cssi/SciSciGPT-SciSciNet huggingface dataset:
Automatic phoneme alignment based on acoustic-phonetic modeling.

This paper presents a method for speaker-independent automatic phonetic alignment that is distinguished from standard HMM-based “forced alignment” in three respects: (1) specific acoustic-phonetic features are used, in addition to PLP features, by the phonetic classifier; (2) the units of classification consist of distinctive phonetic features instead of phonemes; and (3) observation probabilities depend not only on the current state, but also on the state transition information. This proposed method is compared with a state-of-the-art baseline forcedalignment system on a number of corpora, including telephone speech, microphone speech, and children’s speech. The new method has agreement of 92.57% within 20 msec on the TIMIT corpus, which is a 26% reduction in error over the baseline method (with 89.95% agreement on TIMIT). Average reduction in error over all corpora is 28%.
Uncovering the Eros of God

Discussions of God's love focus on agape and rarely consider eros as a quality of love between God and human beings. This effacement of eros leaves theological thinking trying to articulate descriptions of unambiguous love. In fact, love is ambiguous and multiple; by thinking theologically about eros we find new ways to think and write about that ambiguity. This essay represents an attempt at such thinking and writing by describing the problems of ignoring eros by looking at the sexual theology and ethics of Karl Barth and Paul Tillich. It then points to alternatives in light of the apophatic theology of Pseudo-Dionysius.
In Retrospect: The chromosome trail

A new translation of Theodor Boveri's 1914 monograph brings the early origins of contemporary cancer research to a wider readership, contends Robert A. Weinberg. The German biologist Theodor Boveri (1862–1915) theorized that a tumour could develop from a single cell with damaged chromosomes long before the idea became generally accepted. His other achievements included an early confirmation that the seat of heredity lay in the nucleus, not in the cytoplasm, and the discovery of the centrosome. Robert Weinberg welcomes a new translation of Boveri's monograph of 1914, Zur Frage der Entstehung maligner Tumoren, as a fitting tribute to Boveri's work, but also as a good read for biologists interested in finding out how we got to where we are today.
Choosing Peace: Hanoi and the Geneva Agreement on Vietnam, 1954-1955

Based largely on new documentary evidence from Vietnam, this article examines North Vietnamese policymaking immediately after the signing of the 1954 Geneva accords. The article demonstrates that l...
Cell Surface Concentrations and Concentration Ranges for Testing In Vitro Autocrine Loops and Small Molecules

A common assumption made when performing in vitro cellular assays is that the concentration of substances in the culture system is uniform. However, since the cells that internalize and secrete substances reside at the bottom of the well, it is conceivable that a concentration gradient could arise across the fluid layer. Importantly, the concentration of a substance in the vicinity of a cell, which is the concentration of interest, cannot be measured via existing methods. In this work a simple strategy for estimating the concentration of a chemical species at the surface of a cell is presented. Finally, this result is used to outline a method for determining the appropriate concentration ranges for testing in vitro autocrine loops and small molecules.
Molecular cloning of Lassa virus RNA: nucleotide sequence and expression of the nucleocapsid protein gene.

Abstract Lassa virus RNA isolated from purified virus particles was polyadenylated and reverse transcripts were cloned into the Pst I site of plasmid pUC9. Clones containing sequences of the smaller (S) segment of the Lassa virus genome were identified by hybridization with purified S RNA. They were characterized by their ability to hybridize with fragments of 3′-labeled Lassa virus S RNA and with each other, and by restriction mapping. The largest insert was 1830 by long and began with the 3′-terminal 19-base sequence characteristic of all arenavirus S RNAs so far analyzed. The virus complementary strand contained a single large open reading frame, beginning at the ATG nearest its 5′ end (nucleotides 103–105) and terminating with a TGA triplet at position 1813–1815, that encodes a protein of 570 amino acids. A recombinant was constructed which expressed the gene as a fusion protein in Escherichia coli . The product was a 60-kDa polypeptide which reacted with monoclonal antibodies specific for the nucleocapsid protein. Comparison of the predicted amino acid sequence with the corresponding sequences deduced from the nucleotide sequences of the other arenavirus S RNAs, lymphocytic choriomeningitis (LCM) and Pichinde, reveals a considerable degree of similarity between Old and New World arenaviruses.
Nonstandard Maternal Work Schedules: Implications for African American Children's Early Language Outcomes.

Abstract In this study, observed maternal positive engagement and perception of work–family spillover were examined as mediators of the association between maternal nonstandard work schedules and children's expressive language outcomes in 231 African American families living in rural households. Mothers reported their work schedules when their child was 24 months of age and children's expressive language development was assessed during a picture book task at 24 months and with a standardized assessment at 36 months. After controlling for family demographics, child, and maternal characteristics, maternal employment in nonstandard schedules at the 24-month timepoint was associated with lower expressive language ability among African American children concurrently and at 36 months of age. Importantly, the negative association between nonstandard schedules and children's expressive language ability at 24 months of age was mediated by maternal positive engagement and negative work–family spillover, while at 36 months of age, the association was mediated only by negative work–family spillover. These findings suggest complex links between mothers’ work environments and African American children's developmental outcomes.
Error analysis in semiconductor impurity energy level determinations

Abstract Computer analysis is presented of the neutrality expression for a semiconductor such as Ge or Si with a typical donor impurity. The anticipated errors in impurity energy-level determination are thereby demonstrated for different degrees of refinement in common graphical techniques involving Hall or conductivity measurements as a function of temperature. It is shown that the graphical technique may be optimized to either the region where the activation energy is equal to the complete ionization energy or half the ionization energy, but not both. This is accomplished by taking proper cognizance of the temperature dependence in the effective density of states function. Graphical technique not properly optimized to the region may result in errors as much as 20 percent. It is also shown that conductivity plots can be quite accurate through use of a graphical method which properly takes under consideration the temperature dependence in the effective density of states function and the carrier mobility. Hall and conductivity data taken from a gold doped germanium sample are presented to illustrate the nature of the problem and the errors involved.
Vitamin B12 in Lake Washington, USA: Concentration and rate of uptake1

The concentration of vitamin Bla in the surface water of Lake Washington was measured by bioassays and the rate of vitamin uptake by adding “Co-1abcled Ba to samples of surface waters. The concentration of vitamin BIz in the lake water decreased by 60% from late winter to summer, while the rate of uptake increased 16-fold and turnover time decreased from 50 days to 1 day. The uptake process could be described by the MichaelisMenten equation. Regression analyses suggested that the standing crops of blue-green algae and detritus were most important in affecting the concentration of vitamin Blz, but that the standing crops of diatoms and “other” algae affected the rate of uptake most. A hypothesis formulated to explain the necessary coincident variation in rates of vitamin BIG input and output assumes indirect coupling, via detritus, between algal utilization and bacterial production of vitamin B 12; it was tested against data from this and other studies. The potential significance of vitamin B12 for phytoplankton ecology was originally suggested by laboratory studies showing that some algae have an absolute requirement for this vitamin ( e.g. Provasoli 1969). Laboratory investigations have contributed to an understanding of factors affecting the production and uptake of vitamin B12 and, hence, to an understanding of its ecological importance. I have measured the concentration of vitamin B12 in the surface waters of Lake Washington and its rate of uptake. By measuring both parameters I hoped to identify what factors affect the dynamics of vitamin B 12, and what effect the vitamin might have on the ecology of phytoplankton. All experimental work was performed in the Department of Zoology, University of Washington, Seattle. I thank W. T. Edmondson for providing space and discussion, D. Allison for assistance, and the Institute of Radiation Biology for counting radioactive samples. J. P. Wall performed the bioassays for vitamin B12. R. G. Elder, B. R. Shero, and unidentified reviewers commented on the text.
Failure Analysis of Rapid Prototyped Tooling in Sheet Metal Forming—Cylindrical Cup Drawing

This paper presents a failure analysis of cylindrical cup drawing dies machined from a polymer composite rapid tooling material. Cup drawing is a complicated process, involving both bending and stretching. In this study, possible die failure modes are identified experimentally. Finite element analyses (FEA) are performed to obtain the stress-strain responses, which are used to determine the dominant failure mode. As cup drawing involves interactions among process parameters, the statistical design of experiments is employed to perform a parametric study. The resulting die failure mode estimation method is verified through experiments.
To Get Involved or Not: The Relation among Extracurricular Involvement, Satisfaction, and Academic Achievement.

This study examined the relation among extracurricular involvement in psychology-related activities, satisfaction, and academic achievement in graduating psychology majors. We surveyed 71 seniors (...
Trends in the Use and Outcomes of Ventricular Assist Devices Among Medicare Beneficiaries, 2006 Through 2011

Objectives: This study sought to examine trends in mortality, readmission, and costs among Medicare beneficiaries receiving ventricular assist devices (VADs) and associations between hospital-level...
Tardiness heuristic for scheduling Flexible Manufacturing Systems

Abstract This paper evaluates the tardiness performance of a sampling-based adaptive heuristic in a dynamic manufacturing environment. A test bed, following a real world manufacturing system, has been developed. The proposed algorithm has been implemented in this simulated environment. After fine tuning the algorithm, it has been tested in various shop conditions. The results of these simulation studies are summarized.
DNA fragment analysis by capillary polymer seiving electrophoresis using poly(acryloylaminoethoxyethanol)-coated capillaries

Abstract Capillary polymer sieving electrophoresis (CPSE) using dynamic sieving polymer solution provides a reliable technique for the accurate size identification of doublestranded (ds) DNA fragments. The polymer sieving systems described here resolve dsDNA fragments in the 100–4000 base pair size range. The effect of temperature, capillary lenght and sieving polymer concentration were examined. Best performance has been achieved with capillaries coated with a new monomer, poly acrylolyaminoethoxyethanol (AAEE). The poly(AAEE) coating exhibits superior stability at high pH as compared to linear polyacrylamide (LPA). This coating provides the necessary stability to ensure reliable analyses over many runs.
Niche partitioning among frugivorous fishes in response to fluctuating resources in the Amazonian floodplain forest

In response to temporal changes in the quality and availability of food resources, consumers should adjust their foraging behavior in a manner that maximizes energy and nutrient intake and, when resources are limiting, minimizes dietary overlap with other consumers. Floodplains of the Amazon and its lowland tributaries are characterized by strong, yet predictable, hydrological seasonality, seasonal availability of fruits, seeds, and other food resources of terrestrial origin, and diverse assemblages of frugivorous fishes, including morphologically similar species of several characiform families. Here, we investigated how diets of frugivorous fishes in the Amazon change in response to fluctuations in food availability, and how this influences patterns of interspecific dietary overlap. We tested predictions from classical theories of foraging and resource competition by estimating changes in diet breadth and overlap across seasons. We monitored fruiting phenology to assess food availability, and surveyed local fish populations during three hydrological seasons in an oligotrophic river and an adjacent oxbow lake in the Colombian Amazon. We analyzed stomach contents and stable isotope data to evaluate temporal and interspecific relationships for dietary composition, breadth, and overlap. Diets of six species of characiform fishes representing three genera changed according to seasonal fluctuations in food availability, and patterns of diet breadth and interspecific overlap during the peak flood pulse were consistent with predictions of optimal foraging theory. During times of high fruit abundance, fishes consumed items to which their functional morphological traits seemed best adapted, potentially enhancing net energy and nutritional gains. As the annual flood pulse subsided and availability of forest food resources in aquatic habitats changed, there was not a consistent pattern of diet breadth expansion or compression. Nonetheless, shifts in both diet composition and stable isotope ratios of consumer tissues during this period resulted in trophic niche segregation in a pattern consistent with competition theory.
Performance-driven dynamic thermal management of MPSoC based on task rescheduling

High level of integration has led to the advent of Multiprocessor System-on-Chip (MPSoC) which consists of multiple processor cores and accelerators on the same die. A MPSoC programming model is based on a task graph where tasks are assigned to cores to maximize performance. To address thermal hotspots in MPSoCs, coarse-grain power management techniques based on Dynamic Frequency Scaling (DFS) are widely used. DFS is reactive in nature and has detrimental effects on performance. We propose an alternative solution based on dynamic task rescheduling where a temperature prediction scheme is built into the scheduler. The temperature look-ahead scheme is used for task reassignment or delay insertion in scheduling. Since temperature prediction and task assignment are done at runtime, both must be simple and extremely fast. To that end, we propose a heuristic solution based on a limited branch-and-bound search and compare results against an optimal Integer Linear Programming (ILP)-based solution. The proposed approach is shown to be superior to frequency scaling, and the resulting schedule length is within 5p to 10p of the optimal solution as obtained from ILP formulation.
Isomerization of silyl ketene acetals: Models for the propagating chain end in group transfer polymerization

The rate of E/Z isomerization for the propagating end in group transfer polymerization (GTP) of methyl methacrylate (MMA) is comparable to the rate of propagation for bifluoride catalysis, in contrast to bibenzoate catalysis where propagation is faster. Methyl 2,2,4-trimethyl-5-methoxy-5-(trimethylsiloxy)pent-4-enoate, 4 (the product of the initiation step in the GTP of MMA), was used as the model of the GTP living end. The rate of monomer addition to 4 was independent of the starting E/Z isomer ratio. The observation of random tacticity in the polymers prepared via anionically catalyzed GTP can be adequately explained by comparable rates of E/Z isomerization and propagation or in the case of bibenzoate catalysis, by the assumption that E and Z propagating ends react with similar stereochemistry. Silyl ketene acetal 2 (a model of the polyacrylate propagating end) underwent HgI2 catalyzed E/Z isomerization at a rate comparable to the polymerization of ethyl acrylate.
Structural Changes in Tetrahymena rostrata during Induced Encystment

SYNOPSIS. Experimentally induced precystic stages and mature cysts from 3 clones of Tetrahymena rostrata were examined by light and electron microscopy. It was demonstrated by cytochemical staining and fine-structural observations that precystic stages release mucocyst material that provides for the production of a cyst wall. Early and late cysts also contain numerous autophagous vacuoles. In late cysts there is a replacement of depleted mucocyst organelles. The developmental evidence obtained from sampling of sequential developmental stages suggests an ∼24-h timetable of cytoplasmic events associated with encystment in this organism.
Numerical method for studying the detectability of inclusions hidden in optically turbid tissue

We introduce an efficient numerical method for studying the detectability of absorptive inclusions in a multiple-scattering optical medium. Use of the method is demonstrated by the forward calculation of integrated and time-gated photon intensities. Schemes for positioning the light source above an inclusion and otherwise determining the location of a hidden object, involving either reflected or transmitted reemissions, are discussed as examples. They are investigated for several illustrative models, and images are calculated as a function of the size and shape of the inclusion.
Determination of the complex refractive index of individual quantum wells from distributed reflectance

We investigate the measurement of the complex refractive index of individual quantum wells by reflectance spectroscopy. Placing the wells at half‐wavelength spacing to cause resonant feedback produces an order‐of‐magnitude increase in measurement sensitivity over that of nonresonant structures. Quantum well dispersive and absorptive effects on reflectance can be differentiated in certain spectral regions. Experimental data confirm a theoretical model of refractive index and absorption for quantum wells of GaAs in Al0.2Ga0.8As in the region of the well band gap.
Expatriate Games: Interorganizational Coordination and International Counterterrorism

Why is international counterterrorism so difficult? This article argues that international counterterrorism is practically impossible in the absence of interorganizational coordination. Unfortunately, interorganizational coordination does not arise spontaneously. The current “war on terrorism” is based largely on political partnerships, but political partnerships are neither necessary nor sufficient conditions of interorgani-zational coordination. Instead, managers should develop externally oriented cultures and cooperative institutional objectives, which, ideally, should be accountable to international institutions. Results from a controlled experiment within a topically designed simulated environment support the argument.
Specific estradiol-17β binding component in adult rat kidney

Abstract An estradiol-17β (E 2 ) binding component has been identified in adult rat kidney which exhibits characteristics of a specific receptor. Scatchard analysis of kidney cytosol revealed a single class of binding sites for E 2 , having high affinity (~0.6 × 10 10 M) and limited binding capacity (12–20 fmol/mg protein). The eytosol macromolecule has a sedimentation coefficient of approximately 4S in either low or high salt (0.4 M KCl) sucrose density gradients. Competition studies using a 100-fold excess of various unlabeled steroids demonstrated greatest inhibition by various estrogens, with E 2 and DES as the most effective competitors; whereas several androgens, aldosterone and progesterone inhibited binding very little. Incubation of kidney slices with [ 3 H]-E 2 resulted in localization of the steroid in purified nuclei. Addition of a 100-fold excess of unlabeled E 2 or DES inhibited translocation of [ 3 H]-E 2 by 94 and 79% respectively, whereas testosterone, dihydrotestosterone and aldosterone exhibited only minimal inhibition on nuclear translocation of [ 3 H]-E 2 receptor. These data offer strong evidence for the existence of an E 2 receptor in rat kidney. It remains to be determined which specific cellular events are regulated by E 2 in the rat kidney.
Signalling pathways in alcohol-induced liver inflammation☆

The pathogenesis of alcoholic liver injury involves interactions of several intracellular signalling pathways in different cell types of the liver. Alcohol-induced sensitization of liver macrophages to portal endotoxin/lipopolysaccharide (LPS) is considered a hallmark of alcoholic liver disease (ALD). Intracellular mechanisms associated with LPS-induced signalling play a crucial role in the initiation and progression of alcoholic liver injury, and are being extensively explored. LPS recognition by Toll-like receptor 4 (TLR4) on macrophages and other cell types in the liver, activation of downstream signalling pathways culminating in activation of transcription factors such as NFκB, AP-1 leads to increased inflammatory cytokine production in ALD. In addition, LPS-induced MAPK such as ERK and p38 also contribute to liver injury. The importance of alcohol-induced reactive oxygen species and interactions with TLR pathways in macrophages leading to inflammation is becoming increasingly evident. Collectively, these signalling pathways induce pro- and anti-inflammatory cytokines that play an important role in ALD. In this review we describe the key signalling intermediates leading to alcohol-induced inflammation in alcoholic liver disease.
SUCCESSFUL SURGICAL TREATMENT OF COMPLETE RECTAL PROLAPSE.

A review of results of the treatment of complete rectal prolapse in the years 1940 to 1962 at the University of Iowa Hospitals has been presented. The largest series in current medical literature has also been reviewed. The one common feature of procedures which are followed by a low incidence of recurrence is complete mobilization of the rectum together with a method of maintaining the rectum in its corrected position until fixation through scarring occurs.
A prospective evaluation of optimal sampling theory in the determination of the steady-state pharmacokinetics of piperacillin in febrile neutropenic cancer patients.

We examined the use of optimal sampling theory in the determination of the pharmacokinetics of piperacillin in febrile, neutropenic cancer patients. Patients were studied prospectively as part of a randomized, double-blind clinical trial of piperacillin and amikacin versus imipenem and placebo. The results from the analysis of 5 optimal samples were compared with those derived from 15 concentration determinations (10 samples, with the 5 optimal samples assayed in duplicate). The use of a standard least-squares estimator as opposed to a bayesian estimator, with normal prior distributions placed on beta and serum clearance, was also examined. Finally, the use of duplicate determinations in improving the precision of parameter estimation was studied. Plasma concentrations obtained at time points determined by optimal sampling theory, when analyzed with a bayesian estimator, produced estimates of pharmacokinetic parameter values that were in good agreement with those derived from the 15-determination set. Duplicate assay did not improve the precision of parameter estimation. Estimation of plasma clearance was quite robust, irrespective of the estimator used, probably because this evaluation was performed at steady state. Optimal sampling theory is a promising technique that can be employed to determine patient-specific estimates of pharmacokinetic parameter values in target populations. Clinical Pharmacology and Therapeutics (1989) 45, 635–641; doi:10.1038/clpt.1989.84
Transfer reaction sum rules and the interacting boson-fermion model

Spectroscopic factor sum rules for single nucleon transfer are studied in the context of the interacting boson-fermion model. These sum rules are applied to pickup and stripping reactions on even-even targets. It is shown that for such targets the odd-even interacting boson-fermion model intermediate states are essentially complete, so that the evaluation of these sum rules using interacting boson-fermion model wave functions and transfer operators is valid. However, this is not true for reactions on odd-even targets. The interacting boson-fermion model sum rules are derived and applied to experimental data from recent studies of the platinum isotopes. A significant discrepancy exists between experiment and theory.
Oral anticoagulation in the hospital: analysis of patients at risk

Warfarin is one of the most commonly used medications associated with adverse events. Warfarin therapy is often initiated or continued in the hospital, yet hospitalization increases the risk of poor anticoagulation control with warfarin. To help understand this, we retrospectively reviewed the records of patients admitted to our hospital during a 6-month period who were given at least one dose of warfarin. To explore factors that may have contributed to poor anticoagulation control, we compared characteristics of patients with an international normalized ratio (INR) ≥5 at some point during hospitalization with those of a group of matched controls who also received warfarin and had INR <5. Among the 35 patients identified who had an INR ≥5, concomitant use of antibiotics was more common than among 105 matched controls; improper warfarin dosing also appeared to contribute to the high INRs. These findings indicate possible targets for intervention to improve patient safety.
Activation and inactivation properties of voltage-gated calcium currents in developing cat retinal ganglion cells

The correlated activity of developing retinal ganglion cells is essential for the reorganization and refinement of retinogeniculate projections. Previous studies have uncovered marked changes in the spiking properties of retinal ganglion cells during this period of reorganization; however, a full understanding of the changes in the underlying ionic conductances has yet to be obtained. To this end, the whole-cell configuration of the patch-clamp technique was used to record currents conducted by voltage-gated calcium channels in 83 dissociated cat retinal ganglion cells obtained from animals aged between embryonic day 34 and postnatal day 105. Calcium currents, magnified by using barium as the major charge carrier, were isolated by substituting choline for Na+ in the bathing solution and Cs+ for K+ in the electrode solution. Three voltage-gated Ca2+ conductances were identified based on their voltage dependence and kinetics of activation and inactivation: a transient low-voltage-activated conductance, a transient high-voltage-activated conductance and a sustained high-voltage-activated conductance. During the developmental period examined there were significant increases in the densities of all three conductances, as well as significant changes in some of their activation and inactivation properties. These findings, together with those reported previously for the voltage-gated Na+ and K+ conductances, are related to the generation of excitability in developing retinal ganglion cells during a period critical to the normal development of the visual system. Furthermore, while the sustained high-voltage-activated conductance was present in all of the retinal ganglion cells observed, only about 72% expressed the transient high-voltage-activated current. During the developmental period examined, there was also an increase in the proportion of cells expressing the transient low-voltage-activated conductance. This, along with our previous finding that retinal ganglion cells heterogeneously express different types of voltage-gated K+ channels, strongly suggests that the spiking patterns observed in different classes of retinal ganglion cell may be due, in part, to their intrinsic membrane properties.
Rabbit Prostaglandin ω-Hydroxylase (CYP4A4): Gene Structure and Expression

Abstract Genomic DNA containing the entire gene encoding P450 4A4, a cytochrome P450 that is elevated during pregnancy, was isolated on two overlapping recombinant phage. The isolated gene, CYP 4A4, encodes a protein that differs at one amino acid position from the predicted sequence of a previously isolated cDNA. The intron/exon structure is highly conserved in relation to the clofibrate inducible genes CYP 4A1, CYP 4A2, and CYP 4A6. However, the 5′ flanking sequences of these genes exhibit little identity. Two transcriptional start sites of the CYP 4A4 gene have been determined by RNase protection analysis and are located 37 and 40 nucleotides upstream of the initiation codon. Like other CYP 4A genes the CYP 4A4 promoter does not contain a TATA consensus sequence. CYP 4A4 mRNAs are not detected in the lungs, liver, and kidneys of untreated rabbits by RNase protection assays. However, CYP 4A4 mRNA is present to varying degrees in all three of these tissues during pregnancy with the greatest abundance observed in the lung and the lowest in the kidney. Treatment of male rabbits with dexamethasone also increases the levels of CYP 4A4 mRNA in the lung and liver, but the levels are eightfold less than those seen for pregnant rabbits. Consensus recognition sequences for either the glucocorticoid or progesterone receptors were not found in 1086 bp of sequence upstream of the start of transcription.
Does parent education moderate relations between low birth weight and child cognitive development outcomes

Using baseline and 3-year data from The Fragile Families and Child Wellbeing Study, we examined the potential for mothers' and fathers' education to buffer at-risk and low birth weight (LBW) children from poor cognitive development outcomes at age 3. Findings suggest that mothers' and fathers' education may both buffer at-risk children from poor cognitive development outcomes, although in different ways. Whereas fathers' education was associated with better cognitive development among LBW boys, mothers' education was associated with better cognitive development among normal birth weight children, regardless of child gender. We further examined whether parent involvement mediated the relation between parent education and child cognitive development. After controlling for demographic variables and our variables of interest we found no significant associations between parent involvement and child cognitive development. Results suggest that other pathways, such as the development of financial and material cap...
Altered phosphoglycerate kinase from old rat muscle shows no change in primary structure

Abstract Phosphoglycerate kinase (ATP:3-phospho- d -glycerate 1-phosphotransferase, EC 2.7.2.3) from young and old rat muscle was purified to homogeneity. After ascertaining that each preparation of the enzyme obtained from the latter indeed possessed altered properties, matched pairs of young and old enzymes were subjected to amino acid analysis and peptide mapping by HPLC. Following S -carboxymethylation, the respective young and old enzymes were digested with each of the following three proteinases: trypsin, chymotrypsin and S. aureus V8 proteinase. The corresponding peptides were resolved by reverse-phase HPLC. The peptide patterns obtained from both enzyme forms were identical. Even when the peptides obtained from digestion of phosphoglycerate kinase with S. aureus V8 proteinase were further digested with trypsin, no differences were observed. Comparative amino acid analyses also showed no differences. These results provide direct evidence that there are no changes in the sequence of altered rat muscle phosphoglycerate kinase and support the hypothesis that the differences in properties between the young and old forms of the enzyme result from a conformational modification.
Phorbol esters inhibit the synthesis of acetylcholine receptors in cultured muscle cells.

The acetylcholine receptor (AChR) synthesis, insertion and degradation rates are regulated by numerous intracellular and extracellular agents. Recent studies have shown that Ca2+ and Ca2+ ionophores have a profound regulatory effect on the appearance of AChR clusters and AChR synthesis [3, 15, 23]. These regulatory effects may be mediated through the activation of calcium and phospholipid-dependent protein kinases by agents such as phorbol esters. In this study, we have utilized 4-β-phorbol-12-myristate-13-acetate (PMA) in order to determine whether the activation of protein kinase C exerts a regulatory effect on the expression of AChRs in cultured chick myotubes. Our results show that 4-β-phorbol-12-myristate-13-acetate decreased intracellular AChRs and suppressed AChR synthesis without affecting the turnover rate. Control and PMA treated cells labeled with [35S] methionine and immunoprecipitated with a monoclonal antibody to the α subunit of AChRs (mAb35) revealed a significant decrease in radioactivity precipitated after exposure to PMA. Polyacrylamide gel electrophoresis revealed no major changes in protein patterns, or in newly synthesized proteins as determined by [35S] methionine incorporation and autoradiography. Other enzymes important in muscle metabolism were not affected by PMA treatment. Our results indicate that activation of protein kinase C results in the suppression of AChRs synthesis and dispersal of AChR clusters.
Vegetative anatomy of Calypsoeae (Orchidaceae)

Calypsoeae represent a small tribe of anatomically little-known orchids with a wide distribution in the Western Hemisphere. Leaves are present in all genera, except Corallorhiza and Wullschlaegelia both of which are subterranean taxa. Stomata are abaxial (ad- and abaxial in Aplectrum ) and tetracytic (anomocytic in Calypso ). Fiber bundles are absent in leaves of all taxa examined except Govenia tingens . Stegmata are present in leaves of only Cremastra and Govenia . Roots are velamentous, except in filiform roots of Wullschlaegelia . Vegetative anatomy supports a relationship between Wullschlaegelia and Corallorhiza but does not support the grouping of winter-leaved Aplectrum and Tipularia nor proposed groupings of genera based on pollinarium features.
Parallel preconditioning based on h-hierarchical finite elements with application to acoustics

Abstract In this paper, we consider the hierarchical basis preconditioning approach which is closely related to the h-version of the hierarchical finite element method. In general, finite element formulations that employ hierarchical shape functions yield better conditioned matrix problems than those based on the Lagrange nodal basis. These matrix problems are also better-suited to a faster rate of convergence with Krylov-subspace iterative methods. We consider a purely algebraic approach to describe projections between the nodal and the h-hierarchical bases functions, which are then used to construct the preconditioning operator. Implementation details of the preconditioner are provided for solving finite element problems on unstructured grids. We employ the preconditioning approach in the iterative solution of linear systems that arise from finite element discretization of the exterior Helmholtz problem. Numerical results are presented to examine convergence rates for practical discretizations in acoustics, and to illustrate the computational performance of the preconditioning algorithm on serial and data-parallel computers.
The quest for excellence in designing CS1/CS2 assignments

We identify the principles involved in designing effective programming assignments for CS1/CS2. Through a case study of a particularly successful recursion assignment, we establish several prerequisites that must be present in the foundation of a potential assignment and discuss techniques for engineering exceptional assignments through changes to their more malleable components.
Estimating Electronic Parameter End Points for Devices Which Suffer Abrupt Functional Failure during Radiation Testing

The abrupt failure of devices under test - especially during step-stress measurements presents special problems in determining parameter end points. This article shows how past procedures can be replaced by a method which can be applied with equal logical consistency to both the graceful degradation of parts as well as to the abrupt failure of parts. The article gives an example of how the method works and discusses its advantages and disadvantages
Untangling positive and negative biotic interactions: Views from above and below ground in a forest ecosystem

In ecological communities, the outcome of plant-plant interactions represents the net effect of positive and negative interactions occurring above and below ground. Untangling these complex relationships can provide a better understanding of mechanisms that underlie plant-plant interactions and enhance our ability to predict population, community, and ecosystem effects of biotic interactions. In forested ecosystems, tree seedlings interact with established vegetation, but the mechanisms and outcomes of these interactions are not well understood. To explore such mechanisms, we manipulated above- and belowground interactions among tree seedlings, shrubs, and trees and monitored seedling survival and growth of six species (Pinus banksiana, Betula papyrifera, P. resinosa, Quercus rubra, P. strobus, and Acer rubrum) in mature pine-dominated forest in northern Minnesota, USA. The forest had a moderately open canopy and sandy soils. Understory manipulations were implemented in the forest interior and in large gaps and included removal of shrubs (no interactions), tieback of shrubs (belowground), removal of shrubs with addition of shade (aboveground), and unmanipulated shrubs (both below- and aboveground). We found that shrubs either suppressed or facilitated seedling survival and growth depending on the seedling species, source of interaction (e.g., above- or belowground), and ecological context (e.g., gap or forest interior). In general, shrubs strongly influenced survival and growth in gaps, with more modest effects in the forest interior. In gaps, the presence of shrub roots markedly decreased seedling growth and survival, supporting the idea that belowground competition may be more important in dry, nutrient-poor sites. Shrub shade effects were neutral for three species and facilitative for the other three. Facilitation was more likely for shade-tolerant species. In the forest interior, shrub shade negatively affected seedling survival for the most shade-intolerant species. For several species the net effect of shrubs masked the existence of both positive and negative interactions above and below ground. Our results highlight the complexity of plant-plant interactions, demonstrate that outcomes of these interactions vary with the nature of resource limitation and the ecophysiology of the species involved, and suggest that ecological theory that rests on particular notions of plant-plant interactions (e.g., competition) should consider simultaneous positive and negative interactions occurring above and below ground.
Survival of phytoplankton under prolonged darkness: Implications for the cretaceous-tertiary boundary darkness hypothesis

Abstract The fossil record indicates that there have been times when a larger than usual number of taxa have disappeared. In particular, 65 million years ago, at the Cretaceous-Tertiary boundary, many planktonic and other marine organisms became extinct. The hypothesis proposed by Alvarez et al. (1980), states that an asteroid hit the earth and produced a global dust cloud. This dust cloud prevented photosynthesis and thereby caused extinctions in the phytoplankton, which in turn affected organisms at higher trophic levels. Tests of this hypothesis involve the use of extant planktonic organisms. Two of these, Thoracospaera heimii (a dinoflagellate) and Ditylum brighwellii (a diatom) are considered very similar to species that crossed the Cretaceous-Tertiary boundary; others, Gonyaulax polyedra, Ensiculifera loeblichii, Scrippsiella trochoidea and Coccolithus pelagicus are organisms that first appeared in the Tertiary. Organisms were exposed under controlled laboratory conditions to environments resembling those that might have existed during the perturbation. Growth, survival and morphological changes were recorded. The results suggest that extended darkness is a viable hypothesis to explain the selective phytoplankton extinctions, especially if the dark period lasted perhaps three months or less. Although the experimental data cannot prove the cause of the extinctions, they can test the feasibility of the hypothesis. It is concluded that extinction hypotheses can be biologically modeled and that photosynthetic microorganisms are extremely useful tools in the modeling process.
Interview: Recent advances in first-line treatment of metastatic colorectal cancer

Marwan Fakih speaks to Ruth Williamson, Commissioning Editor: Dr Fakih received his medical degree at the American University of Beirut in 1992, following which he completed his internal medicine training at Wayne State University–Detroit Medical Center (MI, USA) and his hematology–oncology training at University of Pittsburgh (PA, USA). He subsequently joined Roswell Park Cancer Institute (NY, USA) where he served as the Section Chief of Gastrointestinal Oncology. He has most recently joined the University of Michigan (MI, USA) as Professor of Medicine and co-director of the Gastrointestinal Oncology Program. His research interests include drug development, outcome and prevention of colorectal cancer. His research has included the investigation of calcitriol, selenomethionine and histone deacetylase inhibitors in advanced solid tumors and colorectal cancer. Other research areas have included the development of attenuated chemotherapy regimens for the elderly and novel neoadjuvant treatments for rectal ca...
DEMONSTRATION OF NEURONAL NETWORKS IN THE HUMAN UPPER URINARY TRACT USING CONFOCAL LASER SCANNING MICROSCOPY

Purpose: To our knowledge innervation of the upper urinary tract and its role in motility and sensation are not clearly understood. The whole mount preparation technique provides 3-dimensional (D) morphology of the innervation and its relationship of branching and interconnecting nerve fibers to each other and to the neighboring tissues. Confocal laser scanning microscopy provides dramatic optical advantages for detecting 3-D structures in thick specimens. We investigated the distribution and morphology of the neuronal structures in the human upper urinary tract using the whole mount preparation technique and confocal laser scanning microscopy.Materials and Methods: Whole mount preparations of the human renal pelvis and ureter were stained by standard immunohistochemical method using various neuronal markers (protein gene product 9.5, neuron specific enolase and neurofilament). The 3-D architecture of the specimens was investigated with the help of confocal laser scanning microscopy.Results: We detected 2...
Binding of Dihydrostreptomycin to Escherichia coli Ribosomes: Characteristics and Equilibrium of the Reaction

The binding of dihydrostreptomycin to ribosomes and ribosomal subunits of a number of different Escherichia coli strains was studied, and the Mg2+ and pH dependence, as well as the effect of salts and polynucleotides, was determined. The only requirement for binding with ribosomes and subunits from susceptible strains was 10 mm Mg2+. Monovalent salts weakened the binding in a manner similar to the effects on ribonucleic acid secondary structure, and this was antagonized to some extent by increased amounts of Mg2+. Bound dihydrostreptomycin could be readily exchanged by streptomycin and any antibiotically active derivative, but not by fragments of the antibiotic or any other aminoglycoside. With native (run-off) 70S ribosomes from streptomycin-susceptible strains, the binding was rapid and relatively temperature independent over the range from 0 to 37 C. Polynucleotides did not stimulate the binding. With concentrations of dihydrostreptomycin up to 10−5m, greater than 95% of native 70S ribosomes bound exactly 1 molecule of the antibiotic tightly, with a Kdiss for the bound complex at 25 C of 9.4 × 10−8m. The following thermodynamic parameters were found for the binding with 70S ribosomes at 25 C:ΔG° = −9.6 kcal/mole, ΔH° = −6.2 kcal/mole, and ΔS° = +11.4 entropy units/mole. Differences in affinity for the antibiotic were found between ribosomes of K-12 strains and those of other E. coli strains. There was insignificant binding to 70S ribosomes or subunits from streptomycin-resistant or -dependent strains, and to 50S subunits from susceptible strains. The binding to 30S subunits from susceptible strains was weaker by an order of magnitude than that to the 70S particle, with a Kdiss at 25 C of 10−6m. Polyuridylic acid stimulated this binding slightly but did not influence the affinity of the bound molecule. At antibiotic concentrations above 10−5m, streptomycin-susceptible 70S and 30S particles bound additional molecules of the antibiotic, and binding also occurred to ribosomes from streptomycin-resistant and -dependent strains, as well as to 50S subunits from all strains. Kdiss for all of these binding equilibria were [Formula: see text] 10−4m. This weaker non-specific binding coincided with the beginning of aggregation phenomena involving the particles, and occurred at sites distinct from the single site which binds the antibiotic tightly. This latter site was completely lost after the one-step mutation to high-level resistance or dependence.
Dimer adsorption on square nanotubes with first-and second-neighbor interactions

The thermodynamic properties of dimer adsorption on square M sites wide terraces, with first- and second-neighbor adsorbate-adsorbate interaction energies, were recently numerically obtained using an extension of the transfer matrix technique developed by the authors in 1993. The rank of the transfer matrix increases rapidly with size M, and required the development of an efficient algorithm for its construction at any temperature of the system, and for all possible values of the adsorbate-adsorbate and adsorbate-substrate interaction energies. This article presents the non-trivial generalization of this algorithm for the study of dimer adsorption problems on a square lattice nanotube surface, with M sites on its circular normal section.
Medical and Surgical Management of Chylothorax and Associated Outcomes

Chylothorax is an uncommon form of pleural effusion that can be associated with traumatic and nontraumatic causes. Optimal management and outcome for patients with chylothorax remain unclear. This retrospective single-center study assessed the modes of management for chylothorax in 74 adult patients (> or =18 years old) and associated outcomes. The role of lymphangiographic imaging was also evaluated. Initial treatment approach was nonsurgical in 57 patients (77%) but a surgical procedure (pleurodesis, thoracic duct ligation, and/or surgical repair) was eventually performed in 44 patients (59%). The rate of resolution with initial treatment measures was significantly worse for patients with nontraumatic chylothorax compared with those with traumatic causes (27% versus 50%, P = 0.048). Even after additional therapeutic maneuvers including surgery, chylous effusion recurred more commonly in nontraumatic chylothorax when compared with the traumatic group (50% versus 13%, respectively, P < 0.001). Lymphatic imaging did not seem to materially influence management. Nonsurgical approaches may lead to resolution of the chylothorax in nearly one half of patients with traumatic chylothorax but in only a minority of those with nontraumatic chylothorax. The majority of patients with nontraumatic chylothorax will eventually require surgical maneuvers, but one third of such patients still fail to resolve their chylothorax.