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1.
Chemosphere ; 247: 125897, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31972489

RESUMO

Composites of polypeptidylated hemoglobin supported on different iron oxide weights (0.5:1 and 1:1) were developed and demonstrated to function as efficient adsorbents for Eriochrome black-T dye removal. The synthesis of these adsorbents were performed through N-carboxyanhydride (NCA) polymerization at low temperature (4 °C) and near-neutral pH for 24 h followed by chemical co-precipitation. The synthesized adsorbents were found to exhibit BET surface area (54-87 m2/g), pore volume (0.30-0.35 cm3/g), average pore diameter (160-218 Å) and average pore width (136-171 Å). The developed adsorbents were tested in a batch dye adsorption system. Adsorption was found to follow pseudo-second order kinetics and the Langmuir adsorption capacities were 123, 204 and 217 mg/g for Fe3O4, 0.5:1 and 1:1 adsorbent samples, respectively. Chemical regeneration was successfully carried out using methanol and the reusability of the adsorbents were demonstrated with a decrease in adsorption capacities from ∼49 to ∼33 mg/g after the fourth reuse.

2.
Food Sci Nutr ; 7(1): 3-13, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30680154

RESUMO

Background: Agave syrups are natural sweeteners that are highly desirable for human consumption because they have low glycemic index. In this work, we explored the potential of 1H-NMR-Chemometrics as a useful tool in the identification and differentiation of Agave syrups. Also, we evaluated the phytochemical screening and antioxidant capacity of Agave syrup compared to other natural sweeteners. Results: The phytochemical screening stands out for Agave syrups containing higher levels of metabolites with antioxidant activity, mainly saponins, glycosides, and terpenoids. Agave syrup antioxidant activity was in a range from 10% to 53%, while the total phenolic content was from 24 to 300 EAG/100 g, and condensed tannins were between 240 and 1,900 mg CE/g. Additionally, 1H-NMR spectroscopy was used to characterize syrup profiles and chemometrics. PCA group analyses allowed the sweeteners' classification by origin and kind of Agave. Conclusion: Thus, we conclude that 1H-NMR and chemometrics can be used for identifying, differentiating, and classifying Agave syrups. Besides, Agave syrups contain significant amounts of antioxidative components and can be considered as an effective source of antioxidant.

3.
J Environ Manage ; 229: 57-66, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30017110

RESUMO

Tree invasions are increasing globally, causing major problems for biodiversity, ecosystem services and human well-being. In South America, conifer invasions occur across many ecosystems and while numerous studies address the ecological consequences of these invasions, little is known about social perceptions and people's attitudes toward their control. The social perceptions on the effect of invasive conifers can include recreational, cultural and conservation dimensions. This study, conducted in the Malalcahuello National Reserve, aims to assess visitor's perception about invasive pines (Pinus spp.) and their effects on the endangered Araucaria araucana forests and determine their willingness to pay for pine control. We used a questionnaire to survey visitors to the reserve in both winter and summer (n = 138 for each season). When confronted with six images of araucaria and pine forests with and without snow, visitors consistently preferred landscapes without pines and disliked those completely dominated by pines the most. Almost half, 46.5%, of the visitors expressed their willingness to pay (WTP) for pine control and after given a brief explanation about pine impacts, this number rose to 79%. Visitors who said they were unwilling to pay argue ethical, aesthetic and pragmatic considerations relating closely to a number of social value systems and beliefs. Our study shows that there is a high variation in how people assess the threat of invasive pine species in natural areas, but education even in a very brief format can help to increase awareness of the problem and build social and financial support for its control.


Assuntos
Espécies Introduzidas , Pinus , Biodiversidade , Florestas , Humanos , Percepção , Estações do Ano , América do Sul , Árvores
4.
PLoS One ; 13(10): e0205287, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30278062

RESUMO

[This corrects the article DOI: 10.1371/journal.pone.0201195.].

5.
PLoS One ; 13(8): e0201195, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30133449

RESUMO

In recent decades large fires have affected communities throughout central and southern Chile with great social and ecological consequences. Despite this high fire activity, the controls and drivers and the spatiotemporal pattern of fires are not well understood. To identify the large-scale trends and drivers of recent fire activity across six regions in south-central Chile (~32-40° S Latitude) we evaluated MODIS satellite-derived fire detections and compared this data with Chilean Forest Service records for the period 2001-2017. MODIS burned area estimates provide a spatially and temporally comprehensive record of fire activity across an important bioclimatic transition zone between dry Mediterranean shrublands/sclerophyllous forests and wetter deciduous-broadleaf evergreen forests. Results suggest fire activity was highly variable in any given year, with no statistically significant trend in the number of fires or mean annual area burned. Evaluation of the variables associated with spatiotemporal patterns of fire for the 2001-2017 period indicate vegetation type, biophysical conditions (e.g., elevation, slope), mean annual and seasonal climatic conditions (e.g., precipitation) and mean population density have the greatest influence on the probability of fire occurrence and burned area for any given year. Both the number of fires and annual area burned were greatest in warmer, biomass-rich lowland Bío-Bío and Araucanía regions. Resource selection analyses indicate fire 'preferentially' occurs in exotic plantation forests, mixed native-exotic forests, native sclerophyll forests, pasture lands and matorral, vegetation types that all provide abundant, flammable and connected biomass for burning. Structurally and compositionally homogenous exotic plantation forests may promote fire spread greater than native deciduous-Nothofagaceae forests which were once widespread in the southern parts of the study area. In the future, the coincidence of warmer and drier conditions in landscapes dominated by flammable and fuel-rich forest plantations and mixed native-exotic and sclerophyll forests are likely to further promote large fires in south-central Chile.


Assuntos
Conservação dos Recursos Naturais/métodos , Fogo/estatística & dados numéricos , Biomassa , Chile , Mudança Climática/estatística & dados numéricos , Ecossistema , Modelos Teóricos , Imagens de Satélites/métodos
6.
Chemosphere ; 206: 502-512, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29778075

RESUMO

Magnetic particles entrapped in different matrices that display high thermal stability, low toxicity, interactive functions at the surface, and high saturation magnetization are of great interest. The objective of this work was to synthesize a novel hemoglobin/iron oxide composite (Hb/Fe3O4) for the removal of different dyes (indigo carmine, naphthol blue black, tartrazine, erythrosine, eriochrome black T and bromophenol blue) from aqueous solutions. The Hb/Fe3O4 composite was characterized using scanning electron microscopy (SEM), laser diffraction particle size analysis, FT-IR spectroscopy, isoelectric point determination and thermogravimetric analysis (TGA). The Hb/Fe3O4 composite showed high removal efficiency toward all the different classes of dyes studied and the mechanism of adsorption was dominated by electrostatic interaction. Adsorption was found to follow pseudo-second order kinetic model and Langmuir isotherm. The Langmuir monolayer adsorption capacities for all the dyes range from 80 to 178 mg/g. The Hb/Fe3O4 composite possesses extra advantage of being easily isolated from aqueous suspension using an external magnet. The stability of the prepared Hb/Fe3O4 composite was also demonstrated.


Assuntos
Corantes/química , Compostos Férricos/química , Hemoglobinas/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Adsorção
7.
J Sci Food Agric ; 97(14): 4822-4826, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28382617

RESUMO

BACKGROUND: Whole blood is a highly complex substance. Hemoglobin, the most abundant blood protein, can function as a flocculant; most of the other blood components exhibit poor flocculant activity. For the purpose of processing raw whole blood into a flocculant product, the practical value of hemoglobin purification is uncertain. RESULTS: This study compares the flocculant performance of whole blood to that of three different semi-purified hemoglobin preparations. The whole blood is processed to remove the plasma proteins, the solid cell components, or both. The flocculant performance of whole blood and each hemoglobin preparation is compared over wide ranges of flocculant dose and suspension pH. The clarified liquids are examined for increases in chemical oxygen demand and Kjeldahl nitrogen. Hemoglobin preparations that excluded plasma gave peak flocculation performance at approximately 30 mg solids per gram of suspended kaolin, and gave greatly reduced performance at higher doses; preparations that included plasma gave very similar peak performance, but also maintained relatively high performance at doses up to at least 200 mg g-1 . CONCLUSION: It is shown that removal of the plasma and the cell solids does not improve the flocculant performance or lessen the residual pollutants in the treated water. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.


Assuntos
Hemoglobinas/química , Hemoglobinas/isolamento & purificação , Animais , Proteínas Sanguíneas/isolamento & purificação , Galinhas/sangue , Floculação , Caulim/química , Nitrogênio/química , Oxigênio/química
8.
Carbohydr Polym ; 140: 233-7, 2016 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-26876849

RESUMO

Graft copolymers of waxy maize starch and poly-γ-glutamic acid (PGA) were produced in an aqueous solution using microwave irradiation. The microwave reaction conditions were optimized with regard to temperature and pH. The temperature of 180°C and pH7.0 were the best reaction conditions resulting in a PGA graft of 0.45% based on nitrogen analysis. The average graft content and graft efficiency for the starch-PGA graft copolymer prepared at 180°C and pH7.0 were 4.20% and 2.73%, respectively. The starch-PGA graft copolymer produced at 180°C and pH7.0 could absorb more than 20 times its own weight amount of water and form a gel. The preliminary rheology study revealed that the starch-PGA graft copolymer gel exhibited viscoelastic solid behavior while the control sample of waxy starch showed viscoelastic liquid behavior.


Assuntos
Micro-Ondas , Ácido Poliglutâmico/análogos & derivados , Amido/química , Absorção Fisico-Química , Nitrogênio/química , Ácido Poliglutâmico/química , Reologia , Solubilidade , Água/química
9.
Ecol Evol ; 6(2): 447-59, 2016 01.
Artigo em Inglês | MEDLINE | ID: mdl-26843929

RESUMO

Understanding biological invasions patterns and mechanisms is highly needed for forecasting and managing these processes and their negative impacts. At small scales, ecological processes driving plant invasions are expected to produce a spatially explicit pattern driven by propagule pressure and local ground heterogeneity. Our aim was to determine the interplay between the intensity of seed rain, using distance to a mature plantation as a proxy, and microsite heterogeneity in the spreading of Pinus contorta in the treeless Patagonian steppe. Three one-hectare plots were located under different degrees of P. contorta invasion (Coyhaique Alto, 45° 30'S and 71° 42'W). We fitted three types of inhomogeneous Poisson models to each pine plot in an attempt for describing the observed pattern as accurately as possible: the "dispersal" models, "local ground heterogeneity" models, and "combined" models, using both types of covariates. To include the temporal axis in the invasion process, we analyzed both the pattern of young and old recruits and also of all recruits together. As hypothesized, the spatial patterns of recruited pines showed coarse scale heterogeneity. Early pine invasion spatial patterns in our Patagonian steppe site is not different from expectations of inhomogeneous Poisson processes taking into consideration a linear and negative dependency of pine recruit intensity on the distance to afforestations. Models including ground-cover predictors were able to describe the point pattern process only in a couple of cases but never better than dispersal models. This finding concurs with the idea that early invasions depend more on seed pressure than on the biotic and abiotic relationships seed and seedlings establish at the microsite scale. Our results show that without a timely and active management, P. contorta will invade the Patagonian steppe independently of the local ground-cover conditions.

10.
Nature ; 529(7586): 364-7, 2016 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-26727160

RESUMO

Magnetic fields play a part in almost all stages of stellar evolution. Most low-mass stars, including the Sun, show surface fields that are generated by dynamo processes in their convective envelopes. Intermediate-mass stars do not have deep convective envelopes, although 10 per cent exhibit strong surface fields that are presumed to be residuals from the star formation process. These stars do have convective cores that might produce internal magnetic fields, and these fields might survive into later stages of stellar evolution, but information has been limited by our inability to measure the fields below the stellar surface. Here we report the strength of dipolar oscillation modes for a sample of 3,600 red giant stars. About 20 per cent of our sample show mode suppression, by strong magnetic fields in the cores, but this fraction is a strong function of mass. Strong core fields occur only in red giants heavier than 1.1 solar masses, and the occurrence rate is at least 50 per cent for intermediate-mass stars (1.6-2.0 solar masses), indicating that powerful dynamos were very common in the previously convective cores of these stars.

11.
Nature ; 529(7585): 181-4, 2016 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-26727162

RESUMO

A knowledge of stellar ages is crucial for our understanding of many astrophysical phenomena, and yet ages can be difficult to determine. As they become older, stars lose mass and angular momentum, resulting in an observed slowdown in surface rotation. The technique of 'gyrochronology' uses the rotation period of a star to calculate its age. However, stars of known age must be used for calibration, and, until recently, the approach was untested for old stars (older than 1 gigayear, Gyr). Rotation periods are now known for stars in an open cluster of intermediate age (NGC 6819; 2.5 Gyr old), and for old field stars whose ages have been determined with asteroseismology. The data for the cluster agree with previous period-age relations, but these relations fail to describe the asteroseismic sample. Here we report stellar evolutionary modelling, and confirm the presence of unexpectedly rapid rotation in stars that are more evolved than the Sun. We demonstrate that models that incorporate dramatically weakened magnetic braking for old stars can--unlike existing models--reproduce both the asteroseismic and the cluster data. Our findings might suggest a fundamental change in the nature of ageing stellar dynamos, with the Sun being close to the critical transition to much weaker magnetized winds. This weakened braking limits the diagnostic power of gyrochronology for those stars that are more than halfway through their main-sequence lifetimes.

12.
Sci Adv ; 2(1): e1500654, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26767193

RESUMO

A significant part of the intrinsic brightness variations in cool stars of low and intermediate mass arises from surface convection (seen as granulation) and acoustic oscillations (p-mode pulsations). The characteristics of these phenomena are largely determined by the stars' surface gravity (g). Detailed photometric measurements of either signal can yield an accurate value of g. However, even with ultraprecise photometry from NASA's Kepler mission, many stars are too faint for current methods or only moderate accuracy can be achieved in a limited range of stellar evolutionary stages. This means that many of the stars in the Kepler sample, including exoplanet hosts, are not sufficiently characterized to fully describe the sample and exoplanet properties. We present a novel way to measure surface gravities with accuracies of about 4%. Our technique exploits the tight relation between g and the characteristic time scale of the combined granulation and p-mode oscillation signal. It is applicable to all stars with a convective envelope, including active stars. It can measure g in stars for which no other analysis is now possible. Because it depends on the time scale (and no other properties) of the signal, our technique is largely independent of the type of measurement (for example, photometry or radial velocity measurements) and the calibration of the instrumentation used. However, the oscillation signal must be temporally resolved; thus, it cannot be applied to dwarf stars observed by Kepler in its long-cadence mode.


Assuntos
Astronomia/métodos , Gravitação , Astros Celestes , Meio Ambiente Extraterreno
13.
Science ; 350(6259): 423-6, 2015 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-26494754

RESUMO

Internal stellar magnetic fields are inaccessible to direct observations, and little is known about their amplitude, geometry, and evolution. We demonstrate that strong magnetic fields in the cores of red giant stars can be identified with asteroseismology. The fields can manifest themselves via depressed dipole stellar oscillation modes, arising from a magnetic greenhouse effect that scatters and traps oscillation-mode energy within the core of the star. The Kepler satellite has observed a few dozen red giants with depressed dipole modes, which we interpret as stars with strongly magnetized cores. We find that field strengths larger than ~10(5) gauss may produce the observed depression, and in one case we infer a minimum core field strength of ≈10(7) gauss.

14.
CCH, Correo cient. Holguín ; 19(2): 329-335, abr.-jun. 2015. ilus
Artigo em Espanhol | LILACS-Express | ID: lil-749562

RESUMO

Se presentó un paciente de 66 años ingresado en el Servicio de Cuidados Intensivos del Hospital Princesa Margarita de la ciudad de Roseau, Dominica, con un diagnóstico de osteoartritis; fue remitido a la unidad luego de la intervención quirúrgica con remplazo protésico total de rodilla izquierda. Llegó somnoliento, aunque consciente, orientado, cooperativo, con respuesta al llamado, con pupilas isocóricas y reactivas a la luz, ventilando espontáneamente. Presentó, además, herida quirúrgica cubierta con apósito estéril en la rodilla izquierda con drenaje quirúrgico, hidratado a través de vena periférica permeable en la región del antebrazo izquierdo. Desde las primeras 24 h el paciente se mantuvo estable, con parámetros vitales normales, recuperó gradualmente la motilidad y el funcionamiento de la articulación de la rodilla intervenida. Luego de cinco días de estadía en el servicio el paciente logró caminar y continuo su evolución favorablemente, por lo que se decidió su egreso hospitalario.


A 66 year old patient admitted to the Intensive Care Unit of the Princesa Margarita Hospital in Roseau, Dominica, with a diagnosis of osteoarthritis was presented. The patient was referred to the unit after surgery with complete prosthetic left knee replacement. He arrived sleepy, though conscious, oriented, cooperative, responsive to the call, with isochoric and reactive to light pupils, spontaneously breathing. He also presented wound covered with sterile dressing on the left knee with surgical drainage, hydrated through permeable peripheral vein in the region of the left forearm. Since the first 24 h the patient was stable, with normal vital parameters, gradually recovered motility and joint function of the operated knee. After five days of stay in the service the patient started to walk and continued a favorably evolution, so the doctors decided to discharge him.

15.
Cardiovasc Pathol ; 24(5): 327-31, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25953280

RESUMO

We present a unique case of sudden death in a 21-year-old man with history of cocaine use and a solitary fibromuscular dysplastic lesion completely occluding the left coronary artery ostium. We document intimal proliferation of myofibroblasts at the opening of the left coronary ostium without other concomitant lesions. This report discusses the gross and histologic features of the lesion, explores in careful detail the possible etiologies, and gives a comprehensive literature review of isolated coronary ostial fibromuscular dysplasia presenting with sudden death.


Assuntos
Vasos Coronários/patologia , Morte Súbita Cardíaca/etiologia , Morte Súbita Cardíaca/patologia , Displasia Fibromuscular/patologia , Displasia Fibromuscular/complicações , Humanos , Masculino , Adulto Jovem
16.
CCM ; 19(2): 329-335, abr. 2015. ilus
Artigo em Espanhol | CUMED | ID: cum-65614

RESUMO

Se presentó un paciente de 66 años ingresado en el Servicio de Cuidados Intensivos del Hospital Princesa Margarita de la ciudad de Roseau, Dominica, con un diagnóstico de osteoartritis; fue remitido a la unidad luego de la intervención quirúrgica con remplazo protésico total de rodilla izquierda. Llegó somnoliento, aunque consciente, orientado, cooperativo, con respuesta al llamado, con pupilas isocóricas y reactivas a la luz, ventilando espontáneamente. Presentó, además, herida quirúrgica cubierta con apósito estéril en la rodilla izquierda con drenaje quirúrgico, hidratado a través de vena periférica permeable en la región del antebrazo izquierdo. Desde las primeras 24 h el paciente se mantuvo estable, con parámetros vitales normales, recuperó gradualmente la motilidad y el funcionamiento de la articulación de la rodilla intervenida. Luego de cinco días de estadía en el servicio el paciente logró caminar y continuo su evolución favorablemente, por lo que se decidió su egreso hospitalario.(AU)


A 66 year old patient admitted to the Intensive Care Unit of the Princesa Margarita Hospital in Roseau, Dominica, with a diagnosis of osteoarthritis was presented. The patient was referred to the unit after surgery with complete prosthetic left knee replacement. He arrived sleepy, though conscious, oriented, cooperative, responsive to the call, with isochoric and reactive to light pupils, spontaneously breathing. He also presented wound covered with sterile dressing on the left knee with surgical drainage, hydrated through permeable peripheral vein in the region of the left forearm. Since the first 24 h the patient was stable, with normal vital parameters, gradually recovered motility and joint function of the operated knee. After five days of stay in the service the patient started to walk and continued a favorably evolution, so the doctors decided to discharge him.(AU)


Assuntos
Humanos , Masculino , Idoso , Artroplastia do Joelho , Osteoartrite do Joelho/diagnóstico , Osteoartrite do Joelho , Osteoartrite do Joelho/cirurgia
17.
J Agric Food Chem ; 62(30): 7567-76, 2014 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-25003597

RESUMO

Changes in the structural and thermal stability of ß-lactoglobulin (ß-LG) induced by interacting with sugar beet pectin (SBP) have been studied by circular dichroism (CD), Fourier transform infrared, and steady-state as well as time-resolved fluorescence spectroscopic techniques. It has been demonstrated that SBP not only is capable of binding to native ß-LG but also causes a significant loss in antiparallel ß-sheet, ∼10%, accompanied by an increase in either random coil or turn structures. In addition, the interaction also disrupted the environments of all aromatic residues including Trp, Phe, and Tyr of ß-LG as evidenced by near-UV CD and fluorescence. When preheated ß-LG was combined with SBP, the secondary structure of ß-LG was partially recovered, ∼4% gain in antiparallel ß-sheet, and Trp19 fluorescence was recovered slightly. Although forming complexes with SBP did not significantly impact the thermal stability of individual secondary structural elements of ß-LG, the environment of Trp19 was protected considerably.


Assuntos
Beta vulgaris/química , Lactoglobulinas/química , Pectinas/química , Aminoácidos/química , Dicroísmo Circular , Proteínas na Dieta/química , Concentração de Íons de Hidrogênio , Estrutura Molecular , Estrutura Secundária de Proteína , Espectrometria de Fluorescência , Espectroscopia de Infravermelho com Transformada de Fourier
18.
Appl Biochem Biotechnol ; 166(5): 1203-14, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22194055

RESUMO

Synthetic polymeric flocculants are used extensively for wastewater remediation, soil stabilization, and reduction in water leakage from unlined canals. Sources of highly active, inexpensive, renewable flocculants are needed to replace synthetic flocculants. High kaolin flocculant activity was documented for bovine blood (BB) and blood plasma with several anticoagulant treatments. BB serum also had high flocculant activity. To address the hypothesis that some blood proteins have strong flocculating activity, the BB proteins were separated by SEC. Then, the major proteins of the flocculant-active fractions were separated by SDS-PAGE. Identity of the major protein components was determined by tryptic digestion and peptide analysis by MALDI TOF MS. The sequence of selected peptides was confirmed using TOF/TOF-MS/MS fragmentation. Hemoglobin dimer (subunits α and ß) was identified as the major protein component of the active fraction in BB; its high flocculation activity was confirmed by testing a commercial sample of hemoglobin. In the same manner, three proteins from blood plasma (fibrinogen, γ-globulin, α-2-macroglobulin) were found to be highly active flocculants, but bovine serum albumin, α-globulin, and ß-globulin were not flocculants. On a mass basis, hemoglobin, γ-globulin, α-2-macroglobulin were as effective as anionic polyacrylamide (PAM), a widely used synthetic flocculant. The blood proteins acted faster than PAM, and unlike PAM, the blood proteins flocculants did not require calcium salts for their activity.


Assuntos
Proteínas Sanguíneas/análise , Resinas Acrílicas/química , Animais , Proteínas Sanguíneas/química , Proteínas Sanguíneas/isolamento & purificação , Bovinos , Cromatografia em Gel , Eletroforese em Gel de Poliacrilamida , Floculação , Peso Molecular , Plasma/química , Soro/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Espectrometria de Massas em Tandem
19.
Nature ; 481(7379): 55-7, 2011 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-22158105

RESUMO

When the core hydrogen is exhausted during stellar evolution, the central region of a star contracts and the outer envelope expands and cools, giving rise to a red giant. Convection takes place over much of the star's radius. Conservation of angular momentum requires that the cores of these stars rotate faster than their envelopes; indirect evidence supports this. Information about the angular-momentum distribution is inaccessible to direct observations, but it can be extracted from the effect of rotation on oscillation modes that probe the stellar interior. Here we report an increasing rotation rate from the surface of the star to the stellar core in the interiors of red giants, obtained using the rotational frequency splitting of recently detected 'mixed modes'. By comparison with theoretical stellar models, we conclude that the core must rotate at least ten times faster than the surface. This observational result confirms the theoretical prediction of a steep gradient in the rotation profile towards the deep stellar interior.

20.
J Agric Food Chem ; 59(22): 11990-6, 2011 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-22010831

RESUMO

Rendered animal proteins are well suited for animal nutrition applications, but the market is maturing, and there is a need to develop new uses for these products. The objective of this study is to explore the possibility of using animal proteins as a nutrient source for microbial production of omega-3 polyunsaturated fatty acids by the microalga Schizochytrium limacinum and the fungus Pythium irregulare. To be absorbed by the microorganisms, the proteins needed to be hydrolyzed into small peptides and free amino acids. The utility of the protein hydrolysates for microorganisms depended on the hydrolysis method used and the type of microorganism. The enzymatic hydrolysates supported better cell growth performance than the alkali hydrolysates did. P. irregulare displayed better overall growth performance on the experimental hydrolysates compared to S. limacinum. When P. irregulare was grown in medium containing 10 g/L enzymatic hydrolysate derived from meat and bone meal or feather meal, the performance of cell growth, lipid synthesis, and omega-3 fatty acid production was comparable to the that of culture using commercial yeast extract. The fungal biomass derived from the animal proteins had 26-29% lipid, 32-34% protein, 34-39% carbohydrate, and <2% ash content. The results show that it is possible to develop a nonfeed application for rendered animal protein by hydrolysis of the protein and feeding to industrial microorganisms which can produce omega-3 fatty acids for making omega-3-fortified foods or feeds.


Assuntos
Biotecnologia/métodos , Ácido Eicosapentaenoico/biossíntese , Microalgas/metabolismo , Proteínas/metabolismo , Pythium/metabolismo , Animais , Animais Domésticos , Biotecnologia/economia , Meios de Cultura/economia , Meios de Cultura/metabolismo , Fermentação , Indústria de Processamento de Alimentos , Hidrólise , Microalgas/crescimento & desenvolvimento , Proteínas/química , Pythium/crescimento & desenvolvimento , Ruminantes , Resíduos/análise
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