Sol Gel-Derived SBA-16 Mesoporous Material

The aim of this article is to review current knowledge related to the synthesis and characterization of sol gel-derived SBA-16 mesoporous silicas, as well as a review of the state of the art in this issue, to take stock of knowledge about current and future applications. The ease of the method of preparation, the orderly structure, size and shape of their pores and control, all these achievable through simple changes in the method of synthesis, makes SBA-16 a very versatile material, potentially applicable in many areas of science and molecular engineering of materials

Overview of Phosphorus Effect in Molybdenum-Based Hydrotreating Catalysts Supported on Ordered Mesoporous Siliceous Materials

This chapter presents an overview of the literature on the effect of phosphorus modification of ordered mesoporous silica (OMS) such as MCM-41, HMS, SBA-15, and SBA-16 to be used as supports for hydrotreating catalysts based on transition metal sulfides (TMS). The influence of the support modification with variable quantities of phosphorus on the performance for hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) reactions is outlined and discussed considering the changes in the structural and textural properties (SBET), acidity, reducibility, etc., of the substrate brought about by phosphorus incorporation

Respuesta fisiológica y productiva de novillos engordados con un sistema de enfriamiento a espacio abierto en un clima árido y seco

Evaluation of the effects of an open space cooling system on weight gain, respiration rate and serum thyroid hormone (T3 and T4) levels in feedlot steers was done using 60 Holstein steers (344 kg) allotted randomly in two treatments: a control with only shade in the corral (n=30), and a cooling with an open space cooling system (n=30). Daily maximum temperature-humidity index (THI) ranged from 82 to 88 during the 12-week study period. The open space cooling system consisted of a fan with 2.4 m diameter blade that displaced 1,416 m3 of air per minute and had a 90º oscillation range, and sprinklers. The fan was installed at 8 m distance on the south side of the shade. Water discharge was 12 L per minute over a 7 h period. Body weight and thyroid hormone levels were measured every two weeks and respiration rate twice a week (1400). Data were analyzed by repeated measures, including initial weight as a covariate. Daily weight gain was different (PCon objeto de evaluar el efecto de un sistema de enfriamiento a espacio abierto sobre la ganancia de peso, frecuencia de respiración y niveles sanguíneos de triiodotironina (T3) y tiroxina (T4) durante el verano, 60 novillos Holstein fueron asignados aleatoriamente a un grupo testigo con únicamente sombra y un segundo grupo con sombra, más enfriamiento. Durante el experimento se registró un Índice de temperatura-humedad máximo que oscilo entre 82 a 88. El sistema de enfriamiento colocado a 8 m a partir de la sombra, consistió de una hélice de 2.4 m de diámetro produciendo 1,416 m3/min de aire con una rotación de 90° y un flujo de agua de 12 L/min. El peso corporal y los niveles de hormonas fueron registrados cada dos semanas, mientras la frecuencia de respiración (1400) en dos ocasiones por semana. Los datos fueron analizados con un diseño de mediciones repetidas, incluyendo el peso inicial como covariable. La ganancia de peso fue mayor (

Enfriamiento al inicio de verano para mitigar el estrés por calor en vacas Holstein del noroeste de México

The objective of this study was to determine the physiological, endocrine and productive response in lactating dairy cows under several series of artificial cooling at the beginning of the summer (June to July, 2011). Fourteen multiparous Holstein cows were assigned in one of two treatments: Cooling (C) before milking (0700 and 1700 h) and additional cooling (AC) each 2 h (from 0700 to 1700h) in the holding pen of the milking parlor. Milk yield (MY), and serum levels of prolactin (PRL) and IGF1 were measured. Rectal temperature and respiratory rate were registered and included as physiological markers of heat stress. Ambient temperature and relative humidity were also collected and used to calculate temperature-humidity index (THI). Both markers of heat stress showed a significant interaction (P<0.001) between treatment and time/week, which were lower in AC treatment (-3.8 breaths per minute and -0.2 °C) during wk 6 and 7. Serum levels of PRL were higher under additional cooling (AC: 35.1 vs C: 29.4 ng/ml; P=0.004), while  IGF1 serum levels showed variation only through the sampling weeks (P=0.014). The MY increased (P<0.05) in AC only during wk 6 (+3.1 kg/d) and 7 (+3.1 kg/d). It was concluded that additional cooling at the beginning of the summer reduced heat stress in dairy cows allowing a better productive performance at the end of the study because such effect relied on the variable time/week.El objetivo de este estudio fue determinar la respuesta fisiológica, endócrina y productiva en vacas lactantes sometidas a varias series de enfriamiento artificial al inicio de verano (junio a julio de 2011). Se asignaron 14 vacas Holstein multíparas a uno de dos tratamientos: enfriamiento (E) antes de la ordeña (0700 y 1700 h) y enfriamiento adicional (EA) cada 2 h de 0700 a 1700 h en el corral de espera a la ordeña. Se midió la producción de leche (PL), niveles de prolactina (PRL) e IGF1, mientras que la temperatura rectal y frecuencia respiratoria fueron registradas y consideradas como indicadores fisiológicos de estrés por calor. La temperatura ambiental y humedad relativa también fueron registradas y utilizadas para calcular el índice de temperatura-humedad (ITH). Los indicadores de estrés calórico mostraron una interacción significativa (P<0.001) entre tratamiento y tiempo/semana, los cuales fueron menores con EA (-3.8 respiraciones por minuto y -0.2 °C) sólo durante las semanas 6 y 7. Los niveles séricos de PRL fueron mayores bajo enfriamiento adicional (EA: 35.1 vs E: 29.4 ng/ml; P=0.004), mientras que los de IGF1 solo variaron a través de las semanas de muestreo (P=0.014). La PL se incrementó (P<0.05) en EA durante las semanas 6 (+3.1kg/día) y 7 (+3.1 kg/día). Se concluye que la mayor frecuencia de baños mitigó la condición de estrés calórico al inicio de verano, permitiéndole a la vaca expresar un mejor desempeño productivo al final del estudio, ya que dicho efecto dependió de la variable tiempo/semana

HAp Nanofibers Grown with Crystalline Preferential Orientation and Its Influence in Mechanical Properties of Organic-Inorganic Composite Materials

There are several synthesis techniques to obtain hydroxyapatite (HAp). Some use surfactant agents, amino acids or halogen salts to control structural nucleation and crystal growth. In others, the use of hydrothermal process to carry out the reaction is effective for HAp synthesis. Microwave-assisted hydrothermal method (MAHM) has been successfully applied in the synthesis of HAp nanostructures, which present well-defined morphologies, high crystallinity and high purity. This is important because nano-HAp is attracting interest as a biomaterial for use in prosthetic applications due to its similarity in size, crystallinity and chemical composition with human hard tissue. In this chapter, developments in obtaining HAp nanofibers, with a crystal growth with preferential orientation, as well as morphology control achieved by using the MAHM is discussed. Also, the synthesized fibers were used to cast ceramics with controlled and interconnected porosity through the modified gelcasting process. Then, these HAp ceramics were impregnated with a water solution of gelatin in order to obtain an organic-inorganic composite material, similar to natural bone tissue. The maximum compressive strengths were determined and the composite materials showed mechanical properties that make them suitable to be used as bone tissue implants

Interaction of HLA Class II rs9272219 and TMPO rs17028450 (Arg690Cys) Variants Affects Neuromyelitis Optica Spectrum Disorder Susceptibility in an Admixed Mexican Population

Neuromyelitis Optica Spectrum Disorder (NMOSD) is a demyelinating autoimmune disease of the central nervous system, more prevalent in individuals of non-European ancestry. Few studies have analyzed genetic risk factors in NMOSD, and HLA class II gene variation has been associated NMOSD risk in various populations including Mexicans. Thymopoietin (TMPO) has not been tested as a candidate gene for NMOSD or other autoimmune disease, however, experimental evidence suggests this gene may be involved in negative selection of autoreactive T cells and autoimmunity. We thus investigated whether the missense TMPO variant rs17028450 (Arg630Cys, frequent in Latin America) is associated with NMOSD, and whether this variant shows an interaction with HLA-class II rs9272219, previously associated with NMOSD risk. A total of 119 Mexican NMOSD patients, 1208 controls and 357 Native Mexican individuals were included. The HLA rs9272219 "T" risk allele frequency ranged from 21 to 68%, while the rs17028450 "T" minor allele frequency was as high as 18% in Native Mexican groups. Both rs9272219 and rs17028450 were significantly associated with NMOSD risk under additive models (OR = 2.48; p = 8 × 10(-10) and OR = 1.59; p = 0.0075, respectively), and a significant interaction between both variants was identified with logistic regression models (p = 0.048). Individuals bearing both risk alleles had an estimated 3.9-fold increased risk of NMOSD. To our knowledge, this is the first study reporting an association of TMPO gene variation with an autoimmune disorder and the interaction of specific susceptibility gene variants, that may contribute to the genetic architecture of NMOSD in admixed Latin American populations

Specifying enough light to feel reassured on pedestrian footpaths

This article discusses lighting for pedestrians and how investigation of reassurance might lead toward an understanding of the right amount of light. A conventional approach is to evaluate reassurance after dark under road lighting of different illuminance: this tends to show the trivial result that higher illuminances enhance reassurance, and that alone does not enable an optimum light level to be identified. One reason is that the category rating procedure widely used is prone to stimulus range bias; experimental results are presented that demonstrate stimulus range bias in reassurance evaluations. This article also recommends alternative methods for future research. One such method is the day–dark rating approach, which does not tend toward ever higher illuminances, and results are presented of two studies using this method

Disentangling signatures of selection before and after European colonization in latin Americans

Throughout human evolutionary history, large-scale migrations have led to intermixing (i.e., admixture) between previously separated human groups. Although classical and recent work have shown that studying admixture can yield novel historical insights, the extent to which this process contributed to adaptation remains underexplored. Here, we introduce a novel statistical model, specific to admixed populations, that identifies loci under selection while determining whether the selection likely occurred post-admixture or prior to admixture in one of the ancestral source populations. Through extensive simulations, we show that this method is able to detect selection, even in recently formed admixed populations, and to accurately differentiate between selection occurring in the ancestral or admixed population. We apply this method to genome-wide SNP data of ∼4,000 individuals in five admixed Latin American cohorts from Brazil, Chile, Colombia, Mexico, and Peru. Our approach replicates previous reports of selection in the human leukocyte antigen region that are consistent with selection post-admixture. We also report novel signals of selection in genomic regions spanning 47 genes, reinforcing many of these signals with an alternative, commonly used local-ancestry-inference approach. These signals include several genes involved in immunity, which may reflect responses to endemic pathogens of the Americas and to the challenge of infectious disease brought by European contact. In addition, some of the strongest signals inferred to be under selection in the Native American ancestral groups of modern Latin Americans overlap with genes implicated in energy metabolism phenotypes, plausibly reflecting adaptations to novel dietary sources available in the Americas

Native American ancestry significantly contributes to neuromyelitis optica susceptibility in the admixed Mexican population

Neuromyelitis Optica (NMO) is an autoimmune disease with a higher prevalence in non-European populations. Because the Mexican population resulted from the admixture between mainly Native American and European populations, we used genome-wide microarray, HLA high-resolution typing and AQP4 gene sequencing data to analyze genetic ancestry and to seek genetic variants conferring NMO susceptibility in admixed Mexican patients. A total of 164 Mexican NMO patients and 1,208 controls were included. On average, NMO patients had a higher proportion of Native American ancestry than controls (68.1% vs 58.6%; p = 5 × 10–6). GWAS identified a HLA region associated with NMO, led by rs9272219 (OR = 2.48, P = 8 × 10–10). Class II HLA alleles HLA-DQB1*03:01, -DRB1*08:02, -DRB1*16:02, -DRB1*14:06 and -DQB1*04:02 showed the most significant associations with NMO risk. Local ancestry estimates suggest that all the NMO-associated alleles within the HLA region are of Native American origin. No novel or missense variants in the AQP4 gene were found in Mexican patients with NMO or multiple sclerosis. To our knowledge, this is the first study supporting the notion that Native American ancestry significantly contributes to NMO susceptibility in an admixed population, and is consistent with differences in NMO epidemiology in Mexico and Latin America.Fil: Romero Hidalgo, Sandra. Instituto Nacional de Medicina Genómica; MéxicoFil: Flores Rivera, José. Instituto Nacional de Neurología y Neurocirugía; MéxicoFil: Rivas Alonso, Verónica. Instituto Nacional de Neurología y Neurocirugía; MéxicoFil: Barquera, Rodrigo. Max Planck Institute For The Science Of Human History; Alemania. Instituto Nacional de Antropología e Historia; MéxicoFil: Villarreal Molina, María Teresa. Instituto Nacional de Medicina Genómica; MéxicoFil: Antuna Puente, Bárbara. Instituto Nacional de Medicina Genómica; MéxicoFil: Macias Kauffer, Luis Rodrigo. Universidad Nacional Autónoma de México; MéxicoFil: Villalobos Comparán, Marisela. Instituto Nacional de Medicina Genómica; MéxicoFil: Ortiz Maldonado, Jair. Instituto Nacional de Neurología y Neurocirugía; MéxicoFil: Yu, Neng. American Red Cross; Estados UnidosFil: Lebedeva, Tatiana V.. American Red Cross; Estados UnidosFil: Alosco, Sharon M.. American Red Cross; Estados UnidosFil: García Rodríguez, Juan Daniel. Instituto Nacional de Medicina Genómica; MéxicoFil: González Torres, Carolina. Instituto Nacional de Medicina Genómica; MéxicoFil: Rosas Madrigal, Sandra. Instituto Nacional de Medicina Genómica; MéxicoFil: Ordoñez, Graciela. Neuroimmunología, Instituto Nacional de Neurología y Neurocirugía; MéxicoFil: Guerrero Camacho, Jorge Luis. Instituto Nacional de Neurología y Neurocirugía; MéxicoFil: Treviño Frenk, Irene. American British Cowdray Medical Center; México. Instituto Nacional de la Nutrición Salvador Zubiran; MéxicoFil: Escamilla Tilch, Monica. Instituto Nacional de la Nutrición Salvador Zubiran; MéxicoFil: García Lechuga, Maricela. Instituto Nacional de la Nutrición Salvador Zubiran; MéxicoFil: Tovar Méndez, Víctor Hugo. Instituto Nacional de la Nutrición Salvador Zubiran; MéxicoFil: Pacheco Ubaldo, Hanna. Instituto Nacional de Antropología E Historia. Escuela Nacional de Antropología E Historia; MéxicoFil: Acuña Alonzo, Victor. Instituto Nacional de Antropología E Historia. Escuela Nacional de Antropología E Historia; MéxicoFil: Bortolini, María Cátira. Universidade Federal do Rio Grande do Sul; BrasilFil: Gallo, Carla. Universidad Peruana Cayetano Heredia; PerúFil: Bedoya Berrío, Gabriel. Universidad de Antioquia; ColombiaFil: Rothhammer, Francisco. Universidad de Tarapacá; ChileFil: Gonzalez-Jose, Rolando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico de Ciencias Sociales y Humanas; ArgentinaFil: Ruiz Linares, Andrés. Colegio Universitario de Londres; Reino UnidoFil: Canizales Quinteros, Samuel. Universidad Nacional Autónoma de México; MéxicoFil: Yunis, Edmond. Dana Farber Cancer Institute; Estados UnidosFil: Granados, Julio. Instituto Nacional de la Nutrición Salvador Zubiran; MéxicoFil: Corona, Teresa. Instituto Nacional de Neurología y Neurocirugía; Méxic

Mendelian Randomization Analysis of the Relationship Between Native American Ancestry and Gallbladder Cancer Risk

Background A strong association between the proportion of Native American ancestry and the risk of gallbladder cancer (GBC) has been reported in observational studies. Chileans show the highest incidence of GBC worldwide, and the Mapuche are the largest Native American people in Chile. We set out to investigate the causal association between Native American Mapuche ancestry and GBC risk, and the possible mediating effects of gallstone disease and body mass index (BMI) on this association. Methods Markers of Mapuche ancestry were selected based on the informativeness for assignment measure and then used as instrumental variables in two-sample mendelian randomization (MR) analyses and complementary sensitivity analyses. Result We found evidence of a causal effect of Mapuche ancestry on GBC risk (inverse variance-weighted (IVW) risk increase of 0.8% for every 1% increase in Mapuche ancestry proportion, 95% CI 0.4% to 1.2%, p = 6.6×10-5). Mapuche ancestry was also causally linked to gallstone disease (IVW risk increase of 3.6% per 1% increase in Mapuche proportion, 95% CI 3.1% to 4.0%, p = 1.0×10-59), suggesting a mediating effect of gallstones in the relationship between Mapuche ancestry and GBC. In contrast, the proportion of Mapuche ancestry showed a negative causal effect on BMI (IVW estimate -0.006 kg/m2 per 1% increase in Mapuche proportion, 95% CI -0.009 to -0.003, p = 4.4×10-5). Conclusions The results presented here may have significant implications for GBC prevention and are important for future admixture mapping studies. Given that the association between Mapuche ancestry and GBC risk previously noted in observational studies appears to be causal, primary and secondary prevention strategies that take into account the individual proportion of Mapuche ancestry could be particularly efficient