12 research outputs found

    Prenatal Diagnosis of Oculocutaneous Albinism by Electron Microscopy of Fetal Skin

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    Oculocutaneous albinism was diagnosed prenatally by electron microscopic examination of fetal skin samples taken during fetoscopy at 20 weeks of gestation. Melanosome development in hair bulb melanocytes progressed no further than stage II, indicating a lack of melanin synthesis. In 4 age-matched control fetuses, numerous stage IV melanosomes, signifying active melanin synthesis, were identified. The diagnosis was confirmed after the pregnancy was terminated at 22 weeks. Examination of the fetal eye showed absence of pigment in the retinal epithelium and uvea at a stage when ocular melanogenesis would normally be active. This study shows that oculocutaneous albinism can be detected in the second trimester using similar techniques to those employed in the prenatal diagnosis of epidermolysis bullosa and ichthyosis

    Improved precision on the experimental E0 decay branching ratio of the Hoyle state

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    Stellar carbon synthesis occurs exclusively via the 3α3\alpha process, in which three α\alpha particles fuse to form 12^{12}C in the excited Hoyle state, followed by electromagnetic decay to the ground state. The Hoyle state is above the α\alpha threshold, and the rate of stellar carbon production depends on the radiative width of this state. The radiative width cannot be measured directly, and must instead be deduced by combining three separately measured quantities. One of these quantities is the E0E0 decay branching ratio of the Hoyle state, and the current 1010\% uncertainty on the radiative width stems mainly from the uncertainty on this ratio. The E0E0 branching ratio was deduced from a series of pair conversion measurements of the E0E0 and E2E2 transitions depopulating the 02+0^+_2 Hoyle state and 21+2^+_1 state in 12^{12}C, respectively. The excited states were populated by the 12^{12}C(p,p)(p,p^\prime) reaction at 10.5 MeV beam energy, and the pairs were detected with the electron-positron pair spectrometer, Super-e, at the Australian National University. The deduced branching ratio required knowledge of the proton population of the two states, as well as the alignment of the 21+2^+_1 state in the reaction. For this purpose, proton scattering and γ\gamma-ray angular distribution experiments were also performed. An E0E0 branching ratio of ΓπE0/Γ=8.2(5)×106\Gamma^{E0}_{\pi}/\Gamma=8.2(5)\times10^{-6} was deduced in the current work, and an adopted value of ΓπE0/Γ=7.6(4)×106\Gamma^{E0}_{\pi}/\Gamma=7.6(4)\times10^{-6} is recommended based on a weighted average of previous literature values and the new result. The new recommended value for the E0E0 branching ratio is about 14% larger than the previous adopted value of ΓπE0/Γ=6.7(6)×106\Gamma^{E0}_{\pi}/\Gamma=6.7(6)\times10^{-6}, while the uncertainty has been reduced from 9% to 5%.Comment: Accepted for publication as a Regular Article in Phys. Rev. C on July 29 202

    Height and timing of growth spurt during puberty in young people living with vertically acquired HIV in Europe and Thailand.

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    OBJECTIVE: The aim of this study was to describe growth during puberty in young people with vertically acquired HIV. DESIGN: Pooled data from 12 paediatric HIV cohorts in Europe and Thailand. METHODS: One thousand and ninety-four children initiating a nonnucleoside reverse transcriptase inhibitor or boosted protease inhibitor based regimen aged 1-10 years were included. Super Imposition by Translation And Rotation (SITAR) models described growth from age 8 years using three parameters (average height, timing and shape of the growth spurt), dependent on age and height-for-age z-score (HAZ) (WHO references) at antiretroviral therapy (ART) initiation. Multivariate regression explored characteristics associated with these three parameters. RESULTS: At ART initiation, median age and HAZ was 6.4 [interquartile range (IQR): 2.8, 9.0] years and -1.2 (IQR: -2.3 to -0.2), respectively. Median follow-up was 9.1 (IQR: 6.9, 11.4) years. In girls, older age and lower HAZ at ART initiation were independently associated with a growth spurt which occurred 0.41 (95% confidence interval 0.20-0.62) years later in children starting ART age 6 to 10 years compared with 1 to 2 years and 1.50 (1.21-1.78) years later in those starting with HAZ less than -3 compared with HAZ at least -1. Later growth spurts in girls resulted in continued height growth into later adolescence. In boys starting ART with HAZ less than -1, growth spurts were later in children starting ART in the oldest age group, but for HAZ at least -1, there was no association with age. Girls and boys who initiated ART with HAZ at least -1 maintained a similar height to the WHO reference mean. CONCLUSION: Stunting at ART initiation was associated with later growth spurts in girls. Children with HAZ at least -1 at ART initiation grew in height at the level expected in HIV negative children of a comparable age

    High overlap between traditional ecological knowledge and forest conservation found in the Bolivian Amazon

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    Unidad de excelencia María de Maeztu MdM-2015-0552Altres ajuts: FBBVA research grant (BIOCON_06_106-07)It has been suggested that traditional ecological knowledge (TEK) may play a key role in forest conservation. However, empirical studies assessing to what extent TEK is associated with forest conservation compared with other variables are rare. Furthermore, to our knowledge, the spatial overlap of TEK and forest conservation has not been evaluated at fine scales. In this paper, we address both issues through a case study with Tsimane' Amerindians in the Bolivian Amazon. We sampled 624 households across 59 villages to estimate TEK and used remote sensing data to assess forest conservation. We ran statistical and spatial analyses to evaluate whether TEK was associated and spatially overlapped with forest conservation at the village level. We find that Tsimane' TEK is significantly and positively associated with forest conservation although acculturation variables bear stronger and negative associations with forest conservation. We also find a very significant spatial overlap between levels of Tsimane' TEK and forest conservation. We discuss the potential reasons underpinning our results, which provide insights that may be useful for informing policies in the realms of development, conservation, and climate. We posit that the protection of indigenous cultural systems is vital and urgent to create more effective policies in such realms

    First-excited state g factors in the stable, even Ge and Se isotopes FIRST-EXCITED STATE g FACTORS in the ... B. P. McCORMICK et al.

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    International audienceTransient-field gg-factor measurements in inverse kinematics were performed for the first-excited states of the stable, even isotopes of Ge and Se. The gg factors of 74^{74}Ge and 74^{74}Se were measured simultaneously using a cocktail beam, which eliminates most possible sources of systematic error in a relative gg-factor measurement. The results are g(74Se)/g(74Ge)=1.34(7)g(^{74}{\rm Se})/g(^{74}{\rm Ge})=1.34(7), g(70Ge)/g(74Ge)=1.16(15)g(^{70}{\rm Ge})/g(^{74}{\rm Ge}) = 1.16(15), g(72Ge)/g(74Ge)=0.92(13)g(^{72}{\rm Ge})/g(^{74}{\rm Ge})=0.92(13), g(76Ge)/g(74Ge)=0.88(5)g(^{76}{\rm Ge})/g(^{74}{\rm Ge})=0.88(5), g(76Se)/g(74Se)=0.96(7)g(^{76}{\rm Se})/g(^{74}{\rm Se})=0.96(7), g(78Se)/g(74Se)=0.82(5)g(^{78}{\rm Se})/g(^{74}{\rm Se})=0.82(5), g(80Se)/g(74Se)=0.99(7)g(^{80}{\rm Se})/g(^{74}{\rm Se})=0.99(7) and g(82Se)/g(74Se)=1.19(6)g(^{82}{\rm Se})/g(^{74}{\rm Se})=1.19(6). The measured gg-factor ratios are in agreement with ratios from previous measurements, despite considerable variation in previous reported absolute values. The absolute values of the gg factors remain uncertain, however the Rutgers parametrization was used to set the transient-field strength and then compare the experimental gg factors with shell-model calculations based on the JUN45 and jj44b interactions. Modest agreement was found between experiment and theory for both interactions. The shell model calculations indicate that the g(21+)g(2^+_1) values and trends are determined largely by the balance of the spin carried by orbital motion of the protons
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