90 research outputs found
A Review of Environmental Implications of Dredging Activities
Dredging is a global anthropogenic excavation activity of removing sediments from water bodies and depositing it elsewhere. It is a mixed blessing as it has both beneficial and adverse impacts. This paper is on a review of environmental implications of dredging. The objective of the paper is to review previous works by researchers on the environmental consequences of dredging. The method used is a review of academic/journal articles, internet materials, conference / workshop papers, textbooks, bulletins and publicly available materials on dredging activities. The results of the study revealed that previous authors whose works were reviewed have a convergent view that apart from the beneficial impacts of dredging (e.g. keeping waterways navigable, flood and storm protection and provision of materials for road construction and building), it has lots of adverse environmental impacts, including environmental pollution, erosion, widespread hydrological changes, reduction in the population of aquatic lives like destruction of fish spawning grounds and benthic organisms and resuspension of particulate matter column that has elevated levels of lead, copper, zinc and nickel in Phytoplankton. Recommendations of the study include: (1) establishment of environmental legislations and regulations for dredging operation; (2) use of green technology in dredging activities to minimize suspension of sediments and contamination/pollution of dredging environments; and (3) creation of awareness among dredging contractors, regulators and marine communities where dredging take place on the economic and ecological values of the marine ecosystems that are usually very sensitive, fragile and productive
Wind Energy Dynamics of the Separately Excited Induction Generator
This paper covers the analysis, dynamic modelling and control of an isolated self-excited induction generator (SEIG) driven by a wind turbine. The proposed dynamic model consists of induction generator, self-excitation capacitance and load model which are expressed in stationary d-q reference frame. The dynamic performance of SEIG is investigated under no load and on load. To predict the performance of the system, a MATLAB based simulation study using matlab embedded function block was carried out. Simulations from the variations of the speed and load display the dynamic behavior of the generator. A constant capacitor value of 100 micro-farads was used in this work. The simulation results obtained illustrate the changes in the voltage, currents, torque and magnetizing inductance of the generator. The wind velocity increase led to the increase in mechanical input from the wind turbine. This results in the increased rotor speed leading also to increased stator phase voltage. The obtained simulations also show that the output voltage of the induction generator depends greatly on its shaft speed and load; this poses a potential threat as it is capable of causing a significant variation in the power consumption in the load of the machine
Outcomes in randomised controlled trials in prevention and management of carious lesions:a systematic review
Abstract Background Inconsistent outcome reporting is one significant hurdle to combining results from trials into systematic reviews. Core outcome sets (COS) can reduce this barrier. The aim of this review was to map outcomes reported in caries prevention and management randomised controlled trials (RCT) as a first step to COS development. We also investigated RCT characteristics and reporting of primary outcomes and sample size calculations. Methods PubMed, Embase, Web of Knowledge and Cochrane CENTRAL were systematically searched (1 January 1968 to 25 August 2015). Inclusion criteria: RCTs comparing any technique for prevention or management of caries with another or placebo and RCTs comparing interventions to support patients undergoing treatment of caries (without setting, dentition or age restrictions). Categories were developed through piloting and group consensus and outcomes grouped accordingly. Results Of 4773 search results, 764 were potentially relevant, full text was available for 731 papers and 605 publications met the inclusion criteria and were included. For all outcomes across the time periods 1968â1980 and 2001â2010, reporting of outcome âcaries experienceâ reduced from 39% to 18%; âclinical performance of the restorationâ reporting increased from 33% to 42% although there was a reduction to 22% in 2011â2015. Emerging outcome domains include âlesion activityâ and âpulp health-related outcomesâ, accounting for 1% and 0%, respectively, during 1968â1980 and 10% and 4% for 2011â2015. Reporting âresource efficiencyâ and âquality of life measuresâ have remained at a low level. No publications reported tooth survival independent of an index such as DMFT or equivalent. Primary outcomes were only identified as such in 414 (68%) of the reports. Conclusions Over the past 50Â years, outcome reporting for trials on prevention and management of carious lesions have tended to focus on outcomes measuring caries experience and restoration material clinical performance with lesion activity and cost-effectiveness increasingly being reported. Patient-reported and patient-focused outcomes are becoming more common (although as secondary outcomes) but remain low in use. The challenge with developing a COS will be balancing commonly previously reported outcomes against those more relevant for the future. Trial registration PROSPERO, CRD42015025310 . Registered on 14 August 2015, Trials (Schwendicke et al., Trials 16:397, 2015) and COMET initiative online (COMET, 2017)
Assessment of health communication practice on hepatitis B in Southwest Nigeria
In line with the Sustainable Development Goal 3:3 of ending the epidemic
of hepatitis by year 2030, there is a global call for strategic information to understand
viral hepatitis. Existing studies on hepatitis B virus (HBV) in Nigeria have
primarily focused on health practitioners and their patients, to the neglect of
detailed empirical data on health communication practice, especially as it relates to
semi-urban and urban demographic information. The study set to find out the
communication strategies employed by government and non-government organisations
working on HBV, as well as the preferred health communication channels for
hepatitis B by semi-urban and urban residents. The study adopted a mixed method.
The qualitative method assessed the communication strategies employed by government
and non-government health-related agencies in informing people on HBV
in Nigeria while, the survey examined the preferred health communication channels
for HBV management among 582 semi-urban and urban residents in Lagos, Oyo,
and Ogun States, Southwest Nigeria. Bivariate analyses were performed on demographic
variables and preferred health communication channels for HBV by states.
This study found that government agencies and non-government organisations
working on hepatitis B predominantly make use of interpersonal communication in
getting the people informed of HBV. Also, residents of Southwest Nigeria (elderly, 71.4% (Lagos), married couples, 53.7% (Ogun)) preferred the internet as a health
communication source for hepatitis B information as against traditional means of
television, radio and print platforms
Assessment of endogenous fibrinolysis in clinical using novel tests - Ready for clinical roll-out?
© The Author(s) 2021. This article is licensed under a Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.The occurrence of thrombotic complications, which can result in excess mortality and morbidity, represent an imbalance between the pro-thrombotic and fibrinolytic equilibrium.The mainstay treatment of these complications involves the use of antithrombotic agents but despite advances in pharmacotherapy, there remains a significant proportion of patients who continue to remain at risk.Endogenous fibrinolysis is a physiological counter-measure against lasting thrombosis and may be measured using several techniques to identify higher risk patients who may benefit from more aggressive pharmacotherapy. However, the assessment of the fibrinolytic systemis not yet accepted into routine clinical practice.In this review, we will revisit the different methods of assessing endogenous fibrinolysis (factorial assays, turbidimetric lysis assays, viscoelastic and the global thrombosis tests), including the strengths, limitations, correlation to clinical outcomes of each method and howwe might integrate the assessment of endogenous fibrinolysis into clinical practice in the future.Peer reviewedFinal Published versio
Mortality, hospital days and treatment costs of current and reduced sugar consumption in Israel
A method for assessing robustness of the results of a star-shaped network meta-analysis under the unidentifiable consistency assumption
Background
In a star-shaped network, pairwise comparisons link treatments with a reference treatment (often placebo or standard care), but not with each other. Thus, comparisons between non-reference treatments rely on indirect evidence, and are based on the unidentifiable consistency assumption, limiting the reliability of the results. We suggest a method of performing a sensitivity analysis through data imputation to assess the robustness of results with an unknown degree of inconsistency.
Methods
The method involves imputation of data for randomized controlled trials comparing non-reference treatments, to produce a complete network. The imputed data simulate a situation that would allow mixed treatment comparison, with a statistically acceptable extent of inconsistency. By comparing the agreement between the results obtained from the original star-shaped network meta-analysis and the results after incorporating the imputed data, the robustness of the results of the original star-shaped network meta-analysis can be quantified and assessed. To illustrate this method, we applied it to two real datasets and some simulated datasets.
Results
Applying the method to the star-shaped network formed by discarding all comparisons between non-reference treatments from a real complete network, 33% of the results from the analysis incorporating imputed data under acceptable inconsistency indicated that the treatment ranking would be different from the ranking obtained from the star-shaped network. Through a simulation study, we demonstrated the sensitivity of the results after data imputation for a star-shaped network with different levels of within- and between-study variability. An extended usability of the method was also demonstrated by another example where some head-to-head comparisons were incorporated.
Conclusions
Our method will serve as a practical technique to assess the reliability of results from a star-shaped network meta-analysis under the unverifiable consistency assumption.This research was supported by a grant of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute, funded by the Ministry of Health & Welfare, Republic of Korea (grant number: HI19C1178). The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
Recommended from our members
Secretome of mesenchymal stem cells and its impact on Chronic Obstructive Pulmonary Disease
Chronic obstructive pulmonary disease (COPD) is characterized by irreversible loss of lung function that stem from two mechanisms, inflammation and senescence. Crosstalk between these two mechanisms accelerate the development of COPD, thus targeting these two pathways may offer benefits in the treatment of COPD. Growing amount of evidence have shown that mesenchymal stem cells as a promising candidate for the treatment of COPD. Over the years, many studies conducted to decipher the therapeutic effect of MSC in COPD and the mechanisms involve, in the hope of utilizing these cells as new therapeutic strategy for COPD. However, the cell-based therapy by using the MSC presented with many obstacles including low engraftment at the site of injury, the risk of microvascular occlusion, unwanted differentiation, and also the risk of malignant transformation. Recently, recently researchers begin to look at the possibility of using MSC derived extracellular vesicles as an alternative to MSC. Here we review the effect of MSC and MSC derived EV in modulating inflammation, and senescence in COPD. We also review current treatment and the side effect in COPD, and senolytic drugs, a new therapeutic strategy targeting the senescent cells
- âŠ