Falls are the leading cause of injury-related deaths in the elderly worldwide. Both gait impairment and cognitive decline have been shown to constitute major fall risk factors. However, further ...investigations are required to establish a more precise link between the influence of age on brain systems mediating executive cognitive functions and their relationship with gait disturbances, and thus help define novel markers and better guide remediation strategies to prevent falls.
Event-related functional magnetic resonance imaging (fMRI) was used to evaluate age-related effects on the recruitment of executive control brain network in selective attention task, as measured with a flanker paradigm. Brain activation patterns were compared between twenty young (21 years ± 2.5) and thirty-four old participants (72 years ± 5.3) with high fall risks. We then determined to what extend age-related differences in activation patterns were associated with alterations in several gait parameters, measured with electronic devices providing a precise quantitative evaluation of gait, as well as with alterations in several aspects of cognitive and physical abilities.
We found that both young and old participants recruited a distributed fronto-parietal-occipital network during interference by incongruent distractors in the flanker task. However, additional activations were observed in posterior parieto-occipital areas in the older relative to the younger participants. Furthermore, a differential recruitment of both the left dorsal parieto-occipital sulcus and precuneus was significantly correlated with higher gait variability. Besides, decreased activation in the right cerebellum was found in the older with poorer cognitive processing speed scores.
Overall results converge to indicate greater sensitivity to attention interference and heightened recruitment of cortical executive control systems in the elderly with fall risks. Critically, this change was associated with selective increases in gait variability indices, linking attentional control with gait performance in elderly with high risks of falls.
•Gait performance in elderly with high risks of falls is partly linked to executive control abilities.•Over-recruitment of posterior cortices might reflect compensatory processes mitigating age-related executive control decline.•Study links higher gait variability with greater increases in both frontal and parieto-occipital areas in elderly.•Gait variability assessment using pressure-sensitive walkways is sensitive to identify neural changes in attentional network.
Local Positioning Systems are collecting high research interest over the last few years. Its accurate application in high-demanded difficult scenarios has revealed its stability and robustness for ...autonomous navigation. In this paper, we develop a new sensor deployment methodology to guarantee the system availability in case of a sensor failure of a five-node Time Difference of Arrival (TDOA) localization method. We solve the ambiguity of two possible solutions in the four-sensor TDOA problem in each combination of four nodes of the system by maximizing the distance between the two possible solutions in every target possible location. In addition, we perform a Genetic Algorithm Optimization in order to find an optimized node location with a trade-off between the system behavior under failure and its normal operating condition by means of the Cramer Rao Lower Bound derivation in each possible target location. Results show that the optimization considering sensor failure enhances the average values of the convergence region size and the location accuracy by 31% and 22%, respectively, in case of some malfunction sensors regarding to the non-failure optimization, only suffering a reduction in accuracy of less than 5% under normal operating conditions.
Scientific research is a human endeavour, performed by communities of people. Disproportionate focus on only some of the features related to this obvious fact has been used to discredit the ...reliability of scientific knowledge and to relativize its value when compared with knowledge stemming from other sources. This epistemic relativism is widespread nowadays and is arguably dangerous for our collective future, as the threat of climate change and its denialism clearly shows. In this work, we argue that even though the social character of science is indeed real, it does not entail epistemic relativism with respect to scientific knowledge, but quite the opposite, as there are several characteristic behaviours of this specific human community that were built to increase the reliability of scientific outputs. Crucially, we believe that present-day scientific education is lacking in the description and analysis of these particularities of the scientific community as a social group and that further investing in this area could greatly improve the possibilities of critical analysis of the often very technical issues that the citizens and future citizens of our modern societies have to confront.
•The influence of plant genetic diversity on soil fungi was studied in N. alpina.•Significant shifts in rhizosphere fungal communities were noticed.•Basidiomycetes dominated in the native forest and ...Ascomycetes in the plantation.•Relationships between plant genetic diversity and rhizosphere fungi were observed.•It is important to consider soil fungi for management and domestication programs.
Fungi are one of the most important soil microorganisms due to their abundance and the importance of the ecosystem processes they carry out, like decomposition, nutrient cycling, and the establishment of biological interactions such as mycorrhizas. Fungi can be used as bioindicators because they are highly sensitive to alterations in their surroundings, thus being useful for monitoring ecological changes and effects of human activity on natural ecosystems. Nothofagus alpina (raulí) is an ecologically and economically important species of South American temperate forests. It is currently included in domestication and conservation programs, and provenance trials have been installed in different ecosystems of Patagonia. These trials are ideal for studying how tree genetics might influence the associated microbiota. Afforestation with fast-growing exotic conifers (mainly Pinus ponderosa) had been promoted as an important economic activity in Patagonia, but nowadays there is an increasing interest for the establishment of mix Pinus + Nothofagus plantations instead of monospecific Pinus stands and for using Pinus plantations as refugee for assisted Nothofagus migration. The main objective of this work was to explore the structure of different fungal communities in the rhizosphere of N. alpina with different genetic diversity (high, intermediate, and low) implanted under a native Nothofagus forest and a P. ponderosa plantation. Fingerprinting based on Temperature Gradient Gel Electrophoresis revealed differences in the structure of the rhizosphere fungal communities. Some relationships between N. alpina genetic diversity and composition of rhizosphere fungal communities were observed. In the native forest, one of the provenances (intermediate genetic diversity) was associated with the highest richness of Basidiomycetes and total fungi. In addition, individual genetic parameters of N. alpina specimens implanted in the native forest significantly correlated with Ascomycetes richness. It was also found that Basidiomycetes were the dominating fungal taxa in the native forest, and Ascomycetes in the P. ponderosa plantation. Factors as soil physicochemical characteristics and the dominant forestry species, which provide different quantity and quality of litter inputs and are associated with different ectomycorrhizal fungi, seemed to be the main factors determining this significant difference between the native forest and the plantation. Beyond highlighting the potential of applying soil fungi as bioindicators, our study contributes to understanding the relationship between host genetics and rhizosphere fungi. This information is relevant not only for conservation and restoration programs, but also for taking management decisions related with sustainable forestry and domestication of native tree species.
Background and Aims
Long‐term harms of cannabis may be exacerbated in adolescence, but little is known about the acute effects of cannabis in adolescents. We aimed to (i) compare the acute effects of ...cannabis in adolescent and adult cannabis users and (ii) determine if cannabidiol (CBD) acutely modulates the effects of delta‐9‐tetrahydocannabinol (THC).
Design
Randomised, double‐blind, placebo‐controlled, crossover experiment. The experiment was registered on ClinicalTrials.gov (NCT04851392).
Setting
Laboratory in London, United Kingdom.
Participants
Twenty‐four adolescents (12 women, 16‐ to 17‐year‐olds) and 24 adults (12 women, 26‐ to 29‐year‐olds) who used cannabis 0.5–3 days/week and were matched on cannabis use frequency (mean = 1.5 days/week).
Intervention
We administered three weight‐adjusted vaporised cannabis flower preparations: ‘THC’ (8 mg THC for 75 kg person); ‘THC + CBD’ (8 mg THC and 24 mg CBD for 75 kg person); and ‘PLA’ (matched placebo).
Measurements
Primary outcomes were (i) subjective ‘feel drug effect’; (ii) verbal episodic memory (delayed prose recall); and (iii) psychotomimetic effect (Psychotomimetic States Inventory).
Findings
Compared with ‘PLA’, ‘THC’ and ‘THC + CBD’ significantly (P < 0.001) increased ‘feel drug effect’ (mean difference MD = 6.3, 95% CI = 5.3–7.2; MD = 6.8, 95% CI = 6.0–7.7), impaired verbal episodic memory (MD = –2.7, 95% CI = −4.1 to −1.4; MD = −2.9, 95% CI = −4.1 to −1.7) and increased psychotomimetic effects (MD = 7.8, 95% CI = 2.8–12.7; MD = 10.8, 95% CI = 6.2–15.4). There was no evidence that adolescents differed from adults in their responses to cannabis (interaction P ≥ 0.4). Bayesian analyses supported equivalent effects of cannabis in adolescents and adults (Bayes factor BF01 >3). There was no evidence that CBD significantly modulated the acute effects of THC.
Conclusions
Adolescent cannabis users are neither more resilient nor more vulnerable than adult cannabis users to the acute psychotomimetic, verbal memory‐impairing or subjective effects of cannabis. Furthermore, in adolescents and adults, vaporised cannabidiol does not mitigate the acute harms caused by delta‐9‐tetrahydocannabinol.
Abstract
Prevalent across societies and times, music has the ability to enhance attention, a property relevant to clinical applications, but the underlying brain mechanisms remain unknown. It is also ...unclear whether music produces similar or differential effects with advancing age. Here, we used event-related functional magnetic resonance imaging to investigate the influence of music exposure evoking four types of emotions on distinct attentional components measured with a modified attention network test, across 19 young (21 ± 2.6) and 33 old participants (72 ± 5.4). We then determined whether music-related effects differed across age groups and whether they were associated with particular acoustic features. Background music during selective attention requiring distractor conflict resolution was associated with faster response times and greater activations of fronto-parietal areas during happy and high-arousing music, whereas sad and low-valence music was associated with slower responses and greater occipital recruitment. Shifting and altering components of attention were unaffected. The influence of music on performance and brain networks was similar between age groups. These behavioral and neuroimaging results demonstrate the importance of affective music dimensions, particularly arousal, in enhancing selective attention processes. This study adds novel support to the benefits of music in the rehabilitation of attention functions.
Core Ericaceae produce delicate hair roots with inflated rhizodermal cells that host plethora of fungal symbionts. These poorly known mycobionts include various endophytes, parasites, saprobes, and ...the ericoid mycorrhizal (ErM) fungi (ErMF) that form the ErM symbiosis crucial for the fitness of their hosts. Using microscopy and high-throughput sequencing, we investigated their structural and molecular diversity in 14 different host × site combinations in Northern Bohemia (Central Europe) and Argentine Patagonia (South America). While we found typical ericoid mycorrhiza in all combinations, we did not detect ectomycorrhiza and arbuscular mycorrhiza. Superficial mantles of various thickness formed by non-clamped hyphae were observed in all combinations except
Calluna vulgaris
from N. Bohemia. Some samples contained frequent intercellular hyphae while others possessed previously unreported intracellular haustoria-like structures linked with intracellular hyphal coils. The 711 detected fungal OTU were dominated by Ascomycota (563) and Basidiomycota (119), followed by four other phyla. Ascomycetes comprised Helotiales (255), Pleosporales (53), Chaetothyriales (42), and other 19 orders, while basidiomycetes Sebacinales (42), Agaricales (28), Auriculariales (7), and other 14 orders. While many dominant OTU from both hemispheres lacked close relatives in reference databases, many were very similar to identical to unnamed sequences from around the world. On the other hand, several significant ericaceous mycobionts were absent in our dataset, incl.
Cairneyella
,
Gamarada
,
Kurtia
,
Lachnum
, and
Leohumicola
. Most of the detected OTU could not be reliably linked to a particular trophic mode, and only two could be reliably assigned to the archetypal ErMF
Hyaloscypha hepaticicola
. Probable ErMF comprised
Hyaloscypha variabilis
and
Oidiodendron maius
, both detected only in N. Bohemia. Possible ErMF comprised sebacinoid fungi and several unnamed members of
Hyaloscypha
s. str. While
H. hepaticicola
was dominant only in
C. vulgaris
, this model ErM host lacked
O. maius
and sebacinoid mycobionts.
Hyaloscypha hepaticicola
was absent in two and very rare in six combinations from Patagonia. Nine OTU represented dark septate endophytes from the
Phialocephala fortinii
s. lat.–
Acephala applanata
species complex, including the most abundant OTU (the only detected in all combinations). Statistical analyses revealed marked differences between N. Bohemia and Patagonia, but also within Patagonia, due to the unique community detected in a Valdivian temperate rainforest. Our results show that the ericaceous hair roots may host diverse mycobionts with mostly unknown functions and indicate that many novel ErMF lineages await discovery. Transhemispheric differences (thousands of km) in their communities may be evenly matched by local differences (scales of km, m, and less).
•Sites with tephra had N. pumilio regeneration and low understory plant richness.•Nothofagus pumilio seedlings in the tephra had ectomycorrhizal fungi (EM).•Differences in plant growth and EM ...behavior were observed between sites.•The composition of EM communities in the tephra was different from that in forest soil.•EM are an effective adaptation mechanism for stressful, post-eruption conditions.
Volcanic eruptions affect ecosystems drastically, and ectomycorrhizal fungi (EM) may play a critical role in forest regeneration. Nothofagus species are usually ectomycorrhizal. The 2011 Puyehue Cordón-Caulle volcanic complex (PCCVC) eruption covered vast areas of N. pumilio forests with thick tephra deposits. The main objectives of this work were to characterize the forest environment following tephra deposition, and to analyze the natural regeneration and development of N. pumilio and associated EM communities. Three study sites were selected and sampled two and three years after the PCCVC eruption. Two sites had a thick tephra layer (50 cm); in one of them most of the tree layer was dead (Highly Affected-Tephra) whereas in the other, most of the adult trees were alive (Affected-Tephra). The third site had minimal tephra deposition (Non-Affected). Physicochemical properties of the substrate, biological environmental factors and EM behavior of N. pumilio seedlings and adults were evaluated in all three sites. The physicochemical properties of the substrate and environmental characteristics differed among sites. Both seedlings and adults had EM in all three sites. The frequency of six-month-old seedlings with EM (40%) and their colonization values (<12%) were significantly lower in both tephra-affected sites than in the Non-affected site (100% and 80 %, respectively). However, all the 18-month-old seedlings from the tephra-affected sites had EM and their colonization increased almost to the value of the seedlings from the Non-Affected site. In both tephra-affected sites N. pumilio seedlings were associated with some exclusive fungal species, which could have a primary successional role. The early, increasing EM colonization recorded in seedlings after the eruption supports the idea of the strong dependence of Nothofagus trees on this symbioses, and highlights that this mutualism could be an effective adaptive mechanism under stressful conditions. Our findings also suggest that EM symbiosis in N. pumilio persists even after a severe disturbance and is regulated by several factors such as time after eruption, availability and type of mycorrhizal inoculum, plant development and physicochemical substrate composition.
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