cssi/SciSciGPT-SciSciNet huggingface dataset:
A first-principle calculation of the binary diffusion coefficients pertinent to kinetic modeling of hydrogen/oxygen/helium flames

First-principle calculations were carrid out to determine the binary diffusion coefficients of H−He, H−Ar, H−H2, and He−H2. Potential energy functions of pair interactions were critically reviewed for H−He and H−Ar and verified against molecular beam scatering and low-temperature diffusion cross-section data. Complementary quantum chemistry calculations were carried out for the interactions of H−He and H−Ar and CCSD(T)/AUG-cc-PV*Z level of theory. The calculation of the H−He and H−Ar diffusion coefficients was performed by direct integration using literature potential functions. For H−H2 and He−H2, the diffusion cross-sections were determined using the close-coupling method, again using ab initio potential energy functions in recent literature. The computed diffusion coefficients of all pairs were compared with experimental data at room temperature, which showed very good agreement for all pairs. With the exception of H−Ar, the diffusion coefficients of the current study of all other pairs differ notably from those predicted by the Sandia TRANFIT and DRFM compilations. The implication of the current result in kinetic modeling of hydrogen-oxygen-helium flames is discussed.
Impact of the C1' configuration of abasic sites on DNA duplex structure.

Naturally occurring abasic sites in DNA exist as an equilibrium mixture of the aldehyde, the hydrated aldehyde, and the hemiacetal forms (dominant). The influence of the configuration of the C1‘ hydroxyl group of the hemiacetal form on duplex structure and abasic site repair has been examined using novel carbocyclic analogues. Both the α- and β-forms of this novel abasic site were introduced into oligomeric DNA using the standard DMT-phosphoramidite approach in an automated solid-phase synthesizer. Solution structures of the d(CGTACXCATGC)·d(GCATGAGTACG) duplex (where X is the α- or β-anomer of the carbocyclic abasic site analogue) were determined by NMR spectroscopy and restrained molecular dynamics simulations. The structures were only minimally perturbed by the presence of either anomer of the abasic site. All residues adopted an anti conformation, and Watson−Crick alignments were observed on all base pairs of the duplexes. At the lesion site, the abasic residues and their partner adenines showed incre...
MODELING STRUCTURES FOR CONTROL DESIGN

Abstract A simply supported beam is used as an example to illustrate the need for more theoretical research on the unification of the modeling and control problems of flexible structures. This paper shows that finite element methods that focus on the convergence of modal data may not be the best approach to modeling structures for control design. This is due primarily to the fact that (1) the importance of a mode in the control problem is measured by its modal costs, and modal cost errors may exceed (by large margins) the errors in modal frequency; (2) the modal costs are not ordered by frequency; and (3) convergence of the modal costs is not monotonic with the number of uniform finite elements. Hence, non-uniform finite element grids may be more efficient. Theorems for convergence of the modal costs are also presented.
Integrated structural electromagnetic shape control of large space anatenna reflectors

The requirements for extremely precise and powerful large space antenna reflectors have motivated the development of a procedure for static shape control of the reflector surface. A mathematical optimization procedure has been developed that improves antenna performance while minimizing necessary shape-correction effort. The control procedure is based on regulating electromagnetic (EM) performance in contrast to previous work, which is based on controlling the rms distortion error of the surface, thereby indirectly improving antenna performance. The application of the control procedure to a radiometer design with a tetrahedral truss backup structure demonstrates the potential for significant improvement. The results indicate the benefit of including EM performance calculations in procedures for shape control of large space antenna reflectors.
Effect of Insulin Sensitizer Therapy on Amino Acids and Their Metabolites

Abstract Aims Prior studies have reported that elevated concentrations of several plasma amino acids (AA), particularly branched chain (BCAA) and aromatic AA predict the onset of type 2 diabetes. We sought to test the hypothesis that circulating BCAA, aromatic AA and related AA metabolites decline in response to the use of insulin sensitizing agents in overweight/obese adults with impaired fasting glucose or untreated diabetes. Methods We performed a secondary analysis of a randomized, double-blind, placebo, controlled study conducted in twenty five overweight/obese (BMI ~ 30 kg/m2) adults with impaired fasting glucose or untreated diabetes. Participants were randomized to three months of pioglitazone (45 mg per day) plus metformin (1000 mg twice per day, N = 12 participants) or placebo (N = 13). We measured insulin sensitivity by the euglycemic-hyperinsulinemic clamp and fasting concentrations of AA and AA metabolites using ultra-pressure liquid chromatography tandem mass spectrometry before and after the three-month intervention. Results Insulin sensitizer therapy that significantly enhanced insulin sensitivity reduced 9 out of 33 AA and AA metabolites measured compared to placebo treatment. Moreover, insulin sensitizer therapy significantly reduced three functionally clustered AA and metabolite pairs: i) phenylalanine/tyrosine, ii) citrulline/arginine, and iii) lysine/α-aminoadipic acid. Conclusions Reductions in plasma concentrations of several AA and AA metabolites in response to three months of insulin sensitizer therapy support the concept that reduced insulin sensitivity alters AA and AA metabolites.
How Do You Say “God” in Dakota?

This essay explores some of the interpretive problems posed by the missionary work of the American Board of Commissioners for Foreign Missions among Minnesota's Dakota Indians in the mid-nineteenth century. Since “success” in conversion has often been defined largely in terms of Native American assimilation to white American societal norms, I argue that the Dakotas' acceptance of a Christianity that was preached to them in their own language poses a problem for understanding what “conversion” meant in this case. The difficulty of knowing what Christianity meant to the Dakotas, a difficulty I see as rooted in the problems attendant upon translation, can be illustrated by showing how distorted some of the missionaries' translations of Dakota religious ideas into English were. Their translation errors took two forms: the postulation of a similarity in reference between Dakota and English terms where it did not exist (as with the English words “god” and “spirit” and what the missionaries identified as their Dakota counterparts), or, conversely, the heightening of differences between Dakota and Protestant Christian religiosity (an effect achieved by associating Dakota terms with English pejoratives). I argue that what unites these two differing types of distortive translations is the missionaries' failure to understand the conceptual universe, or “deep structure”, underlying the Dakota language. And since they failed to perceive the holistic character of this conceptual system, the missionaries may have concluded that they had effected conversions among the Dakotas when they had only scratched the surface of Dakota religiosity.
The entropy theorem via coding bounds

The entropy theorem (also known as the Shannon-McMillan-Breiman theory or the asymptotic equipartition theorem) asserts that, for a stationary ergodic finite alphabet process, the sequence-(1/n)log p(x/sub 1//sup n/) converges almost surely to the entropy-rate H of the process. The entropy theorem has been used to establish asymptotic bounds on the performance of noiseless codes. Here, the coding theorems are established without using the entropy theorem, and the coding theorems are then used to prove the entropy theorem. The principle feature is the direct use of coding ideas to obtain the entropy theorem. >
Mouse behavioral tasks relevant to autism: Phenotypes of 10 inbred strains

Three defining clinical symptoms of autism are aberrant reciprocal social interactions, deficits in social communication, and repetitive behaviors, including motor stereotypies and insistence on sameness. We developed a set of behavioral tasks designed to model components of these core symptoms in mice. Male mice from 10 inbred strains were characterized in assays for sociability, preference for social novelty, and reversal of the spatial location of the reinforcer in T-maze and Morris water maze tasks. Six strains, C57BL/6J, C57L/J, DBA/2J, FVB/NJ, C3H/HeJ, and AKR/J, showed significant levels of sociability, while A/J, BALB/cByJ, BTBR T(+)tf/J, and 129S1/SvImJ mice did not. C57BL/6J, C57L/J, DBA/2J, FVB/NJ, BALB/cByJ, and BTBR T(+)tf/J showed significant preference for social novelty, while C3H/HeJ, AKR/J, A/J, and 129S1/SvImJ did not. Normal scores on relevant control measures confirmed general health and physical abilities in all strains, ruling out artifactual explanations for social deficits. Elevated plus maze scores confirmed high anxiety-like behaviors in A/J, BALB/cByJ, and 129S1/SvImJ, which could underlie components of their low social approach. Strains that showed high levels of performance on acquisition of a T-maze task were also able to reach criterion for reversal learning. On the Morris water maze task, DBA/2J, AKR/J, BTBR T(+)tf/J, and 129S1/SvImJ failed to show significant quadrant preference during the reversal probe trial. These results highlight a dissociation between social task performance and reversal learning. BTBR T(+)tf/J is a particularly interesting strain, displaying both low social approach and resistance to change in routine on the water maze, consistent with an autism-like phenotype. Our multitask strategy for modeling symptoms of autism will be useful for investigating targeted and random gene mutations, QTLs, and microarray analyses.
New techniques for geodetic measurements at sea

Many studies conducted by various government agencies and private organizations on the technology of precise measurement and positioning at sea have established that (1) the need for improved accuracy is great and rapidly increasing, and (2) the state of the art has been advanced to a point where a coordinated, well-planned program aimed at meeting requirements would provide valuable, practical, and economic results. Now is the time to carefully assess the over-all situation, both the identified needs and the estimated potentials, and to decide what the next steps should be for using available knowledge. An efficient program should be designed and initiated to meet at least present critical needs and to build a firm foundation for meeting future needs. This paper is concerned with assessment of only the four systems that Battelle has examined in some detail, namely, Airborne LORAC, Doppler Satellite, C-Band Radar, and Very-Long-Baseline Interferometry (VLBI), and the acoustic system that is required with all presently available systems. Also, the paper is concerned primarily with the geometric aspects of geodesy rather than, for example, with its physical aspects or with such special areas as satellite altimetry.
Solving symmetric indefinite systems in an interior-point method for linear programming

We describe an implementation of a primal--dual path following method for linear programming that solves symmetric indefinite "augmented" systems directly by Bunch--Parlett factorization, rather than reducing these systems to the positive definite "normal equations" that are solved by Cholesky factorization in many existing implementations. The augmented system approach is seen to avoid difficulties of numerical instability and inefficiency associated with free variables and with dense columns in the normal equations approach. Solving the indefinite systems does incur an extra overhead, whose median is about 40% in our tests; but the augmented system approach proves to be faster for a minority of cases in which the normal equations have relatively dense Cholesky factors. A detailed analysis shows that the augmented system factorization is reliable over a fairly large range of the parameter settings that control the tradeoff between sparsity and numerical stability.
Use Of III-V Compounds For Integrated Optical Circuits

Recent progress in the development of integrated optical circuits using the III-V compound semiconductors is reviewed. The application of double heterostructure configurations is emphasized, not only for optical sources, but also for detectors, with reference to both the A.GaAs/GaAs system and the InGaAsP quaternary. Devices utilizing periodic corrugations are described briefly, whereas alternate attempts to fabricate optical circuits by etching or sputtering techniques are discussed in more detail. Recent advances in processing techniques suitable for optical integration, such as reactive-ion etching, and the use of lasers or electron beams for device processing, are described.
Depletion of pituitary follicle-stimulating hormone by beef and pig hypothalamic extracts.

A single intracarotid injection of extracts of beef and pig stalk-median eminence (SME) caused a significant reduction of folliclestimulating hox-mone (FSH) in the anterior pituitary gland of ovariectomized, estrogen- and progesterone-treated rats. Lysine vasopressin and beef cerebral cortex extract were inactive in depleting pituitary FSH. Beef SME extract also provoked a significant depletion of pituitary FSH in the ovariectomized rats not treated with steroids. Study of time pattern of the changes in pituitary FSH after a single intracarotid injection of pig SME extract showed that pituitary FSH started falling immediately, reaching 55% of the initial level 20–30 min later and returning to near-initial levels 60 min after injection. Serum FSH levels rose correspondingly. (Endocrinology 78: 1105, 1966)
Detailed comparison of the pnicogen bond with chalcogen, halogen, and hydrogen bonds

The characteristics of the pnicogen bond are explored using a variety of quantum chemical techniques. In particular, this interaction is compared with its halogen and chalcogen bond cousins, as well as with the more common H-bond. In general, these bonds are all of comparable strength. More specifically, they are strengthened by the presence of an electronegative substituent on the electron-acceptor atom, and each gains strength as one moves down the appropriate column of the periodic table, for example, from N to P to As. These noncovalent bonds owe their stability to a mixture in nearly equal parts of electrostatic attraction and charge transfer, along with a smaller dispersion component. The charge transfer arises from the overlap between the lone pair of the electron donor and a σ* antibond of the acceptor. The angular characteristics of the equilibrium geometry result primarily from a compromise between electrostatic and induction forces. Angular distortions of the H-bond are typically less energetically demanding than comparable bends of the other noncovalent bonds. © 2012 Wiley Periodicals, Inc.
Arthroscopic Thermal Capsulorrhaphy as Treatment for the Unstable Paralytic Shoulder

Patients who present with global capsular laxity and glenohumeral instability frequently can be treated successfully with shoulder girdle musculature strengthening exercises and activity modification. When such injury is caused by a paralytic shoulder, a rehabilitation program may not be a viable treatment option. Presented in this article are 3 patients with global capsular laxity and glenohumeral instability as a result of shoulder paralysis. We also describe an arthroscopic technique of thermal capsulorrhaphy. In our experience, arthroscopic thermal capsulorrhaphy used to treat global capsular laxity and glenohumeral instability resulting from a paralytic shoulder has decreased symptoms of shoulder instability and has significantly reduced shoulder pain.
Enzyme immobilization by adsorption on hydrophobic derivatives of cellulose and other hydrophilic materials.

Abstract Cellulose esters of both alkyl and aryl carboxylic acids have been prepared and tested as noncovalent adsorbents for enzymes. Phenoxyacetyl cellulose strongly bound all 10 of the enzymes tested. The bound enzymes, which were not desorbed by 1 m (NH4)2SO4 or moderate (25–50%) concentrations of nonaqueous solvents but which were at least partially desorbed by solutions containing nonionic detergents, usually exhibited nearly complete retention of catalytic activity. Other materials, paper, string, cotton, and glass beads, have been analogously derivatized with similar results. This simple and effective technique warrants consideration for applications in enzyme immobilization.
Breadth-biased versus focused cognitive control in media multitasking behaviors

Ophir, Nass, and Wagner report in this issue of PNAS (1) that heavy media multitaskers (HMMs) performed worse on task switching than light media multitaskers (LMMs), likely because of HMMs' reduced ability to filter out interference from irrelevant stimuli and representations in memory. Their findings are surprising in that, intuitively, HMMs should be better at task switching (i.e., multitasking) because they frequently switch between tasks, a habit or expertise (if so) that should have helped them to be better multitaskers (task switchers). However, the findings are also not surprising in that, as pointed out by Ophir, Nass, and Wagner, HMMs tend to be breadth-biased in their behaviors and are inclined to pay attention to a larger scope of information instead of focusing on a particular piece of information. Such a behavior or habit has conditioned them to be less selective when it comes to filtering information and tasks in front of them. In other words, HMMs may have developed a habit of treating all of the information in front of them with equal (or almost equal) amounts of attention instead of focusing their attention steadily on a particular task. As a result, they performed worse than LMMs did when they were asked to focus attention on selective pieces.
Ultrasound-guided fine-needle aspiration (FNA) of nonpalpable breast lesions: A review of 1885 FNA cases using the National Cancer Institute- supported recommendations on the uniform approach to breast FNA

BACKGROUND A probabilistic approach to the classification of fine-needle aspirates (FNAs) of the breast recently was recommended and received endorsement from the National Cancer Institute (NCI). In this system, FNAs are classified as benign, indeterminate/atypical, suspicious/probably malignant, and malignant, but to the authors' knowledge the use of these diagnostic categories has not been evaluated on a large scale. Furthermore, this classification scheme has not been applied to FNAs of nonpalpable lesions of the breast obtained under imaging guidance. Thus, the current study focused on whether the diagnostic categories could be applied usefully to ultrasound-guided FNAs (US-FNAs) of nonpalpable breast lesions. METHODS Between 1988-1996, 1885 US-FNAs were performed on 1639 patients. The original FNA diagnoses were reclassified into the NCI-supported recommendations for diagnostic categories of breast FNAs. The cytologic findings were correlated with the tissue specimens, which were available in 851 cases, or with clinical follow-up of a minimum of 2 years in 127 of the 274 patients with benign solid lesions. RESULTS The 1885 cases were categorized as follows: 1057 (56.1%) as benign, 86 (4.6%) as atypical, 79 (4.2%) as probably malignant, 502 (26.6%) as malignant, and 161 (8.5%) as unsatisfactory (defined as < 6 epithelial cell groups on all slides). The benign US-FNAs included 480 (45.4%) cysts and 577 (54.6%) solid lesions. Combined clinical and surgical follow-up showed that the frequency of malignancy was 3.7% in US-FNAs classified as benign, 52.9% in those designated as atypical, 75.8% in those designated as suspicious, and 98.9% in those classified as malignant. Based on combined histologic and clinical follow-up, a sensitivity of 97.1% and specificity of 99.1% were found for US-FNAs when definitive benign and malignant diagnoses were considered. A false-negative rate of 3.7% was attributed to sampling error. A false-positive rate of 0.68% was secondary to interpretative error of proliferative lesions. CONCLUSIONS Application of the NCI-supported diagnostic categories to US-FNA of nonpalpable breast lesions is useful in stratifying aspirates based on the likelihood of underlying malignancy. The subcategories of US-FNAs diagnosed as atypical have similar probabilities of malignancy; this justifies their being grouped as a single category wherein tissue biopsy would be required to exclude carcinoma. Benign and inadequate FNA diagnoses must be correlated with the clinical and imaging findings and in noncorrelative cases the patient should undergo biopsy. US-FNA is a sensitive and specific means with which to diagnose nonpalpable breast lesions. [See editorial on pages 1–4, this issue.] Cancer (Cancer Cytopathol) 1999;87:19–24. © 1999 American Cancer Society.
N-acetyl-L-aspartic acid content of human neural tumours and bovine peripheral nervous tissues.

— Abstract-Tumors of the human nervous system were utilized to investigate the cellular distribution of N-acetyl-L-aspartic acid (NAA). Astroglial tumours contained about 0.144 μmol/g. Oligodendrogliomas and medulloblastomas contained somewhat larger amounts. However, the level of NAA in all gliomas studied was less than that of normal human white matter. NAA was undetectable in meningiomas and acoustic neurinomas. If these results may be taken as representative of normal tissue, they imply a predominantly neuronal localization for NAA. Substantial amounts of NAA were found in peripheral nervous tissues and retina. Neurons seem to vary widely in NAA content.
Adolescent female with withdrawal psychosis following abrupt termination of ziprasidone

It is widely known that discontinuation reactions can occur after neuroleptics are stopped resulting in dyskinesia through its effect on the nigrostriatal pathway. Less discussed is the concept of “supersensitivity psychosis” which has been described as a rapid onset of psychosis after a neuroleptic medication has been withdrawn. Although the concept of supersensitivity psychosis has been described with the discontinuation of some neuroleptics, it has not been described with ziprasidone. Furthermore, the following case report is the first time that this phenomenon has been described in an adolescent patient who has discontinued ziprasidone. Reasons for supersensitivity psychosis are explored in addition to suggestions about precautions about prescribing neuroleptics in young people.
The effect of bovine serum albumin on partial reactions of palmitoyl-CoA chain elongation by rat liver microsomes.

Abstract In the absence of albumin, v s curves for both condensation and overall chain elongation demonstrated that the specific activity for overall chain elongation was 3.7 times that of condensation. When the molar ratio of palmitoyl-CoA to albumin was greater than 2 : 1, the specific activity of chain elongation exceeded that of condensation. At these low albumin concentrations, in the absence of NADPH, the β-ketostearoyl-CoA was converted back to palmitate. This cleavage reaction is inhibited by albumin in a concentrationdependent manner. When the palmitoyl-CoA to albumin molar ratio was less than 2 : 1, the specific activity for condensation exceeded that for overall chain elongation and some β-ketostearate was shown to accumulate under chain elongation conditions. The specific activity for dehydration of β-hydroxystearoyl-CoA was maximal when the acyl-CoA to albumin molar ratio was between 10 : 1 and 4 : 1 but the rate of this reaction was not markedly influenced by variations in albumin concentration. The specific activity for the NADPH-dependent reduction of 2-trans-octadecenoyl-CoA was 18 nmol · min−1 · mg−1 in the absence of albumin and increased to a maximum of 112 when the substrate to albumin molar ratio was 2 : 1. At higher albumin concentrations the reductase reaction was inhibited. Conversely, the specific activity for the reverse dehydrase was maximal at low albumin concentrations and the rate of this reaction declined as the albumin concentration increased. Our results demonstrate that albumin not only alleviates a substrate induced inhibition but also regulates the metabolic fate of 2-trans-octadecenoyl-CoA and in this regard may possibly substitute for acyl-CoA binding proteins.
Blended Learning as a Theoretical Framework for the Application of Podcasting

The use of podcasting has attracted the attention of teachers because it is content-rich and is of wide general interest. Users can listen to podcasts via the Internet or download them on to a portable music player. Some also offer video or animation to make the contents more interesting and easier to understand. Accordingly, podcasts that tend to focus on the use of vocabulary can be very effective in language learning. They help learners hear how to pronounce their words clearly and use them appropriately. In addition to the benefit of its multimodal facilities, the main advantage of podcasting lies in the variety and the control it provides. Many podcasts provide an authentic context including those which are vocationally orientated. In other words, learners can access podcasts linked to their field of study or interest. Therefore, this research project explores how podcasts in an ESL (English for specific purposes) environment can be used with foreign language learners. It then discusses learners’ perspectives of podcasts related to certain subjects. Finally, it proposes a number of suggestions for practical strategies and techniques for teaching English through podcasting.
State-spaces and meaning relations among predicates

It has often been suggested that the meaning of terms is theory dependent. Bas van Fraassen has proposed a particular way of inferring which sentences are true in virtue of meaning, given a theory in so-called “state-space format”. I examine his claims by means of simple examples.
Interaction of alpha-thalassemia genes with each other and with HbC in an American black family.

The relative rates of in vitro synthesis of hemoglobin chains have been studied in an American black family in which the mother is doubly heterozygous for α-thalassemia and HbC and the father is heterozygous for α-thalassemia. The α/non-α synthetic ratio was equally unbalanced in both the bone marrow and the peripheral blood of the mother. Although HbC comprised 35% of her hemoglobin (compared to 42.2±2.2 in individuals with HbC trait and balanced globin synthesis), synthetic data showed that the newly synthesized β C chain was 44% of the total newly synthesized β chains. Isolated membranes contained more newly synthesized β C than β A chains. Three of the offspring were within the normal range, and the remaining three had α-thalassemia. There were two spontaneous abortions during the second trimester of pregnancy. Hydrops fetalis did not occur, and none of the children had HbH disease or HbC trait.
Confirmation of linkage of hereditary partial lipodystrophy to chromosome 1q21-22.

Familial lipodystrophy is a genetically heterogeneous set of disorders characterized by a total or partial absence of subcutaneous fat, diabetes mellitus or impaired glucose tolerance, hyperlipidemia, and hypermetabolism [Senior and Gellis, 1964]. One subtype, familial partial lipodystrophy Dunnigan (FPLD), is a rare autosomal dominant trait that results in an gradual loss of subcutaneous fat in the lower trunk and limbs, Type V hyperlipoproteinemia, hypertriglyceridemia, and insulin-resistant diabetes. Previous reports of this condition have been limited to case reports or very small families. Recently, Peters et al. reported on linkage of five families of Western European descent to a 5.3 cM region on chromosome 1q21-22 between the flanking markers D1S305 and D1S1600 [Peters et al., 1998: Nat Genet 18:292–295]. We performed linkage and haplotype analysis using highly polymorphic, microsatellite markers on a large, multigeneration Caucasian kindred of German ancestry. The maximum two-point lod score achieved was 4.96 at θmax = 0 for marker D1S2721. Multipoint analysis gave an overall maximum lod score of 6.27 near marker D1S2721. The results of the haplotype analysis support the minimal candidate region as reported by Peters et al. Am. J. Med. Genet. 82:161–165, 1999. © 1999 Wiley-Liss, Inc.
THE RADIOTRACER TESTING METHOD IN METAL CLEANING STUDIES

Abstract A pre-requisite for obtaining reproducible results from friction, wear and resistance studies of rubbing surfaces is reproducible cleanliness of the metallic samples. This paper describes radiotracer studies for testing the effectiveness of several cleaning techniques. The contamination of metallic surfaces with sulfates, chromates and fatty acids was investigated. The detection sensitivities for S 35 O 4 =, Cr 51 , palmitic and stearic-C 14 acids were respectively 3 × 10 −8 g, 1·5 × 10 −7 g, 3·2 × 10 −9 g and 6·2 × 10 −10 g. Results show that electropolished copper surfaces retained less than 3 × 10 −8 g SO 4 = and less than 1·5 × 10 −7 g of Cr. Toluene and chromic acid were found to be excellent cleaning agents for fatty acids. The quantity of fatty acid remaining on copper substrates after three successive immersions in toluene averaged 0·01 to 1 monolayer depending on the amount of the contaminant originally present. Less than 3 × 10 −9 g of palmitic acid, i.e. 1·6 × 10 −2 monolayer, or 6 × 10 −10 g of stearic acid, i.e. 3 × 10 −3 monolayer, remained on gold and copper surfaces after anodic polishing in chromic acid at 120°C for 2 min.
Steerable reflect-array antenna formed by loaded electric dipoles

A reflect-array antenna with simple design, low cost, and electronically controlled directivity pattern for centimeter wavelength range is proposed. The antenna is based on a mirror formed by loaded electric dipoles.
Voices from the Field: Veteran Advisors.

Recently veteran academic advisors were asked to share their experiences. The respondents to an E-mailed survey self-identified as advisors or administrators and represented six American regions an...
Time-dependent spectrum of resonance fluorescence

Attention is focused on the dynamic evolution of the emission spectrum following abrupt excitation of a near-resonant two-level absorber by a strong laser field. The multiphoton character of the absorption-emission process is evident in the AC Stark splitting of the spectrum, which begins approximately half an atomic lifetime after excitation, if the laser field is strong enough. Analytic expressions for the spectra are given of arbitrary laser field strength, atomic lifetime, laser-atom detuning, and the bandwidth of the spectrometer used to analyse the spectrum. Selected graphs are included to illustrate various time-dependent features of the spectrum. The influence on the transient spectrum of three different states of atomic excitation prior to laser irradiation and the effect on the spectrum of irradiation by a phase-noisy laser are also considered. Comparison of the transient spectra from atoms initially prepared in ' pi /2' and '3 pi /2' states show clearly that phase relationships between the irradiating field and the emitting dipole are important even in fluorescence.
Dopamine β-hydroxylation in diabetes and diabetic autonomic neuropathy

Abstract Dopamine β-hydroxylase (DBH) has been studied in healthy subjects and diabetic patients, some of whom had autonomic neuropathy. DBH was assayed by a recently described in vivo tritium release method (10,11). Dopamine specifically labeled in the β position, [β-3H]DA, was given intravenously, and the time course of tritiated water (THO) release into the total body water was measure as an index of DBH activity in sympathetic neurons. We simultaneously assayed [3H]norepinephrine metabolite excretion. The DBH activity of patients with autonomic neuropathy as a group did not differ significantly from that of diabetics without neuropathy or healthy controls. Our data do not support the suggestion (7) that a deficit in DBH activity is responsible for sympathetic neuronal dysfunction in diabetic autonomic neuropathy. This syndrome thus differs from idiopathic orthostatic hypotension in which condition there is an impairment in the ability of sympathetic neurons to hydroxylate dopamine (9).
Effect of a moving wall on a fully developed, equilibrium turbulent boundary layer

Experiments were conducted in a wind tunnel to assess the effect of a moving wall on a fully developed, equilibrium turbulent boundary layer. Pitot-static and total head probes were used in conjunction with both single- and two-component hot-wire anemometer probes to quantify the effect of wall motion on the boundary layer velocity statistics. A variable speed, seamless belt formed the wind tunnel test section wall. When stationary, the belt was found to possess a fully developed, equilibrium turbulent boundary layer in excellent agreement with archival data. With the tunnel wall moving at the free-stream speed, and at a sufficient distance above the wall, the velocity statistics in the moving-wall boundary layer were found to collapse well when scaled as a self-preserving turbulent wake. The near-wall mean velocity profile of the moving wall was found to exhibit an extended region of linearity compared to canonical turbulent boundary layer and internal flows. This can be attributed to the reduced shear resulting from wall motion and the subsequent reduction in Reynolds stress.
A Quasi-one-Dimensional Cumulus Cloud Model and Parameterization of Cumulus Heating and Mixing Effects

Abstract The characteristic properties of cumulus convection are investigated using a semi-one-dimensional, axisymmetric, quasi-Lagrangian steady-state model which takes into consideration the influence of the pressure perturbation, density stratification and nearby moist downdraft under two different environmental situations: 1) a potentially more unstable tropical environment and 2) a less unstable middle-latitude environment with prominent stable layers in the middle troposphere. It is found that the compressional heating of the dry environment makes the cloud air warmer and reduces the updraft velocity slightly, and moist downdraft cools the cloud air and reduces both the updraft and the cloud depth, while the influence of pressure perturbation also reduces the updraft but it is effective only for clouds of radii >1000 m. The influence of density stratification is to reduce wc, slightly at low levels and augment wc, at high levels and to slightly increase the cloud depth. The calculated precipitation ...
Classic Maya Political History: Hieroglyphic and Archaeological Evidence

Classic Maya Political History: Hieroglyphic and Archaeological Evidence. T. Patrick Culbert (editor). Cambridge: Cambridge University Press, 1991. xviii + 396 pp. $59.95 (cloth). ISBN 0–521–39210–1.
Molecular mechanisms of canalization: Hsp90 and beyond

The Hsp90 chaperone machine facilitates the maturation of a diverse set of ‘client’ proteins. Many of these Hsp90 clients are essential nodes in signal transduction pathways and regulatory circuits, accounting for the important role Hsp90 plays in organismal development and responses to the environment. Recent findings suggest a broader impact of the chaperone on phenotype: fully functional Hsp90 canalizes wild-type phenotypes by suppressing underlying genetic and epigenetic variation. This variation can be expressed upon challenging the Hsp90 machinery by environmental stress, genetic or pharmaceutical targeting of Hsp90. The existence of Hsp90-buffered genetic and epigenetic variation together with plausible release mechanisms has wide-ranging implication for phenotype and possibly evolutionary processes. Here, we discuss the role of Hsp90 in canalization and organismal plasticity, and highlight important questions for future experimental inquiry.
How do you mend a broken heart? First you diagnose it!

Cardiovascular disease is not only the leading cause of morbidity and mortality in Western nations, it is the leading cause of health care expenditures. It is estimated that the cost of the diagnosis and treatment of cardiovascular disease and stroke will exceed $431 billion in 2007 (1). Cost related to cardiovascular disease is multifactorial with a large component related to the expense of diagnosis. Accurate, rapid diagnosis of cardiac disease is essential for the appropriate triaging and treatment of patients with coronary artery disease. Clearly, patients with acute coronary syndromes or active infarction require immediate medical support and revascularization. These patients typically do not present a diagnostic dilemma and have characteristic symptoms of chest pain or pressure radiating to the left arm or jaw, diaphoresis, nausea, dizziness and anxiety. ECG changes of ST-segment elevation and elevated serum troponin or creatine kinase muscle-brain type (CK-MB) are demonstrated in these patients. Patients presenting in this manner should be transported emergently to the angiography suite for prompt diagnosis and treatment of obstructive coronary disease. Patients with atypical presentations or low-intermediate suspicion for coronary disease pose more of a diagnostic dilemma. It is in this patient population that non-invasive cardiac imaging plays a key role in diagnosis and triage. Evaluation of these patients includes clinical history and physical examination, ECG findings, serial enzyme laboratory investigations and some form of non-invasive imaging (2). This may take the form of exercise stress test-
Pollination effectiveness and pollinator importance in a population of Heterotheca subaxillaris (Asteraceae)

Assessing the relative contributions to seed set for each of a plant species’ floral visitors provides an indication of the relative influence of these visitors on the plant’s reproductive success. This study examined pollinator activity and seed set in a population of Heterotheca subaxillaris, a species that exhibits a floret dimorphism (heads bearing disk and ray florets), and that is visited by both generalist foragers and specialist bees. Visits by nine bee genera and one genus of skipper were recorded in the study population. During the period of study, these insects varied in their relative abundance, in their foraging activity on a head, and in their pollination effectiveness. The pattern of pollination effectiveness shown by the different pollinators was similar for both floret types, although seed set was higher overall for ray florets. Pollinator importance, calculated as the product of pollination effectiveness and relative abundance, was dictated by a pollinator’s relative abundance. The single specialist bee species observed in the study population proved to have neither higher pollination effectiveness nor higher pollinator abundance than other pollinators. This would suggest that H. subaxillaris is not under strong selective pressure to co-specialize with its specialist visitor.
Effect of lifetime limits and differences between TANF leavers who had reached their lifetime limits and those who had exited voluntarily

This study explored different sociodemographic characteristics and differences of employment and income between TANF (Temporary Assistance for Needy Families Program) leavers who reached their lifetime limits and those who leave voluntarily. The study analyzed 656 TANF leavers from the 1999 and 2002 data of the National Survey of America's Family (NASF). Chi-square and t-test results indicated significant differences for age, health, EITC, childcare assistance, food stamp cut-off, employment, and income between the two groups. Multiple regression results showed that TANF leavers who reached their lifetime limits were less likely than voluntary leavers to be employed and to have high family income. Implications suggest the increase in adoption of exemption or extension policies for lifetime limits and providing follow-up services.
Rheology of Reactively Compatibilized Polymer Blends with Varying Extent of Interfacial Reaction

This paper presents the rheology and morphology of immiscible polymer blends compatibilized by a polymer reaction at the interface. Nylon-6 was melt blended in a twin screw extruder with several different grades of maleated polypropylene at 10 and 20 wt %. The extent of polymer reaction at the interface is varied by varying the extent of maleation of polypropylene and affects the phase morphology differently at different phase volume fractions. The rheology of the reactive blends is fit to the Palierne theory to infer values of the equilibrium interfacial tension. The equilibrium interfacial tension of the reactive blends is reduced in proportion to the extent of maleation of the polypropylene. In blends with more reaction product, another mechanical property of the interface is required to fit the low-frequency data well.
Stage-dependent effects of epidermal growth factor on Ca2+ efflux in mouse oocytes.

Epidermal growth factor (EGF) has received much attention recently for its positive effects on mammalian oocyte maturation and embryo development and its potential importance in cytoplasmic maturation of oocytes. Calcium (Ca2+) homeostasis in germinal vesicle stage oocytes has also been suggested to play a role in cytoplasmic maturation. This study examined the effects of EGF on Ca2+ mobilization as measured by its efflux from mouse oocytes at three time periods throughout maturation (0–4 hr, 4–8 hr, and 12 hr). Immature cumulus oocyte complexes (COCs) removed from the ovary for less than 4 hr exhibit oscillations in Ca2+ efflux that initiated 5–30 min following EGF stimulation. This response was not observed in COCs matured for 4–8 hr or 12 hr or in unstimulated 0–4 hr COCs. Denuded oocytes and cumulus cells did not show the same response to EGF (8.2 nM and 16.4 nM). Immunohistochemistry for detection of the EGF receptor along with EGF internalization studies showed that receptors are present both on cumulus cells and the oocyte but EGF appears to be internalized mainly by the cumulus cells. These data demonstrate that EGF induces oscillations in Ca2+ efflux in COCs 0–4 hr old and this response is mediated by the cumulus cells. Mol. Reprod. Dev. 53:244–253, 1999.
Internal target reflections and line-imaging velocimetry

Abstract A commonly observed intensity modulation or “beating” in laser velocimetry (VISAR) data is examined and explained. It is found that internal target reflections between two surfaces moving relative to one another produces this intensity modulation in the VISAR steak record. The two partially reflecting surfaces define a Fabry–Perot cavity that creates an intensity interference pattern that is superimposed upon VISAR measurements. Experiments are conducted that demonstrate this phenomenon. Previous VISAR experiments that observe this beating pattern are presented and explained.
Influence of environmental factors on daily flight activity of the filbertworm, Melissopus latiferreanus (Lepidoptera, Olethreutidae)

. 1 Flight of Melissopus latiferreanus (Walsinghzm), the filbertworm, was influenced by a number of environmental factors including temperature, wind, and rainfall. 2 Few M. latiferreanus moths were trapped in light or suction traps or found in sweep nets samples when air temperatures were above 31°C or below 15°C. Moth captures were optimum when prevailing temperature was between 21 and 26°C. 3 Typically moth flights began at about sunset and continued throughout the night with a peak at 22.00 hours, about an hour after sunset. 4 Very few moths were trapped under showery and gusty conditions when wind velocity was over 16km h−1. 5 More moths were captured in light traps during dark nights than on full moon nights. The pattern of captures indicated that females flew earlier than males.
Visual Acuity Impairment in Patients with Retinitis Pigmentosa

Purpose: The authors evaluated visual acuity impairment in 906 patients from 742 families with either isolated or various identifiable genetic subtypes of retinitis pigmentosa (RP) to determine the severity of their visual acuity impairment. Emphasis was placed on the prevalence of total blindness and visual acuity of 20/200 or worse in this group of patients. Methods: This cross-sectional retrospective study included all patients with RP who met certain entrance criteria and were examined by one of the authors (GAF). The authors analyzed the eye of each patient with the best-corrected visual acuity on their most recent visit. Results: Seventeen patients with a sector form of RP were excluded from the authors' primary analysis. In the remaining group of 889 patients, 710 (80%) had a visual acuity of better than 20/200, 648 (73%) showed a visual acuity of 20/70 or better, and 489 (55%) had a visual acuity of 20/40 or better in at least 1 eye. Seventy-five patients (8%) had visual acuity of count fingers or worse in their best eye. There was only one patient with no light perception in each eye. Patients with autosomal dominant RP, as a group, had the least severe and those with X-linked recessive RP had the most severe impairment in visual acuity. Those with autosomal recessive disease were intermediate in severity of visual impairment. Conclusions: Analysis of visual acuity in this large group of patients with RP, which genetically is representative of patients with RP seen in the United States by those who specialize in retinal disease, showed that it was rare for the patients to lose all visual acuity from the disease itself. Further, legal blindness from visual acuity loss, defined as best-corrected visual acuity that is no better than 20/200 in at least one eye, occurred in a relatively small percentage (20%) of our patient population, whereas approximately half of all patients and 42% of those older than 60 years had a visual acuity of 20/40 or better in at least one eye. The extent of impairment in visual acuity was associated with the genetic subtype of the disease.
Effects of an urban wetland on sediment and nutrient loads in runoff

An urban wetland in the Minneapolis-St. Paul Metropolitan Area was found to retain sediment and nutrient loads in runoff routed through the wetland. Sediment and nutrient loads in runoff were measured during 1982 at the inlet and outlet of the 6.4-bectare urban wetland. Comparison of annual loads entering and leaving the wetland showed that retention of incoming loads in the wetland was 97 percent of nonvolatile suspended solids, 76 percent of volatile suspended solids, 48 percent of total phosphorus, 4 percent of dissolved phosphorus, 3 percent of dissolved nitrite plus nitrate nitrogen, 1 percent of total ammonia nitrogen, and 47 percent of total organic nitrogen. Flow volume was increased on an annual average basis by 5 percent between the wetland inlet and oulet. Most retention of sediment and nutrient loads occurred between late April and mid-July. Retention of sediment and nutrient loads in the wetland was associated with sedimentation processes. Dissolved nutrients generally were not retained in the wetland because the residence time of water passing through was not long enough for removal by biological processes. Effectiveness of the wetland in retaining sediment and nutrient loads in runoff varies annually. Long-term and short-term impacts of the retention of sediment and nutrients in the wetland on wetland flora and fauna are unknown.
Rapid determination of activation energy from a single kinetic experiment with the aid of a small computer.

Abstract The method for the determination of activation energy from a single kinetic experiment has been automated with the aid of a small computer and simple analog interfaces. A program has been written that will collect temperature and absorbance measurements as a function of time and will calculate the energy of activation at the completion of a single reaction. The precision and accuracy of the measurement compare favorably with the more tedious manual methods.