Multireference Ab Initio Study of the Ground and Low-Lying Excited States of Cr(CO)₂ and Cr(CO)₃

We investigate the ground and low-lying excited states of unsaturated chromium carbonyls, Cr­(CO)₂ and Cr­(CO)₃, using multiconfigurational ab initio perturbation theory. Unlike other chromium carbonyls, there are discrepancies between the experiment and theory on the identity of the ground states of Cr­(CO)₂ and Cr­(CO)₃. From multireference ab initio calculations considering the full valence orbitals of Cr­(CO)₂ and Cr­(CO)₃, the differences in the molecular structures of their various electronic states are explained by the electronic structure analysis. On the basis of the result from CASPT2 and MS-CASPT2 calculations, we propose that the ground states of Cr­(CO)₂ and Cr­(CO)₃ are the ⁵Π_g and ¹A₁ states, respectively, addressing the ambiguity regarding their ground states. In addition, the multiconfigurational ab initio perturbation theory calculations reveal that (1) the energy gaps between the ground and first low-lying excited states of Cr­(CO)₂ and Cr­(CO)₃ are quite small and (2) the first low-lying excited states of Cr­(CO)₂ and Cr­(CO)₃ have the same spin multiplicities as the ground states of CrCO and Cr­(CO)₂, respectively, which are the products of ligand dissociation. As a result, the apparent spin-forbidden dissociation of Cr­(CO)₂ and Cr­(CO)₃ into CrCO and Cr­(CO)₂, respectively, are likely to be facilitated by thermal excitation of the ground states of Cr(CO)₂ and Cr(CO)₃ into their first low-lying excited states, which then actually undergoes the spin-allowed dissociation to the ground states of CrCO and Cr­(CO)₂ with the same spin multiplicities

Long-term L1 starvation causes tissue damage and delay in development during recovery.

<p>A Fraction of worms that reach adulthood after indicated days of L1 starvation (see Materials and Methods). Approximately 100 worms were used per experiment and each experiment was done with triplicates. B Cumulative fraction of worms that reach adulthood after indicated days of L1 starvation. Line drawn to show the time when 50% worms reach adulthood after indicated hours of refeeding. C DIC (Differential Interference Contrast) image of wild type gonad: the worm was starved for 3 days as an L1 and recovered to grow to an adult. For all experiments to observe gonad defect, approximately 100 worms were used per experiment and each experiment was done with triplicates. D DIC image of wild type gonad: the worm was starved for 9 days as an L1 at 20°C and recovered to grow to an adult at 20°C. No eggs are visible. E–F DIC images of gonads of <i>daf-16</i> mutants (E) and <i>daf-18</i> mutants (F): worms were starved for 3 days at 20°C as L1s and recovered to grow to adults at 20°C. No eggs are visible. G Percent destroyed gonad increases as L1 starvation continues.</p

Diogenes of Oinoanda – Diogène d’Œnoanda. Epicureanism and Philosophical Debates – Épicurisme et controverses: Epicureanism and Philosophical Debates – Épicurisme et controverses

International audienceThe texts of Diogenes of Oinoanda (2nd century AD) who invited his readers to an Epicurean life is the largest ancient inscription ever discovered. Over 70 new finds have increased the number of known wall blocks and fragments to nearly 300, offering new insights into Diogenes’ distinctive presentation of philosophy. This collection of essays discusses the philosophical significance of these discoveries and is the first publication entirely devoted to Diogenes of Oinoanda. Particular attention is paid to his philosophical aims and polemical strategies. Diogenes was apparently well aware of still ongoing philosophical debates, engaging in polemics against Presocratic philosophers, Platonics, and especially Stoics. His views about important issues like happiness, fear, old age, and the afterlife are explained on the bases of Epicurean physics and theology, ethics, politics, theory of knowledge, and psychology.Les textes de Diogène d’Œnoanda (Deuxième siècle de notre ère), qui invitait ses lecteurs au mode de vie épicurien, constituent la plus grande inscription antique jamais découverte. Les recherches récentes (plus de 70 pièces) ont porté le nombre de morceaux du mur et de fragments à près de 300, offrant ainsi un nouvel aperçu de la pensée propre de Diogène. Les essais réunis dans ce volume, la première publication entièrement consacrée à Diogène d’Œnoanda, examinent la signification de ces découvertes. Ils portent une attention particulière aux intentions philosophiques de Diogène et à ses stratégies polémiques. L’épicurien était manifestement bien averti des débats philosophiques de son temps, engageant lui-même la polémique contre les présocratiques, les platoniciens et, plus spécialement, les stoïciens. Ses idées concernant les problèmes fondamentaux du bonheur, de la peur, de la vieillesse et de la vie après la mort ont pour horizon la pensée épicurienne sous ses différents aspects : physique et théologie, éthique, politique, théorie de la connaissance et psychologie

Down regulation of metabolism or addition of glucose enhances <i>aak-2</i> L1 longevity.

<p>A–B Starvation at 15°C enhances <i>aak-2</i> L1 longevity in <i>aak-2</i> mutants (A: <i>rr48,</i> B: <i>ok524</i>), ***<i>p<0.001</i>. C Mutation in <i>ife-2</i> enhances <i>aak-2</i> L1 longevity, ***<i>p<0.001.</i> D Glucose and fructose (100 mM) slightly enhanced L1 longevity of wild type but sorbitol and L-glucose didn’t. <i>p<0.001</i> between control and the wild type treated with glucose or fructose. D: D-glucose, L: L-glucose, F: fructose, S: sorbitol. E–F Glucose and fructose enhanced <i>aak-2</i> L1 longevity but sorbitol and L-glucose didn’t. <i>p<0.001</i> between control and the <i>aak-2</i> mutants treated with glucose or fructose. For each experiment, approximately 100–200 L1s were used. D: D-glucose, L: L-glucose, F: fructose, S: sorbitol.</p

L1 arrest is a starvation response depending on metabolic rates.

<p>A L1s arrested at low temperature live longer than those arrested at high temperature. Eggs were collected and hatched without food and L1s were maintained at the indicated temperatures <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0044720#pone.0044720-You1" target="_blank">[26]</a>. For all L1 longevity assays, each sample contained approximately 10 worms/µl and each plate was plated with approximately 150–200 worms. Every experiment was repeated at least three times with triplicates (see Materials and Methods). B LT 50 (50% lethality) for worms that arrested at 15°C, 20°C and 25°C. C Life spans of arrested L1s of <i>daf-7</i> and <i>daf-3</i> mutants tested at 25°C. D Rates of oxygen consumption in wild type, <i>daf-2</i> and <i>daf-16</i> mutants (**<i>p<0.01</i>, by two way ANOVA). E Rates of oxygen consumption in wild type and <i>daf-18</i> mutants <i>(*p<0.05</i>, by two way ANOVA).</p

Prospect of Retrieving Vibrational Wave Function by Single-Object Scattering Sampling

The exact shape of wave functions has never been directly measured because an ensemble measurement is often overwhelmed by the contributions of highly populated configurations. In this work, we explore the possibility of directly obtaining vibrational wave functions by single-object scattering sampling (SOSS) using intense, ultrashort X-ray pulses provided by X-ray free electron lasers. Previously, single-molecule diffraction experiments using femtosecond X-ray pulses have been proposed with the prospect of determining three-dimensional structure of macromolecules without the need of single-crystal samples. In contrast to the previous proposals, SOSS is designed for obtaining the structural variations of constantly fluctuating molecules by sampling many single-shot, single-object scattering patterns. From the simulations on iodine molecules adopting various pulse characteristics and molecular parameters, we were able to reconstruct vibrational wave functions of molecular iodine and found that SOSS is feasible under appropriate experimental conditions

AMPK is necessary for L1 longevity.

<p>A Percent survival of wild type (▪) and two independent <i>aak-2</i> mutants (<i>ok524</i> (gray ▴) and <i>rr48</i> (gray ♦)) after L1 starvation at 22.5°C for the indicated number of days. B DIC (Differential Interference Contrast) image of wild type gonad. The black arrow indicates the button like structure of the nucleus of a dying cell. The white arrow indicates an oocyte. C Fluorescent image of the same worm stained with acridine orange to detect cell death. The white arrow indicates the dying cell. D&F DIC images of AMPK mutant gonads. The black arrows indicate dying cells. Gonads are destroyed and no oocytes are visible. E&G Fluorescent images of the same worms stained with acridine orange reveal more dying cells (the white arrows) in the gonads of AMPK mutants. H Percent destroyed gonads in two independent <i>aak-2</i> mutants. I After 3 days of L1 starvation at 22.5°C and recovery, <i>cep-1</i> mutation partially rescued <i>aak-2</i> gonad phenotype.</p

<i>par-4</i> partially phenocopies starvation-induced phenotype of <i>aak-2</i>.

<p>A. Percent damaged gonad of wild type and <i>par-4</i> mutants after L1 starvation for the indicated days. B. Percent survival of wild type (♦), <i>aak-2</i> (gray ▪) and <i>par-4</i> (gray▴) mutants after L1 starvation for the indicated days.</p

Prospect of Retrieving Vibrational Wave Function by Single-Object Scattering Sampling

The exact shape of wave functions has never been directly measured because an ensemble measurement is often overwhelmed by the contributions of highly populated configurations. In this work, we explore the possibility of directly obtaining vibrational wave functions by single-object scattering sampling (SOSS) using intense, ultrashort X-ray pulses provided by X-ray free electron lasers. Previously, single-molecule diffraction experiments using femtosecond X-ray pulses have been proposed with the prospect of determining three-dimensional structure of macromolecules without the need of single-crystal samples. In contrast to the previous proposals, SOSS is designed for obtaining the structural variations of constantly fluctuating molecules by sampling many single-shot, single-object scattering patterns. From the simulations on iodine molecules adopting various pulse characteristics and molecular parameters, we were able to reconstruct vibrational wave functions of molecular iodine and found that SOSS is feasible under appropriate experimental conditions

Coherent Oscillations in Chlorosome Elucidated by Two-Dimensional Electronic Spectroscopy

Chlorosomes are the most efficient photosynthetic light-harvesting complexes found in nature and consist of many bacteriochlorophyll (BChl) molecules self-assembled into supramolecular aggregates. Here we elucidate the presence and the origin of coherent oscillations in chlorosome at cryogenic temperature using 2D electronic spectroscopy. We observe coherent oscillations of multiple frequencies superimposed on the ultrafast amplitude decay of 2D spectra. Comparison of oscillatory features in the rephasing and nonrephasing 2D spectra suggests that an oscillation of 620 cm^–1 frequency arises from electronic coherence. However, this coherent oscillation can be enhanced by vibronic coupling with intermolecular vibrations of BChl aggregate, and thus it might originate from vibronic coherence rather than pure electronic coherence. Although the 620 cm^–1 oscillation dephases rapidly, the electronic (or vibronic) coherence may still take part in the initial step of energy transfer in chlorosome, which is comparably fast