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Fractal morphology of Beta vulgaris L. cell suspension culture permeabilized with Triton X-100
M. Arenas-Ocampo , L. Alamilla-Beltrán , P. E. Vanegas-Espinoza , B. H. Camacho-Díaz , R. Campos-Mendiola , G. Gutiérrez-López , A. Jiménez-Aparicio
International Agrophysics , 2012, DOI: 10.2478/v10247-012-0001-2
Abstract: In this work, morphology of Beta vulgaris L. cells permeabilized with 0.7mM of Triton X-100 was evaluated using digital image processing and concepts of fractal dimension (perimeter- area relations). Important morphometric changes were found when the contact-time with chemical agent was increased. The size of cells decreased, the cells lost the roundness and their shape was more sinuous; this behaviour was a result of a probable shrinkage caused by the excess of exposure with the permeabilization agent. Morphology of B. vulgaris cells after permeabilization, exhibited a fractal nature since the slope of the ratio of the logarithm of the perimeter vs logarithm of the area was higher than unit. Fractal geometry of the cell morphology was affected as a result of the exposure to Triton X-100 . Those changes can be attributed to the loss of turgor and structure of the cell wall.
Inertial frames of reference, space and time measurements, and physical principles of special relativity revisited
Andrew E. Chubykalo,Augusto Espinoza,B. P. Kosyakov
Physics , 2009,
Abstract: We give a critical analysis of the conceptual foundations of special relativity. We formulate a simple operational criterion for distinguishing between noninertial and inertial frames which is introduced prior to geometry. We associate the concept of maximal velocity with the existence of an upper bound for a set of rates of movers which travel in the same direction. We define the standard scale for reading the time flow. We refine the treatment of both Einstein's postulates, the principle of relativity and constancy of the velocity of light. The proposed ``reconstruction'' of the geometry of Minkowski space will hopefully be useful for the ongoing examination of possible Lorentz violations.
No-go theorem for the classical Maxwell-Lorentz electrodynamics in odd-dimensional worlds
Andrew E. Chubykalo,Augusto Espinoza,B. P. Kosyakov
Physics , 2002,
Abstract: If the conventional Maxwell--Lorentz formulation of classical electrodynamics is adopted in a flat spacetime of arbitrary odd dimension, then the retarded vector potential $A^\mu$ generated by a point charge turns out to be pure gauge, $A^\mu=\partial^\mu\chi$. By Gauss' law, the charge shows up as zero. The classical electromagnetic coupling is thus missing from odd-dimensional worlds. If the action is augmented by the addition of the Chern--Simons term, then the classical interaction picture in the three-dimensional world becomes nontrivial.
Edificio multifuncional en El Barranco: Cuenca, Ecuador
Espinoza,Carlos; Espinosa,Pedro; Vanegas,Alejandro;
ARQ (Santiago) , 2009, DOI: 10.4067/S0717-69962009000100006
Abstract: the superimposition of uses in a neighborhood in the hillside of the city of cuenca gives place to a small building of dwellings, offices and a restaurant of 50 m long and 12 m of height. the slope determines interior spaces in a complex relationship intertwined within its context.
Edificio multifuncional en El Barranco: Cuenca, Ecuador
Carlos Espinoza,Pedro Espinosa,Alejandro Vanegas
ARQ , 2009,
Abstract: La superposición de usos en un barrio en una ladera de la ciudad de Cuenca da lugar a un peque o edificio que acoge viviendas, oficinas y un restaurante en 50 m de largo y 12 m de desnivel. La pendiente determina espacios interiores y exteriores en compleja relación, arraigados en su contexto. The superimposition of uses in a neighborhood in the hillside of the city of Cuenca gives place to a small building of dwellings, offices and a restaurant of 50 m long and 12 m of height. The slope determines interior spaces in a complex relationship intertwined within its context.
Non-typeable Haemophilus influenzae and Streptococcus pneumoniae as primary causes of acute otitis media in colombian children: a prospective study
Alexandra Sierra, Pio Lopez, Mercedes A Zapata, Beatriz Vanegas, Maria M Castrejon, Rodrigo DeAntonio, William P Hausdorff, Romulo E Colindres
BMC Infectious Diseases , 2011, DOI: 10.1186/1471-2334-11-4
Abstract: From February 2008 to January 2009, children ≥3 months and < 5 years of age presenting with AOM and for whom a middle ear fluid (MEF) sample was available were enrolled in two medical centers in Cali, Colombia. MEF samples were collected either by tympanocentesis procedure or spontaneous otorrhea swab sampling. Bacteria were identified using standard laboratory methods, and antimicrobial resistance testing was performed based on the 2009 Clinical and Laboratory Standards Institute (CLSI) criteria. Most of the cases included in the study were sporadic in nature.Of the 106 enrolled children, 99 were included in the analysis. Bacteria were cultured from 62/99 (63%) of samples with S. pneumoniae, H. influenzae, or S. pyogenes. The most commonly isolated bacteria were H. influenzae in 31/99 (31%) and S. pneumoniae in 30/99 (30%) of samples. The majority of H. influenzae episodes were NTHi (27/31; 87%). 19F was the most frequently isolated pneumococcal serotype (10/30; 33%). Of the 30 S. pneumoniae positive samples, 8/30 (27%) were resistant to tetracycline, 5/30 (17%) to erythromycin and 8/30 (27%) had intermediate resistance to penicillin. All H. influenzae isolates tested were negative to beta-lactamase.NTHi and S. pneumoniae are the leading causes of AOM in Colombian children. A pneumococcal conjugate vaccine that prevents both pathogens could be useful in maximizing protection against AOM.Acute otitis media (AOM) is one of the most frequent bacterial infections in infancy and early childhood worldwide. Though diagnosed in all ages, AOM is relatively common among children between six months to three years of age with approximately 80% of children having had at least one episode of AOM by the time they are three years old [1]. AOM is one of the main causes of childhood morbidity in both developed and developing countries [2]. The estimated annual disease burden of AOM ranges between 8,200,000 and 12,900,000 cases among children less than five years of age in Latin Amer
Mycobacterium tuberculosis Rv0679c protein sequences involved in host-cell infection: Potential TB vaccine candidate antigen
Diana P Cifuentes, Marisol Ocampo, Hernando Curtidor, Magnolia Vanegas, Martha Forero, Manuel E Patarroyo, Manuel A Patarroyo
BMC Microbiology , 2010, DOI: 10.1186/1471-2180-10-109
Abstract: The gene encoding Rv0679c was detected in all strains of the M. tuberculosis complex (MTC), but was only transcribed in M. tuberculosis H37Rv, M. tuberculosis H37Ra and M. africanum. Anti-Rv0679c antibodies specifically recognized the protein in M. tuberculosis H37Rv sonicate and showed its localization on mycobacterial surface. Four HABPs inhibited invasion of M. tuberculosis to target cells by up to 75%.The results indicate that Rv0679c HABPs and in particular HABP 30979 could be playing an important role during M. tuberculosis invasion of host cells, and therefore could be interesting research targets for studies aimed at developing strategies to control tuberculosis.Tuberculosis (TB) is among the top three leading causes of death by a single infectious agent worldwide. The situation is further aggravated by the increased susceptibility of human immunodeficiency virus (HIV)-positive people to infection with Mycobacterium tuberculosis [1], and by the emergence of multidrug-resistant (MDR)-TB strains in many geographical areas [2]. An estimate of nearly 9.2 million cases of TB occurred during 2007, 4.1 million of which corresponded to new smear-positive cases and 14.8% were reported among HIV-positive people [3].Unfortunately, the bacillus Calmette-Guérin (BCG) vaccine is insufficient to control the worldwide spread of this health threat, especially since it is contraindicated for HIV-positive people and has a variable efficacy, mostly due to its low capacity to stimulate the broad cell spectrum needed for inducing an effective immune response [4,5]. Therefore, a large body of research has focused on searching for new specific antigens of M. tuberculosis that could be used as new prophylactic alternatives with the aim of replacing or improving the currently available BCG vaccine [6-8].The publication of the complete M. tuberculosis H37Rv genome sequence has opened a gate for the identification of genes that encode M. tuberculosis antigens putatively able to trigger
Altered dynamics of visual contextual interactions in Parkinson’s disease
Alessandro Di Rocco,Angelo Quartarone,Annabelle Blangero,James E. Galvin,M. Felice Ghilardi,M. Isabel Vanegas,Simon P. Kelly
- , 2019, DOI: 10.1038/s41531-019-0085-5
Abstract: Background frequency spectrum profiles in patients versus controls. Fast Fourier transforms were computed on the last 2240？ms of all trials with 0% foreground and 0% surround contrast (blank screen, shown in inset) and then averaged across trials and across subjects within each group. Patients showed significantly higher spectral amplitudes, marked with asterisks for each of the corresponding frequency bins (bootstrapping test, p？<？0.05). Shaded error bars indicate mean？±？standard error of the mean (s.e.m.
Tolerancia al calor y humedad atmosférica de diferentes grupos raciales de ganado bovino
Espinoza V,José; Ortega P,Ricardo; Palacios E,Alejandro; Guillén T,Ariel;
Revista MVZ Córdoba , 2011,
Abstract: objective. the objective of the present study was to compare some physiological responses to heat and atmospheric humidity among chinampos (bos taurus; ch), ？ charolais ？ brahman (cb), holstein (h) and jersey (j) cattle. materials and methods. the study was carried out in la paz, mexico; 12 h, 10 j, 15 ch and 8 cb cows were used. during the summer the respiratory frequency (rf) and rectal temperature (rt) were measured each week (at 0600 and 1600 hours). the climatic variables were measured to calculate the temperature-humidity index (thi). results. throughout the summer, the rf was above the physiological values of cattle in the four groups, being higher in h and j than in ch and cb (p<0.01). in all groups, the rt was within the physiological limits of cattle. the most affected group was h (p<0.05). when the physiological constants were analyzed within each of the three categories of thi (<72, ≥72<78, and ≥78), the h and j cows presented higher rf than that of ch and cb (p<0.01). the rt increased as the thi rose, being more pronounced in j and h. increase in the rf between the morning and the afternoon of each day of measurement was higher in h and j than in ch and cb (p<0.05). the rt increased more in h than in ch (p<0.05). conclusions. the breed groups most tolerant to heat stress, based on rf and rt, were ch and cb.
Hábitos de amamantamiento del ganado bovino Chinampo (Bos taurus) de México
José Espinoza V.,Rigoberto López A.,Ricardo Ortega P.,Alejandro Palacios E.
Revista MVZ Córdoba , 2011,
Abstract: Objetivo. Conocer los hábitos de amamantamiento de becerros Chinampos (Bos taurus)en diferentes etapas de su lactancia. Materiales y métodos. Se utilizaron 20 vacas con su cría. A partir de los 30 hasta los 180 días de la lactancia los animales fueron observados durante 24 horas continuas cada mes registrando la frecuencia con la que los becerros mamaron y la duración de cada amamantamiento. Resultados. Los becerros mamaron con mayor frecuencia entre las 06:00 y las 07:00 hr, se observaron otros picos a las 10:00 y a las 19:00 hr. La frecuencia promedio de amamantamiento en 24 horas fue de 4.9±0.21utilizando un total de 66.9 ± 3.1 minutos. Los becerros de 180 días de edad mamaron menos veces comparados con los de edades inferiores a los 150 días; la duración del amamantamiento disminuyó a los 180 días de edad (p<0.05). Las hembras mamaron con más frecuencia que los machos (p<0.05) pero el tiempo que utilizaron para esta actividadfue similar entre sexos (p>0.05). Conclusiones. La frecuencia de amamantamientos es mayor durante las primeras horas de la ma ana y al final de la tarde. Hasta los 5 meses de edad la frecuencia y el tiempo de amamantamiento no variaron pero se redujeron a los180 días y las hembras mamaron con más periodicidad que los machos.
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