Fixing the U-band photometry of Type Ia supernovae

We present previously unpublished photometry of supernovae 2003gs and 2003hv. Using spectroscopically-derived corrections to the U-band photometry, we reconcile U-band light curves made from imagery with the Cerro Tololo 0.9-m, 1.3-m and Las Campanas 1-m telescopes. Previously, such light curves showed a 0.4 mag spread at one month after maximum light. This gives us hope that a set of corrected ultraviolet light curves of nearby objects can contribute to the full utilization of rest frame U-band data of supernovae at redshift ~0.3 to 0.8. As pointed out recently by Kessler et al. in the context of the Sloan Digital Sky Survey supernova search, if we take the published U-band photometry of nearby Type Ia supernovae at face value, there is a 0.12 mag U-band anomaly in the distance moduli of higher redshift objects. This anomaly led the Sloan survey to eliminate from their analyses all photometry obtained in the rest frame U-band. The Supernova Legacy Survey eliminated observer frame U-band photometry, which is to say nearby objects observed in the U-band, but they used photometry of high redshift objects no matter in which band the photons were emitted.Comment: 25 pages, 9 figures, accepted for publication in the Astronomical Journa

Cambios en el perfil bioquímico hepático de alpacas positivas a huevos de Fasciola hepática

The aim of this study was to determine changes in the liver biochemical profile in alpacas with presence of F. hepatica eggs. We used serum and feces samples of 35 male alpaca between 2-5 years old, 18 were positives and 17 were negatives in coproparasitologic analysis for F. hepatica eggs. Differences are showed (p<0.05) in the values of ALT, GGT and direct bilirubin between positives y negatives animals. We concluded that there is relationship between presence of F. hepatica eggs and high levels in the liver biochemical profile, maybe due to alterations in the hepatic parenchyma by chronic infection in alpacas.El objetivo del presente estudio fue determinar cambios en el perfil bioquímico hepático en alpacas con presencia de huevos de F. hepatica en heces. Se utilizaron muestras de suero y heces de 35 alpacas machos de entre 2 y 5 años de edad, de los cuales 18 fueron positivos y 17 negativos al examen coproparasitológico (sedimentación) para identificación de huevos de F. hepática. Se observó diferencia significativa (p<0.05) entre los valores de ALT, GGT y bilirrubina directa entre los animales positivos y negativos. Concluimos que la presencia de huevos de Fasciola hepatica guarda relación con la elevación de algunos parámetros del perfil hepática posiblemente por alguna alteración en el parénquima producto de una infección crónica en alpacas

Exploring the influence of meteorological conditions on the performance of a waste stabilization pond at high altitude with structural equation modeling

Algal photosynthesis plays a key role in the removal mechanisms of waste stabilization ponds (WSPs), which is indicated in the variations of three parameters, dissolved oxygen, pH, and chlorophyll a. These variations can be considerably affected by extreme climatic conditions at high altitude. To investigate these effects, three sampling campaigns were conducted in a high-altitude WSP in Cuenca (Ecuador). From the collected data, the first application of structure equation modeling (SEM) on a pond system was fitted to analyze the influence of high-altitude characteristics on pond performance, especially on the three indicators. Noticeably, air temperature appeared as the highest influencing factors as low temperature at high altitude can greatly decrease the growth rate of microorganisms. Strong wind and large diurnal variations of temperature, 7-20 degrees C, enhanced flow efficiency by improving mixing inside the ponds. Intense solar radiation brought both advantages and disadvantages as it boosted oxygen level during the day but promoted algal overgrowth causing oxygen depletion during the night. From these findings, the authors proposed insightful recommendations for future design, monitoring, and operation of high-altitude WSPs. Moreover, we also recommended SEM to pond engineers as an effective tool for better simulation of such complex systems like WSPs

Architectural Diversity of the Cuticle and Epidermis of Native and Hybrid Tomato Fruit Genotypes and the Relation to Polygalacturonase Expression

The tomato (Solanum lycopersicum L.) fruit has been widely studied because of its high consumption, nutritional value, and well-characterized genome. It also represents a good model for studying the structure and function of the cuticle, a protective film that is deposited on the surface of outer epidermal cell walls, and affects the integrity and firmness of the fruit, and, therefore, its commercialization. To evaluate the differences in their structure and function, we characterized the morphology of the cuticle and the epidermis and their relationship to firmness, brightness, weight loss, and transcript levels of polygalacturonase (PGA) in four hybrid genotypes and four native genotypes of different origins, shapes, and colors. Our results show a different architecture of the epidermis and cell wall among the genotypes. Native genotypes showed irregular-shaped epidermal cells and a thicker epidermis. Anticlinal pegs were also present to only one-third of the depth of the epidermal cells. The hybrid fruit surface was smoother compared to native genotypes, and it was associated with a higher level of brightness and a less weight loss. A negative correlation between firmness and PGA transcript levels was found. The chartreuse yellow genotype was the firmest, and it had the lowest levels of PGA expression. Meanwhile, the black genotype displayed the lowest weight loss and stem scar diameter. Our results suggest that several morphological features of the cuticle and epidermis have been modified through selection of the tomato fruit, altering quality parameters, such as weight loss and firmness

Caracterización citológica de la médula ósea durante el desarrollo fetal en la alpaca (Vicugna pacos)

The present study aimed to investigate the morphology and morphometry of progenitor cells from the bone marrow through cytological examination during foetal development of the alpaca (Vicugna pacos). Bone marrow samples were collected from 18 culled and clinically healthy alpaca foetuses in Pasco, Peru. The eighth and ninth ribs were removed using the cost-chondral junction as reference and smears were made with the bone marrow samples, and then stained with Wright. The percentages of cellularity for each third of pregnancy were 16 ± 0.2 (n= 3), 35 ± 0.16 (n= 5) and 78 ± 0.12 (n=10), respectively, showing the first hematopoietic cells from 201.5 days old. Through the differential count of 500 cells, the myeloid: erythroid ratio was established, being 0.47 ± 0.27 and 0.69 ± 0.19 for the first, second and last third of pregnancy, respectively. In the second third of pregnancy 10.17% of erythroid cells, 5.03% of myeloid cells and 84.80% of other cell types were detected, while in the last third it was 39.99% of erythroid cells, 26.99% of myeloid cells and 33.21% of other cell types. In the morphometric examination, hematopoietic cells revealed characteristics like those found in other species.El presente estudio tuvo como objetivo investigar la morfología y morfometría de las células progenitoras de la médula ósea a través del examen citológico durante el desarrollo fetal de la alpaca (Vicugna pacos). Se colectaron muestras de médula ósea provenientes de 18 fetos de alpacas clínicamente sanas y destinadas a beneficio en Pasco, Perú. Se seccionaron la octava y novena costillas tomando como referencia la unión costo-condral y se hicieron frotis con las muestras de médula ósea, que fueron coloreadas con la tinción Wright. Los porcentajes de celularidad para cada tercio de gestación fueron 16 ± 0.2 (n=3), 35 ± 0.16 (n=5) y 78 ± 0.12 (n=10), respectivamente, evidenciándose las primeras células hematopoyéticas a partir de los 201.5 días de edad. Mediante el conteo diferencial de 500 células se estableció la relación mieloide:eritroide, siendo de 0, 0.47 ± 0.27 y 0.69 ± 0.19 para el primer, segundo y tercer tercio de gestación, respectivamente. En el segundo tercio de gestación se detectó 10.17% de células eritroides, 5.03% de células mieloides y 84.80% de otros tipos celulares, mientras que en el último tercio fue de 39.99% de células eritroides, 26.99% de células mieloides y 33.21% de otros tipos celulares. En el examen morfométrico, las células hematopoyéticas revelaron características similares a las encontradas en otras especies

Optical Photometry of the Type Ia SN 1999ee and the Type Ib/c SN 1999ex in IC 5179

We present UBVRIz lightcurves of the Type Ia SN 1999ee and the Type Ib/c SN 1999ex, both located in the galaxy IC 5179. SN 1999ee has an extremely well sampled lightcurve spanning from 10 days before Bmax through 53 days after peak. Near maximum we find systematic differences ~0.05 mag in photometry measured with two different telescopes, even though the photometry is reduced to the same local standards around the supernova using the specific color terms for each instrumental system. We use models for our bandpasses and spectrophotometry of SN 1999ee to derive magnitude corrections (S-corrections) and remedy this problem. This exercise demonstrates the need of accurately characterizing the instrumental system before great photometric accuracies of Type Ia supernovae can be claimed. It also shows that this effect can have important astrophysical consequences since a small systematic shift of 0.02 mag in the B-V color can introduce a 0.08 mag error in the extinction corrected peak B magnitudes of a supernova and thus lead to biased cosmological parameters. The data for the Type Ib/c SN 1999ex present us with the first ever observed shock breakout of a supernova of this class. These observations show that shock breakout occurred 18 days before Bmax and support the idea that Type Ib/c supernovae are due to core collapse of massive stars rather than thermonuclear disruption of white dwarfs.Comment: 55 pages, 15 figures, accepted by the Astronomical Journa

IDENTIFICACIÓN Y EVALUACIÓN DE TRANSPORTADORES DE GLUCOSA SGLT1 Y GLUT2 Y LA INCRETINA GLP-1 EN INTESTINO DELGADO DE CUYES (Cavia porcellus).

The aim of this study was to identify and assess the presence of glucose transporters SGLT1 and GLUT2 and incretin GLP-1 in the small intestine of guinea pig (Cavia porcellus). Five animals of 90 days old were used. Samples from the duodenum, jejunum and ileum were collected after slaughtering to carry out immunohistochemistry assays. Expression of SGLT1, GLUT2 and GLP-1 was observed in all three portions of the small intestine, where SGLT1 showed the highest expression, with a strong staining intensity in the apical and medium section of the crypt-villus axis. GLUT2 showed a strong staining intensity throughout the crypt-villus axis in the jejunum. GLP-1 expression was indirectly analyzed by calculating the number of L cells per mm2 of intestinal mucosa, resulting that the jejunum had the largest number (8.46 ±1.16 cells/mm2) (p<0.05). The results suggest that SGLT1 glucose transporter would be the most important in the guinea pig, and unlike other species, GLP-1 may be mostly secreted by the jejunum.El presente trabajo tuvo por objetivo identificar y evaluar la presencia de los transportadores de glucosa SGLT1 y GLUT2 y la incretina GLP-1 en intestino delgado de cuyes. Se usaron cinco cuyes (Cavia porcellus) reproductores de 90 días de edad. Luego del sacrificio, se tomaron muestras de duodeno, yeyuno e íleon para el procesamiento inmunohistoquímico. Se pudo identificar la presencia de SGLT1, GLUT2 y GLP-1 en las tres porciones intestinales, siendo SGLT1 la proteína de mayor presencia, con un nivel de marcación fuerte en la parte apical y media del eje cripta-vellosidad. El GLUT2 mostró un nivel de marcación fuerte en todo el eje cripta-vellosidad en el yeyuno. Asimismo, la presencia del GLP-1 fue analizada indirectamente por el número de células L/mm2 de mucosa intestinal, encontrándose el mayor número en el yeyuno (8.46 ± 1.16 células L/mm2) (p<0.05). Los resultados indican que SGLT1 sería el transportador de glucosa más importante en el cuy y, que a diferencia de otras especies, la mayor secreción de GLP-1 sería en yeyuno

Do the photometric colors of Type II-P Supernovae allow accurate determination of host galaxy extinction?

We present infrared photometry of SN 1999em, plus optical photometry, infrared photometry, and optical spectroscopy of SN 2003hn. Both objects were Type II-P supernovae. The V-[RIJHK] color curves of these supernovae evolved in a very similar fashion until the end of plateau phase. This allows us to determine how much more extinction the light of SN 2003hn suffered compared to SN 1999em. Since we have an estimate of the total extinction suffered by SN 1999em from model fits of ground-based and space-based spectra as well as photometry of SN 1999em, we can estimate the total extinction and absolute magnitudes of SN 2003hn with reasonable accuracy. Since the host galaxy of SN 2003hn also produced the Type Ia SN 2001el, we can directly compare the absolute magnitudes of these two SNe of different types.Comment: 24 pages, 6 figure