Certain organizational features of brain networks present in the individual are lost when central tendencies are examined in the group. Here we investigated the detailed network organization of four ...individuals each scanned 24 times using MRI. We discovered that the distributed network known as the default network is comprised of two separate networks possessing adjacent regions in eight or more cortical zones. A distinction between the networks is that one is coupled to the hippocampal formation while the other is not. Further exploration revealed that these two networks were juxtaposed with additional networks that themselves fractionate group-defined networks. The collective networks display a repeating spatial progression in multiple cortical zones, suggesting that they are embedded within a broad macroscale gradient. Regions contributing to the newly defined networks are spatially variable across individuals and adjacent to distinct networks, raising issues for network estimation in group-averaged data and applied endeavors, including targeted neuromodulation.
•Within-individual characterization of brain networks reveals new spatial details•Group-defined networks fractionate into distinct parallel networks in individuals•Parallel networks possess closely juxtaposed regions in numerous cortical zones•Networks share a conserved motif that may be organized along a macroscale gradient
Braga and Buckner examine the detailed organization of brain networks within individual people. They discovered that multiple closely juxtaposed cortical regions form parallel distributed networks. Separate large-scale networks may emerge from a common organizing principle.
Film- and foam-like structures of N-carboxybutylchitosan (CBC) and of agarose (AGA) were prepared and characterized in order to evaluate their potential application as topical membrane-type wound ...dressing materials, mostly regarding their sustained release capacities and fluid handling properties. Polymeric biomaterials were loaded with two natural-origin bioactive compounds (quercetin and thymol, which present anti-inflammatory and anaesthetic properties, respectively), separately or as a mixture of these two substances, and using a supercritical solvent impregnation (SSI) method. Impregnation experiments were carried out with supercritical carbon dioxide (scCO2) at 10 and 20MPa, and at 303 and 323K. Ethanol (10%, v/v) was employed as a co-solvent whenever quercetin was used. Release kinetic studies were performed for all prepared systems and the obtained results showed that higher amounts of quercetin and/or thymol were loaded when higher pressures and temperatures were employed. Results showed that the separated and the simultaneous SSI loading of these two bioactive substances into CBC and AGA is a feasible and advantageous process and that the relative loaded amounts of these substances can be “tuned” simply by changing the operational pressure-temperature conditions. Quercetin presented more sustained release profiles which can be justified by its higher molecular volume and by its lower water solubility as well as by the specific favourable interactions that can be established between quercetin and CBC. Obtained results showed that the employed SSI process also promoted the size reduction of loaded quercetin particles which can significantly improve the solubility of this compound in aqueous solutions. In addition, prepared systems presented adequate water sorption and water vapor sorption capacities as well as water vapor transmission rates that were in the typical and desired ranges for commercial wound dressings.
Southeast Brazil is a neotropical region composed of a mosaic of different tropical habitats and mountain chains, which allowed for the formation of bird-rich communities with distinct ecological ...niches. Although this region has the potential to harbor a remarkable variety of avian parasites, there is a lack of information about the diversity of malarial parasites. We used molecular approaches to characterize the lineage diversity of Plasmodium and Haemoproteus in bird communities from three different habitats in southeast Brazil based on the prevalence, richness and composition of lineages. We observed an overall prevalence of 35.3%, with a local prevalence ranging from 17.2% to 54.8%. Moreover, no significant association between prevalence and habitat type could be verified (p>0.05). We identified 89 Plasmodium and 22 Haemoproteus lineages, with 86% of them described for the first time here, including an unusual infection of a non-columbiform host by a Haemoproteus (Haemoproteus) parasite. The composition analyses of the parasite communities showed that the lineage composition from Brazilian savannah and tropical dry forest was similar, but it was different from the lineage composition of Atlantic rainforest, reflecting the greater likeness of the former habitats with respect to seasonality and forest density. No significant effects of habitat type on lineage richness were observed based on GLM analyses. We also found that sites whose samples had a greater diversity of bird species showed a greater diversity of parasite lineages, providing evidence that areas with high bird richness also have high parasite richness. Our findings point to the importance of the neotropical region (southeast Brazil) as a major reservoir of new haemosporidian lineages.
Background
Analytical morphometric assessment has recently been proposed to improve preoperative risk stratification. However, the relationship between body composition and outcomes following ...pancreaticoduodenectomy is still unclear. The aim of this study was to assess the impact of body composition on outcomes in patients undergoing pancreaticoduodenectomy for cancer.
Methods
Body composition parameters including total abdominal muscle area (TAMA) and visceral fat area (VFA) were assessed by preoperative staging CT in patients undergoing pancreaticoduodenectomy for cancer. Perioperative variables and postoperative outcomes (mortality or postoperative pancreatic fistula) were collected prospectively in the institutional pancreatic surgery database. Optimal stratification was used to determine the best cut‐off values for anthropometric measures. Multivariable analysis was performed to identify independent predictors of 60‐day mortality and pancreatic fistula.
Results
Of 202 included patients, 132 (65·3 per cent) were classified as sarcopenic. There were 12 postoperative deaths (5·9 per cent), major complications developed in 40 patients (19·8 per cent) and pancreatic fistula in 48 (23·8 per cent). In multivariable analysis, a VFA/TAMA ratio exceeding 3·2 and American Society of Anesthesiologists grade III were the strongest predictors of mortality (odds ratio (OR) 6·76 and 6·10 respectively; both P < 0·001). Among patients who developed major complications, survivors had a significantly lower VFA/TAMA ratio than non‐survivors (P = 0·017). VFA was an independent predictor of pancreatic fistula (optimal cut‐off 167 cm2: OR 4·05; P < 0·001).
Conclusion
Sarcopenia is common among patients undergoing pancreaticoduodenectomy. The combination of visceral obesity and sarcopenia was the best predictor of postoperative death, whereas VFA was an independent predictor of pancreatic fistula.
Increased risk of fistula and death
The aims of this study were: (1) to evaluate the overall reproducibility and accuracy of the International Caries Detection and Assessment System (ICDAS) for assessing coronal caries lesions, and (2) ...to investigate the use of systems associated with the ICDAS for activity assessment of coronal caries lesions. Specific search strategies were adopted to identify studies published up to 2016. For the first objective, we selected studies that assessed primary coronal caries lesions using the ICDAS as a reference standard. A total of 54 studies were included. Meta-analyses summarized the results concerning reproducibility and accuracy (correlation with histology, summary ROC curves SROC, and diagnostic odds ratio DOR). The latter 2 were expressed at D1/D3 levels. The heterogeneity of the studies was also assessed. Reproducibility values (pooled) were > 0.65. The ICDAS mostly presented a good overall performance as most areas under SROC were > 0.75 at D1 and > 0.90 at D3; DOR ≥6. For the second objective, we selected studies investigating activity assessment associated with the ICDAS. The meta-analyses pooled results based on the same methodology and parameters as above. Longitudinal findings regarding caries progression were described to estimate the validity of these systems. On average, the systems for activity assessment of caries lesions showed moderate values concerning reproducibility and overall performance. Active caries lesions were more prone to progress than inactive ones after 2 years. In conclusion, the ICDAS presented a substantial level of reproducibility and accuracy for assessing primary coronal caries lesions. Additional systems associated with the ICDAS that classify caries lesion activity can be useful as they are moderately reproducible and accurate.
The Tre2-Bub2-Cdc16 (TBC) domain-containing RAB-specific GTPase-activating proteins (TBC/RABGAPs) are characterized by the presence of highly conserved TBC domains and act as negative regulators of ...RABs. The importance of TBC/RABGAPs in the regulation of specific intracellular trafficking routes is now emerging, as is their role in different diseases. Importantly, TBC/RABGAPs act as key regulatory nodes, integrating signalling between RABs and other small GTPases and ensuring the appropriate retrieval, transport and delivery of different intracellular vesicles.
Avian malaria is a mosquito-borne disease caused by Plasmodium spp. Avian plasmodia are recognized conservation-threatening pathogens due to their potential to cause severe epizootics when introduced ...to bird populations with which they did not co-evolve. Penguins are considered particularly susceptible, as outbreaks in captive populations will often lead to high morbidity and rapid mortality. We used a multidisciplinary approach to investigate an outbreak of avian malaria in 28 Magellanic penguins (Spheniscus magellanicus) at a rehabilitation center during summer 2009 in Florianópolis, Brazil. Hemosporidian infections were identified by microscopic and molecular characterization in 64% (18/28) of the penguins, including Plasmodium (Haemamoeba) tejerai, Plasmodium (Huffia) elongatum, a Plasmodium (Haemamoeba) sp. lineage closely related to Plasmodium cathemerium, and a Haemoproteus (Parahaemoproteus) sp. lineage closely related to Haemoproteus syrnii. P. tejerai played a predominant role in the studied outbreak and was identified in 72% (13/18) of the hemosporidian-infected penguins, and in 89% (8/9) of the penguins that died, suggesting that this is a highly pathogenic parasite for penguins; a detailed description of tissue meronts and lesions is provided. Mixed infections were identified in three penguins, and involved P. elongatum and either P. tejerai or P. (Haemamoeba) sp. that were compatible with P. tejerai but could not be confirmed. In total, 32% (9/28) penguins died over the course of 16 days despite oral treatment with chloroquine followed by sulfadiazine-trimethoprim. Hemosporidian infections were considered likely to have occurred during rehabilitation, probably from mosquitoes infected while feeding on local native birds, whereas penguin-mosquito-penguin transmission may have played a role in later stages of the outbreak. Considering the seasonality of the infection, rehabilitation centers would benefit from narrowing their efforts to prevent avian malaria outbreaks to the penguins that are maintained throughout summer.
Host-parasite interactions represent a selective force that may reduce hosts' lifespan, their reproductive success and survival. Environmental conditions can affect host-parasite communities, leading ...to distinct patterns of interactions with divergent ecological and evolutionary consequences for their persistence. Here, we tested whether climatic oscillation shapes the temporal dynamics of bird-haemosporidian associations, assessing the main mechanisms involved in the temporal dissimilarity of their interactions' networks. For two years, we monthly sampled birds in a tropical coastal ecosystem to avian malaria molecular diagnosis. The studied networks exhibited high specialization, medium modularity, with low niche overlap among parasites lineages. Moreover, alpha and β-diversity of hosts, parasites and their interactions, as well as the structure of their networks were temporally consistent, i.e., stable under fluctuations in temperature or precipitation over seasons. The structure and temporal consistency of the studied antagonistic networks suggest a high fidelity between partners, which is likely relevant for their evolutionary persistence.
Malaria in penguins - current perceptions Grilo, M. L.; Vanstreels, R. E. T.; Wallace, R. ...
Avian Pathology,
07/2016, Letnik:
45, Številka:
4
Journal Article, Book Review
Recenzirano
Odprti dostop
Avian malaria is a mosquito-borne disease caused by protozoans of the genus Plasmodium, and it is considered one of the most important causes of morbidity and mortality in captive penguins, both in ...zoological gardens and rehabilitation centres. Penguins are known to be highly susceptible to this disease, and outbreaks have been associated with mortality as high as 50-80% of affected captive populations within a few weeks. The disease has also been reported in wild penguin populations, however, its impacts on the health and fitness of penguins in the wild is not clear. This review provides an overview of the aetiology, life cycle and epidemiology of avian malaria, and provides details on the strategies that can be employed for the diagnostic, treatment and prevention of this disease in captive penguins, discussing possible directions for future research.
A fundamental property of higher eukaryotes that underpins their evolutionary success is stable cell-cell cohesion. Yet, how intrinsic cell rheology and stiffness contributes to junction ...stabilization and maturation is poorly understood. We demonstrate that localized modulation of cell rheology governs the transition of a slack, undulated cell-cell contact (weak adhesion) to a mature, straight junction (optimal adhesion). Cell pairs confined on different geometries have heterogeneous elasticity maps and control their own intrinsic rheology co-ordinately. More compliant cell pairs grown on circles have slack contacts, while stiffer triangular cell pairs favour straight junctions with flanking contractile thin bundles. Counter-intuitively, straighter cell-cell contacts have reduced receptor density and less dynamic junctional actin, suggesting an unusual adaptive mechano-response to stabilize cell-cell adhesion. Our modelling informs that slack junctions arise from failure of circular cell pairs to increase their own intrinsic stiffness and resist the pressures from the neighbouring cell. The inability to form a straight junction can be reversed by increasing mechanical stress artificially on stiffer substrates. Our data inform on the minimal intrinsic rheology to generate a mature junction and provide a springboard towards understanding elements governing tissue-level mechanics.
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