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We exhibit a randomized algorithm which, given a square matrix [Formula omitted] with [Formula omitted] and [Formula omitted], computes with high probability an invertible V and diagonal D such that [Formula omitted] using [Formula omitted] arithmetic operations, in finite arithmetic with [Formula omitted] bits of precision. The computed similarity V additionally satisfies [Formula omitted]. Here [Formula omitted] is the number of arithmetic operations required to multiply two [Formula omitted] complex matrices numerically stably, known to satisfy [Formula omitted] for every [Formula omitted] where [Formula omitted] is the exponent of matrix multiplication (Demmel et al. in Numer Math 108(1):59-91, 2007). The algorithm is a variant of the spectral bisection algorithm in numerical linear algebra (Beavers Jr. and Denman in Numer Math 21(1-2):143-169, 1974) with a crucial Gaussian perturbation preprocessing step. Our result significantly improves the previously best-known provable running times of [Formula omitted] arithmetic operations for diagonalization of general matrices (Armentano et al. in J Eur Math Soc 20(6):1375-1437, 2018) and (with regard to the dependence on n) [Formula omitted] arithmetic operations for Hermitian matrices (Dekker and Traub in Linear Algebra Appl 4:137-154, 1971). It is the first algorithm to achieve nearly matrix multiplication time for diagonalization in any model of computation (real arithmetic, rational arithmetic, or finite arithmetic), thereby matching the complexity of other dense linear algebra operations such as inversion and QR factorization up to polylogarithmic factors. The proof rests on two new ingredients. (1) We show that adding a small complex Gaussian perturbation to any matrix splits its pseudospectrum into n small well-separated components. In particular, this implies that the eigenvalues of the perturbed matrix have a large minimum gap, a property of independent interest in random matrix theory. (2) We give a rigorous analysis of Roberts' Newton iteration method (Roberts in Int J Control 32(4):677-687, 1980) for computing the sign function of a matrix in finite arithmetic, itself an open problem in numerical analysis since at least 1986., Author(s): Jess Banks [sup.1], Jorge Garza-Vargas [sup.1], Archit Kulkarni [sup.1], Nikhil Srivastava [sup.1] Author Affiliations: (1) https://ror.org/01an7q238, grid.47840.3f, 0000 0001 2181 7878, Department of Mathematics, UC Berkeley, , 94720, Berkeley, [...] more...

This article presents the design of a pedagogical method to produce interactive learning objects that allow users to learn about new statistical process control techniques, such as Data Mining, in order to address the curricular needs of college students enrolled in academic programs related to quality engineering. Acquiring skills in this type of tools enables students to have a more competitive profile to work at different organizations. more...

Agave bagasse (AB), a byproduct of tequila production, is a waste generated in large quantities and an emerging alternative for biofuels production. Nevertheless, the use of lignocellulosic biomass for this purpose requires a pretreatment that maximizes its degradation and utilization. Although there are several pretreatment types, using ionic liquids (IL) has become attractive due to its ability to dissolve the lignocellulosic biomass under mild conditions of time and temperature. As a drawback are the high cost of IL's and their high viscosity; thus mixing them with water is a way to overcome these hindrances. This work aimed to evaluate the effect of pretreatment with three diluted ILs on the A. tequilana bagasse structure and sugars production, as well as the potential of the enzymatic hydrolysate to produce methane in batch mode. The evaluated ILs were: 1-ethyl-3-methylimidazolium acetate [Emim][OAc], choline lysinate [Ch][Lys] and ethanolamine acetate [EOA][OAc]. The results showed that the IL with the best performance was [Ch][Lys], which not only offered the highest yields of sugar production (0.57 ± 0.03 g total sugars / g bagasse) but also, it is possible to use it at 30 % in a mix with water obtaining similar yields as with pure IL. Enzymatic hydrolysis of IL pretreated AB achieved 50.7 kg sugars and 49.3 kg of sugars for 90 %-[Ch][Lys] and 30 %-[Ch][Lys], respectively per 100 kg of untreated biomass. The enzymatic hydrolysate from the 30 %-[Ch][Lys] pretreated AB was able to achieve 0.28 L CH4/g CODfed, demonstrating that both sugar and methane yields are maintained when pure or 30 %-[Ch][Lys] are used for pretreatment, representing a step forward towards process feasibility. more...

BackgroundAlthough specific interventions previously demonstrated benefit in patients with ARDS, use of these interventions is inconsistent, and patient mortality remains high. The impact of variability in center management practices on ARDS mortality rates remains unknown.Research questionWhat is the impact of treatment variability on mortality in patients with moderate to severe ARDS in the United States?Study design and methodsWe conducted a multicenter, observational cohort study of mechanically ventilated adults with ARDS and Pao2 to Fio2 ratio of ≤ 150 with positive end-expiratory pressure of ≥ 5 cm H2O, who were admitted to 29 US centers between October 1, 2016, and April 30, 2017. The primary outcome was 28-day in-hospital mortality. Center variation in ventilator management, adjunctive therapy use, and mortality also were assessed.ResultsA total of 2,466 patients were enrolled. Median baseline Pao2 to Fio2 ratio was 105 (interquartile range, 78.0-129.0). In-hospital 28-day mortality was 40.7%. Initial adherence to lung protective ventilation (LPV; tidal volume, ≤ 6.5 mL/kg predicted body weight; plateau pressure, or when unavailable, peak inspiratory pressure, ≤ 30 mm H2O) was 31.4% and varied between centers (0%-65%), as did rates of adjunctive therapy use (27.1%-96.4%), methods used (neuromuscular blockade, prone positioning, systemic steroids, pulmonary vasodilators, and extracorporeal support), and mortality (16.7%-73.3%). Center standardized mortality ratios (SMRs), calculated using baseline patient-level characteristics to derive expected mortality rate, ranged from 0.33 to 1.98. Of the treatment-level factors explored, only center adherence to early LPV was correlated with SMR.InterpretationSubstantial center-to-center variability exists in ARDS management, suggesting that further opportunities for improving ARDS outcomes exist. Early adherence to LPV was associated with lower center mortality and may be a surrogate for overall quality of care processes. Future collaboration is needed to identify additional treatment-level factors influencing center-level outcomes.Trial registryClinicalTrials.gov; No.: NCT03021824; URL: www.clinicaltrials.gov. more...

Background: Gastric cancer remains a major global health challenge, ranking fourth in cancer-related deaths. Total gastrectomy with lymphadenectomy is the standard treatment, with advancements in surgery shifting towards minimally invasive techniques to reduce surgical trauma and metabolic response. Esophagojejunal anastomotic leak is a frequent complication of gastrectomy, significantly increasing morbidity and mortality rates by up to 64%. Materials and methods: A retrospective cohort study reviewed adults undergoing total gastrectomy for gastric cancer who developed esophagojejunal anastomotic leaks. The study described patient characteristics, diagnostic methods, and management at Clinica Universitaria Colombia from 2013 to 2023. Results: Among 500 patients who had total gastrectomy, 54 developed esophagojejunal leaks. The cohort was 64.8% male, average age 55.2 years (± 14.87), and average BMI 24.5 kg/m². Notably, 18.5% smoked, 11.1% had lung disease, and 9.3% had heart disease or diabetes. Chest tomography was used in 60% of cases, followed by endoscopy in 35.2%. Endoscopic management with fully covered stents was the main strategy, used in 84% of cases. Average hospitalization was 18 days, with 33% needing intensive care, and overall hospital stay was 23.31 ± 16.33 days. Patients undergoing neoadjuvant and elective laparoscopic surgeries had a significant 30-day mortality risk. Conclusions: Despite advances in surgical techniques and perioperative management, esophagojejunal anastomotic leaks continue to represent a serious complication, increasing morbidity and mortality. Therefore, early postoperative detection, based on the patient's clinical signs that allow confirmatory studies to be performed, is crucial. This facilitates the implementation of timely treatments, whether conservative, through the use of endoscopic or percutaneous strategies, or surgical procedures. The next step for the scientific community will be to conduct studies with long-term follow-ups to ensure consistency of the high-quality results reported so far. [ABSTRACT FROM AUTHOR] more...

Background: Metabolic syndrome (MS) is a combination of comorbidities that increase pro-inflammatory cytokines (PIC) production, with subsequent body composition (BC) abnormalities and high cardiovascular risk. Treatment with diet and exercise has been suggested as possible non-pharmacological adjuvant treatment. Objective: To determine changes in BC and PIC in patients with MS after a Mediterranean-type diet (MedDiet) and/or isokinetic exercise (IE). Methods: A controlled randomized clinical trial was conducted at a third-level hospital in Mexico City. Intervention groups: G1: MedDiet + IE; G2: IE; G3: MedDiet; G4: control. Anthropometry, BC, and PIC were collected from the baseline and at 12 weeks post-intervention. MedDiet was estimated from a 24-h recall record. IE consisted of a standard high-intensity anaerobic exercise program. Results: Forty-two patients with MS aged 18–65 years old were included. The most frequent comorbidities were obesity, insulin resistance, and dyslipidemia. After 6 months of intervention, a significant reduction of resistin was observed within the IE group and MedDiet + IE, whereas the former group also showed an increase in adiponectin. Interventions of MedDiet and MedDiet + IE showed a decrease in IL-10. Regarding BC, all groups increased the resistance values in relation to the baseline but were lower than the control group. Conclusions: The results suggest that MedDiet and IE have a selective impact on pro-inflammatory mediators, while the combination of MedDiet and IE may induce only minor changes in BC. [ABSTRACT FROM AUTHOR] more...

Hydropower is currently one of the leading renewable energy sources in developing countries. Despite the benefits that it can provide, it also triggers significant environmental impacts, such as changes in the reservoirs’ water quality. In quantifying those changes, dissolved oxygen (DO) is used as one of the water quality indicators and is the most used variable to quantify water quality and analyze water pollution. This paper aims to establish a relationship between water quality and hydrometeorological variables in tropical reservoirs to better estimate dissolved oxygen. Univariate and multivariate techniques were used to analyze temporal and spatial changes in watersheds to better select vital variables for the forecast model, such as Vector Autoregression (VAR). The results show that, for all monitoring stations, the water quality variables associated with the DO process are COD, BOD, and PO₄. Likewise, precipitation and flow discharge were the hydrometeorological parameters that had the most significant impact on DO. Also, the principal component analysis (PCA) allowed us to identify that the strength of the relationships between water quality and hydrometeorology changes depending on the location of the monitoring site. Finally, the implementation of a VAR model showed good performance metrics for dissolved oxygen predictions based on all analyses. more...

The spinal cord consists of multiple neuronal cell types that are critical to motor control and arise from distinct progenitor domains in the developing neural tube. Excitatory V2a interneurons in particular are an integral component of central pattern generators that control respiration and locomotion; however, the lack of a robust source of human V2a interneurons limits the ability to molecularly profile these cells and examine their therapeutic potential to treat spinal cord injury (SCI). Here, we report the directed differentiation of CHX10+ V2a interneurons from human pluripotent stem cells (hPSCs). Signaling pathways (retinoic acid, sonic hedgehog, and Notch) that pattern the neural tube were sequentially perturbed to identify an optimized combination of small molecules that yielded ∼25% CHX10+ cells in four hPSC lines. Differentiated cultures expressed much higher levels of V2a phenotypic markers (CHX10 and SOX14) than other neural lineage markers. Over time, CHX10+ cells expressed neuronal markers [neurofilament, NeuN, and vesicular glutamate transporter 2 (VGlut2)], and cultures exhibited increased action potential frequency. Single-cell RNAseq analysis confirmed CHX10+ cells within the differentiated population, which consisted primarily of neurons with some glial and neural progenitor cells. At 2 wk after transplantation into the spinal cord of mice, hPSC-derived V2a cultures survived at the site of injection, coexpressed NeuN and VGlut2, extended neurites >5 mm, and formed putative synapses with host neurons. These results provide a description of V2a interneurons differentiated from hPSCs that may be used to model central nervous system development and serve as a potential cell therapy for SCI. more...

Simple Summary: The Wolbachia-based incompatible insect technique (IIT) and the sterile insect technique (SIT) are effective technological innovations to control Aedes mosquitoes and could be implemented as part of integrated, synergistic, and complementary schemes to enhance the efficiency and coverage of traditional control tools. This review presents the implementation of an IIT-SIT strategy for population suppression within an integrated vector management plan operated by the Ministry of Health in Mexico, and assesses its adherence to the different prerequisites, indicators of agreement, concordance, and suggestions proposed in the PAHO guidelines for the adoption of innovations in the control of Ae. aegypti. This experience provides essential evidence for the strategic national plan for the implementation and integration of IIT and SIT for the control of Ae. aegypti and dengue and should serve as an example to other countries in the region interested in implementing these technologies, since it illustrates the complex nature of adopting and trying to scale up this kind of innovative tool in urban settings where Aedes vectors and Aedes-borne diseases are endemic. The future of Aedes aegypti control emphasizes the transition from traditional insecticides toward more sustainable and multisectoral integrated strategies, like using Wolbachia-carrying mosquitoes for population suppression or replacement. We reviewed the integration of the successful Mexican initiative, "Mosquitos Buenos", with the key challenges outlined in the PAHO guidelines for incorporating innovative approaches into vector control programs. These challenges include establishing essential infrastructure, training personnel, managing field operations, and fostering community support. Our experience provides critical evidence to support the strategic National Plan for implementing and integrating IIT-SIT technologies to control Ae. aegypti and dengue. Furthermore, this experience serves as a foundation for other countries in the region interested in adopting these technologies. It underscores the importance of strategic planning, multisectoral collaboration, continuous evaluation, and scaling up innovative tools to ensure their long-term effectiveness and sustainability in urban areas where Aedes vectors and the diseases they transmit are endemic. [ABSTRACT FROM AUTHOR] more...

The document "Mexican statement for the diagnosis and treatment of cardiac amyloidosis" offers a comprehensive overview of the diagnosis and treatment of cardiac amyloidosis by various Mexican medical societies. It emphasizes the importance of early detection, challenges in diagnosis, and the use of innovative imaging techniques for accurate diagnosis. The document also discusses the epidemiology, clinical manifestations, and diagnostic tools for cardiac amyloidosis, as well as recommendations for cardiac rehabilitation, exercise testing, psycho-emotional support, and genetic counseling. Further research and clinical trials are needed to enhance the diagnosis, treatment, and outcomes for patients with cardiac amyloidosis, including transthyretin amyloidosis and light chain amyloidosis. [Extracted from the article] more...

Purpose: The aim of this study was to evaluate the feasibility of a novel technique that focuses on vertical and horizontal stabilization of the acromioclavicular joint using two local autologous grafts, the pectoralis minor (Pm) and the coracoacromial ligament (CAL). Methods: Ten fresh‐frozen shoulder cadaveric pieces were dissected. Length and width of the Pm and CAL were measured in their anatomical position and anatomical variants were noted. The Pm tendon was harvested at the myothendinous junction keeping the insertion at the coracoid process. The CAL was detached from the coracoid process keeping the acromial insertion. The free limbs of both grafts were prepared with the Krackow technique and the Arthrex SpeedWhip technique, respectively. The primary coracoclavicular reduction and fixation were with the button system or with two subcoracoid ultrahigh‐strength suture cerclage through and around the clavicle. The Pm graft was fixed inside a clavicular tunnel by a cortical button and the CAL was transferred and fixed to the lateral clavicle using a knotless anchor or intramedullary when lateral clavicle resection was performed. Results: The median length of the Pm was 50 mm (interquartile range [IQR]: 50–54), and the median length of the CAL was 36.5 mm (IQR 34–40) which decreased by 15% and 23% once were prepared with the Krackow and Arthrex SpeedWhip techniques to 44.5 mm (IQR: 30–65) and 30 mm (IQR: 22–32), respectively. The diameter of the prepared Pm graft was 5 mm (IQR: 4.5–6) and the CAL graft 5.5 mm (5–6). All grafts were able to reach the fixation points. The procedure was feasible in 100% of the cases. Conclusion: A biplanar reconstruction using autologous Pm and CAL appears feasible in restoring the acromioclavicular joint stability. Level of Evidence: Level IV. Basic science, anatomy, cadaveric dissection [ABSTRACT FROM AUTHOR] more...