241 research outputs found
[Book Review of] \u3cem\u3eEuthanasia, Ethics and Public Policy: An Argument Against Legalisation\u3c/em\u3e, by John Keown
Assessing the impact of acid rain and forest harvest intensity with the HD-MINTEQ model â soil chemistry of three Swedish conifer sites from 1880 to 2080
Forest soils are susceptible to anthropogenic acidification. In the past,
acid rain was a major contributor to soil acidification, but, now that
atmospheric levels of S have dramatically declined, concern has
shifted towards biomass-induced acidification, i.e. decreasing soil solution
pH due to tree growth and harvesting events that permanently remove base
cations (BCs) from forest stands. We use a novel dynamic model, HD-MINTEQ (Husby Dynamic MINTEQ), to
investigate possible long-term impacts of two theoretical future harvesting
scenarios in the year 2020, a conventional harvest (CH, which removes stems
only), and a whole-tree harvest (WTH, which removes 100 % of the
above-ground biomass except for stumps) on soil chemistry and weathering
rates at three different Swedish forest sites (Aneboda, GÄrdsjön, and
Kindla). Furthermore, acidification following the harvesting events is
compared to the historical acidification that took place during the 20th century
due to acid rain. Our results show that historical acidification due
to acid rain had a larger impact on pore water chemistry and mineral
weathering than tree growth and harvesting, at least if nitrification
remained at a low level. However, compared to a no-harvest baseline, WTH and
CH significantly impacted soil chemistry. Directly after a harvesting event
(CH or WTH), the soil solution pH sharply increased for 5 to 10Â years before
slowly declining over the remainder of the simulation (until year 2080). WTH
acidified soils slightly more than CH, but in certain soil horizons there
was practically no difference by the year 2080. Even though the pH in the WTH
and CH scenario decreased with time as compared to the no-harvest scenario
(NH), they did not drop to the levels observed around the peak of historic
acidification (1980â1990), indicating that the pH decrease due to tree growth
and harvesting would be less impactful than that of historic atmospheric
acidification. Weathering rates differed across locations and horizons in
response to historic acidification. In general, the predicted changes in
weathering rates were very small, which can be explained by the net effect of
decreased pH and increased Al3+, which affected the weathering rate in
opposite ways. Similarly, weathering rates after the harvesting scenarios in
2020 remained largely unchanged according to the model.</p
Falling for fake news: investigating the consumption of news via social media
In the so called âpost-truthâ era, characterized by a loss of public trust in various institutions, and the rise of âfake newsâ disseminated via the internet and social media, individuals may face uncertainty about the veracity of information available, whether it be satire or malicious hoax. We investigate attitudes to news delivered by social media, and subsequent verification strategies applied, or not applied, by individuals. A survey reveals that two thirds of respondents regularly consumed news via Facebook, and that one third had at some point come across fake news that they initially believed to be true. An analysis task involving news presented via Facebook reveals a diverse range of judgement forming strategies, with participants relying on personal judgements as to plausibility and scepticism around sources and journalistic style. This reflects a shift away from traditional methods of accessing the news, and highlights the difficulties in combating the spread of fake news
Aluminium and base cation chemistry in dynamic acidification models â need for a reappraisal?
Long-term simulations of the water composition in acid forest soils require
that accurate descriptions of aluminium and base cation chemistry are used.
Both weathering rates and soil nutrient availability depend on the
concentrations of Al3+, of H+, and of base cations
(Ca2+, Mg2+, Na+, and K+) .
Assessments of the acidification status and base cation availability will
depend on the model being used. Here we review in what ways different dynamic
soil chemistry models describe the processes governing aluminium and base
cation concentrations in the soil water. Furthermore, scenario simulations
with the HD-MINTEQ model are used to illustrate the difference between model
approaches. The results show that all investigated models provide the same
type of response to changes in input water chemistry. Still, for base cations
we show that the differences in the magnitude of the response may be
considerable depending on whether a cation-exchange equation (GainesâThomas,
Gapon) or an organic complexation model is used. The former approach, which
is used in many currently used models (e.g. MAGIC, ForSAFE), causes stronger
pH buffering over a relatively narrow pH range, as compared to
state-of-the-art models relying on more advanced descriptions in which
organic complexation is important (CHUM, HD-MINTEQ). As for aluminium, a
fixed gibbsite constant, as used in MAGIC, SMART/VSD, and ForSAFE, leads to
slightly more pH buffering than in the more advanced models that consider
both organic complexation and Al(OH)3(s) precipitation, but in this
case the effect is small. We conclude that the descriptions of acidâbase
chemistry and base cation binding in models such as MAGIC, SMART/VSD, and
ForSAFE are only likely to work satisfactorily in a narrow pH range. If the
pH varies greatly over time, the use of modern organic complexation models is
preferred over cation-exchange equations.</p
A genome-wide SNP-association study confirms a sequence variant (g.66493737C>T) in the equine myostatin (MSTN) gene as the most powerful predictor of optimum racing distance for Thoroughbred racehorses
<p>Abstract</p> <p>Background</p> <p>Thoroughbred horses have been selected for traits contributing to speed and stamina for centuries. It is widely recognized that inherited variation in physical and physiological characteristics is responsible for variation in individual aptitude for race distance, and that muscle phenotypes in particular are important.</p> <p>Results</p> <p>A genome-wide SNP-association study for optimum racing distance was performed using the EquineSNP50 Bead Chip genotyping array in a cohort of <it>n </it>= 118 elite Thoroughbred racehorses divergent for race distance aptitude. In a cohort-based association test we evaluated genotypic variation at 40,977 SNPs between horses suited to short distance (†8 f) and middle-long distance (> 8 f) races. The most significant SNP was located on chromosome 18: BIEC2-417495 ~690 kb from the gene encoding myostatin (<it>MSTN</it>) [<it>P</it><sub>unadj. </sub>= 6.96 à 10<sup>-6</sup>]. Considering best race distance as a quantitative phenotype, a peak of association on chromosome 18 (chr18:65809482-67545806) comprising eight SNPs encompassing a 1.7 Mb region was observed. Again, similar to the cohort-based analysis, the most significant SNP was BIEC2-417495 (<it>P</it><sub>unadj. </sub>= 1.61 à 10<sup>-9</sup>; <it>P</it><sub>Bonf. </sub>= 6.58 à 10<sup>-5</sup>). In a candidate gene study we have previously reported a SNP (g.66493737C>T) in <it>MSTN </it>associated with best race distance in Thoroughbreds; however, its functional and genome-wide relevance were uncertain. Additional re-sequencing in the flanking regions of the <it>MSTN </it>gene revealed four novel 3' UTR SNPs and a 227 bp SINE insertion polymorphism in the 5' UTR promoter sequence. Linkage disequilibrium was highest between g.66493737C>T and BIEC2-417495 (<it>r</it><sup>2 </sup>= 0.86).</p> <p>Conclusions</p> <p>Comparative association tests consistently demonstrated the g.66493737C>T SNP as the superior variant in the prediction of distance aptitude in racehorses (g.66493737C>T, <it>P </it>= 1.02 à 10<sup>-10</sup>; BIEC2-417495, <it>P</it><sub>unadj. </sub>= 1.61 à 10<sup>-9</sup>). Functional investigations will be required to determine whether this polymorphism affects putative transcription-factor binding and gives rise to variation in gene and protein expression. Nonetheless, this study demonstrates that the g.66493737C>T SNP provides the most powerful genetic marker for prediction of race distance aptitude in Thoroughbreds.</p
Characterization of the equine skeletal muscle transcriptome identifies novel functional responses to exercise training
<p>Abstract</p> <p>Background</p> <p>Digital gene expression profiling was used to characterize the assembly of genes expressed in equine skeletal muscle and to identify the subset of genes that were differentially expressed following a ten-month period of exercise training. The study cohort comprised seven Thoroughbred racehorses from a single training yard. Skeletal muscle biopsies were collected at rest from the <it>gluteus medius </it>at two time points: T<sub>1 </sub>- untrained, (9 ± 0.5 months old) and T<sub>2 </sub>- trained (20 ± 0.7 months old).</p> <p>Results</p> <p>The most abundant mRNA transcripts in the muscle transcriptome were those involved in muscle contraction, aerobic respiration and mitochondrial function. A previously unreported over-representation of genes related to RNA processing, the stress response and proteolysis was observed. Following training 92 tags were differentially expressed of which 74 were annotated. Sixteen genes showed increased expression, including the mitochondrial genes <it>ACADVL</it>, <it>MRPS21 </it>and <it>SLC25A29 </it>encoded by the nuclear genome. Among the 58 genes with decreased expression, <it>MSTN</it>, a negative regulator of muscle growth, had the greatest decrease.</p> <p>Functional analysis of all expressed genes using FatiScan revealed an asymmetric distribution of 482 Gene Ontology (GO) groups and 18 KEGG pathways. Functional groups displaying highly significant (<it>P </it>< 0.0001) increased expression included mitochondrion, oxidative phosphorylation and fatty acid metabolism while functional groups with decreased expression were mainly associated with structural genes and included the sarcoplasm, laminin complex and cytoskeleton.</p> <p>Conclusion</p> <p>Exercise training in Thoroughbred racehorses results in coordinate changes in the gene expression of functional groups of genes related to metabolism, oxidative phosphorylation and muscle structure.</p
Less time to study, less well prepared for work, yet satisfied with higher education: A UK perspective on links between higher education and the labour market
This paper explores graduatesâ views on the relationship between higher education and employment. It draws on a major European study involving graduates five years after graduation and highlights similarities and differences between UK graduatesâ experiences and their European counterparts. Specifically we address questions raised in the study about subjects studied and their relevance to entry into the labour market, if the academic level obtained was appropriate, whether graduates, with hindsight of five years, would choose the same subjects or the same institution again, and if they were satisfied with their current job. Such specific questions relate to broader perspectives such as the perceived value of higher education study in relation to initial employment and future life histories. These have to be seen in the context of cultural differences in higher education systems at the time of the research and, perhaps increasing convergences in light of the Bologna agreement
The potential of a mobile group blog to support cultural learning among overseas students
We explored the use of mobile social software, in the form of a mobile group blog, to assist cultural learning. The potential of using this technology for cultural adaptation among overseas students was examined as those students adapted to the everyday life of studying abroad. Two pilot studies and a successful field study of a mobile group blog as used by UK overseas students are reported. A further study with prospective overseas students witnessing this âmobloggingâ in China revealed the advantages of communicating through this technology as a form of peer-supported preparation for cultural adaptation. Potential advantages for learning a second language via this system, were highlighted as communication was interweaved with cultural adaptation and exercised in the blog entries. Given mobile internet, the language experience together with cultural observation impressively supported these students' growing confidence with time, space and imagination
Filtering informal learning in everyday life: invoking ordinariness and moving to civic engagement
This article explores the role of informal learning from television as it is anchored within the ordinariness of daily life. It examines the consequences for pedagogy and civic engagement, questioning how informal learning from television can enhance civic engagement. For many, this learning was localized through personalized and interpersonal relations of everyday life. Learning was not viewed as a distant institutional force, but as an embedded part of an ordinary life. The invoking of ordinariness rendered the relationship between learning and civic engagement unproblematic. Learning was localized in subjective terms for self-identity and interpersonal relations rather than critically reflecting on the power structures of everyday life
Good for your soul? Adult learning and mental well-being
Although there is a widely held view that adult learning has a positive impact on well-being, only recently has this proposition been systematically tested. The paper reviews recent research findings on the influence of adult learning on earnings and employability, both of which may influence well-being indirectly. These are more important for some groups than others: in economically advanced societies, additional earnings produce limited gains in well-being for most groups except the poorest, while employability is most significant for groups that are most vulnerable in the labour market. The author then reviews recent research findings showing that participating in learning in adult life has some positive direct influence on well-being; analyses of cohort studies suggest that the influence is comparatively small, but nevertheless significant. There has been less study of learningâs negative consequences for well-being, and the paper draws on history data to illustrate some of these less desirable influences. It concludes by identifying areas for further research, and outlining a number of implications for policy and practice. These are particularly important in the current context, where environmental movements appear to be challenging the primacy of economic growth as the overarching goal of policy
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