56 research outputs found
Fatty Acid Composition in the Mature Milk of Bolivian Forager-Horticulturalists: Controlled Comparisons With a US Sample
Breast milk fatty acid (FA) composition varies greatly among individual women, including in percentages of the long-chain polyunsaturated FAs (LCPUFA) 20:4n-6 (arachidonic acid, AA) and 22:6n-3 (docosahexaenoic acid, DHA), which are important for infant neurological development. It has been suggested that owing to wide variation in milk LCPUFA and low DHA in Western diets, standards of milk FA composition should be derived from populations consuming traditional diets. We collected breast milk samples from Tsimane women at varying lactational stages (6–82 weeks). The Tsimane are an indigenous, natural fertility, subsistence-level population living in Amazonia Bolivia. Tsimane samples were matched by lactational stage to samples from a US milk bank, and analysed concurrently for FA composition by gas-liquid chromatography. We compared milk FA composition between Tsimane (n = 35) and US (n = 35) mothers, focusing on differences in LCPUFA percentages that may be due to population-typical dietary patterns. Per total FAs, the percentages of AA, DHA, total n-3 and total n-6 LCPUFA were significantly higher among Tsimane mothers. Mean percentages of 18:2n-6 (linoleic acid) and trans FAs were significantly higher among US mothers. Tsimane mothers’ higher milk n-3 and n-6 LCPUFA percentages may be due to their regular consumption of wild game and freshwater fish, as well as comparatively lower intakes of processed foods and oils that may interfere with LCPUFA synthesis
Seismic isolation of Advanced LIGO: Review of strategy, instrumentation and performance
The new generation of gravitational waves detectors require unprecedented levels of isolation from seismic noise. This article reviews the seismic isolation strategy and instrumentation developed for the Advanced LIGO observatories. It summarizes over a decade of research on active inertial isolation and shows the performance recently achieved at the Advanced LIGO observatories. The paper emphasizes the scientific and technical challenges of this endeavor and how they have been addressed. An overview of the isolation strategy is given. It combines multiple layers of passive and active inertial isolation to provide suitable rejection of seismic noise at all frequencies. A detailed presentation of the three active platforms that have been developed is given. They are the hydraulic pre-isolator, the single-stage internal isolator and the two-stage internal isolator. The architecture, instrumentation, control scheme and isolation results are presented for each of the three systems. Results show that the seismic isolation sub-system meets Advanced LIGO's stringent requirements and robustly supports the operation of the two detectors.Laser Interferometer Gravitational-Wave ObservatoryNational Science Foundation (U.S.
Natural Selection of Immune and Metabolic Genes Associated with Health in Two Lowland Bolivian Populations
A growing body of work has addressed human adaptations to diverse environments using genomic data, but few studies have connected putatively selected alleles to phenotypes, much less among underrepresented populations such as Amerindians. Studies of natural selection and genotype–phenotype relationships in underrepresented populations hold potential to uncover previously undescribed loci underlying evolutionarily and biomedically relevant traits. Here, we worked with the Tsimane and the Moseten, two Amerindian populations inhabiting the Bolivian lowlands. We focused most intensively on the Tsimane, because long-term anthropological work with this group has shown that they have a high burden of both macro and microparasites, as well as minimal cardiometabolic disease or dementia. We therefore generated genome-wide genotype data for Tsimane individuals to study natural selection, and paired this with blood mRNA-seq as well as cardiometabolic and immune biomarker data generated from a larger sample that included both populations. In the Tsimane, we identified 21 regions that are candidates for selective sweeps, as well as 5 immune traits that show evidence for polygenic selection (e.g., C-reactive protein levels and the response to coronaviruses). Genes overlapping candidate regions were strongly enriched for known involvement in immune-related traits, such as abundance of lymphocytes and eosinophils. Importantly, we were also able to draw on extensive phenotype information for the Tsimane and Moseten and link five regions (containing PSD4, MUC21 and MUC22, TOX2, ANXA6, and ABCA1) with biomarkers of immune and metabolic function. Together, our work highlights the utility of pairing evolutionary analyses with anthropological and biomedical data to gain insight into the genetic basis of health-related traits
Fatty acid composition in the mature milk of Bolivian foragerhorticulturalists: Controlled comparisons with a U.S. sample.
Abstract Breast milk fatty acid (FA) composition varies greatly among individual women, including in percentages of the long-chain polyunsaturated FAs (LCPUFA) 20:4n-6 (arachidonic acid, AA) and 22:6n-3 (docosahexaenoic acid, DHA), which are important for infant neurological development. It has been suggested that owing to wide variation in milk LCPUFA and low DHA in Western diets, standards of milk FA composition should be derived from populations consuming traditional diets. We collected breast milk samples from Tsimane women at varying lactational stages (6-82 weeks). The Tsimane are an indigenous, natural fertility, subsistence-level population living in Amazonia Bolivia. Tsimane samples were matched by lactational stage to samples from a US milk bank, and analysed concurrently for FA composition by gas-liquid chromatography. We compared milk FA composition between Tsimane (n = 35) and US (n = 35) mothers, focusing on differences in LCPUFA percentages that may be due to population-typical dietary patterns. Per total FAs, the percentages of AA, DHA, total n-3 and total n-6 LCPUFA were significantly higher among Tsimane mothers. Mean percentages of 18:2n-6 (linoleic acid) and trans FAs were significantly higher among US mothers. Tsimane mothers' higher milk n-3 and n-6 LCPUFA percentages may be due to their regular consumption of wild game and freshwater fish, as well as comparatively lower intakes of processed foods and oils that may interfere with LCPUFA synthesis
Viewpoint: The economics of hunter-gatherer societies and the evolution of human characteristics
Oxidative Stretching of Metal–Metal Bonds to Their Limits
Oxidation of quadruply bonded Cr<sub>2</sub>(dpa)<sub>4</sub>, Mo<sub>2</sub>(dpa)<sub>4</sub>, MoW(dpa)<sub>4</sub>, and W<sub>2</sub>(dpa)<sub>4</sub> (dpa = 2,2′-dipyridylamido)
with 2 equiv of silver(I) triflate or ferrocenium triflate results
in the formation of the two-electron-oxidized products [Cr<sub>2</sub>(dpa)<sub>4</sub>]<sup>2+</sup> (<b>1</b>), [Mo<sub>2</sub>(dpa)<sub>4</sub>]<sup>2+</sup> (<b>2</b>), [MoW(dpa)<sub>4</sub>]<sup>2+</sup> (<b>3</b>), and [W<sub>2</sub>(dpa)<sub>4</sub>]<sup>2+</sup> (<b>4</b>). Additional two-electron oxidation
and oxygen atom transfer by <i>m</i>-chloroperoxybenzoic
acid results in the formation of the corresponding metal–oxo
compounds [Mo<sub>2</sub>O(dpa)<sub>4</sub>]<sup>2+</sup> (<b>5</b>), [WMoO(dpa)<sub>4</sub>]<sup>2+</sup> (<b>6</b>), and [W<sub>2</sub>O(dpa)<sub>4</sub>]<sup>2+</sup> (<b>7</b>), which feature
an unusual linear M···MO structure. Crystallographic
studies of the two-electron-oxidized products <b>2</b>, <b>3</b>, and <b>4</b>, which have the appropriate number of
orbitals and electrons to form metal–metal triple bonds, show
bond distances much longer (by >0.5 Å) than those in established
triply bonded compounds, but these compounds are nonetheless diamagnetic.
In contrast, the Cr–Cr bond is completely severed in <b>1</b>, and the resulting two isolated Cr<sup>3+</sup> magnetic
centers couple antiferromagnetically with <i>J</i>/<i>k</i><sub>B</sub>= −108(3) K [−75(2) cm<sup>–1</sup>], as determined by modeling of the temperature dependence of the
magnetic susceptibility. Density functional theory (DFT) and multiconfigurational
methods (CASSCF/CASPT2) provide support for “stretched”
and weak metal–metal triple bonds in <b>2</b>, <b>3</b>, and <b>4</b>. The metal–metal distances in
the metal–oxo compounds <b>5</b>, <b>6</b>, and <b>7</b> are elongated beyond the single-bond covalent radii of the
metal atoms. DFT and CASSCF/CASPT2 calculations suggest that the metal
atoms have minimal interaction; the electronic structure of these
complexes is used to rationalize their multielectron redox reactivity
Structural and biological investigation of ferrocene-substituted 3-methylidene-1,3-dihydro-2H-indol-2-ones
The Knoevenagel condensation of 1,3-dihydro-2H-indol-2-one with ferrocene carboxaldehyde afforded an approximate 2:1 mixture of the geometrical isomers (E)- and (Z)-3-ferrocenylmethylidene-1,3-dihydro-2H-indol-2-one respectively in an overall 67% yield; the air and solution-stable isomers were readily separated by preparative thin layer chromatography and their structures were unequivocally elucidated in solution, by (1)H NMR spectroscopy, and in the solid phase, by X-ray crystallography; both isomers of displayed in vitro toxicity against B16 melanoma and Vero cell lines in the micromolar range and inhibited the kinase VEGFR-2 with IC(50) values of ca. 200 nM
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