Abstract

Keywords

1. Introduction

2. Overview of advanced image recognition technologies

3. Advanced image recognition technologies of agricultural diseases

3.1. Methods based on deep learning

3.1.1. Deep learning models

3.1.2. Works based on deep learning

3.1.3. Discussion

3.2. Methods based on transfer learning

3.2.1. Transfer learning models

3.2.2. Works based on transfer learning

3.2.3. Discussion

3.3. Summary

4. Conclusion

Declaration of Competing Interest

Acknowledgment

References

Abstract

Agricultural disease image recognition has an important role to play in the field of intelligent agriculture. Some advanced machine learning methods associated with the development of artificial intelligence technology in recent years, such as deep learning and transfer learning, have begun to be used for the recognition of agricultural diseases. However, the adoption of these methods continues to face a number of important challenges. This paper looks specifically at deep learning and transfer learning and discusses the recent progress in the use of these advanced technologies for agricultural disease image recognition. Analysis and comparison of these two methods reveals that current agricultural disease data resources make transfer learning the better option. The paper then examines the core issues that require further study for research in this domain to continue to progress, such as the construction of image datasets, the selection of big data auxiliary domains and the optimization of the transfer learning method. Creating image datasets obtained under actual cultivation conditions is found to be especially important for the development of practically viable agricultural disease image recognition systems.

1. Introduction

A recent report by the Food and Agriculture Organization of the United Nations suggests that more than one third of the natural loss of agricultural production every year is caused by agricultural diseases and pests [1], making these the most important factors currently affecting agricultural production and food security [2]. Agricultural production is complex and there are numerous agricultural diseases and pests that need to be taken into account. Traditional approaches that rely on laboratory-based observations and experiments can easily lead to incorrect diagnoses.

1. Introduction

2. Materials and methods

3. Results

4. Discussion

Acknowledgement

Appendix A. Supplementary data

References

Abstract

Objective: In this study we execute a rational screen to identify Chinese medical herbs that are commonly used in treating viral respiratory infections and also contain compounds that might directly inhibit 2019 novel coronavirus (2019-nCoV), an ongoing novel coronavirus that causes pneumonia

Methods: There were two main steps in the screening process. In the first step we conducted a literature search for natural compounds that had been biologically confirmed as against sever acute respiratory syndrome coronavirus or Middle East respiratory syndrome coronavirus. Resulting compounds were cross-checked for listing in the Traditional Chinese Medicine Systems Pharmacology Database. Compounds meeting both requirements were subjected to absorption, distribution, metabolism and excretion (ADME) evaluation to verify that oral administration would be effective. Next, a docking analysis was used to test whether the compound had the potential for direct 2019-nCoV interaction. In the second step we searched Chinese herbal databases to identify treatments containing the selected compounds. Plants containing 2 or more of the compounds identified in our screen were then checked against the catalogue for classic herbal usage. Finally, network pharmacology analysis was used to predict the general in vivo effects of each selected herb.

Results: Of the natural compounds screened, 13 that exist in traditional Chinese medicines were also found to have potential anti-2019-nCoV activity. Further, 125 Chinese herbs were found to contain 2 or more of these 13 compounds. Of these 125 herbs, 26 are classically catalogued as treating viral respiratory infections. Network pharmacology analysis predicted that the general in vivo roles of these 26 treatments were related to regulating viral infection, immune/inflammation reactions and hypoxia response.

Conclusion: Chinese herbal treatments classically used for treating viral respiratory infection might contain direct anti-2019-nCoV compounds

Introduction

Toward the end of December 2019, a novel coronavirus (2019-nCoV) with human-to-human transmission and severe human infection, originating in Wuhan, China, was identified [1]. This virus has affected many persons in China and spread to other countries in a very short time. On January 30, 2020, the Director-General of the World Health Organization declared that the outbreak of 2019-nCoV constitutes a public health emergency of international concern and issued temporary recommendations under the International Health Regulations [2]. According to the Daily Report of China National Health Commission, as of this writing on February 2, 2020, 14,488 cases, including 304 deaths, have been confirmed in China; 146 cases, including 1 death, have also been reported among 23 other countries. This pandemic is still ongoing, so it is urgent to find new preventive and therapeutic agents as soon as possible. In addition, commensurate with the risk, strong measures for early detection, isolation and treatment of cases, as well as minimization of transmission through social interaction must be implemented.

Drought risk assessment is a vital part of drought risk management, which plays an important role in drought mitigation. Due to its complexity, drought risk is difficult to define and challenging to quantitatively assess, as the drought impacts associate with many social sectors. This contribution method the issue by quantitatively evaluating the yield loss due to drought as a function of the drought severity indicator in Liaoning province, China for spring maize using logarithmic regression. As crop water deficit is essence to identify agricultural drought, it developed a drought severity indicator using the crop water stress coefficient and duration. The Agricultural Production Systems sIMulator (APSIM) crop model was employed to simulate the spring maize growth to obtain daily water deficit during the growth period (May to September) and yield. The relationship between drought severity frequency and yield loss rate due to drought was established to assess the drought risk of spring maize when drought severity frequency is equal to 20%, 10%, 5% and 2%. The results show that Chaoyang and Fuxin have the highest drought risk in four levels of drought severity frequency whilst the lowest drought risk was identified in Tieling. The central Liaoning province has a moderate drought risk. For a specific drought severity frequency, drought risk increases from east to west in Liaoning province whilst it varies in each city at different drought severities. This method can predict yield loss due to drought for drought early warning. Drought risk maps presents spatial characteristics that can help to agricultural drought mitigation and the development of drought preparedness plan in Liaoning province.

Introduction

Drought is slow-onset and one of the most widespread natural hazards. Drought impacts are nonstructural and the occurrence of drought is associated with significant impacts in water resources, environment, energy, and human lives, especially in agricultural production (Wilhite, 2005;Wilhite and Pulwarty, 2018). These characteristics make it particularly challenging to quantify drought risk and capture drought impacts. In China, the average annual yield loss due to drought has increased from 4.35 million tons in the 1950s, to 34.9 million tons in the early twenty-first century (Lv, 2013). Drought affected approximately 60% of the maize sown area during 1990-2007, which resulted in a 20%-30% reduction in production (Jia et al., 2012). The widespread and costly nature of drought has naturally led to an interest in drought risk assessment. Methods to quantify drought risk help decision makers in drought risk management and drought mitigation. It also has a great significance in the theory and practice of quantitative drought risk assessment (Bachmair et al., 2017;Botterill and Hayes, 2012). To date, a number of previous studies have evaluated the drought risk of different regions and climates across the world at different spatial scales, most of which focus on agricultural drought risk (Xie et al., 2016). Agriculture is directly affected by the occurrence of drought as it reliable on precipitation, temperature and evapotranspiration, which can decrease the soil moisture (Sruthi and Aslam, 2015).

The purpose of waste reduction and cleaner production is achieved by properly managing crop production including efficient fertilization and subsequent crop marketing. In recent years, the issue of colorless arils has turned to a critical damage in the pomegranate orchards of Iran resulting in the probable loss of pomegranate export market. Accordingly, finding suitable methods, which may alleviate such a disorder, is of significance. The foliar application of Fe and Zn mineral fertilization as well as chelated Fe (total of 12 treatments) on pomegranate quality along with genotype effect (two genotypes) was hypothesized. The experiment was a factorial on the basis of a completely randomized block design with three replications, conducted in Bajestan city of Khorasan-Razavi province, Iran. Fruit Fe and Zn content, anthocyanin, sugar, titratable acidity (TitA), pH and colorless arils (PCA) disorder were determined. The results showed the significant interactions of fertilization treatments on Fe and Zn contents compared with the single effects. Fertilization treatments also increased anthocyanin concentrations. Fe fertilization affected fruit taste by significantly affecting fruit sugar, TitA and pH. Some fertilization treatments significantly alleviated the disorder of colorless arils (16.17e14.17%), compared with the other treatments. G1 (higher Fe concentration) was the more tolerant genotype to PCA than G2. The results confirms the necessity of Fe and Zn (both mineral and organic) for alleviating PCA disorder and enhancing pomegranate quality using Fe and Zn mineral and chlelated fertilization, along with the proper genotype. The results are promising and can be used for the further research in this respect.

Introduction

Pomegranate (Punica granatum) is one of the most consumed fruits in different parts of the world including Iran (Jamali, and Bonyanpour, 2017); among the European countries Spain is the main producer of pomegranate (Viuda-Martos et al., 2010). The importance of pomegranate fruit is because of its many desirable traits, taste, medicinal properties, and organic production (Melgarejo-Sanchez et al., 2015
; Zinatloo-Ajabshir et al., 2018). The pomegranate fruit has a major role in human nutrition and health, because it is a source of minerals such as iron (Fe), zinc (Zn), and manganese (Mn), and it also contains vitamin C, A and antioxidants such as anthocyanin. The fruit is also of industrial significance as it is used for the production of different products including the favorable pomegranate juice. It must be noted that the efficient use of pomegranate requires the proper utilization of resources such as the macro and micronutrients required for the plant growth and fruit production (Ozlekci et al., 2013; Ben-Ali et al., 2017; Houshyar et al., 2017). Siebielec et al. (2018) indicated that the use of sewage sludge can enhance the fertility of soil by increasing the population and activities of soil microbes resulting in the higher rate of microbial enzyme production. The essential nutrients such as Fe and Zn can significantly enhance pomegranate fruit quality, which is both of economical and marketing significance, and can considerably decrease the rate of waste in the environment resulting in a cleaner production. Iron and zinc deficiency, especially under calcareous conditions, causes disorders in plant metabolic processes (Sabet and Mortazaeinezhad, 2018).

ACEs education in health professions

ACE awareness spawned from medicine has gained widespread interest in multiple settings like school systems, higher education, criminal justice and policy arenas (Felitti, 2017). Nevertheless, health professionals practicing at the frontline of care have been slow to detect clients at high risk for health problems associated with ACEs. Educating health professionals including nursing students about ACEs is pertinent to ascertain the harmful effects of ACEs on health. Current literature has documented time-limited and/or graded variations of ACEs education/ training. For example, a Child Advocacy Studies Training program was studied to examine the effect of educating first-year medical students about child abuse prevention and intervention by taking a two-semester elective course. The study found that first-year medical students felt prepared to identify and report signs of child maltreatment and recommend services for abused children (Knox, Pelletier, & Vieth, 2014). Another study found that graduate students from nine health professional programs at two campuses reported being more familiar with clinical and scientific findings of ACEs and trauma-informed care after they completed a three-week training (Strait & Bolman, 2017). Finally, another example of ACEs education in health professions is a continuing education article written for pediatric nurse practitioners regarding childhood trauma, toxic stress, resilience and use of screening checklists to identify abuse and neglect (Hornor, 2015). The above-mentioned training and educational offerings have made efforts to educate health professionals about ACEs; yet, no systematic integration of ACEs curriculum in an educational program has been documented. ACEs need to be an integral component of nursing curriculum to equip graduates with essential ACEs knowledge and skills in clinical prevention, population health, health promotion and disease prevention to create a culture of health for diverse groups and communities (American Association of Colleges of Nursing, 2011; Robert Wood Johnson Foundation, 2017). To prepare the nursing workforce with necessary knowledge for promoting health for children and families, LCON designed and initiated a systematical integration of ACEs across BSN curriculum. The project involved developing the ACEs curricular model, selecting key courses for integration, engaging faculty with the integration process and designing future studies. ACEs Curriculum Integration Model The ACEs Curriculum Integration (ACI) Model stems from the Culture of Health (COH) Action Framework developed by the Robert Wood Johnson Foundation (RWJF) in partnership with the RAND Corporation (Robert Wood Johnson Foundation, 2017). The COH Action Framework is an exemplar framework to illustrate building health equity (Plough, 2015a). Health equity is the highest attainment of health for all people and an overarching goal of the ACI Model (Healthy People, 2018). The four major constructs of the COH Action Framework are: a) making health a shared value; b) fostering interdisciplinary collaboration; c) creating healthier, more equitable communities; and d) strengthening integration of health systems and services (Robert Wood Johnson Foundation, 2017). The ACI Model was developed to guide ACEs curriculum integration in the BSN program. The model follows a scaffolding approach to teaching and learning through building concepts across the five semesters of the BSN curriculum. Major conceptual constructs of the ACI Model are: a) develop ACEs awareness and prevention, b) reduce toxic stress and improve socio-ecological conditions, c) build resiliency and enable care providers, d) implement trauma-informed care and e) inform policy (Fig. 1.0). Conceptual definitions and propositions in the ACI Model will be discussed followed by a description of courses selected for curriculum integration.

Introduction

Traditional lecture-focused curricular designs are failing to produce new graduates who can make the transition to safe and competent nurses. Although contemporary practice requirements are increasing, many novice nurses struggle with the ability to effectively critically think when making clinical decisions (Perez et al., 2015; Victor-Chmil, 2013). Today’s nurse is responsible for managing an escalating census composed of patients with multifaceted health care problems, all while navigating convoluted technology platforms in a hurried and outcome-driven environment (Benner, Sutphen, Leonard, & Day, 2010; Fero, Witsberger, Wesmiller, Zullo, & Hoffman, 2009; Missen, McKenna, & Beauchamp, 2015). Considering the intricacies associated with today’s health care arena, less than desirable traits of novice nurses, and demands of the nursing workforce, a revamp of nursing education is in high demand (Accreditation Commission for Education in Nursing [ACEN], 2013; Benner et al., 2010; Institute of Medicine [IOM], 2011; National League for Nursing [NLN], 2008). Utilizing innovative nursing curricula designs, whereby students are engaged in the learning process through methods that challenge their ability to process complex clinical scenarios, is more likely to prepare them for the challenges inherent in a 21st century health care setting (Benner et al., 2010). One curricular model possessing these qualities is a conceptbased curriculum. According to Erickson and Lanning (2014), a concept-based curriculum consolidates information by focusing on key exemplars. An essential component to a concept-based curriculum is the use of active teaching–learning strategies (Giddens, Caputi, & Rodgers, 2015), such as case studies, concept maps, problem-based learning, and simulation. Through the use of active teaching–learning strategies, students can formulate connections with information, leading to learning comprehension, critical thinking development, and the ability to decipher similar material when faced with a new experience (Erickson & Lanning, 2014). For example, a nurse educator in a beginning course may develop a case study regarding the concept of oxygenation when teaching students about the exemplar, pneumonia. As students progress through the nursing program, another nurse educator could reinforce the concept of oxygenation by assigning students to care for a simulated patient diagnosed with the exemplar, respiratory failure. Although different exemplars, both are supported by the concept of oxygenation and require similar nursing care. A conceptual approach to teaching has been applied to prelicensure nursing education for almost a decade and continues to expand in use. However, there remains a dearth of literature analyzing outcomes related to a concept-based curriculum. This study was developed in an attempt to address this gap in the literature and support research priorities created by the IOM (2011) and NLN (2013) regarding the evaluation of innovative nursing curricular designs. The purpose of this study was to evaluate critical thinking skills and National Council Licensure Examination for Registered Nurses (NCLEX-RN) pass rates among associate degree nursing (ADN) students completing a concept-based curriculum. Also assessed in this study were the pass rate prediction test scores for the NCLEX-RN.

Abstract

Successful production of faba bean crops in the presence of a wide range of disease-causing fungi, parasitic weeds, nematodes, insects, mites and other pests depends on the integration of genetic resistance, hygienic management, monitoring of the target organisms and timely application of appropriate chemical and biological treatments. This paper reviews the progress in this area.

Arthropod management is still overly reliant on broad-spectrum insecticides for many pests, particularly aphids, but field assessment, tillage, sowing date, plant density and weed control can minimize pest incursions. Crop assessments, bait and pheromone traps and economic thresholds are used to predict and monitor arthropod pest populations, and biological measures (natural enemy conservation and bioinsecticides) and selective chemicals (less harmful to beneficial insects) are also used. Crop hygiene and seed bank demise is critical for management of broomrape, as much of its damage is done before the parasite is visible above ground. Mild herbicide treatments can prevent ripening of broomrape seeds with minimal damage to the faba bean crop. The main diseases caused by fungi, namely rust, ascochyta blight, chocolate spot and downy mildew, all spread rapidly when weather conditions are appropriate. Since these weather conditions are well characterized for each disease, it is possible to intervene strategically by treating with fungicide at times of high risk. Good sources of resistance are available to the key diseases, although few current cultivars are resistant to more than one disease. Root-lesion, stem and root-knot nematodes can cause severe yield losses but several cultivars and breeding lines of faba bean have good resistance to root-lesion nematodes and at least one has resistance to stem nematode and one to root-knot nematode. These groups of nematode species have broad host spectra so attention to rotations is particularly important. Chemical control of nematodes is difficult and biological control is still experimental. Control of the pathogenic fungi and nematodes requires that clean, non-infested seed be used and that the new crop does not get infected from debris and volunteer from the previous crop or adjacent fields. In the presence of continued selection pressure on the pathogens and pests, continued breeding for novel resistance genes, development of new selective chemicals, screening for new biocontrol agents and the design of new management strategies will all be necessary.

Cereals have a long history of interaction with humans. At around 40–50 thousand years ago (kA), late Neanderthals consumed wild Triticeae grains in a cooked form as suggested by the analysis of the dental calculus from multiple locations in Europe, the Near East, and Africa [1]. The first fossil remnants of plants exhibiting characteristics of the domesticated cereal crops have been discovered at the multiple archaeological sites dated to 8–10 kA — the historic period marking a transition from the huntergatherer lifestyle to the early sedentary agricultural societies. The most prominent examples are the non-brittle spikes of the proto-domesticated wheat (diploid, tetraploid and hexaploid Triticum species) and barley (Hordeum vulgare ssp. vulgare) discovered in the excavations in the Fertile Crescent area of the Near East; the nonshattering panicles of rice (Oryza sativa) from the Yangtze river valley, China; and the starchy enlarged seeds of maize (Zea mays ssp. mays) from the Central Balsas river valley, Mexico, which distinguish maize from its wild progenitor teosinte (Z. mays ssp. parviglumis) [2– 6]. The archaeobotanical analyses of the fossil findings provided direct empirical evidence on the temporal scale and the location of the early events of cereal domestication history, which was packaged in the so-called domestication models [2,3,7]. However, to expand on the archaeological models, detailed understanding of genetic relationships between the cultivated and wild populations is crucial. In the pre-genomics era, the pioneering molecular studies suggested explicit demographic models of cereal domestication based on the population genetic analyses of nucleotide variation in isolated genes and genomic regions [8–12]. The molecular evolutionary models favored a monophyletic origin of crops and strong selective pressures under domestication. On the contrary, the archaeological models assumed a polycentric origin of domestication traits and a millennia-long process of fixation of these traits in the cultivated populations. Advancements in the genome sequencing technologies enabled the elucidation of the genetic ancestry and evolutionary history of domesticated genotypes at the unprecedented resolution and scale [13,14 ,15]. It was anticipated that the genome-wide diversity estimates would provide a solid basis to the demographic history reconstruction. However, for many cereals, the interpretation of the revealed patterns remained controversial hinting at the complexity of their evolutionary history [15,16 ]. Population genomics has recently revealed intriguing patterns in the cultivated barley genomes that shed light on the trajectory of barley domestication [17,18,19].

Because of the growing consumer demand for healthy, natural and convenient foods, attemps are being made to improve snack foods nutritional values by modifying their nutritive composition (Bhaskaran and Hardley, 2002; Gray et al., 2003). Cereal bars are a popular and convenient food and, therefore, would be an ideal food format to deliver fruit derived phenolic antioxidants (Sun-Waterhouse et al., 2010; Damasceno et al., 2016). Phenolics compounds, e.g. flavonoids and phenolics acids, belong to an important class of secondary metabolites and own recognized antioxidant activity. Antioxidant compounds neutralise free radicals and inhibit or interrupt the chain of propagation of oxidative reactions, converting free radicals into less harmful molecules and repairing the oxidative damage in human cells (Borges et al., 2014). This class of compounds is also relevant to insertion in the elaboration of cereal bars. The banana is one of the most extensively consumed fruits in the world and represents approximately 40 per cent of the world fruit trade. World banana production was 102 Mt in 2012, and Brazil was the sixth most important banana-producing country with a total production of 7 Mt (FAO, 2016). The banana peel represents 30-40 per cent of the total weight of the fruit, it is rich in minerals (Emaga et al., 2007) and its quantity of total dietary fiber reaches 43.2 to 49.7 per cent (Mohapatra et al., 2010). González-Montelongo et al. (2010) reported that banana peels contain large amounts of dopamine and l-dopamine, catecholamines that exhibit antioxidant activity, and depending on the variety, ripeness, and on the type of phenolic compound extraction used, the banana peel has from 3.1 to 380 mg GAE.g1 of total phenolic compounds (González-Montelongo et al., 2010; Rebello et al., 2014). In addition, banana peel contains low but permissible concentrations of toxic elements and may be recommended as dietary supplement, especially considering that banana peel contains lower quantities of toxic elements than other by-products, as pineapple peel (Kuppusamy et al., 2017). The application of banana peel flour in cereal bars was performed using a simplex centroid design for mixtures of banana peel flour, rice flakes and oat flour, and the products evaluated regarding sensory acceptability and profile (Carvalho and Conti-Silva, 2018). The cereal bars with 21 and 27.72 per cent of banana peel flour had good overall acceptability and aroma acceptability, respectively, even with different sensory profiles, indicating a relevant use to this by-product, which may favor the development of new products.

Soil physical and chemical properties and crop yields vary spatially and temporally on different scales. The variability is largely influenced by pedogenesis processes (Gilliam and Dick, 2010; Moradi et al., 2016), topography (Jankowski et al., 2011), and agricultural practices including tillage operations, compaction, chemical application, and harvesting (Alaoui et al., 2011; Gajda et al., 2016; Ozpinar and Ozpinar, 2015; Schjønning et al., 2009). Knowledge about soil variability is essential in precise determination of the most appropriate and localized management practices and amendments to improve and align soil conditions and quality for an effective use of water and nutrients and crop growth (Bölenius et al., 2017; Kumhálová and Matějková, 2017; Usowicz and Lipiec, 2017). For example, variable-rate management practices such as fertilization and irrigation based on spatial data of chemical and soil water status (Sadler et al., 2005; Pedrera-Parrilla et al., 2016; Mubarak et al., 2016) help to limit the use of agricultural chemical and water and to reduce leaching and environmental pollution (Adamchuk and Viscarra Rossel, 2011; Bogunovic et al., 2014; Hedley and Yule, 2009). Further, analysis of the spatial dependency of soil water status along with weather conditions are key issues for modelling soil water dynamics and balance (Awe et al., 2015; Kędzior and Zawadzki, 2016; Schwen et al., 2014). The spatial distribution of different soil properties can be evaluated by classical and spatial statistics using direct semivariograms and cross-semivariograms (Goovaerts, 1999; Webster, 2008). Semivariograms describe the dependence of the values of a given variable on the distance between the sampling sites and thereby the spatial structure of the variation. Thus, they help in designing a sampling setup including the number of samples required for adequate description of the soil and yield in agricultural areas (Jabro et al., 2010; Moradi et al., 2016). When different variables are related, their joint spatial patterns can be evaluated by cross-semivariograms. Cross-semivariogram data and maps obtained with the co-kriging procedure allow prediction of time-consuming and/or costly variables from those measured more easily. Using cross-semivariograms, Jabro et al. (2010) found that soil penetration resistance was spatially correlated with water content, total porosity, and saturated hydraulic conductivity. The study by Walter et al. (2002) showed spatial interdependence between weed species density and soil properties such as clay, phosphorus contents and pH, and the extent of the spatial dependence varied among the study years. However, little information is available about the spatial and inter-annual variability of crop yields and soil properties, especially on a field scale, although it is the main methodological means for implementing precision agriculture technology of different intensity to compensate and improve soil conditions for strengthening crop growth (Diacono et al., 2013; Usowicz et al., 2009; Webster, 2008).

Bitterness in almonds (Prunus dulcis Miller D.A. Webb syn. Prunus amygdalus Batsch) is one of the most important and widely studied traits in this species. Almond bitterness is a monogenic trait, and the sweet taste allele is dominant over the bitter taste allele (Heppner, 1923, 1926; Dicenta and García, 1993; Dicenta et al., 2007). The gene responsible for bitterness in almonds is denoted Sweet kernel (Sk), and it is located in linkage group five, out of the eight that almond has (Sánchez-Pérez et al., 2007; 2010; Joobeur et al., 1998; Bliss et al., 2002). Commercial sweet genotypes can be homozygous (SkSk) or heterozygous (Sksk) for this trait, while slightly bitter genotypes are always heterozygous (Sksk), and bitter genotypes are homozygous recessive (sksk) (Grasselly et al., 1980; Vargas et al., 2001). The bitter trait is maternally controlled (Heppner, 1923; Dicenta and García, 1993; Kester and Gradziel, 1996; Socias, 1998; Sánchez-Pérez et al., 2010). As a result, all the fruits of an almond will be sweet, slightly bitter or bitter, and the influence of both progenitors will be seen in the next generation (Kester et al., 1975; Dicenta et al., 2000; Arrázola et al., 2012). Cyanogenic glucosides (CNGLcs) are β-glucosides of α-hydroxinitriles (Conn, 2007; Zheng and Poulton, 1995; Morant et al., 2008). These compounds are present in more than 3000 plant species (Bak et al., 2006a; Sánchez-Pérez et al., 2008; Gleadow and Møller, 2014) like sorghum, cassava and Rosaceous stone fruits. Their main function is to defend plants against pathogens and predators (Bak et al., 2006b; Zagrobelny et al., 2008). There are two cyanogenic glucosides present in almonds: prunasin (mono-glucoside of R-mandelonitrile) and amygdalin [di-glucoside of R-mandelonitrile with a β-(1,6) bond] (Conn, 2007; Sánchez-Pérez et al., 2008; McCarty et al., 1952; Frehner et al., 1990; Møller and Seigler, 1991; Swain et al., 1992a; Poulton and Ping Li, 1994; Dicenta et al., 2002; Franks et al., 2008). These two compounds are de novo synthesized in the almond seed (Sánchez-Pérez et al., 2008), and the amygdalin content is significantly higher in mature bitter almond seeds than in slightly bitter or sweet seeds (between 200 and 1000-fold higher, respectively). On the other hand, there is no clear relationship between the prunasin levels in the vegetative parts of the plant and the bitterness of the fruit (Dicenta et al., 2002). The almond fruit consists of maternal tissues (endocarp, mesocarp, tegument – also called the seed coat – and nucellus) and parental tissues endosperm (2n (mother) + n (father)) and cotyledon (n (mother) + n (father)). The first difference between sweet and bitter almonds can be found in the tegument, as prunasin only accumulates in the bitte teguments throughout seed development (Sánchez-Pérez et al., 2008). Fig. 1 describes the metabolism of prunasin and amygdalin, which can be divided into the following three parts: biosynthesis, bioactivation and detoxification.

Urban wastewater treatment plants (UWTPs) have a pivotal role in the protection of the environment, in particular, the natural water bodies. The removal of organic matter, chemical pollutants and undesirable microorganisms from sewage, using combinations of physicochemical and biological treatments, was a major technological achievement of the last century, allowing the return to the environment of water with good quality. However, the final UWTPs effluents are far from being sterile and, hence, release to the environment high amounts of bacteria, many of which are of animal (e.g. pets or small husbandry or animal farms) or human origin (Berendonk et al., 2015; Manaia, 2017; Rizzo et al., 2013). Many of these bacteria harbour acquired antibiotic resistance genes (ARGs) and are potential carriers for the dissemination of these genes in the environmental microbiome (Berendonk et al., 2015; Manaia, 2017; Pruden, 2014). As such, these bacteria are considered a potential threat to humans and/or animals health since they may lead to more cases of difficult-to-treat infections. Moreover, although only part of the ARB released from UWTP will be able to cause disease in humans or animals, the risk of enriching the environmental resistome either through selection or horizontal gene transfer (HGT), and therefore contribute to the emergence of resistance in pathogenic bacteria cannot be neglected (Manaia, 2017). UWTPs bring together antibiotic resistant bacteria (ARB), antibiotic residues and other potential selectors that favour the selection towards these bacteria and, simultaneously, offer a rich supply of nutrients and close cell-to-cell interaction, capable of facilitating the horizontal transfer of ARGs. These arguments make the UWTPs environment one of the most exciting niches to unveil the fate of ARB&ARGs. This paper is the result of a think tank of Early Stage Researchers summer school organized by the Marie Skłodowska-Curie Innovative Training Networks, project ANSWER (http://www.answer-itn.eu/), and discusses the tools and the environmental conditions that may rule the fate of ARB&ARGs throughout the wastewater treatment. The paper is divided into four major sections: 1) one dissecting the UWTPs compartments where analyses of ARB&ARGs may be relevant given the potential constraints that are imposed to the microbiota, as well as 2) the bio-physico-chemical conditions that may shape the dynamics of populations and genes within the bacterial communities; 3) another revising the pros and cons of the most commonly used methods to analyse antibiotic resistance in environmental samples; and 4) a final section where the previous three are combined to give an integrated overview of the major information on ARB&ARGs ecology, exemplified through the answers to some frequently asked questions. Above all, this work intends to serve as a guide for wastewater professionals who aim at optimizing wastewater treatment for the removal of ARB&ARGs.