cssi/SciSciGPT-SciSciNet huggingface dataset:
Metal ion coordination to 2′ functionality of guanosine mediates substrate–guanosine coupling in group I ribozymes: implications for conserved role of metal ions and for variability in RNA folding in ribozyme catalysis

Abstract Divalent metal ions are necessary in the self splicing reaction of group I introns, and we report that metal interaction to the 2′ position of guanosine for the Azoarcus ribozyme is required for catalysis. Moreover, this metal coordination promotes the guanosine–substrate coupled binding to the ribozyme, which is another conserved feature seen across phylogenetic boundaries. Typically there is a 4–9-fold difference in binding of G to Efree versus E · S. In the Tetrahymena ribozyme’s case this substrate–guanosine communication was attributed to conformational change(s) that lead to cooperative binding of the two cofactors which is almost nonexistent at low temperatures (4 °C). In the prokaryotic Azoarcus ribozyme we also see a 4–5-fold difference in binding of the guanosine/substrate to Efree versus E · G or E · S at 10 °C that is attributed to guanosine–substrate coupling. This coupling is diminished when the metal (Mg2+) coordination to the 2′ is disrupted with use of 2′-amino-2′-deoxyguanosine. The coupling is restored when softer Mn2+ ions are added to the buffer. This evidence generalizes a model for group I ribozyme catalysis that involves metal coordination to the 2′ position of guanosine. However, we see one striking difference in that the guanosine–substrate coupling is reversed. In the Azoarcus system (10 °C) the guanosine/substrate binds 5-fold more tightly to Efree than to E · S or E · G, which is the opposite for Tetrahymena even when the later is run at 4 °C. One implication for this difference in coupling is that the Azoarcus is in a folded state well accommodated for guanosine or substrate binding. This initial binding actually causes a conformational change that retards the subsequent binding of the second cofactor, which contrasts what was found for the Tetrahymena ribozyme. These results indicate that while the role for the metal ions in the chemical catalysis is conserved across phylogenetic boundaries, there is variability in the folding pattern of the ribozyme that leads to phosphoryl transfer.
Overexpression of the proto-oncogene/translation factor 4E in breast-carcinoma cell lines

The expression of the proto-oncogene, translation factor elF-4E, was examined in breast-cell lines: 5 carcinomas and 2 normal. At the protein level, elF-4E was 10 times higher in the carcinoma lines than in normal cells, which is comparable to the level found in breast-cancer biopsies. The elevation appears to be due to increased transcription, since the elF-4E mRNA was correspondingly increased. These results demonstrate that cells isolated from naturally occurring breast carcinomas maintain an elevated expression of the factor. Turnover rates for elF-4E (mRNA and protein) were determined for normal and cancer cells. We found that elF-4e mRNA is relatively stable during an 8-hr incubation with Actinomycin D, but the half-life of the protein is fairly short (approximately 4.5 hr). This suggests that, in proliferating cells, elF-4E may be turning over rapidly, possibly to fine-tune the changes in translation rates which occur during the cell cycle.
Analysis of the targets and tactics of conspecific attack and predatory attack in northern grasshopper mice onychomys leucogaster

Comparisons of tactics of fighting between species are often difficult to make since the body targets attacked may differ. Thus it becomes difficult to assess whether differences in fighting tactics are due to species-specific differences in the tactics themselves or due to the different targets attacked. A solution to this problem is to analyse the tactics of a species that attacks different targets under different circumstances. In this way, differences in tactics can be more readily attributed to differences in targets. In this study, resident male northern grasshopper mice (Onychomys leucogaster) were tested against intruding male conspecifics and against laboratory mice (Mus musculus domesticus). Conspecifics were mainly bitten on the lower dorsum, whereas prey were bitten and killed by bites to the nape of the neck. Therefore, it was possible to analyze the tactics of attack by grasshopper mice when attacking different body targets. For example, in order to defend the lower dorsum and the nape, both intruding conspecifics and prey adopted an upright defensive posture. Resident grasshopper mice used the lateral attack tactic to gain access to the lower flanks but not the nape. This illustrates that the lateral attack tactic is not merely a tactic suitable for overcoming the upright defense tactic, but is used in this context only when the target attacked is on the opponent's posterior dorsum. Such withinpecies comparison enables the identification of the contextual rules which govern the use of fighting tactics. © 1992 Wiley-Liss, Inc.
Influence of Experience, Grade Level, and Subject Area on Teachers' Assessment Practices

Abstract Teachers' self-reported assessment practices and the influence of teaching experience, grade level, and subject area on those practices were explored in this study. Questionnaires were administered to 893 teachers in 34 schools. Teachers reported using performance and observation-based assessment methods most frequently and had the most confidence in the validity of these assessment techniques. Correlational analyses revealed that the more teachers reported using alternative methods of assessment, the more likely they were to report feeling prepared to develop those types of assessments and to report being confident in their validity. The same pattern of results was found for more traditional types of assessment. The most experienced teachers (20 years or more) indicated that they used alternative methods of assessment more often than the least experienced teachers (6 years or less) did. Elementary school teachers reported using alternative assessment strategies significantly more often than did ...
A randomized, double-blind, placebo-controlled trial of duloxetine for the treatment of pain in patients with multiple sclerosis.

Background Patients with multiple sclerosis (MS) often report neuropathic pain (NP-MS). The purpose of this study was to assess the efficacy and tolerability of duloxetine as treatment for NP-MS. Methods In this study, 239 adults with NP-MS (duloxetine = 118, placebo = 121) were randomized to duloxetine 60 mg (30 mg for 1 week, then 60 mg for 5 weeks) or placebo once daily for a 6-week acute therapy phase, followed by a 12-week open-label extension phase (duloxetine 30 to 120 mg/day). Eligible patients had MS for ≥ 1 year and a score ≥ 4 on daily average pain intensity (API) ratings for ≥ 4 of 7 days immediately before randomization. Patients rated API daily on an 11-point numeric scale (0 [no pain] to 10 [worst possible pain]) in an electronic diary. The primary efficacy measure, change in weekly API ratings, was analyzed longitudinally with a mixed-model repeated-measures analysis. Completion, reasons for discontinuation, and treatment-emergent adverse event incidence were compared by Fisher's exact test. Results Duloxetine-treated patients had statistically greater mean improvement in API vs. placebo at Week 6 (−1.83 vs. −1.07, P = 0.001). Treatment completion did not significantly differ between groups. Discontinuation due to adverse events was statistically greater for duloxetine vs. placebo (13.6% vs. 4.1%, P = 0.012). Decreased appetite was reported significantly more often by duloxetine-treated patients (5.9% vs. 0%, P = 0.007). Conclusions This study found analgesic efficacy of duloxetine for NP-MS. Duloxetine is not approved for treatment of this condition. The duloxetine safety profile of this study was consistent with the known profile in other patient populations.
Variability of random telegraph noise in analog MOS transistors

Random telegraph signals (RTS) are investigated on MOSFETs where a systematic procedure is developed to extract the RTS parameters from a large volume of multi-level switching events with a Poisson distribution. RTS measurements can be utilized to identify and characterize gate oxide defects with better resolution than frequency domain power spectral density, deep level transient spectroscopy, or charge pumping techniques. We demonstrate here multi-level RTS method to investigate gate dielectric trap characteristics including type (acceptor or donor), position of the traps from the of Si/SiO2 interface in the oxide, and along the channel, using the effect of gate bias on the mean carrier capture and emission times, and the number of active traps.
Autoradiographic and ultrastructural observations of plaques and hormone-dependent mammary tumors in gr mice.

Abstract Hormone-dependent mammary tumors in GR mice, and the disk-shaped “plaques” from which they originate have been examined by [ 3 H]thymidine labeling and electron microscopy. Plaques consisted of long narrow, radiating duct-like tubules lined by dark and light secretory cells containing mammary tumor virus (MTV) and underlaid by a few myoepithelial cells. Autoradiographic analysis of plaques revealed a labeling index of 26%, whereas pregnancy-dependent tumors within the same mice had a labeling index of 38%. At the periphery of some tumors plaque-like tubules were evident. Hyperplasia occurred (1) within some of these tubules and (2) within nearby alveoli, resulting in cords and clusters of tumor cells. Myoepithelial cells could no longer be identified among the tumor cells. Pregnancy-dependent and hormone-induced tumors both contained club-like extensions having distorted lumens. Intracytoplasmic lumina were sometimes observed, as were dark spindle-shaped tumor cells containing MTV. Regression of the tumors was due to rapid cell degeneration which left only a few isolated ducts and/or tubules, some of which presumably have the potential of responding to hormones and initiating another tumor at the same site.
Review of oral hygiene patient education

Abstract Oral hygiene patient education continues to evolve, building on an already extensive history. Based on a review of the literature, current approaches to the application of patient education in the dental field are described. Traditional as well as innovative techniques are reviewed. The serious omission of educational techniques that integrate materials and information directed toward the effective use of fluorides is noted. Nevertheless, findings support the difficult challenges confronting oral hygiene patient educators owing to lack of a clearly defined cause-and-effect relationship between the incidence of dental disease and recommended oral health practices. There is clear evidence, however, that thorough oral hygiene prevents the onset or progression of periodontal disease and that the use of fluorides reduces dental caries. This review is focused on those educational methods that more accurately apply to one-to-one or small-group targets rather than large-scale programs. Within the limits of this article it has been necessary to exclude a review of several excellent texts. Several opinion pieces have been included to present as comprehensive a review as space permits.
Glucocorticoids Induce Osteocyte Apoptosis by Blocking Focal Adhesion Kinase-mediated Survival EVIDENCE FOR INSIDE-OUT SIGNALING LEADING TO ANOIKIS

Bone fragility induced by chronic glucocorticoid excess is due, at least in part, to induction of osteocyte apoptosis through direct actions on these cells. However, the molecular mechanism by which glucocorticoids shorten osteocyte life span has remained heretofore unknown. We report that apoptosis of osteocytic MLO-Y4 cells induced by the synthetic glucocorticoid dexamethasone is abolished by the glucocorticoid receptor antagonist RU486, but not by inhibition of protein or RNA synthesis. Dexamethasone-induced apoptosis is preceded by a decrease in the number of cytoplasmic processes, an indicator of cell detachment. In addition, the focal adhesion kinase FAK prevents dexamethasone-induced apoptosis, whereas the FAK-related kinase Pyk2 increases the basal levels of apoptosis. Dexamethasone-induced apoptosis is also prevented in cells expressing kinase-deficient or phosphorylation-defective (Y402F) dominant negative mutants of Pyk2. Consistent with the requirement of tyrosine 402, dexamethasone induces rapid Pyk2 phosphorylation in this residue. Moreover, knocking down Pyk2 expression abolishes apoptosis and cell detachment induced by dexamethasone, and transfection with human Pyk2 rescues both responses. Furthermore, induction of apoptosis as well as cell detachment by dexamethasone is abolished by inhibiting the activity of JNK, a recognized downstream target of Pyk2 activation. These results demonstrate that glucocorticoids promote osteocyte apoptosis via a receptor-mediated mechanism that does not require gene transcription and that is mediated by rapid activation of Pyk2 and JNK, followed by inside-out signaling that leads to cell detachment-induced apoptosis or anoikis.
Noise in Pulsed Fibre Optical Communication Systems

Noise associated with pulse propagation in multi-mode optical fibres is investigated. The source is assumed to be a superposition of a coherent component and a thermal component of arbitrary spatio-temporal coherence. The fibre is assumed to suffer from random selective modal attenuation as well as random modal phases. The detector collects only a portion of the transmitted power and the coupling to the detector is allowed to be random. The role played by these noise sources and their mutual interactions at different times during the course of the transmitted pulse is assessed. The c.w. limit reproduces known results.
Separation of mixtures of 2,4,6-trinitrotoluene reduction products with liquid chromatography

Abstract A high-performance liquid Chromatographic procedure is described for the partial separation of 2,4,6-trinitrotoluene and eight reduction products. A methanol gradient effectively separates the components during a 20-min run. Baseline separation of 2-amino-4,6-dinitrotoluene and 4-amino-2,6-dinitrotoluene could not be achieved, even with isocratic runs. The method is responsive to concentrations near 100 ppb (20 ng) by direct injection, and to lower concentrations if SEP-PAK cartridges are used to concentrate the compounds.
Re-evaluating colour constancy algorithms

We present a re-evaluation of previous experimental data for five different colour constancy algorithms, based on experiments on real and synthetic images. Our work is motivated by the observation that previous analysis of algorithm performance is flawed because it uses inappropriate statistical measures of performance. We discuss these flaws in detail and suggest more appropriate statistical tests. We show that using these tests conclusions as to the relative performance of algorithms are significantly changed as compared to the original analysis of the data. In particular we conclude that the performance of two algorithms: Gamut mapping and color by correlation is statistically equivalent and significantly better than the three other algorithms tested (Max-RGB and two versions of Grey-world).
Interval partitions and Stanley depth

In this paper, we answer a question posed by Herzog, Vladoiu, and Zheng. Their motivation involves a 1982 conjecture of Richard Stanley concerning what is now called the Stanley depth of a module. The question of Herzog et al., concerns partitions of the non-empty subsets of {1,2,...,n} into intervals. Specifically, given a positive integer n, they asked whether there exists a partition P(n) of the non-empty subsets of {1,2,...,n} into intervals, so that |B|>=n/2 for each interval [A,B] in P(n). We answer this question in the affirmative by first embedding it in a stronger result. We then provide two alternative proofs of this second result. The two proofs use entirely different methods and yield non-isomorphic partitions. As a consequence, we establish that the Stanley depth of the ideal (x"1,...,x"n)@?K[x"1,...,x"n] (K a field) is @?n/2@?.
Effect of Fluorescence Quenching by Stimulated Emission on the Spectral Properties of a Solvent-Sensitive Fluorophore

We examined the emission spectra and wavelength-dependent anisotropies of the solvent-sensitive fluorophore 4-(dimethylamino)-4‘-cyanostilbene (DCS) under condition of fluorescence quenching by stimulated emission. The sample was illuminated with a train of 10 ps pulses at 285 nm, and a train of stimulating pulses at 570 nm which were delayed by a time td relative to the excitation. Stimulated emission of DCS was demonstrated to occur by observation of gain in the long-wavelength beam. Illumination on the long-wavelength side of the emission spectrum with the long-wavelength time-delayed pulses resulted in a blue shift of the emission spectrum, and a progressive decrease of the emission anisotropy as the observation wavelength increased toward the stimulating wavelength. The spectral shifts and wavelength-dependent anisotropies of DCS were more pronounced in more viscous solvents where spectral relaxation is incomplete during the excited state lifetime. Light quenching of DCS in a low-viscosity solvent re...
The effect of body mass and physical activity on the development of guinea pig osteoarthrosis.

We quantitatively evaluated the morphological and biochemical effects of body mass and physical activity on spontaneously developing guinea pig osteoarthrosis (OA). 6-month-old male guinea pigs were allocated to 3 groups: controls (C) living under standard laboratory conditions with food ad libitum; mobilized animals (M) allowed unrestricted motion in large rooms with food ad libitum; and a diet group (D) weight-matched with the M-group. At 9- and 12-months of age they were killed and the left proximal tibia was processed for quantitative histology and the right tibial articular cartilage for analyses of glycosaminoglycan (GAG). OA mostly occurred on the medial condyleos central part not covered by the meniscus. The thinnest cartilage was found in 12-month-old M-animals (M12), which had 60% of the central cartilage surface affected by lesions that extended down to the mineralized cartilage. C12 had 25% exposed mineralized cartilage and D12, 2%. Subchondral bone density followed the loading patterns N the ...
Robust Bayesian diagnostics

Abstract In robust Bayesian analysis, it is of interest to know which aspect(s) of a model most affects the robustness performance. This is particularly useful when robustness is found lacking, and thus further reflection on the model elicitation is contemplated. Here, we consider a situation where one is concerned with the effect of ‘small’ deviations from a base model, which we express using an e-contamination class. We then develop a measure, based on a derivative w.r.t. e, that can be useful in identifying those aspects which influence the robustness performance most. Some practical examples are provided for illustration.
Limits to the evolution of assortative mating by female choice under restricted gene flow

The evolution of assortative mating is a key component of the process of speciation with gene flow. Several recent theoretical studies have pointed out, however, that sexual selection which can result from assortative mating may cause it to plateau at an intermediate level; this is primarily owing to search costs of individuals with extreme phenotypes and to assortative preferences developed by individuals with intermediate phenotypes. I explore the limitations of assortative mating further by analysing a simple model in which these factors have been removed. Specifically, I use a haploid two-population model to ask whether the existence of assortative mating is sufficient to drive the further evolution of assortative mating. I find that a weakening in the effective strength of sexual selection with strong assortment leads to the existence of both a peak level of trait differentiation and the evolution of an intermediate level of assortative mating that will cause that peak. This result is robust to the inclusion of local adaptation and different genetic architecture of the trait. The results imply the existence of fundamental limits to the evolution of assortment via sexual selection in this situation, with which other factors, such as search costs, may interact.
The stress of elaborate male traits: integrating glucocorticoids with androgen-based models of sexual selection

Stress hormones are emerging as major factors regulating the expression of elaborate male traits. Surprisingly, however, the effects of glucocorticoids on such traits have not been formally integrated with androgen-based models of sexual selection. Here we point out that consideration of glucocorticoid-mediated effects on the phenotype provides new insight into long-standing hypotheses and controversies associated with such models. In particular, androgen-based ‘handicap’ models of sexual selection characteristically hinge on graded effects of androgens on male traits, but few studies have found support for such a relationship, suggesting that androgens may not be a primary target of selection. We propose, however, that in many instances, androgens may not appear to have a graded effect on the phenotype because elevated glucocorticoids mask the effects of androgens. Glucocorticoids may be inextricably linked to elaborate traits because the energetic demands associated with such traits promote glucocorticoid production. We thus propose that glucocorticoid-mediated effects on male traits warrant re-evaluation of androgen-based models of sexual selection. In particular, we argue that androgen-based handicap models cannot be dismissed based on the lack of evidence for a graded relationship between androgen level and the extent or magnitude of the trait. Our review of the literature indicates that most studies have examined either the effects of androgens or the effects of glucocorticoids, but not both. A more integrated approach involving the effects of both steroids is necessary to fully understand the role of androgens and the endocrine targets of selection associated with the expression of elaborate male traits.
Evidence that α-farnesene biosynthesis during fruit ripening is mediated by ethylene regulated gene expression in apples

Abstract The effect of ethylene regulation on α-farnesene biosynthesis in preclimateric ‘Delicious’ and ‘Granny Smith’ apples was studied using an ethylene inducer and inhibitor, α-farnesene biosynthesis precursors, and protein transcription and translation inhibitors. α-Farnesene was not detectable when internal ethylene concentrations were less than 1 μl l −1 . Correlations between internal ethylene and α-farnesene production fit the exponential growth equation and were significant in ‘Delicious’ ( y = e 0.17 ; r 2 =0.68) and ‘Granny Smith’ ( y = e 0.18 ; r 2 =0.83). When applied at harvest, aminoethoxyvinylglycine (AVG) at 200 mg l −1 inhibited both internal ethylene accumulation and α-farnesene production, whereas ethephon at 200 mg l −1 accelerated both. Adding ethephon to AVG-treated fruit after 18 days at 20°C induced internal ethylene accumulation and α-farnesene production. Ethephon induced α-farnesene production in discs from preclimacteric fruit peel as well as AVG-treated fruit peel, but α-farnesene was undetectable when cycloheximide (CHI, 50 mM), actinomycin D (Act D, 50 mM), or silver nitrate (150 mg l −1 ) were added to the ethephon-treated discs. In preclimacteric fruit discs at harvest, with or without AVG treatment, α-farnesene biosynthesis was induced by 50 μM mevalonic acid lactone (MAL) or farnesyl pyrophosphate (FPP), but not by hydroxymethylglutaric acid (HMG). Adding CHI or Act D to these discs did not affect the induction of α-farnesene by MAL or FPP.
Effect of exercise on blood coagulation.

Whole blood clotting time was measured before and after four different intensities and durations of exercise, using 12 male college students as subjects. The exercises consisted of a 15-minute walk on a motor-driven treadmill at 2.5 m.p.h., a 2-hour walk on the treadmill at 2.5 m.p.h., a run to near exhaustion on the treadmill at 6.25 m.p.h., and a stepping exercise on a 12-inch bench, 30 steps per minute for 15 minutes. Thromboplastin generation rate was measured before and after the stepping exercise on blood samples drawn from 14 subjects, and thrombin generation rate was similarly measured on samples drawn from 16 subjects. No statistically significant variation was found in whole blood clotting time of samples drawn before the exercise, 1 minute after the exercise, or 15 and 30 minutes after. Neither was there any significant change in the thromboplastin generation rate of samples drawn before, 1 minute after, and 30 minutes after exercise. Ten of the 16 subjects showed no change in thrombin generati...
A parallel distributed processing model of story comprehension and recall

An optimal control theory of story comprehension and recall is proposed within the framework of a “situation”‐state space. A point in situation‐state space is specified by a collection of propositions, each of which can have the values of either “present” or “absent.” A trajectory in situation‐state space is a temporally ordered sequence of situations. A reader's knowledge that the occurrence of one situation is likely to cause the occurrence of another situation is represented by a subjective conditional probability distribution. A multistate probabilistic (MSP) causal chain notation is also introduced for conveniently describing the knowledge structures implicitly represented by the subjective conditional probability distribution. A story is represented as a partially specified trajectory in situation‐state space, and thus, story comprehension is defined as the problem of inferring the most probable missing features of the partially specified story trajectory. The story‐recall process is also viewed as ...
Reflectance spectra of hydrated Titan tholins at cryogenic temperatures and implications for compositional interpretation of red objects in the outer Solar System

We report the visual and near-infrared (0.4-2.5 micron) laboratory bi-directional reflectance of Titan tholin at cryogenic temperatures (approx. 100-300 K). When compared with room temperature measurements, the visual and near-infrared color of Titan tholin becomes slightly redder by approx. 5% at low temperatures in the 0.4-1.3 micron region. We estimate the influence of these colr changes on the interpretation of the Centaur Pholus and find that the modest color changes will not significantly alter existing interpretations.
Isocratic resolution of amino acid thiohydantoins by high-performance liquid chromatography

Abstract Sixteen amino acid thiohydantoins encountered during COOH-terminal degradation of peptides and proteins with ammonium thiocyanate have been separated and identified by reverse phase high-performance liquid chromatography using a DuPont Zorbax ODS column and a novel procedure for preparation of thiohydantoin derivative of serine and threonine is described. Three isocratic systems were employed: System 1, buffer A alone (0.01 n sodium acetate, pH 4.5); system 2, 10% acetonitrile in buffer A; system 3, 24% acetonitrile in buffer A. All 16 thiohydantoins could be resolved using a combination of systems 1, 2, and 3. The method is rapid and sensitive (1 nmol) and constitutes a step toward automation of the solid-phase COOH-terminal sequencing method.
Studies on circadian rhythm of the house cricket, Gryllus domesticus L.☆

Abstract An investigation was made of the daily rhythmic behaviour of the house cricket, Gryllus domesticus L. Continuous aktograph records were obtained from individual crickets under various lighting conditions. In LD 12:12 (12 hr of light alternating with 12 hr of dark) adult crickets showed a marked rhythm of locomotory activity set to the start of the dark period. This activity rhythm persisted for several days in constant dark or constant light and was circadian. The phase of the adult activity rhythm could be reset by changing the phase of the alternating LD conditions. The patterns of locomotory activity in LD 12:12 showed marked individual variation. Some crickets showed one daily peak of locomotory activity following the onset of the dark period, while others consistently showed a second peak prior to the onset of the dark period. Last instar larvae generally did not show the marked locomotory activity of the adult type. A daily rhythm of feeding and drinking was found in both adults and larvae. Sexual behaviour of adults was also noted to occur with a daily periodicity. It was found that adult crickets could re-entrain their rhythm of locomotory activity to a new LD regime after either the ocelli or the compound eyes had been blacked-out, but not when both ocelli and compound eyes were covered.
Is a previous unplanned pregnancy a risk factor for a subsequent unplanned pregnancy

Objective The objective of the study was to determine whether a history of unplanned pregnancy was a risk factor for a subsequent unplanned pregnancy. Study Design We analyzed 542 women aged 14-35 years, enrolled in Project PROTECT, a randomized clinical trial to promote dual-method contraception use to prevent sexually transmitted diseases and unplanned pregnancy. Predictors of unplanned pregnancy were assessed by comparing women with and without a history of unplanned pregnancy. Results More than 1 in 5 women (22.5%) experienced an unintended pregnancy. History of an unintended pregnancy was a predictor of unintended pregnancy (adjusted odds ratio, 1.91; 95% confidence interval, 1.09-3.34). Other factors that were significantly associated with unplanned pregnancy included young age and low educational status. Conclusions Future efforts should focus on bridging the gap between identifying risk factors for unplanned pregnancy and interventions aimed at reducing the incidence in high-risk groups.
Multiple nature of acetylcholinesterase in nerve tissue.

WITHIN recent years much evidence has been presented on the multiple nature of enzymes. Such enzyme systems as dehydrogenases1, esterases2, phosphatases3, etc., have been shown by various kinetic, electrophoretic and column separation techniques to exist as more than one molecular specie. It is too early to assess the significance of variations in properties of these similar substances because of the paucity of information correlating their biochemical nature and physiological functions. However, a large body of knowledge has accumulated on the physiological function of acetylcholinesterase relating it to the propagation of the nerve impulse. Data on the unitary or multiple nature of acetylcholinesterase in nervous tissue might lead to specific information on the relation of the enzyme to the nerve conduction process, or might shed light on the general problem of the physiological meaning of the occurrence of multiple molecular enzyme species. Bergmann and Segal4 have already shown that more than one acetylcholinesterase may be present in dog tissue and the multiple nature of serum cholinesterases in a variety of animals has been reported5,6.
A first comparison of POLAR magnetic field measurements and magnetohydrodynamic simulation results for field-aligned currents

This letter presents comparisons between POLAR magnetic field measurements and results from a global numerical simulation of the Earth's magnetosphere using WIND measurements of the solar wind parameters as input. The comparison shows that the simulation provides a good representation for the magnetic perturbation associated with an upward Region 1 field-aligned current (FAC) in the prenoon sector. This current system is caused by the interplanetary magnetic field (IMF) negative By component and also features downward current on open field lines at higher latitudes. The results also show effects caused by a gradual rotation of the IMF northward and a sudden return to its initial dawnward direction. The self-consistent simulation Birkeland current pattern at ionospheric altitudes is also presented, and its evolution caused by the IMF rotations is discussed.
MHC Transfer from APC to T Cells Following Antigen Recognition

Recognition of cognate MHC:peptide complexes by T cells leads to large-scale molecular rearrangements resulting in immunological synapse formation at the T cell-antigen-presenting cell (APC) interface. Although the functions of the immunological synapse are not completely understood, a consequence of this event appears to be the intercellular transfer of MHC:peptide complexes, along with other molecules such as CD80, from the APC to the T cell. The expression of APC-derived molecules on the T cell is biologically significant. It has the potential to alter the homing, allow T cells to also act as APC, and may alter the effector functions of the cell. Experimental evidence suggests that intercellular transfer may play a role in the control of an immune response; however, the exact role is unclear. Both potentiation and attenuation of an ongoing response have been postulated. In addition, removal of molecules from APC may be important in controlling homeostatic proliferation, in affinity maturation of T cells, and in maintaining epitope diversity during an immune response. In this review, we highlight recent advances regarding the mechanism of intercellular transfer and focus on the potential biological significance of this event.
Load transfer in composites with a Coulomb friction interface

Abstract The transfer of load across a frictional interface between elastic solids is investigated. We formulate a model two-dimensional problem in which a fiber is extracted from or pressed into a half-plane to which it is connected via Coulomb friction. With a continuous distribution of dislocations to represent the slip, this problem can be reduced to solving a singular integral equation. Results of interest are the extent of the slip zone, the transfer of load from the fiber to the matrix, and the amount by which the fiber is extracted or depressed, all of which depend on the load in a non-linear fashion. Attention is focused on contrasting the results of the present analysis with approximate treatments generally incorporated into micro-mechanical models of composite materials.
Mechanical intestinal obstruction in atlents with gynecologic disease: A review of 368 patients

To review the management of intestinal obstruction associated with gynecologic disease, the authors studied the records of 368 patients with acute intestinal obstruction. Most patients (83%) had gynecologic malignancies. Obstruction of the small intestines was more common than obstruction of the large intestines (77% versus 23%). Major causes of mechanical small bowel obstruction included extrinsic neoplasms (62%, mostly ovarian carcinomas), radiation therapy-associated strictures and adhesions (17%), postoperative adhesions (14%); and inflammatory strictures and adhesions (3%). Obstruction of the colon was caused mainly by extrinsic neoplasms (45%), strictures and adhesions associated with radiation therapy (26%), fecal impaction (9%), and intrinsic neoplasms (8%). Gastrointestinal intubation successfully relieved 81% of small bowel obstructions caused by postoperative adhesions. Tube suction alone was rarely successful when the obstruction was caused by malignant neoplasms. The prognosis was dependent on the cause of the underlying disease. The cases studied in this report were compared with a large number of cases of bowel obstruction in general surgery. It is concluded that bowel obstruction associated with gynecologic disease has unique features deserving wider recognition.
High-resolution NMR characterization of a gel-like surfactant mesophase.

The addition of phosphatidylcholine to AOT water-in-oil microemulsions leads to the formation of a rigid gel as the water content is increased above a specific threshold. This system is a gel-like crystalline phase where the microstructure evolves from reverse hexagonal to lamellar with increasing water content and/or temperature. Couette sheared 1H and 31P NMR experiments carried out at varying temperature and water content show distinct signatures with microstructure evolution. Because the system has been fully characterized through small-angle neutron scattering, it is possible to relate the NMR signatures to the microstructure. The NMR technique therefore complements scattering techniques but is additionally useful because the technique also picks up isotropic signatures from concurrently occurring noncrystalline phases. The use of NMR to identify such lyotropic gel-like crystalline phases allows easy correlation between templated materials synthesis in these phases and phase microstructure. NMR can t...
The Utility of 18F-FDG-PET in the Diagnosis and Management of Colorectal Carcinoma

2- 18 F-fluoro-2-deoxyglucose-positron emission tomography ( 18 F-FDG-PET) has gained wide acceptance as a clinical imaging tool in the evaluation of patients with colorectal carcinoma. Modern scanners consist of a hybrid system combining PET and computed tomography (CT) in one gantry (PET/CT). This provides more accurate assessment of both PET and CT images by allowing better localization of pathology and better discrimination of pathological tracer uptake from physiological tracer uptake. In addition the coregistered PET and CT images can be used to guide biopsy, thermal ablation techniques, and radiotherapy. 18 F-FDG-PET has a high sensitivity for detection of metastatic disease. It is the imaging procedure of choice for accurate identification of patients who might be suitable for surgical resection of metastases. It is also accurate in discriminating fibrosis from active disease in patients who have undergone radiation therapy. It can help differentiate benign from malignant lesions such as hepatic lesions and pulmonary nodules and can be used to monitor the effectiveness of chemotherapy. It is also indicated for assessment of possible recurrence of disease in patients with a rising carcinoembryonic antigen. Although it does not replace traditional anatomic imaging techniques such as standard CT or magnetic resonance imaging, 18 F-FDG-PET may be indicated in patients in whom there is a strong suspicion of metastatic disease despite negative conventional imaging. If done as the first line of testing in the context of increased tumor markers, 18 F-FDG-PET can also guide the use of CT and magnetic resonance imaging to evaluate particular sites.
A data damage tracking quarantine and recovery (DTQR) scheme for mission-critical database systems

Database security research aims to protect a database from unintended activities, such as authenticated misuse, malicious attacks. In recent years, surviving DBMS from an attack is becoming even more crucial because networks have become more open and the increasingly critical role that database servers are playing nowadays. Unlike the traditional database failure/attack recovery mechanisms, in this paper, we propose a light-weight dynamic Data Damage Tracking, Quarantine, and Recovery (DTQR) solution. We built the DTQR scheme into the kernel of PostgreSQL. We comprehensively study this approach from a few aspects (e.g., system overhead, impact of the intrusion detection system), and the experimental results demonstrated that our DTQR can sustain an excellent data service while healing the database server when it is under a malicious attack.
Perspectivism, Criticism and Freedom of Spirit

The paper examines the view that Nietzsche's perspectivism about practical judgments, understood as a form of internalism about practical reasons, implies that any legitimate criticism of judgments emanating from a foreign perspective must be in terms that are internal to this perspective. Insofar as it is thought to be motivated by certain general theoretical strictures of perspectivism, this view is incoherent. The paper argues that, on the contrary Nietzsche's recourse to a strategy of internal criticism is motivated by his own particular commitment to preserving the freedom of spirit of his interlocutors. The paper concludes with a discussion of how freedom of spirit is preserved by internal criticism, and how the nature of freedom of spirit affects the particular form such criticism will assume.
Inviscid melt spinning: As-spun crystalline alumina fibers

Inviscid melt spinning yielded the first crystalline alumina fibers directly from the melts. In this experimental process, a liquid jet having a melt viscosity of 104 for fiberglass) is extruded into propane and is thus chemically stabilized (vs rapidly quenched) before it forms Rayleigh waves and breaks up into droplets. This letter describes a 65.5% alumina-zirconia fiber, an 81.5% and a 90.6% alumina-calcia fiber, a 98.6% alumina-magnesia fiber, and a 100% alumina fiber. The δ-allomorph was identified as the crystalline phase of the melt spun 100% alumina fibers, compared to the α-allomorph reported for FIBER FP, a slurry spun and sintered 100% alumina fiber.
Involvement of a dithiol protein in mitochondrial energy-linked functions and its relation to coupling factor B.

The coupling factor protein isolated previously in pure form with a molecular weight of 11–12 × 103 (K.-S. You and Y. Hatefi, 1976, Biochim. Biophys. Acta423, 398–412) has been shown to restore ATP-induced NAD reduction by succinate, transhydrogenation from NADH to NADP, and ATP-33Pi exchange to submitochondrial particles rendered deficient by extraction with 1 m NH4OH. The factor also stimulated the oxidative phosphorylation activity of the extracted particles 2.5- to >3-fold. The stimulatory effect of the factor was inhibited by mercurials, Cd2+, phenylarsine oxide, and diamide, indicating that it contains an essential dithiol. Dithiothreitol and dihydrolipoate did not replace the protein factor in stimulating the deficient particles. The purified dithiol-containing protein was precipitated and inhibited by antibody raised against coupling factor B. Since this antibody also inhibits coupling factor F2, it is concluded that the active principle of coupling factors B and F2 is the purified dithiol-containing protein of molecular weight 11–12 × 103 referred to above.
A Biographical Footnote to Newman‘s “Lead, Kindly Light”

Newman's famous poem “Lead, Kindly Light” (originally titled “The Pillar of the Cloud”) was written on his return trip to England from Italy in 1833. He had been touring the Mediterranean countries for eight months, the last three of which were spent battling a near-fatal illness in Sicily. On recovering from this illness, he returned to England rejuvenated by his trip and eager for some pending ecclesiastical project. Immediately on his return to Oxford he became involved in the early organizational discussions from which the Oxford Movement evolved. In light of this intensified engagement in reform activities on his return to England, his poem “Lead, Kindly Light” has impressed his biographers as a revealing statement of his resolve to engage in those activities from which he had shrunk only months before. The lines “I was not ever thus, nor prayed that thou shouldst lead me on” and “Pride ruled my will; remember not past years” seem especially to express this shift in resolve. The autobiographical thrust of the poem has therefore seemed quite unmistakable. 1
Rapid identification of protein biomarkers of Escherichia coli O157:H7 by matrix-assisted laser desorption ionization-time-of-flight-time-of-flight mass spectrometry and top-down proteomics.

Six protein biomarkers from two strains of Escherichia coli O157:H7 and one non-O157:H7, nonpathogenic strain of E. coli have been identified by matrix-assisted laser desorption ionization time-of-flight−time-of-flight tandem mass spectrometry (MALDI-TOF−TOF-MS/MS) and top-down proteomics. Proteins were extracted from bacterial cell lysates, ionized by MALDI, and analyzed by MS/MS. Protein biomarker ions were identified from their sequence-specific fragment ions by comparison to a database of in silico fragment ions derived from bacterial protein sequences. Web-based software, developed in-house, was used to rapidly compare the mass-to-charge (m/z) of MS/MS fragment ions to the m/z of in silico fragment ions derived from hundreds of bacterial protein sequences. A peak matching algorithm and a p-value algorithm were used to independently score and rank identifications on the basis of the number of MS/MS-in silico matches. The six proteins identified were the acid stress chaperone-like proteins, HdeA and Hd...
Treatment of chlorine bleaching effluent using a white-rot fungus

This study was undertaken to better understand the reactions related to fungal treatment of pulp bleaching effluents. Color, COD (chemical oxygen demand), glucose, chloride and ammonium concentration were monitored during the course of treatment of alkali extraction stage liquor (E1) with a white-rot fungus Phanerochaete chrysosporium. The color removal rate was independent on the initial glucose concentration. The earlier used glucose concentration of 10 g l−1 was found to be unnecessary high as the residual glucose accounted for about 50% of the final COD of the effluent. The lowest practical glucose concentration was 2 g l−1. Below this the fungus lost its decolorizing activity in a few days. The lignin-related COD decreased 32% and up to 16.5 mM inorganic chloride was liberated (being 34% increase from the original concentration) from the chlorinated organic material in the effluent in 2 d. The observed rapid depletion of added ammonium nitrogen is believed to indicate a switch of a part of the mycelium to primary growth which leads to higher activity and longer active period of time due to renewal of the cells.
Evaluating the stochastic approach to shortwave radiative transfer in the tropical western Pacific

[1] In the last decade numerous advances have been made in parameterizing cloud-radiation interactions. One recent area of improvement involves statistical representations of the influence of three-dimensional cloud fields on the domain averaged radiation. An off-line comparison of a traditional plane-parallel shortwave model against a stochastic model and observations is performed using four years of data from the Atmospheric Radiation Measurement Program's Tropical Western Pacific Clouds and Radiation Testbed site at Nauru Island. Cloud properties are derived from observed cloud chord lengths and input into the stochastic model, removing the necessity of explicitly simulating individual cloud fields and allowing for extended model runs. It is found that for certain cloud field geometries, as observed from the Nauru surface station, the stochastic radiative transfer model simulates more accurate surface fluxes than the traditional plane-parallel model. Results suggest that the relationship between vertical extent of liquid cloud and liquid water path is one indicator of radiatively significant cloud field configurations as is the relationship between solar zenith angle and cloud fraction. The stochastic model performs best when the ratio between diffuse and total shortwave surface irradiance falls between 0.4 and 0.5. A simple parameterization based on criteria developed from these results is applied to the plane-parallel modeled downwelling flux to represent the impact of complex cloud field geometry on the domain-averaged radiation. The plane-parallel simulations with the parameterization applied produce a mean downwelling flux that is 16 Wm -2 closer to observations than the plane-parallel model results and 5 Wm -2 closer than the stochastic model results.
Malignant rhabdoid tumour in the orbit of a horse.

A malignant rhabdoid tumour was diagnosed in the orbit of a 2-year-old Thoroughbred filly. The neoplasm, which was very aggressive, was present in nearly every part of the ocular and periocular structures and had spread to the lymph nodes of the head and neck, the salivary glands and the subcutaneous tissues around the eye. The neoplasm was composed of polygonal cells with abundant eosinophilic cytoplasm. Many cells had a large, vesiculate, indented nucleus and contained a paranuclear globular inclusion. Ultrastructurally, the inclusions were seen to consist of whorls of intermediate filaments. The neoplastic cells were immunoreactive to vimentin and cytokeratin antisera, but were negative for desmin and actin.