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1.
Br J Surg ; 111(1)2024 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-37944025

RESUMEN

BACKGROUND: The rate of incisional hernia after closure of a temporary loop ileostomy is significant. Synthetic meshes are still commonly avoided in contaminated wounds. The Preloop trial was a multicentre RCT designed to evaluate the benefits of synthetic mesh in incisional hernia prevention, and its safety for use in a contaminated surgical site compared with biological mesh. METHODS: Study patients who underwent closure of a loop ileostomy after anterior resection for rectal cancer were assigned to receive either retrorectus synthetic or biological mesh to prevent incisional hernia. The primary outcomes were surgical-site infections within 30 days, and clinical or radiological incisional hernia incidence at 10 months. Secondary outcomes were reoperation rate, operating time, duration of hospital stay, other complications within 30 days of surgery, 5-year quality of life measured by RAND-36, and incisional hernia incidence within 5 years of follow-up. RESULTS: Between November 2018 and September 2021, 102 patients were randomised, of whom 97 received the intended allocation. At 10-month follow-up, 90 patients had undergone clinical evaluation and 88 radiological evaluation. One patient in each group (2 per cent) had a clinical diagnosis of incisional hernia (P = 0.950) and one further patient in each group had a CT-confirmed incisional hernia (P = 0.949). The number of other complications, reoperation rate, operating time, and duration of hospital stay did not differ between the study groups. CONCLUSION: Synthetic mesh appeared comparable to biological mesh in efficacy and safety for incisional hernia prevention at the time of loop ileostomy closure. REGISTRATION NUMBER: NCT03445936 (http://www.clinicaltrials.gov).


Asunto(s)
Hernia Incisional , Humanos , Ileostomía/efectos adversos , Hernia Incisional/etiología , Hernia Incisional/prevención & control , Hernia Incisional/epidemiología , Calidad de Vida , Mallas Quirúrgicas/efectos adversos , Infección de la Herida Quirúrgica/etiología , Infección de la Herida Quirúrgica/prevención & control
2.
Nature ; 562(7725): 57-62, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30258229

RESUMEN

The tundra is warming more rapidly than any other biome on Earth, and the potential ramifications are far-reaching because of global feedback effects between vegetation and climate. A better understanding of how environmental factors shape plant structure and function is crucial for predicting the consequences of environmental change for ecosystem functioning. Here we explore the biome-wide relationships between temperature, moisture and seven key plant functional traits both across space and over three decades of warming at 117 tundra locations. Spatial temperature-trait relationships were generally strong but soil moisture had a marked influence on the strength and direction of these relationships, highlighting the potentially important influence of changes in water availability on future trait shifts in tundra plant communities. Community height increased with warming across all sites over the past three decades, but other traits lagged far behind predicted rates of change. Our findings highlight the challenge of using space-for-time substitution to predict the functional consequences of future warming and suggest that functions that are tied closely to plant height will experience the most rapid change. They also reveal the strength with which environmental factors shape biotic communities at the coldest extremes of the planet and will help to improve projections of functional changes in tundra ecosystems with climate warming.


Asunto(s)
Calentamiento Global , Fenómenos Fisiológicos de las Plantas , Plantas/anatomía & histología , Tundra , Biometría , Mapeo Geográfico , Humedad , Fenotipo , Suelo/química , Análisis Espacio-Temporal , Temperatura , Agua/análisis
3.
Ann Surg ; 278(4): e773-e779, 2023 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-36825495

RESUMEN

OBJECTIVE: The objective of this study was to investigate the short-term and long-term morbidity after liver transplantation (LTx) in patients with primary sclerosing cholangitis (PSC). BACKGROUND: PSC is a common indication for LTx in Scandinavia. Recently, research has focused on long-term survival and morbidity. The Comprehensive Complication Index (CCI) precisely describes postsurgical complications, by considering both number and severity. PATIENTS AND METHODS: Two patient groups were compared: those with classical PSC symptoms (n=148) and those with increased risk of cholangiocarcinoma (n=51, premalignant group). Two CCI scores were calculated, at 1-year post-LTx and a cumulative overall score at the latest follow-up. In addition, we investigated factors potentially related to high CCI. RESULTS: The 1-year median CCI were 29.6 and 26.2 in the classical and premalignant groups, respectively ( P =0.308). The median overall CCI were 43.2 and 46.8 ( P =0.765), respectively. Patient survival was significantly lower in patients with 1-year CCI>42. The most common complications associated with low survival were cholangitis, infections, and hypertension. One-year and overall CCI were similar between sexes and different types of biliary anastomosis. Patients with pre-LTx Model for End-stage Liver Disease scores >20 had higher 1-year and overall CCI (36.2 and 52.6, respectively) than those with lower Model for End-stage Liver Disease scores. Both low (<22) and high (>25 kg/m 2 ) body mass indices were associated with high overall 1-year and overall CCI (50.9 and 41.8, respectively), but median body mass indices were associated with significantly lower 1-year and overall CCI (38.4, P =0.023). CONCLUSIONS: The previously determined 1-year CCI cutoff of 42 could significantly predict survival post-LTx. Mortality and morbidity were not significantly different between the PSC groups analyzed.


Asunto(s)
Neoplasias de los Conductos Biliares , Colangitis Esclerosante , Enfermedad Hepática en Estado Terminal , Trasplante de Hígado , Humanos , Enfermedad Hepática en Estado Terminal/cirugía , Colangitis Esclerosante/complicaciones , Colangitis Esclerosante/cirugía , Trasplante de Hígado/efectos adversos , Índice de Severidad de la Enfermedad , Conductos Biliares Intrahepáticos , Morbilidad , Estudios Retrospectivos
4.
J Anim Ecol ; 92(11): 2228-2239, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37786361

RESUMEN

Determining if ecological communities are saturated (have a limit to the number of species they can support) has important implications for understanding community assembly, species invasions, and climate change. However, previous studies have generally been limited to short time frames that overlook extinction debt and have not explicitly considered how functional trait diversity may mediate patterns of community saturation. Here, we combine data from biodiversity surveys with functional and phylogenetic data to explore if the colonisation events after the Great American Biotic Interchange (closure of the Panamanian Isthmus) resulted in increases in species richness of communities of the snake family Dipsadidae. We determined the number and the direction of dispersal events between Central and South America by estimating ancestral areas based on a Bayesian time-calibrated phylogenetic analysis. We then evaluated whether variation in community saturation was mediated by the functional similarity of six traits for the resident and colonizing snakes and/or local environmental conditions. We found that colonised communities did not support more species than those that were not colonised. Moreover, we did not find an association between the functional diversity across sites and whether they were colonised by members from the lineages dispersing across the Isthmus or not. Instead, variation in species richness was predicted best by covariates such as time since colonisation and local environment. Taken together, our results suggest that snake communities of the Dipsadidae across the neotropics are saturated. Moreover, our research highlights two important factors to consider in studies of community saturation: extinction debt and the functional differences and similarities in species' ecological roles.


Determinar si las comunidades ecológicas están saturadas (si tienen un límite en el número de especies que pueden albergar) tiene importantes implicaciones para entender el ensamblaje de comunidades, las invasiones de especies y el cambio climático. Sin embargo, los estudios previos en esta área se han limitado generalmente a marcos temporales cortos, ignorando el concepto de deuda de extinción y no considerando explícitamente cómo la diversidad de rasgos funcionales puede mediar en los patrones de saturación de las comunidades. En este trabajo combinamos datos publicados de muestreos de campo con datos funcionales y filogenéticos para explorar si los eventos de colonización después del Gran Intercambio Biótico Americano (ocurrido con el cierre del istmo de Panamá) resultaron en aumentos en la riqueza de especies de las comunidades de la familia de serpientes Dipsadidae. Determinamos el número y la dirección de los eventos de dispersión entre América Central y América del Sur mediante la estimación de áreas ancestrales basada en un análisis filogenético Bayesiano calibrado en el tiempo. Luego evaluamos si la variación en la saturación de las comunidades estaba mediada por la similitud funcional de seis rasgos para las serpientes residentes y colonizadoras y/o por las condiciones ambientales locales. Encontramos que las comunidades colonizadas no contienen más especies que aquellas que no fueron colonizadas. Además, no encontramos ninguna relación entre la diversidad funcional de los sitios considerados y el hecho de que estuvieran colonizados o no por miembros de los linajes que se dispersaron a través del Istmo. En cambio, la variación en la riqueza de especies se predijo mejor por covariantes como el tiempo transcurrido desde la colonización y el clima local. En conjunto, nuestros resultados sugieren que las comunidades de Dipsadidae a lo largo del neotrópico están saturadas. Además, nuestra investigación destaca dos factores importantes a considerar en los estudios de saturación de comunidades: la existencia de una deuda de extinción y las diferencias y similitudes funcionales en los papeles ecológicos de las especies.


Asunto(s)
Biodiversidad , Biota , Animales , Filogenia , Teorema de Bayes , Cambio Climático
5.
J Phys Chem A ; 127(15): 3543-3550, 2023 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-37039518

RESUMEN

The Trotterized Unitary Coupled Cluster Single and Double (UCCSD) ansatz has recently attracted interest due to its use in Variation Quantum Eigensolver (VQE) molecular simulations on quantum computers. However, when the size of molecules increases, UCCSD becomes less interesting as it cannot achieve sufficient accuracy. Including higher-order excitations is therefore mandatory to recover the UCC's missing correlation effects. Here, we extend the Trotterized UCC approach via the addition of (true) Triple T excitations introducing UCCSDT. We also include both spin and orbital symmetries. Indeed, in practice, the latter help to reduce unnecessary circuit excitations and thus accelerate the optimization process enabling researchers to tackle larger molecules. Our initial numerical tests (12-14 qubits) show that UCCSDT improves the overall accuracy by at least two orders of magnitude with respect to standard UCCSD. Overall, the UCCSDT ansatz is shown to reach chemical accuracy and to be competitive with the CCSD(T) gold-standard classical method of quantum chemistry.

6.
Proc Natl Acad Sci U S A ; 117(9): 4464-4470, 2020 03 03.
Artículo en Inglés | MEDLINE | ID: mdl-32071212

RESUMEN

Climate strongly shapes plant diversity over large spatial scales, with relatively warm and wet (benign, productive) regions supporting greater numbers of species. Unresolved aspects of this relationship include what causes it, whether it permeates to community diversity at smaller spatial scales, whether it is accompanied by patterns in functional and phylogenetic diversity as some hypotheses predict, and whether it is paralleled by climate-driven changes in diversity over time. Here, studies of Californian plants are reviewed and new analyses are conducted to synthesize climate-diversity relationships in space and time. Across spatial scales and organizational levels, plant diversity is maximized in more productive (wetter) climates, and these consistent spatial relationships are mirrored in losses of taxonomic, functional, and phylogenetic diversity over time during a recent climatic drying trend. These results support the tolerance and climatic niche conservatism hypotheses for climate-diversity relationships, and suggest there is some predictability to future changes in diversity in water-limited climates.


Asunto(s)
Biodiversidad , Cambio Climático , Fenómenos Fisiológicos de las Plantas , California , Filogeografía
7.
Nano Lett ; 21(4): 1831-1838, 2021 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-33587855

RESUMEN

Strong coupling between optical modes can be implemented into nanophotonic design to modify the energy-momentum dispersion relation. This approach offers potential avenues for tuning the thermal emission frequency, line width, polarization, and spatial coherence. Here, we employ three-mode strong coupling between propagating and localized surface phonon polaritons, with zone-folded longitudinal optic phonons within periodic arrays of 4H-SiC nanopillars. Energy exchange, mode evolution, and coupling strength between the three polariton branches are explored experimentally and theoretically. The influence of strong coupling upon the angle-dependent thermal emission was directly measured, providing excellent agreement with theory. We demonstrate a 5-fold improvement in the spatial coherence and 3-fold enhancement of the quality factor of the polaritonic modes, with these hybrid modes also exhibiting a mixed character that could enable opportunities to realize electrically driven emission. Our results show that polariton-phonon strong coupling enables thermal emitters, which meet the requirements for a host of IR applications in a simple, lightweight, narrow-band, and yet bright emitter.

8.
J Endocrinol Invest ; 44(7): 1475-1482, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33155181

RESUMEN

PURPOSE: Xeroderma pigmentosum (XP) is an autosomal recessive disease with defective DNA repair, a markedly increased risk of skin cancer, and premature aging. Reports from North Africa have described thyroid nodules in XP patients, but thyroid nodule prevalence has never been determined in XP patients enrolled in our natural history study at the National Institutes of Health (NIH). METHODS: We performed thyroid ultrasound examinations on all 29 XP patients examined from 2011 to 2019 and assessed nodule malignancy using the Thyroid Imaging Reporting and Data System. Thyroid nodule prevalence was also obtained from comparison cohorts. DNA sequencing was performed on thyroid tissue from XP patients who had surgery for thyroid cancer. RESULTS: Thyroid nodules were identified in 18/29 XP patients (62%). The median age of patients with thyroid nodules in our XP cohort (20 years) was younger than that of three comparison groups: 36 years (California study-208 subjects), 48 years (Korean study-24,757 subjects), and 52 years (NIH-682 research subjects). Multiple (2-4) thyroid nodules were found in 12/18 (67%) of the patients with nodules. Autopsy examination revealed follicular adenomas in 4/8 (50%) additional XP patients. DNA sequencing revealed rare mutations in two other XP patients with papillary thyroid cancer. CONCLUSIONS: XP patients have an increased incidence of thyroid nodules at an early age in comparison to the general population. These finding confirm another premature aging feature of XP.


Asunto(s)
Envejecimiento Prematuro/fisiopatología , Nódulo Tiroideo/epidemiología , Xerodermia Pigmentosa/complicaciones , Adolescente , Adulto , Niño , Femenino , Estudios de Seguimiento , Humanos , Masculino , Maryland/epidemiología , Persona de Mediana Edad , Pronóstico , Nódulo Tiroideo/etiología , Nódulo Tiroideo/patología , Adulto Joven
9.
BMC Genomics ; 21(1): 755, 2020 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-33138786

RESUMEN

BACKGROUND: With 9730 protein-coding genes and a nearly complete gene knockout strain collection, Neurospora crassa is a major model organism for filamentous fungi. Despite this abundance of information, the phenotypes of these gene knockout mutants have not been categorized to determine whether there are broad correlations between phenotype and any genetic features. RESULTS: Here, we analyze data for 10 different growth or developmental phenotypes that have been obtained for 1168 N. crassa knockout mutants. Of these mutants, 265 (23%) are in the normal range, while 903 (77%) possess at least one mutant phenotype. With the exception of unclassified functions, the distribution of functional categories for genes in the mutant dataset mirrors that of the N. crassa genome. In contrast, most genes do not possess a yeast ortholog, suggesting that our analysis will reveal functions that are not conserved in Saccharomyces cerevisiae. To leverage the phenotypic data to identify pathways, we used weighted Partitioning Around Medoids (PAM) approach with 40 clusters. We found that genes encoding metabolic, transmembrane and protein phosphorylation-related genes are concentrated in subsets of clusters. Results from K-Means clustering of transcriptomic datasets showed that most phenotypic clusters contain multiple expression profiles, suggesting that co-expression is not generally observed for genes with shared phenotypes. Analysis of yeast orthologs of genes that co-clustered in MAPK signaling cascades revealed potential networks of interacting proteins in N. crassa. CONCLUSIONS: Our results demonstrate that clustering analysis of phenotypes is a promising tool for generating new hypotheses regarding involvement of genes in cellular pathways in N. crassa. Furthermore, information about gene clusters identified in N. crassa should be applicable to other filamentous fungi, including saprobes and pathogens.


Asunto(s)
Neurospora crassa , Análisis por Conglomerados , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Regulación Fúngica de la Expresión Génica , Neurospora crassa/genética , Neurospora crassa/metabolismo , Fenotipo , Transcriptoma
10.
Glob Chang Biol ; 26(2): 864-875, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31628697

RESUMEN

Whether global change will drive changing forests from net carbon (C) sinks to sources relates to how quickly deadwood decomposes. Because complete wood mineralization takes years, most experiments focus on how traits, environments and decomposer communities interact as wood decay begins. Few experiments last long enough to test whether drivers change with decay rates through time, with unknown consequences for scaling short-term results up to long-term forest ecosystem projections. Using a 7 year experiment that captured complete mineralization among 21 temperate tree species, we demonstrate that trait effects fade with advancing decay. However, wood density and vessel diameter, which may influence permeability, control how decay rates change through time. Denser wood loses mass more slowly at first but more quickly with advancing decay, which resolves ambiguity about the after-life consequences of this key plant functional trait by demonstrating that its effect on decay depends on experiment duration and sampling frequency. Only long-term data and a time-varying model yielded accurate predictions of both mass loss in a concurrent experiment and naturally recruited deadwood structure in a 32-year-old forest plot. Given the importance of forests in the carbon cycle, and the pivotal role for wood decay, accurate ecosystem projections are critical and they require experiments that go beyond enumerating potential mechanisms by identifying the temporal scale for their effects.


Asunto(s)
Ecosistema , Madera , Ciclo del Carbono , Bosques , Árboles
11.
Glob Chang Biol ; 26(12): 7112-7127, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32902066

RESUMEN

Global climate and land use change are causing woody plant encroachment in arctic, alpine, and arid/semi-arid ecosystems around the world, yet our understanding of the belowground impacts of this phenomenon is limited. We conducted a globally distributed field study of 13 alpine sites across four continents undergoing woody plant encroachment and sampled soils from both woody encroached and nearby herbaceous plant community types. We found that woody plant encroachment influenced soil microbial richness and community composition across sites based on multiple factors including woody plant traits, site level climate, and abiotic soil conditions. In particular, root symbiont type was a key determinant of belowground effects, as Nitrogen-fixing woody plants had higher soil fungal richness, while Ecto/Ericoid mycorrhizal species had higher soil bacterial richness and symbiont types had distinct soil microbial community composition. Woody plant leaf traits indirectly influenced soil microbes through their impact on soil abiotic conditions, primarily soil pH and C:N ratios. Finally, site-level climate affected the overall magnitude and direction of woody plant influence, as soil fungal and bacterial richness were either higher or lower in woody encroached versus herbaceous soils depending on mean annual temperature and precipitation. All together, these results document global impacts of woody plant encroachment on soil microbial communities, but highlight that multiple biotic and abiotic pathways must be considered to scale up globally from site- and species-level patterns. Considering both the aboveground and belowground effects of woody encroachment will be critical to predict future changes in alpine ecosystem structure and function and subsequent feedbacks to the global climate system.


Asunto(s)
Ecosistema , Suelo , Clima , Nitrógeno/análisis , Plantas
12.
Oecologia ; 192(4): 1085-1098, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32270268

RESUMEN

Climate change has shifted geographical ranges of species northwards or to higher altitudes on elevational gradients. These changes have been associated with increases in ambient temperatures. For ectotherms in seasonal environments, however, life history theory relies largely on the length of summer, which varies somewhat independently of ambient temperature per se. Extension of summer reduces seasonal time constraints and enables species to establish in new areas as a result of over-wintering stage reaching in due time. The reduction of time constraints is also predicted to prolong organisms' breeding season when reproductive potential is under selection. We studied temporal change in the summer length and its effect on species' performance by combining long-term data on the occurrence and abundance of nocturnal moths with weather conditions in a boreal location at Värriötunturi fell in NE Finland. We found that summers have lengthened on average 5 days per decade from the late 1970s, profoundly due to increasing delays in the onset of winters. Moth abundance increased with increasing season length a year before. Most of the species occurrences expanded upwards in elevation. Moth communities in low elevation pine heath forest and middle elevation mountain birch forest have become inseparable. Yet, the flight periods have remained unchanged, probably due to unpredictable variation in proximate conditions (weather) that hinders life histories from selection. We conclude that climate change-driven changes in the season length have potential to affect species' ranges and affect the structure of insect assemblages, which may contribute to alteration of ecosystem-level processes.


Asunto(s)
Mariposas Nocturnas , Altitud , Animales , Cambio Climático , Ecosistema , Finlandia , Temperatura
13.
Acta Anaesthesiol Scand ; 64(4): 556-563, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-31898315

RESUMEN

BACKGROUND: The increased workload in emergency medical services (EMS) is a global phenomenon in welfare states. It has been suggested that telephone triage by nurses may reduce the increasing use of EMS services, by directing patient flow to appropriate care. This study aimed to investigate whether, after an emergency medical communication centre (EMCC) provider assessed risk, a telephone nurse could assess the patient's needs and guide patients to social and health care services in non-urgent cases. METHODS: This prospective observational study was performed in the Kainuu Hospital District in northern Finland from March to April 2018. All EMS requests classified as non-urgent by the EMCC were transferred to a telephone triage nurse. Subsequent patient guidance was recorded. The International Classifications of Primary Care categories were recorded. RESULTS: We studied phone calls of 700 patients with non-urgent needs. Of these, the nurse transferred 63.7% to EMS and 17.3% were guided to other social and health care services. Nineteen per cent of the calls were handled over the phone by the nurse, who provided health advice and instructions. The most common needs for care were general and unspecified symptoms, musculoskeletal symptoms, mental health problems and substance abuse. CONCLUSION: By providing telephone counseling, care instructions and patient guidance to other social and health services than EMS, the telephone triage reduced non-urgent EMS missions by one third. The results imply that telephone triage could be a viable model for managing non-urgent missions. Patient safety issues should be monitored when developing new service concepts.


Asunto(s)
Ambulancias/estadística & datos numéricos , Consejo/métodos , Servicios Médicos de Urgencia/métodos , Servicios Médicos de Urgencia/estadística & datos numéricos , Enfermeras y Enfermeros , Triaje/métodos , Anciano , Femenino , Finlandia , Humanos , Masculino , Proyectos Piloto , Estudios Prospectivos , Teléfono
14.
Proc Natl Acad Sci U S A ; 114(51): E10937-E10946, 2017 12 19.
Artículo en Inglés | MEDLINE | ID: mdl-29196525

RESUMEN

Our ability to understand and predict the response of ecosystems to a changing environment depends on quantifying vegetation functional diversity. However, representing this diversity at the global scale is challenging. Typically, in Earth system models, characterization of plant diversity has been limited to grouping related species into plant functional types (PFTs), with all trait variation in a PFT collapsed into a single mean value that is applied globally. Using the largest global plant trait database and state of the art Bayesian modeling, we created fine-grained global maps of plant trait distributions that can be applied to Earth system models. Focusing on a set of plant traits closely coupled to photosynthesis and foliar respiration-specific leaf area (SLA) and dry mass-based concentrations of leaf nitrogen ([Formula: see text]) and phosphorus ([Formula: see text]), we characterize how traits vary within and among over 50,000 [Formula: see text]-km cells across the entire vegetated land surface. We do this in several ways-without defining the PFT of each grid cell and using 4 or 14 PFTs; each model's predictions are evaluated against out-of-sample data. This endeavor advances prior trait mapping by generating global maps that preserve variability across scales by using modern Bayesian spatial statistical modeling in combination with a database over three times larger than that in previous analyses. Our maps reveal that the most diverse grid cells possess trait variability close to the range of global PFT means.


Asunto(s)
Ecosistema , Plantas , Carácter Cuantitativo Heredable , Ambiente , Geografía , Modelos Estadísticos , Dispersión de las Plantas , Análisis Espacial
15.
Am J Obstet Gynecol ; 221(2): 154.e1-154.e11, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-30940558

RESUMEN

BACKGROUND: Management of preterm hypertensive disorders remains a clinical dilemma. The maternal benefits of delivery need to be weighed against the adverse neonatal consequences of preterm birth. Long-term consequences of obstetric management in offspring of women with hypertensive disorders in preterm pregnancy are largely unknown. We report child neurodevelopmental and behavioral outcomes at 2 years after the Hypertension and Preeclampsia Intervention Trial at near Term (HYPITAT-II) trial, which compared immediate delivery versus expectant monitoring in mild late preterm hypertensive disorders of pregnancy. OBJECTIVE: To compare effects of immediate delivery vs expectant monitoring on neurodevelopmental and behavioral outcomes at 2 years of age in offspring of women with mild late preterm hypertensive disorders. MATERIALS AND METHODS: We studied children born in the HYPITAT-II trial, a study in which women (n = 704) with hypertensive disorders of pregnancy who were between 34 and 37 weeks' gestation were randomized to immediate delivery or expectant monitoring. Participating women were asked to complete the Ages and Stages Questionnaire for developmental outcome and the Child Behavior Checklist for behavioral problems when their toddlers were 2 years old. RESULTS: We approached 545 of 704 randomized women (77%); 330 of 545 (61%) returned the questionnaires. In the immediate delivery group, 45 of 162 infants (28%) had an abnormal Ages and Stages Questionnaire score compared to 27 of 148 (18%) in the expectant monitoring group (risk difference, 9.6%; 95% CI, 0.3-18.0%); P = .045. In the pregnancies (n = 94) that delivered before reaching 36 weeks, 27% (n = 25) had an abnormal Ages and Stages Questionnaire score compared to 22% (n = 47) when delivered after 36 weeks (odds ratio, 0.77; confidence interval, 0.44-1.34). An abnormal Child Behavior Checklist outcome was found in 31 of 175 (18%) in the delivery group vs 24 of 166 (15%) in the expectant monitoring group (risk difference, 3.2%; 95% CI, -4.6% to 11.0%). After correction for maternal education, management strategy remained an independent predictor of abnormal Ages and Stages Questionnaire score (odds ratio, 0.48; confidence interval, 0.24 to -0.96, P = .03). In multivariable analyses, low birth weight, low maternal education, and immediate delivery policy were all significantly associated with an abnormal Ages and Stages Questionnaire score. CONCLUSION: In this study, we found that early delivery in women with late preterm hypertensive disorders is associated with poorer neurodevelopmental outcomes in their children at 2 years of age. These findings indicate an increased risk of developmental delay after early delivery compared to expectant monitoring. This follow-up study underlines the conclusion of the original HYPITAT-II study that, until the clinical situation deteriorates, expectant monitoring remains the most appropriate management strategy in the light of short- and long-term neonatal outcomes in women with preterm hypertensive disorders.


Asunto(s)
Trastornos de la Conducta Infantil/epidemiología , Hipertensión Inducida en el Embarazo/epidemiología , Hipertensión Inducida en el Embarazo/terapia , Trabajo de Parto Inducido , Espera Vigilante , Desarrollo Infantil , Preescolar , Escolaridad , Femenino , Estudios de Seguimiento , Humanos , Recién Nacido de Bajo Peso , Recién Nacido , Análisis Multivariante , Países Bajos/epidemiología , Embarazo , Encuestas y Cuestionarios
16.
J Anim Ecol ; 88(9): 1319-1331, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31135962

RESUMEN

Large mammalian herbivores are well known to shape the structure and function of ecosystems world-wide, and these effects can in turn cascade through systems to indirectly influence other animal species. A wealth of studies has explored the effects of large mammals on arthropods, but to date they have reported such widely varying results that generalizations have been elusive. Three factors are likely drivers of this variability: the widely varying life-history characteristics of different arthropod groups, the highly variable landscapes that mammalian herbivores commonly inhabit and temporal variation in environmental conditions. Here, we use an 18-year-old exclosure experiment stratified across three distinct coastal prairie habitats in northern California to address the effects of a reintroduced mammalian herbivore, tule elk (Cervus canadensis nannodes) on the composition, richness and abundance of ground-dwelling arthropods over two years with very different precipitation regimes. We found that elk shifted the composition of arthropod communities, increasing the abundance of ants, beetles, spiders and mites, decreasing the abundance of woodlice and bristletails in some but not all habitats types, and having no effect on the abundance of bugs, crickets and springtails. Elk also increased richness and changed the composition of ant genera and beetle morpho-species. Interestingly, the effects of elk on arthropod composition, richness and abundance varied little between years, despite very different precipitation levels, biomass accumulation and thatch height. Elk reduced shrub cover, above-ground herbaceous biomass and thatch height and increased soil compaction, and these changes predicted the abundance and richness of arthropods, although taxonomic groups varied in their responses, presumably due to differences in environmental requirements. Synthesis. Our research highlights the importance of using long-term experiments to assess the cascading effects of large herbivores on the composition of grounddwelling arthropod communities and to identify the mechanisms that indirectly shape arthropod responses to herbivores among variable habitats and years in order to develop a greater understanding of the variable responses of arthropods to large mammalian herbivores.


Asunto(s)
Artrópodos , Animales , Biodiversidad , California , Ecosistema , Herbivoria
17.
Acta Obstet Gynecol Scand ; 98(7): 920-928, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-30723900

RESUMEN

INTRODUCTION: When women with a previous cesarean section and an unfavorable cervix have an indication for delivery, the choice is to induce labor or to perform a cesarean section. This study aims to assess the effectiveness and safety of a balloon catheter as a method of induction of labor in women with one previous cesarean section and an unfavorable cervix compared with an elective repeat cesarean section. MATERIAL AND METHODS: We performed a prospective cohort study in 51 hospitals in the Netherlands on term women with one previous cesarean section, a live singleton fetus in cephalic position, an unfavorable cervix and an indication for delivery. We recorded obstetric, maternal and neonatal characteristics. We compared the outcome of women who were induced with a balloon catheter with the outcome of women who delivered by elective repeat cesarean section. Main outcomes were maternal and neonatal morbidity. Mode of delivery was a secondary outcome for women who were induced. Adjusted odds ratios (aOR) were calculated using logistic regression, adjusted for potential confounders. RESULTS: Analysis was performed on 993 women who were induced and 321 women who had a repeat cesarean section (August 2011 until September 2012). Among the women who were induced, 560 (56.4%) delivered vaginally and 11 (1.1%) sustained a uterine rupture. Composite adverse maternal outcome (uterine rupture, severe postpartum hemorrhage or postpartum infection) occurred in 73 (7.4%) in the balloon and 14 (4.5%) women in the repeat cesarean section group (aOR 1.58, 95% confidence interval [CI] 0.85-2.96). Composite adverse neonatal outcome (Apgar score <7 at 5 minutes or umbilical pH <7.10) occurred in 57 (5.7%) and 10 (3.2%) neonates, respectively (aOR 1.40, 95% CI 0.87-3.48). Women who were induced had a shorter postpartum admission time (2.0 vs 3.0 days (P < 0.0001)). CONCLUSIONS: In women with a previous cesarean section and a need for delivery, induction of labor with a balloon catheter does not result in a significant increase in adverse maternal and neonatal outcomes as compared with planned cesarean section.


Asunto(s)
Cateterismo/métodos , Cuello del Útero/patología , Distocia/terapia , Trabajo de Parto Inducido/métodos , Parto Vaginal Después de Cesárea , Adulto , Maduración Cervical , Cesárea Repetida , Femenino , Humanos , Recién Nacido , Países Bajos , Embarazo , Resultado del Embarazo , Estudios Prospectivos , Rotura Uterina/etiología
18.
Biom J ; 61(3): 729-746, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30537402

RESUMEN

Stochastic search variable selection (SSVS) is a Bayesian variable selection method that employs covariate-specific discrete indicator variables to select which covariates (e.g., molecular markers) are included in or excluded from the model. We present a new variant of SSVS where, instead of discrete indicator variables, we use continuous-scale weighting variables (which take also values between zero and one) to select covariates into the model. The improved model performance is shown and compared to standard SSVS using simulated and real quantitative trait locus mapping datasets. The decision making to decide phenotype-genotype associations in our SSVS variant is based on median of posterior distribution or using Bayes factors. We also show here that by using continuous-scale weighting variables it is possible to improve mixing properties of Markov chain Monte Carlo sampling substantially compared to standard SSVS. Also, the separation of association signals and nonsignals (control of noise level) seems to be more efficient compared to the standard SSVS. Thus, the novel method provides efficient new framework for SSVS analysis that additionally provides whole posterior distribution for pseudo-indicators which means more information and may help in decision making.


Asunto(s)
Biometría/métodos , Algoritmos , Teorema de Bayes , Toma de Decisiones , Cadenas de Markov , Método de Montecarlo , Probabilidad , Programas Informáticos , Procesos Estocásticos
19.
Ecology ; 99(4): 896-903, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29494753

RESUMEN

Extreme droughts such as the one that affected California in 2012-2015 have been linked to severe ecological consequences in perennial-dominated communities such as forests. In annual communities, drought impacts are difficult to assess because many species persist through facultative multiyear seed dormancy, which leads to the development of seed banks. Impacts of extreme drought on the abundance and composition of the seed banks of whole communities are little known. In 80 heterogeneous grassland plots where cover is dominated by ~15 species of exotic annual grasses and diversity is dominated by ~70 species of native annual forbs, we grew out seeds from soil cores collected early in the California drought (2012) and later in the multiyear drought (2014), and analyzed drought-associated changes in the seed bank. Over the course of the study we identified more than 22,000 seedlings to species. We found that seeds of exotic annual grasses declined sharply in abundance during the drought while seeds of native annual forbs increased, a pattern that resembled but was even stronger than the changes in aboveground cover of these groups. Consistent with the expectation that low specific leaf area (SLA) is an indicator of drought tolerance, we found that the community-weighted mean SLA of annual forbs declined both in the seed bank and in the aboveground community, as low-SLA forbs increased disproportionately. In this system, seed dormancy reinforces the indirect benefits of extreme drought to the native forb community.


Asunto(s)
Poaceae , Banco de Semillas , California , Sequías , Suelo
20.
Ecology ; 99(6): 1265-1276, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29569239

RESUMEN

Despite decades of research on the species-pool concept and the recent explosion of interest in trait-based frameworks in ecology and biogeography, surprisingly little is known about how spatial and temporal changes in species-pool functional diversity (SPFD) influence biodiversity and the processes underlying community assembly. Current trait-based frameworks focus primarily on community assembly from a static regional species pool, without considering how spatial or temporal variation in SPFD alters the relative importance of deterministic and stochastic assembly processes. Likewise, species-pool concepts primarily focus on how the number of species in the species pool influences local biodiversity. However, species pools with similar richness can vary substantially in functional-trait diversity, which can strongly influence community assembly and biodiversity responses to environmental change. Here, we integrate recent advances in community ecology, trait-based ecology, and biogeography to provide a more comprehensive framework that explicitly considers how variation in SPFD, among regions and within regions through time, influences the relative importance of community assembly processes and patterns of biodiversity. First, we provide a brief overview of the primary ecological and evolutionary processes that create differences in SPFD among regions and within regions through time. We then illustrate how SPFD may influence fundamental processes of local community assembly (dispersal, ecological drift, niche selection). Higher SPFD may increase the relative importance of deterministic community assembly when greater functional diversity in the species pool increases niche selection across environmental gradients. In contrast, lower SPFD may increase the relative importance of stochastic community assembly when high functional redundancy in the species pool increases the influence of dispersal history or ecological drift. Next, we outline experimental and observational approaches for testing the influence of SPFD on assembly processes and biodiversity. Finally, we highlight applications of this framework for restoration and conservation. This species-pool functional diversity framework has the potential to advance our understanding of how local- and regional-scale processes jointly influence patterns of biodiversity across biogeographic regions, changes in biodiversity within regions over time, and restoration outcomes and conservation efforts in ecosystems altered by environmental change.


Asunto(s)
Ecosistema , Modelos Biológicos , Biodiversidad , Evolución Biológica , Ecología
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