ABSTRACT
Introduction: Early childhood educators (ECEs) play a critical role in supporting the development of young children's executive functions (EF). EF, in turn, underpins lifelong resilience and well-being. Unfortunately, many ECEs report adverse childhood experiences (ACEs) that may compound high stress levels associated with an emotionally and physically demanding profession. ACEs have well-established negative implications for adult well-being and may dampen ECEs' capacities to engage in emotionally responsive interactions with children. However, many individuals who experience ACEs also report post-traumatic growth experiences that foster empathy, self-determination, and resilience. Such post-traumatic growth may equip teachers with skills to engage in responsive interactions with children that support children's EF. The aim of this study was to explore the relations of ECE ACEs and post-traumatic growth to the EF of children in their classrooms. Methods: Fifty-three female ECEs self-reported on their ACEs and post-traumatic growth. Parents of 157 children (53% male, 47% female, M age = 4.38 years) rated children's EF. Results: In a set of linear mixed models that accounted for multiple demographic factors and ECE perceived workplace stressors, ECE ACEs were not significantly related to children's EF scores. However, controlling for ACEs, higher levels of ECE post-traumatic growth were associated with fewer parent-reported EF difficulties in children. Discussion: ECEs may draw on the coping skills they have developed in times of adversity to model and promote healthy EF for children. Mental health supports to facilitate ECEs' processing of their own trauma may be a fruitful means to foster positive early childhood environments that nurture the well-being and resilience of future generations.
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Objective: To examine associations between risks and resources in predicting college students' depressive symptoms at the beginning of one semester and change over the semester. Participants: Participants were undergraduate students taking human development courses at one of 11 universities in the U.S. (N = 854). Methods: Survey data were collected at the beginning and end of the semester. Results: Experiencing more direct abusive or neglectful adverse childhood experiences (ACEs), and attachment preoccupation were associated with higher depressive symptoms at the beginning of the semester. Conversely, greater mindful awareness and attachment security were associated with lower initial depressive symptoms. Experiences of ACEs were associated with increases in depressive symptoms, as were higher levels of attachment dismissiveness. Greater mindful acceptance was associated with decreases in depressive symptoms. In most analyses, resources did not moderate the associations between ACEs and depressive symptoms. Conclusions: Results may inform instructors and counselors in supporting students' well-being.
Subject(s)
Adverse Childhood Experiences , Mindfulness , Humans , Students , Mental Health , Universities , DepressionABSTRACT
Findings suggest that an eight-week mindfulness compassion-based program, Cultivating Healthy Intentional Mindful Educators (CHIME), is a feasible professional development intervention for early childhood (EC) teachers to support their emotion regulation and psychological and workplace well-being. We offer preliminary evidence that learning about mindfulness, self-compassion, and social-emotional learning supports EC teachers in strengthening their knowledge and application of practices to be more mindful and less emotionally reactive and emotionally exhausted at work. In analyzing both EC teacher feedback and survey data from two pilot studies, there was promising evidence that participating in CHIME enhanced awareness of emotions and the development of strategies to manage emotions. As CHIME is further developed and refined it will be integral to have collaborative engagement and participation from EC teachers and programs to ensure that learning these practices are relevant, helpful, meaningful, and sustainable.
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The advancement of high throughput sequencing has greatly facilitated the exploration of viruses that infect marine hosts. For example, a number of putative virus genomes belonging to the Totiviridae family have been described in crustacean hosts. However, there has been no characterization of the most newly discovered putative viruses beyond description of their genomes. In this study, two novel double-stranded RNA (dsRNA) virus genomes were discovered in the Atlantic blue crab (Callinectes sapidus) and further investigated. Sequencing of both virus genomes revealed that they each encode RNA dependent RNA polymerase proteins (RdRps) with similarities to toti-like viruses. The viruses were tentatively named Callinectes sapidus toti-like virus 1 (CsTLV1) and Callinectes sapidus toti-like virus 2 (CsTLV2). Both genomes have typical elements required for -1 ribosomal frameshifting, which may induce the expression of an encoded ORF1-ORF2 (gag-pol) fusion protein. Phylogenetic analyses of CsTLV1 and CsTLV2 RdRp amino acid sequences suggested that they are members of two new genera in the family Totiviridae. The CsTLV1 and CsTLV2 genomes were detected in muscle, gill, and hepatopancreas of blue crabs by real-time reverse transcription quantitative PCR (RT-qPCR). The presence of ~40 nm totivirus-like viral particles in all three tissues was verified by transmission electron microscopy, and pathology associated with CsTLV1 and CsTLV2 infections were observed by histology. PCR assays showed the prevalence and geographic range of these viruses, to be restricted to the northeast United States sites sampled. The two virus genomes co-occurred in almost all cases, with the CsTLV2 genome being found on its own in 8.5% cases, and the CsTLV1 genome not yet found on its own. To our knowledge, this is the first report of toti-like viruses in C. sapidus. The information reported here provides the knowledge and tools to investigate transmission and potential pathogenicity of these viruses.
ABSTRACT
Domoic acid (DA) is produced by almost half of the species belonging to the diatom genus Pseudo-nitzschia and causes amnesic shellfish poisoning (ASP). It is, therefore, important to investigate the diversity and toxin production of Pseudo-nitzschia species for ASP risk assessments. Between 2018 and 2020, seawater samples were collected from various sites around Aotearoa New Zealand, and 130 clonal isolates of Pseudo-nitzschia were established. Molecular phylogenetic analysis of partial large subunit ribosomal DNA and/or internal transcribed spacer regions revealed that the isolates were divided into 14 species (Pseudo-nitzschia americana, Pseudo-nitzschia arenysensis, Pseudo-nitzschia australis, Pseudo-nitzschia calliantha, Pseudo-nitzschia cuspidata, Pseudo-nitzschia delicatissima, Pseudo-nitzschia fraudulenta, Pseudo-nitzschia galaxiae, Pseudo-nitzschia hasleana, Pseudo-nitzschia multiseries, Pseudo-nitzschia multistriata, Pseudo-nitzschia plurisecta, Pseudo-nitzschia pungens, and Pseudo-nitzschia cf. subpacifica). The P. delicatissima and P. hasleana strains were further divided into two clades/subclades (I and II). Liquid chromatography-tandem mass spectrometry was used to assess the production of DA and DA isomers by 73 representative strains. The analyses revealed that two (P. australis and P. multiseries) of the 14 species produced DA as a primary analogue, along with several DA isomers. This study is the first geographical distribution record of P. arenysensis, P.cuspidata, P. galaxiae, and P. hasleana in New Zealand coastal waters.
Subject(s)
Diatoms/genetics , Genetic Variation , Marine Toxins/metabolism , Phytoplankton/metabolism , Diatoms/metabolism , New Zealand , Phytoplankton/geneticsABSTRACT
BACKGROUND: There is limited understanding of the prevalence of psychological distress and associated stressors and supports among displaced adults in low- and middle-income first asylum countries. METHOD: This article reports the findings of a cross-sectional study. We recruited 245 Congolese adults (18-80 years) residing in Nairobi, Kenya using snowball sampling. Data were collected using an interviewer-administered questionnaire consisting of sociodemographic characteristics, the Self-Reporting Questionnaire (SRQ-20), and a locally developed stressors and supports survey. We used multivariable logistic regression to examine associations among sociodemographic, stressor, and support variables and the likelihood of experiencing psychological distress. RESULTS: More than half of the participants (52.8%) reported symptoms indicative of psychological distress. Factors associated with increased psychological distress included perceiving to have a useful role in one's family or community, AOR = 1.85; 95% CI [1.1.17, 3.11], p = .012, feeling confused or not knowing what to do, AOR = 2.13; 95% CI [1.20, 4.6], p = .014, and feeling afraid to leave home for medical/health care to help with an illness, AOR = 1.57; 95% CI [1.17, 2.15], p < .01. Additionally, ethnic Banyamulenge Congolese adults without legal refugee status had an increased likelihood of experiencing psychological distress, AOR = .07; 95% CI [0, .74], p = .035. CONCLUSION: Future research is warranted to understand how to implement targeted mental health and psychosocial support (MHPSS) to improve urban-displaced adults' sense of safety and belonging. Our findings suggest that legal refugee status is an important structural determinant of mental health, which should be considered in MHPSS practice and policy. (PsycInfo Database Record (c) 2021 APA, all rights reserved).
Subject(s)
Psychological Distress , Stress, Psychological , Adult , Cross-Sectional Studies , Humans , Kenya/epidemiology , Prevalence , Stress, Psychological/epidemiologyABSTRACT
PURPOSE: Breastfeeding and responsive feeding are important practices that support the health of infants and women. In the United States, breastfeeding continuation rates remain lower than recommended, and working women face additional challenges with breastfeeding continuation. Providers in a family child care setting are uniquely positioned to support and provide important resources to families in their breastfeeding and infant feeding practices. METHODS: The Go NAP SACC program was designed to improve the nutrition and physical activity environments and practices in child care settings serving infants and young children. This evaluation focuses on Breastfeeding and Infant Feeding in Nebraska Family Child Care Homes (FCCH). ASSESSMENT: Paired-sample t-tests were used to examine differences in pre-post evaluation scores. A repeated measure ANCOVA was used to examine differences between rural-urban settings. Nebraska FCCH met recommendations at pre-test, and exceeded recommendations at post-test (p < .05). Rural and urban FCCH performed equally well in 18 of 22 items, indicating little difference in the ability to provide supportive environments and adhere to best practices in both settings. Improvement in family engagement items were significant at the p < .001 level. Family engagement in FCCH is an important area for intervention that was well-received by provider participants. CONCLUSION: This evaluation shows that the Go NAP SACC program improves breastfeeding and infant feeding environments and practices in rural and urban FCCH. Interventions should continue to focus on basic and practical education and professional development for FCCH providers, with emphasis on intentional family engagement and support.
Subject(s)
Breast Feeding , Child Care , Child , Child Day Care Centers , Child Health , Child, Preschool , Feeding Behavior , Female , Humans , Infant , United StatesABSTRACT
PURPOSE: To examine the psychological well-being of primary caregivers of infants and toddlers with Congenital Zika Syndrome (CZS), and the roles of family resources, parenting stress, and coping strategies in caregivers' adaptation. MATERIALS AND METHODS: Family caregivers (N = 50) of children with CZS who were receiving treatment at a rehabilitation hospital in Recife, Brazil participated a cross-sectional survey study. Caregivers completed measures of anxiety and depression, coping strategies, family resources, and parenting stress. RESULTS: Mild to severe symptoms of depression were identified in 40% of caregivers and were a more prominent concern than symptoms of anxiety. Fewer family resources and high levels of parenting stress were significantly associated with both anxiety and depression. The association between parenting stress and depression was moderated by coping, such that parenting stress was associated with higher caregiver depression at low but not high levels of coping strategy use. CONCLUSIONS: Practitioners in Brazil should consider the role of family coping and resources as important resilience promoting factors in the development of new programs designed to promote psychological adaptation in caregivers to children with CZS. It is recommended that caregiver mental health support services be integrated into existing early intervention programs targeting children with CZS.Implications for RehabilitationParents and other primary caregivers are encouraged to take an active role in the care and developmental monitoring of children born with CZS, but their ability to provide care may be compromised by difficulties in psychological adaptation.Moderate and severe symptoms of depression were more prominent in caregivers than moderate and severe symptoms of anxiety (20% versus 6%, respectively).Practitioners should include assessment of coping strategies, parenting stress and family resources conjointly with evaluation of symptoms of depression and anxiety as part of routine CZS family evaluations.A useful approach for caregivers in Brazil may be to more fully integrate caregiver mental health support services into existing early intervention programs for children with CZS.
Subject(s)
Zika Virus Infection , Zika Virus , Adaptation, Psychological , Anxiety , Brazil , Caregivers , Child, Preschool , Cross-Sectional Studies , Depression , Humans , Infant , Stress, PsychologicalABSTRACT
Researchers who desire to make positive changes for vulnerable populations often conduct problem-focused studies. Although problem-focused research is important, when such studies are not carefully designed, their results can contribute to a deficit discourse. A deficit discourse is a narrative that describes the person through a myopic lens of negativity characterized only by illness, death, depression, failure, or the like. Deficit discourse negatively affects how health care providers and society interact with vulnerable people. This article discusses deficit discourse in health care and strengths-based research: an ethical approach to working with vulnerable individuals in research settings and a strategy to overcome deficit discourse. Strengths-based research approaches balance risks with countermeasures that include areas that are positive and amenable to growth or intervention. Strengths-based research can be conducted using qualitative, quantitative, or mixed-methods methodology. Strengths-based research should be culturally relevant and population-specific, often including the individuals of study throughout the process. By modifying the research approach, critical problems can be identified and addressed while also emphasizing positive ways to empower individuals and improve their lives. Additionally, these changes better the way researchers and health care providers view and care for people while also challenging deficit discourses in society at large.
Subject(s)
Delivery of Health Care , Vulnerable Populations , Ethics, Research , HumansABSTRACT
OBJECTIVE: To examine contextual factors that may influence child care providers' motivators for attending nutrition-related training and their preferences and barriers to attending professional development training. DESIGN: Cross-sectional survey completed between January and April 2017. SETTING: Licensed child care programs (nâ¯=â¯1,490) across urban and rural Nebraska. PARTICIPANTS: Child care center directors (nâ¯=â¯336) and family child care home providers (nâ¯=â¯1,154). MAIN OUTCOME MEASURE(S): Motivators, preferences, and barriers of child care providers for attending professional development. ANALYSIS: Descriptive statistics and multiple logistic regression analyses were conducted. RESULTS: Top motivators for attending nutrition-related training included meeting licensure requirements and improving job performance. Child care providers most commonly selected preferences for receiving training included in-person and online delivery. Top barriers to obtaining training were schedule conflicts, accessibility, and cost. Child care centers and participants in the Child and Adult Care Food Program (CACFP) and Nutrition and Physical Activity Self-Assessment in Child Care (Go NAP SACC) were more likely to be motivated by licensure requirements. Rural providers were also more likely to report barriers such as inability to travel and limited access to training. Results revealed that child care type, geographic location, CACFP and Go NAP SACC participation can influence child care providers' motivators, preferences, and barriers to attending training. CONCLUSIONS AND IMPLICATIONS: Results highlight the importance of offering professional development training that best fits child care providers' needs and preferences.
Subject(s)
Child Nutrition Sciences/education , Education, Continuing , Motivation , School Teachers/psychology , Child Care , Child, Preschool , Cross-Sectional Studies , Education/methods , Education, Continuing/methods , Humans , NebraskaABSTRACT
Monterey Bay, California experiences near-annual blooms of Pseudo-nitzschia that can affect marine animal health and the economy, including impacts to tourism and commercial/recreational fisheries. One species in particular, P. australis, has been implicated in the most toxic of events, however other species within the genus can contribute to widespread variability in community structure and associated toxicity across years. Current monitoring methods are limited in their spatial coverage as well as their ability to capture the full suite of species present, thereby hindering understanding of HAB events and limiting predictive accuracy. An integrated deployment of multiple in situ platforms, some with autonomous adaptive sampling capabilities, occurred during two divergent bloom years in the bay, and uncovered detailed aspects of population and toxicity dynamics. A bloom in 2013 was characterized by spatial differences in Pseudo-nitzschia populations, with the low-toxin producer P. fraudulenta dominating the inshore community and toxic P. australis dominating the offshore community. An exceptionally toxic bloom in 2015 developed as a diverse Pseudo-nitzschia community abruptly transitioned into a bloom of highly toxic P. australis within the time frame of a week. Increases in cell density and proliferation coincided with strong upwelling of nutrients. High toxicity was driven by silicate limitation of the dense bloom. This temporal shift in species composition mirrored the shift observed further north in the California Current System off Oregon and Washington. The broad scope of sampling and unique platform capabilities employed during these studies revealed important patterns in bloom formation and persistence for Pseudo-nitzschia. Results underscore the benefit of expanded biological observing capabilities and targeted sampling methods to capture more comprehensive spatial and temporal scales for studying and predicting future events.
Subject(s)
Biodiversity , Diatoms/physiology , Environmental Monitoring , Eutrophication , California , Marine Toxins/analysisABSTRACT
New sandwich hybridization assay (SHA) probes for detecting Pseudo-nitzschia species (P. arenysensis, P. fraudulenta, P. hasleana, P. pungens) are presented, along with updated cross-reactivity information on historical probes (SHA and FISH; fluorescence in situ hybridization) targeting P. australis and P. multiseries. Pseudo-nitzschia species are a cosmopolitan group of diatoms that produce varying levels of domoic acid (DA), a neurotoxin that can accumulate in finfish and shellfish and transfer throughout the food web. Consumption of infected food sources can lead to illness in humans (amnesic shellfish poisoning; ASP) and marine wildlife (domoic acid poisoning; DAP). The threat of human illness, along with economic loss from fishery closures has resulted in the implementation of monitoring protocols and intensive ecological studies. SHA probes have been instrumental in some of these efforts, as the technique performs well in complex heterogeneous sample matrices and has been adapted to benchtop and deployable (Environmental Sample Processor) platforms. The expanded probe set will enhance future efforts towards understanding spatial, temporal and successional patterns in species during bloom and non-bloom periods.
Subject(s)
Diatoms/isolation & purification , Molecular Probes/genetics , Nucleic Acid Hybridization/methods , Diatoms/classification , Diatoms/genetics , Diatoms/metabolism , Kainic Acid/analogs & derivatives , Kainic Acid/metabolism , Neurotoxins/metabolism , Sensitivity and SpecificityABSTRACT
Supporting children's self-regulation in eating through caregivers' practice of responsive feeding is paramount to obesity prevention, and while much attention has been given to supporting children's self-regulation in eating through parents' responsive feeding practices in the home setting, little attention has been given to this issue in childcare settings. This qualitative study examines childcare providers' perspectives on using responsive feeding practices with young children (2-5years). Individual semi-structured interviews were conducted with providers until saturation was reached. Data was analyzed using thematic analysis. The final sample included 18 providers who were employed full-time in Head Start or state-licensed center-based childcare programs, cared for children (2-5y), and were directly responsible for serving meals and snacks. Providers were primarily (67%) employed in childcare programs that served children from low-income families and received reimbursement for meals and snacks from the US Department of Agriculture's Child and Adult Care Food Program. Three factors emerged that shaped childcare providers' experiences using responsive feeding practices: the providers' perspectives about whether or not young children can self-regulate food intake, their understanding of Child and Adult Care Food Program (CACFP) portion size regulations, and the availability of food at the center where they worked. Future research should examine how childcare providers' understanding of children's ability to self-regulate their food intake, the appropriate use of the CACFP regulations in relationship to serving sizes, and having food available to offer seconds promotes providers' use of responsive feeding practices in center-based childcare programs and children's dietary behaviors.
Subject(s)
Child Care , Diet , Eating , Adult , Caregivers , Child Behavior , Child Day Care Centers , Child Health , Child, Preschool , Cohort Studies , Evaluation Studies as Topic , Follow-Up Studies , Food Supply , Humans , Meals , Middle Aged , Obesity/prevention & control , Snacks , Socioeconomic FactorsABSTRACT
Many species within the diatom genus Pseudo-nitzschia are difficult to distinguish without applying molecular analytical or microscopy-based methods. DNA, antibody and lectin probes have previously been used to provide rapid and specific detection of species and strains in complex field assemblages. Recently, however, well-documented cryptic genetic diversity within the group has confounded results of DNA probe tests in particular. Moreover, the number of species descriptions within the genus continues to increase, as do insights into toxin production by both new and previously described species. Therefore, a combination of classical morphological techniques and modern molecular methodologies is needed to resolve ecophysiological traits of Pseudo-nitzschia species. Here, we present an approach to recover and identify frustules from sample collection filters used for toxin analysis onboard the Environmental Sample Processor (ESP), an in situ sample collection and analytical platform. This approach provides a new and powerful tool for correlating species presence with toxin detected remotely and in situ by the ESP, and has the potential to be applied broadly to other sampling configurations. This new technique will contribute to a better understanding of naturally occurring Pseudo-nitzschia community structure with respect to observed domoic acid outbreaks.
Subject(s)
Diatoms/isolation & purification , Environmental Monitoring/instrumentation , DNA Probes , Diatoms/physiology , Environmental Monitoring/methods , Kainic Acid/analogs & derivatives , Kainic Acid/analysis , Microscopy, Electron, ScanningABSTRACT
BACKGROUND: Hematodinium perezi, a parasitic dinoflagellate, infects and kills blue crabs, Callinectes sapidus, along the Atlantic and Gulf coasts of the United States. The parasite proliferates within host hemolymph and tissues, and also produces free-swimming biflagellated dinospores that emerge from infected crabs. Infections in C. sapidus recur annually, and it is not known if biotic or environmental reservoirs contribute to reinfection and outbreaks. To address this data gap, a quantitative PCR assay based on the internal transcribed spacer 2 (ITS2) region of H. perezi rRNA genes was developed to asses the temporal and spatial incidence of the parasite in Delaware and Maryland coastal bays. RESULTS: A previously-used PCR assay for H. perezi, based on the small subunit rRNA gene sequence, was found to lack adequate species specificity to discriminate non-Hematodinium sp. dinoflagellate species in environmental samples. A new ITS2-targeted assay was developed and validated to detect H. perezi DNA in sediment and water samples using E. coli carrying the H. perezi rDNA genes. Application of the method to environmental samples identified potential hotspots in sediment in Indian River Inlet, DE and Chincoteague Bay, MD and VA. H. perezi DNA was not detected in co-occurring shrimp or snails, even during an outbreak of the parasite in C. sapidus. CONCLUSIONS: H. perezi is present in water and sediment samples in Maryland and Delaware coastal bays from April through November with a wide spatial and temporal variability in incidence. Sampling sites with high levels of H. perezi DNA in both bays share characteristics of silty, organic sediments and low tidal currents. The environmental detection of H. perezi in spring, ahead of peak prevalence in crabs, points to gaps in our understanding of the parasite's life history prior to infection in crabs as well as the mode of environmental transmission. To better understand the H. perezi life cycle will require further monitoring of the parasite in habitats as well as hosts. Improved understanding of potential environmental transmission to crabs will facilitate the development of disease forecasting.
ABSTRACT
Mortality among blue crab Callinectes sapidus in soft shell production facilities is typically 25% or greater. The harvest, handling, and husbandry practices of soft shell crab production have the potential to spread or exacerbate infectious crab diseases. To investigate the possible role of viruses in soft shell crab mortalities, we took advantage of the physicochemical properties of double-stranded RNA (dsRNA) to isolate a putative virus genome. Further characterization confirmed the presence of a reo-like virus that possesses 12 dsRNA genome segments. The virus was present in >50% of dead or dying soft shell crabs, but fewer than 5% of healthy hard crabs. Injection of the virus caused mortality and resulted in the appearance of viral RNA and virus inclusions in hemocytes. The genome of the virus was partially sequenced and the information used to develop a reverse transcription polymerase chain reaction (RT-PCR) assay that is able to detect the virus genome in as little as 7.5 pg of total RNA. The molecular tools developed during this study will allow us to quantify prevalence of the blue crab reo-like virus in captive (soft shell facilities, aquaculture operations) and wild populations and facilitate understanding of the role this virus has in blue crab life history.
Subject(s)
Brachyura/virology , RNA, Double-Stranded/genetics , Reoviridae/isolation & purification , Animals , Base Sequence , Genome, Viral , Molecular Sequence Data , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
Nucleotide ssu and lsu rDNA sequences of all major lineages of autotrophic (Ochrophyta) and heterotrophic (Bigyra and Pseudofungi) heterokonts were combined with amino acid sequences from four protein-coding genes (actin, beta-tubulin, cox1 and hsp90) in a multigene approach for resolving the relationship between heterokont lineages. Applying these multigene data in Bayesian and maximum likelihood analyses improved the heterokont tree compared to previous rDNA analyses by placing all plastid-lacking heterotrophic heterokonts sister to Ochrophyta with robust support, and divided the heterotrophic heterokonts into the previously recognized phyla, Bigyra and Pseudofungi. Our trees identified the heterotrophic heterokonts Bicosoecida, Blastocystis and Labyrinthulida (Bigyra) as the earliest diverging lineages. A separate analysis of the phototrophic lineages, by adding the rbcL gene, further resolved the Ochrophyta lineages by increased support for several important nodes. Except for the positioning of Chrysophyceae, Eustigmatophyceae, Raphidophyceae and Pinguiophyceae, all main branches of Ochrophyta were resolved. Our results support the transfer of classes Dictyochophyceae and Pelagophyceae from subphylum Phaeista to Khakista. Based on all our trees, in combination with current knowledge about ultrastructure of heterokonts we suggest that a more advanced flagellar apparatus originated at one occasion in the ancestor of Phaeista whereas, Khakista independently reduced their flagellar apparatus and gained chlorophyll c(3).
Subject(s)
Eukaryotic Cells/classification , Genes , Phylogeny , Animals , DNA, Ribosomal/genetics , Molecular Sequence Data , Proteins/geneticsABSTRACT
BACKGROUND: Exposure to the dinoflagellate Pfiesteria has, under certain circumstances, been associated with deficits in human learning and memory. However, uncertainties remain about the health risk of chronic, low-level exposures (as seen among occupationally exposed commercial fishermen), particularly in light of studies suggesting that Pfiesteria strains are widespread in the estuarine environment in the U.S. mid-Atlantic region. METHODS: We selected an initial cohort of 152 persons, including 123 persons with regular, occupational exposure to the Chesapeake Bay ; 107 of the cohort members were followed for the full four summer "seasons" of the study. Cohort members were questioned biweekly about symptoms, and data were collected about the areas of the bay in which they worked. These latter data were matched with data on the presence or absence of Pfiesteria in each area, based on polymerase chain reaction analysis of > 3,500 water samples. Cohort members underwent neuropsychological testing at the beginning and end of each summer season. RESULTS: No correlation was found between work in an area where Pfiesteria was identified and specific symptomatology or changes on neuropsychological tests. CONCLUSIONS: Although high-level or outbreak-associated exposure to Pfiesteria species (or specific strains within a species) may have an effect on health, routine occupational exposure to estuarine environments in which these organisms are present does not appear to pose a significant health risk.
Subject(s)
Dinoflagellida/physiology , Occupational Exposure , Adult , Aged , Animals , Dinoflagellida/classification , Humans , Male , Maryland , Middle Aged , Oceans and Seas , Protozoan Infections/parasitology , Risk Factors , Rivers , Time Factors , VirginiaABSTRACT
Species within the class Raphidophyceae were associated with fish kill events in Japanese, European, Canadian, and U.S. coastal waters. Fish mortality was attributable to gill damage with exposure to reactive oxygen species (peroxide, superoxide, and hydroxide radicals), neurotoxins, physical clogging, and hemolytic substances. Morphological identification of these organisms in environmental water samples is difficult, particularly when fixatives are used. Because of this difficulty and the continued global emergence of these species in coastal estuarine waters, we initiated the development and validation of a suite of real-time polymerase chain reaction (PCR) assays. Sequencing was used to generate complete data sets for nuclear encoded small-subunit ribosomal RNA (SSU rRNA; 18S); internal transcribed spacers 1 and 2, 5.8S; and plastid encoded SSU rRNA (16S) for confirmed raphidophyte cultures from various geographic locations. Sequences for several Chattonella species (C. antiqua, C. marina, C. ovata, C. subsalsa, and C. verruculosa), Heterosigma akashiwo, and Fibrocapsa japonica were generated and used to design rapid and specific PCR assays for several species including C. verruculosa Hara et Chihara, C. subsalsa Biecheler, the complex comprised of C. marina Hara et Chihara, C. antiqua Ono and C. ovata, H. akashiwo Ono, and F. japonica Toriumi et Takano using appropriate loci. With this comprehensive data set, we were also able to perform phylogenetic analyses to determine the relationship between these species.
ABSTRACT
Complete small subunit ribosomal RNA, internal transcribed spacer 1 and 2, 5.8S, and partial large subunit ribosomal RNA gene sequences were generated from multiple isolates of Pfiesteria piscicida. Sequences were derived from isolates that have been shown to be ichthyotoxic as well as isolates that have no history of toxic behavior. All of the sequences generated were identical for the different cultures, and we therefore conclude that differences in toxicity seen between isolates of P. piscicida are linked to factors other than genetic strain variation detectable by ribosomal gene sequence analyses.