334 research outputs found

    Venison Flavor: Study of Volatile Compounds in Cooked Deer Meat

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    Venison meat has a characteristic flavor which is acceptable if mild but some venison has a strong and objectionable flavor. The subject is of practical importance where deer is hunted as sport and for food. Each year in the State of Utah, over 180,000 hunters go in search of deer and over 130,000 animals are killed. This contributes about 10 1/2 million dollars to the economy of the state from licenses, lodging, transportation and other expenses of hunting. The problem is not only important in Utah but also in the U.S.A. and other parts of the world where venison is available and included in the diet. Little work has been done in the study of the components which give venison its characteristic flavor. Today, flavor chemistry is relatively a new field. Kurtz (1959) defines flavor as complex sensations resulting from the stimulation of the senses of odor, taste, feel, and sometimes vision and audition. Gas-liquid chromatography is a powerful tool to a flavor chemist. The first classical paper describing both the gas-liquid partition technique and a relatively simple apparatus for resolving the aliphatic acids was published int he year 19552 by James and Martin. In 1956 the number of published papers was approximately 200. By 1960, the use of this technique had increased tremendously as evidenced by the fact that the number of publications were then about 1700. Application of this technique has resulted in a number of papers on volatile compounds in various foods. The ultimate aim of studying these volatiles is to make it possible to improve the flavor of food products. The editor of Food Technology (Stewart, 1963) has stated that flavor is a challenge to a food technologist and that he has to answer such questions as: 1. Does the volatile compound which has been identified int eh sample have sensory properties 2. If so, what is its nature? 3. What combinations of components result in the sensory properties typical of the original product from which they were derived? Only after the studies have been made will we know the significance of these volatile compounds. The present study is a second phase in a project on investigation of venison quality and palatability being made under a federal aid project (W-97-R0 through the Utah Department of Fish and Game. These phases include (a) the effects of field care, aging and cooking on the venison meats and (b) flavor components, their presence, distribution and factors affecting the amounts of these components. In the previous work on item (b) above, a comparative study of water soluble flavor precursors of venison and beef was made (Reddy, 1964). The present study deals with the nature of volatile compounds in cooked venison samples and determination of differences in venison flavor in animals of different ages, sexes, and season of kill. Evaluation of flavor was also made by a panel of judges

    Alterations in Lipids and Adipocyte Hormones in Female-to-Male Transsexuals

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    Testosterone therapy in men and women results in decreased high-density lipoprotein cholesterol (HDL) and increased low-density lipoprotein cholesterol (LDL). We sought to determine whether testosterone therapy has this same effect on lipid parameters and adipocyte hormones in female-to-male (FTM) transsexuals. Twelve FTM transsexuals provided a fasting lipid profile including serum total cholesterol, HDL, LDL, and triglycerides prior to and after 1 year of testosterone therapy (testosterone enanthate or cypionate 50–125mg IM every two weeks). Subjects experienced a significant decrease in mean serum HDL (52 ± 11 to 40 ± 7mg/dL) (P < .001). The mean LDL (P = .316), triglyceride (P = .910), and total cholesterol (P = .769) levels remained unchanged. In a subset of subjects, we measured serum leptin levels which were reduced by 25% but did not reach statistical significance (P =.181) while resistin levels remained unchanged. We conclude that testosterone therapy in FTM transsexuals can promote an increased atherogenic lipid profile by lowering HDL and possibly reduce serum leptin levels. However, long-term studies are needed to determine whether decreases in HDL result in adverse cardiovascular outcomes.National Institutes of Health (M01RR000533

    The local adsorption site of methylthiolate on Au(1 1 1): Bridge or atop?

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    Measurements of the local adsorption geometry of the S head-group atom in the Au(1 1 1)(√3 × √3)R30°–CH3S surface have been made using normal incidence X-ray standing waves (NIXSW) and S 1s scanned-energy mode photoelectron diffraction on the same surface preparations. The results confirm that the local adsorption site is atop an Au atom in a bulk-continuation site with a S–Au bondlength of 2.42 ± 0.02 Å, and that there can be no significant fraction of coadsorbed bridging species as recently proposed in a combined molecular dynamics/experimental study by Mazzarello et al. [R. Mazzarello, A. Cossaro, A. Verdini, R. Rousseau, L. Casalis, M.F. Danisman, L. Floreano, S. Scandolo, A. Morgante, G. Scoles, Phys. Rev. Lett. 98 (2007) 016102]. The results do not, however, clearly distinguish the different local reconstruction (adatom) models proposed for this surface

    Alterations in Lipids and Adipocyte Hormones in Female-to-Male Transsexuals

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    Testosterone therapy in men and women results in decreased high-density lipoprotein cholesterol (HDL) and increased low-density lipoprotein cholesterol (LDL). We sought to determine whether testosterone therapy has this same effect on lipid parameters and adipocyte hormones in female-to-male (FTM) transsexuals. Twelve FTM transsexuals provided a fasting lipid profile including serum total cholesterol, HDL, LDL, and triglycerides prior to and after 1 year of testosterone therapy (testosterone enanthate or cypionate 50–125 mg IM every two weeks). Subjects experienced a significant decrease in mean serum HDL (52 ± 11 to 40 ± 7 mg/dL) (P < .001). The mean LDL (P = .316), triglyceride (P = .910), and total cholesterol (P = .769) levels remained unchanged. In a subset of subjects, we measured serum leptin levels which were reduced by 25% but did not reach statistical significance (P = .181) while resistin levels remained unchanged. We conclude that testosterone therapy in FTM transsexuals can promote an increased atherogenic lipid profile by lowering HDL and possibly reduce serum leptin levels. However, long-term studies are needed to determine whether decreases in HDL result in adverse cardiovascular outcomes

    Alterations in Lipids and Adipocyte Hormones in Female-to-Male Transsexuals

    Get PDF
    Testosterone therapy in men and women results in decreased high-density lipoprotein cholesterol (HDL) and increased low-density lipoprotein cholesterol (LDL). We sought to determine whether testosterone therapy has this same effect on lipid parameters and adipocyte hormones in female-to-male (FTM) transsexuals. Twelve FTM transsexuals provided a fasting lipid profile including serum total cholesterol, HDL, LDL, and triglycerides prior to and after 1 year of testosterone therapy (testosterone enanthate or cypionate 50–125 mg IM every two weeks). Subjects experienced a significant decrease in mean serum HDL (52 ± 11 to 40 ± 7 mg/dL) (P < .001). The mean LDL (P = .316), triglyceride (P = .910), and total cholesterol (P = .769) levels remained unchanged. In a subset of subjects, we measured serum leptin levels which were reduced by 25% but did not reach statistical significance (P = .181) while resistin levels remained unchanged. We conclude that testosterone therapy in FTM transsexuals can promote an increased atherogenic lipid profile by lowering HDL and possibly reduce serum leptin levels. However, long-term studies are needed to determine whether decreases in HDL result in adverse cardiovascular outcomes

    Large magnetoresistance using hybrid spin filter devices

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    A magnetic "spin filter" tunnel barrier, sandwiched between a non-magnetic metal and a magnetic metal, is used to create a new magnetoresistive tunnel device, somewhat analogous to an optical polarizer-analyzer configuration. The resistance of these trilayer structures depends on the relative magnetization orientation of the spin filter and the ferromagnetic electrode. The spin filtering in this configuration yields a previously unobserved magnetoresistance effect, exceeding 100%.Comment: 3.5 pages, 3 figures, submitted to Appl. Phys. Let

    Iron in Ice Cores from Law Dome, East Antarctica: Implications for Past Deposition of Aerosol Iron

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    Total-dissolvable iron has been measured in sections of three ice cores from Law Dome, East Antarctica, and the results used to calculate atmospheric iron deposition over this region during the late Holocene and to provide a preliminary est. of aerosol iron deposition during the Last Glacial Maximum (LGM). Ice-core sections dating from 56-2730 BP (late Holocene) and ∼18 000 BP (LGM) were decontaminated using trace-metal clean techniques, and total-dissolvable iron was determined in the acidified meltwaters by flow-injection analysis. Our results suggest that the atmospheric iron flux onto the Law Dome region has varied significantly over time-scales ranging from seasonal to glacial-interglacial. The iron concentrations in ice-core sections from the past century suggest (1) a 2-4-fold variation in the atmospheric iron flux over a single annual cycle, with the highest flux occurring during the spring and summer, and (2) a nearly 7-fold variation in the annual maximum atmospheric iron flux over a 14 yr period. The average estimated atmospheric iron flux calculated from our late-Holocene samples is 0.056-0.14 mg m-2 a-1, which agrees well with Holocene flux estimates derived from aluminum measurements in inland Antarctic ice cores and a recent order-of-magnitude estimate of present-day atmospheric iron deposition over the Southern Ocean. The iron concentration of an ice-core section dating from the LGM was more than 50 times higher than in the late-Holocene ice samples. Using a snow-accumulation rate est. of 130 kg m-2 a-1 for this period, we calculate 0.87 mg m-2 a-1 as a preliminary estimate of atmospheric iron deposition during the LGM, which is 6-16 times greater than our average Late-Holocene iron flux. Our data are consistent with the suggestion that there was a significantly greater flux of atmospheric iron onto the Southern Ocean during the LGM than during the Holocene

    Lead Isotopes and Selected Metals in Ice from Law Dome, Antarctica

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    The isotopic composition. of Pb and the concentrations of Pb, Ba and Bi were measured in selected ice-core samples from Law Dome, East Antarctica, to a depth of 1196 m. The range of concentrations found in decontaminated ice was 0.03-1.5 pg g-1 for Pb, 0.9-6.1 pg g-1 for Ba and 0.4-17 fg g-1 for Bi, excluding the deepest sample which contained ∼1 ppm of rock dust. The abundances of all four stable lead isotopes were measured and gave 206Pb/207Pb ratios ≤ ∼1.23. A value of 208Pb/207Pb = 2.78 was measured in the deepest sample and is consistent with reported Pb isotope ratios of Antarctic granulites. Although the element concentrations in some samples were lower than have been reported elsewhere, geochemical and isotopic evidence indicated that a number of samples were contaminated with Pb not present in the original ice. However, it appears that the technical skills now available are approaching the level where careful sample selection, decontamination and analysis can yield accurate results for the concentration and isotopic composition of Pb in Earth\u27s purest naturally occurring ice
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