TEMPORAL VARIATION IN THE FEEDING ECOLOGY OF THE BLACK-FACED IBIS (THERISTICUS MELANOPIS) IN PASTURES OF SOUTHERN CHILE

Temporal variation in food availability may generate changes in the feeding strategies and trophic preferences of animals. We studied the temporal variation in feeding behavior, diet composition, and prey availability of the Black-faced Ibis (Theristicus melanopis) in pastures of southern Chile between May 1999 and January 2000. Soil core samples showed that hypogeous invertebrates such as, earthworms (Lumbricus spp.), black cutworm larvae (Agrotis spp.), black pasture caterpillars (Dalaca spp.), and southern green chafers (Hylamorpha elegans) were the most abundant prey in the pastures and that their populations experienced pronounced seasonal variations. Insect larvae were the main prey of the Black-faced Ibis and were consumed in greater proportion than expected by chance. The diet composition (based on feces) and trophic preferences coincided with variations in prey availability. During periods of reduced prey abundance Black-faced Ibises foraged on more different types of prey and their consumption rate diminished. At the same time, the abundance of Black-faced Ibises decreased in the study area. These variations were most evident in late spring and summer, when prey abundance in the pastures was lower than in the other seasons. Our results suggest that the life cycle of the prey is the main causal factor that influences the feeding ecology of the Black-faced Ibis in pastures of southern Chile

Spontaneous circadian rhythms in a cold-Adapted natural isolate of Aureobasidium pullulans

Indexación: Scopus.Circadian systems enable organisms to synchronize their physiology to daily and seasonal environmental changes relying on endogenous pacemakers that oscillate with a period close to 24 h even in the absence of external timing cues. The oscillations are achieved by intracellular transcriptional/translational feedback loops thoroughly characterized for many organisms, but still little is known about the presence and characteristics of circadian clocks in fungi other than Neurospora crassa. We sought to characterize the circadian system of a natural isolate of Aureobasidium pullulans, a cold-Adapted yeast bearing great biotechnological potential. A. pullulans formed daily concentric rings that were synchronized by light/dark cycles and were also formed in constant darkness with a period of 24.5 h. Moreover, these rhythms were temperature compensated, as evidenced by experiments conducted at temperatures as low as 10 °C. Finally, the expression of clock-essential genes, frequency, white collar-1, white collar-2 and vivid was confirmed. In summary, our results indicate the existence of a functional circadian clock in A. pullulans, capable of sustaining rhythms at very low temperatures and, based on the presence of conserved clock-gene homologues, suggest a molecular and functional relationship to well-described circadian systems.https://www.nature.com/articles/s41598-017-14085-

On the Properties of Special Functions on the linear-type lattices

We present a general theory for studying the difference analogues of special functions of hypergeometric type on the linear-type lattices, i.e., the solutions of the second order linear difference equation of hypergeometric type on a special kind of lattices: the linear type lattices. In particular, using the integral representation of the solutions we obtain several difference-recurrence relations for such functions. Finally, applications to $q$-classical polynomials are given

Socio-economic and Technical Characteristics of Backyard Animal Husbandry in Two Rural Communities of Yucatan, Mexico

This research work was conducted in order to asses the socio-economic and technical aspects of backyard animal rearing in two communities of Yucatán, México. One hundred and thirty nine families were interviewed in Sudzal (C1) and 117 families in San Jose Tzal (C2). A structured questionnaire was used to interview the families on technical and socio-economic aspects. Using this information the technical level of animal husbandry and a index of socio-economic status of the families involved in backyard animal rearing in both communities were determined. In C1 46.8% of the interviewed families reared animals in their backyard in comparison to 70.9% in C2. Main animal species kept in the backyard were chickens (C1= 92.3% and C2= 88.0), turkeys (C1= 63.1% and C2= 55.4%) and pigs (C1= 38.5% and 1C2= 5. 7% in C1 and C2 respectively). In C2 100% of pigs kept in the backyard were of the commercial type. Technical level in animal production was significantly higher (P 0.0001) in C2 than in C1, because utilisation of commercial diets was higher in C2 (P 0.001) than in C1. The families of C2 had a higher socio-economic level (P 0.002) than families from C1, because families of C2 have houses built with lasting materials (P 0.0001) and the occupation of the head of the family was associated with higher income (merchants or employees) (P 0.0001). The correlation coefficients between socio-economic status and technical level in backyard animal production showed that 84% of the technical level was explained by the socio-economic status. It can be concluded that socio-economic status has a high influence on backyard animal production characteristics. The socio-economic status determine the number of animals kept and the technical level in animal rearing

Consideraciones biogenéticas sobre los neolignanos presentes en la corteza de mezilaurus itauba (lauraceae)

La biogénesis de 9 neolignanos extraídos de la corteza de Mezilaurus itauba (Meissn) Tauber ex Mez (Lauraceae) puede ser explicada por acoplamiento oxidativo de radicales provenientes de propenil y alilfenoles. En esta planta isoeugenol y eugenol parecen ser metabolizados a través de un acoplamiento oxidativo para dar un intermediario quinonametfdeo el cual por adición de hidroxilo produce neolignanos benzofuránicos y bicHo (3,2.1) octánicos. Un neolignano biciclooctánico puede provenir de isoeugunol y 3,4-dlhidroxialilbenceno. La presencia de neolignanos benzofuránicos en M. itauba es importante porque confirma la ocurrencia natural de una secuencia de reacciones racionalizadas mecanlsticamente por reordenamiento de Cope, retro-Clalsen y Claisen

Glucocorticoids improve acute dizziness symptoms following acute unilateral vestibulopathy.

Acute unilateral vestibulopathy (AUV) is characterized by acute vertigo, nausea, and imbalance without neurological deficits or auditory symptomatology. Here, we explore the effect of glucocorticoid treatment on the degree of canal paresis in patients with AUV, and critically, establish its relationship with dizziness symptom recovery. We recruited consecutive patients who were retrospectively assigned to one of the two groups according to whether they received glucocorticoid treatment (n = 32) or not (n = 44). All patients underwent pure-tone audiometry, bithermal caloric testing, MRI brain imaging, and were asked to complete a dizziness handicap inventory on admission to hospital and just prior to hospital discharge. In the treatment group, the canal paresis at discharge was significantly lower than in the control group (mean ± SD % 38.04 ± 21.57 versus 82.79 ± 21.51, p < 0.001). We also observed a significant reduction in the intensity of nystagmus in patients receiving glucocorticoid treatment compared to the non-treatment group (p = 0.03). DHI test score was significantly lower at discharge in the treatment group (mean ± SD % 23.15 ± 12.40 versus 64.07 ± 12.87, p < 0.001), as was the length of hospital stay (2.18 ± 1.5 days versus 3.6 ± 1.7 days, p = 0.002). Glucocorticoid treatment leads to acute symptomatic improvement, with a reduced hospital stay and reduction in the intensity of acute nystagmus. Our findings suggest that glucocorticoids may accelerate vestibular compensation via a restoration of peripheral vestibular function, and therefore has important clinical implications for the treatment of AUV

Validity of the dental operating microscope and selective dentin removal with ultrasonic tips for locating the second mesiobuccal canal (MB2) in maxillary first molars : an in vivo study

Several investigations have determined whether the use of a dental operating microscope (DOM) in combination with selective dentine removal with ultrasonic tips increases the percentage of location of the Mesiobuccal 2 (MB2) root canal in maxillary firs

Evaluación de dos métodos de análisis dietarios aplicados en la Bandurria Theristicus melanopis (Gmelin 1789) y el Queltehue Vanellus chilensis (Molina 1782)

Dietary studies contribute to our understanding of bird ecology and are an important source of information for programs promoting the conservation of organisms. We contrasted fecal and stomach content methods of dietary analysis in the Black-faced Ibis and the Southern Lapwing, in order to evaluate the degree of sensitivity in distinguishing consumed prey. Diversity and abundance of prey detected were greater in stomach content samples than in fecal samples in both bird species. The Southern Lapwing did not show association in the number of prey, or a similarity in the taxonomic composition of preys between both methods, suggesting a lack of reliability in the fecal analysis that might lead to misunderstanding the trophic ecology of this bird species. The Black-faced Ibis, show a high association in the number of preys between both methods, and the taxonomic composition and abundance of prey in feces were concordant with that detected in the stomach contents, suggesting that the fecal analysis give reliable results which are coherent between both methods of dietary analysis; this method of analysis is, therefore, recommended, and must be complemented with molecular methods of stomach content analysis, such as the stable isotopes if the scopes of the research is to carry out long term studies.Los estudios dietarios contribuyen a comprender la ecología de las aves y son relevantes en programas de conservación de los organismos. Contrastamos los métodos de análisis dietarios fecales y estomacales en la Bandurria y en el Queltehue, para evaluar su sensibilidad para discriminar las presas consumidas. La diversidad y la abundancia de presas detectadas fueron mayores en los estómagos que en las heces en ambas especies de aves. El Queltehue no mostró una asociación en el número de categorías tróficas, ni una similitud en la composición taxonómica de la dieta entre ambos métodos, lo que sugiere que los análisis fecales no son confiables y pueden conducir a interpretaciones erróneas de la ecología trófica de esta especie de ave. La Bandurria mostró una alta asociación en el número de presas entre ambos métodos y la composición taxonómica y abundancia de presas en las heces fue concordante con la detectada en los estómagos, sugiriendo que los análisis fecales entregan resultados confiables y coherentes entre ambos métodos de análisis dietario; se recomienda su uso complementado con métodos moleculares de análisis de contenido estomacal como los isótopos estables si el objetivo de la investigación es desarrollar estudios a largo plazo