As reported, 27-93 % of pregnant women take at least one drug during pregnancy. However, drug exposure during pregnancy still lacks sufficient foetal safety evidence of human origin. It is urgent to fill the knowledge gap about medication safety during pregnancy for optimization of maternal disease treatment and pregnancy drug consultation.The China Teratology Birth Cohort (CTBC) was established in 2019 and is a hospital-based open-ended prospective cohort study with the aim of assessing drug safety during pregnancy. Pregnant women who set up the pregnancy health records in the first trimester or who seek drug consultation regardless of gestational age in the member hospitals are recruited. Enrolled pregnant women need to be investigated four times, namely, 6–14 and 24–28 weeks of gestational age, before discharge after hospital delivery, and 28–42 days after birth.Maternal medication exposure during pregnancy is the focus of the CTBC. For drugs, information on the type, name, and route of medication; start and end time of medication; single dose; frequency of medication; dosage form; manufacturer; and reason for medication is collected. The adverse pregnancy outcomes collected in the study include birth defects, stillbirth, spontaneous abortion, preterm birth, post-term birth, low birth weight, macrosomia, small for gestational age, large for gestational age and low Apgar score. CTBC uses an electronic questionnaire for data collection and a cloud system for data management. Biological samples are collected if informed consents are obtained. Multi-level logistic regression, mixed-effect negative binomial distribution regression and spline function regression are used to explore the effect of drugs on the occurrence of birth defects.The findings of the study will assist in further understanding the risk of birth defects and other adverse pregnancy outcomes associated with maternal drug exposure and developing the optimal treatment plans and drug counselling for pregnant women.http://www.chictr.org.cn/index.aspx, registration number ChiCTR1900022569).This study was approved by the Research Ethics Committee of the West China Second Hospital of Sichuan University and registered at the Chinese Clinical Trial Registry (The online version contains supplementary material available at 10.1186/s12884-021-04073-0. Since the thalidomide disaster occurred in the 1960 s, people have paid increasing attention to the medication safety during pregnancy . Drug exAlthough some drugs are known to potentially be harmful to foetuses, this issue is far from resolved . The limThe types of research commonly used in drug safety studies during pregnancy include case reports, case-control studies, retrospective cohort studies or existing medical databases. Each study design has advantages and disadvantages , 35–40. The CTBC aims to assess the risk of birth defects and other adverse pregnancy outcomes  associated with maternal drug exposure. It was launched in January 2019 and is a hospital-based open-ended prospective cohort study designed to evaluate drug safety during pregnancy, and it is expected to recruit at least 300,000 participants. Pregnant women who meet the inclusion and exclusion criteria (see the following section) are enrolled in the first trimester  of pregnancy when they first receive antenatal care in the member hospitals, and each enrolled pregnant woman is followed up three times, namely, in the second trimester , before discharge from a member hospital after delivery and within 42 days after delivery . Enrolled women complete four investigations in total under face-to-face instruction from a trained investigator. Biological samples, such as maternal peripheral blood, maternal urine, placenta, umbilical cord and diseased tissue, are collected if informed consent is obtained from the pregnant woman.Hospitals can freely apply to participate in the project as long as they meet the following conditions: 1) it must be a county-level or higher hospital with the departments of obstetrics and paediatrics, and (2) it must be a member hospital of the national or provincial birth defect monitoring system in China . As of J it must An executive team of 5–6 staff members with a medical background is set up in each member hospital. The team consists of one manager, at least three investigators and one quality inspector. The manager is responsible for coordinating the obstetrics, pharmacy, paediatrics and other departments involved in the study, as well as organizing the investigators and quality controllers to implement the project as required. The investigators are responsible for recruiting and informing the patients, urging the enrolled pregnant women to come to the member hospital for regular prenatal examinations, directing them to complete the questionnaire and collecting information on the pregnancy outcomes. The quality inspectors are responsible for checking the data quality and data management.The CTBC has developed clear and reasonable inclusion and exclusion criteria for the research subjects, without regard to occupation, education, and any other social demographic characteristics. Two types of pregnant women are recruited in the study: (1) pregnant women who are establishing their pregnancy health record during the first trimester at the pregnancy health record room of a member hospital and also plan to undergo prenatal care and deliver in the same member hospital; and (2) pregnant women who undergone a drug consultation and has established or plan to establish pregnancy health record of a member hospital and also plan to undergo prenatal care and deliver in the same member hospital. Electronic informed consent is obtained before a subject is enrolled in the study. However, women who are under 18 or cannot complete the investigation due to mental problems or disabilities and those who do not wish to participate will not be recruited in the study. It should be emphasized that pregnant women without drug exposure before the first antenatal visit can also be enrolled.Pregnant women are recruited in several ways in the study. Eligible pregnant women are recruited by investigators, obstetric doctors and drug consultants. Furthermore, posters are placed in member hospitals to assist in the enrolment of pregnant women.A structured questionnaire has been designed to collect detailed information for each enrolled pregnant woman. It consists of four sections . Regarding medication, the CTBC collects the type , name, route of medication, start and end time of medication, single dose, frequency of medication, dosage form, manufacturer and reason for taking the medication.The popularization of smart phones in the Chinese population has made electronic data collection an alternative data collection method in China. The study mainly relies on electronic questionnaires for data collection, which is based on a popular social app in China called WeChat. Compared with traditional paper-based questionnaires, electronic questionnaires are more efficient in data management and can avoid more logical errors –44. UndeEach pregnant woman enrolled in the pregnancy health room needs to complete four investigations under the guidance of the investigator Fig. . The firIn the case of spontaneous abortion, artificial abortion or induced labour, pregnant women can skip the middle sections of the questionnaire and complete section D (pregnancy outcome) directly. If the enrolled pregnant women do not go to the member hospital on time to complete the next investigation or do not give birth in the member hospital, investigators will try to conduct the investigation by phone. If an enrolled pregnant woman refuses to answer the phone or refuses to respond to a telephone survey on multiple occasions, she will be deemed as lost to follow-up. For those who are lost to follow-up, the CTBC can obtain their information regarding disease and drug exposure through the medical records in the member hospitals.During the first survey in the first trimester and the second survey in the second trimester, maternal peripheral blood and urine are collected from the enrolled women after obtaining informed consent. The placenta, umbilical cord and diseased tissue of recently delivered newborns who are diagnosed with a major birth defect are collected. To obtain a 1:1 proportion of cases and normal foetuses, the CTBC also collects the placenta, umbilical cord of normal foetuses whose parents sign the informed consent.It is important to identify the drug name, exposure time and cumulative exposure dosage. In China, the types of medicines can be divided into Western medicine, Chinese medicine, Chinese patent medicine and health products. Among them, the types of medicines we focus on are Western medicine and Chinese patent medicine. For Chinese medicine, we investigate only whether pregnant women have taken Chinese medicine rather than the specific ingredients included in the Chinese medicines they have taken. For health products, although we have to carry out related investigations, they are not our focus.The CTBC considers any medication taken during any pregnancy period as a drug exposure, even if it is taken only once. Identification of the time of drug exposure is based on the accurate confirmation of gestational age of the enrolled women. The study collects the time of the last menstrual period of pregnant women, the examination time of prenatal ultrasound and the foetal gestational age confirmed by prenatal ultrasound in the first trimester. Therefore, the gestational age inferred by the time of the last menstrual period and ultrasound examination, combined with the date of drug exposure, determines the pregnancy period of drug exposure. The cumulative exposure dose can be calculated from the single exposure dose, exposure frequency, exposure start and end time collected by us.To ameliorate the problem of inaccurate information recall regarding diseases and drugs, the following methods are used in the study. First, the common diseases and drug names are set with drop-down options in the electronic questionnaire, which could also reduce input errors. Second, each member hospital prints out photographs of names and boxes of common drugs locally to help enrolled women recall details. Third, the pregnant women are advised to recall the start and end time of illness and medication use through important festivals or iconic events. Fourth, if the above methods still fail to allow the pregnant woman to recall the drug information, the pregnant women are asked to go home and look for the medicine box or medical record. In addition, if the drugs not in the drop-down menu are exposed, pregnant women can enter the drug name and other information into the electronic questionnaire, and we will code them.Another difficulty in the investigation of exposure measurement is how to fill in the time of drug exposure across different pregnancy periods. The CTBC requires that the end time of drug use in each survey be filled up to the day of the survey at most. In the next survey, the earliest time when the drug started to be used is filled in the first day after the last survey. In addition, we have set the above filling rules in the electronic questionnaire. In this manner, the time of the two surveys can be linked, and drug exposure of the pregnant women enrolled in the study can be observed throughout their pregnancy. Pregnant women with chronic diseases usually go through the process of taking, stopping, and returning to their medications during pregnancy. This rule also prevents pregnant women with chronic diseases from filling in the end time of drug exposure directly according to their due date of birth in the first survey.Accurate measurement of gestational age at delivery, birth weight, birth defects and related adverse pregnancy outcomes is a key component of this study. The determination of the gestational age at delivery is the same as above and depends on the last menstrual time of the enrolled women, the examination time of prenatal ultrasound and the foetal gestational age as confirmed by prenatal ultrasound in the first trimester as above. The birth weight of newborns is uniformly measured with an electronic scale, and the measurement is accurate to 10 g.The CTBC is concerned with almost all adverse pregnancy outcomes, such as birth defects, stillbirth, spontaneous abortion, preterm birth, post-term birth, low birth weight, macrosomia, small for gestational age, large for gestational age, and low Apgar score. Regarding adverse pregnancy outcomes, we focus most on birth defects. In the study, all birth defects  from the first trimester to 42 days after birth need to be identified, regardless of whether a pregnancy ends in live birth, foetal death, or spontaneous abortion or whether an elective termination is performed. Prenatal ultrasound screening and prenatal diagnosis are the main means to detect birth defects before birth, but the diagnosis of birth defects needs to be confirmed by clinical observation and physical examination of a newborn. Clinical observation of a newborn includes the observation of its spirit, complexion, limb movement, breathing, diet, urine and faeces. Neonatal physical examination should first include a body surface examination, examination of the body surface without deformity, and examination of each part of the organ individually. Physical examination can also yield some information on obvious visceral malformations, and the diagnosis of some visceral malformations should be combined with laboratory examination and clinical symptoms. For infants who are discovered and suspected of having a birth defect within 42 days after birth but are not yet diagnosed, the follow-up will continue until a diagnosis is made. If certain birth defects cannot be clearly diagnosed in member hospitals, a specialist consultation will be conducted to achieve a diagnosis. Regarding the measurement methods of birth defects, we refer to the National Birth Defects Prevention Network (NBDPN) in America  and ChinThe Anatomical Therapeutic Chemical (ATC) classification, a system developed by the World Health Organization (WHO) Collaborating Centre for Drug Statistics Methodology, is recommended for drug coding worldwide . Based oThe study uses the tenth revision of the International Classification of Diseases (ICD-10) to standardize and record maternal diseases and related diseases occurring at the time of pregnancy termination  . We haveThe study also adds the drug and disease codes to the electronic questionnaire and cloud system such that the names and codes of the collected drugs and diseases are directly standardized.We have designed a cloud system related to the electronic questionnaire, which plays an important role in data management Fig. . The cloStrict quality control measures are taken before, during and after the implementation of the project as following:The NCBDMC provides standardized training for each member hospital project executive team. All member hospitals use standardized survey tools, survey methods, survey techniques and quality control methods.Pregnant women who will participate in regular prenatal care and delivery in member hospitals are selected as the enrolled population. These populations are highly compliant and have a high retention rate.To increase the number of enrolled women and the follow-up rate, gifts are provided to enrolled pregnant women to improve their prenatal care compliance.The electronic medical records or paper maternal health manuals of each enrolled pregnant woman are marked so that investigators can identify the enrolled pregnant women at the next investigation sites.Member hospitals notify the enrolled pregnant women of the time and location of the next survey via text messages or phone calls.The CTBC conducts four rounds of quality checks. First, investigators check the completed questionnaire on site focusing on questionnaire integrity and logic error and immediately modify misinformation. Second, quality inspectors check the data quality every week by comparing the information in the medical record system. Third, the NCBDMC checks the data every day focusing on. Fourth, the NCBDMC conducts on-site quality inspections at member hospitals irregulary. In first and third rounds, the questionnaire integrity and logic error are the focus of data inspection.The NCBDMC conducts on-site quality inspections at member hospitals. The specific process is to comparing the disease and medication records of enrolled pregnant women in the hospital medical record system and access all department records in the hospital that may identify infants with congenital anomalies, such as delivery records, neonatology records, prenatal screening and diagnosis records, birth defect monitoring records, newborn screening records, death records and laboratory reports.Most importantly, the relationship between maternal drug exposure and adverse pregnancy outcomes will be assessed in this study. It is also possible to explore the relationship between drug exposure and adverse pregnancy outcomes by comparing the drug-taking group with a certain disease and the non-medicating group suffering from the disease. Moreover, the relationship between the period of pregnancy during drug exposure, the duration of drug exposure, the cumulative dose of drug exposure and adverse pregnancy outcomes also warrants investigation. Finally, grouping according to exposure to drug A and drug B can enable a comparison of the relationship between the two drugs and adverse pregnancy outcomes.In addition, matching, propensity scores and other methods can be used to control the confounding effects between drugs and adverse pregnancy outcomes, and multi-level logistic regression, mixed-effect negative binomial distribution regression and spline function regression can be used to explore the effect of modification and interaction effects between drugs and diseases on the occurrence of adverse pregnancy outcomes.This is a prospective and multicentre cohort study aiming to bridge the knowledge gap on drug safety during pregnancy, including 47 member hospitals from 21 provinces in China since 2019. In the future, the CTBC will continue to increase the number of member hospitals and the number of enrolled pregnant women and plans to collect data on the severity of maternal disease and long-term development outcomes of children. Based on the CTBC, research on the early warning of teratogenic risks and on standardized services for the prevention and control of clinical teratogenic risks can also be carried out, such as the formulation of risk classification principles of drug use during pregnancy, standardized process of clinical drug information consultation service and guidelines for safe drug use during pregnancy.The study has several advantages. First, the CTBC is a prospective cohort study, so it has less recall bias and stronger causal arguments and can quantitatively analyse the risk between exposed drug and adverse pregnancy outcomes  .49 s, eThis study has three main limitations. First, following the China Maternal and Child Health Career Development Report in 2019 , the preIn the world, the role of most national pharmacovigilance centres in monitoring drug safety during pregnancy is limited, and the Terminology Information Service (TIS) was established in many countries, such as The European Network of Teratology Information Services (ENTIS)  and MothAdditional file 1.


The evolutionary success of parasitism is directly related to the huge number of species that have evolved this way of life. Such success could be explained by the mechanisms evolved by these species to confront and evade the responses of their hosts, together with their capacity to adapt the metabolic processes of their hosts for their own benefit . In regaDicrocoelium dendriticum in sheep and the host response in regards to macroscopic lesions, the immunopathological response and histological changes showed by the affected tissues. Despite its high prevalence values in some parts of the world, especially in Europe, and its demonstrated relation to high economic losses in the livestock industry, dicrocoeliosis has received little research attention. The results shown by this manuscript will help to better understand the liver immune response in naturally infected sheep with D. dendriticum, as well as opening up the possibility of using the fecal egg count technique as an indirect index of liver damage in dicrocoeliosis. Similarly, Ptáček et al. [Eimeria).Seven contributions have been published within the Special Issue. These are research papers in which different strategies to unravel host–parasite interactions are carried out. In the first one, Piegari et al.  studied k et al.  exploredAscaris suum. Infective larvae of this parasite hatch from ingested eggs in the host small intestine and, from that point, undergo an extensive migration through the host bloodstream that ends in the same location. For that reason, authors hypothesized that these larvae could interact with the components of the haemostatic system of their host for their own benefit. In fact, the published manuscript demonstrated for the first time the ability of A. suum larvae to inhibit the coagulation cascade of the host, which could be considered as a mechanism facilitating parasite survival, migration and colonization.Following the line of parasitic diseases that cause a great impact on livestock production, Diosdado et al.  studied Fasciola gigantica, whose distribution is restricted to parts of Africa and Asia, apparently. After developing genotyping of these parasites, authors concluded that F. gigantica does not appear to be able to colonize the New World. In the next study, Barbour et al. [F. hepatica, which are the first parasitic stage found within the vertebrate host. These juvenile parasites invade the host tissues by crossing the small intestine and migrating to the liver by secreting cathepsin proteases, among other mechanisms. The authors studied the physio-biochemical characteristics of four of these enzymes  showing their wide variety in terms of activity, optimal pH and substrate specificity, which could be beneficial for the parasite as an efficient digestion system. Finally, in the study published by Molina-Hernández et al. [F. hepatica. They characterized the presence of degenerated adult worms associated with severe granulomatous inflammation in bile ducts from the above-mentioned sheep by immunohistochemistry.The remaining four publications are focused on the field of host–parasite relationships in fasciolosis. In this foodborne zoonotic disease, resistant isolates of the parasite against the drug of choice, triclabendazole, have been increasingly reported in several countries. This fact has encouraged the development of alternative treatment or other control strategies, such as vaccination trials, for which understanding the cross-talk interactions between hosts and parasites is of paramount importance. The study published by Mas-Coma et al.  exploredr et al.  payed thz et al. , these aIn sum, the articles published in this Special Issue gathered different approaches for the study of host–parasite relationships in veterinary parasitology from the point of view of epidemiology, genetics, veterinary medicine, molecular biology and others. This fact reflects the multi-disciplinary concept that is required to deal with the complexity of parasitic systems. Consequently, veterinary parasitology research needs to be transdisciplinary, under the umbrella of One Health, in order to be able to generate all the knowledge that is needed to identify and select potential vaccine targets in a more rational way. To reach this objective, (1) setting up new models to understand the host–parasite relationship ; (2) undertaking omics-based analyses to obtain a comprehensive picture of this interaction; and (3) developing post-genomic approaches  will be needed to select the most promising candidates to target in attempts to fight animal parasites .


Recognizing plant diseases is a major challenge in agriculture, and recent works based on deep learning have shown high efficiency in addressing problems directly related to this area. Nonetheless, weak performance has been observed when a model trained on a particular dataset is evaluated in new greenhouse environments. Therefore, in this work, we take a step towards these issues and present a strategy to improve model accuracy by applying techniques that can help refine the model’s generalization capability to deal with complex changes in new greenhouse environments. We propose a paradigm called “control to target classes.” The core of our approach is to train and validate a deep learning-based detector using target and control classes on images collected in various greenhouses. Then, we apply the generated features for testing the inference of the system on data from new greenhouse conditions where the goal is to detect target classes exclusively. Therefore, by having explicit control over inter- and intra-class variations, our model can distinguish data variations that make the system more robust when applied to new scenarios. Experiments demonstrate the effectiveness and efficiency of the proposed approach on our extended tomato plant diseases dataset with 14 classes, from which 5 are target classes and the rest are control classes. Our detector achieves a recognition rate of target classes of 93.37% mean average precision on the inference dataset. Finally, we believe that our study offers valuable guidelines for researchers working in plant disease recognition with complex input data. Plant diseases and physiological disorders concern farmers and researchers as it directly impacts food security and, therefore, human well-being . QuantifFollowing the success of deep neural networks (DNNs), mainly on large-scale image classification  and objeEncouraged by the results achieved by our previous works, we seek further improvements, especially to make the system more adaptable to new real-world greenhouse conditions . We are In this research, we take a step towards the issues mentioned above and present an approach to improve model accuracy by applying a strategy that can help refine the model’s generalization capability. More specifically, we investigate the interaction between anomalies and their inter- and intra-class variations from the perspective of two categories: target classes and control classes. Based on that concept, our strategy works as follows: First, we utilize the target and control classes to train and validate a detector on images collected on a set of greenhouses (known data). Then, we apply the generated features for testing the system’s performance on an inference dataset (new data) where the goal is to specifically detect the target classes. Finally, our model becomes more robust during inference in new environments by explicitly controlling inter- and intra-class variations of the data utilized during training.The contributions of our work are summarized as follows:We propose and explore a paradigm called “control to target classes” to improve the performance of our deep learning-based detector to deal with changes of new greenhouse conditions using target and control classes.Experimental results on our tomato plant diseases dataset show the efficiency of the proposed framework. We work on a more extended dataset than , 2018 thFrom an information-theory perspective, we analyze the distribution of samples in the feature space using the t-SNE distribution  and confWe believe that our study can offer valuable guidelines for researchers working in domains of plant disease recognition with complex input data. Also, the potential of this technology aims to help farmers and non-expert people find problems associated with plant anomalies and diseases that affect crops.The remainder of this paper is organized as follows: Section “Related Works” presents a review of related works and techniques for plant diseases recognition; Section “Materials and Methods” describes our proposed method; Section “Experimental Results and Discussion” shows the experiments and results; and finally, Section “Conclusion” concludes the paper and presents a discussion and guidelines for future works in the field.In this section, we describe recent works related to our research. We introduce some baseline approaches on deep learning for image classification and object detection. Then, we review some techniques for plant disease recognition.The massive accessibility of media and hardware technology has brought new opportunities for the application of deep learning into various research areas . CNNs haIn recent years, deep learning techniques have shown great efficiency in recognizing diseases and pests that affect plants. Thus, through its implementation, deep learning-based systems have become the leading technology to fulfill this task. Depending on the processing strategy, these methods can be divided into two categories: image-based disease classification and region-based disease recognition.A breakthrough in the area is the work presented in In this category, our previous work  on tomatRecently, region-based frameworks were extended to other crops and diseases. For instance, a method  to detecThe availability of accessible data has also brought the opportunity to improve the accuracy of image-based disease classification approaches. A significant breakthrough is the Plant Village Dataset . Recent The drawbacks of using data collected in the laboratory against images collected in the field are analyzed in Despite the availability of datasets, data is still scarce and hard to collect. Also, the desired performance is challenging to achieve uniformly for all classes since a system tends to prioritize classes with more samples while minimizing the contribution of the other classes. In this regards, a solution to the issues on data imbalance proposed to generate synthetic images using generative adversarial networks for image-to-image translation . This stIn the following subsections, we study the conditions and strategies to achieve the desired performance through the recognition of tomato plant diseases. Each component of the system and the selection criteria for the target and control classes are described below.Tomato plants, like any crop, are vulnerable to several physiological disorders and attacks caused by plant diseases. A plant is considered a bio-physiological organism and a physical object that is subject to physical laws . EffectiSensor: We captured images using different RGB camera devices with various resolutions such as smartphones or other digital cameras, including DSLR cameras.Images: Our dataset includes images of multiple resolutions with various infection stages and locations of the symptom . Also, we collected images of healthy leaves and surrounding regions of the greenhouse.Greenhouses: We obtained data throughout the year since 2015–2020 in different seasons and local farms in Korea. The selected farms include some for research and commercial purposes at different scales. Among them, some utilized controlled environments and technology, while in others, mainly at a small scale, the process is performed more manually. Therefore, plants are more vulnerable to disease spread.Diseases: As tomato is a seasonal product, we visited the farms in coordination with local experts to ensure data collection of various diseases. The current dataset includes images of 12 types of diseases and pests in different amounts based on the presence and availability in the farms.Time: We collected data during the period of 10 am to 3 pm with sunlight.Validation: During the whole data collection process, we had the support of experts in plant diseases who were in charge of selecting and validating the type of diseases and disorders.internal variations  or locally . For instance, some diseases, especially at an early stage, contain features that can cause confusion to the system , and powdery mildew. We support this decision from the experience of our previous works and with the support of the experts.Control classes: Control classes are those that contain particular features that help deploy the system in new greenhouse scenarios. By using these classes, we aim to specifically obtain explicit control over intra- and inter-class variations by adding additional knowledge to improve the model’s generalization capability. Although the model also learns these classes, their application directly influences the final prediction of target classes. Control classes are healthy leaves, miner, physical damage, magnesium deficiency, tomato chlorosis virus (ToCV), plague, whitefly, whitefly egg, and background. The background class, in particular, provides contextual characteristics such as different illumination conditions and surrounding objects of the greenhouse.Motivated by the above observations, this part elaborates the strategy in detail. As shown in Following the promising results of our previous work  with theT = {1, 2, 3, …, t} and control classes C = {1, 2, 3, …, c} are used to build the weights of the baseline model. Both target Training the network end-to-end aims to reduce the final loss function in where Once trained on data from seen farms, the model contains features from both target and control classes. Then, we use the generated weights to evaluate the adaptation capability of the model to new environments and its generalization to new data. This inference dataset includes samples of target classes collected in greenhouse environments other than those used for training. Control classes are omitted for recognition but still contribute the necessary weights to avoid class confusion and misclassification. Our system uses a single input image and generates a set of regions with bounding boxes and class confidence of plant diseases. We evaluate the performance of the detector using the following metrics:Intersection-over-Union: This metric evaluates the detector’s capacity to precisely localize the ROIs concerning the ground truth using the intersection over union (IoU) operation with a threshold value. We utilized a threshold of 50%.A and B represent the ground-truth and predicted box, respectively.(2)where Mean Average Precision: mAP is the area under the precision–recall curve calculated for all classes.(3)r, and (4) where, In this section, we validate the performance of our proposed framework using target and control classes. We use the training/validation dataset to build the core features of the detector. Then, we evaluate the inference of the model with another set of target data from new greenhouses to perform recognition of target classes. Also, we further analyze the influence of control and target classes. Qualitative results show some examples of the output images of the detector evaluated in different scenarios. Finally, we demonstrate the impact of the use of target classes by representing features in the spatial domain.baseline dataset” and use it to build the core weights for further implementation.Following our previous work , we use Additionally, since our data come from different sources, an appropriate distribution is required to ensure that the system learns features adequately. Specifically, we apply an inner-class distribution of samples to capture data from all classes. This setup allows independent data from each class to appear during training and validation, respectively.To further validate the use of target and control classes to improve our model’s generalization capability, we collected an inference dataset. We obtained additional data of target classes from farms other than those used for training. Although these sample images belong to the same type of diseases as the baseline dataset, their visual characteristics and background conditions may vary and contain more features from global and local areas of the leaves. In addition, we also extended the recognition of symptoms in other parts of the plants, such as fruits and flowers. We conducted experiments on a machine with 4 NVIDIA TitanV GPUs, CUDA 9.0, and cuDNN 7.1.2 during the system development. We also implemented the model on a server PC equipped with an NVIDIA Tesla V100 GPU for inference purposes. For all the cases, we set the batch size to two images on a single GPU. We trained the model end-to-end using a pre-trained model on the MS-COCO dataset .We train the model on the baseline dataset  and evalThe use of control classes for training the model represents a valuable performance improvement for all the evaluated feature extractors. However, the results suggest that using an FPN-based architecture satisfactorily contributes to addressing the recognition problem of our approach. We believe that the reason is that FPN uses features obtained from different levels of the backbone and thus influences the recognition of objects at multiple scales. To measure the model’s capacity to deal with features of target classes, we further evaluate the trained model on the inference dataset using the best model of It is also essential to notice that the inference results show the potential characteristics of the proposed approach to deal with new conditions of target diseases. Specifically, healthy leaves and background classes support the model’s adaptation to new environments, while the other control classes add more context information. In this part, we study the inter-and intra-class variations that potentially help determine the correlations between target and control classes. Moreover, we evaluate the capabilities of the detector by studying the spatial distribution of features to demonstrate the contributions of our approach.First, to show the importance of using control classes, we use the model trained on the baseline dataset , applyinAdditionally, to demonstrate the effectiveness of using control classes for training, in To support the results presented above, we evaluate the generated models in terms of the number of true positives (correct predictions) compared to the false positives and false negatives. In this experiment, we also analyze the capability of the system to quantitatively predict target classes and their impact on the false positive and false negative rates, using two cases:Training without control classes: We train the model on the target classes and further evaluate it in the whole dataset. In this setting, the system does not receive any features of the control classes.Training on both target and control classes: We evaluate the impact of adding the control classes to train the model along with the target classes. In this case, the system obtains features of both groups.In the first case, as presented in In the second case, as shown in Despite the satisfactory and robust performance that we presented, there is a limitation of the proposed approach. The main limitation is the data imbalance. This issue directly impacts the selection of the target classes as the recognition objective of a system. Data should be sufficient to capture all features that the system can encounter in real-world greenhouse scenarios. This fact indicates that while we can achieve satisfactory results on the evaluated target classes, the promising model still needs more data to improve its robustness against more variations. Also, an appropriate selection of samples is essential for the success of our approach.In this paper, we proposed a new paradigm called “control to target classes” to refine the generalization capacity of plant disease recognition based on deep learning. We presented a strategy to deal with changes in new greenhouse conditions. The explicit control over inter-and intra-class variations allowed our model to learn more data variations that make the system more adaptable and robust when applied to new scenarios. Experimental results on our extended tomato plant diseases dataset with 5 target classes and 9 control classes validated the performance of the proposed framework. We obtained a recognition rate of 93.37% mAP for the target classes during inference. From an information-theory perspective, we analyzed the distribution of samples in the feature space using the tSNE distribution. We confirmed that our methodology using control classes improved the recognition of target classes. Finally, our study can offer valuable guidelines for researchers working in plant disease recognition with complex input data. Also, the potential of this technology can help farmers and non-expert people find problems associated with plant anomalies and diseases that affect crops. Future studies will apply our proposed method to other crops using data collected in more greenhouse settings.afuentes@jbnu.ac.kr.The datasets presented in this article are not readily available because this research has been carried out as part of a project funded by the Government of Korea. We have an agreement not to open the dataset until the project is concluded. Requests to access the datasets should be directed to AF, AF designed the system, performed the experiments, and wrote the article. DP and SY advised in the design of the system and analysed the strategies to find the best method for plant disease recognition. ML collaborated and advised during data collection and annotation. All authors contributed to the article and approved the submitted version.This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (No.2019R1A6A1A09031717); by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (NRF-2021R1A2C1012174); and by Korea Institute of Planning and Evaluation for Technology in Food, Agriculture and Forestry (IPET) and Korea Smart Farm R&D Foundation (KosFarm) through Smart Farm Innovation Technology Development Program, funded by Ministry of Agriculture, Food and Rural Affairs (MAFRA) and Ministry of Science and ICT (MSIT), Rural Development Administration (RDA) (421005-04).The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


The study of ecological succession to determine how plant communities re-assemble after a natural or anthropogenic disturbance has always been an important topic in ecology. The understanding of these processes forms part of the new theories of community assembly and species coexistence, and is attracting attention in a context of expanding human impacts. Specifically, new successional studies provide answers to different mechanisms of community assemblage, and aim to define the importance of deterministic or stochastic processes in the succession dynamic. Biotic limits, which depend directly on biodiversity , and abiotic filtering, which depends on the environment, become particularly important when they are exceeded, making the succession process more complicated to reach the previous disturbance stage. Plant functional traits (PFTs) are used in secondary succession studies to establish differences between abandonment stages or to compare types of vegetation or flora, and are more closely related to the functioning of plant communities. Dispersal limitation is a PFT considered an important process from a stochastic point of view because it is related to the establishing of plants. Related to it the soil seed bank plays an important role in secondary succession because it is essential for ecosystem functioning. Soil compounds and microbial community are important variables to take into account when studying any succession stage. Chronosequence is the best way to study the whole process at different time scales. Finally, our objective in this review is to show how past studies and new insights are being incorporated into the basis of classic succession. To further explore this subject we have chosen old-field recovery as an example of how a number of different plant communities, including annual and perennial grasslands and shrublands, play an important role in secondary succession. Ecological succession is a process whereby plant communities re-assemble after a natural or anthropogenic perturbation. Odum  formulatUntil the last quarter of the 19th century, the forests of Western Europe were subjected to similar uses in both the north and south; however, northern countries subsequently recognized the importance of restoration, leading to the implementation of reforestation campaigns. At the end of the World War I, large farms began to appear in northern Europe resulting from the concentration of smaller ones . Agricul2 of lands transitioned to grasslands and forest, with an increase of 150% compared to the 1970–1990 period [The Common Agricultural Policies (CAP) introduced by the European Union in 1990 reorganized lands to be more competitive for the global market. Several regions shifted to cultivating other plants owing to the cost of maintaining the old ones, in some cases due to lack of accessibility to cultivated areas. From the beginning of the CAP (1990–2010), 144,733 km0 period . This ab0 period .Land abandonment has opened up opportunities to evaluate the way vegetation recovers . The praThree main drivers have been described as being responsible for land abandonment : (i) ecoThe development of aerial photography in the 1940s created opportunities for studying changes in vegetation. In spite of the difficulties in distinguishing natural vegetation from agricultural land due to the poor quality of the pictures and the lack of vegetation studies, the comparison through aerial photographs confirms the increase in forest cover in the northern Mediterranean Basin in the second half of the 20th century ,23.Competition between individuals for resources exists in all plant communities. No significant differences have been found between inter-and intraspecific competition, and the processes of facilitation, tolerance or inhibition are relative and even simultaneous and have different weights during each successional stage.Plants can alter their environment, changing the availability of resources. General uniformity is higher in the intermediate stages of succession when the periods of coexistence are higher due to the dominance of slow-growing plants.Physiological and energy restrictions hinder species’ capacity to maximize their competitive character in any circumstance. This produces an inverse correlation between certain groups of traits and the relative competitive abilities of species change depending on a range of environmental conditions. These particular traits are different depending on whether the succession is in a late or early stage.Plant community functioning and succession patterns have been extensively studied and discussed . Huston However, the dynamic complexity of plant interaction has recently been studied in depth, using approaches based on valid empirical inquiries which can test general patterns related to coexistence, detect higher rates of population growth at low abundances, validate how these mechanisms operate in the field, identify certain properties of the species that influence features (fitness) in these interactions, and test predictions in community structure models ,41,42,43A secondary succession is a cluster of diverse processes affected by many factors, so the results may differ in each case. Understanding the dynamics of secondary succession will help us to better understand both the final and intermediate stages. There are two different frameworks to evaluate the establishment of plant communities: deterministic and stochastic. In the deterministic framework the local community dynamics are determined by specific species traits and local abiotic or biotic factors. In the stochastic view, the dynamics are determined only by the demographic stochasticity and dispersal limitation. In the deterministic model the beta-diversity decreases along the succession . In the stochastic model, the divergent species composition becomes greater as the beta-diversity increases along the succession ,46,47. TThe succession pattern and its speed depends on the species pool, their biology, local ecological conditions, and the landscape surrounding the abandoned land ,48,54,55Both the deterministic and the stochastic frameworks bring information on the dynamic of secondary succession and are necessary to explain the processes that occur on it. In Mediterranean climates, more studies on secondary succession are necessary to have a better look on the processes.The colonization of abandoned lands by passive and spontaneous regeneration can occur through any type of species or animals that can establish, survive, and grow there. It is usually a quick process in very productive areas such as tropical or humid zones but very slow in environments with low primary production such as the Mediterranean . SuccessThe spontaneous succession pattern in old fields shows that perennials became established in less than four years and remained for over 50 years. There is an initial stage of decreasing annuals that are replaced by perennial herbs, followed by some decades of perennial grasslands or shrubland development. Species richness fluctuates in the first stage of succession due to the turnover between annuals and perennials; the species number subsequently becomes quite stable. Allochthonous species are common in these old fields, but diminish throughout the succession. The success of the succession is influenced by the species pool in the surrounding areas and by seed dispersal ,58,59,60Passive and spontaneous regeneration bring us a valuable information on former land uses of present abandoned lands.Biotic limits, which depend directly on biodiversity , and abiotic filtering, which depends on the environment, become particularly important when they are exceeded, making it more complicated in farmlands to reach the previous stage. For instance, if a biotic limit is exceeded, the vegetation must be manipulated with a new combination of species to recover. If an abiotic filter is exceeded, the environment needs to be modified; in old fields with a strong biotic and abiotic legacy, there may be a permanent stage of degradation due to poor seed distribution and competition with invasive plants. This phenomenon is more exacerbated in Mediterranean areas because of their more limited soils and changes produced by annual pioneer vegetation to the resources necessary for perennial species ,64.The interaction between plants and insects is a good example of biotic interaction. Herbivorous insects can alter the plant community by activating changes in the expression of defense traits . Plants Studies on biotic and abiotic limits in secondary succession are useful for restoration. The natural vegetation dynamic effectively improves ecosystem development but takes 20 years. This time can be shortened with management of well-conserved areas close to sites requiring restoration (roadsides) in order to improve the plant composition in late-successional stages, when soil loss should be avoided with any biological solution  if possible, and soil C and N accumulation should be improved .Rainfall is a direct abiotic filter since it is a resource in itself and is important for recovery. Together with soil type and substrata, it determines which species will develop after abandonment. Rainfall is also influenced by climate change, and as a direct filter, its influence can be unavoidable . Other sBiotic interactions and abiotic filters have been included together as ecological rules for dispersal limitation ,71. ThesBiotic interactions and abiotic filtering play an important role in changes occurring in a secondary succession. They can reveal how any of these can affect the future stages of a secondary succession.The species pool was defined by Eriksson  as the sPriority effects were defined as a competitive process in the model proposed by Slatkin , which rThere are many studies seeking to understand and clarify how species coexist and the mechanism of species assembly, but also much debate ,88,89,90Plant-trait based plant ecology or functional plant ecology ,93 consiPlant functional traits (hereafter PFTs) are morphological, biochemical, physiological, structural, phenological, or behavioral characteristics of organisms that influence their performance or fitness and are widely used to group species. Two common applications of PFTs are: (i) to characterize the responses of plant communities to environmental changes, and (ii) to quantify the influence of community changes on the ecosystem processes . They arThe choice of the traits studied strongly affects the results, and the combination of traits can also alter the patterns observed. During the transition of stages in the succession, functional changes reflect a general pattern from a ruderal and quick-growing to a more competitive-conservative strategy due to the decreasing availability of light and nutrients during the succession . These rOne interesting trait in secondary succession is the leaf life span  than by seed availability  . In the Studies in old fields from 20 to 28 years have used dispersal traits weighted on abundance and unweighted traits. The traits used were the number of means of dispersal for each species, and classification indices for anemochory and epizoochory. Along the succession the authors verified how the richness and dispersal of generalist species diminishes as the species become more specialized. Species richness and epizoochory ranking are indicators of the transition from the early stages of these old fields. Anemochory does not follow similar patterns in different study areas, depending on the succession context . EctozooFinally, Makoto and Wilson  showed hDispersion is one of the more important stochastic processes, determining the species pool in the first stages of a secondary succession with a higher influence of wind on it, then animals are the main dispersal agents in late successional stages.Nitrogen levels in ecosystems are probably one of the main variables determining the succession rate . The patStudies in old fields, when the age of abandonment is known, reveal that microbial communities and the feedback between plants and soils are drivers of species turnover in succession ,123,124.C and N cycles in terrestrial ecosystems are related to plant and microbial activity patterns. The common limitation of N for plant growth and C for microbial growth suggests that these patterns are related . Values Soil organic carbon (SOC) in old fields can be affected by rainfall and is a limiting factor for secondary succession and soil characteristics. In a chronosequence and along a rainfall gradient, SOC concentration increases with abandonment time and precipitation. In arid or drylands such as Mediterranean areas, SOC accumulation in secondary-succession soils is slow, while it is faster in areas of high annual rainfall ,133. SoiAnother important factor in soil nitrogen concentration is the presence of legume species in the area, which fix atmospheric nitrogen. This is a positive driver in SOC accumulation , and hasExtracellular enzymes and microbial biomass play an important role in biochemical soil cycles, carbon dynamics, and soil function and development . After aSoil C and N have a more or less established pattern in a secondary succession, being their use highly recommended, although they can be affected by other abiotic factors, such as the rain.The importance of the seed bank for recovering vegetation after a process of disturbance has been widely highlighted and is recognized as an essential community trait for ecosystem functioning ,146,147,Similarities between the soil seed bank and the aboveground vegetation have been extensively analyzed with different results depending on the study, vegetation type, and the disturbance ,154,163.Other studies on seed banks in the short term or by chronosequence have shown a gradual decrease in seeds with greater depth. After perturbation, shallow soils show lower species richness and abundance, although the first succession is constant in the seed bank ,157,158.Soil seed banks have a recognized role in plant community developing but more studies are needed to establish a more precise pattern.The chronosequence is the set of sites that share the same substrate but differ in regard to the time they were formed. They are appropriate for studying plant succession at different time scales when there is evidence of similar processes, and communities with convergent successional histories, low diversity, fast species turnover, and presence of ecological succession processes .To prepare a chronosequence it is necessary to have different nearby sites with a similar use  with evidence of abandonment or changes in use . AbandonTemporal changes in biotic and abiotic aspects of the soil must be observed, including water availability, nutrients, structure, texture, and biota. Disturbances are responsible for the sudden loss of biomass or structure of an ecosystem but create opportunities for establishment by altering the resources or the physical environment, in addition to initiating and modifying succession. Organisms have complex responses that impact biodiversity ,167,168.To determine whether the chronosequence is correct, each of the chosen sites must be resampled after a certain time to check if the predicted sequence occurs. This resampling also provides other data that is not accessible from a normal chronosequence, such as the successional change rate after the intervention. Foster and Tilman  measuredDisturbation is one of the main drivers to face when starting a chronosequence. It is not always possible to know its origin, being necessary to control as much variables as possible.The comparison of the soil function in a forest stand with natural afforestation (secondary succession) in old fields showed a non-linear soil improvement in the old fields, whereas this improvement was linear in the forest stand. After 40 years, the soil status in the forest stand is comparable to semi-natural vegetation, with typical resource islands . Finally, it takes longer to achieve similar soil recovery in old fields than in afforestation .Another chronosequence study in abandoned crops at five and fifteen years with natural vegetation revealed an increase in diversity and richness of all functional groups in the fields that had been abandoned for a longer time compared to more recently abandoned fields. Diversity was also affected by mechanization, and by the fact that species with long-lived seeds cannot recover in the early stage of succession. As in other secondary succession cases, the recovery of annuals occurred only in the early stages, while the transition to perennials took place after 15 years of abandonment. Total nitrogen increased in the most recently abandoned fields and the percentage of sand was higher in recent old fields, as cultivation techniques produce a gradual degradation of the upper soil layers that is more severe than erosion. A negative correlation was also found between richness and diversity in all functional groups with silt. This is because silt changes the soil pH and reduces the availability of micronutrients, zinc, manganese, and P .Like many other croplands, vineyards have also been abandoned. This is due to the policies of the European Union and France, which promoted changes in the quality of wines and cultivation methods, while subsidizing the displacement of non-productive vineyards, which encouraged abandonment. Where these changes were not implemented, the vineyards were abandoned . These aIn Mediterranean climates there are many vineyards abandoned; it would be necessary to develop more successional studies on them.The data indicate that the anomalous climate of the past half century is affecting the physiology, distribution and phenology of species. Although natural climate change and other non-climatic factors may be responsible for these alterations, human-induced climate and atmospheric change is now the more consistent explanation ,175,176.The study by Thuiller et al.  took datFocusing more on Spain, they obtained two different predictions for northern and southern zones. In the center-north there was an excess of loss of species as these were habitats with little tolerance, and were marginal for most species. In the southern zone, however, there is not loss of species. This is due to the dry warm summers that enable these species to successfully tolerate heat and drought, making them potentially well adapted to future changes .2 on global warming has led to a growing interest in reducing emissions and increasing their sequestration in the soil. This a good option, since abandoned lands can be a low-cost strategy to sequester C and mitigate anthropogenic CO2 emissions [The impact of COmissions .Carrying out a long-term chronosequence can allow us not only to compare different variables across time but also to observe changes due to warming and their direct consequences on secondary succession plant communities.The presence of old fields today allows us to investigate them and learn about their legacy in ancient times. We can determine how these lands recover after they have ceased to be used for growing crops. By doing this with a temporal gradient of sampling areas, we can estimate the time it takes for land to recover to its usual state after being manipulated. In this review, we have seen all the factors that must be considered when carrying out a chronosequence. It is not always possible to guarantee that all these factors can be correctly identified. If it is done correctly, we will obtain a large amount of data providing information on how the secondary succession has occurred or is occurring, which allows us to develop hypotheses. All these data can also be helpful to develop further works in abandoned lands, for instance, a restoration. The results obtained in the chronosequence can guide us in determining what type of use is most recommended.Another important aspect is the relationship of all of the above with climate change. The availability of a chronosequence from fields abandoned 30 years ago to fields abandoned today allows us to quantify the effects of climate change on vegetation, which have become more significant in recent years.However, more studies are needed that combine measurements of several PFTs so that the hypotheses that arise are more exact, such as soil analyses and measurements of chlorophyll and proline in plants . Despite


Quantifying training variables of a physical exercise modality is essential for an appropriate dosage. In training with elastic bands, time under tension (TUT) and force represent the duration and intensity of this force-training modality. The aims of this study were to evaluate the degree of compliance to TUT prescription for three different scenarios of two exercises and the comparison of the force values obtained versus the estimate values. A total of 29 healthy volunteers were evaluated in a clinical environment under controlled conditions in 3 different scenarios (different velocities or ROMs) of both shoulder abduction and knee extension in 2 sets of 10 repetitions per scenario within a single session. Concentric and isometric phases showed a higher degree of compliance for their TUTs than the eccentric phase TUTs for all scenarios of both exercises, whereas the degree of compliance was higher for the total TUT than for the phases’ TUTs. Additionally, the eccentric phase showed a general tendency to develop for longer time periods than prescribed, whilst the fast scenario showed a higher degree of compliance for isometric phase TUTs and total TUTs than the extant two scenarios in both exercises. On the other hand, the force of the elastic bands tends to be overestimated according to the estimates of the manufacturers. These findings, both those related to the degree of compliance with TUTs and the force analysis, can be used by physiotherapists and other exercise professionals as a reference to achieve a good dosage of routine exercises with elastic bands. Physical exercise has been widely implemented in different fields, ranging from training to rehabilitation of injuries ,2. In muAerobic endurance exercise and resistance training have been traditionally implemented as training modalities in rehabilitation programs ,2,17. AlExercise interventions are usually divided into supervised gym-based programs and home-based training programmes . Gym-basAmong the different methods of applying load in resistance training in home-based programmes, elastic bands have proven to be effective in the rehabilitation of shoulder, neck, knee, and hip pain . Home-baA cross-sectional study design was used to determine TUT and force parameters of elastic band training for shoulder abduction and knee extension. Each exercise was performed in three different scenarios (different velocities or ROMs), in 2 sets of 10 repetitions per scenario. All measurements were made in a single session under similar conditions of temperature (21 °C) and light in the clinical research laboratory of the Department of Physiotherapy .A total of 29 healthy volunteers  who were recreationally active   were evaBefore measurements, subjects were requested not to participate in any strenuous exercise during the previous 48 h. The evaluation session started with a standard warm-up, which consisted of walking up and down several flights of stairs and performing weight-free shoulder abductions. Shoulder abduction and knee extension with elastic bands were evaluated in three common elastic band training scenarios: (I) 0–90° at high velocity, (II) 0–90° at low velocity, and (III) 0–45° at low velocity . These sThe guidelines established for performing shoulder abduction were proposed in previous studies  as folloThe elastic bands used were TheraBand CLX : blue for abduction and golden for extension with a length of 40 cm , which are commonly used in rehabilitation studies ,29,30. TThe linear encoder and force gauge information was recorded by the Data Synchronisation Unit (DSU) ML6000  , which iOnce the phases were determined, the TUT and force parameters were calculated. The TUTs calculated were concentric TUT, isometric TUT, eccentric TUT, and single repetition TUT as the sum of concentric, isometric, and eccentric TUT during 1 repetition. The analysed force parameters (Newton) were tension at 50% and 80% in each phase  and maximum tension obtained A. The meParticipant characteristics, force, and TUTs (Newtons (N) or seconds (s)), respectively, for each phase are presented as average (SD) and 95% confidence intervals (CIs). Mean between series was used for analysis. The degree of compliance with the expected TUTs per phase and total was analysed by subject and repetition, considering the obtained TUT as ‘fulfilled’ whenever the error was below 10% with respect to the prescribed TUT. This analysis is shown by frequencies; TUTs of the repetitions were subsequently either in range, exceeded the prescribed TUT, or did not reach the prescribed TUT.t-tests were used to analyse differences between the maximum force obtained and the maximum estimated force per scenario and exercise, and Cohen’s d was calculated to evaluate the effect size  [Paired : large) . All anad > 2.48).The aims of this study were to evaluate the degree of compliance with the prescription of TUTs for three different scenarios of two exercises, and the comparison of the force values obtained versus the estimated values. Four important findings emerged: first, the concentric and isometric phases showed a higher degree of compliance for their TUTs than the eccentric phase TUTs for all scenarios of both exercises, whereas the degree of compliance was higher for the total TUT than for the phases’ TUTs; second, the eccentric phase showed a general tendency to be developed for longer time periods than prescribed; third, the fast scenario showed a higher degree of compliance for the isometric phase TUTs and total TUTs than the other two scenarios in both exercises; fourth, the force of the elastic bands tends to be overestimated according to the estimates of the manufacturers.To our knowledge, this is the first study to examine the degree of compliance on the TUTs of common training exercises with elastic bands per contraction phase. Our findings showed differences in the percentage of repetitions with TUTs in range across the different phases, with a degree of compliance higher for the concentric and isometric phases compared with the eccentric phase for all scenarios and exercises. In addition, the results stemming from the eccentric phase consistently showed how subjects usually tend to perform this phase for a longer time period than prescribed: it may be due to the fact that the eccentric phase corresponds to the return phase and the subjects have to resist the traction force of the elastic band. Thus, the possible fear of performing it faster than prescribed may result in a reactive overaction. Therefore, our results could help health and training professionals who guide exercises with elastic bands, so that they specifically highlight the importance of complying with the TUT for this phase and especially emphasize not performing it slower than the indicated TUT.On the other hand, the total TUT showed a degree of compliance generally higher than TUTs for each one of the phases. Since previous studies have used this parameter ,34 insteThe isometric phase showed a better degree of compliance for the fast scenario than for the slow or restricted scenarios. In all three scenarios, the prescribed TUT for the isometric phase was 2 s, so a difference in the degree of compliance across scenarios is unexpected, given that the TUT remains the same. In addition, except for the slow knee extension, those repetitions in which the TUT was not in range tended to be performed in less time than prescribed, that is, the isometric phase lasted less than 1.8 s. This may be due to the fact that the subjects tend to become fatigued when holding the position and traction of the elastic band, especially in the shoulder, and tend to start the return  earlier than prescribed. Our findings would, therefore, suggest paying special attention to maintaining the prescribed TUT of the isometric phase.On another note, in relation to the force analysis, our findings show a clear overestimation of the force data provided by the manufacturer, since the force obtained was at least 25% less than estimated. Previously, Uchida et al. [To the best of our knowledge, no previous studies have examined the exercises of shoulder abduction and knee extension with elastic bands in the training scenarios proposed in the literature . Furthermore, the use of a reference measure to evaluate velocity and tension , and their simultaneous synchronisation could be considered one of the main strengths of the current study. Despite its novel findings, this study was subject to some limitations: first, analyses were conducted on healthy subjects, mainly males, without recent injuries, limiting the generalisation to other populations. Thus, TUTs for fast or slow scenarios could be different for athletes from sports with a predominant use of a particular lower or upper limb  or between sexes. Additionally, the restricted ROM scenario simulates a situation in which the person has a condition hindering the movement of the segment throughout the ROM. Since we have studied all three scenarios at the same time, we understand that each scenario can be of paramount importance to each target population. Therefore, future studies should examine TUTs in specific populations for which each scenario is the main recommendation. Additionally, measures were made in a controlled environment. Although our study is a first approach to the analysis of the degree of compliance with TUTs and force carried out under the supervision of a physiotherapist, future studies should examine the degree of compliance in a home environment, under no supervision, after familiarisation with the exercises and scenarios.Our study provides insight into the degree of compliance with the TUTs for the different phases of two of the most commonly used training exercises with elastic bands, showing that the eccentric phase has a lower degree of compliance than the concentric and isometric phases and that the total TUT would not be advisable to use since it can mask what happened in the different phases. In addition, the analysis of force for the elastic bands used in our study revealed that the values described by the manufacturer are usually overestimated.


Background: Cancer diseases in children and adolescents are considered to be one of the most serious health problems in the world. It is estimated that about 151,435 cases are diagnosed in children annually. Children with cancer experience many comorbid symptoms related to diagnosis and treatment that can profoundly affect their lives. They experience physical and emotional suffering, which affects their well-being and physical fitness, influencing the prognosis and deteriorating their physical, mental and social functioning. Given the limited data, an attempt was made to assess the problems of the biopsychosocial sphere of need and stressors among children and adolescents treated for cancer. Accurate symptom assessment is essential to ensure high-quality care and effective treatment. Patients and Methods: The qualitative study was conducted in pediatric oncology of hospitals in Poland. Children diagnosed with cancer were invited to participate in the study to assess their problems, stressors and needs. Results: The study included 520 people, where female sex constituted 48% and male 52%. The mean age of the children is 13.2 SD = 2.5. Negative experiences related to the disease are experienced by 82% of children. Among the surveyed children, the most experienced were anxiety (61%). The conducted research shows that as many as 69% of all respondents experienced states that indicate severe depression. The most common somatic problems reported by children were pain (58%). The most dominant areas of life that had a negative impact was body image (85%). Conclusions: Children and adolescents diagnosed with neoplastic disease experience many problems and stressors in every sphere of life, which undoubtedly affects a high level of unmet needs. The main category of needs concerning the challenges faced by children with cancer was psychological and care problems. In the youth group, the needs were mainly related to education and social support. Cancer diseases in children and adolescents are considered to be one of the most serious health problems in the world. It is estimated that about 151,435 cases are diagnosed in children annually . AccordiChildren with cancer experience many comorbid symptoms related to diagnosis and treatment that can profoundly affect their lives. They experience physical and emotional suffering, which affects their well-being and physical fitness, leading to delays or limitation of treatment, influencing the prognosis and deteriorating their physical, mental and social functioning ,14,15. PAlthough cancer is a common problem, the knowledge about the experiences of Polish children and adolescents treated for cancer is very limited. Given the limited data, an attempt was made to assess the problems of the biopsychosocial sphere of need and stressors among children and adolescents treated for cancer. Accurate symptom assessment is essential to ensure high-quality care and effective treatment.The study aims to analyze the problems, stressors and needs of children and adolescents hospitalized due to cancer, which gives the opportunity to better understand the experiences of children, and for health care professionals, it allows a broader view of a child with cancer.The qualitative study was conducted in pediatric oncology and hematology departments of hospitals in Podkarpackie Province in 2009–2019. Hospitals provided treatment and care by the public health care system to pediatric patients diagnosed with cancer. Children diagnosed with cancer were invited to participate in the study to assess their problems, stressors and needs. Due to the small size of the sample, the share of respondents with fairly consistent characteristics was important. The size of the sample resulted from the nature of the study (preliminary study).Each invited person and their guardian were informed about the purpose of the study. The eligible patient and guardian received an information pack from a research group member. The information package consisted of a letter describing the objectives of the study and its course, a consent form to participate in the study, to be completed if patients are interested in the study, and a no consent sheet if they were not. After informed consent was given by the patient and their caregiver, the patient chose the time and place to participate in a face-to-face interview conducted in the clinic by a research group member. The interview lasted approximately 60 min. In case of the patient’s fatigue, the interview was divided into parts to maintain their physical and mental comfort. All participants were asked the same questions, and the interviewer was able to explain the content of the questions if necessary. However, the questions did not seem difficult for any participant, including younger ones, and no explanations were needed.The inclusion criteria were the confirmed diagnosis of childhood cancer in the pathological report, age from 10 to 18 years, no previous chronic or life-threatening disease, knowledge of the Polish language and the consent and willingness of parents to participate in the study. Eligible participants were randomly selected from the general population. The main indicators of participation in the study were the cancer diagnosis at least three months before the study, life expectancy > 6 months, age and awareness of the diagnosis.The exclusion criterion was the diagnosis of neoplastic disease shorter than three months because the initial period of diagnosis and treatment is associated with an enormous psychological burden and the need to adapt to the patient’s situation, which may introduce errors in the results. The study excluded patients with cognitive impairment, patients who did not express their willingness to participate in the study, those under that could not speak Polish.Children and adolescents were invited to participate in the study during their hospitalization. Each invited person was informed about the purpose of the study. After obtaining the written, informed consent of the child and the guardian, the subject was interviewed. The participants chose the place and time of the conversation and decided whether they wanted the parent’s participation in the conversation. The non-participation rate was 10%. Parents of children who chose not to participate reported that they did not have enough time or that their children were tired or not feeling well. Non-participation data are not available.The study was approved by the Bioethics Committee (Resolution No. 386/2009 and 4 December 2017). Participation in this study was voluntary and anonymous, and respondents were informed of their right to refuse or withdraw from the study at any time. Each participant was informed about the purpose of the study and the time of completion of the study. Families were invited to participate during the child’s hospitalization or an outpatient visit. After giving informed consent, the parents completed the questionnaire.The method used in the research was a clinical, direct, individual, structured interview, which was in-depth and focused. The qualitative interview was a standardized measuring instrument, verified by testing a group of 20 patients during the month. It contained open-ended, single and multiple-choice questions, allowing to obtain demographic and epidemiological information concerning problems related to the disease: daily stressors of the child, somatic, psychological and social problems and needs.It is a reliable tool for determining the severity of pain. Cyclically repeated measurements of pain intensity using the VAS scale enable the assessment of the effectiveness of analgesic treatment. The scale is a 10 cm ruler, where 0 is no pain at all, 1–3 is mild, 4–6 is moderate and 7–10 is severe.This questionnaire is used as an aid in individual diagnostics, serving to objectify and quantify the degree of disturbances in the child’s functioning. It is a tool covering a wide spectrum of disorders, intended for filling by schoolchildren. It can be used in situations where it is not possible to obtain information from parents or serve as a supplement to them, constituting an important source of information on the child’s functioning. Having a high score for your child can help highlight symptoms that would otherwise go unnoticed and allow them to be referred to a specialist. The scale consists of 21 multiple-choice questions, in which one should give one of four possible answers, and then summarize the obtained points and compare them to the norms: no depression (0–11 points), mild depression (12–19 points), moderate depression (20–25 points) and severe depression (26–63 points).t-test or the Mann–Whitney U test. Correlations were determined using Pearson’s test, while χ2 was used for intergroup comparison. Significance was assessed at the level of p < 0.05. The manuscript presents the results regarding the comparison of arithmetic means and standard deviation obtained on the Beck scale. The non-parametric t-Student test was used for the comparative analysis. Following the applicable statistical principles, raw results were used for intergroup comparisons. The repeatability of answers to individual questions was assessed using Kappa Cohen statistics.The analysis used descriptive statistics and confidence intervals in the assessment of participants’ characteristics, metric and demographic data, and in the assessment of problems. Statistical characteristics of continuous variables are presented in the form of arithmetic means, standard deviations and medians. Statistical characteristics of step and qualitative variables were presented in the form of numerical and percentage distributions, using the Student The study included 520 people, where female sex constituted 48% and male 52%. The mean age of the children is 13.2 SD = 2.5. Hospitalized for the first time constituted 52% of all respondents, once again 48%. The data analysis shows that the most common neoplasms in the study group are leukemias (44%). All children had a caregiver; most were mothers (83%), while the remaining 17% were fathers. All participants received chemotherapy (100%). In total, 25% of the respondents were primary school students, 41% were middle school students and 34% were high school students. Other descriptive statistics identifying the studied group are presented in p < 0.01). Girls experienced emotional states indicative of depression relatively more often than boys. It was necessary to convert the raw results obtained on the Beck scale according to the norms to determine the number of people affected by the problem of depression. The conducted research shows that as many as 69% of all respondents (95% CI: 63–72) experienced states that indicate severe depression (p < 0.94). This means that the severity of depression features among children with the comparison of hospitalization time is similar (Negative experiences related to the disease are experienced by 82% (95% CI: 79–85) of children. Among the surveyed children, the most experienced were anxiety , depression  and anger  . As manypression . Then, t similar .All examined children were aware of the disease (100%). The vast majority of them received information about the disease from their parents , while the remaining children received such information from health care professionals . When assessing the impact of the disease on the child’s contacts with family and friends, it was shown that children most often complained of communication problems due to isolation , shame about appearance  and overprotection . Most parents spent a great deal of time with their children visiting them daily ; however, 88% (95% CI: 87–89) of children would like to spend more time with their family. According to 64% (95% CI: 62–66) of the respondents, parents had not changed their attitude towards them since the diagnosis of the disease, 28% (95% CI: 27–29) believed that they had become more caring and 8% (95% CI: 7–9) that they had more time for them. The changes in parents’ behavior noticed by the children were mainly sadness  . A totalp ≤ 0.01). Gender was not significantly correlated, as was the incidence of breakthrough pain with anxiety or depression. Children usually described the pain as acute .The most common somatic problems reported by children were pain , weakness  and vomiting  . In asseFactors that, in the opinion of children and adolescents, adversely affected their stay in the ward included limitations in going outside , multiple procedures , no intimacy  as well as unfriendly staff . Despite the presence of factors hindering hospitalization, patients were also able to perceive amenities. The most popular entertainment preferred by respondents is watching TV  and computer games  . The stup < 0.01) and peer relationships . Young people were significantly more worried about their parents’ finances (p = 0.01) , life control  and plans for the future . Significant differences in the negative impact items for the younger age group compared to the older age group concerned education plans (17%: vs. 38%  = 0.01) .p = 0.01).The most common unmet needs were psychological needs, care needs and social needs . Age wasOur study is one of the few that identifies problems and needs among children treated for cancer in Poland. This study focused on somatic, emotional and social problems and needs resulting from illness and hospitalization.p < 0.01). This is true of both so-called severe and moderate depression. According to the classification of mental and behavioral disorders, severe depression is linked to feelings of worthlessness, low self-esteem, guilt and suicidal thoughts. Moderate depression is characterized by the loss of interest and pleasure, as well as increased fatigue [The first thread of this study showed that children had numerous psychological problems resulting from the disease. In total, 82% of children have negative experiences related to the disease; most often, this was fear (61%), depression (58%) and anger (33%). The factor negatively influencing wellbeing mentioned by patients was most often isolation (76%). Similar results were obtained by Reisi-Dehkordi et al., demonstrating that children had psychological problems in contact with the disease; it was found that depression, anxiety and aggression were common among children with cancer . Additio fatigue . What is fatigue , sleep,  fatigue ,26. The  fatigue .Another element of this study showed that children had communication problems in contact with the disease. What hinders communication are isolation (79%) and shame about appearance (67%), as well as changes in parents’ behavior noticed by children. The vast majority of patients maintained contact with their peers less than once a week. Our results are in line with the research of Lee et al., where patients encountered interpersonal communication problems due to a disease affecting their body image . Kamper p < 0.05 for each) and fatigue (65% vs. 43%) compared to children who ended treatment [Somatic problems, which are complex and change over time, are a major challenge in pediatric oncology. Pain and treatment side effects, especially nausea, are a constant problem for many children and adolescents with cancer, as confirmed by numerous studies ,33,34,35reatment . Other areatment ,46. The Another piece of the study showed that children who were exposed to the disease faced care problems. Factors that, in the opinion of children, adversely affected their stay in the ward were mainly limitations in going outside (68%) and the multiplicity of procedures (40%). Despite the presence of factors hindering hospitalization, patients were also able to perceive amenities. The most popular entertainment preferred by respondents is watching TV (56%) and computer games (48%). In studies by Chien et al., participants expressed concerns about poor oncology care associated with misdiagnosis, as well as treatment leading to multiple visits to healthcare before a correct diagnosis . SimilarStudies involving children and adolescents with cancer who are cancer survivors clearly show that cancer and its treatment can affect various spheres of life . HoweverIn the last part of the study, the presence of needs among the surveyed children was assessed. This is a particularly important issue as the unmet psychosocial needs of children and adolescents with cancer increase the negative effects of cancer, fear of death, depression, reduced pain tolerance and disability . This maOur qualitative study includes many predictors of cancer in children and adolescents. The problems, stressors or needs of cancer treatment usually do not occur in isolation, but often occur as multiple problems simultaneously. Our research is multiplicative, which probably supplements the existing gaps in the literature. Most of the research on children remains descriptive. Intervention studies that focus on the problems identified are lacking. In addition, the strength of the study is the confirmation of the results of the studies described in the literature, and the obtained results provide better insight into the analysis of the problems of children and adolescents in all areas of life.The limiting factors are the small size of the research sample and its heterogeneity in terms of diagnosis. Access to the sample is difficult, so we are planning multi-center studies in the future to help develop larger datasets on age groups. We are in the process of reporting studies from all over Poland to other countries.Children and adolescents diagnosed with neoplastic disease experience many problems and stressors in every sphere of life, which undoubtedly affects the high level of unmet needs. The main category of needs concerning the challenges faced by children with cancer was psychological and care problems. In the youth group, the needs were mainly related to education and social support.A thorough symptom assessment at an early stage and during treatment is essential in caring for the development of early and supportive interventions for children and adolescents with cancer.