Evaluation of fermentative activity of lactic cultures for dehydrated yogurt with the use of different additives

Objective: To evaluate the fermentative activity of dehydrated lactic cultures with the use of various additives and vacuum drying, using yogurt as a model system. Design/methodology/approach: The yogurt was made with commercial lactic cultures (YF-L705 Yo-Flex CHR HANSEN) inoculated in whole milk incubated for 4 h/42°C. The yogurt was centrifuged at 6,000 rpm/15 min/4°C. The supernatant was removed, and the following additives were added to the precipitate: 1) SN, without additives, 2) Glycerol, 3) Calcium carbonate, 4) Yeast extract, 5) Glycerol and calcium carbonate, 6) Glycerol, calcium carbonate and yeast extract. The drying of 6 treatments was done up to 96h inside vacuum desiccators. Weight and moisture loss were recorded at 0, 24, 48, 72 and 96h. The dehydrated portions with the additives 1,2,3,4,5,6 was used as inoculums in milk for the production of yogurt; recording the drop in pH up to 24h and FTIR. As a control, non-dehydrated and lyophilized portion of yogurt were used. Results: The drying time at constant weight was 3 days. Dehydrated cultures containing yeast extract and calcium carbonate are associated with faster milk fermentation activity (p ≤ 0.05). Yoghurts manufactured with fresh cultures take 4 hours to ferment, dehydrated ones take over 12 hours. Infrared spectra show that yogurts produced with fresh or dried strains are of similar qualities. Study limitations/implications: The fermentative activity in dehydrated foods improves when alkalis are added, such as calcium carbonate, which is an antacid and releases CO2 upon contact with water and acid, stimulating anaerobiosis. Infrared spectra show that yogurts produced with fresh or dried strains are of similar qualities. Findings/conclusions: The best model to present the fermentation pH change curve is a Boltzman sigmoidal function. Yogurts with fresh or dried cultures differed in the time at which the milk is fermented. The fermentative activity in dehydrated foods improves when alkalis are added, such as calcium carbonate, which is an antacid and releases CO2 on contact with water, stimulating anaerobiosis. Infrared spectra show that yogurts produced with fresh or dried strains are of similar qualities.Objective: To evaluate the fermentative activity of dehydrated lactic cultures with the use of different additives and vacuum desiccation, using yogurt as model system. Design/methodology/approach: The yogurt was elaborated with commercial lactic cultures (YF-L705 Yo-Flex CHR HANSEN) and whole milk incubated at 42 °C for 4 h. Yogurt was centrifuged at 6,000 rpm/15 min/4 °C. The supernatant was eliminated and with the precipitate, 6 treatments were established by addition of additives: T1, Without additive, T2, Glycerol, T3, Calcium carbonate, T4, Yeast extract, T5, Glycerol, and T6, Glycerol, Calcium carbonate and Yeast extract; non-dehydrated and freeze-dried yogurt was used as control: T7 and T8, respectively. The precipitate of the treatments with additives was dehydrated in a silica gel in a desiccator and under vacuum conditions. The weight loss was recorded at 0, 24, 48, 72 and 96 h. The precipitate with dehydrated additives was used as milk inoculates for yogurt elaboration. The change of pH was recorded at 0, 1, 2, 3, 4, 5, 6, 7, 8 and 24 h. With the pH and the fermentation time, a model was established to present the change curve in fermentation pH and the Fourier transform infrared spectroscopy (FTIR). Results: The drying time to constant weight was 3 days. The fermentation pH change curve was a Boltzman sigmoidal function and analysis of variance was conducted with its parameters to assess the different fermentation speeds of the different treatments. The dehydrated cultures with Yeast Extract and Calcium Carbonate are associated with a higher fermentation activity of the milk (p < 0.05). The yogurts manufactured with fresh cultures take 4 to 5 h to ferment and the dehydrated ones take more than 10 h. The infrared spectra showed that the quality of the yogurts produced with fresh or dry cultures are similar, which agrees with other studies. Limitations on study/implications: The dehydrated inoculated with the additives can be used to make yogurt with similar quality as to when inoculate with fresh culture is used, with the disadvantage of the fermentation time being longer. It is possible that this methodology can be used to dehydrate other inoculates based on lactic bacteria, but their effectiveness would have to be assessed experimentally. Findings/conclusions: This study shows an alternative method to dehydrate lactic bacteria in the laboratory with equipment of relatively easy access for any laborator

Luteolytic failure as the cause of low efficiency in synchronization with prostaglandins in cows under tropical grazing

Our objective was to determine the cause of the low response in the exclusive use of prostaglandin in synchronization programs in cows under tropical grazing compared to the use of progesterone (CIDR). Thirty-five cows with the presence of CL were randomly distributed: first group (GPG; n=23), synchronized with two doses of PGF2α (25 mg, Dinoprost®), with an interval of 12 days. The second group (GCIDR; n=12) synchronized with an intravaginal device (1.9 g progesterone), 2 mg estradiol benzoate and 50 mg progesterone), at day 7 a dose of PGF2α (pm) was administered and at day 8 the CIDR (am) was withdrawn. CL regression, luteolitic failure, progesterone concentration and CL size were determined. The data were subjected to normality test, then to Mann-Whitney U test or independent t student test and chi square. Finding that only 82.6% (19/23) of GPG cows at the second dose of prostaglandins have functional CL (<1 ng/ml of progesterone). Obtaining only in 43.5% of the cows a regression of the CL in the GPG, vs. 91.7% in GCIDR (P=0.0001). In addition, GPG cows showed luteolytic failure of 39.1% and asynchrony of 17.4%. It is concluded, a low efficiency of prostaglandins on the synchrony and regression of CL (luteolitic failure) in cows fed under tropical grazing, attributed to the low efficiency in synchronization programs.Objective: To determine the reason for the low response to the exclusive use of prostaglandin in synchronization programs in cows under tropical grazing compared with the use of progesterone (CIDR). Design/Methodology: Thirty-five cows with CL were randomly distributed in two groups. The first group (GPG; n=23) was synchronized using two doses of PGF2α (25 mg of Dinoprost®) with a 12-day interval. The second group (GCIDR; n=12) was synchronized with an intravaginal device (1.9 g of progesterone, 2 mg of estradiol benzoate, and 50 mg of progesterone); a PGF2α (pm) dose was applied on day 7, before removing the CIDR (am) on day 8. CL regression, luteolytic failure, progesterone concentration, and CL size were determined. Data was subjected to a normality test, followed by the Mann-Whitney U test or independent Student's t-test and chi-square test. Results: Only 82.6 % (19 out of 23) of the GPG cows that received the second dose of prostaglandins have a functional CL (<1 ng mL-1 of progesterone). The CL recorded a regression only in 43.5% of the cows in GPG vs. 91.7% in GCIDR (P=0.0001). In addition, GPG cows showed a luteolytic failure of 39.1% and an asynchrony of 17.4%. Conclusions: The low effectiveness of prostaglandin on the synchrony and regression of the CL (luteolytic failure) in cows fed under tropical grazing can be attributed to the low efficiency of the synchronization programs

EDUCACIÓN AMBIENTAL Y SOCIEDAD. SABERES LOCALES PARA EL DESARROLLO Y LA SUSTENTABILIDAD

Este texto contribuye al análisis científico de varias áreas del conocimiento como la filosofía social, la patología, la educación para el cuidado del medio ambiente y la sustentabilidad que inciden en diversas unidades de aprendizaje de la Licenciatura en Educación para la Salud y de la Maestría en Sociología de la SaludLas comunidades indígenas de la sierra norte de Oaxaca México, habitan un territorio extenso de biodiversidad. Sin que sea una área protegida y sustentable, la propia naturaleza de la región ofrece a sus visitantes la riqueza de la vegetación caracterizada por sus especies endémicas que componen un paisaje de suma belleza

Evaluación de la degradación, consumo voluntario y comportamiento productivo de ovinos alimentados con saccharina y maíz/Evaluation of degradation, voluntary consumption and productive behavior of sheep fed with saccharin and corn

El objetivo del estudio fue evaluar el consumo voluntario y el comportamiento productivo de ovinos ali- mentados con una dieta de Saccharina con maíz molido (MM), así como la degradación ruminal in situ en bovinos. Se analizó el consumo voluntario del alimento y la ganancia de peso en 24 ovinos Katahdin x Pelibuey en crecimiento, con un peso inicial promedio de 17 ± 3.0 kg, alimentados con cuatro dietas (10, 20, 30 y 40 % de MM). En dos bovinos canulados se evaluó la degradación efectiva (DE) de la materia seca (MS) y de la bra detergente neutro (FDN) a las 0, 2, 4, 6, 12, 24, 36 h como factor A y cinco niveles de MM (0, 10, 20, 30 y 40 %) como factor B, para lo cual se utilizó una distribución factorial en un diseño completamente al azar. El tratamiento con 10 % de MM presentó los valores más altos de degradación in situ, tanto para la MS como para la FDN, el cual estuvo relacionado con un alto nivel de fracción soluble y una baja fracción no degradable. Las fracciones no degradables, las tasas de degradación, y la degradación efectiva, fueron similares (p ≥ 0.05). La degradación efectiva aumentó a partir del tratamiento con 10 % de MM. Los ovinos alimentados con 40 % de MM tuvieron el mayor consumo (70.7 kg) y la mayor ganancia de peso (0.124 kg). La aportación de maíz molido a la dieta, mejoró la degradación in situ en bovinos, el consumo y las ganancias de peso de ovinos

Comportamiento de toretes en pastos tropicales suplementados con caña de azúcar y enzimas fibrolíticas

Sugar cane as complementary forage to steers grazing bigalta grass was evaluated in different treatments. Thirty two steers (initial BW 220+- 63 kg) were used. Treatments were 1) Control, grazing + 1.0 kg concentrate animal day-1 2) grazing + 1.0 kg concentrate animal day-1+ saccharina, 3) grazing + 1.0 kg concentrate animal day-1+ whole sugarcane + urea (1.5% humid base) + fibrolytic enzymes (Fibrozyme) 15 g animal day-,1 and 4) grazing + 1.0 kg concentrate animal day-1 + whole sugarcane + urea (1.5% humid base). Steers receiving dietary supplements were housed in individual pens daily from 0700 to 1500, to determine individual feed intake, whereas animals in the control group remained in the paddock. No differences in forage DM intake and total DM intake between treatments were observed (P>0.05), nor in digestibility between treatments including sugar cane. Intake of sugar cane processed as saccharina was 1.04 kg day-1, being 1.13 kg and 1.07 for sugar cane with or without fibrolytic enzymes. Average daily gain was similar among treatments (P>0.05), with 566 g d-1 in control group, 580 g day-1 saccharine, and 584 and 559 g day-1 for sugar cane with or without enzyme. Sugar cane processed as saccharina or treated with urea with or without fibrolytic enzymes did not improve steers', performance in grazing conditions.Se evaluó la caña de azúcar con diferentes tratamientos como forraje suplementario a bovinos en pastoreo con predominancia de pasto bigalta. Se utilizaron 32 toretes, con peso vivo inicial de 220 ± 63 kg. Los tratamientos estudiados fueron: 1) Testigo, que consistió en pastoreo + 1.0 kg de concentrado animal día-1, 2) Pastoreo + saccharina + 1.0 kg de concentrado animal día-1, 3) Pastoreo + caña de azúcar integral + urea (1.5 % base húmeda) + 1.0 kg de concentrado + 15 g de enzimas fibrolíticas (Fibrozyme) animal día-1, 4) Pastoreo + caña de azúcar integral + urea (1.5 % base húmeda) + 1.0 kg de concentrado animal día-1. El grupo testigo permaneció en la pradera, mientras que los demás se alojaron en corraletas individuales de 0700 a 1500, donde se cuantificó el consumo de suplemento, saccharina y caña integral. No hubo diferencias en consumo de pasto y consumo total, entre tratamientos (P>0.05), ni en digestibilidad para los tratamientos que consumieron caña. El consumo de materia seca de caña de azúcar como saccharina fue 1.04, 1.13 con enzima y 1.07 kg d-1 sin enzima. La ganancia de peso no fue diferente entre tratamientos (P>0.05) siendo de 566 g animal día-1 para el testigo, 580 g animal día-1 con saccharina, 584 y 559 g animal día-1 para la caña de azúcar con o sin enzima, respectivamente. El uso de caña de azúcar procesada como saccharina, o con la adición de urea con o sin enzimas fibrolíticas, no mejoró el comportamiento productivo de toretes en pastoreo

Composición química, actividad antibacteriana del aceite esencial de Citrus sinensis L. (Na­ranja dulce) y formulación de una forma farmacéutica

This study aimed to characterize the chemical components of essential oil of Citrus sinensis L., determine its antibacterial activity and make dosageforms, mainly for local use. The essential oil was obtained from the dried leaves of the selected species, using a hydrodistillation system with water steam sweep; tests were conducted miscibility and determination of physical constants, such as specific gravity, refractive index and optical rotation. The chemical composition was determined by Gas Chromatography/Mass Spectrometry (CG/EM), standing out in the sugiero: chromatogram spectral signals in the elucidating: Limonene, beta-linalool, decanal and 2 (10)-pinene(1S,5S)-(-)-. The determination of antibacterial activity in vitro was tested by agar diffusion method and the formation of inhibition halos against strains of Gram (+), as Staphylococcus aureus ATCC 25,933 and Staphylococcus epidermidis, demonstrating significant antibacterial activity at concentrations 100 and 50% respectively, but not with Gram (-): Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa ATCC 27853. These results gave us the guidance to design dosage forms for local use, formulated: a carbomer based gel, a lotion based in ethanol and isopropyl alcohol and mouthwash. The results of the stability studies of the formulations, as well as tolerance and irritability with human tissue of the products show favorable results for use in skin diseases like acne, and in the case of mouthwash as a good oral antiseptic. The study has revealed that the essential oil of Citrus sinensis L. has antibacterial activity against strains of Staphylococcus aureus ATCC 25,933 and Staphylococcus epidermidis, also allow the preparation of pharmaceutical forms for local use.El presente estudio tuvo como objetivos, caracterizar los componentes químicos del aceite esencial de Citrus sinensis L. (Naranja dulce), determinar su actividad antibacteriana y formular formas farmacéuticas, principalmente de uso local. El aceite esencial se obtuvo del pericarpio , de la especie seleccionada, utilizando un sistema de hidrodestilación con arrastre de vapor de agua; así mismo, se realizaron los ensayos de miscibilidad y determinación de constantes físicas, como: gravedad específica, índice de refracción y rotación óptica. La composición química se determinó por Cromatografía de Gases/Espectrometría de Masa (CG/EM), destacándose en el cromatograma señales espectrales de identificación en la elucidación de: Limoneno, ß-linalol, decanal y 2(10)-pineno(1S,5S)-(-)-. La determinación de la actividad antibacteriana in vitro se realizó por el método de difusión en agar y en la formación de halos de inhibición contra cepas de microorganismos Gram (+), como: Staphylococcus aureus ATCC 25933 y Staphylococcus epidermidis, demostrando actividad antibacteriana significativa a concentraciones de 100 y 50%, respectivamente; no así con los microorganismos Gram (-): Bacillus subtilis, Escherichia coli y Pseudomonas aeruginosa ATCC 27853. Estos resul¬tados nos dieron la orientación para diseñar formas farmacéuticas de uso local, formulándose: un gel con base de carbomer, una loción con base de etanol y alcohol isopropílico, así como un colutorio. Los resultados de los estudios de estabilidad de las formu¬laciones, así como de tolerancia e irritabilidad con el tejido humano de los productos nos muestran resultados favorables para su utilización en enfermedades de la piel, como el acné, y en el caso del colutorio como un buen antiséptico bucal. El estudio ha permitido concluir que el aceite esencial de Citrus sinensis L. posee actividad antibacteriana contra cepas de Staphylococcus aureus ATCC 25933 y Staphylococcus epidermidis, además de permitir la elaboración de formas farmacéuticas de uso local

Comprehensive study reveals phenotypic heterogeneity in Klebsiella pneumoniae species complex isolates

Abstract Here, we conducted a comprehensive analysis of 356 Klebsiella pneumoniae species complex (KpSC) isolates that were classified as classical (cl), presumptive hypervirulent (p-hv) and hypermucoviscous-like (hmv-like). Overall, K. pneumoniae (82.3%), K. variicola (2.5%) and K. quasipneumoniae (2.5%) were identified. These isolates comprised 321 cl-KpSC, 7 p-hv-KpSC and 18 hmv-like-KpSC. A large proportion of cl-KpSC isolates were extended-spectrum-β-lactamases (ESBLs)-producers (64.4%) and 3.4% of isolates were colistin-resistant carrying carbapenemase and ESBL genes. All p-hv-KpSC showed an antibiotic susceptible phenotype and hmv-like isolates were found to be ESBL-producers (8/18). Assays for capsule production and capsule-dependent virulence phenotypes and whole-genome sequencing (WGS) were performed in a subset of isolates. Capsule amount differed in all p-hv strains and hmv-like produced higher capsule amounts than cl strains; these variations had important implications in phagocytosis and virulence. Murine sepsis model showed that most cl strains were nonlethal and the hmv-like caused 100% mortality with 3 × 108 CFUs. Unexpectedly, 3/7 (42.9%) of p-hv strains required 108 CFUs to cause 100% mortality (atypical hypervirulent), and 4/7 (57.1%) strains were considered truly hypervirulent (hv). Genomic analyses confirmed the diverse population, including isolates belonging to hv clonal groups (CG) CG23, CG86, CG380 and CG25 (this corresponded to the ST3999 a novel hv clone) and MDR clones such as CG258 and CG147 (ST392) among others. We noted that the hmv-like and hv-ST3999 isolates showed a close phylogenetic relationship with cl-MDR K. pneumoniae. The information collected here is important to understand the evolution of clinically important phenotypes such as hypervirulent and ESBL-producing-hypermucoviscous-like amongst the KpSC in Mexican healthcare settings. Likewise, this study shows that mgrB inactivation is the main mechanism of colistin resistance in K. pneumoniae isolates from Mexico

Curiosity's rover environmental monitoring station: Overview of the first 100 sols

In the first 100 Martian solar days (sols) of the Mars Science Laboratory mission, the Rover Environmental Monitoring Station (REMS) measured the seasonally evolving diurnal cycles of ultraviolet radiation, atmospheric pressure, air temperature, ground temperature, relative humidity, and wind within Gale Crater on Mars. As an introduction to several REMS‐based articles in this issue, we provide an overview of the design and performance of the REMS sensors and discuss our approach to mitigating some of the difficulties we encountered following landing, including the loss of one of the two wind sensors. We discuss the REMS data set in the context of other Mars Science Laboratory instruments and observations and describe how an enhanced observing strategy greatly increased the amount of REMS data returned in the first 100 sols, providing complete coverage of the diurnal cycle every 4 to 6 sols. Finally, we provide a brief overview of key science results from the first 100 sols. We found Gale to be very dry, never reaching saturation relative humidities, subject to larger diurnal surface pressure variations than seen by any previous lander on Mars, air temperatures consistent with model predictions and abundant short timescale variability, and surface temperatures responsive to changes in surface properties and suggestive of subsurface layering. Key Points Introduction to the REMS results on MSL mission Overiview of the sensor information Overview of operational constraintsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108302/1/jgre20265.pd

The roles played by the British Chiefs of Staff Committee in the evolution of Britain's nuclear weapon planning and policy-making, 1945-55

SIGLEAvailable from British Library Document Supply Centre- DSC:DX84631 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Discovering HIV related information by means of association rules and machine learning

Acquired immunodeficiency syndrome (AIDS) is still one of the main health problems worldwide. It is therefore essential to keep making progress in improving the prognosis and quality of life of affected patients. One way to advance along this pathway is to uncover connections between other disorders associated with HIV/AIDS-so that they can be anticipated and possibly mitigated. We propose to achieve this by using Association Rules (ARs). They allow us to represent the dependencies between a number of diseases and other specific diseases. However, classical techniques systematically generate every AR meeting some minimal conditions on data frequency, hence generating a vast amount of uninteresting ARs, which need to be filtered out. The lack of manually annotated ARs has favored unsupervised filtering, even though they produce limited results. In this paper, we propose a semi-supervised system, able to identify relevant ARs among HIV-related diseases with a minimal amount of annotated training data. Our system has been able to extract a good number of relationships between HIV-related diseases that have been previously detected in the literature but are scattered and are often little known. Furthermore, a number of plausible new relationships have shown up which deserve further investigation by qualified medical experts