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1.
PLoS Biol ; 21(11): e3002401, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37992072

RESUMEN

There is a burgeoning appreciation for the wide-ranging effects of carbon dioxide on transcriptional regulation and metabolism. Here, Bolshette and colleagues provide the first link between carbon dioxide and the master transcriptional regulator of cholesterol homeostasis.


Asunto(s)
Dióxido de Carbono , Regulación de la Expresión Génica , Dióxido de Carbono/metabolismo , Homeostasis , Colesterol/metabolismo
2.
Bioessays ; 46(7): e2400073, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38760877

RESUMEN

Sterols and the reductant nicotinamide adenine dinucleotide phosphate (NADPH), essential for eukaryotic life, arose because of, and as an adaptation to, rising levels of molecular oxygen (O2). Hence, the NADPH and O2-intensive process of sterol biosynthesis is inextricably linked to redox status. In mammals, cholesterol biosynthesis is exquisitely regulated post-translationally by multiple E3 ubiquitin ligases, with membrane associated Really Interesting New Gene (RING) C3HC4 finger 6 (MARCHF6) degrading at least six enzymes in the pathway. Intriguingly, all these MARCHF6-dependent enzymes require NADPH. Moreover, MARCHF6 is activated by NADPH, although what this means for control of cholesterol synthesis is unclear. Indeed, this presents a paradox for how NADPH regulates this vital pathway, since NADPH is a cofactor in cholesterol biosynthesis and yet, low levels of NADPH should spare cholesterol biosynthesis enzymes targeted by MARCHF6 by reducing its activity. We speculate MARCHF6 helps mammalian cells adapt to oxidative stress (signified by low NADPH levels) by reducing degradation of cholesterogenic enzymes, thereby maintaining synthesis of protective cholesterol.


Asunto(s)
Colesterol , NADP , Estrés Oxidativo , Ubiquitina-Proteína Ligasas , NADP/metabolismo , Colesterol/biosíntesis , Colesterol/metabolismo , Humanos , Animales , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitina-Proteína Ligasas/genética , Proteínas de la Membrana/metabolismo , Proteínas de la Membrana/genética , Oxidación-Reducción , Esteroles/metabolismo , Esteroles/biosíntesis
3.
New Phytol ; 242(6): 2411-2429, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38659154

RESUMEN

Bryophytes, including the lineages of mosses, liverworts, and hornworts, are the second-largest photoautotroph group on Earth. Recent work across terrestrial ecosystems has highlighted how bryophytes retain and control water, fix substantial amounts of carbon (C), and contribute to nitrogen (N) cycles in forests (boreal, temperate, and tropical), tundra, peatlands, grasslands, and deserts. Understanding how changing climate affects bryophyte contributions to global cycles in different ecosystems is of primary importance. However, because of their small physical size, bryophytes have been largely ignored in research on water, C, and N cycles at global scales. Here, we review the literature on how bryophytes influence global biogeochemical cycles, and we highlight that while some aspects of global change represent critical tipping points for survival, bryophytes may also buffer many ecosystems from change due to their capacity for water, C, and N uptake and storage. However, as the thresholds of resistance of bryophytes to temperature and precipitation regime changes are mostly unknown, it is challenging to predict how long this buffering capacity will remain functional. Furthermore, as ecosystems shift their global distribution in response to changing climate, the size of different bryophyte-influenced biomes will change, resulting in shifts in the magnitude of bryophyte impacts on global ecosystem functions.


Asunto(s)
Briófitas , Cambio Climático , Ciclo del Nitrógeno , Agua , Briófitas/fisiología , Agua/metabolismo , Ciclo del Carbono , Carbono/metabolismo , Nitrógeno/metabolismo , Ecosistema
4.
Ecol Appl ; 34(6): e3011, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39030784

RESUMEN

Natural disturbance-based management (NDBM) is hypothesized to maintain managed forest ecosystem integrity by reducing differences between natural and managed forests. The effectiveness of this approach often entails local comparisons of species composition or diversity for a variety of biota from managed and unmanaged forests. Understory vegetation is regularly the focus of such comparison because of its importance in nutrient cycling, forest regeneration, and for wildlife. However, larger scale comparisons between regions with distinct species assemblages may require a trait-based approach to better understand understory responses to disturbance. We compared the long-term effects of retention harvesting on understory vegetation in two large experimental study sites located in eastern and western regions of the Canadian boreal forest. These sites included the Sylviculture en Aménagement Forestier Ecosystémique (SAFE) experiment and the Ecosystem Management Emulating Natural Disturbance (EMEND) experiment, located in the eastern and western regions of Canada, respectively. EMEND and SAFE share common boreal understory species but have distinct tree communities, soils, and climate. Both experiments were designed to evaluate how increasing tree retention after harvest affects biodiversity. Here, we examined taxonomic richness, functional diversity, and functional composition (using community trait mean values) of understory plant communities, and also examine intraspecific trait variability (ITV) for five species common and abundant in both experiments. We observed the limited impacts of retention level on richness, functional diversity, and functional composition of understory plants 20 years postharvest. However, ITV of leaf morphological traits varied between retention levels within each experiment, depending on the species identity. Common species had different functional responses to retention level, showing species-specific reactions to environmental variation. Our result suggests that understory plant communities in the boreal forest achieve resilience to disturbance both in terms of interspecific and intraspecific functional trait diversity. Such diversity may be key to maintaining understory biodiversity in the face of future disturbances and environmental change. Our results reveal the significance of ITV in plant communities for understanding responses to forest harvesting and the importance of choosing appropriate traits when studying species responses to the environment.


Asunto(s)
Biodiversidad , Canadá , Agricultura Forestal/métodos , Conservación de los Recursos Naturales/métodos , Árboles/fisiología , Plantas/clasificación
5.
J Lipid Res ; 64(5): 100362, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36958722

RESUMEN

Cholesterol biosynthesis is a highly regulated pathway, with over 20 enzymes controlled at the transcriptional and posttranslational levels. While some enzymes remain stable, increased sterol levels can trigger degradation of several synthesis enzymes via the ubiquitin-proteasome system. Of note, we previously identified four cholesterol synthesis enzymes as substrates for one E3 ubiquitin ligase, membrane-associated RING-CH-type finger 6 (MARCHF6). Whether MARCHF6 targets the cholesterol synthesis pathway at other points is unknown. In addition, the posttranslational regulation of many cholesterol synthesis enzymes, including the C4-demethylation complex (sterol-C4-methyl oxidase-like, SC4MOL; NAD(P)-dependent steroid dehydrogenase-like, NSDHL; hydroxysteroid 17-beta dehydrogenase, HSD17B7), is largely uncharacterized. Using cultured mammalian cell lines (human-derived and Chinese hamster ovary cells), we show SC4MOL, the first acting enzyme of C4-demethylation, is a MARCHF6 substrate and is rapidly turned over and sensitive to sterols. Sterol depletion stabilizes SC4MOL protein levels, while sterol excess downregulates both transcript and protein levels. Furthermore, we found SC4MOL depletion by siRNA results in a significant decrease in total cell cholesterol. Thus, our work indicates SC4MOL is the most regulated enzyme in the C4-demethylation complex. Our results further implicate MARCHF6 as a crucial posttranslational regulator of cholesterol synthesis, with this E3 ubiquitin ligase controlling levels of at least five enzymes of the pathway.


Asunto(s)
Fitosteroles , Esteroles , Cricetinae , Animales , Humanos , Esteroles/química , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismo , Células CHO , Cricetulus , Colesterol/metabolismo , Oxidorreductasas , 3-Hidroxiesteroide Deshidrogenasas
6.
Br J Nurs ; 32(18): S26-S30, 2023 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-37830854

RESUMEN

When discussing continence care in an acute hospital setting, it can be viewed as a negative subject that is a thinly veiled jab at overstretched nurses. This article takes a fresh and holistic look at continence care, identifying factors that could be causing poor care and how technology could support a change in care. This article includes suggestions on how the data collected could be used to deliver the person-centred care outcomes that may be lacking in some environments, something that one of the authors (DP) has experienced first hand. This article describes the results of a recent trial at Ysbyty Cwm Cynon (Canon Valley Hospital), NHS Wales, which looked at how continence care technology could support positive care outcomes.


Asunto(s)
Personal de Enfermería en Hospital , Vejiga Urinaria , Humanos , Gales , Atención Dirigida al Paciente/métodos , Hospitales
7.
J Lipid Res ; 63(12): 100295, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36216146

RESUMEN

The enzymatic pathway of cholesterol biosynthesis has been well characterized. However, there remain several potential interacting proteins that may play ancillary roles in the regulation of cholesterol production. Here, we identified ERG28 (chromosome 14 open reading frame 1 [C14orf1]), a homologue of the yeast protein Erg28p, as a player in mammalian cholesterol synthesis. ERG28 is conserved from yeast to humans but has been largely overlooked in mammals. Using quantitative RT-PCR, luciferase assays, and publicly available chromatin immunoprecipitation sequencing data, we found that transcription of this gene is driven by the transcription factor SREBP-2, akin to most cholesterol synthesis enzymes, as well as identifying sterol-responsive elements and cofactor binding sites in its proximal promoter. Based on a split luciferase system, ERG28 interacted with itself and two enzymes of cholesterol synthesis (NSDHL and SC4MOL). Huh7 ERG28-KO cell lines were generated, revealing reduced total cholesterol levels in sterol-depleted environments. In addition, radiolabeled metabolic flux assays showed a 60-75% reduction in the rate of cholesterol synthesis in the KO versus wild-type cells, which could be rescued by expression of ectopic ERG28. Unexpectedly, KO of ERG28 also impaired the activation of SREBP-2 under sterol-replete conditions, by a yet-to-be defined mechanism. These results indicate that ERG28 is clearly involved in cholesterol synthesis, although the precise role this noncatalytic protein plays in this complex metabolic pathway remains to be fully elucidated. A deeper understanding of ERG28, and other ancillary proteins of cholesterol synthesis, may help inform therapeutic strategies for diseases associated with aberrant cholesterol metabolism.


Asunto(s)
Proteínas de Saccharomyces cerevisiae , Esteroles , Animales , Humanos , Proteína 1 de Unión a los Elementos Reguladores de Esteroles , Colesterol , Saccharomyces cerevisiae/metabolismo , Proteínas Fúngicas , Proteína 2 de Unión a Elementos Reguladores de Esteroles/genética , Proteínas Potenciadoras de Unión a CCAAT , Mamíferos/metabolismo , 3-Hidroxiesteroide Deshidrogenasas , Proteínas de la Membrana/metabolismo
8.
Environ Microbiol ; 24(8): 3517-3528, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35416394

RESUMEN

The composition of ecologically important moss-associated bacterial communities seems to be mainly driven by host species but may also be shaped by environmental conditions related with tree dominance. The moss phyllosphere has been studied in coniferous forests while broadleaf forests remain understudied. To determine if host species or environmental conditions defined by tree dominance drives the bacterial diversity in the moss phyllosphere, we used 16S rRNA gene amplicon sequencing to quantify changes in bacterial communities as a function of host species (Pleurozium schreberi and Ptilium crista-castrensis) and forest type (coniferous black spruce versus deciduous broadleaf trembling aspen) in eastern Canada. The overall composition of moss phyllosphere was defined by the interaction of both factors, though most of the bacterial phyla were determined by a strong effect of forest type. Bacterial α-diversity was highest in spruce forests, while there was greater turnover (ß-diversity) and higher γ-diversity in aspen forests. Unexpectedly, Cyanobacteria were much more relatively abundant in aspen than in spruce forests, with the cyanobacteria family Nostocaceae differing the most between forest types. Our results advance the understanding of moss-associated microbial communities among coniferous and broadleaf deciduous forests, which are important with the increasing changes in tree dominance in the boreal system.


Asunto(s)
Briófitas/microbiología , Cianobacterias/fisiología , Picea/fisiología , Tracheophyta/crecimiento & desarrollo , Árboles/crecimiento & desarrollo , Bryopsida/microbiología , Cianobacterias/crecimiento & desarrollo , Bosques , Picea/crecimiento & desarrollo , Quebec , ARN Ribosómico 16S/química , ARN Ribosómico 16S/genética
9.
Prev Chronic Dis ; 12: E103, 2015 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-26133646

RESUMEN

INTRODUCTION: Few studies of adults question the validity of the claim that self-management reduces the use of health care services and, as a result, health care costs. The aim of our study was to determine the relationship between self-management and health care use in a population of adolescent and young adult recipients of North Carolina Medicaid with chronic health conditions, who received care in either the pediatric or adult clinic. Our secondary objective was to characterize the patterns of health care use among this same population. METHODS: One hundred and fifty adolescents or young adults aged 14 to 29 were recruited for this study. Participants completed a demographics questionnaire and the self-management subdomain of the University of North Carolina TRxANSITION Scale. Information on each participant's emergency department and inpatient use was obtained by using the North Carolina Medicaid Provider Portal. RESULTS: This cohort had a high level of emergency health care use; average lifetime use was 3.18 (standard deviation [SD], 5.58) emergency department visits, 2.02 (SD, 3.42) inpatient visits, and 12.5 (SD, 23.9 ) days as an inpatient. Age group (pediatric or adult), diagnosis, race/ethnicity, and sex were controlled for in all analyses. Results indicate that patients with a high rate of disease self-management had more emergency department visits and hospitalizations and a longer length of stay in the hospital than did those with a low rate. CONCLUSION: In a group of North Carolina Medicaid recipients with chronic conditions, better self-management is associated with more health care use. This is likely the result of many factors, including more interactions with health care professionals, greater ability to recognize the need for emergency medical attention, and the use of the emergency department for primary health care.


Asunto(s)
Enfermedad Crónica/terapia , Costos de la Atención en Salud , Medicaid , Aceptación de la Atención de Salud , Autocuidado/estadística & datos numéricos , Adolescente , Adulto , Enfermedad Crónica/epidemiología , Estudios de Cohortes , Estudios Transversales , Manejo de la Enfermedad , Servicio de Urgencia en Hospital/estadística & datos numéricos , Etnicidad/psicología , Etnicidad/estadística & datos numéricos , Femenino , Conocimientos, Actitudes y Práctica en Salud , Disparidades en Atención de Salud , Hospitales Pediátricos/estadística & datos numéricos , Humanos , Pacientes Internos/estadística & datos numéricos , Tiempo de Internación/estadística & datos numéricos , Masculino , North Carolina/epidemiología , Aceptación de la Atención de Salud/psicología , Autocuidado/psicología , Índice de Severidad de la Enfermedad , Encuestas y Cuestionarios , Factores de Tiempo , Estados Unidos , Revisión de Utilización de Recursos , Adulto Joven
10.
J Pediatr Nurs ; 30(5): 668-76, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26165785

RESUMEN

INTRODUCTION: The STARx Questionnaire was designed with patient and provider input, to measure self-management and transition skills in adolescents and young adults (AYA) with chronic health conditions. With proven reliability and an empirically-based factor structure, the self-report STARx Questionnaire requires further validation to demonstrate its clinical and research utility. In this study we examine the concurrent, predictive, and discriminant validity of the STARx Questionnaire. METHODS: To examine concurrent validity, the STARx Questionnaire was compared to two other published transition readiness tools. Predictive validity was examined using linear regressions between the STARx Total Score and literacy, medication adherence, quality of life, and health services use. Discriminant validity was examined by comparing the performance of three chronic illness conditions on the STARx Total Score and associated subscales. RESULTS: The STARx Questionnaire and its subscales positively correlated with the scores for both transition readiness tools reflecting strong concurrent validity. The STARx Questionnaire also correlated positively with the literacy, self-efficacy, and adherence measures indicating strong predictive validity; however, it did not correlate with either quality of life or health care utilization. The performance of AYA across three different clinical conditions was not significant, indicating the clinical utility of this HCT tool for a variety of chronic health conditions. CONCLUSION: The strong validity of the STARx Questionnaire, in tandem with its strong reliability, indicated adequate psychometric properties for this generic self-report measure. These strong psychometric properties should contribute to the STARx being a viable measure of health care transition for both research and clinical purposes.


Asunto(s)
Enfermedad Crónica/terapia , Autocuidado/métodos , Encuestas y Cuestionarios , Transición a la Atención de Adultos/organización & administración , Adolescente , Enfermedad Crónica/psicología , Femenino , Humanos , Masculino , Evaluación de Programas y Proyectos de Salud , Calidad de Vida , Reproducibilidad de los Resultados , Adulto Joven
11.
Prev Chronic Dis ; 11: E117, 2014 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-25010999

RESUMEN

INTRODUCTION: The objective of our study was to determine the socioecologic factors that predict readiness for self-management and transition from pediatric to adult health care services, adherence to taking medications, and health care utilization among adolescents and young adults with chronic kidney disease. METHODS: We enrolled 52 adolescents and young adults aged 13 to 21 (96.5% participation). Participants were administered measures that examined: socioecologic factors, individualized education plans or 504 plans, readiness for self-management and transition (the University of North Carolina TRxANSITION scale), triangulated measures of adherence to taking medications (parent reported, physician reported, and medication-possession ratios), and health care utilization (number of visits to the emergency department, number of inpatient admissions, and number of inpatient days in the previous year). RESULTS: Overall, our sample had moderate levels of readiness for self-management and transition, high rates of parent- and physician-reported medication adherence, and high rates of health care utilization. Age was a significant positive predictor of readiness for self-management and transition. Compared with participants who had private health insurance, participants who had public insurance had more emergency department visits, inpatient admissions, and inpatient days, and lower rates of physician-reported medication adherence. Participants who did not have an individualized education plan or 504 plan had significantly more emergency department visits, inpatient admissions, and inpatient days. CONCLUSION: Socioecologic factors play an important role in readiness for self-management and transition, medication adherence, and health care utilization in pediatric patients with chronic kidney disease. Age, insurance status, and having an individualized education plan or 504 plan may be key factors.


Asunto(s)
Conocimientos, Actitudes y Práctica en Salud , Cumplimiento de la Medicación/estadística & datos numéricos , Insuficiencia Renal Crónica/terapia , Autocuidado/psicología , Adolescente , Adulto , Continuidad de la Atención al Paciente , Femenino , Servicios de Salud/estadística & datos numéricos , Transición de la Salud , Hospitalización/estadística & datos numéricos , Humanos , Cobertura del Seguro/estadística & datos numéricos , Masculino , North Carolina/epidemiología , Evaluación de Resultado en la Atención de Salud/estadística & datos numéricos , Cooperación del Paciente/estadística & datos numéricos , Transferencia de Pacientes , Insuficiencia Renal Crónica/diagnóstico , Insuficiencia Renal Crónica/epidemiología , Factores Socioeconómicos , Encuestas y Cuestionarios , Adulto Joven
12.
Sci Total Environ ; 927: 172148, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38569957

RESUMEN

Boreal landscapes face increasing disturbances which can affect cultural keystone species, i.e. culturally salient species that shape in a major way the cultural identity of a people. Given their importance, the fate of such species should be assessed to be able to act to ensure their perennity. We assessed how climate change and forest harvesting will affect the habitat quality of Rhododendron groenlandicum and Vaccinium angustifolium, two cultural keystone species for many Indigenous peoples in eastern Canada. We used the forest landscape model LANDIS-II in combination with species distribution models to simulate the habitat quality of these two species on the territories of three Indigenous communities according to different climate change and forest harvesting scenarios. Climate-sensitive parameters included wildfire regimes as well as tree growth. Moderate climate change scenarios were associated with an increased proportion of R. groenlandicum and V. angustifolium in the landscape, the latter species also responding positively to severe climate change scenarios. Harvesting had a minimal effect, but slightly decreased the probability of presence of both species where it occurred. According to the modeling results, neither species is at risk under moderate climate change scenarios. However, under severe climate change, R. groenlandicum could decline as the proportion of deciduous trees would increase in the landscape. Climate change mitigation strategies, such as prescribed fires, may be necessary to limit this increase. This would prevent the decrease of R. groenlandicum, as well as contribute to preserve biodiversity and harvestable volumes.


Asunto(s)
Cambio Climático , Conservación de los Recursos Naturales , Ecosistema , Bosques , Rhododendron , Vaccinium , Agricultura Forestal , Árboles , Canadá
13.
Ecology ; 94(9): 1993-2006, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24279271

RESUMEN

Why are plant species found in certain locations and not in others? The study of community assembly rules has attempted to answer this question, and many studies articulate the historic dichotomy of deterministic (predictable niches) vs. stochastic (random or semi-random processes). The study of successional sequences to determine whether they converge, as would be expected by deterministic theory, or diverge, as stochastic theory would suggest, has been one method used to investigate this question. In this article we ask the question: Do similar boreal bryophyte communities develop in the similar habitat created by convergent succession after fires of different severities? Or do the stochastic processes generated by fires of different severity lead to different communities? Specifically we predict that deterministic structure will be more important for large forest-floor species than stochastic processes, and that the inverse will be true for small bryophyte species. We used multivariate regression trees and model selection to determine the relative weight of structure (forest structure, substrates, soil structure) and processes (fire severity) for two groups of bryophyte species sampled in 12 sites (seven high-severity and five low-severity fires). Contrary to our first hypothesis, processes were as important for large forest-floor bryophytes as for small pocket species. Fire severity, its interaction with the quality of available habitat, and its impact on the creation of biological legacies played dominant roles in determining community structure. In this study, sites with nearly identical forest structure, generated via convergent succession after high- and low-severity fire, were compared to see whether these sites supported similar bryophyte communities. While similar to some degree, both the large forest-floor species and the pocket species differed after high-severity fire compared to low-severity fire. This result suggests that the "how," or process of habitat generation, influences community composition in this system and that a snapshot of habitat conditions taken at only one point in time is insufficient to explain species distribution.


Asunto(s)
Briófitas/fisiología , Ecosistema , Animales , Ontario , Quebec , Procesos Estocásticos , Árboles
14.
Front Microbiol ; 14: 1148157, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37089542

RESUMEN

Plant-microbe interactions play a crucial role in maintaining biodiversity and ecological services in boreal forest biomes. Mining for minerals, and especially the emission of heavy metal-enriched dust from mine sites, is a potential threat to biodiversity in offsite landscapes. Understanding the impacts of mining on surrounding phyllosphere microbiota is especially lacking. To investigate this, we characterized bacterial and fungal communities in the phyllosphere of feather moss Pleurozium schreberi (Brid). Mitt in boreal landscapes near six gold mine sites at different stages of the mine lifecycle. We found that (1) both mining stage and ecosystem type are drivers of the phyllosphere microbial community structure in mine offsite landscapes; (2) Bacterial alpha diversity is more sensitive than fungal alpha diversity to mining stage, while beta diversity of both groups is impacted; (3) mixed and deciduous forests have a higher alpha diversity and a distinct microbial community structure when compared to coniferous and open canopy ecosystems; (4) the strongest effects are detectable within 0.2 km from operating mines. These results confirmed the presence of offsite effects of mine sites on the phyllosphere microbiota in boreal forests, as well as identified mining stage and ecosystem type as drivers of these effects. Furthermore, the footprint was quantified at 0.2 km, providing a reference distance within which mining companies and policy makers should pay more attention during ecological assessment and for the development of mitigation strategies. Further studies are needed to assess how these offsite effects of mines affect the functioning of boreal ecosystems.

15.
Artículo en Inglés | MEDLINE | ID: mdl-36528253

RESUMEN

Glucose metabolism and cholesterol synthesis are often regarded in isolation. Increasing evidence not only links these pathways but also suggests glucose catabolism regulates cholesterol synthesis. Uptake of glucose increases cholesterol production. However, the precise mechanism by which this occurs is not fully understood and is likely to involve many aspects of cellular pathways participating in energy sensing, cholesterol regulation, and synthesis. Here, we review some interesting links between cholesterol synthesis and glucose metabolism. Given glucose breakdown produces energy (both via glycolysis and its products through oxidative phosphorylation), and considering cholesterol synthesis is an energetically demanding process, it would seem logical that glucose metabolism impacts cholesterol synthesis. The energy sensing kinase AMPK carefully monitors energy supply to induce or suppress cholesterol synthesis as needed. Akt, activated by the insulin signalling cascade, regulates key transcription factors involved in lipid metabolism. The insulin signalling pathway also activates machinery involved in the deubiquitination of a key cholesterol synthesis enzyme. Moreover, glucose metabolites, acetyl-CoA, and GlcNAc are substrates for protein acetylation and N-glycosylation, respectively, and can stabilise proteins involved in cholesterol synthesis. As glucose and cholesterol dysregulation are both associated with numerous diseases, understanding the mechanisms of how glucose metabolism and cholesterol synthesis intersect may offer new avenues for therapeutics that make use of these findings.


Asunto(s)
Proteínas Quinasas Activadas por AMP , Transducción de Señal , Proteínas Quinasas Activadas por AMP/metabolismo , Procesamiento Proteico-Postraduccional , Glucosa/metabolismo , Insulina/metabolismo
16.
PLoS One ; 17(1): e0260543, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34990454

RESUMEN

In Canadian boreal forests, bryophytes represent an essential component of biodiversity and play a significant role in ecosystem functioning. Despite their ecological importance and sensitivity to disturbances, bryophytes are overlooked in conservation strategies due to knowledge gaps on their distribution, which is known as the Wallacean shortfall. Rare species deserve priority attention in conservation as they are at a high risk of extinction. This study aims to elaborate predictive models of rare bryophyte species in Canadian boreal forests using remote sensing-derived predictors in an Ensemble of Small Models (ESMs) framework. We hypothesize that high ESMs-based prediction accuracy can be achieved for rare bryophyte species despite their low number of occurrences. We also assess if there is a spatial correspondence between rare and overall bryophyte richness patterns. The study area is located in western Quebec and covers 72,292 km2. We selected 52 bryophyte species with <30 occurrences from a presence-only database (214 species, 389 plots in total). ESMs were built from Random Forest and Maxent techniques using remote sensing-derived predictors related to topography and vegetation. Lee's L statistic was used to assess and map the spatial relationship between rare and overall bryophyte richness patterns. ESMs yielded poor to excellent prediction accuracy (AUC > 0.5) for 73% of the modeled species, with AUC values > 0.8 for 19 species, which confirmed our hypothesis. In fact, ESMs provided better predictions for the rarest bryophytes. Likewise, our study revealed a spatial concordance between rare and overall bryophyte richness patterns in different regions of the study area, which have important implications for conservation planning. This study demonstrates the potential of remote sensing for assessing and making predictions on inconspicuous and rare species across the landscape and lays the basis for the eventual inclusion of bryophytes into sustainable development planning.


Asunto(s)
Biodiversidad , Briófitas/crecimiento & desarrollo , Simulación por Computador/estadística & datos numéricos , Ecosistema , Tecnología de Sensores Remotos/métodos , Taiga , Curva ROC , Desarrollo Sostenible
17.
PLoS One ; 16(3): e0234587, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33705414

RESUMEN

Citizen science (CS) currently refers to the participation of non-scientist volunteers in any discipline of conventional scientific research. Over the last two decades, nature-based CS has flourished due to innovative technology, novel devices, and widespread digital platforms used to collect and classify species occurrence data. For scientists, CS offers a low-cost approach of collecting species occurrence information at large spatial scales that otherwise would be prohibitively expensive. We examined the trends and gaps linked to the use of CS as a source of data for species distribution models (SDMs), in order to propose guidelines and highlight solutions. We conducted a quantitative literature review of 207 peer-reviewed articles to measure how the representation of different taxa, regions, and data types have changed in SDM publications since the 2010s. Our review shows that the number of papers using CS for SDMs has increased at approximately double the rate of the overall number of SDM papers. However, disparities in taxonomic and geographic coverage remain in studies using CS. Western Europe and North America were the regions with the most coverage (73%). Papers on birds (49%) and mammals (19.3%) outnumbered other taxa. Among invertebrates, flying insects including Lepidoptera, Odonata and Hymenoptera received the most attention. Discrepancies between research interest and availability of data were as especially important for amphibians, reptiles and fishes. Compared to studies on animal taxa, papers on plants using CS data remain rare. Although the aims and scope of papers are diverse, species conservation remained the central theme of SDM using CS data. We present examples of the use of CS and highlight recommendations to motivate further research, such as combining multiple data sources and promoting local and traditional knowledge. We hope our findings will strengthen citizen-researchers partnerships to better inform SDMs, especially for less-studied taxa and regions. Researchers stand to benefit from the large quantity of data available from CS sources to improve global predictions of species distributions.


Asunto(s)
Ciencia Ciudadana/tendencias , Animales , Biodiversidad , Bases de Datos Factuales , Modelos Lineales , Revisión de la Investigación por Pares
18.
J Clin Psychol Med Settings ; 17(4): 340-8, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21076935

RESUMEN

Sixty young adult survivors of a serious childhood illness completed quantitative and qualitative measures assessing the relationship between specific disease and distress factors and posttraumatic growth (PTG). Individuals who had recovered from their illness reported greater growth than those who were currently experiencing their illness. The regression model accounted for 47% of the variance in PTG, with perceived severity, illness status, and posttraumatic stress symptoms emerging as significant predictors. Qualitative analyses identified salient positive and negative factors associated with having had an illness, such as a positive shift in perspective and frequent medical requirements. Being past the daily demands of illness management may allow for greater PTG. Realization of positive aspects of having had an illness may require prompting.


Asunto(s)
Adaptación Psicológica , Enfermedad Crónica/psicología , Crecimiento , Acontecimientos que Cambian la Vida , Trastornos por Estrés Postraumático/psicología , Sobrevivientes/psicología , Adulto , Análisis de Varianza , Niño , Femenino , Humanos , Masculino , Índice de Severidad de la Enfermedad , Encuestas y Cuestionarios , Adulto Joven
20.
Data Brief ; 21: 2616-2621, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30560164

RESUMEN

Soil data and soil mapping are indispensable tools in sustainable forest management. In northern boreal ecosystems, paludification is defined as the accumulation of partially decomposed organic matter over saturated mineral soils, a process that reduces tree regeneration and forest growth. Given this negative effect on forest productivity, spatial prediction of paludification in black spruce stands is important in forest management. This paper provides a description of the soil database to predict organic layer thickness (OLT) as a proxy of paludification in northeastern Canada. The database contains 13,944 OLT measurements (in cm) and their respective GPS coordinates. We collected OLT measurements from georeferenced ground plots and transects from several previous projects. Despite the variety of sources, the sampling design for each dataset was similar, consisting of manual measurements of OLT with a hand probe. OLT measurements were variable across the study area, with a mean ± standard deviation of 21 ± 24 cm (ranging from a minimum of 0 cm to a maximum of 150 cm), and the distribution tended toward positive skewing, with a large number of low OLT values and fewer high OLT values. The dataset has been used to perform OLT mapping at 30-m resolution and predict the risk of paludification in northeastern Canada (Mansuy et al., 2018) [1]. The spatially explicit and continuous database is also available to support national and international efforts in digital soil mapping.

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