep data can be represented by a power of the stress over the entire test range. This simple behavior allowed a new unified creep-plasticity model to be applied with some confidence. The resulting model recognizes no inherent difference between plastic and creep strains yet models the total inelastic strain reasonably well including primary and secondary creep and reverse loadings. A multiaxial formulation is applied with a back stress. A Bauschinger effect is exhibited as a consequence and is present regardless of the timemore » scale over which the loading is applied. The model would be interpreted as kinematic hardening in the sense of classical plasticity. Comparisons are made between test data and model behavior.« less
Multi-Body Flow Field Calculations with Overlapping-Mesh Method

An efficient overlapping-mesh method for Euler flow solvers is developed and applied to two-body flow field problems. It features simple procedures to determine the interface cells on which the flow quantities are to be transferred from one mesh system to the other. This allows a great flexibility of mesh arrangements. The method is applied to two cases; one is the transonic flow field around vertically-laid, two NACA0012 airfoils. The present method demonstrates its capability to handle the cases in which strong interaction between the airfoils exists, predicting symmetric flow field in spite of the asymmetric mesh configuration. It is found that the overlap ping region can be kept small unless the interaction effect of the flow becomes very large, and there is a large disparity in corresponding cell sizes in the interaction region. The other case is the subsonic flow around Williams airfoil with a flap, to which an exact potential solution is available for comparison. Though the geometry imposes severe restriction for the mesh arrangement, once a minor modification to the meshes is carried out, the method yields an excellent result.
Simple spectral stray light correction method for array spectroradiometers

A simple, practical method has been developed to correct a spectroradiometer's response for measurement errors arising from the instrument's spectral stray light. By characterizing the instrument's response to a set of monochromatic laser sources that cover the instrument's spectral range, one obtains a spectral stray light signal distribution matrix that quantifies the magnitude of the spectral stray light signal within the instrument. By use of these data, a spectral stray light correction matrix is derived and the instrument's response can be corrected with a simple matrix multiplication. The method has been implemented and validated with a commercial CCD-array spectrograph. Spectral stray light errors after the correction was applied were reduced by 1-2 orders of magnitude to a level of approximately 10(-5) for a broadband source measurement, equivalent to less than one count of the 15-bit-resolution instrument. This method is fast enough to be integrated into an instrument's software to perform real-time corrections with minimal effect on acquisition speed. Using instruments that have been corrected for spectral stray light, we expect significant reductions in overall measurement uncertainties in many applications in which spectrometers are commonly used, including radiometry, colorimetry, photometry, and biotechnology.
Effects of extended pleurectomy and decortication on quality of life and pulmonary function in patients with malignant pleural mesothelioma.

Background Maximal cytoreductive surgeries—extrapleural pneumonectomy and extended pleurectomy and decortication (EPD)—are effective surgical treatments in selected patients with malignant pleural mesothelioma. Extended pleurectomy and decortication results in equivalent survival yet better health-related quality of life (HRQoL). Methods Patients with malignant pleural mesothelioma were studied for the effects of EPD on HRQoL and pulmonary function. The European Organization for Research and Treatment of Cancer Core Quality of Life Questionaire-C30 was used to evaluate HRQoL before operation, and at 4 to 5 and 7 to 8 months postoperatively. Pulmonary function tests were measured immediately before and 5 to 7 months after the operation. Patients were compared according to World Health Organization baseline performance status (PS). Results Of the 36 patients enrolled, 17 were PS 0 and 19 were PS 1 or PS 2 at baseline. Patients in groups PS 1 and PS 2 had significantly worse global health, functional, and symptoms scores. After EPD, PS 0 patients had no change in global health or function and symptoms scores except for emotional function, whereas PS 1 or PS 2 patients showed improvements at 4 to 5 months with further improvements at 7 to 8 months. The PS 0 patients demonstrated a significant decrease in forced vital capacity ( p = 0.001), forced expiratory volume in 1 second ( p = 0.002), total lung capacity ( p = 0.0006) and diffusing capacity of the lung for carbon monoxide ( p = 0.003) after EPD, whereas no change was observed in PS 1 and PS 2 patients. Conclusions Extended pleurectomy and decortication did not improve overall HRQoL and had a negative impact in pulmonary function in minimally symptomatic patients. In symptomatic patients, a significant improvement in HRQoL was observed after EPD, which continued at late follow-up, although the pulmonary function was not affected. As changes in HRQoL are multidimensional, the preservation of the pulmonary function may have contributed to the net benefit observed in PS 1 and PS 2 patients.
Redstar3 array controller-embedding Linux and PCs as a DSP replacement

The design of the Redstar3 array control system including operational requirements and performance is presented. The architecture is intended to support next generation large format infrared/optical arrays and mosaics by using a new scalable approach that takes advantage of commercially available electronics. Specifically, an approach of using a combination of high speed fiber links, networked PCs and Linux to replace the previous generation of VME based DSPs will be discussed in detail. The design will be used to control HAWAII-2RG (1-4.9μm 2Kx2K HgCdTe), Aladdin II and III (1-5 μm 1Kx1K InSb) arrays in facility class instruments for Gemini, NSO and IRTF. It is also intended to be the platform for high count curvature correction, waveform sense and control for adaptive optics.
Positive-contrast computed cranial tomographic encephalography in children.

Abstract Positive-contrast computed tomographic encephalography is a safe and effective technique for the evaluation of intraventricular, paraventricular, and cystic intracranial lesions in children. It provides dynamic as well as morphologic information not readily available by routine computed tomographic scanning alone. Our experience with the use of this technique in 21 children forms the basis for this paper.
Two Vitamin D Response Elements Function in the Rat 1,25-Dihydroxyvitamin D 24-Hydroxylase Promoter

The interaction between the two vitamin D response elements (DRE) located at −154 to −134 base pairs (bp) and −262 to −238 bp from the transcription initiation site has been studied using reporter gene assays and binding assays by electrophoretic gel shift measurements. 3 half-sites separated by 3 bp were found necessary for transactivation by the −154 to −125 DRE, while 2 half-sites separated by 3 bp were needed for the DRE at −262 to −238 to function. However, the two DREs together provided maximal activity. The 93-bp fragment separating the two DREs was not required and could be deleted. The most effective binding by receptor was found with the two complete DREs (dissociation constant (Kd) = 13.7 pM), although each DRE bound to the receptor and nuclear accessory factor with about 5 nMKd. The two DREs (a total of 5 half-sites) apparently account for most if not all of the transactivation of the rat 24-hydroxylase by 1,25-dihydroxyvitamin D3. This system represents the most powerful of the DREs reported to date.
Blockade of accumbens 5-HT3 receptor down-regulation by ondansetron administered during continuous cocaine administration

The present experiment examined whether ondansetron, co-administered with continuous cocaine, would block the down regulation of accumbens 5-HT3 receptors. Rats were exposed to a 14-day pretreatment regimen that involved the continuous infusion of 40 mg kg(-1) day(-1) cocaine or 0.9% saline via a subcutaneously implanted osmotic minipump. In addition to the continuous cocaine or saline administration, all subjects received daily subcutaneous (s.c.) injections of either vehicle or 0.1 mg kg(-1) ondansetron for the entire 14-day pretreatment regimen. The rats were then withdrawn from this pretreatment regimen for seven days, and slices from the nucleus accumbens obtained. The slices were perfused with 25 mM K+ in the absence and presence of 0, 12.5, 25, or 50 microM m-Chlorophenyl-biguanide HCl (mCPBG). The efflux samples were assayed for dopamine content by high pressure liquid chromatography (HPLC) with electrochemical detection. Continuous cocaine administration significantly attenuated the ability of mCPBG to facilitate K+-induce dopamine overflow compared to saline control rats. In addition, the rats that received ondansetron and cocaine during the 14-day pretreatment period, the ability of mCPBG to enhance K+ stimulated dopamine release was not significantly different from the saline control subjects. For all groups except the cocaine alone group, the effects of mCPBG on K+ stimulated dopamine release were Ca2+ dependent, suggesting that these effects are receptor mediated. These results suggest that continuous cocaine administration functionally down-regulates 5-HT3 receptors in the nucleus accumbens, and that this down-regulation can be blocked by chronic ondansetron administration. Hence, a functional down regulation of accumbens 5-HT3 receptors represents a significant contribution to the tolerance induced by continuous cocaine administration.
Hackers: computer heroes or electronic highwaymen?

In his book, Hackers: Heroes of the Computer Revolution (Doubleday, 1984), Steven Levy documents the linguistic evolution of the word "hacker." He argues that among computer aficionados the term has been long used to express respect and admiration for another's superior computer programming expertise. In the last ten years (particularly among members of the law enforcement community), however, the concept has taken on an extremely negative connotation and is regularly used to refer to electronic vandals and computer criminals. Yet, recent surveys of computer crime victims indicate that the typical computer criminal is an employee, not an outsider trying to "hack" into the system. In trying to explain this paradox, comparisons are made with earlier historical periods when highwaymen and train robbers were also viewed by law enforcement as criminals but considered by their peers as folk heroes. These modern day "electronic highwaymen" are innovative deviants who prey on the inherent vulnerabilities of our pioneering (and sometimes unpopular) communication and information corporations. The social construction of "hackers" as the principal focus of computer criminalization is explained by examining the specific characteristics of the victims, offenses, offenders, and law enforcement agencies within the scope of the larger computer and information technology revolution.
Effect of Channel Geometry Variations on the Performance of a Microscale Bubble Absorber

The effect of microchannel geometry variations on heat transfer and absorption rate of an ammonia-water constrained thin film bubble absorber are presented. Experiments are performed at an absolute pressure of four bar and at a fixed inlet mass concentration of ammonia of 15 percent. The mass flow rate of the inlet weak solution are varied from 10 g/min to 30 g/min, and that of ammonia gas are varied from 1 g/min to 3 g/min. Five geometries, including two smooth-bottom-walled channels of differing depths, and three channels with structured bottom walls are considered. For identical rates of vapor absorption, the overall heat transfer coefficient for the 400 μm smooth microchannel is significantly larger than of the 150 μm smooth channel as well as that of the cross-ribbed and angled-cross-ribbed structured channel. The streamwise-finned channel exhibit high overall heat transfer coefficients for vapor flow rates of up to 2 g/min.Copyright © 2007 by ASME
Ethylene Production by Plant Cell Cultures: Variations in Production during Growing Cycle and in Different Plant Species

Suspension cultures of Rosa sp., soybean (Glycine max L.), wheat (Triticum monococcum L.), sweet clover (Melilotus alba Desc.), Haplopappus gracilis Nutt., and rue (Ruta graveolens) produced ethylene. The amount varied with the species. The rate of formation in rose and Haplopappus cells paralleled growth but accelerated when the stationary phase was reached, after which the rate declined sharply. Light was not required for ethylene production. Exogenous ethylene could not replace 2,4-dichlorophenoxyacetic acid or naphthalineacetic acid in the cell cultures, and there was no stimulation of growth in the normal medium. Ethylene at 20 mm reduced growth of Ruta and rose cells by 30 and 20%, respectively. The amounts of ethylene produced by the cultures do not affect growth.
Leguminous Cover Crops to Enhance Population Development of Euseius tularensis (Acari: Phytoseiidae) in Citrus

Abstract Pollens from various field-grown legumes, including clovers, vetches, pea, and bell bean plants, were fed to laboratory colonies of the predacious mite Euseius tularensis (Congdon). The survival, sex ratio, and reproduction of E. tularensis were compared with those for colonies fed pollen from ice plant, Malephora crocea (Jacquin). Predacious mites fed a diet of pollen from bell bean, Vicia faba L.; ‘Austrian winter’ pea, Pisum sativum (L.) var. ‘arvense’ Poir.; and New Zealand white clover, Trifolium repens L. survived and reproduced as well as those fed ice plant pollen. Predacious mites fed common vetch, Vicia sativa L.; woollypod vetch, Vicia villosa Roth ssp. dasycarpa Ten. var. ‘Lana’; and crimson clover Trifolium incarnatum L. var. ‘Flame’ pollens exhibited reduced fecundity. E. tularensis did not survive more than one generation when fed pollens from rose clover, Trifolium hirtum Allioni var. ‘Hykon’ or red clover, Trifolium pratense L. var. ‘Kingsland’. When E. tularensis was released into a field-grown cover crop mixture of woollypod vetch, bell bean, and ‘Austrian winter’ pea, the predacious mite population exhibited a significantly greater population increase on the cover crop over a 4-week period than in nonrelease areas. Addition of ice plant pollen did not significantly improve population growth of E. tularensis on the cover crop. The majority of the E. tularensis population was recovered from the bell bean plants in the cover crop mixture. When E. tularensis-infested cover crop was cut and placed in young citrus trees that had low natural densities of predacious mites, densities on trees were significantly increased.
Child Abuse and Neglect: Perspectives on a National Emergency

Hundreds of thousands of children are being abused and neglected in the United States annually. The structures devised to respond to this abuse and neglect have been unsuccessful. The United States government continues to spend billions of dollars on programs to deal with the effects of these unsuccessful responses. Child abuse and neglect in the United States now represent a national emergency. In this article, we will provide a historical, cultural, and contemporary perspective on child abuse and neglect. This perspective throws light on the complexity of the national emergency and provides a context for further exploration of the issue.
Interaction of aflatoxin and hepatitis B virus in the pathogenesis of hepatocellular carcinoma.

Abstract Aflatoxin-B1 (AFB) and chronic hepatitis B virus (HBV) infection epidemiologically correlate with the geographic distribution of hepatocellular carcinoma (HCC). Integration of HBV DNA into the cellular genome of HCCs and the in vivo formation of adducts between AFB and nucleic Acids lead us to suggest that hepatocytes with integrated HBV DNA preferentiallys accumulate AFB; the AFB-adducts formed may then initiate cell transformation by modifying the expression of critical host genes. The altered molecular biology of liver cells in HCC is evidenced by the fact that HBV does not replicate in HCC tissues or cell lines. The effect of AFB on the expression of cellular genes such as endogenous retrovirus(es) and possibly cellular oncogene(s) can be analyzed in HCC cell lines with and without integrated HBV DNA. In addition, human HCC tissues can be probed for HBV sequences and AFB-DNA adducts at the single-cell level. The presence of HBV and AFB can be correlated with the expression of putative transforming genes, providing a new insight into the interaction between liver cells, HBV and AFB in the pathogenesis of HCC.
New Insights into the Pathogenesis and Treatment of Idiopathic Pulmonary Fibrosis: A Potential Role for Stem Cells in the Lung Parenchyma and Implications for Therapy

Idiopathic Pulmonary Fibrosis (IPF) is a chronic, progressive, and often fatal form of interstitial lung disease. It is characterized by injury with loss of lung epithelial cells and abnormal tissue repair, resulting in replacement of normal functional tissue, abnormal accumulation of fibroblasts and myofibroblasts, deposition of extracellular matrix, and distortion of lung architecture which results in respiratory failure. Despite improvements in the diagnostic approach to IPF and active research in recent years, the molecular mechanisms of the disease remain poorly understood. This highly lethal lung disorder continues to pose major clinical challenges since an effective therapeutic regimen has yet to be identified and developed. For example, a treatment modality has been based on the assumption that IPF is a chronic inflammatory disease, yet most available anti-inflammatory drugs are not effective in treating it. Hence researchers are now focusing on understanding alternative underlying mechanisms involved in the pathogenesis of IPF in the hope of discovering potentially new pharmaceutical targets. This paper will focus on lung tissue repair, regeneration, remodeling, and cell types that may be important to consider in therapeutic interventions and includes a more detailed discussion of the potential targets of current therapeutic attack in pulmonary fibrosis. The discovery that adult bone marrow stem cells can contribute to the formation of differentiated cell types in other tissues, especially after injury, implies that they have the potential to participate in tissue remodeling, and perhaps regeneration. The current promise of the use of adult stem cells for tissue regeneration, and the belief that once irreversibly damaged tissue could be restored to a normal functional capacity using stem cell-based therapy, suggests a novel approach for treatment of diverse chronic diseases. However this optimism is tempered by current evidence that the pathogenesis of pulmonary fibrosis may involve the recruitment of bone marrow-derived fibroblasts, which are the key contributors to the pathogenesis of this chronic progressive disorder. Nevertheless, stem cell-related therapies are widely viewed as promising treatment options for patients suffering from various types of pulmonary diseases. Gender mismatched bone marrow or lung transplant recipients serve as natural populations in which to study the role of bone marrow-derived stem cells in recovery from pulmonary diseases. Understanding the mechanism of recruitment of stem cells to sites of injury, and their involvement in tissue repair, regeneration, and remodeling may offer a novel therapeutic target for developing more effective treatments against this fatal disorder. This article reviews the new concepts in the pathogenesis, current and future treatment options of pulmonary fibrosis, and the recent advances regarding the roles of stem cells in lung tissue repair, regeneration, and remodeling.
The lesson of Newcomb’s paradox

In Newcomb’s paradox you can choose to receive either the contents of a particular closed box, or the contents of both that closed box and another one. Before you choose though, an antagonist uses a prediction algorithm to accurately deduce your choice, and uses that deduction to fill the two boxes. The way they do this guarantees that you made the wrong choice. Newcomb’s paradox is that game theory’s expected utility and dominance principles appear to provide conflicting recommendations for what you should choose. Here we show that the conflicting recommendations assume different probabilistic structures relating your choice and the algorithm’s prediction. This resolves the paradox: the reason there appears to be two conflicting recommendations is that the probabilistic structure relating the problem’s random variables is open to two, conflicting interpretations. We then show that the accuracy of the prediction algorithm in Newcomb’s paradox, the focus of much previous work, is irrelevant. We end by showing that Newcomb’s paradox is time-reversal invariant; both the paradox and its resolution are unchanged if the algorithm makes its ‘prediction’ after you make your choice rather than before.
Numerical Modeling of Laminar Pulsating Flow in Porous Media

The laminar pulsating flow through porous media was numerically studied. Two-dimensional flows in systems composed of a number of unit cells of generic porous structures were simulated using a computational fluid mechanics tool, with sinusoidal variations in flow with time as the boundary condition. The porous media were periodic arrays of square cylinders. Detailed numerical data for the porosity ranging from 0.64 to 0.84, with flow pulsation frequencies of 20-64 Hz were obtained. Based on these numerical data, the instantaneous as well as the cycle-average permeability and Forchheimer coefficients, to be used in the standard unsteady volume-averaged momentum conservation equation for flow in porous media, were derived. It was found that the cycle-average permeability coefficients were nearly the same as those for steady flow, but the cycle-average Forchheimer coefficients were significantly larger than those for steady flow and were sensitive to the flow oscillation frequency. Significant phase lags were observed between the volume-averaged velocity and the pressure waves. The phase difference between pressure and velocity waves, which is important for pulse tube cryocooling, depended strongly on porosity and the mean-flow Reynolds number.
Metamorphism of eucrite meteorites studied quantitatively using induced thermoluminescence

Induced thermoluminescence studies provide a new and quantitative means of determining relative metamorphic intensities for eucrite meteorites, the simplest and most ancient products of basaltic volcanism. Using this technique, it is shown that the eucrites constitute a continuous metamorphic series and not, as commonly assumed, two groups of metamorphosed and nonmetamorphosed meteorites. It is suggested that the method may have applications to other basalts.
Legislative Organization and the Second Face of Power: Evidence from U.S. State Legislatures

A vast literature argues that the majority party in most legislatures enjoys a policymaking advantage through its access to gatekeeping institutions that let it block bills from reaching the floor. However, agenda-setting institutions vary substantially across legislatures. We propose that this variation should have demonstrable consequences for the majority party’s influence. In this article, we develop hypotheses about the institutional features of legislatures that enable the majority party to block bills. Then, we canvass all 99 U.S. state legislative chambers to measure whether those institutions are present and test whether they lower the rate at which the majority party is rolled. We find that in legislatures where majority-appointed committees can decline to hear bills or decline to report them to the floor, or where the majority leadership can block bills from appearing on the calendar, majority roll rates are significantly lower than in legislatures where those veto points are absent.
Effect of cellular quiescence on the success of targeted CML therapy.

BackgroundSimilar to tissue stem cells, primitive tumor cells in chronic myelogenous leukemia have been observed to undergo quiescence; that is, the cells can temporarily stop dividing. Using mathematical models, we investigate the effect of cellular quiescence on the outcome of therapy with targeted small molecule inhibitors.Methods and ResultsAccording to the models, the initiation of treatment can result in different patterns of tumor cell decline: a biphasic decline, a one-phase decline, and a reverse biphasic decline. A biphasic decline involves a fast initial phase (which roughly corresponds to the eradication of cycling cells by the drug), followed by a second and slower phase of exponential decline (corresponding to awakening and death of quiescent cells), which helps explain clinical data. We define the time when the switch to the second phase occurs, and identify parameters that determine whether therapy can drive the tumor extinct in a reasonable period of time or not. We further ask how cellular quiescence affects the evolution of drug resistance. We find that it has no effect on the probability that resistant mutants exist before therapy if treatment occurs with a single drug, but that quiescence increases the probability of having resistant mutants if patients are treated with a combination of two or more drugs with different targets. Interestingly, while quiescence prolongs the time until therapy reduces the number of cells to low levels or extinction, the therapy phase is irrelevant for the evolution of drug resistant mutants. If treatment fails as a result of resistance, the mutants will have evolved during the tumor growth phase, before the start of therapy. Thus, prevention of resistance is not promoted by reducing the quiescent cell population during therapy (e.g., by a combination of cell activation and drug-mediated killing).ConclusionsThe mathematical models provide insights into the effect of quiescence on the basic kinetics of the response to targeted treatment of CML. They identify determinants of success in the absence of drug resistant mutants, and elucidate how quiescence influences the emergence of drug resistant mutants.
Low temperature diffusion of cobalt and cadmium in silver

Abstract The diffusion of 109Cd and 60Co in monocrystalline silver was investigated over a temperature range from about 375 to 650°C using a chemical film sectioning technique. Penetration depths studied were limited to a region that has previously exhibited unusually steep penetration profiles for high temperature diffusion of 60Co in Ag. This anomalous behavior or “near-surface effect” is characterized by abnormally low diffusivities for penetration depths up to several microns from the surface. For both of the isotope tracers, a near-surface effect was observed at the higher temperatures of the range. However, the diffusivities measured at the lower temperatures were in agreement with extrapolations of hightemperature lattice diffusion data in the literature. An apparent transition in diffusion mechanism was noted from plots of the logarithm of the diffusivity vs. the reciprocal of the absolute temperature. The transitional behavior is described in terms of oxidation kinetics. A possible mechanism for the near surface effect, that has an activation energy and pre-exponential factor corresponding to that observed in the transition is discussed in detail.