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Leptothrix ochracea creates distinctive iron-mineralized mats that carpet streams and wetlands. Easily recognized by its iron-mineralized sheaths, L. ochracea was one of the first microorganisms described in the 1800s. Yet it has never been isolated and does not have a complete genome sequence available, so key questions about its physiology remain unresolved. It is debated whether iron oxidation can be used for energy or growth and if L. ochracea is an autotroph, heterotroph, or mixotroph. To address these issues, we sampled L. ochracea-rich mats from three of its typical environments (a stream, wetlands, and a drainage channel) and reconstructed nine high-quality genomes of L. ochracea from metagenomes. These genomes contain iron oxidase genes cyc2 and mtoA, showing that L. ochracea has the potential to conserve energy from iron oxidation. Sox genes confer potential to oxidize sulfur for energy. There are genes for both carbon fixation (RuBisCO) and utilization of sugars and organic acids (acetate, lactate, and formate). In silico stoichiometric metabolic models further demonstrated the potential for growth using sugars and organic acids. Metatranscriptomes showed a high expression of genes for iron oxidation; aerobic respiration; and utilization of lactate, acetate, and sugars, as well as RuBisCO, supporting mixotrophic growth in the environment. In summary, our results suggest that L. ochracea has substantial metabolic flexibility. It is adapted to iron-rich, organic carbon-containing wetland niches, where it can thrive as a mixotrophic iron oxidizer by utilizing both iron oxidation and organics for energy generation and both inorganic and organic carbon for cell and sheath production. IMPORTANCE: Winogradsky's observations of L. ochracea led him to propose autotrophic iron oxidation as a new microbial metabolism, following his work on autotrophic sulfur-oxidizers. While much culture-based research has ensued, isolation proved elusive, so most work on L. ochracea has been based in the environment and in microcosms. Meanwhile, the autotrophic Gallionella became the model for freshwater microbial iron oxidation, while heterotrophic and mixotrophic iron oxidation is not well-studied. Ecological studies have shown that Leptothrix overtakes Gallionella when dissolved organic carbon content increases, demonstrating distinct niches. This study presents the first near-complete genomes of L. ochracea, which share some features with autotrophic iron oxidizers, while also incorporating heterotrophic metabolisms. These genome, metabolic modeling, and transcriptome results give us a detailed metabolic picture of how the organism may combine lithoautotrophy with organoheterotrophy to promote Fe oxidation and C cycling and drive many biogeochemical processes resulting from microbial growth and iron oxyhydroxide formation in wetlands.
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Phosphorus (P) limitation often constrains biological processes in Arctic tundra ecosystems. Although adsorption to soil minerals may limit P bioavailability and export from soils into aquatic systems, the contribution of mineral phases to P retention in Arctic tundra is poorly understood. Our objective was to use X-ray absorption spectroscopy to characterize P speciation and associations with soil minerals along hillslope toposequences and in undisturbed and disturbed low-lying wet sedge tundra on the North Slope, AK. Biogenic mats comprised of short-range ordered iron (Fe) oxyhydroxides were prevalent in undisturbed wet sedge meadows. Upland soils and pond sediments impacted by gravel mining or thermokarst lacked biogenic Fe mats and were comparatively iron poor. Phosphorus was primarily contained in organic compounds in hillslope soils but associated with Fe(III) oxyhydroxides in undisturbed wet sedge meadows and calcium (Ca) in disturbed pond sediments. We infer that phosphate mobilized through organic decomposition binds to Fe(III) oxyhydroxides in wet sedge, but these associations are disrupted by physical disturbance that removes Fe mats. Increasing disturbances of the Arctic tundra may continue to alter the mineralogical composition of soils at terrestrial-aquatic interfaces and binding mechanisms that could inhibit or promote transport of bioavailable P from soils to aquatic ecosystems.
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Hierro , Fósforo , Tundra , Fósforo/química , Regiones Árticas , Hierro/química , Ecosistema , Espectroscopía de Absorción de Rayos X , Suelo/química , Sedimentos Geológicos/químicaRESUMEN
Rates of microbial processes are fundamental to understanding the significance of microbial impacts on environmental chemical cycling. However, it is often difficult to quantify rates or to link processes to specific taxa or individual cells, especially in environments where there are few cultured representatives with known physiology. Here, we describe the use of the redox-enzyme-sensitive molecular probe RedoxSensor™ Green to measure rates of anaerobic electron transfer physiology (i.e., sulfate reduction and methanogenesis) in individual cells and link those measurements to genomic sequencing of the same single cells. We used this method to investigate microbial activity in hot, anoxic, low-biomass (~103 cells mL-1) groundwater of the Death Valley Regional Flow System, California. Combining this method with electron donor amendment experiments and metatranscriptomics confirmed that the abundant spore formers including Candidatus Desulforudis audaxviator were actively reducing sulfate in this environment, most likely with acetate and hydrogen as electron donors. Using this approach, we measured environmental sulfate reduction rates at 0.14 to 26.9 fmol cell-1 h-1. Scaled to volume, this equates to a bulk environmental rate of ~103 pmol sulfate L-1 d-1, similar to potential rates determined with radiotracer methods. Despite methane in the system, there was no evidence for active microbial methanogenesis at the time of sampling. Overall, this method is a powerful tool for estimating species-resolved, single-cell rates of anaerobic metabolism in low-biomass environments while simultaneously linking genomes to phenomes at the single-cell level. We reveal active elemental cycling conducted by several species, with a large portion attributable to Ca. Desulforudis audaxviator.
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Ecosistema , Ambiente , Transporte de Electrón , Sulfatos/química , Respiración de la CélulaRESUMEN
Importance: First-line treatment for posttraumatic stress disorder (PTSD) in the US Department of Veterans Affairs (VA), ie, trauma-focused therapy, while effective, is limited by low treatment initiation, high dropout, and high treatment refraction. Objective: To evaluate the effectiveness of Trauma Center Trauma-Sensitive Yoga (TCTSY) vs first-line cognitive processing therapy (CPT) in women veterans with PTSD related to military sexual trauma (MST) and the hypothesis that PTSD outcomes would differ between the interventions. Design, Setting, and Participants: This multisite randomized clinical trial was conducted from December 1, 2015, to April 30, 2022, within 2 VA health care systems located in the southeast and northwest. Women veterans aged 22 to 71 years with MST-related PTSD were enrolled and randomized to TCTSY or CPT. Interventions: The TCTSY intervention (Hatha-style yoga focusing on interoception and empowerment) consisted of 10 weekly, 60-minute group sessions, and the CPT intervention (cognitive-based therapy targeting modification of negative posttraumatic thoughts) consisted of 12 weekly, 90-minute group sessions. Main Outcome and Measures: Sociodemographic data were collected via self-report survey. The primary outcome, PTSD symptom severity, was assessed using the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) and PTSD Checklist for DSM-5 (PCL-5). Assessments were conducted at baseline, midintervention, 2 weeks post intervention, and 3 months post intervention. Results: Of 200 women veterans who consented to participate, the intent-to-treat sample comprised 131 participants (mean [SD] age, 48.2 [11.2] years), with 72 randomized to TCTSY and 59 randomized to CPT. Treatment was completed by 47 participants (65.3%) in the TCTSY group and 27 (45.8%) in the CPT group, a 42.6% higher treatment completion rate in the TCTSY group (P = .03). Both treatment groups improved over time on the CAPS-5 (mean [SD] scores at baseline: 36.73 [8.79] for TCTSY and 35.52 [7.49] for CPT; mean [SD] scores at 3 months: 24.03 [11.55] for TCTSY and 22.15 [13.56]) and the PCL-5 (mean [SD] scores at baseline: 49.62 [12.19] for TCTSY and 48.69 [13.62] for CPT; mean [SD] scores at 3 months: 36.97 [17.74] for TCTSY and 31.76 [12.47]) (P < .001 for time effects). None of the group effects or group-by-time effects were significant. Equivalence analyses of change scores were not significantly different between the TCTSY and CPT groups, and the two one-sided test intervals fell within the equivalence bounds of plus or minus 10 for CAPS-5 for all follow-up time points. Conclusions and Relevance: In this comparative effectiveness randomized clinical trial, TCTSY was equivalent to CPT in reducing PTSD symptom severity, with both groups improving significantly. The higher treatment completion rate for TCTSY indicates its higher acceptability as an effective and acceptable PTSD treatment for women veterans with PTSD related to MST that could address current VA PTSD treatment limitations. Trial Registration: ClinicalTrials.gov Identifier: NCT02640690.
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Terapia Cognitivo-Conductual , Trastornos por Estrés Postraumático , Yoga , Adulto , Anciano , Femenino , Humanos , Persona de Mediana Edad , Adulto Joven , Trauma Sexual Militar , Trastornos por Estrés Postraumático/psicología , Resultado del TratamientoRESUMEN
Water logged habitats in continuous permafrost regions provide extensive oxic-anoxic interface habitats for iron cycling. The iron cycle interacts with the methane and phosphorus cycles, and is an important part of tundra biogeochemistry. Our objective was to characterize microbial communities associated with the iron cycle within natural and disturbed habitats of the Alaskan Arctic tundra. We sampled aquatic habitats within natural, undisturbed and anthropogenically disturbed areas and sequenced the 16S rRNA gene to describe the microbial communities, then supported these results with process rate and geochemical measurements. Undisturbed habitats have microbial communities that are significantly different than disturbed habitats. Microbial taxa known to participate in the iron and methane cycles are significantly associated with natural habitats, whereas they are not significantly associated with disturbed sites. Undisturbed habitats have significantly higher extractable iron and are more acidic than disturbed habitats sampled. Iron reduction is not measurable in disturbed aquatic habitats and is not stimulated by the addition of biogenic iron mats. Our study highlights the prevalence of Fe-cycling in undisturbed water-logged habitats, and demonstrates that anthropogenic disturbance of the tundra, due to legacy gravel mining, alters the microbiology of aquatic habitats and disrupts important biogeochemical cycles in the Arctic tundra.
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Hierro , Microbiota , Agua , ARN Ribosómico 16S/genética , Tundra , Metano , Regiones ÁrticasRESUMEN
This study's purpose is to examine whether resilience, conceptualized by Connor and Davidson (2003) as one's capacity to persevere and rebound under adversity, was a potential mitigating and/or moderating factor in the dynamic between both psychological distress and academic burnout, and student attrition. We concurrently distributed a survey containing a series of psychometric instruments to a convenience sample of 1,119 students pursuing various business majors at four geographically diverse U.S. universities. Via structural equations modeling analysis, we measured the associations between psychological distress, academic burnout, and departure intentions, and investigated whether student resilience levels are associated with lower distress, burnout, and departure intentions levels. The results indicated significant positive associations between psychological distress and each of the elements of academic burnout, and significant positive associations between the academic burnout elements and departure intentions. However, while resilience did not moderate those associations, it did attenuate them through its direct negative associations with both psychological distress and the cynicism and academic inefficacy elements of academic burnout. Based on these findings, we discuss implications for business educators seeking to enhance individual resilience levels as a coping strategy to combat voluntary student turnover, and better prepare students for the demands of the workplace.
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The ocean-atmosphere exchange of CO2 largely depends on the balance between marine microbial photosynthesis and respiration. Despite vast taxonomic and metabolic diversity among marine planktonic bacteria and archaea (prokaryoplankton)1-3, their respiration usually is measured in bulk and treated as a 'black box' in global biogeochemical models4; this limits the mechanistic understanding of the global carbon cycle. Here, using a technology for integrated phenotype analyses and genomic sequencing of individual microbial cells, we show that cell-specific respiration rates differ by more than 1,000× among prokaryoplankton genera. The majority of respiration was found to be performed by minority members of prokaryoplankton (including the Roseobacter cluster), whereas cells of the most prevalent lineages (including Pelagibacter and SAR86) had extremely low respiration rates. The decoupling of respiration rates from abundance among lineages, elevated counts of proteorhodopsin transcripts in Pelagibacter and SAR86 cells and elevated respiration of SAR86 at night indicate that proteorhodopsin-based phototrophy3,5-7 probably constitutes an important source of energy to prokaryoplankton and may increase growth efficiency. These findings suggest that the dependence of prokaryoplankton on respiration and remineralization of phytoplankton-derived organic carbon into CO2 for its energy demands and growth may be lower than commonly assumed and variable among lineages.
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Organismos Acuáticos , Archaea , Bacterias , Ciclo del Carbono , Respiración de la Célula , Plancton , Alphaproteobacteria/genética , Alphaproteobacteria/crecimiento & desarrollo , Alphaproteobacteria/metabolismo , Bacterias/clasificación , Bacterias/genética , Bacterias/crecimiento & desarrollo , Bacterias/metabolismo , Dióxido de Carbono/metabolismo , Plancton/clasificación , Plancton/genética , Plancton/crecimiento & desarrollo , Plancton/metabolismo , Agua de Mar/microbiología , Organismos Acuáticos/clasificación , Organismos Acuáticos/genética , Organismos Acuáticos/crecimiento & desarrollo , Organismos Acuáticos/metabolismo , Archaea/genética , Archaea/crecimiento & desarrollo , Archaea/metabolismo , Respiración de la Célula/fisiología , FotosíntesisRESUMEN
OBJECTIVE: Using a battery of preclinical tests to support development of a light-based treatment for COVID-19, establish a range of 425 nm light doses that are non-hazardous to the tissues of the oral cavity and assess whether a 425 nm light dose in this non-hazardous range can inactivate SARS-CoV-2 in artificial saliva. METHODS: The potential hazards to oral tissues associated with a range of acute 425 nm light doses were assessed using a battery of four preclinical tests: (1) cytotoxicity, using well-differentiated human large airway and buccal epithelial models; (2) toxicity to commensal oral bacteria, using a panel of model organisms; (3) light-induced histopathological changes, using ex vivo porcine esophageal tissue, and (4) thermal damage, by dosing the oropharynx of intact porcine head specimens. Then, 425 nm light doses established as non-hazardous using these tests were evaluated for their potential to inactivate SARS-CoV-2 in artificial saliva. RESULTS: A dose range was established at which 425 nm light is not cytotoxic in well-differentiated human large airway or buccal epithelial models, is not cytotoxic to a panel of commensal oral bacteria, does not induce histopathological damage in ex vivo porcine esophageal tissue, and does not induce thermal damage to the oropharynx of intact porcine head specimens. Using these tests, no hazards were observed for 425 nm light doses less than 63 J/cm2 delivered at irradiance less than 200 mW/cm2. A non-hazardous 425 nm light dose in this range (30 J/cm2 at 50 mW/cm2) was shown to inactivate SARS-CoV-2 in vitro in artificial saliva. CONCLUSION: Preclinical hazard assessments and SARS-CoV-2 inactivation efficacy testing were combined to guide the development of a 425 nm light-based treatment for COVID-19. CLINICAL SIGNIFICANCE: The process used here to evaluate the potential hazards associated with 425 nm acute light dosing of the oral cavity to treat COVID-19 can be extended to other wavelengths, anatomical targets, and therapeutic applications to accelerate the development of novel photomedicine treatments.
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COVID-19 , SARS-CoV-2 , Animales , Humanos , Boca , Orofaringe , Saliva , Saliva Artificial , PorcinosRESUMEN
OBJECTIVES: Antiviral treatments for early intervention in patients with mild-to-moderate COVID-19 are needed as a complement to vaccination. We sought to estimate the impact on COVID-19 cases, deaths, and direct healthcare costs over 12 months following introduction of a novel, antiviral treatment, RD-X19, a light-based, at-home intervention designed for the treatment of mild-to-moderate COVID-19 infection. METHODS: A time-dependent, state transition (semi-Markov) cohort model was developed to simulate infection progression in individuals with COVID-19 in 3 US states with varying levels of vaccine uptake (Alabama, North Carolina, and Massachusetts) and at the national level between 1 June 2020 and 31 May 2021. The hypothetical cohort of patients entering the model progressed through subsequent health states after infection. Costs were assigned to each health state. Number of infections/vaccinations per day were incorporated into the model. Simulations were run to estimate outcomes (cases by severity, deaths, and direct healthcare costs) at various levels of adoption of RD-X19 (5%, 10%, 25%) in eligible infected individuals at the state and national levels and across three levels of clinical benefit based on the results from an early feasibility study of RD-X19. The clinical benefit reflects a decline in the duration of symptomatic disease by 1.2, 2.4 (base case), and 3.6 days. RESULTS: In the base case analysis with 10% adoption, simulated infections/deaths/direct healthcare costs were reduced by 10,059/275/$69 million in Alabama, 21,092/545/$135 million in North Carolina, and 16,670/415/$102 million in Massachusetts over 12 months. At the national level, 10% adoption reduced total infections/deaths/direct healthcare costs by 686,722/17,748/$4.41 billion. CONCLUSION: At-home, antiviral treatment with RD-X19 or other interventions with similar efficacy that decrease both symptomatic days and transmission probabilities can be used in concert with vaccines to reduce COVID-19 cases, deaths, and direct healthcare costs.
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COVID-19 , Antivirales/uso terapéutico , Análisis Costo-Beneficio , Costos de la Atención en Salud , Humanos , VacunaciónRESUMEN
Redox active species in Arctic lacustrine sediments play an important, regulatory role in the carbon cycle, yet there is little information on their spatial distribution, abundance, and oxidation states. Here, we use voltammetric microelectrodes to quantify the in situ concentrations of redox-active species at high vertical resolution (mm to cm) in the benthic porewaters of an oligotrophic Arctic lake (Toolik Lake, AK, USA). Mn(II), Fe(II), O2, and Fe(III)-organic complexes were detected as the major redox-active species in these porewaters, indicating both Fe(II) oxidation and reductive dissolution of Fe(III) and Mn(IV) minerals. We observed significant spatial heterogeneity in their abundance and distribution as a function of both location within the lake and depth. Microbiological analyses and solid phase Fe(III) measurements were performed in one of the Toolik Lake cores to determine the relationship between biogeochemical redox gradients and microbial communities. Our data reveal iron cycling involving both oxidizing (FeOB) and reducing (FeRB) bacteria. Additionally, we profiled a large microbial iron mat in a tundra seep adjacent to an Arctic stream (Oksrukuyik Creek) where we observed Fe(II) and soluble Fe(III) in a highly reducing environment. The variable distribution of redox-active substances at all the sites yields insights into the nature and distribution of the important terminal electron acceptors in both lacustrine and tundra environments capable of exerting significant influences on the carbon cycle.
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Compuestos Férricos , Lagos , Bacterias , Hierro/análisis , Lagos/microbiología , Oxidación-ReducciónRESUMEN
The RD-X19 is an investigational, handheld medical device precisely engineered to emit blue light through the oral cavity to target the oropharynx and surrounding tissues. At doses shown to be noncytotoxic in an in vitro three-dimensional human epithelial tissue model, the monochromatic visible light delivered by RD-X19 results in light-initiated expression of immune stimulating cytokines IL-1α and IL-1ß, with corresponding inhibition of severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) replication. A single exposure of 425 nm blue light at 60 J/cm2 led to greater than 99% reductions against all SARS-CoV-2 strains tested in vitro, including the more transmissible (Alpha) and immune evasive (Beta) variants. These preclinical findings along with other studies led to a randomized, double-blind, sham-controlled early feasibility study using the investigational device as a treatment for outpatients with mild to moderate coronavirus disease 2019 (COVID-19). The study enrolled 31 subjects with a positive SARS-CoV-2 antigen test and at least two moderate COVID-19 signs and symptoms at baseline. Subjects were randomized 2:1 (RD-X19: sham) and treated twice daily for 4 days. Efficacy outcome measures included assessments of SARS-CoV-2 saliva viral load and clinical assessments of COVID-19. There were no local application site reactions and no device-related adverse events. At the end of the study (day 8), the mean change in log10 viral load was -3.29 for RD-X19 and -1.81 for sham, demonstrating a treatment benefit of -1.48 logs (95% confidence internal, -2.88 to -0.071, nominal p = 0.040). Among the clinical outcome measures, differences between RD-X19 and sham were also observed, with a 57-h reduction of median time to sustained resolution of COVID-19 signs and symptoms (log rank test, nominal p = 0.044).
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COVID-19 , Estudios de Factibilidad , Humanos , Pacientes Ambulatorios , SARS-CoV-2 , Resultado del Tratamiento , Carga ViralRESUMEN
The emergence of SARS-CoV-2 variants that evade host immune responses has prolonged the COVID-19 pandemic. Thus, the development of an efficacious, variant-agnostic therapeutic for the treatment of early SARS-CoV-2 infection would help reduce global health and economic burdens. Visible light therapy has the potential to fill these gaps. In this study, visible blue light centered around 425 nm efficiently inactivated SARS-CoV-2 variants in cell-free suspensions and in a translationally relevant well-differentiated tissue model of the human large airway. Specifically, 425 nm light inactivated cell-free SARS-CoV-2 variants Alpha, Beta, Delta, Gamma, Lambda, and Omicron by up to 99.99% in a dose-dependent manner, while the monoclonal antibody bamlanivimab did not neutralize the Beta, Delta, and Gamma variants. Further, we observed that 425 nm light reduced virus binding to host ACE-2 receptor and limited viral entry to host cells in vitro . Further, the twice daily administration of 32 J/cm 2 of 425 nm light for three days reduced infectious SARS-CoV-2 Beta and Delta variants by >99.99% in human airway models when dosing began during the early stages of infection. In more established infections, logarithmic reductions of infectious Beta and Delta titers were observed using the same dosing regimen. Finally, we demonstrated that the 425 nm dosing regimen was well-tolerated by the large airway tissue model. Our results indicate that blue light therapy has the potential to lead to a well-tolerated and variant-agnostic countermeasure against COVID-19.
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The purpose of the present study was to adapt and pilot a trauma-informed, mindfulness-based yoga (TIMBY) intervention focused on enhancing self-regulation among youth in the Georgia Department of Juvenile Justice system. In this article we (1) describe the process by which we systematically adapted an evidence-based protocol specifically for this population, (2) describe the nature of and rationale for those adaptations, (3) present some preliminary qualitative findings based on interviews with youth participants, and (4) briefly summarize how the adapted protocol will be evaluated in the subsequent feasibility trial. The iterative drafting and revision process involved modifications to a well-established, protocolized Trauma-Informed Yoga program and was identified by the project advisory board and t h rough formal interviews with intervention staff. Qualitative interviews were conducted with youth participants concerning intervention impact, credibility, and satisfaction. Several needed modifications were identified so that the intervention would be contextually appropriate for justice-involved youth. Thirty youth were enrolled in the pilot study: 77% we re Non - Hispanic Black/African-American, 18% were Non-Hispanic White, and 5% were Hispanic White. The average age was 16.45 years (range 14-20). The youth consistently reported satisfaction with the sessions and positive beliefs about how the sessions were helping them with a range of physical and psychological/ emotional challenges. Adaptations to the protocol in the present study highlight how mindfulness-based interventions for justice-involved youth need to consider what is both developmentally suitable for youth and appropriate in a justice setting. A feasibility study using this revised TIMBY protocol is underway at four Georgia Department of Juvenile Justice facilities to formally identify the barriers and facilitators to implementation for the present study and a future, larger-scale trial.
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Meditación , Atención Plena , Yoga , Adolescente , Estudios de Factibilidad , Humanos , Proyectos Piloto , Adulto JovenRESUMEN
The delivery of safe, visible wavelengths of light can be an effective, pathogen-agnostic, countermeasure that would expand the current portfolio of SARS-CoV-2 intervention strategies beyond the conventional approaches of vaccine, antibody, and antiviral therapeutics. Employing custom biological light units, that incorporate optically engineered light-emitting diode (LED) arrays, we harnessed monochromatic wavelengths of light for uniform delivery across biological surfaces. We demonstrated that primary 3D human tracheal/bronchial-derived epithelial tissues tolerated high doses of a narrow spectral band of visible light centered at a peak wavelength of 425 nm. We extended these studies to Vero E6 cells to understand how light may influence the viability of a mammalian cell line conventionally used for assaying SARS-CoV-2. The exposure of single-cell monolayers of Vero E6 cells to similar doses of 425 nm blue light resulted in viabilities that were dependent on dose and cell density. Doses of 425 nm blue light that are well-tolerated by Vero E6 cells also inhibited infection and replication of cell-associated SARS-CoV-2 by > 99% 24 h post-infection after a single five-minute light exposure. Moreover, the 425 nm blue light inactivated cell-free betacoronaviruses including SARS-CoV-1, MERS-CoV, and SARS-CoV-2 up to 99.99% in a dose-dependent manner. Importantly, clinically applicable doses of 425 nm blue light dramatically inhibited SARS-CoV-2 infection and replication in primary human 3D tracheal/bronchial tissue. Safe doses of visible light should be considered part of the strategic portfolio for the development of SARS-CoV-2 therapeutic countermeasures to mitigate coronavirus disease 2019 (COVID-19).
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Tratamiento Farmacológico de COVID-19 , COVID-19/prevención & control , Luz , SARS-CoV-2 , Tráquea/efectos de la radiación , Replicación Viral/efectos de la radiación , Adulto , Animales , Antivirales/farmacología , Bronquios , Calibración , Sistema Libre de Células , Chlorocebus aethiops , Epitelio/patología , Femenino , Humanos , Mucosa Respiratoria/efectos de la radiación , Tráquea/virología , Células VeroRESUMEN
Twisted stalks are morphologically unique bacterial extracellular organo-metallic structures containing Fe(III) oxyhydroxides that are produced by microaerophilic Fe(II)-oxidizers belonging to the Betaproteobacteria and Zetaproteobacteria. Understanding the underlying genetic and physiological mechanisms of stalk formation is of great interest based on their potential as novel biogenic nanomaterials and their relevance as putative biomarkers for microbial Fe(II) oxidation on ancient Earth. Despite the recognition of these special biominerals for over 150 years, the genetic foundation for the stalk phenotype has remained unresolved. Here we present a candidate gene cluster for the biosynthesis and secretion of the stalk organic matrix that we identified with a trait-based analyses of a pan-genome comprising 16 Zetaproteobacteria isolate genomes. The "stalk formation in Zetaproteobacteria" (sfz) cluster comprises six genes (sfz1-sfz6), of which sfz1 and sfz2 were predicted with functions in exopolysaccharide synthesis, regulation, and export, sfz4 and sfz6 with functions in cell wall synthesis manipulation and carbohydrate hydrolysis, and sfz3 and sfz5 with unknown functions. The stalk-forming Betaproteobacteria Ferriphaselus R-1 and OYT-1, as well as dread-forming Zetaproteobacteria Mariprofundus aestuarium CP-5 and Mariprofundus ferrinatatus CP-8 contain distant sfz gene homologs, whereas stalk-less Zetaproteobacteria and Betaproteobacteria lack the entire gene cluster. Our pan-genome analysis further revealed a significant enrichment of clusters of orthologous groups (COGs) across all Zetaproteobacteria isolate genomes that are associated with the regulation of a switch between sessile and motile growth controlled by the intracellular signaling molecule c-di-GMP. Potential interactions between stalk-former unique transcription factor genes, sfz genes, and c-di-GMP point toward a c-di-GMP regulated surface attachment function of stalks during sessile growth.
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OBJECTIVE: This study is a follow-up to van der Kolk et al. (2014), a trial conducted through the Trauma Center at Justice Resource Institute, which demonstrated treatment efficacy and remains the only randomized controlled trial of trauma-sensitive yoga. The present process study extends the outcomes study by examining treatment moderators of the original trial. METHOD: Sixty-four women with childhood interpersonal trauma histories and posttraumatic stress disorder participated in the interventions: Trauma Center Trauma-Sensitive Yoga (TCTSY) versus active control (women's health education). Analyses explored if adult-onset interpersonal trauma and baseline psychological measures (clinician-rated and self-reported PTSD, dissociation, depression, psychological functioning) moderated PTSD changes. RESULTS: Three of six measures had small effects in moderating the relationship between adult-onset interpersonal trauma and TCTSY efficacy, in which TCTSY was most efficacious for those with fewer adult-onset interpersonal traumas. Within this subgroup, various levels of all baseline measures except depression indicated that TCTSY was more effective in reducing PTSD than the active control condition. CONCLUSIONS: By delineating client characteristics most associated with PTSD improvements, practitioners may best target yoga interventions to increase effectiveness. (PsycInfo Database Record (c) 2020 APA, all rights reserved).
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Trastornos por Estrés Postraumático/psicología , Trastornos por Estrés Postraumático/terapia , Yoga/psicología , Adulto , Femenino , Humanos , Resultado del TratamientoRESUMEN
The assembly of single-amplified genomes (SAGs) and metagenome-assembled genomes (MAGs) has led to a surge in genome-based discoveries of members affiliated with Archaea and Bacteria, bringing with it a need to develop guidelines for nomenclature of uncultivated microorganisms. The International Code of Nomenclature of Prokaryotes (ICNP) only recognizes cultures as 'type material', thereby preventing the naming of uncultivated organisms. In this Consensus Statement, we propose two potential paths to solve this nomenclatural conundrum. One option is the adoption of previously proposed modifications to the ICNP to recognize DNA sequences as acceptable type material; the other option creates a nomenclatural code for uncultivated Archaea and Bacteria that could eventually be merged with the ICNP in the future. Regardless of the path taken, we believe that action is needed now within the scientific community to develop consistent rules for nomenclature of uncultivated taxa in order to provide clarity and stability, and to effectively communicate microbial diversity.
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Archaea/clasificación , Bacterias/clasificación , Archaea/genética , Bacterias/genética , ADN Bacteriano , Metagenoma , Filogenia , Células Procariotas/clasificación , Análisis de Secuencia de ADN , Terminología como AsuntoRESUMEN
Understanding ion transport mechanisms in the flow expansion section of the first vacuum region of a mass spectrometer (MS) with an atmospheric pressure ionization source is essential for optimizing the MS sampling interface design. In this study, numerical simulations of three types of ions in two different MS interface designs have been carried out. In contrast to previously reported numerical studies, nonequilibrium gas dynamics due to rarefied gas effects has been considered in modeling the flow expansion and a realistic space charge effect has been considered in a continuous ion injection mode. Numerical simulations reveal that a flat plate interface has a higher peak buffer gas velocity but a narrower zone of silence compared to the conical interface. Shock wave structures are clearly captured, and the Knudsen number distribution is displayed. Simulation results show that in the axial direction the buffer gas effect is much stronger than the electric force effect in the current configuration. The conical interface leads to both a strong ion acceleration in the zone of silence and a strong ion deceleration downstream. In the radial direction, both the electric force and buffer gas drag force play an important role. The conical interface introduces a relatively stronger ion focusing effect from the radial buffer gas effect and a stronger ion dispersion from the radial electric force than the flat plate interface. The net effect for the current configuration is an increase in ion losses for the conical interface. Nanoelectrospray ionization experiments were carried out to validate the ion transmission efficiency.
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Red mineral pigment use is recognized as a fundamental component of a series of traits associated with human evolutionary development, social interaction, and behavioral complexity. Iron-enriched mineral deposits have been collected and prepared as pigment for use in rock art, personal adornment, and mortuary practices for millennia, yet little is known about early developments in mineral processing techniques in North America. Microanalysis of rock art pigments from the North American Pacific Northwest reveals a sophisticated use of iron oxide produced by the biomineralizing bacterium Leptothrix ochracea; a keystone species of chemolithotroph recognized in recent advances in the development of thermostable, colorfast biomaterial pigments. Here we show evidence for human engagement with this bacterium, including nanostructural and magnetic properties evident of thermal enhancement, indicating that controlled use of pyrotechnology was a key feature of how biogenic iron oxides were prepared into paint. Our results demonstrate that hunter-gatherers in this area of study prepared pigments by harvesting aquatic microbial iron mats dominated by iron-oxidizing bacteria, which were subsequently heated in large open hearths at a controlled range of 750 °C to 850 °C. This technical gesture was performed to enhance color properties, and increase colorfastness and resistance to degradation. This skilled production of highly thermostable and long-lasting rock art paint represents a specialized technological innovation. Our results contribute to a growing body of knowledge on historical-ecological resource use practices in the Pacific Northwest during the Late Holocene.Figshare link to figures: https://figshare.com/s/9392a0081632c20e9484.