cssi/SciSciGPT-SciSciNet huggingface dataset:
Function of the N terminus of the myosin essential light chain of vertebrate striated muscle.

All but one (LC3-f; a fast skeletal muscle isoform) of the essential light chain isoforms of myosin (ELC) that are expressed in vertebrate striated muscles have an extended N terminus that is found neither in invertebrate ELCs nor in the majority of vertebrate smooth and nonmuscle myosin ELCs. Studies with permeabilized skeletal muscle fibers and in vitro motility assays have demonstrated that the presence of the ELC isoform lacking the N-terminal extension (LC3-f) is correlated with an increased maximal velocity of filament sliding. To examine further this modulatory role of the ELCs, a procedure was developed for the exchange of ELCs that is based on a technique for the removal of regulatory light chains from permeabilized muscle fibers. Different isoforms of the ELCs and mutant ELCs were exchanged into permeabilized skeletal muscle fibers from rabbit psoas muscle. The role of the ELCs of myosin in altering the shortening Vmax of striated muscle was confirmed. Additionally, experiments with mutant ELCs in which lysines at the extreme N terminus were replaced with alanines, demonstrated an increased shortening Vmax that coincided with removal of the positive charges contributed by the lysines. This suggests that charge interactions (i.e., salt bridges) between the N terminus of the ELC and negatively charged amino acids on the surface of actin cause a slowing of filament sliding. Whether this role in altering shortening velocity is the primary function of the extended N terminus of the ELC or whether it is merely a consequence of providing a tether between the thick and thin filaments is discussed.
A LOOK BACK AT LESSONS LEARNED AND NOT LEARNED

Many of the issues and problems of concern to Atwater are still being studied and debated. However, the major nutrition issue today is balancing food preferences against the risk of disease. This affects the relationship between agriculture and nutrition interests. Successful modification of eating habits will rest primarily upon the food industries. Foods with desirable nutritional profiles will sell if they are tasty, competitively priced, and convenient. In developing dietary recommendations, the changes necessary in the food supply must be considered. Unreasonable recommendations should be avoided. In addition, serious consideration should be given to how food consumption data are obtained, what standards are used to evaluate the data, and what legitimate conclusions can be drawn from these data.
Theoretical studies of the unimolecular and bimolecular tautomerization of cytosine

Computational investigations of the unimolecular and bimolecular tautomerization of isolated and dimeric cytosine have been performed. Stationary and transition states of the isolated and dimeric cytosine systems were characterized at the MP2(full)/6-311+G(2d,2p)//MP2(full)/6-31G* and MP2(full)/6-311+G(2d,2p)//B3LYP/6-31G* levels of theory, respectively. In the solid phase, cytosine exists in a single tautomeric state. In contrast, experiments conducted in the gas phase find that cytosine exists as a mixture of several tautomeric forms. The energy barriers for unimolecular tautomerization of the tautomeric form found in solids to those observed in the gas phase are high and vary between 142.2 and 169.9 kJ mol−1. The formation of dimers with dual hydrogen bonding interactions results in a significant lowering of the barriers to tautomerization, thus facilitating tautomerization during the sublimation process. Based on such bimolecular tautomerization mechanisms, we believe that the relative populations of the cytosine tautomers produced in the gas phase via thermal vaporization cannot be accurately predicted without considering intermolecular hydrogen bonding interactions present in the condensed phase.
Experiences with teaching adaptive optimization to engineering graduate students

The paper discusses the first-hand experiences of the author in developing and teaching a graduate level engineering course in adaptive optimization methods inspired by nature. The paper discusses course content, textbooks and supplementary written material, software and computer projects, and grading and evaluation. This course has encouraged many students to pursue research in evolutionary computation, tabu search or simulated annealing, however it is continually being modified to reflect the many changes occurring in the field.
Effect of secreted phospholipase A2 group IID, IIE, and IIF-deficiency on allergen-driven asthma phenotype

Rationale : Exaggerated inflammation and remodeling in the airways of patients with asthma occurs through complex Th2 cytokine, chemokine, growth factor, and eicosanoid interactions. The mammalian genome encodes 10 secreted phospholipase A 2 (sPLA 2 )s. The role of these sPLA 2 s in eicosanoid biosynthesis has been unclear. We have found that mice that lack groups X and V (respectively Henderson, W.R., Jr. et al. J Exp Med 2007; 204:865-77 and Henderson, W.R., Jr. et al. PLOS ONE 2013; DOI:10.1371/journal.pone.0056172) sPLA 2 s show reduction in Th2 cytokine-driven airway hyperresponsiveness (AHR) and inflammation. Data are lacking regarding the effect on asthma phenotype of the group IID, IIE, and IIF sPLA 2 enzymes that share a common three-dimensional structure with group V and X sPLA 2 s. Study Aim : Determine the role of group IID, IIE, and IIF sPLA 2 s in the mediation of airway inflammation and AHR in an ovalbumin (OVA)-induced mouse asthma model. Results : Airway infiltration by eosinophils (by morphometric analysis) and lung IL-5 release (by qPCR) were decreased in OVA-treated sPLA 2 -IID and IIE knockout (KO) mice compared to wildtype (WT) controls. These parameters of the asthma phenotype were unaffected by sPLA 2 -IIF deficiency. OVA-induced airway mucus metaplasia (by alcian blue histopathology) and AHR (by invasive plethysmography to inhaled methacholine) were not different between WT and sPLA 2 -IID, IIE, and IIF KOs. Conclusions : These results direct attention to the potential role of group IID and IIE sPLA 2 s in IL-5-mediated trafficking of eosinophils to the airways in allergen-driven asthma. Research Funding Source : National Institutes of Health grant HL36235.
Stratigraphy along Chattahoochee River, a Connecting Link between Atlantic and Gulf Coastal Plains: ABSTRACT

The geologic section along the Chattahoochee River is one of the best and most complete in the Coastal Plain of the United States. It is the only continuous unweathered section of Cretaceous and Tertiary beds in southeastern Alabama and southwestern Georgia, and comprises a connecting link between the well-known standard section and type exposures to the west in Alabama and beds to the east in Georgia and South Carolina. It is also an important section because of its intermediate position between the clastic facies in the central and western Gulf Coastal Plain and the equivalent carbonate facies in the subsurface in Florida. Upper Cretaceous, Paleocene, lower Eocene, and middle Eocene strata are exposed in an almost continuous section down the dip from the crystalline rocks at the Fall Line at Columbus, Ga., to upper Eocene exposures about 8 miles north of the Alabama-Florida boundary, a distance of 126 miles. This study of a part of that section supplies detailed stratigraphic and structural information on rocks of Tertiary age that are exposed southward from the Upper Cretaceous-Paleocene contact 15 miles south of Eufaula, Ala., to exposures of upper Eocene Crystal River limestone of Moore, 1955, 15 miles south of Columbia, Ala., a distance of 49 miles. The total thickness of Paleocene, lower Eocene, and middle Eocene strata in this part of the river is a little over 600 feet. The average dip is 15 feet per mile to the south, but in places the beds are horizontal for distances of as much as 3 miles. The formations recognized in the river section are those in the standard Alabama stratigraphic section. From the bottom up they are the Clayton formation of Paleocene age, the Nanafalia formation, Tuscahoma End_Page 1258------------------------------ sand, and Hatchetigbee formation of lower Eocene age, and the Tallahatta and Lisbon formations of middle Eocene age. Stratigraphic sections for these studies were combined into longitudinal profiles for the left and right banks of the river, an arrangement that visually describes detailed lithology and structure. Horizontal control was from aerial photographs. Vertical control was from the river surface. The altitude of the river surface was determined from the stage of the river referenced to "the thalweg," as plotted by the U. S. Corps of Engineers, and bench marks of the U. S. Coast and Geodetic Survey. The use of "the thalweg" in determining altitudes of contacts permits rapid and accurate mapping of geologic sections along rivers. End_of_Article - Last_Page 1259------------
Clinical significance of variability of ventricular late potentials detected before discharge in patients after myocardial infarction

Abstract Background Signal-averaged electrocardiography (SAECG) in patients after myocardial infarction (MI) is widely used to identify patients at risk for ventricular tachycardia (VT) and sudden cardiac death (SCD). It is believed that ventricular late potentials when detected after day 5 after MI are relatively stable and carry the most significant relation to subsequent arrhythmic events. This study sought to determine if ventricular late potentials in patients after MI exhibit variability when recordings were made 10 to 12 hours apart on day 7 and to assess the clinical significance of this variability. Methods and Results SAECG was recorded in 261 patients on the 7th day after MI at 7 to 10 AM (morning) and 6 to 8 PM (evening). Forty of these patients also had recordings 30 to 40 minutes apart to determine the 95% confidence interval of variability of each parameter of SAECG. The data were analyzed with the criteria of the American College of Cardiology policy statement. A prospective analysis for the clinical end points of VT and SCD was carried out for a period of 1 year. We identified 3 groups of patients. Group 1 (54, 20.7%) had consistently positive SAECG by at least 2 abnormal parameters in both morning and evening. Group 2 (37, 14.2%) had positive SAECG at 1 time only, either morning or evening. Group 3 (170, 65.1%) had negative SAECG on both occasions. Diabetes mellitus was an independent predictor of the variability of late potentials (P
The Donnan effect in tobacco mosaic virus and its components.

Abstract Osmotic pressure studies were carried on tobacco mosaic virus (TMV) and its components, protein and RNA, as well as on bis(3,3′-aminopropyl)amine, reported to be present in TMV preparations. Solvents were phosphate and barbital buffers at different values of pH and ionic strength. Measurements were made at room temperature. The Donnan effect was exhibited by TMV protein in phosphate buffer of 0.01 ionic strength at pH values ranging between 5.8 and 7.5. The observed values of the Donnan effect at pH 5.8 and 5.97 were in reasonable agreement with theoretical values calculated from the charge obtained by hydrogen ion titration. TMV-RNA in phosphate buffer at pH 7.5 and ionic strength 0.01 did not exhibit more than 1% of the expected Donnan effect. This is explained tentatively as the result of firm binding of metal ions. Negative values of osmotic pressure were observed with bis(3,3′-aminopropyl)amine. Similar anomalous osmosis was sometimes observed with TMV protein and with TMV. In agreement with earlier observations, TMV did not exhibit the Donnan effect in phosphate buffer of 0.01 ionic strength at pH values ranging from 5.5 to 8.0. However, TMV dialysed extensively in the presence of EDTA at pH 8.5 and TMV produced by reconstitution of purified protein and RNA did exhibit the Donnan effect in both phosphate and barbital buffers. The magnitude was of the same order as that calculated from the net charge determined by hydrogen ion titration. When reconstituted TMV, which did exhibit Donnan effect, was treated with calcium ions, the effect was abolished.
HON-DESTRUCTIVE EXTRACTION IECHANIS1 OF BITUMINOUS COALS USING K-IETBTL-2-PY1LR0LID0NE

ABSTRACT A technique whereby substantial portions of bituminous coals are extracted, non-destructively using N-Methyl-2-Pyrrolidone under mild conditions (202° C and 1 atm pressure) was previously reported. Herein, a parametric study on the extraction step is presented and a possible mechanism on the extraction is proposed. The extent of extraction shows little dependence on the solvent-to-coal ratio, coal particle size and treatment time whereas coal type and treatment temperature significantly affect the extent of extraction. Extractions for 26 different coals are reported and the results show reasonable correlation with the ratio of the volatile matter to fixed carbon (VM/FC), i.e. the inverse of the fuel ratio of the coal. A postulated mechanism of extraction is based on the assumption of the two-phase structure of coal. Electron Paramagnetic Resonance (EPR) studies of the raw coal, and unextracted and extracted species support the proposed mechanism and lend support to the two-phase model of coal str...
Electrochemical and electrical aspects of low-frequency electromagnetic current induction in biological systems

The use of electromagnetic current induction to modulate cell and tissue behavior via cell surface electrochemistry is considered in detail. It is shown that a strong correlation exists between electrochemical kinetic phenomena at cell surfaces, observable via transient impedance measurements, and the choice of induced current waveform parameters. In particular, the current pathway involving specific adsorption, such as that of Na+ or K+ at Na−K ATPase sites, appears to provide the strongest mechanistic correlation. Inductively coupled current signals can be constructed with the appropriate frequency content to excite this pathway. The actual electrical dosage appearing at the cellular level has been evaluated using air-gap Helmholtz coils. It is shown that Maxwell's equations, written for cylindrical geometry, accurately describe the spatial variation of current pulses in isotonic saline. An experimental technique for measurement of the induced electric field and current density vectors is described and applied to pure saline, a cell/saline complex, and muscle and bone tissuein vivo. The results obtained provide practical guidelines for the preferred coil/cell (tissue) orientations for the most uniform real-time dosage for cell culture, cell suspension, andin vivo situations.
Lifetime of the long-wavelength chlorophyll fluorescence.

The fluorescence lifetime of chlorophyll in vivo and in vitro was measured with a phase fluorimeter. The lifetime in vivo of the long-wavelength emission (730 mμ) which appears at low temperature was 3.1 mμsec. It is concluded that this emission is fluorescence rather than phosphorescence as had been previously reported by Brody.
Dynamic Alignment and Exact Scaling Laws in Magnetohydrodynamic Turbulence

Magnetohydrodynamic (MHD) turbulence is pervasive in astrophysical systems. Recent high-resolution numerical simulations suggest that the energy spectrum of strong incompressible MHD turbulence is E(k ⊥) ∝ k –3/2 ⊥. So far, there has been no phenomenological theory that simultaneously explains this spectrum and satisfies the exact analytic relations for MHD turbulence due to Politano & Pouquet. Indeed, the Politano-Pouquet relations are often invoked to suggest that the spectrum of MHD turbulence instead has the Kolmogorov scaling –5/3. Using geometrical arguments and numerical tests, here we analyze this seeming contradiction and demonstrate that the –3/2 scaling and the Politano-Pouquet relations are reconciled by the phenomenon of scale-dependent dynamic alignment that was recently discovered in MHD turbulence.
Distributed damage creates flaw tolerance

A qualitative micromechanical fracture mechanics model is presented that shows how a structure that is sensitive to the presence of a single crack or hole can be rendered flaw tolerant by the presence of an interacting distribution of such flaws. The simple model was inspired by the ductile fracture experienced by the under-designed gusset plates recovered from the I-35W Bridge collapse and by the experimentally measured increase in toughness of concrete damaged by fire.
A case study in cross-talk: the histone lysine methyltransferases G9a and GLP

The histone code hypothesis predicts that the post-translational modification of histones can bring about distinct chromatin states, and it therefore serves a key regulatory role in chromatin biology. The impact of one mark on another has been termed cross-talk. Some marks are mutually exclusive, while others act in concert. As multiple marks contributing to one outcome are generally brought about by complexes containing multiple catalytic and binding domains, it appears regulation of chromatin involves a web of writers and readers of histone modifications, chromatin remodeling activities and DNA methylation. Here, we focus on the protein lysine methyltransferases G9a and GLP as examples of this extended cross-talk. G9a and GLP can catalyze the formation of and bind to the same methyl mark via distinct domains. We consider the impact of other histone modifications on G9a/GLP activity and the coordination of activities within G9a/GLP containing complexes. We evaluate the potential impact of product binding on product specificity and on maintenance and propagation of the methyl mark. Lastly, we examine the recruitment of other silencing factors by G9a/GLP. Regulated assembly of specific complexes around key marks may reinforce or alter the biological outcome associated with given histone modifications.
Effectively identifying user profiles in network and host metrics

This work presents a collection of methods that is used to effectively identify users of computers systems based on their particular usage of the software and the network. Not only are we able to identify individual computer users by their behavioral patterns, we are also able to detect significant deviations in their typical computer usage over time, or compared to a group of their peers. For instance, most people have a small, and relatively unique selection of regularly visited websites, certain email services, daily work hours, and typical preferred applications for mandated tasks. We argue that these habitual patterns are sufficiently specific to identify fully anonymized network users. We demonstrate that with only a modest data collection capability, profiles of individual computer users can be constructed so as to uniquely identify a profiled user from among their peers. As time progresses and habits or circumstances change, the methods presented update each profile so that changes in user behavior can be reliably detected over both abrupt and gradual time frames, without losing the ability to identify the profiled user. The primary benefit of our methodology allows one to efficiently detect deviant behaviors, such as subverted user accounts, or organizational policy violations. Thanks to the relative robustness, these techniques can be used in scenarios with very diverse data collection capabilities, and data privacy requirements. In addition to behavioral change detection, the generated profiles can also be compared against pre-defined examples of known adversarial patterns.
Viral Double-Stranded RNA, Cytokines, and the Flu

The symptoms of the flu, such as fever, drowsiness, and malaise, are the sole means by which this common clinical syndrome is defined. The syndrome is usually the first clinical manifestation of both acute bacterial and viral infections. In the case of acute bacterial infections, several proinflammatory cytokines induced by bacterial products have been implicated as the causative agents of the flu syndrome. Viruses induce similar cytokines to bacteria, plus substantial amounts of interferon-alpha (IFN-alpha), although the direct association of these cytokines with the viral flu syndrome is less clear. Furthermore, the viral inducer(s) of cytokines has not been defined. The best candidate cytokine inducer associated with a majority of viral infections is virus-associated double-stranded RNA (dsRNA). This review examines the essential physical properties of toxic dsRNA, the cytokines induced by it, its viral and cellular sources, evidence for its presence in infected cells, its quantities in normal and infected cells, its cytotoxic mechanisms, and its cell-penetration properties. Toxic effects of viruses and dsRNA are compared. Energetics and extraction artifact issues are also discussed. Whereas most research on dsRNA toxicity has employed synthetic dsRNA, studies with virus-associated dsRNA are featured when available. Finally, a model for how viral dsRNA might initiate systemic disease is presented.
A fracture mechanics-based approach for quantifying delamination of spray-applied fire-resistive insulation from steel moment-resisting frame subjected to seismic loading

Abstract This article presents a numerical approach based on fracture mechanics theory for evaluating crack initiation, propagation, and delamination of fire insulation at the interface of spray-applied fire insulation and steel surface of a moment resisting frame under the action of earthquake loading. Progression of delamination at the fire insulation-steel interface during cyclic loading is simulated through contact interaction analysis in which Cohesive Zone Model is adopted to model the interface damage and softening. The developed 3D finite element model is validated by comparing predictions from the model, namely crack initiation, crack propagation pattern and the extent of delamination of insulation, against test data generated both at material and structural levels. The validated model is applied to quantify the effect of cyclic damage accumulation at SFRM-steel interface through a parametric study in terms of interfacial critical fracture energy. The influence of local buckling occurring in flange on the extent of delamination is considered in the analysis. Results from the parametric studies indicate that critical fracture energy at steel-insulation interface has significant influence on the extent of damage accumulation over the plastic hinge zone. Further, flange local buckling can substantially enhance the development of tensile stresses at the crack tip leading to delamination over a larger surface area.
A comparison of homotopies for alternative formulations of the L 2 optimal model order reduction problem

Abstract A fundamental problem in control systems theory is finding a reduced order model that is optimal in the L 2 sense to a given (full order) system model. The numerical solution of this problem is challenging and the global convergence properties of homotopy methods are advantageous. A number of homotopy-based approaches have been developed. The primary numerical issues are the number of degrees of freedom in the homotopy parameter vector, the well-posedness of the finite-dimensional optimization problem, and the numerical robustness of the resulting homotopy algorithm. This paper develops two new homotopy algorithms for optimal model reduction and uses several examples to compare their performance with the performance of two previous algorithms. The results show that the numerical well-conditioning is inversely related to the algorithmic efficiency and that the relative performance of a given algorithm is problem dependent.
Extrapolation of the aerosol reflectance from the near-infrared to the visible: the single-scattering epsilon vs multiple-scattering epsilon method

In the atmospheric correction algorithm for Sea-viewing Wide Field-of-view Sensor, the effects of the spectral variation of the aerosol radiance contributions at the two near-infrared (NIR) bands are estimated directly from sensor-measured radiance. The aerosol effects at the NIR are then extrapolated into the visible through a process of aerosol model selection from evaluation of the NIR single-scattering epsilon value, which is defined as the ratio of the single-scattering aerosol reflectance between two NIR bands. The aerosol radiance contribution at the visible wavelengths is then removed. In this paper, a slightly different approach in the aerosol model selection and extrapolation, i.e. using the NIR multiple-scattering epsilon instead of the single-scattering epsilon, is examined. The NIR multiple-scattering epsilon is the ratio of the aerosol multiple-scattering reflectance between two NIR wavelengths. Simulations show that, in general, both methods give comparable results. Statistically, more than...
Inhibition of human immunodeficiency virus reverse transcriptase by 2′,3′-dideoxynucleoside triphosphates: Template dependence, and combination with phosphonoformate

The 2′,3′-dideoxynucleoside triphosphates (ddNTPs) are potent substrate analog inhibitors of human immunodeficiency virus (HIV) reverse transcriptase and have clinical utility in the treatment of acquired immunodeficiency syndrome. Several issues regarding the interaction of these compounds with HIV reverse transcriptase were examined. The potency of unsubstituted ddNTPs and the 3′-azido analog of dTTP (AZTTP) was influenced by the choice of template. Both compounds were more potent with the complementary homopolymer templates than with gapped duplex DNA, although the Km for the competing dNTP was similar with different templates. The KI for AZTTP was greater than for the unsubstituted ddNTPs with either a homopolymer or a gapped duplex DNA template. HIV reverse transcriptase incorporated ddCMP and AZTMP into primed phage m13 DNA at sites specified for insertion of dCMP and dTMP, respectively. ddCTP was more efficiently utilized as a substrate than was AZTTP. Primer elongation due to base misincorporation was observed in the absence of one dNTP. The combined effect of ddNTPs and the pyrophosphate analog phosphonoformate (PFA) on HIV reverse transcriptase was also examined, and inhibition by PFA in combination with ddTTP or AZTTP was mutually exclusive.
Influence of Tooth Profile Deviations on Helical Gear Wear

In this study, a surface wear prediction model for helical gears pairs is employed to investigate the influence of tooth profile deviations in the form of intentional tooth profile modifications or manufacturing errors on gear tooth surface wear. The wear model combines a finite-element-based gear contact mechanics model that predicts contact pressures, a sliding distance computation algorithm, and Archard's wear formulation to predict wear of the contacting tooth surfaces. Typical helical gear tooth modifications are parameterized by an involute crown, a lead crown, and an involute slope. The influence of these parameters on surface wear are studied within typical tolerance ranges achievable using hob/shave process. The results indicate that wear is related to the combined modification parameters of a gear pair rather than individual gear parameters. At the end, a design formula is proposed that relates the mismatch of contacting surface slopes to the maximum initial wear rate.
Fake ID ownership and heavy drinking in underage college students: prospective findings.

The authors examined the ownership of false identification (fake ID) for the purpose of obtaining alcohol and the relation of fake ID ownership to heavy drinking in a longitudinal sample of college students under 21 years of age. A sample of 3,720 undergraduates was assessed the summer prior to college entrance and during the 4 semesters comprising freshman and sophomore years. Regression analyses were used to estimate bidirectional relations between consumption and fake ID ownership. Sex, Greek membership, and prior drinking were controlled. Results showed that fake ID ownership increased over time (12.5% precollege to 32.2% fourth semester) and that Greek members were more likely than others to own fake IDs. Fake ID ownership predicted concurrent and next-semester heavy drinking with increasing strength over time. Also, the acquisition (onset) of fake ID ownership at each time point was predicted by previous-semester consumption. When traditional, robust risk factors of consumption are controlled, fake ID ownership meaningfully relates to heavy drinking in college. It thus presents a significant public health problem, addressable through training for alcohol servers and retailers, punitive measures toward fake ID owners, and other possible interventions.
An electrophoretic study of protein synthesis in brain regions of senescent male mice

Abstract C57BL/6J male mice of characterized health status were injected i.p. with 3 H-leucine. Incorporation of 3 H-leucine into 1 per cent Triton-saline soluble proteins of liver and brain regions did not change with age. In contrast, the patterns of 3 H-leucine after gel electrophoresis indicated selective and regionally specific patterns of changes of protein synthesis during ageing.
An electrical circuit model of chemoreceptor cells based on adaptation and disadaptation time constants: implications for temporal filtering

Abstract Chemoreceptor cells have temporally dynamic physiological properties that serve as filters for fluctuating odor patterns. A computational model, based on an electrical circuit, of a peripheral chemoreceptor cell was developed based on two time constants (τ1 and τ2) that model sensory adaptation and recovery from adaptation. With τ1 set to 0.1 s and τ2 to 3.8 s, our model receptor cell responded like real olfactory cells when presented with a series of odor pulse trains. As in real olfactory cells, changes in response magnitude and frequency filtering were observed with changes in stimulation frequency. When presented with chaotic stimulus patterns, model receptor cells responded with brief periods of current flow and adapted quickly. Decreases in the first time constant (τ1) decreased the response magnitude, while decreases in the second time constant (τ2) increased the response magnitude and pulse frequency resolution during chaotic odor stimulation. The two time constants are important for determining different filter properties of the chemoreceptor cells and define the temporal range of chemical fluctuations to which a single cell will respond.
Sensitivity analysis of the optimal location of a facility

We perform a sensitivity analysis of the Euclidean, single-facility minisum problem, which is also known as the Weber problem. We find the sensitivity of the optimal site of the new facility to changes in the locations and weights of the demand points. We apply these results to get the optimal site if some of the parameters in the problem are changed. We also get approximate formulas for the set of all possible optimal sites if demand points are restricted to given areas, and weights must be within given ranges, which is a location problem under conditions of uncertainty.
Stationary and non-stationary models of bacterial kinetics in well-mixed flow reactors

Abstract A reaction scheme is proposed which reflects the autocatalytic nature of bacterial reaction kinetics. It is shown that the usual Monod Kinetic equation may be obtained when the stationary state assumption is applied. A mathematical model which does not assume stationary-state kinetics is then employed to represent the dynamics of the continuous flow, stirred-tank bacterial reactor, or “chemostat.” This “non-stationary chemostat model” is intended to account for lags observed between the predictions of the “Monod chemostat model” and experimental responses to temperature [12], concentration [14] and flow changes. Methods used in the comparisons between stationary and non-stationary models include small perturbation analysis and numerical simulation. In the process, the small perturbation analysis of the Monod chemostat model presented earlier by Koga and Humphrey [8] is extended. It is shown that this model predicts markedly different transient responses to flow and to concentration changes. Conditions under which the stationary-state assumption may be applied are also derived and compared with others presented for simple non-autocatalytic enzyme kinetics [4] and for consecutive chemical reactions [7].
A general model of the planetary radiation pressure on a satellite with a complex shape

The purpose of this paper is to present a general model for the acceleration exerted on a spacecraft by the radiation coming from a planet. Both the solar radiation reflected by the planet and the thermal emission associated with its temperature are considered. The planet albedo and the planet emissive power are expanded in spherical harmonics with respect to an equatorial reference frame attached to the planet. The satellite external surface is assumed to consist of a juxtaposition of planar surfaces. A particular choice of variables allows to reduce the surface integrals over the lit portion of the planet visible to the satellite to one-dimension integrals.
Synthesis and Mass Spectral Characterization of Poly(amic methyl ester) Oligomers

A series of monodisperse oligomers of poly(amic methyl ester) were synthesized by a stepwise, convergent-divergent strategy, starting from pyromellitic dianhydride (PMDA) and 4,4‘-oxydianiline (ODA). All of the fully protected, selectively protected, and nonprotected oligomers were studied by MALDI mass spectrometry. The oligomers with protected end groups proved to be stable during MALDI ionization and the possibility of imidization as the result of synthesis or during MALDI experiments was discounted based on mass spectra of imide analogue oligmers. The effect of end groups and oligomer length on the MALDI ionization efficiency was determined. Higher molecular weight oligomers had more intense fragment peaks. MALDI−CID was used to examine the fragmentation patterns of selected oligomers. It was found that the end groups affected the fragmentation of the oligomers. The use of different CID gases (helium, argon, and xenon) had no effect on the fragmentation pattern, but xenon caused more intense fragment ...
Nickel crystallite thermometry during ethane hydrogenolysis

Abstract A magnetic method to measure the average temperature of superparamagnetic nickel crystallites during ethane hydrogenolysis over Ni SiO 2 is detailed. The method uses the temperature dependence of the magnetic moment per unit volume of crystallite for nickel, which is determined from the low magnetic field sample moment measured with an ac permeameter. Small corrections for hydrogen partial pressure changes are required. Two applications of this catalytic crystallite thermometry are discussed: (1) kinetics in the presence of external temperature gradients, and (2) interphase heat transfer experiments.
Evidence for the Occurrence of Violent Events in the Nuclei of Galaxies

A number of phenomena, all associated with the nuclei of galaxies, which may suggest that in these nuclei there may take place violent events manifested by a very large energy output and a time scale as short as 10/sup 6/ years, are investigated. Optical and radio data that lead to these conclusions are analyzed. (C.E.S.)
The fatty acids of cottonmouth moccasin depot fat

From the investigation of the moccasin (Agkistrodon piscivorus) fat it is found that it is intermediate between the composition of fish oil and mammalia fats for the fatty acids present. The amount of saturated fatty acids in moccasin snake oil is more than that present in fish oils while the amount of unsaturated fatty acids present in moccasin snake oil is less than that for fish oil. It might be pointed out that at least two separate methods were used to determine the percentages of each fatty acid present.
Elevational trends in the fluxes of sulphur and nitrogen in throughfall in the southern Appalachian mountains : some surprising results

From 1986–1989, a team of scientists measured atmospheric concentrations and fluxes in precipitation and throughfall, and modeled dry and cloudwater deposition in a spruce-fir forest of the Great Smoky Mountains National Park which is located in the Southern Appalachian Region of the United States. The work was part of the Integrated Forest Study (IFS) conducted at 12 forests in N. America and Europe. The spruce-fir forest at 1740 m consistently received the highest total deposition rates (∼2200, 1200, and 700 eq ha−1 yr−1 for SO42−, NO3−, and NH4+). During the summers of 1989 and 1990 we used multiple samplers to measure hydrologie, SO42−, and NO3− fluxes in rain and throughfall events beneath spruce forests above (1940 m) and below (1720 m) cloud base. Throughfall was used to estimate total deposition using relationships determined during the IFS. Although the SO42− fluxes increased with elevation by a factor of ∼2 due to higher cloudwater interception at 1940 m, the NO3− fluxes decreased with elevation by ∼30%. To investigate further, we began year round measurements of fluxes of all major ions in throughfall below spruce-fir forests at 1740 m and at 1920 m in 1993–1994. The fluxes of most ions showed a 10–50% increase with elevation due to the ∼70 cm yr−1 cloudwater input at 1920 m. However, total inorganic nitrogen exhibited a 40% lower flux in throughfall at 1920 m than at 1740 m suggesting either higher dry deposition to trees at 1740 m or much higher canopy uptake of nitrogen by trees at 1920 m. Differential canopy absorption of N by trees at different elevations would have significant consequences for the use of throughfall N fluxes to estimate deposition. We used artificial trees to understand the foliar interactions of N.
The knowledge most worth having: Otis W. Caldwell (1869–1947) and the rise of the general science course

In 1860 Herbert Spencer asked the famous rhetorical question ‘What Knowledge is of Most Worth?’ The unequivocal answer was science. Giving greater attention to science and scientific knowledge would not only produce additional scientists; more important, argued Spencer, it would make better parents, better church-goers, better citizens and workers, better artists and better consumers of art. It would lead to a ‘command of fundamental processes’, ‘worthy home membership’, ‘worthy use of leisure’, ‘ethical character’ — the goals of a general education spelled out by Spencerians within the National Educational Association in 1918. Here is our puzzle, then: how are we to interpret a definition of science, one widely accepted both in Spencer's time and in our own, that comes so close descriptively to a commonsensical view of what constitutes non-science? The answer to this question lies in part in the historical relationship between science and general education, a relationship established in the opening decades of this century, when the authority of science and scientific objectivity was in the minds of most educators unimpeachable. The high school general science course, developed in its early stages by the botanist and educator, Otis W. Caldwell, was a potent symbol of this new relationship. Organized around broad, topical issues and claiming to teach the mundane truths of life, general science was more than a loose collection of facts from the various earth, biological, and physical sciences. Its many advocates viewed the new unified science course as pedagogically independent of the specialties yet central to education in general. In 1949, two years after Caldwell's death, 72 percent of the total science enrollments in the United States were in general science and biology, its closest cognate. This paper examines the rise of the general science course and its implications for the reform of secondary school science education. It concludes that while recent reforms may impress students with the personal and social character of science, introducing them to a broad use of the scientific method, they will not necessarily make them more scientifically literate or train them to think about problems in anything like the way professional scientists do. Much less will they introduce students to alternative ways of problem-solving, arguably one of the most important goals of good science teaching.
Internal Energy Distribution of the NCO Fragment from Near-Threshold Photolysis of Isocyanic Acid, HNCO

We report the first measurement of the vibrational- and rotational-state distributions in the NCO fragment resulting from photolysis of HNCO. Recent studies have drawn conclusions about the photochemistry of HNCO and the vibrational distribution in the NCO fragment from observations of the kinetic energy distribution of the H atom produced in this photolysis; however, there has been no direct observation of the NCO fragment itself. We use laser-induced fluorescence to detect the nascent NCO photoproducts and spectral simulations to extract vibrational-state populations. The rotational distributions, where we can measure them, show little excitation, and the vibrational energy preferentially appears in the bending mode. The vibrational-state distribution results directly from the excited-state geometry of the HNCO parent, in which the NCO group is bent. The dissociation proceeds from this bent NCO group to a linear NCO fragment, strongly exciting the bending mode. We find about 65% of the total energy in r...
THE RESTORATION OF LOST ORGAN TISSUE : THE RATE AND DEGREE OF RESTORATION.

1. When half of the total kidney, suprarenal, ovarian, or testicular mass is removed the rate of growth of the remaining half is independent of the rate of growth of the organ at the time of removal. 2. The removal of half of the prostate, or seminal vesicular tissue, or of one uterine horn is not followed by any appreciable growth of the part that remains. 3. The rate of restoration of renal, ovarian, testicular, and suprarenal tissue after removal of half of these organs is at first very rapid, but quickly decelerates and at about 40 days after the removal there is a complete cessation of growth. 4. In none of these organs is all the lost tissue restored. In the testicle the 50 per cent left increases to 56 per cent and in the kidney, suprarenal, and ovary to 70 per cent of the original amount before operation.
Research Note: The Use of Carcass Halves for Reducing the Variability in Salmonellae Numbers with Broiler-Processing Trials

Abstract Two similar trials were conducted in order to compare the variability in the number of salmonellae between the right and left sides of individual broiler carcasses with the variability among carcasses. In both trials, the variation between carcass sides was equal and was significantly less than the variation among carcasses. For trials involving bactericidal treatment, the authors would suggest that the utilization of carcass halves (one side for control, the other for treatment) would allow for a more-sensitive evaluation of treatment effects.
Approximate paleomagnetic poles for some of the New England Seamounts

Abstract Paleomagnetic pole positions were estimated for several of the New England Seamounts by a simple dipole method. Computer poles are in agreement with poles determined by others for several seamounts in the chain using three-dimensional modeling. Collectively the poles plot in a swath which follows the late Mesozoic polar wander path across northern Siberia to the Bering Strait. It is shown that for relatively simple seamount geometries and dipole-like magnetic anomalies inclinations and declinations determined by the dipole method agree within a few degrees with those found by three-dimensional methods. Paleopole determinations by either method may be degraded by interfering neighboring anomalies and other effects, but the five poles considered best-determined are consistent with the overall distribution of poles. The distribution is not consistent with a model involving a hot spot origin or with geologic evidence suggesting origin during a brief time within the Cretaceous normal interval. Statistically, the poles are in much better agreement with the hypothesis that the seamounts are the same age as the sea floor underlying them.
In vivo adenosine receptor preconditioning reduces myocardial infarct size via subcellular ERK signaling.

The protective effects of adenosine receptor acute preconditioning (PC) are well known; however, the signaling mechanism mediating this effect has not been determined in in vivo models. The purpose...
On-line monitoring of boring tools for control of boring operations

In order to carry out precision and quality control of boring operations, on-line monitoring of boring tools is essential. Fourteen features were extracted by processing cutting force signals using virtual instrumentation. A Sequential Forward Search (SFS) algorithm was employed to select the best combination of features. Backpropagation neural networks (BPNs) and adaptive neuro-fuzzy inference systems (ANFIS) were used for on-line classification and measurement of tool wear. The input vectors consist of selected features. For the on-line classification, the outputs are boring tool conditions, which are either usable or worn out. For the on-line measurement, the outputs are estimated value of the tool wear. Using BPN, five features were needed for the on-line classification of boring tools. They are the average longitudinal force, average value of the ratio between the tangential and radial forces, skewness of the longitudinal force, skewness of the tangential force, and kurtosis of the longitudinal force. Three features, the average longitudinal force, average of the ratio between the tangential and radial forces, and kurtosis of the longitudinal force, were needed for on-line measurement of tool wear. Using ANFIS, three features were needed for the on-line classification of boring tools. They are the average longitudinal force, average of the ratio between the tangential and radial forces, and kurtosis of the longitudinal force. Only one feature, kurtosis of the longitudinal force, was needed for the on-line measurement of tool wear using ANFIS. Both 5x20x1BPN and 3x5 ANFIS can achieve a 100% success rate for the on-line classification of boring tool conditions. Using a 3x20x1BPN for neural computing, the minimum flank wear estimation error is 0.29% while the minimum flank wear estimation error is 2.04% using a 1x5 ANFIS.
The diagnosis of complete extrahepatic obstruction by Rose Bengal I131

Complete extrahepatic obstruction can be diagnosed by the Rose Bengal I 131 excretion test. In 8 patients with extrahepatic atresia, fecal isotope excretion was 6.5 per cent or less. Six infants with intrinsic liver disease simulating obstructive jaundice excreted more than 10 per cent. The advantages of this procedure as well as the technical errors most likely to lead to inaccurate results are discussed. After studying 39 patients, we fell that this test accurately predicts which infants need immediate surgical intervention.
Testing a single dominant gene theory without an accepted criterion variable.

Summary In testing a single dominant gene hypothesis we often are not able directly to measure the inherited trait. A typical situation is one where we only have one or more fallible indicators of the trait under study. The statistica1 method proposed requires that we have measurements on several such indicators for each of the parents of probands known to possess the trait.
Cosmic-ray positrons from annihilation of weakly interacting massive particles in the galaxy.

The production of cosmic-ray positrons from the annihilation of weakly interacting massive particles (WIMP's) is considered. Conventional supersymmetric-neutralino annihilation generally yields an unobservably small {ital e}{sup +} flux. However, a massive WIMP ({approx gt}20 GeV) with a large annihilation cross section into a single {ital e}{sup +}e{sup {minus}} pair produces a distinctive and observable shelf in the cosmic-ray {ital e}{sup +} spectrum. Only Dirac neutrinos obviously generate such a feature, but it may also appear in more elaborate neutralino models. Such models are constrained by upper limits on the low-energy antiproton flux.