A moment-based Kalman filtering approach for estimation in ensemble systems.

A persistent challenge in tasks involving large-scale dynamical systems, such as state estimation and error reduction, revolves around processing the collected measurements. Frequently, these data suffer from the curse of dimensionality, leading to increased computational demands in data processing methodologies. Recent scholarly investigations have underscored the utility of delineating collective states and dynamics via moment-based representations. These representations serve as a form of sufficient statistics for encapsulating collective characteristics, while simultaneously permitting the retrieval of individual data points. In this paper, we reshape the Kalman filter methodology, aiming its application in the moment domain of an ensemble system and developing the basis for moment ensemble noise filtering. The moment system is defined with respect to the normalized Legendre polynomials, and it is shown that its orthogonal basis structure introduces unique benefits for the application of Kalman filter for both i.i.d. and universal Gaussian disturbances. The proposed method thrives from the reduction in problem dimension, which is unbounded within the state-space representation, and can achieve significantly smaller values when converted to the truncated moment-space. Furthermore, the robustness of moment data toward outliers and localized inaccuracies is an additional positive aspect of this approach. The methodology is applied for an ensemble of harmonic oscillators and units following aircraft dynamics, with results showcasing a reduction in both cumulative absolute error and covariance with reduced calculation cost due to the realization of operations within the moment framework conceived.

Multiple events determine the distribution of fishes' early life stages in the Abrolhos Bank, Southwestern Atlantic.

Fluctuations in reef fish settlement and recruitment significantly impact local population dynamics and adult population size. We use light traps to evaluate reef fish settlement in inshore and offshore reefs in the Abrolhos Bank, in addition to the spatio-temporal distribution patterns, and environmental variables' influence. Data were collected from inshore and offshore reefs, and statistical analyses, including GLMs, PERMANOVA and nMDS, aimed to understand spatial-temporal species distribution patterns and the relationship between environmental variables. Results indicate greater species abundance and diversity offshore, influenced by winds, tides, and distance from shore, explaining 50% of larval patterns and highlighting the importance of spatial-temporal variations in early-life reef fish assemblages. However, several factors, including habitat type, quality, complexity, seascape configuration, and MPA location, may influence these patterns. Additionally, we provide evidence that commercially important species like Lutjanids use Abrolhos reef areas as nursery grounds.

Daily age, growth rate, and pelagic larval duration of commercially important snapper species in Abrolhos National Marine Park.

The age and daily growth of fish are registered through the deposition of increments in their otoliths, which are concretions formed by the precipitation of substances present in the endolymphatic fluid, mainly calcium carbonate (CaCO3). Faced with the need to fill some of the gaps in the knowledge on the occurrence and duration of the initial stages of snapper species' life cycles in the Abrolhos Bank, this study aimed to describe the growth rates, age, and period of pelagic larval duration (PLD) of three snapper species during the larval pre-settlement phase, in the Abrolhos Bank region. The post-larvae were captured using light traps. Otoliths were removed from 117 samples of snapper species; however, only 69 were viable for age estimation, of which 15 were Lutjanus analis, 25 were Lutjanus jocu, and 29 were Lutjanus synagris. Together, the samples presented individuals with total lengths ranging from 16.14 to 24.76 mm and ages from 21 to 39 days. Settlement marks were found for all three species, and the average PLD was ~25 days. The somatic growth of the snapper species was positively correlated with otolith growth. L. jocu presented the greatest daily growth compared to the other species. The three species use the Abrolhos Bank as a larval settlement site, demonstrating plasticity by using different habitats throughout their lives.

Reference genes for Eucalyptus spp. under Beauveria bassiana inoculation and subsequently infestation by the galling wasp Leptocybe invasa.

Relative gene expression analysis through RT-qPCR is an important molecular technique that helps understanding different molecular mechanisms, such as the plant defense response to insect pests. However, the use of RT-qPCR for gene expression analysis can be affected by factors that directly affect the reliability of the results. Among these factors, the appropriate choice of reference genes is crucial and can strongly impact RT-qPCR relative gene expression analyses, highlighting the importance in correctly choosing the most suitable genes for the success of the analysis. Thus, this study aimed to select and validate reference genes for relative gene expression studies through RT-qPCR in hybrids of Eucalyptus tereticornis × Eucalyptus camaldulensis (drought tolerant and susceptible to Leptocybe invasa) under conditions of inoculation by the Beauveria bassiana fungus and subsequent infestation by L. invasa. The expression level and stability of eleven candidate genes were evaluated. Stability was analyzed using the RefFinder tool, which integrates the geNorm, NormFinder, BestKeeper, and Delta-Ct algorithms. The selected reference genes were validated through the expression analysis of the transcriptional factor EcDREB2 (dehydration-responsive element-binding protein 2). For all treatments evaluated, EcPTB, EcPP2A-1, and EcEUC12 were the best reference genes. The triplets EcPTB/EcEUC12/EcUBP6, EcPP2A-1/EcEUC12/EcPTB, EcIDH/EcSAND/Ecα-TUB, EcPP2A-1/Ecα-TUB/EcPTB, and EcPP2A-1/EcUPL7/EcSAND were the best reference genes for the control plants, mother plants, plants inoculated with B. bassiana, plants infested with L. invasa, and plants inoculated with B. bassiana and subsequently infested with L. invasa, respectively. The best determined reference genes were used to normalize the RT-qPCR expression data for each experimental condition evaluated. The results emphasize the importance of this type of study to ensure the reliability of relative gene expression analyses. Furthermore, the findings of this study can be used as a basis for future research, comprising gene expression analysis of different eucalyptus metabolic pathways.

Early life stage mechanisms of an active fish species to cope with ocean warming and hypoxia as interacting stressors.

Ocean's characteristics are rapidly changing, modifying environmental suitability for early life stages of fish. We assessed whether the chronic effects of warming (24 °C) and hypoxia (<2-2.5 mg L-1) will be amplified by the combination of these stressors on mortality, growth, behaviour, metabolism and oxidative stress of early stages of the white seabream Diplodus sargus. Combined warming and hypoxia synergistically increased larval mortality by >51%. Warming induced faster growth in length and slower gains in weight when compared to other treatments. Boldness and exploration were not directly affected, but swimming activity increased under all test treatments. Under the combination of warming and hypoxia, routine metabolic rate (RMR) significantly decreases when compared to other treatments and shows a negative thermal dependence. Superoxide dismutase and catalase activities increased under warming and were maintained similar to control levels under hypoxia or under combined stressors. Under hypoxia, the enzymatic activities were not enough to prevent oxidative damages as lipid peroxidation and DNA damage increased above control levels. Hypoxia reduced electron transport system activity (cellular respiration) and isocitrate dehydrogenase activity (aerobic metabolism) below control levels. However, lactate dehydrogenase activity (anaerobic metabolism) did not differ among treatments. A Redundancy Analysis showed that ∼99% of the variability in mortality, growth, behaviour and RMR among treatments can be explained by molecular responses. Mortality and growth are highly influenced by oxidative stress and energy metabolism, exhibiting a positive relationship with reactive oxygen species and a negative relationship with aerobic metabolism, regardless of treatment. Under hypoxic condition, RMR, boldness and swimming activity have a positive relationship with anaerobic metabolism regardless of temperature. Thus, seabreams may use anaerobic reliance to counterbalance the effects of the stressors on RMR, activity and growth. The outcomes suggests that early life stages of white seabream overcame the single and combined effects of hypoxia and warming.

Contrasting water-use strategies revealed by species-specific transpiration dynamics in the Caatinga dry forest.

In forest ecosystems, transpiration (T) patterns are important for quantifying water and carbon fluxes and are major factors in predicting ecosystem change. Seasonal changes in rainfall and soil water content can alter the sensitivity of sap flux density to daily variations in vapor pressure deficit (VPD). This sensitivity is species-specific and is thought to be related to hydraulic strategies. The aim of this work is to better understand how the sap flux density of species with low versus high wood density differ in their sensitivity to VPD and soil water content and how potentially opposing water-use strategies influence T dynamics, and ultimately, correlations to evapotranspiration (ET). We use hysteresis area analysis to quantify the sensitivity of species-specific sap flux density to changes in the VPD, breakpoint-based models to determine the soil water content threshold instigating a T response and multiscalar wavelet coherency to correlate T to ET. We found that low wood density Commiphora leptophloeos (Mart.) Gillett had a more dynamic T pattern, a greater sensitivity to VPD at high soil water content, required a higher soil water content threshold for this sensitivity to be apparent, and had a significant coherency correlation with ET at daily to monthly timescales. This behavior is consistent with a drought avoidance strategy. High wood density Cenostigma pyramidale  (Tul.)  E. Gagnon & G. P. Lewis, conversely, had a more stable T pattern, responded to VPD across a range of soil water content, tolerated a lower soil water content threshold to T, and had a significant coherency correlation with ET at weekly timescales. This behavior is consistent with a drought-tolerant strategy. We build on previous research to show that these species have contrasting water-use strategies that should be considered in large-scale modeling efforts.

Aortic branches and rete mirabile of the limbs of two-toed sloth (Choloepus didactylus).

Choloepus didactylus has reduced metabolism and difficulty in thermoregulation owing to its low body mass, and there are few studies related to the vascularization of abdominal and thoracic organs in this species. Therefore, we macroscopically described the arteries that comprise the aortic arch, thoracic aorta, and abdominal aorta. Six specimens were used, and their arterial systems filled with red latex before fixation in 10% formaldehyde, and fragments of the rete mirabile were processed for histological analysis using light and scanning electron microscopy. In these species, the aortic arch had two branches: the brachiocephalic trunk and left subclavian artery. The initial portion of the abdominal aorta presented four different ramifications, besides to the peculiarities of the adrenal, renal, and iliac arteries. Microscopy of the rete mirabile revealed a muscular artery surrounded by smaller muscular arteries, veins, nerves, and lymphatic tissue joined by connective tissue. Thus, the data obtained have clinical and surgical importance, with applicability in procedures involving vascularization of the thoracic and abdominal organs. We suggest that the rete mirabile is an efficient thermoregulatory structure because it allows the accumulation of blood and the countercurrent heat exchange, as there is no blood mixing.

Citizen science expanding knowledge: a new record of the lizard Heterodactylusimbricatus (Squamata, Gymnophthalmidae) in south-eastern Brazil.

Background: Through citizen science projects, like Projeto Bromélias, community members contribute valuable data on species diversity, notably those with low detectability like the Heterodactylusimbricatus lizard. A recent observation in the State of Espírito Santo (south-eastern Brazil), amidst coffee and eucalyptus crops, highlights the utility of widespread technology use in tracking and documenting wildlife. Such initiatives are especially beneficial for mapping the distribution of rare, endemic or endangered reptiles. Therefore, we advocate for more citizen science initiatives near protected areas, involving local communities. New information: We provide a new record for the species Heterodactylusimbricatus, a microteiid lizard of low detectability from the Atlantic Forest of south-eastern Brazil. Heterodactylusimbricatus (Rio de Janeiro Teiid) was recorded near the protected area "Reserva Biológica Augusto Ruschi" by a citizen volunteer who contributes herpetofauna records to the Bromelias Project (https://www.inaturalist.org/projects/projeto-bromelias). Heterodactylusimbricatus is a very poorly-known species in the localities where it occurs, probably due to its fossorial habit, genera's restricted occurrence range, habitat specificity and the absence of proper survey methods fitted to fossorial species, such as the utilisation of pitfall traps. By publishing the records of volunteer citizens, we hope that more people will contribute to increase the knowledge of biodiversity in the mountainous region of Espírito Santo State and expand our collective knowledge.

Metataxonomy of acid mine drainage microbiomes from the Santa Catarina Carboniferous Basin (Southern Brazil).

Mining activities generate large quantities of wastes that significantly alter the biogeochemistry and ecological structure of entire river basins. Microbial communities that develop in these areas present a variety of survival and adaptation mechanisms. Knowing this diversity at the molecular level is strategic both for understanding adaptive processes and for identifying genomes with potential use in bioremediation and bioprospecting. In this work, prokaryotic and eukaryotic communities were evaluated by meta-taxonomics (16S and 18S amplicons) in sediments and water bodies impacted by acid mine drainage in an important coal mining area in southern Brazil. Five sampling stations were defined on a gradient of impacts (pH 2.7-4.25). Taxon diversity was directly proportional to pH, being greater in sediments than in water. The dominant prokaryotic phyla in the samples were Proteobacteria, Actinobacteria, Acidobacteria, OD1, Nitrospirae, and Euryarchaeota, and among the eukaryotes, algae (Ochrophyta, Chlorophyta, Cryptophyceae), fungi (Basidiomycota, Ascomycota, and Cryptomycota), and protists (Ciliophora, Heterolobosea, Cercozoa). The prokaryotic genera Leptospirillum, Acidithiobacillus, Acidiphilium, Thiomonas, Thermogymnomonas, and Acidobacterium, and the eukaryotic genera Pterocystis and Poteriospumella were associated with more acidic conditions and higher metal concentrations, while the prokaryotic genera Sediminibacterium, Gallionella Geothrix, and Geobacter were more abundant in transitional environments.

Quantifying the effects of sea level rise driven marsh migration on wave attenuation.

Sea level rise (SLR) is the most significant climate change-related threat to coastal wetlands, driving major transformations in coastal regions through marsh migration. Landscape transformations due to marsh migration are manifested in terms of horizontal and vertical changes in land cover and elevation, respectively. These processes will have an impact on saltmarsh wave attenuation that is yet to be explored. This study stands as a comprehensive analysis of spatially distributed wave attenuation by vegetation in the context of a changing climate. Our results show that: i) changes in saltmarsh cover have little to no effect on the attenuation of floods, while ii) changes in elevation can significantly reduce flood extents and water depths; iii) overland wave heights are directly influenced by marsh migration, although iv) being indirectly attenuated by the water depth limiting effects of water depth attenuation driven by changes in elevation; v) the influence of saltmarsh accretion on wave attenuation is largely evident near the marsh edge, where the increasing elevations can drive major wave energy losses via wave breaking. Lastly, vi) considering the synergy between SLR, marsh migration, and changes in elevation results in significantly more wave attenuation than considering the eustatic effects of SLR and/or horizontal marsh migration alone, and therefore should be adopted in future studies.

Intestinal health of broilers challenged with Eimeria spp. using functional oil blends in two physical forms with or without anticoccidials.

This study aimed to assess the impact of a commercial blend of functional oils, specifically cashew nutshell liquid and castor oil (FO), in two physical forms (solid: P; liquid: S), in comparison to a combination of virginiamycin and anticoccidials on the gut health of broilers challenged with coccidiosis. A total of 1760 1-day-old male chicks were randomly distributed in a study design with eight treatments. The treatments included: a control group (without additive), OFS_0.75_kg/t (FO spray), OFP_1.0_kg/t (FO powder), OFP_1.5_kg/t (FO liquid spray), Sal (anticoccidials), Sal_Vir (virginiamycin and anticoccidials), Sal_OFS_0.5_ kg/t (anticoccidials plus FO spray), and Sal_OFP_1.0_kg/t (anticoccidials plus FO powder). All birds were challenged with Eimeria spp. at 14 days. The physical form of FO did not affect performance and intestinal health parameters. At 42 days, broilers from the control and OFS_0.75 treatments were the lightest, while those from the Sal_Vir and Sal_OFP_1.0 treatments were the heaviest (P < 0.05). FO reduced the presence of Clostridium perfringens. The individual phytogenic additives did not prevent weight loss in birds challenged with Eimeria, but they mitigated the effects of the infection by modulating the intestinal microbiota. A synergistic effect was observed between the FO and anticoccidials, yielding satisfactory results in substituting virginiamycin.

Are hospital wastewater treatment plants a source of new resistant bacterial strains?

To understand which type of hospital waste may contain the highest amount of antibiotic resistant microorganisms that could be released into the environment, the bacterial strains entering and leaving a hospital wastewater treatment plant (HWTP) were identified and tested for their antibiotic susceptibility. To achieve this goal, samples were collected from three separate sites, inlet and outlet wastewater positions, and sludge generated in a septic tank. After microbiological characterization according to APHA, AWWA, and WEF protocols, the relative susceptibility of the bacterial strains to various antibiotic agents was assessed according to the Clinical and Laboratory Standards Institute guidelines, to determine whether there were higher numbers of resistant bacterial strains in the inlet wastewater sample than in the outlet wastewater and sludge samples. The results showed more antibiotic resistant bacteria in the sludge than in the inlet wastewater, and that the Enterobacteriaceae family was the predominant species in the collected samples. The most antibiotic-resistant families were found to be Streptococcacea and non-Enterobacteriaceae. Some bacterial strains were resistant to all the tested antibiotics. We conclude that the studied HWTP can be considered a source of resistant bacterial strains. It is suggested that outlet water and sludge generated in HWTPs should be monitored, and that efficient treatment to eliminate all bacteria from the different types of hospital waste released into the environment is adopted.

Obesity and recurrent miscarriage: The interconnections between adipose tissue and the immune system.

Currently, obesity is considered a global public health problem. It is the main risk factor for noncommunicable diseases and reproductive complications, such as recurrent miscarriage (RM). RM affects approximately 1% of couples of reproductive age, and recent studies suggest that its prevalence is increasing. Immunological abnormalities may be responsible for a significant number of cases of unexplained RM. Obesity is recognized as a chronic low-grade inflammatory condition. The accumulation of fat in obese adipose tissue promotes changes in the local and systemic immune response. Adipokines, exosomes, micro-RNAs, lipids, and other factors released or secreted by adipose tissue are responsible for the interconnection between obesity and the immune system. Obesity-induced dysregulation of the innate and acquired immune response is also involved in the immunopathology of pregnancy loss in patients with unexplained RM. Therefore, understanding the communication pathways between maternal adipose tissue and the immune response in women living with obesity and RM is an important objective. Thus, diagnostic tools and new immunomodulatory therapies may be proposed for the management of patients with concurrent obesity and RM.

Numerical modeling of wave attenuation: implications of representing vegetation found in coastal saltmarshes in the Chesapeake Bay.

Coastal communities are vulnerable to wave and storm surges during extreme events, highlighting the need to increase community resilience. The effectiveness of natural wetlands in attenuating waves is vital to designing strategies for protecting public safety. This study aimed to understand how vegetation attenuates waves and determine the best method for modeling vegetation's impact on wave dynamics. The researchers compared two different vegetation representations in numerical models, implicit and explicit, using SWAN and XBeach at varying spatial resolutions. The study focused on two marshes in the Chesapeake Bay, using field measurements to investigate the accuracy of each method in representing wave attenuation by vegetation and the implications of explicitly representing average characteristics of one vegetation species on a regional level. Results showed that explicit modeling using average vegetation characteristics provided more accurate results than the implicit model, which only showed wave attenuation due to topography. The finer scale resolution and site-specific vegetation characteristics further improved the accuracy of wave attenuation observed. Understanding the trade-offs between different vegetation representations in numerical models is essential to accurately represent wave attenuation and design effective protection strategies for coastal communities.

Time Evolution of Ultrasmall Gold Nanoparticle-Protein Interactions.

To date, much effort has been devoted toward the study of protein corona formation onto large gold nanoparticles (GNPs). However, the protein corona concept breaks down for GNPs in the ultrasmall size regime (<3 nm), and, as a result, our understanding of ultrasmall GNP (usGNP)-protein interactions remains incomplete. Herein, we used anionic usGNPs and six different proteins as model systems to systematically investigate usGNP-protein interactions, with particular focus on the time evolution and long-term behavior of complex formation. The different proteins comprised chymotrypsin (Cht), trypsin (Try), thrombin (Thr), serum albumin (HSA), cytochrome c (Cyt c), and factor XII (FXII). We used a range of biochemical and biophysical methods to estimate binding affinities, determine the effects of usGNPs on protein structure and function, assess the reversibility of any protein structural and functional changes, and evaluate usGNP-protein complex stability. Among the main findings, we observed that prolonged (24 h)─but not short-term (10 min)─interactions between proteins and usGNPs permanently altered protein function, including enzyme activities (Try, Thr, and FXIIa), peroxidase-like activity (Cyt c), and ligand-binding properties (HSA). Remarkably, this occurred without any large-scale loss of the native global conformation, implying time-dependent effects of usGNPs on local protein conformation or dynamics. We also found that both short-(10 min) and long-term (24 h) interactions between proteins and usGNPs yielded short-lived complexes, i.e., there was no time-dependent "hardening" of the interactions at the binding interface as usually seen with large GNPs. The present study increases our fundamental understanding of nano-bio interactions in the ultrasmall size regime, which may assist the safe and effective translation of usGNPs into the clinic.

Risk factors for cancer in patients with primary biliary cholangitis and autoimmune hepatitis and primary biliary cholangitis overlap syndrome.

INTRODUCTION AND OBJECTIVES: Primary biliary cholangitis (PBC) and autoimmune hepatitis (AIH) and PBC overlap syndrome (AIH/PBC) have been associated with a higher risk of hepatocellular carcinoma (HCC) and extra-hepatic malignancy (EHM). This study aims to assess potential risk factors associated with cancer development in PBC and AIH/PBC. MATERIALS AND METHODS: The Brazilian Cholestasis Study Group database was reviewed to compare clinical and laboratory features of PBC patients with HCC and EHM with those without cancer. RESULTS: Among the 752 PBC patients enrolled, 64 of them with AIH/PBC, 87 cancers were identified in 72 patients, including 20 cases of HCC and 67 of EHM. Patients with HCC had a higher prevalence of cirrhosis (95% vs. 32.5% of those subjects without cancer, p≤0.001), smoking (55% vs. 12.3%, p≤0.001), CREST syndrome (30% vs 7.6%, p=0.003) and prior azathioprine (30% vs 8%, p= 0.005) and prednisone (35% vs 14%, p= 0.018) use, whereas patients with EHM had a higher prevalence of smoking (42.3% vs 12.4% of those subjects without cancer, p= <0.001), AMA positivity (96.6% vs 80.1%, p≤0.001), azathioprine therapy (21% vs 7.9%, p= 0.01) and concurrent other autoimmune diseases. In multivariate analysis, cirrhosis, obesity and prior azathioprine therapy were independent risk factors for HCC, while Sjogren syndrome and psoriasis were associated with EHM. Fibrates reduced EHM risk. CONCLUSIONS: The prevalence of EHM is higher when compared to HCC in PBC patients. Cirrhosis, obesity, prior azathioprine use, and concurrent autoimmune diseases were significantly associated with cancer in PBC.

Acute bouts of aerobic and resistance exercise similarly alter inhibitory control and response time while inversely modifying plasma BDNF concentrations in middle-aged and older adults with type 2 diabetes.

Impairments in several domains of cognitive functions are observed in people with Type 2 Diabetes Mellitus (T2DM), often accompanied by low Brain-derived neurotrophic factor (BDNF) concentrations. Although aerobic and resistance exercise enhances cognitive functions and raises BDNF concentrations in several populations, it remained uncertain in T2DM subjects. This study compared the effects of a single bout of aerobic (AER, 40 min of treadmill walk at 90-95% of the maximum walk speed) or resistance (RES, 3 × 10 repetitions in eight exercises at 70% of 10-RM) exercise on specific cognitive domain performance and plasma BDNF concentrations of physically active T2DM subjects. Eleven T2DM subjects (9 women/2 men; 63 ± 7 years) performed two counterbalanced trials on non-consecutive days. Stroop Color and Word (SCW) task [assessing the attention (congruent condition) and inhibitory control (incongruent condition)], Visual response time (assessing the response time), and blood collection (for plasma BDNF concentrations) were performed pre and post-exercise sessions. With distinct magnitude, both AER and RES improved the incongruent-SCW (d = - 0.26 vs. - 0.43 in AER and RES, respectively; p < 0.05), RT(best) (d = - 0.31 vs. - 0.52, p < 0.05), and RT(1-5) (d = - 0.64 vs. - 0.21, p < 0.05). The congruent-SCW and RT(6-10) were not statistically different. Plasma BDNF concentrations were elevated 11% in AER (d = 0.30) but decreased by 15% in RES (d = - 0.43). A single session of aerobic or resistance exercise similarly improved the inhibitory control and response time of physically active T2DM subjects. Nevertheless, aerobic and resistance exercise sessions induced an opposite clinical effect in plasma BDNF concentrations.

Interchangeable Biomass Fuels for Paper-Based Microfluidic Fuel Cells: Finding Their Power Density Limits.

Paper batteries are self-pumping emerging tools for powering portable analytical systems. These disposable energy converters must be low-cost and must achieve enough energy to power electronic devices. The challenge is reaching high energy while keeping the low cost. Here, for the first time, we report a paper-based microfluidic fuel cell (PµFC) equipped with Pt/C on a carbon paper (CP) anode and a metal-free CP cathode fed by biomass-derived fuels to deliver high power. The cells were engineered in a mixed-media configuration, where methanol, ethanol, ethylene glycol, or glycerol is electro-oxidized in an alkaline medium, while Na2S2O8 is reduced in an acidic medium. This strategy allows for optimizing each half-cell reaction independently. The colaminar channel of the cellulose paper was chemically investigated by mapping the composition, which reveals a majority of elements from the catholyte and anolyte on each respective side and a mixture of both at the interface, assuring the existing colaminar system. Moreover, the colaminar flow was studied by investigating the flow rate by considering recorded videos for the first time. All PµFCs show 150-200 s to build a stable colaminar flow, which matches the time to reach a stable open circuit voltage. The flow rate is similar for different concentrations of methanol and ethanol, but it decreases with the increase in ethylene glycol and glycerol concentrations, suggesting a longer residence time for the reactants. The cells perform differently for the different concentrations, and their limiting power densities are composed of a balance among anode poisoning, residence time, and viscosity of the liquids. The sustainable PµFCs can be interchangeably fed by the four biomass-derived fuels to deliver ∼2.2-3.9 mW cm-2. This allows choosing the proper fuel due to their availability. The unprecedented PµFC fed by ethylene glycol delivered 6.76 mW cm-2, which is the benchmark output power for a paper battery fed by alcohol.

Histological Skin Assessment of Patients Submitted to Bariatric Surgery: A Prospective Longitudinal Cohort Study.

BACKGROUND: Obesity is a stigmatizing disease that can cause dermatological aberrations, such as sagging after rapid weight loss. OBJECTIVE: This study is to evaluate the effects of obesity and massive weight loss following bariatric surgery on collagen and elastic fibers of the extracellular matrix of the skin. METHODS: Thirty-three skin biopsies were collected from patients prior to bariatric surgery and one year after surgery. Histological analyses were performed using hematoxylin-eosin and Weigert's resorcin-fuchsin staining for collagen and elastic and elaunin fibers, respectively. Differences between means were submitted to the Student's t-test or Mann-Whitney U test, with p < 0.05 significant. RESULTS: The study demonstrated an architectural alteration of the skin 1 year after bariatric surgery. In the histological analysis of the skin samples, a significant difference in the thickness of the epidermis was found 1 year after surgery in all age groups as well as in the 38-to-68-kg weight loss group (p < 0.0001). In addition to laxity, disorganization of collagen was found, with an apparent decrease in quantity and an increase in elastic fibers, although fragmented (p < 0.0001). CONCLUSION: Obesity and massive weight loss following bariatric surgery cause the disorganization of collagen fibers and the fragmentation of elastic fibers of the extracellular matrix of the skin.