Impact of dietary calcium on vitamin D dietary requirements and bio-fortified food solutions for vitamin D deficiency

Recent re-evaluations of Dietary Reference Intakes/Values (DRI/DRVs) for vitamin D on either side of the Atlantic have established intake requirements at the 97.5th percentile between 10 and 20 µg/d, and between 7.5 and 10 µg/d at the 50th percentile. However, national nutrition surveys indicate that mean habitual intakes of vitamin D in young and adult populations are typically in the range 3-7 µg/d. DRV/DRIs for vitamin D are established on the premise that the needs of all other nutrients are being met, however, the US Dietary Guidelines Committee has again recently identified both vitamin D and calcium as nutrients of public health concern. Furthermore, the US-based Institute of Medicine in their DRI report on calcium and vitamin D highlighted that the relationship between habitual calcium intakes and vitamin D activation and catabolism was a key knowledge gap. Vitamin K nutritional status may also be of concern at a population level. Thus, the main objectives of this PhD thesis were i) to address key knowledge gaps in terms of calcium-vitamin D interactions in the body and how these may influence dietary vitamin D requirements, ii) to devise evidence-based and sustainable food-based solutions (particularly, bio-fortification approaches) for the prevention of vitamin D deficiency, and iii) to estimate the mean daily intake of phylloquinone and its adequacy in Irish adults. This thesis provides key new data which will be of use to various regulatory bodies in their future revisions of DRI/DRVs. In addition, considering the pressing need for creative food-based solutions to bridge the gap between current intakes and these vitamin D recommendations, the present work contributes to our understanding of bio-fortified foods, as one subset of such food-based solutions, and provides the first RCT proof of efficacy for bio-fortified eggs as an exemplar in protecting against low vitamin D status in winter

Polyaniline-silver hybrid materials for ink-jet printing

The synthesis of PANI/Ag hybrid materials has been carried out via a rapid chemical oxidative, in-situ polymerisation method, using silver nitrate and ammonium peroxydisulfate as oxidant precursors. These species react together to produce Ag2+, an oxidising intermediate which has greater oxidising power than either persulphate or Ag+ alone. The reaction thus proceeds at a much accelerated rate than that of pure PANI, approximately 6 times faster. Various characterisation techniques were used to characterise this new hybrid material, PANI-Ag. UV-vis absorption spectroscopy was used to follow the formation of polymer over time and monitor the rate at which the reaction progresses for both PANI and PANI-silver. It is evident from the absorption spectra that the polymer forms via the fully-oxidised pernigraniline state initially, before reducing back into the more stable emeraldine salt form. This process is significantly accelerated using both APS and AgNO3, as opposed to when using APS or AgNO3 alone. These new composites could potentially find use as functional materials for the printed electronics industry where new processable, hybrid materials as required for applications in sensing, memory, logic and photovoltaics

Food-based solutions for vitamin D deficiency: putting policy into practice and the key role for research

Recent re-evaluations of dietary reference values (DRV) for vitamin D have established intake requirements between 10 and 20 µg/d. National nutrition surveys indicate that habitual mean intakes of vitamin D in the population are typically in the range 3–7 µg/d. As vitamin D supplementation will not be effective at a population level because the uptake is generally low, creative food-based solutions are needed to bridge the gap between current intakes and these new requirement values. The overarching aim of this review is to highlight how food-based solutions can have an important role in bridging this gap and counteracting vitamin D inadequacy in Europe and elsewhere. The present review initially briefly overviews very recent new European DRV for vitamin D and, while not in agreement on requirement estimates, how they point very clearly to the need for food-based solutions. The review discusses the need for traditional fortification of foods in the dairy and other sectors, and finally overviews recent advances in the area of biofortification of food with vitamin D. In conclusion, increasing vitamin D intakes across the population distribution is important from a public health perspective to reduce the high degree of inadequacy of vitamin D intake in Europe. Fortification, including biofortification, of a wider range of foods, which accommodate diversity, is likely to have the potential to increase vitamin D intakes across the population distribution. Research has had, and will continue to have, a key role in terms of developing food-based solutions and tackling vitamin D deficiency

Inkjet Printable Organic-Inorganic Hybrids Based On Polyaniline

Polyaniline (PANI) is an organic polymer that has generated significant interest as an electrically conductive material component, and is used in applications such as sensors and flexible displays. A significant number of PANI-based devices have been prepared using inkjet printing; a fabrication technique favoured for its additive patterning ability and its efficient use of material. Combining precious metals and conducting organic polymers through compositing provides combinatorial materials, potentially possessing both the properties of the metallic component and the conducting polymer, as well as unique ensuing properties due to the compositing itself. The type of research is critical for driving innovation in materials research. Exploiting an established oxidative polymerisation protocol for producing stable nanodispersions of PANI was used where the standard oxidant was replaced with HAuCl4 or AgNO3 at a range of monomer:oxidant ratios to produce a range of composite dispersions. The morphology and populations of the metallic structures (including spherical nanoparticles and nano-whiskers), as well as the quality of the PANI were shown to be influenced by the concentration and type of oxidant used. This area of research is currently in its infancy where the research is focusing on demonstrating composite synthesis rather than the application of these materials for device fabrication. However, anticipated applications of these composite materials include noble metal deposition, electro-catalysis, neural tissue engineering, sensors, photovoltaic cells and memory devices

HIV Infection among Young People in Northwest Tanzania: The Role of Biological, Behavioural and Socio-Demographic Risk Factors.

BACKGROUND: Young people are at high risk of HIV and developing appropriate prevention programmes requires an understanding of the risk factors for HIV in this age group. We investigated factors associated with HIV among participants aged 15-30 years in a 2007-8 cross-sectional survey nested within a community-randomised trial of the MEMA kwa Vijana intervention in 20 rural communities in northwest Tanzania. METHODS: We analysed data for 7259(53%) males and 6476(47%) females. Using a proximate-determinant conceptual framework and conditional logistic regression, we obtained sex-specific Odds Ratios (ORs) for the association of HIV infection with socio-demographic, knowledge, behavioural and biological factors. RESULTS: HSV-2 infection was strongly associated with HIV infection (females: adjOR 4.4, 95%CI 3.2-6.1; males: adjOR 4.2, 95%CI 2.8-6.2). Several socio-demographic factors (such as age, marital status and mobility), behavioural factors (condom use, number and type of sexual partnerships) and biological factors (blood transfusion, lifetime pregnancies, genital ulcers, Neisseria gonorrhoeae) were also associated with HIV infection. Among females, lifetime sexual partners (linear trend, p<0.001), ≥2 partners in the past year (adjOR 2.0, 95%CI 1.4-2.8), ≥2 new partners in the past year (adjOR 1.9 95%CI 1.2, 3.3) and concurrent partners in the past year (adjOR 1.6 95%CI 1.1, 2.4) were all associated with HIV infection. CONCLUSIONS: Efforts must be intensified to find effective interventions to reduce HSV-2. Effective behavioural interventions focusing on reducing the number of sexual partnerships and risk behaviour within partnerships are also needed. An increase in risky sexual behaviour may occur following marriage dissolution or when a young woman travels outside of her community and interventions addressing the needs of these subgroups of vulnerable women may be important. TRIAL REGISTRATION: ClinicalTrial.gov NCT00248469

Uptake of voluntary counselling and testing among young people participating in an HIV prevention trial: comparison of opt-out and opt-in strategies.

BACKGROUND: HIV voluntary counselling and testing (VCT) is an integral component of HIV prevention and treatment programmes. However, testing coverage in sub-Saharan Africa is still low, particularly among young people. As treatment becomes more widely available, strategies to expand VCT coverage are critically important. We compare VCT uptake using two delivery strategies (opt-in and opt-out) within the MEMA kwa Vijana trial in 20 communities in northwest Tanzania. METHODS: We analysed data from 12,590 young persons (median (IQR) age 22 years (20-23)) to assess the effect of delivery strategy on VCT uptake. Ten communities used an opt-in approach and 10 used opt-out, balanced across intervention and control. Conditional logistic regression was used to examine factors associated with uptake within each strategy. RESULTS: VCT uptake was significantly higher with the opt-out approach (90.9% vs 60.5%, prevalence ratio = 1.51, CI = 1.41-1.62). Among females, uptake in the opt-out approach was associated with decreased knowledge of HIV acquisition, sex with a casual partner, and being HSV-2 seronegative; among males, uptake was associated with lower education and increasing lifetime partners. In contrast, uptake using the opt-in approach varied by ethnic group, religion and marital status, and increased with increasing knowledge of STI acquisition (males) or pregnancy prevention (females). CONCLUSION: VCT uptake among young people was extremely high when offered an opt-out strategy. Sociodemographic and knowledge factors affected uptake in different ways depending on delivery strategy. Increased knowledge may increase young persons' self-efficacy, which may have a different impact on testing uptake, depending on the approach used

The long-term impact of the MEMA kwa Vijana adolescent sexual and reproductive health intervention: effect of dose and time since intervention exposure.

BACKGROUND: Despite recent decreases in HIV incidence in many sub-Saharan African countries, there is little evidence that specific behavioural interventions have led to a reduction in HIV among young people. Further and wider-scale decreases in HIV require better understanding of when behaviour change occurs and why. The MEMA kwa Vijana adolescent sexual and reproductive health intervention has been implemented in rural Mwanza, Tanzania since 1999. A long-term evaluation in 2007/8 found that the intervention improved knowledge, attitudes to sex and some reported risk behaviours, but not HIV or HSV2 prevalence. The aim of this paper was to assess the differential impact of the intervention according to gender, age, marital status, number of years of exposure and time since last exposure to the intervention. METHODS: In 2007, a cross-sectional survey was conducted in the 20 trial communities among 13,814 young people (15-30 yrs) who had attended intervention or comparison schools between 1999 and 2002. Outcomes for which the intervention had an impact in 2001 or 2007 were included in this subgroup analysis. Data were analysed using cluster-level methods for stratified cluster-randomised trials, using interaction tests to determine if intervention impact differed by subgroup. RESULTS: Taking into account multiplicity of testing, concurrence with a priori hypotheses and consistency within the results no strong effect-modifiers emerged. Impact on pregnancy knowledge and reported attitudes to sex increased with years of exposure to high-quality intervention. CONCLUSIONS: The desirable long-term impact of the MEMA kwa Vijana intervention did not vary greatly according to the subgroups examined. This suggests that the intervention can have an impact on a broad cross-section of young people in rural Mwanza. TRIAL REGISTRATION: ClinicalTrials.gov NCT00248469

Evaluating the national multisite implementation of dialectical behaviour therapy in a community setting: a mixed methods approach

BACKGROUND: The implementation of evidence-based interventions for borderline personality disorder in community settings is important given that individuals with this diagnosis are often extensive users of both inpatient and outpatient mental health services. Although work in this area is limited, previous studies have identified facilitators and barriers to successful DBT implementation. This study seeks to expand on previous work by evaluating a coordinated implementation of DBT in community settings at a national level. The Consolidated Framework for Implementation Research (CFIR) (Damschroder et al., Implementation Sci. 4:50, 2009) provided structural guidance for this national level coordinated implementation. METHODS: A mixed methods approach was utilised to explore the national multisite implementation of DBT from the perspective of team leaders and therapists who participated in the coordinated training and subsequent implementation of DBT. Qualitative interviews with DBT team leaders (n = 8) explored their experiences of implementing DBT in their local service and was analysed using content analysis. Quantitative surveys from DBT therapists (n = 74) examined their experience of multiple aspects of the implementation process including orienting the system, and preparations and support for implementation. Frequencies of responses were calculated. Written qualitative feedback was analysed using content analysis. RESULTS: Five themes were identified from the interview data: team formation, implementation preparation, client selection, service level challenges and team leader role. Participants identified team size and support for the team leader as key points for consideration in DBT implementation. Key challenges encountered were the lack of system support to facilitate phone coaching and a lack of allocated time to focus on DBT. Implementation facilitators included having dedicated team members and support from management. CONCLUSIONS: The barriers and facilitators identified in this study are broadly similar to those reported in previous research. Barriers and facilitators were identified across several domains of the CFIR and are consistent with a recently published DBT implementation Framework (Toms et al., Borderline Personal Disord Emot Dysregul. 6: 2, 2019). Future research should pay particular attention to the domain of characteristics of individuals involved in DBT implementation. The results highlight the importance of a mandated service plan for the coordinated implementation of an evidence-based treatment in a public health service

Long-term biological and behavioural impact of an adolescent sexual health intervention in Tanzania: follow-up survey of the community-based MEMA kwa Vijana Trial.

BACKGROUND: The ability of specific behaviour-change interventions to reduce HIV infection in young people remains questionable. Since January 1999, an adolescent sexual and reproductive health (SRH) intervention has been implemented in ten randomly chosen intervention communities in rural Tanzania, within a community randomised trial (see below; NCT00248469). The intervention consisted of teacher-led, peer-assisted in-school education, youth-friendly health services, community activities, and youth condom promotion and distribution. Process evaluation in 1999-2002 showed high intervention quality and coverage. A 2001/2 intervention impact evaluation showed no impact on the primary outcomes of HIV seroincidence and herpes simplex virus type 2 (HSV-2) seroprevalence but found substantial improvements in SRH knowledge, reported attitudes, and some reported sexual behaviours. It was postulated that the impact on "upstream" knowledge, attitude, and reported behaviour outcomes seen at the 3-year follow-up would, in the longer term, lead to a reduction in HIV and HSV-2 infection rates and other biological outcomes. A further impact evaluation survey in 2007/8 ( approximately 9 years post-intervention) tested this hypothesis. METHODS AND FINDINGS: This is a cross-sectional survey (June 2007 through July 2008) of 13,814 young people aged 15-30 y who had attended trial schools during the first phase of the MEMA kwa Vijana intervention trial (1999-2002). Prevalences of the primary outcomes HIV and HSV-2 were 1.8% and 25.9% in males and 4.0% and 41.4% in females, respectively. The intervention did not significantly reduce risk of HIV (males adjusted prevalence ratio [aPR] 0.91, 95%CI 0.50-1.65; females aPR 1.07, 95%CI 0.68-1.67) or HSV-2 (males aPR 0.94, 95%CI 0.77-1.15; females aPR 0.96, 95%CI 0.87-1.06). The intervention was associated with a reduction in the proportion of males reporting more than four sexual partners in their lifetime (aPR 0.87, 95%CI 0.78-0.97) and an increase in reported condom use at last sex with a non-regular partner among females (aPR 1.34, 95%CI 1.07-1.69). There was a clear and consistent beneficial impact on knowledge, but no significant impact on reported attitudes to sexual risk, reported pregnancies, or other reported sexual behaviours. The study population was likely to have been, on average, at lower risk of HIV and other sexually transmitted infections compared to other rural populations, as only youth who had reached year five of primary school were eligible. CONCLUSIONS: SRH knowledge can be improved and retained long-term, but this intervention had only a limited effect on reported behaviour and no significant effect on HIV/STI prevalence. Youth interventions integrated within intensive, community-wide risk reduction programmes may be more successful and should be evaluated. TRIAL REGISTRATION: ClinicalTrials.gov NCT0024846