scholarly journals Density-dependence can be revealed by modelling the variance in the stock–recruitment process: an application to flatfish

2014 ◽  
Vol 71 (8) ◽  
pp. 2127-2140 ◽  
Author(s):  
B. Archambault ◽  
O. Le Pape ◽  
N. Bousquet ◽  
E. Rivot
Keyword(s):  
Density Dependence ◽  
Meta Analysis ◽  
Marine Species ◽  
Recruitment Rate ◽  
High Concentration ◽  
Recruitment Process ◽  
Residual Variability ◽  
Nursery Habitats ◽  
Almost All ◽  
Spawning Biomass

Abstract Recruitment success in marine species is mostly driven by the high and variable mortality of first life stages, and the relationships between stock and recruitment are then largely dominated by residual variability. We show that analysing the residual variability may provide insights on the density-dependence process occurring during the recruitment. Following the seminal formulation of Minto et al. (Survival variability and population density in fish populations. Nature, 2008), we show that when recruitment is considered as a sequence of a pelagic stage with stochastic density-independent mortality followed by a second stage with stochastic density-dependent mortality, then the variability of the recruitment rate per spawning biomass (RPSB) should be a decreasing function of the spawning biomass. Using stock–recruit data of 148 stocks from the RAM legacy database, we provide a test of this hypothesis by showing that the variability of RPSB is lower for fish species with the higher concentration during juvenile stages. Second, a hierarchical Bayesian model (HBM) is built to derive a meta-analysis of stock–recruit data for 39 flatfish stocks, characterized by a high concentration of juveniles in coastal nursery habitats. Results of the HBM show that the variance of the RPSB decreases with the spawning biomass for almost all stocks, thus providing strong evidence of density-dependence during the recruitment process. Finally, we attempt to relate patterns in recruitment variance to relevant life-history traits of flatfish species.

Effect of Silver Content on the Crystalline Phase and Microstructure of TiO2 Coating Deposited on Unglazed Ceramics Tile

2020 ◽  
Vol 17 (3) ◽  
pp. 8179-8185
Author(s):  
N.Z. Hafizah ◽  
J. M. Juoi ◽  
M.R. Zulkifli ◽  
M.A. Musa
Keyword(s):  
Particle Growth ◽  
Dip Coating ◽  
Tio2 Coating ◽  
High Concentration ◽  
Ceramic Tiles ◽  
Soaking Time ◽  
Heat Treated ◽  
Ag Particles ◽  
Tio2 Sol ◽  
Almost All

The synthesis of Ag-TiO2 coating using AgNO3 precursor is expected to give the properties as pure as Ag nanoparticles. Commonly, high concentration of Ag attributed to agglomeration of silver species and reduction to Ag0 particles on TiO2 surface. In contrast, at lower concentration, Ag species exist as AgO, Ag2O and Ag0. Hence, the exact amount of Ag, which can effectively control the particle growth and agglomeration, surface area, thermal stability and band gap of the TiO2 coating, are still vague and stated differently. In the present study, the effect of Ag content on the phase transformation and surface morphology of Ag-TiO2 coating were reported. TiO2 sol were prepared by incorporating Ag at 2.5, 5 and 7.5 mol % and deposited on unglazed ceramic tiles thru five times dip coating. The deposited Ag-TiO2 coatings were heat treated at 500 °C for 1 hour soaking time. XRD analyses revealed that the deposited Ag-TiO2 coating consists of anatase, rutile, Ag2O and metallic Ag. Almost all the coating surfaces illustrated cracks. Increased Ag content lead to presence of tiny particles on the surfaces and EDX spectrum revealed the presence of Ti, O and metallic Ag particles. However, at the addition of 5 mol % Ag, there was no metallic Ag presence and a dense coating with the lowest thickness of ±11.4µm is observed.

Does coffee, tea and caffeine consumption reduce the risk of incident breast cancer? A systematic review and network meta-analysis

2021 ◽  
pp. 1-13
Author(s):  
Shu Wang ◽  
Xiang Li ◽  
Yue Yang ◽  
Jingping Xie ◽  
Mingyue Liu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Systematic Review ◽  
Postmenopausal Women ◽  
Meta Analysis ◽  
High Dose ◽  
Dependent Manner ◽  
Tea Consumption ◽  
Case Control Studies ◽  
High Concentration ◽  
Coffee Intake

Abstract Objective: We aimed to evaluate the association between coffee and/or tea consumption and breast cancer (BC) risk among premenopausal and postmenopausal women and to conduct a network meta-analysis. Design: Systematic review and network meta-analysis. Setting: We conducted a systematic review of electronic publications in the last 30 years to identify case–control studies or prospective cohort studies that evaluated the effects of coffee and tea intake. Results: Forty-five studies that included more than 3 323 288 participants were eligible for analysis. Network meta-analysis was performed to determine the effects of coffee and/or tea consumption on reducing BC risk in a dose-dependent manner and differences in coffee/tea type, menopause status, hormone receptor and the BMI in subgroup and meta-regression analyses. According to the first pairwise meta-analysis, low-dose coffee intake and high-dose tea intake may exhibit efficacy in preventing ER(estrogen receptor)− BC, particularly in postmenopausal women. Then, we performed another pairwise and network meta-analysis and determined that the recommended daily doses were 2–3 cups/d of coffee or ≥5 cups/d of tea, which contained a high concentration of caffeine, particularly in postmenopausal women. Conclusions: Coffee and tea consumption is not associated with a reduction in the overall BC risk in postmenopausal women and is associated with a potentially lower risk of ER− BC. And the highest recommended dose is 2–3 cups of coffee/d or ≥5 cups of tea/d. They are potentially useful dietary protectants for preventing BC.

scholarly journals A living WHO guideline on drugs to prevent covid-19

BMJ ◽  
2021 ◽  
pp. n526
Author(s):  
François Lamontagne ◽  
Thomas Agoritsas ◽  
Reed Siemieniuk ◽  
Bram Rochwerg ◽  
Jessica Bartoszko ◽  
...  
Keyword(s):  
Systematic Review ◽  
Guideline Development ◽  
Meta Analysis ◽  
World Health ◽  
Policy And Practice ◽  
Assessment Development ◽  
Research Priority ◽  
Health Organization ◽  
Almost All ◽  
Drug Interventions

Abstract Clinical question What is the role of drugs in preventing covid-19? Why does this matter? There is widespread interest in whether drug interventions can be used for the prevention of covid-19, but there is uncertainty about which drugs, if any, are effective. The first version of this living guideline focuses on the evidence for hydroxychloroquine. Subsequent updates will cover other drugs being investigated for their role in the prevention of covid-19. Recommendation The guideline development panel made a strong recommendation against the use of hydroxychloroquine for individuals who do not have covid-19 (high certainty). How this guideline was created This living guideline is from the World Health Organization (WHO) and provides up to date covid-19 guidance to inform policy and practice worldwide. Magic Evidence Ecosystem Foundation (MAGIC) provided methodological support. A living systematic review with network analysis informed the recommendations. An international guideline development panel of content experts, clinicians, patients, an ethicist and methodologists produced recommendations following standards for trustworthy guideline development using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Understanding the new recommendation The linked systematic review and network meta-analysis (6 trials and 6059 participants) found that hydroxychloroquine had a small or no effect on mortality and admission to hospital (high certainty evidence). There was a small or no effect on laboratory confirmed SARS-CoV-2 infection (moderate certainty evidence) but probably increased adverse events leading to discontinuation (moderate certainty evidence). The panel judged that almost all people would not consider this drug worthwhile. In addition, the panel decided that contextual factors such as resources, feasibility, acceptability, and equity for countries and healthcare systems were unlikely to alter the recommendation. The panel considers that this drug is no longer a research priority and that resources should rather be oriented to evaluate other more promising drugs to prevent covid-19. Updates This is a living guideline. New recommendations will be published in this article and signposted by update notices to this guideline. Readers note This is the first version of the living guideline for drugs to prevent covid-19. It complements the WHO living guideline on drugs to treat covid-19. When citing this article, please consider adding the update number and date of access for clarity.

scholarly journals Heterogeneous Photo-Fenton Catalytic Degradation of Practical Pharmaceutical Wastewater by Modified Attapulgite Supported Multi-Metal Oxides

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 156
Author(s):  
Manjing Lu ◽  
Jiaqi Wang ◽  
Yuzhong Wang ◽  
Zhengguang He
Keyword(s):  
Photocatalytic Oxidation ◽  
Removal Rate ◽  
Catalytic Degradation ◽  
Gas Chromatography Mass Spectrometry ◽  
Pharmaceutical Wastewater ◽  
High Concentration ◽  
Modified Attapulgite ◽  
Cod Removal Rate ◽  
Pre Treatment ◽  
Almost All

Chemical synthetic pharmaceutical wastewater has characteristics of high concentration, high toxicity and poor biodegradability, so it is difficult to directly biodegrade. We used acid modified attapulgite (ATP) supported Fe-Mn-Cu polymetallic oxide as catalyst for multi-phase Fenton-like ultraviolet photocatalytic oxidation (photo-Fenton) treatment with actual chemical synthetic pharmaceutical wastewater as the treatment object. The results showed that at the initial pH of 2.0, light distance of 20 cm, and catalyst dosage and hydrogen peroxide concentration of 10.0 g/L and 0.5 mol/L respectively, the COD removal rate of wastewater reached 65% and BOD5/COD increased to 0.387 when the reaction lasted for 180 min. The results of gas chromatography-mass spectrometry (GC-MS) indicated that Fenton-like reaction with Fe-Mn-Cu@ATP had good catalytic potential and significant synergistic effect, and could remove almost all heterocycle compounds well. 3D-EEM (3D electron microscope) fluorescence spectra showed that the fluorescence intensity decreased significantly during catalytic degradation, and the UV humus-like and fulvic acid were effectively removed. The degradation efficiency of the nanocomposite only decreased by 5.8% after repeated use for 6 cycles. It seems appropriate to use this process as a pre-treatment for actual pharmaceutical wastewater to facilitate further biological treatment.

Heparin locks with low and high concentration in haemodialysis patients: A systematic review and meta‐analysis

2020 ◽  
Author(s):  
Jiajia Tan ◽  
Tingting Ning ◽  
Wenting Zhang ◽  
Zhuru Qian ◽  
Xuqin Jiang ◽  
...  
Keyword(s):  
Systematic Review ◽  
Meta Analysis ◽  
High Concentration

Statistical and measurement pitfalls in the use of meta-regression in meta-analysis

2017 ◽  
Vol 22 (5) ◽  
pp. 469-476 ◽  
Author(s):  
Frank L. Schmidt
Keyword(s):  
Social Sciences ◽  
Organizational Behavior ◽  
Meta Analysis ◽  
Social Science Research ◽  
Science Research ◽  
Content Type ◽  
Marketing Social ◽  
Meta Regression ◽  
Meta Analyses ◽  
Almost All

Purpose Meta-regression is widely used and misused today in meta-analyses in psychology, organizational behavior, marketing, management, and other social sciences, as an approach to the identification and calibration of moderators, with most users being unaware of serious problems in its use. The purpose of this paper is to describe nine serious methodological problems that plague applications of meta-regression. Design/methodology/approach This paper is methodological in nature and is based on well-established principles of measurement and statistics. These principles are used to illuminate the potential pitfalls in typical applications of meta-regression. Findings The analysis in this paper demonstrates that many of the nine statistical and measurement pitfalls in the use of meta-regression are nearly universal in applications in the literature, leading to the conclusion that few meta-regressions in the literature today are trustworthy. A second conclusion is that in almost all cases, hierarchical subgrouping of studies is superior to meta-regression as a method of identifying and calibrating moderators. Finally, a third conclusion is that, contrary to popular belief among researchers, the process of accurately identifying and calibrating moderators, even with the best available methods, is complex, difficult, and data demanding. Practical implications This paper provides useful guidance to meta-analytic researchers that will improve the practice of moderator identification and calibration in social science research literatures. Social implications Today, many important decisions are made on the basis of the results of meta-analyses. These include decisions in medicine, pharmacology, applied psychology, management, marketing, social policy, and other social sciences. The guidance provided in this paper will improve the quality of such decisions by improving the accuracy and trustworthiness of meta-analytic results. Originality/value This paper is original and valuable in that there is no similar listing and discussion of the pitfalls in the use of meta-regression in the literature, and there is currently a widespread lack of knowledge of these problems among meta-analytic researchers in all disciplines.

scholarly journals Investigation of moderator factors in e-business adoption: A quantitative meta-analysis of moderating effects on the drivers of intention and behavior

2017 ◽  
Vol 14 (1) ◽  
pp. 75-102 ◽  
Author(s):  
Bostjan Sumak ◽  
Marjan Hericko ◽  
Zoran Budimac ◽  
Maja Pusnik
Keyword(s):  
Technology Acceptance ◽  
New Technologies ◽  
Causal Effect ◽  
Meta Analysis ◽  
Moderating Effect ◽  
Factors Affecting ◽  
Adoption Research ◽  
Acceptance Model ◽  
Almost All ◽  
Business Technology

E-business technology is becoming one of the most important global markets where e-business solutions will have to adapt to new technologies. The main objective in this study was to synthesize existing knowledge in the field of e-business technology acceptance and to understand differences in Technology Acceptance Model (TAM) related causal effect sizes for different e-business contexts. A quantitative meta-analysis of existing empirical research about factors affecting e-business adoption was conducted using 89 published papers that provided empirical data about causal relationships. A moderator analysis was carried out to investigate the moderating effect of four factors: consumer type, device type, continent and respondent type. The results of the study showed a moderating effect for all four proposed factors in almost all TAM-related causal paths. The study also showed that TAM is the most common theory being applied in e-business adoption research.

scholarly journals MULTI-CHANNEL FRY COUNTER DESIGN USING OPTOCOUPLER SENSOR

2019 ◽  
Vol 4 (2) ◽  
pp. 97-104
Author(s):  
Lazuardi Umar ◽  
Yanuar Hamzah ◽  
Rahmondia N. Setiadi
Keyword(s):  
Counting Process ◽  
Production Capacity ◽  
High Accuracy ◽  
Limited Capacity ◽  
High Concentration ◽  
Counting System ◽  
Channel Detection ◽  
Accuracy Level ◽  
High Level ◽  
Almost All

This paper describes a design of a fry counter intended to be used by consuming fish farmer. Along this time, almost all the fry counting process is counted by manual, which is done by a human. It is requiring much energy and needs high concentration; thus, can cause a high level of exhaustion for the fry counting worker. Besides that, the human capability and capacity of counting are limited to a low level. A fry counter design in this study utilizes a multi-channel optocoupler sensor to increase the counting capacity. The multi-channel fry counter counting system is developed as a solution to a limited capacity of available fry counter. This design uses an input signal extender system on controller including the interrupt system. From the experiment, high accuracy level is obtained on the counting and channel detection, therefore, this design can be implemented and could help farmers to increase the production capacity of consuming fish.

scholarly journals Cerebrospinal Fluid IgM and Oligoclonal IgG Bands in Multiple Sclerosis: A Meta-Analysis of Prevalence and Prognosis

2021 ◽  
Vol 11 (11) ◽  
pp. 1444
Author(s):  
Mattia Fonderico ◽  
Emilio Portaccio ◽  
Lorenzo Razzolini ◽  
Luisa Pastò ◽  
Angelo Bellinvia ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Systematic Review ◽  
Clinical Course ◽  
Meta Analysis ◽  
Clinically Isolated Syndrome ◽  
Relapsing Remitting ◽  
Oligoclonal Igg ◽  
Almost All ◽  
Present Systematic Review ◽  
Oligoclonal Igg Bands

The presence of intrathecal IgM synthesis (ITMS) has been associated with an aggressive multiple sclerosis (MS) clinical course. In the present systematic review, we aimed at assessing the prevalence of ITMS among different MS phenotypes. Moreover, we aimed at quantifying the risk of a second relapse in ITMS positive and oligoclonal IgG bands (OCGBs)-positive patients. We selected clinical studies reporting the ITMS prevalence assessed as oligoclonal IgM Bands (OCMBs), lipid-specific OCMBs (LS-OCMBs), and/or as an intrathecal IgM production > 0% (IgMLoc, Reiber formula). The overall prevalence of ITMS was higher in relapsing-remitting (RR) than clinically isolated syndrome (CIS) patients (40.1% versus 23.8%, p < 0.00001), while was in line with that detected in primary progressive MS (PPMS, 26.7%). Almost all patients (98%) with ITMS had also OCGBs. The risk of having a second relapse was higher in OCGBs positive patients (HR = 2.18, p = 0.007) but much higher in ITMS positive patients (HR = 3.62, p = 0.0005). This study revealed that the prevalence of ITMS is higher in RRMS patients. It suggests that the risk of having a second relapse, previously ascribed to OCGBs, may, to a certain extent, be related to the presence of intrathecal IgM.

Aggressions of the Socio-Economic System on the Natural Capital

2017 ◽  
pp. 109-140
Author(s):  
Constanţa Popescu ◽  
Constantin Popescu ◽  
Maria Luiza Hrestic
Keyword(s):  
Global Warming ◽  
Adverse Effects ◽  
Economic System ◽  
Acid Rain ◽  
Natural Environment ◽  
Natural Capital ◽  
Marine Species ◽  
Vertebrate Species ◽  
New Beginning ◽  
Almost All

Nearly 250 million years ago, the Earth was shaken by the amplest extinction known so far, which led to the extinction of up to 96% of all the marine species, 70% of the vertebrate species, and almost all the insects. This extinction affected the whole range of biodiversity so much. Nature took almost 10 million years to recover after this event. Life was really in danger on our planet at that moment, due to the dismal conditions that were created, and the current research shows that these dire conditions continued to occur, in the natural environment, after that, triggering numerous outbreaks that occurred for five to six million years following the initial crisis, triggered by the carbon rise and the repeated shortages of oxygen, the increased warming and other such adverse effects, which, once initiated, were uncontrollable and had disastrous effects. When life returned to normal and, gradually, after several million years, a new beginning was possible, the significant elements that caused the disaster - global warming, acid rain - sound strangely familiar to us today.

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