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81.
82.
Regime shifts of Mediterranean forest carbon uptake and reduced resilience driven by multidecadal ocean surface temperatures 总被引:1,自引:0,他引:1
Jofre Carnicer Cristina Domingo‐Marimon Miquel Ninyerola Jesus Julio Camarero Ana Bastos Jorge Lpez‐Parages Laura Blanquer Beln Rodríguez‐Fonseca Timothy M. Lenton Vasilis Dakos Montserrat Ribas Emilia Gutirrez Josep Peuelas Xavier Pons 《Global Change Biology》2019,25(8):2825-2840
The mechanisms translating global circulation changes into rapid abrupt shifts in forest carbon capture in semi‐arid biomes remain poorly understood. Here, we report unprecedented multidecadal shifts in forest carbon uptake in semi‐arid Mediterranean pine forests in Spain over 1950–2012. The averaged carbon sink reduction varies between 31% and 37%, and reaches values in the range of 50% in the most affected forest stands. Regime shifts in forest carbon uptake are associated with climatic early warning signals, decreased forest regional synchrony and reduced long‐term carbon sink resilience. We identify the mechanisms linked to ocean multidecadal variability that shape regime shifts in carbon capture. First, we show that low‐frequency variations of the surface temperature of the Atlantic Ocean induce shifts in the non‐stationary effects of El Niño Southern Oscillation (ENSO) on regional forest carbon capture. Modelling evidence supports that the non‐stationary effects of ENSO can be propagated from tropical areas to semi‐arid Mediterranean biomes through atmospheric wave trains. Second, decadal changes in the Atlantic Multidecadal Oscillation (AMO) significantly alter sea–air heat exchanges, modifying in turn ocean vapour transport over land and land surface temperatures, and promoting sustained drought conditions in spring and summer that reduce forest carbon uptake. Third, we show that lagged effects of AMO on the winter North Atlantic Oscillation also contribute to the maintenance of long‐term droughts. Finally, we show that the reported strong, negative effects of ocean surface temperature (AMO) on forest carbon uptake in the last decades are unprecedented over the last 150 years. Our results provide new, unreported explanations for carbon uptake shifts in these drought‐prone forests and review the expected impacts of global warming on the profiled mechanisms. 相似文献
83.
Caterina R. Giner Vanessa Balagu Anders K. Krabberd Isabel Ferrera Albert Re Esther Garcs Josep M. Gasol Ramiro Logares Ramon Massana 《Molecular ecology》2019,28(5):923-935
How much temporal recurrence is present in microbial assemblages is still an unanswered ecological question. Even though marked seasonal changes have been reported for whole microbial communities, less is known on the dynamics and seasonality of individual taxa. Here, we aim at understanding microbial recurrence at three different levels: community, taxonomic group and operational taxonomic units (OTUs). For that, we focused on a model microbial eukaryotic community populating a long‐term marine microbial observatory using 18S rRNA gene data from two organismal size fractions: the picoplankton (0.2–3 µm) and the nanoplankton (3–20 µm). We have developed an index to quantify recurrence in particular taxa. We found that community structure oscillated systematically between two main configurations corresponding to winter and summer over the 10 years studied. A few taxonomic groups such as Mamiellophyceae or MALV‐III presented clear recurrence (i.e., seasonality), whereas 13%–19% of the OTUs in both size fractions, accounting for ~40% of the relative abundance, featured recurrent dynamics. Altogether, our work links long‐term whole community dynamics with that of individual OTUs and taxonomic groups, indicating that recurrent and non‐recurrent changes characterize the dynamics of microbial assemblages. 相似文献
84.
Eva Teira Ramiro Logares Alberto Gutiérrez-Barral Isabel Ferrera Marta M. Varela Xosé Anxelu G. Morán Josep M. Gasol 《Environmental microbiology》2019,21(4):1482-1496
The impact of grazing, resource competition and light on prokaryotic growth and taxonomic composition in subtropical and tropical surface waters were studied through 10 microcosm experiments conducted between 30°N and 30°S in the Atlantic, Pacific and Indian oceans. Under natural sunlight conditions, significant changes in taxonomic composition were only observed after the reduction of grazing by sample filtration in combination with a decrease in resource competition by sample dilution. Sunlight exposure significantly reduced prokaryote growth (11 ± 6%) and community richness (14 ± 4%) compared to continuous darkness but did not significantly change community composition. The largest growth inhibition after sunlight exposure occurred at locations showing deep mixed layers. The reduction of grazing had an expected and significant positive effect on growth, but caused a significant decrease in community richness (16 ± 6%), suggesting that the coexistence of many different OTUs is partly promoted by the presence of predators. Dilution of the grazer-free prokaryotic community significantly enhanced growth at the level of community, but consistently and sharply reduced the abundance of Prochlorococcus and SAR11 populations. The decline of these oligotrophic bacterial taxa following an increase in resource availability is consistent with their high specialization for exploiting the limited resources available in the oligotrophic warm ocean. 相似文献
85.
86.
Antoni Sureda Pedro Tauler Antoni Aguiló Nuria Cases Isabel Llompart Josep A. Tur Antoni Pons 《Central European Journal of Biology》2007,2(1):56-70
Intense exercise induces inflammatory-like changes and oxidative stress in immune cells. Our aim was to study the effects
of antioxidant diet supplementation on the neutrophil inflammatory response and on the tocopherol associated protein (TAP)
expression after exhaustive exercise. Fourteen male-trained amateur runners were randomly divided in two placebo and supplemented
groups. Vitamins C (152 mg/d) and E (50 mg/d) supplementation were administrated to the athletes for a month, using an almond
based isotonic and energetic beverage. Non-enriched beverage was given to the placebo group. After one month, the subjects
participated in a half-marathon race (21 km-run). Neutrophil TAP mRNA expression and markers of the inflammatory response
were determined before, immediately after, and 3 h after finishing the half-marathon race. TAP expression increased after
exercise mainly in the neutrophils of the placebo group. Exercise induced an inflammatory response in both placebo and supplemented
groups, manifested with neutrophilia, increased creatine kinase and lactate dehydrogenase serum activities, neutrophil luminol
chemiluminescence and myeloperoxidase release. Plasma malondialdehyde only increased in the placebo group after exercise.
Diet supplementation with moderate levels of antioxidant vitamins avoids plasma damage in response to exhaustive exercise
without the effects on the inflammatory process. Neutrophil degranulation and increased tocopherol associated protein could
contribute to the neutrophil protection from the oxidative stress. 相似文献
87.
88.
Josep J. Centelles Antonio Ramos-Montoya Shu Lim Sara Bassilian Laszlo G. Boros Silvia Marín Marta Cascante Wai-Nang Paul Lee 《Metabolomics : Official journal of the Metabolomic Society》2007,3(2):105-111
Traditional tracer studies of cell proliferation fail to distinguish between label enrichment due to increased DNA repair
versus DNA replication. We used the emerging stable (non-radiating) isotope-based dynamic metabolic profiling technique on
HepG2 cells to determine synthesis pathways of nucleic acids from glucose and rates of proliferation using CG-MS assay of
RNA and DNA enrichment. Comparing the isotopic enrichment curve in DNA with the theoretical curve based on cell growth, we
observed that the measured tracer enrichment was significantly higher, indicating that surplus label was acquired during DNA
repair. In particular, after the first duplication (3 days), 80.13% of the total enrichment observed corresponds to duplication
and 19.87% corresponds to DNA repair as calculated from the [1, 2-13C2]-glucose incorporation curve. Our data indicate contemporary measurements of cell proliferation rates relying on tracer incorporation
may be overestimated. 13C label was distributed between m1 (m1/Σm = 80) and m2 (m2/Σm = 14) of deoxyribose, indicating that most of the glucose carbon was acquired via direct glucose oxidation in the pentose
cycle. The stable isotope technique distinguishes rates of DNA synthesis and repair via the oxidative and non-oxidative pentose
cycle, separately, in one test, without inhibition of either process. The contribution of DNA repair in malignant cells to
isotope accumulation in deoxyribose remains to be investigated. 相似文献
89.
Feliciano Villar Montserrat Celdrán Rodrigo Serrat Josep Fabà Teresa Martínez 《Revista espa?ola de geriatría y gerontología》2019,54(1):12-18
Objectives
The study had three objectives: (a) To determine how staff perceives the frequency of different sexual expressions in long-term care facilities for older people; (2) to quantify policies aimed at guaranteeing residents’ sexual rights in such institutions, and (3) to determine factors influencing the presence of these kind of policies.Methods
A total of 160 Directors of Nursing and 623 technical staff from Spanish long term care residential facilities completed a self-administered questionnaire including ítems to assess the experience and estimated frequency of different sexual expressions, an inventory of policies regarding sexual expression, and the Spanish version of the Person-Centred Care Assessment Tool.Results
Certain sexual behaviours, such as kisses and hugs, or masturbation, are very frequent in nursing homes. Many participants have reported to staff members on having witnessed inappropriate sexual behaviours, such as exhibitionism (39%) or unwanted touching (27%). Policies in relation to guaranteeing residents’ sexual rights were the most frequently mentioned. In contrast, there were fewer participants who mentioned policies regarding training or availability of helpful materials and resources. Factors such as occupational level (Directors of Nursing vs.technical staff), personal education, the centre commitment to person-centred care, and estimated frequency of sexual behaviour were associated with a higher presence of sexual expression policies.Conclusion
Although sexual behaviours among residents are quite frequent, there is still room for improvement in policies that support residents’ expression of sexuality. Person-centred care models might help to guarantee sexual rights of older people living in long-term care facilities. 相似文献90.
David Gmez‐Blanco Simone Santoro Antoni Borrs Josep Cabrera Juan Carlos Senar Pim Edelaar 《Journal of avian biology》2019,50(12)
Dozens of morphologically differentiated populations, subspecies and species of crossbills (genus Loxia) exist. It has been suggested that this divergence is due to variation in the conifer cones that each population specialises upon, requiring a specific beak size to efficiently separate the cone scales. If so, apparent survival should depend on beak size. To test this hypothesis, we undertook multievent capture–recapture modelling for 6844 individuals monitored during 27 years in a Pyrenean common crossbill L. curvirostra population in a forest of mountain pine Pinus uncinata. Apparent survival was indeed related to beak width, resulting in stabilizing selection around an optimum that was close to the observed mean beak width, indicating that local crossbill beak morphology is adapted to the conifer they feed upon. Both natural selection (selective mortality) and selective emigration of maladapted individuals may explain our findings. As is often the case in capture–recapture analyses but rarely recognised, we could not formally decompose apparent survival into selective mortality versus selective permanent emigration. Nonetheless, there are several indications that selective permanent emigration should not be fully excluded. First, natural selection by itself would have to be unusually strong compared to other empirical estimates to create the observed pattern of apparent survival. Second, the observed mean beak width was a bit lower than the estimated optimum beak width. This can be explained by immigration of crossbills with smaller beaks originating from southern populations, which may subsequently have left the study area permanently in response to low food intake. This is in line with a detected transient effect in the data, yet apparently little influx from crossbills from northern Europe. When permanent emigration is phenotypically selective this will have ecological and evolutionary consequences, so this possibility deserves more attention in general. 相似文献