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BACKGROUND: People with schizophrenia spectrum disorders (SSD) engage less in physical activity than healthy individuals. The impact of subjectively assessed physical fitness levels on motivation for sports engagement and its relation to objective fitness parameters in SSD is unclear. METHODS: 25 patients with SSD (P-SSD) and 24 healthy controls (H-CON) participated in a randomized controlled study. Individual anaerobic thresholds (AT) were determined by an incremental exercise test and on separate days, aerobic exercise (cycling at 80% of workload at AT) and non-exercise control (sitting on an ergometer without cycling) sessions were performed. Demographic, clinical and objective physical fitness data (i.e., weekly physical activity, workload at AT, heart rate) were collected. Subjective physical fitness parameters were assessed before and after exercise and control sessions. RESULTS: Weekly physical activity in P-SSD was lower than in H-CON (p < 0.05) attributed to reduced engagement in sport activities (p < 0.001). Workload and percentage of predicted maximal heart rate at AT were also reduced in P-SSD compared to H-CON (both p < 0.05). Although objective and subjective physical fitness parameters were related in H-CON (p < 0.01), this relationship was absent in P-SSD. However, during exercise sessions subjective physical fitness ratings increased to a stronger extent in P-SSD than H-CON (p < 0.05). CONCLUSION: The missing relationship between subjective and objective physical fitness parameters in people with SSD may represent a barrier for stronger engagement in physical activity. Accordingly, supervised exercise interventions with individually adjusted workload intensity may support realistic subjective fitness estimations and enhance motivation for sports activity in individuals with SSD.
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Inbreeding can depress individuals' fitness traits and reduce population viability. However, studies that directly translate inbreeding depression on fitness traits into consequences for population viability, and further, into consequences for management choices, are lacking. Here, we estimated impacts of inbreeding depression (B, lethal equivalents) across life-history stages for an extinct-in-the-wild species, the sihek (Guam kingfisher, Todiramphus cinnamominus). We then projected population growth under different management alternatives with our B estimates incorporated, as well as without inbreeding depression (B = 0) or with a conventional default B. We found that inbreeding depression severely impacted multiple life-history stages, and directly translated into an effect on population viability under management alternatives. Simulations including our B estimates indicated rapid population decline, whereas projections without inbreeding depression or with default B suggested very gradual population decline. Further, our results demonstrate that incorporation of B across life-history stages can influence management decisions, as projections with our B estimates suggested a need to switch to increased breeding management to avoid species extinction and support wild releases. Our results demonstrate that magnitude of B across life-history stages can translate into demographic consequences, such that incorporation of multiple life-stage B into population models can be important for informed conservation management decision-making.
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Conservação dos Recursos Naturais , Extinção Biológica , Depressão por Endogamia , Endogamia/métodos , Fenótipo , Densidade Demográfica , Animais , Animais Selvagens , Aves , DemografiaRESUMO
A detailed understanding of the behaviour of confined fluids is critical to a range of industrial applications, for example to control friction in engineering components. In this study, a combination of tribological experiments and confined nonequilibrium molecular dynamics simulations has been used to investigate the effect of base fluid molecular structure on nonequilibrium phase behaviour and friction. An extensive parameter study, including several lubricant and traction fluid molecules subjected to pressures (0.5-2.0 GPa) and strain rates (104-1010 s-1) typical of the elastohydrodynamic lubrication regime, reveals clear relationships between the friction and flow behaviour. Lubricants, which are flexible, broadly linear molecules, give low friction coefficients that increase with strain rate and pressure in both the experiments and the simulations. Conversely, traction fluids, which are based on inflexible cycloaliphatic groups, give high friction coefficients that only weakly depend on strain rate and pressure. The observed differences in friction behaviour can be rationalised through the stronger shear localisation which is observed for the traction fluids in the simulations. Higher pressures lead to more pronounced shear localisation, whilst increased strain rates lead to a widening of the sheared region. The methods utilised in this study have clarified the physical mechanisms of important confined fluid behaviour and show significant potential in both improving the prediction of elastohydrodynamic friction and developing new molecules to control it.
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CASE HISTORY: Salmonellosis was suspected as the cause of death in eight wild animals on Tiritiri Matangi Island, in the Hauraki Gulf of New Zealand, between November and September 2011, including three hihi (Notiomystis cincta), a tuatara (Sphenodon punctatus), a masked lapwing (Vanellus miles novaehollandiae), and a saddleback (Philesturnus carunculatus). An outbreak investigation to identify the source and distribution of infection was undertaken over the summer of 2011-2012. CLINICAL AND LABORATORY FINDINGS: Surveillance of five species of forest bird (n=165) in December 2011 returned a single positive result for Salmonella spp. Environmental sampling of 35 key water sources and hihi supplementary feeding stations conducted in December 2011 and March 2012 returned isolates of S. enterica subspecies houtenae and S. enterica serovar Saintpaul from a stream, a dam and a supplementary feeding station. The same serotypes were identified in tissue samples collected from post mortem specimens of the affected birds, and their similarity was confirmed by pulsed-field gel electrophoresis. DIAGNOSIS: Mortality in wildlife associated with infection with S. enterica subspecies houtenae and S. enterica serovar Saintpaul. CLINICAL RELEVANCE: This is the first detection of these Salmonella spp. from wild birds in New Zealand. Our study highlights how active surveillance in response to observed disease emergence (here mortalities) can provide important insight for risk assessment and management within populations of endangered species and inform risk assessment in translocation planning.
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Animais Selvagens , Doenças das Aves/mortalidade , Surtos de Doenças/veterinária , Salmonelose Animal/mortalidade , Animais , Doenças das Aves/epidemiologia , Doenças das Aves/microbiologia , Aves , Microbiologia Ambiental , Genótipo , Ilhas , Nova Zelândia/epidemiologia , Salmonella/genética , Salmonella/isolamento & purificação , Salmonelose Animal/epidemiologiaRESUMO
Why do some bird species show dramatic sexual dichromatism in their plumage? Sexual selection is the most common answer to this question. However, other competing explanations mean it is unwise to assume that all sexual dichromatism has evolved by this mechanism. Even if sexual selection is involved, further work is necessary to determine whether dichromatism results from competition amongst rival males, or by female choice for attractive traits, or both. Here, we test whether sexually dichromatic hihi (Notiomystis cincta) plumage is currently under sexual selection, with detailed behavioural and genetic analyses of a free-living island population. Bateman gradients measured for males and females reveal the potential for sexual selection, whilst selection gradients, relating reproductive success to specific colourful traits, show that there is stabilizing selection on white ear tuft length in males. By correlating colourful male plumage with different components of reproductive success, we show that properties of yellow plumage are most likely a product of male-male competition, whilst properties of the black and white plumage are an outcome of both male-male competition and female choice. Male plumage therefore potentially signals to multiple receivers (rival males and potential mates), and this may explain the multicoloured appearance of one of the most strikingly dichromatic species in New Zealand.
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Comportamento Competitivo/fisiologia , Plumas/fisiologia , Preferência de Acasalamento Animal/fisiologia , Passeriformes/fisiologia , Pigmentação/fisiologia , Animais , Feminino , Genótipo , Masculino , Repetições de Microssatélites/genética , Modelos Estatísticos , Nova Zelândia , Reprodução/fisiologiaRESUMO
BACKGROUND/OBJECTIVES: Sprint Fidelis and Riata defibrillator leads are prone to early failure. Few data exist on the comparative failure rates and mortality related to lead failure. The aims of this study were to determine the failure rate of Sprint Fidelis and Riata leads, and to compare failure rates and mortality rates in both groups. METHODS: Patients implanted with Sprint Fidelis leads and Riata leads at a single centre were identified and in July 2012, records were reviewed to ascertain lead failures, deaths, and relationship to device/lead problems. RESULTS: 113 patients had Sprint Fidelis leads implanted between June 2005 and September 2007; Riata leads were implanted in 106 patients between January 2003 and February 2008. During 53.0 ± 22.3 months of follow-up there were 13 Sprint Fidelis lead failures (11.5%, 2.60% per year) and 25 deaths. Mean time to failure was 45.1 ± 15.5 months. In the Riata lead cohort there were 32 deaths, and 13 lead failures (11.3%, 2.71% per year) over 54.8 ± 26.3 months follow-up with a mean time to failure of 53.5 ± 24.5 months. There were no significant differences in the lead failure-free Kaplan-Meier survival curve (p=0.77), deaths overall (p=0.17), or deaths categorised as sudden/cause unknown (p=0.54). CONCLUSIONS: Sprint Fidelis and Riata leads have a significant but comparable failure rate at 2.60% per year and 2.71% per year of follow-up respectively. The number of deaths in both groups is similar and no deaths have been identified as being related to lead failure in either cohort.
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Desfibriladores Implantáveis/tendências , Falha de Equipamento , Adulto , Idoso , Idoso de 80 Anos ou mais , Eletrodos Implantados/tendências , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Taxa de Sobrevida/tendênciasRESUMO
The accumulation of significant pools of sulfidic sediments in inland wetlands and creeks is an emerging risk for the management of inland waterways. We used replicated plot trials to appraise the viability of various strategies for neutralizing oxidized, acidified sulfidic sediments in a highly degraded wetland. Of the twenty different treatments trialed only addition of calcium hydroxide or calcium carbonate, burning of wood, and planting of Phragmites australis, Typha domingensis and Atriplex nummularia into beds prepared with CaCO3 or P. australis and T. domingensis into beds of sediment and mulch, decreased total actual acidity (TAA) in the top 5 cm of sediment in the first two weeks following treatment. Only the calcium hydroxide treatments and planting of P. australis, T. domingensis and A. nummularia into beds prepared with CaCO3 decreased TAA for a longer period of time (6 months). None of the treatments, except the planting of P. australis into beds prepared with lime, decreased TAA in the 5-30 cm layer of sediments. Therefore, the only effective treatment appears to be the application of highly alkaline ameliorants which need to be transported to the site. A survey of the wetland was undertaken to estimate the total amount of actual and potential acidity stored in the wetland's sediment and overlying water and showed that up to 1200 tonnes of calcium carbonate would be required to neutralise all of the actual and potential acidity in the 10 ha wetland. However, neutralisation of the remaining water in the wetland (about 12.5 ML) would produce approximately 2750 m3 of metal rich sludge (approximately 100 tonnes dry weight) that would require separate disposal.
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Conservação dos Recursos Naturais/métodos , Sedimentos Geológicos/química , Sulfetos/análise , Água/química , Áreas Alagadas , Atriplex/crescimento & desenvolvimento , Atriplex/metabolismo , Hidróxido de Cálcio/química , Carbono/química , Poaceae/crescimento & desenvolvimento , Poaceae/metabolismo , Typhaceae/crescimento & desenvolvimento , Typhaceae/metabolismo , Vitória , MadeiraRESUMO
Ablation for atrial fibrillation is now widespread and may involve the delivery of relatively high doses of ionizing radiation to both patients and operators. Until now, atrial septal puncture has mandated the use of either fluoroscopy or additional expensive imaging modalities for its safe deployment. We describe a novel technique using the EnSite NavX three-dimensional imaging system for visualization of the transseptal needle throughout the puncture-without the need for either fluoroscopy or additional imaging. This may be important in reducing the need for fluoroscopy for left atrial ablation procedures.
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Fibrilação Atrial/diagnóstico , Fibrilação Atrial/cirurgia , Ablação por Cateter/métodos , Átrios do Coração/cirurgia , Septos Cardíacos/cirurgia , Punções/métodos , Cirurgia Assistida por Computador/métodos , Fluoroscopia , Humanos , Proteção Radiológica/métodos , Resultado do TratamentoRESUMO
There is an urgent need for accurate prediction of climate change impacts on species ranges. Current reliance on bioclimatic envelope approaches ignores important biological processes such as interactions and dispersal. Although much debated, it is unclear how such processes might influence range shifting. Using individual-based modelling we show that interspecific interactions and dispersal ability interact with the rate of climate change to determine range-shifting dynamics in a simulated community with two growth forms--mutualists and competitors. Interactions determine spatial arrangements of species prior to the onset of rapid climate change. These lead to space-occupancy effects that limit the rate of expansion of the fast-growing competitors but which can be overcome by increased long-distance dispersal. As the rate of climate change increases, lower levels of long-distance dispersal can drive the mutualists to extinction, demonstrating the potential for subtle process balances, non-linear dynamics and abrupt changes from species coexistence to species loss during climate change.
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Comportamento Animal , Clima , Animais , Biodiversidade , Comportamento Competitivo , Ecossistema , Meio Ambiente , Modelos Biológicos , Dinâmica PopulacionalRESUMO
Syntheses, crystal structures, and polymerization data for new isospecific metallocenes (heterocenes) having cyclopentenyl ligands b-fused to substituted thiophenes (Tp) and pyrroles (Pyr) are reported. The C2- and C1-symmetric heterocenes are dimethylsilyl bridged, have methyl groups adjacent to the bridgehead carbon atoms, and have aryl substituents protruding in the front. rac-Me2Si(2,5-Me2-3-Ph-6-Cp[b]Tp)2ZrCl2/MAO (MAO = methyl alumoxanes) is the most active metallocene catalyst for polypropylene reported to date. rac-Me2Si(2,5-Me2-3-Ph-6-Cp[b]Tp)2ZrCl2 and rac-Me2Si(2,5-Me2-1-Ph-4-Cp[b]Pyr)2ZrCl2 have the same structure, and the former is 6 times more active, produces half the total enantiofacial errors, and is 3.5 times less regiospecific in propylene polymerizations at the same conditions. rac-Me2Si(2-Me-4-Ph-1-Ind)2ZrCl2/MAO is 3.5 times lower in activity than rac-Me2Si(2,5-Me2-3-Ph-6-Cp[b]Tp)2ZrCl2 catalyst, and while the former is the more stereospecific and the less regiospecific, the sum of these two enantioface errors is the same for both species. Fine-tuning the heterocene sterics by changing selected hydrogen atoms on the ligands to methyl groups influenced their catalyst activities, stereospecificites, regiospecificites, and isotactic polypropylene (IPP) Mw. Thus, both substituting a hydrogen atom adjacent to the phenyl ring with a methyl group on an azapentalenyl ligand system and replacing one and then two hydrogens on the phenyl ring with methyls on thiopentalenyl ligands provided increased polymer Tm and Mw with increasing ligand bulk. Polymer molecular weights are sensitive to and inversely proportional to MAO concentration, and the catalyst activities increase when hydrogen is added for molecular weight control. The polymer Tm values with the thiopentalenyls as TIBAL/[Ph3C][B(C6F5)4] systems were higher than with MAO as catalyst activator. A racemic C1, pseudo-meso complex with a hybrid dimethylsilyl-bridged 2-Me-4-Ph-1-Ind/2,5-Me2-4-Ph-1-Cp[b]Pyr ligand produced the first sample of IPP with all the steric pentad intensities fitting the enantiomorphic site control model. Speculative mechanistic considerations are offered regarding electronic effects of the heteroatoms and steric effects of the ligand structures, the preferred phenyl torsion angles, and anion effects.
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PURPOSE: High myopia in early childhood is a recognised association of ocular and systemic disease. The aim of this study was to describe the types, pattern and frequency of these associations. METHODS: All children presenting to two ophthalmology units over 3 years who were found to have high myopia were recruited. High myopia was defined as one or both eyes demonstrating 6 dioptres spherical equivalent or more of myopic refractive error on retinoscopy. We limited the age to less than 10 years old. A retrospective case review was undertaken of the 112 consecutive children who fulfilled the criteria above. The demographic data, source and indication for referral were recorded along with the ocular and systemic findings and diagnosis. RESULTS: Only 9 (8%) of the children had 'simple high myopia' with no associated ocular or systemic associations. In 54% there was an underlying systemic association with or without further ocular problems (e.g. developmental delay, prematurity, Marfan, Stickler, Noonan, Down syndrome) and in the remaining 38% there were further ocular problems associated with the high myopia (e.g. lens subluxation, coloboma, retinal dystrophy, anisometropic amblyopia). A family history of high myopia did not preclude associated abnormality: in 4 cases the diagnosis of a systemic condition in the child led to the identification of the disease in at least one myopic relative. Asian (p < 0.001) and male (p < 0.05) patients were overrepresented in the series. CONCLUSION: High myopia is strongly associated with systemic and ocular problems; it may be the reason for the child's initial medical referral and an important clue to an underlying systemic or ocular condition. Referrals infrequently originated from community optometrists despite prior attendance. We suggest that all children under 10 years of age with high myopia are referred to a paediatric ophthalmology clinic for review and we propose a structured clinical evaluation in the hospital eye clinic.
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Miopia/complicações , Criança , Pré-Escolar , Deficiências do Desenvolvimento/complicações , Oftalmopatias/complicações , Feminino , Seguimentos , Humanos , Lactente , Recém-Nascido , Recém-Nascido Prematuro , Masculino , Miopia/genética , Miopia/fisiopatologia , Transtornos da Motilidade Ocular/complicações , Encaminhamento e Consulta , Refração Ocular , Doenças Retinianas/complicações , Estudos RetrospectivosRESUMO
With the use of a newly developed Imaging Cryomicrotome to determine the spatial location of fluorescent microspheres in organs, we validate and report our processing algorithms for measuring regional blood flow in small laboratory animals. Microspheres (15-microm diameter) of four different fluorescent colors and one radioactive label were simultaneously injected into the left ventricle of a pig. The heart and kidneys were dissected, and the numbers of fluorescent and radioactive microspheres were determined in 10 randomly selected pieces. All microsphere counts fell well within the 95% expected confidence limits as determined from the radioactive counts. Fluorescent microspheres (15-microm diameter) of four different colors were also injected into the tail vein of a rat and the left ventricle of a rabbit. After correction for Poisson noise, correlation coefficients between the colors were 0.99 +/- 0.02 (means +/- SD) for the rabbit heart and 0.99 +/- 0.02 for the rat lung. Mathematical dissection algorithms, statistics to analyze the spatial data, and methods to visualize blood flow distributions in small animal organs are presented.
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Velocidade do Fluxo Sanguíneo , Rim/irrigação sanguínea , Pulmão/irrigação sanguínea , Miocárdio/metabolismo , Fluxo Sanguíneo Regional/fisiologia , Animais , Corantes Fluorescentes/farmacocinética , Rim/citologia , Pulmão/citologia , Microesferas , Modelos Cardiovasculares , Distribuição de Poisson , Coelhos , Ratos , Suínos , Distribuição TecidualRESUMO
The physically based river catchment modelling system SHETRAN incorporates components representing water flow, sediment transport and radionuclide transport both in solution and bound to sediments. The system has been applied to simulate hypothetical future catchments in the context of post-closure radiological safety assessments of a potential site for a deep geological disposal facility for intermediate and certain low-level radioactive wastes at Sellafield, west Cumbria. In order to have confidence in the application of SHETRAN for this purpose, various blind validation studies have been undertaken. In earlier studies, the validation was undertaken against uncertainty bounds in model output predictions set by the modelling team on the basis of how well they expected the model to perform. However, validation can also be carried out with bounds set on the basis of how well the model is required to perform in order to constitute a useful assessment tool. Herein, such an assessment-based validation exercise is reported. This exercise related to a field plot experiment conducted at Calder Hollow, west Cumbria, in which the migration of strontium and lanthanum in subsurface Quaternary deposits was studied on a length scale of a few metres. Blind predictions of tracer migration were compared with experimental results using bounds set by a small group of assessment experts independent of the modelling team. Overall, the SHETRAN system performed well, failing only two out of seven of the imposed tests. Furthermore, of the five tests that were not failed, three were positively passed even when a pessimistic view was taken as to how measurement errors should be taken into account. It is concluded that the SHETRAN system, which is still being developed further, is a powerful tool for application in post-closure radiological safety assessments.
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Água Doce/análise , Sedimentos Geológicos/química , Modelos Teóricos , Resíduos Radioativos , Segurança , Reino UnidoRESUMO
Calculations of radiological risk are required to assess the safety of any potential future UK deep underground repository for intermediate-level and certain low-level solid radioactive wastes. In support of such calculations, contaminant movement and dilution in the terrestrial biosphere is investigated using the physically based modelling system SHETRAN. Two case studies are presented involving modelling of contaminants representing long-lived poorly sorbed radionuclides in the near-surface aquifers and surface waters of hypothetical catchments. The contaminants arise from diffuse sources at the base of the modelled aquifers. The catchments are characterised in terms of detailed spatial data for topography, the river network, soils and vegetation. Simulations are run for temperate and boreal climates representing possible future conditions at a repository site. Results are presented in terms of the concentration of contaminants in the aquifer, in soils and in surface waters; these are used to support the simpler models used in risk calculations.
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Ecossistema , Poluição Ambiental/análise , Modelos Biológicos , Resíduos Radioativos/análise , Clima , Simulação por Computador , Poluição Ambiental/efeitos adversos , Previsões , Meia-Vida , Resíduos Perigosos/efeitos adversos , Humanos , Resíduos Radioativos/efeitos adversos , Medição de Risco , Fatores de Risco , Segurança , Poluentes Radioativos do Solo/efeitos adversos , Poluentes Radioativos do Solo/análise , Reino Unido , Poluentes Radioativos da Água/efeitos adversos , Poluentes Radioativos da Água/análise , Abastecimento de Água/análiseAssuntos
Citocromos/metabolismo , Fígado/metabolismo , Animais , Temperatura Baixa , Grupo dos Citocromos a/metabolismo , Grupo dos Citocromos c/metabolismo , Técnicas In Vitro , NAD/metabolismo , NADP/metabolismo , Preservação de Órgãos/instrumentação , Preservação de Órgãos/métodos , Oxirredução , Consumo de Oxigênio , Perfusão/instrumentação , Perfusão/métodos , Ratos , Ratos Endogâmicos F344 , Ratos Sprague-Dawley , Espectrometria de Fluorescência/instrumentação , Espectrometria de Fluorescência/métodos , Espectrofotometria/instrumentação , Espectrofotometria/métodosRESUMO
The immediate and residual response to single doses of oral diazepam 10 mg was measured in 11 young and 12 elderly healthy volunteers using postural sway, digit symbol substitution scores and subjective ratings. The effect on postural sway was markedly accentuated in the older volunteers, but the difference between groups in the effect on the other measures used did not achieve significance. The corresponding plasma total diazepam concentrations were lower in the older subjects beyond 0.5 h post dose and the concentrations of plasma desmethyldiazepam did not differ between the groups. Diazepam plasma protein binding was significantly reduced in the elderly subjects, but the plasma free (unbound) diazepam concentrations did not exceed those in the young group. There was poor correlation between the responses measured and the concentrations of either total diazepam, desmethyldiazepam or free diazepam. The results suggest the occurrence of a non-uniform effect of age on different aspects of benzodiazepine response, and that where an accentuated effect occurs the mechanisms are substantially pharmacodynamic.
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Diazepam/farmacologia , Adulto , Idoso , Envelhecimento , Diazepam/administração & dosagem , Diazepam/sangue , Relação Dose-Resposta a Droga , Feminino , Humanos , Hipnóticos e Sedativos , Masculino , Nordazepam/sangue , Postura/efeitos dos fármacos , Ligação Proteica , Desempenho Psicomotor/efeitos dos fármacosRESUMO
Fluomine is a cobalt chelate compound which complexes molecular oxygen and releases it on heating. This property has led to its use a a regenerable oxygen source in high-altitude aircraft. Investigations into the acute effects of exposure to fluomine by various routes were undertaken as first steps in the toxicological characterization of the material. Single-dose rat and mouse oral administration led to LD50 values of 123 mg/kg for male CF1 mice and 187 mg/kg for male Sprague-Dawley rats. The LC50 values for single four-hour inhalation periods varied from 112 mg/m3 for male rats to 416 mg/m3 for male mice. Fluomine proved to be highly irritating when instilled in the eyes of rabbits and to the lungs of rats on inhalation. Exposure of rabbit skin to the compound demonstrated moderate irritancy particularly in areas of abrasion. Positive reactions to intradermal challenge were demonstrated after both intradermal and inhalation sensitization of guinea pigs.