186 research outputs found
Heavy metal pollution of vegetable crops irrigated with wastewater 41 Heavy Metal Pollution of Vegetable Crops Irrigated with Wastewater in Accra, Ghana
Heavy metal concentrations in irrigation water (samples =120), soil (samples =144) and edible parts of both exotic and traditional vegetables (samples = 240) irrigated with wastewater from some parts of Accra were studied. The concentrations of heavy metals in mg/l were quantified in wastewater from Accra and groundwater at Mampong as Fe (0.67; 1.00), Mn (0.78; 0.31), Cu (0.06; 0.07), Zn (0.14; 0.13), Pb (0.08; 0.12), Ni (0.06; 0.13), Cr (< 0.006), Cd (< 0.002) and Co (< 0.005), soil Fe (164.38; 162.92), Mn (39.39; 20.09), Cu (7.21; 6.13), Zn (6.03; 7.45), Pb (9.31; 7.63), Ni (5.00; 2.97), Cr (0.51;0.85), Cd (0.07;0.09) and Co (0.73;0.87), and vegetables from Accra and Mampong. The wastewater used for irrigation had the highest concentration (mg/l) of Mn (0.78), followed by Fe (0.67), Zn (0.14), Pb (0.08), Cu (0.06), Ni (0.06) while Cr, Cd and Co were below detection limits. Fe (164.38; 162.92), Mn (39.39; 20.09), Cu (7.21; 6.13), Pb (9.31; 7.63) and Ni (5.00; 2.97) levels were higher in wastewater irrigated soils than groundwater irrigated soils, respectively. However, average values were all below the FAO/WHO recommended mean levels in mg/l for wastewater and soil as Fe (5.00; 50,000), Mn (0.20; 2,000), Cu (0.20; 100), Zn (2.00; 300), Pb (5.00; 100), Ni (0.20; 50.00), Cr (0.10;50.00), Cd (0.01;3.00) and Co (0.05;100), respectively. Concentration levels of heavy metals (mg/kg) in vegetables crops analysed from all sites were not elevated except for Pb in cabbage, (10.51), lettuce (10.19), green pepper (9.44), hot pepper (7.61) and ayoyo (9.05) compared to the FAO/WHO maximum recommended limit of 0.30 mg/kg for Pb. Health risk assessments showed that hazard indexes for the crops were below 1 (USEPA), indicating that normal consumption of vegetables analysed pose no risk from heavy metal toxicities. However, to prevent any chronic health risk and extent of heavy metal contamination, steps must be taken to reduce human activities at the sites. Regular monitoring of heavy metals in the vegetables grown in wastewater irrigated areas is also necessary
Investigation of dielectric anomalies at cryogenic temperatures in the (1-x)[Pb(Mg1/3 Nb2/3)O3]-xPbTiO3 system
Complex electrical permittivity measurements in (1-x)[Pb(Mg1/3
Nb2/3)O3]-xPbTiO3 ceramics for 0.10 x 0.40 were performed in the frequency and
temperature range from 1 kHz to 100 kHz and from 15 to 600 K, respectively.
Unexpected dielectric anomalies, which were frequency dependent, were found at
cryogenic temperatures. It was verified that this dielectric behavior is always
observed, independently of whether the composition presents a "normal"
ferroelectric or a relaxor characteristic. The results were analyzed within the
framework of two current models found in the literature. It was concluded that
none of the proposed mechanisms uniquely satisfies the experimental results in
the composition range investigated here.Comment: 9 pages, 7 figures - Accepted for publication in the Applied Physics
Lette
Oral health-related impact profile of patients treated with fixed, removable, and telescopic dental prostheses in student courses — a prospective bicenter clinical trial
Objectives!#!To analyze the oral health-related impact profile in patients treated with three different types of dental prosthesis in student courses.!##!Materials and methods!#!This prospective bicenter clinical trial was conducted with 151 patients being treated with fixed (n = 70), removable (n = 61), or telescopic dental prostheses (n = 20) in clinical student courses of two German universities from October 2018 to October 2019. All patients completed three standardized German versions of the Oral Health Impact Profile (OHIP-G49/53) before prosthetic treatment (T0), at control after 1 week (T1), and after 3 months (T2), divided into five dimensions: (a) appearance, (b) oral function, (c) psychosocial impact, (d) linguistic limitations, and (e) orofacial pain. Data were analyzed with Kolmogorov-Smirnov, Wilcoxon signed-rank, Kruskal-Wallis, Mann-Whitney, and Cronbach's alpha tests.!##!Results!#!Within T0-T1 and T0-T2, greater improvements were determined for removable compared with fixed dental prostheses for the dimensions' oral function (p ≤ 0.014), linguistic limitations (p ≤ 0.016), and appearance (p ≤ 0.003). No significant differences were found between fixed and telescopic dental prostheses (p ≥ 0.104) or between removable (partial dental prosthesis with clasps and complete dental prosthesis) and telescopic dental prostheses (p ≥ 0.100). Within T1-T2, a significant improvement in orofacial pain could be determined (p = 0.007).!##!Conclusions!#!Restorations presented an improvement in oral health-related quality of life. Removable dental prostheses showed better improvement than fixed ones in various dimensions.!##!Clinical relevance!#!Knowledge about the influence of oral health-related quality of life on the three different types of prosthesis used in student courses can be of decisive help in dental consultations
Stochastic Approach to Enantiomeric Excess Amplification and Chiral Symmetry Breaking
Stochastic aspects of chemical reaction models related to the Soai reactions
as well as to the homochirality in life are studied analytically and
numerically by the use of the master equation and random walk model. For
systems with a recycling process, a unique final probability distribution is
obtained by means of detailed balance conditions. With a nonlinear
autocatalysis the distribution has a double-peak structure, indicating the
chiral symmetry breaking. This problem is further analyzed by examining
eigenvalues and eigenfunctions of the master equation. In the case without
recycling process, final probability distributions depend on the initial
conditions. In the nonlinear autocatalytic case, time-evolution starting from a
complete achiral state leads to a final distribution which differs from that
deduced from the nonzero recycling result. This is due to the absence of the
detailed balance, and a directed random walk model is shown to give the correct
final profile. When the nonlinear autocatalysis is sufficiently strong and the
initial state is achiral, the final probability distribution has a double-peak
structure, related to the enantiomeric excess amplification. It is argued that
with autocatalyses and a very small but nonzero spontaneous production, a
single mother scenario could be a main mechanism to produce the homochirality.Comment: 25 pages, 6 figure
Fluctuation Induced Homochirality
We propose a new mechanism for the achievment of homochirality in life
without any autocatalytic production process. Our model consists of a
spontaneous production together with a recycling cross inhibition in a closed
system.
It is shown that although the rate equations for this system predict no
chiral symmetry breaking, the stochastic master equation predicts complete
homochirality. This is because the fluctuation induced by the discreteness of
population numbers of participating molecules plays essential roles. This
fluctuation conspires with the recyling cross inhibition to realize the
homochirality.Comment: 13 pages, 6 figure
SATURN: assessing the feasibility of utilising existing registries for real-world evidence data collection to meet patients, regulatory, health technology assessment and payer requirements
Background: SATURN (Systematic Accumulation of Treatment practices and Utilisation, Real world evidence, and Natural history data) for the rare condition osteogenesis imperfecta (OI) has the objective to create a common core dataset by utilising existing, well-established data sources to meet the needs of the various stakeholders (physicians, registry/dataset owners, patients and patient associations, OI community leaders, European [EU] policymakers, regulators, health technology assessments [HTA]s, and healthcare systems including payers). This paper describes the steps taken to assess the feasibility of one existing OI registry (i.e., the Registry of OI [ROI]) as a candidate for SATURN. The same methodology will be applied to other existing OI registries in the future and this same concept could be utilised for other rare disease registries. Methods: The approach to assessing the feasibility of the ROI registry consisted of three steps: (1) an assessment of the registry characteristics using the Registry Evaluation and Quality Standards Tool (REQueST); (2) a gap analysis comparing SATURN required Core Variables to those being captured in the registry’s Case Report Form (CRF); and (3) a compliance check on the data exchange process following the Title 21 of Code of Federal Regulations (CFR) Part 11/EudraLex Annex 11 Compliance Checklist. The first registry that SATURN has assessed is the ROI database at the Istituto Ortopedico Rizzoli (IOR) in Italy. Results: The results from the ROI REQueST have demonstrated satisfactory complete responses in terms of methodology, essential standards, interpretability, and interoperability—readiness for data linkage, data sources, and ethics to meet the needs of data customers. However, the ROI data is from a tertiary referral centre which may limit the ability to understand the full patient journey. The gap analysis has revealed that an exact or logical match between SATURN requested variables and the ROI current variables exists for the following items: patient characteristics, treatment of OI (medical and surgical) and treatment of pain (with the exception of frequency of treatment and reasons for discontinuation), fracture history and bone density. However, data on safety was missing. The compliance check has implied that the ROI implemented appropriate controls for the web-based platform (i.e., Genotype–phenotype Data Integration Platform [GeDI]) that is involved in processing the electronic patient data, and GeDI is a validated/compliant application that follows relevant 21 CFR Part 11/EudraLex Annex 11 regulations. Conclusions: This robust feasibility process highlights potential limitations and opportunities to develop and to refine the collaboration with the ROI as the SATURN programme moves forward. It also ensures that the existing datasets in the rare condition OI are being maximised to respond to the needs of patients, data customers and decision-makers. This feasibility process has allowed SATURN to build a compliant methodology that aligns with the requirements from the European Medicines Agency (EMA) and HTAs. More data variables will continue to be developed and refined along the way with more registries participating in SATURN. As a result, SATURN will become a meaningful and truly collaborative core dataset, which will also contribute to advancing understanding of OI diagnosis, treatment, and care
Innovation, low energy buildings and intermediaries in Europe: systematic case study review
As buildings throughout their lifecycle account for circa 40% of total energy use in Europe, reducing energy use of the building stock is a key task. This task is, however, complicated by a range of factors, including slow renewal and renovation rates of buildings, multiple non- coordinated actors, conservative building practices, and limited competence to innovate. Drawing from academic literature published during 2005-2015, this article carries out a systematic review of case studies on low energy innovations in the European residential building sector, analysing their drivers. Specific attention is paid to intermediary actors in facilitating innovation processes and creating new opportunities. The study finds that qualitative case study literature on low energy building innovation has been limited, particularly regarding the existing building stock. Environmental concerns, EU, national and local policies have been the key drivers; financial, knowledge and social sustainability and equity drivers have been of modest importance; while design, health and comfort, and market drivers have played a minor role. Intermediary organisations and individuals have been important through five processes: (1) facilitating individual building projects, (2) creating niche markets, (3) implementing new practices in social housing stock, (4) supporting new business model creation, and (5) facilitating building use post construction. The intermediaries have included both public and private actors, while local authority agents have acted as intermediaries in several cases
Physiological Correlates of Volunteering
We review research on physiological correlates of volunteering, a neglected but promising research field. Some of these correlates seem to be causal factors influencing volunteering. Volunteers tend to have better physical health, both self-reported and expert-assessed, better mental health, and perform better on cognitive tasks. Research thus far has rarely examined neurological, neurochemical, hormonal, and genetic correlates of volunteering to any significant extent, especially controlling for other factors as potential confounds. Evolutionary theory and behavioral genetic research suggest the importance of such physiological factors in humans. Basically, many aspects of social relationships and social activities have effects on health (e.g., Newman and Roberts 2013; Uchino 2004), as the widely used biopsychosocial (BPS) model suggests (Institute of Medicine 2001). Studies of formal volunteering (FV), charitable giving, and altruistic behavior suggest that physiological characteristics are related to volunteering, including specific genes (such as oxytocin receptor [OXTR] genes, Arginine vasopressin receptor [AVPR] genes, dopamine D4 receptor [DRD4] genes, and 5-HTTLPR). We recommend that future research on physiological factors be extended to non-Western populations, focusing specifically on volunteering, and differentiating between different forms and types of volunteering and civic participation
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