Arctic cyanobacterial mat community diversity decreases with latitude across the Canadian Arctic

Cyanobacterial mats are commonly reported as hotspots of microbial diversity across polar environments. These thick, multi-layered microbial communities provide a refuge from extreme environmental conditions, with many species able to grow and coexist despite the low allochthonous nutrient inputs. The visibly dominant phototrophic biomass is dependent on internal nutrient recycling by heterotrophic organisms within the mats, however the specific contribution of heterotrophic protists remains little explored. In this study, mat community diversity was examined along a latitudinal gradient (55-83°N), spanning subarctic taiga, tundra, polar desert, and the High Arctic ice shelves. The prokaryotic and eukaryotic communities were targeted respectively by V4 16S and V9 18S rRNA gene amplicon high-throughput sequencing. Prokaryotic and eukaryotic richness decreased, in tandem with decreasing temperatures and shorter seasons of light availability, from the subarctic to the High Arctic. Taxonomy-based annotation of the protist community revealed diverse phototrophic, mixotrophic and heterotrophic genera in all mat communities, with fewer parasitic taxa in High Arctic communities. Co-occurrence network analysis identified greater heterogeneity in eukaryotic than prokaryotic community structure among cyanobacterial mats across the Canadian Arctic. Our findings highlight the sensitivity of microbial eukaryotes to environmental gradients across northern high latitudes.

Penile Evaluation: An Illustrated Review

ABSTRACT

High-frequency ultrasound is the imaging modality of choice for evaluating penile pathology because of its easy access, low cost, and patient tolerance ( The Penis, Diagnostic Ultrasound, second edtion . Boca Raton: CRC Press; 2007:957-978). This pictorial review will illustrate the sonographic features of emergent and nonemergent penile conditions such as penile fracture, spongial tear, urethral injury, various types of priapism, erectile dysfunction, penile abscess, and Mondor disease.

Infection of Norway lobster (Nephrops norvegicus) by the parasite Hematodinium sp.: insights from 30 years of field observations

The Norway lobster, Nephrops norvegicus, is an important representative of the benthos and also supports valuable fisheries across Europe. Nephrops are susceptible to infection by Hematodinium sp., an endoparasitic dinoflagellate that causes morbidity and mortality. From an epizootiological perspective, the Clyde Sea Area (CSA; west of Scotland) is the best-studied Hematodinium-Nephrops pathosystem, with historical data available between 1988 and 2008. We have revisited this pathosystem by curating and updating prevalence values, differentiating host traits associated with disease exposure and progression, and comparing Hematodinium sp. disease dynamics in the CSA to other locations and to other decapod hosts (Cancer pagurus, Carcinus maenas). Prevalence from a 2018/2019 survey (involving 1739 lobsters) revealed Hematodinium sp. still mounts a synchronized patent infection in the CSA; hence this pathogen can be considered as enzootic in this location. We highlight for the first time that Nephrops size is associated with high severity infection, while females are more exposed to Hematodinium sp. More generally, regardless of the host (Norway lobster, brown and shore crabs) or the geographical area (Ireland, Wales, Scotland), Hematodinium sp. patent infections peak in spring/summer and reach their nadir during autumn. We contend that Hematodinium must be considered one of the most important pathogens of decapod crustaceans in temperate waters.

18S rDNA gene metabarcoding of microeukaryotes and epi-endophytes in the holobiome of seven species of large brown algae

Brown algae (Phaeophyceae) are habitat-forming species in coastal ecosystems and include kelp forests and seaweed beds that support a wide diversity of marine life. Host-associated microbial communities are an integral part of phaeophyte biology, and whereas the bacterial microbial partners have received considerable attention, the microbial eukaryotes associated with brown algae have hardly been studied. Here, we used broadly targeted "pan-eukaryotic" primers (metabarcoding) to investigate brown algal-associated eukaryotes (the eukaryome). Using this approach, we aimed to investigate the eukaryome of seven large brown algae that are important and common species in coastal ecosystems. We also aimed to assess whether these macroalgae harbor novel eukaryotic diversity and to ascribe putative functional roles to the host-associated eukaryome based on taxonomic affiliation and phylogenetic placement. We detected a significant diversity of microeukaryotic and algal lineages associated with the brown algal species investigated. The operational taxonomic units (OTUs) were taxonomically assigned to 10 of the eukaryotic major supergroups, including taxonomic groups known to be associated with seaweeds as epibionts, endobionts, parasites, and commensals. Additionally, we revealed previously unrecorded sequence types, including novel phaeophyte OTUs, particularly in the Fucus spp. samples, that may represent fucoid genomic variants, sequencing artifacts, or undescribed epi-/endophytes. Our results provide baseline data and technical insights that will be useful for more comprehensive seaweed eukaryome studies investigating the evidently lineage-rich and functionally diverse symbionts of brown algae.

Dementia care navigation: Building toward a common definition, key principles, and outcomes

INTRODUCTION

As the complexity of medical treatments and patient care systems have increased, the concept of patient navigation is growing in both popularity and breadth of application. Patient navigators are trained personnel whose role is not to provide clinical care, but to partner with patients to help them identify their needs and goals and then overcome modifiable patient-, provider-, and systems-level barriers. Due to its high incidence, duration, and medical-social complexity, dementia is an ideal candidate for a patient-centric health care delivery model such as care navigation.

METHODS

The Alzheimer's Association formed an expert workgroup of researchers in the field of dementia care navigation to identify evidence-based guidelines.

RESULTS

Recognizing the unique and challenging needs of persons living with dementia and their care partners, several U.S. dementia care navigation programs have been developed and assessed in recent years. Collectively these programs demonstrate that persons living with dementia and their care partners benefit from dementia care navigation. Improved care system outcomes for the person living with dementia include reduced emergency department visits, lower hospital readmissions, fewer days hospitalized, and shorter delays in long-term care placement. Well-being is also increased, as there is decreased depression, illness, strain, embarrassment, and behavioral symptoms and increased self-reported quality of life. For care partners, dementia navigation resulted in decreased depression, burden, and unmet needs.

DISCUSSION

This article presents principles of dementia care navigation to inform existing and emerging dementia care navigation programs.

Highlights

Several U.S. dementia care navigation programs have demonstrated outcomes for persons living with dementia, care partners, and health systems.The Alzheimer's Association formed an expert workgroup of researchers in the field of dementia care navigation to create a shared definition and identify evidence-based guidelines or principles.These outlined principles of dementia care navigation can inform existing and emerging dementia care navigation programs.

Microbiomes in the context of developing sustainable intensified aquaculture

With an ever-growing human population, the need for sustainable production of nutritional food sources has never been greater. Aquaculture is a key industry engaged in active development to increase production in line with this need while remaining sustainable in terms of environmental impact and promoting good welfare and health in farmed species. Microbiomes fundamentally underpin animal health, being a key part of their digestive, metabolic and defense systems, in the latter case protecting against opportunistic pathogens in the environment. The potential to manipulate the microbiome to the advantage of enhancing health, welfare and production is an intriguing prospect that has gained considerable traction in recent years. In this review we first set out what is known about the role of the microbiome in aquaculture production systems across the phylogenetic spectrum of cultured animals, from invertebrates to finfish. With a view to reducing environmental footprint and tightening biological and physical control, investment in "closed" aquaculture systems is on the rise, but little is known about how the microbial systems of these closed systems affect the health of cultured organisms. Through comparisons of the microbiomes and their dynamics across phylogenetically distinct animals and different aquaculture systems, we focus on microbial communities in terms of their functionality in order to identify what features within these microbiomes need to be harnessed for optimizing healthy intensified production in support of a sustainable future for aquaculture.

Optimised protocol for monitoring SARS-CoV-2 in wastewater using reverse complement PCR-based whole-genome sequencing

Monitoring the spread of viral pathogens in the population during epidemics is crucial for mounting an effective public health response. Understanding the viral lineages that constitute the infections in a population can uncover the origins and transmission patterns of outbreaks and detect the emergence of novel variants that may impact the course of an epidemic. Population-level surveillance of viruses through genomic sequencing of wastewater captures unbiased lineage data, including cryptic asymptomatic and undiagnosed infections, and has been shown to detect infection outbreaks and novel variant emergence before detection in clinical samples. Here, we present an optimised protocol for quantification and sequencing of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in influent wastewater, used for high-throughput genomic surveillance in England during the COVID-19 pandemic. This protocol utilises reverse compliment PCR for library preparation, enabling tiled amplification across the whole viral genome and sequencing adapter addition in a single step to enhance efficiency. Sequencing of synthetic SARS-CoV-2 RNA provided evidence validating the efficacy of this protocol, while data from high-throughput sequencing of wastewater samples demonstrated the sensitivity of this method. We also provided guidance on the quality control steps required during library preparation and data analysis. Overall, this represents an effective method for high-throughput sequencing of SARS-CoV-2 in wastewater which can be applied to other viruses and pathogens of humans and animals.

Environmental DNA/RNA for pathogen and parasite detection, surveillance, and ecology

Detection of pathogens, parasites, and other symbionts in environmental samples via eDNA/eRNA (collectively eNA) is an increasingly important source of information about their occurrence and activity. There is great potential for using such detections as a proxy for infection of host organisms in connected habitats, for pathogen monitoring and surveillance, and for early warning systems for disease. However, many factors require consideration, and appropriate methods developed and verified, in order that eNA detections can be reliably interpreted and adopted for surveillance and assessment of disease risk, and potentially inclusion in international standards, such as the World Organisation for Animal Health guidelines. Disease manifestation results from host-symbiont-environment interactions between hosts, demanding a multifactorial approach to interpretation of eNA signals.

A Mitosome With Distinct Metabolism in the Uncultured Protist Parasite Paramikrocytos canceri (Rhizaria, Ascetosporea)

Ascetosporea are endoparasites of marine invertebrates that include economically important pathogens of aquaculture species. Owing to their often-minuscule cell sizes, strict intracellular lifestyle, lack of cultured representatives and minimal availability of molecular data, these unicellular parasites remain poorly studied. Here, we sequenced and assembled the genome and transcriptome of Paramikrocytos canceri, an endoparasite isolated from the European edible crab Cancer pagurus. Using bioinformatic predictions, we show that P. canceri likely possesses a mitochondrion-related organelle (MRO) with highly reduced metabolism, resembling the mitosomes of other parasites but with key differences. Like other mitosomes, this MRO is predicted to have reduced metabolic capacity and lack an organellar genome and function in iron-sulfur cluster (ISC) pathway-mediated Fe-S cluster biosynthesis. However, the MRO in P. canceri is uniquely predicted to produce ATP via a partial glycolytic pathway and synthesize phospholipids de novo through the CDP-DAG pathway. Heterologous gene expression confirmed that proteins from the ISC and CDP-DAG pathways retain mitochondrial targeting sequences that are recognized by yeast mitochondria. This represents a unique combination of metabolic pathways in an MRO, including the first reported case of a mitosome-like organelle able to synthesize phospholipids de novo. Some of these phospholipids, such as phosphatidylserine, are vital in other protist endoparasites that invade their host through apoptotic mimicry.

AN EVIDENCE-BASED APPROACH TO TELEPHONE REASSURANCE CALLS: A RANDOMIZED CONTROLLED TRIAL PROTOCOL

The COVID-19 Pandemic forced many health and community organizations to suspend some previously offered services and supports for older adults. This created heightened concerns about negative impacts of isolation and loneliness on already vulnerable older adults. In response, the Western Reserve Area Agency on Aging (WRAAA) began the TeleCare Program, providing weekly telephone reassurance calls to home and congregate meal clients to maintain contact and identify unmet service needs. Because of its success, the TeleCare Program has continued as a regularly offered service, but the WRAAA sought to improve the Program by integrating it with BRI Care ConsultationTM, an evidence-based program of the Benjamin Rose Institute on Aging (BRIA). This poster reports on initial results of a randomized controlled trial to test the efficacy and feasibility of a new protocol for delivering telephone reassurance calls. The new protocol is modeled after the Initial Assessment in BRI Care Consultation, which is a semi-structured, telephone conversation covering a comprehensive range of potentials problems. The protocol also connects high-risk clients to existing available home- and community-based services. Results demonstrate that components of proven evidence-based interventions are feasible to integrate into existing programs and services. This includes adapting a model for problem-identification and assessment based on a consumer-driven conceptual framework, a record keeping system to enhance consistency and fidelity of program delivery, and establishing a formal referral protocol to more seamlessly link clients to other available services.

PREDICTING DYADIC RELATIONSHIP STRAIN IN INDIVIDUALS WITH DEMENTIA

Recent literature has addressed the perceptions of individuals with dementia to understand how they experience their illness, with evidence suggesting these perceptions are impactful. Few studies, however, have used a conceptual model to explore different aspects of the illness. One aspect to consider is dyadic relationship strain, or feelings of tension, manipulation, and stress between the individual and caregiver. Little work has addressed this strain from the perspective of the individual with dementia who may have different feelings about the quality of the relationship. Cognition and function are two hallmark symptoms in dementia, however little work has addressed how the perception of these two areas impacts the illness experience. Perceptions of difficulties in these two areas may impact dyadic relationship strain as they necessitate increased care and changes in the relationship. Guided by the Stress Process Model for Individuals with Dementia, this study assessed potential predictors of dyadic relationship strain, finding personal activities of daily living (PADLs) to be impactful. In a multiple regression, PADLS (b=.319, p = 02) predicted strain above and beyond two measures of cognition: objective cognitive impairment (b =-.011, p =.93) and perceived memory difficulty (b=.003, p=.311) suggesting that perceived function is impactful for dyadic relationship strain. Because PADLS include more hands-on assistance, the perception of difficulty may create more feelings of embarrassment or stress and impact the perception of relationship strain. Future intervention work may target perceptions of function to improve the dyadic relationship by using techniques such as open communication about difficulties.

CARING FOR THOSE WHO CARE: EVALUATION OF A COMPREHENSIVE CULTURAL COMPETENCY TRAINING CURRICULUM

By 2030, nearly 3 in 10 older Americans will identify as a member of a diverse or underrepresented group. To better support diverse, aging communities and help professionals meet the growing needs of family and friend caregivers, the Diverse Elders Coalition developed a comprehensive cultural competency training curriculum that, in the first year of development, engaged over 2,500 healthcare and social service providers. To evaluate the short and long-term impact of the training curriculum, this paper focuses on two types of anonymous evaluations that were electronically distributed to training attendees: 1) Subjective knowledge post-tests (n=162), and 2) 3-month post-training follow-ups (n=232). Majority of participants identified as female, White/Caucasian, and earned at least a college degree. Upon completion of the trainings, participants reported improved subjective knowledge about diverse communities, more confidence and preparedness to meet diverse caregivers’ needs, and also indicated that because of the training they would engage in a variety of diversity related actions (e.g., use more inclusive language, share training resources with colleagues, attend additional diversity trainings). At the 3-month follow-up, 91.8% of respondents reported they engaged in two or more diversity related actions since attending the training. Respondents (73.8%) also indicated that their organization engaged in one or more diversity-related actions since attending the training (e.g., provided staff additional diversity-related trainings, translated materials). Discussion will focus on ways to improve healthcare and social service providers’ advocacy efforts and awareness surrounding the needs of older adults and caregivers from diverse communities.

Amoebic crab disease (ACD) in edible crab Cancer pagurus from the English Channel, UK

The genera Paramoeba and Neoparamoeba (Amoebozoa, Dactylopodida, Paramoebidae) include well-known opportunistic pathogens associated with fish (N. peruans; amoebic gill disease), lobsters, molluscs and sea urchins, but only rarely with crabs (grey crab disease of blue crabs). Following reports of elevated post-capture mortality in edible crabs Cancer pagurus captured from a site within the English Channel fishery in the UK, a novel disease (amoebic crab disease, ACD) was detected in significant proportions of the catch. We present histopathological, transmission electron microscopy and molecular phylogenetic data, showing that this disease is defined by colonization of haemolymph, connective tissues and fixed phagocytes by amoeboid cells, leading to tissue destruction and presumably death in severely diseased hosts. The pathology was strongly associated with a novel amoeba with a phylogenetic position on 18S rRNA gene trees robustly sister to Janickina pigmentifera (which groups within the current circumscription of Paramoeba/Neoparamoeba), herein described as Janickina feisti n. sp. We provide evidence that J. feisti is associated with ACD in 50% of C. pagurus sampled from the mortality event. A diversity of other paramoebid sequence types, clustering with known radiations of N. pemaquidensis and N. aestuarina and a novel N. aestuarina sequence type, was detected by PCR in most of the crabs investigated, but their detection was much less strongly associated with clinical signs of disease. The discovery of ACD in edible crabs from the UK is discussed relative to published historical health surveys for this species.

Discovery of the parasite Marteilia cocosarum sp. nov. In common cockle (Cerastoderma edule) fisheries in Wales, UK and its comparison with Marteilia cochillia

Diseases of bivalve molluscs caused by paramyxid parasites of the genus Marteilia have been linked to mass mortalities and the collapse of commercially important shellfish populations. Until recently, no Marteilia spp. have been detected in common cockle (Cerastoderma edule) populations in the British Isles. Molecular screening of cockles from ten sites on the Welsh coast indicates that a Marteilia parasite is widespread in Welsh C. edule populations, including major fisheries. Phylogenetic analysis of ribosomal DNA (rDNA) gene sequences from this parasite indicates that it is a closely related but different species to Marteilia cochillia, a parasite linked to mass mortality of C. edule fisheries in Spain, and that both are related to Marteilia octospora, for which we provide new rDNA sequence data. Preliminary light and transmission electron microscope (TEM) observations support this conclusion, indicating that the parasite from Wales is located primarily within areas of inflammation in the gills and the connective tissue of the digestive gland, whereas M. cochillia is found mainly within the epithelium of the digestive gland. The impact of infection by the new species, here described as Marteilia cocosarum n. sp., upon Welsh fisheries is currently unknown.

Infection cycle of Marteilia pararefringens in blue mussels Mytilus edulis in a heliothermic marine oyster lagoon in Norway

Agapollen is a traditional heliothermic marine oyster lagoon in western Norway, representing the northernmost site of any Marteilia sp. protists detected in Europe. The semi-closed lagoon is a unique site to study the life cycle and development of M. pararefringens in naïve mussels. Two baskets with uninfected mussels were deployed in the lagoon outlet in May and October 2018, respectively, and sampled every 6 wk. The parasite was first detected in the mussels by PCR in early July and by histology in late August. By then, M. pararefringens had developed into mature stages, indicating a rapid development during mid-summer. Sporulation occurred during autumn. Mussels deployed in October never became infected, indicating that transmission was restricted to the warmest period of the year. Pronounced pathology was observed in infected mussels, including degenerated digestive tubules and infiltration of haemocytes. Mussel mortality was observed in the baskets, but whether this was due to infections of M. pararefringens or other environmental factors could not be determined. Plankton samples from the lagoon were also collected for PCR analysis. These samples, dominated by copepods, were positive for M. pararefringens in summer. In sorted samples, M. pararefringens was detected in the Acartia spp. and Paracartia grani fractions between July and October. These plankton copepods are therefore potentially involved in the life cycle of M. pararefringens.

High prevalence of Paramarteilia canceri infecting velvet swimming crabs Necora puber in Ireland

The velvet swimming crab Necora puber has been fished in Ireland since the early 1980s and contributes significant income to smaller fishing vessels. From 2016 onwards, reduced landings have been reported. We undertook a full pathological investigation of crabs from fishing grounds at 3 sites on the west (Galway), southwest (Castletownbere) and east (Howth) coasts of Ireland. Histopathology, transmission electron microscopy and molecular taxonomic and phylogenetic analyses showed high prevalence and infection level of Paramarteilia canceri, previously only reported from the edible crab Cancer pagurus. This study provides the first molecular data for P. canceri, and shows its phylogenetic position in the order Paramyxida (Rhizaria). Other parasites and symbionts detected in the crabs were also noted, including widespread but low co-infection with Hematodinium sp. and a microsporidian consistent with the Ameson and Nadelspora genera. This is the first histological record of Hematodinium sp. in velvet crabs from Ireland. Four N. puber individuals across 2 sites were co-infected by P. canceri and Hematodinium sp. At one site, 3 velvet crabs infected with P. canceri were co-infected with the first microsporidian recorded from this host; the microsporidian 18S sequence was almost identical to Ameson pulvis, known to infect European shore crabs Carcinus maenas. The study provides a comprehensive phylogenetic analysis of this and all other available Ameson and Nadelspora 18S sequences. Together, these findings provide a baseline for further investigations of N. puber populations along the coast of Ireland.

Imaging and Clinical Findings in a Series of Six Cases of Rare Primary Mediastinal Liposarcoma

Primary mediastinal liposarcoma is a rare, fat-containing malignant lesion that can manifest incidentally with varied imaging appearances. The size and location within the mediastinum can vary among patients. Here, the authors describe the clinical presentation, radiographic characteristics, management, and prognosis in a series of six patients with primary mediastinal liposarcoma. The following case series suggests that even simple-appearing fatty intrathoracic lesions may lead to the development of malignant imaging features. Keywords: Conventional Radiography, CT, MR Imaging, PET/CT, Soft Tissues/Skin, Thorax, Mediastinum ©RSNA, 2022.

Cardiac conduction disturbances in rheumatologic disease: a cross-sectional study

BACKGROUND

Cardiovascular abnormalities are common in patients with rheumatologic disorders. Tachy-arrhythmias occur more frequently in these patients than the general population; however, the prevalence of bradyarrhythmias in this group is less clear. This investigation aimed to analyze the incidence and predictors of bradyarrhythmias and conduction disturbances, as well as the presence and influence of cardiologist management, in patients with rheumatologic disorders.

METHODS

We performed a retrospective chart review of 57 consecutive patients with rheumatologic conditions evaluated at a tertiary-care safety-net hospital. Conduction disturbances were defined by any electrocardiogram (ECG) finding indicating: bradycardia, sinoatrial block of any degree, atrioventricular nodal block of any degree, left anterior or posterior fascicular block, non-specific intraventricular conduction delay, complete or incomplete right bundle branch block, left bundle branch block, or paced rhythm. Univariate and multivariate analyses were used to assess the association of relative predictors of conduction disturbance, the primary outcome of this investigation, as well as the secondary outcome of cardiologist involvement in patient care. Statistical significance was defined as P<0.05. Variables found to be statistically significant in a univariate analysis were included in a multivariable logistic regression analysis.

RESULTS

The most common rheumatologic condition in our patient population was systemic lupus erythematous (21 patients, 36.8%) followed by gout (15 patients, 26.3%), rheumatoid arthritis (13 patients, 22.8%), sarcoidosis (6 patients, 10.5%), and two patients (3.5%) with other autoimmune diseases. A total of 31.6% of patients in this study were found to have conduction disturbances, higher than the prevalence of conduction disturbances in the general population. Multivariate logistic regression analysis showed significantly increased odds for conduction disturbances with increased age (odds ratio (OR): 1.05, 95% confidence interval (CI): 1.01-1.10, P<0.05). Similar analysis for the involvement of a cardiologist in the care of a patient with a rheumatologic disorder found increased odds for cardiologist involvement with advanced age (OR: 1.05, 95% CI: 1.002-1.09, P<0.05) and cardiovascular disease (OR: 5.0, 95% CI 1.24-21.90, P<0.05).

CONCLUSION

Prevalence of conduction abnormalities is greater in rheumatologic patients than the general population. Odds for conduction abnormalities increased with age; and the odds of cardiologist involvement increased with age and cardiovascular disease.

Diversity and Ecological Guild Analysis of the Oil Palm Fungal Microbiome Across Root, Rhizosphere, and Soil Compartments

The rhizosphere microbiome is a major determinant of plant health, which can interact with the host directly and indirectly to promote or suppress productivity. Oil palm is one of the world’s most important crops, constituting over a third of global vegetable oil production. Currently there is little understanding of the oil palm microbiome and its contribution to plant health and productivity, with existing knowledge based almost entirely on culture dependent studies. We investigated the diversity and composition of the oil palm fungal microbiome in the bulk soil, rhizosphere soil, and roots of 2-, 18-, and 35-year old plantations in Selangor, Malaysia. The fungal community showed substantial variation between the plantations, accounting for 19.7% of community composition, with compartment (root, rhizosphere soil, and bulk soil), and soil properties (pH, C, N, and P) contributing 6.5 and 7.2% of community variation, respectively. Rhizosphere soil and roots supported distinct communities compared to the bulk soil, with significant enrichment of Agaricomycetes, Glomeromycetes, and Lecanoromycetes in roots. Several putative plant pathogens were abundant in roots in all the plantations, including taxa related to Prospodicola mexicana and Pleurostoma sp. The mycorrhizal status and dependency of oil palm has yet to be established, and using 18S rRNA primers we found considerable between-site variation in Glomeromycotinian community composition, accounting for 31.2% of variation. There was evidence for the selection of Glomeromycotinian communities in oil palm roots in the older plantations but compartment had a weak effect on community composition, accounting for 3.9% of variation, while soil variables accounted for 9% of community variation. While diverse Mucoromycotinian fungi were detected, they showed very low abundance and diversity within roots compared to bulk soil, and were not closely related to taxa which have been linked to fine root endophyte mycorrhizal morphology. Many of the fungal sequences showed low similarity to established genera, indicating the presence of substantial novel diversity with significance for plant health within the oil palm microbiome.

A seafood risk tool for assessing and mitigating chemical and pathogen hazards in the aquaculture supply chain

Intricate links between aquatic animals and their environment expose them to chemical and pathogenic hazards, which can disrupt seafood supply. Here we outline a risk schema for assessing potential impacts of chemical and microbial hazards on discrete subsectors of aquaculture-and control measures that may protect supply. As national governments develop strategies to achieve volumetric expansion in seafood production from aquaculture to meet increasing demand, we propose an urgent need for simultaneous focus on controlling those hazards that limit its production, harvesting, processing, trade and safe consumption. Policies aligning national and international water quality control measures for minimizing interaction with, and impact of, hazards on seafood supply will be critical as consumers increasingly rely on the aquaculture sector to supply safe, nutritious and healthy diets.

Recent advances in bivalve-microbiota interactions for disease prevention in aquaculture

In bivalves, no clear-cut functional role of microbiota has yet been identified, although many publications suggest that they could be involved in nutrition or immunity of their host. In the context of climate change, integrative approaches at the crossroads of disciplines have been developed to explore the environment-host-pathogen-microbiota system. Here, we attempt to synthesize work on (1) the current methodologies to analyse bivalve microbiota, (2) the comparison of microbiota between species, between host compartments and their surrounding habitat, (3) how the bivalve microbiota are governed by environmental factors and host genetics and (4) how host-associated microorganisms act as a buffer against pathogens and/or promote recovery, and could thereby play a role in the prevention of disease or mortalities.

Emerging Parasitic Protists: The Case of Perkinsea

The last century has witnessed an increasing rate of new disease emergence across the world leading to permanent loss of biodiversity. Perkinsea is a microeukaryotic parasitic phylum composed of four main lineages of parasitic protists with broad host ranges. Some of them represent major ecological and economical threats because of their geographically invasive ability and pathogenicity (leading to mortality events). In marine environments, three lineages are currently described, the Parviluciferaceae, the Perkinsidae, and the Xcellidae, infecting, respectively, dinoflagellates, mollusks, and fish. In contrast, only one lineage is officially described in freshwater environments: the severe Perkinsea infectious agent infecting frog tadpoles. The advent of high-throughput sequencing methods, mainly based on 18S rRNA assays, showed that Perkinsea is far more diverse than the previously four described lineages especially in freshwater environments. Indeed, some lineages could be parasites of green microalgae, but a formal nature of the interaction needs to be explored. Hence, to date, most of the newly described aquatic clusters are only defined by their environmental sequences and are still not (yet) associated with any host. The unveiling of this microbial black box presents a multitude of research challenges to understand their ecological roles and ultimately to prevent their most negative impacts. This review summarizes the biological and ecological traits of Perkinsea-their diversity, life cycle, host preferences, pathogenicity, and highlights their diversity and ubiquity in association with a wide range of hosts.

Experiences From Healthcare and Community Organizations Delivering Evidence-Based Dementia Caregiving Programs

Best Practice Caregiving surveyed 324 healthcare and community organizations that replicated one or more of the 44 evidence-based programs about delivery organization characteristics, delivery staff, caregivers and persons with dementia served, funding sources, delivery challenges, perceived impact, and satisfaction. 211 (65.1%) organizations completed surveys about 30 different evidence-based programs. The most common types of organizations that delivered programs were healthcare organizations (23.8%) and Area Agencies on Aging (23.8%). Results showed on average organizations delivered programs for 49 months and served 68 families/year. The most common program delivery challenges were marketing (69.8%) and engaging participants (66.3%). Organizations generally agreed that programs had positive impacts on caregivers (59.5% strongly agree) but were less positive about benefits for persons with dementia (25.1% strongly agree). Discussion provides insights into successes and challenges organizations face when adopting evidence-based dementia caregiving programs in their communities.

Psychometric Testing of the BRI Unmet Need Instrument: A Comprehensive Measure of Dementia Caregivers' Needs

Compared to non-dementia caregivers, family/friend caregivers of individuals with dementia experience more negative caregiving consequences. One reason is the myriad of negatively impacted life domains including: managing symptoms; family communication; financial and legal matters; and finding and coordinating services. Few psychometrically tested measures exist for assessing the range of potential unmet needs of dementia caregivers. Such a measure would describe the frequency and correlates of unmet needs and provide a key outcome for intervention research. This study tested the psychometric properties of a comprehensive measure of unmet needs, the BRI Unmet Need Instrument. Data from 192 family/friend dementia caregivers was used to test reliability and four validity types. Results showed total unmet needs, as well as its nine subscales, had good reliability (Cronbach’s alpha .70 - .95). Discriminant validity was confirmed through factor analyses of the 45 unmet needs and items in measures of depression and care-related strain. Unmet need items loaded on separate factors that were deemed acceptable (.72-.38). Predictive validity was assessed by the association with depression, which was significant and an acceptable range (r = .22, p < .01). Convergent validity was confirmed by significant associations with three caregiver strain measures, mastery (r = .40, p <.01), emotional strain (r = .19, p < .01), and relationship strain (r = .15, p <.05). Good structural validity for nine predetermined unmet needs subscales was found using principal component analysis (loadings = .82-.39). Results suggest the BRI Unmet Needs Instrument is a ready-to-use, reliable and valid comprehensive measure.

Types of Assistances of Evidence-Based Dementia Caregiving Programs: Data Results and Future Directions

A key feature displayed in Best Practice Caregiving are the types of assistances. Data on 54 areas of care were collected for all 44 programs. These were analyzed through factor analysis and grouped into 19 types of assistance. Types were analyzed by the number of assistances provided, delivery method, and recipient of assistance. On average, programs delivered 11.8 types of assistances, with the most common types being Supporting CG/Individual-with-Dementia (IWD) Communication, Encouraging Positive CG-IWD Activities, and Assisting with Coping (93.2%), with the least common being Getting a Dementia Diagnosis (29.5%) and Monitoring Benefits of Services (20.5%). Assistance was delivered most often through information/referral delivery (M=11.07, SD=5.41) than direct (M=3.77, SD=4.54) or skills training (M= 7.50, SD=4.54). Results of the data show the breadth and characteristics of assistances programs provide to support caregivers of persons with dementia, along with gaps in types of assistances and future directions for programs.

Description and Demo of the Best Practice Caregiving Database on 44 Research Proven Dementia Caregiving Programs

A major advance in family caregiving has been the development, testing, and community delivery of research-proven, evidence-based support programs for family or friend caregivers of persons living with dementia. This presentation showcases and demos Best Practice Caregiving (BPC), a new online resource with comprehensive profiles for 44 of the top evidence-based dementia caregiving programs that are ready for scaling in communities. For these 44 programs, BPC is a database that presents key research findings with links to all its published articles, comprehensive program descriptions including all implementation features, and survey data on program delivery experiences from 324 healthcare and community organizations that offered the program as a regular part of their service portfolio 2019. BPC enables professionals to make side-by-side comparisons of the 44 programs, with the goal of increasing implementations of these evidence-based programs by healthcare and community service organizations.

Exploring Well-Being Outcomes Among Persons Living with Dementia: Self-Reports Versus Caregiver Proxy Reports

Literature documents positive effects of religion and spirituality on health including improved cognitive function, quality of life, and well-being. Extant research suggests that persons living with dementia (PWD) are more likely to have spiritual needs and rely on others to support their spiritual well-being than those without dementia. However, spiritual care is absent or minimally present in dementia care. To effectively address spiritual needs of PWDs, accurate screening and assessment is critical. We conducted an integrative review of the current literature on measures of religion and spiritualty for PWDs by searching five databases (ATLA Religion, CINAHL, PsychInfo, PubMed, and SocIndex) and identified 14 studies that were peer-reviewed original research articles focusing on assessment of religion/spirituality among PWDs and published between 2000-2020 in English. Most were conducted in Europe (n=7), included PWD in mild stage (n=68) from various settings, and were cross-sectional in design (n=8). Of a total of 17 measures identified, 6 were originally developed for the general population and then adapted for PWD, and only 3 were validated for PWD. A majority of the studies were limited in sample size, generalizability, methodological rigor, and measure validation. More research is needed using diverse samples and rigorous study designs to develop valid screening and assessment tools for this population. Improving religious and spiritual measures could greatly impact public health by improving quality of life for millions of individuals suffering from dementia and their caregivers who carry a heavy burden.

The Illness Experience of Veterans With Dementia: Perceived Measures Related to Depressive Symptoms

Recent work has examined how individuals with dementia (IWDs) experience their illness, although few studies have looked at IWDs who report heightened depressive symptoms, a key well-being outcome. Stressing the ability of IWDs to self-report and guided by the Stress Process Model for Individuals with Dementia, this study examined the relationships between depressive symptoms and various aspects of the illness experience including objective cognition, perceived memory difficulty, perceived functional difficulty, and dyadic relationship strain. The sample includes IWDs with mild to severe dementia who are veterans (N=69). Significant positive correlations emerged between depressive symptoms and several measures of the illness experience: perceived cognition (r=.48, p&lt;.001), perceived function (r =.43, p&lt;.001), and dyadic relationship strain (r=.32, p=.01). In contrast, objective cognition, measured by a modified version of the Blessed Orientation Memory Concentration test, was not significant (r =-.06, p=.63). A multiple regression found the total variance explained by all independent variables was 32% (R2=.32, F(4,68)=7.58, p&lt;.001), with perceived memory difficulty (B=.26, p&lt;.01) and dyadic relationship strain (B=.25, p=.04) accounting for unique and significant variance in depressive symptoms. A mediation analysis indicated perceived memory difficulty fully mediated the relationship between perceived functional difficulty and depressive symptoms. Findings highlight the importance of IWDs perceptions of their illness experience for psychosocial well-being outcomes, such as depressive symptoms. Findings add to the literature by showing the importance of IWDs perceptions of their illness and their impact on well-being outcomes. Results also demonstrate the utility and feasibility of including self-reported data from IWDs in research studies.

Outcome Priorities Among Evidence-Based Dementia Caregiving Programs: A Closer Look

Currently, the Best Practice Caregiving website provides information on 231 published studies from 44 dementia caregiving evidence-based programs that have demonstrated beneficial outcomes for dementia caregivers within health care and community-based settings. Across all programs, a total of 34 biopsychosocial outcomes were identified. Supported by the commonly used stress-related frameworks (e.g., Stress-Health Process, Cognitive Behavioral Theory) for which the programs were developed, the most frequently utilized program outcomes included: 1) Caregiver stress, strain, and/or burden (84.1%); 2) Caregiver depressive symptomology (79.5%); and 3) Caregiving efficacy, skills, and/or confidence (63.6%). The least common programmatic outcomes included: 1) Access to support information/Community service use (9.1%); 2) Unmet needs (6.8%); and 3) Respite/break from care (2.3%). The lesser utilized outcomes provide critical insight into current evidence-based programmatic priorities and ways in which professionals can seek to fill gaps in dementia caregiving interventions. Discussion will also focus on future directions of caregiver-related outcome assessments.

Exploring the Subjective Caregiving Experience Among Chinese, Korean, and Southeast Asian Communities

Although the Asian American community is one of the fastest growing racial groups in the US, members of this group continue to be underserved and understudied, especially when it comes to the needs of family caregivers. Therefore, through a national initiative to understand the lived experiences of diverse family and friend caregivers, survey data was collected from a variety of Asian American ethnic subgroups including Chinese (n=148), Korean (n=131), and Southeast Asian (i.e., Vietnamese, Hmong, Cambodian, Laotian; n=161). Surveys were distributed in-person and online, and also offered in the translated native languages of the abovementioned groups. Caregivers had to be 18 years and older and providing care to a person aged 55 and older who needed assistance because of ongoing health problems or disabilities. For the overall sample of Asian American caregivers (n=440), participants were on average 51.68 years of age (SD=15.98), identified as female (n=336), were not born in the US (n=348), lived with the care receiver (n=247), and reported less than $10,000 in income per year (n=199). As guided by the Stress Process Model and through a series of ANOVA tests, when compared on all major outcomes, Southeast Asian caregivers significantly reported: 1) more difficulty with care related tasks (e.g., financial/legal decisions), 2) a stronger cultural commitment to caregiving, 3) higher work strain, and 4) more depressive symptomology. Discussion will focus on opportunities for professionals to meet the needs of Asian American caregivers through the use of available trainings and programs aimed to support diverse caregivers.

High-Throughput Sequencing of faeces provides evidence for dispersal of parasites and pathogens by migratory waterbirds

Examination of faecal material has demonstrated how a broad range of organisms are distributed by bird movements. Such research has largely focused on dispersal of plant seeds by frugivores and of freshwater organisms by waterbirds. However, with few exceptions (e.g. avian influenza, Ebola virus), there is a dearth of evidence for transport of parasites and pathogens. High-throughput sequencing methods now provide a powerful means of addressing this knowledge gap by elucidating faecal contents in unprecedented detail. We collected faeces excreted by a range of migratory waterbirds in south-west Spain and pooled faecal DNA to create libraries reflective of feeding behavior. We created sets of libraries using high-throughput metagenomic and amplicon sequencing. For the latter we employed two sets of primers to broadly target the V4 region of the 18S rRNA gene (one set amplifying the region across all eukaryotes, the other excluding amplification of metazoans). Libraries revealed a wide diversity of eukaryotes, including parasites of the faecal producers themselves, parasites of food items, or those incidentally ingested. We also detected novel microbial eukaryotic taxa and found that parasite assemblage profiles were relatively distinct. Comparing the performance of the methods used supports their joint use for future studies of diversity and abundance. Because viable stages of many parasites are likely to be present in faeces, our results suggest significant levels of bird-mediated dispersal of parasites (both from avian and other hosts). Our methods revealed much hidden biodiversity, and allowed identification of the individuals who produced the faecal samples to species level, facilitating the study of interaction networks.

Txikispora philomaios n. sp., n. g., a Micro-Eukaryotic Pathogen of Amphipods, Reveals Parasitism and Hidden Diversity in Class Filasterea

This study provides a morphological, ultrastructural, and phylogenetic characterization of a novel micro-eukaryotic parasite (2.3-2.6 µm) infecting amphipod genera Echinogammarus and Orchestia. Longitudinal studies across two years revealed that infection prevalence peaked in late April and May, reaching 64% in Echinogammarus sp. and 15% in Orchestia sp., but was seldom detected during the rest of the year. The parasite infected predominantly haemolymph, connective tissue, tegument, and gonad, although hepatopancreas and nervous tissue were affected in heavier infections, eliciting melanization and granuloma formation. Cell division occurred inside walled parasitic cysts, often within host haemocytes, resulting in haemolymph congestion. Small subunit (18S) rRNA gene phylogenies including related environmental sequences placed the novel parasite as a highly divergent lineage within Class Filasterea, which together with Choanoflagellatea represent the closest protistan relatives of Metazoa. We describe the new parasite as Txikispora philomaios n. sp. n. g., the first confirmed parasitic filasterean lineage, which otherwise comprises four free-living flagellates and a rarely observed endosymbiont of snails. Lineage-specific PCR probing of other hosts and surrounding environments only detected T. philomaios in the platyhelminth Procerodes sp. We expand the known diversity of Filasterea by targeted searches of metagenomic datasets, resulting in 13 previously unknown lineages from environmental samples.

Pathogens co-transported with invasive non-native aquatic species: implications for risk analysis and legislation

Invasive Non-Native Species (INNS) can co-transport externally and internally other organisms including viruses, bacteria and other eukaryotes (including metazoan parasites), collectively referred to as the symbiome. These symbiotic organisms include pathogens, a small minority of which are subject to surveillance and regulatory control, but most of which are currently unscrutinized and/or unknown. These putatively pathogenetic symbionts can potentially pose diverse risks to other species, with implications for increased epidemiological risk to agriculture and aquaculture, wildlife/ecosystems, and human health (zoonotic diseases). The risks and impacts arising from co-transported known pathogens and other symbionts of unknown pathogenic virulence, remain largely unexplored, unlegislated, and difficult to identify and quantify. Here, we propose a workflow using PubMed and Google Scholar to systematically search existing literature to determine any known and potential pathogens of aquatic INNS. This workflow acts as a prerequisite for assessing the nature and risk posed by co-transported pathogens of INNS; of which a better understanding is necessary to inform policy and INNS risk assessments. Addressing this evidence gap will be instrumental to devise an appropriate set of statutory responsibilities with respect to these symbionts, and to underpin new and more effective legislative processes relating to the disease screening and risk assessment of INNS.

Pathogens co-transported with invasive non-native aquatic species: implications for risk analysis and legislation

Invasive Non-Native Species (INNS) can co-transport externally and internally other organisms including viruses, bacteria and other eukaryotes (including metazoan parasites), collectively referred to as the symbiome. These symbiotic organisms include pathogens, a small minority of which are subject to surveillance and regulatory control, but most of which are currently unscrutinized and/or unknown. These putatively pathogenetic symbionts can potentially pose diverse risks to other species, with implications for increased epidemiological risk to agriculture and aquaculture, wildlife/ecosystems, and human health (zoonotic diseases). The risks and impacts arising from co-transported known pathogens and other symbionts of unknown pathogenic virulence, remain largely unexplored, unlegislated, and difficult to identify and quantify. Here, we propose a workflow using PubMed and Google Scholar to systematically search existing literature to determine any known and potential pathogens of aquatic INNS. This workflow acts as a prerequisite for assessing the nature and risk posed by co-transported pathogens of INNS; of which a better understanding is necessary to inform policy and INNS risk assessments. Addressing this evidence gap will be instrumental to devise an appropriate set of statutory responsibilities with respect to these symbionts, and to underpin new and more effective legislative processes relating to the disease screening and risk assessment of INNS.

Improved high throughput protocol for targeting eukaryotic symbionts in metazoan and eDNA samples

Eukaryote symbionts of animals are major drivers of ecosystems not only because of their diversity and host interactions from variable pathogenicity but also through different key roles such as commensalism and to different types of interdependence. However, molecular investigations of metazoan eukaryomes require minimising coamplification of homologous host genes. In this study we (1) identified a previously published “antimetazoan” reverse primer to theoretically enable amplification of a wider range of microeukaryotic symbionts, including more evolutionarily divergent sequence types, (2) evaluated in silico several antimetazoan primer combinations, and (3) optimised the application of the best performing primer pair for high throughput sequencing (HTS) by comparing one‐step and two‐step PCR amplification approaches, testing different annealing temperatures and evaluating the taxonomic profiles produced by HTS and data analysis. The primer combination 574*F – UNonMet_DB tested in silico showed the largest diversity of nonmetazoan sequence types in the SILVA database and was also the shortest available primer combination for broadly‐targeting antimetazoan amplification across the 18S rRNA gene V4 region. We demonstrate that the one‐step PCR approach used for library preparation produces significantly lower proportions of metazoan reads, and a more comprehensive coverage of host‐associated microeukaryote reads than the two‐step approach. Using higher PCR annealing temperatures further increased the proportion of nonmetazoan reads in all sample types tested. The resulting V4 region amplicons were taxonomically informative even when only the forward read is analysed. This region also revealed a diversity of known and putatively parasitic lineages and a wider diversity of host‐associated eukaryotes.

Identifying Potential Hosts of Short-Branch Microsporidia

Microsporidia are obligate parasites that are closely related to Fungi. While the widely known "long-branch" Microsporidia infect mostly metazoans, the hosts of "short-branch" Microsporidia are only partially characterized or not known at all. Here, we used network analyses from Neotropical rainforest soil metabarcoding data, to infer co-occurrences between environmental lineages of short-branch microsporidians and their potential hosts. We found significant co-occurrences with several taxa, especially with Apicomplexa, Cercozoa, and Fungi, as well as some Metazoa. Our results are the first step to identify potential hosts of the environmental lineages of short-branch microsporidians, which can be targeted in future molecular and microscopic studies.

pr2-primers: An 18S rRNA primer database for protists

Metabarcoding of microbial eukaryotes (collectively known as protists) has developed tremendously in the last decade, almost solely relying on the 18S rRNA gene. As microbial eukaryotes are extremely diverse, many primers and primer pairs have been developed. To cover a relevant and representative fraction of the protist community in a given study system, an informed primer choice is necessary, as no primer pair can target all protists equally well. As such, a smart primer choice is very difficult even for experts and there are very few online resources available to list existing primers. We built a database listing 285 primers and 83 unique primer pairs that have been used for eukaryotic 18S rRNA gene metabarcoding. In silico performance of primer pairs was tested against two sequence databases: PR² version 4.12.0 for eukaryotes and a subset of silva version 132 for bacteria and archaea. We developed an R-based web application enabling browsing of the database, visualization of the taxonomic distribution of the amplified sequences with the number of mismatches, and testing any user-defined primer or primer set (https://app.pr2-primers.org). Taxonomic specificity of primer pairs, amplicon size and location of mismatches can also be determined. We identified universal primer sets that matched the largest number of sequences and analysed the specificity of some primer sets designed to target certain groups. This tool enables guided primer choices that will help a wide range of researchers to include protists as part of their investigations.

Parasites, pathogens, and other symbionts of copepods

There is a large diversity of eukaryotic symbionts of copepods, dominated by epizootic protists such as ciliates, and metazoan parasites. Eukaryotic endoparasites, copepod-associated bacteria, and viruses are less well known, partly due to technical limitations. However, new molecular techniques, combined with a range of other approaches, provide a complementary toolkit for understanding the complete symbiome of copepods and how the symbiome relates to their ecological roles, relationships with other biota, and responses to environmental change. In this review we provide the most complete overview of the copepod symbiome to date, including microeukaryotes, metazoan parasites, bacteria, and viruses, and provide extensive literature databases to inform future studies.

Abstract P346: Segmentation of Chronic Subdural Hematomas Using 3D Convolutional Neural Networks

Objective: Chronic subdural hematomas (cSDH) are an increasingly prevalent neurological disease that often requires surgical intervention to alleviate compression of the brain. Management of cSDHs relies heavily upon computed tomography (CT) imaging, and serial imaging is frequently obtained to help direct management. The volume of hematoma provides critical information in guiding therapy and evaluating new methods of management. We set out to develop an automated program to compute the volume of hematoma on CT scans for both preoperative and postoperative images.

Methods: A total of 128 CT scans (21,710 images) were manually segmented and used to train a convolutional neural network to automatically segment chronic subdural hematomas. We included both preoperative and postoperative coronal head CTs from patients undergoing surgical management of cSDHs.

Results: Our best model achieved a Dice score of 0.8351 on the testing dataset and an average Dice score of 0.806 +/- 0.06 on the validation set. This model was trained on the full data set with reduced volumes, a network depth of 4, and post activation residual blocks within the context modules of the encoder pathway. Patch trained models did not perform as well and decreasing the network depth from 5 to 4 did not appear to significantly improve performance.

Conclusions: We successfully trained a convolutional neural network on a dataset of pre and postoperative head CTs containing cSDH. This tool could assist with automated, accurate measurements for evaluating treatment efficacy.

Identification of microbial signatures linked to oilseed rape yield decline at the landscape scale

BACKGROUND

The plant microbiome plays a vital role in determining host health and productivity. However, we lack real-world comparative understanding of the factors which shape assembly of its diverse biota, and crucially relationships between microbiota composition and plant health. Here we investigated landscape scale rhizosphere microbial assembly processes in oilseed rape (OSR), the UK's third most cultivated crop by area and the world's third largest source of vegetable oil, which suffers from yield decline associated with the frequency it is grown in rotations. By including 37 conventional farmers' fields with varying OSR rotation frequencies, we present an innovative approach to identify microbial signatures characteristic of microbiomes which are beneficial and harmful to the host.

RESULTS

We show that OSR yield decline is linked to rotation frequency in real-world agricultural systems. We demonstrate fundamental differences in the environmental and agronomic drivers of protist, bacterial and fungal communities between root, rhizosphere soil and bulk soil compartments. We further discovered that the assembly of fungi, but neither bacteria nor protists, was influenced by OSR rotation frequency. However, there were individual abundant bacterial OTUs that correlated with either yield or rotation frequency. A variety of fungal and protist pathogens were detected in roots and rhizosphere soil of OSR, and several increased relative abundance in root or rhizosphere compartments as OSR rotation frequency increased. Importantly, the relative abundance of the fungal pathogen Olpidium brassicae both increased with short rotations and was significantly associated with low yield. In contrast, the root endophyte Tetracladium spp. showed the reverse associations with both rotation frequency and yield to O. brassicae, suggesting that they are signatures of a microbiome which benefits the host. We also identified a variety of novel protist and fungal clades which are highly connected within the microbiome and could play a role in determining microbiome composition.

CONCLUSIONS

We show that at the landscape scale, OSR crop yield is governed by interplay between complex communities of both pathogens and beneficial biota which is modulated by rotation frequency. Our comprehensive study has identified signatures of dysbiosis within the OSR microbiome, grown in real-world agricultural systems, which could be used in strategies to promote crop yield. Video abstract.

Protist taxonomic and functional diversity in soil, freshwater and marine ecosystems

Protists dominate eukaryotic diversity and play key functional roles in all ecosystems, particularly by catalyzing carbon and nutrient cycling. To date, however, a comparative analysis of their taxonomic and functional diversity that compares the major ecosystems on Earth (soil, freshwater and marine systems) is missing. Here, we present a comparison of protist diversity based on standardized high throughput 18S rRNA gene sequencing of soil, freshwater and marine environmental DNA. Soil and freshwater protist communities were more similar to each other than to marine protist communities, with virtually no overlap of Operational Taxonomic Units (OTUs) between terrestrial and marine habitats. Soil protists showed higher γ diversity than aquatic samples. Differences in taxonomic composition of the communities led to changes in a functional diversity among ecosystems, as expressed in relative abundance of consumers, phototrophs and parasites. Phototrophs (eukaryotic algae) dominated freshwater systems (49% of the sequences) and consumers soil and marine ecosystems (59% and 48%, respectively). The individual functional groups were composed of ecosystem- specific taxonomic groups. Parasites were equally common in all ecosystems, yet, terrestrial systems hosted more OTUs assigned to parasites of macro-organisms while aquatic systems contained mostly microbial parasitoids. Together, we show biogeographic patterns of protist diversity across major ecosystems on Earth, preparing the way for more focused studies that will help understanding the multiple roles of protists in the biosphere.

Segmentation of Chronic Subdural Hematomas Using 3D Convolutional Neural Networks

OBJECTIVE

Chronic subdural hematomas (cSDHs) are an increasingly prevalent neurologic disease that often requires surgical intervention to alleviate compression of the brain. Management of cSDHs relies heavily on computed tomography (CT) imaging, and serial imaging is frequently obtained to help direct management. The volume of hematoma provides critical information in guiding therapy and evaluating new methods of management. We set out to develop an automated program to compute the volume of hematoma on CT scans for both pre- and postoperative images.

METHODS

A total of 21,710 images (128 CT scans) were manually segmented and used to train a convolutional neural network to automatically segment cSDHs. We included both pre- and postoperative coronal head CTs from patients undergoing surgical management of cSDHs.

RESULTS

Our best model achieved a DICE score of 0.8351 on the testing dataset, and an average DICE score of 0.806 ± 0.06 on the validation set. This model was trained on the full dataset with reduced volumes, a network depth of 4, and postactivation residual blocks within the context modules of the encoder pathway. Patch trained models did not perform as well and decreasing the network depth from 5 to 4 did not appear to significantly improve performance.

CONCLUSIONS

We successfully trained a convolutional neural network on a dataset of pre- and postoperative head CTs containing cSDH. This tool could assist with automated, accurate measurements for evaluating treatment efficacy.

Revised Taxonomy and Expanded Biodiversity of the Phytomyxea (Rhizaria, Endomyxa)

Phytomyxea (phytomyxids) is a group of obligate biotrophic pathogens belonging to the Rhizaria. Some phytomyxids are well studied and include known plant pathogens such as Plasmodiophora brassicae, the causal agent of clubroot disease. Despite this economic importance, the taxonomy and biodiversity of this group are largely cryptic, with many species described in the premolecular area. Some of these species were key for establishing the morphotaxonomic concepts that define most genera to this day, but systematic efforts to include and integrate those species into molecular studies are still lacking. The aim of this study was to expand our understanding of phytomyxid biodiversity in terrestrial environments. Thirty-eight environmental samples from habitats in which novel and known diversity of Phytomyxea was expected were analysed. We were able to generate 18S rRNA sequences from Ligniera verrucosa, a species which is well defined based on ultrastructure. Phylogenetic analyses of the collected sequences rendered the genera Lignera, Plasmodiophora and Spongospora polyphyletic, and identified two novel and apparently diverse lineages (clade 17, clade 18). Based on these findings and on data from previous studies, we formally establish the new genera Pseudoligniera n. gen. for L. verrucosa,Hillenburgia n. gen. for Spongospora nasturtii and revert Plasmodiophora diplantherae to its original name Ostenfeldiella diplantherae.

D-CARE: The Dementia Care Study: Design of a Pragmatic Trial of the Effectiveness and Cost Effectiveness of Health System-Based Versus Community-Based Dementia Care Versus Usual Dementia Care

BACKGROUND/OBJECTIVES

Although several approaches have been developed to provide comprehensive care for persons living with dementia (PWD) and their family or friend caregivers, the relative effectiveness and cost effectiveness of community-based dementia care (CBDC) versus health system-based dementia care (CBDC) and the effectiveness of both approaches compared with usual care (UC) are unknown.

DESIGN

Pragmatic randomized three-arm superiority trial. The unit of randomization is the PWD/caregiver dyad.

SETTING

Four clinical trial sites (CTSs) based in academic and clinical health systems.

PARTICIPANTS

A total of 2,150 English- or Spanish-speaking PWD who are not receiving hospice or residing in a nursing home and their caregivers.

INTERVENTIONS

Eighteen months of (1) HSDC provided by a nurse practitioner or physician's assistant dementia care specialist who works within the health system, or (2) CBDC provided by a social worker or nurse care consultant who works at a community-based organization, or (3) UC with as needed referral to the Alzheimer's Association Helpline.

MEASUREMENTS

Primary outcomes: PWD behavioral symptoms and caregiver distress as measured by the Neuropsychiatric Inventory Questionnaire (NPI-Q) Severity and Modified Caregiver Strain Index scales.

SECONDARY OUTCOMES

NPI-Q Distress, caregiver unmet needs and confidence, and caregiver depressive symptoms. Tertiary outcomes: PWD long-term nursing home placement rates, caregiver-reported PWD functional status, cognition, goal attainment, "time spent at home," Dementia Burden Scale-Caregiver, a composite measure of clinical benefit, Quality of Life of persons with dementia, Positive Aspects of Caregiving, and cost effectiveness using intervention costs and Medicare claims.

RESULTS

The results will be reported in the spring of 2024.

CONCLUSION

D-CARE will address whether emphasis on clinical support and tighter integration with other medical services has greater benefit than emphasis on social support that is tied more closely to community resources. It will also assess the effectiveness of both interventions compared with UC and will evaluate the cost effectiveness of each intervention.

A Novel RNA Virus, Macrobrachium rosenbergii Golda Virus (MrGV), Linked to Mass Mortalities of the Larval Giant Freshwater Prawn in Bangladesh

Mass mortalities of the larval stage of the giant freshwater prawn, Macrobrachium rosenbergii, have been occurring in Bangladesh since 2011. Mortalities can reach 100% and have resulted in an 80% decline in the number of hatcheries actively producing M. rosenbergii. To investigate a causative agent for the mortalities, a disease challenge was carried out using infected material from a hatchery experiencing mortalities. Moribund larvae from the challenge were prepared for metatranscriptomic sequencing. De novo virus assembly revealed a 29 kb single‑stranded positive-sense RNA virus with similarities in key protein motif sequences to yellow head virus (YHV), an RNA virus that causes mass mortalities in marine shrimp aquaculture, and other viruses in the Nidovirales order. Primers were designed against the novel virus and used to screen cDNA from larvae sampled from hatcheries in the South of Bangladesh from two consecutive years. Larvae from all hatcheries screened from both years were positive by PCR for the novel virus, including larvae from a hatchery that at the point of sampling appeared healthy, but later experienced mortalities. These screens suggest that the virus is widespread in M. rosenbergii hatchery culture in southern Bangladesh, and that early detection of the virus can be achieved by PCR. The hypothesised protein motifs of Macrobrachium rosenbergii golda virus (MrGV) suggest that it is likely to be a new species within the Nidovirales order. Biosecurity measures should be taken in order to mitigate global spread through the movement of post-larvae within and between countries, which has previously been linked to other virus outbreaks in crustacean aquaculture.

Environmental Parameters and Substrate Type Drive Microeukaryotic Community Structure During Short-Term Experimental Colonization in Subtropical Eutrophic Freshwaters

Microeukaryotes are key components of aquatic ecosystems and play crucial roles in aquatic food webs. However, influencing factors and potential assembly mechanisms for microeukaryotic community on biofilms are rarely studied. Here, those of microeukaryotic biofilms in subtropical eutrophic freshwaters were investigated for the first time based on 2,585 operational taxonomic units (OTUs) from 41 samples, across different environmental conditions and substrate types. Following conclusions were drawn: (1) Environmental parameters were more important than substrate types in structuring microeukaryotic community of biofilms in subtropical eutrophic freshwaters. (2) In the fluctuating river, there was a higher diversity of OTUs and less predictability of community composition than in the stable lake. Sessile species were more likely to be enriched on smooth surfaces of glass slides, while both free-swimming and attached organisms occurred within holes inside PFUs (polyurethane foam units). (3) Both species sorting and neutral process were mechanisms for assembly of microeukaryotic biofilms, but their importance varied depending on different habitats and substrates. (4) The effect of species sorting was slightly higher than the neutral process in river biofilms due to stronger environmental filtering. Species sorting was a stronger force structuring communities on glass slides than PFUs with more niche availability. Our study sheds light on assembly mechanisms for microeukaryotic community on different habitat and substrate types, showing that the resulting communities are determined by both sets of variables, in this case primarily habitat type. The balance of neutral process and species sorting differed between habitats, but the high alpha diversity of microeukaryotes in both led to similar sets of lifecycle traits being selected for in each case.

A novel nudivirus infecting the invasive demon shrimp Dikerogammarus haemobaphes (Amphipoda)

The Nudiviridae are a family of large double-stranded DNA viruses that infects the cells of the gut in invertebrates, including insects and crustaceans. The phylogenetic range of the family has recently been enhanced via the description of viruses infecting penaeid shrimp, crangonid shrimp, homarid lobsters and portunid crabs. Here we extend this by presenting the genome of another nudivirus infecting the amphipod Dikerogammarus haemobaphes. The virus, which infects cells of the host hepatopancreas, has a circular genome of 119,754 bp in length, and encodes a predicted 106 open reading frames. This novel virus encodes all the conserved nudiviral genes (sharing 57 gene homologues with other crustacean-infecting nudiviruses) but appears to lack the p6.9 gene. Phylogenetic analysis revealed that this virus branches before the other crustacean-infecting nudiviruses and shares low levels of gene/protein similarity to the Gammanudivirus genus. Comparison of gene synteny from known crustacean-infecting nudiviruses reveals conservation between Homarus gammarus nudivirus and Penaeus monodon nudivirus; however, three genomic rearrangements in this novel amphipod virus appear to break the gene synteny between this and the ones infecting lobsters and penaeid shrimp. We explore the evolutionary history and systematics of this novel virus, suggesting that it be included in the novel Epsilonnudivirus genus (Nudiviridae).