621 research outputs found

    trans-Bis{1-[2-(2,6-diisopropyl­anilino)phenyl]-3-isopropyl­imidazolin-2-ylidenyl-κC 2}diiodidopalladium(II) benzene disolvate

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    In the title complex, [PdI2(C24H31N3)2]·2C6H6, the Pd2+ ion is located on an inversion centre in a slightly distorted square-planar geometry. The angle between the I2C2 square plane and the mean plane of the N-heterocyclic carbene ring is 79.8 (2)°, with I—Pd—C—N torsion angles of −81.1 (6) and −78.2 (5)°. The Pd—carbene and Pd—I distances are 2.016 (6) and 2.5971 (10) Å, respectively

    Revisiting the hyperdominance of Neotropical tree species under a taxonomic, functional and evolutionary perspective

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    Recent studies have leveraged large datasets from plot-inventory networks to report a phenomenon of hyperdominance in Amazonian tree communities, concluding that few species are common and many are rare. However, taxonomic hypotheses may not be consistent across these large plot networks, potentially masking cryptic diversity and threatened rare taxa. In the current study, we have reviewed one of the most abundant putatively hyperdominant taxa, Protium heptaphyllum (Aubl.) Marchand (Burseraceae), long considered to be a taxonomically difficult species complex. Using morphological, genomic, and functional data, we present evidence that P. heptaphyllum sensu lato may represent eight separately evolving lineages, each warranting species status. Most of these lineages are geographically restricted, and few if any of them could be considered hyperdominant on their own. In addition, functional trait data are consistent with the hypothesis that trees from each lineage are adapted to distinct soil and climate conditions. Moreover, some of the newly discovered species are rare, with habitats currently experiencing rapid deforestation. We highlight an urgent need to improve sampling and methods for species discovery in order to avoid oversimplified assumptions regarding diversity and rarity in the tropics and the implications for ecosystem functioning and conservation

    Age-related changes in afferent pathways and urothelial function in the male mouse bladder

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    Key points •The prevalence of bladder conditions such as overactive bladder syndrome and urinary incontinence significantly increases with age, but how bladder function is altered by ageing is unclear. •Sensory nerves together with the epithelial lining of the bladder known as the urothelium play a key role in mediating bladder function. •In aged male mice we find a significant increase in natural bladder voiding, augmented afferent nerve firing during bladder filling and a significant increase in urothelial responses to purinergic receptor stimulation. •This suggests that with ageing there is increased purinergic transmission in the mouse bladder which may lead to increased sensation and result in bladder hypersensitivity. •These findings help us better understand how the function of the bladder may be affected by advancing age. Abstract The prevalence of lower urinary tract storage disorders such as overactive bladder syndrome and urinary incontinence significantly increase with age. Previous studies have demonstrated age-related changes in detrusor function and urothelial transmitter release but few studies have investigated how the urothelium and sensory pathways are affected. The aim of this study was to investigate the effect of ageing on urothelial-afferent signalling in the mouse bladder. Three-month-old control and 24-month-old aged male mice were used. In vivo natural voiding behaviour, sensory nerve activity, urothelial cell function, muscle contractility, transmitter release and gene and protein expression were measured to identify how all three components of the bladder (neural, contractile and urothelial) are affected by ageing. In aged mice, increased voiding frequency and enhanced low threshold afferent nerve activity was observed, suggesting that ageing induces overactivity and hypersensitivity of the bladder. These changes were concurrent with altered ATP and acetylcholine bioavailability, measured as transmitter overflow into the lumen, increased purinergic receptor sensitivity and raised P2X3 receptor expression in the urothelium. Taken together, these data suggest that ageing results in aberrant urothelial function, increased afferent mechanosensitivity, increased smooth muscle contractility, and changes in gene and protein expression (including of P2X3). These data are consistent with the hypothesis that ageing evokes changes in purinergic signalling from the bladder, and further studies are now required to fully validate this idea

    Variable coordination of amine functionalised N-heterocyclic carbene ligands to Ru, Rh and Rr: C-H and N-H activation and catalytic transfer hydrogenation

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    Chelating amine and amido complexes of late transition metals are highly valuable bifunctional catalysts in organic synthesis, but complexes of bidentate amine–NHC and amido–NHC ligands are scarce. Hence, we report the reactions of a secondary-amine functionalised imidazolium salt 2a and a primary-amine functionalised imidazolium salt 2b with [( p -cymene)RuCl 2 ] 2 and [Cp*MCl 2 ] 2 (M = Rh, Ir). Treating 2a with [Cp*MCl 2 ] 2 and NaOAc gave the cyclometallated compounds Cp*M(C,C)I (M = Rh, 3 ;M = Ir, 4 ), resulting from aromatic C–H activation. In contrast, treating 2b with [( p -cymene)RuCl 2 ] 2 ,Ag 2 O and KI gave the amine–NHC complex [( p -cymene)Ru(C,NH 2 )I]I ( 5 ). The reaction of 2b with [Cp*MCl 2 ] 2 (M = Rh, Ir), NaO t Bu and KI gave the amine–NHC complex [Cp*Rh(NH 2 )I]I ( 6 ) or the amido–NHC complex Cp*Ir(C,NH)I ( 7 ); both protonation states of the Ir complex could be accessed: treating 7 with trifluoroacetic acid gave the amine–NHC complex [Cp*Ir(C,NH 2 )I][CF 3 CO 2 ]( 8 ). These are the first primary amine– or amido–NHC complexes of Rh and Ir. Solid-state structures of the complexes 3–8 have been determined by single crystal X-ray diffraction. Complexes 5 , 6 and 7 are pre-catalysts for the catalytic transfer hydrogenation of acetophenone to 1-phenylethanol, with ruthenium complex 5 demonstrating especially high reactivity

    Comparison of Radio Observations and Numerical Simulations of the Radio Lobes of Cygnus A

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    We present a comparison of radio observations of the archetypal powerful radio galaxy Cygnus A and 2-D numerical hydrodynamical simulations. We characterize some global trends in the observed radio properties and compare them with the properties of a simulated radio source. The numerical results are the following. Jets propagating in a constant density atmosphere will decelerate with time. Thus, the estimated dynamical age of the source will be greater than the actual age of the source. For a source similar to Cygnus A the difference will be about a factor of 2. The second moment gives an accurate representation of the "true" width of the simulated source. The Gaussian FWHM tends to be about 40% larger than the true width and can be systematically in error if the surface brightness exhibits multiple peaks. We suggest that the ratio of the Gaussian FWHM to the second moment may be a diagnostic of the emissivity profile in the lobes. The simulations can qualitatively reproduce the overall observed morphology and the behavior of the cross-sections in surface brightness, the decline in surface brightness with distance from the hot spots, and the width of the lobes. This suggests that the 2-D simulations give a reasonable representation of the properties of Cygnus A.Comment: the larger figures are available as gif

    Taxing the Informal Economy: The Current State of Knowledge and Agendas for Future Research

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    This paper reviews the literature on taxation of the informal economy, taking stock of key debates and drawing attention to recent innovations. Conventionally, the debate on whether to tax has frequently focused on the limited revenue potential, high cost of collection, and potentially adverse impact on small firms. Recent arguments have increasingly emphasised the more indirect benefits of informal taxation in relation to economic growth, broader tax compliance, and governance. More research is needed, we argue, into the relevant costs and benefits for all, including quasi-voluntary compliance, political and administrative incentives for reform, and citizen-state bargaining over taxation

    Exome Sequencing Identifies Genes and Gene Sets Contributing to Severe Childhood Obesity, Linking PHIP Variants to Repressed POMC Transcription.

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    Obesity is genetically heterogeneous with monogenic and complex polygenic forms. Using exome and targeted sequencing in 2,737 severely obese cases and 6,704 controls, we identified three genes (PHIP, DGKI, and ZMYM4) with an excess burden of very rare predicted deleterious variants in cases. In cells, we found that nuclear PHIP (pleckstrin homology domain interacting protein) directly enhances transcription of pro-opiomelanocortin (POMC), a neuropeptide that suppresses appetite. Obesity-associated PHIP variants repressed POMC transcription. Our demonstration that PHIP is involved in human energy homeostasis through transcriptional regulation of central melanocortin signaling has potential diagnostic and therapeutic implications for patients with obesity and developmental delay. Additionally, we found an excess burden of predicted deleterious variants involving genes nearest to loci from obesity genome-wide association studies. Genes and gene sets influencing obesity with variable penetrance provide compelling evidence for a continuum of causality in the genetic architecture of obesity, and explain some of its missing heritability
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