889 research outputs found
Economics and Biodiversity in Intensively Managed Agro-Ecosystems
This paper explores the dynamic effects of biodiversity conservation on agricultural production in the context of specialised intensive farming systems. The focus is on the analysis of the dynamic effects of changes in the levels of agrobiodiversity, on technical change and productivity in intensive agricultural systems. A theoretical model is used to derive hypotheses regarding these linkages that are empirically tested using a stochastic production frontier model with data from a panel of UK cereal farms for the period 1989-2000. The results suggest that the increased agrobiodiversity has positively helped to shift the production frontier outwards. This indicates that the evolution of an intensive agricultural system to less intensive use of inputs can be consistent with non-decreasing output levels and an enhancement of biodiversity in agricultural landscapes.Agrobiodiversity, Intensive Agriculture, Productivity, Technical change, Resource /Energy Economics and Policy, Q12, Q16, Q24,
The Economics of Biodiversity Conservation in Agricultural Transition
This paper explores the dynamic effects of biodiversity conservation on agricultural production in the context of specialised intensive farming systems that may be in transition towards more sustainable farming. The focus is on the analysis of the dynamic effects of changes in the levels of agrobiodiversity, on technical change and productivity in intensive agricultural systems. A theoretical model is used to derive hypotheses regarding these linkages that are empirically tested using a stochastic production frontier model with data from a panel of UK cereal farms for the period 1989-2000. The results suggest that the increased agrobiodiversity has positively helped to shift the production frontier outwards. This indicates that agricultural transition from more to less intensive agricultural systems can be consistent with non-decreasing output levels and an enhancement of biodiversity in agricultural landscapes.agrobiodiversity, intensive agriculture, productivity, technical change, Environmental Economics and Policy, Q12, Q16, Q24,
Environmental Impacts of Emerging Biomass Feedstock Markets: Energy, Agriculture, and the Farmer
The tighter linkages between energy and crop markets due to recent climate and energy legislation in the US have large potential environmental impacts beyond carbon sequestration and climate mitigation. These range from effects on water quality and quantity, soil erosion, habitat and biodiversity preservation. These impacts are very location and management-decision specific, as they are the product of atomistic decisions and depend on soil and landscape specific variables. In order to fully understand the effects of biomass markets, the new and stronger linkages and feedback effects between national- and global-scale energy and commodity markets must be properly understood and identified using an integrated perspective. We discuss the various interactions between agricultural and energy markets and their environmental impacts for existing biomass crops and detail how these interactions may be strengthened with the emergence of corn stover as a second generation biofuel feedstock. The tighter coupling of land use and management and energy systems needs to be accounted for to ensure that we have accurate indicators of the sustainability of biomass as an energy resource
Prevalence of Complementary and Alternative Medicine-use by UK Cancer Patients: A Systematic Review of Surveys
This is a freely-available open access publication. Please cite the published version which is available via the DOI link in this record.Background: Cancer patients seem to frequently use Complementary and Alternative Medicine (CAM).
However, estimates of the level of usage vary widely. This systematic review is aimed at determining the prevalence
of CAM-use in cancer patients of the United Kingdom (UK).
Method: Five databases were searched for English language peer-reviewed surveys published between 01
January 2000 and 07 October 2011. In addition, relevant book chapters and our own departmental files were handsearched.
Results: 25 surveys were included with a total sample size of 6798. Across all studies, the median prevalence
rate of CAM-use was 30.5 (standard deviation=10.3). Herbal medicine was the most popular CAM modality, followed
by homeopathy, aromatherapy, reflexology and relaxation. Conclusions: Many UK cancer patients use CAM.
Oncologists need to be aware of these numbers as they can impact daily practice on the management of cancer
patients
Suppressing Diffusion-Mediated Exciton Annihilation in 2D Semiconductors Using the Dielectric Environment
Atomically thin semiconductors such as monolayer MoS2 and WS2 exhibit
nonlinear exciton-exciton annihilation at notably low excitation densities
(below ~10 excitons/um2 in MoS2). Here, we show that the density threshold at
which annihilation occurs can be tuned by changing the underlying substrate.
When the supporting substrate is changed from SiO2 to Al2O3 or SrTiO3, the rate
constant for second-order exciton-exciton annihilation, k_XX [cm2/s], is
reduced by one or two orders of magnitude, respectively. Using transient
photoluminescence microscopy, we measure the effective room-temperature exciton
diffusion coefficient in chemical-treated MoS2 to be D = 0.06 +/- 0.01 cm2/s,
corresponding to a diffusion length of LD = 350 nm for an exciton lifetime of
{\tau} = 20 ns, which is independent of the substrate. These results, together
with numerical simulations, suggest that the effective exciton-exciton
annihilation radius monotonically decreases with increasing refractive index of
the underlying substrate. Exciton-exciton annihilation limits the overall
efficiency of 2D semiconductor devices operating at high exciton densities; the
ability to tune these interactions via the dielectric environment is an
important step toward more efficient optoelectronic technologies featuring
atomically thin materials
Blue shifting of the A exciton peak in folded monolayer 1H-MoS2
The large family of layered transition-metal dichalcogenides is widely
believed to constitute a second family of two-dimensional (2D) semiconducting
materials that can be used to create novel devices that complement those based
on graphene. In many cases these materials have shown a transition from an
indirect bandgap in the bulk to a direct bandgap in monolayer systems. In this
work we experimentally show that folding a 1H molybdenum disulphide (MoS2)
layer results in a turbostratic stack with enhanced photoluminescence quantum
yield and a significant shift to the blue by 90 meV. This is in contrast to the
expected 2H-MoS2 band structure characteristics, which include an indirect gap
and quenched photoluminescence. We present a theoretical explanation to the
origin of this behavior in terms of exciton screening.Comment: 16 pages, 8 figure
Reconstructing a String-Inspired Non-minimally Coupled Quintom Model
Motivated by the recent work of Zhang and Chen \cite{bin}, we generalize
their work to the non-minimally coupled case. We consider a quintom model of
dark energy with a single scalar field given by a Lagrangian which inspired
by tachyonic Lagrangian in string theory. We consider non-minimal coupling of
tachyon field to the scalar curvature, then we reconstruct this model in the
light of three forms of parametrization for dynamical dark energy.Comment: 12 pages, 5 figure
A non-ordinary state-based peridynamics formulation for thermoplastic fracture
In this study, a three-dimensional (3D) non-ordinary state-based peridynamics (NOSB-PD) formulation for thermomechanical brittle and ductile fracture is presented. The Johnson–Cook (JC) constitutive and damage model is used to taken into account plastic hardening, thermal softening and fracture. The formulation is validated by considering two benchmark examples: 1) The Taylor-bar impact and 2) the Kalthoff–Winkler tests. The results show good agreements between the numerical simulations and the experimental results
National Non-Communicable Diseases Conferences- A Platform to Inform Policies and Practices in Tanzania
Background:
Non-communicable diseases (NCDs) arise from diverse risk factors with differences in the contexts and variabilities in regions and countries. Addressing such a complex challenge requires local evidence. Tanzania has been convening stakeholders every year to disseminate and discuss scientific evidence, policies, and implementation gaps, to inform policy makers in NCDs responses. This paper documents these dissemination efforts and how they have influenced NCDs response and landscape in Tanzania and the region.
Methods:
Desk review was conducted through available MOH and conference organizers’ documents. It had both quantitative and qualitative data. The review included reports of the four NCDs conferences, conference organization, and conduct processes. In addition, themes of the conferences, submitted abstracts, and presentations were reviewed. Narrative synthesis was conducted to address the objectives. Recommendations emanated from the conference and policy uptake were reviewed and discussed to determine the impact of the dissemination.
Findings:
Since 2019, four theme-specific conferences were organized. This report includes evidence from four conferences. The conferences convened researchers and scientists from research and training institutions, implementers, government agencies, and legislators in Tanzania and other countries within and outside Africa. Four hundred and thirty-five abstracts were presented covering 14 sub-themes on health system improvements, financing, governance, prevention intervention, and the role of innovation and technology. The conferences have had a positive effect on governments’ response to NCDs, including health care financing, NCDs research agenda, and universal health coverage.
Conclusion:
The National NCDs conferences have provided suitable platforms where stakeholders can share, discuss, and recommend vital strategies for addressing the burden of NCDs through informing policies and practices. Ensuring the engagement of the right stakeholders, as well as the uptake and utilization of the recommendations from these platforms, remains crucial for addressing the observed epidemiological transition in Tanzania and other countries with similar contexts
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