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Skull-stripping and region segmentation are fundamental steps in preclinical magnetic resonance imaging (MRI) studies, and these common procedures are usually performed manually. We present Multi-task U-Net (MU-Net), a convolutional neural network designed to accomplish both tasks simultaneously. MU-Net achieved higher segmentation accuracy than state-of-the-art multi-atlas segmentation methods with an inference time of 0.35 s and no pre-processing requirements. We trained and validated MU-Net on 128 T2-weighted mouse MRI volumes as well as on the publicly available MRM NeAT dataset of 10 MRI volumes. We tested MU-Net with an unusually large dataset combining several independent studies consisting of 1782 mouse brain MRI volumes of both healthy and Huntington animals, and measured average Dice scores of 0.906 (striati), 0.937 (cortex), and 0.978 (brain mask). Further, we explored the effectiveness of our network in the presence of different architectural features, including skip connections and recently proposed framing connections, and the effects of the age range of the training set animals. These high evaluation scores demonstrate that MU-Net is a powerful tool for segmentation and skull-stripping, decreasing inter and intra-rater variability of manual segmentation. The MU-Net code and the trained model are publicly available at https://github.com/Hierakonpolis/MU-Net.
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Encéfalo/diagnóstico por imagem , Bases de Dados Factuais , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Redes Neurais de Computação , Crânio/diagnóstico por imagem , Animais , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
Consumers demand the use of eco-friendly fungicides to treat fruit and vegetables and governmental authorities have unauthorized the application of chemical antifungals for the efficient control of sour rot. In the present research, the microwave irradiation (MW) method was used to encapsulate thymol into 2-hydroxylpropyl-beta-cyclodextrin (HP-ß-CD) and the effect of these HP-ß-CD on controlling sour rot in citrus fruit, caused by Geotrichum citri-aurantii, was evaluated. Amounts of 25 and 50 mM of HP-ß-CD-thymol were used, and compared with propiconazole, to control the decay of inoculated lemon fruit. The treatments were performed in curative and preventive experiments. The incidence and severity of Geotrichum citri-aurantii in 25 and 50 mM HP-ß-CD-thymol-treated fruit were reduced in both experiments. The preventive 50 mM HP-ß-CD-thymol treatment showed the best effect, reducing the sour rot, respiration rate and fruit weight loss during storage at 20 °C. HP-ß-CD-thymol increased polyphenol concentration and the activity of antioxidant enzymes, such as catalase (CAT), ascorbate peroxidase (APX) and peroxidase (POD) in lemon peel, and the highest effects were found with the 50-mM dose. In conclusion, the results show that the use of thymol encapsulated by MW into HP-ß-CD could be an effective and sustainable tool, a substitute to the synthetic fungicides, for G. citri-auriantii control in citrus fruit.
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2-Hidroxipropil-beta-Ciclodextrina/química , Farmacorresistência Fúngica/efeitos dos fármacos , Fungicidas Industriais/química , Fungicidas Industriais/farmacologia , Doenças das Plantas/microbiologia , Timol/química , Timol/farmacologia , Cápsulas , Citrus/microbiologia , Geotrichum/efeitos dos fármacos , Geotrichum/fisiologia , Testes de Sensibilidade MicrobianaRESUMO
BACKGROUND: Sweet cherries are much appreciated by consumers as a result of their organoleptic quality attributes and antioxidant properties, although they deteriorate rapidly after harvest. Different preharvest strategies have been carried out to increase their quality at the time of harvest. We present data regarding the effect of preharvest salicylic acid (SA) and acetyl salicylic acid (ASA) treatments on sweet cherry quality during postharvest storage. RESULTS: At harvest and during postharvest storage, sweet cherry fruits ('Sweet Heart', 'Sweet Late' and 'Lapins') from SA (0.5 mmol L-1 ) and ASA (1 mmol L-1 ) treated trees had a higher colour (lower chroma index), firmness, total soluble solids, total phenolics, total anthocyanins and hydrophilic total antioxidant activity. In addition, the activity of the antioxidant enzymes catalase, peroxidase, superoxide dismutase and ascorbate peroxidase was also enhanced in SA- and ASA-treated cherries. CONCLUSION: Both SA and ASA preharvest treatments could be promising tools for improving sweet cherry quality at harvest and after storage, with an additional effect on delaying the postharvest ripening process by increasing the levels of antioxidant compounds and the activity of the antioxidant enzymes. © 2016 Society of Chemical Industry.
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Agricultura/métodos , Antioxidantes/metabolismo , Aspirina , Conservação de Alimentos/métodos , Frutas , Prunus , Ácido Salicílico , Antocianinas/metabolismo , Ascorbato Peroxidases/metabolismo , Ácido Ascórbico/metabolismo , Catalase/metabolismo , Cor , Manipulação de Alimentos , Armazenamento de Alimentos , Frutas/metabolismo , Frutas/normas , Dureza , Humanos , Oxirredução , Peroxidase/metabolismo , Fenóis/metabolismo , Superóxido Dismutase/metabolismo , PaladarRESUMO
While humans are known to have several premotor cortical areas, secondary motor cortex (M2) is often considered to be the only higher-order motor area of the mouse brain and is thought to combine properties of various human premotor cortices. Here, we show that axonal tracer, functional connectivity, myelin mapping, gene expression, and optogenetics data contradict this notion. Our analyses reveal three premotor areas in the mouse, anterior-lateral motor cortex (ALM), anterior-lateral M2 (aM2), and posterior-medial M2 (pM2), with distinct structural, functional, and behavioral properties. By using the same techniques across mice and humans, we show that ALM has strikingly similar functional and microstructural properties to human anterior ventral premotor areas and that aM2 and pM2 amalgamate properties of human pre-SMA and cingulate cortex. These results provide evidence for the existence of multiple premotor areas in the mouse and chart a comparative map between the motor systems of humans and mice.
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Córtex Motor , Humanos , Córtex Motor/fisiologia , Animais , Camundongos , Masculino , Camundongos Endogâmicos C57BL , Adulto , Feminino , Mapeamento EncefálicoRESUMO
We present MedicDeepLabv3+, a convolutional neural network that is the first completely automatic method to segment cerebral hemispheres in magnetic resonance (MR) volumes of rats with ischemic lesions. MedicDeepLabv3+ improves the state-of-the-art DeepLabv3+ with an advanced decoder, incorporating spatial attention layers and additional skip connections that, as we show in our experiments, lead to more precise segmentations. MedicDeepLabv3+ requires no MR image preprocessing, such as bias-field correction or registration to a template, produces segmentations in less than a second, and its GPU memory requirements can be adjusted based on the available resources. We optimized MedicDeepLabv3+ and six other state-of-the-art convolutional neural networks (DeepLabv3+, UNet, HighRes3DNet, V-Net, VoxResNet, Demon) on a heterogeneous training set comprised by MR volumes from 11 cohorts acquired at different lesion stages. Then, we evaluated the trained models and two approaches specifically designed for rodent MRI skull stripping (RATS and RBET) on a large dataset of 655 MR rat brain volumes. In our experiments, MedicDeepLabv3+ outperformed the other methods, yielding an average Dice coefficient of 0.952 and 0.944 in the brain and contralateral hemisphere regions. Additionally, we show that despite limiting the GPU memory and the training data, our MedicDeepLabv3+ also provided satisfactory segmentations. In conclusion, our method, publicly available at https://github.com/jmlipman/MedicDeepLabv3Plus , yielded excellent results in multiple scenarios, demonstrating its capability to reduce human workload in rat neuroimaging studies.
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Cérebro , Processamento de Imagem Assistida por Computador , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Redes Neurais de Computação , EncéfaloRESUMO
Spain is a great producer of organic lemon; however, it is necessary to reduce the losses caused by post-harvest diseases. Melatonin (MEL) is a naturally occurring compound with physiological functions in fruit growth and ripening and is able to modulate postharvest ripening and senescence, most of it being concentrated in climacteric fruit. Thus, the aim of this study was to apply MEL to organic lemon fruit with stems and leaves (LEAF) and to organic lemon without those components (LEAFLESS) after harvesting and storage during 21 days at 2 °C to understand the effects of this treatment on the fruit quality. For this purpose, two experiments were carried out. First, MEL was applied at 0.01 mM, 0.1 mM and 1.0 mM by immersion for 15 min on lemon fruits, and the quality parameters and bioactive compounds of the fruit were analysed. Subsequently, a second experiment was carried out where the best concentration (1 mM) was selected and another time (15 and 30 min) was added, with the same quality parameters being analysed. As a result, we observed that all MEL treatments showed positive effects on weight loss reduction, softening (higher fruit firmness), total acidity and lower colour changes. Total phenols increased in MEL-treated lemons, both in peel and juice. For the three concentrations tested, the best efficiency was obtained with MEL at 1.0 mM, while LEAF lemons were the most effective. In conclusion, lemons containing stems and leaves (LEAF) improved preservability by using MEL at 1.0 mM with better organoleptic quality and enhanced phenolic compounds.
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Registration-based methods are commonly used in the automatic segmentation of magnetic resonance (MR) brain images. However, these methods are not robust to the presence of gross pathologies that can alter the brain anatomy and affect the alignment of the atlas image with the target image. In this work, we develop a robust algorithm, MU-Net-R, for automatic segmentation of the normal and injured rat hippocampus based on an ensemble of U-net-like Convolutional Neural Networks (CNNs). MU-Net-R was trained on manually segmented MR images of sham-operated rats and rats with traumatic brain injury (TBI) by lateral fluid percussion. The performance of MU-Net-R was quantitatively compared with methods based on single and multi-atlas registration using MR images from two large preclinical cohorts. Automatic segmentations using MU-Net-R and multi-atlas registration were of excellent quality, achieving cross-validated Dice scores above 0.90 despite the presence of brain lesions, atrophy, and ventricular enlargement. In contrast, the performance of single-atlas segmentation was unsatisfactory (cross-validated Dice scores below 0.85). Interestingly, the registration-based methods were better at segmenting the contralateral than the ipsilateral hippocampus, whereas MU-Net-R segmented the contralateral and ipsilateral hippocampus equally well. We assessed the progression of hippocampal damage after TBI by using our automatic segmentation tool. Our data show that the presence of TBI, time after TBI, and whether the hippocampus was ipsilateral or contralateral to the injury were the parameters that explained hippocampal volume.
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(1) Background: Transfer learning refers to machine learning techniques that focus on acquiring knowledge from related tasks to improve generalization in the tasks of interest. In magnetic resonance imaging (MRI), transfer learning is important for developing strategies that address the variation in MR images from different imaging protocols or scanners. Additionally, transfer learning is beneficial for reutilizing machine learning models that were trained to solve different (but related) tasks to the task of interest. The aim of this review is to identify research directions, gaps in knowledge, applications, and widely used strategies among the transfer learning approaches applied in MR brain imaging; (2) Methods: We performed a systematic literature search for articles that applied transfer learning to MR brain imaging tasks. We screened 433 studies for their relevance, and we categorized and extracted relevant information, including task type, application, availability of labels, and machine learning methods. Furthermore, we closely examined brain MRI-specific transfer learning approaches and other methods that tackled issues relevant to medical imaging, including privacy, unseen target domains, and unlabeled data; (3) Results: We found 129 articles that applied transfer learning to MR brain imaging tasks. The most frequent applications were dementia-related classification tasks and brain tumor segmentation. The majority of articles utilized transfer learning techniques based on convolutional neural networks (CNNs). Only a few approaches utilized clearly brain MRI-specific methodology, and considered privacy issues, unseen target domains, or unlabeled data. We proposed a new categorization to group specific, widely-used approaches such as pretraining and fine-tuning CNNs; (4) Discussion: There is increasing interest in transfer learning for brain MRI. Well-known public datasets have clearly contributed to the popularity of Alzheimer's diagnostics/prognostics and tumor segmentation as applications. Likewise, the availability of pretrained CNNs has promoted their utilization. Finally, the majority of the surveyed studies did not examine in detail the interpretation of their strategies after applying transfer learning, and did not compare their approach with other transfer learning approaches.
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Lemon trees (Citrus limon (L.) Burm. F) were treated monthly with oxalic acid (OA) at 0.1, 0.5, and 1 mM from initial fruit growth on the tree until harvest in2019. The experiment was repeated in 2020, with the application of OA 1 mM (according to the best results of 2019). In both years, fruit from OA-treated trees and the controls were stored for 35 days at 10 °C. Results showed that all treatments reduced weight loss (WL) and maintained higher firmness, total soluble solids (TSS), and total acidity (TA) than in the controls. Meanwhile, colour (hue angle) did not show significant differences. The activity of antioxidant enzymes, catalase (CAT), ascorbate peroxidase (APX), and peroxidase (POD) in the flavedo of the fruit from the OA-treated trees was higher than in the controls at harvest and after 35 days of storage. Similarly, the total phenolic content (TPC) in the flavedo and juice of the fruit from the OA-treated trees were higher than in the controls. The increase in the activity of the antioxidant enzymes and TPC started with the first preharvest OA treatment and were maintained during fruit development on the tree until harvest. Preharvest OA treatments enhanced the antioxidant system of the lemon fruits, reducing the postharvest incidence of decay. Thus, OA could be a useful tool to increase the quality and functional properties of lemon fruits.
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We present a fully convolutional neural network (ConvNet), named RatLesNetv2, for segmenting lesions in rodent magnetic resonance (MR) brain images. RatLesNetv2 architecture resembles an autoencoder and it incorporates residual blocks that facilitate its optimization. RatLesNetv2 is trained end to end on three-dimensional images and it requires no preprocessing. We evaluated RatLesNetv2 on an exceptionally large dataset composed of 916 T2-weighted rat brain MRI scans of 671 rats at nine different lesion stages that were used to study focal cerebral ischemia for drug development. In addition, we compared its performance with three other ConvNets specifically designed for medical image segmentation. RatLesNetv2 obtained similar to higher Dice coefficient values than the other ConvNets and it produced much more realistic and compact segmentations with notably fewer holes and lower Hausdorff distance. The Dice scores of RatLesNetv2 segmentations also exceeded inter-rater agreement of manual segmentations. In conclusion, RatLesNetv2 could be used for automated lesion segmentation, reducing human workload and improving reproducibility. RatLesNetv2 is publicly available at https://github.com/jmlipman/RatLesNetv2.
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The main goal of this study was to describe impact of preharvest application of methyl salicylate (MeSA), acetyl salicylic acid (ASA) and salicylic acid (SA) on the reduction of disease caused by Botrytis cinerea in two table grape cultivars ('Crimson' and 'Magenta'). Based on previous studies, MeSA and SA were applied at 0.1 and 0.01â¯mM for both cultivars, while ASA was applied at 1â¯mM in 'Crimson' and 0.1â¯mM in 'Magenta'. At time of harvest, berry maturity-quality attributes, bioactive compounds and antioxidant enzymes were determined. In addition, grapes were artificially inoculated with B. cinerea spores, and the berries were ranked for visual decay incidence after 5â¯days of inoculation. Salicylates preharvest treatments led to higher total acidity, content of bioactive compounds and activity of antioxidant enzymes in treated than in control berries. The application of salicylate derivatives induced resistance to B. cinerea spoilage, since higher percentage of berries with no symptoms was observed and on the contrary, the highest percentages of berries were obtained in control grapes. All preharvest treatments with SA, ASA and MeSA alleviated postharvest disease caused by B. cinerea probably due to increasing levels of phenolic compounds and activity of antioxidant enzymes, although the best results were obtained with MeSA at 0.1â¯mM. Also, for this treatment and dose, higher quality properties, such as higher concentrations of ascorbic, succinic and fumaric acids, were observed compared with no treated-grapes.
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Antioxidantes/metabolismo , Botrytis/efeitos dos fármacos , Doenças das Plantas/prevenção & controle , Ácido Salicílico/farmacologia , Vitis/microbiologia , Aspirina/farmacologia , Resistência à Doença/efeitos dos fármacos , Conservação de Alimentos/métodos , Fenóis/metabolismo , Doenças das Plantas/microbiologia , Salicilatos/farmacologia , Vitis/efeitos dos fármacos , Vitis/metabolismoRESUMO
In this paper, the role of carvacrol vapour atmosphere on Botrytis cinerea inoculated in PDA or in grape berries was studied. Four concentrations inside packages were assayed (0.05, 0.2, 0.5 and 1.0 ml l(-1)). All concentrations inhibited totally the growth of B. cinerea in PDA, while in berries the reduction of decayed fruits was significantly greater as carvacrol concentration increased. In addition, the fungal growth (area and volume of infection) was also reduced and dependent on carvacrol concentration. Ethylene and respiration rate (berry physiological parameters) increased drastically in control inoculated-grapes, while these increases were lower as higher were the carvacrol applied doses. The data presented in this work suggest that carvacrol could be used as an innovative tool to control fungal decay during table grape storage, as alternative to the use of synthetic fungicides such as SO2.
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Botrytis/efeitos dos fármacos , Botrytis/crescimento & desenvolvimento , Conservação de Alimentos/métodos , Monoterpenos/farmacologia , Vitis/microbiologia , Contagem de Colônia Microbiana , Cimenos , Relação Dose-Resposta a Droga , Microbiologia de Alimentos , Embalagem de Alimentos/métodosRESUMO
Table grapes (Vitis vinifera L. cv. Crimson Seedless) were coated with Aloe vera gel according to our developed patent (SP Patent P200302937) and then stored for 35 days at 1 degrees C, and the subsequent shelf life (SL) was monitored at 20 degrees C. Uncoated clusters showed a rapid loss of functional compounds, such as total phenolics and ascorbic acid. These changes were accompanied by reduction of the total antioxidant activity (TAA) and increases in total anthocyanins, showing an accelerated ripening process. On the contrary, table grapes coated with Aloe vera gel significantly delayed the above changes, such as the retention of ascorbic acid during cold storage or SL. Consequently, Aloe vera gel coating, a simple and noncontaminating treatment, maintained the functional properties during postharvest storage of table grapes.
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Aloe/química , Conservação de Alimentos/métodos , Frutas , Géis , Vitis , Antocianinas/análise , Antioxidantes/análise , Ácido Ascórbico/análise , Frutas/química , Fenóis/análiseRESUMO
Table grape is a nonclimacteric fruit that shows a rapid loss of quality during storage and is very susceptible to colonization by fungi, especially Botrytis cinerea, which is considered the most important disease of this commodity. To solve this problem, synthetic fungicides have been used, although legal restrictions and consumer's concern demand the search of other safe means. In the present paper, and as an alternative of synthetic fungicides, an active packaging to improve MAP effectiveness on preserving table grape (cv. Crimson Seedless) quality and safety was developed by the addition of 0.5 mL of eugenol, thymol, or menthol inside the packages. Packages were stored at 1 degree C for 35 days. The final gas composition inside the packages was 1.4-2.0 and 10.0-14.5 kPa of CO(2) and O(2), respectively, with no significant slight differences among treatments. Results showed that the addition of eugenol, thymol, or menthol improved the beneficial effect of MAP in terms of delaying weight loss and color changes, retarding degrees Brix/acidity ratio evolution, and maintaining of firmness. Thereafter, these treatments showed additional benefit in terms of delayed rates of rachis deterioration and berry decay. Finally, the total viable counts for both mesophilic aerobics and especially yeast and molds were significantly reduced in the grapes packaged with the natural antimicrobial compounds. All of the above effects led to maintenance of table grape quality and safety for longer storage periods (3 additional weeks as compared to controls under MAP only).
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Eugenol , Embalagem de Alimentos/métodos , Frutas , Mentol , Timol , Vitis , Dióxido de Carbono/análise , Frutas/microbiologia , Oxigênio/análise , Controle de QualidadeRESUMO
A novel edible coating based on Aloe vera gel obtained according to SP Patent Filed 200302937 has been used as a means of preservation to maintain the quality and safety of cv. Crimson Seedless table grapes during cold storage and subsequent shelf life. Table grapes have a crucial economic value as a dessert fruit, but once harvested show a reduction of shelf life due to a rapid loss of quality. Uncoated clusters showed a rapid deterioration with an estimated shelf life period of 7 days at 1 degrees C plus 4 days at 20 degrees C, based on the fast weight loss, color changes, accelerated softening and ripening, rachis browning, and high incidence of berry decay. On the contrary, those clusters treated with A. vera gel significantly delayed the above parameters related to postharvest quality losses, and storability could be extended up to 35 days at 1 degrees C. Interestingly, this edible coating was able to reduce the initial microbial counts for both mesophillic aerobic and yeast and molds, which significantly increased in uncoated berries over storage. Moreover, the sensory analyses revealed beneficial effects in terms of delaying rachis browning and dehydration and maintenance of the visual aspect of the berry without any detrimental effect on taste, aroma, or flavors. To the authors' knowledge, this is the first time A. vera gel has been used as an edible coating in fruits, which would be an innovative and interesting means for commercial application and an alternative to the use of postharvest chemical treatments.
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Aloe/química , Manipulação de Alimentos/métodos , Frutas , Vitis , Etilenos/análise , Conservação de Alimentos , Frutas/microbiologia , Géis , Controle de QualidadeRESUMO
The effects of salicylic acid (SA) or acetylsalicylic acid (ASA) treatments during on-tree cherry growth and ripening on fruit quality attributes, especially those related with the content on bioactive compounds and antioxidant activity were analysed in this research. For this purpose, two sweet cherry cultivars, 'Sweet Heart' and 'Sweet Late', were used and SA or ASA treatments, at 0.5, 1.0 and 2.0mM concentrations, were applied at three key points of fruit development (pit hardening, initial colour changes and onset of ripening). These treatments increased fruit weight and ameliorated quality attributes at commercial harvest, and led to cherries with higher concentration in total phenolics and in total anthocyanins, as well as higher antioxidant activity, in both hydrophilic and lipophilic fractions. Thus, preharvest treatments with SA or ASA could be promising tools to improve sweet cherry quality and health beneficial effects for consumers.
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Antocianinas/análise , Antioxidantes/análise , Aspirina/química , Frutas/química , Extratos Vegetais/química , Prunus/química , Ácido Salicílico/análiseRESUMO
Ethylene is a plant hormone controlling a wide range of physiological processes in plants. During postharvest storage of fruit and vegetables ethylene can induce negative effects including senescence, over-ripening, accelerated quality loss, increased fruit pathogen susceptibility, and physiological disorders, among others. Apart from the endogenous ethylene production by plant tissues, external sources of ethylene (e.g. engine exhausts, pollutants, plant, and fungi metabolism) occur along the food chain, in packages, storage chambers, during transportation, and in domestic refrigerators. Thus, it is a great goal in postharvest to avoid ethylene action. This review focuses on tools which may be used to inhibit ethylene biosynthesis/action or to remove ethylene surrounding commodities in order to avoid its detrimental effects on fruit and vegetable quality. As inhibitors of ethylene biosynthesis and action, good results have been found with polyamines and 1-methylcyclopropene (1-MCP) in terms of maintenance of fruit and vegetable quality and extension of postharvest shelf-life. As ethylene scavengers, the best results can be achieved by adsorbers combined with catalysts, either chemical or biological (biofilters).