1,517 research outputs found

    Comparisons between OMI SO\u3csub\u3e2\u3c/sub\u3e data and ground-based SO\u3csub\u3e2\u3c/sub\u3e measurements at Turrialba volcano

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    Turrialba is one of the largest and most active stratovolcanoes in the Central Cordillera of Costa Rica and an excellent target for validation of satellite data using ground based measurements due to its high elevation, relative ease of access, and persistent elevated SO2 degassing. The Ozone Monitoring Instrument (OMI) aboard the Aura satellite makes daily global observations of atmospheric trace gases and it is used in this investigation to obtain volcanic SO2 retrievals in the Turrialba volcanic plume. We present and evaluate the relative accuracy of two OMI SO2 data analysis procedures, the automatic Band Residual Index (BRI) technique and the manual Normalized Cloud-mass (NCM) method. We find a linear correlation and good quantitative agreement between SO2 burdens derived from the BRI and NCM techniques, with an improved correlation when wet season data are excluded. We also present the first comparisons between volcanic SO2 emission rates obtained from ground-based mini-DOAS measurements at Turrialba and three new OMI SO2 data analysis techniques: the MODIS smoke estimation, OMI SO2 lifetime, and OMI SO2 transect techniques. A robust validation of OMI SO2 retrievals was made, with both qualitative and quantitative agreements under specific atmospheric conditions, proving the utility of satellite measurements for estimating accurate SO2 emission rates and monitoring passively degassing volcanoes

    Infinite-dimensional representations of the rotation group and Dirac's monopole problem

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    Within the context of infinite-dimensional representations of the rotation group the Dirac monopole problem is studied in details. Irreducible infinite-dimensional representations, being realized in the indefinite metric Hilbert space, are given by linear unbounded operators in infinite-dimensional topological spaces, supplied with a weak topology and associated weak convergence. We argue that an arbitrary magnetic charge is allowed, and the Dirac quantization condition can be replaced by a generalized quantization rule yielding a new quantum number, the so-called topological spin, which is related to the weight of the Dirac string.Comment: JHEP style. Extended version of hep-th/0403146. Revised version, title and some notations are changed. References and Appendix B are adde

    Efectividad de la metodología de aula invertida en un curso de álgebra para ingenieros

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    En el presente trabajo se discute un análisis comparativo en la implementación de la metodología tradicional y de aula invertida para la enseñanza de un curso de Algebra para Ingeniería a estudiantes de primer año de la Facultad de Ingeniería Mecánica y Eléctrica de la Universidad Autónoma de Nuevo León (FIME- UANL). Se consideraron dos grupos de la misma asignatura durante el semestre Enero- Junio 2015. El grupo 1(G1) con 29 estudiantes fue elegido para la metodología de aula inversa, la cual fue bien aceptada. Se identificaron y determinaron algunos factores como la dependencia al profesor, disciplina de trabajo en casa, bajo nivel de conocimientos previos, la carga de cursos de ciencias exactas en primer año y el proceso de adaptación, entre otros. En el grupo 2(G2) con 43 estudiantes, el mismo curso se impartió de manera tradicional, tomando en cuenta que un sondeo inicial, reveló una actitud de escasa aceptación de nuevas metodologías correlacionada con el horario del curso (14h30). El desempeño académico en ambos grupos fue notablemente distinto, el G1 obtuvo un aprovechamiento mayor en trece puntos porcentuales con respecto al grupo G2, que resultó estadísticamente significativo. Nuestros resultados coinciden cualitativamente con estudios internacionales previos y corroboran además que la metodología de aula invertida promueve un mayor interés y participación que la metodología tradicional, aunque no parece aconsejable en todas las circunstancias. El estudio nos permitió reflexionar sobre la importancia de explorar e implementar nuevas metodologías que permitan desarrollar en el estudiante de ingeniería el perfil analítico necesario para el desempeño de su profesión

    Escala de Calgary para el diagnóstico del síncope vasovagal. Estudio de pruebas diagnósticas

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    ResumenObjetivoEvaluar la utilidad de la escala de Calgary en el diagnóstico de síncope vasovagal comparada con los resultados de la prueba de mesa inclinada (Tilt test) bajo protocolo sensibilizado con medicamentos.MetodologíaEstudio prospectivo de pruebas diagnósticas en pacientes con sospecha de síncope vasovagal sometidos a prueba de mesa inclinada (Tilt test) con vasodilatación inducida con nitroglicerina por vía sublingual. Se incluyeron pacientes mayores de 18 años de edad y se excluyeron pacientes con cardiopatía estructural documentada.ResultadosSe analizaron 100 pacientes, promedio de 48,7 años (DE 19,7), 69% de género femenino y 4% residentes en área rural. La mediana de síncopes al momento del Tilt test fue de 5 (RIQ 2-15) con presentación del primer episodio a los 41 años (RIQ 21-57), en el 52% de los pacientes no se identificaron desencadenantes y las manifestaciones clínicas referidas en los episodios previos al Tilt test fueron diaforesis (58%), palidez (55%), mareo (70%), palpitaciones (50%) y náuseas (42%); durante el Tilt test se reportaron mareo (65%), diaforesis (19%), náuseas (18%) y visión borrosa (18%). Se obtuvo una sensibilidad del 77,7% (IC95%: 66,7-88,8) y una especificidad del 40,5% (IC95%: 23,3-57,7) para la escala de Calgary.ConclusionesDebido a su buena sensibilidad y fácil aplicación, la escala de Calgary es un instrumento útil para el abordaje diagnóstico de pacientes con sospecha de síncope vasovagal y corazón estructuralmente sano, especialmente en menores de 50 años de edad.AbstractObjectiveEvaluate the utility of Calgary score for the diagnosis of vasovagal syncope compared with the results of the Tilt table test using sensibilized protocol with medicines.MethodologyProspective study of diagnostic tests in patients with suspected diagnostic of vasovagal syncope who underwent tilt table test with induced vasodilation with sublingual nitroglycerin. Patients over 18 years were included and patients with documented structural heart disease were excluded.Results100 patients were analyzed, averaging 48.7 years of age (SD 19.7), 69% of feminine genre and 4% residents in rural area. Medium of syncope at the moment of tilt table test was 5 (IQR 2-15), with presentation of first episode at 41 years (IQR 21-57), in 52% of the patients triggers were not identified and the clinical manifestations referred in episodes previous to Tilt test were diaphoresis (58%), pallor (55%), dizziness (70%), palpitations (50%) and nausea (42%); during the test dizziness (65%), diaphoresis (19%), nausea (18%) and blurred vision (18%) were reported. A sensitivity of 77.7% was obtained (95% CI 88.8 66.7) and specificity of 40.5% (95% CI 23.3 - 57.7) for the Calgary score.ConclusionsDue to its high sensitivity and easy application, the Calgary score is a useful diagnostic approach instrument for patients with suspected vasovagal syncope and who have a structurally healthy heart, especially in those younger than 50 years

    Revising the diversity within the Dwarf Dog-faced Bat, Molossops temminckii (Chiroptera, Molossidae), with the revalidation of the endangered Molossops griseiventer

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    The genus Molossops includes two monotypic species of insectivore bats distributed in South America: Molossops neglectus and Molossops temminckii. Both can be differentiated, based on sizes, M. temminckii being smaller (forearm less than 33 mm). Despite being monotypic, at least two additional subspecies have been described for M. temminckii, of which M. temminckii griseiventer from the inter-Andean Valley of the Magdalena River in Colombia might represent a valid taxon. To test the taxonomic status of M. t. griseiventer, we reviewed specimens of M. temminckii from cis- and trans-Andean localities in Colombia. We used Cytochrome-b and Cytochrome Oxidase I comparisons to test the phylogenetic position of cis- and trans-Andean samples and compared qualitative morphology, morphometric and bioacoustics. Our results show that M. t. griseiventer is differentiated from cis-Andean specimens, providing further evidence of its validity at the species level. Furthermore, M. temminckii (sensu stricto) is also distributed in Colombia, but both M. griseiventer and M. temminckii are allopatric, with the Andes acting as a barrier. The specific identity of the specimens from the Caribbean Region of Colombia needs a new evaluation, but our results clearly show that the diversity of Molossops is underestimated

    Detekcija polimorfizama jednog nukleotida (SNP-a) u HER2, MUC1, ESR1 i BRCA1 gena povezanih s tumorom mliječne žlijezde kuja

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    Worldwide, canine mammary cancer (CMC) is the most frequent type of neoplasia in female dogs, and it is three times more frequent in dogs than in humans. In Colombia, CMC is the second most frequent type of cancer, after skin neoplasia. Genetics is one of the most important factors involved in any type of cancer, and the genetic basis of this disease is reflected through line breeding due to changes in allelic frequencies that are traceable using molecular markers. This study aimed to detect single nucleotide polymorphisms (SNPs) associated with CMC in blood samples collected from collected from healthy and CMC female dogs at Diego Villegas Toro Veterinary Hospital of Universidad de Caldas (Manizales, Colombia). We designed primers using Primer-BLAST and Primer3, and gene fragments from HER2, MUC1, ESR1, and BRCA1 were amplified to identify SNPs through genome mapping using the UCSC Genome Institute genome browser. We used the genome of Canis lupus familaris Boxer breed [GCF_000002285.3, (CanFam 3.1)] as a reference to compare the gene fragments and SNPs. We associated SNPs with the CMC and control groups by testing odds ratios (OR) through Fisher’s exact tests to determine an association or risk for CMC. We detected two SNPs for ESR1, three for MUC1, six for HER2, and one for BRCA1. MUC1 was the only gene to display an SNP in an exonic region that resulted in an amino acid substitution (Pro>Thr). No significant differences based on the OR were found, though the majority of SNPs, with the exception of four, were found in females with CMC. We report a novel molecular marker for HER2 that amplifies exons 25–26 and introns 24-25, and highlight the importance of conducting further studies on MUC1 and elucidating the role of introns and splicing in candidate genes associated with CMC.Diljem svijeta, tumor mliječne žlijezde kuja (CMC) najčešća je skupina neoplazija kuja te je tri puta učestalija u pasa nego u ljudi. U Kolumbiji, CMC je bio druga najčešća vrsta tumora, nakon neoplazija na koži. Nadalje, genetika je jedan od najvažnijih čimbenika uključenih u bilo koju vrstu tumora, a genetska baza ove bolesti održava se kroz linijski uzgoj uslijed promjena alelnih frekvencija, koje se mogu pratiti preko molekularnih markera. Ova studija imala je za cilj detektirati polimorfizme jednog nukleotida (SNP-e) povezane s CMC-om u uzorcima krvi prikupljenih od kuja s CMC-om i zdravih kuja u veterinarskoj bolnici Diego Villegas Toro Sveučilišta Caldas (Manizales, Kolumbija). Dizajnirali smo početnice uporabom Primer-BLAST i Primer3 te su fragmenti gena HER2, MUC1, ESR1 i BRCA1 pojačani za identifikaciju SNP-a preko mapiranja genoma uporabom preglednika genoma Instituta za genom Sveučilišta Santa Cruz u Kaliforniji (UCSC). Rabili smo genom Canis lupus familaris pasmine bokser [GCF_000002285.3, (CanFam 3.1)] kao referencu za usporedbu fragmenata gena i SNP-a. Povezali smo SNP-e s CMC-om i kontrolnim skupinama testiranjem omjera izgleda (OR) pomoću Fisherovih egzaktnih testova za određivanje povezanosti ili rizika od CMC-a. Detektirali smo dva SNP-a za ESR1, tri za MUC1, šest za HER2 i jedan za BRCA1. MUC1 je bio jedini gen koji je pokazao SNP u regiji egzona što je rezultiralo supstitucijom aminokiseline (Pro>Thr). Nismo pronašli značajne razlike na temelju OR-a, premda je većina SNP-a, izuzev četiri, pronađena u kuja s CMC-om. Prijavljujemo novi molekularni marker za HER2 koji pojačava egzone 25 - 26 i introne 24 - 25 te naglašavamo važnost provođenja dodatnih studija na MUC1, kao i pojašnjenja uloge introna i izrezivanja u gena kandidata poveznih s CMC-om

    In silico selection and in vitro evaluation of new molecules that inhibit the adhesion of Streptococcus mutans through Antigen I/II

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    Streptococcus mutans is the main early colonizing cariogenic bacteria because it recognizes salivary pellicle receptors. The Antigen I/II of S. mutans is one of the most important adhesins in this process, is involved in the adhesion to the tooth surface and the bacterial co-aggregation in the early stage of biofilm formation. However, this protein has not been used as a target in a virtual strategy search for inhibitors. Based on the predicted binding affinities, drug-like properties and toxicity, molecules were selected and evaluated for their ability to reduce S. mutans adhesion. A virtual screening of 883,551 molecules was conducted, cytotoxicity analysis on fibroblast cells, S. mutans adhesion studies, scanning electron microscopy analysis for bacterial integrity and molecular dynamics simulation were also performed. We have found three molecules (ZI-187, ZI-939, ZI-906) without cytotoxic activity, which inhibited about 90% the adhesion of S. mutans to polystyrene microplates. Molecular dynamic simulation by 300 nanoseconds showed stability of the interaction between ZI-187 and Ag I/II (PDB: 3IPK). This work provides new molecules that targets Ag I/II and have the capacity to inhibit in vitro the S. mutans adhesion on polystyrene microplates

    Procjena gama-aktina, beta-aktina, gliceraldehid-3-fosfat dehidrogenaze i 18S kao referentnih gena za qRT-PCR uporabom uzoraka krvi u istraživanju mliječnih žlijezda kujica

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    Mammary tumours are the most frequent group of neoplasia in female dogs. Tumorigenesis is associated with gene expression changes in a wide variety of genes. For this reason, real-time quantitative PCR (qRT-PCR) is used in routine diagnostic procedures in clinical practice due to its the specificity, sensitivity, simplicity, and high performance. qRT-PCR is also widely used to measure the expression of target genes compared to reference genes in several tissues. We collected blood samples from healthy female dogs and females with canine mammary cancer in Manizales, Colombia between June 2018 and January 2019, and mRNA was isolated from each sample for cDNA synthesis. qRT-PCR-based expression assays were performed using primers designed for gamma-actin, beta-actin, GAPDH, and 18S genes. We calculated the amplification efficiency, specificity, and stability using geNorm, NormFinder, BestKeeper, and the ΔCt comparative method. We obtained linear regressions to verify constant gene expression and conducted an ANOVA to detect expression differences regarding Ct values and healthy vs. ill conditions. We found stability for primers 18S-1, GAPDH-1, GAPDH-NM, and Gamma-actin-1 (in increasing order). Furthermore, these genes showed constant expression levels in patients (R2>0.80). We report novel primers for gamma-actin and GAPDH, which proved to be efficient endogenous control genes for qRT-PCR applications in blood tissue. These primers are useful for gene expression research in canine mammary cancer.Tumori mliječnih žlijezda najčešća su skupina neoplazija u kujica. Tumorogeneza je povezana s promjenama u ekspresiji gena u širokom rasponu gena. Iz tog razloga se rabi kvantitativna lančana reakcija polimerazom u stvarnom vremenu (qRT-PCR) u rutinskim dijagnostičkim postupcima u kliničkoj praksi, uslijed specifičnosti, osjetljivosti, jednostavnosti i visoke učinkovitosti ove tehnike. qRT-PCR se široko rabi i za mjerenje ekspresije ciljanih gena u usporedbi s referentnim genima u više vrsta tkiva. Prikupili smo uzorke krvi zdravih kujica i kujica s tumorom mliječnih žlijezda u Manizalesu, Kolumbiji, od lipnja 2018. do siječnja 2019. godine. Izolirali smo mRNK iz svakog uzorka za cDNK sintezu. Pokusi ekspresije na bazi qRT-PCR obavljeni su uporabom primera dizajniranih za gama-aktin, beta-aktin, gliceraldehid- 3-fosfat dehidrogenazu (GAPDH) i 18S gene. Izračunali smo pojačanu učinkovitost, specifičnost i stabilnost uporabom geNorm, NormFinder, BestKeeper i ΔCt komparativne metode. Dobili smo linearne regresije za potvrđivanje stalne ekspresije gena i proveli smo analizu varijance (ANOVA) za detekciju razlika u ekspresiji s obzirom na Ct vrijednosti te zdrava u usporedbi s bolesnim stanjima. Otkrili smo i stabilnost za primere 18S-1, GAPDH-1, GAPDH-NM i Gamma-actin-1 (rastućim redoslijedom). Nadalje, ovi geni su pokazali konstantne razine ekspresije u pacijenata (R2>0,80). Izvještavamo o novim primerima za gama-aktin i GAPDH, koji su se pokazali učinkovitim endogenim kontrolnim genima za qRT-PCR primjene u krvnom tkivu. Ti primeri su korisni za istraživanje ekspresije gena u tumora psećih mliječnih žlijezda

    Maternal genetic inheritance of red pericarp in the grain of maize

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    The diversity of colors in the grain of corn is wide, from whites to blacks and including a continuum of various shades of yellows, pinks, reds, purples and blues. The most abundant commercial colors are yellow and white, however other colors have become more important because of the presence of pigments to which are attributed favorable effects as a food. The pigments are also considered natural barriers of the grain against the invasion of pests and diseases in the production fields. The colors of the grain of corn occur in three different parts of the seed: the cover of the grain or pericarp, derived from the maternal tissue, with a diploid genetic content; the endo-sperm, including the aleurone layers that are cells in the grain immediately below the pericarp with a chromosome content of 3n; and the embryo, with a genetic content of 2n. The red color considered in this study is present in the pericarp ignoring possible effects in other tissues of grain and other organs of the plant. In this study, we used materials with colorless or red pericarp, and white or yellow endosperm; with the purpose of describing the type of inheritance of this character in the grain of corn. The results indicated a maternal genetic inheritance with classical complete dominance of the red color of pericarp over the clear or transparent phenotype, where the red color of the grains on ear is determined by the genotype of the mother grain but not by the seed embryo genotypes, which is characterized by uniformity of grain color of the ear. This type of inheritance could be useful in the development of pigmented varieties of higher food quality for humans
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