283 research outputs found
Highly feminised sex ratio estimations for the world’s third largest nesting aggregation of loggerhead sea turtles
Despite being a fundamental life-history character, there is a paucity of populationwide, data-driven studies of primary sex ratios for any marine turtle species. The Republic of Cape Verde hosts the third-largest nesting population of loggerhead turtles Caretta caretta in the world (hosting up to 15% of global nesting by the species). Weighting for the spatial distribution of nests, we estimate that 84% of female hatchlings are currently likely produced across the population, with 85% of nests laid on Boa Vista, where incubation temperatures are coolest. In future climate change scenarios (by 2100), irrespective of beach, island or sand colour, sex ratios reach over 99% female, and 3 islands (Fogo, Sao Nicolau, Santiago) would cease to produce males, with >90% of nests incubating at lethally high temperatures. Given that most of the population cannot move to nest on cooler islands, we highlight that temporal refugia are amongst the primary means available to this population to adapt. Under a low-emissions scenario, without phenological adaptation, there would only be an estimated 0.14% males produced across the whole population, while under mid- and high-emissions scenarios, male production may cease on most islands.</p
Highly feminised sex ratio estimations for the world’s third largest nesting aggregation of loggerhead sea turtles
Despite being a fundamental life-history character, there is a paucity of populationwide, data-driven studies of primary sex ratios for any marine turtle species. The Republic of Cape Verde hosts the third-largest nesting population of loggerhead turtles Caretta caretta in the world (hosting up to 15% of global nesting by the species). Weighting for the spatial distribution of nests, we estimate that 84% of female hatchlings are currently likely produced across the population, with 85% of nests laid on Boa Vista, where incubation temperatures are coolest. In future climate change scenarios (by 2100), irrespective of beach, island or sand colour, sex ratios reach over 99% female, and 3 islands (Fogo, Sao Nicolau, Santiago) would cease to produce males, with >90% of nests incubating at lethally high temperatures. Given that most of the population cannot move to nest on cooler islands, we highlight that temporal refugia are amongst the primary means available to this population to adapt. Under a low-emissions scenario, without phenological adaptation, there would only be an estimated 0.14% males produced across the whole population, while under mid- and high-emissions scenarios, male production may cease on most islands.</p
Chemistry and Pharmacokinetics of Gallium Maltolate, a Compound With High Oral Gallium Bioavailability
Gallium maltolate, tris(3-hydroxy-2-methyl-4H-pyran-4-onato)gallium (GaM), is an orally active gallium compound for therapeutic use. It is moderately soluble in water (10.7 ± 0.9 mg/mL at 25∘C) with an octanol partition coefficient of 0.41±0.08. The molecule is electrically neutral in aqueous solution at neutral pH; a dilute aqueous solution (2.5 ×10−-5 M) showed little dissociation at pH 5.5-8.0. Single crystal X-ray diffraction analysis found the GaM molecule to consist of three maltolate ligands bidentately bound to a central gallium atom in a propeller-like arrangement, with one of the ligands disordered in two possible orientations. The compound is orthorhombic, space group Pbca, unit cell a = 16.675(3), b = 12.034(2), c = 18.435(2) Å at 158K. GaM was administered to healthy human volunteers at single doses of 100, 200, 300, and 500 mg (three subjects per dose). GaM was very well tolerated. Oral absorption of Ga into plasma was fairly rapid (absorption half life = 0.8-2.0h), with a central compartment excretion half life of 17-21h. Absorption appeared dose proportional over the dosage range studied. Estimated oral gallium bioavailability was approximately 25-57%, based on comparison with published data on intravenous gallium nitrate. Urinary Ga excretion following oral GaM administration was approximately 2% of the administered dose over 72h, in contrast to 49-94% urinary Ga excretion over 24h following i.v. gallium nitrate administration. We suggest that oral administration of GaM results in nearly all plasma gallium being bound to transferrin, whereas i.v. administration of gallium nitrate results in formation of considerable plasma gallate [Ga(OH)4−], which is rapidly excreted in the urine. These data support the continued investigation of GaM as an orally active therapeutic gallium compound
Evaluation of the Free School Meals Pilot
Report presenting evidence on the effect of universal and extended access to free school meals on a range of pupil outcomes. The evaluation report analyses the effect and value for money of a 2-year pilot that tested different approaches to free school meals (FSM) provision
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