10,783 research outputs found
Seasonal rather than spatial variability drives planktonic and benthic bacterial diversity in a microtidal lagoon and the adjacent open sea
Coastal lagoons are highly productive ecosystems, which are experiencing a variety of human disturbances at increasing frequency. Bacteria are key ecological players within lagoons, yet little is known about the magnitude, patterns and drivers of diversity in these transitional environments. We carried out a seasonal study in the Venice Lagoon (Italy) and the adjacent sea, to simultaneously explore diversity patterns in different domains (pelagic, benthic) and their spatio-temporal variability, and test the role of environmental gradients in structuring assemblages. Community composition differed between lagoon and open sea, and between domains. The dominant phyla varied temporally, with varying trends for the two domains, suggesting different environmental constraints on the assemblages. The percentage of freshwater taxa within the lagoon increased during higher river run-off, pointing at the lagoon as a dynamic mosaic of microbial taxa that generate the metacommunity across the whole hydrological continuum. Seasonality was more important than spatial variability in shaping assemblages. Network analyses indicated more interactions between several genera and environmental variables in the open sea than the lagoon. Our study provides evidences for a temporally dynamic nature of bacterial assemblages in lagoons and suggests that an interplay of seasonally influenced environmental drivers shape assemblages in these vulnerable ecosystems
Sea-level rise along the Emilia-Romagna coast (Northern Italy) in 2100: scenarios and impacts
As a consequence of climate change and land subsidence, coastal zones are
directly impacted by sea-level rise. In some particular areas, the effects on
the ecosystem and urbanisation are particularly enhanced. We focus on the
Emilia-Romagna (E-R) coastal plain in Northern Italy, bounded by the Po river
mouth to the north and by the Apennines to the south. The plain is
∼ 130 km long and is characterised by wide areas below mean sea
level, in part made up of reclaimed wetlands. In this context, several
morphodynamic factors make the shore and back shore unstable. During next
decades, the combined effects of land subsidence and of the sea-level rise as
a result of climate change are expected to enhance the shoreline instability,
leading to further retreat. The consequent loss of beaches would impact the
economy of the region, which is tightly connected with tourism
infrastructures. Furthermore, the loss of wetlands and dunes would threaten
the ecosystem, which is crucial for the preservation of life and the
environment. These specific conditions show the importance of a precise
definition of the possible local impacts of the ongoing and future climate
variations. The aim of this work is the characterisation of vulnerability in
different sectors of the coastal plain and the recognition of the areas in
which human intervention is urgently required. The Intergovernmental Panel on
Climate Change (IPCC) Fifth Assessment Report (AR5) sea-level scenarios are
merged with new high-resolution terrain models, current data for local
subsidence and predictions of the flooding model in_CoastFlood in
order to develop different scenarios for the impact of sea-level rise
projected to year 2100. First, the potential land loss due to the combined
effect of subsidence and sea-level rise is extrapolated. Second, the increase
in floodable areas as a result of storm surges is quantitatively determined.
The results are expected to support the regional mitigation and adaptation
strategies designed in response to climate change
Lack of Temporal Impairment in Patients With Mild Cognitive Impairment
In the present study, we investigate possible temporal impairment in patients with mild cognitive impairment (MCI) and the amount of temporal distortions caused by the presentation of emotional facial expressions (anger, shame, and neutral) in MCI patients and controls. Twelve older adults with MCI and 14 healthy older adults were enrolled in the present study. All participants underwent a complete neuropsychological evaluation. We used three timing tasks to tap temporal abilities, namely time bisection (standard intervals lasting 400 and 1600 ms), finger-tapping (free and 1 s), and simple reaction-time tasks. The stimuli used in the time bisection task were facial emotional stimuli expressing anger or shame to investigate a possible contribution of emotional information as previously observed in healthy adults. MCI patients showed temporal abilities comparable to controls. We observed an effect of facial emotional stimuli on time perception when data were analyzed in terms of proportion of long responses, and this result was mainly driven by the temporal overestimation when a facial expression of anger was presented in controls. Results seem to suggest that the severity of the cognitive dysfunction accounts more for subjective temporal impairment than a compromised internal clock
Many-nodes/many-links spinfoam: the homogeneous and isotropic case
I compute the Lorentzian EPRL/FK/KKL spinfoam vertex amplitude for regular
graphs, with an arbitrary number of links and nodes, and coherent states peaked
on a homogeneous and isotropic geometry. This form of the amplitude can be
applied for example to a dipole with an arbitrary number of links or to the
4-simplex given by the compete graph on 5 nodes. All the resulting amplitudes
have the same support, independently of the graph used, in the large j (large
volume) limit. This implies that they all yield the Friedmann equation: I show
this in the presence of the cosmological constant. This result indicates that
in the semiclassical limit quantum corrections in spinfoam cosmology do not
come from just refining the graph, but rather from relaxing the large j limit.Comment: 8 pages, 4 figure
MYCN Amplification, along with Wild-Type RB1 Expression, Enhances CDK4/6 Inhibitors’ Efficacy in Neuroblastoma Cells
Neuroblastoma (NB) is one of the primary causes of death for pediatric malignancies. Given the high heterogeneity in NB's mutation landscape, optimizing individualized therapies is still challenging. In the context of genomic alterations, MYCN amplification is the most correlated event with poor outcomes. MYCN is involved in the regulation of several cellular mechanisms, including cell cycle. Thus, studying the influence of MYCN overexpression in the G1/S transition checkpoint of the cell cycle may unveil novel druggable targets for the development of personalized therapeutical approaches. Here, we show that high expression of E2F3 and MYCN correlate with poor prognosis in NB despite the RB1 mRNA levels. Moreover, we demonstrate through luciferase reporter assays that MYCN bypasses RB function by incrementing E2F3-responsive promoter activity. We showed that MYCN overexpression leads to RB inactivation by inducing RB hyperphosphorylation during the G1 phase through cell cycle synchronization experiments. Moreover, we generated two MYCN-amplified NB cell lines conditionally knockdown (cKD) for the RB1 gene through a CRISPRi approach. Indeed, RB KD did not affect cell proliferation, whereas cell proliferation was strongly influenced when a non-phosphorylatable RB mutant was expressed. This finding revealed the dispensable role of RB in regulating MYCN-amplified NB's cell cycle. The described genetic interaction between MYCN and RB1 provides the rationale for using cyclin/CDK complexes inhibitors in NBs carrying MYCN amplification and relatively high levels of RB1 expression
Reference genes for transcriptional analysis of flowering and fruit ripening stages in apple (Malus 3 domestica Borkh.).
Apple (Malus 9 domestica Borkh.) is the most important deciduous tree fruit crop grown around the world. Comparisons of gene expression profiles from different tissues, conditions or cultivars are valuable scientific tools to better understand the gene expression changes behind important silvicultural and nutritional traits. However, the accuracy of techniques employed to access gene expression is dependent on the evaluation of stable reference genes for data normalization to avoid statistical significance undue or incorrect conclusions. The objective of this work was to select the best genes to be used as references for gene expression studies in apple trees by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Vegetative and reproductive tissues of the apple ??Gala?? cultivar were evaluated during their seasonal cycle of growth and dormancy. The expression of 23 traditional housekeeping genes or genes suggested as constitutive by microarray data was investigated. Tested combinations of primers allowed the specific amplification and the generation of suitable efficiency curves for gene expression studies by RT-qPCR. Gene stability was determined by two different statistical descriptors, geNorm and Norm-Finder. The known variable PAL gene expression was used to validate selected normalizers. Results obtained allowed us to conclude that MDH, SAND, THFS, TMp1 and WD40 are the best reference genes to accurately normalize the relative transcript abundances using RT-qPCR in various tissues of apple.DOI 10.1007/s11032-014-0078-
Reference gene selection for gene expression studies in apple.
Apple (Malus x domestica Borkh.) is the most important deciduous tree fruit crop grown around the world, and also in the Southern of Brazil. Researches on apple genetic breeding include disease resistance mechanisms, grafting, chilling requirement, fruit ripening and production of nutraceutical compounds.Resumo
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