Reactions of Tetracyclone Molybdenum Complexes with Electrophilic Alkynes: Cyclopentadienone-Alkyne Coupling and Alkyne Coordination

The reactions of the complexes [Mo(CO)2(η4-C4Ph4CO)2] and [Mo(CO)3(NCMe)(η4-C4Ph4CO)] with the alkynes dimethyl acetylenedicarboxylate (DMAD; RC≡CR where R = CO2Me) and methyl propiolate (RC≡CH) have been studied. In the case of DMAD, the initial product is the green carbonyl complex [Mo(CO)(RC≡CR)(η5,σ-C4Ph4COCR═CR)] (3), in which two alkyne molecules have been incorporated: one is linked to the carbonyl group of the tetracyclone ligand, whereas the other is π-bound to the metal as a four-electron donor. Oxidation of this compound affords yellow [Mo(O)(RC≡CR)(η5,σ-C4Ph4COCR═CR)] (8). When the π-acceptor carbonyl ligand is replaced by the π-donor oxo group, the alkyne ligand changes orientation: it lies parallel to the Mo–CO bond in 3 but perpendicular to the Mo═O group in 8. Analogous complexes (9, 10) were isolated in the case of methyl propiolate; each exists as a mixture of two isomers depending on the orientation of the unsymmetrical alkyne ligand

Reactions of Tetracyclone Molybdenum Complexes with Electrophilic Alkynes: Cyclopentadienone-Alkyne Coupling and Alkyne Coordination

The reactions of the complexes [Mo(CO)2(η4-C4Ph4CO)2] and [Mo(CO)3(NCMe)(η4-C4Ph4CO)] with the alkynes dimethyl acetylenedicarboxylate (DMAD; RC≡CR where R = CO2Me) and methyl propiolate (RC≡CH) have been studied. In the case of DMAD, the initial product is the green carbonyl complex [Mo(CO)(RC≡CR)(η5,σ-C4Ph4COCR═CR)] (3), in which two alkyne molecules have been incorporated: one is linked to the carbonyl group of the tetracyclone ligand, whereas the other is π-bound to the metal as a four-electron donor. Oxidation of this compound affords yellow [Mo(O)(RC≡CR)(η5,σ-C4Ph4COCR═CR)] (8). When the π-acceptor carbonyl ligand is replaced by the π-donor oxo group, the alkyne ligand changes orientation: it lies parallel to the Mo–CO bond in 3 but perpendicular to the Mo═O group in 8. Analogous complexes (9, 10) were isolated in the case of methyl propiolate; each exists as a mixture of two isomers depending on the orientation of the unsymmetrical alkyne ligand

Gravitational waves from inspiralling compact binaries: Parameter estimation using second-post-Newtonian waveforms

The parameters of inspiralling compact binaries can be estimated using matched filtering of gravitational-waveform templates against the output of laser-interferometric gravitational-wave detectors. Using a recently calculated formula, accurate to second post-Newtonian (2PN) order [order $(v/c)^4$, where $v$ is the orbital velocity], for the frequency sweep ($dF/dt$) induced by gravitational radiation damping, we study the statistical errors in the determination of such source parameters as the ``chirp mass'' $\cal M$, reduced mass $\mu$, and spin parameters $\beta$ and $\sigma$ (related to spin-orbit and spin-spin effects, respectively). We find that previous results using template phasing accurate to 1.5PN order actually underestimated the errors in $\cal M$, $\mu$, and $\beta$. For two inspiralling neutron stars, the measurement errors increase by less than 16 percent.Comment: 14 pages, ReVTe

Post-Newtonian SPH calculations of binary neutron star coalescence. I. Method and first results

We present the first results from our Post-Newtonian (PN) Smoothed Particle Hydrodynamics (SPH) code, which has been used to study the coalescence of binary neutron star (NS) systems. The Lagrangian particle-based code incorporates consistently all lowest-order (1PN) relativistic effects, as well as gravitational radiation reaction, the lowest-order dissipative term in general relativity. We test our code on sequences of single NS models of varying compactness, and we discuss ways to make PN simulations more relevant to realistic NS models. We also present a PN SPH relaxation procedure for constructing equilibrium models of synchronized binaries, and we use these equilibrium models as initial conditions for our dynamical calculations of binary coalescence. Though unphysical, since tidal synchronization is not expected in NS binaries, these initial conditions allow us to compare our PN work with previous Newtonian results. We compare calculations with and without 1PN effects, for NS with stiff equations of state, modeled as polytropes with $\Gamma=3$. We find that 1PN effects can play a major role in the coalescence, accelerating the final inspiral and causing a significant misalignment in the binary just prior to final merging. In addition, the character of the gravitational wave signal is altered dramatically, showing strong modulation of the exponentially decaying waveform near the end of the merger. We also discuss briefly the implications of our results for models of gamma-ray bursts at cosmological distances.Comment: RevTeX, 37 pages, 17 figures, to appear in Phys. Rev. D, minor corrections onl

Analysis of LIGO data for gravitational waves from binary neutron stars

We report on a search for gravitational waves from coalescing compact binary systems in the Milky Way and the Magellanic Clouds. The analysis uses data taken by two of the three LIGO interferometers during the first LIGO science run and illustrates a method of setting upper limits on inspiral event rates using interferometer data. The analysis pipeline is described with particular attention to data selection and coincidence between the two interferometers. We establish an observational upper limit of $\mathcal{R}<$1.7 \times 10^{2}$per year per Milky Way Equivalent Galaxy (MWEG), with 90coalescence rate of binary systems in which each component has a mass in the range 1--3$M_\odot$.Comment: 17 pages, 9 figure

Meta-analysis of data from animal studies:A practical guide

AbstractMeta-analyses of data from human studies are invaluable resources in the life sciences and the methods to conduct these are well documented. Similarly there are a number of benefits in conducting meta-analyses on data from animal studies; they can be used to inform clinical trial design, or to try and explain discrepancies between preclinical and clinical trial results. However there are inherit differences between animal and human studies and so applying the same techniques for the meta-analysis of preclinical data is not straightforward. For example preclinical studies are frequently small and there is often substantial heterogeneity between studies. This may have an impact on both the method of calculating an effect size and the method of pooling data. Here we describe a practical guide for the meta-analysis of data from animal studies including methods used to explore sources of heterogeneity

Psychosocial Treatment of Children in Foster Care: A Review

A substantial number of children in foster care exhibit psychiatric difficulties. Recent epidemiologi-cal and historical trends in foster care, clinical findings about the adjustment of children in foster care, and adult outcomes are reviewed, followed by a description of current approaches to treatment and extant empirical support. Available interventions for these children can be categorized as either symptom-focused or systemic, with empirical support for specific methods ranging from scant to substantial. Even with treatment, behavioral and emotional problems often persist into adulthood, resulting in poor functional outcomes. We suggest that self-regulation may be an important mediat-ing factor in the appearance of emotional and behavioral disturbance in these children

Longitudinal retinal changes in MOGAD

OBJECTIVE: Patients with myelin oligodendrocyte glycoprotein antibody (MOG-IgG) associated disease (MOGAD) suffer from severe optic neuritis (ON) leading to retinal neuro-axonal loss, which can be quantified by optical coherence tomography (OCT). We assessed whether ON-independent retinal atrophy can be detected in MOGAD. METHODS: Eighty MOGAD patients and 139 healthy controls (HC) were included. OCT data was acquired with 1) Spectralis spectral domain OCT (MOGAD (N=66) and HC (N=103)) and 2) Cirrus HD-OCT (MOGAD (N=14) and HC (N=36)). Macular combined ganglion cell and inner plexiform layer (GCIPL) and peripapillary retinal nerve fibre layer (pRNFL) were quantified. RESULTS: At baseline, GCIPL and pRNFL were lower in MOGAD eyes with a history of ON (MOGAD-ON) compared with MOGAD eyes without a history of ON (MOGAD-NON) and HC (p12 months ago (p<0.001). The overall MOGAD cohort did not exhibit faster GCIPL thinning compared with HC. INTERPRETATION: Our study suggests the absence of attack-independent retinal damage in MOGAD. Yet, ongoing neuroaxonal damage or oedema resolution seems to occur for up to 12 months after ON, which is longer than what has been reported with other ON forms. These findings support that the pathomechanisms underlying optic nerve involvement and the evolution of OCT retinal changes after ON is distinct in MOGAD. This article is protected by copyright. All rights reserved