Perinatal epidemiology: Issues, challenges, and potential solutions

2020 ◽  
pp. 1753495X2094898
Author(s):  
Konstantinos Giannakou
Keyword(s):  
Observational Studies ◽  
Statistical Power ◽  
Randomized Trials ◽  
Epidemiological Studies ◽  
Research Field ◽  
Ethical Considerations ◽  
Perinatal Epidemiology ◽  
Different Types ◽  
Inadequate Statistical Power ◽  
Methodological Difficulties

Perinatal epidemiology research is concerned with identifying the effects of events during pregnancy on pregnancy outcomes that include maternal, fetal, and neonatal health outcomes. Randomized trials in perinatal research face many challenges, including randomization difficulties, ethical considerations, and inadequate statistical power due to the small number of subjects eligible for participation. For these reasons, most epidemiological studies conducted in this research field are observational and include different types of bias. This review describes the key methodological difficulties in the design and analysis of randomized and observational studies in perinatal epidemiology, and provides potential corrective approaches.

scholarly journals A Survey on Blockchain-Based Search Engines

2021 ◽  
Vol 11 (15) ◽  
pp. 7063
Author(s):  
Esmaeel Rezaee ◽  
Ali Mohammad Saghiri ◽  
Agostino Forestiero
Keyword(s):  
Search Engines ◽  
Research Field ◽  
The Internet ◽  
Context Aware ◽  
Search System ◽  
Search Results ◽  
Related Information ◽  
Research Article ◽  
Different Types ◽  
Search History

With the increasing growth of different types of data, search engines have become an essential tool on the Internet. Every day, billions of queries are run through few search engines with several privacy violations and monopoly problems. The blockchain, as a trending technology applied in various fields, including banking, IoT, education, etc., can be a beneficial alternative. Blockchain-based search engines, unlike monopolistic ones, do not have centralized controls. With a blockchain-based search system, no company can lay claims to user’s data or access search history and other related information. All these data will be encrypted and stored on a blockchain. Valuing users’ searches and paying them in return is another advantage of a blockchain-based search engine. Additionally, in smart environments, as a trending research field, blockchain-based search engines can provide context-aware and privacy-preserved search results. According to our research, few efforts have been made to develop blockchain use, which include studies generally in the early stages and few white papers. To the best of our knowledge, no research article has been published in this regard thus far. In this paper, a survey on blockchain-based search engines is provided. Additionally, we state that the blockchain is an essential paradigm for the search ecosystem by describing the advantages.

scholarly journals PRO: Carbapenems should be used for ALL infections caused by ceftriaxone-resistant Enterobacterales

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
David L Paterson ◽  
Burcu Isler ◽  
Patrick N A Harris
Keyword(s):  
Antibiotic Resistance ◽  
Observational Studies ◽  
Randomized Trials ◽  
Antibiotic Resistance Genes ◽  
Definitive Treatment ◽  
In Vitro Activity ◽  
Genes Encoding ◽  
Amoxicillin Clavulanate ◽  
Trial Outcomes

Abstract Ceftriaxone resistance in the Enterobacterales is typically the result of production of ESBLs or AmpC β-lactamases. The genes encoding these enzymes are often co-located with other antibiotic resistance genes leading to resistance to aminoglycosides, quinolones and trimethoprim/sulfamethoxazole. Carbapenems are stable to ESBLs and AmpC giving them reliable in vitro activity against producers of these β-lactamases. In contrast, piperacillin/tazobactam and amoxicillin/clavulanate are compromised by co-production of OXA-1, which is not inhibited by tazobactam or clavulanate. These in vitro findings provide an explanation for the MERINO trial outcomes, where 3.7% (7/191) randomized to meropenem died compared with 12.3% (23/187) randomized to piperacillin/tazobactam as definitive treatment of bloodstream infection due to ceftriaxone-resistant organisms. No randomized trials have yet put cefepime and carbapenems head to head, but some observational studies have shown worse outcomes with cefepime. We argue that carbapenems are the antibiotics of choice for ceftriaxone-resistant Enterobacterales.

Preschoolers' Imaginativeness: Subtypes, Correlates, and Maladaptive Extremes

1985 ◽  
Vol 4 (4) ◽  
pp. 349-364 ◽  
Author(s):  
Roni Beth Tower
Keyword(s):  
Preschool Children ◽  
Child Development ◽  
Healthy Child ◽  
Observational Studies ◽  
Two Dimensions ◽  
Different Types ◽  
Research Questions ◽  
Negative Implication

In a study of forty-three preschool children, ratings of four types of the children's imaginativeness were correlated with observational, behavioral, and interview measures. Research questions were: 1) Do correlates of imaginativeness found in observational studies replicate if trait rather than state measures are examined? 2) Do different types of imaginativeness have different correlates? and 3) What characteristics distinguish children at the maladaptive extremes of imaginativeness from those at more moderate levels? The conceptual and empirical utility of considering imaginativeness to have two dimensions, Expressive and Constructive, was demonstrated. While optimal levels of Constructive Imaginativeness correlated significantly with other indices of healthy child development, the correlations were fewer and tended to be weaker for Expressive Imaginativeness. The negative implication of extremes was documented.

scholarly journals Effects of Polyphenol Intake on Metabolic Syndrome: Current Evidences from Human Trials

2017 ◽  
Vol 2017 ◽  
pp. 1-18 ◽  
Author(s):  
Gemma Chiva-Blanch ◽  
Lina Badimon
Keyword(s):  
Metabolic Syndrome ◽  
Type Ii Diabetes ◽  
Randomized Trials ◽  
Virgin Olive Oil ◽  
Epidemiological Studies ◽  
Current Evidence ◽  
Aromatic Plants ◽  
Polyphenol Intake ◽  
Public Health Strategies

Metabolic syndrome (MetS) is a cluster of cardiovascular risk factors which severely increases the risk of type II diabetes and cardiovascular disease. Several epidemiological studies have observed a negative association between polyphenol intake and MetS rates. Nevertheless, there are relatively small numbers of interventional studies evidencing this association. This review is focused on human interventional trials with polyphenols as polyphenol-rich foods and dietary patterns rich in polyphenols in patients with MetS. Current evidence suggests that polyphenol intake has the potential to alleviate MetS components by decreasing body weight, blood pressure, and blood glucose and by improving lipid metabolism. Therefore, high intake of polyphenol-rich foods such as nuts, fruits, vegetables, seasoning with aromatic plants, spices, and virgin olive oil may be the cornerstone of a healthy diet preventing the development and progression of MetS, although there is no polyphenol or polyphenol-rich food able to influence all MetS features. However, inconsistent results have been found in different trials, and more long-term randomized trials are warranted to develop public health strategies to decrease MetS rates.

scholarly journals Power Quality: Scientific Collaboration Networks and Research Trends

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2067 ◽  
Author(s):  
Francisco Montoya ◽  
Raul Baños ◽  
Alfredo Alcayde ◽  
Maria Montoya ◽  
Francisco Manzano-Agugliaro
Keyword(s):  
Power Quality ◽  
Scientific Collaboration ◽  
Research Field ◽  
Research Trends ◽  
Collaboration Network ◽  
Collaboration Networks ◽  
Different Types ◽  
Voltage Frequency ◽  
Advanced Model ◽  
Proper Operation

Power quality is a research field related to the proper operation of devices and technological equipment in industry, service, and domestic activities. The level of power quality is determined by variations in voltage, frequency, and waveforms with respect to reference values. These variations correspond to different types of disturbances, including power fluctuations, interruptions, and transients. Several studies have been focused on analysing power quality issues. However, there is a lack of studies on the analysis of both the trending topics and the scientific collaboration network underlying the field of power quality. To address these aspects, an advanced model is used to retrieve data from publications related to power quality and analyse this information using a graph visualisation software and statistical tools. The results suggest that research interests are mainly focused on the analysis of power quality problems and mitigation techniques. Furthermore, they are observed important collaboration networks between researchers within and across countries.

Optimal Sample Allocation Under Unequal Costs in Cluster-Randomized Trials

2020 ◽  
Vol 45 (4) ◽  
pp. 446-474
Author(s):  
Zuchao Shen ◽  
Benjamin Kelcey
Keyword(s):  
Optimal Design ◽  
Statistical Power ◽  
Randomized Trials ◽  
Intraclass Correlation ◽  
R Package ◽  
Design Parameters ◽  
Cluster Randomized Trials ◽  
Cost Structures ◽  
Cluster Randomized ◽  
Sample Allocation

Conventional optimal design frameworks consider a narrow range of sampling cost structures that thereby constrict their capacity to identify the most powerful and efficient designs. We relax several constraints of previous optimal design frameworks by allowing for variable sampling costs in cluster-randomized trials. The proposed framework introduces additional design considerations and has the potential to identify designs with more statistical power, even when some parameters are constrained due to immutable practical concerns. The results also suggest that the gains in efficiency introduced through the expanded framework are fairly robust to misspecifications of the expanded cost structure and concomitant design parameters (e.g., intraclass correlation coefficient). The proposed framework is implemented in the R package odr.

scholarly journals The association between rs16917496 T/C polymorphism of SET8 gene and cancer risk in Asian populations: a meta-analysis

2018 ◽  
Vol 38 (6) ◽  
Author(s):  
Hui-Xia Wei ◽  
Guo-Xiang Tian ◽  
Ju-Kun Song ◽  
Lian-Jie Yang ◽  
Yu-Pei Wang
Keyword(s):  
Cancer Risk ◽  
Statistical Power ◽  
Genetic Model ◽  
Meta Analysis ◽  
Critical Role ◽  
Epidemiological Studies ◽  
Asian Populations ◽  
Online Databases ◽  
Cancer Types ◽  
Diversity Control

Epidemiological studies have demonstrated close associations between SET8 rs16917496 T/C polymorphism and cancer risk, but the results of published studies were not consistent. We therefore performed this meta-analysis to explore the associations between rs16917496 T/C polymorphism and cancer risk. Five online databases were searched. Odds ratios (ORs) with a 95% confidence interval (CI) were calculated to assess the association between rs16917496 T/C polymorphism and cancer risk. In addition, heterogeneity, accumulative, sensitivity analysis, and publication bias were conducted to check the statistical power. Overall, 13 publications involving 5878 subjects were identified according to included criteria. No significant cancer risk was observed in genetic model of SET8 rs16917496 T/C polymorphism in Asian populations (C vs. T: OR = 1.04, 95%CI = 0.88–1.23, P = 0.63%; TC vs. TT: OR = 1.17, 95%CI = 0.96–1.24, P = 0.11%; CC vs. TT: OR = 0.90, 95%CI = 0.60–1.37, P = 0.63; TC+CC vs. TT: OR = 1.11, 95%CI = 0.90–1.38, P = 0.33; CC vs. TT+TC: OR = 0.92, 95%CI = 0.65–1.30, P = 0.63). Furthermore, similar associations were found in the subgroup analysis of race diversity, control design, genotyping methods, and different cancer types. In summary, our meta-analysis indicated that the SET8 rs16917496 T/C polymorphism may not play a critical role in cancer development in Asian populations.

scholarly journals Dietary patterns and CVD: a systematic review and meta-analysis of observational studies

2015 ◽  
Vol 114 (9) ◽  
pp. 1341-1359 ◽  
Author(s):  
Míriam Rodríguez-Monforte ◽  
Gemma Flores-Mateo ◽  
Emília Sánchez
Keyword(s):  
Cohort Studies ◽  
Dietary Patterns ◽  
Observational Studies ◽  
Protective Factor ◽  
Meta Analysis ◽  
Epidemiological Studies ◽  
Case Control ◽  
Case Control Studies ◽  
Chd Risk ◽  
Control Comparison

AbstractEpidemiological studies show that diet is linked to the risk of developing CVD. The objective of this meta-analysis was to estimate the association between empirically derived dietary patterns and CVD. PubMed was searched for observational studies of data-driven dietary patterns that reported outcomes of cardiovascular events. The association between dietary patterns and CVD was estimated using a random-effects meta-analysis with 95 % CI. Totally, twenty-two observational studies met the inclusion criteria. The pooled relative risk (RR) for CVD, CHD and stroke in a comparison of the highest to the lowest category of prudent/healthy dietary patterns in cohort studies was 0·69 (95 % CI 0·60, 0·78; I2=0 %), 0·83 (95 % CI 0·75, 0·92; I2=44·6 %) and 0·86 (95 % CI 0·74, 1·01; I2=59·5 %), respectively. The pooled RR of CHD in a case–control comparison of the highest to the lowest category of prudent/healthy dietary patterns was 0·71 (95 % CI 0·63, 0·80; I2=0 %). The pooled RR for CVD, CHD and stroke in a comparison of the highest to the lowest category of western dietary patterns in cohort studies was 1·14 (95 % CI 0·92, 1·42; I2=56·9 %), 1·03 (95 % CI 0·90, 1·17; I2=59·4 %) and 1·05 (95 % CI 0·91, 1·22; I2=27·6 %), respectively; in case–control studies, there was evidence of increased CHD risk. Our results support the evidence of the prudent/healthy pattern as a protective factor for CVD.

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