223 research outputs found
Effect of Irrigation Management Methods on Growth, Grain Yield and Water Productivity of Three Lowland Rice (Oryza sativa L.) Varieties
It has been predicted that Ghana will face water shortage by the year 2025 due to increased demand of water resources from all sectors of the economy. Rice production will be negatively affected since rice consumes the highest amount of water in the agricultural sector. To develop a strategy to reduce water use for rice production while maintaining or increasing rice yield, a pot experiment was carried out in the screen house at Soil and Irrigation Research Centre - Kpong during 2016 and 2017 cropping seasons to determine the effect of irrigation management methods on growth, yield and water productivity of three rice varieties. A three by five (3 x 5) factorial experiment was laid out in a randomized complete block design and replicated six (6) times. The levels of the variety were: Agra (VA), Ex Baika (VB) and a hybrid (VH). Irrigation management methods included: continuous submergence (I1), alternate wet and dry soil condition (AWD) from transplanting to panicle initiation (PI) then submergence to harvest (I2), AWD from transplanting to booting then submergence to harvest (I3), AWD from transplanting to lowering then submergence to harvest (I4), and continuous AWD (I5). Results from the experiment revealed that, I3 saved 21.7% and 20.4% of water used when compared with I1 in 2016 and 2017, respectively however, these treatments produced similar growth and yield in both seasons. I3VH recorded 21.2% and 20.8% of water saved in 2016 and 2017, respectively however, it produced similar grain yield with I2VH and I1VH treatments in both seasons
Willingness of marine artisanal fishermen to integrate aquaculture in enterprise mix: Evidence from Ghana
Marine resources are depleting, making the dependence of economies on fish from such sources no longer the best option. Aquaculture has been suggested as an alternative livelihood. This study assesses the willingness of marine artisanal fishermen in the coastal region of Ghana to adopt aquaculture. The Effutu municipality in the central region of Ghana was purposely selected for the study. A multi stage cluster sampling procedure was used to randomly select150 artisanal fishermen from two communities in the coastal area of the district. Data was collected using semi structured questionnaire. The study employed the Binary Logit model to assess the influence of technical, socioeconomic and institutional factors on the decision to integrate the aquaculture enterprise into household enterprises of fishermen. The results of the study showed that about62 percent of the marine fishermen were willing to adopt and integrate aquaculture into their enterprise mix. The Logit estimation results reveal that fishermen who lacked savings, had difficulty in accessing credit, did not belong to fishermen's association, and were new in marine fishing were more likely to be convinced about integrating aquaculture. There is potential for marine fishers to explore and use aquaculture to enhance their wealth. The study recommends that targeting marine fishers who are youthful and inexperienced for training and capacity building is the best policy option for stakeholders who are interested in aquaculture development. Key Words: Marine artisanal fishermen, aquaculture, enterprise mix, Binary Logit Model, Ghan
Toxicity and Safety Implications of Herbal Medicines Used in Africa
The use of herbal medicines has seen a great upsurge globally. In developing countries, many patronize them largely due to cultural acceptability, availability and cost. In developed countries, they are used because they are natural and therefore assumed to be safer than allopathic medicines. In recent times, however, there has been a growing concern about their safety. This has created a situation of ambivalence in discussions regarding their use. Some medicinal plants are intrinsically toxic by virtue of their constituents and can cause adverse reactions if inappropriately used. Other factors such as herb-drug interactions, lack of adherence to good manufacturing practice (GMP), poor regulatory measures and adulteration may also lead to adverse events in their use. Many in vivo tests on aqueous extracts largely support the safety of herbal medicines, whereas most in vitro tests on isolated single cells mostly with extracts other than aqueous ones show contrary results and thus continue the debate on herbal medicine safety. It is expected that toxicity studies concerning herbal medicine should reflect their traditional use to allow for rational discussions regarding their safety for their beneficial use. While various attempts continue to establish the safety of various herbal medicines in man, their cautious and responsible use is required
The Australian Early Years Learning Framework: learning what?
Early childhood education and care have assumed importance in many government policy agendas. This attention is often accompanied by calls for greater accountability regarding the anticipated learning outcomes for young children. In Australia, the expected learning outcomes for children aged birth to five years are outlined in the recently published Early Years Learning Framework (EYLF). In this article, the author examines the relationship between the EYLFâs outcomes and subject area or content knowledge. The article draws from post-structural and social constructionist understandings of knowledge as unfinished, contestable and contextual. The author concludes that it is not content knowledge itself that is problematic, but it is the way the child and teacher are often positioned in relation to that knowledge that constrains the potential for effective teaching and learning in the early years. The author suggests that revisiting traditional assumptions about content knowledge extends and develops many of the ideas about teaching and learning that are identified in the EYLF, and opens up new identity positions for both children and early childhood educators
Distances sets that are a shift of the integers and Fourier basis for planar convex sets
The aim of this paper is to prove that if a planar set has a difference
set satisfying for suitable than
has at most 3 elements. This result is motivated by the conjecture that the
disk has not more than 3 orthogonal exponentials. Further, we prove that if
is a set of exponentials mutually orthogonal with respect to any symmetric
convex set in the plane with a smooth boundary and everywhere non-vanishing
curvature, then # (A \cap {[-q,q]}^2) \leq C(K) q where is a constant
depending only on . This extends and clarifies in the plane the result of
Iosevich and Rudnev. As a corollary, we obtain the result from \cite{IKP01} and
\cite{IKT01} that if is a centrally symmetric convex body with a smooth
boundary and non-vanishing curvature, then does not possess an
orthogonal basis of exponentials
When does the action start and finish? Making the case for an ethnographic action research in educational research
This paper explores how ethnographic and action research methodologies can be justifiably combined to create a new methodological approach in educational research. It draws on existing examples in both educational research and
development studies that have discussed the use of ethnography and action research in specific projects. Interpretations of ethnography and action research
are developed that aim to minimise the epistemological differences between them.
The paper also contextualises an âethnographic action researchâ approach with reference to an example of the authorâs research into participation in three âreceptionâ (first year of schooling) classes in the United Kingdom. It is argued that research into the theme of participation in early years education, using participative methods, was particularly suitable for this new methodological
approach
Reprogramming of pancreatic adenocarcinoma immunosurveillance by a microbial probiotic siderophore
There is increasing evidence suggesting the role of microbiome alterations in relation to pancreatic adenocarcinoma and tumor immune functionality. However, molecular mechanisms of the interplay between microbiome signatures and/or their metabolites in pancreatic tumor immunosurveillance are not well understood. We have identified that a probiotic strain (Lactobacillus casei) derived siderophore (ferrichrome) efficiently reprograms tumor-associated macrophages (TAMs) and increases CD8â+âT cell infiltration into tumors that paralleled a marked reduction in tumor burden in a syngeneic mouse model of pancreatic cancer. Interestingly, this altered immune response improved anti-PD-L1 therapy that suggests promise of a novel combination (ferrichrome and immune checkpoint inhibitors) therapy for pancreatic cancer treatment. Mechanistically, ferrichrome induced TAMs polarization via activation of the TLR4 pathway that represses the expression of iron export protein ferroportin (FPN1) in macrophages. This study describes a novel probiotic based molecular mechanism that can effectively induce anti-tumor immunosurveillance and improve immune checkpoint inhibitors therapy response in pancreatic cancer
Theorising interprofessional pedagogic evaluation: framework for evaluating the impact of interprofessional CPD on practice change
This paper outlines the development of a conceptual framework to guide the evaluation of the impact of the pedagogy employed in continuing professional development for professionals in education, health and social care. The work is developed as part of the Centre for Excellence in Teaching and Learning: Interprofessional Learning across the Public Sector (CETL: IPPS) at the University of Southampton. The paper briefly outlines the field for pedagogic research and comments on the underpinning theories that have so far been used to guide research into interprofessional learning (IPL). It maps out the development of interprofessional CPD in its specific context as part of the CETL: IPPS with its links to a local authority undergoing service reorganisation and the role of the continuing professional development (CPD) in effecting change. It then brings together a theoretical framework with the potential toexplore, explain and evaluate the essential features of the model of pedagogy used in interprofessional CPD, in which professionals from education have for the first time been included alongside those from health and social care. The framework draws upon elements of situated learning theory, Activity Theory and Dreierâs work (2002, 1999) on trajectories of participation, particularly Personal Action Potency. By combining the resulting analytic framework with an adapted version of an established evaluation model, a theoretically-driven, practicable evaluation matrix is developed. The matrix has potential use in evaluating the impact of pedagogic input on practice change. The paper models a process for developing a conceptual framework to steer pedagogic evaluation. Such a process and the resulting matrix may be of use to other researchers who are similarly developing pedagogic evaluation
CGILS: Results From The First Phase of An International Project to Understand The Physical Mechanisms of Low Cloud Feedbacks in Single Column Models
CGILSâthe CFMIP-GASS Intercomparison of Large Eddy Models (LESs) and single column models (SCMs)âinvestigates the mechanisms of cloud feedback in SCMs and LESs under idealized climate change perturbation. This paper describes the CGILS results from 15 SCMs and 8 LES models. Three cloud regimes over the subtropical oceans are studied: shallow cumulus, cumulus under stratocumulus, and well-mixed coastal stratus/stratocumulus. In the stratocumulus and coastal stratus regimes, SCMs without activated shallow convection generally simulated negative cloud feedbacks, while models with active shallow convection generally simulated positive cloud feedbacks. In the shallow cumulus alone regime, this relationship is less clear, likely due to the changes in cloud depth, lateral mixing, and precipitation or a combination of them. The majority of LES models simulated negative cloud feedback in the well-mixed coastal stratus/stratocumulus regime, and positive feedback in the shallow cumulus and stratocumulus regime. A general framework is provided to interpret SCM results: in a warmer climate, the moistening rate of the cloudy layer associated with the surface-based turbulence parameterization is enhanced; together with weaker large-scale subsidence, it causes negative cloud feedback. In contrast, in the warmer climate, the drying rate associated with the shallow convection scheme is enhanced. This causes positive cloud feedback. These mechanisms are summarized as the âNESTSâ negative cloud feedback and the âSCOPEâ positive cloud feedback (Negative feedback from Surface Turbulence under weaker SubsidenceâShallow Convection PositivE feedback) with the net cloud feedback depending on how the two opposing effects counteract each other. The LES results are consistent with these interpretations
Recommended from our members
The uronic acid content of coccolith-associated polysaccharides provides insight into coccolithogenesis and past climate
Unicellular phytoplanktonic algae (coccolithophores) are among the most prolific producers of calcium carbonate on the planet, with a production of âŒ1026 coccoliths per year. During their lith formation, coccolithophores mainly employ coccolith-associated polysaccharides (CAPs) for the regulation of crystal nucleation and growth. These macromolecules interact with the intracellular calcifying compartment (coccolith vesicle) through the charged carboxyl groups of their uronic acid residues. Here we report the isolation of CAPs from modern day coccolithophores and their prehistoric predecessors and we demonstrate that their uronic acid content (UAC) offers a species-specific signature. We also show that there is a correlation between the UAC of CAPs and the internal saturation state of the coccolith vesicle that, for most geologically abundant species, is inextricably linked to carbon availability. These findings suggest that the UAC of CAPs reports on the adaptation of coccolithogenesis to environmental changes and can be used for the estimation of past CO2 concentrations
- âŠ