5,684 research outputs found
The social practice of sustainable agriculture under audit discipline: initial insights from the ARGOS project in New Zealand
One of the most interesting recent developments in global agri‐food systems has been the rapid
emergence and elaboration of market audit systems claiming environmental qualities or
sustainability. In New Zealand, as a strongly export‐oriented, high‐value food producer, these
environmental market audit systems have emerged as an important pathway for producers to
potentially move towards more sustainable production. There have, however, been only sporadic
and fractured attempts to study the emerging social practice of sustainable agriculture – particularly
in terms of the emergence of new audit disciplines in farming. The ARGOS project in New Zealand
was established in 2003 as a longitudinal matched panel study of over 100 farms and orchards using
different market audit systems (e.g., organic, integrated or GLOBALG.A.P.). This article reports on the
results of social research into the social practice of sustainable agriculture in farm households within
the ARGOS projects between 2003‐2009. Results drawn from multiple social research instruments
deployed over six years provide an unparalleled level of empirical data on the social practice of
sustainable agriculture under audit disciplines. Using 12 criteria identified in prior literature as
contributing a significant social dynamic around sustainable agriculture practices in other contexts,
the analysis demonstrated that 9 of these 12 dimensions did demonstrate differences in social
practices emerging between (or co‐constituting) organic, integrated, or conventional audit
disciplines. These differences clustered into three main areas: 1) social and learning/knowledge
networks and expertise, 2) key elements of farmer subjectivity – particularly in relation to subjective
positioning towards the environment and nature, and 3) the role and importance of environmental
dynamics within farm management practices and systems. The findings of the project provide a
strong challenge to some older framings of the social practice of sustainable agriculture: particularly
those that rely on paradigm‐driven evaluation of social motivations, strong determinism of
sustainable practice driven by coherent farmer identity, or deploying overly categorical
interpretations of what it means to be ‘organic’ or ‘conventional’. The complex patterning of the
ARGOS data can only be understood if the social practice of organic, integrated or (even more
loosely) conventional production is understood as being co‐produced by four dynamics:
subjectivity/identity, audit disciplines, industry cultures/structure and time. This reframing of how
we might research the social practice of sustainable agriculture opens up important new
opportunities for understanding the emergence and impact of new audit disciplines in agriculture
Willingness to participate in future HIV prevention studies among gay and bisexual men in Scotland, UK: a challenge for intervention trials
This article examines willingness to participate in future HIV prevention research among gay and bisexual men in Scotland, UK. Anonymous, self-complete questionnaires and Orasure Gäó oral fluid samples were collected in commercial gay venues. 1,320 men were eligible for inclusion. 78.2% reported willingness to participate in future HIV prevention research; 64.6% for an HIV vaccine, 57.4% for a behaviour change study, and 53.0% for a rectal microbicide. In multivariate analysis, for HIV vaccine research, greater age, minority ethnicity, and not providing an oral fluid sample were associated with lower willingness; heterosexual orientation and not providing an oral fluid sample were for microbicides; higher education and greater HIV treatment optimism were for behaviour change. STI testing remained associated with being more willing to participate in microbicide research and frequent gay scene use remained associated with being more willing to participate in behaviour change research. Having an STI in the past 12 months remained significantly associated with being willing to participate in all three study types. There were no associations between sexual risk behaviour and willingness. Although most men expressed willingness to participate in future research, recruitment of high-risk men, who have the potential to benefit most, is likely to be more challenging
Why not? Understanding the spatial clustering of private facility-based delivery and financial reasons for homebirths in Nigeria.
BACKGROUND: In Nigeria, the provision of public and private healthcare vary geographically, contributing to variations in one's healthcare surroundings across space. Facility-based delivery (FBD) is also spatially heterogeneous. Levels of FBD and private FBD are significantly lower for women in certain south-eastern and northern regions. The potential influence of childbirth services frequented by the community on individual's barriers to healthcare utilization is under-studied, possibly due to the lack of suitable data. Using individual-level data, we present a novel analytical approach to examine the relationship between women's reasons for homebirth and community-level, health-seeking surroundings. We aim to assess the extent to which cost or finance acts as a barrier for FBD across geographic areas with varying levels of private FBD in Nigeria. METHOD: The most recent live births of 20,467 women were georeferenced to 889 locations in the 2013 Nigeria Demographic and Health Survey. Using these locations as the analytical unit, spatial clusters of high/low private FBD were detected with Kulldorff statistics in the SatScan software package. We then obtained the predicted percentages of women who self-reported financial reasons for homebirth from an adjusted generalized linear model for these clusters. RESULTS: Overall private FBD was 13.6% (95%CI = 11.9,15.5). We found ten clusters of low private FBD (average level: 0.8, 95%CI = 0.8,0.8) and seven clusters of high private FBD (average level: 37.9, 95%CI = 37.6,38.2). Clusters of low private FBD were primarily located in the north, and the Bayelsa and Cross River States. Financial barrier was associated with high private FBD at the cluster level - 10% increase in private FBD was associated with + 1.94% (95%CI = 1.69,2.18) in nonusers citing cost as a reason for homebirth. CONCLUSIONS: In communities where private FBD is common, women who stay home for childbirth might have mild increased difficulties in gaining effective access to public care, or face an overriding preference to use private services, among other potential factors. The analytical approach presented in this study enables further research of the differentials in individuals' reasons for service non-uptake across varying contexts of healthcare surroundings. This will help better devise context-specific strategies to improve health service utilization in resource-scarce settings
Altered SMRT levels disrupt vitamin D3 receptor signalling in prostate cancer cells.
We hypothesized that key antiproliferative target genes for the vitamin D receptor (VDR) were repressed by an epigenetic mechanism in prostate cancer cells resulting in apparent hormonal insensitivity. To explore this possibility, we examined nuclear receptor corepressor expression in a panel of nonmalignant and malignant cell lines and primary cultures, and found frequently elevated SMRT corepressor mRNA expression often associated with reduced sensitivity to 1alpha,25-dihydroxyvitamin D(3) (1alpha,25(OH)2D3). For example, PC-3 and DU-145 prostate cancer cell lines had 1.8-fold and twofold increases in SMRT mRNA relative to normal PrEC cells (P<0.05). Similarly, 10/15 primary tumour cultures (including three matched to normal cells from the same donors) had elevated SMRT mRNA levels; generally NCoR1 and Alien were not as commonly elevated. Corepressor proteins often have associated histone deacetylases (HDAC) and reflectively the antiproliferative action of 1alpha,25(OH)2D3 can be restored by cotreatment with low doses of HDAC inhibitors such as trichostatin A (TSA, 15 nM) to induce apoptosis in prostate cancer cell lines. To decipher the transcriptional events that lead to these cellular responses, we undertook gene expression studies in PC-3 cells after cotreatment of 1alpha,25(OH)2D3 plus TSA after 6 h. Examination of known VDR target genes and cDNA microarray analyses revealed cotreatment of 1alpha,25(OH)2D3 plus TSA cooperatively upregulated eight (out of 1176) genes, including MAPK-APK2 and GADD45alpha. MRNA and protein time courses and inhibitor studies confirmed these patterns of regulation. Subsequently, we knocked down SMRT levels in PC-3 cells using a small interfering RNA (siRNA) approach and found that GADD45alpha induction by 1alpha,25(OH)2D3 alone became very significantly enhanced. The same distortion of gene responsiveness, with repressed induction of GADD45alpha was found in primary tumour cultures compared and to matched peripheral zone (normal) cultures from the same donor. These data demonstrate that elevated SMRT levels are common in prostate cancer cells, resulting in suppression of target genes associated with antiproliferative action and apparent 1alpha,25(OH)2D3-insensitivity. This can be targeted therapeutically by combination treatments with HDAC inhibitors
On the Schoenberg Transformations in Data Analysis: Theory and Illustrations
The class of Schoenberg transformations, embedding Euclidean distances into
higher dimensional Euclidean spaces, is presented, and derived from theorems on
positive definite and conditionally negative definite matrices. Original
results on the arc lengths, angles and curvature of the transformations are
proposed, and visualized on artificial data sets by classical multidimensional
scaling. A simple distance-based discriminant algorithm illustrates the theory,
intimately connected to the Gaussian kernels of Machine Learning
Impact of shortened crop rotation of oilseed rape on soil and rhizosphere microbial diversity in relation to yield decline
Oilseed rape (OSR) grown in monoculture shows a decline in yield relative to virgin OSR of up to 25%, but the mechanisms responsible are unknown. A long term field experiment of OSR grown in a range of rotations with wheat was used to determine whether shifts in fungal and bacterial populations of the rhizosphere and bulk soil were associated with the development of OSR yield decline. The communities of fungi and bacteria in the rhizosphere and bulk soil from the field experiment were profiled using terminal restriction fragment length polymorphism (TRFLP) and sequencing of cloned internal transcribed spacer regions and 16S rRNA genes, respectively. OSR cropping frequency had no effect on rhizosphere bacterial communities. However, the rhizosphere fungal communities from continuously grown OSR were significantly different to those from other rotations. This was due primarily to an increase in abundance of two fungi which showed 100% and 95% DNA identity to the plant pathogens Olpidium brassicae and Pyrenochaeta lycopersici, respectively. Real-time PCR confirmed that there was significantly more of these fungi in the continuously grown OSR than the other rotations. These two fungi were isolated from the field and used to inoculate OSR and Brassica oleracea grown under controlled conditions in a glasshouse to determine their effect on yield. At high doses, Olpidium brassicae reduced top growth and root biomass in seedlings and reduced branching and subsequent pod and seed production. Pyrenochaeta sp. formed lesions on the roots of seedlings, and at high doses delayed flowering and had a negative impact on seed quantity and quality
Molecular Evolutionary Characterization of a V1R Subfamily Unique to Strepsirrhine Primates
Vomeronasal receptor genes have frequently been invoked as integral to the establishment and maintenance of species boundaries among mammals due to the elaborate one-to-one correspondence between semiochemical signals and neuronal sensory inputs. Here, we report the most extensive sample of vomeronasal receptor class 1 (V1R) sequences ever generated for a diverse yet
phylogenetically coherent group of mammals, the tooth-combed primates (suborder Strepsirrhini). Phylogenetic analysis confirms our intensive sampling from a single V1R subfamily, apparently unique to the strepsirrhine primates. We designate this subfamily as V1Rstrep. The subfamily retains extensive repertoires of gene copies that descend from an ancestral gene duplication that appears to have occurred prior to the diversification of all lemuriform primates excluding the basal genusDaubentonia (the aye-aye). We refer to the descendent clades as V1Rstrep-a and V1Rstrep-b. Comparison of the two clades reveals different amino acid compositions corresponding to the predicted ligand-binding site and thus potentially to altered functional profiles between the two. In agreement with previous studies of the mouse lemur (genus, Microcebus), the majority of V1Rstrep gene copies appear to be intact and under strong positive selection, particularly within transmembrane regions. Finally, despite the surprisingly high number of gene copies identified in this study, it is nonetheless probable that V1R diversity remains underestimated in these nonmodel primates and that
complete characterization will be limited until high-coverage assembled genomes are available
A Self-Consistent Model for Positronium Formation from Helium Atoms
The differential and total cross sections for electron capture by positrons
from helium atoms are calculated using a first-order distorted wave theory
satisfying the Coulomb boundary conditions. In this formalism a parametric
potential is used to describe the electron screening in a consistent and
realistic manner. The present procedure is self consistent because (i) it
satisfies the correct boundary conditions and post-prior symmetry, and (ii) the
potential and the electron binding energies appearing in the transition
amplitude are consistent with the wave functions describing the collision
system. The results are compared with the other theories and with the available
experimental measurements. At the considered range of collision energies, the
results agree reasonably well with recent experiments and theories.
[Note: This paper will be published on volume 42 of the Brazilian Journal of
Physics
A qualitative exploratory study: Using medical students’ experiences to review the role of a rural clinical attachment in KwaZulu-Natal
Objectives: There are challenges when it is considered that a main role of a rural clinical attachment for medical students is to encourage students to return after graduation to practise in rural areas. This view may lead to the relative neglect of other potential valuable roles with regard to rural exposure. This paper draws on the Force Field Model of teacher development to describe medical students’ experiences, illustrate the complexity of interacting factors during rural exposure, caution that experiences cannot be predicted and highlight the positive incentives of a rural clinical attachment.Design: The design was explorative, descriptive and qualitative.Setting: The study setting was a district hospital in rural KwaZulu-Natal.Subjects: The participants were four final-year medical students who had completed a compulsory attachment during their Family Medicine rotation.Outcome measures: Data were collected using photo elicitation and analysed using the Force Field Model.Results: The participants felt that overall the experience was positive. The effect of biography and contextual forces were not as strong as expected. Institutional forces were important and programmatic forces tended to have a negative effect on experiences. The participants particularly enjoyed being acknowledged and felt empathy for the difficult tasks of doctors.Conclusion: The potential role of a clinical attachment may go beyond attracting students to practise in rural areas. The experience can be beneficial, irrespective of where the student decides to practise after graduation. There is a need for a review of the rural attachment curriculum and paedagogy. Caution should be used when screening medical students for suitability to work in rural areas prior to rural exposure.Keywords: rural clinical attachment, family medicine rotation, medical students, experiences, Force Field Mode
Use of mixed methods designs in substance research: a methodological necessity in Nigeria
The utility of mixed methods (qualitative and quantitative) is becoming increasingly accepted in health sciences, but substance studies are yet to substantially benefit from such utilities. While there is a growing number of mixed methods alcohol articles concerning developed countries, developing nations are yet to embrace this method. In the Nigerian context, the importance of mixed methods research is yet to be acknowledged. This article therefore, draws on alcohol studies to argue that mixed methods designs will better equip scholars to understand, explore, describe and explain why alcohol consumption and its related problems are increasing in Nigeria. It argues that as motives for consuming alcohol in contemporary Nigeria are multiple, complex and evolving, mixed method approaches that provide multiple pathways for proffering solutions to problems should be embraced
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