Publications by authors named "Stephen Newman"

Hydrosilanes and Lewis bases are known to promote various reductive defunctionalizations, rearrangements, and silylation reactions, facilitated by enigmatic silicon/Lewis base-derived reactive intermediates. Despite the wide variety of transformations enabled by this reagent combination, no examples of intermolecular C(sp3)-C(sp3) forming reactions have been reported. In this work, we've identified 1,1,3,3-tetramethyldisiloxane (TMDSO) and KOtBu as a unique reagent combination capable of generating benzylic nucleophiles in-situ from styrene derivatives, which can subsequently react with alkyl halides to give a new C(sp3)-C(sp3) linkage via formal hydroalkylation.

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Article Synopsis
  • This study highlights the importance of understanding population structure in harvested fish species to prevent stock depletion, emphasizing the lack of empirical data in this area.
  • Researchers analyzed genetic variation in three species of tropical snappers over a large area in north-western Australia, finding similar genetic structures despite differences in their biological traits.
  • Results suggest strong genetic connectivity among fish populations, indicating that current management practices may need to adapt, as these species do not adhere to the idea of completely isolated stocks.
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We report a palladium-catalyzed synthesis of α-vinyl boronates via a regioselective Mizoroki-Heck reaction between aryl triflates and vinyl boronates. This selectivity is achieved by the use of a 1,5-diaza-3,7-diphosphacyclooctane (PN) ligand, which results in minimal formation of the more commonly observed (linear) β-product. The choice of base, solvent, and presence of water are shown to be critical for controlling this outcome, with organic bases, nonpolar solvents, and anhydrous conditions favoring the Heck product and suppressing the competitive Suzuki-Miyaura coupling product.

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We report a dual metal-catalyzed method for the cross-coupling of unprotected alcohols by exploiting the β-Si effect. This deoxygenative Suzuki-Miyaura reaction tolerates a range of primary, secondary, and tertiary alcohol substrates along with diverse functional groups and heterocycles. Mechanistic experiments including KIE, VTNA, and Eyring analyses suggest the existence of a carbocation intermediate on the reaction pathway, consistent with a rare S1 pathway for the activation of an electrophile in cross-coupling reactions.

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Many shark populations are in decline around the world, with severe ecological and economic consequences. Fisheries management and marine protected areas (MPAs) have both been heralded as solutions. However, the effectiveness of MPAs alone is questionable, particularly for globally threatened sharks and rays ('elasmobranchs'), with little known about how fisheries management and MPAs interact to conserve these species.

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Background: Prior research has established a link between thalamic pathology and cognitive impairment (CI) in people with multiple sclerosis (pwMS). However, the translation of these findings to pwMS in everyday clinical settings has been insufficient.

Objective: To assess which global and/or thalamic imaging biomarkers can be used to identify pwMS at risk for CI and cognitive worsening (CW) in a real-world setting.

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Alcohols are abundant and attractive feedstock molecules for organic synthesis. Many methods for their functionalization require them to first be converted into a more activated derivative, while recent years have seen a vast increase in the number of complexity-building transformations that directly harness unprotected alcohols. This Review discusses how transition metal catalysis can be used toward this goal.

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We report a high throughput evaluation of the Mizoroki-Heck reaction of diverse olefin coupling partners. Comparison of different ligands revealed the 1,5-diaza-3,7-diphosphacyclooctane (PN) scaffold to be more broadly applicable than common "gold standard" ligands, demonstrating that this family of readily accessible diphosphines has unrecognized potential in organic synthesis. In particular, two structurally related PN ligands were identified to enable the regiodivergent arylation of styrenes.

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  • Scientists use loud sounds to find oil and gas under the ocean, which might harm sea creatures like the silverlip pearl oyster.
  • They tested around 11,000 oysters for four days during a seismic survey and checked their survival and pearl quality over two years.
  • While some oysters showed lower survival and fewer pearls, most did fine, so they didn't find strong proof that the loud sounds hurt the oysters.
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The sympatric red snappers, Lutjanus erythropterus and Lutjanus malabaricus, are highly valued by commercial and recreational fishers along the tropical northern coasts of Australia and throughout their distribution. Studies on the life history and ecology of these congeners are confounded by difficulties in distinguishing the cryptic juveniles of each species (i.e.

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A global survey of coral reefs reveals that overfishing is driving resident shark species toward extinction, causing diversity deficits in reef elasmobranch (shark and ray) assemblages. Our species-level analysis revealed global declines of 60 to 73% for five common resident reef shark species and that individual shark species were not detected at 34 to 47% of surveyed reefs. As reefs become more shark-depleted, rays begin to dominate assemblages.

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A reductive detrifluoromethylation protocol has been developed making use of an earth-abundant alkoxide base and silicon hydride species. A variety of pyridine and quinoline substrates bearing alkyl, aryl, and amino functional groups are reduced in moderate to high yields. The reaction is chemoselective for C(sp)-CF groups located at the 2-position on the pyridine ring, leaving trifluoromethyl groups located elsewhere on the molecule intact.

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A new species of deep-water epinephelid fish is described from the west coast of Australia based on 14 specimens, 99-595 mm standard length. Hyporthodus griseofasciatus sp. nov.

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The management of human-shark interactions can benefit from the implementation of effective shark hazard mitigation measures. A Shark-Management-Alert-in-Real-Time (SMART) drumline trial in the Capes region of Western Australia was instigated after several serious incidents involving surfers and white sharks (). The project aimed to determine whether white sharks (target species), which were relocated after capture, remained offshore using satellite and acoustic tagging.

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We report an intermolecular Ni-catalyzed reductive coupling of aryl iodides and isatins to form 3-hydroxyoxindoles. In contrast to common metal-mediated methods, -butanol is used as a mild stoichiometric reductant resulting in benign waste products. This formal 1,2-addition reaction is facilitated by a 1,5-diaza-3,7-diphosphacyclooctane (PN) ligand.

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Fine Particle Fraction: The Good and the Bad.

J Aerosol Med Pulm Drug Deliv

January 2022

Fine particle fraction (FPF) is defined in general terms as the fraction or percentage of the drug mass contained in an aerosol cloud that may be small enough to enter the lungs and exert a clinical effect. An aerodynamic diameter of 5 μm represents the approximate border between "fine" and "coarse" particles, but there is no universally agreed upon definition of FPF in terms of an aerodynamic particle size range. FPF alone does not adequately describe a heterodisperse aerodynamic particle size distribution, and it needs to be combined with another measure or measures indicating the width of the distribution.

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Understanding the connectivity of exploited fish populations is critical to their management under both rapid and long-term environmental change. Patterns of connectivity are unknown for most fishes in the Shark Bay World Heritage Area (Western Australia), a large, shallow embayment in the eastern Indian Ocean, vulnerable to marine heatwaves. The composition of oxygen (δO) and carbon (δC) stable isotopes in whole otoliths of the recreationally-important reef fish Lethrinus laticaudis did not differ between Shark Bay's two large inner gulfs, separated by the Peron Peninsula.

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• A unique sequela of COVID-19 is COVID-related ventricular thrombus formation. • Diagnosis of a ventricular thrombus can only be confirmed through imaging. • COVID-related myocarditis can ultimately lead to ventricular thrombus formation.

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We report a catalytic method to access secondary alcohols by the coupling of aryl iodides. Either aldehydes or alcohols can be used as reaction partners, making the transformation reductive or redox-neutral, respectively. The reaction is mediated by a Ni catalyst and a 1,5-diaza-3,7-diphosphacyclooctane.

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The yellowspotted rockcod, Epinephelus areolatus, is a small-sized grouper that is widely distributed throughout the Indo-Pacific, where it forms a valuable component of the harvest derived from multispecies fisheries along continental and insular shelves. Samples of E. areolatus were collected from 2012 to 2018 from commercial catches and research surveys in the Kimberley, Pilbara and Gascoyne regions of north-western Australia to improve the understanding of the life history, inherent vulnerability and stock status of this species.

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Article Synopsis
  • Marine fisheries have historically targeted large-bodied fish, which can disrupt ecosystems and affect fish population sustainability.
  • This study used baited remote underwater stereo-video to analyze the body-size structure of targeted marine fish across Australia, revealing that seascape features and human impacts are key factors in fish abundance and occurrence.
  • Findings suggest that no-take marine reserves positively influence the presence of legal-sized fish, with significant declines in fish abundance linked to higher human impact, emphasizing the need for effective marine management strategies.
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Seismic surveys are used to locate oil and gas reserves below the seabed and can be a major source of noise in marine environments. Their effects on commercial fisheries are a subject of debate, with experimental studies often producing results that are difficult to interpret. We overcame these issues in a large-scale experiment that quantified the impacts of exposure to a commercial seismic source on an assemblage of tropical demersal fishes targeted by commercial fisheries on the North West Shelf of Western Australia.

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A large (~2450 km) offshore (~75 km) targeted fisheries closure (TFC) area was implemented on the North West Shelf of Australia (NWS) in 1998 as part of a suite of management controls to address overfishing concerns, and in the process to potentially mitigate any impacts of trawling to benthic habitats. Twelve years later, the benthic biota and fish assemblages in the TFC were assessed using stereo-video and compared with adjacent areas that have been consistently fished with a range of commercial fishing methods. The remote nature of the region has meant that these areas would be inaccessible to recreational fishers.

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