Confinement Effects in Lewis Acid-Catalyzed Sugar Conversion: Steering Toward Functional Polyester Building Blocks

We report the use of solid Lewis acid catalysts for the conversion of tetrose sugars to four-carbon α-hydroxy acid esters (C_4-AHA), which are useful as functional polyester building blocks. Sn-β was by far the most active and selective catalyst, yielding up to 80% methyl vinyl glycolate (MVG), methyl-4-methoxy-2-hydroxybutanoate (MMHB), and α-hydroxy-γ-butyrolactone (HBL) combined at 95% conversion. A very high turnover frequency (TOF) of 330 mol_(C4-AHA) mol_(Sn) h^(–1) was attained using Sn-β, a more than 6-fold increase compared with homogeneous SnCl_4·5H_2O. It is shown that, using different Sn-based catalysts with various pore sizes, the product distribution is strongly dependent on the size of the catalyst pores. Catalysts containing mainly mesopores, such as Sn-MCM-41 or Sn-SBA-15, prefer the production of the more bulky MMHB, whereas microporous catalysts such as Sn-β or Sn-MFI favor the production of MVG. This effect can be further enhanced by increasing the reaction temperature. At 363 K, only 20% MVG is attained using Sn-β, but at 433 K, this increases to 50%. Using a kinetic analysis, it was found that, in microporous catalysts, steric hindrance near the Sn active site in the catalyst pores plays a dominant role in favoring the reaction pathway toward MVG. Moreover, the selectivity toward both products is kinetically controlled

The Knight of Malta

BACKGROUND: For most women, participation in decision-making during maternity care has a positive impact on their childbirth experiences. Shared decision-making (SDM) is widely advocated as a way to support people in their healthcare choices. The aim of this study was to identify quality criteria and professional competencies for applying shared decision-making in maternity care. We focused on decision-making in everyday maternity care practice for healthy women. METHODS: An international three-round web-based Delphi study was conducted. The Delphi panel included international experts in SDM and in maternity care: mostly midwives, and additionally obstetricians, educators, researchers, policy makers and representatives of care users. Round 1 contained open-ended questions to explore relevant ingredients for SDM in maternity care and to identify the competencies needed for this. In rounds 2 and 3, experts rated statements on quality criteria and competencies on a 1 to 7 Likert-scale. A priori, positive consensus was defined as 70% or more of the experts scoring >/=6 (70% panel agreement). RESULTS: Consensus was reached on 45 quality criteria statements and 4 competency statements. SDM in maternity care is a dynamic process that starts in antenatal care and ends after birth. Experts agreed that the regular visits during pregnancy offer opportunities to build a relationship, anticipate situations and revisit complex decisions. Professionals need to prepare women antenatally for unexpected, urgent decisions in birth and revisit these decisions postnatally. Open and respectful communication between women and care professionals is essential; information needs to be accurate, evidence-based and understandable to women. Experts were divided about the contribution of professional advice in shared decision-making and about the partner's role. CONCLUSIONS: SDM in maternity care is a dynamic process that takes into consideration women's individual needs and the context of the pregnancy or birth. The identified ingredients for good quality SDM will help practitioners to apply SDM in practice and educators to prepare (future) professionals for SDM, contributing to women's positive birth experience and satisfaction with care

Near-infrared Imaging of a Spiral in the CQ Tau Disk

We present L'-band Keck/NIRC2 imaging and H-band Subaru/AO188+HiCIAO polarimetric observations of the CQ Tau disk with a new spiral arm. Apart from the spiral feature, our observations could not detect any companion candidates. We traced the spiral feature from the r[SUP]2[/SUP]-scaled High-Contrast Coronographic Imager for Adaptive Optics (HiCIAO) polarimetric intensity image and the fitted result is used for forward modeling to reproduce the ADI-reduced NIRC2 image. We estimated the original surface brightness after throughput correction in the L' band to be ∼126 mJy arcsec[SUP]-2[/SUP] at most. We suggest that the grain temperature of the spiral may be heated up to ∼200 K in order to explain both of the H- and L'-band results. The H-band emission at the location of the spiral originates from the scattering from the disk surface while both scattering and thermal emission may contribute to the L'-band emission. If the central star is only the light source of scattered light, the spiral emission at the L' band should be thermal emission. If an inner disk also acts as the light source, the scattered light and the thermal emission may equally contribute to the L'-band spiral structure

Deep Exploration of ϵ Eridani with Keck Ms-band Vortex Coronagraphy and Radial Velocities: Mass and Orbital Parameters of the Giant Exoplanet

We present the most sensitive direct imaging and radial velocity (RV) exploration of epsilon Eridani to date. epsilon Eridani is an adolescent planetary system, reminiscent of the early solar system. It is surrounded by a prominent and complex debris disk that is likely stirred by one or several gas giant exoplanets. The discovery of the RV signature of a giant exoplanet was announced 15 yr ago, but has met with scrutiny due to possible confusion with stellar noise. We confirm the planet with a new compilation and analysis of precise RV data spanning 30 yr, and combine it with upper limits from our direct imaging search, the most sensitive ever performed. The deep images were taken in the Ms band (4.7 μm) with the vortex coronagraph recently installed in W.M. Keck Observatory's infrared camera NIRC2, which opens a sensitive window for planet searches around nearby adolescent systems. The RV data and direct imaging upper limit maps were combined in an innovative joint Bayesian analysis, providing new constraints on the mass and orbital parameters of the elusive planet. epsilon Eridani b has a mass of 0.78_(-0.12)^(+0.38} M_(Jup) and is orbiting epsilon Eridani at about 3.48 ± 0.02 au with a period of 7.37 ± 0.07 yr. The eccentricity of epsilon Eridani b's orbit is 0.07_(-0.05)^(+0.06), an order of magnitude smaller than early estimates and consistent with a circular orbit. We discuss our findings from the standpoint of planet–disk interactions and prospects for future detection and characterization with the James Webb Space Telescope

Genome Sequence of the Pea Aphid Acyrthosiphon pisum

Aphids are important agricultural pests and also biological models for studies of insect-plant interactions, symbiosis, virus vectoring, and the developmental causes of extreme phenotypic plasticity. Here we present the 464 Mb draft genome assembly of the pea aphid Acyrthosiphon pisum. This first published whole genome sequence of a basal hemimetabolous insect provides an outgroup to the multiple published genomes of holometabolous insects. Pea aphids are host-plant specialists, they can reproduce both sexually and asexually, and they have coevolved with an obligate bacterial symbiont. Here we highlight findings from whole genome analysis that may be related to these unusual biological features. These findings include discovery of extensive gene duplication in more than 2000 gene families as well as loss of evolutionarily conserved genes. Gene family expansions relative to other published genomes include genes involved in chromatin modification, miRNA synthesis, and sugar transport. Gene losses include genes central to the IMD immune pathway, selenoprotein utilization, purine salvage, and the entire urea cycle. The pea aphid genome reveals that only a limited number of genes have been acquired from bacteria; thus the reduced gene count of Buchnera does not reflect gene transfer to the host genome. The inventory of metabolic genes in the pea aphid genome suggests that there is extensive metabolite exchange between the aphid and Buchnera, including sharing of amino acid biosynthesis between the aphid and Buchnera. The pea aphid genome provides a foundation for post-genomic studies of fundamental biological questions and applied agricultural problems

The Developing Human Connectome Project Neonatal Data Release

The Developing Human Connectome Project has created a large open science resource which provides researchers with data for investigating typical and atypical brain development across the perinatal period. It has collected 1228 multimodal magnetic resonance imaging (MRI) brain datasets from 1173 fetal and/or neonatal participants, together with collateral demographic, clinical, family, neurocognitive and genomic data from 1173 participants, together with collateral demographic, clinical, family, neurocognitive and genomic data. All subjects were studied in utero and/or soon after birth on a single MRI scanner using specially developed scanning sequences which included novel motion-tolerant imaging methods. Imaging data are complemented by rich demographic, clinical, neurodevelopmental, and genomic information. The project is now releasing a large set of neonatal data; fetal data will be described and released separately. This release includes scans from 783 infants of whom: 583 were healthy infants born at term; as well as preterm infants; and infants at high risk of atypical neurocognitive development. Many infants were imaged more than once to provide longitudinal data, and the total number of datasets being released is 887. We now describe the dHCP image acquisition and processing protocols, summarize the available imaging and collateral data, and provide information on how the data can be accessed

The CLAS12 Forward Tagger

This document presents the technical layout and the performance of the CLAS12 Forward Tagger (FT). The FT, composed of an electromagnetic calorimeter based on PbWO4 crystals (FT-Cal), a scintillation hodoscope (FT-Hodo), and several layers of Micromegas trackers (FT-Trk), has been designed to detect electrons and photons scattered at polar angles from 2∘ to 5∘ and to meet the physics goals of the hadron spectroscopy program and other experiments running with the CLAS12 spectrometer in Hall B