Community assembly theory is founded on the premise that the relative importance of local environmental processes and dispersal shapes the compositional structure of metacommunities. The species ...sorting model predicts that assemblages are dominated by the environmental filtering of species that are readily able to disperse to suitable sites. We propose an ecophysiological hypothesis (EH) for the mechanism underlying the organization of species-sorting odonate metacommunities based on the interplay of thermoregulation, body size and the degree of sunlight availability in small-to-medium tropical streams. Due to thermoregulatory restrictions, the EH predicts (i) that larger species are disfavored in small streams and (ii) that streams exhibit a nested compositional pattern characterized by species' size distribution. To test the EH, we evaluate the longitudinal distribution of adult Odonata at 19 sites in 1st- to 6th-order streams in the Tropical Cerrado of Brazil. With increasing channel width, the total abundance and species richness of Anisoptera increased, while the abundance of Zygoptera decreased. The first axis of an ordination analysis of the species abundance data was directly related to channel width. Mean and maximum thorax size are positively correlated to channel width, but no relationship was found for the minimum thorax size, suggesting that there is no lower size constraint on the occurrence of these species. Additionally, a nested compositional pattern related to body size was observed. Our results support the EH and its use as an ecological assembly rule based on abiotic factors. Forest cover functions as a filter to determine which species successfully colonize a given site within a metacommunity. As a consequence, the EH also indicates higher treats for small-bodied zygopterans in relation to the loss of riparian forests in tropical streams.
The distribution and composition of aquatic insect communities in streams at a local scale are considered to be primarily determined by environmental factors and interactive relationships within the ...system. Here, we evaluated the effects of forest fragmentation and forest cover changes on habitat characteristics of streamlets (igarapés) in Amazonian forests and on the aquatic insect communities found there. We also developed a habitat integrity index (HII) based on Petersen's protocol (1992) to evaluate physical integrity of these streamlets and to determine its efficiency to interpret the environmental impacts on this system. We studied 20 small streams at the Biological Dynamics of Forest Fragments Project (BDFFP INPA/SI) study areas, Central Amazonia, 80 km north of Manaus, Amazonas State, Brazil. The vegetation cover was estimated by using LANDSAT images and classified in the following categories: exposed soil, pastures, secondary forests (capoeiras), and primary forests. Stream habitat features were evaluated by using a HII based on visual assessment of local characteristics. Aquatic insects were sampled in four major stream substrates: litter deposited in pools or backwaters, litter retained in riffles, sand, and marginal banks. Stream habitat characteristics were significantly correlated to land use and riparian forest condition. Overall aquatic insect richness and Ephemeroptera, Plecoptera, and Trichoptera (EPT) richness were significantly lower in pasture streams, and their taxonomic composition differed significantly from streams in forested areas. However, these metrics were not significantly correlated to the stream HII. Taxonomic composition of bank insect assemblages changed significantly between streams with low and high values of HII. There was no significant relationship between the proportion of primary forest cover and the faunal metrics. Only drastic changes in the vegetal cover seem to induce significant changes in the aquatic insect community. Matrix habitat heterogeneity, distance to forest fragments, the presence of areas of secondary forest, and the intrinsic capacity to disperse in many of the insect groups may have contributed to attenuate the effects of habitat disturbance on aquatic insect assemblages in streamlets.
Odonata can be sampled following different types of protocols. In Brazil, the most used protocol is the scanning in fixed areas method, where a 100-meter transect is delimited in one of the stream ...margins, subdivided into 20 segments measuring 5 meters. Despite being universally used, the methodological efficiency or limitations of this protocol for Odonata has never been tested. In this scenario, our objective was to assess the efficiency of the sampling protocol to measure the richness and composition of Odonata in three fundamental aspects: the time of sampling and sampling effort over time and space. We show that the best sampling efficiency was achieved in collections performed at noon, in transects measuring 100 meters, requiring at least two samplings in the same location, supporting the procedures traditionally adopted by many studies with the group. While comparing species composition, we did not see any implication between the different treatments on the capture of the local species pool. However, we highlight and discuss some possible methodological flaws when using this protocol to sample specific Odonata groups. We believe the results obtained are fundamental in the inventory of species and to conduct future studies, as well as to aid conservative measures that use the order Odonata as a tool for environmental monitoring.
Almost one-third of epileptic patients fail to achieve seizure control through anti-epileptic drug administration. In the scarcity of completely controlling a patient's epilepsy, seizure prediction ...plays a significant role in clinical management and providing new therapeutic options such as warning or intervention devices. Seizure prediction algorithms aim to identify the preictal period that Electroencephalogram (EEG) signals can capture. However, this period is associated with substantial heterogeneity, varying among patients or even between seizures from the same patient. The present work proposes a patient-specific seizure prediction algorithm using post-processing techniques to explore the existence of a set of chronological events of brain activity that precedes epileptic seizures. The study was conducted with 37 patients with Temporal Lobe Epilepsy (TLE) from the EPILEPSIAE database. The designed methodology combines univariate linear features with a classifier based on Support Vector Machines (SVM) and two post-processing techniques to handle pre-seizure temporality in an easily explainable way, employing knowledge from network theory. In the Chronological Firing Power approach, we considered the preictal as a sequence of three brain activity events separated in time. In the Cumulative Firing Power approach, we assumed the preictal period as a sequence of three overlapping events. These methodologies were compared with a control approach based on the typical machine learning pipeline. We considered a Seizure Prediction horizon (SPH) of 5 mins and analyzed several values for the Seizure Occurrence Period (SOP) duration, between 10 and 55 mins. Our results showed that the Cumulative Firing Power approach may improve the seizure prediction performance. This new strategy performed above chance for 62% of patients, whereas the control approach only validated 49% of its models.
Microalgae are recognized as a relevant source of bioactive compounds. Among these bioactive products, lipids, mainly glycolipids, have been shown to present immunomodulatory properties with the ...potential to mitigate chronic inflammation. This study aimed to evaluate the anti-inflammatory effect of polar lipids isolated from
and
. Three fractions enriched in (1) digalactosyldiacylglycerol (DGDG) and sulfoquinovosyldiacylglycerol (SQDG), (2) monogalactosyldiacylglycerol (MGDG), and (3) diacylglyceryl-trimethylhomoserine (DGTS) and phospholipids (PL) were obtained from the total lipid extracts (TE) of
and
, and their anti-inflammatory effect was assessed by analyzing their capacity to counteract nitric oxide (NO) production and transcription of pro-inflammatory genes
,
,
and
in lipopolysaccharide (LPS)-activated macrophages. For both microalgae, TE and Fractions 1 and 3 strongly inhibited NO production, although to different extents. A strong reduction in the LPS-induced transcription of
,
,
and
was observed for
and
lipids. The most active fractions were the DGTS-and-PL-enriched fraction from
and the DGDG-and-SQDG-enriched fraction from
. Our results reveal that microalgae lipids have strong anti-inflammatory capacity and may be explored as functional ingredients or nutraceuticals, offering a natural solution to tackle chronic inflammation-associated diseases.
One of the major challenges of ecologists and biogeographers is to understand how species are globally distributed. Two of the most well-studied large-scale patterns in species distributions are the ...Rapoport’s rule and the Latitudinal Diversity Gradient (LDG). We aimed to address whether Neotropical odonates follow the Rapoport’s rule and if there is a latitudinal gradient in species diversity. A total of 1076 records for 190 species, covering a large area from southeastern to the northern regions of Brazil that extends from 23°S (Cerrado) to 3°N (Amazon Rainforest). Generalized Linear Models were used to address whether Neotropical odonates follow the Rapoport’s rule, and if there is a latitudinal gradient in species diversity, based on our predictions. We found a Rapoport effect in the Amazon biome and an inverse Rapoport effect in the Amazon-Cerrado Transition Forest and Cerrado biome. Regarding LDG, we found no significant effect of latitude on species richness patterns when we considered all the species, and a significant relationship between species richness and latitude for zygopterans. The spatial patterns of odonates geographic distribution may be an outcome of geographical barriers, for instance, the continental geometry of South America, which is broader in the north and limits geographical expansion towards the south. Furthermore, species ecophysiological mechanisms may also hamper their expansion and drive the pattern observed in our study, mainly because of evolutionary thermoregulatory adaptations that each taxon exhibits along its environmental gradient.
In combination with microspotting, whole-blood microfluidics can provide high-throughput information on multiple platelet functions in thrombus formation. Based on assessment of the inter- and ...intra-subject variability in parameters of microspot-based thrombus formation, we aimed to determine the platelet factors contributing to this variation. Blood samples from 94 genotyped healthy subjects were analyzed for conventional platelet phenotyping: i.e. hematologic parameters, platelet glycoprotein (GP) expression levels and activation markers (24 parameters). Furthermore, platelets were activated by ADP, CRP-XL or TRAP. Parallel samples were investigated for whole-blood thrombus formation (6 microspots, providing 48 parameters of adhesion, aggregation and activation). Microspots triggered platelet activation through GP Ib-V-IX, GPVI, CLEC-2 and integrins. For most thrombus parameters, inter-subject variation was 2-4 times higher than the intra-subject variation. Principal component analyses indicated coherence between the majority of parameters for the GPVI-dependent microspots, partly linked to hematologic parameters, and glycoprotein expression levels. Prediction models identified parameters per microspot that were linked to variation in agonist-induced α
β
activation and secretion. Common sequence variation of
and
, associated with GPVI-induced α
β
activation and secretion, affected parameters of GPVI-and CLEC-2-dependent thrombus formation. Subsequent analysis of blood samples from patients with Glanzmann thrombasthenia or storage pool disease revealed thrombus signatures of aggregation-dependent parameters that were subject-dependent, but not linked to GPVI activity. Taken together, this high-throughput elucidation of thrombus formation revealed patterns of inter-subject differences in platelet function, which were partly related to GPVI-induced activation and common genetic variance linked to GPVI, but also included a distinct platelet aggregation component.
Several hypotheses have been proposed to explain the mechanisms that generate temporal and spatial species richness patterns. We tested four common hypotheses (water, energy, climatic heterogeneity ...and net primary productivity) to evaluate which factors best explain patterns of Zygoptera species richness. Of these, we predicted that climatic heterogeneity would be the most important predictor for Zygoptera richness patterns. We sampled communities of adult Zygoptera in 100 small Amazonian streams. Based on generalized linear mixed models (GLMM), we found that net primary productivity and climatic heterogeneity comprised the best model of Zygoptera species richness in Amazonian streams, with an pseudo r2 of 39.5%. Results indicate that species richness increases by one species per 1kg of biomass per square meter in NPP, or with an increase of 2°C in air temperature variability. Our work corroborates a recent study with other taxa in Brazilian Bioms. This suggests that temporal variation in climate and net primary productivity are important predictors of the macroecological patterns of richness for aquatic organisms in tropical regions.
Veredas
environments play a critical role on the perennialization of streams in the
Cerrado
Biome, but alterations to their physiognomies are becoming increasingly more common, which directly affects ...abiotic variation and the structure of biological communities. Our study evaluates the effect of abiotic variations and environmental alterations upon the abundance, richness, and composition of species of semiaquatic bugs, where we test whether there are significant differences in conserved and altered veredas. Species richness was higher on altered
veredas
and there was no difference in abundance between altered and preserved
veredas
. The composition of conserved
veredas
was more homogeneous. Five species were associated with altered
veredas
and one to
conserved
areas. There were abiotic changes in the veredas that affected the abundance, richness, and/or composition of Gerromorpha. Ease of access to soil usage and to water for farming activities and pasture might be the main factors contributing to the alteration of
veredas
in this region. Gerromorpha community structure was modified by the environmental passive in areas of
veredas
, thus allowing to measure the degree of alterations to these systems, being a useful tool for monitoring and conservation.
Chronic thromboembolic pulmonary hypertension (CTEPH) is a progressive, but potentially curable, form of pulmonary hypertension. Pulmonary endarterectomy (PEA) is a complex surgery that frequently ...achieves hemodynamic normalization and symptom resolution, although not all patients are suitable for the procedure. We aimed to assess long-term outcomes of CTEPH, namely all-cause mortality and hospital admission for decompensated heart failure, according to treatment modalities in patients who underwent PEA or non-surgical therapy.
A 10-year retrospective study of patients with CTEPH at a referral center was conducted. Forty-five patients were included and median follow-up time was 57 (IQR 24-93) months. Survival analysis was performed and a multivariate Cox regression model was used to identify independent predictors of outcomes.
Patients were mostly female (59%) and mean age was 63±16 years. Two-thirds were severely symptomatic at diagnosis, with 62.2% of patients presenting in WHO functional class (WHO FC) III or IV. One-, two- and three-year survival was 93.3%, 82.4% and 75.9%, respectively. Serum BNP (HR 1.003; 95% CI: 1.001-1.005; p=0.003) and creatinine (HR 12.092; 95% CI: 1.121-130.390; p=0.040) were predictors of death. Mortality was numerically lower in those who underwent PEA (p=0.135). PEA was associated with decreased risk of the combined endpoint of all-cause mortality and hospital admission for decompensated heart failure (HR 0.198; 95% CI: 0.040-0.982; p=0.047), as were lower serum BNP (HR 1.003; 95% CI: 1.001-1.005; p=0.008) and mPAP (HR 1.073; 95% CI: 1.022-1.128; p=0.005) at diagnosis. Most patients who underwent PEA presented improved WHO FC (92.9%) and post-surgical residual pulmonary hypertension was identified in only 21.4%.
PEA provided a better overall prognosis than non-surgical therapy, improving symptoms and frequently achieving hemodynamic normalization, with a numerical trend for lower mortality. Higher serum BNP, creatinine and mPAP at diagnosis were independently associated with worse outcomes.
A hipertensão pulmonar tromboembólica crónica (HPTEC) é uma forma progressiva, mas potencialmente curável, de hipertensão pulmonar. A endarterectomia pulmonar (EAP) é uma cirurgia complexa que frequentemente alcança a normalização hemodinâmica e resolução sintomática, embora nem todos os doentes sejam candidatos ao procedimento. O objetivo foi avaliar o prognóstico dos doentes com HPTEC submetidos a EAP ou a terapêutica não cirúrgica.
Estudo retrospetivo dos doentes com HPTEC num centro de referência durante 10 anos. O tempo mediano de seguimento foi 57 (IQR 24-93) meses. Foi realizada análise de sobrevivência e utilizado um modelo de regressão de Cox para identificar preditores independentes de prognóstico.
Foram incluídos 45 doentes, maioritariamente mulheres (59%), com 63±16 anos. Ao diagnóstico, 62,2% dos doentes encontravam-se nas classes III ou IV da OMS. A sobrevivência a 1, 2 e 3 anos foi 93,3%, 82,4% e 75,9%, respetivamente. O BNP (HR 1,003;95%CI1,001-1,005; p=0,003) e a creatinina (HR 12,092;95%CI1,121-130,390; p=0,040) foram preditores de mortalidade. A mortalidade foi numericamente inferior no grupo da EAP (p=0,135). A EAP associou-se a menor risco de ocorrência do endpoint combinado de mortalidade e admissão hospitalar por insuficiência cardíaca descompensada (HR 0,198;95%CI0,040-0,982; p=0,047), tal como menores valores de BNP (HR 1,003;95%CI1,001-1,005; p=0,008) e pressão arterial pulmonar média (HR 1,073;95%CI 1,022-1,128; p=0,005). A maioria dos doentes operados apresentou melhoria da classe funcional (92,9%) e hipertensão pulmonar residual foi identificada em apenas 21,4%.
A EAP providenciou melhor prognóstico que a terapêutica não cirúrgica, associando-se a melhoria sintomática e frequente normalização hemodinâmica, com tendência numérica para menor mortalidade.
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