Stress tensors and quantification of fracture patterns to analyze connectivity and potential fluid flow in a mesa landform of the Northern Andes

This work applies stress tensors inversions and quantification of fracture patterns along the Mesa de Los Santos, in the Eastern Cordillera of Colombia, to better understand the potential fluid flow. It thus contributes to the conceptual hydrogeological model. The area was subdivided into three blocks, separated by the NW Potreros and the Los Santos faults, having minor inner faults of different orientations. This separation facilitates the analysis of the fractures measured in the field, which in general show high dip angles and a conjugate geometry in the northern block, tension fractures(Mode I) in the central block, and a random distribution in the southwestern block. WinTensor treatment of slickensides yielded a maximum horizontal stress(SHmax) of 111o, which coincides with the WNW-ESE tensor observed from the conjugate and tension joints. We then used Frac Pa Q to generate interpolation maps of fracture intensity and density. The maps show the highest values in the central block and the lowest in the northern block,where the precipitation is higher, causing intensive rock weathering and homogenization of the fracture planes. Although the highest values of connectivity by line are found to the south of the mesa, we suggest the possibility of greater flow from the recharge zone(NE) along bedding planes and open NW-SE fractures.

AN OPTIMAL CONTROL PROBLEM FOR A LOTKA-VOLTERRA COMPETITION MODEL WITH CHEMO-REPULSION

In this paper we study a bilinear optimal control problem for a diffusive Lotka-Volterra competition model with chemo-repulsion in a bounded domain of ℝ^(ℕ),N=2,3.This model describes the competition of two species in which one of them avoid encounters with rivals through a chemo-repulsion mechanism.We prove the existence and uniqueness of weak-strong solutions,and then we analyze the existence of a global optimal solution for a related bilinear optimal control problem,where the control is acting on the chemical signal.Posteriorly,we derive first-order optimality conditions for local optimal solutions using the Lagrange multipliers theory.Finally,we propose a discrete approximation scheme of the optimality system based on the gradient method,which is validated with some computational experiments.

Mobility Habitus in the Literature From 2020 to 2024

The objective of the present work is modeling the mobility habitus in the public transport system with low Co2 emission mechanics in the center of Mexico.In this sense,a documentary work was carried out with a review of sources indexed to national repositories,using the Delphi technique for the content analysis and the specification of the model.A study was conducted with a selection of 100 students to establish the reliability,linearity,sphericity,adequacy,and validity of an instrument from which a relationship of dependence between income and mobility habitus was observed.The limits of the search,selection,and processing of information are recognized,and it is recommended to extend the research to international repositories,as well as to employ a more sophisticated technique.

Design of multilayer hybrid sol-gel coatings with bifunctional barrier-bioactive response on the Elektron 21 magnesium alloy for biomedical applications

The present study aims to develop multilayer barrier-bioactive hybrid sol-gel coatings from a mixture of the silane precursors tetraethylorthosilicate(TEOS)and glycidoxypropyltriethoxysilane(GPTMS)deposited on the Elektron 21 magnesium alloy.The purpose of the inner layer(barrier coating)was to provide corrosion protection to the magnesium alloy,whereas the outer layer(bioactive coating)was doped with different Ca and Mg contents to produce a bioactive material.The coatings were characterised using scanning electron microscopy(SEM)and their corrosion behaviour was evaluated by anodic polarisation and electrochemical impedance spectroscopy after immersion in simulated body fluid(SBF)at 37±0.5°C.The experimental results showed that the multilayer coatings increased the corrosion resistance of the alloy up to three orders of magnitude during immersion in SBF solution.On the other hand,the presence of Ca and Mg in the bioactive coating promoted the growth of apatite-like phases.However,an increment of salt content favoured the formation of porous coatings,which allowed the access of the electrolyte to the substrate leading to their rapid deterioration.Despite the latter,this research endorses the premise that the TEOS-GPTMS hybrid system represents a promising alternative to produce bifunctional barrier-bioactive coatings.

Two disulfide mutants in domain I of <i>Bacillus thuringiensis</i>Cry3Aa δ-endotoxin increase stability with no effect on toxicity

To increase protein stability and test protein function, three double-cysteine mutations were individually introduced by protein engineering into the cysteine-free Cry3Aa δ-endotoxin from Bacillus thuringiensis. These mutations were designed to create disulfide bonds between α-helices 2 and 5 (positions 110 - 193), and α-helices 5 and 7 (positions 195 - 276 and 198 - 276). Comparison of the CD spectra of the wild-type and the double-cysteine mutant proteins indicates a tighter helical packing consistent with formation of at least two of the disulfide bonds between the central and the outer helices. Thermal stability analysis indi-cates that potential covalent linkages between the central α-helix 5 and the other helices increase resistance to thermal denaturation by 10?C to 14?C com-pared to the thermal stability of the wild-type protein. Spectroscopic analysis of the disulfide-specific absorbance band indicates that the double mutant proteins are more stable to temperature and denaturant (guanidine hydrochloride) than the wild-type protein, as a result of the formation of two of the disulfide bridges. These results indicate that the double muta-tions M110C/F193C and A198C/V276C successfully established disulfide bonds, resulting in a more stable structure of the entire toxin. Despite the increase in stability and structural changes introduced by the disulfide bonds, no effect on toxicity was observed. A possible mechanism involving the insertion of all of domain I of Cry3Aa toxin into the target membrane accounts for these observations.

Removal of As(V)in the presence of Cr(VI)in contaminated water from the Bajio region of Mexico using ferrihydrite-functionalized graphene oxide(GOFH):A case study

The presence of heavy metals such as arsenic(As)and chromium(Cr)can be considered one of the most toxic heavy metals.This study aims to develop and evaluate a graphene oxide(GO)based material functionalized with ferrihydrite for the removal of As(V)in the presence of Cr(VI).The adsorbent ferrihydrite-functionalized graphene oxide(GOFH)was characterized by SEM,FTIR,XRD,XPS,surface charge,BET and TGA.Individual adsorption capacities for As(V)and Cr(VI)were 160 and 66 mg g^(-1)respectively at pH 4 and 298 K,fitting the Langmuir model.In binary systems,GOFH adsorbed As(V)with an adsorption capacity of 137 mg g^(-1)in the presence of 20 mg L^(-1)Cr(VI)at room temperature.Thermodynamic analysis revealed an exothermic and spontaneous process.Additionally,GOFH effectively removed several coexisting anions from groundwater,including SO_(4)^(2-),CO_(3)^(2-)and Cl^(-).This work evidences the potential of GOFH for competitive adsorption of priority pollutants from complex matrices.The GOFH material represents a technically and economically viable technology for application in groundwater decontamination,as it requires inexpensive precursors and ambient conditions during synthesis and operation.

Deep optics preconditioner for modulation-free pyramid wavefront sensing

The pyramid wavefront sensor(PWFS)can provide the sensitivity needed for demanding adaptive optics applications,such as imaging exoplanets using the future extremely large telescopes of over 30 m of diameter(D).However,its exquisite sensitivity has a limited linear range of operation,or dynamic range,although it can be extended through the use of beam modulation—despite sacrificing sensitivity and requiring additional optical hardware.Inspired by artificial intelligence techniques,this work proposes to train an optical layer—comprising a passive diffractive element placed at a conjugated Fourier plane of the pyramid prism—to boost the linear response of the pyramid sensor without the need for cumbersome modulation.We develop an end-2-end simulation to train the diffractive element,which acts as an optical preconditioner to the traditional least-square modal phase estimation process.Simulation results with a large range of turbulence conditions show a noticeable improvement in the aberration estimation performance equivalent to over 3λ∕D of modulation when using the optically preconditioned deep PWFS(DPWFS).Experimental results validate the advantages of using the designed optical layer,where the DPWFS can pair the performance of a traditional PWFS with 2λ∕D of modulation.Designing and adding an optical preconditioner to the PWFS is just the tip of the iceberg,since the proposed deep optics methodology can be used for the design of a completely new generation of wavefront sensors that can better fit the demands of sophisticated adaptive optics applications such as ground-to-space and underwater optical communications and imaging through scattering media.

Evaluation of the Finnish Diabetes Risk Score to predict type 2 diabetes mellitus in a Colombian population: A longitudinal observational study

AIM: To assess the performance of the Finnish Diabetes Risk Score(FINDRISC) questionnaire for detecting and predicting type 2 diabetes mellitus(DM2) in a Colombian population.METHODS: This is a longitudinal observational study conducted in Floridablanca, Colombia. Adult subjects(age ≥ 35 years) without known diabetes, were included. A modified version of FINDRISC was completed, and the glycemia values from all the subjects were collected from the hospital's database. Firstly, a cross-sectional analysis was performed and then, the subsample of prediabetic participants was followed for diabetes incidence. RESULTS: A total of 772 subjects were suitable for the study. The overall prevalence of undiagnosed DM2 was 2.59%, and the incidence of DM2 among the prediabetic participants was 7.5 per 100 person-years after a total of 265257 person-years follow-up. The FINDRISC at baseline was significantly associated with undiagnosed and incident DM2. The area under receiver operating characteristics curve of the FINDRISC score for detecting undiagnosed DM2 in both men and women was 0.7477 and 0.7175, respectively; and for predicting the incidence of DM2 among prediabetics was 71.99% in men and 67.74% in women. CONCLUSION: The FINDRISC questionnaire is a useful screening tool to identify cross-sectionally unknown DM2 and to predict the incidence of DM2 among prediabetics in the Colombian population.

Constructed Wetland Systems as a Methodology for the Treatment of Wastewater in Bucaramanga Industrial Park

Effluent discharges from municipal, industrial, and agricultural activities constitute major sources of pollution on land and water bodies. During the 1990s, large-scale application of Constructed Wetlands (CWs) as a remediation option drew much attention globally from the public and green groups alike. The most common application of CWs is for flow management in river system and little is documented on using CWs for treating polluted river water. This article goes beyond constructed wetlands as a stand-alone methodology to propose an integrated remediation system incorporating constructed wetlands in Bucaramanga Industrial Park S.A., Santander (Colombia), which will form part of an innovation park. In addition to pollution abatement, the project is projected to provide other environmental benefits to the entire Oro River Sub-basin. Other benefits of the project include mitigation of environmental impacts, improvement in water quality, landscape amenity, as well as tourism and recreational benefits.

Mid-term results of patterned laser trabeculoplasty for uncontrolled ocular hypertension and primary open angle glaucoma

AIM:To describe the safety and efficacy of patterned laser trabeculoplasty(PLT)as an adjunctive treatment in primary open angle glaucoma(POAG)and ocular hypertension(OHT)after 18-month follow-up in Hispanic population.METHODS:A single-center,retrospective study was conducted.All patients with OHT or POAG undergoing PLT from June 2016 to August 2016 were included in the study.Investigated parameters were intraocular pressure(IOP),the number of IOP-lowering medications,best corrected visual acuity(BCVA),laser parameters and postoperative adverse events.Primary efficacy outcome measures were the proportion of eyes achieving an IOP reduction≥20%at 18 mo versus baseline medicated IOP or a reduction in the number of medications while maintaining IOP values.RESULTS:From 40 PLT-treated eyes(mean baseline IOP 20.3±1.7 mm Hg),24 patients were analyzed(age 63.4±7.3 y).The mean IOP reductions from baseline across visits(months 1,3,6,9,12,and 18)ranged from 14.1%to 20.8%.Success rate after 18-month follow-up was 61.7%with a mean IOP of 16±3.2 mm Hg(P<0.001).The number of glaucoma IOP-lowering medications per eye(preoperative 2.1±1.1 and postoperative 2.3±1.1,P=0.86)and the mean BCVA(preoperative 0.10±0.22 and postoperative 0.11±0.22 logMAR,P=0.42)remained stable.Adverse events comprised transitory IOP spikes in 4 eyes(10%)and peripheral anterior synechiae in 7 eyes(17.5%).CONCLUSION:Mid-term results of PLT show that this procedure may be an efficacious and safe technique to approach medically uncontrolled OHT or POAG patients.

Correlation between the Childhood-Asthma Control Test and the Criterion for Clinical Asthma Control

Setting: Three pediatric pneumatologist offices in Bucaramanga, Colombia. Objective: To establish the concordance between medical criteria and the Childhood-Asthma Control Test (cACT). Design: Study of the assessment of diagnostic technology using transverse sampling. 127 asthma patients aged between 4 and 11 years and their parents filled before clinical evaluation made by a pediatric pneumologist. Patients were classified as controlled or not controlled. Criteria validity was established comparing this classification using Cohen’s kappa and performance indicators according to ROC analysis. Results: 78% of the patients were controlled;patients who are not controlled have a higher score in cACT (mean difference: 3.25 points). Concordance among cACT subscales is acceptable (ρ = 0.554). cACT’s sensitivity was 53.6%, specificity 78.8%, positive likelihood ratio (LR+) 2.53, and negative likelihood ratio (LR-) 0.59. The best cut-off point is 15, with 98% sensitivity, a specificity of 14.3%, LR+ in 1.14, and LR- in 0.14. Conclusions: cACT is a valid tool to determine asthma control in children without replacing medical criteria or other clinical tests. In populations with difficult access to high complexity services, it is useful to decide whether urgent referral to the specialist is necessary.

Use of antiepileptic drugs in children with brain tumors: A review for acute management

Patients with primary or secondary tumors in the central nervous system may have seizures resulting from direct tissue damage,metabolic abnormalities,infection,or toxic side effects of medications.In pediatric patients,it is more frequent to use drugs to control secondary epilepsy.In this article,we discuss the main nuances of antiepileptic drugs for the proper management of children with central nervous system tumors.

A Check List to Reduce Misuse of Primary Cesarean Sections in Women with a Single Fetus in Cephalic Position

Background: Avoiding primary C-section is the safest and most effective way of decreasing C-section rates. We analyzed circumstances and decisions made among pregnant women without history of C-section and cephalic single fetus (group B), who ended up having a Cesarean birth, to identify opportunities that may optimize the decisions about delivery. Methodology: We evaluated the clinical histories of pregnant women from group B who completed their pregnancies in the Hospital Universitario de Santander (Bucaramanga, Colombia) during 2013. We evaluated the decision moments from admission until birth, including the registry of the reasons for having a C-section, compliance of all the criteria to support the decision and its appropriateness, and how adequate were the procedures done during the induction or augmentation of labor. Results: We evaluated 1320 histories;666 (55.7%) ended by C-Section. In 59.8% of the histories, we identified at least one decision that could have been addressed differently to optimize the delivery type and, potentially, avoid ending in a Cesarean birth. The most frequent opportunities arise due to a lack of clarity in the record of the reason for performing the C-section (70.1%), and inadequate use of labor induction in the patients that had to end their gestation (38.5%). Conclusion: In the Hospital Universitario de Santander during 2013, despite observing a meaningful subregistry of the indication to perform a C-section, we found that in one out of every two patients there are opportunities of improvement in the registry and attention to reduce the high incidence of C-sections in the institution. This analysis allowed us to create a checklist to fill out before making the final decision of performing a Cesarean birth.

Gastrointestinal tuberculosis:An autopsy-based study

Background:Tuberculosis is a disease of great relevance since it is one of the leading causes of morbidity and mortality worldwide.Gastrointestinal tuberculosis is an unusual presentation.It is defined as the involvement of any segment of the digestive tract,associated viscera,and peritoneum.The study’s main objective is to collect information from autopsies of patients diagnosed with gastrointestinal tuberculosis in a Pathology reference center in Colombia.Methods:This is a retrospective and descriptive study of autopsy reports.A total of 4,500 autopsies were performed between January 2004 and December 2020.The inclusion criteria were authorization of a family member following local law regulations and a final autopsy diagnosis of gastrointestinal tuberculosis using microscopic visualization.Results:Forty-eight patients with gastrointestinal tuberculosis autopsies were included in our study.Most of the patients were male(n=35,72.9%)with a median age of 40.5 years old.Human immunodeficiency virus infection history was reported in 28 cases(58.33%).The most affected gastrointestinal tract site was the terminal ileum.Ulcers and thickened epithelium were common autopsies macroscopic findings.Tuberculosis multiorgan compromise was a relevant finding in patients with gastrointestinal tuberculosis.Conclusions:Gastrointestinal tuberculosis is a disease of great importance,being its diagnosis a clinical challenge.Underdiagnosis can be reported in a high percentage of cases,so autopsy diagnosis can help reveal more accurate data about this condition.

Actinobacteria-enhanced plant growth, nutrient acquisition, and crop protection:Advances in soil, plant, and microbial multifactorial interactions

Agricultural areas of land are deteriorating every day owing to population increase, rapid urbanization, and industrialization. To feed today’s huge populations, increased crop production is required from smaller areas, which warrants the continuous application of high doses of inorganic fertilizers to agricultural land. These cause damage to soil health and, therefore, nutrient imbalance conditions in arable soils. Under these conditions, the benefits of microbial inoculants (such as Actinobacteria) as replacements for harmful chemicals and promoting ecofriendly sustainable farming practices have been made clear through recent technological advances. There are multifunctional traits involved in the production of different types of bioactive compounds responsible for plant growth promotion, and the biocontrol of phytopathogens has reduced the use of chemical fertilizers and pesticides. There are some well-known groups of nitrogen-fixing Actinobacteria, such as Frankia, which undergo mutualism with plants and offer enhanced symbiotic trade-offs.In addition to nitrogen fixation, increasing availability of major plant nutrients in soil due to the solubilization of immobilized forms of phosphorus and potassium compounds, production of phytohormones, such as indole-3-acetic acid, indole-3-pyruvic acid, gibberellins, and cytokinins, improving organic matter decomposition by releasing cellulases, xylanase, glucanases, lipases, and proteases, and suppression of soil-borne pathogens by the production of siderophores, ammonia, hydrogen cyanide, and chitinase are important features of Actinobacteria useful for combating biotic and abiotic stresses in plants.The positive influence of Actinobacteria on soil fertility and plant health has motivated us to compile this review of important findings associated with sustaining plant productivity in the long run.