2,632 research outputs found

    Towards a historical ecology of intertidal foraging in the Mafia Archipelago: archaeomalacology and implications for marine resource management

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    Understanding the timing and nature of human influence on coastal and island ecosystems is becoming a central concern in archaeological research, particularly when investigated within a historical ecology framework. Unfortunately, the coast and islands of eastern Africa have not figured significantly within this growing body of literature, but are important given their historically contingent environmental, social, and political contexts, as well as the considerable threats now posed to marine ecosystems. Here, we begin developing a longer-term understanding of past marine resource use in the Mafia Archipelago (eastern Africa), an area of high ecological importance containing the Mafia Island Marine Park. Focusing on the comparatively less researched marine invertebrates provides a means for initiating discussion on potential past marine ecosystem structure, human foraging and environmental shifts, and the implications for contemporary marine resource management. The available evidence suggests that human-environment interactions over the last 2000 years were complex and dynamic; however, these data raise more questions than answers regarding the specific drivers of changes observed in the archaeomalacological record. This is encouraging as a baseline investigation and emphasizes the need for further engagement with historical ecology by a range of cognate disciplines to enhance our understanding of these complex issues

    Influential Article Review - Asian HR Analysis on Methodological Options

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    This paper examines human resources management. We present insights from a highly influential paper. Here are the highlights from this paper: A twenty-year study of the Human Resource (HR) practices– outcome relationship has found that more rigorous methodologies have been adopted over time. However, several problematic features such as cross-sectional, single-informant, and single-level designs continue to be adopted (Bainbridge et al., Human Resource Management, 2016). Responding to calls for increased contextualization of research by investigating the relationship between the location of data collection and the methodological choices of researchers, this study answers the question “How unique are the methodological choices of HR research conducted in Asia?” Applying content analysis to 241 published articles, we compare internal, external, construct and statistical conclusion validity of studies collected in North America (n=66), Europe (n=95) and Asia (n=80, including 57 studies from China). Results show that despite similarities in cross-sectional, single-informant and single-level designs across regions, research conducted in Asia is mainly undertaken via field studies, using subjective outcome measures at the organizational level, following a post-predictive design. In addition, studies from Asia are more recent, and show a shorter time gap between data collection and publication. Theoretical and practical implications embedded in the dynamic context of Asia in general, and China more specifically are discussed. For our overseas readers, we then present the insights from this paper in Spanish, French, Portuguese, and German

    Stochastic Methods for the Neutron Transport Equation II: Almost sure growth.

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    The neutron transport equation (NTE) describes the flux of neutrons across a planar cross-section in an inhomogeneous fissile medium when the process of nuclear fission is active. Classical work on the NTE emerges from the applied mathematics literature in the 1950s through the work of R. Dautray and collaborators, [7, 8, 19]. The NTE also has a probabilistic representation through the semigroup of the underlying physical process when envisaged as a stochastic process; cf. [7, 17, 18, 20]. More recently, [6] and [16] have continued the probabilistic analysis of the NTE, introducing more recent ideas from the theory of spatial branching processes and quasi-stationary distributions. In this paper, we continue in the same vein and look at a fundamental description of stochastic growth in the supercritical regime. Our main result provides a significant improvement on the last known contribution to growth properties of the physical process in [20], bringing neutron transport theory in line with modern branching process theory such as [14, 12].Comment: one figur

    Stable and unstable regimes in Bose-Fermi mixture with attraction between components

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    A collapse of the trapped boson- fermion mixture with the attraction between bosons and fermions is investigated in the framework of the effective Hamiltonian for the Bose system. The properties of the 87^{87}Rb and 40^{40}K mixture are analyzed quantitatively at T=0T= 0. We find numerically solutions of modified Gross- Pitaevskii equation which continuously go from stable to unstable branch. We discuss the relation of the onset of collapse with macroscopic properties of the system. A comparison with the case of a Bose condensate of atomic 7Li^7Li system is given.Comment: 7 pages, 5 figure

    Errors in Heat Flux Measurement by Flux Plates of Contrasting Design and Thermal Conductivity

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    The thermal conductivity (λ) of soils may vary by a factor of about 4 for a range of field soil water contents. Measurement of soil heat flux (G) using a heat flux plate with a fixed λ distorts heat flow through the plates and in the adjacent soil. The objectives of this research were to quantify heat flow distortion errors for soil heat flux plates of widely contrasting designs and to evaluate the accuracy of a previously reported correction. Six types of commercially available heat flux plates with varying thickness, face area, and thermal conductivity (λm) were evaluated. Steady-state laboratory experiments at flux densities from 20 to 175 W m−2 were completed in a large box filled with dry or saturated sand having λ of 0.36 and 2.25 W m−1K−1 A field experiment compared G measured with pairs of four plate types buried at 6 cm in a clay soil with G determined using the gradient technique. The flux plates underestimated G in the dry sand by 2.4 to 38.5% and by 13.1 to 73.2% in saturated sand while in moist clay plate performance ranged from a 6.2% overestimate to a 71.4% underestimate. Application of the correction generally improved agreement between plate estimates and independent Gmeasurements, especially when λ \u3e λm, although most plate estimates were still significantly lower than the actual G Limitations of the correction procedure indicate that renewed effort should be placed on innovative sensor designs that avoid or minimize heat flow distortion and/or provide direct, in situ calibration capability

    Funk What You Heard: Hip Hop Is a Field of Study

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    “Funk What You Heard” is a beaconing call to all scholars who engage with Hip Hop studies. This article lays out the ways in which Hip Hop studies should properly respond to the wave of oppressions currently pounding the world. With several key date markers in place for Hip Hop studies, Tricia Rose’s Black Noise in 1994 and Murray Foreman and Mark Anthony Neal’s That’s the Joint in 2004, “Funk What You Heard” charts the path forward for the future of Hip Hop studies. Black Noise provided the original blueprint for studying Hip Hop and That’s the Joint! stamped “hip-hop studies” into history. Although we are close to thirty years since Black Noise, lyrical analysis is a dominant method for Hip Hop studies. Also, although we have a clearly identifiable field, academics still treat Hip Hop as an interesting topic they can write about without speaking to the field. “Funk What You Heard” calls for something more. We can no longer continue down this path of weak analysis and rewriting Hip Hop theories that have been discussed time and time again. Our contemporary waves of oppression have raised the stakes. With the path charted out, we ultimately call on Hip Hop scholars to answer their ancestral call. Answering this call pragmatically looks like building on the field, developing new and innovative research methods, and engaging with all the elements of Hip Hop. As far as the unseen, we will leave that up to your reflection with Hip Hop’s collective consciousness that is not bound by space and time

    Yaglom limit for critical nonlocal branching markov processes

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    Many-to-few for non-local branching Markov process

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    We provide a many-to-few formula in the general setting of non-local branching Markov processes. This formula allows one to compute expectations of k-fold sums over functions of the population at k different times. The result generalises [14] to the non-local setting, as introduced in [11] and [8]. As an application, we consider the case when the branching process is critical, and conditioned to survive for a large time. In this setting, we prove a general formula for the limiting law of the death time of the most recent common ancestor of two particles selected uniformly from the population at two different times, as t → ∞. Moreover, we describe the limiting law of the population sizes at two different times, in the same asymptotic regime
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