cssi/SciSciGPT-SciSciNet huggingface dataset:
Two Roles for the Leucine-Responsive Regulatory Protein in Expression of the Alanine Catabolic Operon (dadAB) in Klebsiella aerogenes

The lrp gene, which codes for the leucine-responsive regulatory protein (Lrp), was cloned from Klebsiella aerogenes W70. The DNA sequence was determined, and the clone was used to create a disruption of the lrp gene. The lack of functional Lrp led to an increased expression of the alanine catabolic operon (dad) in the absence of the inducer l-alanine but also to a decreased expression of the operon in the presence of l-alanine. Thus, Lrp is both a repressor and activator of dad expression. Lrp is also necessary for glutamate synthase formation but not for the formation of two other enzymes controlled by the nitrogen regulatory (Ntr) system, glutamate dehydrogenase and histidase.
Simplified Scatchard-Plot Assay for Estrogen Receptor in Human Breast Tumor

In this two-point Scatchard-plot assay, with which a test of competitive inhibition is combined, the sample is mechanically homogenized in a buffer containing dithiothreitol, ultracentrifuged to obtain a fat-free cytosol, the protein content of which is then adjusted, and free and bound labeled estradiol are separated with dextran-coated charcoal after overnight incubation. We tested the method for precision and reliability by assaying such cytosols from pregnant rabbit uteri before and after dilution with kidney cytosol, and by assaying several other target and nontarget animal and human tissues. The Scatchard plot data were more reliable than tests for percent inhibition of binding by a competitor (diethylstilbestrol). For a tumor tissue to be judged positive it must bind at least 8 fmol of estradiol per milligram of protein and have a Kd of 0.1 to 5 X 10(-10) mol/liter. Some non-target tissues showed less than 70% inhibition by 10(4)-fold concentrations (over labeled estradiol) of inhibitor. Of 19 breast-tumor specimens, seven were found to be positive.
Isolation and Characterization of a Gene Encoding a Carboxypeptidase Y-Like Protein from Arabidopsis thaliana.

Serine carboxypeptidases are proteolytic enzymes that play an important role in the intracellular turnover of proteins and in protein maturation (3, 6). In yeast and mammals, carboxypeptidase proteins have been identified that can alter another protein's activity and/or stability by removal of amino acid residues from C termini (6, 7). In plants, protein degradation is particularly important during germination, when seed storage proteins are being broken down and utilized for rapid growth. Carboxypeptidases are usually glycoproteins that are sequestered to vacuoles in plants and fungi (3, 9) and are localized to lysosomes in animals (3). Human, rat, yeast, and wheat carboxypeptidase-like genes have been isolated and their DNA sequences determined (1, 6, 7, 9). In this report, the isolation and DNA sequence determination of a carboxypeptidase Y-like gene from Arabidopsis thaliana are described. A genomic clone was isolated from a X library using a wheat cDNA clone as a hybridization probe (1). The deduced DNA sequence and carboxypeptidase Y-like protein sequence are described in Table I and Figure 1. The results of Southern blot hybridization experiments suggest that there is only one carboxypeptidase Y-like gene in the genome of Arabidopsis. All of the conserved DNA sequence features that are required for gene expression and RNA processing can be found within the DNA sequence (Table I). S 1 nuclease protection experiments were done to map the 5' end of the mRNA (Fig. 1) and to demonstrate that the cloned gene is functional. The carboxypeptidase Ylike gene consists of nine exons and eight introns. Interestingly, the deduced exon-intron boundaries are exactly conserved between the wheat and Arabidopsis genes, and five of the eight splice junctions occur between amino acid codons, whereas three junctions divide codons. Three amino acid domains have been implicated in the formation of the catalytic site of serine carboxypeptidases (24), and all three of these domains are found in the deduced Arabidopsis protein (Fig. 1, amino acids in brackets). All of the serine carboxypeptidases proteins that have been identified to date have these three amino acid domains.
Phase Coherence in Multiple Pulse Optical Spectroscopy

In this paper we describe a new technique for the generation of multiple pulse phase coherent sequences in optical spectroscopy. The technique is an extension of the acousto-optic modulation and fluorescence detection methods developed for optical transitions by Zewail and Orlowski (Zewail et al., Chem. Phys. Lett. 48, 256 (1977); Orlowski et al., Chem. Phys. Lett. 54, 197 (1978)). Application of these multiple pulse trains (of different phases) to optical transitions of two-level and multilevel systems is demonstrated experimentally. It is shown that they can be used to (i) suppress spontaneous emission background, (ii) enhance coherent transients such as photon echoes, (iii) measure additional relaxation parameters in systems with complex rotational-vibrational levels, and (iv) enhance the effective laser bandwidths through composite pulse trains, as demonstrated on I2 gas. Finally, the potential of this development is extended to the possibility of observing selective multiquantum excitation in molecules.
Reversal of Multidrug-Resistance Phenotype by Surfactants: Relationship to Membrane Lipid Fluidity

Abstract Previous studies have suggested that multidrug resistance (MDR) reversal by polyoxyethylene surfactants involves alterations in plasma membrane lipid physical state of resistant cells as one of the possible mechanism(s). To date, however, a detailed and critical examination of the relationship between membrane lipid fluidity and MDR reversal by these surfactants has not been performed. In the present studies, therefore, a series of experiments were conducted to critically examine the role of membrane lipid physical state in MDR reversal by employing a unique class of clinically important nontoxic lipophilic surfactants and the KB-8-5-11 drug-resistant cell line. MDR reversal was assessed by rhodamine-123 uptake. The effect of surfactants on plasma membrane lipid fluidity of these cells was assessed utilizing a fluorescence polarization technique with fluorophores DPH, TMA, DPH, 2-AS, and 12-AS. Our studies demonstrated that: (i) in vitro addition of active MDR-reversing surfactants (Solutol HS-15, Tween 40, and Cremophor EL, 10 μg/ml each) decreased lipid fluidity of isolated crude plasma membranes of resistant cells; (ii) the inactive surfactants (octylglucoside, hecameg) failed to influence membrane lipid fluidity; (iii) cells grown in the presence of active surfactants also exhibited a decreased plasma membrane lipid fluidity as measured with intact cells utilizing the probe TMA.DPH; and (iv) active surfactants did not influence lifetimes of the excited state of the fluorophores, These findings demonstrate that decrease of the plasma membrane lipid fluidity of KB 8-5-11 resistant cells may be one of the important mechanism(s) of MDR reversal by polyoxyethylene surfactants.
Optical implementation of entangled multi-spin states in a CdTe quantum well

Ultrafast optical pulses and coherent techniques are used to create spin entangled states of non-interacting electrons bound to donors in a CdTe quantum well. Our method, relying on the exchange interaction between optically excited holes and the impurities, can in principle, be applied to entangle a large number of spins. Results are presented for resonant excitation of localized excitons below the gap, and above the gap where the signatures of entanglement are significantly enhanced.
Electromyographic analysis of the functional components of the lateral pterygoid muscle in the rhesus monkey (Macaca mulatta)

Electromyographic recordings (EMG) obtained from intramuscular electrodes inserted in the lateral pterygoid muscle (lat. pt.) of 29 juvenile and adolescent monkeys were assessed in relation to the recorded activity of three jaw elevating muscles, temporalis, masseter and medial pterygoid, and a jaw muscle depressor, the geniohyoid. The lat. pt. was recruited in one of three patterns: (1) only during mandibular depression, (2) during both depression and elevation, or (3) only during elevation of the jaw. The discharge of fibres in the lat. pt. during closing movements occurred bilaterally in 9 of 21 recordings. Simultaneous recordings from the anterior temporalis, medial pterygoid and the ipsilateral lat. pt. indicated completely different discharge patterns of the three muscles. In 9 recording sessions, two pairs of electrodes were placed in the same lat. pt. The discharge patterns from the two pairs were different in 5 of the recordings. In one region, the fibres were active only during depression, whereas in the other region fibres discharged only during elevation of the mandible. The data support the concept of two groups of fibres with separate functions within the lat. pt. and suggest that adaptation to oral respiration utilizes the two groups in distinctive patterns.
John Scottus Eriugena on the Composition of Material Bodies

This paper examines John Scottus Eriugena's account of material bodies. Some scholars have argued that Eriugena's account prefigures Berkeleyan idealism. The interpretation offered in the paper rejects the Berkeleyan interpretation on the grounds that Eriugena, unlike Berkeley, did not propose a thoroughly immaterialist view of reality.
Variation of deoxyribonucleic acid polymerase activities during avian erythropoiesis

Abstract Amounts of DNA polymerase α and β were determined in extracts of chicken erythroid cells at various stages of development. Concentrations of both polymerase activities are high in erythroblasts which are still dividing, decline after the cells cease dividing and begin maturation, and become almost undetectable in the fully mature erythrocytes. While DNA polymerase α activity declines gradually, firmly bound DNA polymerase β activity in the nuclei drops abruptly after the cells finish DNA synthesis and dividing. The amount of a low molecular weight DNA polymerase extractable with the cytoplasmic fraction, possibly DNA polymerase β, is low in erythroblasts, increases in the more mature erythroid population and then declines to an undectable level in the fully mature erythrocytes.
Thermorespiratory responses of shorn and unshorn sheep to mild heat stress.

Abstract Three 3-year-old ewes with surgically exterized carotid loops were twice exposed to ambient temperatures (Ta) of 25, 30, 35 and 40 C (at constant 40% relative humidity) tor 120 min in the presence (6.6 cm) and absence (less than 0.3 cm) of fleece Thermoregulatory responses were evaluated during the last 30 min of each exposure by measurements of rectal (Tre), 6 skin surface temperatures (Ts), respiratory frequency (f), oxygen consumption ( o 2 and respiratory evaporative heat (E r ): arterial blood samples were analyzed for pH, P co 2 and HCO 3 concentration. Both shorn and unshorn sheep exhibited a progressive increase in f, E r and Ts as Ta was elevated, with the unshorn group show ing a higher E r than the shorn sheep at each Ta without a significant change in heat production. E r was found to be the principal avenue of heat loss. accounting for as much as 59% the total in the shorn sheep compared to 65% for the unshorn sheep. Increases in E r were accompanied by a decline in the arterial P co 2 which was linearly related to the Ta in both shorn and unshorn sheep. These data suggest that in defending against hyperthermia, sheep appear unable to increase E r without a concurrent elevation in V a at nearly all stages of acute heat stress.
Biophysical characterization of α-synuclein and its controversial structure.

α-synuclein, a presynaptic protein of poorly defined function, constitutes the main component of Parkinson disease-associated Lewy bodies. Extensive biophysical investigations have provided evidence that isolated α-synuclein is an intrinsically disordered protein (IDP) in vitro. Subsequently serving as a model IDP in numerous studies, α-synuclein has aided in the development of many technologies used to characterize IDPs and arguably represents the most thoroughly analyzed IDP to date. Recent reports, however, have challenged the disordered nature of α-synuclein inside cells and have instead proposed a physiologically relevant helical tetramer. Despite α-synuclein’s rich biophysical history, a single coherent picture has not yet emerged concerning its in vivo structure, dynamics, and physiological role(s). We present herein a review of the biophysical discoveries, developments, and models pertinent to the characterization of α-synuclein’s structure and analysis of the native tetramer controversy.
On “The congressional fellowship as an ethnographic extravaganza”

Josh Trapani's emerging experience as an AGU Congressional Fellow (Eos, 87(7), 76, 2006) is educational. Spectacular developments in the physical sciences tempt us to believe that finer and finer dissection of matter and sophisticated manipulation of molecules will soon enable us to control nature at will. Increasing knowledge, though, about the Earth and its interconnected biological systems makes us skeptical about the enthusiastic vision of physical sciences. Living things, unlike the nonliving things that are the concern of physical sciences, possess the attribute of ‘behavior,’ associated with ‘mind’ and ‘instinct.’ Trapani's ethnographic extravaganza is merely a subset of behavior, which lies beyond the scope of relativity, quantum mechanics, or thermodynamics.
Contour cut: Identifying salient contours in images by solving a Hermitian eigenvalue problem

The problem of finding one-dimensional structures in images and videos can be formulated as a problem of searching for cycles in graphs. In [11], an untangling-cycle cost function was proposed for identifying persistent cycles in a weighted graph, corresponding to salient contours in an image. We have analyzed their method and give two significant improvements. First, we generalize their cost function to a contour cut criterion and give a computational solution by solving a family of Hermitian eigenvalue problems. Second, we use the idea of a graph circulation, which ensures that each node has a balanced in- and out-flow and permits a natural random-walk interpretation of our cost function. We show that our method finds far more accurate contours in images than [11]. Furthermore, we show that our method is robust to graph compression which allows us to accelerate the computation without loss of accuracy.
Sagittal diameter in comparison with single slice CT as a predictor of total visceral adipose tissue volume

BACKGROUND: Abdominal obesity has an important biological and epidemiological relationship to disease. The gold standard for measurement of visceral adipose tissue (VAT) is assessment by computerized tomography (CT) or magnetic resonance imaging (MRI), but because of simplicity and ease in collection, anthropometric variables are a desirable alternative to estimate VAT. OBJECTIVE: To compare the abilities of a single slice CT scan through the L4-L5 interspace (L4-L5 VAT), sagittal diameter, and body mass index (BMI) to estimate total volume VAT. Total volume VAT (the gold standard) was measured by total abdominal CT scanning, with a mean of 42 CT slices per patient. Estimation of VAT in subjects of similar body size was emphasized. DESIGN: Retrospective study of subjects undergoing complete abdominal and pelvic CT scanning for clinical reasons. SUBJECTS: 40 subjects (20 men and 20 women) mean age 56.5 y, with a balanced selection for BMI 27. RESULTS: In univariate regression models, L4-L5 VAT explained the largest proportion of the variance in total VAT (R 2 a 0.87 (P< 0.001)), though age (R 2 a 0.11 (Pa 0.04)), BMI (R 2 a 0.37 (P< 0.001)), and sagittal diameter (R 2 a 0.50 (P< 0.001)) were also statistically significantly related to total VAT. When limited to individuals with a BMI 27 however, L4-L5 VAT explained a large proportion of the variance in total VAT (R 2 a 0.87 (P< 0.001)) whereas sagittal diameter was only of borderline significance (R 2 a 0.20 (Pa 0.06)), and BMI was not associated with total VAT (R 2 a 0.04 (Pa NS)). In multiple regression analyses, L4-L5 VAT area explained a large proportion of the variance (0.84‐ 0.90), and once in the model, BMI, sagittal diameter, and age did not additionally contribute significantly to the explained variance in total VAT. CONCLUSIONS: Abdominal sagittal diameter is poorly correlated to total VAT for men and women with a BMI 27. Within a 2 cm range of sagittal diameter, there is nearly a three-fold variability in total VAT.
Heterograft biocompatibility without proteolytic digestion.

Bovine and sheep carotid heterografts (BED and S-ED) were modified by sequential treatment with 95% ethanol and 1.3% dialdehyde starch and stored in 70% ethanol. Compared with ficin digested, dialdehyde tanned bovine carotid artery (B-FD), chemical treatment produced heterografts with greater in vitro anastomotic tensile strength and significantly reduced surface clotting time. Seven of 20 canine inferior caval implants of B-ED heterografts remained patent for periods up to 4 weeks while 4 of 5 B-FD interpositions thrombosed within 2 hr. A patency rate of over 90% was obtained in canine abdominal and thoracic aorta B-ED and S-ED interpositions during a follow up period of 3 to 6 months. As arteriovenous fistulas B-ED heterografts maintained excellent patency, tolerated repetitive percutaneous puncture and exhibited self sealing capability. Microscopic examination of longterm B-ED implants showed smooth intimal surfaces with no fibrin deposition or morphologic evidence of rejection. In contrast to the ficin digested heterograft, ethanol-dialdehyde processing suppresses antigenic potential but preserves structural integrity. The end product retains components of the heterograft wall and results in a nonviable, biocompatible conduit with improved thromboresistance and greater strength.
Risk factors for squamous cell carcinoma of the oesophagus

Cancer of the oesophagus has great diversity in geographical distribution and incidence. The rate of oesophageal cancer has been increasing in some areas and the reasons for this are not clear. This review outlines fascinating epidemiological aspects and the risk factor for squamous cell carcinoma of the oesophagus. While in the Western world the effects of alcohol and tobacco are substantial preconditions, worldwide other factors, such as diet, nutritional deficiencies, environmental exposure and infectious agents (especially papillomavirus and fungi), play a significant role. Chronic irritation of the oesophagus appears to participate in the process of carcinogenesis, particularly in patients with thermal and/or mechanical injury, achalasia, oesophageal diverticulum, chronic lye stricture, radiation therapy, injection sclerotherapy and gastric resection before the appearance of oesophageal tumour. The association of Plummer-Vinson syndrome, coeliac disease, tylosis and scleroderma with oesophageal cancer has also been reviewed.
Transformations of sugars in alkaline solutions

Abstract A comparative study has been made of the rates of enolization of sugars in alkaline, tritiated water by measurement of their rates of tritium uptake; the rates for two inososes were found to be more than 1000 times the rate for D -glucose. The low rates of reaction of the sugars in comparison with those for the inososes suggest that one of the factors controlling the rate of enolization is the concentration of an intermediate carbonyl form of the sugar. To account for differences in the behavior of epimeric sugars in alkaline solution and the well-known differences between the rates of mutarotation and of exchange of 18 O of an aldose- 1 - 18 O with 16 O of water, it is suggested that the mutarotation reaction proceeds through pseudo-acyclic intermediates that possess some characteristics of the respective ring-forms. This new concept, applied to the interpretation of enolization reactions, leads to the possibility of formation of cis - and trans -enediols, the proportions of which may differ from sugar to sugar. Enolization experiments were conducted for a variety of sugars in a 0.5 M solution of sodium carbonate in water- t at 25°. The rates of tritium uptake, based on the rate for D -glucose as unity, range from 0.5 to 4.8 for aldohexoses, 0.5 to 10.7 for aldoheptoses, 4.1 to 28 for aldopentoses, 2.6 to 25 for various ketoses, 0.3 to 0.8 for some 6-deoxy sugars, and 90 to 155 for some 2-deoxy sugars. The comparative rates found for the disaccharides studied range from 2.0 to 240; of these, turanose was the most reactive sugar.
Progress and Challenges Using 40Ar/39Ar Geochronology in Costa Rica and Nicaragua

To better estimate the extrusive flux of the Central American Arc, from 2002-2008, we obtained sixty one high precision 40Ar/39Ar ages on geographically well-situated lavas and tephra from Costa Rica and Nicaragua. Here, we describe a number of observations encountered during this study using four examples that well document the preci- sion, accuracy and general reliability of the 40Ar/39Ar ages. First, low K2O values, particularly in samples from Nicara- gua, is a major limitation in or attempts to obtain reliable dates on samples under 1 My. Second, extensive weathering of samples due to the tropical climate of Central America has resulted in various levels of argon loss even when the hand sample appeared unaltered. Third, our field and geochronological data lead us to conclude that eruptive rates have not been constant over the past 15 to 20 My, but rather appears punctuated by gaps of up to several million years. We attempted to address the temporal gaps in several ways. First, geochemical analyses were used to identify samples that may have erupted during time periods without known volcanism. For example, U/Th values in the active Central American arc are significantly higher than those obtained from the Miocene Coyol Group except for four samples with intermediate values that were dated to determine if their ages were intermediate as well. However, all of these samples were found to be from a period with known volcanism. Second, we sought to locate the oldest sections of the active arc and the youngest sections of the Coyol Group in order to better constrain the timing and duration of the apparent gap in volcanic productivity. This approach also failed to locate samples from periods without known volcanism. When these methods proved largely unsuccessful, our focus shifted to dating regions of minor volcanism between the active and Coyol volcanic fronts as well as between Cosiguina and San Cristobal, the longest stretch of the Central American Volcanic Front without active volcanism. This effort yielded ages on samples ranging from 1.1 to 3.6 Ma and, thus, substantially reduced the apparent volcanic gap in Nicaragua.
The Myth of Lesbian Impunity Capital Laws from 1270 to 1791

The standard history of antihomosexual legislation states that lesbian acts were not punished by medieval or later laws. This essay challenges this view by documenting capital laws since 1270 in Europe and America. A major influence was Paul's condemnation in Romans I, 26. By 1400, the lex foedissimam, and edict of the Emperors Diocletian and Maximianus, issued in 287, was interpreted to justify the death penalty. Execution took place in Germany, France, Italy, Switzerland, and Spain. A brief survey of presently known male deaths in Europe and the Americas, which number about 400, also is included. This study draws on canon law and the commentaries of such jurists as Cino da Pistoia, Saliceto, Lopez, Gomez, Farinacio, Cotton, Carpzow, Sinistrari, de Vouglans, and Jousse. It also discusses the records of a German trail of 1721, published elsewhere in this issue that also led to the execution of women. Dr. Crompton is in the Department of English, University of Nebraska, and Lincoln, Nebraska 68588. He wish...
The effects of Cl2 on the oxidation of single crystal silicon carbide

Corrosion studies of single crystal SiC in modified oxidizing ambients with additions of chlorine gas (1–5% Cl2/O2) at elevated temperatures (1100–1350°C) demonstrated that chlorine greatly enhances the oxidation rate of SiC. The parabolic rate constants for the oxidation of SiC in an 5% Cl2/O2 ambient are more than 10 times those in pure oxygen. Bubbles formed during the SiC oxidation in the presence of chlorine, and caused oxide surface roughening. The observed bubbling on the (0001) carbon face of SiC crystal is more severe than that on the (0001) silicon face of SiC crystal. The compositions of the oxide films were characterized using SIMS. The chlorine incorporated into the oxide grown in Cl2/O2 could be easily removed upon further short oxidation in a pure oxygen environment. The chlorine concentration dependence of the oxidation rate indicates that it is the dissolved Cl, not Cl2, which is responsible for the acceleration of the oxidation of SiC in Cl2/O2 environments. The results observed for the corrosion of SiC were compared with those for the corrosion of Si reported in the literature.
Cation Interdiffusion in Polycrystalline Calcium and Strontium Titanate

This paper discusses a method that has been developed to study bulk lattice interdiffusion between calcium and strontium titanate by fabrication of a diffusion couple using cosintering. The measured interdiffusion coefficients, D(C), indicate that strontium impurity diffusion in calcium titanate occurs at a faster rate than calcium impurity diffusion in strontium titanate. These interdiffusion coefficients are composition independent when the concentration of the calcium cation exceeds that of the strontium cation; otherwise D(C) is strongly composition dependent. Investigations into the effect of cation nonstoichiometry give results that are consistent with a defect incorporation reaction in which excess TiO{sub 2}, within the solid solubility limit, produces A-site cation vacancies as compensating defects. The interdiffusion coefficients increase with increasing concentrations of TiO{sub 2}, so it is concluded that interdiffusion of these alkaline-earth cations in their titanates occurs via a vacancy mechanism.
Propranolol-verapamil versus propranolol-nifedipine in severe angina pectoris of effort: A randomized, double-blind, crossover study

Abstract To compare a propranolol-verapamil with a propranolol-nifedipine combination in patients with severe angina of effort, 16 patients (11 men and 5 women, aged 56 ± 8 years [mean ± standard deviation]) with more than 5 episodes/week of angina and a positive exercise tolerance test despite propranolol (229 ± 44 mg/day [range 180 to 360]) were maintained on this dose of propranolol and, in addition, received verapamil (360 mg/day) and nifedipine (60 mg/day) for 3 weeks each in a double-blind, randomized fashion. In comparison with propranolol alone, anginal frequency and nitroglycerin usage were reduced by propranolol-verapamil but not by propranolol-nifedipine. Exercise time (standard Bruce protocol) was similar for the 2 combinations (6.4 ± 2.0 minutes with propranol-olverapamil, 6.6 ± 2.1 minutes with propranolol-nifedipine, difference not significant), but the magnitude of ST-segment depression at peak exercise was less (p
The Rhetoric of Antiblack Racism: Lewis R. Gordon's Radical Phenomenology of Embodiment

Lewis R. Gordon is a well-known philosopher and social critic who has written extensively on a wide range of issues in race theory, Africana philosophy, film and literature, postcolonial phenomenology, and the philosophy of the human sciences. His work deals with issues that have an impact on the field of communication, yet his research has not been studied widely across the discipline. The purpose of this article is to outline a rhetoric of antiblack racism employing Gordon's work and apply it to an analysis of “postracial rhetoric.”
Slip MHD viscous flow over a stretching sheet - An exact solution

Abstract In this paper, the magnetohydrodynamic (MHD) flow under slip condition over a permeable stretching surface is solved analytically. The solution is given in a closed form equation and is an exact solution of the full governing Navier–Stokes equations. The effects of the slip, the magnetic, and the mass transfer parameters are discussed. Results show that there is only one physical solution for any combination of the slip, the magnetic, and the mass transfer parameters. The velocity and shear stress profiles are greatly influenced by these parameters.
Regular polygons and their application to digital curves

In this note, we discuss various kinds of 2D unit cells, or surface-unit cells, made by regular polygons (simplexes) in the plane R X R. Mathematically, the plane can be divided by simplexes or regular polygons (decomposition). If we only allow one kind of surface-unit in the plane, there are only three possible choices: regular triangle (3-regular- polygon), square (4-regular-polygon), or 6-regular-polygon. Using Euler's formula for planar graphs, we give a type of topological proofs to that a closed digital curve has at least 6 points in a 3-regular-polygon decomposition plane, has at least 8 points in a 4-regular-polygon decomposition plane, and has at least 12 points in a 6-regular-polygon decomposition plane, respectively. On the other hand, a plane can also be divided by combinations of two kinds of regular polygons. We have obtained two types of {3,6}-regular-polygon combinations, two types of {4,8}-regular-polygon combinations, and one type of {3,12}-regular-polygon combination. We also discuss the application of polygons or closed paths to digital surfaces in 3D digital spaces.
Bees and pollination in our changing environment

Les recherches anterieures ont montre que, avant le developpement de l'agriculture intensive, des monocultures et l'utilisation des pesticides, la pollinisation des fleurs par les populations d'abeilles indigenes (Apoides) etait satisfaisante. Quand ces populations d'abeilles ont decline, des abeilles moins efficaces (principalement l'abeille domestique Apis mellifera) ont ete utilisees pour la pollinisation parce qu'elles etaient deja utilisees pour la production de miel et de cire. Il y a des dizaines d'annees des chercheurs ont identifie les insectes pollinisateurs les mieux adaptes et decrit leurs habitats et leurs modes d'elevage. La prise de conscience actuelle de la destruction de leurs habitats, le besoin de biodiversite parmi les pollinisateurs, une plus grande connaissance de la specificite insecte-plante, la valeur economique des pollinisateurs choisis, et les menaces pesant actuellement sur les populations d'abeilles domestiques ont fait de la pollinisation par les apoides en general un sujet d'actualite. Cette publication presente une revue des references les plus interessantes en incluant les recherches anterieures qui sont rarement citees mais cependant encore tres actuelles. Elle decrit egalement les conditions historiques qui ont favorise l'utilisation de l'abeille domestique, les implications economiques de la pollinisation, les changements dans l'environnement et dans les populations d'apoides, l'impact des abeilles domestiques etrangeres et l'importance qu'il y a a comprendre le comportement des insectes pollinisateurs sur les fleurs.
Image qualification of high-speed film for crash tests

The Department of Transportation, National Highway Traffic Safety Administration (NHTSA) desires to develop qualifications for the film received from independent organizations that perform automobile collision performance tests. All crash tests are recorded on high-speed film. Running 18 cameras at frame rates up to 1000 frames per second is not uncommon. Some of the films acquired during the 150 to 200 ms time-frame of the actual crash are used for computation of both human and vehicle kinematics. Detailed recommendations for performing the tests are outlined by NHTSA in SAE documents. However, no specifications for film quality are defined. Problems arise when unclear and/or incorrectly exposed films result in images unsuitable for analysis. Aspects of the optical data channel that are evaluated in this paper include lighting, lenses, cameras, film, film processing, and timing. Recommendations for reliable data acquisition as well as a set of criteria are also developed.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Descriptive epidemiology of selected neurologic and myopathic disorders with particular reference to a survey in Rochester, Minnesota.

Abstract The results of the analysis of data for selected neurologic diseases from surveys and from several sources of mortality data were reviewed. The results of a survey in the population of Rochester, Minnesota, were presented in some detail, and the data from this source and others which are available were used in many instances to obtain estimates of incidence and prevalence for the population of the United States. The uses of such estimates for base-line comparative studies and for matters pertaining to medical care and research resources were considered. The interrelationship of genetics and epidemiology was discussed and examples of the combined effect of exogenous and hereditary factors in the causation of disease have been presented. The concept of a continuum of hereditary diseases of the nervous system was reiterated, and the need for elucidation of the biochemical nature of the genetic lesions was illustrated.
Multiscale periodic assembly of striped nanocrystal superlattice films on a liquid surface

Self-assembly of nanocrystals (NCs) into periodically ordered structures on multiple length scales and over large areas is crucial to the manufacture of NC-based devices. Here, we report an unusual yet universal approach to rapidly assembling hierarchically organized NC films that display highly periodic, tunable microscale stripe patterns over square centimeter areas while preserving the local superlattice structure. Our approach is based on a drying-driven dynamic assembly process occurring on a liquid surface with the stripe pattern formed by a new type of contact-line instability. Periodic ordering of NCs is realized on microscopic and nanoscopic scales simultaneously without the need of any specialized equipment or the application of external fields. The striped NC superlattice films obtained can be readily transferred to arbitrary substrates for device fabrication. The periodic structure imparts interesting modulation and anisotropy to the properties of such striped NC assemblies. This assembly approach is applicable to NCs with a variety of compositions, sizes, and shapes, offering a robust, inexpensive route for large-scale periodic patterning of NCs.
Approximation to Feynman amplitudes valid for small masses

A simple procedure is given for exploiting the smallness of the electron mass in approximating Feynman amplitudes. Using helicity conservation, the Dirac matrices are factored out leaving amplitudes no more complicated than those for spinless particles. For the case of bremsstrahlung the helicity structure is exhibited and the validity of helicity conservation is studied. To exhibit the simplicity and power of the method an amplitude for trident production is written down by inspection. It is shown to agree with the value obtained by Bjorken and Chen using projection operators and traces. (AIP)
Goal Setting as a Strategy for Health Behavior Change

This article discusses the beneficial effects of setting goals in health behavior change and maintenance interventions. Goal setting theory predicts that, under certain conditions, setting specific difficult goals leads to higher performance when compared with no goals or vague, nonquantitative goals, such as "do your best." In contrast to the graduated, easy goals often set in health behavior change programs, goal setting theory asserts a positive linear relationship between degree of goal difficulty and level of performance. Research on goal setting has typically been conducted in organizational and laboratory settings. Although goal setting procedures are used in many health behavior change programs, they rarely have been the focus of systematic research. Therefore, many research questions still need to be answered regarding goal setting in the context of health behavior change. Finally, initial recommendations for the successful integration of goal setting theory in health behavior change programs are offered.
Continuous separation of non-magnetic particles through negative magnetophoresis inside ferrofluids

We present a simple, low-cost, effective, and label-free continuous flow non-magnetic microparticle separation scheme in a microfluidic device under static magnetic fields. The separation process is based on negative magnetophoresis and uses water-based ferrofluids. We exploit the difference in particle sizes to achieve continuous binary separation of fluorescent microparticles with high throughput and efficiency. We demonstrate size-based separation (2.1 μm and 9.9 μm; 2.1 μm and 4.8 μm) of microparticles with close to 100% separation efficiency and a minimum of 10 particles/hour throughput. This new approach opens the door for the development of label-free continuous cellular separation in microfluidic devices with high throughput, efficiency, and reliability.
A model of transverse fuel injection applied to the computation of supersonic combustor flow

A two-dimensional, nonreacting flow model of the aerodynamic interaction of a transverse hydrogen jet within a supersonic mainstream has been developed. The model assumes profile shapes of mass flux, pressure, flow angle, and hydrogen concentration and produces downstream profiles of the other flow parameters under the constraints of the integrated conservation equations. These profiles are used as starting conditions for an existing finite difference parabolic computer code for the turbulent supersonic combustion of hydrogen. Integrated mixing and flow profile results obtained from the computer code compare favorably with existing data for the supersonic combustion of hydrogen.
Progesterone at plasma levels lower than those of mid-pregnancy decreases sexual behavior in ovariectomized rats.

Abstract Progesterone was measured by radioimmunoassay in the plasma of Day 10 pregnant rats and in the plasma of ovariectomized rats injected with doses of progesterone that result in a decrease in sexual receptivity. Doses of progesterone (1–2.5 mg) that result in behavioral refractoriness to further progesterone treatment result in lower plasma levels of progesterone than those measured on the tenth day of pregnancy, a time of naturally-occurring behavioral inhibition. These data re-assert the possibility that endogenous progesterone produced during pregnancy in the rat is at least partially responsible for the decrease in female sexual behavior seen during pregnancy in this species.
THE ANTERIOR HUMAN NASAL PASSAGE AS A FIBROUS FILTER FOR PARTICLES

The anterior adult human nasal passage contains hairs which act as a fibrous filter for inhaled particles. Particles which are collected by these hairs are likely removed by physical means and are unable to produce toxic effects in the respiratory tract. Measurements have been made of the anterior nasal passage and nasal hair of an adult Caucasian subject, and calculations have been carried out using fibrous filter theory to determine the deposition efficiency for unit density spherical particles of diameter ranging from 1 nm-40 μm at three steady inspiratory flow rates For particles > 5 μm, inertial and interception deposition on the nasal hairs was predicted to account for a measurable fraction of the experimentally measured nasal deposition, becoming significant for particles > 20 μm. Diffusion of ultrafine particles to the nasal hair was predicted to be appreciable for particles <5nm. These results have important implications for nasal dose and transport of certain size inhaled particles.
IS CHAOS GENERIC IN ECONOMIC DATA

This paper examines recent developments in nonlinear science in economics. Several claims of findings of chaos in economic data are reviewed. We discuss how each claim has been revised in light of further analysis, and point out several traps for empirical researchers in economic data. These traps suggest certain methodological refinements useful for researchers analyzing very small data sets, including diagnostic tests to detect ill conditioned data, filtering data to exclude nonchaotic alternatives, and nonparametric procedures to check the precision of parameter estimates. Most specialists in the field would say there is no conclusive evidence of chaos in economic or financial data.
Pyroelectric and sensor properties of ferroelectric thin films for energy conversion

Abstract High pyroelectric coefficients and improved conversion effects were successfully demonstrated in highly (111)-oriented ferroelectric PZT 90/10 films on Pt/Si substrates. The strong preferred orientation exhibited by these films was obtained through controlled heat-treatment using a specially developed MOD process on Pt/Ti/SiO 2 /Si substrates. Within the FE LT –FE HT phase transition range of 80∼100°C, the films exhibited significant changes in spontaneous polarization, by roughly a factor of 2 (∼ 7 μC cm −2 ). A pyroelectric current, correlated to a pyroelectric coefficient of 30±10 nC cm 2 K, was obtained around room temperature without poling treatment. A prototype pyroelectric transformer based on these films gave a voltage output of 0·8 volt from a 1 mm 2 area on a 1·0 μm thick film. Compared to bulk ceramics and thick films, these thin films also exhibited at least one order of magnitude higher working frequency.
Microcavities in photonic crystal waveguides for biosensor applications

In this study, resonant microcavities in photonic crystal (PhC) waveguides are investigated for biosensing applications. The device architecture consists of a PhC waveguide with a defect line for guiding the transmission of light. Resonant microcavities created by changing the radius of a hole adjacent to the defect line are coupled to the PhC waveguide. Detection is based on shifts in the resonance wavelength observed in the transmission spectra. The PhC waveguide device is fabricated on silicon-on-insulator (SOI) wafers using electron beam lithography and reactive-ion etching (RIE). Receptor molecules are attached to the defects in the device by standard amino-silane and glutaraldehyde crosslinking chemistry. Preliminary results demonstrate successful detection of human IgG molecules as the target at large concentration levels of 500 μg/ml. Such PhC waveguide devices are advantageous for medical diagnostics and biosecurity applications as they allow rapid, label-free, and sensitive detection of multiple analytes in a single platform.
“The Streets”: An Alternative Black Male Socialization Institution

The primary purpose of this article is to describe the social significance of “the streets” as an alternative to the family, church, and other communitybased institutions that facilitate Black male socialization. A major assumption of this discussion is that for many marginal Black males, “the streets” is a socialization institution that has a major influence on their psychosocial development and life-course trajectories and transitions. In addition, the article addresses some of the problematic consequences associated with the pursuit of manhood and social recognition in “the streets.”
Effects of Continental Slope on the Mean Shelf Circulation

Abstract Csanady's (1978) theory on the mean shelf circulation in a homogeneous ocean was re-examined by including effects of a continental slope. The results suggested that the mean southwestward flow on the Mid-Atlantic Blight is driven by an inflow from the Georges Bank.
Geoengineering the climate : History and prospect

▪ Abstract Geoengineering is the intentional large-scale manipulation of the environment, particularly manipulation that is intended to reduce undesired anthropogenic climate change. The post-war rise of climate and weather modification and the history of U.S. assessments of the CO2-climate problem is reviewed. Proposals to engineer the climate are shown to be an integral element of this history. Climate engineering is reviewed with an emphasis on recent developments, including low-mass space-based scattering systems for altering the planetary albedo, simulation of the climate's response to albedo modification, and new findings on iron fertilization in oceanic ecosystems. There is a continuum of human responses to the climate problem that vary in resemblance to hard geoengineering schemes such as space-based mirrors. The distinction between geoengineering and mitigation is therefore fuzzy. A definition is advanced that clarifies the distinction between geoengineering and industrial carbon management. Asse...
Simultaneous Detection of Catecholamine Exocytosis and Ca2+ Release from Single Bovine Chromaffin Cells Using a Dual Microsensor

A dual microsensor with a 5 μm radius was fabricated to detect simultaneously Ca2+ and catecholamines following their secretion from individual biological cells. Detection of Ca2+ was based on changes in fluorescence as a result of its binding with a surface-attached dye, and catecholamines were detected by amperometry. The fluorescent dye employed, calcium green-1 dextran, is a selective chelator for Ca2+. It was attached to the tip of a carbon fiber electrode by cross-linking with 5% glutaraldehyde. The dual microsensor has a subsecond response time for both Ca2+ and catecholamine concentration changes. Ca2+ concentrations of 100 nM can be detected, while the detection limit for catecholamine is in the micromolar range. The utility of the dual microsensor was evaluated at the surface of bovine adrenal medullary cells. Release of catecholamines by exocytosis was evoked by transient application of histamine. This was detected by amperometry, and it was found to be accompanied by Ca2+ release, as measured ...
A method for coupling the hepatitis B surface antigen to aldehyde-fixed erythrocytes for use in passive hemagglutination

Abstract A method for coupling the hepatitis B surface antigen (HBsAg) to aldehyde-fixed erythrocytes for use in passive hemagglutination assays for anti-HBs is described. This provides a stable and inexpensive reagent having a sensitivity for anti-HBs detection which is only slightly less than solid phase radioimmunoassay.
Towards accurate and robust cross-ratio based gaze trackers through learning from simulation

Cross-ratio (CR) based methods offer many attractive properties for remote gaze estimation using a single camera in an uncalibrated setup by exploiting invariance of a plane projectivity. Unfortunately, due to several simplification assumptions, the performance of CR-based eye gaze trackers decays significantly as the subject moves away from the calibration position. In this paper, we introduce an adaptive homography mapping for achieving gaze prediction with higher accuracy at the calibration position and more robustness under head movements. This is achieved with a learning-based method for compensating both spatially-varying gaze errors and head pose dependent errors simultaneously in a unified framework. The model of adaptive homography is trained offline using simulated data, saving a tremendous amount of time in data collection. We validate the effectiveness of the proposed approach using both simulated and real data from a physical setup. We show that our method compares favorably against other state-of-the-art CR based methods.