In vitro gas production of foliage from three browse tree species treated with different dose levels of exogenous fibrolytic enzymes

The aim of this study was to evaluate the effect of different dose levels of exogenous fibrolytic enzymes (EFE) on in vitro ruminal fermentation kinetics and energy utilization of foliages from three browse trees (Pithecellobium dulce, Heliocarpus velutinus and Guazuma ulmifolia). Mixture of EFE product was added to the leaves of the three browse tree species at three dose levels: 0 (control), 3.5 and 7.0 mg/g of DM. Chemical composition of the foliages, including plant secondary metabolites such as total phenolics (TP), saponins (SAP) and aqueous fraction (AF), was determined. In addition, in vitro assaying of ruminal gas production kinetics was determined for the three browse three foliages treated with EFE. P. dulce had the highest crude protein content (p < 0.05), whereas G. ulmifolia had the highest content of neutral detergent fibre and SAP (p < 0.05) and H. velutinus had the lowest content of TP (p < 0.05). The interaction between tree species and dose level of EFE was significant (p < 0.05) for gas production (GP) at 24 h of incubation, parameters b and c of the accumulated GP curve, short-chain fatty acids (SCFA) and metabolizable energy (ME). The lowest (p < 0.01) extent of accumulated GP as well as the b and c values occurred in G. ulmifolia at 0 mg EFE/g DM. P. dulce had the highest (p < 0.05) values for ME and SCFA at the highest dose of EFE. Tree species and dose level had significant (p < 0.05) effects on all parameters describing in vitro ruminal fermentation kinetics and energy utilization. Addition of EFE improved the fermentation kinetics of the browse species considered in this study.UAE

In vitro gas production kinetics and degradability of a diet for growing lambs: effect of fibrolytic enzyme products at different dose levels

The objective of this study was to evaluate the effects of three fibrolytic enzyme products (cellulase (CEL), xylanase (XYL) and a 1:1 mixture of CEL and XYL (MIX)) at three dose levels (0, 1 and 3 lL/0.5 g DM) on the in vitro fermentation of a diet for growing lambs. Bottles were incubated for 96 h at 39 C. A mathematical model was used to estimate the parameters describing the gas production (GP) curve (b, c and L). Dry matter degradability (DMD) and fibre (NDFD and ADFD) degradability were determined at the end of the incubation period. Metabolisable energy (ME) and short chain fatty acids (SCFA) were calculated at 24 h of incubation. The asymptotic GP (parameter b) was affected (p<0.02) by enzyme product and dose level, with a significant linear response (p<0.05). Dose level affected ME and SCFA with a significant linear (p<0.05) and quadratic (p<0.01) response. The interaction between enzyme product and dose level was significant (p<0.05) for cumulative GP up to 72 and 96 h of incubation, pH, ADFD and DMD. The results suggest that application of exogenous cellulases has the potential to alter asymptotic GP and degradability of ADF and DM of a diet for growing lambs, but most of the results depend on the interaction between enzyme product and dose level. Future studies are required to determine the ideal combination between enzyme product and dose level for optimal degradation of ruminant feeds

Effects of exogenous enzymes and application method on nutrient intake, digestibility and growth performance of Pelibuey lambs

Pelibuey sheep is the main breed in the tropical and subtropical regions of Mexico, and high demand of sheep meat has favored the finishing of lambs in feedlots with diets containing high levels of grains. The objective of this study was to evaluate the effects of exogenous enzymes (EE) and application method on nutrient intake and digestibility and performance of growing Pelibuey lambs. Treatments were based on comparison of two different methods of adding an enzyme product (sprayed on the total mixed ration or applied orally to the lambs) versus control treatment (no added enzyme). Twenty-one Pelibuey lambs, weighing 15.7 kg (SD = 1.8 kg) initial body weight, were individually housed in shaded pens and assigned randomly to one of the three enzyme treatments. At the end of study (lasting for 45 days), three lambs from each treatment were randomly selected and adapted to a pants and harness designed for fecal collection to measure nutrient digestibilities. Total body gain and average daily gain were affected (P < 0.05) by supplemental EE. The application method of EE had significant (P < 0.05) effect on FCE and FCR, but no effects were observed on nutrient intake. Supplemental EE did improve (P < 0.05) the digestibilities of dry matter, organic matter, neutral and acid detergent fiber, but no differences were observed in crude protein digestibility. The application method of EE had significant (P < 0.05) effect on the digestibility of acid detergent fiber. Supplemental EE can improve body weight gain and nutrient digestibilities without affecting nutrient intake in Pelibuey lambs, but the results of feed conversion efficiency and acid detergent fiber digestibility depend on the application method used of the EE

In vitro ruminal fermentation kinetics and energy utilization of three Mexican tree fodder species during the rainy and dry period

A factorial experimental design (3×2×3) was used to evaluate the effect of season of harvest and type of ruminal inoculums on in vitro ruminal fermentation kinetics and energy utilization of three browse tree foliages (Lysiloma acapulcencis, Quercus laeta and Pithecellobium dulce). Browse species were harvested during the dry season (DS) and rainy season (RS) and incubated with three different ruminal inoculums: cow, goats previously adapted (AG) or not adapted (UG) to browse species fed in their daily diet. Chemical composition, total condensed tannin (TCT), free-condensed tannin (free-CT), protein-bound condensed tannin (PCT), fiber-bound condensed tannin (FCT) as well as in vitro assaying of ruminal gas production kinetics was determined, while the short chain fatty acids (SCFA) and metabolizable energy (ME) were estimated. Crude protein (CP) was considerably higher (season×browse; P<0.001) during RS. P. dulce had the lowest neutral detergent fiber (NDFom) and acid detergent fiber (ADFom) in both seasons, while L. acapulcencis had the highest values and Q. laeta values were intermediate, with an overall increase in fiber fractions in DS browse foliages (season×browse; P<0.001). TCT content in tree species revealed differences (P<0.01). FCT and PCT were lower in Q. laeta and P. dulce during the RS than in DS, lower (P<0.01) Free-CT fractions were observed in L. acapulcencis and Q. Laeta than in P. dulce, during both seasons. in vitro gas production parameters was increased (P<0.05) in DS than in RS in browses with low and medium tannins contents (i.e., P. dulce and Q. laeta); consequently, browses energy utilization (i.e., SCFA and ME) and organic matter degradability (OMD) as well as fermentation efficiency (i.e., partition factor; PF) were improved (P<0.05). Generally, P. dulce had the highest (P<0.001) ruminal fermentation parameters and energy utilization values (more in DS than RS), while lowest values were founded in L. acapulcencis. Ruminal fluid ofADandUGhad higher (P<0.001) browse ruminal fermentation kinetics, efficiency and energy utilization than cow’s rumen fluid. The browse fermentation and energy utilization was improved in DS versus in RS and the browse fermentation and utilization were highest (P<0.05) in AG ruminal fluid than the others. Our results suggested a better nutritive value of P. dulce and Q. laeta with low and medium tannins contents and high CP concentration in cows and goats during the DS. Goats previously fed browse species in diets had a better ability to degrade and ferment the browse species than other animals

Internacionalización en el sector aéreo de América Latina: estudio multicaso de Aeroméxico, Avianca y Latam (Internationalization in the Latin American air sector: multi- case study of Aeromexico, Avianca and Latam)

Abstract. The objective of this paper is to analyze the internationalization strategies of the Latin American airlines: Aeromexico (Mexico), Avianca (Colombia) and LATAM (Chile). For this, a qualitative multi-case study technique was applied. The research question that is intended to answer in this paper is: in what way are the main airlines in Latin America internationalized? The results suggest that the airlines studied use similar internationalization strategies, which are based on strategic alliances with other airlines in order to offer a better service to their passengers. They were also identified as the main characteristics of these airlines that are strong in their domestic market (especially Aeromexico) and then they start to expand their operations abroad. Likewise, Avianca and LATAM have the main market in Latin America, while Aeromexico has a greater presence in the United States.Key words: Aeromexico, airline industry, Avianca, internationalization, LATAM, service sectorJEL: F23, M16.Resumen. El objetivo de este trabajo es analizar las estrategias de internacionalización de las aerolíneas latinoamericanas Aeroméxico (México), Avianca (Colombia) y LATAM (Chile). Para esto se aplicó una técnica cualitativa de  estudio multi-caso. La pregunta de investigación que se pretende responder en este trabajo es ¿de qué manera se internacionalizan las principales aerolíneas en América Latina?. Los resultados sugieren que las aerolíneas estudiadas utilizan estrategias similares de internacionalización, las cuáles están basadas en alianzas estratégicas con otras aerolíneas para poder ofrecer un mejor servicio a sus pasajeros. Además fueron identificadas como principales características de estas aerolíneas que son fuertes en su mercado interno (sobre todo Aeroméxico) y de ahí parten para poder expandir sus operaciones hacía el exterior. Asimismo Avianca y LATAM tiene como principal mercado América Latina, en cambio Aeroméxico tiene una mayor presencia en Estados Unidos.Palabras clave: Aeroméxico, Avianca, internacionalización, LATAM, sector aéreo, sector servicio

K2-97b: A (Re-?)Inflated Planet Orbiting a Red Giant Star

Strongly irradiated giant planets are observed to have radii larger than thermal evolution models predict. Although these inflated planets have been known for over 15 years, it is unclear whether their inflation is caused by the deposition of energy from the host star or the inhibited cooling of the planet. These processes can be distinguished if the planet becomes highly irradiated only when the host star evolves onto the red giant branch. We report the discovery of K2-97b, a 1.31 ± 0.11 R_J, 1.10 ± 0.11 M_J planet orbiting a 4.20 ± 0.14 R⊙, 1.16 ± 0.12 M⊙ red giant star with an orbital period of 8.4 days. We precisely constrained stellar and planetary parameters by combining asteroseismology, spectroscopy, and granulation noise modeling along with transit and radial velocity measurements. The uncertainty in planet radius is dominated by systematic differences in transit depth, which we measure to be up to 30% between different light-curve reduction methods. Our calculations indicate the incident flux on this planet was 170^(+140)_(-60) times the incident flux on Earth, while the star was on the main sequence. Previous studies suggest that this incident flux is insufficient to delay planetary cooling enough to explain the present planet radius. This system thus provides the first evidence that planets may be inflated directly by incident stellar radiation rather than by delayed loss of heat from formation. Further studies of planets around red giant branch stars will confirm or contradict this hypothesis and may reveal a new class of re-inflated planets

Rostral Middle Frontal Volumetric Differences in Bipolar Offspring versus Community Controls Offspring

Neuroanatomical findings in the anterior limbic network in bipolar disorder (BD) adults have not been replicated in other populations such as bipolar offspring (BO). The aim of this study was to compare some brain areas volumes between BO with and without a lifetime affective disorder (AD) to a group of community control offspring (CCO). Methods: A descriptive observational cross-sectional study was carried out, with multiple comparison groups. Seven subjects (11-17 years old) from the BO with AD group were compared to seven subjects from the BO without AD group and seven subjects from the CCO group (match by age, gender and Tanner stage). Magnetic resonance imaging was performed with a Philips 3 Teslas device and volumetric segmentation was performed with the Freesurfer image analysis suite. Results: A larger size was found in the right middle frontal rostral region in the BO with AD group compared to the other two groups (p = 0.041). A higher volume was also found in BO with AD group in the left pars opercularis (Cohen d = 0.63) and in the right cingulate isthmus (d = 0.53) when compared with BO without AD group, and in the right hippocampus (d = 0.53) when compared to CCO group. A smaller volume was found in the BO without AD group versus CCO group in the left anterior caudate (d = 0.6). The BO groups (with and without AD) compared to CCO have a higher volume in the right frontal pole (d = 0.52). These volumetric differences can be attributed to the condition of BO with AD

WEAVE spectrograph cameras: the polishing of the spherical lenses

WEAVE is the new wide field multi-object and integral field survey facility for the prime focus of the 4.2 m William Herschel Telescope. WEAVE fiber-fed spectrograph offers two resolutions, R 5000 and 20,000. The dual-beam spectrograph has two cameras: the blue one optimized for the wavelength interval of 366 - 606 nm and the red one for 579 - 959 nm. Each camera is formed by eight lenses, one aspherical and seven spherical. The lenses of the red camera are identical to the lenses of the blue camera only differentiated by the anti-reflection coating wavelength range. The diameter of the largest surface is 320 mm while of the smallest is 195 mm. INAOE, as a member of the collaboration is responsible of the manufacturing of the 14 spherical lenses and the collimator mirror. Here, we describe the main characteristics of WEAVE high precision cameras lenses, the manufacturing challenges giving the combination of OHARA glasses properties, dimensions and specifications. We discuss the solutions developed to achieve the very demanding specifications

Characterization of cassava ORANGE proteins and their capability to increase provitamin A carotenoids accumulation

Cassava (Manihot esculenta Crantz) biofortification with provitamin A carotenoids is an ongoing process that aims to alleviate vitamin A deficiency. The moderate content of provitamin A carotenoids achieved so far limits the contribution to providing adequate dietary vitamin A levels. Strategies to increase carotenoid content focused on genes from the carotenoids biosynthesis pathway. In recent years, special emphasis was given to ORANGE protein (OR), which promotes the accumulation of carotenoids and their stability in several plants. The aim of this work was to identify, characterize and investigate the role of OR in the biosynthesis and stabilization of carotenoids in cassava and its relationship with phytoene synthase (PSY), the rate-limiting enzyme of the carotenoids biosynthesis pathway. Gene and protein characterization of OR, expression levels, protein amounts and carotenoids levels were evaluated in roots of one white (60444) and two yellow cassava cultivars (GM5309-57 and GM3736-37). Four OR variants were found in yellow cassava roots. Although comparable expression was found for three variants, significantly higher OR protein amounts were observed in the yellow varieties. In contrast, cassava PSY1 expression was significantly higher in the yellow cultivars, but PSY protein amount did not vary. Furthermore, we evaluated whether expression of one of the variants, MeOR_X1, affected carotenoid accumulation in cassava Friable Embryogenic Callus (FEC). Overexpression of maize PSY1 alone resulted in carotenoids accumulation and induced crystal formation. Co-expression with MeOR_X1 led to greatly increase of carotenoids although PSY1 expression was high in the co-expressed FEC. Our data suggest that posttranslational mechanisms controlling OR and PSY protein stability contribute to higher carotenoid levels in yellow cassava. Moreover, we showed that cassava FEC can be used to study the efficiency of single and combinatorial gene expression in increasing the carotenoid content prior to its application for the generation of biofortified cassava with enhanced carotenoids levels

Masses, radii, and orbits of small Kepler planets : The transition from gaseous to rocky planets

We report on the masses, sizes, and orbits of the planets orbiting 22 Kepler stars. There are 49 planet candidates around these stars, including 42 detected through transits and 7 revealed by precise Doppler measurements of the host stars. Based on an analysis of the Kepler brightness measurements, along with high-resolution imaging and spectroscopy, Doppler spectroscopy, and (for 11 stars) asteroseismology, we establish low false-positive probabilities (FPPs) for all of the transiting planets (41 of 42 have an FPP under 1%), and we constrain their sizes and masses. Most of the transiting planets are smaller than three times the size of Earth. For 16 planets, the Doppler signal was securely detected, providing a direct measurement of the planet's mass. For the other 26 planets we provide either marginal mass measurements or upper limits to their masses and densities; in many cases we can rule out a rocky composition. We identify six planets with densities above 5 g cm-3, suggesting a mostly rocky interior for them. Indeed, the only planets that are compatible with a purely rocky composition are smaller than 2 R ⊕. Larger planets evidently contain a larger fraction of low-density material (H, He, and H2O).Peer reviewedFinal Accepted Versio