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1.
Respir Res ; 25(1): 180, 2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38664797

RESUMEN

BACKGROUND: Pulmonary ionocytes have been identified in the airway epithelium as a small population of ion transporting cells expressing high levels of CFTR (cystic fibrosis transmembrane conductance regulator), the gene mutated in cystic fibrosis. By providing an infinite source of airway epithelial cells (AECs), the use of human induced pluripotent stem cells (hiPSCs) could overcome some challenges of studying ionocytes. However, the production of AEC epithelia containing ionocytes from hiPSCs has proven difficult. Here, we present a platform to produce hiPSC-derived AECs (hiPSC-AECs) including ionocytes and investigate their role in the airway epithelium. METHODS: hiPSCs were differentiated into lung progenitors, which were expanded as 3D organoids and matured by air-liquid interface culture as polarised hiPSC-AEC epithelia. Using CRISPR/Cas9 technology, we generated a hiPSCs knockout (KO) for FOXI1, a transcription factor that is essential for ionocyte specification. Differences between FOXI1 KO hiPSC-AECs and their wild-type (WT) isogenic controls were investigated by assessing gene and protein expression, epithelial composition, cilia coverage and motility, pH and transepithelial barrier properties. RESULTS: Mature hiPSC-AEC epithelia contained basal cells, secretory cells, ciliated cells with motile cilia, pulmonary neuroendocrine cells (PNECs) and ionocytes. There was no difference between FOXI1 WT and KO hiPSCs in terms of their capacity to differentiate into airway progenitors. However, FOXI1 KO led to mature hiPSC-AEC epithelia without ionocytes with reduced capacity to produce ciliated cells. CONCLUSION: Our results suggest that ionocytes could have role beyond transepithelial ion transport by regulating epithelial properties and homeostasis in the airway epithelium.


Asunto(s)
Células Madre Pluripotentes Inducidas , Mucosa Respiratoria , Humanos , Células Madre Pluripotentes Inducidas/metabolismo , Mucosa Respiratoria/metabolismo , Mucosa Respiratoria/citología , Diferenciación Celular/fisiología , Células Cultivadas , Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismo , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Células Epiteliales/metabolismo , Organoides/metabolismo
2.
Br J Dermatol ; 190(5): 617-627, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38149939

RESUMEN

Patients living with inherited skin diseases have benefited from recent advances in DNA sequencing technologies that provide new or improved diagnostics. However, developing and delivering new treatments for the 'genodermatoses' remains challenging. The goal of creating topical preparations that can recover the inherent gene pathology remains largely aspirational. However, recent progress in two fields - the chemistry of topical delivery formulations (lipid nanoparticles) and the molecular biology of gene repair (CRISPR-Cas9, base and prime editing) - presents new opportunities to address this unmet need. In this review, we discuss how lipid nanoparticle delivery vehicles could be used to deliver gene-editing tools to formulate topical 'gene creams' suitable for the treatment of genodermatoses. We summarize the historical landscape of topical therapeutics and advances in gene editing that may herald an era of new therapies for patients with inherited skin disorders.


Asunto(s)
Liposomas , Nanopartículas , Enfermedades Cutáneas Genéticas , Humanos , Edición Génica , Sistemas CRISPR-Cas , Técnicas de Transferencia de Gen , Enfermedades Cutáneas Genéticas/genética
3.
J Appl Microbiol ; 133(6): 3768-3776, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36106419

RESUMEN

AIMS: We compared the bacterial endophytic communities of three genetically different almond cultivars that were all grafted on the same type of rootstock, growing side by side within a commercial orchard. METHODS AND RESULTS: We examined the diversity of leaf bacterial endophytes using cultivation-independent techniques and assessed the relative abundance of bacterial families. Two of these three cultivars were dominated by Pseudomonadaceae, while the bacterial composition of the third cultivar consisted mainly of Streptococcaceae. CONCLUSIONS: The experimental set up allowed us to analyse the impact of the shoot cultivar on endophytes, minimizing the influence of rootstock, biogeography, and cultivation status. Our data suggest that the shoot cultivar can shape the leaf endophytic community composition of almond trees. SIGNIFICANCE AND IMPACT OF THE STUDY: Our results suggest that the shoot cultivar controls the composition of the foliar bacterial endophytic community of almonds. Overall, our results could provide a first step to develop strategies for a more sustainable almond agriculture.


Asunto(s)
Endófitos , Microbiota , Prunus dulcis , Bacterias/genética , Endófitos/genética , Microbiota/genética , Hojas de la Planta/microbiología , Prunus dulcis/microbiología
4.
Proc Natl Acad Sci U S A ; 116(14): 6891-6896, 2019 04 02.
Artículo en Inglés | MEDLINE | ID: mdl-30877251

RESUMEN

Belowground organisms play critical roles in maintaining multiple ecosystem processes, including plant productivity, decomposition, and nutrient cycling. Despite their importance, however, we have a limited understanding of how and why belowground biodiversity (bacteria, fungi, protists, and invertebrates) may change as soils develop over centuries to millennia (pedogenesis). Moreover, it is unclear whether belowground biodiversity changes during pedogenesis are similar to the patterns observed for aboveground plant diversity. Here we evaluated the roles of resource availability, nutrient stoichiometry, and soil abiotic factors in driving belowground biodiversity across 16 soil chronosequences (from centuries to millennia) spanning a wide range of globally distributed ecosystem types. Changes in belowground biodiversity during pedogenesis followed two main patterns. In lower-productivity ecosystems (i.e., drier and colder), increases in belowground biodiversity tracked increases in plant cover. In more productive ecosystems (i.e., wetter and warmer), increased acidification during pedogenesis was associated with declines in belowground biodiversity. Changes in the diversity of bacteria, fungi, protists, and invertebrates with pedogenesis were strongly and positively correlated worldwide, highlighting that belowground biodiversity shares similar ecological drivers as soils and ecosystems develop. In general, temporal changes in aboveground plant diversity and belowground biodiversity were not correlated, challenging the common perception that belowground biodiversity should follow similar patterns to those of plant diversity during ecosystem development. Taken together, our findings provide evidence that ecological patterns in belowground biodiversity are predictable across major globally distributed ecosystem types and suggest that shifts in plant cover and soil acidification during ecosystem development are associated with changes in belowground biodiversity over centuries to millennia.


Asunto(s)
Biodiversidad , Modelos Biológicos
5.
J Pers Assess ; 104(6): 711-722, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34739345

RESUMEN

The Comprehensive Assessment of Psychopathic Personality Symptom Rating Scale (CAPP SRS) is a relatively new measure of psychopathic personality disorder (PPD) based on the CAPP concept map of psychopathy. To investigate the CAPP SRS, we identified the most plausible formal test structure for the test using the framework proposed by Slaney and Maraun, identified an appropriate quantitative characterization of that test structure, and then statistically evaluated it based on analysis of CAPP SRS data collected from a multisite sample of 314 adult male correctional offenders and secure hospital patients in Scotland and England. Overall, the CAPP SRS survived falsification when observed test data were compared to expectations based on the unidimensional monotone latent variable or UMLV model of Holland and Rosenbaum. CAPP SRS composite scores calculated consistent with the UMLV model had good measurement precision and good external validity with respect to scores on an established test of PPD. The findings provide provisional support for the test validity of the CAPP SRS and highlight the importance of theory-driven evaluations of test validity.


Asunto(s)
Criminales , Determinación de la Personalidad , Adulto , Humanos , Masculino , Trastorno de Personalidad Antisocial/diagnóstico , Psicometría/métodos , Pacientes Internos
6.
Adv Funct Mater ; 31(37): 2104843, 2021 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-35712226

RESUMEN

The authors aim to develop siRNA therapeutics for cancer that can be administered systemically to target tumors and retard their growth. The efficacy of systemic delivery of siRNA to tumors with nanoparticles based on lipids or polymers is often compromised by their rapid clearance from the circulation by the liver. Here, multifunctional cationic and anionic siRNA nanoparticle formulations are described, termed receptor-targeted nanocomplexes (RTNs), that comprise peptides for siRNA packaging into nanoparticles and receptor-mediated cell uptake, together with lipids that confer nanoparticles with stealth properties to enhance stability in the circulation, and fusogenic properties to enhance endosomal release within the cell. Intravenous administration of RTNs in mice leads to predominant accumulation in xenograft tumors, with very little detected in the liver, lung, or spleen. Although non-targeted RTNs also enter the tumor, cell uptake appears to be RGD peptide-dependent indicating integrin-mediated uptake. RTNs with siRNA against MYCN (a member of the Myc family of transcription factors) in mice with MYCN-amplified neuroblastoma tumors show significant retardation of xenograft tumor growth and enhanced survival. This study shows that RTN formulations can achieve specific tumor-targeting, with minimal clearance by the liver and so enable delivery of tumor-targeted siRNA therapeutics.

7.
Eur Respir J ; 58(4)2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-33795320

RESUMEN

BACKGROUND: Development of therapeutic approaches for rare respiratory diseases is hampered by the lack of systems that allow medium-to-high-throughput screening of fully differentiated respiratory epithelium from affected patients. This is a particular problem for primary ciliary dyskinesia (PCD), a rare genetic disease caused by mutations in genes that adversely affect ciliary movement and consequently mucociliary transport. Primary cell culture of basal epithelial cells from nasal brush biopsies followed by ciliated differentiation at the air-liquid interface (ALI) has proven to be a useful tool in PCD diagnostics but the technique's broader utility, including in pre-clinical PCD research, has been restricted by the limited number of basal cells that can be expanded from such biopsies. METHODS: We describe an immunofluorescence screening method, enabled by extensive expansion of basal cells from PCD patients and the directed differentiation of these cells into ciliated epithelium in miniaturised 96-well transwell format ALI cultures. As proof-of-principle, we performed a personalised investigation in a patient with a rare and severe form of PCD (reduced generation of motile cilia), in this case caused by a homozygous nonsense mutation in the MCIDAS gene. RESULTS: Initial analyses of ciliary ultrastructure, beat pattern and beat frequency in the 96-well transwell format ALI cultures indicate that a range of different PCD defects can be retained in these cultures. The screening system in our proof-of-principal investigation allowed drugs that induce translational readthrough to be evaluated alone or in combination with nonsense-mediated decay inhibitors. We observed restoration of basal body formation but not the generation of cilia in the patient's nasal epithelial cells in vitro. CONCLUSION: Our study provides a platform for higher throughput analyses of airway epithelia that is applicable in a range of settings and suggests novel avenues for drug evaluation and development in PCD caused by nonsense mutations.


Asunto(s)
Trastornos de la Motilidad Ciliar , Síndrome de Kartagener , Cilios , Trastornos de la Motilidad Ciliar/diagnóstico , Trastornos de la Motilidad Ciliar/tratamiento farmacológico , Trastornos de la Motilidad Ciliar/genética , Evaluación Preclínica de Medicamentos , Ensayos Analíticos de Alto Rendimiento , Humanos , Síndrome de Kartagener/diagnóstico , Síndrome de Kartagener/tratamiento farmacológico , Síndrome de Kartagener/genética , Depuración Mucociliar
8.
J Pediatr ; 236: 101-107.e3, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34000283

RESUMEN

OBJECTIVE: To determine the risk factors for acquiring a respiratory syncytial virus (RSV) and vaccine-preventable infections (R/VPI) in pediatric heart transplant recipients and the associated morbidity and hospital resource use. STUDY DESIGN: Patients <18 years who underwent heart transplantation from September 2003 to December 2018 at hospitals using the Pediatric Health Information System database were identified. Their transplant hospitalization and subsequent hospitalizations for R/VPI through December 2018 were analyzed. Risk factors for R/VPI hospitalizations were evaluated using negative regression binomial models adjusted for demographic and clinical confounders. Total hospital costs were adjusted for 2018 US$. RESULTS: Of 3815 transplant recipients, 681 (17.9%) had an R/VPI hospitalization during 23 746 available person-years of follow-up. There were 984 R/VPIs diagnosed during 951 hospitalizations, and 440 (44.7%) occurred the first year after transplantation. The most common causes were RSV (n = 380; 38.6%), influenza (n = 265; 26.9%), and pneumococcus (n = 105; 10.7%). In adjusted analyses, there was an increased risk of R/VPI hospitalization in patients requiring mechanical circulatory support before transplantation, patients receiving induction with ≥2 immunosuppressive agents, and patients <2 years in the first year after transplantation. The median length of stay for an R/VPI hospitalization was 4 days (IQR, 2-8 days) with a median total cost of $11 081 (IQR, $6215-$24 322). CONCLUSIONS: Hospitalization for R/VPIs occurred frequently after heart transplantation and were associated with significant costs. Potential strategies to minimize R/VPI include expanding vaccine use through accelerated immunization schedules, further studies of use of palivizumab beyond 2 years of age, and immunogenicity monitoring after vaccination with re-immunization based on guidelines.


Asunto(s)
Cardiopatías/cirugía , Trasplante de Corazón , Hospitalización/estadística & datos numéricos , Infecciones por Virus Sincitial Respiratorio/epidemiología , Enfermedades Prevenibles por Vacunación/epidemiología , Adolescente , Factores de Edad , Niño , Preescolar , Femenino , Cardiopatías/diagnóstico , Cardiopatías/etiología , Costos de Hospital , Hospitalización/economía , Humanos , Lactante , Recién Nacido , Masculino , Infecciones por Virus Sincitial Respiratorio/economía , Estudios Retrospectivos , Factores de Riesgo , Enfermedades Prevenibles por Vacunación/economía
9.
Pediatr Res ; 90(5): 1081-1085, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-33674738

RESUMEN

BACKGROUND: Non-invasive prenatal screening (NIPS) has fundamentally changed the screening process for Down syndrome (DS). Rates of complex congenital heart defects (CHD) have decreased in international studies but whether these shifts exist in the US is unknown. METHODS: Encounters for neonates with DS from 2007 to 2018 were obtained from the Pediatric Health Information System database. CHD were categorized as complex CHD, atrioventricular septal defects (AVSD), ventricular septal defects (VSD), and tetralogy of Fallot (TOF). Comparisons were made between pre-NIPS era (2007-2010) vs. post-NIPS era (2014-2018) and between states with low vs. high access to pregnancy termination as described by the Guttmacher Institute. RESULTS: Among 9122 patients, 6% had complex CHD, 22% had an AVSD, 22% had a VSD, and 4% had TOF. No difference in proportions of CHD was seen between eras. A small difference was observed in the proportion of AVSD between states with low vs. high access to pregnancy termination (23 vs. 17%, p < 0.001). CONCLUSIONS: The proportion of CHD in patients with DS appears to be stable despite widespread adoption of NIPS in the US. Variations were observed between states with low vs. high access to pregnancy termination. Population based studies are needed to fully evaluate the current epidemiology of CHD in DS. IMPACT: Through investigation of the Pediatric Health Information System database, this study assesses contemporary epidemiology of congenital heart disease among patients with Down syndrome. It has been suggested that improved prenatal screening for Down syndrome has altered the cardiac phenotype in international populations. Whether a similar shift also exists in the United States is unknown. In a contemporary United States cohort, a shift in the proportion or type of heart defects over the past decade was not observed. Regional differences in the proportion of heart defects were seen and may be due to differential access to prenatal care.


Asunto(s)
Síndrome de Down/complicaciones , Cardiopatías Congénitas/complicaciones , Diagnóstico Prenatal , Estudios de Cohortes , Síndrome de Down/diagnóstico , Femenino , Cardiopatías Congénitas/diagnóstico , Humanos , Recién Nacido , Masculino , Estados Unidos
10.
Pediatr Cardiol ; 42(5): 1074-1081, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33813599

RESUMEN

We utilized the multicenter Pediatric Acute Care Cardiology Collaborative (PAC3) 2017 and 2019 surveys to describe practice variation in therapy availability and changes over a 2-year period. A high acuity therapies (ATs) score was derived (1 point per positive response) from 44 survey questions and scores were compared to center surgical volume. Of 31 centers that completed the 2017 survey, 26 also completed the 2019 survey. Scores ranged from 11 to 34 in 2017 and 11 to 35 in 2019. AT scores in 2019 were not statistically different from 2017 scores (29/44, IQR 27-32.5 vs. 29.5/44, IQR 27-31, p = 0.9). In 2019, more centers reported initiation of continuous positive airway pressure (CPAP) and Bi-level positive airway pressure (BiPAP) in Acute Care Cardiology Unit (ACCU) (19/26 vs. 4/26, p < 0.001) and permitting continuous CPAP/BiPAP (22/26 vs. 14/26, p = 0.034) compared to 2017. Scores in both survey years were significantly higher in the highest surgical volume group compared to the lowest, 33 ± 1.5 versus 25 ± 8.5, p = 0.046 and 32 ± 1.7 versus 23 ± 5.5, p = 0.009, respectively. Variation in therapy within the ACCUs participating in PAC3 presents an opportunity for shared learning across the collaborative. Experience with PAC3 was associated with increasing available respiratory therapies from 2017 to 2019. Whether AT scores impact the quality and outcomes of pediatric acute cardiac care will be the subject of further investigation using a comprehensive registry launched in early 2019.


Asunto(s)
Cardiología/métodos , Cardiopatías Congénitas/terapia , Unidades de Cuidado Intensivo Pediátrico/estadística & datos numéricos , Procedimientos Quirúrgicos Cardíacos/estadística & datos numéricos , Niño , Cuidados Críticos/métodos , Humanos , Evaluación de Resultado en la Atención de Salud/estadística & datos numéricos , Encuestas y Cuestionarios
11.
Cardiol Young ; 31(2): 248-251, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33143784

RESUMEN

OBJECTIVES: Advanced practice providers (APPs) are being employed at increasing rates in order to meet new in-hospital care demands. Utilising the Paediatric Acute Care Cardiology Collaborative (PAC3) hospital survey, we evaluated variations in staffing models regarding first-line providers and assessed associations with programme volume, acuity of care, and post-operative length of stay (LOS). STUDY DESIGN: The PAC3 hospital survey defined staffing models and resource availability across member institutions. A resource acuity score was derived for each participating acute care cardiology unit. Surgical volume was obtained from The Society of Thoracic Surgeons database. Pearson's correlation coefficients were used to evaluate the relationship between staffing models and centre volume as well as unit acuity. A previously developed case-mix adjustment model for total post-operative LOS was utilised in a multinomial regression model to evaluate the association of APP patient coverage with observed-to-expected post-operative LOS. RESULTS: Surveys were completed by 31 (91%) PAC3 centres in 2017. Nearly all centres (94%) employ APPs, with a mean of 1.7 (range 0-5) APPs present on weekday rounds. The number of APPs present has a positive correlation with surgical volume (r = 0.49, p < 0.01) and increased acuity (r = 0.39, p = 0.03). In the multivariate model, as coverage by APPs increased from low to moderate or high, there was greater likelihood of having a shorter-than-expected post-operative LOS (p < 0.001). CONCLUSIONS: The incorporation of paediatric acute care cardiology APPs is associated with reduced post-operative LOS. Future studies are necessary to understand how APPs impact these patient-specific outcomes.


Asunto(s)
Cardiología , Cirujanos , Niño , Cuidados Críticos , Humanos , Tiempo de Internación , Encuestas y Cuestionarios
12.
Violence Vict ; 36(2): 195-213, 2021 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-33361449

RESUMEN

Mental health professionals are at heightened risk of stalking victimization, however minimal research has examined empirically supported risk factors for stalking and the efficacy of risk management strategies. Three hundred and six counselors were surveyed, and the present study focuses on the 7% (n = 23) who had been stalked by clients. Results describe the characteristics of stalking, perpetrators, and victims and the perceived efficacy of management strategies employed. Stalking behaviors tended to be of lower severity. Common perpetrator risk factors included relationship problems, anger, and obsession. Victim vulnerabilities were identified, where many victims engaged in behavior considered ineffective in response to stalking. Victims often encountered problems coping with victimization due to inadequate access to resources. Results indicate that risk management plans must be individualized and highlight ways that mental health professionals can and would like to be protected from stalking.


Asunto(s)
Consejeros , Víctimas de Crimen , Acecho , Adaptación Psicológica , Víctimas de Crimen/psicología , Humanos , Factores de Riesgo , Acecho/psicología , Acecho/terapia
13.
Neuroophthalmology ; 45(1): 29-35, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33762785

RESUMEN

Posterior globe flattening has been well-documented in astronauts both during and after long-duration space flight (LDSF) and has been observed as early as 10 days into a mission on the International Space Station. Globe flattening (GF) is thought to be caused by the disc centred anterior forces created by elevated volume and/or pressure within the optic nerve sheath (ONS). This might be the result of increased intracranial pressure, increased intraorbital ONS pressure from compartmentalisation or a combination of these mechanisms. We report posterior GF in three astronauts that has persisted for 7 years or more following their return from LDSFs suggesting that permanent scleral remodelling may have occurred.

14.
Mol Ecol ; 29(4): 752-761, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31697860

RESUMEN

Unlike plants and vertebrates, the ecological preferences, and potential vulnerabilities of soil invertebrates to environmental change, remain poorly understood in terrestrial ecosystems globally. We conducted a cross-biome survey including 83 locations across six continents to advance our understanding of the ecological preferences and vulnerabilities of the diversity of dominant and functionally important soil invertebrate taxa, including nematodes, arachnids and rotifers. The diversity of invertebrates was analyzed through amplicon sequencing. Vegetation and climate drove the diversity and dominant taxa of soil invertebrates. Our results suggest that declines in forest cover and plant diversity, and reductions in plant production associated with increases in aridity, can result in reductions of the diversity of soil invertebrates in a drier and more managed world. We further developed global atlases of the diversity of these important soil invertebrates, which were cross-validated using an independent database. Our study advances the current knowledge of the ecological preferences and vulnerabilities of the diversity and presence of functionally important soil invertebrates in soils from across the globe. This information is fundamental for improving and prioritizing conservation efforts of soil genetic resources and management policies.


Asunto(s)
Arácnidos/genética , Invertebrados/genética , Nematodos/genética , Rotíferos/genética , Animales , Ecosistema , Bosques , Suelo
15.
Ecol Appl ; 30(4): e02072, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-31925848

RESUMEN

During the past century, systematic wildfire suppression has decreased fire frequency and increased fire severity in the western United States of America. While this has resulted in large ecological changes aboveground such as altered tree species composition and increased forest density, little is known about the long-term, belowground implications of altered, ecologically novel, fire regimes, especially on soil biological processes. To better understand the long-term implications of ecologically novel, high-severity fire, we used a 44-yr high-severity fire chronosequence in the Sierra Nevada where forests were historically adapted to frequent, low-severity fire, but were fire suppressed for at least 70 yr. High-severity fire in the Sierra Nevada resulted in a long-term (44 +yr) decrease (>50%, P < 0.05) in soil extracellular enzyme activities, basal microbial respiration (56-72%, P < 0.05), and organic carbon (>50%, P < 0.05) in the upper 5 cm compared to sites that had not been burned for at least 115 yr. However, nitrogen (N) processes were only affected in the most recent fire site (4 yr post-fire). Net nitrification increased by over 600% in the most recent fire site (P < 0.001), but returned to similar levels as the unburned control in the 13-yr site. Contrary to previous studies, we did not find a consistent effect of plant cover type on soil biogeochemical processes in mid-successional (10-50 yr) forest soils. Rather, the 44-yr reduction in soil organic carbon (C) quantity correlated positively with dampened C cycling processes. Our results show the drastic and long-term implication of ecologically novel, high-severity fire on soil biogeochemistry and underscore the need for long-term fire ecological experiments.


Asunto(s)
Tracheophyta , Incendios Forestales , Carbono , Ecosistema , Bosques , Suelo
16.
Environ Sci Technol ; 54(4): 2257-2267, 2020 02 18.
Artículo en Inglés | MEDLINE | ID: mdl-31922406

RESUMEN

Sequential chemical extraction has been widely used to study soil phosphorus (P) dynamics and inform nutrient management, but its efficacy for assigning P into biologically meaningful pools remains unknown. Here, we evaluated the accuracy of the modified Hedley extraction scheme using P K-edge X-ray absorption near-edge structure (XANES) spectroscopy for nine carbonate-free soil samples with diverse chemical and mineralogical properties resulting from different degrees of soil development. For most samples, the extraction markedly overestimated the pool size of calcium-bound P (Ca-P, extracted by 1 M HCl) due to (1) P redistribution during the alkaline extractions (0.5 M NaHCO3 and then 0.1 M NaOH), creating new Ca-P via formation of Ca phosphates between NaOH-desorbed phosphate and exchangeable Ca2+ and/or (2) dissolution of poorly crystalline Fe and Al oxides by 1 M HCl, releasing P occluded by these oxides into solution. The first mechanism may occur in soils rich in well-crystallized minerals and exchangeable Ca2+ regardless of the presence or absence of CaCO3, whereas the second mechanism likely operates in soils rich in poorly crystalline Fe and Al minerals. The overestimation of Ca-P simultaneously caused underestimation of the pools extracted by the alkaline solutions. Our findings identify key edaphic parameters that remarkably influenced the extractions, which will strengthen our understanding of soil P dynamics using this widely accepted procedure.


Asunto(s)
Contaminantes del Suelo , Suelo , Minerales , Fosfatos , Fósforo , Espectroscopía de Absorción de Rayos X
17.
Environ Sci Technol ; 54(8): 4984-4994, 2020 04 21.
Artículo en Inglés | MEDLINE | ID: mdl-32181661

RESUMEN

Chemical forms of phosphorus (P) in airborne particulate matter (PM) are poorly known and do not correlate with solubility or extraction measurements commonly used to infer speciation. We used P X-ray absorption near-edge structure (XANES) and 31P nuclear magnetic resonance (NMR) spectroscopies to determine P species in PM collected at four mountain sites (Colorado and California). Organic P species dominated samples from high elevations, with organic P estimated at 65-100% of total P in bulk samples by XANES and 79-88% in extracted fractions (62-84% of total P) by NMR regardless of particle size (≥10 or 1-10 µm). Phosphorus monoester and diester organic species were dominant and present in about equal proportions, with low fractions of inorganic P species. By comparison, PM from low elevation contained mixtures of organic and inorganic P, with organic P estimated at 30-60% of total P. Intercontinental PM transport determined from radiogenic lead (Pb) isotopes varied from 0 to 59% (mean 37%) Asian-sourced Pb at high elevation, whereas stronger regional PM inputs were found at low elevation. Airborne flux of bioavailable P to high-elevation ecosystems may be twice as high as estimated by global models, which will disproportionately affect net primary productivity.


Asunto(s)
Material Particulado/análisis , Fósforo/análisis , Colorado , Ecosistema , Tamaño de la Partícula
18.
Pediatr Cardiol ; 41(2): 258-264, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31728570

RESUMEN

We sought to characterize the shifting epidemiology and resource utilization of Lyme disease and associated carditis in US children's hospitals. We hypothesized that the Lyme carditis burden has increased and that hospitalizations for Lyme carditis are costlier than those for Lyme disease without carditis. The PHIS database was queried for Lyme disease encounters between January 1, 2007 and December 31, 2013. Additional diagnostic codes consistent with carditis identified Lyme carditis cases. Demographic, clinical, and resource utilization data were analyzed. All costs were adjusted to 2014 US dollars. Lyme disease was identified in 3620 encounters with 189 (5%) associated with carditis. Lyme disease (360 cases in 2007 vs. 672 in 2013, p = 0.01) and Lyme carditis (17 cases in 2007 vs. 40 in 2013, p = 0.03) both significantly increased in frequency. This is primarily accounted for by their increase within the Midwest region. Carditis frequency among cases of Lyme disease was stable (p = 0.15). Encounters for Lyme carditis are dramatically costlier than those for Lyme disease without carditis [median $9104 (3741-19,003) vs. 922 (238-4987), p < 0.001] The increase in Lyme carditis cases in US children's hospitals is associated with an increased Lyme disease incidence, suggesting that there has not been a change in its virulence or cardiac tropism. The increasing number of serious cardiac events and costs associated with Lyme disease emphasize the need for prevention and early detection of disease and control of its spread.


Asunto(s)
Hospitales Pediátricos/estadística & datos numéricos , Enfermedad de Lyme/epidemiología , Miocarditis/epidemiología , Adolescente , Niño , Preescolar , Costo de Enfermedad , Demografía , Femenino , Recursos en Salud , Hospitalización/economía , Hospitalización/estadística & datos numéricos , Humanos , Incidencia , Enfermedad de Lyme/tratamiento farmacológico , Enfermedad de Lyme/economía , Masculino , Miocarditis/diagnóstico , Miocarditis/economía , Miocarditis/etiología , Estados Unidos/epidemiología
19.
J Basic Microbiol ; 60(8): 730-734, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32529642

RESUMEN

Endophytes have been defined as microorganisms living inside plant tissues without causing negative effects on their hosts. Endophytic microbes have been extensively studied for their plant growth-promoting traits. However, analyses of endophytes require complete removal of epiphytic microorganisms. We found that the established tests to evaluate surface sterility, polymerase chain reaction, and leaf imprints, are unreliable. Therefore, we used scanning electron microscopy (SEM) as an additional assessment of epiphyte removal. We used a diverse suite of sterilization protocols to remove epiphytic microorganisms from the leaves of a gymnosperm and an angiosperm tree to test the influence of leaf morphology on the efficacy of these methods. Additionally, leaf tissue damage was also evaluated by SEM, as damaging the leaves might have an impact on endophytes and could lead to inaccurate assessment of endophytic communities. Our study indicates, that complete removal of the leaf cuticle by the sterilization technique assures loss of epiphytic microbes, and that leaves of different tree species may require different sterilization protocols. Furthermore, our study demonstrates the importance of choosing the appropriate sterilization protocol to prevent erroneous interpretation of host-endophyte interactions. Moreover, it shows the utility of SEM for evaluating the effectiveness of surface sterilization methods and their impact on leaf tissue integrity.


Asunto(s)
Hojas de la Planta , Esterilización/métodos , Endófitos/aislamiento & purificación , Endófitos/fisiología , Microscopía Electrónica de Rastreo , Pinus/microbiología , Hojas de la Planta/microbiología , Hojas de la Planta/ultraestructura , Populus/microbiología
20.
Law Hum Behav ; 44(1): 37-50, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31697098

RESUMEN

OBJECTIVE: This study empirically evaluated risk judgments made using the Risk for Sexual Violence Protocol (RSVP; Hart et al., 2003), a widely used set of structured professional guidelines for assessing and managing sexual violence risk. HYPOTHESIS: Based on evaluations of other structured professional judgment guidelines, we hypothesized that judgments made using the RSVP would demonstrate good interrater reliability, concurrent validity, and predictive validity. METHOD: Based on file review, research assistants made ratings using the RSVP and two commonly used actuarial tools for sexual violence risk assessment in a sample of 100 adult male sexual offenders who successfully completed a community-based sex offender treatment program. Recidivism information was obtained from official records 10 years after treatment completion. RESULTS: With respect to interrater reliability, judgments of the presence and relevance of individual risk factors ranged from moderate to almost perfect, and those for composite scores reflecting the sum of these ratings were almost perfect. Interrater reliability for integrative summary risk ratings was substantial to almost perfect. Regarding concurrent validity, the findings indicated that judgments made using the RSVP had moderate to large and statistically significant correlations with scores on the actuarial tools. Finally, with respect to predictive validity, RSVP presence total scores and summary risk ratings were predictive of new sexual violence over the follow-up, and the magnitude of their predictive validity effect sizes was similar to that of scores on the actuarial tools. CONCLUSIONS: The findings supported the potential utility of the RSVP in practice. (PsycINFO Database Record (c) 2020 APA, all rights reserved).


Asunto(s)
Psicología Forense , Guías como Asunto , Medición de Riesgo/métodos , Delitos Sexuales/prevención & control , Análisis Actuarial , Adulto , Anciano , Canadá/epidemiología , Humanos , Juicio , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Delitos Sexuales/estadística & datos numéricos , Análisis de Supervivencia
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