Bromostibine complexes of iron(II): hypervalency and reactivity

The halostibine complexes [CpFe(CO)2(SbMe2Br)][CF3SO3] and [CpFe(CO)2(SbMe2Br)][BF4] both contain significant interactions between the anion and the formally neutral Sb(III) ligand, which simultaneously displays Lewis acidic and Lewis basic properties. The unexpected secondary product [CpFe(CO)(Me2BrSb-?-Br-SbBrMe2)] is formed in the presence of excess ligand, the strongly associated Br– anion bridging the two Sb donors to form a four-membered FeSb2Br ring.<br/

The Dimerization of an α/β-Knotted Protein Is Essential for Structure and Function

Summaryα/β-Knotted proteins are an extraordinary example of biological self-assembly; they contain a deep topological trefoil knot formed by the backbone polypeptide chain. Evidence suggests that all are dimeric and function as methyltransferases, and the deep knot forms part of the active site. We investigated the significance of the dimeric structure of the α/β-knot protein, YibK, from Haemophilus influenzae by the design and engineering of monomeric versions of the protein, followed by examination of their structural, functional, stability, and kinetic folding properties. Monomeric forms of YibK display similar characteristics to an intermediate species populated during the formation of the wild-type dimer. However, a notable loss in structure involving disruption to the active site, rendering it incapable of cofactor binding, is observed in monomeric YibK. Thus, dimerization is vital for preservation of the native structure and, therefore, activity of the protein

Anti-Cancer Drugs: The mitochondrial paradox

A structural motif that is found in two cancer drugs may be responsible for their ability to tackle cancers and for the side-effects caused by the drugs

The Role of NMDA Receptor Subtypes in Short-Term Plasticity in the Rat Entorhinal Cortex

We have previously shown that spontaneous release of glutamate in the entorhinal cortex (EC) is tonically facilitated via activation of presynaptic NMDA receptors (NMDAr) containing the NR2B subunit. Here we show that the same receptors mediate short-term plasticity manifested by frequency-dependent facilitation of evoked glutamate release at these synapses. Whole-cell patch-clamp recordings were made from layer V pyramidal neurones in rat EC slices. Evoked excitatory postsynaptic currents showed strong facilitation at relatively low frequencies (3 Hz) of activation. Facilitation was abolished by an NR2B-selective blocker (Ro 25-6981), but unaffected by NR2A-selective antagonists (Zn2+, NVP-AAM077). In contrast, postsynaptic NMDAr-mediated responses could be reduced by subunit-selective concentrations of all three antagonists. The data suggest that NMDAr involved in presynaptic plasticity in layer V are exclusively NR1/NR2B diheteromers, whilst postsynaptically they are probably a mixture of NR1/NR2A, NR1/NR2B diheteromers and NR1/NR2A/NR2B triheteromeric receptors

Improved Mixed Dark Matter Halo Model for Ultralight Axions

We present a complete halo model for mixed dark matter composed of cold dark matter (CDM) and ultralight axion-like particles (ULAs). Our model treats ULAs as a biased tracer of CDM, in analogy to treatments of massive neutrinos and neutral hydrogen. The model accounts for clustering of ULAs around CDM host halos, and fully models the cross correlations of both components. The model inputs include the ULA Jeans scale, and soliton density profile. Our model can be used to predict the matter power spectrum, $P(k)$, on non-linear scales for sub-populations of ULAs across the mass range $10^{-33}\text{ eV}\leq m\leq 10^{-21}\text{ eV}$, and can be calibrated against future mixed DM simulations to improve its accuracy. The mixed DM halo model also allows us to assess the importance of various approximations.Comment: 18 pages, 11 figures, codes are available at https://github.com/SophieMLV/axionHMcode and https://github.com/SophieMLV/nuHMcode, paper was accepted for publication as a Regular Article in Physical Review

ALMA Millimeter/Submillimeter Sources among Spitzer SMUVS Galaxies at z &gt; 2 in the COSMOS Field

Submillimeter observations reveal the star formation activity obscured by dust in the young Universe. It still remains unclear how galaxies detected at submillimeter wavelengths are related to ultraviolet/optical-selected galaxies in terms of their observed quantities, physical properties, and evolutionary stages. Deep near- and mid-infrared observational data are crucial to characterize the stellar properties of galaxies detected with submillimeter emission. In this study, we make use of a galaxy catalog from the Spitzer Matching survey of the UltraVISTA ultra-deep Stripes. By crossmatching with a submillimeter source catalog constructed with archival data of the Atacama Large Millimeter/submillimeter Array (ALMA), we search for galaxies at z &gt; 2 with a submillimeter detection in our galaxy catalog. We find that the ALMA-detected galaxies at z &gt; 2 are systematically massive and have redder K s -[4.5] colors than the nondetected galaxies. The redder colors are consistent with the larger dust reddening values of the ALMA-detected galaxies obtained from spectral energy distribution (SED) fitting. We also find that the ALMA-detected galaxies tend to have brighter 4.5 μm magnitudes. This may suggest that they tend to have smaller mass-to-light ratios and thus to be younger than star-forming galaxies fainter at submillimeter wavelengths with similar stellar masses. We identify starburst galaxies with high specific star formation rates among both ALMA-detected and nondetected SMUVS sources. Irrespective of their brightness at submillimeter wavelengths, these populations have similar dust reddening values, which may suggest a variety of dust SED shapes among the starburst galaxies at z &gt; 2.</p

Beliefs and Self-Efficacy of Parents of Young Children with Hearing Loss

The purpose of this study was to learn more about the beliefs and self-efficacy of parents of young children with hearing loss. Seventy-two parents completed the Scale of Parental Involvement and Self-Efficacy - Revised (SPISE-R), which queries parents about their child’s hearing device use and their perceptions of their own beliefs, knowledge, confidence, and actions pertaining to supporting their child’s auditory access and spoken language development. Two beliefs were identified that related to parents’ action scores and one belief was identified that related to children’s hearing device use. Knowledge and confidence scores were significantly correlated with action scores and children’s hearing device use, whereas only confidence scores were related to scores on a measure of children’s spoken language abilities. Results indicate the SPISE-R is a promising tool for use in early intervention to better understand parents’ strengths and needs pertaining to supporting their young child’s auditory access and spoken language development

ALMA sub-/millimeter sources among SpitzerSpitzer SMUVS galaxies at z>2z>2 in the COSMOS field

Sub-millimeter observations reveal the star-formation activity obscured by dust in the young Universe. It still remains unclear how galaxies detected at sub-millimeter wavelengths are related to ultraviolet/optical-selected galaxies in terms of their observed quantities, physical properties, and evolutionary stages. Deep near- and mid-infrared observational data are crucial to characterize the stellar properties of galaxies detected with sub-millimeter emission. In this study, we make use of a galaxy catalog from the $Spitzer$ Matching Survey of the UltraVISTA ultra-deep Stripes. By cross-matching with a sub-millimeter source catalog constructed with the archival data of the Atacama Large Millimeter/submillimeter Array (ALMA), we search for galaxies at $z>$ 2 with a sub-millimeter detection in our galaxy catalog. We find that the ALMA-detected galaxies at $z>$ 2 are systematically massive and have redder $K_s$-[4.5] colors than the non-detected galaxies. The redder colors are consistent with the larger dust reddening values of the ALMA-detected galaxies obtained from SED fitting. We also find that the ALMA-detected galaxies tend to have brighter 4.5 $\mu$m magnitudes. This may suggest that they tend to have smaller mass-to-light ratios, and thus, to be younger than star-forming galaxies fainter at sub-millimeter wavelengths with similar stellar masses. We identify starburst galaxies with high specific star-formation rates among both ALMA-detected and non-detected SMUVS sources. Irrespective of their brightness at sub-millimeter wavelengths, these populations have similar dust reddening values, which may suggest a variety of dust SED shapes among the starburst galaxies at $z>2$.Comment: 14 pages, 7 figures, 2 tables, Accepted for publication in Ap