Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Más filtros











Base de datos
Intervalo de año de publicación
1.
Sci Diabetes Self Manag Care ; 50(3): 189-200, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38726953

RESUMEN

PURPOSE: The purpose of the study was to develop and validate a food literacy instrument specific to individuals with type 2 diabetes mellitus (T2DM). METHODS: Twelve T2DM-specific, food literacy-related statements underwent content validity and face validity testing, and exploratory factor analysis (EFA) was conducted (phase 1). The 6 statements remaining after EFA testing were added to an existing food literacy questionnaire called the Eating and Food Literacy Behaviors Questionnaire (EFLBQ). Confirmatory factor analysis (CFA) examined the EFLBQ plus the T2DM-specific statements, and the instrument was called the Eating and Food Literacy Questionnaire for Diabetics (EFLBQ-D; phase 2). Both EFA and CFA were administered by third-party provider Centiment via Qualtrics to adults with T2DM residing in the 13 United States Department of Agriculture Southern region states. Reliability was assessed via point estimate reliability testing. RESULTS: The EFA items clustered into 2 factors each with 3 statements: (1) carbohydrate counting and nutrition label reading and (2) healthy food preparation methods. The CFA indicated that the EFLBQ-D had good fit and that the factors had good reliability. The EFLBQ's integrity was maintained with its items loading on the respective constructs. CONCLUSIONS: The EFLBQ-D appears to be a valid, reliable instrument for use by researchers and professionals to better understand food behaviors and food literacy skills of those with T2DM. This is an important tool to help individualize medical nutrition therapy, improving patient care in this population.


Asunto(s)
Diabetes Mellitus Tipo 2 , Alfabetización en Salud , Psicometría , Humanos , Diabetes Mellitus Tipo 2/psicología , Femenino , Masculino , Encuestas y Cuestionarios , Psicometría/métodos , Persona de Mediana Edad , Reproducibilidad de los Resultados , Adulto , Anciano , Conducta Alimentaria/psicología , Análisis Factorial
2.
Sci Data ; 11(1): 305, 2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-38509110

RESUMEN

Plant biomass is a fundamental ecosystem attribute that is sensitive to rapid climatic changes occurring in the Arctic. Nevertheless, measuring plant biomass in the Arctic is logistically challenging and resource intensive. Lack of accessible field data hinders efforts to understand the amount, composition, distribution, and changes in plant biomass in these northern ecosystems. Here, we present The Arctic plant aboveground biomass synthesis dataset, which includes field measurements of lichen, bryophyte, herb, shrub, and/or tree aboveground biomass (g m-2) on 2,327 sample plots from 636 field sites in seven countries. We created the synthesis dataset by assembling and harmonizing 32 individual datasets. Aboveground biomass was primarily quantified by harvesting sample plots during mid- to late-summer, though tree and often tall shrub biomass were quantified using surveys and allometric models. Each biomass measurement is associated with metadata including sample date, location, method, data source, and other information. This unique dataset can be leveraged to monitor, map, and model plant biomass across the rapidly warming Arctic.


Asunto(s)
Ecosistema , Plantas , Árboles , Regiones Árticas , Biomasa
4.
Proc Natl Acad Sci U S A ; 120(34): e2209735120, 2023 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-37579162

RESUMEN

The hydroxyl radical (OH) fuels atmospheric chemical cycling as the main sink for methane and a driver of the formation and loss of many air pollutants, but direct OH observations are sparse. We develop and evaluate an observation-based proxy for short-term, spatial variations in OH (ProxyOH) in the remote marine troposphere using comprehensive measurements from the NASA Atmospheric Tomography (ATom) airborne campaign. ProxyOH is a reduced form of the OH steady-state equation representing the dominant OH production and loss pathways in the remote marine troposphere, according to box model simulations of OH constrained with ATom observations. ProxyOH comprises only eight variables that are generally observed by routine ground- or satellite-based instruments. ProxyOH scales linearly with in situ [OH] spatial variations along the ATom flight tracks (median r2 = 0.90, interquartile range = 0.80 to 0.94 across 2-km altitude by 20° latitudinal regions). We deconstruct spatial variations in ProxyOH as a first-order approximation of the sensitivity of OH variations to individual terms. Two terms modulate within-region ProxyOH variations-water vapor (H2O) and, to a lesser extent, nitric oxide (NO). This implies that a limited set of observations could offer an avenue for observation-based mapping of OH spatial variations over much of the remote marine troposphere. Both H2O and NO are expected to change with climate, while NO also varies strongly with human activities. We also illustrate the utility of ProxyOH as a process-based approach for evaluating intermodel differences in remote marine tropospheric OH.

5.
Glob Chang Biol ; 27(7): 1408-1430, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33394532

RESUMEN

Climate change is creating widespread ecosystem disturbance across the permafrost zone, including a rapid increase in the extent and severity of tundra wildfire. The expansion of this previously rare disturbance has unknown consequences for lateral nutrient flux from terrestrial to aquatic environments. Lateral loss of nutrients could reduce carbon uptake and slow recovery of already nutrient-limited tundra ecosystems. To investigate the effects of tundra wildfire on lateral nutrient export, we analyzed water chemistry in and around the 10-year-old  Anaktuvuk River fire scar in northern Alaska. We collected water samples from 21 burned and 21 unburned watersheds during snowmelt, at peak growing season, and after plant senescence in 2017 and 2018. After a decade of ecosystem recovery, aboveground biomass had recovered in burned watersheds, but overall carbon and nitrogen remained ~20% lower, and the active layer remained ~10% deeper. Despite lower organic matter stocks, dissolved organic nutrients were substantially elevated in burned watersheds, with higher flow-weighted concentrations of organic carbon (25% higher), organic nitrogen (59% higher), organic phosphorus (65% higher), and organic sulfur (47% higher). Geochemical proxies indicated greater interaction with mineral soils in watersheds with surface subsidence, but optical analysis and isotopes suggested that recent plant growth, not mineral soil, was the main source of organic nutrients in burned watersheds. Burned and unburned watersheds had similar δ15 N-NO3 - , indicating that exported nitrogen was of preburn origin (i.e., not recently fixed). Lateral nitrogen flux from burned watersheds was 2- to 10-fold higher than rates of background nitrogen fixation and atmospheric deposition estimated in this area. These findings indicate that wildfire in Arctic tundra can destabilize nitrogen, phosphorus, and sulfur previously stored in permafrost via plant uptake and leaching. This plant-mediated nutrient loss could exacerbate terrestrial nutrient limitation after disturbance or serve as an important nutrient release mechanism during succession.


Asunto(s)
Ecosistema , Incendios Forestales , Alaska , Regiones Árticas , Nutrientes , Suelo , Tundra
6.
Nat Clim Chang ; 9: 852-857, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35069807

RESUMEN

Recent warming in the Arctic, which has been amplified during the winter1-3, greatly enhances microbial decomposition of soil organic matter and subsequent release of carbon dioxide (CO2)4. However, the amount of CO2 released in winter is highly uncertain and has not been well represented by ecosystem models or by empirically-based estimates5,6. Here we synthesize regional in situ observations of CO2 flux from arctic and boreal soils to assess current and future winter carbon losses from the northern permafrost domain. We estimate a contemporary loss of 1662 Tg C yr-1 from the permafrost region during the winter season (October through April). This loss is greater than the average growing season carbon uptake for this region estimated from process models (-1032 Tg C yr-1). Extending model predictions to warmer conditions in 2100 indicates that winter CO2 emissions will increase 17% under a moderate mitigation scenario-Representative Concentration Pathway (RCP) 4.5-and 41% under business-as-usual emissions scenario-RCP 8.5. Our results provide a new baseline for winter CO2 emissions from northern terrestrial regions and indicate that enhanced soil CO2 loss due to winter warming may offset growing season carbon uptake under future climatic conditions.

7.
Glob Chang Biol ; 24(12): 5841-5852, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30230664

RESUMEN

Fire frequency and severity are increasing in tundra and boreal regions as climate warms, which can directly affect climate feedbacks by increasing carbon (C) emissions from combustion of the large soil C pool and indirectly via changes in vegetation, permafrost thaw, hydrology, and nutrient availability. To better understand the direct and indirect effects of changing fire regimes in northern ecosystems, we examined how differences in soil burn severity (i.e., extent of soil organic matter combustion) affect soil C, nitrogen (N), and phosphorus (P) availability and microbial processes over time. We created experimental burns of three fire severities (low, moderate, and high) in a larch forest in the northeastern Siberian Arctic and analyzed soils at 1, 8 days, and 1 year postfire. Labile dissolved C and N increased with increasing soil burn severity immediately (1 day) postfire by up to an order of magnitude, but declined significantly 1 week later; both variables were comparable or lower than unburned soils by 1 year postfire. Soil burn severity had no effect on P in the organic layer, but P increased with increasing severity in mineral soil horizons. Most extracellular enzyme activities decreased by up to 70% with increasing soil burn severity. Increasing soil burn severity reduced soil respiration 1 year postfire by 50%. However, increasing soil burn severity increased net N mineralization rates 1 year postfire, which were 10-fold higher in the highest burn severity. While fires of high severity consumed approximately five times more soil C than those of low severity, soil C pools will also be driven by indirect effects of fire on soil processes. Our data suggest that despite an initial increase in labile C and nutrients with soil burn severity, soil respiration and extracellular activities related to the turnover of organic matter were greatly reduced, which may mitigate future C losses following fire.


Asunto(s)
Carbono/análisis , Cambio Climático , Incendios , Bosques , Nutrientes , Microbiología del Suelo , Suelo/química , Regiones Árticas , Ecosistema , Larix , Nitrógeno , Hielos Perennes , Fósforo , Siberia , Tundra
8.
Heart Fail Rev ; 22(6): 743-752, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-28721466

RESUMEN

Cardiomyopathies are complex diseases of multifactorial pathogenesis and have a high morbidity and mortality. Over the past decades, several revisions of classifications and definitions of cardiomyopathies have been proposed, primarily focusing on the phenotypic characterization of cardiomyopathies. The MOGE(S) classification system published in 2013 encompasses the classification of rapidly growing knowledge on genetic mutations, acquired causes (i.e., intramyocardial inflammation, viral infections), and further conditions involved in the induction of cardiomyopathies (e.g., storage diseases, toxicity). It is based on five attributes, including morphofunctional characteristics (M), organ involvement (O), genetic or familial inheritance pattern (G), etiological annotation (E), and optional information about the heart failure functional status (S). This review summarizes the development, the cornerstones of the MOGE(S) classification, and the published data on the clinical relevance of the MOGE(S) classification. We furthermore discuss new issues which might be considered for future updates of the MOGE(S) classification of cardiomyopathies.


Asunto(s)
Cardiología , Cardiomiopatías , Predicción , Marcadores Genéticos/genética , Predisposición Genética a la Enfermedad/clasificación , Cardiomiopatías/clasificación , Cardiomiopatías/diagnóstico , Cardiomiopatías/genética , Predisposición Genética a la Enfermedad/genética , Humanos , Fenotipo
9.
PLoS Genet ; 10(11): e1004762, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25411845

RESUMEN

Intercellular communication is critical for the survival of unicellular organisms as well as for the development and function of multicellular tissues. Cell-to-cell signaling is also required to develop the interconnected mycelial network characteristic of filamentous fungi and is a prerequisite for symbiotic and pathogenic host colonization achieved by molds. Somatic cell-cell communication and subsequent cell fusion is governed by the MAK-2 mitogen activated protein kinase (MAPK) cascade in the filamentous ascomycete model Neurospora crassa, yet the composition and mode of regulation of the MAK-2 pathway are currently unclear. In order to identify additional components involved in MAK-2 signaling we performed affinity purification experiments coupled to mass spectrometry with strains expressing functional GFP-fusion proteins of the MAPK cascade. This approach identified STE-50 as a regulatory subunit of the Ste11p homolog NRC-1 and HAM-5 as cell-communication-specific scaffold protein of the MAPK cascade. Moreover, we defined a network of proteins consisting of two Ste20-related kinases, the small GTPase RAS-2 and the adenylate cyclase capping protein CAP-1 that function upstream of the MAK-2 pathway and whose signals converge on the NRC-1/STE-50 MAP3K complex and the HAM-5 scaffold. Finally, our data suggest an involvement of the striatin interacting phosphatase and kinase (STRIPAK) complex, the casein kinase 2 heterodimer, the phospholipid flippase modulators YPK-1 and NRC-2 and motor protein-dependent vesicle trafficking in the regulation of MAK-2 pathway activity and function. Taken together, these data will have significant implications for our mechanistic understanding of MAPK signaling and for homotypic cell-cell communication in fungi and higher eukaryotes.


Asunto(s)
Proteínas Fúngicas/genética , Quinasas de Proteína Quinasa Activadas por Mitógenos/genética , Proteínas Quinasas/genética , Proteínas Serina-Treonina Quinasas/genética , Proteínas ras/genética , Comunicación Celular/genética , Membrana Celular/genética , Membrana Celular/metabolismo , Proteínas Fúngicas/metabolismo , Histidina Quinasa , Sistema de Señalización de MAP Quinasas/genética , Quinasas de Proteína Quinasa Activadas por Mitógenos/metabolismo , Neurospora crassa/genética , Neurospora crassa/metabolismo , Fosforilación , Proteínas Quinasas/metabolismo , Proteínas ras/metabolismo
10.
Mol Biol Cell ; 25(8): 1312-26, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24523289

RESUMEN

Fungal hyphae are among the most highly polarized cells. Hyphal polarized growth is supported by tip-directed transport of secretory vesicles, which accumulate temporarily in a stratified manner in an apical vesicle cluster, the Spitzenkörper. The exocyst complex is required for tethering of secretory vesicles to the apical plasma membrane. We determined that the presence of an octameric exocyst complex is required for the formation of a functional Spitzenkörper and maintenance of regular hyphal growth in Neurospora crassa. Two distinct localization patterns of exocyst subunits at the hyphal tip suggest the dynamic formation of two assemblies. The EXO-70/EXO-84 subunits are found at the peripheral part of the Spitzenkörper, which partially coincides with the outer macrovesicular layer, whereas exocyst components SEC-5, -6, -8, and -15 form a delimited crescent at the apical plasma membrane. Localization of SEC-6 and EXO-70 to the plasma membrane and the Spitzenkörper, respectively, depends on actin and microtubule cytoskeletons. The apical region of exocyst-mediated vesicle fusion, elucidated by the plasma membrane-associated exocyst subunits, indicates the presence of an exocytotic gradient with a tip-high maximum that dissipates gradually toward the subapex, confirming the earlier predictions of the vesicle supply center model for hyphal morphogenesis.


Asunto(s)
Hifa/crecimiento & desarrollo , Neurospora crassa/crecimiento & desarrollo , Vesículas Secretoras/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Citoesqueleto de Actina , Membrana Celular , Polaridad Celular , Exocitosis , Proteínas Fúngicas/metabolismo , Proteínas Fluorescentes Verdes/genética , Hifa/metabolismo , Microtúbulos , Estructura Terciaria de Proteína
11.
Mol Microbiol ; 90(4): 796-812, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24028079

RESUMEN

Intercellular communication and somatic cell fusion are important for fungal colony establishment, multicellular differentiation and have been associated with host colonization and virulence of pathogenic species. By a combination of genetic, biochemical and live cell imaging techniques, we characterized the Neurospora crassa STRIPAK complex that is essential for self-signalling and consists of the six proteins HAM-2/STRIP, HAM-3/striatin, HAM-4/SLMAP, MOB-3/phocein, PPG-1/PP2A-C and PP2A-A. We describe that the core STRIPAK components HAM-2 and HAM-3 are central for the assembly of the complex at the nuclear envelope, while the phosphatase PPG-1 only transiently associates with this central subcomplex. Our data connect the STRIPAK complex with two MAP kinase pathways: (i) nuclear accumulation of the cell wall integrity MAP kinase MAK-1 depends on the functional integrity of the STRIPAK complex at the nuclear envelope, and (ii) phosphorylation of MOB-3 by the MAP kinase MAK-2 impacts the nuclear accumulation of MAK-1. In summary, these data support a model, in which MAK-2-dependent phosphorylation of MOB-3 is part of a MAK-1 import mechanism. Although self-communication remained intact in the absence of nuclear MAK-1 accumulation, supporting the presence of multiple mechanisms that co-ordinate robust intercellular communication, proper fruiting body morphology was dependent on the MAK-2-phosphorylated N-terminus of MOB-3.


Asunto(s)
Núcleo Celular/metabolismo , Proteínas Fúngicas/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Neurospora crassa/metabolismo , Membrana Nuclear/metabolismo , Transporte Activo de Núcleo Celular , Núcleo Celular/genética , Pared Celular/metabolismo , Regulación Fúngica de la Expresión Génica , Sistema de Señalización de MAP Quinasas , Mutagénesis , Neurospora crassa/genética , Fenotipo , Fosforilación
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA