Sample records for MACLADO (twinning)
from WorldWideScience.org

Sample records 1 - 20 shown. Select sample records:



1

Ética científica de la clonación humana/ Scientific ethics of human cloning

Valenzuela, Carlos Y
2005-01-01

Resumen en inglés True cloning is fission, budding or other types of asexual reproduction. In humans it occurs in monozygote twinning. This type of cloning is ethically and religiously good. Human cloning can be performed by twinning (TWClo) or nuclear transfer (NTClo). Both methods need a zygote or a nuclear transferred cell, obtained in vitro (IVTec). They are under the IVTec ethics. IVTecs use humans (zygotes, embryos) as drugs or things; increase the risk of malformations; increase dev (mas) elopment and size of abnormalities and may cause long-term changes. Cloning for preserving extinct (or almost extinct) animals or humans when sexual reproduction is not possible is ethically valid. The previous selection of a phenotype in human cloning violates some ethical principles. NTClo for reproductive or therapeutic purposes is dangerous since it increases the risk for nucleotide or chromosome mutations, de-programming or re-programming errors, aging or malignancy of the embryo cells thus obtained (Rev Méd Chile 2005; 133: 105-12)

Scientific Electronic Library Online (Spanish)

4

The impact of droughts and water management on various hydrological systems in the headwaters of the Tagus River (central Spain)

Lorenzo-Lacruz, J.; Vicente Serrano, Sergio M.; López-Moreno, Juan I.; Beguería, Santiago; García-Ruiz, José María; Cuadrat, José María
2010-05-01

Digital.CSIC (Spain)

6

Spatial patterns of the transient ultrasonic field radiated by a dual-transducer NDE probe

Azbaid, Abdelhalim; Ramos, Antonio; San Emeterio, José Luis; Sanz Sánchez, Pedro Tomás
2002-09-01

Digital.CSIC (Spain)

7

Sexual polyembryony in almond

Martínez-Gómez, Pedro; Gradziel, Thomas M.
2003-09-01

Digital.CSIC (Spain)

9

Quantum properties of tranverse pattern formation in second-harmonic generation

Bache, Morten; Scotto, Pierre; Zambrini, Roberta; San Miguel, Maxi; Saffman, Mark
2002-07-19

Digital.CSIC (Spain)

10

Plasma pregnancy-associated glycoprotein and progesterone concentrations in pregnant Assaf ewes carrying single and twin lambs

Ranilla, María José; Sulon, J.; Mantecón, Ángel R.; Carro Travieso, Mª Dolores
1997-01-01

Digital.CSIC (Spain)

12

New approaches to Prunus tree crop breeding

Martínez-Gómez, Pedro; Sozzi, Gabriel O.; Sánchez-Pérez, Raquel; Rubio, Manuel; Gradziel, Thomas M.
2003-01-01

Digital.CSIC (Spain)

13
14

Mecanismos de construcción-destrucción de patrones macroestructurales en microclimas como sistemas complejos

Sánchez-Muñoz, L.; Rover, O.; Sanz Lázaro, Jesús; García Guinea, Javier
2006-09-01

Digital.CSIC (Spain)

15

Magnetoelastic effects and magnetic anisotropy in Ni2MnGa polycrystals

Albertini, Franca; Morellón, Luis; Algarabel, Pedro A.; Ibarra, M. Ricardo; Pareti, Luigi
2001-05-15

Digital.CSIC (Spain)

16

La epigenética y los estudios en gemelos en el campo de la psiquiatría/ Epigenetics and twin studies in psychiatric domains

González Ramírez, Adriana Estrella; Díaz Martínez, Alejandro; Díaz-Anzaldúa, Adriana
2008-06-01

Resumen en español La secuencia de ADN genómico que caracteriza a nuestra especie constituye la piedra fundamental de la vida humana; parte de ella se refleja en la secuencia del ARN y a través de éste se dicta la información necesaria para que nuestras células produzcan proteínas. La genética contribuye de manera importante a los avances en el campo médico. Los descubrimientos genéticos han permitido desarrollar estrategias para modificar, prevenir y proponer nuevas terapias para (mas) diversas enfermedades. En el siglo XIX, Gregor Johann Mendel desarrolló un modelo teórico capaz de predecir la naturaleza y propiedades de los mecanismos de la herencia, que sigue siendo indispensable para explicar la base de la herencia humana. Otro suceso determinante en la historia de la Medicina se dio a conocer casi nueve décadas después cuando James Watson y Francis Crick describieron su modelo estructural para el ADN. Posteriormente se introdujeron la clonación posicional y la reacción en cadena de la polimerasa; más recientemente se publicó cerca del 99% de la secuencia del genoma humano. El período actual se conoce como la era post-genómica, ya que además de descifrar genomas completos, los investigadores pretenden, entre otras cosas, esclarecer los mecanismos que influyen en la activación e inactivación de los genes, lo cual en parte involucra un nivel epigenético. En las ciencias médicas los gemelos constituyen un grupo idóneo para abordar el estudio de las enfermedades hereditarias. En este tipo de padecimientos suelen observarse similitudes entre parientes, en especial si se trata de gemelos monocigóticos. Sin embargo, aun en este tipo de hermanos se detectan diferencias importantes. Parámetros como los grados de concordancia y porcentajes de heredabilidad han puesto de manifiesto que un gemelo monocigótico puede presentar trastornos hereditarios que su co-gemelo nunca tendrá. La epigenética es el estudio de los cambios en la función de los genes que no afectan la secuencia del ADN, por modificaciones que tienen lugar principalmente en las citosinas de éste y en las histonas de la cromatina. Se ha determinado que las modificaciones epigenéticas son mucho más frecuentes que aquellas que modifican la secuencia del ADN, por lo que constituyen uno de los fundamentos de la diversidad biológica, muestran la manera en que el ambiente puede modular la expresión genética y contribuyen así a nuestro fenotipo. Esta revisión reúne datos sobre la posible relevancia de la epigenética en el estudio de los trastornos mentales y como posible explicación parcial de las diferencias observadas entre gemelos >. Un conocimiento más profundo de los patrones epigenéticos podría contribuir a identificar factores de riesgo para estos trastornos. Resumen en inglés The sequence of the human genome integrates the keystone of our life. Part of it is transcribed to RNA, which in turn provides the information required by our cells to produce proteins. Discoveries in the genetics field have been essential to medicine and have been used to develop strategies to modify, prevent and propose new therapeutic approaches for human diseases. In the 19th Century, Gregor Johann Mendel developed a theoretical model which was able to predict in an a (mas) ccurate way hereditary mechanisms; indeed, his laws still explain the basis of human inheritance. Almost ninety years later, James Watson and Francis Crick announced their double-helix model of the DNA molecule. Then, positional cloning and the polymerase chain reaction (PCR) were introduced; more recently, almost 99% of the sequence of our genome was made public. The current period of time is known as the post-genomic era, due to the fact that researchers are not only obtaining the complete sequences of thousands of genomes, but are also searching for clues that may help understand the mechanisms that affect gene activation and deactivation, in which epigenetic factors are also involved. In medical domains, twins constitute a suitable group to study inherited disorders. Dizygotic or fraternal twins are produced by different egg and sperm cells, and even when these two fertilization events occur simultaneously, dizygotic twins share approximately the same percentage of genetic material than any pair of siblings, that is, around 50%. Some authors have suggested that the tendency for spontaneous dizygotic twinning could be attributed to a double ovulation which is genetically determined in an autosomal dominant manner. Monozygotic, as opposed to dizygotic twins, are produced by a single zygote whose cells are dissociated and originate two independent organisms; approximately a third of monozygotic twins are separated before the 5th day after fertilization, and the rest between the 5th and the 15th day. Most monozygotic twins are very similar; nevertheless, some few exceptions prove that in fact they actually do not have to be identical. Relatives of a person with a mental disorder tend to share traits associated with this disease, especially if the patient and the relative are monozygotic twins. However, important differences may be detected even between each pair of identical twins. Parameters such as concordance and heritability have shown that a monozygotic twin can develop an inherited disorder while his or her co-twin will always be disease-free. In addition to differences in susceptibility to inherited diseases, this kind of twins can display dissimilarities in somatic cell mutations (more overtly noticeable when ageing), their set of antibodies and T cell receptors, their number of mitochondrial DNA molecules, and chromosome X inactivation patterns in women, all of which are the main subject of many ongoing studies. A recent report shows that from 160 monozygotic twin pairs who were 3 to 74 years old, epigenetic patterns were identical early in life, but differences were more obvious at older ages, especially if twins were raised apart or if they had different medical history. Medical conditions, but also environmental factors such as pregnancy tobacco exposure, physical activity, and diet could contribute to differences in epigenetic patterns. It has been shown that epigenetic modifications (or epi-mutations) are more frequent than the ones that modify DNA sequence, so they are part of the fundamental causes of biological diversity, and they show how environment can modulate gene expression and contribute to our phenotype. Even when twin studies are sometimes considered purely genetic, they also give information about the influence of environmental factors. However, it is important to consider with caution the results from this type of studies. Heritability estimates are not unchangeable facts. They depend on the sample being analyzed, the genes involved in the specific sample, the characteristics of the environmental factors which members of this group were exposed to, and the precise moment the study was done. Epigenetics refers to changes that do not alter the DNA sequence but affect gene function due to chemical modifications which mainly occur in DNA cytosines and in chromatin-related histones. Epigenetic processes are covalent modifications which include the addition of functional groups (methyl, acetyl, phosphate, etc.) or proteins (ubiquitin, SUMO, etc.) to the DNA molecule or to associated proteins. These modifications contribute to the activation or inhibition of transcription, which leads to changes in messenger ARN expression that can ultimately influence the onset of disease. Pseudogenes are still being excluded while new genes are being confirmed in our genome sequence, but the current estimates indicate that each one of our nucleated cells contains almost 22000 genes (excluding mitochondrial DNA) which encode for polypeptides and more than 4,000 whose final product is RNA. Gene expression is partially controlled by DNA coiling around globular proteins called histones, which constitute a structure known as chromatin, a DNA-protein complex that represents the packaging of 3.25 billion base pairs of our genetic information. Physical and chemical chromatin modifications can also affect gene expression by changing DNA-protein interactions; in general terms, genes are inhibited when chromatin is packed and they are active when it is free. These dynamic states are controlled by epigenetic reversible modifications on DNA methylation or by changes in histones. It has been shown that subtle epigenetic differences between any two human beings are associated with dissimilar final chromatin remodeling, as well as expression/repression of genes.

Scientific Electronic Library Online (Spanish)

17

Ionoluminiscencia de silicatos de utilización en cerámica a temperaturas criogénicas

García Guinea, Javier; Hole, D.; Finch, A.; Correcher, Virgilio; Valle Fuentes, Francisco José; Can, N.; Townsend, P. D.
2004-09-01

Digital.CSIC (Spain)

18
19

Inducción de mellizos mediante la transferencia de un segundo embrión ipsilateral o contralateral al cuerpo lúteo en vacas cubiertas/ Twin induction by transfer of a second embryo ipsilateral or contralateral to the corpus luteum in mated cows

Silva, M. E.; Gatica, R.; Correa, J. E.
2000-01-01

Resumen en español El objetivo de este trabajo fue comparar el efecto del sitio de depósito (ipsi o contralateral al CL) de un segundo embrión en vacas cubiertas sobre la tasa de preñez y de gestaciones dobles. Treinta y dos vacas receptoras recibieron un embrión congelado-descongelado ipsilateralmente a su cuerpo lúteo y 28 contralateralmente, 7 días posterior a su cubierta. En el grupo de transferencias ipsilaterales 21 receptoras se preñaron al primer servicio (65,6%), mientras (mas) que en el grupo contralateral 21 de las 28 receptoras se diagnosticaron preñadas (75%), no existiendo diferencias entre ambos grupos. Sin embargo, sí se observó diferencias en la tasa de preñez doble, entre los 60 y 90 días post servicio en ambos grupos (57,1 v/s 14,3% y 45 v/s 4,8% respectivamente). Contrariamente a algunos antecedentes que señalan la mayor sobrevida de embriones transferidos ipsilateralmente al ocurrir la muerte del embrión nativo, no se observó diferencias entre los porcentajes de preñez en ambos grupos. La diferencia observada en el número de gestaciones dobles entre el grupo de transferencia ipsilateral y el contralateral es mayor a la descrita en la literatura, pero confirma antecedentes de que la existencia de dos embriones en el cuerno uterino ipsilateral no aumenta la tasa de mortalidad embrionaria ni fetal. De acuerdo a lo descrito, se concluye que la transferencia de un segundo embrión al cuerno uterino ipsilateral de vacas previamente cubiertas es un método más efectivo de inducción de mellizos que la transferencia contralateral Resumen en inglés SUMMARY The purpose of this work was to compare the effect of the site of transfer (ipsilateral or contralateral to the corpus luteum) of a second embryo to already mated cows on pregnancy and twinning rate. Thirty two frozen-thawed embryos were transferred ipsilateral to the corpus luteum of recipient cows and twenty eight were transferred contralaterally. On the ipsilateral group 21 cows became pregnant after first service (65.6%), while 21 out of 28 recipients were (mas) diagnosed as pregnant in the contralateral group (75%). No significant differences were observed between both groups. Twin pregnancy rate at 60 and 90 days after service was 57.1 and 45% of pregnant recipients for the ipsilateral group and 14.3 and 4.8% for the contralateral group. Significant differences (P< 0.05) were observed between groups at both times. Although embryos transferred to the ipsilateral horn have higher probabilities to survive when the native embryos are reabsorbed in comparison with the ones transferred to the contralateral horn, we did not observe differences on the pregnancy rate of both groups after first service. The difference we observed in the number of twin pregnancies between groups was higher than that described in the literature. These results confirm the fact that the existence of 2 embryos in one uterine horn does not increase the embryo or foetal mortality rate. According to our findings we can conclude that the transfer of a second embryo to the ipsilateral uterine horn of already mated cows is a better twin induction technique than contralateral transfers

Scientific Electronic Library Online (Spanish)

20

How to prevent twin formation in epitaxial ZnO thin films grown on c-plane sapphire

Steplecaru, C. S.; Martín-González, Marisol S.; Fernández Lozano, José Francisco; Costa Krämer, José Luis
2010-06-01

Digital.CSIC (Spain)

21

Highly ordered antigorite from Cerro del Almirez HP–HT serpentinites, SE Spain

Padrón-Navarta, J. A.; López Sánchez-Vizcaíno, V.; Garrido, C. J.; Gómez-Pugnaire, M. T.; Jabaloy, Antonio; Capitani, Giancarlo; Mellini, Marcello
2008-11-01

Digital.CSIC (Spain)

22

Growth and nutritional response of Pinus pinaster after a large pine weevil (Hylobius abietis) attack

Sampedro, Luis; Moreira, Xoaquín; Martíns, Patricia; Zas Arregui, Rafael
2009-12-01

Digital.CSIC (Spain)

23

Fluid inclusion analysis of twinned selenite gypsum beds from the Miocene of the Madrid basin (Spain). Implication on dolomite bioformation

Ayllón-Quevedo, Fernando; Souza-Egipsy, Virginia; Sanz-Montero, M. E.; Rodríguez-Aranda, J. P.
2007-06-29

Digital.CSIC (Spain)

27

Estudio de las propiedades electrónicas de cúmulos de Pd: un estudio comparativo usando distintas técnicas y aproximaciones

Aguilera-Granja, F; Montejano-Carrizales, J.M; Vega, A; Ferrer, J; Rogan, J; García, G
2008-04-01

Resumen en español Realizamos un estudio sistemático de las propiedades magnéticas colineales y no-colineales, así como de la metalicidad en cúmulos libres de PdN (2(mas) e fuerte (TB), que son dos de las técnicas más utilizadas en el campo cuando se trata de estudiar propiedades electrónicas de cúmulos. Encontramos que el magnetismo colineal presenta un comportamiento decreciente no-monotono como función del tamaño del cúmulo. Observamos también que la gemelación de los cúmulos puede, en algunos casos, aumentar el momento magnético en cúmulos de tamaño relativamente grande. En el caso de magnetismo no-colineal, encontramos que corresponde siempre a un estado excitado de baja energía, presentando el estado base siempre un orden magnético colineal. En cuanto a los métodos usados encontramos, en general, que las propiedades electrónicas, como el magnetismo, que se obtienen de la diferencia entre poblaciones electrónicas, están en general bien descritas por modelos semi-empíricos, aunque otras propiedades como el carácter metálico, cuya descripción requiere de la determinación exacta de la posición de los estados electrónicos, son también razonablemente descritas si el tamaño de los cúmulos es suficientemente grande. Comparamos nuestros resultados con cálculos previos reportados en la literatura así como con los resultados experimentales disponibles. Resumen en inglés A systematic study of the colineal and no-colineal magnetic properties and the metallic behavior in free standing clusters of PdN (2(mas) used techniques to study the electronic properties of clusters. We found that the colineal magnetism has a no-monotonic decreasing behavior as a function of the cluster size. We observe that the twinning of clusters in some cases can increase the magnetic moment of relatively large size clusters. We found that the no-colineal magnetism always corresponds to a low energy excited state, and that the ground state always presents a colineal magnetic order. Respect to the methods, in general we found that the semi-empirical ones describe very well the electronic properties, as the magnetism; that are obtained from the difference between electronic populations. Although the metallicity requires of the exact determination of the position of the electronic states, it is razonably described by the semi-empirical method if the clusters size is big enough. We compare our results with previous calculations as well as with some experiments reported in the literature.

Scientific Electronic Library Online (Spanish)

28

ESTUDIO TECNOLÓGICO DE 13 COLLARES ETNOGRÁFICOS PATAGÓNICOS/ A TECHNOLOGICAL STUDY OF 13 ETHNOGRAPHIC NECKLACES FROM PATAGONIA

SALAS ROSSENBACH, KAI
2007-01-01

Resumen en español Los relatos etnográficos describen a menudo los largos collares compuestos de pequeñas conchas que llevaban los canoeros de Patagonia. Se conservan numerosos ejemplares de éstos en varios museos del mundo. Si la función decorativa de estos collares se supone obviamente, pocos datos están disponibles en cuanto a su fabricación. Para enriquecer nuestro conocimiento de las técnicas de los canoeros modernos, emprendimos el estudio de 13 de estos collares. Doce están c (mas) onservados en el Museo Salesiano de Punta Arenas y un collar en el Museo Regional de Magallanes en la misma ciudad. El estudio es tecnológico, interesándose en los métodos de fabricación y utilización de estos collares. Las perlas muestran una selección precisa de la concha, modificaciones estéticas de la concha y técnicas de perforación recurrentes. Se observaron también la materia de las fibras y las técnicas de trenzado. Los collares fueron a veces coloreados. El estudio muestra una gran complejidad técnica y todo el cuidado para la fabricación de estos objetos de adorno. Aporta un nuevo elemento a la comprensión de los sistemas técnicos de los indígenas Resumen en inglés Ethnographic accounts often describe the long shell bead necklaces worn by Patagonian canoe indians. Numerous exemplars of these artefacts are curated in museums around the world. Whilst the decorative function of these necklaces is generally taken for granted, little is known about the ways in which they were manufactured. In order to expand our knowledge of these techniques, twelve necklaces from the Salesian Museum in Punta Arenas and a further necklace from the Region (mas) al Museum of Magallanes were studied focusing on the manufacturing techniques employed and the ways in which they were used. The beads evidence a careful selection of shells, their modification according to a particular aesthetic, and recurrently employed drilling techniques. Also recorded are the types of fibres used for cordage and related twinning techniques. We also observe occasional painting/colouring of some of them. The study demonstrates outstanding technical complexity coupled with careful craftsmanship in the production of these ornaments, offering new insights to understand the technical systems of indigens

Scientific Electronic Library Online (Spanish)

29

Diagnosis and management of a large oropharyngeal teratoma (epignathus) in a twin pregnancy

Antiñolo, Guillermo; Agustín, Juan Carlos de; Losada, Antonio; Ontanilla, Antonio; García Perla, Alberto
2009-02-01

Digital.CSIC (Spain)

30

Derivation of Major Yolk Proteins from Parental Vitellogenins and Alternative Processing During Oocyte Maturation in Fundulus heteroclitus

LaFleur, Gary J.; Raldúa, Demetrio; Fabra, Mercedes; Carnevali, Oliana; Denslow, Nancy; Wallace, Robin A.; Cerdà, Joan
2005-01-01

Digital.CSIC (Spain)

31

Dam effects on droughts magnitude and duration in a transboundary basin: The Lower River Tagus, Spain and Portugal.

López-Moreno, Juan I.; Vicente Serrano, Sergio M.; Beguería, Santiago; García-Ruiz, José María; Portela, María M.; Almeida, Antonio B.
2009-01-01

Digital.CSIC (Spain)

32
33

Control of spatial quantum fluctuations using photonic crystals

Moreno, María; Gomila, Damià; Zambrini, Roberta
2008-08-28

Digital.CSIC (Spain)

34

Chatkalita, nekrasovita y otros minerales del grupo de la estannita de Veta María Eugenia, Cerro Atajo, Catamarca/ Chatkalita, nekrasovita y otros minerales del grupo de la estannita de veta María Eugenia, Cerro Atajo, Catamarca

Márquez-Zavalía, M. F.; Galliski, M. A.
2007-06-01

Resumen en español En veta María Eugenia, Cerro Atajo, Catamarca, se encontró una asociación de minerales de estaño integrada por: chatkalita Cu6Fe2+Sn2S8, nekrasovita Cu26V2(Sn,As,Sb)6S32, colusita Cu26V2(As,Sn,Sb)6S32, kësterita Cu2(Zn,Fe)SnS4 y estannoidita Cu8(Fe,Zn)3Sn2S12. Estos minerales, incluidos en watanabeíta, están acompañados principalmente por pirita, esfalerita, calcopirita, tetraedrita, bornita y galena; aikinita, enargita, luzonita, marcasita, arsenopirita y pirroti (mas) na participan como minerales accesorios. Chatkalita se presenta en agregados irregulares de hasta 40 µm, asociados con kësterita y estannoidita, es de color rosa-anaranjado claro, birreflectante y anisótropa, con colores de polarización pardos; su composición química (% en peso) es: S=29,76-30,37, Fe=4,53-7,92, Cu=39,13-43,21, Zn=0,75-5,53, As=0,19- 2,42, Sn=15,27-20,50 y Sb=0,00-0,32. Nekrasovita es isótropa, de color pardo con leve tinte rosa-violáceo y está asociada con estannoidita; su composición química es: S=30,29-30,63, Fe=3,41-4,75, Cu=44,26-45,70, Zn=0,56-1,00, As=4,18-4,71, Sn=12,53-13,64 y Sb=0,71- 0,77. Colusita es pardo amarillenta, isótropa, se presenta como parches irregulares y cintas discontinuas en tennantita; su composición química es: S=30,59-30,74, Fe=2,18-3,58, Cu=47,22-48,13, Zn=0,21-0,64, As=6,38-6,61, Sn=9,04-9,33 y Sb=0,49-1,66. Kësterita es pardo grisácea, con débil birreflectancia y anisotropía y colores de polarización pardos, a menudo se presenta bordeada por chatkalita; su composición química es: S=28,68-29,14, Fe=1,98-2,14, Cu=31,06-32,51, Zn=9,03-11,57 y Sn=26,39-27,03. Estannoidita es de color castaño, pleocroica (castaño-rosado a pardo-grisáceo) y anisótropa con colores de polarización pardos y pardo-amarillentos, ocurre en parches irregulares y como bandas bordeando tennantita; su composición química es: S=29,11-29,83, Fe=8,45-10,30, Cu=38,05-41,01, Zn=3,18-4,90, y Sn=15,84-18,94. La reflectividad y dureza de pulido de todos estos minerales es similar a las de watanabeíta; en ninguno de ellos se observaron evidencias de clivaje, maclas o reflejos internos. Resumen en inglés The association of tin minerals integrated by: chatkalite Cu6Fe2+Sn2S8, nekrasovite Cu26V2(Sn,As,Sb)6S32, colusite Cu26V2(As,Sn,Sb)6S32, kësterite Cu2(Zn,Fe)SnS4 and stannoidite Cu8(Fe,Zn)3Sn2S12 was found at veta María Eugenia, Cerro Atajo, Catamarca. These minerals are included in watanabeite and accompanied by pyrite, sphalerite, chalcopyrite, tetrahedrite, bornite and galena as the main minerals, and aikinite, enargite, luzonite, marcasite, arsenopyrite and pyrrhoti (mas) te as accessory minerals. Chatkalite is light pink with a delicate orange hue, birreflectant and anisotropic with brown polarization colours, occurs as irregular aggregates up to 40 µm, associated to kësterite and stannoidite; its chemical composition (wt.%) range is: S=29.76-30.37, Fe=4.53-7.92, Cu=39.13-43.21, Zn=0.75-5.53, As=0.19-2.42, Sn=15.27-20.50 and Sb=0.00-0.32. Nekrasovite is isotropic, brown with a violet-pink hue; it is associated with stannoidite, and its chemical composition range is: S=30.29-30.63, Fe=3.41-4.75, Cu=44.26- 45.70, Zn=0.56-1.00, As=4.18-4.71, Sn=12.53-13.64 and Sb=0.71-0.77. Colusite is yellowish-brown, isotropic, occurs as irregular patches and discontinue ribbons in tennantite and its chemical composition range is: S=30.59-30.74, Fe=2.18-3.58, Cu=47.22-48.13, Zn=0.21-0.64, As=6.38-6.61, Sn=9.04-9.33 and Sb=0.49-1.66. Kësterite is greyish-brown, with a weak birreflectance and brown polarization colours and sometimes is surrounded by chatkalite; its chemical composition range is: S=28.68-29.14, Fe=1.98-2.14, Cu=31.06-32.51, Zn=9.03-11.57 and Sn=26.39-27.03. Stannoidite is brown, pleochroic (pinkish-brown to greyish-brown), anisotropic, with brown and yellowish-brown polarization colours; it occurs as irregular patches or as bands bordering tennantite. Its chemical composition range is: S=29.11-29.83, Fe=8.45-10.30, Cu=38.05-41.01, Zn=3.18- 4.90, and Sn=15.84-18.94. The reflectivity and polishing hardness of all these minerals are similar to that of watanabeite; in none of them were observed cleavage, twinning or internal reflections.

Scientific Electronic Library Online (Spanish)

35

Characterization of twin embryos in almond

Martínez-Gómez, Pedro; Arulsekar, S.; Gradziel, Thomas M.
2002-01-01

Digital.CSIC (Spain)

36

Caracterización de embriones múltiples en almendro

Martínez-Gómez, Pedro; Sánchez-Pérez, Raquel; Dicenta, Federico; Gradziel, Thomas M.
2003-06-01

Digital.CSIC (Spain)

37

Application of recent biotechnologies to prunus tree crop genetic improvement

Martínez-Gómez, Pedro; Sánchez-Pérez, Raquel; Rubio, Manuel; Dicenta, Federico
2005-08-01

Digital.CSIC (Spain)

38
40

Ag2CuMnO4: A new silver copper oxide with delafossite structure.

Muñoz-Rojas, David; Subías, G.; Oró-Solé, Judith; Fraxedas, Jordi; Martínez, Benjamín; Casas-Cabanas, Montse; Canales-Vázquez, Jesús; Gonzalez-Calbet, Jose; García-González, Ester; Walton, Richard I.; Casañ-Pastor, Nieves
2006-12-01

Digital.CSIC (Spain)

41