Natural Time Analysis of Seismicity within the Mexican Flat Slab before the M7.1 Earthquake on 19 September 2017.

One of the most important subduction zones in the world is located in the Mexican Pacific Coast, where the Cocos plate inserts beneath the North American plate. One part of it is located in the Mexican Pacific Coast, where the Cocos plate inserts beneath the North American plate with different dip angles, showing important seismicity. Under the central Mexican area, such a dip angle becomes practically horizontal and such an area is known as flat slab. An earthquake of magnitude M7.1 occurred on 19 September 2017, the epicenter of which was located in this flat slab. It caused important human and material losses of urban communities including a large area of Mexico City. The seismicity recorded in the flat slab region is analyzed here in natural time from 1995 until the occurrence of this M7.1 earthquake in 2017 by studying the entropy change under time reversal and the variability ß of the order parameter of seismicity as well as characterize the risk of an impending earthquake by applying the nowcasting method. The entropy change ΔS under time reversal minimizes on 21 June 2017 that is almost one week after the observation of such a minimum in the Chiapas region where a magnitude M8.2 earthquake took place on 7 September 2017 being Mexico's largest quake in more than a century. A minimum of ß was also observed during the period February-March 2017. Moreover, we show that, after the minimum of ΔS, the order parameter of seismicity starts diminishing, thus approaching gradually the critical value 0.070 around the end of August and the beginning of September 2017, which signals that a strong earthquake is anticipated shortly in the flat slab.

Mexican oregano (Lippia graveolens) essential oil-in-water emulsions: impact of emulsifier type on the antifungal activity of Candida albicans.

This study examined the impact of emulsifier type on the physicochemical characteristics and antifungal capacity of oregano oil-in-water emulsions: Tween 80, hydroxylated soy lecithin, and gum arabic. GC/MS analysis showed that the major components of the Lippia graveolens essential oils were thymol (31.7%), p-cymene (18.7%), and carvacrol (14.6%). The oil-in-water emulsions were made using ultrasonic technology in which thymol and carvacrol quantities were 12.26-13.67 g/L and 5.6-6.2 g/L, respectively. The droplet size of the emulsions followed the next descendent order: gum arabic > lecithin > T80. The zeta potential of the emulsions favored the stability against coalescence. Finally, the antifungal activity of the emulsions was evaluated, in which, 30 µL/mL of gum arabic or hydroxylated soy lecithin emulsions inhibited the growth of Candida albicans. The result suggests that Mexican oregano essential oil emulsions can be used as an antifungal against of C. albicans.

Molecular and morphometric characterization of two dental morphs of Saccodon dariensis (Parodontidae).

This study reports for the first time the roles of genetic and body phenotypic variation in two Saccodon dariensis dental morphs. Results showed a lack of ancient mitochondrial differentiation between morphs and body variations concordant with genetic polymorphism or differential plastic responses to diet quality and foraging strategies of S. dariensis.

Variations of body geometry in Brycon henni (Teleostei: Characiformes, Bryconidae) in different rivers and streams.

Landmark-based geometric morphometrics were used to evaluate the effect of flow and depth in the water column on the body size and shape of Brycon henni from river and stream populations. The dendrogram showed that stream populations clustered apart and showed significantly smaller centroid size and narrower bodies than river populations, indicating a role for flow and depth on whole body morphometric variation. The results are concordant with morphometric variation described in other fish species and provide the first insights into phenotypic variation in natural populations of B. henni.

Heritability of Wing Size and Shape of the Rice and Corn Strains of Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae).

Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) represents a pest of economic importance in all Western Hemisphere. This polyphagous species has diverged into two populations that have been mainly recognized with various mitochondrial and nuclear molecular markers and named "the rice" and "the corn" strains. In Colombia, both strains have evolved prezygotic and postzygotic isolation. They differ in tolerance to Bacillus thuringiensis (Cry1Ac and Cry1Ab endotoxins) and the insecticides lambda-cyhalothrin and methomyl. In 2014, a wing morphometric analysis made in 159 individuals from a colony showed that both strains significantly differ in wing shape. The species also exhibits sexual dimorphism in the rice strain as in females wing size is larger than in males. Here, we continued this work with another wing morphometric approach in laboratory-reared strains to calculate wing size and shape heritabilities using a full-sib design and in wild populations to determine if this method distinguishes these strains. Our results show that male heritabilities of both traits were higher than female ones. Wild populations were significantly different in wing shape and size. These results suggest that wing morphometrics can be used as an alternative method to molecular markers to differentiate adults from laboratory-reared populations and wild populations of this pest, particularly in males of this species. Finally, Q ST values obtained for wing size and shape further demonstrated that both strains are genetically differentiated in nature.

Rhodnius prolixus and Rhodnius robustus-like (Hemiptera, Reduviidae) wing asymmetry under controlled conditions of population density and feeding frequency.

Habitat change in Rhodnius spp may represent an environmental challenge for the development of the species, particularly when feeding frequency and population density vary in nature. To estimate the effect of these variables in stability on development, the degree of directional asymmetry (DA) and fluctuating asymmetry (FA) in the wing size and shape of R. prolixus and R. robustus-like were measured under laboratory controlled conditions. DA and FA in wing size and shape were significant in both species, but their variation patterns showed both inter-specific and sexual dimorphic differences in FA of wing size and shape induced by nutrition stress. These results suggest different abilities of the genotypes and sexes of two sylvatic and domestic genotypes of Rhodnius to buffer these stress conditions. However, both species showed non-significant differences in the levels of FA between treatments that simulated sylvan vs domestic conditions, indicating that the developmental noise did not explain the variation in wing size and shape found in previous studies. Thus, this result confirm that the variation in wing size and shape in response to treatments constitute a plastic response of these genotypes to population density and feeding frequency.

Free jejunal intrathoracic graft after esophageal replacement failure

We present the case of a 24 year old man who suffered from severe chronic esophagitis and an esophageal stricture. He was managed by gastric pull-up but complicated by leakage of the anastomosis. Subsequent sophageasurgical treatment with free jejunal graft was performed and the rationale for the technique selected is discussed.

Beneficios independientes de la reducción de la presión arterial en pacientes tratados con nifedipina en microgránulos / Independent benefits of the reduction of the arterial pressure in patients treaties with nifedipine in micro-granules

El estado dippers es un factor de riesgo independiente en los pacientes hipertensos (Risers-R-) Non-dippers-ND-> Dippers-D>Dippers extremos-DE). Se evaluó el efecto de la nueva nifedipina en microgránulos (NMG) una vez al día en la disminución de la presión arterial nocturna medida a través del MAPA con Mobil-o-Graph-CE0434-(I.E.MGmbh-Cockerillstr. 69 D-Stolberg. Germany). Se incluyeron pacientes hipertensos (PAS mayor igual 140 y/o PAD mayor igual 90 mmHg, medidas con esfigmomanómetro de Hg) que recibieron de 30 a 60 mgrs/día de NMG, en un estudio prospectivo abierto comparativo y cruzado en time-doses 8 am ó 8 pm; que luego de 6 semanas de tratamiento mantuvieran PAS < 140 mmHg. Se reclutaron 73 pacientes. 40 pacientes (54.8 por ciento), mantuvieron su estado: NDn = 22 (disminución de la PAS nocturna entre 0 y 10 por ciento), D n= 16 (disminución de PAS nocturna entre 10 y 20 por ciento) y Rn = 2 (incremento de la PAS nocturna). Los otros 33 pacientes (45.2 por ciento) modificaron su estado: cinco: 3D y 2ND cambiaron a DE (disminución de la PAS nocturna > 20 por ciento), once: 2DE y 9ND se transformaron en D, catorce: 6R, 1DE y 7D hacia ND y 3D cambiaron a R. No hubo diferencias significativas en el cambio de estado dippers en ambos grupos (30 ó 60 mgrs), 17 pacientes mejoraron su estado (9ND y 2DE) se transformaron en D y 6R pasaron a ND; 16 pacientes dipper se mantuvieron. Estos resultados sugieren que la NMG ofrece en el 45 por ciento de los pacientes estudiados un beneficio independiente de la reducción de la presión arterial, manteniendo o mejorando el estado dippers ofreciendo una mejor predicción en la disminución de eventos cardiovasculares y del pronóstico de los accidentes cerebrovasculares

[Analysis of a proposal for changing the educational paradigm in bacteriology and virology. Facultad de Ciencias Médicas, Universidad Nacional de Córdoba]. / Análisis de una propuesta para el cambio de paradigma educacional en bacteriología y virología médicas, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba.

The productive character of the scientific thought points out a methodological means that include the demand of the students' job about the information and not his mere reception and reproduction. It is essential to give the students the opportunity of discovering the cognitive processes used in the production of the scientific knowledge. In this work, we present the result of the starting of a workshop dynamic in a basic subject, the students' answers, and the analysis of the subject. In the Chair of Medical Bacteriology and Virology of the School of Medical Sciences, the National University of Córdoba, 1700 students attended classes in 1997. The subject was developed with the activities that worked the same contents from two different learning conceptions: (I) workshop activity, non obligatory, constructive, and (II) theorico-practical activity, obligatory and traditional. Two voluntary and anonymous interviews were done about the valuation that the student gave to these two activities and their basis, one in the middle and the other at the end of the course. 90.55% classified the traditional activity as positive, and 9.45% as negative. Regarding the workshop activity, the 60.5% classified it as positive and the 39.5% as negative. The same developed content with two activities made possible the analysis of the impact that the two different methodologies produced on the students. The student's answer to the traditional activity was better than the workshop activity (p < 0.001). The differences in the student's acceptance between the two option revealed the major difficulty of an alternative methodological strategy in the current educational model.

Análisis de una propuesta para el cambio de paradigma educacional en bacteriología y virología médicas, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba. / [Analysis of a proposal for changing the educational paradigm in bacteriology and virology. Facultad de Ciencias Médicas, Universidad Nacional de Córdoba]

The productive character of the scientific thought points out a methodological means that include the demand of the students job about the information and not his mere reception and reproduction. It is essential to give the students the opportunity of discovering the cognitive processes used in the production of the scientific knowledge. In this work, we present the result of the starting of a workshop dynamic in a basic subject, the students answers, and the analysis of the subject. In the Chair of Medical Bacteriology and Virology of the School of Medical Sciences, the National University of Córdoba, 1700 students attended classes in 1997. The subject was developed with the activities that worked the same contents from two different learning conceptions: (I) workshop activity, non obligatory, constructive, and (II) theorico-practical activity, obligatory and traditional. Two voluntary and anonymous interviews were done about the valuation that the student gave to these two activities and their basis, one in the middle and the other at the end of the course. 90.55

classified the traditional activity as positive, and 9.45

as negative. Regarding the workshop activity, the 60.5

classified it as positive and the 39.5

as negative. The same developed content with two activities made possible the analysis of the impact that the two different methodologies produced on the students. The students answer to the traditional activity was better than the workshop activity (p < 0.001). The differences in the students acceptance between the two option revealed the major difficulty of an alternative methodological strategy in the current educational model.

Clonal population structure of Colombian sylvatic Trypanosoma cruzi.

Isoenzyme variability and evidence of genetic exchange were evaluated in 75 wild stocks of Trypanosoma cruzi obtained from different hosts from 5 geographical regions within the endemic area in Colombia. Cluster analysis of genetic variability was attempted. Thirty-three multilocus enzyme genotypes (clonets) were identified from 75 stocks, 27 of which clustered with zymodeme Z1 and 6 with zymodeme Z3. Two stocks isolated from human infections showed the potential risk to rural communities in Colombia. The stocks exhibited departures from Hardy-Weinberg expectations, including both fixed heterozygote and fixed homozygote demes, where both segregation and recombination were absent. To inspect for population subdivision that might falsely imply clonality in these stocks, Wright's F statistics were calculated. Theta values (Fst) were significantly different from 0 when 33 clonets, 27 Z1-like clonets, and 5 geographical subpopulations were compared; thus, a significant amount of divergence has occurred between and within them. In addition, linkage disequilibrium was detected for most possible pairwise comparisons of loci. In conclusion, the above results all support a scenario of long-term clonal evolution in Colombian sylvatic T. cruzi populations.

Estudio comparativo con análisis de elemento finito y modelo fotoelastico de distribución de esfuerzos de prótesis parcial fija implanto soportada camentada Vs atornillada / Comparative study with análisis of finite element and photo static model of efforts distribution of implant supported fixed partial denture cemented versus screwed

El propósito de este estudio fue realizar una simulación computarizada de la distribución de cargas aplicadas a una P.P.F. implanto-soportada cementada Vs atornillada, utilizando el sofware COSMOS/M. Con el mismo propósito se realizó un análisis de modelo fotoelástico el cual por medio de la distribución de franjas isocromáticas al someterse a una carga permite conocer y analizar los puntos de máxima y miníma concentración de la tensión. Se observó que en el análisis de elemento finito de la prótesis atornillada el punto de máxima concentración de fuerzas en las dos angulaciones fue a nivel del tornillo de fijación y en la prótesis cementada se observa que la fuerza se concentra en los puntos de aplicación de la carga y se distribuye proporcionalmente hacia apical del implante y hacia el hueso alveolar. Con el análisis de modelo fotoelástico se observo que en la prótesis atornillada hay mayor concentración de franjas isocromáticas hacia los implantes y en la prótesis cementada se distribuyen a lo largo de los tejidos de soporte (material fotoelástico.

[Cholesterol content in longissimus muscle beef from slaughter cattle in Venezuela]. / Contenido de colesterol en el músculo longissimus de bovinos venezolanos.

An observational study was conducted with 149 cattle, raised under tropical conditions of Venezuela (mostly grassfed), to study the relationships of sex class (62 bulls, 67 steers, 20 heifers), age by dentition (2.5; 3.0; 3.5 and 4.0 yr), physiological maturity (A or B), cattle type (17 Dairy or 132 Zebu type crossbreds), Venezuelan carcass grade (Optima, Excelente, Selecta or Superior), marbling level (four levels from "None" to "Small quantity"), carcass fat cover (four level: "Even", "Uneven", "patch-like" and "Devoid") and subcutaneous fat thickness (SFT) over the ribeye (1 = 0.1-0.2 cm; 2 = 0.3-0.4 cm; 3 = 0.5-0.9 cm and 4 = > 1.0 cm) on cholesterol content (mg/ 100 g wet weight) of longissimus muscle. Cholesterol content, as determined colormetrically, did not vary in response to the differences in sex class, age, maturity level, carcass grade, marbling level or SFT represented in the present survey. However, cattle type affected (P = 0.08) cholesterol content. Least square means analysis showed that dairy type contained 12.2 mg more of cholesterol/100 g of muscle than Zebu type. The overall mean (+/- SD) muscle cholesterol for the kind of cattle sampled herein (66.6 +/- 16 mg/100 g) was not considered to be different from those of cattle fed in other latitudes.

Prevention of recurrent esophageal bleeding and survival in patients with alcoholic cirrhosis: a randomized study.

OBJECTIVES: To compare endoscopic sclerotherapy, propranolol and distal splenorenal shunt in the prevention of rebleeding esophageal varices and mortality in alcoholic cirrhotics. METHODS: Forty-three alcoholic cirrhotics that had bled from esophageal varices were randomized to sclerotherapy (13), shunt (15) or propranolol(15). Outcomes measured were rebleeding from varices and death. RESULTS: There was no significant difference between the three treatment groups in relation to rebleeding rate or death. Continued alcohol consumption did not influence outcome. CONCLUSIONS: All three therapies were equally effective in preventing rebleeding from varices.

Prevention of recurrent esophageal bleeding and survival in patients with alcoholic cirrhosis: a randomized study

OBJECTIVES: To compare endoscopic sclerotherapy, propranolol and distal splenorenal shunt in the prevention of rebleeding esophageal varices and mortality in alcoholic cirrhotics. METHODS: Forty-three alcoholic cirrhotics that had bled from esophageal varices were randomized to sclerotherapy (13), shunt (15) or propranolol(15). Outcomes measured were rebleeding from varices and death. RESULTS: There was no significant difference between the three treatment groups in relation to rebleeding rate or death. Continued alcohol consumption did not influence outcome. CONCLUSIONS: All three therapies were equally effective in preventing rebleeding from varices

Optimización de la técnica de inmunoelectrotransferencia (western blot) para la confirmación de la infección por el virus de immunodeficiencia humana (VIH) en Panamá / Optimization of the immunoelectrophoresis technic (western blot) for the confirmation of human immunodeficiency virus infection (HIV) in Panama

The purpose of this study is to report the results of the authors' investigation to apply the western blot technique (WB UP-LCS) in the diagnosis of human immunodeficiency virus type 1 (HIV-1) infection. To do this, the authors separated the proteins of the HIV-1 virus by electrophoresis, based on their molecular weight, in poliacilamide gel with SDS (SDS-PAGE) during 3 hours at 200 volts. Then they electrotransferred these proteins to nitrocellulose paper during four hours at 200 milliamperes, with the aid of external cooling. The nitrocellulose strips were evaluated considering the incubation time (1 and 16 hours), two conjugates (human anti IgG with Peroxidase and human anti IgG Biotin plus Streptatividine with Peroxidase) and two dilutions of the patients' sera (1/50 and 1/100). Based on their results the Authors conclude that, in the first place, the optimal conditions for the test include a dilution of 1/100 of the patients serum, incubation of the serum for 16 hours and the use of the conjugate of anti human IgG with Biotin and Streptavidine with Peroxidase; secondary, that the immunologic reactivity against proteins p24 and gp 160/120 is the most important diagnostic criterion for the confirmation of infection with HIV-1 and that they obtained a diagnostic correlation of 100% at a cost which was 5 to 7 times less than that of the commercial system

[Optimization of the immunoelectrophoresis technic (western blot) for the confirmation of human immunodeficiency virus infection (HIV) in Panama]. / Optimización de la técnica de inmunoelectrotransferencia (western blot) para la confirmación de la infección por el virus de immunodeficiencia humana (VIH) en Panamá.

The purpose of this study is to report the results of the authors' investigation to apply the western blot technique (WB UP-LCS) in the diagnosis of human immunodeficiency virus type 1 (HIV-1) infection. To do this, the authors separated the proteins of the HIV-1 virus by electrophoresis, based on their molecular weight, in poliacilamide gel with SDS (SDS-PAGE) during 3 hours at 200 volts. Then they electrotransferred these proteins to nitrocellulose paper during four hours at 200 milliamperes, with the aid of external cooling. The nitrocellulose strips were evaluated considering the incubation time (1 and 16 hours), two conjugates (human anti IgG with Peroxidase and human anti IgG Biotin plus Streptatividine with Peroxidase) and two dilutions of the patients' sera (1/50 and 1/100). Based on their results the Authors conclude that, in the first place, the optimal conditions for the test include a dilution of 1/100 of the patients serum, incubation of the serum for 16 hours and the use of the conjugate of anti human IgG with Biotin and Streptavidine with Peroxidase; secondary, that the immunologic reactivity against proteins p24 and gp 160/120 is the most important diagnostic criterion for the confirmation of infection with HIV-1 and that they obtained a diagnostic correlation of 100% at a cost which was 5 to 7 times less than that of the commercial system.

Expression of the hemolysin trait in a proteolytic transconjugant of Streptococcus faecalis.

Streptococcus faecalis 31H-1 is a proteolytic transconjugant of strain 31B, that harbors the 38.5 Mdal plasmid which codes for hemolysin in strain X14. It fails to express the hemolytic character in broth due to its proteolytic character. Hemolytic activity can be demonstrated when the proteolytic activity is inhibited by 10(-4) M EDTA. The effect of erythromycin (on the donor cells) and of proteinase K during conjugation suggests that the conjugation system involving the 38.5 Mdal plasmid of S. faecalis strain X14 is sex-pherormone mediated.