800 research outputs found

    Mongoose Manor: Herpestidae remains from the Early Pleistocene Cooper’s D locality in the Cradle of Humankind, Gauteng, South Africa

    Get PDF
    Mongooses (Herpestidae) are an important component of African ecosystems, and a common constituent of southern African fossil assemblages. Despite this, mongoose fossils from the Cradle of Humankind, Gauteng, South Africa, have received relatively little interest. This paper presents the diverse mongoose craniodental assemblage from the early Pleistocene fossil locality Cooper’s D. A total of 29 mongoose specimens from five genera were identified at Cooper’s, including numerous first appearances in the Cradle or in South Africa. The exceptional mongoose assemblage at Cooper’s likely reflects the effects of an unknown taphonomic process, although mongooses follow other carnivore groups in the Cradle in displaying an apparent preference for the southern part of the Cradle. This investigation shows the value of mongooses as palaeoecological indicators and supports previous interpretations of the environment at Cooper’s as grassland with a strong woody component near a permanent water source.Palaeontological Scientific Trust (PAST); DST-NRF Centre of Excellence, Palaeosciences (CoE-Pal); the South African National Research Foundation; and the University of the Witwatersrand Postgraduate Merit Award.JNC201

    Partnership, high performance work systems and organizational effectiveness

    Get PDF
    Using data gathered from 132 organizations operating in Ireland, we examined the impact of high performance work systems (HPWS) and partnership on firm-level performance. Our results reveal that HPWS and partnership practices are positively associated with labour productivity, workplace innovation and negatively associated with voluntary turnover. More specifically, both HPWS and partnership are positively associated with labour productivity and employee retention, and the positive relationship between partnership and workplace innovation is mediated by HPWS

    Mustelid and viverrid remains from the Pleistocene site of Cooper’s D, Gauteng, South Africa

    Get PDF
    Fossil mustelids and viverrids are rare in the African Pleistocene fossil record. The careful examination of sieved sediments from the well-dated Cooper’s D locality in Gauteng has revealed six new mustelid and viverrid specimens. These represent three uncommon genera – two mustelids, Propoecilogale bolti and Mellivora capensis, and a viverrid, Civettictis cf. civetta. We describe and figure these six specimens here. Cooper’sD is only the fourth African locality at which P. bolti has been identified, and it is the first of the Witwatersrand sites to contain remains of the African civet.Palaeontological Scientific Trust NRF/DST Centre of Excellence in Palaeosciences South African National Research Foundation University of the Witwatersrand Postgraduate Merit Award Liverpool John Moores University Early Career Researcher Awar

    A comparative analysis of biogas and hydrogen, and the impact of the certificates and blockchain new paradigms

    Get PDF
    Solar and wind energy technologies, due to their nature of weather dependency, have been recognized as not the complete solution for the renewable energy transition. Creating a solution for the short fall is empirical if we are to remove the dependency on fossil fuels and reach net zero targets. The production of hydrogen, biogas and other gases can be produced sustainably, which can also allow for the utilization of waste materials or the ability to store energy and allow a greater positive impact on our environment. However, production of these gases is not always as transparent or environmentally friendly as perceived, so with the aid of certification and blockchain, we can create a system that can guarantee their environmentally positive origin, and ultimately help assist the transition to a greener future. This paper explores the varying production methods, with consideration to their environmental impact, and the implications of the use of certificates and blockchain to monitor production, trade and usage

    Estimating the Power of Indirect Comparisons: A Simulation Study

    Get PDF
    Indirect comparisons are becoming increasingly popular for evaluating medical treatments that have not been compared head-to-head in randomized clinical trials (RCTs). While indirect methods have grown in popularity and acceptance, little is known about the fragility of confidence interval estimations and hypothesis testing relying on this method.We present the findings of a simulation study that examined the fragility of indirect confidence interval estimation and hypothesis testing relying on the adjusted indirect method.Our results suggest that, for the settings considered in this study, indirect confidence interval estimation suffers from under-coverage while indirect hypothesis testing suffers from low power in the presence of moderate to large between-study heterogeneity. In addition, the risk of overestimation is large when the indirect comparison of interest relies on just one trial for one of the two direct comparisons.Indirect comparisons typically suffer from low power. The risk of imprecision is increased when comparisons are unbalanced

    Quaternary paleoceanography of the central arctic based on Integrated Ocean Drilling Program Arctic Coring Expedition 302 foraminiferal assemblages

    Get PDF
    The Integrated Ocean Drilling Program (IODP) Arctic Coring Expedition (ACEX) Hole 4C from the Lomonosov Ridge in the central Arctic Ocean recovered a continuous 18 m record of Quaternary foraminifera yielding evidence for seasonally ice-free interglacials during the Matuyama, progressive development of large glacials during the mid-Pleistocene transition (MPT) �1.2–0.9 Ma, and the onset of high-amplitude 100-ka orbital cycles �500 ka. Foraminiferal preservation in sediments from the Arctic is influenced by primary (sea ice, organic input, and other environmental conditions) and secondary factors (syndepositional, long-term pore water dissolution). Taking these into account, the ACEX 4C record shows distinct maxima in agglutinated foraminiferal abundance corresponding to several interglacials and deglacials between marine isotope stages (MIS) 13–37, and although less precise dating is available for older sediments, these trends appear to continue through the Matuyama. The MPT is characterized by nearly barren intervals during major glacials (MIS 12, 16, and 22–24) and faunal turnover (MIS 12–24). Abundant calcareous planktonic (mainly Neogloboquadrina pachyderma sin.) and benthic foraminifers occur mainly in interglacial intervals during the Brunhes and very rarely in the Matuyama. A distinct faunal transition from calcareous to agglutinated foraminifers 200–300 ka in ACEX 4C is comparable to that found in Arctic sediments from the Lomonosov, Alpha, and Northwind ridges and the Morris Jesup Rise. Down-core disappearance of calcareous taxa is probably related to either reduced sea ice cover prior to the last few 100-ka cycles, pore water dissolution, or both

    Cultural relativism and the discourse of intercultural communication: aporias of praxis in the intercultural public sphere

    Get PDF
    The premise of much intercultural communication pedagogy and research is to educate people from different cultures towards open and transformative positions of mutual understanding and respect. This discourse in the instance of its articulation realises and sustains Intercultural Communication epistemologically – as an academic field of social enquiry, and judgementally – as one which locates itself on a moral terrain. By adopting an ethical stance towards difference, the discourse of intercultural communication finds itself caught in a series of aporias, or performative contradictions, where interculturalists are projected simultaneously into positions of cultural relativism on the one hand and ideological totalism on the other. Such aporias arise because the theoretical premises upon which the discourse relies are problematic. We trace these thematics to a politics of presence operating within the discourse of intercultural communication and links this to questions of judgement and truth in the intercultural public sphere. We propose that the politics of presence be set aside in favour of an intercultural praxis which is oriented to responsibility rather than to truth

    Expedition 302 summary

    No full text
    The first scientific drilling expedition to the central Arctic Ocean was completed in September 2004. Integrated Ocean Drilling Program Expedition 302, Arctic Coring Expedition (ACEX), recovered sediment cores to 428 meters below seafloor (mbsf) in water depths of ~1300 m, 250 km from the North Pole.Expedition 302's destination was the Lomonosov Ridge, hypothesized to be a sliver of continental crust that broke away from the Eurasian plate at ~56 Ma. As the ridge moved northward and subsided, marine sedimentation occurred and continues to the present, resulting in what was anticipated from seismic data to be a continuous paleoceanographic record. The elevation of the ridge above the surrounding abyssal plains (~3 km) ensured that sediments atop the ridge were free of turbidites. The primary scientific objective of Expedition 302 was to continuously recover this sediment record and to sample the underlying sedimentary bedrock by drilling and coring from a stationary drillship.The biggest challenge during Expedition 302 was maintaining the drillship's location while drilling and coring in 2–4 m thick sea ice that moved at speeds approaching 0.5 kt. Sea-ice cover over the Lomonosov Ridge moves with one of the two major Arctic sea-ice circulation systems, the Transpolar Drift, and responds locally to wind, tides, and currents. Until now, the high Arctic Ocean Basin, known as "mare incognitum" within the scientific community, had never before been deeply cored because of these challenging sea-ice conditions.Initial results reveal that biogenic carbonate is present only in the Holocene–Pleistocene interval. The upper 198 mbsf represents a relatively high sedimentation rate record of the past 18 m.y. and is composed of sediment with ice-rafted debris and dropstones, suggesting that ice-covered conditions extended at least this far back in time. Details of the ice type (e.g., iceberg versus sea ice), timing, and characteristics (e.g., perennial versus seasonal) await further study. A hiatus occurs at 193.13 mbsf, spanning a 25 m.y. interval from the early Miocene to the middle Eocene between ~18 Ma and 43 Ma. The sediment record during the middle Eocene is of dark, organic-rich biosiliceous composition. Isolated pebbles, interpreted as ice-rafted dropstones, are present down to 239 mbsf, well into this middle Eocene interval. Around the lower/middle Eocene boundary an abundance of Azolla spp. occurs, suggesting that a fresh and/or low-salinity surface water setting dominated the region during this time period. Although predrilling predictions based on geophysical data had placed the base of the sediment column at 50 Ma, drilling revealed that the uppermost Paleocene to lowermost Eocene boundary interval, well known as the Paleocene/Eocene Thermal Maximum (PETM), was recovered. During the PETM, the temperature of the Arctic Ocean surface waters exceeded 20°C.Drilling during Expedition 302 also penetrated into the underlying sedimentary bedrock, revealing a shallow-water depositional environment of Late Cretaceous age

    Methods

    No full text
    Information assembled in this chapter will help the reader understand the basis for the preliminary conclusions of the Expedition 302 Scientists and will also enable the interested investigator to select samples for further analyses. This information concerns offshore and onshore operations and analyses described in the "Sites M0001–M0004" chapter. Methods used by various investigators for shore-based analyses of Expedition 302 samples will be described in the individual contributions published in the Expedition Research Results and in various professional journals
    corecore