395 research outputs found

    Silicon based oxidation-resistant coatings on Ti6242 alloy by dynamic ion mixing

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    The influence of SixCy and SixNy amorphous coatings on the oxidation resistance of a Ti6242 (Ti–6Al–2Sn–4Zr–2Mo) alloy was investigated. They were produced at room temperature by the dynamic ion mixing technique combining physical vapour deposition with simultaneous bombardment with 120 keV Ar+ ions. Isothermal oxidation tests were carried out at 600 °C in 1 atm flowing synthetic air (80% N2, 20% O2) demonstrating a considerable reduction (not, vert, similartwo orders of magnitude) of the oxidation rate for at least 100 h. The structural modifications after oxidation were investigated by XPS, XRD, SEM, SIMS. The formation of SiO2 is detected as the main oxidation product in the coating and the formation of Ti–Si compounds is also observed in the coating/substrate interface region. The crystallisation of SixNy is not detected and for SixCy only some traces of β-SiC could exist. The improvement of oxidation resistance of Ti6242 is discussed in relation with the intrinsic properties of the coatings and with the interface mixing and ion beam densification

    Lesser Adjutant nests in S.W. Kalimantan

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    Reintroduction of confiscated and displaced mammals risks outbreeding and introgression in natural populations, as evidenced by orang-utans of divergent subspecies

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    Confiscated and displaced mammals are often taken to sanctuaries, where the explicit goal may be reintroduction to the wild. By inadvertently collecting animals from different source populations, however, such efforts risk reintroducing individuals that have not been in genetic contact for significant periods of time. Using genetic analyses and 44 years of data from Camp Leakey, an orang-utan rehabilitation site on Borneo, we determined the minimum extent to which orang-utans representing non-native, geographically and reproductively isolated taxa were reintroduced into the surrounding wild population. We found two reintroduced females were from a non-native subspecies, and have since produced at least 22 hybridized and introgressed descendants to date, of which at least 15 are living. Given that Bornean orang-utan subspecies are thought to have diverged from a common ancestor around 176,000 years ago, with marked differentiation over the last 80,000 years, we highlight the need for further evaluation of the effects of hybridizing orang-utans of different taxa — particularly in light of the ~1500 displaced orang-utans awaiting urgent reintroduction. As endangered mammals are increasing in number in sanctuaries worldwide, we stress the need for re-examination of historical reintroductions, to assess the extent and effects of de facto translocations in the past

    Birds of Tanjung Puting National Park, Kalimantan Tengah. A Preliminary list

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    Tanjung Puting National Park is located on the south coast of Kalimantan (Borneo) in the province of Kalimantan Tengah, between 2"35'S and 3° 20'S and 111° 50' and 112° 15'E. Tanjung Puting was first established as a game reserve in two parts during 1936 and 1937 by the Dutch colonial government and the Sultan of Kotawaringin. Consisting of 305,000 ha the reserve was established primarily for the protection of orangutans Pongo pygmaeus, Proboscis Monkeys Nasalls larvatus and rhinoceros Dicerorhinus sumatrensis with the latter, however, becoming extinct in the 1940's due to severe hunting pressure for its horns. Orangutans and proboscis monkeys still remain plentiful. In 1982 the status of Tanjung puting was upgraded to National park

    Increase in hypoglycaemia and hyperglycaemia in people with diabetes admitted to hospital during COVID-19 pandemic

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    BACKGROUND: We used detailed information on patients with diabetes admitted to hospital to determine differences in clinical outcomes before and during the COVID-19 pandemic in the UK. METHODS: The study used electronic patient record data from Imperial College Healthcare NHS Trust. Hospital admission data for patients coded for diabetes was analysed over three time periods: pre-pandemic (31st January 2019-31st January 2020), Wave 1 (1st February 2020-30th June 2020), and Wave 2 (1st September 2020-30th April 2021). We compared clinical outcomes including glycaemia and length of stay. RESULTS: We analysed data obtained from 12,878, 4008 and 7189 hospital admissions during the three pre-specified time periods. The incidence of Level 1 and Level 2 hypoglycaemia was significantly higher during Waves 1 and 2 compared to the pre-pandemic period (25 % and 25.1 % vs. 22.9 % for Level 1 and 11.7 % and 11.5 % vs. 10.3 % for Level 2). The incidence of hyperglycaemia was also significantly higher during the two waves. The median hospital length of stay increased significantly (4.1[1.6, 9.8] and 4.0[1.4, 9.4] vs. 3.5[1.2, 9.2] days). CONCLUSIONS: During the COVID-19 pandemic in the UK, hospital in-patients with diabetes had a greater number of hypoglycaemic/hyperglycaemic episodes and an increased length of stay when compared to the pre-pandemic period. This highlights the necessity for a focus on improved diabetes care during further significant disruptions to healthcare systems and ensuring minimisation of the impact on in-patient diabetes services. SUMMARY: Diabetes is associated with poorer outcomes from COVID-19. However the glycaemic control of inpatients before and during the COVID-19 pandemic is unknown. We found the incidence of hypoglycaemia and hyperglycaemia was significantly higher during the pandemic highlighting the necessity for a focus on improved diabetes care during further pandemics

    Transmission of Human and Macaque Plasmodium spp. to Ex-Captive Orangutans in Kalimantan, Indonesia

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    We identified 4 discrete Plasmodium spp. sequences from the blood of orangutans, including 1 of P. vivax, which has implications for human residents and orangutan rehabilitation programs

    Fostering appropriate behaviour in rehabilitant orangutans (Pongo pygmaeus)

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    Rehabilitation centres in Indonesia and Malaysia accommodate displaced orangutans (Pongo pygmaeus and P. abelii) and aim to facilitate their release into the wild by developing in them the skills that are necessary for survival. Regular forest excursions are provided but their efficacy in improving learning of appropriate behaviours is unknown. We observed forty rehabilitating orangutans from the Orangutan Care and Quarantine Centre during three forest excursions each to determine whether their behaviour fostered the development of survival skills. In total 38% of their time was spent in locomotion, particularly quadrupedal arboreal travel (13%), walking (8%), climbing (7%) and vine-swinging (4%). 26.5% of their time was spent 5 m or more from the ground, at heights up to 25 m. Arboreal activities were more 2 common early in the excursions and interaction with c are-givers more common later (hour 1: 0.3% of time; hour 5: 0.9% of time). Animals of lower body weight were significantly more likely to engage in arboreal movement, locomotion in general, eating of bark and leaves, and social play, and less likely to eat insects. Those that had been at the Centre the longest were less likely to perform arboreal activities and significantly more likely to be found standing and at ground level, than those that were there for a shorter time. During this study, many forest food items were consumed, particularly leaves and fruit, but also invertebrates and bark. Little time was spent in sexual behaviour, tool use, nest building or socially-mediated learning, but social play occupied almost 6% of their time. We conclude that regular excursions into the forest are likely to assist in the development of locomotion and feeding skills for survival in rehabilitating orangutans, but special attention is needed to encourage nest building, social activities and arboreal activity. Animals least likely to benefit are heavy animals and those that have been captive for a long time

    Orientation toward humans predicts cognitive performance in orang-utans

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    The authors acknowledge the Swiss National Science Foundation and following foundations who have financially supported this project: A. H. Schultz Foundation, Paul Schiller Foundation and the Claraz Foundation in Switzerland and Waldemar von Frenckells Foundation, Ella and Georgh Ehrnrooths Foundation, Otto A. Malms Donationsfond, Nordenskiöld Samfundet and Oskar Öflunds Foundation in Finland.Non-human animals sometimes show marked intraspecific variation in their cognitive abilities that may reflect variation in external inputs and experience during the developmental period. We examined variation in exploration and cognitive performance on a problem-solving task in a large sample of captive orang-utans (Pongo abelii & P. pygmaeus, N = 103) that had experienced different rearing and housing conditions during ontogeny, including human exposure. In addition to measuring exploration and cognitive performance, we also conducted a set of assays of the subjects’ psychological orientation, including reactions towards an unfamiliar human, summarized in the human orientation index (HOI), and towards novel food and objects. Using generalized linear mixed models we found that the HOI, rather than rearing background, best predicted both exploration and problem-solving success. Our results suggest a cascade of processes: human orientation was accompanied by a change in motivation towards problem-solving, expressed in reduced neophobia and increased exploration variety, which led to greater experience, and thus eventually to higher performance in the task. We propose that different experiences with humans caused individuals to vary in curiosity and understanding of the physical problem-solving task. We discuss the implications of these findings for comparative studies of cognitive ability.Publisher PDFPeer reviewe
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