cssi/SciSciGPT-SciSciNet huggingface dataset:
Potential sedimentation impacts related to dam removal: Icicle Creek, Washington, U.S.A.

Abstract A series of small dams were built in Icicle Creek in 1937 to facilitate the operations of Leavenworth National Fish Hatchery. However, several of those dams have been abandoned spurring recent discussions among local watershed conservation groups, as well as state and federal agencies, about removing the dams and the potential impact to the lower reaches of Icicle Creek due to elevated sedimentation. The objective of this study was to measure the total volume of sediment trapped behind the Icicle Creek dams and estimate the potential sedimentation impacts for the lower portion of Icicle Creek should the dams be removed. Another objective was to assess the ability of the river to flush the sediments and naturally restore the system to as close to its predam condition as possible. A flow-competence approach was used to assess the restoration potential of the river to do the work of flushing sediments and reestablishing the predam stream channel characteristics. A sediment probe, a total station, a GPS and aerial photographs were used to map out sediment deposits and measure their depths to determine sediment volumes. Grain size distributions from bed sediments, bars, islands and stream banks were used to assess potential downstream sedimentation impacts. The total volume of sediment trapped behind the dams was estimated at 36,000 m 3 (± 4000 m 3 ). The river has sufficient stream power to flush these sediments over 90% of its natural discharge regime. Controlled flushing of the trapped sediments over several years poses very little threat to the water quality and spawning habitats in the lower Icicle Creek scaled against natural flux rates.
Segmental specificity and lateral asymmetry in the differentiation of developmentally homologous neurons during leech embryogenesis.

Abstract This paper describes the embryonic development of three leech neurons which undergo spatially regulated patterns of differentiation. In leeches, the nervous system arises from an iterated array of embryonic cell lineages, and each neuron is represented by a set of bilaterally symmetric and segmentally repeated homologs. Two of the cells discussed here, the neurons nz4 and mz3, stain with antibodies to the neuropeptides SCP and FMRFamide during the course of their embryonic differentiation, but only a subset of the initially immunoreactive homologs continue to express this immunoreactivity into postembryonic life. Those nz4 cells which retain immunoreactivity are referred to as RAS neurons, and the persistently immunoreactive mz3 cells referred to as CAS neurons. The subset of homologs which show persistent expression is segment specific, such that the mature RAS and CAS neurons occupy different segmental domains. In addition, both neurons display a final pattern of expression which is laterally asymmetric, with only one of the two homologs in each segment maintaining the RAS or CAS phenotype. Asymmetric differentiation can occur in either orientation for any given segment, although there is a very strong tendency for the persistently immunoreactive cells to lie on opposite sides of successive segments. The fate of the transiently immunoreactive homologs is unclear, but labeling with intracellular lineage tracers suggests that there are some mz3 neurons which survive late into postembryonic life and never express detectable levels of immunoreactivity. Intracellular lineage tracers also allowed us to follow the development of a third neuron, mz4, which does not stain for either peptide. The mz4 neuron is initially paired, but undergoes an asymmetric pattern of cell death which also shows a strong tendency to alternate sides in successive segments. These spatially coordinated patterns of neuronal survival and/or differentiation suggest that cell interactions play a role in determining the developmental choices made by individual neurons, and a subsequent paper will characterize those interactions through experimental manipulation.
Effect of alpha-chlorohydrin on epididymal sperm and epididymal plasma in swine.

Investigation of the contraceptive mechanism of α-chlorohydrin was done by analyses of epididymal plasma and certain epididymal sperm characteristics after oral administration of 0, 5, 10 or 30 mg/kg, day of the drug to boars for 15 days. Water resorption in caput epididymidis was slightly decreased in all treatment groups. Sodium, potassium, chloride, glycerylphosphorylcholine levels, and seminal antigens in epididymal plasma were not altered significantly by 10 or 30 mg/kg of the drug. The boars on 5 mg/kg exhibited significantly elevated sodium, potassium, or chloride values in various segments. Motility was significantly lower on corpus and proximal cauda epididymal spermatozoa from α-chlorohydrin treated boars. Only boars receiving 30 mg/kg exhibited impaired sperm motility in the distal cauda. The movement of the cytoplasmic droplets to the distal position was retarded in boars on the two highest dose levels. The results suggest that the contraceptive effects of α-chlorohydrin in the boar is probabl...
Critical Care of the Rabbit

Emergency and critical care principles are similar for all mammals. However, because they are stressed easily, rabbits require specialized handling techniques. Rabbits must be evaluated efficiently and stabilized quickly before moving into the definitive diagnostic phase of their care. A thorough clinical history, systematic physical examination, and multiple diagnostic tests are ideal, but when a rabbit is in critical condition, emergency stabilization and fluid resuscitation must take priority. Common emergency presentations include gastrointestinal disorders, such as prolonged anorexia, respiratory distress, neoplasia, neurologic symptoms, exposure to toxins, trauma, and urinary tract infections or obstruction.
Locoweed-induced neuronal storage disease characterized by meganeurite formation☆☆☆

Golgi staining was performed on cerebral cortex and thalamus of adult animals chronically intoxicated with an alpha-mannosidase inhibitor found in locoweed (Astragalus lentiginosus). The widespread occurrence of large, aspiny meganeurites was discovered on cortical pyramidal and thalamic principal neurons but aberrant spines and neurite growth were not observed. Ectopic neurite growth is known to be characteristic of alpha-mannosidosis of early onset in inherited and induced feline models. The absence of neuritogenesis in a storage disease known to be so characterized when induced in younger animals suggests that this unusual phenomenon is in some way linked to normal developmental processes associated with brain maturation.
Continuum and multi-scale simulation of mixed kinematics polymeric flows with stagnation points: Closure approximation and the high Weissenberg number problem

Abstract It is a well known fact that the upper We limit encountered in continuum level viscoelastic flow simulations with typical constitutive equations for dilute polymeric solutions that predict bounded extensional viscosities in geometries with internal stagnation points on solid surfaces is a strong function of the strain hardening nature of the fluid. Specifically, the upper We limit decreases as the level of strain hardening of the fluid is increased. To provide further insight into the high We limitations in continuum level computations of this class of flows, we have performed extensive continuum and multiscale flow simulations in two benchmark flow problems, namely sedimentation of sphere in a tube and flow past a cylinder in a channel, utilizing the FENE-P (continuum and Brownian Configuration Fields (BCF)) and Giesekus (continuum) constitutive equations as well as the FENE (BCF) dumbbell micromechanical model. Extremely large stress gradients in the axial normal stress along the plane of symmetry in the wake of the cylinder and sphere are observed in FENE-P and Giesekus predictions using both multiscale and continuum numerical techniques at We of O(1) where the numerical simulations begin to breakdown for significantly strain hardening fluids, i.e., b > 300, α
Reconstructing the Differentiation Niche of Embryonic Stem Cells Using Biomaterials

The biochemical cues and topographical architecture of the extracellular environment extensively influence ES cell fate. The microenvironment surrounding the developing embryo presents these instructive cues in a complex and interactive manner in order to guide cell fate decisions. Current stem cell research aims to reconstruct this multifaceted embryonic niche to recapitulate development in vitro. This review focuses on 2D and 3D differentiation niches created from natural and synthetic biomaterials to guide the differentiation of ES cells toward specific lineages. Biomaterials engineered to present specific physical constraints are also reviewed for their role in differentiation.
Design methodology for biomimetic propulsion of miniature swimming robots

Miniature and energy-efficient propulsion systems hold the key to maturing the technology of swimming microrobots. In this paper, two new methods of propulsion inspired by the motility mechanism of prokaryotic and eukaryotic microorganisms are proposed. Hydrodynamic models for each of the two methods are developed, and the optimized design parameters for each of the two propulsion modes are demonstrated. To validate the theoretical result for the prokaryotic flagellar motion, a scaled-up prototype of the robot is fabricated and tested in silicone oil, using the Buckingham PI theorem for scaling. The proposed propulsion methods are appropriate for the swimming robots that are intended to swim in low-velocity fluids.
Effect of thermal variables on human breast cancer in cryosurgery.

There is a growing interest in the use of cryosurgery to treat breast cancer, following recent breakthroughs in non-invasive imaging and in cryotechnology, as well as the recent success of cryosurgery in treating various types of cancer. However, since haphazard freezing does not guarantee tissue destruction, in order to apply this technique effectively it is essential to determine the thermal parameters that produce complete destruction of malignant tissue. This study seeks to quantitatively identify the relationship between thermal variables and the degree of freezing damage to human breast cancer cells. In order to do this, human breast cancer and normal cells were frozen with controlled thermal parameters using a directional solidification apparatus. Cell viability was determined after thawing using trypan blue, and correlated to the thermal variables used during freezing. Cellular damage is observed to increase with increasing cooling rates, due to the higher probability of intracellular ice formation. A double freeze thaw cycle significantly increases the extent of cell damage, and is sufficient to ensure complete cell destruction at final freezing temperatures of −40°c for a 25°c/min cooling rate, and −20°C for a 50°C/min cooling rate. The correlations between cell death and thermal parameters are qualitatively identical for all the cell types in this study, although there is some variation from one cell type to another in the overall susceptibility to freezing damage. The correlations established in this study can be used to design systematic and optimal breast cryosurgery protocols.
Angiotensin converting enzyme inhibitor therapy in severe postcardiotomy dysfunction: a prospective randomized study.

Background: Occurrence of severe postcardiotomy dysfunction requiring prolonged postoperative support with intra-aortic balloon counterpulsation (IABP) and inotropes, complicating surgery for coronary artery disease and valvular heart disease carries important hospital morbidity and mortality. This study evaluated the impact of angiotensin converting enzyme inhibitor (captopril) therapy in these patients in the early postoperative period. Methods: During a 5-year period, 298 patients with prolonged diminished cardiac output required support (> 48 to 72 hours) with IABP plus two or three inotropes. This cohort was randomized to two groups, group A (195 patients) who were continued on IABP and inotropes alone and group B (103 patients) who were given an angiotensin converting enzyme (ACE) inhibitor, captopril 48 to 72 hours postoperatively and continued on IABP and inotropes. Results: Tissue perfusion and he-modynamic parameters improved (p < 0.0001) in group B with early termination of IABP (duration of support mean 86 hours in group B vs 169 hours in group A) and inotropes. Peak improvement in tissue perfusion and hemodynamic parameters correlated with decreased serum angiotensin converting enzyme levels. Hospital mortality occurred in 31% of patients in group A and 14.5% in group B. Morbidity complications developed in 37% of patients in group A and 20% in group B. The average length of hospital stay in group A was 27 days and 17 days in group B. Cardiac, pulmonary, infective, gastrointestinal, renal, and neurological complications were common in both groups. Conclusion: Administration of ACE inhibitors in the early postoperative period to patients with severe postcardiotomy dysfunction caused improvement in tissue perfusion with decreases in mortality, morbidity, and length of hospital stay. These drugs, by effectively limiting physiological effects induced by renin angiotensin-aldosterone axis and other mechanisms, caused recovery of stunned myocardium. More randomized trials are needed before recommending these drugs for routine use in similar patients. (J Card Surg 1998;13;11–17)
Using Teacher Evaluation for Improving Instruction

(1987). Using Teacher Evaluation for Improving Instruction. The Clearing House: A Journal of Educational Strategies, Issues and Ideas: Vol. 61, No. 1, pp. 23-24.
Clamp loader structure predicts the architecture of DNA polymerase III holoenzyme and RFC

Recent determinations of the crystal structure of the Escherichia coli gamma complex and delta-beta assembly have shed light on the bacterial clamp loading reaction. In this review, we discuss the structures of delta-beta and the gamma(3)deltadelta' complex and its mechanism of action as a clamp loader of the E. coli beta sliding clamp. We also expand upon the implications of the structural findings to the structure and function of the eukaryotic clamp loader, RFC, and the structure of E. coli DNA polymerase III holoenzyme.
Fluorine-NMR studies of chimpanzee hemoglobin.

Abstract It has been demonstrated that 4-fluorophenylalanine, a known inhibitor of protein synthesis, becomes incorporated into hemoglobin when present in the diet of a chimpanzee. 19F-NMR spectra of various forms of this protein show well-resolved lines, each line presumably corresponding to a unique phenylalanine / fluorophenylalanine position of the primary sequence. Fluorine chemical shifts and, by implication, tertiary structures vary with the oxidation state and ligand.
Unbreakable ethnic bonds: information-seeking behavior of Korean graduate students in the United States

Everyday life information seeking (ELIS) is a relatively new branch of user studies that examines information behavior in daily life activities. In this study, as an example of ELIS, Korean graduate students' everyday lives in the United States are explored, focusing on their perspectives with respect to main stream society and the role of their ethnic church in their everyday lives. This study combines the grounded theory method with in-depth interviews of eight students and their spouses, as well as participant observation and informal interactions with others. The findings showed two dissimilation mechanisms in the typical Korean student's information-seeking behavior: language barrier and the strong bonds in their ethnic church. Their limited English prevents them from interacting with American society, and the students gather within the ethnic community in settings such as the Korean church for the receipt of information for their ELIS and for social comfort. However, the church maintains strong ethnic bonds with the students by monitoring them and impeding their assimilation into American society.
Analytical modeling and damage assessment of shallow embedment pile-deck connections

This paper presents a simple, yet accurate, approach for analytically describing the nonlinear behavior of shallow embedment pile-deck connections under cyclic loading. The approach is based on incorporating at the pile-deck interface a rotational spring fiber-based element connecting to frame elements where the nonlinearity is distributed along the pile length. This additional element directly takes into account the impacts of the pile's rigid body motion, as well as the interaction between the softening of concrete and slipping of the reinforcement at the end of the pile. Experimental results of four test specimens from the literature are used to calibrate and validate this analytical modeling approach. Comparison between analytical and experimental results shows that the proposed modeling technique is capable of accurately describing the cyclic behavior and damage progression in pile-deck connections.
Reason, Nostalgia, and Eschatology in the Critical Theory of Max Horkheimer

Max Horkheimer's dramatic retreat from youthful radicalism to the nostalgic conservatism of his later years has prompted considerable bewilderment and consternation among friends and foes of Critical Theory alike. An examination of the whole of Horkheimer's oeuvre, however, reveals the common origin of both these tendencies in a constant eschatological impulse. Horkheimer's early hyper-radicalism, his eventual articulation of the fatal "dialectic of enlightenment," and his final turn to a pessimistic Jewish transcendentalism can all be traced to the inevitable disappointment of this messianic impulse.
Galloping: nonlinear oscillation in a periodically forced loaded hanging cable

Abstract In this paper, we consider the long-term behaviour of a loaded cable subjected to different types of periodic forcing. Numerical evidence is presented, showing how long-term behaviour depends on initial conditions, and can be either large or small.
Oxidative Stress and Aging: Role of Exercise and Its Influences on Antioxidant Systems

Strenuous exercise is characterized by an increased oxygen consumption and disturbance of intracellular prooxidant-antioxidant homeostasis. At least three biochemical pathways, that is, mitochondrial electron transport chain, xanthine oxidase, and polymorphoneutrophil have been identified as potential sources of intracellular free radical generation during exercise. These deleterious reactive oxygen species pose a serious threat to the cellular antioxidant defense system, such as diminished reserve of antioxidant vitamins and glutathione, and have been shown to cause oxidative damage in exercising and/or exercised muscle and other tissues. However, enzymatic and nonenzymatic antioxidants have demonstrated great versatility and adaptability in response to acute and chronic exercise. The delicate balance between prooxidants and antioxidants during exercise may be altered with aging. Study of the complicated interaction between aging and exercise under the influence of reactive oxygen species would provide more definitive information as to how much aged individuals should be involved in physical activity and whether supplementation of nutritional antioxidants would be desirable.
Impact of Distributed Generation on the IEEE 34 Node Radial Test Feeder with Overcurrent Protection

The use of distributed generation (DG) in power systems has many possible benefits, but also presents many challenges. Notable among these challenges is the effect DG can have on overcurrent protection. This paper contains results pertinent to the addition of DG to the IEEE 34 node test feeder. After an overcurrent protection scheme was implemented for the benchmark system, DG of various sizes was added at specific locations. The impact of these generators was evaluated in terms of steady state normal and short circuit currents as well as protection coordination. In the studies performed so far, generally DG did not adversely affect protection selectivity and coordination for penetration levels of 20% of the original feeder load, but there were some problematic situations. The overcurrent protection must be modified so that the circuit remains correctly protected for specific DG cases.
An exact solution procedure to determine the optimal dispatching times for complex rail networks

Trains operating in densely populated metropolitan areas typically encounter complex track configurations. To make optimal use of the available rail capacity, some portions of the rail network may consist of single-track lines whereas other locations may consist of double- or triple-track lines. This paper develops a branch-and-bound procedure that is able to determine the optimal dispatching times for trains traveling in complex rail networks. We demonstrate the efficiency of our branch-and-bound algorithm by comparing it to CPLEX, a commercially available integer program solver, on an actual rail network in Los Angeles County.
Behavioral and Functional Evidence of Metabotropic Glutamate Receptor 2/3 and Metabotropic Glutamate Receptor 5 Dysregulation in Cocaine-Escalated Rats: Factor in the Transition to Dependence

Background Rats with extended daily cocaine access show escalating cocaine self-administration and behavioral signs of dependence. Regulation of glutamatergic transmission by metabotropic glutamate receptors has emerged as a mechanism in the addictive actions of drugs of abuse. We examined here whether neuroadaptive dysregulation of metabotropic glutamate receptor function is a factor in escalating cocaine self-administration. Methods Rats with 1 hour daily cocaine access (short access [ShA]) versus 6-hour access (long access [LgA]) were tested for differences in the effects of the metabotropic glutamate receptor 2/3 (mGluR2/3) agonist (−)-2-oxa-4-aminobicylco(3.1.0)hexane-4,6-dicarboxylic acid (LY379268) and the metabotropic glutamate receptor 5 (mGluR5) antagonist 3-[(2-methyl-1,3-thiazol-4-yl)ethynyl]-pyridine (MTEP) on cocaine-reinforced progressive-ratio responding and differences in expression levels and functional activity of mGluR2/3 and mGluR5. Results The LgA groups showed higher progressive-ratio breakpoints than ShA groups. LY379268 (0–3 mg/kg subcutaneous) dose-dependently lowered breakpoints in the LgA group but reduced breakpoints only at 3 mg/kg in the ShA group. Consistent with this behavioral effect, functional mGluR2/3 activity was significantly elevated following LgA cocaine exposure. MTEP (0–3 mg/kg intraperitoneal) reduced breakpoints in the ShA group only. Long access cocaine exposure was associated with decreased mGluR5 expression, accompanied by reduced functional mGluR5 activity in the nucleus accumbens. A downward trend developed in mGluR5 protein expression in the medial prefrontal cortex and hippocampus. Conclusions Functional upregulation of mGluR2/3 and downregulation of mGluR5 are likely factors in the transition to cocaine dependence. The differential behavioral effects of LY379268 and MTEP in rats with a history of long access to cocaine have implications for the treatment target potential of mGluR2/3 and mGluR5.
Tuning and timing of excitation and inhibition in primary auditory nerve fibers.

Information about the tuning and timing of excitation, adaptation and suppression in an auditory primary afferent axon can be obtained from the second-order Wiener kernel. Through the process of singular-value decomposition, this information can be extracted from the kernel and displayed graphically in separate two-dimensional images for excitation and inhibition1. For low- to mid-frequency units, the images typically include checkerboard patterns. For all units they may include patterns of parallel diagonal lines. The former represent non-linearities in the phase-locked (ac) response of the unit; the latter reflect non-linear envelope-following (dc) responses. Examples of detailed interpretation are presented for three amphibian-papillar units from the American bullfrog. The second-order Wiener kernel itself is derived from second-order reverse correlation between spikes and a continuous, non-repeating, broad-band white-noise stimulus.
Work rhythm and physiological rhythms in repetitive computer work: Effects of synchronization on well‐being

This study tested the hypothesis that asynchrony between the work rhythm and a worker's internal physiological rhythms may be a source of stress in repetitive computer work. Experienced typists (N=20) entered lines of numeric data using a video display terminal in a simulated office environment. Each day of the 2‐day experiment consisted of six 40‐min work periods. The work rhythm was varied between work periods by adjusting the field length of data entry lines (3–13 characters). Breathing and cardiac responses were monitored continuously throughout work periods, and a mood survey was administered at the end of each work period. The extent of synchronization between (1) breathing response and the work rhythm, (2) cardiac response and the work rhythm, and (3) all three measures (breathing and cardiac responses, and the work rhythm) was scored for each work period using cross‐spectral analysis. Synchronization scores were then evaluated as predictors of mood state and physiological response using multiple r...
On the Occurrence of Transient Puffs in a Rotary Kiln Incinerator Simulator II. Contained Liquid Wastes on Sorbent

The generation of transient puffs resulting from the batch introduction of liquid waste into a 73 kW (250,000 Btu/h) rotary kiln incinerator simulator was investigated. The liquid was added onto a sorbent, enclosed in cylindrical cardboard containers that were introduced into the combustion chamber one at a time. A statistically designed parametric investigation determined the effects of liquid mass, liquid composition, kiln temperature, and kiln rotation speed on the total magnitude and instantaneous intensity of the pollutant puff leaving the kiln. Liquid "wastes" investigated included toluene, methylene chloride, carbon tetrachloride, and No. 5 fuel oil. Transient puffs from these wastes were monitored using on-line measurements for FID-measurable hydrocarbons, CO, and integrated particulate filter loadings, although the suitability of any one of these indicators depended on the chemical nature of the waste involved. Results demonstrate that puffs formed during transient conditions are generated easily...
Quaternary derivatives of granatanol diesters : Potent, ultrashort acting non-depolarizing neuromuscular relaxants

Abstract The purpose of this study was to explore the feasibility of utilizing the granatanol: N -methyl [9-azabicyclo (3.3.1) nonane] 3-alpha-ol as the terminal group in a series of new bisquaternary azabicycyclic diester-type neuromuscular blocking agents. Fifty two bisquaternary ammonium derivatives of several dicarboxylic acid esters of granatanol and three similar derivatives of pseudo granatanol have been investigated for neuromuscular blocking (NMB) potency (ED 50 s), onset and recovery of action and for cardiovascular side effects. All agents were studied first in anesthetized rats, and selected agents were subjected to further pharmacodynamic testing in rabbits, juvenile pigs, cats, dogs and monkeys. One agent was tested in continuous i.v. infusion mode in comparison with its corresponding tropine diester and the aminosteroid muscle relaxant, rocuronium. Several new and highly potent NMB granatanol derivatives are described, which are largely similar in NMB potency to the previously described tropine: N -methyl [8-azabicyclo (3.2.1)] 3-alpha-ol diester derivatives. The majority of the presently described granatanol derivatives displayed ultrashort onset and duration of actions. In that respect some of these agents proved to be the fastest and shortest acting non-depolarizing muscle relaxants described so far. On the negative side, many, but not all, granatanol derivatives produced cardiovascular side effects: e.g. changes in heart rate and blood pressure. Like with the similar tropinyl diester derivatives, cardiac vagal block was present with the majority of these agents as assessed in the rat, pig and cat. Few glutaryl, fumaryl and cyclobutane ( trans ) 1,2-dicarboxylyl granatanol diesters quaternized with disubstituted benzyl halides, bearing p -acyloxy radicals, showed excellent NMB profile. In these derivatives, however, the rapid decomposition of the p -acyloxy groups leads to formation of toxic quinone methene metabolites which precludes their further pharmaceutical development. The pseudo granatanol derivatives were less potent in the rat than the corresponding granatanols and were not further investigated. We conclude that the 9-azabicyclo (3.3.1) nonane (granatane) ring system can successfully replace the similar 8-azabicyclo (3.2.1) octane (tropane) ring system in building potent, utrashort acting NMB agents.
Taxonomy and phylogeny of the Hister servus group (Coleoptera: Histeridae): a Neotropical radiation

Summary The Hister servus group contains ten species and two species complexes. Although the group’s diversity is centred in Mexico and Central America, one lineage, comprising H. indistinctus Say, H. defectus LeConte and H. fungicola Schaeffer, has probably diversified entirely in the south-eastern U.S. The servus group also contains the following species: H. servusErichson, H. nodatuslewis, H. doyeni sp.n., H. lagoi sp.n., H. bullatuslewis, H. coronatus Marseul and H. diadema Marseul and two diverse species complexes, dubbed the comes complex and the montivagus complex. These two complexes require additional sampling and study before species within them can be recognized. They are, however, closely related to each other and appear to be paraphyletic with respect to a clade comprising H. bullatus, H. coronatus and H. diadema. A prior hypothesis that the servus group includes H. sallei, H. matador sp.n. and the species of Hister (Spilodiscus) is not well supported. Several sister groups within the servus group show geographical disjunction between seasonal tropical habitats of western North America and wetter montane habitats of the eastern parts of the continent along the Gulf and Caribbean coasts.
Adenosine modulation of tumor necrosis factor-α-induced neutrophil activation

We hypothesized that adenosine, known to be release from inflammatory sites, could lessen the potentially damaging activity of neutrophils (PMN) primed by tumor necrosis factor-alpha (TNF alpha) at sites of infection. We investigated the effect of adenosine on PMN primed with cell-free medium from mononuclear leukocytes (MNL) that had been treated with lipopolysaccharide (LPS) yielding a conditioned medium rich in TNF alpha and on PMN primed with recombinant human TNF alpha (rhTNF alpha). LPS (10 ng/mL) minimally primed PMN, but LPS-MNL-conditioned medium increased PMN chemiluminescence in response to f-Met-Leu-Phe (fMLP) 1242% compared with unprimed PMN. LPS-MNL-conditioned medium contained adenosine (approximately 30 nM). Converting the adenosine in the LPS-MNL-conditioned medium to inosine with adenosine deaminase (ADA) or blocking adenosine binding to PMN with the adenosine receptor antagonist 1,3-dipropyl-8-(phenyl-p-acrylate)-xanthine (BW A1433U) resulted in a near doubling of chemiluminescence. The LPS-MNL-conditioned medium contained TNF alpha (836 pg/mL; approximately 1 U/mL). Recombinant human TNF alpha (1 U/mL) primed PMN for a 1033% increase in chemiluminescence. Added adenosine decreased rhTNF alpha-primed PMN chemiluminescence (IC50 approximately 100 nM), and adenosine (100 nM) decreased both superoxide and myeloperoxidase release from rhTNF alpha-primed fMLP-stimulated PMN. The activity of adenosine was counteracted by ADA and BW A1433U, and the modulating effect of adenosine was on the primed response rather than on priming per se. Thus, physiological concentrations of adenosine reduce the effects of recombinant human TNF alpha and native human TNF alpha (released from LPS-treated MNL) on PMN activity. Endogenous adenosine may preclude or minimize damage to infected tissue by damping the TNF alpha-primed PMN oxidative response.
The fluctuating-force formulation of friction drag coefficients

Abstract A very simple and exact derivation of the relation between the fluctuating force on a brownian particle and its friction drag coefficient is presented. The fluctuating force in the present treatment is that experienced by a fixed brownian particle, rather than that experienced by a brownian particle moving along its natural trajectory in the fluid. This same treatment is extended to rotational diffusion.
Identification and analysis of the RNA degrading complexes and machinery of Giardia lamblia using an in silico approach

RNA degradation is critical to the survival of all cells. With increasing evidence for pervasive transcription in cells, RNA degradation has gained recognition as a means of regulating gene expression. Yet, RNA degradation machinery has been studied extensively in only a few eukaryotic organisms, including Saccharomyces cerevisiae and humans. Giardia lamblia is a parasitic protist with unusual genomic traits: it is binucleated and tetraploid, has a very compact genome, displays a theme of genomic minimalism with cellular machinery commonly comprised of a reduced number of protein components, and has a remarkably large population of long, stable, noncoding, antisense RNAs. Here we use in silico approaches to investigate the major RNA degradation machinery in Giardia lamblia and compare it to a broad array of other parasitic protists. We have found key constituents of the deadenylation and decapping machinery and of the 5'-3' RNA degradation pathway. We have similarly found that all of the major 3'-5' RNA degradation pathways are present in Giardia, including both exosome-dependent and exosome-independent machinery. However, we observe significant loss of RNA degradation machinery genes that will result in important differences in the protein composition, and potentially functionality, of the various RNA degradation pathways. This is most apparent in the exosome, the central mediator of 3'-5' degradation, which apparently contains an altered core configuration in both Giardia and Plasmodium, with only four, instead of the canonical six, distinct subunits. Additionally the exosome in Giardia is missing both the Rrp6, Nab3, and Nrd1 proteins, known to be key regulators of noncoding transcript stability in other cells. These findings suggest that although the full complement of the major RNA degradation mechanisms were present - and likely functional - early in eukaryotic evolution, the composition and function of the complexes is more variable than previously appreciated. We suggest that the missing components of the exosome complex provide an explanation for the stable abundance of sterile RNA species in Giardia.
EEG topography of response to visual stimuli in generalized anxiety disorder

EEG activity was recorded in 11 normal subjects and 19 patients with generalized anxiety disorder (GAD) at rest and while they were viewing a series of ten 4 sec continuous lights. Topographical cortical changes were assessed using 32-channel EEG power estimate maps. The percent changes from baseline to stimulation, for the first 5 and the last 5 light stimuli, were calculated and topographically mapped. Patients with GAD showed less decrease in alpha activity during the first 5 stimuli and more alpha activity during the last 5 stimuli in comparison to normal controls. Delta, theta, alpha, beta I and beta II did not show any difference during the resting periods. The topographical distribution of response to light was different in each group. Normal controls had a parieto-occipital reactivity and GAD patients a centro-parietal one with the maximum difference between the two groups being located in the occipital region. During the stimulation, beta I activity was decreased in controls and increased in patients. The diminishing reactivity of the patients is interpreted as a diminution of attention to external stimulation because of competing internal interferences. The pattern of regional reactivity suggests the importance of the centro-parietal and/or occipital regions in anxiety.
Gluconokinase and the oxidative path for glucose-6-phosphate utilization.

STUDIES of the oxidation of glucose-6-phosphate and 6-phosphogluconate by extracts of many types of cells have indicated the existence of an oxidative pathway leading through pentose phosphate to triose phosphate, in addition to the anaerobic steps of the Embden–Meyerhof scheme. We have recently obtained an indication of the potential importance of the oxidative pathway in the economy of the cell from a study of gluconate utilization in Escherichia coli, strain B.
Predatory control of copepod seasonal cycles on Georges bank

A stimulation model of copepod population dynamics (development rate, fecundity, and mortality) was used to compute the predatory consumption necessary to control population growth in three dominant copepod species (Pseudocalanus sp., Paracalanus parvus, and Calanus finmarchicus) on Georges Bank, given observed seasonal cycles of copepod and predator populations. The model also calculated secondary production of each species. Copepod development rate and fecundity were functions of temperature while mortality was a function of predator abundance and consumption rate. Daily inputs of temperature and predator abundance (chaetognaths, ctenophores, and Centropages spp.) were derived from equations fit to field data. Model runs were made with various consumption rates until the model output matched observed copepod seasonal cycles. Computed consumption rates were low compared with published values from field and laboratory studies indicating that, even at conservative estimates of consumption, predators are able to control these copepod populations. Combined annual secondary production by the small copepod species, Pseudocalanus sp. and P. parvus, was nearly twice that of the larger C. finmarchicus with P. parvus having the highest total annual production.
Steam chugging calculations with the pele-ic code

Abstract Vapor region collapse mechanisms during chugging in Boiling Water Reactor (BWR) pressure suppression systems are identified by the role of condensation in locally destabilizing the vapor-liquid interface in the vicinity of the submerged tube exit. Vapor collapse is shown to be further hastened by complete vapor separation from the end of the tube. Equivalent adiabatic vapor systems are shown to exhibit stable gas-liquid interfaces and therefore have no tendencies for collapse.
In search of useful theory of innovation

This essay presents an overview of selected aspects of prevailing theoretical understanding of innovation, and attempts to sketch some directions that would seem fruitful to follow if we are to achieve a theoretical structure that can be helpful in guiding thinking about policy. We are using the term innovation as a portmanteau to cover the wide range of variegated processes by which man’s technologies evolve over time. By a theory we mean a reasonable coherent intellectual framework which integrates existing knowledge, and enables predictions to go beyond the particulars of what actually has been observed. It seems apparent that if scholarly knowledge is to be helpful to deliberation about policy directions, theory must be wide enough to encompass and link the relevant variables and their effects, and strong enough to give guidance as to what would happen if some of these variables changed.
Arms Control's New Moment

A spate of newly elected national leaders offers an opportunity to rethink nonproliferation strategies.
P1-02-03: The Reciprocal Roles of E-Cadherin and ZEB1 Demonstrate the Mesenchymal-Epithelial Transition as a Primary Characteristic of Inflammatory Breast Cancer.

Background: Inflammatory breast cancer (IBC) is a rare but very aggressive form of breast cancer. IBC is characterized by nests of tightly aggregated cells, defined as tumor emboli, that exhibit characteristics of cancer stem cells (CSCs). IBC tumor emboli express E-cadherin which is required to maintain their integrity and our recent evidence demonstrates that expression of E-cadherin by tumor emboli is associated with lack of ZEB1 expression, a transcriptional repressor of E-cadherin. This is at odds with the current hypothesis that metastatic progression is associated with the process of epithelial mesenchymal transition (EMT), with loss of E-cadherin and gain of transcription factors including ZEB1, acquisition of CSC characteristics and enhanced invasive capabilities. Materials and Methods: shRNA knockdown and over-expression methods, real time PCR arrays, western blotting, and in vitro assays to evaluate proliferation, invasion, growth in soft agar and clonogenicity and in vivo animal studies were used. Results: Expression of E-cadherin was reduced by shRNA and ZEB1 was expressed in SUM149 IBC tumor cells. Numerous EMT-related genes were upregulated with loss of E-cadherin and gain of ZEB1, including N-cadherin and vimentin. However, there were marginal differences in the in vitro parameters of proliferation, Matrigel invasion and anchorage independent growth in soft agar between SUM149-shECad or SUM149-ZEB1 clones and their respective vector control cells. The loss of E-cadherin and gain of ZEB1 altered the morphology of SUM149 cells when cultured under low adherence conditions permissive for the enrichment of CSC, exhibiting a reversion in grape-like morphology to more well defined spheres, which was accompanied by increased clonogenicity in both SUM149-shECad and SUM149-ZEB1 cells. The loss of E-cadherin and the gain of ZEB1 significantly inhibited tumor growth of cells injected in the mammary fat pad of NOD.Cg-Prkdc scid Il2rg tm1Wjl /SzJ mice. Tumor volume at 56 days for E-cadherin vector control cells was 771.9 mm 3 +/− 185.6 compared to shECadherin tumors, which was 13.6 mm 3 +/− 7.2. Tumor volume of ZEB1 vector control tumors was 346.1 mm 3 +/− 96 compared to volume of ZEB1 expressing tumors, which was 21.5 mm 3 +/− 7.2.Conclusions: E-cadherin with lack of ZEB1 expression in IBC is consistent with a mesenchymal-epithelial transition (MET), consistent with the retention of the epithelial phenotype while maintaining a program of rapid metastasis and colonization of lymph nodes and distant organ sites. Furthermore, we demonstrate that the E-cadherin-ZEB1 axis is critical for the in vivo growth of IBC tumor cells. Although SUM149 cells are fully capable of undergoing an EMT process, which is under negative regulation by E-cadherin, the process of EMT does not drive in vivo tumor growth in IBC. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-02-03.
Attracting Students to Transportation Engineering: Gender Differences and Implications of Student Perceptions of Transportation Engineering Careers

With a significant fraction of the nation's transportation workforce nearing retirement age, it is essential to attract new talent to transportation fields and to retain that talent. In addition, it is also important to attract a diverse workforce, because women and minorities are still significantly under-represented in transportation engineering and related fields. To address the nation's transportation workforce needs, FHWA, the U.S. Department of Transportation, the Institute of Transportation Engineers, and other leading transportation organizations emphasize the importance of outreach activities in kindergarten through 12th grade. In particular, programs directed at middle and high school students are essential for increasing the pipeline of transportation students and professionals. One such program at the University of Memphis in Tennessee, Transportation Engineering Careers (TREC), is designed to increase high school students' interest in transportation careers through a week-long, fast-paced, ac...
Transbilayer complementarity of phospholipids. Proof of principle.

A series of nearest-neighbor recognition (NNR) experiments have been carried out, which provide a rigorous test of the existence of transbilayer complementarity of phospholipids, that is, the ability of phospholipids to select complementary phospholipids from an adjoining monolayer as nearest neighbors. The application of this test to membranes derived from exchangeable phospholipids bearing myristoyl groups (A), stearoyl groups (B), and one stearoyl and one n-dodecyl group (C) in the presence of analogous nonexchangeable templates made from A‘, B‘ and C‘ provides compelling evidence for such complementarity in the physiologically relevant fluid phase.
Role of Suspended Fiber Structural Stiffness and Curvature on Single-Cell Migration, Nucleus Shape, and Focal-Adhesion-Cluster Length

It has been shown that cellular migration, persistence, and associated cytoskeletal arrangement are highly dependent on substrate stiffness (modulus: N/m(2) and independent of geometry), but little is known on how cells respond to subtle changes in local geometry and structural stiffness (N/m). Here, using fibers of varying diameter (400, 700, and 1200 nm) and length (1 and 2 mm) deposited over hollow substrates, we demonstrate that single mouse C2C12 cells attached to single suspended fibers form spindle morphologies that are sensitive to fiber mechanical properties. Over a wide range of increasing structural stiffness (2 to 100+ mN/m), cells exhibited decreases in migration speed and average nucleus shape index of ∼57% (from 58 to 25 μm/h) and ∼26% (from 0.78 to 0.58), respectively, whereas the average paxillin focal-adhesion-cluster (FAC, formed at poles) length increased by ∼38% (from 8 to 11 μm). Furthermore, the increase in structural stiffness directly correlates with cellular persistence, with 60% of cells moving in the direction of increasing structural stiffness. At similar average structural stiffness (25 ± 5 mN/m), cells put out longer FAC lengths on smaller diameters, suggesting a conservation of FAC area, and also exhibited higher nucleus shape index and migration speeds on larger-diameter fibers. Interestingly, cells were observed to deform fibers locally or globally through forces applied through the FAC sites and cells undergoing mitosis were found to be attached to the FAC sites by single filamentous tethers. These varied reactions have implications in developmental and disease biology models as they describe a strong dependence of cellular behavior on the cell's immediate mechanistic environment arising from alignment and geometry of fibers.
Metal nanoparticle and quantum dot metamaterials for near resonant surface plasmon waveguides

We analyze metamaterials based on silver nanospheres hosted in a lossless dielectric for use in high confinement surface plasmon waveguides. Propagation lengths and lateral confinement orders of magnitude better than bulk materials are shown.
A Note on the Instantaneous Rotational Velocity of Mercury

The fluctuation in the angular velocity of the present rotation of Mercury is investigated. The instantaneous rotational rate in terms of orbital mean motion at different positions along Mercury's orbit is given. At aphelion the rotational velocity decreases substantially because the solar gravitational torque on the two thermal bulges on Mercury's surface tends to retard the rotation of Mercury before aphelion passage. It is found that the difference between the rotational periods derived from the motions at perihelion and aphelion is 4.68 min and that the maximum rate of rotation occurs atf=π/4 andf=7π/4, wheref is the true anomaly.
What Is a Physically Reasonable Space-Time?*

Cosmologists often use certain global properties to exclude “physically unreasonable” cosmological models from serious consideration. But, on what grounds should these properties be regarded as physically unreasonable if we cannot rule out, even with a robust type of inductive reasoning, the possibility of the properties obtaining in our own universe?