cssi/SciSciGPT-SciSciNet huggingface dataset:
Neutron inelastic scattering and reactions in natural Pb as a background in neutrinoless double-β-decay experiments

Inelastic neutron scattering and reactions on Pb isotopes can result in $\ensuremath{\gamma}$ rays near the signature end-point energy in a number of $\ensuremath{\beta}\ensuremath{\beta}$ isotopes. In particular, there are $\ensuremath{\gamma}$-ray transitions in $^{206,207,208}\mathrm{Pb}$ that might produce energy deposits at the $^{76}\mathrm{Ge}{Q}_{\ensuremath{\beta}\ensuremath{\beta}}$ in Ge detectors used for $0\ensuremath{\nu}\ensuremath{\beta}\ensuremath{\beta}$ searches. The levels that produce these $\ensuremath{\gamma}$ rays can be excited by ($n,{n}^{'}\ensuremath{\gamma}$) or ($n,\mathit{xn}\ensuremath{\gamma}$) reactions, but the cross sections are small and previously unmeasured. This work uses the pulsed neutron beam at the Los Alamos Neutron Science Center to directly measure reactions of interest to $\ensuremath{\beta}\ensuremath{\beta}$-decay experiments. The cross section on $^{\mathrm{nat}}\mathrm{Pb}$ to produce the 2041-keV $\ensuremath{\gamma}$ ray from $^{206}\mathrm{Pb}$ is measured to be 3.6 \ifmmode\pm\else\textpm\fi{} 0.7 (stat.) \ifmmode\pm\else\textpm\fi{} 0.3 (syst.) mb at $\ensuremath{\approx}9$.6 MeV. The cross section on $^{\mathrm{nat}}\mathrm{Pb}$ to produce the 3061,3062-keV $\ensuremath{\gamma}$ rays from $^{207}\mathrm{Pb}$ and $^{208}\mathrm{Pb}$ is measured to be 3.9 \ifmmode\pm\else\textpm\fi{} 0.8 (stat.) \ifmmode\pm\else\textpm\fi{} 0.4 (syst.) mb at the same energy. We report cross sections or place upper limits on the cross sections for exciting some other levels in Pb that have transition energies corresponding to ${Q}_{\ensuremath{\beta}\ensuremath{\beta}}$ in other $\ensuremath{\beta}\ensuremath{\beta}$ isotopes.
Physical activity, diet, and health: independent and interactive effects.

Much work on the relationship of exercise level to cardiovascular risk factors has been stimulated by the pioneering epidemiological studies of Dr. Ralph Paffenbarger. At Stanford we have conducted a series of studies since 1973, with the following major findings. Very active middle-aged men and women (compared with sedentary controls) have higher plasma lipoprotein concentrations of high-density lipoprotein (HDL) cholesterol, lower levels of very-low-density-lipoprotein (VLDL) cholesterol and triglyceride (TG), and often moderately lower levels of low-density lipoprotein (LDL) cholesterol. Lipoprotein subfractions are also different: higher levels of HDL2 and lower levels of "small" LDL in the active groups. Very active people are leaner and smoke less. All of these characteristics predict lower risk of coronary heart disease (CHD). A 1-yr trial of jogging in sedentary men suggested that 8-10 miles.wk-1 of running is required for significant HDL changes. Body fat loss correlated positively with distance run, with increase in HDL, and with increase in caloric intake. A 1-yr trial in overweight men showed that fat loss by dieting alone or by exercising alone results in similar elevation of HDL cholesterol. A 1-yr trial in sedentary, overweight men and women losing weight on a hypocaloric low-fat diet showed that addition of regular exercise increases weight loss, improves lipoprotein pattern, and further decreases 12-yr CHD risk.
Revolution, reform and the Soviet telephone system, 1917–1927

WHEN KARL MARX DIED in March 1883 there were already 1000 telephone subscribers in Russia. The telephone had come to Russia a mere six years after its invention, and only a year after the first urban telephone exchanges were opened on the European continent. On the eve of the Bolshevik seizure of power there was roughly one telephone for every 200 city-dwellers in Russia, compared to about one for every 50 Britons (and one for every 10 Americans).2 Ten years after the October Revolution, however, the number of subscribers connected to urban telephone exchanges was unchanged. As Figure 1 shows, Russia alone among European combatants saw its phone system actually shrink over the war decade. The stagnation of the Soviet telephone system during this period is so startling that Soviet statistical sources routinely omit the years between 1913 and 1928 when reporting the growth of telephones, since this is the shortest interval for which the resulting figures in fact suggest some growth. Naturally, some of the shrinkage of the Soviet phone system was due to the loss of some of the country's most advanced territories in the post-revolution period. However, the statistics do not indicate a sudden contraction, as we might expect if territorial changes were the culprit. Rather, the number of telephone subscribers fell continuously from the revolution to the mid-1920s, as shown in Figure 2.3
Compositional and textural correlations between Olduvai Gorge Bed I tephra and volcanic sources in the Ngorongoro Volcanic Highlands, Tanzania

Abstract Tephra layers from Bed I of Olduvai Gorge, Tanzania, are correlated directly to their source volcanoes in the nearby Ngorongoro Volcanic Highlands (NVH) based on composition, texture, and age. Tephra in lower Bed I are more silicic than the upper Bed I tephra, and most contain quartz. The Naabi Ignimbrite from lower Bed I is compositionally similar to an ignimbrite exposed close to Ngorongoro Crater. None of the sampled tephra from the Ngorongoro Crater wall is an exact match for the Naabi Ignimbrite or other lower Bed I tephra, although overall composition and mineral assemblages suggest a common source. The uppermost Bed I tephra, Tuff IF, contains at its base a pyroclastic surge component rich in trachytic lava fragments that match (in texture, mineral assemblage, and mineral composition) with trachytic lavas exposed in the crater wall of the NVH Olmoti volcano. Tuff IF is compositionally similar to other upper Bed I tephra (especially Tuffs IB, IC, and IE), so Olmoti is the most likely source for most upper Bed I marker tephra. Geochemical correlations indicate that widespread ignimbrites and airfall tephra erupted from Ngorongoro during Olduvai lower Bed I time, reaching at least 40 km from source. Upper Bed I records a switch in NVH volcanic activity from Ngorongoro to Olmoti, coinciding with the first appearance of stone artifacts in the Olduvai record. Olmoti continued to supply pyroclastic deposits to the Olduvai Basin until the end of Bed I.
Amygdalostriatal projections in the neurocircuitry for motivation: a neuroanatomical thread through the career of Ann Kelley.

Abstract In MacLean's triune brain, the amygdala putatively subserves motivated behavior by modulating the “reptilian” basal ganglia. Accordingly, Ann Kelley, with Domesick and Nauta, influentially showed that amygdalostriatal projections are much more extensive than were appreciated. They highlighted that amygdalar projections to the rostral ventromedial striatum converged with projections from the ventral tegmental area and cingulate cortex, forming a “limbic striatum”. Caudal of the anterior commissure, the entire striatum receives afferents from deep basal nuclei of the amygdala. Orthologous topographic projections subsequently were observed in fish, amphibians, and reptiles. Subsequent functional studies linked acquired value to action via this neuroanatomical substrate. From Dr. Kelley's work evolved insights into components of the distributed, interconnected network that subserves motivated behavior, including the nucleus accumbens shell and core and the striatal-like extended amygdala macrostructure. These heuristic frameworks provide a neuroanatomical basis for adaptively translating motivation into behavior. The ancient amygdala-to-striatum pathways remain a current functional thread not only for stimulus–response valuation, but also for the psychopathological plasticity that underlies addiction-related memory, craving and relapse.
Overview of QTL mapping software and introduction to map manager QT.

At least ten software packages are available for marker-based detection and localization of loci contributing to quantitative traits in experimental animals and plants. Many of these have unique strengths or situations in which they are particularly useful. Six were developed by or in collaboration with plant geneticists and may not be well known to mammalian geneticists. These software packages are reviewed here and compared with a previously undescribed program, Map Manager QT, a Mac OS microcomputer program for mapping quantitative trait loci in populations derived from backcrosses, intercrosses, and recombinant inbred lines. Map Manager QT is an enhanced version of Map Manager Classic (Map Manager v2.6.5, Manly 1993), designed for mapping Mendelian loci. This review describes the methods Map Manager QT uses for mapping quantitative trait loci and describes other features that differ from those in Map Manager Classic. A complete description of both Map Manager Classic and Map Manager QT is available in the user manual, the on-line version of which can be found at http://mcbio.med.buffalo.edu/MMM/MMM.html.
Mating behavior, egg deposition, incubation period, and hatching in the clearnose skate, Raja eglanteria

Adult clearnose skates, Raja eglanteria, were captured during the winters of 1981 and 1983, and observed to mate in captivity. Mating and egg depositions take place on the central west coast of Florida from December through mid-May. During copulation the male holds the trailing edge of the female's right or left pectoral fin firmly in his mouth, swings his tail beneath hers and inserts one clasper into the distal end of her reproductive tract. Copulation may last one to four hours during which time sperm pass from the urogenital papilla of the male along the clasper groove to the female. Sperm move cranially to the upper portion of the shell gland where they are stored and remain viable for at least three months. The ovum is fertilized in the shell gland. The egg case bears a prominent projection or ‘horn’ at each corner. The two posterior ones are shorter and bear tendrils which are covered with a sticky substance that insures attachment to the substrate when the egg is deposited. Fertilized eggs are laid in pairs at intervals ranging from 1 to 13 days (mean of 4.5 ± 2.2 days). As development proceeds within the egg case a plugged slit on the lateral side of each horn opens and permits seawater to wash the developing embryo. Incubation periods for eggs maintained between 20–22°C decrease in duration throughout the egg laying season, ranging from 94 days initially to 77 days for eggs laid later in the spring. At hatching, the anterior end of the egg case ruptures, and the skate emerges abruptly with its pectoral fins rolled dorsally.
An experimental investigation of BWR parallel channel effects

Abstract An experimental study was conducted to investigate the influence of parallel channel effects (PCE) on the distribution of emergency core spray cooling water in a simulated Boiling Water Nuclear Reactor (BWR) following a postulated design basis loss of coolant accident (LOCA), and of the potential for BWR Steam Binding. A series of nine transient experiments were performed using Freon-114 in a scaled test section. This paper presents the background, scaling bases, apparatus and experimental results.
Changes in Speech Breathing Following Cochlear Implant in Postlingually Deafened Adults

Three postlingually deafened adults who received cochlear implants read passages before and after their prostheses were activated while their lung volumes were measured with an Inductive plethysmog...
Harmful Moratorium on Stem Cell Research

D uring the deliberations of the U.S. President's Council on Bioethics, we raised many questions about the comparative usefulness of embryonic and adult human stem cells for treating a host of fatal and nonfatal but debilitating diseases. We never received clear answers, so the prospect of stem cell
The Statistical Analysis of Low-level Radioactivity in the Presence of Background Counts

Abstract The analysis of low-level or background dominant radioactivity is complicated by the fact that sample net rate of activity above background may be negative, because of random fluctuations. The traditional large sample confidence intervals can contain negative values for the net rate, although we know the net rate is positive. This problem leads to statistically unsound practices such as the reporting of “less than” values when the net value lies below a certain “detectable limit”. In this paper we present two Bayesian analyses of the data which take account of the fact that the net rate is positive, and thus always lead to positive estimates and probability intervals for the true underlying rate. The estimates and intervals are compared with classical results far twenty trial data sets.
Nutritional indices in the gypsy moth (Lymantria dispar (L.)) under field conditions and host switching situations

A large proportion of gypsy moths (Lymantria dispar (L.)) are likely to experience multiple species diets in the field due to natural wandering and host switching which occurs with these insects. Nutritional indices in fourth and fifth instar gypsy moth larvae were studied in the field for insects that were switched to a second host species when they were fourth instars. The tree species used as hosts were northern pin oak (Quercus ellipsoidalis E. J. Hill), white oak (Q. alba L.), big-tooth aspen (Populus grandidentata Michx.), and trembling aspen (P. tremuloides Michx.). Conclusions of this study include: 1) Insects which fed before the host switch on northern pin oak performed better after the host switch than did insects with other types of early dietary experience. While the northern pin oak-started insects had very low relative food consumption rates on their second host species immediately after the switch, one instar later they had the highest ranked consumption rates. During both instars they had the second highest efficiencies of converting ingested and digested food to body mass. High food consumption rates and relatively high efficiency of food conversion helped these insects to obtain the highest ranked mean relative growth rates in the fifth instar compared to the relative growth rates obtained by insects from any of the other first host species. 2) Among the four host species examined, a second host of trembling aspen was most advantageous for the insects. Feeding on this species after the switch led to higher larval weights and higher relative growth rates for insects than did any of the other second host species. The insects on trembling aspen attained excellent growth despite only mediocre to low food conversion efficiencies. The low efficiencies were offset by high relative food consumption rates. 3) Low food consumption rates often tend to be paired with high efficiency of conversion and vice versa. 4) There is no discernable tendency for the first plant species eaten to cause long-term inductions which affect the ability of gypsy moths to utilize subsequent host plants. Insects did not tend to consume more, grow faster, or be more efficient if their second host plant was either the same as their rearing plant or congeneric to it. Methods are delineated which allow values of nutritional indices to be obtained for insects on intact host plants under field conditions. These methods are useful for the purpose of answering questions about the relative effects that different diet treatments have on insect response.
A preliminary length factor for erosion on steep slopes in Guatemala and its use to evaluate “curvas a nivel”

Abstract The objectives of this study were to determine a length factor for steep slopes in the highlands of Guatemala and to use the factor to evaluate the effectiveness of contour grass barriers called curvas a nivel used in that region. Six erosion plots on a 45% slope were established in San Juan Comalapa, Guatemala on an Ultic Haplustalf. Two plots each of 7.3, 9.8, and 14.7 m were maintained for one-half of the 1980 rainy season. During the second half of the 1980 rainy season the 7.3 and 14.7 m plots were shortened to 2.4 and 4.9 m. The 9.8 m plots were maintained as “control” plots. Plot surfaces were kept smooth and free of vegetation. Soil loss ranged from 50.5 T/ha on the 2.4 m plots to 144 T/ha on the 14.7 m plots. Soil loss from the 9.8 m control plots was 127 T/ha during the first half of the rainy season and 126 T/ha during the second half of the rainy season. From these data, a length factor was calculated. The preliminary results suggest the length factor for the 45% slope in Guatemala is not significantly different from the USLE length factor. In order to reduce soil loss with curvas a nivel on these steep slopes, terrace formation is necessary. It appears from these preliminary data that the appropriate horizontal distance between curvas a nivel and vertical height of the benches formed can be estimated using the USLE.
Nuclear shape coexistence in a schematic model

The phenomenon of shape coexistence, occurring frequently in the vicinity of nuclear subshell closures, is investigated within a schematic model with protons in two subshells and neutrons in a single shell. The results of this study shed some light on how one should model the phenomenon within the interacting-boson framework and relates to previous phenomenological studies. Our model employs an SO(8${)}_{\ensuremath{\nu}}$\ensuremath{\bigotimes}SO(8${)}_{\mathrm{\ensuremath{\pi}}+}$\ensuremath{\bigotimes}SO(8${)}_{\mathrm{\ensuremath{\pi}}\mathrm{\ensuremath{-}}}$ dynamic symmetry to ensure exact decoupling of an S-D-pair space, thus providing a tight conceptual link with the interacting-boson model. The model has a critical point, namely, below a certain number of valence neutrons the deformed configuration ceases to coexist. This is intriguingly reminiscent of the data.
Calculating High Energy Charge Transfer States Using Optimally Tuned Range-Separated Hybrid Functionals

Recently developed optimally tuned range-separated hybrid (OT-RHS) functionals within time-dependent density functional theory have been shown to address existing limitations in calculating charge transfer excited state energies. The RSH success in improving the calculation of CT states stems from enforcing the correspondence of the frontier molecular orbitals (FMOs) to physical properties, where the highest occupied MO energy relates to the ionization potential and the lowest unoccupied MO energy relates to the electron affinity. However, in this work, we show that a less accurate description of CT states that involves non-FMOs is afforded by the RSH approach. In order to achieve a high quality description of such higher energy CT states, the parameter tuning procedure, which lies at the foundation of the RSH approach, needs to be generalized to consider the CT process. We demonstrate the need for improved description of such CT states in donor–acceptor systems, where the optimal tuning parameter is acco...
Interactive mutagenicity of sodium nitrite, dimethylamine, methylurea and ethylurea.

Abstract Groups of mice were treated per os with sodium nitrate either alone or in combination with nitrosatable amino compounds and tested in the most mediated assay. When mice were treated with sodium nitrate in combination with demethylamine a small(4-fold) but significant increase in mutant frequency (MF) was observed. Ethylurea or methylurea in combination with sodium nitrate induced 10- or 850-fold increases in MF, respectively. The response to methylurea was dose-dependent with a 6- and 30- fold increase in MF at 5.4 and 11.5 mg/kg NaNO 2 and a 6-fold increase at 108 mg/kg methylurea. That this response reflected gastric nitrosation was shown by the disappearance of the response if NaNO 2 administration preceded methylurea treatment by 10 min. High MF's were observed if NaNO 2 was administered 10 or 20 min after methylurea.
Heterogeneous Uptake Kinetics of Volatile Organic Compounds on Oxide Surfaces Using a Knudsen Cell Reactor: Adsorption of Acetic Acid, Formaldehyde, and Methanol on α-Fe2O3, α-Al2O3, and SiO2

The role of heterogeneous reactions on particulate matter present in the Earth's atmosphere remains an important question in tropospheric chemistry. It has been proposed in several modeling studies that mineral dust may provide reactive surfaces for trace atmospheric gases. Laboratory studies can provide some answers concerning the kinetics of these reactions, so that heterogeneous chemistry can be quantitatively assessed in atmospheric chemistry models. In this study, the heterogeneous uptake kinetics of several volatile organic compounds (VOCs) on oxide surfaces have been measured with a Knudsen cell reactor at 295 K. In particular, the heterogeneous uptake of acetic acid, methanol, and formaldehyde on α-Fe2O3, α-Al2O2, and SiO2 has been investigated. These VOCs are representative of some of the different types of oxygenated organics found in the atmosphere. The oxide particles used in this study are models for mineral dust found in the Earth's atmosphere. Initial uptake coefficients, γ0, have been extr...
Suppression of MHD Fluctuations Leading to Improved Confinement in a Gun-Driven Spheromak

Magnetic fluctuations have been reduced to approximately 1% during discharges on the Sustained Spheromak Physics Experiment by shaping the spatial distribution of the bias magnetic flux in the device. In the resulting quiescent regime, the safety factor profile is nearly flat in the plasma and the dominant ideal and resistive MHD modes are greatly reduced. During this period, the temperature profile is peaked at the magnetic axis and maps onto magnetic flux contours. Energy confinement time is improved over previous reports in a driven spheromak.
Histopathologic responses to severe alloxan diabetes in arteriosclerotic and nonarteriosclerotic rats.

Male and female virgin rats having no arteriosclerosis and male and female breeder rats having established, naturally-occurring arteriosclerosis and relatively mild diabetes were given a single injection of alloxan which induced severe ketosis, hyperglycemia and hyperlipidemia. Animals were sacrificed one, two, three, four, five, six, and seven days, four and eight weeks after the onset of severe diabetes. Their livers showed prompt severe fatty metamorphosis and their islet beta cells total degranulation. After one week of untreated severe diabetes, the fatty infiltration of the liver became somewhat reduced as did the ketosis, hyperglycemia and hyperlipidemia. Concomitantly, the islets of Langerhans were greatly hypertrophied, the beta cells remaining degranulated. Male rats exhibited testicular atrophy and calcification; female rats manifested marked ovarian hypertrophy and corpora lutea formation. Many animals developed extensive areas of renal medullary necrosis. Approximately half of the animals of each group became emaciated with depleted islet beta cells; the remaining half had partially regranulated beta cells and were obese. The formerly nonarteriosclerotic virgin rats had developed microscopic arterial lesions, the emaciated and formerly arteriosclerotic breeder rats had developed extremely severe, calcific arteriosclerosis, but the obese, formerly arteriosclerotic breeder rats manifested very little evidence of arteriosclerosis indicating regression of arterial disease. It is concluded that partial restoration of insulin ameliorated while severe insulin deficiency caused acceleration and worsening of the arteriosclerosis in both the virgin and breeder rats and that the increased arteriosclerosis was due to the abnormal levels of glucose and lipid and to the effects of insulin deficiency on aortic metabolism per se.
Pedagogy and Social Action: A Role for Narrative in Professional Communication

Scholars in professional communication have called for a reexamination of pedagogy, asking that it instruct students not simply in the forms of workplace discourse but also in the connections between that discourse and socially responsible communicative action. This article posits that narrative can provide a basis for a pedagogy of social action—for a pedagogy, that is, that enables students to understand the workings of power and cultural reproduction in professional settings and that fosters reflection, critique, and dialogue. The article first reviews narrative theory supporting this claim, then discusses ways that teachers can use narrative to help students critique examples of professional discourse and their own composing choices. The article closes by discussing both the concerns about and the possibilities for such a pedagogy.
Competitive analysis of a contact lens market

Purpose – This paper aims to present a broader industry-level competitive analysis of a contact lens market. Design/methodology/approach – Porter’s Five Forces model can be used for a broader and rigorous competitive analysis of a contact lens market to determine the competitive intensity and to form a well-rounded business strategy. Findings – The contact lens market is highly competitive and unattractive. Because growth has been stagnant, traditional competition has become more intense to steal share from each other. However, the competition in the market could not be defined narrowly between traditional competition but is broad with substitutes, and bargaining power of customers and distributors. A contact lens manufacturer has to look beyond the traditional competition to not only compete with traditional competitors within the industry but also with substitutes, and bargaining power of customers and distributors. Practical implications – This paper will benefit contact lens manufacturers/businesses in forming a well-rounded business strategy.
Searching for genomic organizational motifs: Explorations of the Escherichia coli chromosome☆

Understanding the coordinated control of gene expression is a central goal for much of the work in molecular biology. In order to understand how the mechanics of these control systems operate at the genome level, the data for the genetic organization of the model organism in question needs to be accessible. In previous work, we developed an integrated database to support analysis of the Escherichia coli genome. That system provided a pidgin English query facility, rudimentary pattern matching capabilities, and the ability to rapidly extract answers to a wide variety of questions about the organization of the E. coli genome. We have used a parser/grammar approach to identify the chromosomal positions of all of the mapped tRNA genes to be found in the aligned sequence fragments. Also, we have used this integrated data set to explore the global organization of the E. coli chromosome. We have begun to develop regulation classifications based on the arrangements of control features in relation to specific genetic control components. For example, using the individual DNA sequences for 111 known transcriptional promoters as a the starting position for analysis, we have identified the relative positions of potential control sites for 47 different procaryotic transcription factors, sigma factor 70 binding sites, and potential ribosome binding sites that occur within the region −500 to +500 bases upstream or downstream of the anchor position (the first base of the sequence feature). We have defined local descriptions for regulation based on the cross-correlated control features revealed through these analyses.
Dynamic expression of ganglion cell markers in retinal progenitors during the terminal cell cycle.

The vertebrate neural retina contains seven major cell types, which arise from a common multipotent progenitor pool. During neurogenesis, these cells stop cycling, commit to a single fate, and differentiate. The mechanism and order of these steps remain unclear. The first-born type of retinal neurons, ganglion cells (RGCs), develop through the actions of Math5 (Atoh7), Brn3b (Pou4f2) and Islet1 (Isl1) factors, whereas inhibitory amacrine and horizontal precursors require Ptf1a for differentiation. We have examined the link between these markers, and the timing of their expression during the terminal cell cycle, by nucleoside pulse-chase analysis in the mouse retina. We show that G2 phase lasts 1-2 h at embryonic (E) 13.5 and E15.5 stages. Surprisingly, we found that cells expressing Brn3b and/or Isl1 were frequently co-labeled with EdU after a short chase ( E15), Brn3b and Isl1 were exclusively expressed in post-mitotic cells, even as new RGCs are still generated. In contrast, Ptf1a and amacrine marker AP2α were detected only after terminal mitosis, at all developmental stages. Using a retroviral tracer in embryonic retinal explants (E12-E13), we identified two-cell clones containing paired ganglion cells, consistent with RGC fate commitment prior to terminal mitosis. Thus, although cell cycle exit and fate determination are temporally correlated during retinal neurogenesis, the order of these events varies according to developmental stage and final cell type.
Perfectly conducting elliptic flow past an insulator

Pour illustrer les effets d'un champ magnetique sur un ecoulement plan stationnaire d'un fluide non visqueux ideal, parfait conducteur d'electricite, on envisage les cas particuliers ou le champ magnetique a une composante differente de zero. On utilise l'analyse lineaire pour etudier les faibles perturbations d'un ecoulement initialement uniforme.
Asymmetric Small Protein Structure Determination by Individual Particle Electron Tomography

Single-particle reconstruction of electron microscopy has been successfully used to determine high-resolution structure of proteins that are highly symmetric with a large macromolecular complex (molecular weight, MW > 200 kDa). However, for asymmetric small proteins (MW < 100 kDa), this approach still faces challenges to obtain intermediate resolution structure due to difficulties attaining a reliable initial model. To obtain the initial model, especially from an asymmetric small protein, we present a novel method by individual particle electron tomography (IPET). In this method, an individual protein particle was targeted and imaged from a serials of tilt-angles by electron tomography (ET) using our reported focused ET reconstruction (FETR) algorithm to reconstruct the three-dimensional (3D) structure from those tilt serial of images that were acquired from each instance of the molecule. To demonstrate the method, we imaged and reconstructed structure of small protein, cholesteryl ester transfer protein (CETP), whose molecular weight is only 53 kDa. The experimental sample was prepared by an optimized negative-staining protocol and was acquired under the near Scherzer-focus imaging condition. To investigate the reliability of the 3D density map reconstructed from single-instance particle, we statistically analyzed the map by comparing it with the crystal structure and the density map refined from this initial model, followed by the single-particle refinement procedure. Although Fourier shell cross-correlation (FSC) analysis shows the resolution of the tomographic reconstruction and single-particle reconstruction are both around 15 A. These results suggest this approach can be used to obtain the initial model for single-particle reconstruction, moreover, the similar quality and resolution obtained from the IPET and single-particle reconstruction suggest that our reported IPET and FETR reconstruction can be used directly to determine the single-instance molecule structure at intermediate resolution (1-2 nm).
Divine immutability, properties and time

Dans un article de 1987, Dieu et le monde : Un coup d'oeil a la theologie du devenir, Thomas V. Morris propose un argument contre la doctrine traditionnelle de l'immutabilite de Dieu. L'A. decrit comment Morris traite cette question et indique quelques-unes de ses difficultes. Puis il examine la replique d'un des critiques de Morris, Brian Leftow, et montre qu'elle affronte ces difficultes. Pour finir, il donne une observation concernant un aspect deconcertant de l'argument de Morris.
Saturated superfluid-/sup 4/He film flow: Characteristic oscillations induced by persistent circulation

We report observations of characteristic reservoir oscillations induced by persistent circulation in saturated $^{4}\mathrm{He}$ films for several different geometries. The shape of the oscillation structure appears to be in qualitative agreement with the predictions of Campbell. Within the constraints imposed by theoretical approximations and uncertainties in the experimental parameters, the quantitative agreement is satisfactory.
The estrogen-responsive Agr2 gene regulates mammary epithelial proliferation and facilitates lobuloalveolar development

Agr2 is a putative protein disulfide isomerase (PDI) initially identified as an estrogen-responsive gene in breast cancer cell lines. While Agr2 expression in breast cancer is positively correlated with estrogen receptor (ER) expression, it is upregulated in both hormone dependent and independent carcinomas. Several in vitro and xenograft studies have implicated Agr2 in different oncogenic features of breast cancer; however, the physiological role of Agr2 in normal mammary gland development remains to be defined. Agr2 expression is developmentally regulated in the mammary gland, with maximum expression during late pregnancy and lactation. Using a mammary gland specific knockout mouse model, we show that Agr2 facilitates normal lobuloalveolar development by regulating mammary epithelial cell proliferation; we found no effects on apoptosis in Agr2−/− mammary epithelial cells. Consequently, mammary glands of Agr2−/− females exhibit reduced expression of milk proteins, and by two weeks post-partum their pups are smaller in size. Utilizing a conditional mouse model, we show that Agr2 constitutive expression drives precocious lobuloalveolar development and increased milk protein expression in the virgin mammary gland. In vitro studies using knock down and overexpression strategies in estrogen receptor positive and negative mammary epithelial cell lines demonstrate a role for Agr2 in estradiol-induced cell proliferation. In conclusion, the estrogen-responsive Agr2, a candidate breast cancer oncogene, regulates epithelial cell proliferation and lobuloalveolar development in the mammary gland. The pro-proliferative effects of Agr2 may explain its actions in early tumorigenesis.
Human AKR1C Isoforms Oxidize the Potent Proximate Carcinogen 7,12-DMBA-3,4-diol in the Human Lung A549 Carcinoma Cell Line

Aldo-keto reductases (AKRs) oxidize structurally diverse PAH trans -dihydrodiols to yield reactive and redox active o -quinones. This study examined the ability of AKR1C2 and AKR1C4 to oxidize PAH trans -dihydrodiols of the benz[ a ]anthracene series. The enzymes oxidized 100% of the racemic trans -dihydrodiols and the highest utilization ratios were observed for the more potent proximate carcinogens 7,12-dimethylbenz[ a ]anthracene-3,4-diol (DMBA-3,4-diol) and 7-methylbenz[ a ]anthracene-3,4-diol (7-MBA-3,4-diol). Human multiple tissue expression array analysis revealed high expression of AKR1C isoforms in the human lung carcinoma cell line A549. Both Western blot analysis using AKR1C9 antisera and enzymatic assays using 1-acenapthanol as substrate confirmed the presence of active AKR1C enzymes in A549 cells. To determine the importance of AKR1C-mediated trans -dihydrodiol oxidation in A549 cells, DMBA-3,4-diol was incubated with cell lysates in the presence of 2-mercaptoethanol. Liquid chromatography/ma...
A computational framework for evaluating residual stress distributions from diffraction-based lattice strain data

Abstract Modern high energy X-ray and neutron diffraction capabilities can provide lattice strain measurements from spatially-resolved diffraction volumes over the full domain of mechanical components with complex, three dimensional geometries. Each measurement is an average of strains in those crystals within one diffraction volume whose orientations lie along a common crystallographic fiber. Presented here is a computational framework for determining residual stress fields that fully utilizes these data while simultaneously satisfying equilibrium locally over the domain of a component and traction conditions over its surface. Key attributes of the framework are the definition of two stress fields, a continuum field and a crystal scale field, and a solution methodology for minimizing the difference between these fields. The continuum field satisfies the constraints from equilibrium and surface tractions; the crystal scale field is derived from the lattice strain measurements. To effectively handle the distinct demands required of the two fields, the framework combines a traditional, element-based discretization for the continuum stress field with an element-free discretization for the crystal scale stress field. The classical example of a residual stress field imparted by an interference fit of a disk onto a circular shaft is used to demonstrate the framework. Using lattice strain data generated by high energy X-ray diffraction, residual stress distributions are determined for two different cases, one having a two-dimensional and the other a three-dimensional stress field.
Establishing target track history by digital watermarking

Automatic tracking of targets in image sequences is an important capability. Although effective algorithms exist to implement frame to frame registration, connecting the tracks across frames is of recent interest. The current approach to this problem is by building a spatio-temporal graph. In this work we argue that the same rationale used to fingerprint multimedia content for tracing purposes can be used to follow targets across frames. Riding on top of a tracker, tracked targets receive unique watermarks which propagate throughout the video. These watermarks can then be searched for and used in a newly defined target adjacency matrix. The properties of this matrix establishes how target sequencing evolves across frames. The watermarked video is self-contained and does not require buiding and maintaining of a spati-temporal graphs.
Chromium (VI) induces both bulky DNA adducts and oxidative DNA damage at adenines and guanines in the p53 gene of human lung cells

Chromium (VI) [Cr(VI)], a ubiquitous environmental carcinogen, is generally believed to induce mainly mutagenic binary and ternary Cr(III)–deoxyguanosine (dG)-DNA adducts in human cells. However, both adenine (A) and guanine (G) mutations are found in the p53 gene in Cr exposure-related lung cancer. Using UvrABC nuclease and formamidopyrimidine glycosylase (Fpg), and ligation-mediated PCR methods, we mapped the distribution of bulky DNA adducts (BDA) and oxidative DNA damage (ODD) in the p53 gene in Cr(VI)-treated human lung cells. We found that both BDA and ODD formed at 2ʹ-deoxyadenosine (dA) and dG bases. To understand the causes for these Cr-induced DNA damages, we mapped the distribution of BDA adducts and ODD in the p53 gene DNA fragments induced by Cr(III), Cr(VI) and Cr(V), the three major cellular Cr forms. We found that (i) dA at –CA- is a major Cr(VI) binding site followed by -GG- and –G-. Cr(VI) does not bind to –GGG-, (ii) Cr(VI)–DNA binding specificity is distinctly different from the Cr(III)–DNA binding in which –GGG- and –GG- are preferential sites, (iii) Cr(V) binding sites include all of Cr(VI) and Cr(III)–DNA binding sites and (iv) Cr(VI) and Cr(V) induce Fpg-sensitive sites at –G-. Together, these results suggest that Cr(VI) induction of BDA and ODD at dA and dG residues is through Cr(V) intermediate. We propose that these Cr(VI)-induced BDA and ODD contribute to mutagenesis of the p53 gene that leads to lung carcinogenesis.
Simultaneously enhancing ionic conductivity and mechanical properties of solid polymer electrolytes via a copolymer multi-functional filler

Abstract It is a compelling challenge to both improve ionic conductivity and mechanical properties in polymeric electrolytes, and to accomplish it through a simple processing method. This study reveals that poly(ethylene oxide)-block-polyethylene (PEO- b -PE) possesses a capability for enhancing the multiple performances of PEO-based polymer electrolyte, i.e., it functions as a multi-functional miscible filler for obtaining poly(ethylene oxide)(PEO)/lithium perchlorate (LiClO 4 ) having such enhanced performances. In this paper, remarkable enhancements in both ionic conductivity and mechanical properties are presented and analyzed. Investigations on the ion transportation behavior in the polymer electrolytes through optical micrograph, X-ray diffraction, Fourier transform infrared, and dielectric spectrum analyses revealed that the ionic conductivity of a ternary polymer electrolyte, PEO/PEO- b -PE/LiClO 4 , was enhanced by an order of magnitude with the addition of this copolymer. The results of tensile tests showed the ultimate stress of the ternary polymer electrolyte increased to 7.29 MPa, modulus 114.21 MPa, and breaking strain 1142.53%, which are 2252%, 688% and 274% higher than that of PEO/LiClO 4 , respectively. This study highlights that this kind of copolymer is a promising candidate for high performance solid polymer electrolytes in lithium battery applications.
Constructions of the Obedience Experiments: A Focus Upon Domains of Relevance

The significance of the Milgram obedience experiments resides inevitably in the constructions of these studies—in the meaning and interpretations that this research holds for students and researchers. This paper reviews these constructions, with an emphasis upon the domains of relevance that have been associated with the obedience experiments. Considered first are issues bearing on the internal validity of the obedience paradigm. A brief historical excursion then examines Hannah Arendt's thesis of the “banality of evil,” a thesis with a powerful and controversial legacy of its own. To understand what those who are encountering the Milgram experiments for the first time are learning, I consider next the manner in which the ecological validity of the obedience research is discussed in contemporary texts. The paper concludes with a review of recent conceptual analyses of evil from the perspective of the obedience experiments.
Spatial and temporal variation in results of purple urchin (Strongylocentrotus purpuratus) toxicity tests with zinc

Purple urchins (Strongylocentrotus purpuratus) were maintained in year-round spawning condition in the laboratory for use in fertilization and larval development experiments designed to assess temporal variability in response to zinc. Results of these tests were compared to those from tests using gametes obtained from a field-collected population. Fertilization and larval development tests were also conducted comparing field-collected purple urchins from three geographically distinct groups on the West Coast of the United States. Fertilization tests conducted to assess temporal variability produced variable median effects concentrations (EC50s) ranging from 4.1 to >100 {micro}g/L zinc. Larval development tests did not demonstrate significant differences in response to zinc between geographically distinct purple urchin populations. Fertilization test variability was examined in terms of sperm concentration and sperm collection method during two seasons. Reduced variability was found with dry sperm collection in tests conducted in March 1995 but increased again in tests conducted in June 1995, regardless of sperm collection method. Increased variability in response to zinc may be caused by seasonal temperature effects.
Mechanical characterization of corn-derived poly-L-lactic acid

The development of corn-derived polymers is increasing. These biodegradable polymers are being highly promoted due to their pro-environmental qualities [1]. Corn-based materials can potentially help lower greenhouse gases from bioprocesses [2]. It has been found that corn chemistry products have numerous advantages over other synthetic materials [1]. Corn is the most abundant crop in the United States and its derivatives are being studied because of their biodegradable nature [1]. Many corn-derived polymers have been found useful in the oil, construction and medical industries. Within the medical industry these materials are useful in biomedical processes such as tissue-engineering scaffolds [3] and bone-replacement implants [4].
EVALUATION OF MITOTIC TIME IN VIVO, USING TRITIATED THYMIDINE AS A CELL MARKER: SUCCESSIVE LABELING WITH TIME OF SEPARATE MITOTIC PHASES.

Abstract Following a single injection of tritiated thymidine in dogs, a reproducible type of curve was obtained for the time sequence of the progression of labeled cells in separate mitotic phases, as observed on serial bone marrow aspirations. The duration of mitosis in erythroblasts at an advanced stage of maturation toward erythrocytes was shown to be of the order of 30 to 40 min for at least 50 per cent of the cells undergoing division at that stage. Mitotic duration did not appear to vary markedly for the remaining 50 per cent. The variability in the duration of the premitotic synthetic gap appeared more pronounced than the variability in the duration of mitosis. The incorporated tritiated thymidine did not of itself cause any appreciable change in these durations. The values obtained were shown not to be influenced by morphological criteria used to register cells in mitosis.
Cyclical presence of Amoebidium parasiticum on mosquito (Culicidae) hosts in central Nebraska.

tached to the arthropod host by a basal holdfast. The holdfast is composed of an amorphous cement secreted from one end ofthe thallus through discrete pores (Whisler and Fuller, 1968). Amoebidium parasiticum is found on the external cu? ticle of a number of aquatic Crustacea (Branchiopoda, Amphipoda, Isopoda, Copepoda and Cladocera) and Insecta, including larvae of Dip? tera (Chironomidae, Culicidae), Ephemeroptera, Trichoptera, and in the rectum of Odonata (Lichtwardt, 1986). Contrary to the specific ep? ithet, the fungus does not penetrate the host cu? ticle and has not been reported to be parasitic. Amoebidium parasiticum was the first axenically cultured trichomycete (Whisler, 1960,1962). The fungus has been placed in the order Amoebidales (Lichtwardt, 1986) and may reproduce by amoeboid cells which encyst and form cytospores, or by sporangiospores. Typically, reproduction is by the sporangio? spore phase where growth occurs from a sporan? giospore to a mature thallus apparently in the presence of a low calcium ion concentration. Un? der standard culture conditions, the young thal? lus enlarges in size and nuclear number until the cell reaches a mature length of approximately 52 pm. The cytoplasm cleaves into approximately 13 diagonally elongated sporangiospores which increase in volume and rupture the sporangial wall (Whisler, 1968). In the alternate reproductive pathway amoebae are produced instead of sporangiospores. In this pathway, under culture conditions, the thallus enlarges in volume and nuclear number until the cell reaches a length of approximately 45 pm, at which time a transverse cytoplasmic cleavage occurs, in contrast to the diagonally oriented cleavage of sporangiospore formation; in nature there can be sizable varia? tion in thallus dimensions. No wall forms around the cleaved units, and as the thallus wall ruptures, naked amoebae escape. Following a period of active migration, the amoebae become rotund and inactive and deposit a wall to form a cyst (Whisler, 1966,1968). Whisler (1966,1968) outlined several factors which may induce A. parasiticum to switch from the sporangiospore phase to the amoeba-cyst phase in its life cycle under laboratory conditions. A dialyzed extract of daphnids (of unknown composition) induced amoebagenesis. A pH value near 8, and a tem? perature near 30 C and a relatively high calcium concentration (about 0.01 M) were optimal for amoeba formation.
Persistent Left Superior Vena Cava: An Incidental Finding

![Figure][1] [![Graphic][3] ][3] A 29-year-old Hispanic man with palpitations was found to have a large and dilated coronary sinus (CS) on transthoracic echocardiogram ( A , [Online Video 1][3]). Agitated saline injected into the left antecubital vein opacified the CS and then the