A coordinated response to environmental drivers amongst individual functional traits is central to the plant strategy concept. However, whether the trait co-ordination observed at the global scale ...occurs at other ecological scales (especially within species) remains an open question. Here, for sapling communities of two tropical dry forest types in Costa Rica, we show large differences amongst traits in the relative contribution of species turnover and intraspecific variation to their directional changes in response to environmental changes along a successional gradient. We studied the response of functional traits associated with the leaf economics spectrum and drought tolerance using intensive sampling to analyse inter- and intra-specific responses to environmental changes and ontogeny. Although the overall functional composition of the sapling communities changed during succession more through species turnover than through intraspecific trait variation, their relative contributions differed greatly amongst traits. For instance, community mean specific leaf area changed mostly due to intraspecific variation. Traits of the leaf economics spectrum showed decoupled responses to environmental drivers and ontogeny. These findings emphasise how divergent ecological mechanisms combine to cause great differences in changes of individual functional traits over environmental gradients and ecological scales.
Zika virus (ZIKV) can be transmitted sexually between humans. However, it is unknown whether ZIKV replicates in the vagina and impacts the unborn fetus. Here, we establish a mouse model of vaginal ...ZIKV infection and demonstrate that, unlike other routes, ZIKV replicates within the genital mucosa even in wild-type (WT) mice. Mice lacking RNA sensors or transcription factors IRF3 and IRF7 resulted in higher levels of local viral replication. Furthermore, mice lacking the type I interferon (IFN) receptor (IFNAR) became viremic and died of infection after a high-dose vaginal ZIKV challenge. Notably, vaginal infection of pregnant dams during early pregnancy led to fetal growth restriction and infection of the fetal brain in WT mice. This was exacerbated in mice deficient in IFN pathways, leading to abortion. Our study highlights the vaginal tract as a highly susceptible site of ZIKV replication and illustrates the dire disease consequences during pregnancy.
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•Zika virus replicates in the vaginal tract of wild-type virgin and pregnant mice•Innate RNA sensors and type I interferons control vaginal Zika virus replication•Vaginal Zika virus infection in early pregnancy leads to fetal growth restriction•Vaginal Zika virus infection of pregnant dams leads to fetal brain infection
Vaginal mucosa is permissive to the replication of Zika virus, and infection through this route can lead to fetal brain infection even in mice with an intact immune system.
Spawning behaviour of Atlantic bluefin tuna (Thunnus thynnus) was investigated using electronic satellite tags deployed in the western Mediterranean spawning ground, around the Balearic Islands ...(years 2009-2011). All the fish were tagged underwater and released within schools. In general, the fish tagged in the same year/school displayed common migratory trends. Following extended residency around the Balearic Islands, most tagged tuna crossed the Strait of Gibraltar heading for the North Atlantic. Discrepancies between the migratory tracks reconstructed from this and previous electronic tagging studies suggest that the bluefin tuna Mediterranean population may comprise distinct units exhibiting differing migratory behaviours. The diving behaviour varied between oceanic regions throughout the migratory pathways, the shallowest distribution taking place in the spawning ground and the deepest at the Strait of Gibraltar. A unique diving pattern was found on the majority of nights while the fish stayed at the spawning ground; it consisted of frequent and brief oscillatory movements up and down through the mixed layer, resulting in thermal profiles characterized by oscillations about the thermocline. Such a pattern is believed to reflect recent courtship and spawning activity. Reproductive parameters inferred from the analysis of vertical profiles are consistent with those estimated in previous studies based on biological samples.
In this work, we deepen in the characterization of two protic ionic liquids (PILs), ethylammonium nitrate (EAN) and propylammonium nitrate (PAN). With this aim, we determined the influence of ...inorganic nitrate salts addition on their physical properties and their electrochemical potential window (EPW). Thus, experimental measurements of electrical conductivity, density, viscosity, refractive index and surface tension of mixtures of {EAN or PAN + LiNO
, Ca(NO
)
, Mg(NO
)
or Al(NO
)
} at a temperature range between 5 and 95 °C are presented first, except for the last two properties which were measured at 25 °C. In the second part, the corresponding EPWs were determined at 25 °C by linear sweep voltammetry using three different electrochemical cells. Effect of the salt addition was associated mainly with the metal cation characteristics, so, generally, LiNO
showed the lower influence, followed by Ca(NO
)
, Mg(NO
)
or Al(NO
)
. The results obtained for the EAN + LiNO
mixtures, along with those from a previous work, allowed us to develop novel predictive equations for most of the presented physical properties as functions of the lithium salt concentration, the temperature and the water content. Electrochemical results showed that a general order of EPW can be established for both PILs, although exceptions related to measurement conditions and the properties of the mixtures were found.
Moving grate boilers are widely used in the combustion of solid biomass at industrial scale for heat and power production. This type of systems allows to use wide range of fuels, including those with ...a high moisture and ash content. However, biomass boilers present several associated problems, such as e pollutant missions or ageing phenomena that can reduce the efficiency of the boilers or damage them such as fouling, slagging or corrosion. CFD tools can be used to study biomass combustion systems providing information useful to optimize the operation and design of the boilers. In this work, an Eulerian fixed-bed biomass combustion model coupled with the CFD commercial code ANSYS-Fluent will be used to carry out the simulation of a large-scale moving grate biomass furnace. New procedures have to be developed to adapt the model operation to the characteristics of this case. The numerical results are compared with experimental data from literature. The new procedures provide a solution of the bed morphology, which is validated against the experimental data.
•Three-dimensional transient simulation of a 4 MW biomass grate-fired furnace•Development of a new Eulerian feeding model•Validation of the simulation against experimental results from literature•Bed combustion pattern in accordance with literature data
We present NeuralIL, a model for the potential energy of an ionic liquid that accurately reproduces first-principles results with orders-of-magnitude savings in computational cost. Built on the basis ...of a multilayer perceptron and spherical Bessel descriptors of the atomic environments, NeuralIL is implemented in such a way as to be fully automatically differentiable. It can thus be trained on ab initio forces instead of just energies, to make the most out of the available data, and can efficiently predict arbitrary derivatives of the potential energy. Using ethylammonium nitrate as the test system, we obtain out-of-sample accuracies better than 2 meV atom
(<0.05 kcal mol
) in the energies and 70 meV Å
in the forces. We show that encoding the element-specific density in the spherical Bessel descriptors is key to achieving this. Harnessing the information provided by the forces drastically reduces the amount of atomic configurations required to train a neural network force field based on atom-centered descriptors. We choose the Swish-1 activation function and discuss the role of this choice in keeping the neural network differentiable. Furthermore, the possibility of training on small data sets allows for an ensemble-learning approach to the detection of extrapolation. Finally, we find that a separate treatment of long-range interactions is not required to achieve a high-quality representation of the potential energy surface of these dense ionic systems.
Astrocytes represent central regulators of brain glucose metabolism and neuronal function. They have recently been shown to adapt their function in response to alterations in nutritional state ...through responding to the energy state-sensing hormones leptin and insulin. Here, we demonstrate that glucagon-like peptide (GLP)-1 inhibits glucose uptake and promotes β-oxidation in cultured astrocytes. Conversely, postnatal GLP-1 receptor (GLP-1R) deletion in glial fibrillary acidic protein (GFAP)-expressing astrocytes impairs astrocyte mitochondrial integrity and activates an integrated stress response with enhanced fibroblast growth factor (FGF)21 production and increased brain glucose uptake. Accordingly, central neutralization of FGF21 or astrocyte-specific FGF21 inactivation abrogates the improvements in glucose tolerance and learning in mice lacking GLP-1R expression in astrocytes. Collectively, these experiments reveal a role for astrocyte GLP-1R signaling in maintaining mitochondrial integrity, and lack of GLP-1R signaling mounts an adaptive stress response resulting in an improvement of systemic glucose homeostasis and memory formation.
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•GLP-1 inhibits glucose uptake and promotes β-oxidation in cultured astrocytes•Lack of astrocyte GLP-1R in vivo activates a stress response and increases FGF21•Adaptations to astrocyte GLP-1R deletion improve glucose metabolism and memory
Astrocytes regulate brain glucose metabolism and neuronal function. Timper et al. describe a role for astrocyte GLP-1R signaling in maintaining mitochondrial integrity and demonstrate that lack of astrocyte GLP-1R signaling mounts an adaptive stress response to increase astrocyte FGF21 expression resulting in an improvement of systemic glucose homeostasis and memory formation.
In recent years, the use of virtual reality (VR) as a complementary intervention in treating cognitive impairment has significantly increased. VR applications based on instrumental activities of ...daily living (iADL-VR) could offer a promising approach with greater ecological validity for intervention in groups with cognitive impairments. However, the effectiveness of this approach is still debated.
This systematic review aims to synthesize the effects of iADL-VR interventions to rehabilitate, train, or stimulate cognitive functions in healthy adults and people with mild cognitive impairment (MCI) and different types of dementia.
A systematic search was performed in the Scopus, PubMed, IEEE Xplore, Web of Science, and APA PsycNet databases until September 2022 and repeated in April 2023. The selected studies met the search terms, were peer-reviewed, included an iADL-VR intervention, and were written in English. Descriptive, qualitative studies, reviews, cognitive assessment, non-intervention studies, those unrelated to VR or iADL, those focused on motor aspects, and non-degenerative disorders were excluded. The PEDro scale was used to assess the methodological quality of the controlled studies. To present and synthesize the results, we organized the extracted data into three tables, including PEDro scores, participant characteristics, and study characteristics.
Nineteen studies that met the inclusion and exclusion criteria were included. The total sample reached 590 participants, mostly women (72.67%). Approximately 30% were diagnosed with Alzheimer's disease or dementia, and 20% had mild cognitive impairment. Variables such as authors and year of publication, study design, type of intervention and VR applied, duration of the intervention, main findings, and conclusions were extracted. Regarding demographic characteristics, the sample size, age, sex, years of education, neurological diagnosis, dropouts, and the city and country where the intervention took place were recorded. Almost all studies showed improvements in some or all the outcomes after the intervention, generally greater in the iADL-VR group than in the control group.
iADL-VR interventions could be beneficial in improving the performance of cognitive functions in older adults and people with MCI and different types of dementia. The ecological component of these tasks makes them very suitable for transferring what has been learned to the real world. However, such transfer needs to be confirmed by further studies with larger and more homogeneous samples and longer follow-up periods. This review had no primary funding source and was registered with PROSPERO under registration ID: 375166.
Abstract
Background
Loss of cognitive and executive functions is a problem that affects people of all ages. That is why it is important to perform exercises for memory training and prevent early ...cognitive deterioration. The aim of this work was to compare the cognitive performance of the participants after an intervention by using two mnemonic techniques to exercise memory functions (paired-associate learning and method of loci).
Methods
A longitudinal study was conducted with 21 healthy participants aged 18 to 55 years over a 2-month period. To assess the impact of this proposal, the NEUROPSI brief battery cognitive assessment test was applied before and after the intervention. In each session, a previous cognitive training was carried out using the paired-associate learning technique, to later perform a task based on the loci method, all from a smart device-based application. The accuracy response and reaction times were automatically collected in the app.
Results
After the intervention, a statistically significant improvement was obtained in the neuropsychological assessment (NEUROPSI neuropsychological battery) reflected by the Wilcoxon paired signed-rank test (
P
< .05).
Conclusion
The task based on the method of loci also reflected the well-known age-related effects common to memory assessment tasks. Episodic memory training using the method of loci can be successfully implemented using a smart device app. A stage-based methodological design allows to acquire mnemic skills gradually, obtaining a significant cognitive improvement in a short period of time.
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