1,861 research outputs found

    Reconsidering power and distance

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    A wide range of studies indicate that power and distance affect the production and interpretation of language. However, this paper argues that greater consideration needs to be given to the conceptual nature of these dimensions, and to terminological usage. In the first half of the paper, the need for this consideration is explained. A number of pragmatic studies are examined, and this reveals that authors often use the same terms with different meanings, or different terms with the same meaning, and that the parameters are rarely explicitly defined. Then the paper reviews recent calls for an extra parameter of interlocutor relations to be added: for affect to be separated from distance. In the second half of the paper, relevant social psychological research is reported, and it is concluded that the number of ‘horizontal’ dimensions of interlocutor relations needs to be reconsidered. Power, on the other hand, emerges as a robust and relatively unitary dimension, yet its label has connotations that may not be cross-culturally valid

    Rock geochemistry induces stress and starvation responses in the bacterial proteome

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    Interactions between microorganisms and rocks play an important role in Earth system processes. However, little is known about the molecular capabilities microorganisms require to live in rocky environments. Using a quantitative label-free proteomics approach, we show that a model bacterium (Cupriavidus metallidurans CH34) can use volcanic rock to satisfy some elemental requirements, resulting in increased rates of cell division in both magnesium- and iron-limited media. However, the rocks also introduced multiple new stresses via chemical changes associated with pH, elemental leaching and surface adsorption of nutrients that were reflected in the proteome. For example, the loss of bioavailable phosphorus was observed and resulted in the upregulation of diverse phosphate limitation proteins, which facilitate increase phosphate uptake and scavenging within the cell. Our results revealed that despite the provision of essential elements, rock chemistry drives complex metabolic reorganization within rock-dwelling organisms, requiring tight regulation of cellular processes at the protein level. This study advances our ability to identify key microbial responses that enable life to persist in rock environments

    Properties of Dark Matter Haloes and their Correlations: the Lesson from Principal Component Analysis

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    We study the correlations between the structural parameters of dark matter haloes using Principal Component Analysis (PCA). We consider a set of eight parameters, six of which are commonly used to characterize dark matter halo properties: mass, concentration, spin, shape, overdensity, and the angle (ΦL\Phi_L) between the major axis and the angular momentum vector. Two additional parameters (\x_{off} and ρrms\rho_{rms}) are used to describe the degree of `relaxedness' of the halo. We find that we can account for much of the variance of these properties with halo mass and concentration, on the one hand, and halo relaxedness on the other. Nonetheless, three principle components are usually required to account for most of the variance. We argue that halo mass is not as dominant as expected, which is a challenge for halo occupation models and semi-analytic models that assume that mass determines other halo (and galaxy) properties. In addition, we find that the angle ΦL\Phi_L is not significantly correlated with other halo parameters, which may present a difficulty for models in which galaxy disks are oriented in haloes in a particular way. Finally, at fixed mass, we find that a halo's environment (quantified by the large-scale overdensity) is relatively unimportant.Comment: 14 pages, 8 figures; minor revisions; MNRAS, in pres

    The Lives of High Redshift Mergers

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    We present a comparative study of recent works on merger-timescales with dynamical friction and find a strong contrast between idealized/isolated mergers (Boylan-Kolchin et al. 2008) and mergers from a cosmological volume (Jiang et al. 2008). Our study measures the duration of mergers in a cosmological N-body simulation of dark matter, with emphasis on higher redshifts (z < 10) and a lower mass range. In our analysis we consider and compare two merger definitions; tidal disruption and coalescence. We find that the merger-time formula proposed by Jiang et al. (2008) describes our results well and conclude that cosmologically motivated merger-time formulae provide a more versatile and statistically robust approximation for practical applications such as semi-analytic/hybrid models.Comment: 11 pages, 9 figures, Accepted for publication in MNRA

    Development and implementation of an herbal and natural product elective in undergraduate medical education

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    <p>Abstract</p> <p>Background</p> <p>Medical students have consistently expressed interest in learning about alternative healing modalities, especially herbal and natural products. To fill this void in medical education at our institution, a novel elective was developed and implemented for fourth year medical students. This herbal/natural product course uses guest lecturers, classroom presentations, and active learning mechanisms that include experiential rotations, case-based learning, and team-based learning to increase student knowledge of herbal/natural product safety and efficacy.</p> <p>Methods</p> <p>Knowledge outcomes were evaluated via administration of a pre- and post-course test (paired student <it>t</it>-test). End-of-course evaluations (Likert-type questions and narrative responses) were used to assess student opinion of knowledge and skills imparted by the elective and overall course content (mean, standard deviation).</p> <p>Results</p> <p>Over three academic years, 23 students have enrolled in this elective. More than 60% of participants have been female and nearly half of the students (43%) have pursued residencies in primary care. Completion of the course significantly increased student knowledge of common herbal/natural product mechanisms, uses, adverse effects, and drug-interactions as determined by a pre- and post-course knowledge assessment (45% ± 10% versus 78% ± 6%; p < 0.0001). The course was highly rated by enrollees (overall course quality, 4.6 of 5.0 ± 0.48) who appreciated the variety of activities to which they were exposed and the open classroom discussions that resulted. While students tended to view some alternative medical systems with skepticism, they still believed it was valuable to learn what these modalities encompass.</p> <p>Conclusions</p> <p>Development and implementation of a herbal/natural product elective that engages undergraduate medical students through active learning mechanisms and critical analysis of the literature has proven effective in increasing knowledge outcomes and is deemed to be a valuable curricular addition by student participants. In the future, it will be of interest to explore mechanisms for expanding the course to reach a larger number of students within the time, financial, and logistical constraints that currently exist.</p

    Multilingual Repertoire Management and Illocutionary Functions in Yiddish Signage in Manchester

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    Drawing on a corpus of annotated images that capture the linguistic landscape of a residential neighbourhood in Greater Manchester (UK) with a large Hasidic-Haredi (so-called ‘ultra-Orthodox’) Jewish population, we show how choices within a multilingual repertoire are both indicative and constitutive of different communicative acts and illocutions. Written Yiddish is embedded into an established tradition of literacy where creativity is accompanied by authoritative citations from Hebrew scripture. We discuss the use of Yiddish in affective, appellative, mobilising, regulatory and prohibitive actions. Semi-public use of written Yiddish is directed at participants who share a repertoire of closely intertwined social, religious and linguistic practices. Unlike many other lesser-used languages, the use of Yiddish in Haredi communities is not restricted to indexical identity flagging or commodification purposes. We show how in this multilingual setting, the indexical ordering of languages on written artefacts does not represent a hierarchy of absolute valorisation but rather a complementarity of functions that draws on simultaneous activation of several repertoire components

    Dry conditions disrupt terrestrial-aquatic linkages in northern catchments.

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    Aquatic ecosystems depend on terrestrial organic matter (tOM) to regulate many functions, such as food web production and water quality, but an increasing frequency and intensity of drought across northern ecosystems is threatening to disrupt this important connection. Dry conditions reduce tOM export and can also oxidize wetland soils and release stored contaminants into stream flow after rainfall. Here, we test whether these disruptions to terrestrial-aquatic linkages occur during mild summer drought and whether this affects biota across 43 littoral zone sites in 11 lakes. We use copper (Cu) and nickel (Ni) as representative contaminants, and measure abundances of Hyalella azteca, a widespread indicator of ecosystem condition and food web production. We found that tOM concentrations were reduced but correlations with organic soils (wetlands and riparian forests) persisted during mild drought and were sufficient to suppress labile Cu concentrations. Wetlands, however, also became a source of labile Ni to littoral zones, which was linked to reduced abundances of the amphipod H. azteca, on average by up to 70 times across the range of observed Ni concentrations. This reveals a duality in the functional linkage of organic soils to aquatic ecosystems whereby they can help buffer the effects of hydrologic disconnection between catchments and lakes but at the cost of biogeochemical changes that release stored contaminants. As evidence of the toxicity of trace contaminant concentrations and their global dispersion grows, sustaining links among forests, organic soils and aquatic ecosystems in a changing climate will become increasingly important.Natural Environment Research Council (Grant ID: NE/L006561/1)This is the final version of the article. It first appeared from Wiley via https://doi.org/10.1111/gcb.1336
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