Publications by authors named "Andrew R Butler"

Generalized linear models (GLMs) are an integral tool in ecology. Like general linear models, GLMs assume linearity, which entails a linear relationship between independent and dependent variables. However, because this assumption acts on the link rather than the natural scale in GLMs, it is more easily overlooked.

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Swift foxes () are endemic to the Great Plains of North America, but were extirpated from the northern portion of their range by the mid-1900s. Despite several reintroductions to the Northern Great Plains, there remains a ~350 km range gap between the swift fox population along the Montana and Canada border and that in northeastern Wyoming and northwestern South Dakota. A better understanding of what resources swift foxes use along the Montana and Canada border region will assist managers to facilitate connectivity among populations.

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Background: Critically ill people may lose fluid because of serious conditions, infections (e.g. sepsis), trauma, or burns, and need additional fluids urgently to prevent dehydration or kidney failure.

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Background: Hypothermia has been used in the treatment of brain injury for many years. Encouraging results from small trials and laboratory studies led to renewed interest in the area and some larger trials.

Objectives: To determine the effect of mild hypothermia for traumatic brain injury (TBI) on mortality, long-term functional outcomes and complications.

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Background: Successful tracheal intubation during general anaesthesia traditionally requires a line of sight to the larynx attained by positioning the head and neck and using a laryngoscope to retract the tongue and soft tissues of the floor of the mouth. Difficulties with intubation commonly arise, and alternative laryngoscopes that use digital and/or fibreoptic technology have been designed to improve visibility when airway difficulty is predicted or encountered. Among these devices, a rigid videolaryngoscope (VLS) uses a blade to retract the soft tissues and transmits a lighted video image to a screen.

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Article Synopsis
  • Proximal femoral fractures (PFF) are common emergencies in elderly patients, with uncertain benefits from advanced fluid management techniques during surgical treatment.
  • This study aims to evaluate the safety and effectiveness of different fluid optimization methods for adults undergoing hip fracture surgery, comparing advanced invasive monitoring to standard measures and usual care.
  • An update of previous reviews, the research involved thorough searches of medical databases for randomized controlled trials that assessed various fluid management strategies in this patient population.
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The antibacterial properties of macrolide antibiotics (such as erythromycin, tylosin, and narbomycin) depend ultimately on the glycosylation of otherwise inactive polyketide lactones. Among the sugars commonly found in such macrolides are various 6-deoxyhexoses including the 3-dimethylamino sugars mycaminose and desosamine (4-deoxymycaminose). Some macrolides (such as tylosin) possess multiple sugar moieties, whereas others (such as narbomycin) have only single sugar substituents.

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Type I polyketide synthases (PKSs) are complexes of large, multimodular enzymes that catalyse biosynthesis of polyketide compounds via repetitive reaction sequences, during which each step is catalysed by a separate enzymic domain. Many type I PKSs, and also non-ribosomal peptide synthetase clusters, contain additional thioesterase genes located adjacent to PKS genes. These are discrete proteins called type II thioesterases (TE IIs) to distinguish them from chain-terminating thioesterase (TE I) domains that are usually fused to the terminal PKS module.

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Tylosin is produced by Streptomyces fradiae via a combination of polyketide metabolism and synthesis of three deoxyhexose sugars, of which mycaminose is the first to be added to the polyketide aglycone, tylactone (protylonolide). Previously, disruption of the gene (tylMII) encoding attachment of mycaminose to the aglycone unexpectedly abolished accumulation of the latter, raising the possibility of a link between polyketide metabolism and deoxyhexose biosynthesis in S. fradiae.

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The tylCK region of the Streptomyces fradiae genome was sequenced, revealing an incomplete set of five tylC genes encoding all-but-one of the enzymes involved in the biosynthesis of mycarose. The latter is a 6-deoxyhexose sugar required during production of the macrolide antibiotic, tylosin. The missing mycarose-biosynthetic gene, tylCVI, was found about 50 kb distant from its functional partners, on the other side of the tylG (polyketide synthase) gene complex.

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