Multiple contact zones and karyotypic evolution in a neotropical frog species complex.

Previous studies of DNA sequence and karyotypic data have revealed high genetic diversity in the Physalaemus cuvieri - Physalaemus ephippifer species complex-a group of small leptodactylid frogs in South America. To date, seven major genetic lineages have been recognized in this group, with species delimitation tests supporting four to seven of them as valid species. Among these, only P. ephippifer shows heteromorphic sex chromosomes, but the implications of cytogenetic divergence for the evolution of this group are unknown. We analyzed karyotypic, mitochondrial DNA, and 3RAD genomic data to characterize a putative contact zone between P. ephippifer and P. cuvieri Lineage 1, finding evidence for admixture and karyotypic evolution. We also describe preliminary evidence for admixture between two other members of this species complex-Lineage 1 and Lineage 3 of P. cuvieri. Our study sheds new light on evolutionary relationships in the P. cuvieri - P. ephippifer species complex, suggesting an important role of karyotypic divergence in its evolutionary history and underscoring the importance of hybridization as a mechanism of sex chromosome evolution in amphibians.

Quantifying the impact of non-stationarity in reinforcement learning-based traffic signal control.

In reinforcement learning (RL), dealing with non-stationarity is a challenging issue. However, some domains such as traffic optimization are inherently non-stationary. Causes for and effects of this are manifold. In particular, when dealing with traffic signal controls, addressing non-stationarity is key since traffic conditions change over time and as a function of traffic control decisions taken in other parts of a network. In this paper we analyze the effects that different sources of non-stationarity have in a network of traffic signals, in which each signal is modeled as a learning agent. More precisely, we study both the effects of changing the context in which an agent learns (e.g., a change in flow rates experienced by it), as well as the effects of reducing agent observability of the true environment state. Partial observability may cause distinct states (in which distinct actions are optimal) to be seen as the same by the traffic signal agents. This, in turn, may lead to sub-optimal performance. We show that the lack of suitable sensors to provide a representative observation of the real state seems to affect the performance more drastically than the changes to the underlying traffic patterns.

Detecting cells in intravital video microscopy using a deep convolutional neural network.

The analysis of leukocyte recruitment in intravital video microscopy (IVM) is essential to the understanding of inflammatory processes. However, because IVM images often present a large variety of visual characteristics, it is hard for an expert human or even conventional machine learning techniques to detect and count the massive amount of cells and extract statistical measures precisely. Convolutional neural networks are a promising approach to overcome this problem, but due to the difficulty of labeling cells, large data sets with ground truth are rare. The present work explores an adaptation of the RetinaNet model with a suite of augmentation techniques and transfer learning for detecting leukocytes in IVM data. The augmentation techniques include simulating the Airy pattern and motion artifacts present in microscopy imaging, followed by traditional photometric, geometric and smooth elastic transformations to reproduce color and shape changes in cells. In addition, we analyzed the use of different network backbones, feature pyramid levels, and image input scales. We have found that even with limited data, our strategy not only enables training without overfitting but also boosts generalization performance. Among several experiments, the model reached a value of 94.84 for the average precision (AP) metric as our best outcome when using data from different image modalities. We also compared our results with conventional image processing techniques and open-source tools. The results showed an outstanding precision of the method compared with other approaches, presenting low error rates for cell counting and centroid distances. Code is available at: https://github.com/brunoggregorio/retinanet-cell-detection.

Adherence to Medical Treatment in Inflammatory Bowel Disease Patients from a Referral Center in Bahia-Brazil.

METHODS: Observational, analytical, and cross-sectional studies carried out from June/2017 to July/2018, with questionnaire application and medical record review at a referral center in inflammatory bowel diseases in Salvador, Bahia. The Morisky Green Levine Scale was applied to assess adherence. Mean, standard deviation, and frequency analyses were performed using the statistical package SPSS, and chi-square was used to evaluate the association between categorical variables and adherence degree to treatment. Significant associations were considered with p < 0.05. RESULTS: 302 patients with inflammatory bowel diseases were included. Nonadherence was highlighted in the sample. Most part of the study population was female, declared themselves to be mixed race, claimed to be from urban areas, and married. Nonadherence was more frequent than adherence in most sociodemographic variables of the present study. Nonadherence also stood out among the clinical variables, such as disease activity, drug side effect, and use of more than two additional medications. The association between all studied variables and adherence degree to treatment, considering the general sample, did not show statistical significance. When Crohn's disease and ulcerative colitis patients were evaluated separately, a statistically significant association between nonadherence and female patients with ulcerative colitis was observed. CONCLUSIONS: The high frequency of nonadherence was observed in the studied sample. Female gender was associated to nonadherence in the subpopulation with ulcerative colitis.

Author Correction: Optical Absorption Exhibits Pseudo-Direct Band Gap of Wurtzite Gallium Phosphide.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Optical Absorption Exhibits Pseudo-Direct Band Gap of Wurtzite Gallium Phosphide.

Definitive evidence for the direct band gap predicted for Wurtzite Gallium Phosphide (WZ GaP) nanowires has remained elusive due to the lack of strong band-to-band luminescence in these materials. In order to circumvent this problem, we successfully obtained large volume WZ GaP structures grown by nanoparticle-crawling assisted Vapor-Liquid-Solid method. With these structures, we were able to observe bound exciton recombination at 2.14 eV with FHWM of approximately 1 meV. In addition, we have measured the optical absorption edges using photoluminescence excitation spectroscopy. Our results show a 10 K band gap at 2.19 eV and indicate a weak oscillator strength for the lowest energy band-to-band absorption edge, which is a characteristic feature of a pseudo-direct band gap semiconductor. Furthermore, the valence band splitting energies are estimated as 110 meV and 30 meV for the three highest bands. Electronic band structure calculations using the HSE06 hybrid density functional agree qualitatively with the valence band splitting energies.

The Chelating Mineral on Organic Acid Salts Modulates the Dynamics and Richness of the Intestinal Microbiota of a Silver Catfish Rhamdia quelen.

The aim of this study was to evaluate the influence of the chelating mineral on propionic acid, calcium or sodium on the composition, dynamics and richness of the intestinal microbiota of a native silver catfish Rhamdia quelen through high-throughput sequencing (HTS). A total of 225 fish (8.43 ± 0.18 g) were distributed in tanks, 15 fish per tank in five groups with three replicates each: Control, Ca-propionate 0.25% (Ca0.25%) Ca-propionate 1% (Ca1%), Na-propionate 0.25% (Na0.25%) and Na-propionate 1% (Na1%). The feed was provided four times a day for 60 days. After experimental period, the fish were fasted for 24 h and the intestine was aseptically collected, pooled by treatment, and fixed in pure absolute ethanol for subsequent DNA extraction and HTS. The HTS showed that the supplementation of the propionic acid chelated to the mineral calcium or sodium in the different concentrations increased the operational taxonomic units and richness in comparison to control group. The main phyla found were Fusobacteria, Firmicutes, Proteobacteria and Bacteroides. Both the fusobacteria and the genus Cetobacterium, especially C. somerae, were positively modulated with Ca0.25% and Na1% supplementation. It can be emphasized that supplementation with calcium or sodium propionate at different concentrations changed the natural microbiota of R. quelen.

Hypokalemia and hyperkalemia in patients on peritoneal dialysis: incidence and associated factors.

BACKGROUND: Hypokalemia is a well-described electrolyte disturbance in patients on peritoneal dialysis (PD). Hyperkalemia, however, is still overlooked, although it also represents a risk factor for mortality. Angiotensin-converting enzyme inhibitors and/or angiotensin receptor blockers (ACE/ARB), diuretics, and proton pump inhibitor (PPI) can interfere with potassium levels in these patients. METHODS: This is a retrospective study that evaluated monthly serum potassium in a 5-year period. Serum potassium disturbances were evaluated as time-average and number of hypo- and hyperkalemia episodes per patient. Prescribed medication such as ACE/ARB, diuretics, and omeprazole were recorded. RESULTS: We evaluated 2025 potassium measurements obtained from 146 patients on PD. Serum potassium ranged from 2.5 to 8.3 mEq/L with an average of 4.72 ± 0.74 mEq/L. Hypokalemia was found in 59 measurements (2.9%) obtained from 35 patients (23.9%) whereas hyperkalemia was demonstrated in 269 (13.3%) measurements obtained from 74 patients (50.7%). Hypokalemia was associated with low albumin (p = 0.022), and omeprazole use (p = 0.024). Black race was a protector factor (p = 0.031). Omeprazole-associated hypokalemia was seen only in non-anuric patients and remained an independent risk factor even after adjustments. Patients who had hyperkalemia were more likely to be anuric (p = 0.001) and in use of furosemide (p = 0.0001). CONCLUSION: Hyperkalemia and hypokalemia are very frequent in patients on PD and should be closely monitored. Interventional studies should address the impact of discontinuing omeprazole in the levels of potassium.

High-Flux versus High-Retention-Onset Membranes: In vivo Small and Middle Molecules Kinetics in Convective Dialysis Modalities.

BACKGROUND: Patients undergoing maintenance hemodialysis (HD) exhibit increased levels of uremic toxins, which are associated with poor outcomes. Recently, new dialysis membranes have allowed clearance of solutes with higher molecular weight, without significant albumin losses high-retention-onset-HD (HRO-HD). METHODS: Prospective crossover trial, in which 16 prevalent patients switched from high-flux HD (HF-HD) to online hemodiafiltration (olHDF) and HRO-HD for 4 weeks. The following variables were evaluated: pre- and post-dialysis serum concentrations of albumin, urea, phosphate (P), beta-2 microglobulin (ß2M), and total mass (TM) extraction and dialyzer clearance of urea, P, and ß2M. RESULTS: Comparing HF-HD, olHDF, and HRO-HD, respectively, there were no differences regarding pre-dialysis serum concentrations of albumin (3.94 ± 0.36, 4.06 ± 0.22, and 3.93 ± 0.41 g/dL, p = 0.495), urea (166 ± 29, 167 ± 30, and 164 ± 27 mg/dL, p = 0.971), P (4.9 ± 2.1, 5.2 ± 1.6, and 4.9 ± 2.1 mg/dL, p = 0.879), and ß2M (31.3 ± 7.1, 32.6 ± 8.6, and 33.7 ± 5.9 µg/mL, p = 0.646). ß2M clearance was significantly lower in HF-HD in comparison to both olHDF and HRO-HD: 43 (37-53) versus 64 (48-85) mL/min, p = 0.013, and 69 (58-86) mL/min, p = 0.015, respectively. Post-dialysis ß2M serum concentration was higher in HF-HD in comparison to olHDF and HRO-HD: 11.6 (9.6-12.4) vs. 5.7 (4.5-7.0) µg/mL, p = 0.001, and 5.6 (5.3-7.6) µg/mL, p = 0.001, respectively. TM extraction of urea, P, and ß2M were similar across the 3 dialysis modalities. CONCLUSIONS: olHDF and HRO-HD were superior to HF-HD regarding ß2M clearance, leading to lower post-dialysis ß2M levels.

Genetic diversity and aquaculture conservation for a threatened Neotropical catfish

Due to the ecological importance of Lophiosilurus alexandri, the present work evaluated its genetic representativeness by comparing wild stocks to broodstocks that were kept at three restocking hatcheries along the São Francisco River. A total of 97 samples were genotyped for newly developed microsatellite markers. Low levels of genetic diversity (average alleles number of 4.2 alleles) were detected in all cases, being more severe in captive groups. Significant pairwise FST and DEST values, Structure, and DAPC analyses showed that wild animals were structured in two groups, and a third group was formed by captive animals, evidencing the need to adopt genetic criteria to retain genetic diversity in the hatcheries. For this reason, three full-sib families were constructed to select the best relatedness estimator for L. alexandri and establish a cut-off value aimed to avoid full-sibling matings in the hatcheries. Two estimators, Wang (RW) and Lynch & Li (RLL), were accurate in reflecting the relatedness level for full-sibs in this species. According to them, less than 50% of the potential breeding matings in the three hatcheries are advisable. The innate low diversity of L. alexandri highlights the importance of minimizing inbreeding and retaining genetic diversity towards the species recovery.(AU)

Devido à importância ecológica de Lophiosilurus alexandri, o presente trabalho avaliou sua representatividade genética, comparando estoques selvagens com plantéis de reprodutores de três larviculturas ao longo do Rio São Francisco. Noventa e sete amostras foram genotipadas com marcadores microssatélites recém-desenvolvidos. Baixos níveis de diversidade genética (número médio de alelos de 4,2) foram detectados em todos os casos, sendo mais severo no cativeiro. Os valores de FST e DEST par a par, as análises do Structure e DAPC mostraram a estruturação dos animais selvagens em dois grupos, e um terceiro formado pelas larviculturas, evidenciando a necessidade de adoção de critérios genéticos para retenção da diversidade genética no cativeiro. Por essa razão, três famílias de irmãos completos foram construídas para selecionar o melhor estimador de parentesco para a espécie e estabelecer os valores mínimos de corte para evitar cruzamentos indesejados. Dois estimadores, Wang (RW) e Lynch & Li (RLL), foram eficientes em refletir as relações de parentesco para irmãos completos nessa espécie. Segundo eles, menos de 50% dos potenciais cruzamentos são recomendáveis nas três larviculturas. A baixa diversidade genética inerente ao L. alexandri destaca a importância de minimizar a consanguinidade e evitar perda de diversidade genética, visando a recuperação da espécie.(AU)

Early Start Peritoneal Dialysis: Technique Survival in Long-Term Follow-Up.

BACKGROUND/AIMS: Peritoneal dialysis (PD) has gained interest over the last decade as a viable option for early start dialysis. It is still unknown if shorter break-in periods and less time for proper patient evaluation and training could influence technique survival in comparison to planned-start PD. METHODS: A prospective and observational study that compared technique survival in a cohort of patients who started either early or planned PD. Early start PD was defined as break-in period from 3 to 14 days with no previous nephrologist follow-up or patient training. RESULTS: A total of 154 patients were included (40 as early start PD), followed by a median time of 381 days. Comparing early vs. planned-start PD, groups were similar concerning age 56 (40; 70) vs. 48 (32; 63) years, p=0.071, body mass index (BMI) 23.3 ± 4.2 vs. 23.8 ± 4.0 kg/m2, p=0.567 and male gender (60 vs. 48%, p=0.201), respectively. Comparing early vs. planned-start groups, there were no differences regarding PD dropout for peritonitis (7.5 vs. 11.4%, p=0.764), catheter dysfunction (12.5 vs. 17.5%, p=0.619) and patient burnout (0 vs. 4.4%, p=0.328), respectively. Less patients in early start group quit PD for peritoneal membrane failure in comparison to planned-start group (2.5 vs. 16.7%, p=0.026). In multivariate cox-regression analysis, the only factors independently associated with technique failure were BMI> 25 kg/m² (p=0.033) and Diabetes Mellitus (p=0.013), whereas no differences regarding early vs. planned-PD start were observed (p=0.184). CONCLUSION: Despite the adverse scenario for initiating dialysis, early start PD had similar outcomes in comparison to planned-start PD in long-term follow-up.

Kidney injury and other complications related to colonoscopy in inpatients at a tertiary teaching hospital.

OBJECTIVES: To describe clinical complications related to colonoscopy in inpatients with multiple diseases. Among the known complications, acute kidney injury was the primary focus. METHODS: This was an observational retrospective study of 97 inpatients. Data relating to age; gender; comorbidities; current medication; blood tests (renal function, blood glucose and LDL cholesterol levels); length of hospital stay; indication, results, and complications of colonoscopies; and time to the development of kidney injury were collected between June 2011 to February 2012. RESULTS: A total of 108 colonoscopies (9 screening and 88 diagnostic) were conducted in 97 patients. Renal injury occurred in 41.2% of the patients. The univariate analysis revealed that kidney injury was related to the use of diuretics, statins, calcium channel blockers, and angiotensin converting enzyme inhibitor; however, the multivariate analysis showed that only the use of diuretics was associated with kidney injury. The occurrence of kidney injury and the time to its development were independent of the previous glomerular filtration rate as calculated with the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. CONCLUSIONS: The use of diuretics was the only independent variable associated with the development of kidney injury in inpatients with multiple comorbidities who underwent colonoscopy. The occurrence of kidney injury and the time to its development were independent of previous CKD-EPI-based assessments of renal function. These results highlight the increased risk of colonoscopy in such patients, and its indication should be balanced strictly and perhaps avoided as a screening test.

Decision-making process in the pre-dialysis CKD patients: do anxiety, stress and depression matter?

BACKGROUND: The transition from pre-dialysis chronic kidney disease (CKD) to renal replacement therapy (RRT) is a stressful event. Anxiety, depression and stress are frequent conditions in this population, and might play a role on the choice of dialysis modality. METHODS: This is a prospective study that included stages 4-5 CKD patients during a dialysis multi-disciplinary education program. Demographic, clinical, and laboratory data were evaluated. Hospital Anxiety and Depression Scale and a Perceived Stress Scale assessed levels of anxiety, depression and stress, respectively. RESULTS: A total of 67 from 190 recruited patients were included (59 ± 15 years, 54% males). Comparing patients who chose peritoneal dialysis (PD) and hemodialysis (HD), there were no differences on anxiety (p = 0.55), and depression scores (p = 0.467), and stress (p = 0.854). Anxious (p = 0.007) and depressive (p = 0.030) patients presented lower levels of phosphate than those not affected. There was a significant correlation (p < 0.0001) between anxiety and depression scores (R2 = 0.573), anxiety and stress scores (R2 = 0.542), depression and stress scores (R2 = 0.514). At the end of study, 29.8% of patients had already started on dialysis, and scores of anxiety, depression and stress reduced significantly (all p values < 0.0001), from 5.9 ± 3.3 to 1.8 ± 1.8, from 7.7 ± 4.0 to 3.8 ± 2.9 and from 28.6 ± 7.8 to 10.0 ± 6.2, respectively, regardless of which therapy was chosen. CONCLUSION: Depression, anxiety and perceived stress during final stages of CKD do not seem to be related to the choice of dialysis therapy and tend to decrease after dialysis initiation.

Kidney injury and other complications related to colonoscopy in inpatients at a tertiary teaching hospital

OBJECTIVES: To describe clinical complications related to colonoscopy in inpatients with multiple diseases. Among the known complications, acute kidney injury was the primary focus. METHODS: This was an observational retrospective study of 97 inpatients. Data relating to age; gender; comorbidities; current medication; blood tests (renal function, blood glucose and LDL cholesterol levels); length of hospital stay; indication, results, and complications of colonoscopies; and time to the development of kidney injury were collected between June 2011 to February 2012. RESULTS: A total of 108 colonoscopies (9 screening and 88 diagnostic) were conducted in 97 patients. Renal injury occurred in 41.2% of the patients. The univariate analysis revealed that kidney injury was related to the use of diuretics, statins, calcium channel blockers, and angiotensin converting enzyme inhibitor; however, the multivariate analysis showed that only the use of diuretics was associated with kidney injury. The occurrence of kidney injury and the time to its development were independent of the previous glomerular filtration rate as calculated with the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. CONCLUSIONS: The use of diuretics was the only independent variable associated with the development of kidney injury in inpatients with multiple comorbidities who underwent colonoscopy. The occurrence of kidney injury and the time to its development were independent of previous CKD-EPI-based assessments of renal function. These results highlight the increased risk of colonoscopy in such patients, and its indication should be balanced strictly and perhaps avoided as a screening test.

Exploring Au Droplet Motion in Nanowire Growth: A Simple Route toward Asymmetric GaP Morphologies.

Here we show a new nanowire growth procedure, exploring the thermally activated motion of Au droplets on III-V surfaces. We show that by setting a single growth parameter we can activate the crawling motion of Au droplets in vacuum and locally modify surface composition in order to enhance vapor-solid (VS) growth along oxide-free areas on the trail of the metal particle. Asymmetric VS growth rates are comparable in magnitude to the vapor-liquid-solid growth, producing unconventional wurtzite GaP morphologies, which shows negligible defect density as well as optical signal in the green spectral region. Finally, we demonstrate that this effect can also be explored in different substrate compositions and orientations with the final shape finely tuned by group III flow and nanoparticle size. This distinct morphology for wurtzite GaP nanomaterials can be interesting for the design of nanophotonics devices.

Physical-chemical characteristics and potential use of a novel alginate/zein hydrogel as the sorption phase for polar organic compounds.

A novel alginate based hydrogel was successfully prepared and tested for the solid phase microextraction of medium-to-high polarity compounds, when supported in a polypropylene (PP) fiber. Pure alginate when added onto the surface of the PP fiber, resulted in a significant improvement in the extraction efficiency of the analytes (except for ß-estradiol). The alginate hydrogel was modified upon the incorporation of a small amount of zein, a corn protein. Interestingly, the alginate/zein-supported hydrogel was capable of successfully extracting compounds with low partition constant (Kow), such as 17-α-ethinyl estradiol, progesterone and estriol, since the initial water uptake decreased dramatically in this gel, therefore, leaving the alginate hydroxyl groups more available to interact with the polar compounds. In conclusion, this paper presents the preparation of a simple, low cost, reusable, and efficient sorption phase for the extraction of polar compounds with different polarities in aqueous samples, which is a current technological challenge in developing efficient wastewater treatment.

Impact of Compression Stockings vs. Continuous Positive Airway Pressure on Overnight Fluid Shift and Obstructive Sleep Apnea among Patients on Hemodialysis.

INTRODUCTION: Obstructive sleep apnea (OSA) is common in edematous states, notably in hemodialysis patients. In this population, overnight fluid shift can play an important role on the pathogenesis of OSA. The effect of compression stockings (CS) and continuous positive airway pressure (CPAP) on fluid shift is barely known. We compared the effects of CS and CPAP on fluid dynamics in a sample of patients with OSA in hemodialysis, through a randomized crossover study. METHODS: Each participant performed polysomnography (PSG) at baseline, during CPAP titration, and after 1 week of wearing CS. Neck circumference (NC) and segmental bioelectrical impedance were done before and after PSG. RESULTS: Fourteen patients were studied (53 ± 9 years; 57% men; body mass index 29.7 ± 6.8 kg/m2). Apnea-hypopnea index (AHI) decreased from 20.8 (14.2; 39.6) at baseline to 7.9 (2.8; 25.4) during CPAP titration and to 16.7 (3.5; 28.9) events/h after wearing CS (CPAP vs. baseline, p = 0.004; CS vs. baseline, p = 0.017; and CPAP vs. CS, p = 0.017). Nocturnal intracellular trunk water was higher after wearing CS in comparison to baseline and CPAP (p = 0.03). CS reduced the fluid accumulated in lower limbs during the day, although not significantly. Overnight fluid shift at baseline, CPAP, and CS was -183 ± 72, -343 ± 220, and -290 ± 213 ml, respectively (p = 0.006). Overnight NC increased at baseline (0.7 ± 0.4 cm), decreased after CPAP (-1.0 ± 0.4 cm), and while wearing CS (-0.4 ± 0.8 cm) (CPAP vs. baseline, p < 0.0001; CS vs. baseline, p = 0.001; CPAP vs. CS, p = 0.01). CONCLUSION: CS reduced AHI by avoiding fluid retention in the legs, favoring accumulation of water in the intracellular component of the trunk, thus avoiding fluid shift to reach the neck. CPAP improved OSA by exerting local pressure on upper airway, with no impact on fluid redistribution. CPAP performed significantly better than CS for both reduction of AHI and overnight reduction of NC. Complementary studies are needed to elucidate the mechanisms by which CPAP and CS reduce NC.

High Dialysate Calcium Concentration May Cause More Sympathetic Stimulus During Hemodialysis.

BACKGROUND/AIMS: Acute activation of sympathetic activation during hemodialysis is essential to maintain blood pressure (BP), albeit long-term overactivity contributes to higher mortality. Low heart rate variability (HRV), a measure of autonomic nervous system activity, and abnormal ankle-brachial index (ABI) are associated with higher mortality in patients on hemodialysis. In this study, we assessed HRV and ABI pre and post dialysis in incident patients on hemodialysis using high (1.75mmol/l) and low (1.25mmol/l) dialysate calcium concentration (DCa). METHODS: HRV was measured as the ratio between low frequency and high frequency power (LF/HF). Thirty patients (age 47±16 years, 67% men) were studied in two consecutive mid-week hemodialysis sessions. RESULTS: Mean BP variation was positive with DCa 1.75 and negative with DCa 1.25 [4.0 (-6.0, 12.2 mmHg) vs. -3.2 (-9.8, 1.3 mmHg); p=0.050]. Reduction of ABI from pre to post HD was related to higher sympathetic activity (p=0.031). The increase in LF/HF ratio was higher with DCa 1.75 (58.3% vs. 41.7% in DCa 1.75 and 1.25, respectively, RR 2.8; p=0.026). CONCLUSION: Although higher DCa is associated with better hemodynamic tolerability during hemodialysis, this occurs at the expense of increased sympathetic activity. Higher sympathetic activity was associated with a decrease of ABI during hemodialysis.