1,240 research outputs found
Economic Consequences of Mandated Grading and Food Safety Assurance: Ex Ante Analysis of the Federal Marketing Order for California Pistachios
Crop Production/Industries, Food Consumption/Nutrition/Food Safety, Marketing,
Formal Quantum Efficiencies for the Photocatalytic Reduction of CO2 in a Gas Phase Batch Reactor
The photocatalytic reduction of CO2 to fuels, or useful products, is an area of active research. In this work, nanoengineering and surface modification of titania were investigated as approaches for improving the CO2 reduction efficiency in a fixed-bed gas phase batch photoreactor under UV–vis irradiation. Titania nanotubes were prepared by a hydrothermal method, and TiO2 (P25) was surface modified with copper clusters. Unmodified TiO2 (P25) was used as the bench-mark comparison. The titania nanotubes and Cu-TiO2 materials showed higher efficiency for the photocatalytic reduction of CO2 to yield CH4 as compared to P25. Carbon monoxide yields were similar for all photocatalysts tested. The photocatalytic reduction of CO2 was observed on all photocatalyst tested, with the nanotubes proving to be the most efficient for the production of CH4. The product yields per mass of catalyst observed in this work are similar to those reported in the literature (with similar reactor parameters) but the calculated formal quantum efficiencies for CO2 reduction are very low (4.41 × 10−5 to 5.95 × 10-4)
Multifunctional photo/thermal catalysts for the reduction of carbon dioxide
The photochemical fixation of CO2 to energy rich products for solar energy storage or feedstock chemicals is an attractive, albeit daunting, challenge. The overall feasibility of CO2 conversion is limited by the availability of efficient photo-active materials that meet the energetic requirements for CO2 reduction and are optically matched to the solar spectrum. Surface modification of TiO2 with earth abundant metal oxides presents one approach to develop visible active photocatalysts through band gap narrowing, while providing catalytic sites to lower the activation energy for CO2 reduction. In this work density functional theory was used to model the effect of surface modification of rutile and anatase using MnOx nanoclusters. The results indicate the formation of inter-band gap states following surface modification with MnOx, but surface water can change this. Oxygen vacancies are predicted to form in supported MnOx and the interaction with CO2 was investigated. MnOx-TiO2 was synthesized and characterised using surface analytical methods and photoelectrochemistry. The interaction of CO2 with the materials under irradiation was probed using in-situ FTIR to interrogate the role of oxygen vacancies in CO2 binding and reaction. These results provide insights into the requirements of a multifunctional catalyst for CO2 conversion
Facilitators and barriers to home-based toothbrushing practices by parents of young children to reduce tooth decay: a systematic review
Objectives
Parental supervised toothbrushing (PSB) is a collection of behaviours recommended by national guidance to improve oral health. This systematic review aimed to identify the barriers and facilitators to PSB.
Materials and methods
Studies investigating parental involvement in home-based toothbrushing in children under 8 years old and the impact on tooth decay were included. Electronic databases, references and unpublished literature databases were searched. The Theoretical Domains Framework (TDF) was used to code barriers/facilitators to PSB.
Results
Of the 10,176 articles retrieved, 68 articles were included. Barriers and facilitators were found across all 12 TDF domains. Barriers included an inadequate toothbrushing environment and resources, knowledge of what PSB entails and child behaviour management. Facilitators were increased oral health knowledge, the adaption of the social environment to facilitate PSB and positive attitudes towards oral health. When only high-quality articles were synthesized, knowledge was not a common barrier/facilitator.
Conclusions
There are a comprehensive range of barriers/facilitators to PSB acting across all domains and at multiple levels of influence. This review identifies the most popular domains, thus informing the focus for supporting resources to supplement oral health conversations.
Clinical relevance
PSB is a complex behaviour. Practitioners need to understand and be able to explore the wide range of potential barriers and have practical suggestions to enable PSB. This review provides pragmatic examples of different barriers and facilitators and emphasises the importance of listening to parents and exploring their story to identify the barriers and solutions that are relevant to each family
Estimates of marker effects for measures of milk flow in the Italian brown Swiss dairy cattle population
Background: Milkability is a complex trait that is characterized by milk flow traits including average milk flow rate, maximum milk flow rate and total milking time. Milkability has long been recognized as an economically important trait that can be improved through selection. By improving milkability, management costs of milking decrease through reduced labor and improved efficiency of the automatic milking system, which has been identified as an important factor affecting net profit. The objective of this study was to identify markers associated with electronically measured milk flow traits, in the Italian Brown Swiss population that could potentially improve selection based on genomic predictions.Results: Sires (n = 1351) of cows with milk flow information were genotyped for 33,074 single nucleotide polymorphism (SNP) markers distributed across 29 Bos taurus autosomes (BTA). Among the six milk flow traits collected, ascending time, time of plateau, descending time, total milking time, maximum milk flow and average milk flow, there were 6,929 (time of plateau) to 14,585 (maximum milk flow) significant SNP markers identified for each trait across all BTA. Unique regions were found for each of the 6 traits providing evidence that each individual milk flow trait offers distinct genetic information about milk flow. This study was also successful in identifying functional processes and genes associated with SNPs that influences milk flow.Conclusions: In addition to verifying the presence of previously identified milking speed quantitative trait loci (QTL) within the Italian Brown Swiss population, this study revealed a number of genomic regions associated with milk flow traits that have never been reported as milking speed QTL. While several of these regions were not associated with a known gene or QTL, a number of regions were associated with QTL that have been formerly reported as regions associated with somatic cell count, somatic cell score and udder morphometrics. This provides further evidence of the complexity of milk flow traits and the underlying relationship it has with other economically important traits for dairy cattle. Improved understanding of the overall milking pattern will aid in identification of cows with lower management costs and improved udder health
On the Geometry of Super Yang-Mills Theories: Phases and Irreducible Polynomials
We study the algebraic and geometric structures that underly the space of
vacua of N=1 super Yang-Mills theories at the non-perturbative level. Chiral
operators are shown to satisfy polynomial equations over appropriate rings, and
the phase structure of the theory can be elegantly described by the
factorization of these polynomials into irreducible pieces. In particular, this
idea yields a powerful method to analyse the possible smooth interpolations
between different classical limits in the gauge theory. As an application in
U(Nc) theories, we provide a simple and completely general proof of the fact
that confining and Higgs vacua are in the same phase when fundamental flavors
are present, by finding an irreducible polynomial equation satisfied by the
glueball operator. We also derive the full phase diagram for the theory with
one adjoint when Nc is less than or equal to 7 using computational algebraic
geometry programs.Comment: 87 pages; v2: typos and eq. (4.44) correcte
On the complete classification of the unitary N=2 minimal superconformal field theories
Aiming at a complete classification of unitary N=2 minimal models (where the
assumption of space-time supersymmetry has been dropped), it is shown that each
modular invariant candidate of a partition function for such a theory is indeed
the partition function of a minimal model. A family of models constructed via
orbifoldings of either the diagonal model or of the space-time supersymmetric
exceptional models demonstrates that there exists a unitary N=2 minimal model
for every one of the allowed partition functions in the list obtained from
Gannon's work.
Kreuzer and Schellekens' conjecture that all simple current invariants can be
obtained as orbifolds of the diagonal model, even when the extra assumption of
higher-genus modular invariance is dropped, is confirmed in the case of the
unitary N=2 minimal models by simple counting arguments.Comment: 53 pages; Latex; minor changes in v2: intro expanded, references
added, typos corrected, footnote added on p31; renumbering of sections; main
theorem reformulated for clarity, but contents unchanged. Minor revisions in
v3: typos corrected, footnotes 5, 6 added, lemma 1 and section 3.3.2
rewritten for greater generality, section 3.3 review removed. To appear in
Comm. Math. Phy
“Strong Teeth”: the acceptability of an early-phase feasibility trial of an oral health intervention delivered by dental teams to parents of young children
Background
Dental caries (tooth decay) in children is a worldwide public health problem. The leading cause of caries is poor oral hygiene behaviours and the frequent consumption of sugary foods and drinks. Changing oral health habits requires effective behaviour change conversations. The dental practice provides an opportunity for dental teams to explore with parents the oral health behaviours they undertake for their young children (0–5 years old). However, evidence suggests that dental teams need further support, training and resources. Therefore, “Strong Teeth” (an oral health intervention) was co-developed to help dental teams undertake these behaviour change conversations. The current paper will explore the acceptability of the “Strong Teeth” intervention with dental teams and parents of children aged 0–5 years old using multiple datasets (interviews, focus groups and dental team member diaries)
Methods
Following the delivery of the “Strong Teeth” intervention, qualitative interviews with parents and focus groups with dental team members were undertaken. Interviews were audio-recorded, transcribed and analysed using a theoretical framework of acceptability. The self-reported dental team diaries supplemented the interviews and focus groups and were analysed using framework analysis.
Results
Four themes were developed: (1) integration within the dental practice; (2) incorporating the Oral-B electric toothbrush; (3) facilitating discussions and demonstrations; and (4) the practicality of the Disney Magic Timer app. Overall, the “Strong Teeth” intervention was acceptable to parents and dental teams. Parents felt the Oral-B electric toothbrush was a good motivator; however, the Disney Magic Timer app received mixed feedback on how well it could be used effectively in the home setting. Findings suggest that the intervention was more acceptable as a “whole team approach” when all members of the dental practice willingly participated.
Conclusions
There are limited studies that use a robust process evaluation to measure the acceptability of an intervention. The use of the theoretical framework of acceptability helped identify aspects of the intervention that were positive and helped identify the interventions areas for enhancement moving forwards. Future modifications include enhanced whole team approach training to optimise acceptability to all those involved.
Trial registration
ISRCTN Register, (ISRCTN10709150)
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