Rubisco function, evolution, and engineering

Carbon fixation is the process by which CO2 is converted from a gas into biomass. The Calvin Benson Bassham (CBB) cycle is the dominant carbon fixation pathway on earth, driving >99.5% of the ~120 billion tons of carbon that are "fixed" as sugar, by plants, algae and cyanobacteria. The carboxylase enzyme in the CBB, ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco), fixes one CO2 molecule per turn of the cycle. Despite being critical to the assimilation of carbon, rubisco's kinetic rate is not very fast and it is a bottleneck in flux through the pathway. This presents a paradox - why hasn't rubisco evolved to be a better catalyst? Many hypothesize that the catalytic mechanism of rubisco is subject to one or more trade-offs, and that rubisco variants have been optimized for their native physiological environment. Here we review the evolution and biochemistry of rubisco through the lens of structure and mechanism in order to understand what trade-offs limit its improvement. We also review the many attempts to improve rubisco itself and, thereby, promote plant growth

Mechanisms of Carbapenemase-Mediated Resistance among High-Risk \u3cem\u3ePseudomonas aeruginosa \u3c/em\u3e Lineages in Peru

Objectives: Pseudomonas aeruginosa is one of the leading causes of healthcare-associated infections globally. High-risk carbapenemase-encoding P. aeruginosa clones are disseminating in many regions. The aim of this study was to learn more about the lineages and mechanisms of resistance of P. aeruginosa circulating in Peru. Methods: A total of 141 carbapenemase-producing isolates recovered from hospitalized and ambulatory patients in Lima were sequenced and analyzed to infer their lineages through whole-genome sequence typing (wgST) and to identify their antimicrobial resistance genes. Results: wgST identified nine sequence types (STs); ST111 and ST357 were the most frequently encountered (44.0% and 38.3%, respectively), followed by ST179 (8.5%), with the remaining six detected only sporadically. Among ST357 isolates, 96.3% carried the novel blaIMP-93 allele, whereas the remainder harbored blaIMP-74. 74.2% of ST111 isolates co-harbored blaIMP-18 and blaVIM-2, while the rest carried either of these genes individually. All other ST lineages carried a single carbapenemase, which was either blaIMP-16, blaIMP-74, or blaVIM-2. Conclusion: Our study shows that the high-risk P. aeruginosa clones ST357, which harbors the novel blaIMP-93, and ST111, which carries blaIMP-18 and blaVIM-2, have apparently become endemic in the region

Apéndice cecal en el conducto herniario. A propósito de un caso: Cecal appendix in the hernial duct. About a case

  La hernia de Amyand es una enfermedad rara que se observa en aproximadamente el 1 % de todas las hernias, y sus complicaciones como la apendicitis aguda o perforada, son aún más raras, aproximadamente el 0,1 %. Su diagnóstico es muy difícil en el período preoperatorio y suele ser un hallazgo incidental. Se recibió un paciente masculino de setenta y tres años de edad que acudió al servicio de emergencias debido a dolor abdominal tipo punzante de moderada intensidad localizado en región inguinal derecha de 4 días de evolución, no refirió otros síntomas acompañantes. Se diagnosticó una hernia inguinal Nyhus III, Amyand tipo 2 y se le realizó apendicectomía incidental y reducción del saco herniario. Durante el postoperatorio no se observaron complicaciones.   Palabras clave: Hernia de Amyand, hernia de Garengeot, hernia inguinal, apendicitis aguda, apéndice cecal.   Abstract Amyand's hernia is a rare disease seen in approximately 1% of all hernias, and its complications such as acute or perforated appendicitis are even rarer, approximately 0.1%. Its diagnosis is very difficult in the preoperative period and is usually an incidental finding. A seventy-three-year-old male patient was received who came to the emergency service due to stabbing abdominal pain of moderate intensity located in the right inguinal region of 4 days of evolution, he did not refer other accompanying symptoms. A Nyhus III, Amyand type 2 inguinal hernia was diagnosed and incidental appendectomy and reduction of the hernial sac were performed. During the postoperative period, no complications were observed.   Keywords: Amyand hernia, Garengeot hernia, inguinal hernia, acute appendicitis, cecal appendix

Aplicación e importancia de la estrategia y toma de decisiones empresariales en el simulador Capstone

Este documento presenta el trabajo realizado en el simulador de negocios Capstone, en donde se trabajó en la administración de una empresa de sensores. Los miembros del equipo crearon estrategias para mejorar el desarrollo de la compañía durante los ocho años que cubre la simulación. Se presentan las decisiones tomadas, los estudios de mercado realizados, las estrategias de negocios, los resultados y las oportunidades de mejora

Rapid Determination of the ‘Legal Highs’ 4-MMC and 4-MEC by Spectroelectrochemistry: Simultaneous Cyclic Voltammetry and In Situ Surface-Enhanced Raman Spectroscopy

The synthetic cathinones mephedrone (4-MMC) and 4-methylethcathinone (4-MEC) are two designer drugs that represent the rise and fall effect of this drug category within the stimulants market and are still available in several countries around the world. As a result, the qualitative and quantitative determination of ‘legal highs’, and their mixtures, are of great interest. This work explores for the first time the spectroelectrochemical response of these substances by coupling cyclic voltammetry (CV) with Raman spectroscopy in a portable instrument. It was found that the stimulants exhibit a voltammetric response on a gold screen-printed electrode while the surface is simultaneously electro-activated to achieve a periodic surface-enhanced Raman spectroscopy (SERS) substrate with high reproducibility. The proposed method enables a rapid and reliable determination in which both substances can be selectively analyzed through the oxidation waves of the molecules and the characteristic bands of the electrochemical SERS (EC-SERS) spectra. The feasibility and applicability of the method were assessed in simulated seized drug samples and spiked synthetic urine. This time-resolved spectroelectrochemical technique provides a cost-effective and user-friendly tool for onsite screening of synthetic stimulants in matrices with low concentration analytes for forensic applications.Universidad de Costa Rica//UCR/Costa RicaMinisterio de Innovación, Ciencia, Tecnología y Telecomunicaciones//MICITT/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Electroquímica y Energía Química (CELEQ)UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Químic

Selección de levaduras nativas productoras de etanol a partir de “chicha de jora” elaborada artesanalmente en el distrito de Santiago de Chuco, La Libertad-Perú.

La presente investigación tuvo como objetivos aislar, seleccionar y conservar levaduras nativas  productoras de etanol a partir de “chicha de jora” elaborada artesanalmente en el distrito de Santiago de Chuco, La Libertad-Perú. Las muestras de “chicha de jora” fueron recolectadas en frascos estériles de 200 mL de capacidad, acondicionadas adecuadamente y trasladadas a Laboratorio de Microbiología Industrial de la Facultad de Ciencias Biológicas de la Universidad Nacional de Trujillo, para su posterior procesamiento. Para el aislamiento y selección de los cultivos se utilizó la técnica de dilución y agotamiento por estría en placas Petri conteniendo Agar Sabouraud enriquecido con extracto de levadura, fueron incubadas a 30°C durante 24 horas, las colonias desarrolladas fueron analizadas macroscópica y microscópicamente. Las células observadas con características  morfológicas de levadura, fueron purificadas y conservadas. En la Selección secundaria los cultivos conservados fueron reactivados en agar sabouraud e incubados para obtener biomasa de levaduras luego, se “cosecharon” con solución fisiológica estéril y se centrifugaron en tubos de ensayo estériles,  a 4000 g durante 10 minutos,  La capacidad fermentativa fue medida mediante el método de Davies-Griffith modificado, utilizando caldo sabouraud sacarosado. Seleccionándose ocho cultivos puros de levaduras nativas que mostraron diferentes productividades (en g etanol/g lev. h), y con diferencias estadísticamente significativas entre algunas de ellas. Estas levaduras nativas  no superaron la productividad alcanzada por el cultivo control referente Saccharomyces cerevisiae MIT-L51, pero si igualaron su productividad según la evaluación estadística de comparaciones múltiples realizada lo cual nos mostró una información relevante ya que los aislados realizados son levaduras de altas productividades con un potencial uso industrial.Palabras clave: Saccharomyces, Levaduras nativas, Chicha de jora

EVALUATION OF THE HEMATOLOGY TEST IN THE DIAGNOSIS OF CANINE EHRLICHIOSIS

Se determinó el grado de concordancia entre el examen hematológico y la prueba de ELISA directa en el diagnóstico de ehrlichiosis canina. Se emplearon 77 muestras de sangre de perros con signos clínicos compatibles a ehrlichiosis canina y 20 controles clínicamente normales que fueron obtenidos en la Clínica de Animales Menores de la Universidad Nacional Mayor de San Marcos. Se encontró un 84.7 ± 11.0% de grado de concordancia mediante la prueba de Kappa. Así mismo, se determinó que la trombocitopenia, leucopenia, anemia y el antecedente de contacto con garrapatas tuvieron una relación significativa con la presencia de la enfermedad (p<0.05). Se concluye que el examen hematológico es muy importante en el diagnóstico de la ehrlichiosis canina y que el ELISA directo es una excelente prueba confirmatoriaThe present study evaluated the level of agreement between the hematology test and the direct ELISA assay for the diagnosis of canine ehrlichiosis. It was used 77 samples from dogs with clinical signs compatible with canine ehrlichiosis and 20 control samples from the Hospital of Small Animals of the Veterinary Medicine Faculty, San Marcos National University. The results showed 84.7 ± 11.0% of concordance by the Kappa test. Likewise, the thrombocytopenia, leukopenia, anemia and history of tick infestation were significantly related (p<0.05) to clinical evidence of the disease. The results revealed that the hematology test was important in the diagnosis of canine ehrlichiosis and that the direct ELISA was an excellent confirmatory test

A beam-beam monitoring detector for the MPD experiment at NICA

The Multi-Purpose Detector (MPD) is to be installed at the Nuclotron Ion Collider fAcility (NICA) of the Joint Institute for Nuclear Research (JINR). Its main goal is to study the phase diagram of the strongly interacting matter produced in heavy-ion collisions. These studies, while providing insight into the physics of heavy-ion collisions, are relevant for improving our understanding of the evolution of the early Universe and the formation of neutron stars. In order to extend the MPD trigger capabilities, we propose to include a high granularity beam-beam monitoring detector (BE-BE) to provide a level-0 trigger signal with an expected time resolution of 30 ps. This new detector will improve the determination of the reaction plane by the MPD experiment, a key measurement for flow studies that provides physics insight into the early stages of the reaction. In this work, we use simulated Au+Au collisions at NICA energies to show the potential of such a detector to determine the event plane resolution, providing further redundancy to the detectors originally considered for this purpose namely, the Fast Forward Detector (FFD) and the Hadron Calorimeter (HCAL). We also show our results for the time resolution studies of two prototype cells carried out at the T10 beam line at the CERN PS complex.Comment: 16 pages, 12 figures. Updated to published version with added comments and correction