COMPETITIVIDAD EN LA COMERCIALIZACIÓN DE MANGO (Mangifera indica L.) DE MÉXICO

The analysis of competitiveness in mango (Mangifera indica L.) commercialization was analyzed between México, Brazil and India, highlighting the evolution of the first two countries as principal providers to the United States market. Data for production, exports, imports and apparent consumption from the 1993-2013 period were obtained, as well as the global market participation (GMP), import penetration rate (IPR), coefficient of revealed comparative advantage (RCA), and production exposed to competition (PEC). It was found that Brazil and India’s GMP increased 4 % and 7 %, respectively, while that of México decreased 24 %. The three countries analyzed presented a RCA higher than 100. México is the countrythat has the highest external PEC in mango production, and it is a leader in exports to the United States;however, due to the fluctuation in export volumes, its competitiveness has decreased, causing a lower participation in the international market.Se analizó la competitividad en la comercialización del mango (Mangifera indica L.) entre México, Brasil y la India, resaltando la evolución de los dos primeros países como principales proveedores al mercado estadunidense. Se obtuvieron datos de producción, exportación, importación y consumo aparente del periodo 1993-2013 y midió la participación en el mercado mundial (PMM), tasa de penetración de las importaciones (TPI), coeficiente de ventaja comparativa revelada (VCR) y producción expuesta a la competencia (PEC). Se registró que la PMM de Brasil e India aumentaron 4% y 7% respectivamente, mientras que la de México disminuyó 24%. Los tres países analizados presentaron una VCR mayor a 100. México es el país que tiene la mayor PEC externa en la producción de mango y es líder en la exportación a Estados Unidos; no obstante, debido a la fluctuación de los volúmenes de exportación, su competitividad ha disminuido, ocasionando menor participación en el mercado internacional

Effects of Combining Feed Grade Urea and a Slow-release Urea Product on Performance, Dietary Energetics and Carcass Characteristics of Feedlot Lambs Fed Finishing Diets with Different Starch to Acid Detergent Fiber Ratios.

Recent findings have shown that microbial nitrogen flow and digestible energy of diets are increased when urea is combined with a slow-release urea (SRU) in diets with a starch to acid detergent fibre ratio (S:F) 4:1. This affect is attributable to enhanced synchrony between ruminal N availability for microbial growth and carbohydrate degradation. To verify the magnitude of this effects on lamb performance, an experiment was conducted to evaluate the effects of combining urea and a SRU in diets containing S:F ratios of 3:1, 4:1, or 5:1 on performance, dietary energetics and carcass characteristics of finishing lambs. For that, 40 Pelibuey×Katahdin lambs (36.65±3 kg) were assigned to one of five weight groupings in 20 pens (5 repetition/treatments). The S:F ratio in the diet was manipulated by partially replacing the corn grain and dried distiller's grain with solubles by forage (wheat straw) and soybean meal to reach S:F ratios of 3:1, 4:1 or 5:1. An additional treatment of 4:1 S:F ratio with 0.8% urea as the sole source of non-protein nitrogen was used as a reference for comparing the effect of urea combination vs. conventional urea at the same S:F ratio. There were no treatment effects on dry matter intake (DMI). Compared the urea combination vs urea at the same S:F ratio, urea combination increased (p<0.01) average daily gain (ADG, 18.3%), gain for feed (G:F, 9.5%), and apparent energy retention per unit DMI (8.2%). Irrespective of the S:F ratio, the urea combination improved the observed-to-expected dietary ratio and apparent retention per unit DMI was maximal (quadratic effect, p≤0.03) at an S:F ratio of 4:1, while the conventional urea treatment did not modify the observed-to-expected net energy ratio nor the apparent retention per unit DMI at 4:1 S:F ratio. Urea combination group tended (3.8%, p = 0.08) to have heavier carcasses with no effects on the rest of carcass characteristics. As S:F ratio increased, ADG, G:F, dietary net energy, carcass weight, dressing percentage and longissimus thoracis (LM) area increased linearly (p≤0.02). Combining urea and a slow-release urea product results in positive effects on growth performance and dietary energetics, but the best responses are apparently observed when there is a certain proportion (S:F ratio = 4:1) of starch to acid detergent fibre in the diet

Influence of Ionophore Supplementation on Growth Performance, Dietary Energetics and Carcass Characteristics in Finishing Cattle during Period of Heat Stress.

Forty-eight crossbred heifers (378.1±18 kg) were used in a 56-d feeding trial (four pens per treatment in a randomised complete block design) to evaluate the influence of ionophore supplementation on growth performance, dietary energetics and carcass characteristics in finishing cattle during a period of heat stress. Heifers were fed a diet based on steam-flaked corn (2.22 Mcal NEm/kg) with and without an ionophore. Treatments were: i) control, no ionophore; ii) 30 mg/kg monensin sodium (RUM30); iii) 20 mg/kg lasalocid sodium (BOV20), and iv) 30 mg/kg lasalocid sodium (BOV30). Both dry matter intake (DMI) and climatic variables were measured daily and the temperature humidity index (THI) was estimated. The maximum THI during the study averaged 93, while the minimum was 70 (THI average = 79.2±2.3). Compared to controls, monensin supplementation did not influence average daily gain, the estimated NE value of the diet, or observed-to-expected DMI, but tended (p = 0.07) to increase (4.8%) gain to feed. Compared to controls, the group fed BOV30 increased (p≤0.03) daily gain (11.8%), gain to feed (8.3%), net energy of the diet (5%), and observed-to-expected DMI (5.2%). Daily weight gain was greater (7.6%, p = 0.05) for heifers fed BOV30 than for heifers fed MON30. Otherwise, differences between the two treatments in DMI, gain to feed, and dietary NE were not statistically significant (p>0.11). Plotting weekly intakes versus THI, observed intake of controls was greater (p<0.05) at THI values ≤77 than ionophore groups. When THI values were greater than 79, DMI of control and MON30 were not different (p = 0.42), although less than that of groups fed lasalocid (p = 0.04). Variation in energy intake was lower (p>0.05) in the ionophores group (CV = 1.7%) than in the control group (CV = 4.5%). Inclusion of ionophores in the diet resulted in relatively minor changes in carcass characteristics. It is concluded that ionophore supplementation did not exacerbate the decline of DM intake in heat-stressed cattle fed a high-energy finishing diet; on the contrary, it stabilised feed intake and favoured feed efficiency. Ionophore supplementation reduced estimated maintenance coefficients around 10% in finishing cattle during a period of heat stress. This effect was greatest for heifers supplemented with 30 mg lasalocid/kg of diet

Effects of Replacing Dry-rolled Corn with Increasing Levels of Corn Dried Distillers Grains with Solubles on Characteristics of Digestion, Microbial Protein Synthesis and Digestible Energy of Diet in Hair Lambs Fed High-concentrate Diets.

Four male lambs (Katahdin; average live weight 25.9±2.9 kg) with "T" type cannulas in the rumen and proximal duodenum were used in a 4×4 Latin square experiment to evaluate the influence of supplemental dry distillers grain with solubles (DDGS) levels (0, 10, 20 and 30%, dry matter basis) in substitution for dry-rolled (DR) corn on characteristics of digestive function and digestible energy (DE) of diet. Treatments did not influence ruminal pH. Substitution of DR corn with DDGS increased ruminal neutral detergent fiber (NDF) digestion (quadratic effect, p<0.01), but decreased ruminal organic matter (OM) digestion (linear effect, p<0.01). Replacing corn with DDGS increased (linear, p≤0.02) duodenal flow of lipids, NDF and feed N. But there were no treatment effects on flow to the small intestine of microbial nitrogen (MN) or microbial N efficiency. The estimated UIP value of DDGS was 44%. Postruminal digestion of OM, starch, lipids and nitrogen (N) were not affected by treatments. Total tract digestion of N increased (linear, p = 0.04) as the DDGS level increased, but DDGS substitution tended to decrease total tract digestion of OM (p = 0.06) and digestion of gross energy (p = 0.08). However, it did not affect the dietary digestible energy (DE, MJ/kg), reflecting the greater gross energy content of DDGS versus DR corn in the replacements. The comparative DE value of DDGS may be considered similar to the DE value of the DR corn it replaced up to 30% in the finishing diets fed to lambs

The Mango Value Network (Mangifera indica L.) in Campeche, Mexico

Objective: Characterize the mango value network in the State of Campeche and identify its problems. Design/methodology/approach: Based on documentary information and 40 semi-structured interviews, the structure of the value network, its key actors, and technologies were identified. Results: Researchers advise to establish high-density orchards (3 333 plants ha-1), although growers accept to increment from 69 to only 278 plants ha-1. New production technologies are required for important cultivars, such as Tommy Atkins, Manila, and creole. Their vegetative growth responds differently to local humidity, rain, and soil conditions, due to their monoembryonic or polyembryonic origin. Limitations of the study/implications:  Producers in the social sector do not keep accounting and production records. An estimate of mango yields, investment, income, and profits was obtained based on the opinion of producers from the social and business sector of Campeche. Findings/conclusions: Social sector producers of mango are willing to grow their orchards with 278 plants ha-1; it is required to evaluate the production technologies of Tommy Atkins, Manila, and creole cultivars, and to estimate the production costs. Private sector growers are choosing to substitute mango for high-density Persian lemon; they also prioritize fruit fly management and commercialization of fruits.Objective: Characterize the mango value network in the State of Campeche and identify its problems. Design/methodology/approach: Based on documentary information and 40 semi-structured interviews, the structure of the value network, its key actors, and technologies were identified. Results: Researchers advise to establish high-density orchards (3 333 plants ha-1), although growers accept to increment from 69 to only 278 plants ha-1. New production technologies are required for important cultivars, such as Tommy Atkins, Manila, and creole. Their vegetative growth responds differently to local humidity, rain, and soil conditions, due to their monoembryonic or polyembryonic origin. Limitations of the study/implications:  Producers in the social sector do not keep accounting and production records. An estimate of mango yields, investment, income, and profits was obtained based on the opinion of producers from the social and business sector of Campeche. Findings/conclusions: Social sector producers of mango are willing to grow their orchards with 278 plants ha-1; it is required to evaluate the production technologies of Tommy Atkins, Manila, and creole cultivars, and to estimate the production costs. Private sector growers are choosing to substitute mango for high-density Persian lemon; they also prioritize fruit fly management and commercialization of fruits

A novel combined scientific and artistic approach for the advanced characterization of interactomes: The akirin/subolesin model

The main objective of this study was to propose a novel methodology to approach challenges in molecular biology. Akirin/Subolesin (AKR/SUB) are vaccine protective antigens and are a model for the study of the interactome due to its conserved function in the regulation of different biological processes such as immunity and development throughout the metazoan. Herein, three visual artists and a music professor collaborated with scientists for the functional characterization of the AKR2 interactome in the regulation of the NF-¿B pathway in human placenta cells. The results served as a methodological proof-of-concept to advance this research area. The results showed new perspectives on unexplored characteristics of AKR2 with functional implications. These results included protein dimerization, the physical interactions with different proteins simultaneously to regulate various biological processes defined by cell type-specific AKR– protein interactions, and how these interactions positively or negatively regulate the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-¿B) signaling pathway in a biological context-dependent manner. These results suggested that AKR2-interacting proteins might constitute suitable secondary transcription factors for cell-and stimulus-specific regulation of NF-¿B. Musical perspective supported AKR/SUB evolutionary conservation in different species and provided new mechanistic insights into the AKR2 interactome. The combined scientific and artistic perspectives resulted in a multidisciplinary approach, advancing our knowledge on AKR/SUB interactome, and provided new insights into the function of AKR2–protein interactions in the regulation of the NF-¿B pathway. Additionally, herein we proposed an algorithm for quantum vaccinomics by focusing on the model proteins AKR/SUB. © 2020 by the authors. Licensee MDPI, Basel, Switzerland

Clinical Prediction Rule for Stratifying Risk of Pulmonary Multidrug-Resistant Tuberculosis

Multidrug-resistant tuberculosis (MDR-TB), resistance to at least isoniazid and rifampin, is a worldwide problem.To develop a clinical prediction rule to stratify risk for MDR-TB among patients with pulmonary tuberculosis.Derivation and internal validation of the rule among adult patients prospectively recruited from 37 health centers (Perú), either a) presenting with a positive acid-fast bacillus smear, or b) had failed therapy or had a relapse within the first 12 months.Among 964 patients, 82 had MDR-TB (prevalence, 8.5%). Variables included were MDR-TB contact within the family, previous tuberculosis, cavitary radiologic pattern, and abnormal lung exam. The area under the receiver-operating curve (AUROC) was 0.76. Selecting a cut-off score of one or greater resulted in a sensitivity of 72.6%, specificity of 62.8%, likelihood ratio (LR) positive of 1.95, and LR negative of 0.44. Similarly, selecting a cut-off score of two or greater resulted in a sensitivity of 60.8%, specificity of 87.5%, LR positive of 4.85, and LR negative of 0.45. Finally, selecting a cut-off score of three or greater resulted in a sensitivity of 45.1%, specificity of 95.3%, LR positive of 9.56, and LR negative of 0.58.A simple clinical prediction rule at presentation can stratify risk for MDR-TB. If further validated, the rule could be used for management decisions in resource-limited areas

La alfabetización matemática y su relación con el intercambio comercial, la escolaridad elemental y el trabajo

En este artículo abordo algunos aspectos de la adquisición del conocimiento y las herramientas matemáticas elementales en diferentes contextos: la educación básica de personas jóvenes y adultas, algunas actividades laborales que no requieren una escolaridad importante, y la experiencia de intercambio comercial que se desarrolla en la cotidianeidad. Mi intención es contribuir a la reflexión sobre los aportes de la educación básica, la experiencia cotidiana y el trabajo a la alfabetización matemática de las personas. Para ilustrar mis afirmaciones, tomo como centro la noción de proporcionalidad. Esta noción cruza la educación básica, es fundamento de la matemática más avanzada y, también, es instrumento de trabajo e interacción en distintos ámbitos de la actividad social. Adelanto que, en México, el sistema educativo para jóvenes y adultos incumple en buena medida un compromiso fundamental: lograr que las personas se apropien de herramientas simbólicas que potencien su pensamiento y su forma de vinculación con el mundo. En cambio, algunas actividades laborales y comerciales contribuyen al desarrollo de conocimientos y habilidades útiles para resolver problemas matemáticos que el propio contexto plantea. Este tipo de aprendizaje, no debe empero olvidarse, es un aprendizaje situado cuyos límites conviene también señalar