Raman spectroscopy and field emission measurements on catalytically grown carbon nanotubes

We used microcontact printing to pattern a silicon surface with an iron-containing catalytic solution. Multi-wall carbon nanotubes were subsequently grown on the patterned areas by chemical vapor deposition at temperatures between 650 and 1000C. We demonstrate that the diameter of the catalytically grown multi-wall nanotubes increases with the deposition temperature. Raman spectroscopy has been used to investigate the crystalline character of the obtained structures and it is found that the fraction of the nano-crystalline shell increases with the temperatures. The measurement of the field emission properties shows a correlation between the tube diameter and the emission field values.Comment: 6 pages, 6 figures, 1 tabl

Isovector One-Quadrupole-Phonon Excitations of Heavy Vibrational Nuclei

The investigation and identification of mixed-symmetry states stand in the focus of this work. They are formed from collective vibrations and rotations of valence neutrons and protons, where the two nucleon groups oscillate partly out-of-phase with respect to each other. In vibrational nuclei, the $2^+_\mathrm{1,ms}$ state is the lowest-lying mixed-symmetry level. For the $N=80$ isotones, the sub-shell closure at $Z=58$ highly effects the structure of the $2^+_\mathrm{1,ms}$ state. Up to $Z=56$, the isotones have isolated $2^+_\mathrm{1,ms}$ states, but for $^{138}$Ce ($Z=58$), it is strongly fragmented. This behaviour is explained by the valence-shell stabilization, which is lacking at the proton sub-shell closure $Z=58$. For addressing the question how the $2^+_\mathrm{1,ms}$ state behaves while going beyond the proton sub-shell closure, projectile Coulomb-excitation experiments were performed. They took place at HIE-ISOLDE at CERN using the $\gamma$-ray spectrometer Miniball with the radioactive ion beams of the $N=80$ isotones $^{140}$Nd and $^{142}$Sm. The enhanced $B(M1;2^+_3\to2^+_1)=0.26^{+0.11}_{-0.10}\,\mu_\mathrm{N}^2$ strength and the low upper limit $B(M1;2^+_4\to2^+_1)<0.04\,\mu_\mathrm{N}^2$ of $^{140}$Nd showed the restoration of the valence-shell stabilization at $Z=60$. From the $M1$ strength distribution, the quality of the $F$ spin of $^{140}$Nd was determined by the $F$-spin mixing matrix element $V_\mathrm{F-mix}<7^{+13}_{-7}\,\mathrm{keV}$. The reduced mixing matrix element supports the proposed restoration of the valence-shell stabilization. For $^{142}$Sm, the Coulomb-excitation analysis delivered an upper limit $B(M1;2^+_3\to2^+_1)<0.14^{+0.37}_{-0.01}\,\mu_\mathrm{N}^2$, which is not in conflict with the conclusions from the $^{140}$Nd experiment. A complementary $\gamma$-$\gamma$ correlation measurement after $\beta^+$/$\epsilon$ decay to determine the indispensable $E2$/$M1$ multipole-mixing ratio $\delta$ of the $2^+_3\to2^+_1$ transition of $^{142}$Sm was designed for the Heavy Ion Laboratory in Warsaw and accepted. For the stable $^{202}$Hg, a projectile Coulomb-excitation experiment was conducted at the ATLAS facility at the ANL using the $\gamma$-ray spectrometer Gammasphere. Simultaneously, angular particle-$\gamma$ correlations were measured with the aim of deducing $\delta$. In $^{202}$Hg a pronounced $B(M1;2^+_7\to2^+_1)=0.18(8) \,\mu_\mathrm{N}^2$ with $\delta=0.06(4)$ was found, while an upper limit for the neighboring transition was obtained, $B(M1;2^+_8\to2^+_1)<0.027 \,\mu_\mathrm{N}^2$. For the first time in the mass region $A\approx200$, the $F$-spin mixing quality was determined, for $^{202}$Hg and $^{204}$Hg, $V_\mathrm{F-mix}=9(2)^{+3}_{-3}\,\mathrm{keV}$ and $11(1)^{+4}_{-5}\,\mathrm{keV}$, respectively. Consequently, $F$ spin can be considered a sufficiently good approximate quantum number in the investigated nuclei of $N,Z=80$ near doubly-magic isotopes

Mitochondrial DNA Content in Human Omental Adipose Tissue

Background: Impairment of mitochondrial function plays an important role in obesity and the development of insulin resistance. The aim of this project was to investigate the mitochondrial DNA copy number in human omental adipose tissue with respect to obesity. Methods: The mitochondrial DNA (mtDNA) content per single adipocyte derived from abdominal omental adipose tissue was determined by quantitative RT-PCR in a group of 75 patients, consisting of obese and morbidly obese subjects, as well as non-obese controls. Additionally, basal metabolic rate and fat oxidation rate were recorded and expressed as total values or per kilogram fat mass. Results: MtDNA content is associated with obesity. Higher body mass index (BMI) resulted in a significantly elevated mtDNA count (ratio = 1.56; p = 0.0331) comparing non-obese (BMI < 30) to obese volunteers (BMI ≥ 30). The mtDNA count per cell was not correlated with age or gender. Diabetic patients showed a trend toward reduced mtDNA content. A seasonal change in mtDNA copy number could not be identified. In addition, a substudy investigating the basal metabolic rate and the fasting fat oxidation did not reveal any associations to the mtDNA count. Conclusions: The mtDNA content per cell of omental adipose tissue did not correlate with various clinical parameters but tended to be reduced in patients with diabetes, which may partly explain the impairment of mitochondrial function observed in insulin resistance. Furthermore, the mtDNA content was significantly increased in patients suffering from obesity (BMI above 30). This might reflect a compensatory response to the development of obesity, which is associated with impairment of mitochondrial functio

Analysis of the “Sonar Hopf” Cochlea

The “Sonar Hopf” cochlea is a recently much advertised engineering design of an auditory sensor. We analyze this approach based on a recent description by its inventors Hamilton, Tapson, Rapson, Jin, and van Schaik, in which they exhibit the “Sonar Hopf” model, its analysis and the corresponding hardware in detail. We identify problems in the theoretical formulation of the model and critically examine the claimed coherence between the described model, the measurements from the implemented hardware, and biological data

Of Roots and Fruits: A Comparison of Psychedelic and Nonpsychedelic Mystical Experiences

Experiences of profound existential or spiritual significance can be triggered reliably through psychopharmacological means using psychedelic substances. However, little is known about the benefits of religious, spiritual, or mystical experiences (RSMEs) prompted by psychedelic substances, as compared with those that occur through other means. In this study, 739 self-selected participants reported the psychological impact of their RSMEs and indicated whether they were induced by a psychedelic substance. Experiences induced by psychedelic substances were rated as more intensely mystical ( d = .75, p &lt; .001), resulted in a reduced fear of death ( d = .21, p &lt; .01), increased sense of purpose ( d = .18, p &lt; .05), and increased spirituality ( d = .28, p &lt; .001) as compared with nonpsychedelically triggered RSMEs. These results remained significant in an expanded model controlling for gender, education, socioeconomic status, and religious affiliation. These findings lend support to the growing consensus that RSMEs induced with psychedelic substances are genuinely mystical and generally positive in outcome. </jats:p

Di-(2-Ethylhexyl)-Phthalate (DEHP) Causes Impaired Adipocyte Function and Alters Serum Metabolites

Di-(2-ethylhexyl)-phthalate (DEHP), an ubiquitous environmental contaminant, has been shown to cause adverse effects on glucose homeostasis and insulin sensitivity in epidemiological studies, but the underlying mechanisms are still unknown. We therefore tested the hypothesis that chronic DEHP exposure causes impaired insulin sensitivity, affects body weight, adipose tissue (AT) function and circulating metabolic parameters of obesity resistant 129S6 mice in vivo. An obesity-resistant mouse model was chosen to reduce a potential obesity bias of DEHP effects on metabolic parameters and AT function. The metabolic effects of 10-weeks exposure to DEHP were tested by insulin tolerance tests and quantitative assessment of 183 metabolites in mice. Furthermore, 3T3-L1 cells were cultured with DEHP for two days, differentiated into mature adipocytes in which the effects on insulin stimulated glucose and palmitate uptake, lipid content as well as on mRNA/protein expression of key adipocyte genes were investigated.We observed in female mice that DEHP treatment causes enhanced weight gain, fat mass, impaired insulin tolerance, changes in circulating adiponectin and adipose tissue Pparg, adiponectin and estrogen expression. Serum metabolomics indicated a general increase in phospholipid and carnitine concentrations. In vitro, DEHP treatment increases the proliferation rate and alters glucose uptake in adipocytes. Taken together, DEHP has significant effects on adipose tissue (AT) function and alters specific serum metabolites. Although, DEHP treatment led to significantly impaired insulin tolerance, it did not affect glucose tolerance, HOMA-IR, fasting glucose, insulin or triglyceride serum concentrations. This may suggest that DEHP treatment does not cause impaired glucose metabolism at the whole body level

VSI: a milli-arcsec spectro-imager for the VLTI

VLTi Spectro-Imager (VSI) is a proposition for a second generation VLTI instrument which is aimed at providing the ESO community with the capability of performing image synthesis at milli-arcsecond angular resolution. VSI provides the VLTI with an instrument able to combine 4 telescopes in a baseline version and optionally up to 6 telescopes in the near-infrared spectral domain with moderate to high spectral resolution. The instrument contains its own fringe tracker in order to relax the constraints onto the VLTI infrastructure. VSI will do imaging at the milli-arcsecond scale with spectral resolution of: a) the close environments of young stars probing the initial conditions for planet formation; b) the surfaces of stars; c) the environment of evolved stars, stellar remnants and stellar winds, and d) the central region of active galactic nuclei and supermassive black holes. The science cases allowed us to specify the astrophysical requirements of the instrument and to define the necessary studies of the science group for phase A.Comment: 12 page

Important mitochondrial proteins in human omental adipose tissue show reduced expression in obesity.

Obesity is associated with impaired mitochondrial function. This study compares mitochondrial protein expression in omental fat in obese and non-obese humans. Omental adipose tissue was obtained by surgical biopsy, adipocytes were purified and mitochondria isolated. Using anion-exchange chromatography, SDS-PAGE and mass-spectrometry, 128 proteins with potentially different abundances in patient groups were identified, 62 of the 128 proteins are mainly localized in the mitochondria. Further quantification of 12 of these 62 proteins by immune dot blot analysis revealed four proteins citrate synthase, HADHA, LETM1 and mitofilin being inversely associated with BMI, and mitofilin being inversely correlated with gender

A community-maintained standard library of population genetic models

The explosion in population genomic data demands ever more complex modes of analysis, and increasingly, these analyses depend on sophisticated simulations. Recent advances in population genetic simulation have made it possible to simulate large and complex models, but specifying such models for a particular simulation engine remains a difficult and error-prone task. Computational genetics researchers currently re-implement simulation models independently, leading to inconsistency and duplication of effort. This situation presents a major barrier to empirical researchers seeking to use simulations for power analyses of upcoming studies or sanity checks on existing genomic data. Population genetics, as a field, also lacks standard benchmarks by which new tools for inference might be measured. Here, we describe a new resource, stdpopsim, that attempts to rectify this situation. Stdpopsim is a community-driven open source project, which provides easy access to a growing catalog of published simulation models from a range of organisms and supports multiple simulation engine backends. This resource is available as a well-documented python library with a simple command-line interface. We share some examples demonstrating how stdpopsim can be used to systematically compare demographic inference methods, and we encourage a broader community of developers to contribute to this growing resource.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]