Reimagining physiology education with interactive content developed in H5P.

The amalgamation of educational technologies in higher education is widespread and has become essential for contemporary practice on a large scale. Foundational anatomy and physiology knowledge is integral to all courses in health education. To tackle the volume and complexity of the content taught at the foundation level, the incorporation of online tools embedded within curricula provides a unique opportunity to engage students through active learning strategies in a blended design (Means B, Toyama Y, Murphy R, Baki M. Teach Coll Rec 115: 1-47, 2013). This article reports on the use of H5P as a platform to foster self-paced and self-directed learning, critically outlining the developmental process involved in scaffolding activities to learning outcomes. The H5P activities were embedded within the online learning management system, which enabled tracking of student access to these resources. Students were asked to complete an online survey about their perspectives on the effectiveness of H5P activities. This work is part of a comprehensive study evaluating the blended design for delivery of first-year physiology subjects.

Genomic signature of successful colonization of Eurasia by the allopolyploid shepherd's purse (Capsella bursa-pastoris).

Polyploidization is a dominant feature of flowering plant evolution. However, detailed genomic analyses of the interpopulation diversification of polyploids following genome duplication are still in their infancy, mainly because of methodological limits, both in terms of sequencing and computational analyses. The shepherd's purse (Capsella bursa-pastoris) is one of the most common weed species in the world. It is highly self-fertilizing, and recent genomic data indicate that it is an allopolyploid, resulting from hybridization between the ancestors of the diploid species Capsella grandiflora and Capsella orientalis. Here, we investigated the genomic diversity of C. bursa-pastoris, its population structure and demographic history, following allopolyploidization in Eurasia. To that end, we genotyped 261 C. bursa-pastoris accessions spread across Europe, the Middle East and Asia, using genotyping-by-sequencing, leading to a total of 4274 SNPs after quality control. Bayesian clustering analyses revealed three distinct genetic clusters in Eurasia: one cluster grouping samples from Western Europe and Southeastern Siberia, the second one centred on Eastern Asia and the third one in the Middle East. Approximate Bayesian computation (ABC) supported the hypothesis that C. bursa-pastoris underwent a typical colonization history involving low gene flow among colonizing populations, likely starting from the Middle East towards Europe and followed by successive human-mediated expansions into Eastern Asia. Altogether, these findings bring new insights into the recent multistage colonization history of the allotetraploid C. bursa-pastoris and highlight ABC and genotyping-by-sequencing data as promising but still challenging tools to infer demographic histories of selfing allopolyploids.

Limited genomic consequences of mixed mating in the recently derived sister species pair, Collinsia concolor and Collinsia parryi.

Highly selfing species often show reduced effective population sizes and reduced selection efficacy. Whether mixed mating species, which produce both self and outcross progeny, show similar patterns of diversity and selection remains less clear. Examination of patterns of molecular evolution and levels of diversity in species with mixed mating systems can be particularly useful for investigating the relative importance of linked selection and demographic effects on diversity and the efficacy of selection, as the effects of linked selection should be minimal in mixed mating populations, although severe bottlenecks tied to founder events could still be frequent. To begin to address this gap, we assembled and analysed the transcriptomes of individuals from a recently diverged mixed mating sister species pair in the self-compatible genus, Collinsia. The de novo assembly of 52 and 37 Mbp C. concolor and C. parryi transcriptomes resulted in ~40 000 and ~55 000 contigs, respectively, both with an average contig size ~945. We observed a high ratio of shared polymorphisms to fixed differences in the species pair and minimal differences between species in the ratio of synonymous to replacement substitutions or codon usage bias implying comparable effective population sizes throughout species divergence. Our results suggest that differences in effective population size and selection efficacy in mixed mating taxa shortly after their divergence may be minimal and are likely influenced by fluctuating mating systems and population sizes.

Evidence for biological nitrification inhibition in Brachiaria pastures.

Nitrification, a key process in the global nitrogen cycle that generates nitrate through microbial activity, may enhance losses of fertilizer nitrogen by leaching and denitrification. Certain plants can suppress soil-nitrification by releasing inhibitors from roots, a phenomenon termed biological nitrification inhibition (BNI). Here, we report the discovery of an effective nitrification inhibitor in the root-exudates of the tropical forage grass Brachiaria humidicola (Rendle) Schweick. Named "brachialactone," this inhibitor is a recently discovered cyclic diterpene with a unique 5-8-5-membered ring system and a gamma-lactone ring. It contributed 60-90% of the inhibitory activity released from the roots of this tropical grass. Unlike nitrapyrin (a synthetic nitrification inhibitor), which affects only the ammonia monooxygenase (AMO) pathway, brachialactone appears to block both AMO and hydroxylamine oxidoreductase enzymatic pathways in Nitrosomonas. Release of this inhibitor is a regulated plant function, triggered and sustained by the availability of ammonium (NH(4)(+)) in the root environment. Brachialactone release is restricted to those roots that are directly exposed to NH(4)(+). Within 3 years of establishment, Brachiaria pastures have suppressed soil nitrifier populations (determined as amoA genes; ammonia-oxidizing bacteria and ammonia-oxidizing archaea), along with nitrification and nitrous oxide emissions. These findings provide direct evidence for the existence and active regulation of a nitrification inhibitor (or inhibitors) release from tropical pasture root systems. Exploiting the BNI function could become a powerful strategy toward the development of low-nitrifying agronomic systems, benefiting both agriculture and the environment.

Fluctuations in measured radioactive decay rates inside a modified Faraday cage: Correlations with space weather.

For several years, reports have been published about fluctuations in measured radioactive decay time-series and in some instances linked to astrophysical as well as classical environmental influences. Anomalous behaviors of radioactive decay measurement and measurement of capacitance inside and outside a modified Faraday cage were documented by our group in previous work. In the present report, we present an in-depth analysis of our measurement with regard to possible correlations with space weather, i.e. the geomagnetic activity (GMA) and cosmic-ray activity (CRA). Our analysis revealed that the decay and capacitance time-series are statistically significantly correlated with GMA and CRA when specific conditions are met. The conditions are explained in detail and an outlook is given on how to further investigate this important finding. Our discovery is relevant for all researchers investigating radioactive decay measurements since they point out that the space weather condition during the measurement is relevant for partially explaining the observed variability.

[Forced spirometry in healthy preschool children]. / Espirometría forzada en preescolares sanos bajo las recomendaciones de la ATS/ERS: estudio CANDELA.

INTRODUCTION: Reference values for spirometry in healthy preschool children have not yet been obtained in accordance with American Thoracic Society (ATS) and the European Respiratory Society (ERS) guidelines. The objective was to establish reference values for spirometry in healthy preschoolers under the ATS/ERS 2007 statement. MATERIAL AND METHOD: Children of at least 2 and under 7 years of age were tested in 9 pediatric pulmonary function laboratories. The technicians were trained to apply a standardized protocol to perform spirometry. RESULTS: Valid spirometry results were obtained in 455 (81.54%) out of 558 children: 242 boys (53.2%) and 213 girls (46.8%). Ages were as follows: 31 at least 2 and under 3 years old; 96, at least 3 and under 4; 108, at least 4 and under 5; 122, at least 5 and under 6 years, and 98, at least 6 and under 7 years. Formulas were used to calculate the reference values for all the spirometry variables in preschoolers. CONCLUSIONS: Spirometry is feasible in the majority of preschool children under the new guidelines. The availability of the reference values presented is an important step, both for the care of preschoolers and for further research on pulmonary function.

Strong Dependence of Atmospheric Feedbacks on Mixed-Phase Microphysics and Aerosol-Cloud Interactions in HadGEM3.

We analyze the atmospheric processes that explain the large changes in radiative feedbacks between the two latest climate configurations of the Hadley Centre Global Environmental model. We use a large set of atmosphere-only climate change simulations (amip and amip-p4K) to separate the contributions to the differences in feedback parameter from all the atmospheric model developments between the two latest model configurations. We show that the differences are mostly driven by changes in the shortwave cloud radiative feedback in the midlatitudes, mainly over the Southern Ocean. Two new schemes explain most of the differences: the introduction of a new aerosol scheme and the development of a new mixed-phase cloud scheme. Both schemes reduce the strength of the preexisting shortwave negative cloud feedback in the midlatitudes. The new aerosol scheme dampens a strong aerosol-cloud interaction, and it also suppresses a negative clear-sky shortwave feedback. The mixed-phase scheme increases the amount of cloud liquid water path (LWP) in the present day and reduces the increase in LWP with warming. Both changes contribute to reducing the negative radiative feedback of the increase of LWP in the warmer climate. The mixed-phase scheme also enhances a strong, preexisting, positive cloud fraction feedback. We assess the realism of the changes by comparing present-day simulations against observations and discuss avenues that could help constrain the relevant processes.

Micellar electrokinetic chromatographic method for the determination of letrozole, citalopram and their metabolites in human urine.

A new micellar electrokinetic chromatographic method has been developed to analyse human urine samples containing a combination of a drug used for the treatment of breast cancer (letrozole), an antidepressant (citalopram) and their main metabolites. Best results were obtained by using 15 mM borate buffer (pH 9.2) containing 20 mM sodium dodecyl sulphate and 12% (v/v) 2-propanol as the background electrolyte. The separation was performed through a fused silica capillary at 40 degrees C with the application of 6s (3.45 kPa) of hydrodynamic injection and 30 kV of separation voltage. Detection wavelength was 240 nm. Under these conditions, the migration times for all the studied compounds were ranged between 3.0 and 8.0 min. Linearity ranges were determined as 0.4-5.0 microg/mL for all the compounds. Detection limits between 12.5 and 25 ng/mL were determined in urine samples. According to the validation study, the developed method has been proven to be accurate, precise, sensitive, specific, rugged and robust. This method has been used to determine letrozole, citalopram and their metabolites in human urine at clinical levels. Prior to determination, the samples are purified and enriched by means of an extraction-preconcentration step with a preconditioned C(18) cartridge and by eluting the compounds with methanol. The developed method was applied to the determination of these analytes in three urine samples from patients undergoing treatment with letrozole or citalopram.

IGF-1 Mediates EphrinB1 Activation in Regulating Tertiary Dentin Formation.

Eph receptors belong to a subfamily of receptor tyrosine kinases that are activated by membrane-spanning ligands called ephrins. Previously, we demonstrated that the ephrinB1-EphB2 interaction regulates odontogenic/osteogenic differentiation from dental pulp cells (DPCs) in vitro. The goal of this study was to identify the molecular mechanisms regulated by the EphB2/ephrinB1 system that govern tertiary dentin formation in vitro and in vivo. During tooth development, ephrinB1, and EphB2 were expressed in preodontoblast and odontoblasts at postnatal day 4. EphrinB1 was continuously expressed in odontoblasts and odontoblastic processes until the completion of tooth eruption. In addition, ephrinB1 was expressed in odontoblastic processes 2 wk following tooth injury without pulp exposure, whereas EphB2 was expressed in the center of pulp niches but not odontoblasts. In a model of tooth injury with pulp exposure, ephrinB1 was strongly expressed in odontoblasts 4 wk postinjury. In vitro studies with human and mouse DPCs treated with calcium hydroxide (CH) or mineral trioxide aggregate (MTA) showed an increased expression of insulin-like growth factor 1 (IGF-1). Experiments using several inhibitors of IGF-1 receptor signaling revealed that inhibiting the Ras/Raf-1/MAPK pathway inhibited EphB2 expression, and inhibiting the PI3K/Akt/mTOR pathway specifically inhibited ephrinB1 gene expression. Tooth injury in mice with odontoblast-specific IGF-1 receptor ablation exhibited a reduced tertiary dentin volume, mineral density, and ephrinB1 expression 4 wk following injury. We conclude that the IGF-1/ephrinB1 axis plays significant roles in the early stages of tooth injury. Further research is needed to fully understand the potential of targeting ephrinB1 as a regenerative pulp therapy.

Antimicrobial therapy for pulmonary pathogenic colonisation and infection by Pseudomonas aeruginosa in cystic fibrosis patients.

Pseudomonas aeruginosa colonisation has a negative effect on pulmonary function in cystic fibrosis patients. The organism can only be eradicated in the early stage of colonisation, while reduction of bacterial density is desirable during chronic colonisation or exacerbations. Monthly, or at least 3-monthly, microbiological culture is advisable for patients without previous evidence of P. aeruginosa colonisation. Cultures should be performed at least every 2-3 months in patients with well-established colonisation, and always during exacerbations or hospitalisations. Treatment of patients following the first isolation of P. aeruginosa, but with no clinical signs of colonisation, should be with oral ciprofloxacin (15-20 mg/kg twice-daily for 3-4 weeks) plus inhaled tobramycin or colistin (intravenous treatment with or without inhaled treatment can be used as an alternative), while patients with acute infection should be treated for 14-21 days with high doses of two intravenous antimicrobial agents, with or without an inhaled treatment during or at the end of the intravenous treatment. Maintenance treatment after development of chronic P. aeruginosa infection/colonisation (pathogenic colonisation) in stable patients (aged>6 years) should be with inhaled tobramycin (300 mg twice-daily) in 28-day cycles (on-off) or, as an alternative, colistin (1-3 million units twice-daily). Colistin is also a possible choice for patients aged<6 years. Treatment can be completed with oral ciprofloxacin (3-4 weeks every 3-4 months) for patients with mild pulmonary symptoms, or intravenously (every 3-4 months) for those with severe symptoms or isolates with ciprofloxacin resistance. Moderate and serious exacerbations can be treated with intravenous ceftazidime (50-70 mg/kg three-times-daily) or cefepime (50 mg/kg three-times-daily) plus tobramycin (5-10 mg/kg every 24 h) or amikacin (20-30 mg/kg every 24 h) for 2-3 weeks. Oral ciprofloxacin is recommended for patients with mild pulmonary disease. If multiresistant P. aeruginosa is isolated, antimicrobial agents that retain activity are recommended and epidemiological control measures should be established.

Nonaqueous capillary electrophoresis method for the analysis of gleevec and its main metabolite in human urine.

The viability of nonaqueous capillary electrophoresis (NACE) was investigated for determination of gleevec and its main metabolite in human urine using a fused-silica capillary. Baseline separation of the studied solutes was obtained using a nonaqueous solution composed of 12 mM ammonium acetate and 87.6 mM acetic acid in methanol-acetonitrile (ACN) (80:20, v:v) providing analysis time shorter than 3 min. Different aspects including stability of the solutions, linearity, accuracy and precision were studied in order to validate the method in the urine matrix. Detection limits of 24 microg L(-1) for gleevec and its metabolite were obtained. A robustness test of the method was carried out using the Plackett-Burman fractional factorial model with a matrix of 15 experiments. The developed method is simple, rapid and sensitive and has been used to determine gleveec and its metabolite at clinically relevant levels in human urine. Before NACE determination, a solid-phase extraction (SPE) procedure with a C18 cartridge was necessary. Real determination of these analytes in two patient urines were done.

Assay validation for three antidepressants in pharmaceutical formulations: practical approach using capillary gas chromatography.

An easy and fast capillary gas chromatographic FID method, which was already described by the same authors for the simultaneous determination of fluoxetine, fluvoxamine and clomipramine without derivatization step, is now submitted to a validation procedure in several pharmaceutical formulations. Main aspects of the validation method are examined and discussed, since methods for regulatory submission in most cases must demonstrate: specificity in presence of all potential components, concentration range over which the response is lineal, accuracy, precision, acceptable detection and quantitation limits and stability of the procedure. The pharmaceutical preparations subject of validation were: 'Prozac' (capsules), 'Dumirox' (tablets) and 'Anafranil' (tablets) containing fluoxetine, fluvoxamine and clomipramine, respectively. The results presented in this report show the applied gas chromatographic method is acceptable for the determination of the three antidepressants in the pharmaceutical formulations above mentioned.

Congestive heart failure from left ventricular diastolic dysfunction in systemic hypertension.

Previous studies have pointed out that congestive heart failure (CHF) with normal ejection fraction presents a uniform clinical profile that is indistinguishable from heart failure with low ejection fraction. Thirty-six patients with systemic hypertension who had recently experienced CHF with normal ejection fraction (> or = 50%) and no clinical history of ischemic cardiomyopathy were studied. The patients were divided into 2 groups according to degree of echocardiographic hypertrophy: group A (19 patients) with a ventricular mass/volume ratio > 1.8, and group B (17 patients) with a ratio < 1.8. Group A patients had a higher ejection fraction (67 +/- 6 vs 57 +/- 3%, p < 0.01), smaller ventricular diameters and a lower thallium-201 positive rate at peak stress (10 vs 70% in group B, p < 0.001), with 8 of 10 showing severe coronary stenosis. Clinically, group A had a more frequent audible fourth sound (79 vs 17%, p < 0.001), a low incidence of audible third sound (5 vs 55%, p < 0.001) and a cardiothoracic ratio < or = 0.5 (63 vs 17%, p < 0.01). The degree of radionuclide-detected resting diastolic dysfunction and exercise intolerance was similar in both groups. In conclusion, CHF with normal ejection fraction in hypertensive patients presents 2 different profiles: one characterized by severe hypertrophy and the other by a high rate of myocardial regional ischemia. Therapy should be aimed at pathophysiologic regression of the hypertrophy in the first case, and at improvement of the ischemia in the second.

Prevalence and risk of cysticercosis and taeniasis in an urban population of soldiers and their relatives.

To determine markers of Taenia solium transmission and risk factors in an urban community, we studied 1,000 soldiers from a military camp in Mexico City and their relatives. Serum samples were used to detect antigens and antibodies and fecal specimens were examined for Taenia coproantigens and helminth eggs. Prevalences of 12.2% and 5.8% for cysticercosis were found among soldiers and their relatives, respectively. Taeniasis was found in 0.5% and none of the groups, respectively. Relatives of soldiers positive for cysticercosis and taeniasis markers ate more pork from street stores than restaurants or markets compared with relatives of soldiers without these indicators of infection. Also, 12.0% of the relatives of positive soldiers had a history of expelling tapeworm proglottids in the feces in contrast to 3.7% of the family members of the control group. Prevalence values and risk factors in this urban population are similar to those of previous studies performed in rural populations.

Seroepidemiology of amebiasis in Mexico.

The presence of serum antibodies to Entamoeba histolytica was detected by indirect hemagglutination in a representative sample of the 32 federal entities of the Mexican Republic. This study was designed to include biologic, geographic, social, economic, and educational variables. The total percentage of positive sera was 8.41%. Seroprevalence varied with geographic zones, with the South Central, South Pacific, and Yucatan Peninsula areas showing the highest values (> or = 9%), and the North, Northeast, and Gulf of Mexico areas showing the lowest values (< or = 8.0%). Seroprevalence of anti-E. histolytica antibodies seemed to increase from the northern regions to the southern areas of Mexico. These results indicated that amebiasis is endemic in the Mexican Republic, with areas of high seroprevalence not related to climatic conditions. Exposure to infectious contact with E. histolytica occurred at all ages, with a higher frequency at school age.

Micellar electrokinetic capillary chromatography for the determination of fluoxetine and its metabolite norfluoxetine in biological fluids.

A micellar electrokinetic capillary chromatography (MEKC) for determining fluoxetine and its metabolite (norfluoxetine) is proposed. Optimal conditions for the quantitative separation were investigated. A background electrolyte solution consisting of 5 mM phosphate buffer adjusted to pH 12.3 and 40 mM of 1-decanesulfonic acid sodium salt (DSS), hydrodynamic injection and 25 kV of separation voltage were used. Good linearity and precision were obtained for both compounds. Detection limits of 0.2 mg/l for fluoxetine and norfluoxetine were obtained. The developed method is rapid and it has been applied to determine fluoxetine and its metabolite in human serum and urine. The samples were purified and enriched by means of extraction-preconcentration step with a preconditioned C18 cartridge and eluting the compounds with methanol.

Simultaneous determination of carminic acid, riboflavine, curcumin and erythrosine by derivative spectrophotometry and ratio spectra derivative.

A quaternary mixture of carminic acid, riboflavine, curcumin and erythrosine can be resolved with a previous extraction step into metyl-isobutyl ketone and, resolving the binary mixtures obtained in the aqueous phase and organic phase, using derivative spectrophotometry on the basis of the zero-crossing measurements in the first derivative spectra as well as the first derivative of ratio spectra. The conditions of extraction established and the proposed methods have been tested to determine these colorants in several synthetic mixtures of four dyes, obtaining good recoveries. The methods have been applied in yoghurt samples spiked with the dyes.

Simultaneous spectrophotometric determination of three food dyes by using the first derivative of ratio spectra.

Ternary mixtures of colorants E-123 (Amaranth), E-124 (Ponceau 4R) and E-120 (Carminic acid) are resolved by using the first derivative ratio spectrum-zero crossing method without the need for any separation step. Calibration graphs were linear up to 64 mg l(-1) of carminic acid, 32 mg l(-1) of Amaranth and 32 mg l(-1) of Ponceau 4R. The method was applied to different commercial food products and results concordant with high performance liquid chromatography were obtained.

Resolution of ternary mixtures of Tartrazine, Sunset yellow and Ponceau 4R by derivative spectrophotometric ratio spectrum-zero crossing method in commercial foods.

A very simple spectrophotometric method is described for resolving ternary mixtures of the food colorants Tartrazine, Sunset Yellow and Ponceau 4R by using the first derivative of the ratio spectra with measurements at zero-crossing wavelengths. Calibration graphs are linear up to 20 mg l(-1) of Tartrazine (E-102), 40 mg l(-1) of Sunset Yellow (E-110) and 32 mg l(-1) of Ponceau 4R (E-124). Standard deviations of 0.9, 0.8 and 2.4% were obtained for nine standards of 8 mg l(-1) of Tartrazine, 8 mg l(-1) of Sunset Yellow and 8 mg l(-1) of Ponceau 4R, respectively. This method was satisfactorily used for determining synthetic mixtures of these colorants in different ratios (from 1:1:1 to 1:5:5 or even higher) with recoveries in 94-105% range and it was successfully applied over three commercial products containing the three dyes and it did not require any separation step. The results were compared with those obtained by HPLC and very similar values were found by both methods.

Omentum flap versus pectoralis major flap in the treatment of mediastinitis.

The outcome of mediastinal reconstruction during the past 10 years at the "Instituto Nacional de Cardiología Ignacio Chávez" (INCIC), Mexico City was compared. A total of 7136 patients were submitted to open heart surgery. Eighty-two patients (1.15 percent) developed mediastinitis, and 33 patients (0.46 percent) developed sternal osteomyelitis. Only patients who developed mediastinitis with sternal osteomyelitis were included in the study. Reconstruction was performed either with a major omentum flap (12 patients) or a pectoralis major flap (21 patients). The sepsis-related mortality rate was higher in the pectoralis group (28.6 percent) than in the omentum group (0 percent) (p < 0.05). All of the postoperative deaths of the pectoralis group were caused by septic shock; in the omentum group, there were no such deaths. It is concluded that mediastinal reconstruction using the omentum flap in patients with mediastinitis secondary to open heart surgery is associated with fewer septic complications than using the pectoralis major flap.