Microplastics (MPs) are emerging contaminants of freshwater ecosystems. Once in aquatic systems, most of these plastic particles undergo processes of fragmentation, biofouling, and sedimentation, ...resulting in increased concentrations of smaller sized and irregularly-shaped particles in the sediment. High levels of MPs in freshwater sediments can denote a potential threat to benthic and sediment-dwelling organisms such as dipteran larvae. This study evaluates the ecotoxicological effect of three pools of irregularly-shaped polyethylene (PE) microplastics (pools containing 90% of the particles within 32–63 μm (size-class A), 63–250 μm (size-class B) and 125–500 μm (size-class C)), with concentrations ranging from 1.25 to 20 g Kg−1 sediment, on the dipteran Chironomus riparius life-history traits. After ten days of exposure, larvae ingested PE particles typically in the 32–63 μm range, even when 90% of the particles possessed higher size (i.e., in size-classes B and C) and the larvae mandible allowed the ingestion of such bigger-sized particles. Thus, the number of ingested particles was higher in size-class A, followed by B and C, and led to a significant reduction with similar magnitude on larval growth (Lowest Observed Effect Concentrations (LOEC) = 2.5 g Kg−1 sediment DW) and a significant delay on imagoes emergence (e.g., LOEC = 1.5 g Kg−1 sediment DW for females).
The results from this study show that the ingestion and persistence of small-sized polyethylene microplastics caused significant impairments on life-history traits of C. riparius. Considering their role on freshwater food-webs and the potential persistence of small-sized PE particles in their larval gut, these results also point for the potential adverse effects of small-sized microplastics at the community and ecosystem level.
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•Chironomus riparius larvae ingested polyethylene (PE) particles.•Polyethylene particles in the larval gut were mainly in the range of 32–63 μm.•Effects of PE particles on C. riparius growth and emergence were dose-dependent.•Emergence was the most sensitive endpoint for female imagoes.
Systems developed to work with computational intelligence have become very efficient, and in some cases obtain more accurate results than evaluations by humans. Hence, this work proposes a new online ...approach based on deep learning tools according to the concept of transfer learning to generate a computational intelligence framework for use with the Internet of Health Things (IoHT) devices. This framework allows the user to add their images and perform platform training almost as easily as creating folders and placing files in regular cloud storage services. The trials carried out with the tool showed that even people with no programming and image processing knowledge were able to set up projects in a few minutes. The proposed approach is validated using three medical databases, which include cerebral vascular accident images for stroke type classification, lung nodule images for malignant classification, and skin images for the classification of melanocytic lesions. The results show the efficiency and reliability of the framework, which reached 91.6% Accuracy in the stroke images and lung nodules databases, and 92% Accuracy in the skin images databases. This prove the immense contribution that this work can bring to assist medical professionals in analyzing complex examinations quickly and accurately, allowing a large medical examination database through a consolidated collaborative IoT platform.
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•Chironomus riparius larvae ingested PE-MPs from contaminated sediment.•Highest accumulation of PE-MPs in larvae guts was within the size range of 32-63 μm.•Depletion of lipid content ...was observed in larvae exposed to PE-MPs.•Ingested PE-MPs induced oxidative damage and reduced the aerobic energy production.
Riverine sediments are major sinks of microplastics from inland anthropogenic activities, imposing a threat to freshwater benthic invertebrates. This study investigated the ingestion of three size-classes (SC) of irregularly shaped polyethylene microplastics (PE-MPs; SC I: 32−63 μm; II: 63−250 μm; III: 125−500 μm) after 48 h by dipteran larvae (detritivore/collector) Chironomus riparius, and the consequent effects on neurotransmission, energy allocation and oxidative stress. The tested PE-MPs concentrations (1.25; 5; 20 g kg−1) were within the range of concentrations reported in riverbanks from highly urbanised areas (1 - 9 g kg−1), except for 20 g kg−1 representing the worst-case scenario. After exposure to SC I, larvae presented high amounts (up to ∼2400 particles/organism) of PE-MPs in their guts, with an average size-range of 30−60 μm. In the SC II and III, larvae presented PE-MPs of higher diameter (up to 125 μm) and a visible gut obstruction. The high number of particles in the larval gut (SC I) and/or difficulties for their egestion (SC I, II and III) induced oxidative damage and reduced aerobic energy production. In addition, larvae exposed to SC II and III revealed depletion in their total lipid reserves as a consequence of lacking nutrients, and the ones exposed to SC III presented a decrease in their detoxification capacity.
These results highlight that freshwater detritivores with low selective feeding behaviour (e.g., chironomids) are more prone to ingest microplastics, with potentially adverse effects on cellular metabolism, redox status and antioxidant-detoxification defences. These harmful effects at lower levels of the biological organisation may ultimately affect organisms’ physiology and fitness.
The activation of insects’ immune system due to the ingestion of microplastics (MPs) has only been evidenced by the upregulation of specific genes. The activation of phenoloxidase (PO) system is one ...of the primary responses involved in insects' innate immunity when facing parasites and pathogens, and ingestion of MPs can trigger a similar process. This study aimed at addressing the activities of basal PO and total PO (PO+ prophenoloxidase – proPO), in Chironomus riparius larvae (a model species in ecotoxicology) exposed to sediments spiked with polyethylene microplastics (PE-MPs; size-range 32–63 µm; concentrations: 1.25; 5; to 20 g kg–1) for 48 h. The ingestion of PE-MPs by larvae triggered a significant increase of basal PO activity at 5 and 20 g PE-MPs kg–1, by 26% and 29%, respectively, whereas total PO increased significantly in the latter (+48%), suggesting de novo synthesis of proPO by organisms. Considering the particle size, the immune response's activation is probably linked to damage in the epithelial cells of the gut lumen. This research work provides the first evidence on the activation of the insect's innate immune system after ingestion of MPs and underlines the PO activity as a good indicator of the immune response induced by MPs' ingestion.
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•Phenoloxidase was characterised in Chironomus riparius larvae whole-body homogenates.•Phenoloxidase activity was induced by ingestion of microplastics in C. riparius larvae.•Immune responses can be sensitive indicator of the sub lethal effects induced by microplastics ingestion.
The high levels of microplastics (MPs) found in freshwaters, particularly in riverine sediments, may impose a threat to the macroinvertebrate communities with possible consequences at ...ecosystem-level. The present study aimed to assess the effects of a mixture of different sizes of polyethylene microplastics (PE-MPs) on the composition and structure of macroinvertebrate communities and key-functions, such as primary production and leaf litter decomposition. MPs were mixed in the sediment at three different concentrations (0.1, 1, and 10 g kg-1) already found in freshwater sediments to enhance the relevance of the work. After eight days of exposure to PE-MPs, the observed changes in macroinvertebrate community structure were mostly due to the reduction in the abundance of deposit-feeders and grazers that were reduced by ca 31-50% and 34-39%, in the two highest MPs concentrations respectively, in comparison with the control treatment after 8 days of exposure. MPs internal concentrations were detected only in organisms exposed to plastic particles within artificial streams with chironomids and mayflies presenting higher MPs internal levels (average of 115 particles/individual found in chironomids, 166/individual for Baetis sp. and 415 particles/individual for Ephemerella sp.) suggesting higher ingestion of plastic microparticles. Nevertheless, the alterations in the community structure did not translate into impairments in the functional endpoints analysed, leaf litter decomposition and primary production, that were expected due to possible sub-lethal effects (e.g., feeding inhibition) on detritivores and grazers.
This study represents one of the few assessments of MPs effects on freshwater benthic macroinvertebrate community structure and the first that simultaneously considered ecosystem-level functional endpoints. Further research combining different microplastics and longer exposure periods are needed to raise knowledge on potential ecological consequences of MPs to freshwaters.
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•Ecological effects of polyethylene microplastics (PE-MPs) were examined in indoor mesocosms.•PE-MPs exposure induced alterations in benthic macroinvertebrate community structure.•Higher Internal concentrations of PE-MPs detected for deposit-feeders and grazers.•Leaf litter decomposition and primary production were not significantly altered by PE-MPs in sediments.
Cerebral vascular accidents (CVA) affect about 16 million people worldwide annually. CVA, also know as stroke, is a serious global health problem, and can cause significant physical limitations to ...those affected. Computed tomography is the most appropriate procedure to diagnose and evaluate the dimensions and magnitude of a stroke. Thus, in this article we present an Internet of Things (IoT) framework for the classification of stroke from CT images applying Convolutional Neural Networks (CNN) in order to identifying a healthy brain, an ischemic stroke or a hemorrhagic stroke. Following the Transfer Learning concept CNN was combined with different consolidated Machine Learning methods such as Bayesian Classifier, Multilayer Perceptron, k-Nearest Neighbor, Random Forest and Support Vector Machines. Our approach contributes to the automation of the diagnostic process by a competent method that is able to obtain information imperceptible to the human eye, and thus it contributes to a more precise diagnosis. In addition, with the advent of IoT, a highly efficient and flexible new instrument emerges to address issues related to health care services and specifically in our approach can provide remote diagnoses and monitoring of patients. The approach was validated by analyzing the parameters Accuracy, F1-Score, Recall, Precision and processing time. The results showed that CNN obtained 100% Accuracy, F1-Score, Recall and Precision in combination with most of the classifiers tested. The shortest training and test times were 0.015 s and 0.001 s, respectively, both in combination with the Bayesian Classifier. Thus, our proposed approach demonstrates efficiency and reliability to detect strokes.
The objective of this study was to describe the profile of bicycle users, their perceived difficulty to cycle, and the most frequent trip origins and destinations in Aracaju, Northeast Brazil. Our ...cross-sectional study sampled 1001 participants and we collected information through structured interviews. Aged ≥15 years, participants were residents of all Aracaju's neighborhoods and used a bicycle for commuting to work or for leisure. We observed that bicycle users in Aracaju are predominantly employed male subjects, aged between 18 and 40 years, and were the heads of their households. Most of the them reported "work" as the main reason for their bicycle trips and, "health" and "practicality" aspects as their main motivations for using bicycles. In general, the neighborhoods in the north and center of the city were identified as the most difficult for cycling, and the easiest trips occurred in places with cycle paths. As a conclusion of this study, we reaffirm the need for intersectoral actions that create favorable environments for active commuting and more sustainable cities.
To evaluate the impact of COVID-19 on clinical practice, income, health and lifestyle behavior of Brazilian urologists during the month of April 2020.
A 39-question, web-based survey was sent to all ...urologist members of the Brazilian Society of Urology. We assessed socio-demographic, professional, health and behavior parameters. The primary goal was to evaluate changes in urologists' clinical practice and income after two months of COVID-19. We also looked at geographical differences based on the incidence rates of COVID-19 in different states.
Among 766 urologists who completed the survey, a reduction ≥ 50% of patient visits, elective and emergency surgeries was reported by 83.2%, 89.6% and 54.8%, respectively. An income reduction of ≥ 50% was reported by 54.3%. Measures to reduce costs were implemented by most. Video consultations were performed by 38.7%. Modifications in health and lifestyle included weight gain (32.9%), reduced physical activity (60.0%), increased alcoholic intake (39.9%) and reduced sexual activity (34.9%). Finally, 13.5% of Brazilian urologists were infected with SARS-CoV-2 and about one third required hospitalization. Urologists from the highest COVID-19 incidence states were at a higher risk to have a reduction of patient visits and non-essential surgeries (OR=2.95, 95% CI 1.86 - 4.75; p< 0.0001) and of being infected with SARS-CoV-2 (OR=4.36 95%CI 1.74-10.54, p=0.012).
COVID-19 produced massive disturbances in Brazilian urologists' practice, with major reductions in patient visits and surgical procedures. Distressing consequences were also observed on physicians' income, health and personal lives. These findings are probably applicable to other medical specialties.
Freshwater riverbeds are a major repository of microplastics (MPs) from inland activities. Benthic macroinvertebrates that live in close contact with sediments seem to ingest a considerable amount of ...such plastic particles. The effects of MPs on life-history traits are relatively well-known, but the suborganismal mechanisms underlying such effects remain unclear. This study addressed the potential effects of low-density polyethylene (LDPE) MPs on Chironomus riparius larvae at cellular and molecular levels. Fourth instar C. riparius larvae were exposed to 0.025 and 2.5 g/kg LDPE of dry sediment (sizes: <32 and 32–45 μm; with irregular shape) under laboratory conditions for 48 h. These short-term exposures to environmental concentrations of LDPE MPs induced changes in the energy reserves (mostly by decreasing carbohydrates and increasing lipids), increased antioxidant and detoxification responses (tGSH, CAT, and GST), and induced increases in the activity of AChE (related to neurotransmission). In addition, at the gene level, exposure to MPs modified mRNA levels of InR, Dis, EcR, Dronc, Met (endocrine system), Def (immune system), PARP, ATM, NLK, and Decay (DNA repair), generating important alterations in the C. riparius development and response to unfavorable situations. This study provides new evidence of the effects of LDPE MPs at the suborganismal level, filling the gap in knowledge regarding the mechanisms underlying the toxicity of MPs and spotlighting gene expression analyses as early indicators of MP toxicity in C. riparius which were confirmed by Integrated biomarker response analyses highlighting the gene expression as sensible and useful endpoints for LPDE pollution in freshwaters. These results, coupled with previous investigations on responses at the organismal level, emphasizes the potential adverse effects of LDPE MPs on C. riparius, which may compromise freshwater benthic communities, considering its ecological role within these habitats.
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•32–45 μm LDPE particles showed higher toxicity at the cellular level in C. riparius.•Increased GST and CAT activities and Def expression support oxidative stress damage.•The endocrine disruption observed confirmed LDPE MPs as EDCs.•LDPE MPs altered DNA-repairing gene expression, acting as genotoxic compounds.•Gene expression is an appropriate early alarm signal of MPs toxicity in chironomids.
Inherited genetic factors can influence the severity of COVID-19, but the molecular explanation underpinning a genetic association is often unclear. Intracellular antiviral defenses can inhibit the ...replication of viruses and reduce disease severity. To better understand the antiviral defenses relevant to COVID-19, we used interferon-stimulated gene (ISG) expression screening to reveal that 2′-5′-oligoadenylate synthetase 1 (OAS1), through ribonuclease L, potently inhibits severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We show that a common splice-acceptor single-nucleotide polymorphism (Rs10774671) governs whether patients express prenylated OAS1 isoforms that are membrane-associated and sense-specific regions of SARS-CoV-2 RNAs or if they only express cytosolic, nonprenylated OAS1 that does not efficiently detect SARS-CoV-2. In hospitalized patients, expression of prenylated OAS1 was associated with protection from severe COVID-19, suggesting that this antiviral defense is a major component of a protective antiviral response.
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