cssi/SciSciGPT-SciSciNet huggingface dataset:
Molecular characteristics of rat liver arginase.

Abstract The molecular weight of approximately 1,500-fold purified arginase from rat liver (specific activity = 19,500 µmoles of urea per min at 25° per mg of protein nitrogen) was determined by the method of sedimentation equilibrium to be 118,000. The sedimentation velocity constant is 6.1 S, the diffusion coefficient 5.2 x 10-7 cm2 per sec. Alteration in pH, removal of Mn2+, and replacement of Mn2+ by Co2+ did not yield evidence of a change in molecular size. The partial specific volume (V) was determined by a differential sedimentation equilibrium technique in heavy water. Dissociation of the enzyme in 8 m urea yielded a protein which sedimented in a single boundary and gave one protein band after acrylamide gel electrophoresis. Sedimentation equilibrium analysis of the dissociation compound gave a molecular weight of 30,800, which suggests that rat liver arginase is composed of four subunits. Amino acid analysis has been carried out and the values compared to those of arginases from other species.
The Rule of Text: Is it Possible to Govern Using (Only) Statutes?

This essay explores whether it is possible to govern solely by means of written text, with little or no interpretive discretion allowed to judges. The rule of text, as we might refer to this concept, appears to be a goal that textualist judges are hoping to achieve. The essay first reviews the attractions of written law, which came into being not long after writing was invented. Yet it was only in the late eighteenth and early nineteenth centuries that rulers like Frederick the Great of Prussia and later the French revolutionaries tried to govern their nations by means of comprehensive codes of law, which judges were forbidden to interpret. Those efforts to implement a pure form of the rule of text largely failed. Next, we consider several U.S. Supreme Court cases that involved interpretive questions. Could the problems have been avoided by more careful drafting? I conclude that mistakes and ambiguities can in principle be prevented at the drafting stage or be solved by means of amendment after they are discovered, but that vagueness is a far more difficult problem. To the extent that the rule of text demands that judges not interpret, they would have to refer statutory uncertainties to the legislature. Both the Prussians and the French had a procedure of this kind, sometimes known as refere legislatif. Asking the legislature to interpret statutes ultimately proved impractical. Although to some extent it violates the separation of powers, there seems to be no feasible alternative to giving judges the authority to resolve the uncertainties that inevitably arise in written text.
Efficiency and Emissions of a Stratified Charge Engine Optimized for Various Fuels

Experimental work was done with a Texaco stratified-charge engine to investigate the effect of fuel type, spark timing, and fuel injection timing on efficiency and emissions. Gasoline, diesel fuel, and a mixture of the two in equal proportions were used as fuels. The mixture of gasoline and diesel fuel simulates a broad-boiling-range fuel, referred to as ''broadcut fuel.'' Data were taken during full-load and part-load operations; the part-load operation simulated road-load conditions for a 3,000-lb vehicle. Results show engine efficiency ranges from about 20 percent at light-load to over 30 percent at full-load. The difference in efficiency attributable to fuel type was one to two percent. Between the two fuels gasoline and diesel, greater efficiency was associated with diesel fuel at part-load while the greater efficiency at full-load was seen with gasoline. Broadcut fuels generally resulted in efficiencies similar to the efficiencies of operation with diesel fuel at part-load or with gasoline at full-load. The results for all fuels show that spark timing set equal to fuel injection timing generally produced the best efficiency and, except for nitrogen oxides, the lowest emissions.
Minimum energy multicast routing for wireless ad-hoc networks with adaptive antennas

Energy conservation is a critical issue in wireless multihop ad-hoc networks, which have nodes powered by batteries only. One major metric for energy conservation is to route a communication session along the routes that require the lowest total energy consumption. We consider wireless ad hoc networks that use adaptive antennas and have limited energy resources. To explore the advantages of power saving offered by the use of adaptive antennas, we consider the case of source initiated multicast traffic. We present a constraint formulation for the MEM (minimum-energy multicast) problem in terms of MILP (mixed integer linear programming) for wireless ad hoc networks. Experiment results show that an optimal solution of the MEM problem using our MILP model can always be obtained in a timely manner for moderately sized network, and it also provides a way to evaluate the realistic performance of different heuristic algorithms.
Clock recovery for high-speed optical communication

This paper reviews recent results for clock recovery circuits operating at speeds in excess of 1 Gbit/sec or realized as multichannel arrays. The emphasis is on Synchronous Optical NETwork (SONET) type systems, their requirements, and the effect of the clock recovery circuits on system performance. Clock recovery approaches include filter based, phase-lockcd-loops, and all-optical methods.
Development of a Novel Reformer for Tar-free Syngas Production

Abstract A novel reformer using highly efficient heat regeneration for tar-free syngas production is developed and its performance demonstrated in a pilot-scale plant using steam gasification. Basic design parameters of the regenerative tar reformer, namely residence time and amount of oxidant are determined based on numerical results. It has been predicted that good performance could be achieved at an operation temperature about 1573 K, the residence time exceeding 4 sec and an oxidant addition of 12% of the syngas flow rate. The regenerative tar reformer so designed shows stable operation. Over 99% of light and heavy tars are reformed to gas in the case of 11.3% oxygen addition to syngas. Further it is seen that a reduction of oxygen consumption more than 30% compared to a conventional oxidation reformer can be achieved. The formation of a high temperature zone has a strong influence on the tar reforming efficiency.
Non-vacuum processing of CIGS solar cells

A promising pathway to minimizing cost per watt and maximizing return on investment is the use of nonvacuum techniques for depositing PV thin films. Nonvacuum techniques based on nanoparticulate materials are particularly useful for forming both CuIn/sub 1-x/Ga/sub x/Se/sub 2/ (CIGS) absorber films and metal oxide transparent conductor (TC) coatings. Spraying and printing techniques have been used for depositing layers of particulate precursor materials that are subsequently sintered into CIGS films. Printing is faster than pneumatic spraying, and printed layers are more planar and better packed than sprayed layers. Non-vacuum processes have also been used to deposit TC coatings. TC coatings have been deposited using organic reactants, nanoparticulate precursor materials, and conducting polymers. Further work is required to achieve adequate sheet conductances at low processing temperatures.
Tighter Bounds on the Performance of First Fit Bin Packing

First Fit is the simplest approximation algorithm for Bin Packing. Its asymptotic performance ratio of 1.7 has long been determined. Small examples with FF(I) = 1.7 OPT(I) are also known. Initially, FF(I) has been shown to be at most 1.7 OPT(I) + 2 for every instance I, and at least 1.7 OPT(I) – 2 for some instances with an arbitrary large optimum number of bins OPT(I). These bound have been considerably tightened since. It is shown that FF(I) indeed is equal to 1.7 OPT(I) for infinitely many values of OPT(I). This result is optimal.
Cardiovascular Complications of Obesity

Obesity is a costly public health epidemic which contributes to increased morbidity and mortality from cardiovascular disease (CVD) and diabetes mellitus (DM). Insulin resistance (IR), the crucial underlying link between obesity and CVD, is associated with adipose tissue dysfunction. IR drives unopposed upregulation of proinflammatory and prothrombic factors resulting in systemic inflammation, oxidative stress, and a prothrombic environment. Among the resultant effects are hypertension, atherogenic dyslipidemia, and impaired glycemic control, which are all risk factors for CVD. Inflammation and oxidative stress also underlie vascular endothelial dysfunction and a favorable milieu for the promotion of atherosclerosis. Through understanding the mechanisms by which IR links obesity to CVD, health professionals can educate their patients about ways to maintain weight loss and prevent weight gain and, thus, slow the obesity epidemic and reduce CVD morbidity and mortality.
Immuno‐Spin Trapping: Detection of Protein‐Centered Radicals

Protein-centered radicals are involved in biological oxidative damage induced by drugs, environmental hazards, and cellular reactive oxygen species. Presently, the technique most widely used to study protein-centered radicals is electron spin resonance (ESR; also known as electron paramagnetic resonance, EPR); used either directly or in combination with the spin-trapping technique. Protein-centered radicals may be trapped with the nitrone spin trap 5,5-dimethyl-1-pyrroline N-oxide (DMPO) forming DMPO-radical adducts. However, after a few minutes these adducts decay, often by oxidation to DMPO-protein radical-derived nitrone adducts, which are ESR-silent species. Because nitrone adducts are not free radicals and their formation involves the creation of a covalent linkage, they are stable long after the ESR signal decays. In the new alternative technique of immuno-spin trapping, nitrone adducts are detected by using an antibody, i.e., anti-DMPO, that recognizes their nitrone moiety. Immuno-spin trapping is a simple, reliable, affordable, sensitive, and specific approach to detecting protein-centered radicals, and its development brings the power of immunoassays to bear on the field of toxicology of free radical-mediated biological damage.
Computer‐Delivered Screening and Brief Intervention for Alcohol Use in Pregnancy: A Pilot Randomized Trial

Background Although screening and brief intervention (SBI) for unhealthy alcohol use has demonstrated efficacy in some trials, its implementation has been limited. Technology-delivered approaches are a promising alternative, particularly during pregnancy when the importance of alcohol use is amplified. The present trial evaluated the feasibility and acceptability of an interactive, empathic, video-enhanced, and computer-delivered SBI (e-SBI) plus 3 tailored mailings, and estimated intervention effects. Methods We recruited 48 pregnant women who screened positive for alcohol risk at an urban prenatal care clinic. Participants were randomly assigned to the e-SBI plus mailings or to a control session on infant nutrition, and were re-evaluated during their postpartum hospitalization. The primary outcome was 90-day period prevalence abstinence as measured by timeline follow-back interview. Results Participants rated the intervention as easy to use and helpful (4.7 to 5.0 on a 5-point scale). Blinded follow-up evaluation at childbirth revealed medium-size intervention effects on 90-day period prevalence abstinence (OR = 3.4); similarly, intervention effects on a combined healthy pregnancy outcome variable (live birth, normal birthweight, and no neonatal intensive care unit stay) were also of moderate magnitude in favor of e-SBI participants (OR = 3.3). As expected in this intentionally underpowered pilot trial, these effects were nonsignificant (p = 0.19 and 0.09, respectively). Conclusions This pilot trial demonstrated the acceptability and preliminary efficacy of e-SBI plus tailored mailings for alcohol use in pregnancy. These findings mirror the promising results of other trials using a similar approach and should be confirmed in a fully powered trial.
Relationship Between Simulated Common Synaptic Input and Discharge Synchrony in Cat Spinal Motoneurons

Synchronized discharge of individual motor units is commonly observed in the muscles of human subjects performing voluntary contractions. The amount of this synchronization is thought to reflect th...
A Method of Showing the Invisibility of Transparent Objects under Uniform Illumination

As is well known, a perfectly transparent object is visible only in virtue of a variable illumination. This condition might be approximately realised, as Lord Rayleigh points out in his article on “Optics” in the “Encyclopaedia Britannica,” on the top of a high monument in a dense fog. It is doubtful, however, if the experiment would be very successful even under these conditions, as the observer's body screens the light in certain directions, making the illumination far from uniform. The following method I have found to give very good results:—
Characterization of capillary-channeled polymer fiber stationary phases for high-performance liquid chromatography protein separations: Comparative analysis with a packed-bed column.

Capillary-channeled polymer (C-CP) fibers are investigated as reversed-phase (RP) stationary phases for high-performance liquid chromatography of proteins. A comparative analysis of column characteristics for polypropylene and poly(ethylene terephthalate) C-CP fiber columns and a conventional packed-bed (C4-derivatized silica) column has been undertaken. Five proteins (ribonuclease A, cytochrome c, lysozyme, myoglobin, bovine serum albumin) were used to investigate the separation characteristics under typical RP gradient conditions. Column performance was compared under standard (identical) and optimized RP chromatographic conditions. The gradient compositions utilized with the C-CP fiber columns are similar to those used with conventional columns, employing flow rates in the 1−6 mL/min range and gradient rates of ∼1%/min. The packed-bed column was operated as prescribed by the column manufacturer. The retention factor (k‘), separation factor (α), resolution (Rs), asymmetry factor (As), elution order, and...
Nurse practitioner and physician assistant staffing in the patient-centered medical homes in New York State

Abstract Background A cornerstone of patient-centered medical homes (PCMHs) is team-based care; however, there is little information about the composition of staff who deliver direct primary care in PCMHs. Purpose The purpose of this study was to examine the number and distribution of primary care physicians (PCPs), nurse practitioners (NPs), and physician assistants (PAs) in PCMH and non-PCMH practices located in New York State ( N = 7,431). Method Practice based ratios of primary care NPs and PAs to PCP were calculated and compared by PCMH designations. Designated PCMHs had more NPs and PAs per PCP relative to non-PCMHs. The ratios of NPs to PCPs were almost twice as high in PCMHs compared with non-PCMHs (0.20 and 0.11), and ratios were similarly different for PAs to PCPs (0.16 and 0.09, respectively). The multivariate analyses also support that higher NP and PA staffing was associated with PCMH designation (i.e., there was one additional NP and/or PA for every 25 PCPs). Discussion The growth of PCMHs may require more NPs and PAs to meet the anticipated growth in demand for health care. Policy- and practice-level changes are necessary to use them in the most effective ways.
TAT-mediated transduction of NF-Ya peptide induces the ex vivo proliferation and engraftment potential of human hematopoietic progenitor cells.

Retroviral overexpression of NF-Ya, the regulatory subunit of the transcription factor NF-Y, activates the transcription of multiple genes implicated in hematopoietic stem cell (HSC) self-renewal and differentiation and directs HSCs toward self-renewal. We asked whether TAT-NF-Ya fusion protein could be used to transduce human CD34+ cells as a safer, more regulated alternative approach to gene therapy. Here we show that externally added recombinant protein was able to enter the cell nucleus and activate HOXB4, a target gene of NF-Ya, using real-time polymerase chain reaction RNA and luciferase-based protein assays. After TAT-NF-Ya transduction, the proliferation of human CD34+ cells in the presence of myeloid cytokines was increased 4-fold. Moreover, TAT-NF-Ya-treated human primary bone marrow cells showed a 4-fold increase in the percentage of huCD45+ cells recovered from the bone marrow of sublethally irradiated, transplanted NOD-Scid IL2Rγnull mice. These data demonstrate that TAT-peptide therapies are an alternative approach to retroviral stem cell therapies and suggest that NF-Ya peptide delivery should be further evaluated as a tool for HSC/progenitors ex vivo expansion and therapy.
A urea-sensing membrane electrode for whole blood measurements.

Abstract The construction and properties of a new urea-sensing membrane electrode capable of making direct urea measurements in whole blood are described. The electrode has a layered structure in which a small quantity of EDTA-stabilized urease enzyme solution is held between an external dialysis membrane and the gas-permeable membrane of a conventional ammonia selective electrode. It is shown that the electrode functions reliably in whole blood samples, used with minimal pretreatment, as well as in serum or aqueous solutions. The range, dynamic response, lifetime, precision, and accuracy of the electrode system are appropriate for clinical measurements in whole blood or serum, and promise to simplify such analyses with an attendant reduction in costs.
Humor as an Attributional Index

The present study examined the circumstances under which observers make attributional judgments about an actor on the basis of his humor. Subjects read a description of a group disucssion in which a nan told an anti-wonen's liberation Joke to a group of women. The variables nanipulated were the audience's anticipated reaction (approval or disapproval) and the audience's actual reaction (approval or disapproval). The resluts indicated that the actor was seen as least chauvinistic when disapnroval was anticipated but approval was received. The actor was seen as most chauvinistic when disanproval was both anticipated and received.
Rapid insulin assay for intraoperative confirmation of complete resection of insulinomas

Abstract Background. Solitary insulinomas are usually the cause of organic hypoglycemia, whereas 13% to 24% of patients with hyperinsulinemia have multiple tumors or nesidioblastosis. Intraoperative glucose levels confirming complete excision have variable accuracy. Intraoperative insulin levels have been shown to predict operative outcome. The purpose of this study was to establish criteria for predicting operative success by using a new, rapid insulin assay as an intraoperative adjunct. Methods. Eight consecutive patients with organic hypoglycemia underwent pancreatic exploration. With an 8-minute immunochemiluminescent insulin assay, peripheral blood levels were obtained preoperatively, during resection, and at 5-minute intervals after surgical excisions. Operative findings and outcome were compared with intraoperative insulin/glucose ratios (I/G), glucose, and insulin levels. Results. By using the return of insulin levels to normal range and I/G ratios ≤ 0.4 15 minutes after tumor(s) resection as criteria to predict operative success, 6 patients had their outcomes correctly predicted (5 true-positive and 1 true-negative). One patient with nesidioblastosis had a false-negative result. One could not be evaluated because of diazoxide medication. These criteria predicted postoperative absence of hypoglycemia with specificity of 100% and accuracy of 89%. Conclusions. These 8-minute insulin assay and criteria can be a useful adjunct for intraoperative assurance of complete insulinoma resection and prediction of postoperative outcome. (Surgery 2002;132:937-43.)
Electrooptic Modulation in Thin Film Barium Titanate Plasmonic Interferometers

We demonstrate control of the surface plasmon polariton wavevector in an active metal-dielectric plasmonic interferometer by utilizing electrooptic barium titanate as the dielectric layer. Arrays of subwavelength interferometers were fabricated from pairs of parallel slits milled in silver on barium titanate thin films. Plasmon-mediated transmission of incident light through the subwavelength slits is modulated by an external voltage applied across the barium titanate thin film. Transmitted light modulation is ascribed to two effects, electrically induced domain switching and electrooptic modulation of the barium titanate index.
Is agricultural sustainability a useful concept

Abstract This paper examines conceptual and methodological barriers to using sustainability as a criterion for guiding change in agriculture and proposes elements necessary for approaches to characterizing sustainability to be generally useful. Two broad interpretations of agricultural sustainability have emerged with different underlying goals: sustainability interpreted as an approach to agriculture developed in response to concerns about impacts of agriculture, with motivating adherence to sustainable ideologies and practices as its goal; and sustainability interpreted as a property of agriculture developed in response to concerns about threats to agriculture, with the goal of using it as a criterion for guiding agriculture as it responds to change. Interpreting sustainability as an approach has been useful for motivating change. However, usefulness of this interpretation as a criterion for guiding change is hindered by a lack of generality of prescribed approaches, a distorted view of conventional agriculture and circular logic. Although interpreting sustainability as a system property is logically more consistent, conceptual and practical problems with its characterization have limited its usefulness as a criterion for guiding change. In order for sustainability to be a useful criterion for guiding change in agriculture, its characterization should be literal, system-oriented, quantiative, predictive, stochastic and diagnostic.
Media Framing of Capital Punishment and Its Impact on Individuals' Cognitive Responses

It is well known that mass media have the ability to frame a sociopolitical issue in specific ways, which can have considerable impact on the public's thoughts and perceptions regarding the issue. Through analyzing coverage of capital punishment in the New York Times since 1960 and then conducting an experiment in which we assessed individual-level responses to differently framed news stories, we show (a) the dramatic emergence of a new “innocence frame” within the past 10 years that accentuates imperfections in the justice system, and (b) the much greater impact of this frame on individuals' thoughts—in particular on those who favor the death penalty—when compared to the traditional morality-based frame. We suggest that the latter finding can be explained because individuals tend to resist changing their interpretations of issues based on arguments that contradict their core moral or religious beliefs; however, they seem quite receptive to new information along dimensions that they previously had not con...
Electromagnetic theory of microstretch elasticity and bone modeling

A continuum theory of microstretch elasticity subject to electromagnetic fields is introduced as a microstructural model to determine deformations and stress fields in elastic solids having interconnected voids, microcracks or stretchable microelements. Such materials include animal bones and solids with deformable microstructures, e.g., nanocomposites in solids.
Substrate-induced stability of the lipase from candida cylindracea in reversed micelles

Activity of lipase (candida cylindracea) in reversed micelles was found to be sustained over extended periods of time in the presence of amphiphilic substrates. Esterification of palmitic or oleic acid and octanol was studied to characterize the lipase activity in AOT/isooctane reversed micelles. Complete conversion was possible even in the presence of stoichiometric excess of water. In the absence of acyl substrates, the enzyme lost all its activity within a few hours in reversed micelles. Thermal effects on the enzyme activity were studied, and the enzyme stability in reversed micelles was compared to that in a bulk organic solvent.
Application of the antiferromagnetic-Fermi-liquid theory to NMR experiments on YBa2Cu3O6.63.

NMR experiments on the ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{6.63}$ material provide an important test of the antiferromagnetic-Fermi-liquid model for the spin-spin correlation function proposed by Millis, Monien, and Pines. We show that their theory provides a quantitative fit, with parameters determined from experiment, to the NMR experiments of Takigawa et al. on the Cu(2),O(2,3) nuclei, and of Alloul et al. on the Y nuclei in the ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{6.63}$ material. We find that the hyperfine couplings do not change in going from the ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7}$ to the ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{6.63}$ material, whereas the antiferromagnetic correlation length is increased. We present results for the changes in relevant magnetic parameters brought about by reducing the oxygen content from ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7}$ to ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{6.63}$ and discuss the implications of a small energy scale \ensuremath{\Elzxh}${\mathrm{\ensuremath{\omega}}}_{\mathrm{SF}}$${\mathit{k}}_{\mathit{B}}$${\mathit{T}}_{\mathit{c}}$ emerging from the analysis of the NMR experiments. Our results support the proposal by Pines that the excitations in the normal state of superconducting Y-Ba-Cu-O are best described as those of an antiferromagnetic Fermi liquid and suggest that this description is equally applicable to other cuprate oxide superconductors.
Single dendrite seeks stable relationship

Getting two neurons to correctly connect their axons and dendrites into a meaningful circuit is no easy task, but new findings reported in this issue suggest that developing synapses may actually help guide young dendrites to where they need to be.
Evidence for distinct serial processes in animals: the multiplicative-factors method

The assumption that responses are controlled by distinct serially arranged processes was used by Sternberg (1969a) to explain the result, observed in many human experiments, that two factors have additive effects on reaction time (RT). With slight changes, Sternberg’s explanation of additive factors with RT also explains the result, observed in animal experiments, that two factors have multiplicative effects on response rate. This article describes and interprets 17 examples of multiplicative factors from response-rate experiments with rats, pigeons, and goldfish, as well as some other animal evidence for distinct serial processes. The examples suggest and/or support new and old ideas about generalization, attention, timing, learning, motivation, and response production. Most important, the animal evidence makes the case for distinct serial processes considerably stronger. Since the procedures used in the two sets of experiments (human and animal) have little in common, distinct serial processes may control behavior in a very wide range of situations.
Solubility ofp-phenylazophenol in low molecular weight liquid crystalline precursors

Freezing point temperatures for binary mixtures containing phenylazophenol (PAP) with p-(p-methoxyphenylazo)phenol (MOPAP), p-(p-ethylphenylazo)phenol (EPAP) and p-(p-ethoxyphenylazo)phenol (EOPAP) have been experimentally determined using differential scanning calorimetry. Enthalpies and entropies of fusion for the four phenylazophenol derivatives were also measured. Results of these measurements indicate that the three binary systems exhibit only slight deviations from ideality at temperatures between the melting points of the pure components. Deviations become more pronounced in the PAP+EOPAP system as the temperature decreases below the melting pont of the ethoxy-derivative.
Traitement précoce du diabète de type 2 chez l’obèse après gastric bypass et diversion bilio-pancréatique : rôle de l’axe entéro-insulinique

Traitement precoce du diabete de type 2 chez l’obese apres gastric bypass et diversion bilio-pancreatique: Role de l’axe entero-insulinique. J-C Lifante, W.-B. Inabnet Le gastric bypass et la diversion bilio-pancreatique ameliorent le diabete de type 2 dans 80 a 98 % des cas des patients obeses diabetiques. Cette amelioration apparait tres tot apres l’operation avant qu’une perte significative de poids n’ait ete observee. Dans la litterature, la physiologie de cette amelioration precoce du diabete a ete abordee par de nombreuses etudes mais reste non elucidee. Le mecanisme le plus etudie est celui des modifications de l’axe entero-insulinique. L’axe entero-insulinique a comme mediateurs des hormones gluco-incretines GIP and GLP-1, qui relient l’intestin aux cellules s des ilots de Langerhans. Mais les etudes experimentales et cliniques sont contradictoires du fait de methodologies et modeles utilises differents. D’autres mecanismes ont ete proposes, pour expliquer l’amelioration precoce du diabete de type 2 apres gastric bypass et diversion bilio-pancreatique. L’axe adipo-insulinique dont les transmetteurs sont l’adiponectine et la leptine semble jouer un grand role dans l’insulino-resistance, mais leur action est dependante de la perte de poids. D’autres mecanismes tels que la restriction calorique postoperatoire, peuvent egalement contribuer a la resolution precoce du diabete de type 2 apres gastric bypass et diversion bilio-pancreatique.
β1-Adrenergic receptor blockade extends the life span of Drosophila and long-lived mice

Chronic treatment with β-adrenergic receptor (βAR) agonists increases mortality and morbidity while βAR antagonists (β-blockers) decrease all-cause mortality for those at risk of cardiac disease. Levels of sympathetic nervous system βAR agonists and βAR activity increase with age, and this increase may hasten the development of age-related mortality. Here, we show that β-blockers extend the life span of healthy metazoans. The β-blockers metoprolol and nebivolol, administered in food daily beginning at 12 months of age, significantly increase the mean and median life span of isocalorically fed, male C3B6F1 mice, by 10 and 6.4 %, respectively (P < 0.05). Neither drug affected the weight or food intake of the mice, indicating that induced CR is not responsible for these effects, and that energy absorption and utilization are not altered by the drugs. Both β-blockers were investigated to control for their idiosyncratic, off-target effects. Metoprolol and nebivolol extended Drosophila life span, without affecting food intake or locomotion. Thus, βAR antagonists are capable of directly extending the life span of two widely divergent metazoans, suggesting that these effects are phylogenetically highly conserved. Thus, long-term use of β-blockers, which are generally well-tolerated, may enhance the longevity of healthy humans.
Dissociation Energetics and Mechanisms of Leucine Enkephalin (M + H)+ and (2M + X)+ Ions (X = H, Li, Na, K, and Rb) Measured by Blackbody Infrared Radiative Dissociation

The dissociation kinetics of protonated leucine enkephalin and its proton and alkali metal bound dimers were investigated by blackbody infrared radiative dissociation in a Fouriertransform mass spectrometer. From the temperature dependence of the unimolecular dissociation rate constants, Arrhenius activation parameters in the zero-pressure limit are obtained. Protonated leucine enkephalin dissociates to form b4 and (M-H2O)+ ions with an average activation energy (E a ) of 1. 1 eV and an A factor of 1010. 5 s−1. The value of the A factor indicates that these dissociation processes are rearrangements. The b4 ions subsequently dissociate to form a4 ions via a process with a relatively high activation energy (1.3 eV), but one that is entropically favored. For the cationized dimers, the thermal stability decreases with increasing cation size, consistent with a simple electrostatic interaction in these noncovalent ion-molecule complexes. The E a and A factors are indistinguishable within experimental error with values of ∼1.5 eV and 1017 s−1, respectively. Although not conclusive, results from master equation modeling indicate that all these BIRD processes, except for b4 → a4, are in the rapid energy exchange limit. In this limit, the internal energy of the precursor ion population is given by a Boltzmann distribution and information about the energetics and dynamics of the reaction are obtained directly from the measured Arrhenius parameters.
Work in progress — Enhancing the entrepreneurial mindset of freshman engineers

Our research reports on an ongoing study of the impact of entrepreneurial interventions within first-year engineering courses on changes in the mindsets of engineering students. Entrepreneurial mindset in our study is operationally defined as a more growth oriented mindset versus a fixed oriented mindset. This operational definition and an accompanying mindset measurement instrument was developed and validated by Carol Dweck of Stanford University. Based on Dweck's research results we assume a growth mindset is a reasonable surrogate for a student engineer's creative and innovative or entrepreneurial skills. Mindsets of student engineers are benchmarked at the beginning of the freshman year and again at the end of the freshman year, soon after completion of a team based poverty alleviation freshman capstone project. Pre- and post- control samples of freshman engineer mindsets are being collected from similar sized engineering programs at comparable colleges in our geographic vicinity. A pilot study indicated a statistically significant tilt toward a fixed mindset in freshman engineering students compared to a growth mindset observed in an opportunity sample of freshman business students. We are currently tracking engineering students both at the group and at the individual level. Our long-term research goal is to determine how and why engineering course assignments affect a student engineer's entrepreneurial skill set. We hypothesize that a student engineer's creative and innovation skills are in part a learned behavior that is influenced by the student engineer's learning experiences and course assignments. In order to study this phenomenon we are establishing a baseline of the change in engineering student mindset over time. Once we have established this baseline of mindset data, we will then alter interventions to evaluate their differentiated impact on engineer mindset changes.
Magnetic resonance studies of Mn(II)-, Mn(III)-, and Fe(III)-conalbumin complexes.

Abstract Apoconalbumin binds Mn(II) at two sites with association constants of K 1 = 7(±1) × 10 4 and K 2 = 0.4(±0.25) × 10 4 M −1 . The binding is tighter in the presence of excess bicarbonate resulting in K 1 = 1.8(±0.2) × 10 5 and K 2 = 3(±2) × 10 4 M −1 . The electron paramagnetic resonance spectrum (at both 9 and 35 GHz) of Mn(II) bound at the tight site reveals a rhombic distortion (λ = E/D ≅ 0.25–0.31) in the protein ligand environment of the metal ion. An evaluation of the 1/ pT 1 p , paramagnetic contribution to the longitudinal relaxation rate of solvent protons with Mn(II)-, Mn(III)-, and Fe(III)-derivatives of conalbumin revealed that the metal ion in each site of conalbumin is accessible to one water molecule. For Mn(II)-conalbumin and Mn(III)-conalbumin species, inner coordination sphere protons are rapidly exchanging with the bulk solvent, while slow exchange conditions prevail for Fe(III)-conalbumin.
Automatic impedance control

The authors describe circuits and techniques that provide automatic on-chip impedance matching between a series-terminated, low-voltage swing, CMOS I/O pad, and an external interconnect. The automatic impedance control technique employs a digitally controlled output impedance driver, a high-gain, low-voltage differential receiver, and an IEEE-1149.1-1990 compatible test access port. The techniques presented here design circuits that compensate for external environmental variations. A component to test these circuits uses a 0.8- mu m effective gate-length process. The test components exhibit 2-ns I/O latencies with 1-ns rise/fall times and match impedances between 30 and 100 Omega . >
In vitro maintenance of Eperythrozoon suis

Abstract In vitro maintenance of Eperythrozoon suis was attempted using a Petri dish erythrocyte culture system. In preliminary experiments, the optimal conditions for maintaining E. suis attachment to erythrocytes during incubation were anticoagulation with heparin or citrate solution, incubation with 5 or 10% CO2 at 37°C, and incubation with reduced or non-reduced Eagle's minimum essential medium. Using heparin, a CO2 incubator and reduced Eagle's medium (rEM), E. suis metabolic activity was evaluated by measuring glucose consumption, and lactate and pyruvate production. Glucose consumption and lactate production were measurable while pyruvate production was not detected. Erythrocyte integrity was improved by the addition of inosine although no effect was observed on maintenance of E. suis attachment to erythrocytes or the rate of glucose consumption. To determine whether the glucose consumption observed in culture was due to E. suis glycolytic activity or enhanced erythrocyte glycolytic activity, the effect of E. suis killing by EDTA addition to medium was evaluated using rEM containing inosine (rEMI). Glucose consumption decreased proportionally with the decline in the percentage of parasitized erythrocytes induced by EDTA, indicating that glucose consumption was due to E. suis. In a subsequent experiment, the effect of different types of serum (pig or fetal calf serum) and different gaseous environments (5% CO2 incubator or candle jar) were evaluated using rEMI. Glucose consumption by E. suis was significantly increased by the addition of fetal calf serum; however, no difference in the maintenance of E. suis attachment to erythrocytes and in E. suis glycolytic activity was observed between a 5% CO2 incubator and a candle jar. Finally, the effect of medium refreshment (rEMI containing fetal calf serum) was evaluated. Maintenance of E. suis parasitism on erythrocytes and E. suis glycolytic activity were significantly improved by frequent medium refreshment. The maintenance system developed enabled successful metabolic radiolabeling of E. suis for protein/antigen analysis.
A Low-Profile High-Gain Substrate-Integrated Waveguide Slot Antenna Enabled by an Ultrathin Anisotropic Zero-Index Metamaterial Coating

A low-profile high-gain unidirectional antenna is proposed and demonstrated using both metamaterial (MM) and substrate-integrated waveguide (SIW) technologies. First, the leaky modes supported by a grounded anisotropic slab are studied. These investigations reveal that a grounded slab consisting of an anisotropic zero/low index material can provide an extremely low value for the real part of the propagation constant of the leaky mode, thereby facilitating stable unidirectional broadside radiation over a wide frequency range. The truncation effect of the slab is then investigated through full-wave simulations, which is found to be beneficial for a practical implementation of dispersive metamaterials. Finally, to validate the proposed concept, a subwavelength end-loaded dipole array is designed to realize the required anisotropic zero-index property and is applied to a SIW fed longitudinal slot antenna for the 5.8 GHz wireless local area network (WLAN) band. Measurements of the fabricated antenna prototype are shown to be in strong agreement with simulation results, thus confirming the proposed antenna design. The resulting antenna is only 0.12 λ thick, all while accomplishing a broadside gain of more than 10 dBi and a front-to-back ratio larger than 26 dB, which is ~ 7 dB and ~ 10 dB higher than that of the SIW fed slot alone, respectively. The -10 dB impedance bandwidth is more than 9% both with and without the presence of the MM coating. The proposed technique offers a means for realizing low-cost and low-profile unidirectional antennas with moderate bandwidth.
Reactive mononuclear phagocytes release neurotoxins after ischemic and traumatic injury to the central nervous system

Reactive microglia and invading macrophages, which appear in brain damaged by stroke or trauma, secrete neuron-killing factors. This release of cytotoxic substances is a delayed process and is not detected until inflammatory cells reach a peak of reactivity by the second day after injury. Proximity to the site of injury and density of mononuclear phagocytes determine in part the amount of neurotoxic activity released by injured tissues. Moreover, drugs that suppress the accumulation of reactive microglia and macrophages also reduce tissue production of neuron poisons. Neurotoxins released by brain inflammatory cells or extracted directly from inflamed tissues are heat-stable, protease-resistant molecules < 500 daltons with actions blocked by N-methyl-D-aspartate (NMDA) receptor antagonists. These molecules are distinguished from free radical intermediates, bind to cation exchange resins, lack carboxyl moieties, and are separated from excitatory amino acids including glutamate or aspartate and from the NMDA receptor-mediated toxin quinolinic acid by ion exchange and reverse phase chromatography. Our data suggest that an unrecognized class of neuron-killing molecules produced by inflammatory cells mediate the delayed neuronal loss associated with stroke and trauma.
Ion Channel Selectivity through Stepwise Changes in Binding Affinity

Voltage-gated Ca2+ channels select Ca2+ over competing, more abundant ions by means of a high affinity binding site in the pore. The maximum off rate from this site is ∼1,000× slower than observed Ca2+ current. Various theories that explain how high Ca2+ current can pass through such a sticky pore all assume that flux occurs from a condition in which the pore's affinity for Ca2+ transiently decreases because of ion interactions. Here, we use rate theory calculations to demonstrate a different mechanism that requires no transient changes in affinity to quantitatively reproduce observed Ca2+ channel behavior. The model pore has a single high affinity Ca2+ binding site flanked by a low affinity site on either side; ions permeate in single file without repulsive interactions. The low affinity sites provide steps of potential energy that speed the exit of a Ca2+ ion off the selectivity site, just as potential energy steps accelerate other chemical reactions. The steps could be provided by weak binding in the nonselective vestibules that appear to be a general feature of ion channels, by specific protein structures in a long pore, or by stepwise rehydration of a permeating ion. The previous ion-interaction models and this stepwise permeation model demonstrate two general mechanisms, which might well work together, to simultaneously generate high flux and high selectivity in single file pores.
The trpE Gene Negatively Regulates Differentiation of Heterocysts at the Level of Induction in Anabaena sp. Strain PCC 7120

Levels of 2-oxoglutarate (2-OG) reflect nitrogen status in many bacteria. In heterocystous cyanobacteria, a spike in the 2-OG level occurs shortly after the removal of combined nitrogen from cultures and is an integral part of the induction of heterocyst differentiation. In this work, deletion of one of the two annotated trpE genes in Anabaena sp. strain PCC 7120 resulted in a spike in the 2-OG level and subsequent differentiation of a wild-type pattern of heterocysts when filaments of the mutant were transferred from growth on ammonia to growth on nitrate. In contrast, 2-OG levels were unaffected in the wild type, which did not differentiate under the same conditions. An inverted-repeat sequence located upstream of trpE bound a central regulator of differentiation, HetR, in vitro and was necessary for HetR-dependent transcription of a reporter fusion and complementation of the mutant phenotype in vivo. Functional complementation of the mutant phenotype with the addition of tryptophan suggested that levels of tryptophan, rather than the demonstrated anthranilate synthase activity of TrpE, mediated the developmental response of the wild type to nitrate. A model is presented for the observed increase in 2-OG in the trpE mutant.
Ab initio study of low-energy electron-methane scattering.

The complex Kohn method is used to study electron-methane scattering with polarized trial functions at incident energies ranging from 0.2 to 10 eV. A perturbative method, which only requires the construction of Fock operators, is used to generate a set of polarized virtual orbitals. These polarized orbitals are then used to construct a compact {ital ab} {ital initio} scattering function that produces cross sections that are in excellent agreement with experiments in the region of the Ramsauer-Townsend minimum and at higher energies, where a broad maximum is present in the integral cross section. This is the first {ital ab} {ital initio} study to accurately characterize low-energy electron-methane scattering.
Clinical characteristics of trigeminal nerve injury referrals to a university centre

The aim of this retrospective study was to determine the aetiology and characteristics of trigeminal nerve injuries referred to a university centre with nerve injury care. Fifty-nine patients with 73 injured trigeminal nerves were referred in 10 months. The most common aetiologies were odontectomy (third molar surgery) (52.1% of nerves), local anaesthetic (LA) injections (12.3%), orthognathic surgery (12.3%) and implant surgery (11.0%). The inferior alveolar nerve (IAN) was most commonly injured nerve (64.4%), followed by the lingual nerve (LN) (28.8%). About a quarter of IAN injuries (27.3%) and half of LN injuries (57.1%) from odontectomy had severe sensory impairment. There were twice as many LN than IAN injuries from local anaesthetic injections, but all had mild or no sensory impairment. Nerve injuries from implant surgery occurred only in IAN injuries; none had severe sensory impairment. Neuropathic pain occurred in 14.9% of IAN injuries and only in those with mild or no sensory impairment. Nerve surgery was offered to 45.8% of patients; a third underwent surgery.
Monte Carlo models for the production of β-delayed gamma-rays following fission of special nuclear materials

Abstract A Monte Carlo method for the estimation of β-delayed γ-ray spectra following fission is described that can accomodate an arbitrary time-dependent fission rate and photon collection history. The method invokes direct sampling of the independent fission yield distributions of the fissioning system, the branching ratios for decay of individual fission products and the spectral distributions for photon emission for each decay mode. Though computationally intensive, the method can provide a detailed estimate of the spectrum that would be recorded by an arbitrary spectrometer, and can prove useful in assessing the quality of evaluated data libraries, for identifying gaps in these libraries, etc. The method is illustrated by a first comparison of calculated and experimental spectra from decay of short-lived fission products following the reactions 235U(nth,f) and 239Pu(nth,f). For general purpose transport calculations, where detailed consideration of the large number of individual γ-ray transitions in a spectrum may be unnecessary, it is shown that an accurate and simple parameterization of a γ-ray source function can be obtained. These parametrizations should provide high-quality average spectral distributions that should prove useful in calculations describing photons escaping from thick attenuating media.