cssi/SciSciGPT-SciSciNet huggingface dataset:
Use of pseudorabies virus to delineate multisynaptic circuits in brain: opportunities and limitations

Transsynaptic tracing with live virus is a powerful tool that has been used extensively to analyze central efferents that regulate peripheral targets. More recently, investigators have begun to use this new methodology with central injections to identify circuit anatomy within the brain. Although transsynaptic tracing with peripheral injection of pseudorabies virus has been extensively characterized, several methodological issues related to central application of this tracer have not been addressed. Here, we review the following issues relevant to the use of pseudorabies virus (PRV; Bartha strain) in experiments involving injection of virus into rat brain: (i) factors that determine the zone of viral uptake; (ii) uptake of pseudorabies virus by fibers of passage; (iii) viral invasion of the brain after leakage of virus into the brain ventricles; (iv) considerations for double labeling for PRV with peptides and neurotransmitters; (v) use of PRV with conventional retrograde tracers to anatomically identify relays in a multisynaptic pathway; and (vi) transport of PRV throughout the dendritic tree as a means of identifying inputs to distal dendrites. Collectively, the data demonstrate that PRV provides a powerful means of dissecting the synaptology of CNS circuitry when appropriate controls are incorporated into the experimental design. A set of recipes for various procedures are included at the end of this article.
Physiological effects of exercising with handweights

Research demonstrates a positive and graded relationship between handweighted exercise energy costs, the distance through which handweights are swung and the weight used. The energy costs of handweighted exercise when swinging 0.45 to 1.36kg handweights have been shown to be 3 to 155% greater than costs of unweighted exercise at any pace. The upper limit of such increases is unknown. Moreover, the use of handweighted arm swings can convert walking, benchstepping or running from leg dominated endurance training modalities to exercises that simultaneously challenge muscles of both the upper and lower body.
Fish oil supplementation enhanced CPT-11 (irinotecan) efficacy against MCF7 breast carcinoma xenografts and ameliorated intestinal side-effects.

The cancer chemotherapeutic efficacy of the topoisomerase I inhibitor, CPT-11 (irinotecan) is often limited by the induction of severe delayed diarrhoea. In animal studies, CPT-11 use is associated with histopathological damage to the mucosa of the small and large intestines. Results from the present study demonstrate that 60 mg CPT-11 per kg body weight (i.v. q4d × 6) halted the growth, but did not cause significant regression, of MCF7 human breast carcinoma xenografts in mice fed a diet containing 7% corn oil. However, when the diet of the MCF7-bearing mice was supplemented with 3% or 6% fish oil, the same CPT-11 treatment caused significant regression of the MCF7 xenograft. Histomorphometric analyses of intestinal mucosa of mice treated with CPT-11 and fed the diet containing 7% corn oil indicated that treatment with CPT-11 induced structural changes in the intestinal mucosa which persisted at least 5 days after the last dose of CPT-11. The intestinal mucosal architecture of mice that were treated with CPT-11 and fed the diets containing fish oil was largely unchanged from the architecture of the group of mice which did not receive CPT-11. These findings indicate that fish oil supplements may be a useful adjunct to CPT-11 treatment. © 1999 Cancer Research Campaign
Chiron: interpreting signals from capacitive patterns and inertial sensors for intuitive shape modeling

In this paper we introduce Chiron (abbr. Chironomia ): A wearable device for the hand that reads the digital and analogous signals from capacitive sensor patterns and orientation sensors, to interpret user-intent. Here, we explore two cases -- (a) an unconventional and low-cost method for intuitive shape modeling and control, (b) ergonomically designing these patterns from conductive ink, for reading localized finger interactions (swiping or pinching). We also exploit Chiron's thumb-based interaction mechanism and discuss future novel applications.
Estrogen and insulin synergism in neurite growth enhancement in vitro: mediation of steroid effects by interactions with growth factors?

Abstract Addition of estradiol to organotypic cultures of the fetal murine hypothalamus, preoptic area and cerebral cortex has been shown to elicit a striking enhancement of neurite growth which appears restricted to estrogen receptor-containing explant regions. The mechanisms underlying this response are unknown. An important question is whether the neurite enhancement which follows exposure to estradiol is due directly to the interaction of estrogen with the cell that was stimulated (the receptor-containing cell) or whether intermediate steps involving the possible interaction of estrogen and the endogenous polypeptide neurite-promoting growth factors or their receptors may play an important role. Recent findings in the cultures suggest that the effect of estrogen on neurite growth may involve synergistic interactions between estradiol and insulin-related peptides and may be important in regulating estrogen-responsive neurite growth in the central nervous system. Concurrent addition of estradiol and high levels of insulin (10 gmg/ml or 50 gmg/ml) to cultures of the olfactory bulb, hypothalamus, preoptic area and cerebral cortex of the fetal rat and mouse results in a dramatic acceleration and increase of neurite outgrowth which appears localized to estrogen receptor-containing explant regions. The supraphysiological concentrations of insulin required to elicit this response suggest that the factor(s) involved is unlikely to be insulin per se. Insulin may activate the receptor of different but closely related molecules such as the insulin-like growth factors (IGF)-I or -II to which it exhibits a relatively low affinity. Interactions between hormones and endogenous growth factors have been implicated in the modulation or mediation of an increasing number of endocrine-dependent, differentiative processes in vivo and in vitro. For circulating hormone such as estradiol, with actions in multiple tissues, synergistic interactions with local (endogenous) growth factors might be an important mechanism by which hormones with varied effects could exert local control and exhibit tissue and developmental stage specificities.
Tandem mass spectrometric identification of eicosanoids: Leukotrienes and hydroxyeicosatetraenoic acids

The product ion spectra of the fast atom bombardment (FAB) desorbed [M - H]− ions of leukotrienes (LTs) and hydroxyeicosatetraenoic acids (HETEs) have been obtained on a tandem magnetic sector mass spectrometer with introduction by coaxial continuous flow FAB. Upon collisional activation, the product ion spectra of the [M - H]− ions of these derivatives of arachidonic acid reveal structurally informative product ions. The location of the hydroxy groups on the fatty acid chain, and the position and type of the cysteine-containing moiety of the LTs, can be readily determined from the product ion spectra. Tandem mass spectrometry was used to identify 11-and 15-HETE produced in a low-temperature microsomal enzymatic oxidation of arachidonic acid.
Materials in clean power systems: Applications, status and challenges

The selected papers of the special issue of the International Journal of Hydrogen Energy on ■Degradation and modification of metallic materials for bipolar or interconnect applications in SOFCs and PEFCs. ■Brazes and sealing materials for applications in high-temperature electrochemical devices. ■Oxidation and corrosion of metals and alloys in hydrocarbon gases, as well as in an air/hydrogen dual environment, conditions under which fuel cell interconnects are exposed during use. ■Metallic and ceramic membranes and novel structures for gas (e.g. hydrogen) separation. ■Interactions of hydrogen with metals, hydrogen embitterment and remediation. ■Chromium volatility of oxidation alloys and its poisoning effects in SOFCs stacks. ■Advanced alloys for compact, high-efficiency, high-temperature heat-exchangers. ■Materials and catalysts for hydrogen production from gasoline
Suppression by heparin of injury-induced myointimal thickening

Abstract To ascertain the effect of heparin upon intimal smooth muscle cell proliferation after arterial endothelial injury, we subjected young male Sprague-Dawley rats to right carotid air injury and infused them with heparin intravenously for 5, 10, and 14 days after surgery. Control animals received lactated Ringer's solution. Marked inhibition of intimal smooth muscle cell proliferation was observed in the heparinized rats as compared to controls. This profound heparin effect may be due to the enhancement by heparin of antithrombin III inhibition of thrombin and suggests a hitherto unsuspected role of the clotting system in an injury-induced smooth muscle cell proliferation.
Analytical solution for networks of irreversible first-order reactions

A new analytical solution technique for networks of irreversible chemical reactions in batch reactors with first-order kinetics is presented. The solution technique involves the iterative calculation of a coefficient matrix that is then applied for direct calculation of species concentrations at any time. The derivation, which is based on Laplace transforms of an arbitrary network, is presented in the appendix. Several examples and extensions to the solution are discussed. Extensions made to the solution include the consideration of phase equilibria, first-order and zero-order sources and sinks, common reaction products outside the network, and combined networks of reactions and CSTRs. Rate-limited mass transfer effects and reversible reactions were not considered. The solution is general, compact, easy to use, and allows several extensions that will likely aid scientists and engineers in solving problems related to the dynamics of these networks.
Wind power generation impact on electricity price in ERCOT

Texas continues to lead as the top wind power producer in the USA. The Electric Reliability Council of Texas (ERCOT) is an Independent System Operator (ISO), transmission operator and reliability coordinator in Texas. In recent years, numerous policies and incentives to promote renewable energies have been enacted. These policies were very appealing to many states including Texas because of its richness in renewable energy potential. It has been almost a year since ERCOT transitioned from the zonal to nodal market operation. This electricity market has seen significant improvements and consumers are reaping the benefits of lower spot electricity price based on a recent ERCOT report for the first 6 months since the transition took effect. This paper discusses the impact of wind power generation, based on favorable renewable energy policies coupled with the transition from zonal to nodal market, on the electricity price. The analysis performed in this paper indicates that it is very difficult to compute fairly the impact of wind energy on electricity price due to the number of uncertain variables involved and the scale of the problems.
Venous duplex scanning for suspected deep vein thrombosis: results before and after elimination of after-hours studies.

Objective: A 24-hour venous duplex ultrasound (VDU) for suspected deep vein thrombosis (DVT) imposes significant resource burdens on a hospital. We hypothesize that termination of after-hours services increases empiric therapy without affecting clinical outcomes. Methods: A retrospective review of patients evaluated by the emergency department (ED) for suspected DVT in 2005 and 2007. Demographics, empiric treatment, and complications were compared using propensity scores and multivariate regression models. Results: In 2005 and 2007, 318 and 365 patients, respectively, had VDU after referral by the ED. In all, 49 (16%) tests during 2005 were after-hours, with 31 and 25 acute DVTs in 2005 and 2007, respectively. More patients received empiric treatment in 2007: 51 (14%) vs 26 ([8%]; P = .019) and tended to be more likely to have acute DVT: 7 (28%) vs 3 ([10%]; P = .08). We detected no complications from empiric anticoagulation and no difference in outcome. Estimated annual savings were $11 864. Conclusions:...
Determinants of Continuity in Conventional Industrial Channel Dyads

Recently, increasing attention has been paid to the question of how to build stable, long-term relationships between manufacturers and members of conventional channels. This descriptive field study concerns a basic requirement for building long-term relationships, which is the expectation by a marketing intermediary that the relationship will last. Hypotheses about the continuity of relationships are developed from the literature on social exchange, bargaining, and negotiation. These hypotheses are framed as a simultaneous equation system, which is estimated via three-stage least squares on a sample of 690 relationships dyads involving manufacturers and their independent sales agents manufacturers' representatives. Results substantially support the model, highlighting the importance of interpersonal relationships in insuring the continuity of the dyad.
Microstome-macrostome transformation in Tetrahymena vorax strain V2 type S induced by a transforming principle, stomatin.

SYNOPSIS. Microstome macrostome transformation in Tetrahymena vorax was induced by suspending microstomes in a transforming principle, stomatin, released by a potential prey, T. pyriformis. It was found that 70–90% of the microstomes formed macrostomes within 7 hours following suspension in this transforming principle. Macrostome formation occurred by the process of oral replacement. This process involved resorption of the microstome oral apparatus and its replacement with a larger (macrostome) one, which arose from an anarchic field that formed behind the resorbing oral area. Ninety-five percent of those microstomes which were destined to form macrostomes were in some stage of oral replacement 195 minutes after their suspension in stomatin. Several commercially produced products were tested over a wide range of concentrations to determine their ability to act as an inducer of macrostomes. Only 2, Trypticase and Bactocasitone, had any activity, and it was too small to be considered really effective. An attempt was also made to destroy the activity of stomatin by using enzymes. RNAse was effective but only in very high concentrations, so it was suggested that this activity might be related to the destruction of RNA within the transforming cell and not related to hydrolysis of stomatin. None of the other enzymes tested had any effect in reducing the activity of stomatin.
Fuzzy matching of Web queries to structured data

Recognizing the alternative ways people use to reference an entity, is important for many Web applications that query structured data. In such applications, there is often a mismatch between how content creators describe entities and how different users try to retrieve them. In this paper, we consider the problem of determining whether a candidate query approximately matches with an entity. We propose an off-line, data-driven, bottom-up approach that mines query logs for instances where Web content creators and Web users apply a variety of strings to refer to the same Web pages. This way, given a set of strings that reference entities, we generate an expanded set of equivalent strings for each entity. The proposed method is verified with experiments on real-life data sets showing that we can dramatically increase the queries that can be matched.
The electrosorption of phenol onto activated carbon

The electrosorption isotherms of phenol on an activated carbon were measured over a concentration range of 0 to 100mg−11−1 at 25°C and pH=7.7, 6.5, 4.1 and 1.9. Cathodic polarizations relative to the open circuit potential decreased the amount of phenol adsorbed while anodic polarizations apparently increased the amount adsorbed; however, electro-oxidation of phenol masked adsorption at anodic polarizations. Electro-regeneration of spent activated carbon beds was studied. Within defined potential limits, the electro-regenerated bed maintains its virgin capacity. Application of a cathodic polarization to the bed enhanced the degree to which it was regenerated relative to that in a nonpolarized bed; the effect is, however, modest.
The financial prerogatives of excellence

T HE COLLABORATION between the members of a rowing team is highlighted during the race, but the behind-the-scenes organization is apparent from the moment the team takes the shell out of the boathouse. The task of moving an eight from the storage rack to the water is not inconsequential and definitely not likely to be accomplished successfully without planning, coordination, and a series of clearly articulated instructions. Equally, the discipline associated with playing a team sport successfully depends not only on knowing, understanding, and obeying the rules of the game but also on integrating individual efforts to support team function. The athlete involved in an individual sport requires the same knowledge of the rules, but the adoption of a personal style or approach is more likely to be tolerated and, if competitive, successful with respect to outcome. Interdependence of individual and team function is perhaps best identified in those positions whose success requires not only personal skill and dedication but also excellent team support; baseball pitchers, football quarterbacks, and special teams members are examples of this concept. The captain's success in an America's Cup 12-meter race depends on the excellent performance of the crew, the functional design of the boat, a clear understanding of the rules of encounter, and a carefully honed irreverence for authority. Ultimately, however, success in all of the above endeavors requires the organization of the venue and the timely appearance of defined opponents. Analogies to the practice of medicine should be obvious.
Validation of a model simulating the feeding effects of the potato leafhopper (Empoasca fabae) on potato growth

Abstract A model that simulates feeding effects of potato leafhopper nymphs on potato growth and yield was modified and then validated with independent field data. The principal modification was to implement a response function to estimate accurately the feeding intensity of nymphs within individual leaf age-classes from a count of nymph populations on leaves located in the middle of the canopy. The response function was developed from field observations and included both linear and quadratic terms for leaf and crop physiological age as well as an interaction term. Growth, yield and hopperburn responses of the model to high and intermediate nymphal infestations were similar to responses observed in the field. Analysis with the model indicated that potatoes are most sensitive to potato leafhopper-induced yield reductions from full bloom until 2 weeks before harvest, but are relatively insensitive for the first month after plant emergence.
Optimally of shortest queue routing for dependent service stations

We consider a system in which customers arrive singly or in batches to a group of service stations. Via a Markov decision process argument, we establish general conditions on the state-dependent arrival, service and holding cost rates such that shortest queue routing (SQR) is optimal. In particular, our conditions allow each station to be a ?/M/s queue.
Evaluating the impact of an educational intervention to increase CRC screening rates in the African American community: a preliminary study

Despite the acknowledged importance of colorectal cancer (CRC) screening and its proven prognostic benefit, African American men and women simultaneously possess the highest rates of CRC-related incidence and mortality (Swan et al. in Cancer 97(6):1528–1540, 2003) and lowest screening rates in the United States (Polite et al. in Med Clin N Am 89(4):771–793, 2005). Effective, targeted interventions that promote CRC screening for this community are therefore critical. The current study evaluated the impact of a print-based educational intervention on screening behavior and associated patient-based factors, including cancer-related knowledge, fatalism, worry, and decisional balance (pros–cons). One hundred and eighteen individuals (mean age = 56.08, SD = 5.58) who had not undergone screening were recruited from two health clinics in New York City. Each participant received educational print materials regarding the need for screening, the process of undergoing screening, and the benefits of regular CRC screening. One in four individuals had undergone post-intervention screening at a three-month follow-up. Whereas all participants reported a decrease in cancer-related worry (p < .05), it was a decrease in fatalism (p < .05) and an increase in decisional balance (p < .05) that was associated with post-intervention screening behavior. These preliminary results suggest that fatalistic beliefs and an individual’s assessment of the benefits and barriers of screening may be critical in the decision to undergo CRC screening. Future interventions to increase CRC-screening rates for this community may be improved by focusing on these patient-based factors.
Photo-induced structural changes associated with the Staebler-Wronski effect in hydrogenated amorphous silicon

Abstract The light-induced degradation of the electronic properties of hydrogenated amorphous silicon (a-Si:H) and related alloys, discovered by Staebler and Wronski, has been associated with the creation of metastable dangling bond defects. Recent experiments have shown that several light-induced effects are not correlated with the concentration of dangling bond defects. To explain these experiments we propose that photo-induced structural changes occur in these materials in addition to the creation of dangling bond defects.
A theory of the origin of life

Life on Earth is essentially nucleic acids (NAs) influencing peptide synthesis such that NA replication is favored. It is proposed that the ability to synthesize polypeptides evolved gradually — one peptide bond at a time. The proposed evolution of the peptide synthesis apparatus begins with a ‘transfer NA’ (tNA) which catalyzes the transfer of activated amino acids to accessible amino groups in its environment. The resulting ‘capped molecules’ (with single amino acid ‘caps’) in turn favor NA replication. The proposed evolution of the peptide synthesis apparatus from the tNA onward is characterized by a progressive increase in the number of amino acids per cap: two tNAs jointly produce a ‘dipeptide cap’, three tNAs jointly produce a ‘tripeptide cap’, etc. Messenger NAs evolve because they can specify the composition and sequence order of the peptide caps. Lastly, ribosomal NAs evolve. The origin, expansion, and standardization of the genetic code are discussed. It is proposed that the present triplet code evolved by a process of codon length refinement, and that originally codons of varying lengths were allowable, as were unassigned bases between codons. An environmental supply of activated compounds for early evolving entities is proposed. An environmental NA replication process via single template-directed bond formation events is proposed. An ‘environmental retention and redistribution process’ is proposed to have acted as a functional substitute for the cell wall and cell division of early evolving entities.
Research on dust explosions at the University of Michigan

Dust explosion research carried out at the University of Michigan during the last two decades has been summarized. Significant results are presented on the smoldering combustion of dust heaps, turbulent combustion of premixed dust clouds, entrainment and combustion of layered dust, and on shock wave ignition of particles and shock wave initiated detonative combustion. Also, information on the detonation of hybrid mixtures and gaseous mixtures containing nonreactive particles is given.
Optimal Income Distribution Rules and Representative Consumers

This paper derives observable properties of economies with optimal income distribution rules that specify consumers' incomes as functions of aggregate income and prices. Optimality implies that the aggregate demand function is generated by a single "representative" consumer, cf. Samuelson (1956). We derive an additional implication which, when consumers receive fixed shares of aggregate income, requires that the consumers' demands become more dispersed when aggregate income rises. This last condition has empirical support. The results relate the representative consumer's preferences to a version of Kaldor's compensation criterion and show when both can be used for normative analysis without internal inconsistency.
The mean photospheric magnetic field from solar magnetograms Comparisons with the interplanetary magnetic field.

Large-scale averages of daily solar magnetograms have been compared by cross-correlation with the interplanetary magnetic sector pattern during a 2.5 yr interval. A significant correlation was found at a lag of about 4.5 days, with the amplitude of the correlation depending on the area included in the magnetogram averages. The highest correlation was found when an area of one quarter of the solar disk was used, which is consistent with the idea that the photospheric features which are to be associated with the interplanetary sector pattern are large scale features.
Unsteady heat transfer problems related to a high-power laser flow loop

Introduction A PULSED closed-cycle electric discharge laser (EDL) is a very important device for achieving high energy intensity laser beams. Figure 1 shows a simplified sketch of the EDL. A working gas flows through a closed loop as in a closed circuit wind tunnel used in aerodynamic applications. The flow is circulated by the fan. In the cavity section, pulsed electron beam energy is deposited into the flowing gas to achieve population inversion leading to lasing action. Pulse frequencies of 100 Hz are typical, and each pulse typically lasts for 5 //s. As far as the fluid dynamics of the cavity flow is concerned, the energy deposition is instantaneous, and, therefore, the process can be described as an instantaneous constant volume heating process. Thus, the gas pressure and temperature are instantaneously increased by the energy deposition in the cavity. Because of this, shock waves traveling away from the cavity in both upstream and downstream directions are created. Acoustic mufflers for attenuating these shocks are located upstream and downstream of the cavity. The pressure in the cavity region relaxes back to near its original value in a short period of time. However, the temperature discontinuities created by the energy deposition do not relax in a short period of time. A hot region of gas remains long after the pressure waves have traveled away. This hot slug of gas flows from the cavity at the speed of the flow and encounters the heat exchanger located downstream. The heat exchanger not only removes the heat from the hot slug of gas but also causes longitudinal mixing of this hot slug with the previous cold slug which passed through the heat exchanger. The fan also causes mixing and, thus, the working gas enters the cavity at a lower temperature. For the cavity medium to produce a high-quality output laser beam, there are stringent requirements on density homogeneity. Typically (Ap/p) rms ~ 10~. Variations in density are due to several sources. One source is the unsteady temperature profile at the inlet of the heat exchanger, shown in Fig. 2. The pulse width in Fig. 2 is small compared to the interpulse time, and, therefore, the pulse width is considered infinitesimal. A second source of density variation is the temperature balance between the gas and the solid surfaces in the loop the gas temperature changes with time. Estimating the relaxation times and density changes requires a knowledge of unsteady heat transfer. One unique feature of these unsteady heat transfer problems is that the fluid bulk temperature fluctuates as opposed to problems where the body surface temperature fluctuates. Available literature shows that even though a large number of papers are published concerning unsteady heat transfer, little work is available which considers fluid bulk temBOUNDARY LAYER SUCTION
Reversible modification of the sulfhydryl groups of Escherichia coli succinic thiokinase with methanethiolating reagents, 5.5'-Dithio-bis(2-nitrobenzoic acid), p-hydroxymercuribenzoate, and ethylmercurithiosalicylate.

Abstract Inhibition of Escherichia coli succinic thiokinase by either methyl methanethiolsulfonate (MeS-SO 2 Me) or by methoxycarbonylmethyl disulfide was reversed completely by addition of tributylphosphine, but not by incubation with dithiothreitol. At a point where about 4 moles of MeS- were incorporated per mole of enzyme ( M r 140,000), no loss of antigenicity (as measured by microcomplement fixation) was observed, but at least 80% of thiokinase activity was lost. No significant conformational change was indicated for this methanethiolated enzyme in the ultracentrifuge. In contrast, losses of both thiokinase activity and antigenicity were brought about by incubation with 5,5′-dithiobis 2-nitrobenzoic acid) (Nbs 2 ), ethylmercurithiosalicylate, and p -hydroxymercuribenzoate. These losses were restored totally by incubation of modified enzyme with dithiothreitol but not with tributylphosphine. Preincubation of succinic thiokinases with MeSSO 2 Me and with Nbs 2 protected the enzyme partially, and to the same degree, against the inhibiting effects of N -ethylmaleimide. These data suggest that, while both MeSSO 2 Me and Nbs 2 may attack identical thiol groups on the enzyme, each may also react specifically with other thiol groups. Inhibition by MeS-SO 2 Me and by Nbs 2 both appear not to be accompanied by dissociation into subunits and, in the later case, significant aggregation appears to be involved.
Cost analysis of implant-based breast reconstruction with acellular dermal matrix

AbstractA comparative cost analysis of breast reconstruction using acellular dermal matrix (ADM) and traditional tissue expander-/implant-based techniques was carried out. Medicare reimbursement costs were calculated for tissue expander/implant alone (TE/I), TE/I with ADM (TE/I + ADM), and single-st
Residues Essential for Catalysis and Stability of the Active Site of Escherichia coli Adenylosuccinate Synthetase as Revealed by Directed Mutation and Kinetics

Examined here by directed mutation, circular dichroism spectroscopy, and kinetics are the relationships of five residues, Asp13, Glu14, Lys16, His41, and Arg131, to the catalytic function and structural organization of adenylosuccinate synthetase from Escherichia coli. The D13A mutant has no measurable activity. Mutants E14A and H41N exhibit 1% of the activity of the wild-type enzyme and 2–7-fold increases in theK m of substrates. The mutant K16Q has 34% of the activity of wild-type enzyme and K m values for substrates virtually unchanged from those of the wild-type system. Mutation of Arg131 to leucine caused only a 4-fold increase in the K m for aspartate relative to the wild-type enzyme. The dramatic effects of the D13A, E14A, and H41N mutations onk cat are consistent with the putative roles assigned to Asp13 (catalytic base), His41(catalytic acid), and Glu14 (structural organization of the active site). The modest effect of the R131L mutation on the binding of aspartate is also in harmony with recent crystallographic investigations, which suggests that Arg131 stabilizes the conformation of the loop that binds the β-carboxylate of aspartate. The modest effect of the K16Q mutation, however, contrasts with significant changes brought about by the mutation of the corresponding lysines in the P-loop of other GTP- and ATP-binding proteins. Crystallographic structures place Lys16 in a position of direct interaction with the γ-phosphate of GTP. Furthermore, lysine is present at corresponding positions in all known sequences of adenylosuccinate synthetase. We suggest that along with a modest role in stabilizing the transition state of the phosphotransfer reaction, Lys16 may stabilize the enzyme structurally. In addition, the modest loss of catalytic activity of the K16Q mutant may confer such a selective disadvantage to E. coli that this seemingly innocuous mutation is not tolerated in nature.
A demonstration of ultra-low-latency data center optical circuit switching

We designed and constructed a 24x24-port optical circuit switch (OCS) prototype with a programming time of 68.5 μs, a switching time of 2.8 μs, and a receiver electronics initialization time of 8.7 μs [1]. We demonstrate the operation of this prototype switch in a data center testbed under various workloads.
Offering assistance at the OPACs

Summary As technology races forward, public library OPACs have established a barrier to access. Computer literacy is required of the patron to access the collection through the OPAC. This barrier may be addressed with more active service. Rather than the librarian at the reference desk waiting to be asked, go to the patron. But will the patron accept? This study looks at who did accept and how often. Patrons heading towards the OPAC were greeted by an individual and offered assistance. Conducted at the Guilderland Public Library, a suburb of Albany, NY, in the fall of 1996, this study compares the responses of these patrons grouped by sex and approximate age. In 20 hours over five consecutive days, 189 patrons were recorded. Additionally the study touches upon other factors such as sex, race, dress, and more effective wording for the approach and offer.
Impulse Breakdown in the 10 − 9 -Sec. Range of Air at Atmospheric Pressure

The formative lag of spark breakdown has been measured over the range from 0.5 to 50\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}9}$ sec. using transmission line circuits in conjunction with the micro-oscillograph. It is found to be a function only of the applied field (independent of gap-width) for the shorter times (high fields), but to increase for decreasing gapwidths for the longer times (low fields). A calculation of the formative lag is presented which is based on the assumption that it consists mainly of the time for a single electron avalanche to build up a space-charge field comparable with the applied field. This predicts the observed formative lags within the experimental accuracy of the measurements over the entire range used. The increasing times for decreasing gap-widths for the longer times is interpreted as the transition from a single avalanche to a multiple avalanche mechanism of breakdown. The critical field where this transition takes place for a given gap-width is computed and found to predict the observed critical fields within the experimental accuracy. The good agreement between theory and experiment enables a more reliable prediction than has previously been possible of the critical gap-width above which the threshold field is determined by a single avalanche mechanism.A sharp drop in the rate of fall of the breakdown voltage is observed for the shorter times. It is suggested that this may be a change in the mechanism of electron release from the cathode.
Numerical Simulation of Oil-Droplet Cleavage by Surfactant

We present numerical computations of the deformation of an oil-droplet under the influence of a surface tension gradient generated by the surfactant released at the poles (the Greenspan experiment). We find this deformation to be very small under the pure surface tension gradient. To explain the large deformation of oil droplets observed in Greenspan's experiments, we propose the existence of a phoretic force generated by the concentration gradient of the surfactant. We show that this hypothesis successfully explains the available experimental data and we propose some further tests.
Compositional analysis of electrodeposited bismuth telluride thermoelectric thin films using combined electrochemical quartz crystal microgravimetry--stripping voltammetry.

Bismuth telluride (Bi2Te3) is a benchmark material for thermoelectric power generation and cooling applications. Electrodeposition is a versatile technique for preparing thin films of this material; however, it affords films of variable composition depending on the preparation history. A simple and rapid assay of electrodeposited films, therefore, has both fundamental and practical importance. In this study, a new protocol for the electroanalysis of Bi2Te3 thin films is presented by combining the two powerful and complementary techniques of electrochemical quartz crystal microgravimetry (EQCM) and stripping voltammetry. First, any free (and excess) tellurium in the electrodeposited film was reduced to soluble Te2- species by scanning to negative potentials in a 0.1 M Na2SO4 electrolyte, and the accompanying frequency increase (mass loss) was used to determine the content of free tellurium. The film was again subjected to cathodic stripping in the same medium (to generate Bi0 and soluble Te2- from the Bi2T...
SKELETAL MUSCLE MITOCHONDRIAL MYOPATHY AS A CAUSE OF EXERCISE INTOLERANCE IN A HORSE

Although exertional myopathies are commonly recognized in horses, specific etiologies have not been identified. This is the first report in the horse of a deficiency of Complex I respiratory chain enzyme associated with profound exercise intolerance. Physical examination, routine blood tests, endoscopy, and ultrasonograms of the heart and iliac arteries were unremarkable. With slow, incremental exercise (speeds 1.5–7 m/s), the Arabian mare showed a marked lactic acidosis, increased mixed venous PVO2, and little change in oxygen consumption. Muscle biopsies contained large accumulations of mitochondria with bizarre cristae formations. Biochemical analyses revealed a very low activity of the first enzyme complex in the mitochondrial respiratory chain (NADH CoQ reductase). The exercise intolerance and muscle stiffness in this horse were attributed to a profound lactic acidosis resulting from impaired oxidative energy metabolism during exercise. © 1994 John Wiley & Sons, Inc.
Maximum-likelihood estimation of restriction-fragment mobilities from 1-D electrophoretic agarose gels

We have developed a technique for finding maximum-likelihood estimates of DNA restriction- fragment mobilities from images of fluorescently stained electrophoretic gels. Gel images are acquired directly using a CCD camera. The likelihood model incorporates the Poisson nature of the photon counts and models the fluorescence intensity as the superposition of Gaussian functions (corresponding to the fragment bands) of varying magnitude and width. An expectation-maximization algorithm is used to find maximum-likelihood estimates of the number of fragments, fragment mobilities, widths of the bands, background contributions, and DNA concentration. This approach has several advantages. Closely spaced and overlapping fragments are accurately resolved into their components. No a priori knowledge of the number or positions of fragments is required. Fragment lengths estimated by the maximum-likelihood method from experimental data were compared to the known lengths of fragments generated from three different restriction digests of bacteriophage (lambda) DNA. Preliminary results using the maximum-likelihood method indicate residual sizing errors on the order of 1%.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Repeated reserpine administration reduces in vivo [18F]GBR 13119 binding to the dopamine uptake site.

The effects of repeated reserpine on the in vivo regional brain distribution of [18F]GBR 13119 (1-[(4-[18F]fluorophenyl)(phenyl)methoxy)ethyl]-4-(3-phenylpropyl)piperazine), a dopamine uptake inhibitor, have been examined. Repeated parenteral administration of reserpine (2 mg/kg i.p., once daily for three days) causes a decrease of the in vivo specific binding of [18F]GBR 13119 in mouse striatum, consistent with a down-regulation of available uptake sites in response to dopamine depletion. These results indicate that modification of endogenous dopamine concentrations, either due to pathological disturbance or pharmacological interventions, may affect in vivo studies of the dopamine uptake system using radioligands of the 1,4-dialk(en)ylpiperazine class, and complicate the interpretation of in vivo human studies of these radioligands using positron emission tomography.
Incidence and effects of botfly parasitism in the Eastern chipmunk.

Comparison of bot-infested and bot-free chipmunks collected during 1966–1969 revealed no significant differences in rate of infestation among sex-age classes. Splenomegaly and thymic involution were associated with bot infestation, and adrenal weights were greater in bot-infested adult females. Parasitized animals of all sex-age classes tended to be larger than non-parasitized individuals, and reproductive organs were heavier in infested adults of both sexes. Evidence of bot-induced mortality was not found, but results indicate the possibility of differential loss of bot-infested animals from the population.
Duties to the Distant: Aid, Assistance, and Intervention in the Developing World

In his classic article, “Famine, Affluence, and Morality (Philosophy and Public Affairs 1 (1972), pp. 229–243),” Peter Singer claimed that affluent people in the developed world are morally obligated to transfer large amounts of resources to poor people in the developing world. For present purposes I will not call Singer’s argument into question. While people can reasonably disagree about exactly how demanding morality is with respect to duties to the desperate, there is little question in my mind that it is much more demanding than common sense morality or our everyday behavior suggests. Even someone who disagrees with this might still find some interest in seeing what a demanding morality would imply for well-off residents of the rich countries of the world. I proceed in the following way. First, I survey humanitarian aid, development assistance, and intervention to protect human rights as ways of discharging duties to the desperate. I claim that we should be more cautious about such policies than is often thought. I go on to suggest two principles that should guide our actions, based on an appreciation of our roles, relationships, and the social and political context in which we find ourselves.
Unit analysis of prose memory in clinical and elderly populations

Interpretation of clinical memory tests generally emphasizes the quantitative aspects of recall. This study presents an additional unit analysis of the Logical Memory subtest of Russell's revision of the Wechsler Memory Scale for a variety of older adult groups. Patients' neuropsychological test data were reviewed, and the paragraphs from the Logical Memory subtest were analyzed using unit analysis (Rubin, 1978). The older adults consisted of a healthy group as well as groups whose diagnoses included Alzheimer's and multi‐infarct dementias, head trauma, and metabolic and affective disorders. Quantitative analyses of recall revealed group differences. Qualitative analysis of which memory units were recalled, however, showed similarities in memory processing among these groups.
Application of Genetic Algorithm Combined with BP Neural Network in Soft Sensor of Molten Steel Temperature

In this paper, a new soft sensor model of LF molten steel temperature is introduced after analyzing the process of LF refining and the factors of influencing molten steel temperature. A genetic algorithm combined with improved back-propagation (BP) neural network is used in this model. Genetic algorithm is used to optimize weight and bias values of BP network. The simulation studies show this new combined algorithm has global searching abilities and can improve the prediction model precision and convergence speed. Based on the results, the model is programmed by C language to use in real process. The heats that error between the temperature predicted by the combined algorithm model and real temperature dose not go beyond plusmn 5 degree is more than 85% of all
Antibody-Mediated Elimination of the Obligate Intracellular Bacterial Pathogen Ehrlichia chaffeensis during Active Infection

It is generally accepted that cellular, but not humoral immunity, plays an important role in host defense against intracellular bacteria. However, studies of some of these pathogens have provided evidence that antibodies can provide immunity if present during the initiation of infection. Here, we examined immunity against infection by Ehrlichia chaffeensis, an obligate intracellular bacterium that causes human monocytic ehrlichiosis. Studies with mice have demonstrated that immunocompetent strains are resistant to persistent infection but that SCID mice become persistently and fatally infected. Transfer of immune serum or antibodies obtained from immunocompetent C57BL/6 mice to C57BL/6 scid mice provided significant although transient protection from infection. Bacterial clearance was observed when administration occurred at the time of inoculation or well after infection was established. The effect was dose dependent, occurred within 2 days, and persisted for as long as 2 weeks. Weekly serum administration prolonged the survival of susceptible mice. Although cellular immunity is required for complete bacterial clearance, the data show that antibodies can play a significant role in the elimination of this obligate intracellular bacterium during active infection and thus challenge the paradigm that humoral responses are unimportant for immunity to such organisms.
Outphasing Energy Recovery Amplifier With Resistance Compression for Improved Efficiency

We describe a new outphasing energy recovery amplifier (OPERA) which replaces the isolation resistor in the conventional matched combiner with a resistance-compressed rectifier for improved efficiency. The rectifier recovers the power normally wasted in the isolation resistor back to the power supply, while a resistance compression network (RCN) reduces the impedance variation of the rectifier as the output power varies. Because the combiner requires a fixed resistance at the isolation port to ensure matching and isolation between the two outphased power amplifiers (PAs), the RCN serves to maintain high linearity as well as high efficiency in the switching-mode PAs. For demonstration, a prototype OPERA system is designed and implemented with discrete components at an operating frequency of 48 MHz, delivering 20.8 W peak power with 82.9% PAE. The measurement results show an efficiency improvement from 17.9% to 42.0% for a 50-kHz 16-QAM signal with a peak-to-average power ratio of 6.5 dB.