1,126 research outputs found
Modeling cultural dissemination and divergence between rural and urban regions
The process by which beliefs, opinions, and other individual, socially malleable attributes spread across a society, known as "cultural dissemination," is a broadly recognized concept among sociologists and political scientists. Yet fundamental aspects of how this process can ultimately lead to cultural divergences between rural and urban segments of society are currently poorly understood. This article uses an agent-based model to isolate and analyze one very basic yet essential facet of this issue, namely, the question of how the intrinsic differences in urban and rural population densities influence the levels of cultural homogeneity/heterogeneity that emerge within each region. Because urban and rural cultures do not develop in isolation from one another, the dynamical interplay between the two is of particular import in their evolution. It is found that, in urban areas, the relatively high number of local neighbors with whom one can interact tends to promote cultural homogeneity in both urban and rural regions. Moreover, and rather surprisingly, the higher frequency of potential interactions with neighbors within urban regions promotes homogeneity in urban regions but tends to drive rural regions towards greater levels of heterogeneity.publishedVersio
Scots lovage, Ligusticum scoticum, is spreading in the Ă land Islands, SW Finland
Scots lovage, Ligusticum scoticum L., was probably collected already in 1892 in the Ă
land Islands, but it was not reported from Ă
land until 1970. Since then, the species has been found in an increasing number of localities. Here we report about 25 new localities found 1992â2008. There seemto be two centres for the species, one in thewesternmost islands of Ă
land, between the mainland of EckerĂś and the Signilskär archipelago, and the other in the northern islands of FĂśglĂś.Amore systematic investigation in the archipelagos of Ă
land could yield new localities
Grain legume-cereal intercropping enhances the use of soil-derived and biologically fixed nitrogen in temperate agroecosystems: a meta-analysis
Grain legumes are known for their benefits to deliver ecosystem services on provisioning of protein-rich food and feed, reducing greenhouse gas emissions through the symbiotic nitrogen fixation function and diversification of cropping systems. Intercropping is an agroecological practice in which two or more crop species are grown simultaneously in the same field, thereby maximizing the use of resources to enhance yields in low input systemsand the resilience of cropping systems. We quantified the effect of grain legume-cereal intercropping on the useof N resources in temperate agroecosystems, focusing on dinitrogen (N2) fixation and soil-derived nitrogenacquisition using a meta-analysis of 29 field-scale studies. We estimated and compared effects of different intercrop compositions (proportion of each species in the intercrops), fertilization rates, crop species, soil properties, and other management practices on the symbiotic N2 fixation and the acquisition of soil-derived nitrogenby the cereals and grain legumes. The proportion of N derived from N2 fixation was on average 14 % (95 % CI =[11, 16]) higher in intercropped grain legumes (76 %) compared to legume sole crops (66 %). On the other hand,intercropping reduced the amount of N2 fixed (kg haâ1) by about 15 %, when N2 fixation in inter- and solecropped legumes was expressed at equivalent density by compensating for the sown legume proportion in intercrops relative to their sole crop sowing rate. The results were mainly influenced by the intercrop composition,legumes species and the method used to quantify N2 fixation. Soil-derived nitrogen acquisition in intercroppedgrain legumes was significantly reduced (â47 %, 95 % CI = [â56, â36]) compared to sole crop legumes,expressed at equivalent density, while the soil N acquired by intercropped cereals was much higher (+61 %, 95% CI = [24, 108]) than in sole crop cereals. Total soil N acquisition (legume + cereal) was significantly higherin intercrops than in legume sole crops (+25 %, 95 % CI = [1, 54]), while there was no significant differencebetween intercrops and cereal sole crops. The meta-analysis confirms and highlights that intercropping consistently stimulates complementary N use between legumes and cereals by increasing N2 fixation by grain legumes and increasing soil N acquisition in cereals. Based on the results of this analysis it would be suggested thatcropping systems diversification via intercropping can be used for simultaneous production of both cereals andgrain legumes, while increasing the use of N-sources and reducing external inputs of N fertilizers, thereby enhancing the sustainability of agriculture
The school environment and student health: a systematic review and meta-ethnography of qualitative research
Background
There is increasing interest in promoting young peopleâs health by
modifying the school
environment. However, existing research offers little guidance on how
the school context
enables or constrains studentsâ health behaviours, or how studentsâ backgr
ounds relate to
these processes. For these reasons, this paper reports on a meta-et
hnography of qualitative
studies examining: through what processes does the school environment (s
ocial and physical)
influence young peopleâs health?
Methods
Systematic review of qualitative studies. Sixteen databases
were searched, eliciting 62, 329
references which were screened, with included studies quality ass
essed, data extracted and
synthesized using an adaptation of Noblit and Hareâs meta-ethnographic approach.
Results
Nineteen qualitative studies were synthesised to explore processe
s through which school-
level influences on young peopleâs health might occur. Four over-arching
meta-themes
emerged across studies focused on a range of different health is
sues. First, aggressive
behaviour and substance use are often a strong source of status and bonding
at schools where
students feel educationally marginalised or unsafe. Second, health
-risk behaviours are
concentrated in unsupervised âhotspotsâ at the school. Third, positive relat
ionships with
teachers appear to be critical in promoting student wellbeing and li
miting risk behaviour;
however, certain aspects of schoolsâ organisation and education policies c
onstrain this,
increasing the likelihood that students look for a sense of identity
and social support via
health-risk behaviours. Fourth, unhappiness at school can cause students to se
ek sources of
âescapeâ, either by leaving school at lunchtime or for longer unaut
horized spells or through
substance use. These meta-themes resonate with Markham and Aveyar
dâs theory of human
functioning and school organisation, and we draw on these qualitative data to
refine and
extend this theory, in particular conceptualising more fully the rol
e of young peopleâs agency
and student-led âsystemsâ in constituting school environments and generating health ri
sks.
Conclusion
Institutional features which may shape student health behaviours such a
s lack of safety, poor
student-staff relationships and lack of student voice are amenable t
o interventions and should
be the subject of future investigation. Future qualitative research
should focus on health
behaviours which are under-theorised in this context such as physical
activity, sexual and
mental health
Functional Traits of Tropical Trees and Lianas Explain Spatial Structure across Multiple Scales
Dispersal and density dependence are major determinants of spatial structure, population dynamics and coexistence for tropical forest plants. However, because these two processes can jointly influence spatial structure at similar scales, analysing spatial patterns to separate and quantify them is often difficult. Species functional traits can be useful indicators of dispersal and density dependence. However, few methods exist for linking functional traits to quantitative estimates of these processes that can be compared across multiple species. We analysed static spatial patterns of woody plant populations in the 50 ha Forest Dynamics Plot on Barro Colorado Island, Panama with methods that distinguished scaleâspecific differences in species aggregation. We then tested how these differences related to seven functional traits: growth form, dispersal syndrome, tree canopy layer, adult stature, seed mass, wood density and shade tolerance. Next, we fit analytically tractable spatial moment models to the observed spatial structure of species characterized by similar trait values, which allowed us to estimate relationships of functional traits with the spatial scale of dispersal, and the spatial scale and intensity of negative density dependence. Our results confirm that lianas are more aggregated than trees, and exhibit increased aggregation within canopy gaps. For trees, increased seed mass, wood density and shade tolerance were associated with less intense negative density dependence, while higher canopy layers and increased stature were associated with decreased aggregation and better dispersal. Spatial structure for trees was also strongly determined by dispersal syndrome. Averaged across all spatial scales, zoochory was more effective than wind dispersal, which was more effective than explosive dispersal. However, at intermediate scales, zoochory was associated with more aggregation than wind dispersal, potentially because of differences in shortâdistance dispersal and the intensity of negative density dependence. Synthesis. We develop new tools for identifying significant associations between functional traits and spatial structure, and for linking these associations to quantitative estimates of dispersal scale and the strength and scale of density dependence. Our results help clarify how these processes influence woody plant species on Barro Colorado, and demonstrate how these tools can be applied to other sites and systems
Single step synthesis and organization of gold colloids assisted by copolymer templates
We report here an original single-step process for synthesis and
self-organization of gold colloids by simply incorporating gold salts into a
solution prepared with Polystyrene (PS) - Polymethylmethacrylate (PMMA)
copolymer, thiolated PS and Propylene Glycol Methyl Ether Acetate (PGMEA) as
solvent. The spin-coating and annealing of this solution allows then the
formation of PS domains. Depending on the polymer concentration of the
as-prepared solution, there can be either one or several gold nanoparticles
(NPs) per PS domains. For high concentration of gold nanoparticles in PS
domains, the coupling between plasmonic nanoparticles leads to the observation
of second peak in the optical extinction spectrum. Such collective effect could
be relevant for the development of optical strain sensors in the next future.Comment: 8 pages, 6 figure
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Iraq: International Attitudes to Operation Iraqi Freedom and Reconstruction
Although there was widespread international disagreement in the period leading up to the U.S.-led war in Iraq, forty-nine countries demonstrated support for the coalitionâs actions in Iraq by publicly agreeing to be included in the Bush Administrationâs âcoalition of the willing." This report tracks countriesâ current political stances on the postwar situation, as well as major foreign monetary and military contributions to postwar Iraq
Longâterm anticholinergic, benzodiazepine and Zâdrug use in communityâdwelling older adults: What is the impact on cognitive and neuropsychological performance?
BACKGROUND
Long-term use of anticholinergics, benzodiazepines and related drugs (or "Z-drugs") have been associated with cognitive impairment and dementia. However, the relationship of these medications with cognitive function and domain-specific neuropsychological performance in older adults without dementia, is unclear.
METHODS
5135 older adults (74.0 ¹ 8.3 years; 67.4% female) without a diagnosis of dementia were recruited in Ireland to the Trinity-Ulster-Department of Agriculture (TUDA) study. Detailed cognitive and neuropsychological assessment was conducted using the Mini-Mental State Examination (MMSE), Frontal Assessment Battery (FAB) and Repeatable Battery for Assessment of Neuropsychological Status (RBANS).
RESULTS
A total of 44% (2259 of 5153) used either a potential or definite anticholinergic medication. Overall, 9.7% (n = 500) used a definite anticholinergic medication. Regular benzodiazepine use was reported by 7% (n = 363), whilst 7.5% (n = 387) used a "Z-drug". Use of definite, but not potential anticholinergic medication was associated with poorer performance on all three assessments (β: -0.09; 95% CI: -0.14, -0.03, p = 0.002 for MMSE; β: -0.04; 95% CI: -0.06, -0.02; p < 0.001 for FAB; β: -4.15; 95% CI: -5.64, -2.66; p < 0.001 for RBANS) in addition to all domains of the RBANS. Regular benzodiazepine use was also associated with poorer neuropsychological test performance, especially in Immediate Memory (β: -4.98; 95% CI: -6.81, -3.15; p < 0.001) and Attention (β: -6.81; 95% CI: -8.60, -5.03; p < 0.001) RBANS domains.
CONCLUSIONS
Regular use of definite anticholinergic medications and benzodiazepines, but not potential anticholinergics or "Z-drugs", was associated with poorer overall and domain-specific neuropsychological performance in older adults
The Lantern Vol. 10, No. 1, December 1941
⢠Misty ⢠The Evils of Initiations ⢠Ursinus, Fifty Years Ago ⢠My Conversion ⢠Our Gang ⢠From Rabble to Royalty ⢠So You Want to be an Editor! ⢠Tempo ⢠A Musician\u27s Allegory ⢠Flotsam ⢠The Years ⢠Common Things ⢠Sea Moods ⢠Aunt Agatha\u27s Pillow ⢠Peace at Autumn Twilighthttps://digitalcommons.ursinus.edu/lantern/1025/thumbnail.jp
Reduced Kidney Function is Associated with Poorer DomainâSpecific Cognitive Performance in CommunityâDwelling Older Adults
OBJECTIVES: Whilst chronic kidney disease has been associated with cognitive impairment, the association between reduced estimated Glomerular Filtration Rate (eGFR) and domainâspecific cognitive performance is less clear and may represent an important target for the promotion of optimal brain health in older adults. METHODS: Participants aged >60 years from the TrinityâUlsterâDepartment of Agriculture study underwent detailed cognitive assessment using the MiniâMental State Examination (MiniâMental State Examination (MMSE)), Frontal Assessment Battery (FAB) and Repeatable Battery for Assessment of Neuropsychological Status (RBANS). Poisson and linear regression models assessed the relationship between eGFR strata and cognitive performance. RESULTS: In 4887 older adults (73.9 ¹ 8.3 years; 67.7% female), declining eGFR strata was associated with greater likelihood of error on the MMSE/FAB and poorer overall performance on the RBANS. Following robust covariate adjustment, findings were greatest for GFR 80 years. CONCLUSIONS: Reduced kidney function was associated with poorer global and domainâspecific neuropsychological performance. Associations were strongest with eGFR <45 ml/min/1.73 m(2) and in those aged 60â70 years, suggesting that this population may potentially benefit from potential multiâdomain interventions aimed at promoting optimal brain health in older adults
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