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Si x es trascendente sobre el campo K el grupo G de los automorfismos de K(x) que dejan fijo a K  esta constituido por los automorfismos  0a,b,c,d donde a,b,c,d(x) = ax+b/cx+d con ad - bc ǂ 0. G es isomorfo al grupo proyectivo lineal de grado 2 sobre

Epidemia de Salmonellosis producida por ingestión de alimentos

En junio de 1962 se presentó un brote de gastroenteritis, en el Hospital Neuropsiquiátrico de Mujeres, Bogotá, D. E., que produjo aproximadamente 79 casos de la enfermedad. La tasa de ataque fue de 52,7% entre las 150 personas estudiadas, la mayoría de ellas empleadas de la institución. El germen causal fue una salmonella paratyphi B, que se aisló en quince de ellas. El estudio epidemiológico sugirió la probabilidad de que el alimento responsable de la diseminación fue una ensalada de verduras, la cual fue ingerida en e! 64% de las personas que presentaron síntomas. No se pudo aislar el germen causal en las manipuladoras de los alimentos, que no presentaron síntomas de la enfermedad.During June 1962 an outbreak of gastroenteritis occurred at the Neuropsychiatric Hospital for Women, Bogotá, D. E. (Hospital Neuropsiquátrico de Mujeres) and caused approximately 79 cases of this disease. The percentage rate attacked amounted to 52,7 % of the 150 persons examined; of which the great majority were employed in the institution. The causing agent was Salmonella Paratyphi B, which was isolated in 15 of the patients The epidemiologic findings suggested that the food responsible for its dissemination was a vegetable salad consumed by 64% of the persons who manifested symptoms.The causing agent could not be isolated in the food handlers since these did not present symptoms of the disease

Carbon capture and flow in a sylvopastoral system of the Colombian Andean zone

A protocol was developed to measure carbon capture and monitor the flow of C as an environmental service provided by a sylvopastoril system (SSP) of Acacia decurrens + Pennisetum clandestinum in the Colombian Andes (2538 m latitude), employing two densities of sowing of trees: high (HD) and low (LD) (1111 and 407 trees/ha) and as the control treatment, areas of pasture only devoid of trees. In addition, the carbon flow between grazing Holstein cows and the soil was evaluated by measuring feces production resulting from consumption of the biomass system. Six years after establishment of the SSP, the total amount of C in trees, pasture plants and soil was estimated at 260 and 251 t/ha for HD and LD, respectively, as compared to 154t/ha for the control. The animal flow of C through animal feces was estimated as 0.50, 0.47, and 0.48 t per standard cow unit (600 kg liveweight) for HD, LD and control, respectively. Averaged across two years, the respective annual increases of C in the aerial part of the trees were 9.9 and 11.2 tC for HD and LD

Effects of different amounts of crude glycerol supplementation on dry matter intake, milk yield, and milk quality of lactating dairy cows grazing on a Kikuyu grass pasture

The aim of this study was to determine the effects of different amounts of crude glycerol (CGL) on dry matter intake, milk yield, milk protein yield, and milk fatty acid profile of dairy cows grazing on a Kikuyu-based pasture. Six Holstein cows were used in the first third of lactation (mean ± SD 559 ± 22.5 kg body weight, 43 ± 10 days in milk, and 26.8 ± 1.2 kg milk/day) and were randomized within a replicated 3 × 3 Latin square arrangement. Animals grazed the Kikuyu grass and were supplemented with a commercial energy-protein concentrate at 1.0 kg/4.0 kg of milk. The experimental period was 69 days. The following treatments were administered: CGL0 (control, without glycerol), CGL1 (750 g/cow/day), and CGL2 (1,500 g/cow/day). The addition of 750 and 1,500 g of CGL did not affect grass and concentrate intake (P > 0.05). However, milk yield (FCM 3.5%) increased by 14.2% in the CGL2 group compared to that obtained in the control group (CGL0) (P = 0.02). The addition of 1,500 g of CGL to the diet resulted in a 2.1% greater yield of milk protein compared to that obtained with CGL0 treatment (P = 0.01). Further, the addition of 1,500 g of CGL did not impact grass intake, milk fat concentration, or fatty acid composition (P < 0.05). Thus, the inclusion of CGL as a co-product may be a nutritional strategy to increase the productivity of dairy production systems in tropical perennials, such as Kikuyu grass

Endomyocardial fibrosis: a restrictive cardiomyopathy in developing countries

Objetivo: La fibrosis endomiocárdica (FE) es una cardiomiopatía restrictiva infrecuente. En América Latina son escasos los reportes. En el presente trabajo se realiza una descripción de una serie de pacientes diagnosticados de FE en Colombia. Método: Realizamos una búsqueda en los registros de imágenes de resonancia magnética (RM) cardiaca realizadas en nuestra institución entre 2016 y 2019 en busca de pacientes con diagnóstico de FE. Se describieron sus características sociodemográficas, clínicas y de imagen. Resultados: Nueve pacientes fueron diagnosticados de FE (el 66.7% mujeres), con una edad promedio de 69 años. Los pacientes presentaron un promedio de 2.6 años de evolución. El principal síntoma referido fue disnea, seguido de síncope, dolor torácico y palpitaciones. En ninguno de ellos se sospechó FE como diagnóstico inicial. En cuanto a los hallazgos ecocardiográficos, se identificó compromiso predominante del ventrículo izquierdo, seguido de compromiso biventricular. Todos los pacientes presentaron patrón de llenado restrictivo con dilatación auricular izquierda severa. En el análisis retrospectivo se cumplieron los criterios de Mocumbi para el diagnóstico de FE en el 100% de los pacientes con gravedad moderada (77.8%). Las imágenes de RM mostraron función sistólica biventricular y volúmenes preservados. Se observó depósito focal de gadolinio subendocárdico a nivel apical y se confirmó la presencia de trombo en el 66% de los casos Conclusión:: La FE es una cardiomiopatía restrictiva infrecuente circunscrita a países tropicales. La mayoría de los pacientes en nuestra serie presentaron compromiso aislado del ventrículo izquierdo, seguido de compromiso biventricular, con función ventricular usualmente preservada.Objective: Endomyocardial fibrosis (EF) is an unusual restrictive cardiomyopathy. In Latin America there are few reports. Here, we made a description of patients diagnosed with EF in Colombia. Method: We conducted a search in the records of cardiac magnetic resonance imaging (MRI) performed in our institution between 2016-2019 looking for patients with a diagnosis of EF; sociodemographic, clinical and imaging characteristics were described. Results: Nine patients were diagnosed with EF (66.7% female), with an average age of 69 years. Patients presented an average evolution of 2.6 years. The main reported symptom was dyspnea, followed by syncope, chest pain, and palpitations. None of them was initially suspected for EF. Regarding echocardiographic findings, predominant left ventricular involvement was identified, followed by bi-ventricular involvement. All the patients presented a restrictive filling pattern with severe left atrial dilation. In a retrospective analysis, Mocumbi criteria for diagnosis of EF were met in 100% of the patients, majority with moderate severity (77.8%). Cardiac MRI showed biventricular systolic function and volumes preserved. Focal subendocardial late gadolinium enhancement was observed on the apex and apical thrombus was confirmed in 66% of the patients Conclusion: FE is an uncommon restrictive cardiomyopathy limited to tropical countries. Most of patients in our series presented isolated involvement of left ventricle, followed by bi-ventricular involvement, with ventricular function usually preserved

Cellulolytic and Butyrivibrio fibrisolvens bacteria population density, after supplementing fodder diets (Pennisetum clandestinum)

ABSTRACT Objective. Determine the population density of cellulolytic bacteria, Butyrivibrio fibrisolvens and the concentration of vaccenic acid, by supplementing diets consisting of kikuyu grass (Pennisetum clandestinum Hoechst. Ex Chiov.) as base ingredient, together with cassava flour and biomass (effluent from ethanol production) in rumen simulator-Rusitec. Materials and methods. Four treatments (T) were evaluated, these were composed as: T1/Control 1: 100% kikuyu grass with a total protein intake of 23.9%, T2: a mixture of 70% kikuyu grass, 20% biomass and 10% cassava flour with a total protein intake of 19.4%; T3/Control 2: 100% kikuyu grass, with a 17.8% protein intake and T4: 70% kikuyu grass, 20% biomass and 10% cassava flour with a 15.3% protein intake. One and two-way variance analysis was made and the Pearson correlation coefficient was determined. Results. An increase was observed in the population density of viable cellulolytic bacteria (CFU/ml) and B. fibrisolvens statistically significant (p<0.005) with treatment T2, in contrast to T1, T3 and T4 treatments. In addition, there was a significant increase in the concentration of vaccenic acid (mg/L) in the ruminal content in Rusitec with the same treatment (T2). Conclusions. Results obtained in this ruminal simulation study are evidence to the benefits of kikuyu grass together with cassava flour and biomass diet implementation on the growth of ruminal cellulolytic and B. fibrisolvens bacteria, as well as on the production of vaccenic acid. The study also suggests the nutritional potential that such supplements could provide to grazing bovine feeding

Phenomenology of a three-family model with gauge symmetry SU(3)_c X SU(4)_L X U(1)_X

We study an extension of the gauge group SU(3)_c X SU(2)_L X U(1)_Y of the standard model to the symmetry group SU(3)_c X SU(4)_L X U(1)_X (3-4-1 for short). This extension provides an interesting attempt to answer the question of family replication in the sense that models for the electroweak interaction can be constructed so that anomaly cancellation is achieved by an interplay between generations, all of them under the condition that the number of families must be divisible by the number of colours of SU(3)_c. This method of anomaly cancellation requires a family of quarks transforming differently from the other two, thus leading to tree-level flavour changing neutral currents (FCNC) transmitted by the two extra neutral gauge bosons $Z'$ and $Z''$ predicted by the model. In a version of the 3-4-1 extension, which does not contain particles with exotic electric charges, we study the fermion mass spectrum and some aspects of the phenomenology of the neutral gauge boson sector. In particular, we impose limits on the $Z-Z'$ mixing angle and on the mass scale of the corresponding physical new neutral gauge boson $Z_2$, and establish a lower bound on the mass of the additional new neutral gauge boson $Z'' \equiv Z_3$. For the analysis we use updated precision electroweak data at the Z-pole from the CERN LEP and SLAC Linear Collider, and atomic parity violation data. The mass scale of the additional new neutral gauge boson $Z_3$ is constrained by using updated experimental inputs from neutral meson mixing in the analysis of the sources of FCNC in the model. The data constrain the $Z-Z'$ mixing angle to a very small value of O(0.001), and the lower bounds on $M_{Z_2}$ and on $M_{Z_3}$ are found to be of O(1 TeV) and of O(7 TeV), repectively.Comment: 22 pages, 6 tables, 1 figure. To appear in J. Phys. G: Nuclear and Particle Physic

Molecular and descriptive epidemiology of intestinal protozoan parasites of children and their pets in Cauca, Colombia: A cross-sectional study

Background: Parasitic infections, particularly those caused by protozoa, represent a considerable public health problem in developing countries. Blastocystis, Giardia duodenalis, Cryptosporidium spp. and the Entamoeba complex (Entamoeba histolytica, Entamoeba dispar and Entamoeba moshkovskii) are the most common etiological causes of intestinal parasitic infections. Methods: We carried out a descriptive cross-sectional study in school-age children attending a daycare institution in commune eight of Popayán, Cauca (Southwest Colombia). A total of 266 fecal samples were collected (258 from children and eight from pets). Blastocystis, G. duodenalis, Cryptosporidium spp. and the Entamoeba complex were identified by microscopy, quantitative real-time PCR (qPCR) and conventional PCR. The concordance of qPCR and microscopy was assessed using the Kappa index. Molecular characterization was conducted to identify Blastocystis subtypes (18S), G. duodenalis assemblages (tpi and gdh) and Cryptosporidium species/subtypes (18S and GP60). Potential associations between intestinal parasitism and sociodemographic factors were examined using bivariate analyses. Results: A total of 258 fecal samples from children were analyzed by microscopy and 255 samples were analyzed by qPCR. The prevalence of Blastocystis was between 25.19% (microscopy) and 39.22% (qPCR), that of G. duodenalis was between 8.14% (microscopy) and 10.59% (qPCR), that of Cryptosporidium spp. was estimated at 9.8% (qPCR), and that of the Entamoeba complex was between 0.39% (conventional PCR) and 0.78% (microscopy). The concordance between microscopy and qPCR was very low. Blastocystis ST1 (alleles 4, 8, and 80), ST2 (alleles 11, 12, and 15), ST3 (alleles 31, 34, 36, 38,57, and 151), and ST4 (alleles 42 and 91), G. duodenalis assemblages AII, BIII, BIV and D, C. parvum subtype IIa and C. hominis subtype IbA9G3R2 were identified. The only identified member of the Entamoeba complex corresponded to E. histolytica. No statistically significant association was identified between parasitic infection and any sociodemographic variable. Conclusion: This study revealed the usefulness of molecular methods to depict the transmission dynamics of parasitic protozoa in southwest Colombia. The presence of some of these protozoa in domestic animals may be involved in their transmission. © 2019 The Author(s)

Characterization of Actinobacterial Communities from Arauca River Sediments (Colombia) Reveals Antimicrobial Potential Presented in Low Abundant Isolates

Q3Artículo original181-194Introduction: New strategies have been arisen to set a rapid and effective screening for selection of microorganism with bioactive potential. This study suggests that combination of physicochemical pretreatments and taxonomic dereplication of microbial collections through MALDI-TOF MS, facilitates the detection of low abundance actinobacteria with potential as a source of antimicrobial agents. Material and Methods: An unstudied microbial community from a tropical river sediment in Colombian Orinoquía is described, applying an extended cultivation strategy using physicochemical pretreatments, biological screenings and taxonomic dereplication through MALDI-TOF MS approach. Results: Actinobacteria-like isolates (790) were growth and their antimicrobial activity was assessed against methicillin-resistant Staphylococcus aureus, Vancomycin-resistant Enterococcus faecium, extended-spectrum β-lactamase Klebsiella pnumoniae, and clinical isolates of Cladosporium cladosporioides and Epicoccum nigrum. Seventy-eight isolates, belonging to the Streptomycetaceae family according to 16S rDNA analysis were found to have antimicrobial activity and were categorized as low abundance actinobacteria by MALDI-TOF MS. Conclusion: The results suggest that combination of physicochemical pretreatments and taxonomic dereplication of microbial collections through MALDI-TOF MS, facilitates the detection of low abundance actinobacteria with potential as a source of antimicrobial agents

Minimal Scalar Sector of 3-3-1 Models without Exotic Electric Charges

We study the minimal set of Higgs scalars, for models based on the local gauge group $SU(3)_c \otimes SU(3)_L \otimes U(1)_X$ which do not contain particles with exotic electric charges. We show that only two Higgs $SU(3)_L$ triplets are needed in order to properly break the symmetry. The exact tree-level scalar mass matrices resulting from symmetry breaking are calculated at the minimum of the most general scalar potential, and the gauge bosons are obtained, together with their couplings to the physical scalar fields. We show how the scalar sector introduced is enough to produce masses for fermions in a particular model which is an $E_6$ subgroup. By using experimental results we constrain the scale of new physics to be above 1.3 TeV.Comment: LaTeX, 22 pages, 1 figure include