cssi/SciSciGPT-SciSciNet huggingface dataset:
USE OF THE FLUORESCENT LANTHANIDE Tb3+ AS A PROBE FOR CATION‐BINDING SITES ASSOCIATED WITH ISOLATED CHLOROPLAST THYLAKOID MEMBRANES

Abstract— The fluorescent properties of the rare-earth ion, Tb3+ have been utilized to probe the nature of cation-binding sites associated with thylakoid membranes. At low concentrations (< 100μM), Tb3+ was observed to inhibit the increase in chlorophyll a fluorescence normally seen on adding 5 mM MgCl2 (or 100 mM NaCl) to isolated, broken chloroplasts. We also observed under these conditions, the appearance of a new band around 280 nm in the excitation spectrum of Tb3+ ion fluorescence. However, similar changes in Tb3+ fluorescence could be observed in the presence of a membrane-free preparation of chloroplast coupling factor protein (CF1). From this and other results it is concluded that changes in Tb3+ fluorescence reflect an association of the ion with CF1 followed by intermolecular transfer of excitation energy from protein ligands (possibly un-ionized tyrosine residues) to the lanthanide. The interaction of Tb3+ with sites which control chlorophyll a fluorescence does not seem to modify Tb3+ fluorescence, suggesting that in this case, simple membrane-bound ligands such as carboxyl or phosphate groups are involved.
Financing professional partnerships

Increases in net-debt obligations of profit sharing partnerships give these organizations a strong incentive to expand. This paper argues that when capital structure is transparent, partnerships can signal their hiring intentions to uninformed clients by their net-debt levels. Levin and Tadelis (2005) predicts that professional service firms with fewer informed clients will tend to choose to organize as partnerships rather than corporations. The present paper demonstrates that this prediction only holds when financial frictions are present.
Very-Low-Density Lipoprotein Triglyceride Metabolism in Non-insulin-dependent Diabetes Mellitus: Relationship to Plasma Insulin and Free Fatty Acids

To investigate the mechanism of elevated plasma triglycerides in non-insulin-dependent (type II) diabetes, very-low-density lipoprotein triglyceride (VLDL-TG) metabolism was studied in 10 untreated male Pima Indian diabetics and compared with that of 15 weightmatched male nondiabetic controls. VLDL-TG metabolism was studied using tritiated glycerol as an endogenous precursor of VLDL-TG, and the resultant kinetic data were analyzed using a multicompartmental model, which includes two pathways for VLDL-TG synthesis and a stepwise delipidation process for VLDL catabolism. Pima diabetics had VLDL-TG concentrations approximately 150% those of nondiabetics. Rates of VLDL-TG production in the diabetics were not significantly different from those of controls. On the other hand, the fractional catabolic rate for VLDL-TG was significantly lower in the diabetics compared with the nondiabetics. Other catabolic parameters, such as the fraction of VLDL-TG delipidized at each step and the stepwise delipidation rate, were also decreased in the diabetics. To determine the relationships between the increased triglycerides and determinants of lipid metabolism that are altered in diabetes, insulin and free fatty acid concentrations were also assessed. Basal C-peptide levels in the diabetics during the metabolic study were slightly but not significantly higher than those of the nondiabetics. There was a highly significant correlation in the diabetics between plasma C-peptides and VLDL-TG production, whereas VLDL production in Pima nondiabetics was not related to insulin levels. Free fatty acid levels were not significantly elevated in the Pima diabetics. The data indicate that (1) the rise in VLDL-TG in Pima diabetics was a result of decreased capacity for clearance and (2) the absence of elevated VLDL-TG production may be attributed to the lack of increase in free fatty acids.
Evidence for a quantum phase transition in two dimensions

Abstract For a broad range of electron densities n and temperatures T, data for the in-plane magnetoconductance of the two-dimensional system of electrons in silicon MOSFET's is shown to collapse onto a universal curve using a single parameter Hσ(n,T); the scaling parameter Hσ obeys the empirical relation Hσ=A(n)[Δ(n)2+T2]1/2. The characteristic energy kBΔ associated with the magnetic field dependence of the conductivity decreases with decreasing density, and extrapolates to 0 at a critical density n0, signaling the approach to a zero-temperature quantum phase transition. For densities near n0 Hσ=AT so that the magnetoconductance scales with H/T. We suggest that this behavior is associated with a ferromagnetic instability.
Directed evolution of the dioxygenase complex for the synthesis of furanone flavor compounds

Abstract Herein we report a new preparation of 4-hydroxy-2,5-dimethyl-2,3-dihydrofuran-3-one, the flavor compound strawberry furanone, based on a ‘green’ approach with a minimum number of steps. The first step is an enzymatic dioxygenation of p -xylene to form cyclohexadiene- cis -diol, followed by ring opening via ozonolysis, and ring closure to form the furanone. In efforts to improve the efficiency of the enzymatic step, a directed evolution approach was taken to increase the substrate specificity and selectivity of the toluene dioxygenase enzyme system.
β-Adrenergic Mechanisms Affect Cell Division and Differentiation in Cultured Chick Lens Epithelial Cells

Abstract Primary cultures of chick lens annular pad (CLAP) cells were exposed to β-adrenergic drugs and lipid soluble cAMP analogues. In dose-dependent manners, these agents inhibited re-entry into the cell cycle when these normally post-mitotic cells were cultured in the presence of serum. The inhibition of cell division was evidenced by a lack of DNA accumulation and greatly reduced tritiated thymidine incorporation into DNA. Treated cells were also largely inhibited from spreading onto the substrate. Instead, the epithelial monolayers originally placed into culture formed nearly spherical aggregates. Treated cultures continued to synthesize crystallins and exhibited increased levels of a 49-kDa cytoskeletal protein which accumulates in fiber cells. These results indicate that β-adrenergic mechanisms may be involved in regulating cell division and terminal differentiation of lens fiber cells.
Optimization of hydrogen feeding procedure in PEM fuel cell systems for transportation

Abstract The hydrogen feeding sub-system is one of balance of plant (BOP) components necessary for the correct operation of a fuel cell system (FCS). In this paper the performance of a 6 kW PEM (Proton Exchange Membrane) FCS, able to work with two fuel feeding procedures (dead-end or flow-through), was experimentally evaluated with the aim to highlight the effect of the anode operation mode on stack efficiency and durability. The FCS operated at low reactant pressure (
Preclinical and clinical results with pomalidomide in the treatment of relapsed/refractory multiple myeloma.

Abstract Despite the evolution of effective frontline treatment strategies, many patients with myeloma inevitably relapse. Treatment can be complicated by the interplay of disease-, treatment-, and patient-related factors. Unfortunately, many patients eventually develop disease that is refractory to lenalidomide and bortezomib and have few treatment options. Pomalidomide is a distinct IMiD ® agent recently approved in the US and Europe. We review the pomalidomide mechanism of action, summarizing its direct antimyeloma, immunomodulatory, and stromal-support inhibitory activities. We also detail its clinical development, including establishment of the approved dose/schedule, phase 2 and 3 trials in relapsed and refractory patients, and novel pomalidomide-based combinations.
Current research in composite structures at NASA’s langley research center

Research on the mechanics of composite structures atnasa’s Langley Research Center is discussed. The advantages and limitations of special purpose and general purpose analysis tools used in research are reviewed. Future directions in computational structural mechanics are described to address analysis short-comings. Research results on the buckling and postbuckling of unstiffened and stiffened composite structures are presented. Recent investigations of the mechanics of failure in compression and shear are reviewed. Preliminary studies of the dynamic response of composite structures due to impacts encountered during crash-landings are presented. Needs for future research are discussed.
Proximate and ultimate influences on the regulation of mating in the great apes.

Laboratory research on the great apes has revealed similarities in the proximate regulation of sexual behavior by hormonal, social, and spatial variables but differences among the species in various sexual and reproductive characteristics. Laboratory research indicated that all three species of great ape exhibited heightened female sexual motivation during the midcycle, periovulatory phase of the menstrual cycle, consistent with an interpretation of estrus. All three species were also similar in terms of mating at other times in the cycle as a result, primarily, of male sexual initiative/agression. Field research on the sexual behavior and social organization of the great apes under natural conditions suggested that the species differences were related, in part, to the species' mating systems-that is, to differences in intermale competition and female choice at estrus. Consideration of both proximate and ultimate influences on behavioral regulation facilitates the separate objectives of research directed primarily toward one or the other type of influence. © 1995 Wiley-Liss, Inc.
Analysis of extrudate swell behaviour of rubber compounds using laser scan detector

Controlling the elastic response of filled rubbers, as it manifests itself in extrudate swell, is a major problem in rubber processing.
Analysis by mass spectrometry of the hydrolysis/condensation reaction of a trialkoxysilane in various dental monomer solutions†‡§

3-Methacryloxypropyltrimethoxysilane (MPTMS) was converted to silsesquioxane oligomers by hydrolysis/condensation in three dental monomer solutions. The molecular mass distribution and molecular structures of these oligomers was studied by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Each dental monomer imparted distinct characteristics on the oligomeric silsesquioxane produced. Ethoxylated bisphenol A dimethacrylate (EBPADMA) produced low-mass oligomer silsesquioxanes that showed complete hydrolysis and a very high degree of intramolecular condensation (i.e., there were no methoxy and few silanol groups remaining on the oligomers). 1,6-Bis(methacryloxy-2-ethoxycarbonylamino) 2,4,4-trimethylhexane also produced fully hydrolyzed oligomeric silsesquioxanes but with twice the average molecular mass as the EBPADMA. Finally, triethylene glycol dimethacrylate produced higher mass oligomeric silsesquioxanes than EBPADMA even though it showed incomplete hydrolysis. The degree of hydrolysis increased with increasing mass, as did the degree of intramolecular condensation. Oligomers with degrees of polymerization below 8 were poorly hydrolyzed and showed little if any intramolecular condensation. Those with degrees of polymerization of 9 or greater were almost completely hydrolyzed with a high level of intramolecular condensation. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1842–1847, 2006
Human sensitivity to vibration

Abstract Vibration of the ground or of a building beneath one's feet is generally disliked and can be annoying. Man is sensitive to mechanical oscillations ranging in frequency from well below 1 Hz up to at least 100 kHz. This range of sensitivity to vibration is much broader than the range of human hearing. The sensory mechanisms of man are reviewed. These are numerous and each individual mechanism works over a limited frequency range. This situation is compared to that of sound for which man has only one kind of receptor. Work on the subjective rating of vibration is reviewed. This work has been mainly in the low frequency region of 1–100 Hz and has led to some general results in terms of frequency dependence of human sensitivity to vibration. The conclusion is drawn that there is a need for more basic research into the factors determining human reaction to vibration of relatively low intensity of the kind induced in buildings and other structures excited by traffic or industrial operations outside.
The IT model curriculum: a status update

The first complete draft of the IT model curriculum was posted on the ACM website in October 2005. Since then, a number of comments and requests for changes have been received, the most significant of which occurred in January 2007. In response to these comments, a number of meetings and discussions have been held. In addition, committee membership has evolved. During the review process it became clear that there were clarity issues in the writing, structural issues in the curriculum and also that the release of the CC2005 document included information that needed to be correlated with the IT document. In order to address these issues the following updates were integrated into the current revision, IT2008:1. Potential areas of misunderstanding were revised.2. The IT2008 was more closely tied to the CC2005 document.3. Math was moved from the "rounding the curriculum" section to become part of the core and one of the Knowledge Areas.4. Outcomes were fully aligned with ABET program outcomes for IT programs.5. The relationship between the core IT material, the advanced material, and the overall IT curriculum was revised.6. The concept of pervasive themes was integrated more completely into the overall document.7. The curricular example was revised and another example was added.8. The Body of Knowledge was updated structurally and the learning levels were revised.The purpose of this paper is to explain the reasoning and context of the revisions present in the IT2008 from the perspective of two participants in the process from its inception.
Nonconvulsive seizures : Developing a rational approach to the diagnosis and management in the critically ill population

Originally described in patients with chronic epilepsy, nonconvulsive seizures (NCSs) are being recognized with increasing frequency, both in ambulatory patients with cognitive change, and even more so in the critically ill. In fact, the majority of seizures that occur in the critically ill are nonconvulsive and can only be diagnosed with EEG monitoring. The semiology of NCSs and the associated EEG findings are quite variable. There are a number of periodic, rhythmic or stimulation-related EEG patterns in the critically ill of unclear significance and even less clear treatment implications. The field struggles to develop useful diagnostic criteria for NCSs, to standardize nomenclature for the numerous equivocal patterns, and to devise studies that will help determine which patterns should be treated and how aggressively. This review surveys the evidence for and against NCSs causing neuronal injury, and attempts to develop a rational approach to the diagnosis and management of these seizures, particularly in the encephalopathic population.
Aim Identification with a Minimal Parameter Set

This paper considers the problem of using passive (line-of-sight angle) observations of a surface to air or an air to air missile (pursuer) from an aircraft (evader), to infer whether the missile is or is not aimed at the aircraft. The observations are assumed to be made only on an initial portion of the pursuer's trajectory. The approach is to model the trajectory of the missile with a number of kinematic and guidance parameters, estimate them and use statistical tools to infer whether the missile is guided toward the aircraft. A mathematical model is presented for a missile under pure proportional navigation with a changing velocity (direction change as well as speed change), to intercept a nonma-neuvering aircraft. A maximum likelihood estimator (MLE) is used for estimating the missile's motion parameters and a goodness-of-fit test is formulated to test if the aircraft is the aim or not. Using measurement data from several realistic missiles aimed at an aircraft, it is shown that the proposed method can solve this problem successfully. The key to the solution, in addition to the missile model parametrization, is the use of a reliable global optimization algorithm for the MLE. The estimation/decision algorithm presented here can be used for an aircraft to decide, in a timely manner, whether appropriate countermeasures are necessary.
Hindrance Factors for Diffusion and Convection in Pores

It is well-known that solutes in liquid-filled pores of molecular dimensions have reduced diffusivities and are sieved during filtration. For solute molecules that are large enough to act as hydrodynamic particles, these phenomena can be explained by a combination of particle−wall hydrodynamic interactions and steric restrictions. Theoretical expressions that include those effects have been available for many years, but, even for spheres in pores of constant cross-section, certain hydrodynamic information has been lacking until recently. In particular, the local enhanced drag and local lag coefficient for off-axis positions had not been fully characterized, requiring that results for symmetrically positioned particles (“centerline approximations”) be employed in predicting diffusional and convective hindrances. In this paper the current status of hindered transport theory is reviewed for neutral spheres in long cylindrical pores or slits, and it is shown that such approximations are no longer necessary. N...
Comparison between Wavenumber Truncation and Horizontal Diffusion Methods in Spectral Models

Abstract Commonly used horizontal diffusion and wavenumber truncation dealiasing methods in spectral models are verified using the National Center for Atmospheric Research Community Climate Model version 3. For the same horizontal grid resolution, time step, physical processes, boundary conditions, and initial conditions, the simulated climate, using the horizontal diffusion alone model, is better than that using the wavenumber truncation method. In comparison with the observed climate data, the global root-mean-square of simulated January monthly mean 500-hPa geopotential using the horizontal diffusion alone model is 25% less than that using the wavenumber truncation model. However, for the same spectral resolution, the wavenumber truncation model (high horizontal grid resolution) leads to more accurate solutions than the horizontal diffusion model (low horizontal grid resolution).
Hippocampal Neurons Express a Calcineurin-Activated Adenylyl Cyclase

Ca2+-stimulated adenylyl cyclases are important for several forms of neuroplasticity because they couple activity-dependent Ca2+ increases to cAMP in neurons. For example, the calmodulin-stimulated adenylyl cyclases, AC1 and AC8, are required for hippocampus-dependent memory and long-lasting long-term potentiation. To identify other mechanisms for Ca2+ stimulation of adenylyl cyclases, cultured hippocampal neurons from transgenic mice lacking both AC1 and AC8 [double knock-out (DKO) mice] were analyzed for Ca2+ stimulation of intracellular cAMP. Surprisingly, neurons from DKO mice showed significant Ca2+-stimulated cAMP accumulation that was blocked by inhibitors of calcineurin [PP2B (protein phosphatase 2B)], a Ca2+-activated protein phosphatase. Analysis of cultured neurons from calcineurin-/- mice confirmed that hippocampal neurons exhibit a calcineurin-dependent cAMP increase, which may contribute to some forms of neuroplasticity.
The Compass Elbow Hinge: indications and initial results.

The Compass Elbow Hinge uses Illizarov's methods of fixation to externally hold the elbow reduced and allow both passive and active motion. Eleven patients with degenerative disease, contracture or instability were treated with the Compass Elbow Hinge and were retrospectively evaluated at an average follow-up of 29 months (range: 18-62 months). One was lost to follow-up. Patients with degenerative changes underwent fascia lata interposition while those treated for contractures underwent anterior and posterior capsular release with or without fascia lata interposition. Those with elbow instability underwent ligament reconstruction. The device was removed after 6 weeks and seven of the 11 patients were satisfied with the outcome of the operation. Stability could not be achieved in two patients with coronoid fractures that were not reconstructed. One patient did not tolerate the device and requested its removal with subsequent subluxation. We conclude that patient selection and compliance are key elements in achieving a satisfactory outcome with the device.
Heterogeneous Time and Space: Han Shaogong’s Rethinking of Chinese Modernity

This article is set against the post-Mao official discourse on modernity, in which the conceptualization of a homogeneous, progressive time dominates the public consciousness. The focus is on Han Shaogong, one of the most important writers and cultural theorists in contemporary China, and on how he imagines a heterogeneous spatiotemporality away from the centralized and teleological paradigm. Han’s emphasis on the heterogeneity of time and space puts the homogenized, Hegelian-Marxist, developmentalist logic at the core of China’s modernization project into question. The article begins by examining how the linear and evolutionary concept of time has determined the perception of history and reality in modern China. It then moves to an exegesis of Han’s famous literary treatise “The Roots of Literature,” illustrating how Han’s insistence on tracing multiple roots rather than one singular Root challenges the monocultural, essentialized notion of Chineseness that prevails hegemonically in the discussion of Chinese modernity. The last section analyzes Han’s “Homecoming,” a story centered on an educated youth’s compulsive return to the village where he was rusticated. Moving beyond the conventional interpretation of identity crisis, the present study illuminates a different sense of time toward which Han gestures—a multi-directional and displaced temporality, to which the unconscious and the repressed both claim access.
From rings to layers: surprising patterns of protein deposition during bacterial spore assembly.

Elucidation of the mechanisms of assembly of subcellular structures is often an elusive goal. The large number of component parts and the intricate ways in which they interact make experimental analysis a significant challenge and, in particular, frustrate attempts at traditional reductionist analysis. Frequently, key insights come from thoughtful cell biological observations that identify the most important steps in assembly. In the best cases, not only do these observations provide critical clues to old problems, but they also generate novel areas of investigation. An example of a finding that does both of these things comes from the work of van Ooij et al. (36a), published in this issue, who used careful cell biological analysis to uncover a novel dimension of the process by which bacterial spores assemble their external armor plating. These authors found that the deposition of external proteins on the spore surface is unexpectedly dynamic, pointing towards as-yet-unknown regulatory mechanisms controlling spore formation.
The Limitations of Pigouvian Taxes as a Long-Run Remedy for Externalities: Comment

Carlton and Loury [1980, p. 565] are the first to show that the competitive firm should operate in the range of decreasing returns to scale if ". . . the average pollution damage function is falling at the optimal output level," or in the range of increasing returns if it is rising.' There is no reason, however, for them to conclude from their discovery ". . . that contrary to widely held beliefs, use of a (Pigouvian per unit) tax will not in general lead to an efficient allocation of resources in the long run" [p. 559]. C & L prove that, in general, a tax upon the output of a polluting firm must be accompanied by a lump sum tax-subsidy scheme. This comment shows that a single per unit tax on emissions, rather than output, does lead to an efficient allocation of resources, even where a single tax on output does not. The model allows for emissions that are variable with respect to output as well as emissions that are independent of the level of output, both of which cases are treated by C & L. C & L [p. 560n] observe that their . . . results are unchanged if the problem is reformulated as one in which the number and output of firms of one industry affect the cost curves of other competitive industries." Following this suggestion, a simple economy is assumed in which there are two industries whose total outputs, x and y, are produced by a variable and divisible number of firms, n and m, respectively. The production of good y causes pollution that mixes uniformly throughout the airshed in which the economy is situated. The total quantity of emissions per time period is
Examining the time course of endothelium-independent dilation by nitroglycerin.

Arterial smooth muscle function is commonly assessed by measuring the dilation response to sublin- gual nitroglycerin (NTG), and is referred to as endothelium-independent dilation (EID). The time point at which the brachial artery dilates maximally after NTG administration is generally believed to occur somewhere between three and five minutes. The aim of this study was to examine the time course of brachial artery dilation response to a single dose of sublingual NTG to identify the time point at which maximal dilation occurs and to assess factors effecting EID. Endothelial independent dilation was measured in 125 normal, healthy subjects (male 67, female 58) via high-resolution ultrasound on the brachial artery. Mean time to maximal EID was 279.0 26.9 s. There was a significant (p < 0.0001) difference between brachial EID at three minutes vs. five minutes post NTG. There was also a significant gender difference in EID response (p < 0.0001). The results of this study indicate that maximal EID occurs approximately five minutes after NTG administration. Measuring EID at three minutes after NTG administration likely underestimates the true dilation capacity of the artery. (E-mail: athelen@stphc.com) © 2008 World Federation for Ultrasound in Medicine & Biology.
Learning with misspecification in an artificial currency market

Abstract Agents evolve their forecast rules over time via a modified genetic algorithm in a simple artificial currency market. These forecast rules can be nonlinearly misspecified. When the misspecification is suppressed, learning tends to be complete. When it is not suppressed, learning can generate persistent exchange rate dynamics.
Pretreatment Plasma HVA Predicts Neuroleptic Response in Manic Psychosis

Elevated pretreatment plasma free homovanillic acid (HVA) predicted acute response to neuroleptic treatment in patients with manic psychosis. These findings suggest that plasma HVA may be a useful predictor of a successful short-term response in manic as well as schizophrenic psychoses, and that elevated pre-synaptic dopaminergic release may play a role in more than one group of psychotic disorders.
p300 Functions as a Coactivator of Transcription Factor GATA-4 *

Transcription factor GATA-4 plays critical roles in controlling heart development and cardiac hypertrophy. To understand how GATA-4 functions under diverse conditions, we sought to identify its coactivators. We tested p300 as a coactivator in GATA-4-dependent transient transcription assays in NIH3T3 cells and found that p300 synergistically activated GATA-4-dependent transcription on both synthetic and natural promoters. Direct physical interactions between the N- and C-zinc finger domains of GATA-4 and the cysteine/histidine-rich region 3 (C/H3) of p300 were identified in immunoprecipitation and glutathioneS-transferase pull-down experiments. Deletion of the C/H3 region of p300 abolished its coactivator activity indicating that the physical interaction was required for functional synergy. Through the use of a series of GATA-4 zinc finger mutants, the amino acids WRR in the C finger were identified as critical to the interaction. The adenoviral E1A protein or a peptide encoding the C/H3 region of p300 could inhibit GATA-4-dependent transcription, presumably by competing for p300 binding. Furthermore, deletion of the region of p300 encoding the histone acetyltransferase activity abolished its effect on GATA-4-dependent transcriptional activity. These results establish that p300 acts as a GATA-4 coactivator and that the p300 histone acetyltransferase activity is necessary for the functional interaction.
Procedure for incorporation of radioisotopically labeled metabolites into embryos of dipterous insects.

Abstract Dechorionated embryos of the dipterous insect Phormia regina will undergo normal development in an aqueous environment if treated with sodium dodecyl sulfate and given ample aeration. Under these conditions, labeled metabolites such as 32 P-, 3 H-, or 14 C-labeled uridine, thymidine, leucine, glycerol, and glucose are incorporated into the embryos. The level of labeling obtained under these conditions was sufficient to allow extraction, purification, and chromatography of 3 H-uridine and 32 P-labeled RNA on columns of methylated albumin-kieselguhr. The ability to use labeled metabolites with these embryos should facilitate future biochemical studies concerned with embryonic development in the dipterous insects.
Vibration-based damage assessment using local attractor variance

Recently proposed methodologies in the field of vibration- based structural health monitoring have focused on the incorporation of statistical-based analysis. The structure in question is dynamically excited, some feature is identified for extraction from a measured data set, and that feature is classified as coming from a damaged or undamaged structure by means of some statistical approach. Perhaps the most important aspect of this new paradigm is the selection of a `feature' which accurately details the appearance, and possibly the location and scope, of the damage. In this paper we propose a feature derived from the field of nonlinear time-series analysis. Specifically, system response is classified according to the geometry of its dynamical attractor.
The Effects of Age on the Plasma Catecholamine Response to Mental Stress in Man

To determine if sympathetic nervous system activity is heightened during psychological stress in older adults, plasma norepinephrine (NE), epinephrine (EPI), heart rate, and blood pressure were measured in 10 healthy old (mean age, 68.5 yr) men and 10 healthy young (mean age, 26.6 yr) men during a 12-min mental stress test. Basal NE was higher in old than in young men (400 ± 33 vs. 286 ± 32 pg/ml; P < 0.01). Consistent significant increases in plasma NE occurred only in the elderly, and the mean increases (Δ) in NE during testing were significantly greater (P < 0.01) in the old than in the young men. Compared to basal levels, plasma EPI increased by 2 min in both young (ΔEPI, 50 ± 20 pg/ml; P < 0.02) and old subjects (ΔEPI, 41 ± 11; P < 0.01) and remained significantly increased throughout the test. There was no difference in either basal or ΔEPI between young and old men. Heart rate and blood pressure were significantly increased throughout testing for both age groups. Although the Δ blood pressure durin...
Peer-Led Team Learning: Adjunct to lectures in an electrical engineering course for non-majors

Peer-Led Team Learning (PLTL) is a recognized model for teaching and learning in which select students in a course return in later semesters to serve as peer leaders who facilitate small learning groups. At our institution (a small, private, research-intensive university), this technique is adopted in Workshops; our peer leaders meet weekly with small groups of students to guide them through sets of exercises designed by the instructor(s) of the course. Peer leaders receive instruction and support in pedagogy and group dynamics in a course jointly taught by a learning specialist from the Center for Excellence in Teaching and Learning (CETL) and the instructor of the course. Workshops have been adopted in many courses, ranging from Chemistry, Biology, Earth Sciences, Physics, and Optics, to Economics and Business. This paper describes the use of Workshops for several years in an Electrical and Computer Engineering (ECE) course intended for non-ECE majors. We discuss the processes and pitfalls for initiating the use of Workshops in this and other courses, present an example of Workshop problems and questions currently in use, and discuss the value of the Workshops to students, peer leaders, and faculty as told to us in surveys, course journals, and reflective sessions held after the course.
Understanding the behavior of users of interactive computer music systems

Abstract In order to understand the behavior of musicians working in an interactive task environment, it is useful to document their decision‐making processes in the form of action protocols. (Such protocols are linear lists of statements indicating the operators that were utilized by a musician during a task performance.) During the attempt of gaining insight into the deep structure (control structure) of such protocols, the problem arises of understanding the semantic decision‐making of the musician, viz. the way in which acoustic input has been musically interpreted by him for the purpose of solving some predefined problem. For formulating an explicit and formal description of semantic decision making, an operationally effective notion of long‐term memory is required. Two knowledge representations relevant to dealing with semantic information in protocols are discussed; they are shown to provide, in their mutual interaction, the basis for a cognitive description of (auditory) information processing.
A STEP-FUNCTION APPROXIMATION FOR THE EXPERIMENTAL DETERMINATION OF THE EFFECTIVE SCATTERING PHASE FUNCTION OF PARTICLES

Abstract A step-function approximation is introduced to determine the coefficients of the Legendre polynomial expansion of the highly-forward-scattering phase-functions from experiments. It is shown that by using this approximation with a limited number of angular intensity data, as many as 10 coefficients can be recovered within a 10% error bound. The errors in the first two coefficients determined by employing a delta-phase-function approximation are at least an order of magnitude greater than that for the step-function approximation. The effect of the recovered phase-function on the accuracy of radiative transfer calculations is also discussed. The results show that the phase-function coefficients may be determined from experiments using the new step-function. For radiative transfer calculations, a delta-function approximation with coefficients based on those derived from the step-function approximation should be employed.
Decomposable processes and continuous products of probability spaces

Abstract Sequences of independent random variables and products of probability spaces are just two ways of looking at the same thing. The natural generalization of a sequence of independent random variables is a decomposable process. We introduce a corresponding generalization of a product of probability spaces, which will be called a factored probability space, and study the structure and classification of such systems and their relation to decomposable processes.
Lek Mating System and Large Male Aggressive Advantage in a Gall-forming Tephritid Fly (Diptera: Tephritidae)

Field and laboratory studies revealed that the mating system of a tephritid fly, Procecidochares sp., meets even the most stringent definition of lekking behavior. Mark-recapture and plant-preference experiments confirmed that newly emerged adult Procecidochares sp. left their larval host plant (Chrysothamnus nauseosus) and flew to Atriplex canescens. The flies used A. canescens solely as a mate encounter site. Sex ratios of emerging flies did not differ from unity, but sex ratios at the leks were extremely male-biased. An advantage for larger individuals in male-male aggressive encounters was quantified and observations suggested that females might be choosing mates based on outcomes of fights. Lekking behavior, previously reported among polyphagic tephritids, is considered exceptional for a monophagous species. Factors favoring a lek mating system in this species are discussed.
Technical communique: On event design in event-triggered feedback systems

This paper studies event design in event-triggered feedback systems. A novel event-triggering scheme is presented to ensure exponential stability of the resulting sampled-data system. The scheme postpones the triggering of events over previously proposed methods and therefore enlarges the intersampling period. The resulting intersampling periods and deadlines are bounded strictly away from zero when the continuous time system is input-to-state stable with respect to measurement errors.
Current, luminosity, and X-ray emission in the early phase of dielectric surface flashover in vacuum

With high-speed electrical and optical diagnostics, an attempt is made to elucidate the physical mechanisms leading to surface flashover. The experimental device uses a cable discharge to study self-breakdown along the surface of an insulator in vacuum. Preflashover current, breakdown voltage, luminosity, and soft X-ray emission are measured in temporal correlation with a resolution of 1 ns. The results show a linearly increasing current in the subampere range, and a corresponding linearly increasing luminosity, before an exponential increase of both signals takes over. The linear phase is accompanied by X-ray emission which ceases at the onset of the exponential phase. The strong influence of externally applied magnetic fields on the linear phase points to the existence of free electrons above the surface during the early phase of flashover. A linear current rise without magnetic field and the formation of a current plateau with an insulating magnetic field indicate a saturation of the current amplification mechanism in the early phase. >
Less “Catholic,” More “catholic”? American Catholic Universities Since Vatican II

How has Catholic higher education in the U.S. changed since Vatican II? Evolving in three historical periods in the last six decades, Catholic institutions have experienced tumultuous upheaval and radical transformation, becoming more secular or “catholic” in orientation and less orthodox or “Catholic.” This essay discusses both the positive and problematic developments of these changes, and it concludes with several proposals for a Catholic core curriculum and a revitalized intellectual tradition.
Optimized injection for determination of free phenols by gas chromatography using fused silica columns

Optimisation des conditions d'injection, en particulier, de la temperature de la chambre d'injection
Drosophila melanogaster Importin α1 and α3 Can Replace Importin α2 During Spermatogenesis but Not Oogenesis

Importin α’s mediate the nuclear transport of many classical nuclear localization signal (cNLS)-containing proteins. Multicellular animals contain multiple importin α genes, most of which fall into three conventional phylogenetic clades, here designated α1, α2, and α3. Using degenerate PCR we cloned Drosophila melanogaster importin α 1 , α 2 , and α 3 genes, demonstrating that the complete conventional importin α gene family arose prior to the split between invertebrates and vertebrates. We have begun to analyze the genetic interactions among conventional importin α genes by studying their capacity to rescue the male and female sterility of importin α 2 null flies. The sterility of α 2 null males was rescued to similar extents by importin α 1 , α 2 , and α 3 transgenes, suggesting that all three conventional importin α’s are capable of performing the important role of importin α2 during spermatogenesis. In contrast, sterility of α 2 null females was rescued only by importin α 2 transgenes, suggesting that it plays a paralog-specific role in oogenesis. Female infertility was also rescued by a mutant importin α 2 transgene lacking a site that is normally phosphorylated in ovaries. These rescue experiments suggest that male and female gametogenesis have distinct requirements for importin α2.
Dipeptidyl Peptidase - 4 as a New Target of Action for Type 2 Diabetes Mellitus : A Systematic Review

Type 2 diabetes mellitus is a metabolic disease leading to microvascular and macrovascular complications including coronary artery disease and stroke. Management of diabetes has been challenging, particularly in the presence of the enormous prevalence of obesity. In recent years, various inhibitors of the enzyme dipeptidyl peptidase (DPP)-4 have been developed to treat diabetes. The enzyme DPP-4 cleaves incretins, which, among other functions, stimulate insulin and suppresses glucagon. Inhibition of this enzyme results in an increase in the half-life and the sustained physiologic action of incretins, leading to an improvement in hyperglycemia. One such agent, namely sitagliptin (MK-04,310), has been introduced into the United States market, and another agent, vildagliptin (LAF237), is being used in Europe and elsewhere. This article is intended to evaluate the effectiveness of DPP-4 inhibitors as a therapeutic modality for managing type 2 diabetes. The authors conducted a literature search of various databases to identify the clinical trials involving the DPP inhibitors and concluded that the DPP-4 inhibitors, for example, sitagliptin and vildagliptin, are efficacious for managing diabetes as monotherapy or combination therapy.
A literature search tool for intelligent extraction of disease-associated genes.

Objective To extract disorder-associated genes from the scientific literature in PubMed with greater sensitivity for literature-based support than existing methods. Methods We developed a PubMed query to retrieve disorder-related, original research articles. Then we applied a rule-based text-mining algorithm with keyword matching to extract target disorders, genes with significant results, and the type of study described by the article. Results We compared our resulting candidate disorder genes and supporting references with existing databases. We demonstrated that our candidate gene set covers nearly all genes in manually curated databases, and that the references supporting the disorder–gene link are more extensive and accurate than other general purpose gene-to-disorder association databases. Conclusions We implemented a novel publication search tool to find target articles, specifically focused on links between disorders and genotypes. Through comparison against gold-standard manually updated gene–disorder databases and comparison with automated databases of similar functionality we show that our tool can search through the entirety of PubMed to extract the main gene findings for human diseases rapidly and accurately.
Reverse Nested Miller Compensation Using Current Buffers in a Three-Stage LDO

A novel frequency compensation scheme called reverse nested Miller compensation using current buffers (RNMCCB) for three-stage amplifiers is proposed. As opposed to previous reverse nested schemes, our work uses inverting gain stages for both the second and third stages. The outer compensation loop utilizes a current mirror as an inverting current buffer (CB), and the inner loop uses a common-gate amplifier as a CB, creating two left-half-plane (LHP) zeros. We introduce a simple and effective method of placing a resistor in series with a CB for accurate placement of LHP zeros. As a design example of the RNMCCB scheme, we propose a three-stage low dropout voltage regulator (LDO) in a 0.5-?m CMOS process to supply 1.21 V to a load ranging from 1 ?A to 100 mA. Our design goals were to simultaneously achieve very high current efficiency and very low transient output voltage variation. As such, we achieved a 99.95% current efficiency and a maximum load transient output voltage variation of ±48 mV with an output capacitor of 100 nF. Experimental results, in good agreement with theoretical analysis, validate the novel RNMCCB frequency compensation scheme.
Crystal structure of O-methyltransferase CalO6 from the calicheamicin biosynthetic pathway: a case of challenging structure determination at low resolution

Calicheamicins (CAL) are enedyine natural products with potent antibiotic and cytotoxic activity, used in anticancer therapy. The O-methyltransferase CalO6 is proposed to catalyze methylation of the hydroxyl moiety at the C2 position of the orsellinic acid group of CAL. Crystals of CalO6 diffracted non-isotropically, with the usable data extending to 3.4 A. While no single method of crystal structure determination yielded a structure of CalO6, we were able to determine its structure by using molecular replacement-guided single wavelength anomalous dispersion by using diffraction data from native crystals of CalO6 and a highly non-isomorphous mercury derivative. The structure of CalO6 reveals the methyltransferase fold and dimeric organization characteristic of small molecule O-methyltransferases involved in secondary metabolism in bacteria and plants. Uncommonly, CalO6 was crystallized in the absence of S-adenosylmethionine (SAM; the methyl donor) or S-adenosylhomocysteine (SAH; its product). Likely as a consequence of the dynamic nature of CalO6 in the absence of its cofactor, the central region of CalO6, which forms a helical lid-like structure near the active site in CalO6 and similar enzymes, is not observed in the electron density. We propose that this region controls the entry of SAM into and the exit of SAH from the active site of CalO6 and shapes the active site for substrate binding and catalysis.
Extensible message passing application development and debugging with Python

The authors describe how they have parallelized Python, an interpreted object oriented scripting language, and used it to build an extensible message-passing molecular dynamics application for the CM-5, Cray T3D, and Sun multiprocessor servers running MPI. This allows one to interact with large-scale message-passing applications, rapidly prototype new features, and perform application specific debugging. It is even possible to write message passing programs in Python itself. They describe some of the tools they have developed to extend Python and results of this approach.
The Impact of Online or F2F Lecture Choice on Student Achievement and Engagement in a Large Lecture-Based Science Course: Closing the Gap.

Blended learning options vary and universities are exploring an assortment of instructional combinations, some involving video lectures as a replacement for face-to-face (f2f) lectures. This methodological study investigates the impact of the provision of lecture choice (online or f2f) on overall student achievement and course engagement. This research uses a within-group design to obtain baseline data on a single set of physics students (n=168), and investigates the impact of providing a lecture viewing choice (online, f2f) mid-semester on student achievement (tests, homework, and standardized conceptual evaluation scores), and course engagement (student lecture viewing, homework submissions, bonus project submissions, and note taking behaviors). The study reveals that the type of lecture does not serve to significantly impact overall student achievement or engagement. However, although recorded and f2f lectures demonstrate an overall educationally equivalent impact, students who elect a high level of recorded lecture use were significantly lower performing and less engaged before the option to watch recorded lectures was introduced and largely continued to be so after the option was introduced, but there was evidence of a reduction in achievement and engagement differences after the option is introduced. Therefore, results of this study suggest weaker performing students self-select higher levels of recorded lecture use, and the use of these video lectures may assist this specific group of students in closing the gap between themselves and students who were initially higher performing and more engaged.