Environmental niche modeling (ENM) is commonly used to develop probabilistic maps of species distribution. Among available ENM techniques, MaxEnt has become one of the most popular tools for modeling ...species distribution, with hundreds of peer-reviewed articles published each year. MaxEnt's popularity is mainly due to the use of a graphical interface and automatic parameter configuration capabilities. However, recent studies have shown that using the default automatic configuration may not be always appropriate because it can produce non-optimal models; particularly when dealing with a small number of species presence points. Thus, the recommendation is to evaluate the best potential combination of parameters (feature classes and regularization multiplier) to select the most appropriate model. In this work we reviewed 244 articles published between 2013 and 2015 to assess whether researchers are following recommendations to avoid using the default parameter configuration when dealing with small sample sizes, or if they are using MaxEnt as a "black box tool." Our results show that in only 16% of analyzed articles authors evaluated best feature classes, in 6.9% evaluated best regularization multipliers, and in a meager 3.7% evaluated simultaneously both parameters before producing the definitive distribution model. We analyzed 20 articles to quantify the potential differences in resulting outputs when using software default parameters instead of the alternative best model. Results from our analysis reveal important differences between the use of default parameters and the best model approach, especially in the total area identified as suitable for the assessed species and the specific areas that are identified as suitable by both modelling approaches. These results are worrying, because publications are potentially reporting over-complex or over-simplistic models that can undermine the applicability of their results. Of particular importance are studies used to inform policy making. Therefore, researchers, practitioners, reviewers and editors need to be very judicious when dealing with MaxEnt, particularly when the modelling process is based on small sample sizes.
Mapping ecosystem services is a challenging task, particularly for regulating services presenting spatial mismatches between the areas providing the services and those benefiting from them, such as ...the temperature reduction ecosystem service (TRES) provided by urban vegetation. The challenge for mapping TRES arises because vegetation not only reduces temperatures at the immediate location, but also in distance-decaying rates in surrounding areas. Furthermore, different functional types of vegetation have differential cooling capabilities, making difficult to assess the accumulated level of TRES provided by vegetated areas if these are heterogeneous in terms of vegetation cover and functional types. To help overcoming these challenges, this work presents a GIS-based methodological approach for mapping TRES that takes explicit consideration of the differential cooling capabilities of vegetation functional types and the distance-decaying spatial transference of services from vegetated to surrounding areas. This approach is applied to the city of Santiago, comparing the mapping results with two other potential alternative mapping methods. The mapping approach presented in this work consistently outperformed the alternative methods. This approach could be easily applied to other urban areas and adapted to be used for mapping other regulating services, such as air and noise pollution mitigation provided by urban vegetation.
Benzothiadiazole (BTH) and methyl jasmonate (MeJ) have been described as exogenous elicitors of some plant defense compounds, polyphenols among them. The objective of this study was to determine ...whether the application of BTH or MeJ to grape clusters at the beginning of the ripening process had any effect on the accumulation of the main flavonoid compounds in grapes (anthocyanins, flavonols, and flavanols) and the technological significance of these treatments in the resulting wines. The results obtained after a 2 year experiment indicated that both treatments increased the anthocyanin, flavonol, and proanthocyanidin content of grapes. The wines obtained from the treated grapes showed higher color intensity and total phenolic content than the wines made from control grapes. The exogenous application of these elicitors, as a complement to fungicide treatments, could be an interesting strategy for vine protection, increasing, at the same time, the phenolic content of the grapes and the resulting wines.
The brain requires large quantities of energy to sustain its functions. At the same time, the brain is isolated from the rest of the body, forcing this organ to develop strategies to control and ...fulfill its own energy needs. Likely based on these constraints, several brain‐specific mechanisms emerged during evolution. For example, metabolically specialized cells are present in the brain, where intercellular metabolic cycles are organized to separate workload and optimize the use of energy. To orchestrate these strategies across time and space, several signaling pathways control the metabolism of brain cells. One of such controlling systems is the endocannabinoid system, whose main signaling hub in the brain is the type‐1 cannabinoid (CB1) receptor. CB1 receptors govern a plethora of different processes in the brain, including cognitive function, emotional responses, or feeding behaviors. Classically, the mechanisms of action of CB1 receptors on brain function had been explained by its direct targeting of neuronal synaptic function. However, new discoveries have challenged this view. In this review, we will present and discuss recent data about how a small fraction of CB1 receptors associated to mitochondrial membranes (mtCB1), are able to exert a powerful control on brain functions and behavior. mtCB1 receptors impair mitochondrial functions both in neurons and astrocytes. In the latter cells, this effect is linked to an impairment of astrocyte glycolytic function, resulting in specific behavioral outputs. Finally, we will discuss the potential implications of (mt)CB1 expression on oligodendrocytes and microglia metabolic functions, with the aim to encourage interdisciplinary approaches to better understand the role of (mt)CB1 receptors in brain function and behavior.
The type‐1 cannabinoid (CB1) receptors exert a powerful control of brain function and behavior. Noteworthy, it has been shown recently that CB1 receptors can be associated with mitochondrial membranes (mtCB1 receptors). Their engagement impairs the metabolic functions of neurons and astrocytes, thereby altering brain function and behavior. However, our knowledge about the relationship between CB1 receptors and the brain metabolic function is still limited, both at the level of the metabolic pathways engaged, and the cell types involved. Further interdisciplinary approaches will be necessary to explore the interplay between CB1 receptors, energy metabolism, brain function, and behavior.
This review is focused on iron-based homogeneous catalytic systems described so far for the reduction of carbonyl compounds (ketones and aldehydes) into alcohols via hydrosilylation. It begins by ...explaining the basic concepts of the hydrosilylation reaction, addressing its main advantages and procedural differences with other common reduction methods, and highlighting the interest for its use in organic chemistry. Then, the advances in the development of iron-based catalysts, as a more sustainable alternative to the traditional noble-metal catalysts, that have taken place to date are reviewed in depth. The revision of the different types of catalysts is followed by a profound discussion of the mechanistic proposals found in the literature.
Update on the role of T cells in cognitive impairment Ruiz‐Fernández, Ignacio; Sánchez‐Díaz, Raquel; Ortega‐Sollero, Enrique ...
British journal of pharmacology,
March 2024, 2024-03-00, 20240301, Letnik:
181, Številka:
6
Journal Article
Recenzirano
Odprti dostop
The central nervous system (CNS) has long been considered an immune‐privileged site, with minimal interaction between immune cells, particularly of the adaptive immune system. Previously, the ...presence of immune cells in this organ was primarily linked to events involving disruption of the blood–brain barrier (BBB) or inflammation. However, current research has shown that immune cells are found patrolling CNS under homeostatic conditions. Specifically, T cells of the adaptive immune system are able to cross the BBB and are associated with ageing and cognitive impairment. In addition, T‐cell infiltration has been observed in pathological conditions, where inflammation correlates with poor prognosis. Despite ongoing research, the role of this population in the ageing brain under both physiological and pathological conditions is not yet fully understood. In this review, we provide an overview of the interactions between T cells and other immune and CNS parenchymal cells, and examine the molecular mechanisms by which these interactions may contribute to normal brain function and the scenarios in which disruption of these connections lead to cognitive impairment. A comprehensive understanding of the role of T cells in the ageing brain and the underlying molecular pathways under normal conditions could pave the way for new research to better understand brain disorders.
LINKED ARTICLES
This article is part of a themed issue From Alzheimer's Disease to Vascular Dementia: Different Roads Leading to Cognitive Decline. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.6/issuetoc
Tomato composition and nutritional value are attracting increasing attention and interest from both consumers and producers. The interest in enhancing fruits' quality with respect to beneficious ...nutrients and flavor/aroma components is based not only in their economic added value but also in their implications involving organoleptic and healthy properties and has generated considerable research interest among nutraceutical and horticultural industries. The present article reviews up to March 2020 some of the most relevant studies based on the application of NMR coupled to multivariate statistical analysis that have addressed the investigation on tomato (
). Specifically, the NMR untargeted technique in the agri-food sector can generate comprehensive data on metabolic networks and is paving the way towards the understanding of variables affecting tomato crops and composition such as origin, variety, salt-water irrigation, cultivation techniques, stage of development, among many others. Such knowledge is helpful to improve fruit quality through cultural practices that divert the metabolism towards the desired pathways and, probably more importantly, drives further efforts towards the differentiation of those crops developed under controlled and desired agronomical conditions.
Modeling pedestrian dynamics and their implementation in a computer are challenging and important issues in the knowledge areas of transportation and computer simulation. The aim of this article is ...to provide a bibliographic outlook so that the reader may have quick access to the most relevant works related to this problem. We have used three main axes to organize the article’s contents: pedestrian models, validation techniques, and multiscale approaches. The backbone of this work is the classification of existing pedestrian models; we have organized the works in the literature under five categories, according to the techniques used for implementing the operational level in each pedestrian model. Then the main existing validation methods, oriented to evaluate the behavioral quality of the simulation systems, are reviewed. Furthermore, we review the key issues that arise when facing multiscale pedestrian modeling, where we first focus on the behavioral scale (combinations of micro and macro pedestrian models) and second on the scale size (from individuals to crowds). The article begins by introducing the main characteristics of walking dynamics and its analysis tools and concludes with a discussion about the contributions that different knowledge fields can make in the near future to this exciting area.
Background
Asthma is a syndrome characterized by airway inflammation and obstruction. Due to its heterogeneity, the difficulties in asthma diagnosis and treatment make the discovery of new biomarkers ...a focus of research. So, we determined the differential miRNA expression of eosinophils between healthy and asthmatic patients and to establish a differentially expressed miRNA profile detectable in sera for use as biomarker.
Methods
MicroRNAs from peripheral eosinophils from healthy and asthmatic subjects were isolated and analyzed by next‐generation sequencing and confirmed by quantitative PCR in 29 asthmatics and 10 healthy individuals. The levels of serum miRNAs were performed by quantitative PCR in 138 asthmatics and 39 healthy subjects. Regression analysis and Random Forest models were performed.
Results
We found a set of miRNAs whose expression differs between eosinophils from asthmatics and healthy subjects. These miRNAs can classify asthmatics into two clusters that differed in the number of eosinophils and periostin concentration in serum. Some of these miRNAs were also confirmed in sera, as miR‐185‐5p which discriminates asthmatics from healthy subjects. Together with other two miRNAs, miR‐185‐5p allowed us to create a logistic regression model to discriminate better both conditions and a Random Forest model that can even sort the asthmatics into intermittent, mild persistent, moderate persistent, and severe persistent asthma.
Conclusion
Our data show that miRNAs profile in eosinophils can be used as asthma diagnosis biomarker in serum and that this profile is able to rank asthma severity.
Eosinophils from asthmatics present a different profile in microRNAs (miRNAs) compared to eosinophils from healthy subjects. As eosinophils obtention from patients is not a standardized method, we analyzed these miRNAs in serum showing that miRNAs profile expression in this biofluid can be used for asthma diagnosis and for severity classification.
Abstract
Recognition and fusion between gametes during fertilization is an ancient process. Protein HAP2, recognized as the primordial eukaryotic gamete fusogen, is a structural homolog of viral ...class II fusion proteins. The mechanisms that regulate HAP2 function, and whether virus-fusion-like conformational changes are involved, however, have not been investigated. We report here that fusion between
plus
and
minus
gametes of the green alga
Chlamydomonas
indeed requires an obligate conformational rearrangement of HAP2 on
minus
gametes from a labile, prefusion form into the stable homotrimers observed in structural studies. Activation of HAP2 to undergo its fusogenic conformational change occurs only upon species-specific adhesion between the two gamete membranes. Following a molecular mechanism akin to fusion of enveloped viruses, the membrane insertion capacity of the fusion loop is required to couple formation of trimers to gamete fusion. Thus, species-specific membrane attachment is the gateway to fusion-driving HAP2 rearrangement into stable trimers.
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