The Experts below are selected from a list of 486 Experts worldwide ranked by ideXlab platform
Bruce G. Charles - One of the best experts on this subject based on the ideXlab platform.
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Toxicokinetics of the active doxorubicin metabolite, doxorubicinol, in sulphur-crested cockatoos (Cacatua galerita).
Research in veterinary science, 2007Co-Authors: C. M. Gilbert, Lucio J. Filippich, Ross P. Mcgeary, Bruce G. CharlesAbstract:The pharmacokinetics of doxorubicinol, a cytotoxic metabolite of the anticancer drug, doxorubicin, were studied in four healthy sulphur-crested cockatoos (Cacatua galerita) after a 20 min intravenous infusion of 2 mg/kg. Plasma doxorubicinol concentrations were measured by HPLC. The pharmacokinetic parameters were estimated using a non-compartmental method. The mean (±SD) peak concentration was 8341 ± 3132 μg/L at 17.5 ± 5.0 min after the start of the infusion, and doxorubicinol concentrations declined biexponentially to 154.3 ± 34.5 μg/L, 40 min after the end of the infusion. Systemic clearance was 0.940 ± 0.473 L/h/kg, mean residence time was 0.165 ± 0.133 h, and steady-state volume of distribution was 0.123 ± 0.0526 L/kg. The terminal half-life was 0.660 ± 0.611 h. Detectible but unquantifiable concentrations of doxorubicinol were present in the plasma ultrafiltrate of two birds during the infusion, indicating very extensive plasma protein binding. Physiological, haematological and biochemical monitoring over 3 weeks showed that doxorubicinol at a single infused dose of 2 mg/kg caused no toxicities of major concern.
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Carboplatin Administration in Sulphur-crested Cockatoos (Cacatua galerita): Clinical Observations
Journal of Avian Medicine and Surgery, 2005Co-Authors: Lucio J. Filippich, Bruce G. Charles, Richard H. Sutton, A. M. BucherAbstract:To determine the clinical effect of systemic carboplatin administration in birds, 6 sulphur-crested cockatoos (Cacatua galerita) were anesthetized and infused intravenously or intraosseously with carboplatin at 5 mg/kg over 3 minutes. Four birds were euthanatized 96 hours after infusion and 2 birds given an intravenous dose were euthanatized 21 days after dosing. All birds tolerated the anesthesia and carboplatin infusion and recovered uneventfully. At 24 hours after dosing, all birds were bright and active. Within 12 hours of dosing, feed intake was reduced and 3 birds vomited, but these signs abated by 48 hours after dosing. Mean body weight decreased by 4% at 24 hours after dosing and continued to decrease, but not significantly, until 96 hours after dosing. Changes in packed cell volume (PCV) and plasma total solids reflected blood loss caused by sampling. The mean PCV decreased significantly by 6 hours after dosing, and the concentration of plasma total solids decreased significantly at 1 hour after dosing and continued to decrease until 12 hours after dosing before progressively and significantly increasing toward baseline values by 96 hours after dosing. At necropsy, myelosuppression was not observed in any bird and no evidence of carboplatin toxicity was found. These results provide veterinarians with useful data for formulating efficacious and safe protocols for platinum-containing compounds when treating neoplasia in parrots and other companion birds.
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Doxorubicin pharmacokinetics following a single-dose infusion to sulphur-crested cockatoos (Cacatua galerita).
Australian veterinary journal, 2004Co-Authors: C. M. Gilbert, Lucio J. Filippich, Bruce G. CharlesAbstract:Objective To determine the pharmacokinetics of doxorubicin in sulphur-crested cockatoos, so that its use in clinical studies in birds can be considered. Design A pharmacokinetic study of doxorubicin, following a single intravenous (IV) infusion over 20 min, was performed in four healthy sulphur-crested cockatoos (Cacatua galerita). Procedure Birds were anaesthetised and both jugular veins were cannulated, one for doxorubicin infusion and the other for blood collection. Doxorubicin hydrochloride (2 mg/kg) in normal saline was infused IV over 20 min at a constant rate. Serial blood samples were collected for 96 h after initiation of the infusion. Plasma doxorubicin concentrations were assayed using an HPLC method involving ethyl acetate extraction, reverse-phase chromatography and fluorescence detection. The limit of quantification was 20 ng/mL. Established non-parametric methods were used for the analysis of plasma doxorubicin data. Results During the infusion the mean +/- SD for the C-max of doxorubicin was 4037 +/- 2577 ng/mL. Plasma concentrations declined biexponentially immediately after the infusion was ceased. There was considerable intersubject variability in all pharmacokinetic variables. The terminal (beta-phase) half-life was 41.4 +/- 18.5 min, the systemic clearance (Cl) was 45.7 +/- 18.0 mL/min/kg, the mean residence time (MRT) was 4.8 +/- 1.4 min, and the volume of distribution at steady state (V-SS) was 238 131 mL/kg. The extrapolated area under the curve (AUC(0-infinity)) was 950 +/- 677 ng/mL.h. The reduced metabolite, doxorubicinol, was detected in the plasma of all four parrots but could be quantified in only one bird with the profile suggesting formation rate-limited pharmacokinetics of doxorubicinol. Conclusions and clinical relevance Doxorubicin infusion in sulphur-crested cockatoos produced mild, transient inappetence. The volume of distribution per kilogram and terminal half-life were considerably smaller, but the clearance per kilogram was similar to or larger than reported in the dog, rat and humans. Traces of doxorubicinol, a metabolite of doxorubicin, were detected in the plasma.
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Platinum pharmacokinetics in sulphur-crested cockatoos (Cacatua galerita) following single-dose cisplatin infusion
Australian veterinary journal, 2000Co-Authors: Lucio J. Filippich, A. M. Bucher, Bruce G. CharlesAbstract:Objective To determine the pharmacokinetics of platinum (Pt) in cockatoos. Design A pharmacokinetic study of Pt, following a single IV infusion of cisplatin, was done in six healthy sulphur-crested cockatoos (Cacatua galerita). Procedure Birds were hydrated for 1 h before and 2 h after a 1-h cisplatin infusion (1 mg/kg, IV). Serial blood samples were collected for 96 h after initiation of the infusion and urine was collected for 2 h during the hydration period after cisplatin administration. Tissue samples from 10 organs were obtained at necropsy, 96 h after cisplatin infusion. Total Pt and filterable Pt in plasma, urinary Pt and tissue Pt concentrations were assayed by inductively coupled plasma-mass spectrometry. A noncompartmental pharmacokinetic analysis was performed on the plasma and urine data. Results For total Pt and filterable Pt, the respective mean systemic clearances were 0.373 and 0.699 L/kg hourly, the steady stale volumes of distribution were 4.19 and 0.356 L/kg, and the mean residence times were 111 and 0.512 h. Total plasma Pt displayed a bi-exponential decay profile with average half-lives of 0.398 and 79.0 h, while filterable Pt had a monoexponential decay with mean half-life of 0.413 h. The renal clearance during the 2-h postinfusion period was 0.167 L/kg hourly. The kidneys had the highest Pt accumulation (4.54 mu g/g DM). Conclusions and Clinical Relevance Cisplatin infusion in cockatoos was well tolerated and PI plasma concentrations were similar to those measured during treatment of solid tumours in human patients. Despite anatomical, physiological and biochemical differences among animal species, the pharmacokinetic disposition of Pt in the cockatoo shares some features with the kinetics reported previously in rodents, dogs and human beings.
Alice M. I. Auersperg - One of the best experts on this subject based on the ideXlab platform.
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Goffin's Cockatoos (Cacatua goffiniana) Can Solve a Novel Problem After Conflicting Past Experiences
'Frontiers Media SA', 2021Co-Authors: Alice M. I. Auersperg, Katarzyna Bobrowicz, Mark O'hara, Chelsea Carminito, Mathias OsvathAbstract:Novel problems often partially overlap with familiar ones. Some features match the qualities of previous situations stored in long-term memory and therefore trigger their retrieval. Using relevant, while inhibiting irrelevant, memories to solve novel problems is a hallmark of behavioral flexibility in humans and has recently been demonstrated in great apes. This capacity has been proposed to promote technical innovativeness and thus warrants investigations of such a mechanism in other innovative species. Here, we show that proficient tool—users among Goffin's cockatoos—an innovative tool—using species—could use a relevant previous experience to solve a novel, partially overlapping problem, even despite a conflicting, potentially misleading, experience. This suggests that selecting relevant experiences over irrelevant experiences guides problem solving at least in some Goffin's cockatoos. Our result supports the hypothesis that flexible memory functions may promote technical innovations
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notes on ecology of wild goffin s cockatoo in the late dry season with emphasis on feeding ecology
Treubia, 2019Co-Authors: Berenika Monika Mioduszewska, Alice M. I. Auersperg, Ludwig Huber, Mark Ohara, Tri Haryoko, Dewi M PrawiradilagaAbstract:Experimental work on captive Goffin’s cockatoos (Cacatua goffiniana) has highlighted the remarkable cognitive abilities of this species. However, little is known about its behavior in the natural habitat on the Tanimbar Archipelago in Indonesia. In order to fully understand the evolutionary roots leading to cognitively advanced skills, such as multi-step problem solving or flexible tool use and manufacture, it is crucial to study the ecological challenges faced by the respective species in the wild. The three-month expedition presented here aimed at gaining first insights into the cockatoos’ feeding ecology and breeding behavior. We could confirm previous predictions that Goffin’s cockatoos are opportunistic foragers and consume a variety of resources (seeds, fruit, inflorescence, roots). Their breeding season may be estimated to start between June and early July and they face potential predation from ground and aerial predators. Additionally, the observational data provide indications that Goffin’s cockatoos are extractive foragers, which together with relying on multiple food sources might be considered a prerequisite of tool use.
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Video to Prospective but not retrospective tool selection in the Goffin’s cockatoo (Cacatua goffiniana)
2018Co-Authors: T. Bugnyar, Alice M. I. AuerspergAbstract:Video showing prospective tool selection by Goffin cockatoos (Cacatua goffiniana)
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Inference by Exclusion in Goffin Cockatoos (Cacatua goffini).
PLOS ONE, 2015Co-Authors: Mark O’hara, Thomas Bugnyar, Alice M. I. Auersperg, Ludwig HuberAbstract:Inference by exclusion, the ability to base choices on the systematic exclusion of alternatives, has been studied in many nonhuman species over the past decade. However, the majority of methodologies employed so far are hard to integrate into a comparative framework as they rarely use controls for the effect of neophilia. Here, we present an improved approach that takes neophilia into account, using an abstract two-choice task on a touch screen, which is equally feasible for a large variety of species. To test this approach we chose Goffin cockatoos (Cacatua goffini), a highly explorative Indonesian parrot species, which have recently been reported to have sophisticated cognitive skills in the technical domain. Our results indicate that Goffin cockatoos are able to solve such abstract two-choice tasks employing inference by exclusion but also highlight the importance of other response strategies.
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Object permanence in the Goffin cockatoo (Cacatua goffini).
Journal of Comparative Psychology, 2013Co-Authors: Alice M. I. Auersperg, Birgit Szabo, Auguste Marie Philippa Von Bayern, Thomas BugnyarAbstract:The ability to represent hidden objects plays an important role in the survival of many species. In order to provide an inclusive synopsis of the current benchmark tasks used to test object permanence in animals for a psittacine representative, we tested eight Goffin cockatoos (Cacatua goffini) on Stages 3–6 of Piagetian object permanence as well as derivations of spatial transposition, rotation, and translocation tasks. Subjects instantly solved visible displacement 3b and 4a but showed an extended plateau for solving Stage 5a at a very late age (10 months). Subjects readily solved most invisible displacement tasks including double hidings and four angles (90°, 180°, 270°, and 360°) of rotation and translocations at high performance levels, although Piagetian Stage 6 invisible displacement tasks caused more difficulties for the animals than transposition, rotations, and translocation tasks.
Thomas Bugnyar - One of the best experts on this subject based on the ideXlab platform.
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Inference by Exclusion in Goffin Cockatoos (Cacatua goffini).
PLOS ONE, 2015Co-Authors: Mark O’hara, Thomas Bugnyar, Alice M. I. Auersperg, Ludwig HuberAbstract:Inference by exclusion, the ability to base choices on the systematic exclusion of alternatives, has been studied in many nonhuman species over the past decade. However, the majority of methodologies employed so far are hard to integrate into a comparative framework as they rarely use controls for the effect of neophilia. Here, we present an improved approach that takes neophilia into account, using an abstract two-choice task on a touch screen, which is equally feasible for a large variety of species. To test this approach we chose Goffin cockatoos (Cacatua goffini), a highly explorative Indonesian parrot species, which have recently been reported to have sophisticated cognitive skills in the technical domain. Our results indicate that Goffin cockatoos are able to solve such abstract two-choice tasks employing inference by exclusion but also highlight the importance of other response strategies.
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Object permanence in the Goffin cockatoo (Cacatua goffini).
Journal of Comparative Psychology, 2013Co-Authors: Alice M. I. Auersperg, Birgit Szabo, Auguste Marie Philippa Von Bayern, Thomas BugnyarAbstract:The ability to represent hidden objects plays an important role in the survival of many species. In order to provide an inclusive synopsis of the current benchmark tasks used to test object permanence in animals for a psittacine representative, we tested eight Goffin cockatoos (Cacatua goffini) on Stages 3–6 of Piagetian object permanence as well as derivations of spatial transposition, rotation, and translocation tasks. Subjects instantly solved visible displacement 3b and 4a but showed an extended plateau for solving Stage 5a at a very late age (10 months). Subjects readily solved most invisible displacement tasks including double hidings and four angles (90°, 180°, 270°, and 360°) of rotation and translocations at high performance levels, although Piagetian Stage 6 invisible displacement tasks caused more difficulties for the animals than transposition, rotations, and translocation tasks.
C. M. Gilbert - One of the best experts on this subject based on the ideXlab platform.
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Toxicokinetics of the active doxorubicin metabolite, doxorubicinol, in sulphur-crested cockatoos (Cacatua galerita).
Research in veterinary science, 2007Co-Authors: C. M. Gilbert, Lucio J. Filippich, Ross P. Mcgeary, Bruce G. CharlesAbstract:The pharmacokinetics of doxorubicinol, a cytotoxic metabolite of the anticancer drug, doxorubicin, were studied in four healthy sulphur-crested cockatoos (Cacatua galerita) after a 20 min intravenous infusion of 2 mg/kg. Plasma doxorubicinol concentrations were measured by HPLC. The pharmacokinetic parameters were estimated using a non-compartmental method. The mean (±SD) peak concentration was 8341 ± 3132 μg/L at 17.5 ± 5.0 min after the start of the infusion, and doxorubicinol concentrations declined biexponentially to 154.3 ± 34.5 μg/L, 40 min after the end of the infusion. Systemic clearance was 0.940 ± 0.473 L/h/kg, mean residence time was 0.165 ± 0.133 h, and steady-state volume of distribution was 0.123 ± 0.0526 L/kg. The terminal half-life was 0.660 ± 0.611 h. Detectible but unquantifiable concentrations of doxorubicinol were present in the plasma ultrafiltrate of two birds during the infusion, indicating very extensive plasma protein binding. Physiological, haematological and biochemical monitoring over 3 weeks showed that doxorubicinol at a single infused dose of 2 mg/kg caused no toxicities of major concern.
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Doxorubicin pharmacokinetics following a single-dose infusion to sulphur-crested cockatoos (Cacatua galerita).
Australian veterinary journal, 2004Co-Authors: C. M. Gilbert, Lucio J. Filippich, Bruce G. CharlesAbstract:Objective To determine the pharmacokinetics of doxorubicin in sulphur-crested cockatoos, so that its use in clinical studies in birds can be considered. Design A pharmacokinetic study of doxorubicin, following a single intravenous (IV) infusion over 20 min, was performed in four healthy sulphur-crested cockatoos (Cacatua galerita). Procedure Birds were anaesthetised and both jugular veins were cannulated, one for doxorubicin infusion and the other for blood collection. Doxorubicin hydrochloride (2 mg/kg) in normal saline was infused IV over 20 min at a constant rate. Serial blood samples were collected for 96 h after initiation of the infusion. Plasma doxorubicin concentrations were assayed using an HPLC method involving ethyl acetate extraction, reverse-phase chromatography and fluorescence detection. The limit of quantification was 20 ng/mL. Established non-parametric methods were used for the analysis of plasma doxorubicin data. Results During the infusion the mean +/- SD for the C-max of doxorubicin was 4037 +/- 2577 ng/mL. Plasma concentrations declined biexponentially immediately after the infusion was ceased. There was considerable intersubject variability in all pharmacokinetic variables. The terminal (beta-phase) half-life was 41.4 +/- 18.5 min, the systemic clearance (Cl) was 45.7 +/- 18.0 mL/min/kg, the mean residence time (MRT) was 4.8 +/- 1.4 min, and the volume of distribution at steady state (V-SS) was 238 131 mL/kg. The extrapolated area under the curve (AUC(0-infinity)) was 950 +/- 677 ng/mL.h. The reduced metabolite, doxorubicinol, was detected in the plasma of all four parrots but could be quantified in only one bird with the profile suggesting formation rate-limited pharmacokinetics of doxorubicinol. Conclusions and clinical relevance Doxorubicin infusion in sulphur-crested cockatoos produced mild, transient inappetence. The volume of distribution per kilogram and terminal half-life were considerably smaller, but the clearance per kilogram was similar to or larger than reported in the dog, rat and humans. Traces of doxorubicinol, a metabolite of doxorubicin, were detected in the plasma.
Stuart J Marsden - One of the best experts on this subject based on the ideXlab platform.
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Protected by dragons: Density surface modeling confirms large population of the critically endangered Yellow-crested Cockatoo on Komodo Island
The Condor, 2020Co-Authors: Anna Reuleaux, Benny A Siregar, Nigel J. Collar, Maria R Panggur, Ani Mardiastuti, Martin Jones, Stuart J MarsdenAbstract:Intense trapping of the critically endangered Yellow-crested Cockatoo (Cacatua sulphurea) for the international pet trade has devastated its populations across Indonesia such that populations of >100 individuals remain at only a handful of sites. We combined distance sampling with density surface modeling (DSM) to predict local densities and estimate total population size for one of these areas, Komodo Island, part of Komodo National Park (KNP) in Indonesia. We modeled local density based on topography (topographic wetness index) and habitat types (percentage of palm savanna and deciduous monsoon forest). Our population estimate of 1,113 (95% CI: 587–2,109) individuals on Komodo Island was considerably larger than previous conservative estimates. Our density surface maps showed cockatoos to be absent over much of the island, but present at high densities in wooded valleys. Coincidence between our DSM and a set of independent cockatoo observations was high (93%). Standardized annual counts by KNP staff in selected areas of the island showed increases in cockatoo records from
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factors influencing nest site occupancy and low reproductive output in the critically endangered yellow crested cockatoo Cacatua sulphurea on sumba indonesia
Bird Conservation International, 2005Co-Authors: Jonathan S Walker, Alexis J Cahill, Stuart J MarsdenAbstract:Summary We studied nest-site selection and nesting success in the critically endangered Yellow-crested Cockatoo Cacatua sulphurea throughout a breeding season in Manupeu-Tanadaru National Park, Sumba. Within a 6 km 2 study area, which supported about 60 birds, cockatoos displayed disproportionate interest in cavities in trees containing other active nests, and cavities already actually occupied by parrots or owls. Actual nesting attempts were made at only eight cavities, and a single chick fledged. Interspecific interactions were observed at every one of these nests. Breeding activity was negatively correlated with monthly rainfall, which was the heaviest for at least 10 years, and it is possible that adverse weather conditions disrupted cockatoo nesting this season. Whether this is the case or not, our study shows how low reproductive output can be in the species and this has serious implications for survival of the population on Sumba.
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status abundance and habitat use of blue eyed cockatoo Cacatua ophthalmica on new britain papua new guinea
Bird Conservation International, 2001Co-Authors: Stuart J Marsden, John D Pilgrim, Roger WilkinsonAbstract:Summary Most research on cockatoos Cacatua outside Australia has focused on species that figure significantly in the pet trade. Here, we examine the status of Blue-eyed Cockatoo Cacatua ophthalmica, an extremely poorly known species endemic to the island of New Britain, in three lowland forest types: primary forest, forest that had been commercially logged of selected large trees in the previous eight years, and forest gardens (small-scale mixed agroforests or ‘‘homegardens’’ tended by indigenous people). During fieldwork at two lowland study sites on New Britain between December 1998 and April 1999, groups of C. ophthalmica were recorded in all forest types (maximum group size = 40), but the species was largely absent from non-forested areas. Estimated cockatoo density in selectively logged forest (64 individuals per km 2 ) was similar to that in primary forest but densities in forest gardens at both sites (6 and 28 per km
