Phonon-like hydrogen-bond modes in protic ionic liquids

Gigahertz- to terahertz-frequency infrared and Raman spectra contain a wealth of information concerning the structure, intermolecular forces, and dynamics of ionic liquids. However, these spectra generally have a large number of contributions ranging from slow diffusional modes to underdamped librations and intramolecular vibrational modes. This makes it difficult to isolate effects such as the role of Coulombic and hydrogen-bonding interactions. We have applied far-infrared and ultrafast optical Kerr effect spectroscopies on carefully selected ions with a greater or lesser degree of symmetry in order to isolate spectral signals of interest. This has allowed us to demonstrate the presence of longitudinal and transverse optical phonon modes and a great similarity of alkylammonium-based protic ionic liquids to liquid water. The data show that such phonon modes will be present in all ionic liquids, requiring a reinterpretation of their spectra

Produced water treatment by advanced oxidation processes

Abstract Different Advanced Oxidation Processes (AOPs) such as photocatalysis, Fenton-based processes and ozonation were studied to include one of these technologies within an integrated solution for produced water (PW) polishing. Synthetic PW was prepared adding toluene, xylene, naphthalene, phenol, acetic and malonic acids to a seawater matrix. Despite that in all AOPs studied in this work BTEX and naphthalene were removed, the efficiency (in terms of TOC removal) of each treatment varied largely. Among these techniques, photocatalysis was found to be the less effective for the treatment of PW, as TOC removals lower than 20% were obtained for the best scenario after 4 h treatment. In the contrary, best results were obtained by ozonation combined with H2O2, where all the organic components were removed, including a high percentage of acetic acid, which was not abated by the rest of the AOPs studied. The optimum conditions for ozonation were 4 g h−1 O3 and 1500 mg L−1 H2O2 at pH 10, where after 2 h a 74% of TOC removal was achieved and the acetic acid elimination was 78%. This condition enabled that ozonation process accounted for the lowest electric energy consumption per order of target compound destruction regarding total organic carbon (TOC)

Weed control in jalapeño pepper with pre and post-emergent herbicide mixtures at two localities in Costa Rica

Se realizaron dos experimentos en dos localidades: uno en la Estación Experimental Fabio Baudrit M., localizada en el Barrio San José de Alajuela a 840 msnm y precipitación de 2000 mm y el otro, en la Reserva Biológica de Carara, ubicada a 150 msnm y una precipitacion de 2487 mm. Se usó un diseño de bloques completos al azar, en parcelas divididas en el tiempo y cuatro repeticiones; la unidad experimental fue de 6 m2. En la EEFBM se probó el método de aplicación total y los tratamientos fueron: napropamida (4 kg/ha), atrazina (1,5 kg/ha), metribuzin (0,20 kg/ha) y linuron (1,5 kg/ha), además de un testigo deshierbado y uno a libre crecimiemto. El experimento que se realizó en Carara se estableció con los resultados obtenidos en la EEFBM, para estudiar la aplicación dirigida (sin contacto con las plantas de chile). Se usaron los siguientes tratamientos: difenomida (4 kg/ha), oxadiazon (0,5 kg/ha), cada una se mezcló con pendimetalina (1 kg/ha) + paraquat (0,5 kg/ha) y alaclor (1,5 kg/ha) + paraquat (0,5 kg/ha). Además se incluyó un testigo que consistió en aplicaciones frecuenciales de paraquat y testigo a libre crecimiento. Todas las mezclas de herbicidas usadas en la EEFBM causaron fitotoxicidad a las plantas de chile. Los tratamientos que combatieron mejor las malezas fueron pendimetalina + atrazina y alaclor + linuron, la producción promedio fue de 7,2 t/ha. En Carara, el mejor tratamiento fue alaclor + metribuzin + paraquat con una producción de chile de 54,3 t/ha; la producción promedio de chile fue de 34,5 t/ha.The trials were conducted at two localities in Costa Rica: at the Fabio Baudrit Experiment Station in Alajuela at 840 m.a.s.l. and 2487 mm of rainfall and at the Carara Biological Reservation located at 150 m.a.s.l. and 2487 mm of rainfall. A Complete Randomized Block, with split plots on the time, experimental design wi th four replications was used. The experimental unit was 6 m2. At the Fabio Baudrit Experiment Station, the total application method was tested with the following treatments: napropamide (4 kg/ha), atrazine (1.5 kg/ha), metribuzin (0.20 kg/ha) and linuron (1.5 kg/ha), besides of a weeded control and another one left unweeded. The trial conducted at Carara was established according to the results obtained at the Fabio Baudrit Experiment Station, in order to study the aimed application (without contacting the pepper plants). The treatments applied were: diphenamid (4 kg/ha), oxadiazon (0.5 kg/ha), each one mixed wi th pendimethalin (1 kg/ha) + paraquat (0. 5 kg/ha) and alachlor (1.5 kg/ha) + paraquat (0.5 kg/ha). Control consisting of frequent paraquat applications and free weed growth were also included. All herbicide mixtures used at the Fabio Baudrit Experiment Station caused phytotoxicity to the pepper plants. The treatments which best controlled weeds were pendimethalin + atrazine and alachlor + linuron, the average yield was 7.2 t/ha. At Carara, the best treatment was alachlor + metribuzin + paraquat with a yield of 54.3 t/ha. The average yield was 34.5 t/ha.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Estación Experimental Agrícola Fabio Baudrit Moreno (EEAFBM

Closure of a large lumbosacral myelomeningocele post operative defect with a human cadaveric split-thickness skin graft: a case report

Spina bifida is the most common birth defect of the central nervous system that is compatible with life, and myelomeningocele represents its most frequent form. Congenital myelomeningocele (CMM) has a worldwide incidence of 0.5 to 0.8 per 1,000 live newborns. CMM is a complex condition resulting from incomplete closure of the neural tube, mainly in the lumbosacral region. The objective of the surgical repair of the CMM is the reconstruction of all the tissue layers of the defect, avoiding possible postoperative complications. The aim of this case review is to present a re-epithelialization closure in a patient with a large CMM defect in who primary hermetic closure was not possible because there was too much tension at the edges of the defect. Therefore, human cadaveric split-thickness skin grafts were placed over the dura mater and the aponeurotic layer, covering the entire defect and an adequate healing and completely closure of the defect were observed in eight weeks. The surgical management of large meningomyelocele defects represents a major challenge and no single protocol exists for its reconstruction. The repair of an MMC defect should be performed during the first 72 hours after birth. After neurosurgical closure of the neural tube and dura, the myelomeningocele defect requires good quality skin and subcutaneous tissue with minimal wound tension for stable coverage. Human cadaveric skin grafts are considered a useful technique for temporary wound coverage because they lead to a more natural healing environment, possess ideal properties, and provide a physiological barrier that reduces microbiological contamination, in addition, it acts as a bridge to adhere to and to seal wound beds

A Review of the Enviro-Net Project

Ecosystems monitoring is essential to properly understand their development and the effects of events, both climatological and anthropological in nature. The amount of data used in these assessments is increasing at very high rates. This is due to increasing availability of sensing systems and the development of new techniques to analyze sensor data. The Enviro-Net Project encompasses several of such sensor system deployments across five countries in the Americas. These deployments use a few different ground-based sensor systems, installed at different heights monitoring the conditions in tropical dry forests over long periods of time. This paper presents our experience in deploying and maintaining these systems, retrieving and pre-processing the data, and describes the Web portal developed to help with data management, visualization and analysis.Comment: v2: 29 pages, 5 figures, reflects changes addressing reviewers' comments v1: 38 pages, 8 figure

Modelling of Multi-Agent Systems: Experiences with Membrane Computing and Future Challenges

Formal modelling of Multi-Agent Systems (MAS) is a challenging task due to high complexity, interaction, parallelism and continuous change of roles and organisation between agents. In this paper we record our research experience on formal modelling of MAS. We review our research throughout the last decade, by describing the problems we have encountered and the decisions we have made towards resolving them and providing solutions. Much of this work involved membrane computing and classes of P Systems, such as Tissue and Population P Systems, targeted to the modelling of MAS whose dynamic structure is a prominent characteristic. More particularly, social insects (such as colonies of ants, bees, etc.), biology inspired swarms and systems with emergent behaviour are indicative examples for which we developed formal MAS models. Here, we aim to review our work and disseminate our findings to fellow researchers who might face similar challenges and, furthermore, to discuss important issues for advancing research on the application of membrane computing in MAS modelling.Comment: In Proceedings AMCA-POP 2010, arXiv:1008.314

Noninvasive monitoring of serial changes in pulmonary vascular resistance and acute vasodilator testing using cardiac magnetic resonance

Objectives The study sought to evaluate the ability of cardiac magnetic resonance (CMR) to monitor acute and long-term changes in pulmonary vascular resistance (PVR) noninvasively. Background PVR monitoring during the follow-up of patients with pulmonary hypertension (PH) and the response to vasodilator testing require invasive right heart catheterization. Methods An experimental study in pigs was designed to evaluate the ability of CMR to monitor: 1) an acute increase in PVR generated by acute pulmonary embolization (n = 10); 2) serial changes in PVR in chronic PH (n = 22); and 3) changes in PVR during vasodilator testing in chronic PH (n = 10). CMR studies were performed with simultaneous hemodynamic assessment using a CMR-compatible Swan-Ganz catheter. Average flow velocity in the main pulmonary artery (PA) was quantified with phase contrast imaging. Pearson correlation and mixed model analysis were used to correlate changes in PVR with changes in CMR-quantified PA velocity. Additionally, PVR was estimated from CMR data (PA velocity and right ventricular ejection fraction) using a formula previously validated. Results Changes in PA velocity strongly and inversely correlated with acute increases in PVR induced by pulmonary embolization (r = –0.92), serial PVR fluctuations in chronic PH (r = –0.89), and acute reductions during vasodilator testing (r = –0.89, p ≤ 0.01 for all). CMR-estimated PVR showed adequate agreement with invasive PVR (mean bias –1.1 Wood units,; 95% confidence interval: –5.9 to 3.7) and changes in both indices correlated strongly (r = 0.86, p < 0.01). Conclusions CMR allows for noninvasive monitoring of acute and chronic changes in PVR in PH. This capability may be valuable in the evaluation and follow-up of patients with PH

Linking Endotoxins, African Dust PM 10

African Dust Events (ADE) are a seasonal phenomenon that has been suggested to exacerbate respiratory and proinflammatory diseases in Puerto Rico (PR). Increases in PM10 concentration and the effects of biological endotoxins (ENX) are critical factors to consider during these storms. ENX promote proinflammatory responses in lungs of susceptible individuals through activation of the Toll-like receptors (TLR2/4) signaling pathways. The objective of the study was to evaluate the toxicological and proinflammatory responses stimulated by ADE PM10 ENX reaching PR using human bronchial epithelial cells. PM10 organic extracts from a rural and urban site in PR (March 2004) were obtained from ADE and non-ADE and compared. A retrospective data analysis (PM10 concentration, aerosol images, and pediatric asthma claims) was performed from 2000 to 2012 with particular emphasis in 2004 to classify PM samples. Urban extracts were highly toxic, proinflammatory (IL-6/IL-8 secretion), and induced higher TLR4 expression and NF-κB activation compared to rural extracts. ENX were found to contribute to cytotoxicity and inflammatory responses provoked by urban ADE PM10 exposure suggesting a synergistic potency of local and natural ENX incoming from ADE. The contribution of ADE PM10 ENX is valuable in order to understand interactions and action mechanisms of airborne pollutants as asthma triggers in PR

Detection of malaria parasites in dried human blood spots using mid-infrared spectroscopy and logistic regression analysis

Background: Epidemiological surveys of malaria currently rely on microscopy, polymerase chain reaction assays (PCR) or rapid diagnostic test kits for Plasmodium infections (RDTs). This study investigated whether mid-infrared (MIR) spectroscopy coupled with supervised machine learning could constitute an alternative method for rapid malaria screening, directly from dried human blood spots. Methods: Filter papers containing dried blood spots (DBS) were obtained from a cross-sectional malaria survey in 12 wards in southeastern Tanzania in 2018/19. The DBS were scanned using attenuated total reflection-Fourier Transform Infrared (ATR-FTIR) spectrometer to obtain high-resolution MIR spectra in the range 4000 cm−1 to 500 cm−1. The spectra were cleaned to compensate for atmospheric water vapour and CO2 interference bands and used to train different classification algorithms to distinguish between malaria-positive and malaria-negative DBS papers based on PCR test results as reference. The analysis considered 296 individuals, including 123 PCR-confirmed malaria positives and 173 negatives. Model training was done using 80% of the dataset, after which the best-fitting model was optimized by bootstrapping of 80/20 train/test-stratified splits. The trained models were evaluated by predicting Plasmodium falciparum positivity in the 20% validation set of DBS. Results: Logistic regression was the best-performing model. Considering PCR as reference, the models attained overall accuracies of 92% for predicting P. falciparum infections (specificity = 91.7%; sensitivity = 92.8%) and 85% for predicting mixed infections of P. falciparum and Plasmodium ovale (specificity = 85%, sensitivity = 85%) in the field-collected specimen. Conclusion: These results demonstrate that mid-infrared spectroscopy coupled with supervised machine learning (MIR-ML) could be used to screen for malaria parasites in human DBS. The approach could have potential for rapid and high-throughput screening of Plasmodium in both non-clinical settings (e.g., field surveys) and clinical settings (diagnosis to aid case management). However, before the approach can be used, we need additional field validation in other study sites with different parasite populations, and in-depth evaluation of the biological basis of the MIR signals. Improving the classification algorithms, and model training on larger datasets could also improve specificity and sensitivity. The MIR-ML spectroscopy system is physically robust, low-cost, and requires minimum maintenance

Producción de biodiesel por esterificación y transesterificación simultánea de aceite de pulpa de coco (Acrocomia aculeata) utilizando metanol y etanol en condiciones de fluido supercrítico.

El objetivo general del proyecto es contribuir al conocimiento del sistema de colecta y almacenamiento de los frutos de Acrocomia aculeata y aprovechamiento del aceite de la pulpa con miras a su utilización como materia prima para la obtención de biodiesel.CONACYT - Consejo Nacional de Ciencias y TecnologíaPROCIENCI