2,599 research outputs found

    Justifications-on-demand as a device to promote shifts of attention associated with relational thinking in elementary arithmetic

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    Student responses to arithmetical questions that can be solved by using arithmetical structure can serve to reveal the extent and nature of relational, as opposed to computational thinking. Here, student responses to probes which require them to justify-on-demand are analysed using a conceptual framework which highlights distinctions between different forms of attention. We analyse a number of actions observed in students in terms of forms of attention and shifts between them: in the short-term (in the moment), medium-term (over several tasks), and long-term (over a year). The main factors conditioning students´ attention and its movement are identified and some didactical consequences are proposed

    Interviewer: 'Are women and girls ever responsible for the domestic violence they encounter?' Student: 'No, well, unless they did something really, really bad …'

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    Research shows the ‘gendered nature’ of domestic violence, with Women’s Aid (a UK-based charity) estimating that 1 in 4 women are affected (2014). This paper reports on a project - funded by Comic Relief, completed by Nottinghamshire Domestic Violence Forum (now known as Equation) and evaluated by Nottingham Trent University. The project adopts a Whole School Approach in seeking to prevent domestic violence. Students at three secondary schools attended between one and five blocks of work, and special events. There is evidence of positive developments - with young people showing understanding of domestic violence as well as the margins between healthy and unhealthy relationships. However, not all students could reply ‘never’ to the question of ‘are women and girls to blame for the domestic violence they experience?’, remarking that if the woman had done something ‘really, really bad’ then violence might be justified. We argue that young people’s uncertainties need to be situated within the gender-unequal socio-contexts of contemporary society, and further call for a WSA to domestic violence prevention to be a compulsory part of the UK national curriculum

    New developments in canine hepatozoonosis in North America: a review

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    Canine hepatozoonosis is caused by Hepatozoon canis and Hepatozoon americanum, apicomplexan parasites transmitted to dogs by ingestion of infectious stages. Although the two agents are phylogenetically related, specific aspects, including characteristics of clinical disease and the natural history of the parasites themselves, differ between the two species. Until recently, H. canis infections had not been clearly documented in North America, and autochthonous infection with H. americanum has yet to be reported outside of the southern United States. However, recent reports demonstrate H. canis is present in areas of North America where its vector tick, Rhipicephalus sanguineus, has long been endemic, and that the range of H. americanum is likely expanding along with that of its vector tick, Amblyomma maculatum; co-infections with the two organisms have also been identified. Significant intraspecific variation has been reported in the 18S rRNA gene sequence of both Hepatozoon spp.-infecting dogs, suggesting that each species may represent a complex of related genogroups rather than well-defined species. Transmission of H. americanum to dogs via ingestion of cystozoites in muscle of infected vertebrates was recently demonstrated, supporting the concept of predation as a means of natural transmission. Although several exciting advances have occurred in recent years, much remains to be learned about patterns of infection and the nature of clinical disease caused by the agents of canine hepatozoonosis in North America

    Interleukin 12 (IL-12) is increased in tumour bearing human liver and expands CD8C and CD56C T cells in vitro but not in vivo

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    Human liver is enriched with CD8CT- and CD3CCD56C natural T (NT)-lymphocytes, important anti-tumour effectors, similar to murine NKTs. IL-12 promotes anti-tumour functions of NKTs. We quantified IL-12 and CD56C/CD8CT lymphocytes in normal and tumour bearing liver. We also examined the effect of IL-12 on the expansion/activation of peripheral blood cells in vitro. IL-12 was detected in normal (n ¼ 13, median 2032 pg/100 mg protein) and increased in tumour bearing liver (n ¼ 9, 3678 pg, p!0:01). Infiltrating monocytes appear to be the principal producers. Culture with IL-12 selectively expanded CD8CT and CD3CCD56CNT cells and polarised their cytokine responses to Th1-type. However, there was no in vivo expansion of these cells in tumour bearing liver. Changes observed in culture required addition of IL-2. We therefore quantified IL-2 in hepatic tissue. IL-2 was detected in normal liver (median 4700 pg/100 mg protein). Surprisingly, there was no increase in tumour-infiltrated liver (4910 pg). The presence of IL-12 may create an environment in healthy liver that promotes the accumulation of CD8CT and CD56CNT cells. Therefore, the development of metastases in the presence of high levels of IL-12 may be due to an insufficient IL-12 response. Alternatively, lack of IL-2 rather than a defect in IL-12, may be responsible for insufficient expansion/activation of tumour specific cytotoxic T lymphocytes

    Microplastic in Riverine Fish is Connected to Species Traits

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    Microplastic is a contaminant of concern worldwide. Rivers are implicated as major pathways of microplastic transport to marine and lake ecosystems, and microplastic ingestion by freshwater biota is a risk associated with microplastic contamination, but there is little research on microplastic ecology within freshwater ecosystems. Microplastic uptake by fish is likely affected by environmental microplastic abundance and aspects of fish ecology, but these relationships have rarely been addressed. We measured the abundance and composition of microplastic in fish and surface waters from 3 major tributaries of Lake Michigan, USA. Microplastic was detected in fish and surface waters from all 3 sites, but there was no correlation between microplastic concentrations in fish and surface waters. Rather, there was a significant effect of functional feeding group on microplastic concentration in fish. Neogobius melanostomus (round goby, a zoobenthivore) had the highest concentration of gut microplastic (19 particles fish−1) compared to 10 other fish taxa measured, and had a positive linear relationship between body size and number of microplastic particles. Surface water microplastic concentrations were lowest in the most northern, forested watershed, and highest in the most southern, agriculturally dominated watershed. Results suggest microplastic pollution is common in river food webs and is connected to species feeding characteristics. Future research should focus on understanding the movement of microplastic from point-source and diffuse sources and into aquatic ecosystems, which will support pollution management efforts on inland waters

    Interleukin 12 (IL-12) is increased in tumour bearing human liver and expands CD8C and CD56C T cells in vitro but not in vivo

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    Human liver is enriched with CD8CT- and CD3CCD56C natural T (NT)-lymphocytes, important anti-tumour effectors, similar to murine NKTs. IL-12 promotes anti-tumour functions of NKTs. We quantified IL-12 and CD56C/CD8CT lymphocytes in normal and tumour bearing liver. We also examined the effect of IL-12 on the expansion/activation of peripheral blood cells in vitro. IL-12 was detected in normal (n ¼ 13, median 2032 pg/100 mg protein) and increased in tumour bearing liver (n ¼ 9, 3678 pg, p!0:01). Infiltrating monocytes appear to be the principal producers. Culture with IL-12 selectively expanded CD8CT and CD3CCD56CNT cells and polarised their cytokine responses to Th1-type. However, there was no in vivo expansion of these cells in tumour bearing liver. Changes observed in culture required addition of IL-2. We therefore quantified IL-2 in hepatic tissue. IL-2 was detected in normal liver (median 4700 pg/100 mg protein). Surprisingly, there was no increase in tumour-infiltrated liver (4910 pg). The presence of IL-12 may create an environment in healthy liver that promotes the accumulation of CD8CT and CD56CNT cells. Therefore, the development of metastases in the presence of high levels of IL-12 may be due to an insufficient IL-12 response. Alternatively, lack of IL-2 rather than a defect in IL-12, may be responsible for insufficient expansion/activation of tumour specific cytotoxic T lymphocytes

    Synthesizing diverse evidence: the use of primary qualitative data analysis methods and logic models in public health reviews

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    Objectives: The nature of public health evidence presents challenges for conventional systematic review processes, with increasing recognition of the need to include a broader range of work including observational studies and qualitative research, yet with methods to combine diverse sources remaining underdeveloped. The objective of this paper is to report the application of a new approach for review of evidence in the public health sphere. The method enables a diverse range of evidence types to be synthesized in order to examine potential relationships between a public health environment and outcomes. Study design: The study drew on previous work by the National Institute for Health and Clinical Excellence on conceptual frameworks. It applied and further extended this work to the synthesis of evidence relating to one particular public health area: the enhancement of employee mental well-being in the workplace. Methods: The approach utilized thematic analysis techniques from primary research, together with conceptual modelling, to explore potential relationships between factors and outcomes. Results: The method enabled a logic framework to be built from a diverse document set that illustrates how elements and associations between elements may impact on the well-being of employees. Conclusions: Whilst recognizing potential criticisms of the approach, it is suggested that logic models can be a useful way of examining the complexity of relationships between factors and outcomes in public health, and of highlighting potential areas for interventions and further research. The use of techniques from primary qualitative research may also be helpful in synthesizing diverse document types. (C) 2010 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved

    Environmental and microbial controls on microbial necromass recycling, an important precursor for soil carbon stabilization

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    There is an emerging consensus that microbial necromass carbon is the primary constituent of stable soil carbon, yet the controls on the stabilization process are unknown. Prior to stabilization, microbial necromass may be recycled by the microbial community. We propose that the efficiency of this recycling is a critical determinant of soil carbon stabilization rates. Here we explore the controls on necromass recycling efficiency in 27 UK grassland soils using stable isotope tracing and indicator species analysis. We found that recycling efficiency was unaffected by land management. Instead, recycling efficiency increased with microbial growth rate on necromass, and was highest in soils with low historical precipitation. We identified bacterial and fungal indicators of necromass recycling efficiency, which could be used to clarify soil carbon stabilization mechanisms. We conclude that environmental and microbial controls have a strong influence on necromass recycling, and suggest that this, in turn, influences soil carbon stabilization

    The Grism Lens-Amplified Survey from Space (GLASS) X. Sub-kpc resolution gas-phase metallicity maps at cosmic noon behind the Hubble Frontier Fields cluster MACS1149.6+2223

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    (Abridged) We combine deep HST grism spectroscopy with a new Bayesian method to derive maps of gas-phase metallicity, nebular dust extinction, and star-formation rate for 10 star-forming galaxies at high redshift (1.2<z<2.31.2<z<2.3). Exploiting lensing magnification by the foreground cluster MACS1149.6+2223, we reach sub-kpc spatial resolution and push the stellar mass limit associated with such high-z spatially resolved measurements below 108M10^8M_\odot for the first time. Our maps exhibit diverse morphologies, indicative of various effects such as efficient radial mixing from tidal torques, rapid accretion of low-metallicity gas, etc., which can affect the gas and metallicity distributions in individual galaxies. Based upon an exhaustive sample of all existing sub-kpc metallicity gradients at high-z, we find that predictions given by analytical chemical evolution models assuming a relatively extended star-formation profile in the early disk formation phase can explain the majority of observed gradients, without involving galactic feedback or radial outflows. We observe a tentative correlation between stellar mass and metallicity gradient, consistent with the downsizing galaxy formation picture that more massive galaxies are more evolved into a later phase of disk growth, where they experience more coherent mass assembly at all radii and thus show shallower metallicity gradients. In addition, we compile a sample of homogeneously cross-calibrated integrated metallicity measurements spanning three orders of magnitude in stellar mass at z1.8z\sim1.8. We use this sample to study the mass-metallicity relation (MZR) and test the fundamental metallicity relation (FMR). The slope of the observed MZR can rule out the momentum-driven wind model at 3-σ\sigma confidence level. We find no significant offset with respect to the FMR, taking into account the intrinsic scatter and measurement uncertainties.Comment: 26 pages, 14 figures, and 6 table

    Lines, Circles, Planes and Spheres

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    Let SS be a set of nn points in R3\mathbb{R}^3, no three collinear and not all coplanar. If at most nkn-k are coplanar and nn is sufficiently large, the total number of planes determined is at least 1+k(nk2)(k2)(nk2)1 + k \binom{n-k}{2}-\binom{k}{2}(\frac{n-k}{2}). For similar conditions and sufficiently large nn, (inspired by the work of P. D. T. A. Elliott in \cite{Ell67}) we also show that the number of spheres determined by nn points is at least 1+(n13)t3orchard(n1)1+\binom{n-1}{3}-t_3^{orchard}(n-1), and this bound is best possible under its hypothesis. (By t3orchard(n)t_3^{orchard}(n), we are denoting the maximum number of three-point lines attainable by a configuration of nn points, no four collinear, in the plane, i.e., the classic Orchard Problem.) New lower bounds are also given for both lines and circles.Comment: 37 page
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