Solid organ transplant recipients are at increased risk for infections due to chronic immunosuppression. Diarrhea is a commonly encountered problem post transplantation, with infectious causes of diarrhea being a frequent complication. Viral infections/enteritides in solid organ transplant recipients often result from frequently encountered pathogens in this population such as cytomegalovirus, adenovirus, and norovirus. However, several emerging viral pathogens are increasingly being recognized as more sensitive diagnostic techniques become available. Treatment is often limited to supportive care and reduction in immunosuppression, though antiviral therapies mayplay a role in the treatment in certain diseases. Viral enteritis is an important entity that contributes to morbidity and mortality in transplant recipients. Solid-organ transplant (SOT) recipients face unique infectious risks in the setting of chronic immunosuppression. Diarrhea is a commonly encountered problem in SOT recipients, with prevalence in the range of 20–50% . DiarrheBetaherpesvirinae subfamily, is endemic worldwide, with approximately 50% seroprevalence among adults in the United States [CMV, a double-stranded, enveloped DNA virus and member of the d States ,3. CMV id States ,5,6. Fold States . Rates od States . In the d States . CMV infd States ,7.The diagnosis of CMV gastrointestinal (GI) disease is based on the presence of upper and/or lower GI symptoms with CMV identified in biopsied tissue via histopathology, immunohistochemistry, or DNA hybridization from macroscopic mucosal lesions visualized during endoscopy . Cases aAssessment of the level of immune response and risk for CMV infection in SOT recipients is gaining traction within clinical practice in the transplant community. CMV-specific cell-mediated immunity (CMV-CMI) may be utilized on a case-by-case basis to help guide management, including adjusting depth of immunosuppression, duration of CMV therapies, and prevention strategies ,12,13,1410 after two weeks of treatment, genotypic resistance testing targeting UL97 and UL54 genes should be performed [UL97 mutations confer different degrees of GCV resistance, but often, the anti-viral activity of foscarnet or cidofovir (CDV) is retained; both drugs have significant nephrotoxicity and electrolyte wasting associated with their use [UL54 may result in variable resistance to GCV, foscarnet, and CDV, leading to limited therapeutic options [Careful reduction in immunosuppression plays an important role in the control of CMV disease, particularly in cases of drug resistance or intolerance . Parenteerformed . The UL9heir use . MutatioUL56 of the terminase enzyme complex, is approved for primary CMV prophylaxis in allogeneic stem cell transplant recipients [UL97 protein kinase, has the potential to redefine treatment for refractory and/or resistant CMV infections [Letermovir, an inhibitor of the subunit pcipients . Mixed rcipients . Maribavfections . In a refections . Maribavfections . A recenfections . Non-phafections .Caliciviridae family, is prevalent worldwide and the most common cause of gastroenteritis globally. The high transmissibility and overall stability of the virus in harsh environments result in outbreaks, both in community and healthcare settings. While the incubation period is short, usually 24–48 h, the virus can be shed in the stool for several weeks or even months in immunocompromised hosts. Vomiting is usually the predominant symptom, though watery diarrhea is a common manifestation. Immunocompetent hosts typically have shorter and self-resolving episodes [Norovirus, a nonenveloped RNA virus from the C. difficile, medications, and CMV) during the same period without norovirus infection; the study showed a significant protracted course of diarrhea in the norovirus group, with an average of 241 days vs. 75 days in the control group [Immunocompromised hosts are at risk for developing recurrent or chronic infection with norovirus. A large retrospective study in kidney, heart, and lung transplant recipients showed that 22.8% of the patients infected with norovirus developed chronic infection; the median shedding period was 218 days (range 32–1164 days) . Anotherol group .Unfortunately, there are no specific therapies approved for norovirus treatment at this time. Strategies focus on rehydration, antimotility agents, and reduction in immunosuppression, which may help decrease viral shedding . SeveralNitazoxanide, a thiazolide antimicrobial with antibacterial, antiviral, and antiparasitic properties, is thought to target cellular pathways involved in the synthesis of viral proteins . A doublReoviridae family, is known to cause enteritis in infants and children under 5 years of age [Rotavirus, a nonenveloped double-stranded RNA virus in the s of age ,33. It hs of age ,32,34. Rs of age . A cohors of age .Supportive therapy, including fluid resuscitation and electrolyte replacement, is the mainstay of treatment as currently there are no antiviral therapies available for rotavirus ,18,32. TAdenoviridae family, cause infections in both immunocompetent and immunocompromised hosts. Adenoviruses are classified into 7 subgroups (A–G), and these subgroups can be further divided into more than 50 serotypes. Serotypes have been identified to have tissue tropism; for example, gastroenteritis has been associated with serotypes 40, 41, and 52 [Adenoviruses, nonenveloped lytic double-stranded DNA viruses from the , and 52 . Adenovi, and 52 . Infecti, and 52 . Definit, and 52 . Dissemi, and 52 .In SOT recipients, adenovirus causes a variety of clinical syndromes ranging from asymptomatic infection to life-threatening disseminated disease. Clinical manifestations vary with the type of allograft and commonly involve the graft . SeveralThe incidence of adenovirus infections in SOT recipients varies with organ type and differs among pediatric and adult SOT populations. Reported incidence among liver and kidney recipients ranges from 4.1 to 6.5%. In a study of viral enteritis in intestinal transplant recipients, adenoviral enteritis was noted in 25% of pediatric and adult intestinal transplant recipients with the median time from transplantation to diagnosis being 53 days .As with the many other causes of viral enteritis, supportive care, including rehydration, antimotility agents, and reduction in immunosuppression, is the mainstay treatment . PatientCDV, a nucleotide analog of cytosine, has activity against all serotypes of adenovirus, and it is considered the standard of care for the treatment of adenovirus. However, its use is limited by severe nephrotoxicity and bone marrow suppression. CDV is usually considered for severe infections, with two different dosing options including the 1 mg/kg three times per week dose or 5 mg/kg per week dose, though a direct comparison of the two dosing strategies has never been carried out ,40. CDV An oral option and lipid conjugate of CDV, brincidofovir (Tembexa) was recently approved by FDA for the treatment of smallpox. As smallpox has been eradicated, brincidofovir was studied in patients that were infected with viruses closely related to the variola virus. It appears to have several advantages over CDV, including more potent antiviral activity and less nephrotoxicity. Most of the data regarding side effects, including severe diarrhea and liver toxicity (transaminitis), come from the adult hematopoietic stem cell transplant literature. Brincidofovir causes epithelial apoptosis and crypt injury that is very difficult to distinguish from graft-versus-host disease and mycophenolate mofetil toxicity, and this could inadvertently lead to increased immunosuppression. However, brincidofovir seems to be better tolerated in stem-cell and solid-organ transplant recipients . In a reGammaherpesvirinae subfamily. EBV is a commonly encountered virus and nearly all adults are seropositive by age 40. As with other herpesviruses, EBV establishes latency in its host and persists during the host’s lifetime, with its primary target being the naïve B cell [Epstein–Barr virus (EBV) is an enveloped, double-stranded DNA virus of the e B cell . Primarye B cell . There ae B cell ,45. Recue B cell . CurrentSome of the once unexplained gastroenteritides are now recognized to be caused by infectious agents . The list of emerging enteric viral pathogens is constantly expanding, with the recent additions of astroviruses, bocavirus, cosavirus, torovirus, picobirnavirus, salivirus, bufavirus, Aichivirus, and Saffold virus. Since very few institutions perform electron microscopy, real-time PCR, or nested reverse transcription PCR for the diagnosis of gastroenteritis, these emerging viruses are probably underdiagnosed. As there is no specific antiviral therapy for any of these viruses, the treatment is based on rehydration, nutritional supplementation, and decreasing immunosuppression whenever possible.Astroviridae. They are divided into classic human astroviruses (HAstV 1–8), MLB (HAstV-MLB 1–3), and VA (HAstV-VA 1–5) [Human astroviruses (HastVs) are positive-sense, single-stranded RNA viruses belonging to the family -VA 1–5) . HAstV i-VA 1–5) . In immu-VA 1–5) ,50. On p-VA 1–5) . HastVs -VA 1–5) . Several-VA 1–5) . Reverse-VA 1–5) . In certParvoviridae. HBoVs can cause respiratory infections and gastroenteritis in immunocompromised patients [Human bocaviruses (HboVs) are nonenveloped, single-stranded DNA viruses belonging to the family patients . There apatients ,53. The patients ,53. Recepatients . Most ofpatients ,54. In tpatients . HBoV depatients . Conventpatients . ELISA apatients .Picornaviridae family. They are classified into six species  [Human cosaviruses (HCoSVs) are positive-sense, single-stranded RNA viruses belonging to the D, E, F) . The virD, E, F) . The virD, E, F) .Caliciviridae family. Sapovirus has been identified as an important cause of gastroenteritis in immunocompromised patients after the introduction of reverse transcription-PCR (RT-PCR) [Sapovirus, a nonenveloped, single-stranded RNA virus, belongs to the (RT-PCR) ,59. Pati(RT-PCR) . RT-PCR (RT-PCR) .Tobaniviridae family. Torovirus, an established agent of gastroenteritis in animals, is now recognized as the cause of gastroenteritis in pediatric patients [Torovirus, an enveloped, positive-stranded RNA virus, belongs to the patients . In a prpatients . A high patients . A high patients , and corpatients .Picobirnaviridae family. These viruses can cause diarrhea as a single pathogen or co-infection with rotavirus, astrovirus, and E. coli [Picobirnaviruses are small, nonenveloped, bi-segmented double-stranded RNA viruses belonging to the  E. coli . Picobir E. coli . In a sm E. coli .Coronaviridae family. SARS-CoV-2 may play a direct role in the gastrointestinal symptoms in COVID-19 illness. Currently, the data regarding enterocolitis due to SARS-CoV-2 are limited. In a recently published study, diarrhea was more frequent in SOT recipients, compared with nontransplant patients (54% vs. 17%) [Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a positive-sense, single-stranded RNA virus, is a member of the vs. 17%) . In a cavs. 17%) .Viral enteritis continues to be a frequent and vexing complication following transplantation. In addition to their potentially prolonged and/or severe GI illnesses, the viral gastroenteritides threaten the already tenuous balance of immunosuppression, risking medication-induced toxicity and/or rejection with allograft dysfunction. Recent advances in pharmacologic and other treatment modalities are promising, but ongoing efforts to develop novel antiviral agents and prevention strategies are essential. Given the ever-changing nature of transplant medicine and the field of infectious diseases, clinicians and microbiologists working with SOT populations must remain constantly vigilant and investigative to optimize detection, prevention, and treatment of viral enteritis in transplant recipients.


Pathogen surveillances in wild marine fish populations need to be carefully designed to address specific research or management objectives. Surveillance strategies should be designed around host life history characteristics, host and pathogen geographic ranges, laboratory diagnostic tools that are specific to the epidemiology of each pathogen, and the goal of the surveillance program. We demonstrate how the potential impacts of viral hemorrhagic septicemia can be under-appreciated in populations of Pacific herring by comparing results from opportunistically collected samples with those from more targeted epidemiological investigations that were focused on times and locations with high disease probability.C. pallasii are more common than previously appreciated; however, they are easily overlooked if biosurveillance efforts are not designed around times and locations with high disease potential.Throughout a 20 year biosurveillance period, viral hemorrhagic septicemia virus was isolated in low titers from only 6/7355 opportunistically sampled adult Pacific herring, reflecting the typical endemic phase of the disease when the virus persists covertly. However, more focused surveillance efforts identified the presence of disease hot spots occurring among juvenile life history stages from certain nearshore habitats. These outbreaks sometimes recurred annually in the same temporal and spatial patterns and were characterized by infection prevalence as high as 96%. Longitudinal sampling indicated that some epizootics were relatively transient, represented by positive samples on a single sampling date, and others were more protracted, with positive samples occurring throughout the first 10 weeks of the juvenile life history phase. These results indicate that viral hemorrhagic septicemia (VHS) epizootics in free-ranging Pacific herring  Clupea pallasii Valenciennes, 1847) and other hosts [C. pallasii and Pacific sardine represents a source of viral spillover to cultured Atlantic salmon in marine pet pens in Washington (USA) and British Columbia (Canada), which experience periodic VHS epizootics [Viral hemorrhagic septicemia virus, genogroup IVa (hereafter referred to as VHS virus) has a broad host range in marine fishes throughout the coastal waters of North America and Asia, including China, Japan, and Korea ,2,3. Threr hosts . All avaer hosts . FurtherC. pallasii from Puget Sound, Washington, USA, where the disease sometimes occurs in confined wild cohorts [Epizootics of VHS periodically occur in wild marine fishes ,2,3, pre cohorts ,7, epizo cohorts .C. pallasii from the same geographic locations in consecutive years and to document the progression of a single epizootic throughout the disease onset, peak, and recovery phases. To emphasize the ease with which these epizootics can be overlooked, we also report the results from 20 years of VHS virus surveillances in Pacific herring C. pallasii populations throughout the NE Pacific Ocean, including annual sampling from pre-spawn aggregations in Prince William Sound and Sitka Sound as well as opportunistic sampling from other locations.This study was performed to document the interannual occurrence of VHS epizootics in Pacific herring C. pallasii (n = 7355) were collected from locations throughout coastal areas of the NE Pacific Ocean using various gear types and sampled for presence of VHS virus  among positive samples. The fish were randomly sampled and dead/moribund individuals were not noted. This epizootic occurred at a time when cross sectional sampling indicated that adult conspecifics failed to test positive from Long Island, AK, USA, approximately 12 km away  that provide a much more accurate view of exposure history than attempted virus isolation from kidney/spleen homogenates [Results from 20 years of surveillance efforts indicate that attempted VHS virus isolations from opportunistically collected adult Pacific herring  results , and thiogenates .C. pallasii, which largely returned negative results, targeted surveillances in juvenile cohorts effectively identified periodic VHS epizootics, some of which recurred at the same time and locations in multiple years  and higher potential for VHS outbreaks compared to those subscribing to the open water phenotype. This immediate reduction in survival potential may be offset by long term immunological gains among the survivors, which generate adaptive resistance against future outbreaks of the disease [Shortly after their metamorphosis from larvae to juveniles, age 0 Pacific herring  disease . Future


Bombyx mori bidensovirus (BmBDV) is one of the pathogens that cause flacherie disease in silkworms. Most silkworm strains die after BmBDV infection. However, certain silkworm strains show resistance to the virus, which is determined by a single recessive gene, nsd-2. The +nsd-2 gene  encodes a putative amino acid transporter expressed only in the insect’s midgut, where BmBDV can infect, suggesting that this membrane protein may function as a receptor for BmBDV. Interestingly, the expression analysis revealed no changes in the +nsd-2 gene expression levels in virus-uninfected silkworms, whereas the gene expression drastically decreased in the virus-infected silkworm. This condition indicates that the host factor’s expression, the putative virus receptor, is affected by BmBDV infection. It has recently been reported that the expression levels of some host genes encoding cuticle, antioxidant, and immune response-related proteins were significantly regulated by BmBDV infection. In this review, we discuss the host response against virus infection based on our knowledge and long-term research experience in this field.Silk cocoons obtained from silkworms are the primary source of commercial silk, making the silkworm an economically important insect. However, the silk industry suffers significant losses due to various virus infections.  Bombyx mori has been bred in captivity for around 5000 years, and it is now a completely domesticated species of the silkworm . Thnfection . Interes78420  [2BmCat, BmSOD3, BmSOR4, and peroxisomes genes peroxin-5, peroxin-10, peroxin-13 were significantly up-regulated after BmBDV infection. These results indicate that this virus causes silkworms to produce excessive ROS, which induces an antioxidant mechanism to prevent oxidative stress and triggers anti-viral peroxisomes against BmBDV, thereby protecting the host [Sun et al.  also repthe host . Moreovethe host  and Sun the host  revealedThus, recent studies have revealed host-derived genes that are altered by BmBDV infection. We expect that further analysis of these genes will elucidate the host stress response mechanism due to insect virus infection.


Harvesting beach-cast can help mitigate marine eutrophication by closing land-marine nutrient loops and provide a blue biomass raw material for the bioeconomy. Cost–benefit analysis was applied to harvest activities during 2009–2018 on the island of Gotland in the Baltic Sea, highlighting benefits such as nutrient removal from the marine system and improved recreational opportunities as well as costs of using inputs necessary for harvest. The results indicate that the activities entailed a net gain to society, lending substance to continued funding for harvests on Gotland and assessments of upscaling of harvest activities to other areas in Sweden and elsewhere. The lessons learnt from the considerable harvest experience on Gotland should be utilized for developing concrete guidelines for carrying out sustainable harvest practice, paying due attention to local conditions but also to what can be generalized to a wider national and international context.The online version contains supplementary material available at 10.1007/s13280-021-01641-8. The biogeochemical flows of nitrogen (N) and phosphorus (P) are judged to exceed planetary boundaries , ex post (after a project is completed) or in medias res (for an ongoing project) and is typically described as a stepwise procedure, which will be referred to in the following: (1) Explain the purpose; (2) Specify the project(s) to be assessed including the reference alternative; (3) Specify standing, i.e. whose benefits and costs are to be counted; (4) Identify consequences and select metrics; (5) Quantify consequences; (6) Monetize consequences; (7) Discount benefits and costs to obtain present values; (8) Compute net present values; (9) Perform sensitivity analysis; (10) Make a recommendation  relies on the anthropocentric approach of mainstream welfare economics for assessing positive and negative consequences (benefits and costs) of a project in terms of how human wellbeing is affected relative to a reference alternative (baseline) . Harvest refers to moving beach-cast from the shores to piles for decomposition , with project costs partly being covered by national governmental grants administrated by the County Administrative Board of Gotland (CABG). During the period of 2009–2018, 40 LOVA beach-cast harvest projects were carried out on Gotland. These 40 projects constitute together the harvest activities to be assessed ex post by the CBA.Beach-cast harvesting on Gotland has largely been carried out as local water protection projects (Swedish: S2a). After 2018, additional LOVA projects have been conducted but are not included in this CBA.Project owners included Gotland Municipality, but most of them were non-governmental organizations (NGOs) such as local community associations focusing on a specific beach. The CBA is based on results reported by these projects to CABG, including harvest costs and nutrient removal estimates based on chemical analysis. To account for uncertainties inferred by the self-reporting of results by project owners, the results are compared to other sources of information about harvest costs and nutrient concentrations in beach-cast. Besides results from earlier literature, complementary data were obtained from semi-structured interviews carried out in another research project in December 2019–May 2020 with 18 stakeholders of Gotland-based beach-cast harvesting activities, representing six NGOs, six actors in the public sector and six actors in the private sector (Appendix 2018 in the following), if not otherwise stated. Relevant currency rates and, for benefits and costs that occurred before 2018, consumer price indices were applied, see Appendix S4–S7 for details. The monetization of the benefits of nutrient removal is based on earlier valuation studies of such benefits. Recent and peer-reviewed studies of the benefits of reducing eutrophication effects specifically in the Baltic Sea were selected for maximizing quality and relevance of the results (Appendix S4).In the CBA, benefits and costs are expressed as total monetary amounts for all the 40 LOVA projects during the whole period of 2009–2018, if not otherwise stated. All monetized benefits and costs are expressed in US dollars and 2018 prices , which suggests that LOVA projects during the 10-year period in question (2009–2018) have accounted for 60–75% of the total beach-cast and associated nutrient removal on Gotland .The total annual harvest of beach-cast on Gotland has been estimated to 12 000–15 000 metric tons (t) fresh weight (FW) . Using the mean value of USD2018 38 kg−1 reduced PO4-eq captures numerical information from all these studies, implying that the nutrient removal accomplished by the LOVA projects from 2009 to 2018 corresponds to benefits amounting to USD2018 11.5 million . Malodour caused by the release of sulphur compounds from beach-cast decomposition is perceived to decrease if beach-cast is gathered in piles, potentially because the malodour is concentrated around the piles (Appendix S2b). The value of the improved recreational opportunities is also indicated by the high degree of volunteering in harvest activities (cf. “S2c). Overall, a positive net benefit with respect to recreational opportunities for residents and tourists is therefore expected, but we refrain from monetizing it because of the lack of local valuation results on recreational beach use on Gotland.Beach-cast harvesting tends to increase the use of beaches by making them and the waters more physically accessible and also more pleasant to visit (Appendix ies cf. “” sectionies cf. “. Moreoveies cf. “. The preS2c). While this is likely to reduce negative habitat effects, the net effect in terms of benefits or costs cannot be assessed from current data.Harvesting affects the specific habitat associated to the bands of beach-cast and may result in decrease in species abundance and number of species. Some localities with beach-cast bands can be classified as a vulnerable habitat for threatened annual plant species according to the EU habitat directive COM . The adv4) and nitrous oxide (N2O) in anaerobic conditions and CO2 emissions in aerobic conditions both occur in bands and piles . Applying the social cost of carbon applied in transportation related CBAs in Sweden gives a total cost of USD2018 0.24 million for the harvesting and associated transports of the LOVA projects (Appendix S5). This cost is incurred by the global population.Given the knowledge gaps relating to GHG emissions from both beach-cast bands and piles, the present study only accounts for those GHG emissions which can be estimated, i.e., emissions of harvesting activities. The diesel consumption associated with machinery used for harvesting and transporting this machinery to and from harvest locations indicates COAccumulating bands of beach-cast over the course of years can alter the geomorphology and topography of a beach and potentially provide natural coastal protection by supporting dune formation and providing sand stabilization  but also investment and maintenance costs for the machinery. The total invoiced costs for all projects amounted to about USDon Table . The proon Table . These c2018 0.39 million for the period of 2009–2018 (Appendix S7).Transaction costs related to the LOVA project system are delimited to the costs for administrating LOVA applications and reporting at CABG. Administrative costs incurred by LOVA project owners and other project participants are probably to a large extent included in the volunteering reported in harvest costs. Based on annual reporting from CABG to the Swedish Agency for Marine and Water Management, the total administrative costs incurred by the Swedish government are estimated to about USDx and NH3 emissions applied in transportation related CBAs in Sweden, and amount to about USD2018 0.0018 million (Appendix S5). The latter is difficult to monetize, but would add to society’s social capital, and interview data indicate a positive impact of the increased community networking implied by the LOVA projects (Appendix S2d). The LOVA projects have also supported knowledge-building about harvest practices that might imply cost reductions in future projects. There might also be marine ecosystem effects beyond those associated with nutrient removal; for example, indications of improved conditions for flatfish recruitment because of less humus accumulation on coastal sea-beds in initial studies should be subject to further investigation  exceed the total costs (USD2018 1.73 million)  and that an alternative estimation of total nutrient removal did not result in any lower estimates (Appendix S3). As to the cost side, the harvest costs of USD2018 1.1 million have to increase by a factor of ten before reaching break-even, other things being equal. A comparison with other harvest cost estimates suggests that such a substantial underestimation of harvest costs is not likely (Appendix S6). Further, the LOVA projects have small incentives to underreport harvest costs, because grants through the LOVA grant system are based on the projects’ reported costs. We therefore conclude that a positive economic profitability is the most probable outcome of this CBA. It should be acknowledged that the non-monetized consequences add uncertainty to this conclusion, but the non-monetized costs would have to be remarkably substantial to outweigh the monetized net benefit and the non-monetized benefit due to improved recreational opportunities on beaches subject to beach-cast harvest.Based on benefits and costs that can currently be monetized, the total benefits of the beach-cast harvest in the LOVA projects (USDn) Table . This woWe found that the harvest activities in the analyzed LOVA projects are likely to have been economically profitable to society, though there are considerable uncertainties that should be acknowledged and deserve further investigations, including currently non-monetized benefits and costs. For example, the benefits of nutrient removal and improved recreational opportunities could be monetized more precisely by carrying out local valuation studies that are designed specifically for Gotland. Similarly, more detailed protocols for reporting harvesting costs, nutrient concentrations in beach-cast and harvested beach-cast fate, combined with systematic follow-up studies, could also reduce uncertainties. Another uncertainty is due to potential nutrient run-off to the sea from piles of harvested beach-cast. If piles are left unused at unsuitable places from a run-off perspective, the nutrient removal benefits in the CBA become temporary, but could be secured by identifying piling locations that minimize run-off risks and/or using beach-cast in a way that recirculates nutrients (see below). Note also that the benefits related to improved recreational opportunities on land arise largely from the mere relocation of beach-cast from beaches to piles.2018 17, 30 and 47 kg−1 reduced PO4-eq in Table The positive economic profitability suggests that policies that helped realizing the analyzed LOVA projects have been motivated, particularly because nutrient removal can be viewed as a positive externality of harvesting. The policy instrument was in this case a Swedish national grant system, which suggests that the regional approach to standing applied in the CBA should be discussed. It could be argued that a Swedish grant system is consistent with giving standing to only Swedish citizens in a CBA. Such a national approach to standing would motivate a delimitation of nutrient removal benefits to those enjoyed by Swedes, i.e., the estimates of USDAs to future beach-cast harvesting, continued subsidization is an option, which suggests that the role of beach-cast harvest in relation to other subsidized land- and sea-based nutrient removal measures should be explored further, i.e., adding beach-cast harvest into cost-effectiveness analyses such as Hyytiäinen et al. . Such anAlso the choice of system boundary is crucial: The value chain steps in the present study focus on harvesting, but extending the analysis to post-harvest processes might affect the economic outcome. On Gotland, there is small-scale agricultural use of beach-cast that may increase soil fertility and to some extent substitute mineral fertilizer and thus possibly imply cost reductions for farmers . Broadening the geographical perspective nationally and internationally implies considerable harvest opportunities. For example, the total beach-cast biomass potential for the whole southern Sweden can be estimated to 241 000–257 000 t FW yr2018 1.73 million Below is the link to the electronic supplementary material.


Thanks to the development of HTS technologies, a vast amount of genetic information on the virosphere of temperate forests has been gained in the last seven years. To estimate the qualitative/quantitative impact of HTS on forest virology, we have summarized viruses affecting major tree/shrub species and their fungal associates, including fungal plant pathogens, mutualists and saprotrophs. The contribution of HTS methods is extremely significant for forest virology. Reviewed data on viral presence in holobionts allowed us a first attempt to address the role of virome in holobionts. Forest health is dependent on the variability of microorganisms interacting with the host tree/holobiont; symbiotic microbiota and pathogens engage in a permanent interplay, which influences the host. Through virus–virus interplays synergistic or antagonistic relations may evolve, which may drastically affect the health of the holobiont. Novel insights of these interplays may allow practical applications for forest plant protection based on endophytes and mycovirus biocontrol agents. The current analysis is conceived in light of the prospect that novel viruses may initiate an emergent infectious disease and that measures for the avoidance of future outbreaks in forests should be considered. Forests represent a major natural resource and provider of ecosystem services, products and jobs in Europe. They cover 35% of Europe’s total land area , their eChryso-, Endorna- Megabirna-, Quadri-, Partiti-, Reo- and Totiviridae. The linear (+)ssRNA viruses were classified into five families: Alphaflexi-, Barna-, Gammaflexi-, Hypo- and Narnaviridae. The linear (–)ssRNA belonged to the proposed family “Mycomononegaviridae”, while the circular ssDNA viruses were still unclassified.Land plants are known to own a virome of a distinct composition, heavily dominated by diverse positive sense RNA ((+)RNA) viruses, with a more limited representation of double-stranded RNA (dsRNA), negative sense RNA ((−)RNA) viruses, reverse-transcribing (RT) viruses and single-stranded DNA (ssDNA) viruses, to the exclusion of bona fide dsDNA viruses . The virVirus diseases of forest tree species represent a threat for the forest health that has been underestimated thus far ,6. UnforBetula spp. in Europe [Badna-, Nepo- and Capillovirus) [Emaravirus within the family Fimoviridae, which is the causal agent of the “European mountain ash ringspot disease” in Sorbus aucuparia [Karpatiosorbus x hybrid in Finland [Sorbus intermedia in Sweden [Amelanchier spp. in Germany [Due to the utilization of high-throughput sequencing (HTS) methodologies, forest virology has gained a significant momentum in identifying viruses-infecting forest trees and associated fungi ,9,10,11.n Europe ,13 reprelovirus) , while alovirus) . Anotherucuparia ,17. Rega Finland , Sorbus n Sweden  and Amel Germany .Partitiviridae have also been largely ignored as they maintain a persistent lifestyle and they do not generally cause plant diseases. These are characterized by vertical transmission through seeds and/or pollen and a lack of pathogenicity and infectivity (ability to infect new hosts de novo via plant-to-plant transmission) [Regarding mycoviruses, a significant amount of data derive from the last decade through metagenomic analyses . These vmission) . The tremission) ). ViruseThis review aims to describe and comprehend the current status of the virosphere of a forest by summarizing the viral species coexisting in a forest. We name this “forest virome” and consider all existing genetic information of viral origin to be related to common forest trees and shrubs. Although the interactions between the host and viral agent are not always adequately defined, we have considered the following categories of interactions: a. pathogenic virus versus tree/shrub host, b. non-pathogenic virus versus tree/shrub host, c. pathogenic virus versus fungal host or d. non-pathogenic virus versus fungal host. In the term “forest”, we consider the natural temperate and boreal forest ecosystems in the Northern Hemisphere as well as urban parks and urban green areas mainly covered by forest trees and shrubs, which constitute separate ecosystems within urban environments. However, it is beyond the aim of the present review to list all studies performed to date; this work has been thoroughly carried out previously . The aimThe need for a current review about forest viruses is further strengthened by the fact that advances in plant virology are traditionally restricted in crop or fruit tree pathogenic viruses. This becomes apparent when considering the latest reviews ,25 resumFinally, this review presents various lines of evidence regarding why further research on forest virome is required in order to a. biologically characterize the newly described pathogens, including their modes of dispersal and possible vectors; b. build the knowledge base of virus–tree interactions as well as of virus–fungus interactions; c. gather knowledge on the behavior of the forest parasites, in preparation for future outbreaks as a consequence of significant changes in the climate and the environment; d. explore alternative means of controlling fungal and viral forest diseases. As our understanding of the viruses of fungal endophytes and forest pathogens is only at the very beginning, it is an ideal time to apply the most modern sequenced-based tools in favor of forest virology.The current analysis was based on two main principles. The first was the hologenome theory of evolution ,27. Accowww.scopus.com/search/; accessed on 20 June 2021).To explore the studies involved in the described subject, we first listed viruses alphabetically, ordering them in three categories: 1. plant viruses infecting tree/shrub hosts and cryptoviruses , 2. mycoBetaflexiviridae (11 viruses), Secoviridae (seven viruses), Bromoviridae (five viruses), Tombusviridae (four viruses), Virgaviridae (three viruses) and Mayoviridae (one virus). Apart from the (+)ssRNA viruses, there is also a genus of (–)ssRNA, the Emaravirus, which is represented in the forest virome with four different species. There are also two reverse-transcribing dsDNA viruses: the birch leafroll-associated virus (BLRaV) in Betula spp. and the chestnut mosaic virus in Castanea sativa, both belonging to the Badnavirus genus (Family Caulimoviridae). Additionally, the first genetic evidence of the presence of another reverse-transcribing DNA virus has been reported in white ash (Fraxinus americana). Finally, three dsRNA viruses have been also detected in pines and in ash trees, two from the family Partitiviridae and one from Amalgaviridae.In the present review, we listed 43 plant viruses that affect 19 forest tree and shrub species present in the temperate forest and urban zone (Emaravirus with four species to date (aspen mosaic-associated virus [Badnavirus with two species (birch leafroll-associated virus [Carlavirus with eight species (birch carlavirus [Idaeovirus (unassigned species and family), a Capillovirus (Betaflexiviridae), a Bromovirus (Bromoviridae) and a Aureusvirus (Tombusviridae).In total, 21 viruses have been newly discovered within the last five years by applying HTS methodologies, which represent 49% of the total number of viral species in forest trees. Among these, three virus genera are overwhelmingly represented. These are the genus ed virus , common ed virus ,57, mapled virus  and Euroed virus ), the geed virus  and chesed virus ) and therlavirus , blueberrlavirus ,44, elderlavirus ,60 and erlavirus ,62,63). From the current knowledge, the majority of viruses detected in forest/shrub tree species exhibit a broad host range and were isolated in many other crops or trees  before their discovery in forest trees, but our aim is to reform this knowledge base, as there is a remarkably increasing number of novel viruses. The 21 novel viruses discovered through HTS to date are host specific and, following the nomenclature principles, the host name is included in the new species name. As a result, all novel virus species are named after their forest tree host. Only four viruses were named after a forest tree name before the discovery of the HTS: the poplar mosaic virus, the European mountain ash rinspot-associated virus, the elm mottle virus and the white ash mosaic virus.Partitiviridae family (17 viruses) but also families Totiviridae (three viruses) and Curvulaviridae (two viruses), while the family Reoviridae was represented by one virus species. As dsRNA viruses can be readily detected based on classical cellulose chromatography analysis, most of these viruses were already known before the employment of HTS methods. Similarly, some (+)ssRNA viruses, including members of Hypoviridae, Endornaviridae and Mitoviridae, had been already discovered prior to the HTS era based on their dsRNA replicative intermediates. HTS analysis has, however, revealed mitoviruses to be highly common in fungi, also in fungal species where members of this family were not earlier detected by classical virus screening methods. From the total of 33 (+)ssRNA viruses detected, 23 belong to the family Mitoviridae; 11 novel mitoviruses have been detected during the last five years applying HTS, while Cryphonectria parasitica mitovirus 1 [Virgaviridae) and an ourmia-like virus (family Botourmiaviridae) in Armillaria spp. [Mymonaviridae). Finally, new unclassified ambisense viruses were very recently identified and characterized: Cryphonectria parasitica ambivirus 1- NB631 [Rosellinia necatrix that infects many fruit trees and related natural trees, also leading to the discovery of members of Hypoviridae, as well as unclassified ”fusagraviruses“ and ”megatotiviruses“ [Gremmeniella abietina by HTS [In this study, we have summarized 63 viral species infecting ten highly important fungal or oomycete pathogens occurring in more than 11 genera of forest trees  and the rest to the families Curvulaviridae (two viruses) and Totiviridae (one virus). Thanks to HTS, novel dsRNA viruses were detected for first time in several species of ECM fungi in Turkey: Picoa juniperi  and Endornaviridae (two viruses). For the first time, a mitovirus was, by means of HTS, fully genetically characterized in the ectomycorrhizal fungus Geopora sumneriana [In viridae, ), Sarcos member, ), Hygroptivirus, ), and insculenta . Regardimneriana .Tuber), and only recently, viral diversity in mycorrhizal fungi has been addressed more from an ecological viewpoint. While HTS studies have already revealed hitherto unknown evolutionary trajectories and new viral genome organizations in ECM fungi and other mycorrhizae [The first viruses infecting ECM fungi were discovered in commercially valuable truffles  is found on many broadleaved tree species, and although virus-like particles were found in this species already in the 1970s, HTS has recently revealed many new virus taxa, most notably, (–)ssRNA viruses not detected by traditional methods [Mymonaviridae and a partitivirus were also identified with the use of RNA-Seq in the Bondarzewia berkeleyi from oak wood [Flammulina velutipes) [Pleurotus ostreatus) [Saprotrophs that consume coarse or fine woody debris are somewhat less intimately connected with the plant host than mycorrhizal fungi and pathogens, and most of them cannot be connected to a single genus of host trees. Some of them produce edible fruiting bodies and for this reason have been subjected to virus screening studies by HTS. The shiitake mushroom   and the treatus) , favouriArabis mosaic virus, cucumber mosaic virus, maple mottle-mssociated virusA. pseudoplatanus (sycamore) and A. platanoides (Norway maple), representing a natural component of birch (Betula spp.) and fir (Abies spp.) forests [A. saccharum, A. nigrum, A. negundo, A. rubrum, A. pseudoplatanus. Maple sugar and maple syrup can be primarily produced from sugar maple (A. saccharum), black maple (A. nigrum) and manitoba maple (A. negundo) [Maples are abundantly found in temperate forests and urban parks, with the most common species,  forests . With a negundo) . As withnegundo) .Acer spp. However, until recently, maple has never been unambiguously described as a host for any well-characterized viral agent. Employing HTS methodology, a novel emaravirus was recently reported in sycamore maple (A. pseudoplatanus) exhibiting leaf mottle symptoms in Germany and was genetically characterized [Viral diseases in different maple species have since long been reported ,181. Aracterized . RNA-Seqcterized .apple mosaic virus; arabis mosaic virus; birch leafroll-associated virus; birch capillo-virus; birch carlavirus; birch idaeovirus; cherry leaf roll virus; Phytophthora cactorum RNA virus 1; tobacco necrosis virus; tomato ringspot virusB. pedula and B. pubescens, due to the numerous strengths and potentials of these tree species, it is recommended by Dubois et al. [Birches are an essential ecological component in northern temperate and boreal forests . They ars et al.  to expanSeveral common tree viruses have been since long reported in birch: apple mosaic virus ,34, arabPhytophthora cactorum is a birch pathogen that causes stem lesions and infects mostly nursery seedlings [P. cactorum isolated from strawberry plants [Armillaria root rot fungi, which typically attack trees weakened by drought or other pathogens. A recent NGS study detected a novel virus group called “ambiviruses” in Armillaria borealis growing on birch wood [The oomycete eedlings . Besidesy plants . Furtherrch wood .chestnut mosaic virus, Cryphonectria hypovirus 1, mycoreovirus 1Castanea sativa) is the only native species of the genus in Europe [The sweet chestnut  represents one more case in the forest pathology, where knowledge concerning the causal agent was gained thanks to HTS and bioinformatics analysis. The disease was described several decades ago in Italy  associatCryphonectria parasitica. As stated above, hypoviruses infecting the pathogen have been successfully used to control the fungus, and the subsequent natural spread of these viruses has protected European chestnut trees from complete devastation [Chestnut blight is another serious disease of chestnut caused by the ascomycete astation ,168. Addastation .arabis mosaic virus; cherry leaf roll virus; Hymenoscyphus fraxineus mitovirus 1; tobacco mocaic virus; tobacco necrosis virus; tobacco ringspot virus; white ash mosaic vi-rus; putative cryptovirus; putative caulimovirusAlthough several viruses are reported in ash trees, all of them are generalists, and none of them is host specific. The most common are arabis mosaic virus ,38, cherFraxinus americana [Partitiviridae are not pathogenic for their host; recently, however, new members of the family were found to be associated with symptom development. Nevertheless, further studies are needed in order to fully characterize the new viruses in ash.With the use of HTS, a novel putative partitivirus and a novel putative caulimovirus have been identified in mericana , exhibitH. fraxineus is a pathogen recently introduced into Europe from Asia, causing ash dieback and threatening ash stands all across the continent [H. fraxineus isolates from Europe were previously shown to harbor HfMV1, while later, a viral population with higher genetic diversity was detected in H. albidus, a harmless litter saprotroph native in Europe. This fact suggests multiple interspecific virus transfers from H. albidus to H. fraxineus [A recently discovered mycovirus related to the ash microbiome/virome is Hymenoscyphus fraxineus mitovirus 1 (HfMV1) . H. fraxontinent . H. fraxraxineus .Heterobasidion mitovirus 1, 2 and 3; Heterobasidion RNA virus 6; Heterobasidion partitiviruses; Picea mariana tenuivirus; tomato mosaic virus; tomato mosaic virusHeterobasidion parviporum and Ips typographus, as well as health problems of unidentified aetiology, its popularity for reforestation, particularly outside its natural range in central European forests, has been reduced, although it remains the most commercially valuable tree species in the Nordic countries.Concerning Norway spruce, it is a long-living species (>200 years-old) with a long tradition of cultivation for its straight trunk, particularly used for timber constructions, pulpwood for paper and furniture . Its higPicea mariana has been reported to host (–)ssRNA viruses of the genus Tenuivirus [From the plant pathogenic viruses, only tomato mosaic virus has been reported in spruce ,94. Picenuivirus .Heterobasidion parviporum, which causes economic losses of hundreds of millions of euros annually in Europe [H. annosum prefers pines as its host, and H. parviporum hosts partiti-, curvula- and mitoviruses  and H. irregulare (North America and Europe as an introduced invasive species). These pine pathogens host viruses of the families Partitiviridae and Mitoviridae, and both virus families also have apparently cryptic members infecting plants . The Heterobasidion partitivirus 13 (HetPV13-an1) of H. annosum is associated with host debilitation , a member of a newly classified family, Curvulaviridae  [F. circinatum is also commonly infected with mitoviruses  . F. circectively .Thelephora terrestris, which hosts a “phlegivirus” that was also detected in soil oribatid mites, suggesting that even some RNA mycoviruses could have arthropod vectors [Lactarius rufus is a highly common ectomycorrhizal symbiont of pine trees and has been shown to be commonly infected by members of the family Curvulaviridae  in Spain and was later PCR-detected in Pinus nigra samples from the vicinity of where the air samples were collected. This suggests that this new virus is likely a pathogen of Pinus [Pinus is tobacco necrosis virus [Pinus nigra virus 1, an unclassified of Pinus . Anotheris virus , but it arabis mosaic virus; Armillaria borealis mycovirgavirus 1; Armillaria borealis am-bi-like virus 1 and 2; aspen mosaic-associated virus; poplar mosaic virus; tobacco necrosis vi-rus; tomato black ring virusPopulus is a tree native to most of the Northern Hemisphere including 25–30 species. Six of these aspen species play a disproportionately important role in promoting biodiversity, sequestering carbon, limiting forest disturbances and providing other ecosystem services [services . ImportaRegarding viruses affecting poplars, four viruses have been previously identified: arabis mosaic virus , tomato Armillaria. One of the most common species is A. borealis occurring in both conifers and hardwoods. Recently, HTS analysis revealed a Siberian isolate of A. borealis from Populus spp. to be infected by multiple viruses, including a novel ssRNA(+) virus named Armillaria borealis mycovirgavirus 1 and three ambi-like viruses [Poplars, as many other hardwood trees, are also readily infected by species of  viruses .Armillaria mellea negative strand RNA virus 1; Armillaria mellea ourmia-like virus 2; common oak ringspot-associated virus; tobacco mocaic virus; tobacco necrosis virusQuercus contains over 500 species. Oaks are amongst the most economically and ecologically important deciduous trees in Europe providing wood for fuel, bark for tanning, timber for construction and acorns for livestock [Q. robur (common oak), Q. petraea, Q. variabilis (chinese oak), and Q. rubra that are native in Europe, North America and Asia.The genus ivestock . Here, wEmaravirus comprising five RNA segments. Typically for emaraviruses, the RdRP is encoded by RNA 1, while RNA 2 encodes the GPP. The viral nucleocapsid protein (N) is encoded by RNA 3, and RNA 4 encodes the MP. RNA 5 of CORaV contains one major open reading frame, coding for a protein P5 of 179 aa; however, the function of P5 remains to be elucidated. This is one more occasion where metagenomic analysis provided the diagnostic answer to a problem that has remained unsolved for a long time.Apart from two viruses with wide host spectra reported to occur in oaks, tobacco necrosis virus  and tobaPhytophthora ramorum—an oomycete that can kill oaks within a few weeks—and from “Oak Wilt”—caused by the fungus Ceratocystis fagacearum. The oak forest decline is a serious problem in North and South America. In the USA, entire oak ecosystems have declined due to a combination of factors that remain unclear [Phytophthora ramorum isolates from various host plants, including Rhododendron and Viburnum species, both in the United States and Europe, but unfortunately, they do not seem to cause host debilitation that could be used for disease mitigation [Armillaria root rot fungi. Recent discoveries of viruses in Armillaria spp. [A. mellea from oak trees in South Africa did not seem to reduce the growth of their host in laboratory conditions.Apart from the virus diseases, oaks also suffer from the “Sudden Oak Death” caused by  unclear ; it is, tigation . Alreadyria spp.  also proTuber spp.) and Cenococcum geophilus, as well as basidiomycetes, such as species of Lactarius, Russula and Cortinarius. Viruses have been found in the ectomycorrhizal fungus Hygrophorus penarioides, but their possible effects on the tree-fungus association are unknown to date [Tuber spp. (T. excavatum and T. aestivum) have been shown to harbor diverse viruses of the families Totiviridae, Endornaviridae and Mitoviridae  is a deciduous tree native to Europe and North America. Its flowers and berries are used to prepare infusions, syrups and jellies and in traditional medicine. The popularity of this plant has increased in recent years in the pharmaceutical and food industries, due to its antiseptic and antiviral properties as well as to the interest in the colour compounds present in the berries [Elderberry , inducing chlorotic ringspots, mottle and line pattern on leaves and is widespread in central/northern Europe and England [Amelanchier spp. in Germany [Karpatiosorbus x hybrid in Finland [Sorbus intermedia in Sweden [S. intermedia (Swedish whitebeam), it was revealed through high-throughput Illumina RNASeq that EMARaV in this host possesses two additional RNA segments, in contrast to the four RNAs known to be possessed by EMARaV in mountain ash [S. aucuparia, together with the previously known RNA1–RNA4 segments. The systematic presence of RNAs 5 and 6 in diseased Sorbus spp. and their absence in healthy trees suggest that the two newly identified genome segments encode proteins that are indispensable for the virus. Future studies are required to functionally confirm that the RNA5-encoded protein is the EMARaV MP and to investigate the role of the P27 encoded by the novel RNA6 in the life cycle of EMARaV.The main disease affecting  England . In addi Germany , Karpati Finland  and Sorbn Sweden . Concrettain ash . The fifApart from EMARaV, only a few viruses have been detected in mountain ash: the apple mosaic virus , the appcherry leaf roll virus; elm carlavirus; elm mottle virus; tomato ringspot virus; Ophi-ostoma mitovirusesSeveral viruses have been reported to affect elms: elm mottle virus ,65, tomaOphiostoma ulmi and O. novo-ulmi, the causal agents of the Dutch elm disease (DED), devastating American elms but also causing epidemics in Europe and North America after new introductions. Some of these mitoviruses are associated with the reduced growth and sporulation of the host fungus [O. novo-ulmi, while two more mitoviruses were detected in a Canadian isolate of O. novo-ulmi [O. novo-ulmi to date are located in mitochondria and can only be transmitted during anastomosis between compatible hyphae or induced forms of cytoplasmic mixing [Mitoviruses are common in t fungus . Eight it fungus  in one dovo-ulmi . The usec mixing . These fPrunus spp.: Prunus trees may suffer from infections by Chondrostereum purpureum, which causes silver leaf disease and has been developed as a biocontrol tool for the prevention of sprouting. The fungus hosts an alphapartitivirus called Chondrostereum cryptic virus 1 [Rosellinia necatrix that has a very broad host range, including both tropical and temperate fruit and forest trees. virus 1 . This trAesculus spp.: Some plant pathogenic viruses have been reported in Aesculus   . Cryphoncastanum .Fagus spp.: Earlier reports exist on the occurrence of cherry leaf roll virus and tobacco necrosis virus in beech. A recent RNA-Seq investigation revealed a novel carlavirus related to leaf symptoms in trees in Germany [ Germany .Robinia spp.: Strawberry latent ringspot virus and peanut stunt virus (Iran) (s (Iran)  have beeSalix spp.: A few generalist viruses may occur in Salix, such as brome mosaic virus, tomato mosaic virus and tobacco necrosis virus.Cedrus libani: The ectomycorrhizal ascomycete Geopora sumneriana is associated with Lebanon cedar. Recently, Geopora sumneriana mitovirus 1 was identified in this fungal species [ species .Abies spp.: No plant pathogen has been reported. Several partitivirus have been reported in Heterobasidion basidiomycetes infecting diverse Abies species: Heterobasidion partitivirus 1 in A. cephalonica; Heterobasidion partitivirus 10 in A. concolor; and Heterobasidion RNA virus 6 (an orthocurvulavirus) in A. alba, A. sibirica, A. cephalonica, A. cilicica, A. equi-trojani and A. concolor  that contribute to what a forest is. Analogically, our knowledge regarding virus communities in urban parks has considerably increased. Almost half of the plant pathogenic viruses and cryptoviruses in plants (21 out of 43), 35% of the mycoviruses infecting pathogenic fungi (22 out of 63) and 54% of the mycoviruses occurring in non-pathogenic fungi (7 out of 13) were discovered due to the employment of HTS strategies. Specifically considering phytopathogenic viruses, novel viruses were not identified in random environmental or host samplings, but after targeting diseased trees, where the disease has been previously identified and the disease distribution was monitored for a long time period; however, the causal agent had not been identified due to limitations in the existing conventional molecular diagnostic methods. Concerning mycoviruses, even in species that have previously been extensively investigated, the HTS of a small number of isolates has revealed novel (+)ssRNA and (–)ssRNA viruses, which were viruses undetectable by traditional methods. The ability of HTS methods to extend the genetic investigation to a depth that had not been earlier achieved has resulted in extraordinary discoveries that have radically changed the view of forest pathology.Emaravirus (Fimoviridae), and two families of dsRNA viruses  were found, and this was achieved via HTS technologies. From the Pararnavira kingdom, only the family Caulimoviridae is represented with several RT viruses in the plant section of the forest virome. These are novel pathogenic viruses in birch, chestnut, pine and ash, which were unsuccessfully investigated with conventional diagnostic methods for many years, until HTS finally provided the solution. Concerning mycoviruses, analogously to land plants, dsRNA viruses also predominate in the forest, while RT viruses and circular ssDNA viruses have not yet been detected. By employing HTS, numerous novel dsRNA viruses, members of the families Partitiviridae, Totiviridae, Megatotiviridae ssRNA viruses were detected in the fungal section of the forest virome: two of them belong to the family Mymonaviridae [Ambivirus [The vast majority of the viral families described in land plants are also shown to be present in the forest virome. Only viruses belonging to the realm Monodnaviria are not found in the forest, neither in tree nor in fungal hosts. Similarly to the taxonomical content of viruses described in plants, from the kingdom Orthornavirae, the (+)ssRNA viruses dominate the forest virome (members from seven families detected). Additionally, from the Orthornavirae, one virus genus of (–)ssRNA viruses, which are scarce in plants, the  family; ) and Megof ICTV; ) were chescribed , but ratescribed . Apart faviridae  and one mbivirus .The massive discoveries of viruses in the forest ecosystem based on HTS technologies usually only refer to the full or partial genome sequence of the novel viruses, while knowledge on its biology and symptom expression is limited. To provide a basis for assessing the risk the novel viruses pose and make scientifically based decisions, a series of unavoidable steps need to be taken . The earBased on the data of the last seven years, it has been revealed that the genetic variation of the forest virome is much larger than estimated. After gathering information about the viral presence in the holobionts, we could—as a next step—estimate the role of this virome in holobionts, the need for which was underlined by Rosenbeng and Zilber-Rosenberg . One of Physcomitrella patens were acquired by HGT from prokaryotes, fungi or viruses [P. patens genes are clustered in DNA stretches (up to 13 kb) containing up to 16 NCLDV-like ORFs [Caulimoviridae, were discovered in birch and chestnut and one unclassified Caulimoviridae member was discovered in pines. Pararetroviruses are often present as integrated, complete or fragmented and/or re-arranged genomic sequences in some host plant genomes and are then referred to as endogenous viral elements (EVEs). Some banana streak viruses (BSV) are found in episomal form with an endogenous counterpart (eBSV) [An important source of genetic variation is the horizontal gene transfer (HGT). As an example, 128 genes identified in the genome of moss  viruses . Interesike ORFs . The acqt (eBSV) . In a fet (eBSV) . Moreovet (eBSV) . Evidenct (eBSV) . WhetherViruses often coinfect single holobionts—in our study trees/shrubs—in nature. This was already known before the development of HTS technology, but the deep sequencing methods profoundly revealed the complexity of plants and tree viromes. Novel data on the birch virome clearly demonstrate in holobionts mixed infections by multiple plant viruses as well as multiple variants of the same virus species ,15,189. Cryphonectria parasitica; for example, the (+)ssRNA virus Cryphonectria hypovirus 1 (CHV1) exerts a one-way synergistic effect on a co-infecting mycoreovirus 1 (MyRV1), resulting in enhanced virus accumulation and increased vertical transmission of MyRV1 [S. sclerotiorum individuals to create a bridge donor strain for mycovirus spread under natural conditions [Viruses often coinfect single fungal hosts in nature, and interesting virus–virus interplays in coinfected hosts have been reported that may be synergistic, apparently neutral or antagonistic . Strong of MyRV1 . In anotof MyRV1 . Recentlof MyRV1 . In anotnditions . Such exCryphonectria parasitica, and a sympatric unidentified Cryphonectria species via hyphal anastomosis [H. parviporum and H. australe growing in the same region in Bhutan, an observation that suggests recent virus transmission between these taxonomically distant Heterobasidion species in nature [Fraxinus spp., hyphal anastomosis and transfer of the mitovirus Hymenoscyphus fraxineus mitovirus 1 (HfMV1) between both Hymenoscyphus albidus and H. fraxineus in ash is also hypothesized [Interspecific virus transmission is often suggested in mycoviruses ,228. In n nature . In anotthesized . Bearingthesized ,230, thiThe efforts to untangle the complex world of the microbiota—virome interaction has been initiated for the human holobiont. Evidence is provided that bacteria aid in the antiviral response to certain viruses; however, occasionally, they may act as promoters of viral infection . The preCryphonectria parasitica) in Europe [C. parasitica, the introduction of a partitivirus and a megabirnavirus originating from another host fungus, Rosellinia necatrix, was also shown to reduce host virulence [R. necatrix viruses, including a fungal reovirus, also show potential for controlling their native host [H. annosum and H. parviporum [The accumulation of knowledge regarding abundant mycoviruses in plant pathogenic fungi in forests offers new possibilities for pathogen control and management. It was previously found that endophytes could potentially be utilized as biocontrol agents in integrated pest and disease management . Practicn Europe ,168. Morirulence ,234. Sevive host ,237,238.rviporum ,200. TheLymantria dispar on birches [Condylorrhiza vestigialis on poplars [Orgyia leucostigma on birches, firs and spruces [Neodiprion abietis on conifers [N. sertifer [In the present review, we did not address viruses of arthropods; however, it should be noted that baculoviruses of insect pests of temperate forest trees have been investigated for their biocontrol potential. The most prominent, which we mention here, are the nuclear polyhedrosis virus affecting  birches , oaks an birches ; the Con poplars ; the Org spruces ,243; andconifers . As partsertifer . To the Sphaerotheca lanestris). Vector studies of forest viruses were not reported until 2012 when Mielke and Mühlbach [Phytoptus pyri) conclusively shown with several emaraviruses: European mountain ash ringspot-associated virus (EMARaV), fig mosaic virus (FMV), rose rosette virus (RRV), raspberry leaf blotch virus (RLBV) and pigeonpea sterility mosaic virus.Regarding vectors that transmit viruses, little is known. The only corresponding reference in the past was given in 1972 when Nienhaus detected tobamoviruses in Californian oak leaves  and expeMühlbach  highlighHealthy trees and healthy forests are translated into forests providing better regulating services , maintenance/habitat services (increased biodiversity) and multiple ecosystem services . However, the question arises as to how the “healthy forest virome” is defined, taking into consideration that virus–host relationships span the entire range from aggressive parasitism to mutualism. The corresponding question was previously posed concerning the “healthy human virome”. In humans, the same virus can be either a symbiont or a pathogen depending on conditions such as the health status and developmental stage of the host. Koonin et al.  suggest The characterization of many novel—pathogenic or non-pathogenic—viruses in a short time raises the question of how to profit from these new data in order to avoid forest disease outbreaks in the future. It is possible for a pathogen to initiate an emerging infectious disease (EID)? According to the pathogen–host–environment interplay theory , emergen


Smart sensors, coupled with artificial intelligence (AI)-enabled remote automated monitoring (RAMs), can free a nurse from the task of in-person patient monitoring during the transportation process of patients between different wards in hospital settings. Automation of hospital beds using advanced robotics and sensors has been a growing trend exacerbated by the COVID crisis. In this exploratory study, a polynomial regression (PR) machine learning (ML) RAM algorithm based on a Dreyfusian descriptor for immediate wellbeing monitoring was proposed for the autonomous hospital bed transport (AHBT) application. This method was preferred over several other AI algorithm for its simplicity and quick computation. The algorithm quantified historical data using supervised photoplethysmography (PPG) data for 5 min just before the start of the autonomous journey, referred as pre-journey (PJ) dataset. During the transport process, the algorithm continued to quantify immediate measurements using non-overlapping sets of 30 PPG waveforms, referred as in-journey (IJ) dataset. In combination, this algorithm provided a binary decision condition that determined if AHBT should continue its journey to destination by checking the degree of polynomial (DoP) between PJ and IJ. Wrist PPG was used as algorithm’s monitoring parameter. PPG data was collected simultaneously from both wrists of 35 subjects, aged 21 and above in postures mimicking that in AHBT and were given full freedom of upper limb and wrist movement. It was observed that the top goodness-of-fit which indicated potentials for high data accountability had 0.2 to 0.6 cross validation score mean (CVSM) occurring at 8th to 10th DoP for PJ datasets and 0.967 to 0.994 CVSM at 9th to 10th DoP for IJ datasets. CVSM was a reliable metric to pick out the best PJ and IJ DoPs. Central tendency analysis showed that coinciding DoP distributions between PJ and IJ datasets, peaking at 8th DoP, was the precursor to high algorithm stability. Mean algorithm efficacy was 0.20 as our proposed algorithm was able to pick out all signals from a conscious subject having full freedom of movement. This efficacy was acceptable as a first ML proof of concept for AHBT. There was no observable difference between subjects’ left and right wrists. Developing highly skilled nurses, often called Advanced Practice Nurses (APNs), has been identified as a strategic thrust for Singapore to deliver healthcare in the community . In contSmart functions such as remote automated monitoring (RAM) ,3, definHospital bed transport (HBT) is an OJT identified with high potential for smart function automation. HBT refers to a low-risk variant described in the body of robotic bed mover research ,7 where The aim is to develop a RAM solution for assessing HBT patient’s immediate health monitoring. Under this solution, real-time advisories on patient’s general wellbeing will be conveyed remotely to a nurse. This is the very first time that RAM solution, together with HBT patient monitoring is introduced. Extending the full capabilities of RAM for HBT application, Dreyfusian philosophy and human skill acquisition model ,10,11,12Our proposed method uses PPG measurements to quantify cardiac-induced blood volumetric changes in a patient’s veins as a sign of his/ her wellbeing. With this critical information, the decision-making process of proceeding of AHBT’s journey to its final destination is based on the correlation of the monitored patient’s current PPG data with his or her previously supervised measurement. Four reported AI algorithms were studied for suitability in the ABHT application in this work. First was single feature polynomial regression , which wN = 35) of 21 years and above, building upon our earlier pilot study [The objective of this first of its kind research is an exploratory study of the proposed PPG RAM ML algorithm for HBT. The scope of this study will focus on algorithm’s efficacy to transport a patient without false positives or stoppages via goodness-of-fit, central tendencies and efficacy metrics. PPG wristband sensors were used across a statistically significant population .N = 30). Second, immediate measurement was defined as obtained information of patient immediate wellbeing. Specifically, they were the latest, continuous and non-overlapping sets of 30 PPG waveforms during AHBT travel towards its destination, hence pre-fixed as in-journey (IJ). Similarly, 30 PPG waveforms per IJ dataset were required for statistically significant data in the shortest possible time.First, historical data of the subject was defined as known priori of his/ her normal condition. For AHBT, supervised and authorized PPG measurement was taken for 5 min just prior to the start of autonomous journey, hence pre-fixed as pre-journey (PJ). These quantifications had taken into consideration of both operational needs and statistical requirement as PJ phase should not be too short where waveforms per dataset would fall below statistical significance under central limit theorem   to highlWeightage for each consideration factor were first evenly distributed at 20% each. They were further adjusted to allow heavier weightage on “easy to understand” while reducing the need for “computational time”. This was important to ensure that the nursing profession was receptive to AHBT concept. Whereas for computation time, it was foreseeable that advancement of microprocessors would bring forth improving computational capability over time and future processors would be further miniaturized.Polynomial regression (PR) ML technique was found to be best suited for AHBT. In terms of easy to understand and explicability factors, PR was the easiest to understand due to mathematical simplicity with the concept of “line of best fit” which most nurses’ learnt in their math curriculum. Single feature in degree-of-polynomial (DoP), defined as the highest exponent power of a modelled PR function, was also easy to communicate. There were some challenges involved communication of ML specific concepts such as train-test split and cross validation. Other techniques were deemed unsuitable due to their abstract mathematical concepts, multiple features or AI deep learning blackbox  and hencIn terms of data and computation factors, PR, rule-based and multi-feature techniques required only raw PPG measurements from the subject himself to function, while deep learning required the use of multiple public datasets in order to mitigate large amount of annotations. Annotations were still present in PR and multi-feature techniques but were limited only binary “good” or “bad” classifications. Rule based was the best option in this regard as it did not require any annotation work while deep learning inherently required extensive annotations.Computational time were scored based on complexity of their algorithm. Each of them had their reported hardware and relative performance ,22. For Evaluating all the possibilities on based on the design matrix consideration factors, the most suitable AI algorithm for binary decision making was chosen. Single feature PR relationship between historical data and immediate measurement would be the best algorithm. Specifically, degree-of-polynomial (DoP) matching between PJ and IJ datasets was designed to quantitatively corelate immediate wellbeing of the subject. DoP was used as metric in quantifying time-series based PPG dataset. During operation of AHBT, the subject’s IJ dataset’s DoP would be compared to its PJ dataset’s DoP under the proposed ML algorithm. The algorithm would be able to determine with certain level of confidence if AHBT could proceed with patient transportation.These operational perspectives could be depicted as shown in An experimental run was designed to collect PPG data of individual subjects in a simulated environment similar to patient during hospital bed transport (HBT). This was based on Singapore hospitals’ settings which were often multi-building and multi-storey institutions where delays factors included lift-use priority protocols and foot traffic peaking in tandem with daily activities. A nominal HBT could easily take up to 30 min. Therefore, duration of each run was set at 1 h which covered a 5-min PJ phase, followed by 45 min time frame under simulated HBTs to study the efficacy of ML algorithm with enough data buffer. Posture of the subject was interchangeable between sitting or lying down in bed which were representative of HBTs scenario. Total freedom of the subject’s upper limb and wrist movements were allowed to capture naturally occurring movements. Also, subjects could be either awoke, resting or sleeping.N ≥ 30) to meet statistical significance. Healthy subjects aged 21 years and above were recruited for this voluntary study, as shown in Experiment proceedings and data collection were approved by Nanyang Technological University’s Institutional Review Board (NTU-IRB), reference number IRB-2019-09-012. A total of 35 subjects (1 subject per run) were studied under central limit theorem guidance , was calculated based on the average modeling of each dataset for 5 times between 1st and 20th DoP to aggregate potential ML permutation effects. All results from modelling across 1st to 20th DoP were analyzed.The top five and worst five CVSMs across from left and right wrists are presented in Top 5 PJ datasets were consolidated between 0.2 and 0.6 CVSM at 8th to 10th DoP, under the T subplots in The worst five PJ datasets were consolidated between near-zero to small magnitude negative CVSM at 18th to 20th DoP, as shown in the W subplots under An exception in PJ instances was from Subject 32 with 0.903 CVSM at 9th DoP, as shown in L-1T subplot in IJ datasets used continuous measurement which was different from PJ’s 5 min measurement window. The difference in data definitions would then be analyzed and compared with PJ outcomes.The top five IJ datasets were consolidated between 0.967 and 0.994 CVSM at 9th to 10th DoP, as shown in all T subplots in In contrast to the earlier PJ datasets, the worst five IJ CVSM were consolidated near-zero or negative CVSM hovered between 1st and 4th DoP, as shown in all W subplots in Comparing both PJ and IJ duration differences, a shorter time would result in instances of exceptionally good CVSM due to ease in assembling a coherent sets of PPG waveforms. However, the probability of low CVSM datasets also increased resulting in a wide CVSM spread when compared to PJ. This meant that shorter measurement duration comes with a cost of general difficulty to quantitatively converge a patient’s condition into a single mode. Patient wellbeing monitoring would then face increased difficulty by design to address multiple modes correlation to a single patient safe condition.Conversely, a longer time would then result in a narrower CVSM window due to a larger probability in amassing a coherent body of PPG waveforms that can outweigh stray waveforms. However, mean CVSM was relatively lower due to minor variations within the coherent body of PPG waveforms. This meant that AHBT decision would be more spaced apart to achieve a more stable wellbeing monitoring. However, waiting too long to arrive at a decision would risk patient uncertainties during AHBT journey.Moreover, other modes of CVSM extremities were observed and they will be discussed with further analysis in the next section.In this study central tendency served as an analysis on whether algorithm was stable or not. Ideally, only one mode should be associated with the highest goodness of fit to reduce uncertainties in algorithm decision making. Visually, this should be seen with a single peak DoP distribution in contrast to multiple peaks across DoP domain, as shown in PJ and IJ DoP distributions of highest CVSM per dataset were shown to have coinciding single peak DoP distributions, shown as discrete histograms in Extending DoP search to 50th DoP showed no other mode of DoP peaks existed as there were no significant occurrence beyond 20th DoP. For PJ, lowest DoP occurrence was from left wrist single instance at 4th DoP while highest was also single instance but from right wrist at 16th DoP. Whereas for IJ, lowest DoP occurrence was 133 instances at 1st DoP while the highest was a single instance from right wrist at 40th DoP. The original search boundary of 1st to 20th DoP was adequate to model PPG data for both PJ and IJ datasets.Single peak DoP distribution study was applied uniformly across 35 subjects with peaks observed between 7th and 10th DoP without any peculiarities in PJ datasets as shown in CVSM spreads for PJ and IJ dataset’s DoP were shown in CVSM spreads were greater in IJ datasets as compared to PJ datasets, as shown in Efficacy was defined as the ratio of positive matches to match attempts between PJ and IJ datasets within a subject. An efficacy of 0 would mean the algorithm did not allow the hospital bed to proceed with the journey at all, while 1 would mean the algorithm would allow AHBT to successfully complete its journey.For each match attempted, the binary output was either 0 or 1 to indicate either a negative or positive match. As shown earlier in Our algorithm performed well to pick up all PPG signals which resulted in mean efficacy of 0.20 in There was no peculiar trend observed that would suggest age as a factor on efficacy in Novice nurse. Dreyfusian concept was used in designing three essential constituents of the algorithm. These included historical data where algorithm characterized patient’s known status 5 min just before the start of an autonomous transport journey. Second, immediate measurements during autonomous transport journey were taken and recorded. Finally, a binary decision condition based on ML algorithm was employed to control AHTB’s advance or stoppages.A first of its kind patient remote automated monitoring (RAM) PR for automated hospital bed transport (AHBT) was proposed and conducted using machine learning (ML) algorithm in this paper. The concept of autonomous patient monitoring was not new, but to apply it for AHBT would require a higher level of understanding and appreciation of the on the topic of Dreyfusian descriptor of a N ≥ 30) who were above the age of 21. Studies showed that both wrists exhibited similar results.Various AI algorithms with potential for AHBT application were considered using a nurse centric design matrix evaluation system. PPG was chosen as the parameter for wellbeing monitoring due to its proven deployment in hospital settings and privacy protection. Both wrists were measured simultaneously to study need for multiple sensor measurements. Data collection was done with a statistically significant population  occurring at 8th to 10th DoP for PJ datasets and 0.967 to 0.994 CVSM at 9th to 10th DoP for IJ datasets, which meant the proposed algorithm was able to model PPG waveform trends. With the worst goodness of fit PJ consolidated at  and IJ  demonstrated CVSM to be a reliable metric to pick out best PJ and IJ DoPs for further analysis and AHBT decision making.Central tendencies of both PJ and IJ DoPs coincided between 7th and 10th DoP. For PJ datasets, 8th DoP was considered to be the dominant DoP due to higher number of occurrences compared to 9th DoP and higher mean compared to 7th DoP. For IJ datasets, 8th DoP was considered to be the dominant DoP due to highest number of occurrences. CVSM spread were different between PJ and IJ DoPs, where PJ ones showed tighter convergence but lower CVSM mean in comparison to IJ datasets. This was due to dataset definition differences in PJ’s 5 min data sets as compared to the shorter IJ’s 30 PPG waveforms. Nonetheless, the coinciding DoP distribution showed a good stability qualities of our proposed algorithm.Mean efficacy was 0.20 due to algorithm’s performance in capturing PPG signal variations from a conscious subject with freedom of movement. This was acceptable as a first AHBT proof of concept as most HBT were meant for unconscious or sedated patients where PPG signals were expected to be more stable.The presented findings are important as a first ML proof of concept for AHBT application. Improving algorithm development is set for future work. These include using the same data definitions for PJ and IJ datasets, but with further implementation of a DoP tolerance band during DoP matching to increase efficacy; or developing acceptable standards to ensure CVSM values consistently lies in a specific window before algorithm decisions can be put to use. This study has further demonstrated the potential of time savings of nurse productive manhours up to 45 min for each HBT. These savings can be used towards more holistic patient caring tasks that would accelerate career progression of nurses towards advanced practice nurses (APN).Extending this concept further towards in-community healthcare, a nurse can now better assess authenticity of patients’ near real time health data remotely to facilitate remote healthcare delivery. The use of commercial off-the-shelf sensors demonstrate technology readiness with more work to be done on algorithm in realizing a full RAM solution.