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Journal of Hazardous Materials Oct 2023Marine mammals, due to their long life span, key position in the food web, and large lipid deposits, often face significant health risks from accumulating contaminants.... (Review)
Review
Marine mammals, due to their long life span, key position in the food web, and large lipid deposits, often face significant health risks from accumulating contaminants. This systematic review examines published literature on pollutant-induced adverse health effects in the International Union for Conservation of Nature (IUCN) red-listed marine mammal species. Thereby, identifying gaps in literature across different extinction risk categories, spatial distribution and climatic zones of studied habitats, commonly used methodologies, researched pollutants, and mechanisms from cellular to population levels. Our findings reveal a lower availability of exposure-effect data for higher extinction risk species (critically endangered 16%, endangered 15%, vulnerable 66%), highlighting the need for more research. For many threatened species in the Southern Hemisphere pollutant-effect relationships are not established. Non-destructively sampled tissues, like blood or skin, are commonly measured for exposure assessment. The most studied pollutants are POPs (31%), metals (30%), and pesticides (17%). Research on mixture toxicity is scarce while pollution-effect studies primarily focus on molecular and cellular levels. Bridging the gap between molecular data and higher-level effects is crucial, with computational approaches offering a high potential through in vitro to in vivo extrapolation using (toxico-)kinetic modelling. This could aid in population-level risk assessment for threatened marine mammals.
Topics: Animals; Endangered Species; Environmental Pollution; Mammals; Ecosystem; Environmental Pollutants
PubMed: 37567134
DOI: 10.1016/j.jhazmat.2023.132203 -
Environmental Evidence 2022Management actions that address local-scale stressors on coral reefs can rapidly improve water quality and reef ecosystem condition. In response to reef managers who... (Review)
Review
BACKGROUND
Management actions that address local-scale stressors on coral reefs can rapidly improve water quality and reef ecosystem condition. In response to reef managers who need actionable thresholds for coastal runoff and dredging, we conducted a systematic review and meta-analysis of experimental studies that explore the effects of sediment on corals. We identified exposure levels that 'adversely' affect corals while accounting for sediment bearing (deposited vs. suspended), coral life-history stage, and species, thus providing empirically based estimates of stressor thresholds on vulnerable coral reefs.
METHODS
We searched online databases and grey literature to obtain a list of potential studies, assess their eligibility, and critically appraise them for validity and risk of bias. Data were extracted from eligible studies and grouped by sediment bearing and coral response to identify thresholds in terms of the lowest exposure levels that induced an adverse physiological and/or lethal effect. Meta-regression estimated the dose-response relationship between exposure level and the magnitude of a coral's response, with random-effects structures to estimate the proportion of variance explained by factors such as study and coral species.
REVIEW FINDINGS
After critical appraisal of over 15,000 records, our systematic review of corals' responses to sediment identified 86 studies to be included in meta-analyses (45 studies for deposited sediment and 42 studies for suspended sediment). The lowest sediment exposure levels that caused adverse effects in corals were well below the levels previously described as 'normal' on reefs: for deposited sediment, adverse effects occurred as low as 1 mg/cm/day for larvae (limited settlement rates) and 4.9 mg/cm/day for adults (tissue mortality); for suspended sediment, adverse effects occurred as low as 10 mg/L for juveniles (reduced growth rates) and 3.2 mg/L for adults (bleaching and tissue mortality). Corals take at least 10 times longer to experience tissue mortality from exposure to suspended sediment than to comparable concentrations of deposited sediment, though physiological changes manifest 10 times faster in response to suspended sediment than to deposited sediment. Threshold estimates derived from continuous response variables (magnitude of adverse effect) largely matched the lowest-observed adverse-effect levels from a summary of studies, or otherwise helped us to identify research gaps that should be addressed to better quantify the dose-response relationship between sediment exposure and coral health.
CONCLUSIONS
We compiled a global dataset that spans three oceans, over 140 coral species, decades of research, and a range of field- and lab-based approaches. Our review and meta-analysis inform the no-observed and lowest-observed adverse-effect levels (NOAEL, LOAEL) that are used in management consultations by U.S. federal agencies. In the absence of more location- or species-specific data to inform decisions, our results provide the best available information to protect vulnerable reef-building corals from sediment stress. Based on gaps and limitations identified by our review, we make recommendations to improve future studies and recommend future synthesis to disentangle the potentially synergistic effects of multiple coral-reef stressors.
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1186/s13750-022-00256-0.
PubMed: 35154667
DOI: 10.1186/s13750-022-00256-0 -
Global Change Biology Sep 2014Eutrophication, coupled with loss of herbivory due to habitat degradation and overharvesting, has increased the frequency and severity of macroalgal blooms worldwide.... (Meta-Analysis)
Meta-Analysis Review
Eutrophication, coupled with loss of herbivory due to habitat degradation and overharvesting, has increased the frequency and severity of macroalgal blooms worldwide. Macroalgal blooms interfere with human activities in coastal areas, and sometimes necessitate costly algal removal programmes. They also have many detrimental effects on marine and estuarine ecosystems, including induction of hypoxia, release of toxic hydrogen sulphide into the sediments and atmosphere, and the loss of ecologically and economically important species. However, macroalgal blooms can also increase habitat complexity, provide organisms with food and shelter, and reduce other problems associated with eutrophication. These contrasting effects make their overall ecological impacts unclear. We conducted a systematic review and meta-analysis to estimate the overall effects of macroalgal blooms on several key measures of ecosystem structure and functioning in marine ecosystems. We also evaluated some of the ecological and methodological factors that might explain the highly variable effects observed in different studies. Averaged across all studies, macroalgal blooms had negative effects on the abundance and species richness of marine organisms, but blooms by different algal taxa had different consequences, ranging from strong negative to strong positive effects. Blooms' effects on species richness also depended on the habitat where they occurred, with the strongest negative effects seen in sandy or muddy subtidal habitats and in the rocky intertidal. Invertebrate communities also appeared to be particularly sensitive to blooms, suffering reductions in their abundance, species richness, and diversity. The total net primary productivity, gross primary productivity, and respiration of benthic ecosystems were higher during macroalgal blooms, but blooms had negative effects on the productivity and respiration of other organisms. These results suggest that, in addition to their direct social and economic costs, macroalgal blooms have ecological effects that may alter their capacity to deliver important ecosystem services.
Topics: Animals; Biodiversity; Biota; Ecosystem; Eutrophication; Harmful Algal Bloom; Invertebrates; Marine Biology; Oceans and Seas; Phototrophic Processes; Population Dynamics; Species Specificity
PubMed: 24890042
DOI: 10.1111/gcb.12644 -
Toxics May 2023Nano- and microplastic fragments (NMPs) exist ubiquitously in all environmental compartments. The literature-based evidence suggests that NMPs interact with other... (Review)
Review
Nano- and microplastic fragments (NMPs) exist ubiquitously in all environmental compartments. The literature-based evidence suggests that NMPs interact with other environmental contaminants in freshwater ecosystems through sorption mechanisms, thereby playing a vector role. Chemically bound NMPs can translocate throughout the environment, reaching long distances from the contaminant discharge site. In addition, they can be ab/adsorbed by freshwater organisms. Although many studies show that NMPs can increase toxicity towards freshwater biota through the carrier role, little is known regarding their potential to influence the bioaccumulation of environmental contaminants (EC) in freshwater species. This review is part II of a systematic literature review regarding the influence of NMPs on bioaccumulation. Part I deals with terrestrial organisms and part II is devoted to freshwater organisms. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA ScR) was used for the literature search and selection. Only studies that assessed the bioaccumulation of EC in the presence of NMPs and compared this with the bioaccumulation of the isolated EC were considered. Here, we discuss the outcome of 46 papers, considering NMPs that induced an increase, induced a decrease, or caused no effect on bioaccumulation. Lastly, knowledge gaps are identified, and future directives for this area of research are discussed.
PubMed: 37368574
DOI: 10.3390/toxics11060474 -
PloS One 2015Managing the pathways by which non-native species are introduced and spread is considered the most effective way of preventing species invasions. Tourism and outdoor... (Meta-Analysis)
Meta-Analysis Review
Managing the pathways by which non-native species are introduced and spread is considered the most effective way of preventing species invasions. Tourism and outdoor recreation involve the frequent congregation of people, vehicles and vessels from geographically diverse areas. They are therefore perceived to be major pathways for the movement of non-native species, and ones that will become increasingly important with the continued growth of these sectors. However, a global assessment of the relationship between tourism activities and the introduction of non-native species-particularly in freshwater and marine environments-is lacking. We conducted a systematic review and meta-analysis to determine the impact of tourism and outdoor recreation on non-native species in terrestrial, marine and freshwater environments. Our results provide quantitative evidence that the abundance and richness of non-native species are significantly higher in sites where tourist activities take place than in control sites. The pattern was consistent across terrestrial, freshwater and marine environments; across a variety of vectors (e.g. horses, hikers, yachts); and across a range of taxonomic groups. These results highlight the need for widespread biosecurity interventions to prevent the inadvertent introduction of invasive non-native species (INNS) as the tourism and outdoor recreation sectors grow.
Topics: Animals; Biodiversity; Conservation of Natural Resources; Ecosystem; Humans; Introduced Species; Movement; Recreation; Travel
PubMed: 26485300
DOI: 10.1371/journal.pone.0140833 -
The Lancet. Planetary Health Aug 2022As sustainable development practitioners have worked to "ensure healthy lives and promote well-being for all" and "conserve life on land and below water", what progress... (Review)
Review
As sustainable development practitioners have worked to "ensure healthy lives and promote well-being for all" and "conserve life on land and below water", what progress has been made with win-win interventions that reduce human infectious disease burdens while advancing conservation goals? Using a systematic literature review, we identified 46 proposed solutions, which we then investigated individually using targeted literature reviews. The proposed solutions addressed diverse conservation threats and human infectious diseases, and thus, the proposed interventions varied in scale, costs, and impacts. Some potential solutions had medium-quality to high-quality evidence for previous success in achieving proposed impacts in one or both sectors. However, there were notable evidence gaps within and among solutions, highlighting opportunities for further research and adaptive implementation. Stakeholders seeking win-win interventions can explore this Review and an online database to find and tailor a relevant solution or brainstorm new solutions.
Topics: Communicable Disease Control; Humans; Sustainable Development
PubMed: 35932789
DOI: 10.1016/S2542-5196(22)00148-6 -
International Journal of Reproductive... Oct 2023Polycystic ovary syndrome (PCOS) is a prevalent endocrine disorder in females. Nesfatin-1 is a neuropeptide synthesized in the hypothalamus and other peripheral organs,... (Review)
Review
BACKGROUND
Polycystic ovary syndrome (PCOS) is a prevalent endocrine disorder in females. Nesfatin-1 is a neuropeptide synthesized in the hypothalamus and other peripheral organs, and there are conflicting opinions about its correlation with PCOS.
OBJECTIVE
This study aims to investigate the correlation between nesfatin-1 and PCOS and evaluates the effectiveness of nesfatin-1 as a biomarker for the detection of PCOS in women.
MATERIALS AND METHODS
A systematic review and meta-analysis were conducted to identify pertinent articles from databases such as PubMed, Web of Science, Cochrane, EMBASE, Scopus, and Google Scholar. The standardized mean difference (SMD) and 95% confidence interval (CI) were calculated using a random effects model to compare group outcomes. Additionally, meta-regression and subgroup analysis were performed to elucidate sources of heterogeneity.
RESULTS
The meta-analysis involved 12 studies with 1222 participants, and the findings revealed a significant relationship between PCOS and nesfatin-1 levels. The pooled (SMD = 0.54; 95% CI: 0.00-1.07; p = 0.04) indicated a significant difference between the evaluated groups. Moreover, a subgroup analysis showed that there was a substantial difference in nesfatin-1 levels among women with PCOS and higher homeostatic model assessment for insulin resistance ratio (SMD = 1.46; 95% CI: 0.92-2.00; p 0.001).
CONCLUSION
Our meta-analysis indicates an association between high nesfatin-1 levels and PCOS. This suggests a potential role of nesfatin-1 in the development of PCOS and proposes it as a potential diagnostic biomarker for the disease. However, further research is necessary to validate these findings.
PubMed: 38077942
DOI: 10.18502/ijrm.v21i10.14533 -
International Journal of Cancer Aug 2024The role of diet in colorectal cancer prognosis is not well understood and specific lifestyle recommendations are lacking. We searched for randomised controlled trials... (Meta-Analysis)
Meta-Analysis
Post-diagnosis dietary factors, supplement use and colorectal cancer prognosis: A Global Cancer Update Programme (CUP Global) systematic literature review and meta-analysis.
The role of diet in colorectal cancer prognosis is not well understood and specific lifestyle recommendations are lacking. We searched for randomised controlled trials (RCTs) and longitudinal observational studies on post-diagnosis dietary factors, supplement use and colorectal cancer survival outcomes in PubMed and Embase from inception until 28th February 2022. Random-effects dose-response meta-analyses were conducted when at least three studies had sufficient information. The evidence was interpreted and graded by the CUP Global independent Expert Committee on Cancer Survivorship and Expert Panel. Five RCTs and 35 observational studies were included (30,242 cases, over 8700 all-cause and 2100 colorectal cancer deaths, 3700 progression, recurrence, or disease-free events). Meta-analyses, including 3-10 observational studies each, were conducted for: whole grains, nuts/peanuts, red and processed meat, dairy products, sugary drinks, artificially sweetened beverages, coffee, alcohol, dietary glycaemic load/index, insulin load/index, marine omega-3 polyunsaturated fatty acids, supplemental calcium, circulating 25-hydroxyvitamin D (25[OH]D) and all-cause mortality; for alcohol, supplemental calcium, circulating 25(OH)D and colorectal cancer-specific mortality; and for circulating 25(OH)D and recurrence/disease-free survival. The overall evidence was graded as 'limited'. The inverse associations between healthy dietary and/or lifestyle patterns (including diets that comprised plant-based foods), whole grains, total, caffeinated, or decaffeinated coffee and all-cause mortality and the positive associations between unhealthy dietary patterns, sugary drinks and all-cause mortality provided 'limited-suggestive' evidence. All other exposure-outcome associations provided 'limited-no conclusion' evidence. Additional, well-conducted cohort studies and carefully designed RCTs are needed to develop specific lifestyle recommendations for colorectal cancer survivors.
Topics: Humans; Colorectal Neoplasms; Dietary Supplements; Prognosis; Diet; Vitamin D; Randomized Controlled Trials as Topic; Observational Studies as Topic
PubMed: 38692645
DOI: 10.1002/ijc.34906 -
The Lancet. Planetary Health Jul 2020Agrochemical pollution of surface waters is a growing global environmental challenge, especially in areas where agriculture is rapidly expanding and intensifying.... (Review)
Review
BACKGROUND
Agrochemical pollution of surface waters is a growing global environmental challenge, especially in areas where agriculture is rapidly expanding and intensifying. Agrochemicals might affect schistosomiasis transmission through direct and indirect effects on Schistosoma parasites, their intermediate snail hosts, snail predators, and snail algal resources. We aimed to review and summarise the effects of these agrochemicals on schistosomiasis transmission dynamics.
METHODS
We did a systematic review of agrochemical effects on the lifecycle of Schistosoma spp and fitted dose-response models to data regarding the association between components of the lifecycle and agrochemical concentrations. We incorporated these dose-response functions and environmentally relevant concentrations of agrochemicals into a mathematical model to estimate agrochemical effects on schistosomiasis transmission. Dose-response functions were used to estimate individual agrochemical effects on estimates of the agrochemically influenced basic reproduction number, R, for Schistosoma haematobium. We incorporated time series of environmentally relevant agrochemical concentrations into the model and simulated mass drug administration control efforts in the presence of agrochemicals.
FINDINGS
We derived 120 dose-response functions describing the effects of agrochemicals on schistosome lifecycle components. The median estimate of the basic reproduction number under agrochemical-free conditions, was 1·65 (IQR 1·47-1·79). Agrochemical effects on estimates of R for S haematobium ranged from a median three-times increase (R 5·05, IQR 4·06-5·97) to transmission elimination (R 0). Simulations of transmission dynamics subject to interacting annual mass drug administration and agrochemical pollution yielded a median estimate of 64·82 disability-adjusted life-years (DALYs) lost per 100 000 people per year (IQR 62·52-67·68) attributable to atrazine use. In areas where aquatic arthropod predators of intermediate host snails suppress transmission, the insecticides chlorpyrifos (6·82 DALYs lost per 100 000 people per year, IQR 4·13-8·69) and profenofos (103·06 DALYs lost per 100 000 people per year, IQR 89·63-104·90) might also increase the disability burden through their toxic effects on arthropods.
INTERPRETATION
Expected environmental concentrations of agrochemicals alter schistosomiasis transmission through direct and indirect effects on intermediate host and parasite densities. As industrial agricultural practices expand in areas where schistosomiasis is endemic, strategies to prevent increases in transmission due to agrochemical pollution should be developed and pursued.
FUNDING
National Science Foundation, National Institutes of Health.
Topics: Agrochemicals; Animals; Environmental Pollutants; Environmental Pollution; Food Chain; Host-Parasite Interactions; Humans; Schistosoma; Schistosomiasis
PubMed: 32681899
DOI: 10.1016/S2542-5196(20)30105-4 -
Frontiers in Systems Neuroscience 2021It is only in recent decades that subjective experience - or consciousness - has become a legitimate object of scientific inquiry. As such, it represents perhaps the...
It is only in recent decades that subjective experience - or consciousness - has become a legitimate object of scientific inquiry. As such, it represents perhaps the greatest challenge facing neuroscience today. Subsumed within this challenge is the study of subjective experience in non-human animals: a particularly difficult endeavor that becomes even more so, as one crosses the great evolutionary divide between vertebrate and invertebrate phyla. Here, we explore the possibility of consciousness in one group of invertebrates: cephalopod molluscs. We believe such a review is timely, particularly considering cephalopods' impressive learning and memory abilities, rich behavioral repertoire, and the relative complexity of their nervous systems and sensory capabilities. Indeed, in some cephalopods, these abilities are so sophisticated that they are comparable to those of some higher vertebrates. Following the criteria and framework outlined for the identification of hallmarks of consciousness in non-mammalian species, here we propose that cephalopods - particularly the octopus - provide a unique test case among invertebrates for examining the properties and conditions that, at the very least, afford a basal faculty of consciousness. These include, among others: (i) discriminatory and anticipatory behaviors indicating a strong link between perception and memory recall; (ii) the presence of neural substrates representing functional analogs of thalamus and cortex; (iii) the neurophysiological dynamics resembling the functional signatures of conscious states in mammals. We highlight the current lack of evidence as well as potentially informative areas that warrant further investigation to support the view expressed here. Finally, we identify future research directions for the study of consciousness in these tantalizing animals.
PubMed: 35495582
DOI: 10.3389/fnsys.2021.787139