cssi/SciSciGPT-SciSciNet huggingface dataset:
Electrocatalysis of hydrogen production by active site analogues of the iron hydrogenase enzyme: structure/function relationships

A series of binuclear FeIFeI complexes, (μ-SEt)2[Fe(CO)2L]2 (L = CO (1), PMe3 (1-P)), (μ-SRS)[Fe(CO)2L]2 (R = CH2CH2 (μ-edt): L = CO (2), PMe3 (2-P); R = CH2CH2CH2(μ-pdt): L = CO (3), PMe3 (3-P); and R = o-CH2C6H4CH2 (μ-o-xyldt): L = CO (4), PMe3 (4-P)), that serve as structural models for the active site of Fe-hydrogenase are shown to be electrocatalysts for H2 production in the presence of acetic acid in acetonitrile. The redox levels for H2 production were established by spectroelectrochemistry to be Fe0Fe0 for the all-CO complexes and FeIFe0 for the PMe3-substituted derivatives. As electrocatalysts, the PMe3 derivatives are more stable and more sensitive to acid concentration than the all-CO complexes. The electrocatalysis is initiated by electrochemical reduction of these diiron complexes, which subsequently, under weak acid conditions, undergo protonation of the reduced iron center to produce H2. An (η2-H2)FeII–Fe0/I intermediate is suggested and probable electrochemical mechanisms are discussed.
X‐Ray Powder Diffraction

X-ray powder diffraction is used to determine the atomic structure of crystalline materials without the need for large (∼100-μm) single crystals. “Powder” can be a misnomer; the technique is applicable to polycrystalline phases such as cast solids or films grown on a substrate. X-ray powder diffraction can be useful in a wide variety of situations. A number of questions that can be effectively addressed by this technique are listed. This is an attempt to illustrate the versatility of x-ray powder diffraction and not, by any means, a complete list. Six experiments are described as concrete examples and constitute an assortment of problems of varying difficulty. X-ray powder diffraction is an old technique, in use for most of this century. The capabilities of the technique have recently grown for two main reasons: (1) development of x-ray sources and optics (e.g., synchrotron radiation, Gobel mirrors) and (2) the increasing power of computers and software for analysis of powder data. This article discusses the fundamental principles of the technique, including the expression for the intensity of each diffraction peak, gives a brief overview of experimental techniques, describes several illustrative examples, gives a description of the procedures to interpret and analyze diffraction data, and discusses weaknesses and sources of possible errors. Keywords: x-ray powder diffraction; competitive techniques; related techniques; principles; practical aspects; data analysis; interpretation; crystal lattice; x-ray powder; bragg peaks; rietveld refinement; standard deviations; sample preperation; problems; examples; database comparisons; phase analysis; structure determination
Sympatric speciation based on allelic changes at three Loci: evidence from natural populations in two habitats.

Allelic changes at three loci largely explain Chrysopa downesi9s sympatric speciation from a Chrysopa carnea-like ancestor. Disruptive selection first produced a stable polymorphism based on a single pair of alleles that adapted individuals to two habitats, and second, it established seasonal asynchrony in reproduction through allelic substitutions at two loci.
Bubbles in Japan's stock market: A macroeconomic analysis

Since the 1950s, Japan's stock market has gone into bubbles every ten years or so (early 1950s, early 1960s, and early 1970s). Then the 1980s saw a strong bubble that continued for several years (late 1982 to the end of 1989). What caused this bubble to be so strong? Our analysis of the fundamental equation reveals that the key factor was the nominal interest rate which continued to decline until the late 1980s owing to the extremely relaxed monetary policy pursued by the Bank of Japan. The forecasts for stock prices made by investors added to the effect of the low interest rates. We will show that investors tend to forecast fluctuations on the real side two-to three-quarters ahead of time. The bubble crashed when the forecasts of the investors collapsed. Since then investors have remained bearish and the stock market has remained in the doldrums.
In support of the early presence of functional categories in second language acquisition

This commentary focuses on whether the full set of categories is available to beginning L2 learners. After critiquing Epstein et al.'s experimental evidence for the presence of functional categories, I outline the results of an experiment involving English speakers learning Japanese as a second language that does indeed point toward the early presence of fuuctional categories.
Further observations on a uterine response to SKF 525-A and tolbutamide

Abstract Short-term treatment with tolbutamide at 125 mg/kg increased the 4-hour uterine response to mestranol. Short-term treatment with tolbutamide at 250 mg/kg or SKF 525-A at 30 mg/kg increased both the uterine wet weight and the 4-hour response to mestranol. Long-term treatment with tolbutamide at 250 mg/kg increased uterine wet weight; similar treatment with SKF 525-A increased both wet and dry weight of the uterus. Neither tolbutamide nor SKF 525-A affected vaginal smears or resulted in the characteristic histological changes seen after estrogen stimulation.
Sweetpotato Weevil, Cylas formicarius elegantulus (Summers): Development, Fecundity, and Longevity

Temperature affected the development and longevity of the sweetpotato weevil, Cylas formicarius elegantulus (Summers), reared on sweet potato variety Jewel. Mean developmental time decreased as temperature increased from 20 to 30°C. Adult weevils lived longest at 15°C, indicating that prolonged storage of sweet potatoes at 15°C will not eliminate weevil populations. Frequency of mating, availability of males, and crowding significantly affected fecundity.
Young Adult Literature and Alternative Assessment Measures

The principal purpose of assessment, regardless of teaching level, should be to guide instruction. Unlike evaluation, the goal of assessment is not to arrive at a grade for students. Rather, it is to inform the educator as to what needs to be addressed in the classroom. Assessment in a young adult literature (YAL) curriculum is no different. Its function is to aid the teacher in determining what should be taught, from novel selections to literary skills to instructional practices. Even though exams and their results can enlighten instruction, other authentic, alternative assessment measures may also be employed. To this end, this article highlights four such assessment measures (interest inventory, knowledge rating chart, cyber-hunt, and Twitter retelling) and offer suggestions for classroom implementation in various disciplines at the middle school, high school, and university/college levels.
Effects of chronic upper temperature regimes on growth of two geographical strains of channel and hybrid catfish

Summary Climate change is a growing concern for pond culture of catfish, due to possible exacerbation of temperature fluctuations and increased maximum daily temperatures. Because channel catfish (Ictalurus punctatus) have a broad natural distribution from Canada to Mexico, it was hypothesized that natural differences in thermal tolerance and seasonal growth may be attributed to different geographical strains. Furthermore, it was hypothesized that these differences would be observed in hybrid catfish (I. punctatus x [blue catfish] I. furcatus). Chronic thermal tolerance and growth rate were quantified in two geographically distinct strains of channel catfish and a corresponding hybrid catfish from one of these strains with a cross to an industry standard blue catfish strain. In a 6-week growth experiment, catfish were subjected to daily cycling temperatures of either 27–31°C or 32–36°C, mimicking pond fluctuations. Hybrid catfish had the highest survival at both temperatures, and both strains of channel catfish had greater growth in weight or length at 27–31°C than at 32–36°C. Therefore, these results indicate that physiological performance, in terms of growth, decreases in channel catfish at temperatures greater than 27–31°C regardless of geographical origin of strain, whereas hybrid catfish did not show a decrease in weight under the same temperature conditions.
Technique for performing direct lymphangiography in pigs.

Rationale and Objectives. The authors developed a porcine model for direct lymphangiography to be used as a reference for lymph node harvesting. Methods. A pilot animal was studied first to develop the protocol, which was used successfully in 24 pigs. An indicator dye was first injected into each foot to make the lymphatic vessels visible. Then, ethiodized poppy seed oil was injected directly through cutdowns in both groins. Radiographs were obtained before and after lymph node harvesting. Results. Images were of diagnostic quality in all animals. The pilot animal developed transient respiratory distress, which was thought to be due to the oil-based contrast material. The amount injected was reduced by half, and no episodes occurred thereafter in the study group. There were no other immediate or delayed complications. Conclusion. Direct lymphangiography is safe, easy, and reliable in a porcine model.
Effect of short-term strenuous exercise on erythrocyte 2,3-diphosphoglycerate in untrained men: a time-course study.

The literature on the response of erythrocyte 2,3-diphosphoglycerate (2,3-DPG) following exercise is replete with inconsistencies, and recent studies have shown that the time of blood sampling during and following exercise, as well as the duration of exercise, are important in evaluating the response of 2,3-DPG. Experiments were designed to measure the response of 2,3-DPG following short-term strenuous exercise in two groups of untrained men. Twelve men, 19-22 years old (study 1), exercised on a bicycle ergometer at 122.5 W for 10 min and red blood cell (RBC) 2,3-DPG was measured at 0 and 50 min following exercise. The level of 2,3-DPG (mumol.ml-1 RBC) increased after exercise (P < 0.05), but this increase was not significant when 2,3-DPG was expressed as mol.mol-1 hemoglobin (Hb). However, following 50 min of rest, 2,3-DPG (mol.mol-1 Hb) decreased significantly. In a second group (study 2), nine other men, aged 18-19 years, exercised at the same workload for 15 min and 2,3-DPG was measured at 0, 30, 60, 180, and 330 min respectively after exercise, and no significant mean changes in the level of the phosphate were observed. Findings from these studies suggest that 2,3-DPG does not provide a compensatory adjustment to facilitate oxygen delivery in the hypoxia of short-term strenuous exercise in untrained males immediately following exercise and when recovery intervals of up to 330 min are also examined. It is suggested that 2,3-DPG be reported as mol.mol-1 Hb, since the phosphate exists on Hb in an equimolar ratio in normal physiological states.
Acid phosphatase in prostatic tissue homogenates from patients with benign prostatic hyperplasia and prostatic carcinoma

Acid phosphatase activity biochemically in the primary tumor of 20 patients with prostatic carcinoma, was studied in an attempt to understand the basis for a correlation or lack of correlation between serum and/or bone marrow acid phosphatase levels and the presence and/or clinical behavior of prostatic carcinoma. The enzyme activity was similarly measured in 19 patients with benign prostatic hyperplasia as controls. On the average, enzyme activities were lower (P less than 0.002) in the tissues from patients with carcinoma. There was no correlation of enzyme activity in tumor with the age of the patient, stage of disease, degree of differentiation of the tumor, or serum acid phosphatase activity.
Bioavailability of Hydrophobic Compounds Partitioned into the Micellar Phase of Nonionic Surfactants

The apparent solubility of polycyclic aromatic hydrocarbon compounds such as phenanthrene can be increased in the presence of surfactants above their critical micelle concentration. A fraction of the phenanthrene partitioned into the micellar phase of some nonionic surfactants can be directly bioavailable to phenanthrene-degrading microorganisms. A model describing the biodegradation of the directly bioavailable micellar-phase substrate is presented. The hypothesis on which the model is based considers the following steps: (a) the contaminant is transported by filled micelles from the bulk solution to the proximity of the cells; (b) the exchange of the filled micelle with the hemimicellar layer around the cell delivers the contaminant to the cell; (c) the contaminant diffuses into the cell and is biodegraded. The biodegradation kinetics were explained in terms of a series of mass-transfer processes, which lead to a similar equation as the Monod kinetics. The theoretically derived expression, describing t...
Large-Subunit Ribosomal RNA Systematics of Symbiotic Dinoflagellates: Morphology Does Not Recapitulate Phylogeny☆

Biochemical, histological, physiological, and genetic evidence indicates that dinoflagellates symbiotic with marine invertebrates are a heterogeneous complex of taxa, representing at least five genera in three orders. Despite a wealth of data regarding morphological, biochemical, and behavioral differences among symbiotic dinoflagellates, knowledge concerning patterns of diversification is limited. I analyzed approximately 900 bp of the 5′ end of the large-subunit ribosomal RNA gene from 14 dinoflagellate isolates: six culturedSymbiodiniumspecimens, two cultured symbioticGymnodinium,two algal samples isolated from reef-building corals, an algal sample obtained from cultures of the jellyfishCassiopea xamachana,and three free-livingGymnodiniumisolates. Results show that morphological similarities among the examined symbiotic taxa do not necessarily correspond with molecular phylogeny. The includedSymbiodiniumtaxa represent a paraphyletic assemblage whileGymnodiniumis reconstructed as a polyphyletic assemblage. Analysis indicates that all the included symbiotic dinoflagellates descended from a common, symbiotic ancestor (though within the dinoflagellates, symbiosis is a polyphyletic trait). Additionally, two free-living dinoflagellates emerge within the symbiotic clade, suggesting that the symbiotic lifestyle has been lost at least once in this group. It has been hypothesized that rates of evolution within mutualistic endosymbioses should be reduced relative to free-living taxa. However, results indicate that rates of molecular, morphological, biochemical and behavioral change are similar among branches leading to symbiotic and free-living dinoflagellates.
Measurement of Fluorescein Angiograms of the Optic Disc and Retina Using Computerized Image Analysis

Abstract Computerized image analysis was used to quantify objectively fluorescein angiograms of the optic disc, peripapillary choroid, and retina. Techniques were developed to measure fluorescein filling rates of the optic disc and the retinal vessels and the area of fluorescein filling defects within the optic disc. Two subjects, one, with glaucoma and the other with ocular hypertension, showed increases of areas of fluorescein filling defects of the optic disc on follow-up and are presented here as examples of the application of these techniques. This methodology can be applied to the longitudinal follow-up of individual patients with glaucoma and retinal diseases, as well as to cross-sectional studies of patient populations.
A Unified Dynamical Approach to High- and Low-Energy Strong Interactions

A discussion is presented of work conducted on lowenergy scattering, forward dispersion relations and peripheral contributions to high-energy, low- mementum transfer scattering, in which the region of application is enlarged, and the dynamics of high- and low-energy strong interactions are treated in a unified way. General consequences of the Mandeletam representation are discussed to understand low-energy scattering potential. The strip approximation is discussed which is introduced to the extent that the generalized one-meson- pi potential can be calculated. The asymptotic behavior and oscillations in the strip directions are described for the occurrence of forward-diffraction peaks ih the physical regions of high energies and low-momentumtum transfers near the strip. An outline is included of investigations proposed or in progress for: computer calculations of the spectral functions generated by iteration of a non- relativistic Yukawa potential; a calculation of adiabatic pi - pi scattering for increasihg values of the interaction parameter, lambda ; and the application of analogous methods to pi -N, and N-N scattering. (B.O.G.)
Nutrition and Inflammatory Events: Highly Unsaturated Fatty Acids (ω-3 vs ω-6) in Surgical Injury

Given the poor prognosis and high cost of care for patients with acute inflammatory responses (often leading to organ failure and/or allograft rejection), immunomodulation of this hyperresponse represents an important priority for research in nutritional medicine. The primary goal of nutritional support in inflammatory disease is to provide adequate energy, particularly through use of novel lipids (to alter eicosanoid pathway toward a more regulated inflammatory state), and protein to meet endogenous requirements for tissue repair IL-1 production, and restored cellular function, thus preventing secondary infection (52). Manipulation of macrophage eicosanoid production by use of omega-3 PUFA may reduce the cellular immune response (by competing with arachidonic acid, which produces inflammatory eicosanoids of the 2- and 4-series), whereas inclusion of MCT found in coconut oil may lower the arachidonic acid content of membrane phospholipids. As more data are obtained on the use of such tailored therapies in critically ill patients, a new generation of parenteral and enteral diets will be developed to reduce inflammation and immune dysfunction.
Apparatus for instantaneously measuring ultraviolet, visible, or infrared dichroism from thin polymer during high-speed stretching

An apparatus has been constructed for following changes in the dichroism of a polymer film undergoing rapid elongation. By means of a rapidly rotating mirror with evenly spaced open sectors, a beam of radiation is passed through the sample and then alternately polarized in the horizontal and vertical direction so that the horizontal and vertical absorbances may be rapidly compared in time as compared with the time of sample elongation (a few milliseconds). The apparatus utilizes reflection optics and a grating monochromator so that measurements may be made by using ultraviolet, visible, or infrared radiation. The transmitted intensity is detected by a photomultiplier or semiconductor infrared device, the output of which is amplified and displayed on an oscilloscope. A temperature-controlled sample chamber is provided. The operation of the apparatus is illustrated by following the change in dichroism of a sample of dehydrohalogenated poly(vinyl chloride) with visible radiation during rapid extension.
Myers-Briggs Type and Keeping Appointments for an Experiment on Problem-Solving:

The Myers-Briggs Type Indicator is a measure of individual differences in cognitive style, that is, the way people prefer to approach the external world of people and objects and the internal world of ideas. People with different cognitive styles are believed to deal with problems dfferently (Myers & McCadey, 1985). The Myers-Briggs identifies 16 different types. Since the topic of interest was problem solving, an internal task, subjects were divided according to the function they were expected to use internally. This division resulted in four groups: thinking, intuition, sensing or feeling. One hundred seven introductory psychology students completed the Myers-Briggs Type Indicator in groups of 5 to 20. After subjects completed the indicator, they scheduled individual appointments to complete the problem-solving part of the study by signing their names and phone numbers on a schedule sheet at times convenient for them. If subjects failed to keep appointments they were called and arrangements were made for a new time. Some subjects made several appointments before coming and others never appeared for the problem-solving part of the study. The experimenter did not know a person's type when appointments were made. There was a difference in the probability that various cognitive types would keep their appointments. While 20 out of 21 thinking types (95.2%) completed the study, only 11 out of 19 intuitive types (57.9%) kept appointments for the problem-solving sessions. For the other two types, 31 out of 38 sensing types (81.6%) and 25 out of 29 feeling types (86.2%) completed the problem-solving task. The differences in appointment-keeping rate were significant [xj2(n = 107) = 8.19, p < .05]. It may be that intuitive persons were less likely to appear for appointments to avoid the problem-solving task, while thinking types found such an activity attractive. It could also be that intuitive types are less likely, and thinking types more likely, to keep appointments regardless of the nature of the psychology experiment. This difference in the probability of keeping appointments by people of different cognitive styles suggests that the findings of previous studies of problem-solving reflect the abilities, methods, and tactics of thinking types more than those of intuitive types.
Hydrocarbons of Biological Origin from a One-Billion-Year-Old Sediment.

The isoprenoid hydrocarbons, phytane (C20H42) and pristane (C19H40), are present in the oil seeping from the Precambrian Nonesuch formation at the White Pine Mine, Michigan. Gas-liquid chromatography and mass spectrometry provide the isolation and identification procedures.
The effect of misclassification in screening trials: A simulation study

Abstract Background Misclassification of study endpoints in randomized clinical trials of screening tests has been well documented, yet its effect on study power, type I error rate, and risk ratio estimate have not been studied in depth. Methods We constructed a Markov model to depict the natural history of disease and the effect of screening on it. Using this model we simulated subjects in a two-arm RCT. We varied the type and amount of misclassification, and studied the effect on two endpoints — disease-specific mortality and the incidence of disease-specific symptoms. Results Failure to identify disease-specific events in a RCT of screening has a small effect on the risk ratio estimate and study power. In contrast, the false identification of events as being attributable to the target disease greatly reduces study power. Conclusions Investigators of RCTs of screening tests should carefully consider the potential for misclassification and the type of misclassification that their study is as risk for. Studies should be designed to minimize misclassification. The effect of misclassification on power should be considered in sample size calculations.
A configuration interaction program

Abstract Given expressions for the evaluation of an interaction matrix, either in the non-relativistic LS formalism or the Breit-Pauli LSJ formalism, the MCHF_CI program determines some or all the eigenvalues and associated eigenvectors of the matrix. In the case of a relativistic calculation, the program will determine eigenvalues and eigenvectors for a range of J values. The mass correction may also be included in the evaluation of the interaction matrix.
Detecting submarine groundwater discharge with synoptic surveys of sediment resistivity, radium, and salinity

[1] A synoptic geophysical and geochemical survey was used to investigate the occurrence and spatial distribution of submarine discharges of water to upper Nueces Bay, Texas. The 17 km survey incorporated continuous resistivity profiling; measurements of surface water salinity, temperature, and dissolved oxygen; and point measurements of dissolved Ra isotopes. The survey revealed areas of interleaving, vertical fingers of high and low conductivity extending up through 7 m of bay bottom sediments into the surface water, located within 100 m of surface salinity and dissolved Ra maxima along with peaks in water temperature and lows in dissolved oxygen. These results indicate either brackish submarine groundwater discharge or the leakage of oil field brine from submerged petroleum pipelines.
A Slow Dance for El Niño

The El NiA±o-Southern Oscillation (ENSO) influences year-to-year climate variability in many parts of the world. In her Perspective, [Cole][1] discusses the evidence for past ENSO variability and its likely causes. She highlights the study by [ Tudhope et al .][2], whose New Guinea coral records represent an important step toward understanding what drives ENSO variability. [1]: http://www.sciencemag.org/cgi/content/full/291/5508/1496 [2]: http://www.sciencemag.org/cgi/content/short/291/5508/1511
Theoretical investigation of ionic effects in actuation and sensing of IPMCs of various geometries

Ionic polymer-metal composite (IPMC) electromechanical and mechanoelectrical phenomena for rectangular and tube-shaped IPMC devices have been examined through simulation and experimental investigation. There is a specific focus on investigating the anion and cation effects in actuation versus sensing. Simulations were performed using COMSOL Multiphysics 4.3b. Sample IPMCs were fabricated in lab in the desired geometries by techniques described herein. The sample sizes were roughly 1 mm thick and 20-25 mm in length. Actuation and sensor experiments were performed with the samples and compared to simulation results, which exhibit good agreement for voltage and tip displacement measurements. Fundamental differences in the electromechanical and mechanoelectrical transductions of IPMCs are highlighted in the simulation results. These results display the negligible effect of anion motion in actuation as compared to during sensing. In actuation, the cation motion is dominated by an electric potential flux, and the anions move only slightly in accordance with the deformed polymer membrane. In sensing, the electric potential is induced by the ionic migration in the polymer, and both cation and anion concentration variations are of similar magnitudes.
Intergeniculate leaflet and ventral lateral geniculate nucleus afferent connections: An anatomical substrate for functional input from the vestibulo-visuomotor system

The intergeniculate leaflet (IGL) has widespread projections to the basal forebrain and visual midbrain, including the suprachiasmatic nucleus (SCN). Here we describe IGL-afferent connections with cells in the ventral midbrain and hindbrain. Cholera toxin B subunit (CTB) injected into the IGL retrogradely labels neurons in a set of brain nuclei most of which are known to influence visuomotor function. These include the retinorecipient medial, lateral and dorsal terminal nuclei, the nucleus of Darkschewitsch, the oculomotor central gray, the cuneiform, and the lateral dorsal, pedunculopontine, and subpeduncular pontine tegmental nuclei. Intraocular CTB labeled a retinal terminal field in the medial terminal nucleus that extends dorsally into the pararubral nucleus, a location also containing cells projecting to the IGL. Distinct clusters of IGL-afferent neurons are also located in the medial vestibular nucleus. Vestibular projections to the IGL were confirmed by using anterograde tracer injection into the medial vestibular nucleus. Other IGL-afferent neurons are evident in Barrington's nucleus, the dorsal raphe, locus coeruleus, and retrorubral nucleus. Injection of a retrograde, trans-synaptic, viral tracer into the SCN demonstrated transport to cells as far caudal as the vestibular system and, when combined with IGL injection of CTB, confirmed that some in the medial vestibular nucleus polysynaptically project to the SCN and monosynaptically to the IGL, as do cells in other brain regions. The results suggest that the IGL may be part of the circuitry governing visuomotor activity and further indicate that circadian rhythmicity might be influenced by head motion or visual stimuli that affect the vestibular system.
Demonstration of tissue-specific promoters in nonprimate species that express aromatase P450 in placentae.

Conversion of androgens to estrogens is catalyzed by aromatase P450 (P450 arom ;the product of the CYP19 gene). Regulation of tissue-specific expression of P450 arom in humans is due, in part, to alternative transcriptional start sites that arise as a consequence of the use of tissue-specific promoters. We used the rapid amplification of cDNA ends (RACE) technique to characterize RNA extracted from ovarian granulosa cells and placental tissue from cows, horses, and pigs (ungulates) in order to determine whether these species, like the human, utilize tissue-specific promoters to drive P450 arom expression. The majority of transcripts in the placenta have 5'-termini that differ from those in the ovary upstream of a common site of divergence, indicative of a splice junction. The use of tissue-specific promoters by the bovine CYP19 gene would produce these results, as it does in the case of the human CYP19 gene. A bovine genomic library was then screened with probes that hybridize to ovary- or placenta-specific transcripts. Two clones of approximately 15 kb each in length were isolated ; one hybridized with the ovary-specific sequence and the other hybridized with the placenta-specific sequence. Whereas the former sequence was contiguous with the downstream sequence containing the translational start site, the latter was identical only with the sequence of the placental transcripts upstream of the putative splice junction, indicating that this was the distal sequence. Bovine and human ovary-specific genomic sequences share 77% bp identity, while bovine and human placenta-specific sequences demonstrated only 39% bp identity. These results mirror those obtained in comparisons of human, bovine, equine, and porcine ovarian and placental RACE cDNA 5'-termini. Thus, there is a high degree of sequence identity in the 5'-flanking region of the ovarian promoter for P450 arom in spite of marked differences between species in the pattern of estrogen biosynthesis. Although the use of a distal promoter to drive placental CYP19 gene expression may be the norm in species in which estrogen biosynthesis occurs in the placenta, this may be a result of convergence, rather than divergence, in evolution.
Trajectory optimization for a National Launch System vehicle

A trajectory design process is presented for a proposed National Launch System (NLS) vehicle configuration. A software trajectory planner was developed to generate near optimal pitch plane trajectories for variable mission plans, variable launch site selections, and last minute wind conditions at the time of launch. In addition, the trajectory planner performs in-flight near optimal trajectory redesign in the event of an engine-out or unexpected wind dispersions. The trajectory planner iteratively simulates trial trajectories defined by variables corresponding to a parameterized trajectory shape. The trajectory planner optimizes these trajectory parameters according to the fuel used to realize the trajectories. For prelaunch scenarios, the trajectory planner generated near optimal trajectories of consistent fuel performance irrespective of the winds encountered at the launch site. In-flight trajectory redesigns were also shown to be effective in fulfilling the mission plan and preserving the structural integrity of the vehicle. The in-flight redesign results indicate that closed-loop guidance in the early stages of ascent is highly effective in accommodating engine failures or wind dispersions. All trajectory designs were verified using a 6DOF simulation with flight controllers.
Eskimo Language and Eskimo Song in Alaska: A Sociolinguistics of Deglobalisation in Endangered Language

Across Alaska, the popularity of indigenous forms of dance has risen, particularly in indigenous communities in which English dominates the heritage languages and Native youth have become monolingual English speakers. Some indigenous people say that Native dance accompanied by indigenous song is a way of preserving their endangered languages. With two case studies from Alaskan Eskimo communities, Yupiget on St. Lawrence Island and Inupiat in Barrow, this article explores how use of endangered languages among Alaskan Eskimos is related to the activity of performing Eskimo dance. I suggest that practice of Eskimo dancing and singing that local people value as an important linguistic resource can be considered as a de-globalised sociolinguistic phenomenon, a process of performance and localisation in which people construct a particular linguistic repertoire withdrawn from globalisable circulation in multilingualism.
Level Densities in Nuclear Physics

In the independent particle model which forms the basis for the nuclear level density expressions of Bethe1, Van Lier and Uhlenbeck2 and Bloch3 nucleons move independently in a central potential. There is a well-defined set of single-particle orbitals, each nucleon occupies one of these orbitals subject to Fermi statistics, and the total energy of the nucleus is equal to the sum of the energies of the individual nucleons. The basic question is what is the range of validity of this Fermi gas description and, in particular, what are the roles of the residual interactions and collective modes. In this talk I will try to provide some insight into these questions through a detailed examination of experimental level densities in light mass systems.
Decreased Feed Consumption and Increased Calcium Intake Associated with Pullet’s First Egg

Abstract INTRODUCTION IT was shown many years ago (Halnan, 1925; Common, 1933) than an increase in skeletal storage of calcium by pullets begins two to three weeks before egg production commences. Common also showed that the amount of calcium stored varied with the level of dietary calcium. Tyler and Wilcox (1942) reported that calcium retention increases approximately two weeks prior to the onset of egg production. The increase in retention leads to the increased skeletal mineral which the pullet later uses as a calcium source (reservoir) for egg shell calcification (Taylor and Moore, 1958). However, it was not reported until recently (Foster, 1968; and Meyer, 1968) that a decrease in feed consumption occurred shortly before and after the first oviposition. Foster (1968) investigated the extent to which the drop in consumption was genetically controlled and what correlation existed between the decrease and such factors as age of first egg, body weight,…
Common inventory modeling assumptions that fall short: Arborescent networks, Poisson demand, and single-echelon approximations

Abstract Traditional multi-echelon inventory theory focuses on arborescent supply chains that use a central warehouse which replenishes remote warehouses. The remote warehouses serve customers in their respective regions. Common assumptions in the academic literature include use of the Poisson demand process and instantaneous unit-by-unit replenishment. In the practitioner literature, single-echelon approximations are advised for setting safety stock to deal with lead time, demand, and supply variations in these settings. Using data from a U.S. supplier of home improvement products, we find that neither the assumptions from the academic literature nor the approximations from the practitioner literature necessarily work well in practice. In a variation of the strictly arborescent supply chain, the central warehouse at our real company not only replenishes other warehouses but also meets demand from customers in the region near the central warehouse. In this paper, we study this dual-role central warehouse structure, which we believe is common in practice. Using high and low volume product demand data from this company, we use Monte Carlo simulations to study the impact of (1) the use of a dual-role centralized warehouse, (2) common demand assumptions made in multi-echelon research, and (3) single-echelon approximations for managing a multi-echelon supply chain. We explore each of these under both centralized and decentralized control logic. We find that the common assumptions of theoretical models impede their usefulness and that heuristics that ignore the actual supply chain structure fail to account for additional opportunities to utilize safety stock more effectively. Researchers should be aware of the gap between standard assumptions in traditional literature and actual practice, and critically evaluate their assumptions to find a reasonable balance between tractability and relevance.
The response to iron deprivation in Saccharomyces cerevisiae: expression of siderophore-based systems of iron uptake

The budding yeast Saccharomyces cerevisiae responds to growth in limiting amounts of iron by activating the transcription factor Aft1p and expressing a set of genes that ameliorate the effects of iron deprivation. Analysis of iron-regulated gene expression using cDNA microarrays has revealed the set of genes controlled by iron and Aft1p. Many of these genes are involved in the uptake of siderophore-bound iron from the environment. One family of genes, FIT1, FIT2 and FIT3 , codes for mannoproteins that are incorporated into the cell wall via glycosylphosphatidylinositol anchors. These genes are involved in the retention of siderophore-iron in the cell wall. Siderophore-bound iron can be taken up into the cell via two genetically separable systems. One system requires the reduction and release of the iron from the siderophore prior to uptake by members of the Fre family of plasma-membrane metalloreductases. Following reduction and release from the siderophore, the iron is then taken up via the high-affinity ferrous transport system. A set of transporters that specifically recognizes siderophore-iron chelates is also expressed under conditions of iron deprivation. These transporters, encoded by ARN1, ARN2/TAF1, ARN3/SIT1 and ARN4/ENB1 , facilitate the uptake of both hydroxamate- and catecholate-type siderophores. The Arn transporters are expressed in intracellular vesicles that correspond to the endosomal compartment, which suggests that intracellular trafficking of the siderophore and/or its transporter may be important for uptake.
Reaction dynamics of Na*(4 (2)P)+H2: Effect of reactant orbital alignment on reactivity and product rotational state distribution.

We have investigated the direct reaction of Na{sup *}(4 {sup 2}{ital P}) with H{sub 2} to form the product NaH. Using far-wing absorption techniques, we have measured absorption into the NaH{sub 2} collision complex, followed by branching into nonreactive (formation of Na{sup *}) or reactive (formation of NaH({ital X} {sup 1}{Sigma}{sup +}({ital v}{prime}{prime},{ital J}{prime}{prime}))) channels. We have observed the reaction to occur both via the attractive potential-energy surfaces and over a barrier on the repulsive surfaces. We have studied the effect of reactant orbital alignment on product rotational distribution for {ital v}{prime}{prime}=1. Specifically we find reaction on the repulsive surfaces leads preferentially to low rotational product states of NaH, while reaction on the attractive surfaces leads preferentially to high rotational states.
Structure and Substance: The Politics of Decentralization in the United Nations

A RGUMENTS ABOUT STRUCTURE are usually arguments about substance. While no one would claim that this insight is of theoretical proportions, it does provide a useful starting point for analyzing the recurring argument about decentralization of the economic and social activities of the United Nations. Despite the relative lack of material on the subject,' the possible ramifications of the arguments over how far decentralization should go may be critical to the future of the UN in this whole general area. A close examination of the recent debates in ECOSOC and the General Assembly's Second Committee reveals at least four separate groups with different objectives for the UN. What is at stake is control over the UN's activities in the economic and social sphere.
Brittle Fracture versus Quasi Plasticity in Ceramics: A Simple Predictive Index

Simple relations for the onset of competing brittle and quasi-plastic damage modes in Hertzian contact are presented. The formulations are expressed in terms of well-documented material parameters, elastic modulus, toughness, and hardness, enabling a priori predictions for given ceramics and indenter radii. Data from a range of selected ceramic (and other) materials are used to demonstrate the applicability of the critical load relations, and to evaluate coefficients in these relations. The results confirm that quasi plasticity is highly competitive with fracture in ceramics, over a sphere radius range 1–10 mm. Implications concerning the brittleness of ceramics in the context of indentation size effects are discussed.
Retrograde amnesia: prolonging the fixation phase of memory consolidation by paradoxical sleep deprivation.

Abstract Mice given one-trial training in a passive avoidance task after 3 days of paradoxical sleep (PS) deprivation, and given electroconvulsive shock (ECS) at one of several intervals after training, display a protracted retrograde amnesia gradient on a retention test given 3 days later. ECS produces only a sharp gradient in comparable groups of animals that are not deprived of PS. The findings suggest that PS plays an important functional role in the processes that underlie the fixation of long-term memory.
TH‐C‐AUD A‐05: Experimental Validation of An Iterative Forward Projection Matching Algorithm for Seeds Center Localization Using Conebeam‐CT X‐Ray Projections

Purpose: To experimentally validate a new algorithm for reconstructing the 3D positions of implanted brachytherapy seeds from 2D projection images.Method and materials: The iterative forward projection matching (IFPM) algorithm consists of finding the 3D seed geometry that minimizes the sum‐of‐squared‐difference of the pixel‐by‐pixel intensities between computed projection images and measured auto‐segmented images of implanted seeds. IFPM starts with an approximation to the initial seeds configuration, e.g., the pre‐implant seed arrangement. It then iteratively refines the 3D seed coordinates until the computed projections match with the measured projections. Three pairs of computed and measured projection images, with known imaging geometry, are used. Two brachytherapy phantoms were fabricated with 12 and 72 seeds in known configurations. Three projections of each phantom were acquired using an Acuity digital simulator along with a full 660 projection Conebeam CT(CBCT).Image pre‐processing steps were performed to create the binary seed centroids images for use by IFPM algorithm. To quantify IFPM accuracy, the actual seed positions were extracted from the CBCTimages by the Brachy Vision‐planning system. Results: For the 12 seed phantom data, the mean reconstruction error was found to be 0.83±0.34mm where as for 72 seed phantom it was 0.97±0.37mm. The each test trials converged in 4–10 iterations with computation time of 2.8–62 min on a 2 GHz processor. Discussion: The IFPM algorithm avoids establishing seed projection correspondence required by standard back‐projection methods. In phantom studies we have demonstrated 1 mm accuracy in reconstructing the 3D positions of brachytherapy seeds from 2D projection images. This supports the potential of this algorithm for accurate and robust seed reconstruction in patients. This project was supported by grant from Varian Medical Systems.
Inhibition of formation of filopodia after axotomy by inhibitors of protein tyrosine kinases.

The activity of motile protrusions of the growth cone—filopodia, veils, and lamellipodia—is essential for directed growth of a neuronal process. The regulation of the formation of these protrusions is not well understood. Numerous filopodia and veils or lamellipodia form within minutes of transection of an Aplysia axon in culture, as the initial components of growth cones of regenerating neurites. Axotomy, therefore, provides a robust and reliable protocol for analyzing the formation of these protrusions. We evaluated the involvement of protein phosphorylation in the regulation of protrusive activity. Of the inhibitors of protein kinases assayed, only the inhibitors of protein tyrosine kinases—genistein, lavendustin A, herbimycin A, and erbstatin analogue—suppressed the formation of protrusions, as assessed by high magnification video microscopy. These drugs did not work by preventing resealing of the axon, as evident from visual inspection and by the unimpaired effectiveness of genistein or lavendustin in preventing formation of filopodia when applied after resealing. Inhibition of protein tyrosine kinases not only prevented the formation of actinbased protrusions, but also caused deterioration of the actin network underlying the protrusive area of preexisting growth cones. Consistent with an involvement of protein tyrosine phosphorylation in the generation of protrusive structures, immunocytochemistry revealed that aggregates of phosphotyrosine appeared at the margins of the axon, from which protrusions emerge shortly after axotomy. These results suggest a role for protein tyrosine phosphorylation in the formation and maintenance of actin-based protrusive structures. © 1995 John Wiley & Sons, Inc.
The Student as a Utility Maximizer.

Allen C. Kelley once again applies economic analysis to the educational process in this paper which presents a model “in which the student is viewed as a utility maximizer making choices at the margin between allocating his time among the course in question, all other courses, and leisure….” The model is supported by the results of a classroom experiment in which two alternative “production techniques” were employed. One consisted of the traditional classroom format, the other involved student use of sets of lecture notes. Among the variables included in the regression analysis are performance on the TUCE, ACT-SAT scores, high school standing, major field, sex, student's college level (sophomore or upperclassman), and percentage of sections attended. Conclusions are drawn about the efficiency of the experimental approach.
Deposition and imaging of metal-coated biomolecules with the STM.

Abstract We have applied a simple and reliable procedure for imaging biomolecules with the scanning tunneling microscope (STM). The biomolecules are adsorbed on glow-discharged mica, then coated with a thin film of platinum-carbon. We have tested this method with linear and circular (plasmid) DNA molecules. The contrast and resolution of the STM images are comparable to electron micrographs of the same molecules when shadowes. Though the present lateral resolution (5–6 nm) is limited by the grain size of the conductive film, some details like supercoiled regions in the DNA are resolved. This method is interesting for two reasons. First, as an alternative technique for imaging biomolecules, Second, for use as a control in STM studies of bare biomolecules.
Solubilization of the chemokine receptor CXCR4.

The chemokine receptor CXCR4 was solubilized from the human T-cell line CEM by using the detergent n-dodecyl-beta-maltoside (DDM) and cholesteryl hemisuccinate ester (CHS). Binding studies with (125)I-SDF-1alpha revealed a dissociation constant of 5.33 nM and a receptor density (B(max)) of 2.68 pmol/mg in CEM membranes at 4 degrees C. The affinity of solubilized CXCR4 for SDF-1alpha was identical to membrane-bound CXCR4. Binding of gp120 to solubilized CXCR4 was demonstrated by coprecipitation of gp120 with anti-CXCR4 antibodies.