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1.
Nature ; 620(7975): 807-812, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37612395

RESUMEN

The United Nations recently agreed to major expansions of global protected areas (PAs) to slow biodiversity declines1. However, although reserves often reduce habitat loss, their efficacy at preserving animal diversity and their influence on biodiversity in surrounding unprotected areas remain unclear2-5. Unregulated hunting can empty PAs of large animals6, illegal tree felling can degrade habitat quality7, and parks can simply displace disturbances such as logging and hunting to unprotected areas of the landscape8 (a phenomenon called leakage). Alternatively, well-functioning PAs could enhance animal diversity within reserves as well as in nearby unprotected sites9 (an effect called spillover). Here we test whether PAs across mega-diverse Southeast Asia contribute to vertebrate conservation inside and outside their boundaries. Reserves increased all facets of bird diversity. Large reserves were also associated with substantially enhanced mammal diversity in the adjacent unprotected landscape. Rather than PAs generating leakage that deteriorated ecological conditions elsewhere, our results are consistent with PAs inducing spillover that benefits biodiversity in surrounding areas. These findings support the United Nations goal of achieving 30% PA coverage by 2030 by demonstrating that PAs are associated with higher vertebrate diversity both inside their boundaries and in the broader landscape.


Asunto(s)
Biodiversidad , Conservación de los Recursos Naturales , Objetivos , Clima Tropical , Naciones Unidas , Animales , Conservación de los Recursos Naturales/legislación & jurisprudencia , Conservación de los Recursos Naturales/métodos , Conservación de los Recursos Naturales/tendencias , Mamíferos , Agricultura Forestal/legislación & jurisprudencia , Agricultura Forestal/métodos , Agricultura Forestal/tendencias
2.
Mol Cell ; 77(2): 310-323.e7, 2020 01 16.
Artículo en Inglés | MEDLINE | ID: mdl-31732458

RESUMEN

DNA methylation and histone H1 mediate transcriptional silencing of genes and transposable elements, but how they interact is unclear. In plants and animals with mosaic genomic methylation, functionally mysterious methylation is also common within constitutively active housekeeping genes. Here, we show that H1 is enriched in methylated sequences, including genes, of Arabidopsis thaliana, yet this enrichment is independent of DNA methylation. Loss of H1 disperses heterochromatin, globally alters nucleosome organization, and activates H1-bound genes, but only weakly de-represses transposable elements. However, H1 loss strongly activates transposable elements hypomethylated through mutation of DNA methyltransferase MET1. Hypomethylation of genes also activates antisense transcription, which is modestly enhanced by H1 loss. Our results demonstrate that H1 and DNA methylation jointly maintain transcriptional homeostasis by silencing transposable elements and aberrant intragenic transcripts. Such functionality plausibly explains why DNA methylation, a well-known mutagen, has been maintained within coding sequences of crucial plant and animal genes.


Asunto(s)
Proteínas de Arabidopsis/genética , Metilación de ADN/genética , Elementos Transponibles de ADN/genética , Histonas/genética , Arabidopsis/genética , ADN (Citosina-5-)-Metiltransferasas/genética , Epigénesis Genética/genética , Regulación de la Expresión Génica de las Plantas/genética , Silenciador del Gen/fisiología , Heterocromatina/genética , Mutación/genética , Transcripción Genética/genética
5.
J Physiol ; 2024 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-38533641

RESUMEN

Sympathoexcitation is a hallmark of hypoxic exposure, occurring acutely, as well as persisting in acclimatised lowland populations and with generational exposure in highland native populations of the Andean and Tibetan plateaus. The mechanisms mediating altitude sympathoexcitation are multifactorial, involving alterations in both peripheral autonomic reflexes and central neural pathways, and are dependent on the duration of exposure. Initially, hypoxia-induced sympathoexcitation appears to be an adaptive response, primarily mediated by regulatory reflex mechanisms concerned with preserving systemic and cerebral tissue O2 delivery and maintaining arterial blood pressure. However, as exposure continues, sympathoexcitation is further augmented above that observed with acute exposure, despite acclimatisation processes that restore arterial oxygen content ( C a O 2 ${C_{{\mathrm{a}}{{\mathrm{O}}_{\mathrm{2}}}}}$ ). Under these conditions, sympathoexcitation may become maladaptive, giving rise to reduced vascular reactivity and mildly elevated blood pressure. Importantly, current evidence indicates the peripheral chemoreflex does not play a significant role in the augmentation of sympathoexcitation during altitude acclimatisation, although methodological limitations may underestimate its true contribution. Instead, processes that provide no obvious survival benefit in hypoxia appear to contribute, including elevated pulmonary arterial pressure. Nocturnal periodic breathing is also a potential mechanism contributing to altitude sympathoexcitation, although experimental studies are required. Despite recent advancements within the field, several areas remain unexplored, including the mechanisms responsible for the apparent normalisation of muscle sympathetic nerve activity during intermediate hypoxic exposures, the mechanisms accounting for persistent sympathoexcitation following descent from altitude and consideration of whether there are sex-based differences in sympathetic regulation at altitude.

6.
Am J Physiol Regul Integr Comp Physiol ; 327(2): R133-R144, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-38766771

RESUMEN

Body posture and biological sex exhibit independent effects on the sympathetic neural responses to dynamic exercise. However, the neural mechanisms (e.g., baroreflex) by which posture impacts sympathetic outflow during rhythmic muscular contractions, and whether biological sex affects posture-mediated changes in efferent sympathetic nerve traffic during exercise, remain unknown. Thus, we tested the hypotheses that increases in muscle sympathetic nerve activity (MSNA) would be greater during upright compared with supine rhythmic handgrip (RHG) exercise, and that females would demonstrate smaller increases in MSNA during upright RHG exercise than males. Twenty young (30 [6] yr; means [SD]) individuals (9 males, 11 females) underwent 6 min of supine and upright (head-up tilt 45°) RHG exercise at 40% maximal voluntary contraction with continuous measurements of MSNA (microneurography), blood pressure (photoplethysmography), and heart rate (electrocardiogram). In the pooled group, absolute MSNA burst frequency (P < 0.001), amplitude (P = 0.009), and total MSNA (P < 0.001) were higher during upright compared with supine RHG exercise. However, body posture did not impact the peak change in MSNA during RHG exercise (range: P = 0.063-0.495). Spontaneous sympathetic baroreflex gain decreased from rest to RHG exercise (P = 0.006) and was not impacted by posture (P = 0.347). During upright RHG exercise, males demonstrated larger increases in MSNA burst amplitude (P = 0.002) and total MSNA (P = 0.001) compared with females, which coincided with greater reductions in sympathetic baroreflex gain among males (P = 0.004). Collectively, these data indicate that acute attenuation of baroreflex-mediated sympathoinhibition permits increases in MSNA during RHG exercise and that males exhibit a greater reserve for efferent sympathetic neural recruitment during orthostasis than females.NEW & NOTEWORTHY The impact of posture and sex on cardiovascular control during rhythmic handgrip (RHG) exercise is unknown. We show that increases in muscle sympathetic nerve activity (MSNA) during RHG are partly mediated by a reduction in sympathetic baroreflex gain. In addition, males demonstrate larger increases in total MSNA during upright RHG than females. These data indicate that the baroreflex partly mediates increases in MSNA during RHG and that males have a greater sympathetic vasoconstrictor reserve than females.


Asunto(s)
Ejercicio Físico , Fuerza de la Mano , Frecuencia Cardíaca , Músculo Esquelético , Postura , Sistema Nervioso Simpático , Humanos , Masculino , Femenino , Fuerza de la Mano/fisiología , Sistema Nervioso Simpático/fisiología , Adulto , Músculo Esquelético/inervación , Músculo Esquelético/fisiología , Ejercicio Físico/fisiología , Postura/fisiología , Adulto Joven , Presión Sanguínea/fisiología , Barorreflejo , Factores Sexuales , Contracción Muscular
7.
Glob Chang Biol ; 30(1): e17095, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38273478

RESUMEN

The impacts of climate change are widespread and threaten natural systems globally. Yet, within regions, heterogeneous physical landscapes can differentially filter climate, leading to local response diversity. For example, it is possible that while freshwater lakes are sensitive to climate change, they may exhibit a diversity of thermal responses owing to their unique morphology, which in turn can differentially affect the growth and survival of vulnerable biota such as fishes. In particular, salmonids are cold-water fishes with complex life histories shaped by diverse freshwater habitats that are sensitive to warming temperatures. Here we examine the influence of habitat on the growth of sockeye salmon (Oncorhynchus nerka) in nursery lakes of Canada's Skeena River watershed over a century of change in regional temperature and intraspecific competition. We found that freshwater growth has generally increased over the last century. While growth tended to be higher in years with relatively higher summer air temperatures (a proxy for lake temperature), long-term increases in growth appear largely influenced by reduced competition. However, habitat played an important role in modulating the effect of high temperature. Specifically, growth was positively associated with rising temperatures in relatively deep (>50 m) nursery lakes, whereas warmer temperatures were not associated with a change in growth for fish among shallow lakes. The influence of temperature on growth also was modulated by glacier extent whereby the growth of fish from lakes situated in watersheds with little (i.e., <5%) glacier cover increased with rising temperatures, but decreased with rising temperatures for fish in lakes within more glaciated watersheds. Maintaining the integrity of an array of freshwater habitats-and the processes that generate and maintain them-will help foster a diverse climate-response portfolio for important fish species, which in turn can ensure that salmon watersheds are resilient to future environmental change.


Asunto(s)
Peces , Salmón , Animales , Salmón/fisiología , Ríos , Lagos , Ecosistema , Cambio Climático
8.
Vasc Med ; : 1358863X241281872, 2024 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-39264058

RESUMEN

BACKGROUND: Pulmonary embolism (PE) is the third-leading cause of cardiovascular mortality, accounting for 100,000 deaths per year in the United States. Although sex-based disparities have previously been described in this population, it is unclear if these differences have persisted with the expansion of PE evaluation and treatment approaches. The purpose of this study is to investigate sex-based differences in the evaluation, management, and outcomes of patients with acute PE. METHODS: We performed a retrospective analysis of patients enrolled in the national Pulmonary Embolism Response Team (PERT) Consortium database between October 2015 and October 2022. We evaluated patient demographics, clinical characteristics, diagnostic imaging performed, treatment at several phases of care (pre-PERT, PERT recommendations, and post-PERT), and clinical outcomes. RESULTS: A total of 5722 patients with acute PE (2838 [49.6%] women) from 35 centers were included. There were no differences in PE risk category between male and female patients. Women were less likely to undergo echocardiography (76.9% vs 73.8%) and more likely to receive no anticoagulation prior to PERT evaluation (35.5% vs 32.9%). PERT teams were more likely to recommend catheter-based interventions for men (26.6% vs 23.1%), and men were more likely to undergo these procedures (21.9% vs 19.3%). In a multivariable analysis, female sex was a predictor of in-hospital mortality (OR 1.53, 95% CI 1.06 to 2.21). CONCLUSIONS: In this analysis, we identified sex-based differences in the evaluation and management of patients presenting with acute PE. Subsequently, women presenting with acute PE were at higher risk of in-hospital mortality.

9.
BMC Health Serv Res ; 24(1): 381, 2024 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-38539177

RESUMEN

BACKGROUND: A shortage of healthcare providers, particularly in primary care and mental health, exists in the predominately rural state of Idaho. There are also barriers to retaining healthcare providers to work in rural and remote communities. Limited research using U.S. samples has explored factors that may affect the retention of healthcare providers in rural areas. Additionally, due to differences between communities, it is important to conduct community-level investigations to better understand how these factors may affect retention in rural areas. Therefore, the purpose of this study was to explore factors affecting healthcare provider retention in a rural community in Northern Idaho. METHODS: A modified version of the Nursing Community Apgar Questionnaire (NCAQ) was completed by 30 healthcare providers in a rural and frontier community in Northern Idaho to assess factors influencing healthcare provider retention. Factors were classified into classes including geographic, economic, scope of practice, medical support, and facility and community support classes. Retention factors were assessed on their perceived importance to retention as well as whether they were perceived as an advantage or challenge to retention based on Likert scales. A "Community Apgar" score was also created by combining the importance and advantage/challenge factors. RESULTS: Overall, items in the medical support group had the highest importance of any other class and included factors such as nursing workforce. Additionally, the facility and community support class, which included factors such as televideo support, was rated the highest advantage class and had the highest Apgar score, indicating it contained the factor that healthcare providers identified as the most important advantage (i.e., medical reference resources). CONCLUSION: Our study identified multiple factors that healthcare providers deemed as important advantages or disadvantages to retaining healthcare providers in rural areas. Overall, facility and community support factors were found to have the highest advantage in the retention of rural providers. Rural healthcare organizations looking to increase healthcare provider retention should target retention efforts towards these factors. Additional research should also be conducted on other rural samples across the U.S. to make comparisons of findings.


Asunto(s)
Personal de Enfermería , Servicios de Salud Rural , Humanos , Idaho , Población Rural , Personal de Salud
10.
Int Ophthalmol ; 44(1): 80, 2024 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-38356027

RESUMEN

PURPOSE: Evaluate postoperative visual performance in patients with bilaterally implanted AT LARA or AT LARA/AT LISA tri (Carl Zeiss AG, Jena, Germany) intraocular lenses. METHODS: Multicentered, comparative, open-label, retrospective/prospective study. Post-IOL implantation, patients were prospectively enrolled into this study; preoperative patient data were collected retrospectively. Follow-up was at 2-4 and 5-8 months post-surgery. The primary endpoint was binocular best corrected distance visual acuity (CDVA). The study was retrospectively registered on clinicaltrials.gov (#NCT05462067). RESULTS: Seventy-one patients (142 eyes) were enrolled; 67 patients (134 eyes) have 5-8 months data. The mean binocular CDVA at 2-4 months was -0.10 ± 0.06 logMAR in the bilateral AT LARA group ("bilateral") and -0.11 ± 0.09 logMAR in the combined implantation AT LARA/ AT LISA tri group ("combined implantation"); (P = 0.4856). At 5-8 months, mean binocular CDVA was -0.13 ± 0.06 logMAR in the bilateral group and -0.11 ± 0.09 in the combined implantation group (P = 0.4003). At 5-8 months, more eyes in the bilateral group attained 0.2 logMAR or better binocular uncorrected intermediate VA (UIVA; 67 cm) than those in the combined implantation group (100% vs. 94%, respectively). The bilateral group achieved a mean of 0.24 ± 0.11 logMAR in uncorrected near VA (UCNVA), compared to a mean of 0.16 ± 0.12 logMAR in the combined implantation group at 5-8 months (P = 0.0041). CONCLUSIONS: A combined implantation approach (AT LARA in the distance dominant eye/AT LISA tri in the non-dominant eye) produced similar CDVA outcomes but better UCNVA as bilateral implantation with the AT LARA. UIVA was comparable between groups. No new safety concerns were reported.


Asunto(s)
Lentes Intraoculares , Facoemulsificación , Humanos , Implantación de Lentes Intraoculares , Prioridad del Paciente , Satisfacción del Paciente , Estudios Prospectivos , Diseño de Prótesis , Refracción Ocular , Estudios Retrospectivos , Visión Binocular
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