Search results for "SN1"
showing 10 items of 13 documents
Carbon Monoxide in the Cold Debris of Supernova 1987A
2013
We report spectroscopic and imaging observations of rotational transitions of cold CO and SiO in the ejecta of SN1987A, the first such emission detected in a supernova remnant. In addition to line luminosities for the CO J=1-0, 2-1, 6-5, and 7-6 transitions, we present upper limits for all other transitions up to J=13-12, collectively measured from the Atacama Large Millimeter Array (ALMA), the Atacama Pathfinder EXperiment (APEX), and the Herschel Spectral and Photometric Imaging REceiver (SPIRE). Simple models show the lines are emitted from at least 0.01 solar masses of CO at a temperature > 14 K, confined within at most 35% of a spherical volume expanding at ~ 2000 km/s. Moreover, we…
Effects of diet on casein and fatty acid profiles of milk from goats differing in genotype for αS1-casein synthesis
2013
This study investigated the interactions between nutrition and the genotype at αS1-CN loci (CSN1S1) in goats, evaluating the impact of fresh forage-based diets and an energy supplement on the casein and fatty acid (FA) profiles of milk from Girgentana goats. Twelve goats were selected for having the same genotype at the αS2-CN, β- CN, and κ-CN loci and differing in the CSN1S1 genotype: homozygous for strong alleles (AA) or heterozygous for strong and weak alleles (AF). Goats of each genotype were divided into three groups and, according to a 3 × 3 Latin square design, fed ad libitum three diets: sulla fresh forage (SFF), SFF plus 800 g/day of barley (SFB), and mixed hay plus 800 g/day of ba…
Strongly decelerated expansion of SN 1979C
2002
We observed SN1979C in M100 on 4 June 1999, about twenty years after explosion, with a very sensitive four-antenna VLBI array at the wavelength of 18cm. The distance to M100 and the expansion velocities are such that the supernova cannot be fully resolved by our Earth-wide array. Model-dependent sizes for the source have been determined and compared with previous results. We conclude that the supernova shock was initially in free expansion for 6 +/- 2 yrs and then experienced a very strong deceleration. The onset of deceleration took place a few years before the abrupt trend change in the integrated radio flux density curves. We estimate the shocked swept-up mass to be about 1.6 solar masse…
Oxidative Status of Goats with Different CSN1S1 Genotypes Fed ad Libitum with Fresh and Dry Forages
2020
Forty late-lactation Girgentana goats were used to study the effect of diets fed ad libitum and &alpha
Effect of diet and CSN1S1 genotype on nutritional, productive and metabolic responses of milking Girgentana goats
2011
Effects of diet and genotype at CSN1S1 locus on the oxidative stress in lactating goats
2011
Twenty-eight Girgentana goats were selected on the basis of their CSN1S1 genotype as follows: 14 goats homozygous for strong (AA) alleles and 14 goats heterozygous (AF). The goats were used in a 2 x 4 factorial arrangement of treatments, with the two genotypes (G) and four diets (D). The diets were: a pelleted alfalfa hay (100H), a complete feed including alfalfa hay at 65% (65H), fresh sulla (Hedysarum coronarium L.) forage (100S) and fresh sulla plus barley (65S). Each trial consisted of 15d for adaptation and 8d for sample collection, during which the goats received the scheduled diet ad libitum. Blood samples were collected at the end of pre-experimental and experimental period. Plasma …
Intermedios Reactivos en CO2sc
2015
Dióxido de carbono supercrítico (CO2sc) es un medio de reacción alternativo que se considera similar a n-pentano o tetracloruro de carbono. Los parámetros de polaridad caracterizan a CO2sc como apolar (ETN(200 bar) = -0.053), con baja permitividad eléctrica ((200 bar) = 1.5) y sin capacidad para aceptar puentes de hidrógeno ( = 0 ), aunque estas características contrastan con su capacidad disolvente frente a determinados sustratos, particularmente compuestos fluorados, y sus interacciones con los grupos funcionales básicos de moléculas orgánicas, como grupos carbonilo o hidroxilo. El estudio de reacciones orgánicas fuertemente sensibles al disolvente en CO2sc descrito en el presente traba…
Genetic polymorphism at the CSN1S1 gene in Girgentana dairy goat breed
2013
The aim of this work was to evaluate the variability of the αs1-casein locus in the endangered Girgentana dairy goat breed in order to define genetic improvement and a conservation program for this breed. The study was performed on 200 dairy goats by means of different PCR protocols. The most frequent alleles were A (0.590) and F (0.290) followed by B (0.065) and N (0.047). CSN1S1 E allele was identified with a very low frequency (0.008). The most common genotype was AF (0.365) followed by AA (0.340). The high frequency of the strong genotypes is associated with the production of milk with high fat and protein content and with optimal technological properties. In Girgentana goat breed, the …
Addition von Phosphor‐Nucleophilen an Benzothiet
1991
Addition Reactions of Phosphorus Nucleophiles to Benzothiete Trialkyl phosphites 4 add to the o-quinoid form 2 of benzothiete (1) to yield the phosphonates 6. An intermolecular migration of an alkyl group from oxygen to sulfur is the most important feature of this transformation. The rearrangement – related to the Arbuzov reaction – can be avoided in a two-step process by the subsequent action of PCl3 and alcohol; thus the phosphonates 10 are generated. Analogous to 2 6, dimethyl phenylphosphinate (11) furnishes 13. In contrast, the cyclic esters 14a–d form 2:1 adducts, namely the 12- to 15-membered heterocyclic compounds 17a – d. An intramolecular rearrangement in a 1:1 adduct is only obse…
Experimental and DFT study of the conversion of ephedrine derivatives into oxazolidinones. Double SN2 mechanism against SN1 mechanism
2010
Sulfonation of the N-Boc derivatives of 1,2-aminoalcohols, such as ephedrine, pseudoephedrine, norephedrine, norpseudoephedrine, thiomicamine, and chloramphenicol yields a mixture of the corresponding oxazolidinones with inversion (erythro derivatives) and/or retention of configuration (threo derivatives)at C5. We suggest a competition between two mechanisms: an intramolecular SN2 process initiated by attack of the carbonyl oxygen of the Boc group to the benzylic carbon and the other one through a double SN2 process. In the erythro derivatives the first mechanism is predominant, while in the threo derivatives both mechanisms have similar energy. This hypothesis is supported by theoretical c…