114 research outputs found
<Note> Current Status of Bonobos and Other Large Mammals in the Proposed Forest Reserve of Lomako-Yokokala, Equateur Province, Democratic Republic of Congo
Determining effects of areca (betel) nut chewing in a prospective cohort of pregnant women in Madang Province, Papua New Guinea
BACKGROUND: Chewing areca nut (AN), also known as betel nut, is
common in Asia and the South Pacific and the habit has been
linked to a number of serious health problems including oral
cancer. Use of AN in pregnancy has been associated with a
reduction in mean birthweight in some studies, but this
association and the relationship between AN chewing and other
adverse pregnancy outcomes remain poorly understood. METHODS: We
assessed the impact of AN chewing on adverse outcomes including
stillbirth, low birthweight (LBW, <2,500 g) and anaemia at
delivery (haemoglobin <11.0 g/dL) in a longitudinal cohort of
2,700 pregnant women residing in rural lowland Papua New Guinea
(PNG) from November 2009 until February 2013. Chewing habits and
participant characteristics were evaluated at first antenatal
visit and women were followed until delivery. RESULTS: 83.3%
[2249/2700] of pregnant women used AN, and most chewed on a
daily basis (86.2% [1939/2249]. Smoking and alcohol use was
reported by 18.9% (511/2700) and 5.0% (135/2688) of women,
respectively. AN use was not associated with pregnancy loss or
congenital abnormalities amongst women with a known pregnancy
outcome (n = 2215). Analysis of 1769 birthweights did not
demonstrate an association between AN and LBW (chewers: 13.7%
[200/1459] vs. non-chewers: 14.5% [45/310], P = 0.87) or reduced
mean birthweight (2957 g vs. 2966 g; P = 0.76). Women using AN
were more likely to be anaemic (haemoglobin <11 g/dL) at
delivery (75.2% [998/1314] vs. 63.9% [182/285], adjusted odds
ratio [95% CI]: 1.67 [1.27, 2.20], P < 0.001). Chewers more
commonly had male babies than non-chewers (46.1% [670/1455] vs.
39.8% [123/309], P = 0.045). CONCLUSIONS: AN chewing may
contribute to anaemia. Although not associated with other
adverse pregnancy outcome in this cohort gestational AN use
should be discouraged, given the potential adverse effects on
haemoglobin and well-established long-term health risk including
oral cancer. Future research evaluating the potential
association of AN use and anaemia may be warranted. TRIAL
REGISTRATION: ClinicalTrials.gov NCT01136850 (06 April 2010)
Interpreting long-term trends in bushmeat harvest in southeast Cameroon
Measuring hunting sustainability across West/Central African forests remains a challenge. Long-term assessment of trends is crucial. Via hunter-reported surveys we collected offtake data in three villages near the Dja Biosphere Reserve (southeast Cameroon). During four months (March–June) in 2003, 2009 and 2016, we gathered information on hunters, prey species and number of carcasses brought to the three settlements. Because it was not possible to record hunter effort i.e. the time a hunter spent pursuing animals or setting traps, to calculate catch per unit effort (CPUE), we used catch per hunter per day (CPHD) to document hunter returns. We then used the changes in the mean body mass indicator (MBMI) throughout the study period to test for defaunation in the three villages. Differences in CPHD and MBMI by month and year, between villages and hunting method, were investigated using Tweedie regression models. For all species pooled, we found that the mean CPHD remained relatively constant between 2003 and 2016. There was an observed shift from traps to firearms during the study period. CPHD for each of the seven most hunted species did not vary significantly during the entire study period, and a similar change from traps to firearms was observed. MBMI also remained stable for all species pooled, but significantly declined in the remotest village. Starting MBMI values for this village were higher than for the other two settlements perhaps because wildlife here is less depleted. Although hunter effort data may be difficult to obtain over long time periods, CPHD and MBMI may be useful tools as a measure of impact of hunters on prey populations
A zoo-led study of the great ape bushmeat commodity chain in Cameroon
Current levels of bushmeat hunting in west and central Africa are largely unsustainable, and will lead to the loss of an important natural resource and cause the extinction of threatened species. Worryingly, great apes are hunted for their meat despite being protected across their range. In this paper, we highlight the main actors involved in the trafficking of great ape meat around the Dja Biosphere Reserve (DBR) in Cameroon, and describe the commodity chain associated with the trade. In total, 78 hunters, porters, traders and consumers were interviewed. Hunters, all men, were primarily driven by profit, encouraged by middlemen, though some hunt for their own consumption. However, we identify that great ape hunting is undertaken by specialised hunters along a relatively short supply chain. Gorilla and chimpanzee meat is sold to restaurants and wealthy buyers via few intermediaries. The price of great ape meat varied at different stages of the chain. Middlemen obtained the greatest financial gain, whereas wholesale traders profited least. Movement of ape meat to markets was predominantly by public transport and facilitated by drivers who can pass through checkpoints unnoticed. Based on our study we recommend potential interventions, including support of law enforcement, investments in conservation and development initiatives, and monitoring and research
The effectiveness of digital storytelling in the classrooms: a comprehensive study
In recent years the use of new technologies in educational systems has increased worldwide as digital cameras, personal computers, scanners, and easy-to-use software have become available to educators to harness the digital world. The impact of new technologies in educational contexts has been mostly positive as new technologies have given educators the opportunity to enhance their knowledge, skills, and therefore enhance the standard of education. Researchers have found that student engagement, achievement and motivation are enhanced through integration of such technologies. However, education systems still face many challenges: one of these challenges is how to enhance student engagement to provide better educational outcomes. It has become increasingly important to use innovative pedagogical models to engage learners. Digital storytelling is one of the innovative pedagogical approaches that can engage students in deep and meaningful learning. This research project aimed to create a constructivist learning environment with digital storytelling. The research investigated the pedagogical aspects of digital storytelling and the impact of digital storytelling on student learning when teachers and students use digital stories. A multi-site case study was conducted in one Australian school at primary and secondary levels. In selected classrooms, students and teachers had the opportunity to engage in innovative learning experiences based on digital storytelling. In order to enhance the reliability and validity of the research, multiple methods of data collection and analysis were used. Data was collected with qualitative and quantitative methods. An evaluation rubric was used to collect quantitative data, while interviews and observation were used to collect qualitative data. Data collection was guided by a mixed methods research design in order to evaluate if and how digital storytelling enhances teaching and learning outcomes. The findings from this study suggest that digital storytelling is a powerful tool to integrate instructional messages with learning activities to create more engaging and exciting learning environments. It is a meaningful approach for creating a constructivist learning environment based on novel principles of teaching and learning. Thus, this approach has the potential to enhance student engagement and provide better educational outcomes for learners
Isothermal and Cyclic Aging of 310S Austenitic Stainless Steel
Unusual damage and high creep strain rates have been observed on components made of 310S stainless steel subjected to thermal cycles between room temperature and 1143 K (870 °C). Microstructural characterization of such components after service evidenced high contents in sigma phase which formed first from δ-ferrite and then from γ-austenite. To get some insight into this microstructural evolution, isothermal and cyclic aging of 310S stainless steel has been studied experimentally and discussed on the basis of numerical simulations. The higher contents of sigma phase observed after cyclic agings than after isothermal treatments are clearly associated with nucleation triggered by thermal cycling
Maximization of propylene in an industrial FCC unit
YesThe FCC riser cracks gas oil into useful fuels such as gasoline, diesel and some lighter products such as ethylene and propylene, which are major building blocks for the polyethylene and polypropylene production. The production objective of the riser is usually the maximization of gasoline and diesel, but it can also be to maximize propylene. The optimization and parameter estimation of a six-lumped catalytic cracking reaction of gas oil in FCC is carried out to maximize the yield of propylene using an optimisation framework developed in gPROMS software 5.0 by optimizing mass flow rates and temperatures of catalyst and gas oil. The optimal values of 290.8 kg/s mass flow rate of catalyst and 53.4 kg/s mass flow rate of gas oil were obtained as propylene yield is maximized to give 8.95 wt%. When compared with the base case simulation value of 4.59 wt% propylene yield, the maximized propylene yield is increased by 95%
Population dynamics and genetic connectivity in recent chimpanzee history
Knowledge on the population history of endangered species is critical for conservation, but whole-genome data on chimpanzees (Pan troglodytes) is geographically sparse. Here, we produced the first non-invasive geolocalized catalog of genomic diversity by capturing chromosome 21 from 828 non-invasive samples collected at 48 sampling sites across Africa. The four recognized subspecies show clear genetic differentiation correlating with known barriers, while previously undescribed genetic exchange suggests that these have been permeable on a local scale. We obtained a detailed reconstruction of population stratification and fine-scale patterns of isolation, migration, and connectivity, including a comprehensive picture of admixture with bonobos (Pan paniscus). Unlike humans, chimpanzees did not experience extended episodes of long-distance migrations, which might have limited cultural transmission. Finally, based on local rare variation, we implement a fine-grained geolocalization approach demonstrating improved precision in determining the origin of confiscated chimpanzees
Population dynamics and genetic connectivity in recent chimpanzee history
The European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement no. 864203) (to T.M.-B.). BFU2017-86471-P (MINECO/FEDER, UE) (to T.M.-B.). “Unidad de Excelencia María de Maeztu”, funded by the AEI (CEX2018-000792-M) (to T.M.-B.). Howard Hughes International Early Career (to T.M.-B.). NIH 1R01HG010898-01A1 (to T.M.-B.). Secretaria d’Universitats i Recerca and CERCA Program del Departament d’Economia i Coneixement de la Generalitat de Catalunya (GRC 2017 SGR 880) (to T.M.-B.). UCL’s Wellcome Trust ISSF3 award 204841/Z/16/Z (to A.M.A. and J.M.S.). Generalitat de Catalunya (2017 SGR-1040) (to M. Llorente). Wellcome Trust Investigator Award 202802/Z/16/Z (to D.A.H.). The Pan African Program: The Cultured Chimpanzee (PanAf) is generously funded by the Max Planck Society, the Max Planck Society Innovation Fund, and the Heinz L. Krekeler Foundation.Knowledge on the population history of endangered species is critical for conservation, but whole-genome data on chimpanzees (Pan troglodytes) is geographically sparse. Here, we produced the first non-invasive geolocalized catalog of genomic diversity by capturing chromosome 21 from 828 non-invasive samples collected at 48 sampling sites across Africa. The four recognized subspecies show clear genetic differentiation correlating with known barriers, while previously undescribed genetic exchange suggests that these have been permeable on a local scale. We obtained a detailed reconstruction of population stratification and fine-scale patterns of isolation, migration, and connectivity, including a comprehensive picture of admixture with bonobos (Pan paniscus). Unlike humans, chimpanzees did not experience extended episodes of long-distance migrations, which might have limited cultural transmission. Finally, based on local rare variation, we implement a fine-grained geolocalization approach demonstrating improved precision in determining the origin of confiscated chimpanzees.Publisher PDFPeer reviewe
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