Racemic tricarbonyl[(4a,5,6,7,8,8a-η)-2-phenyl-3,4-dihydro-2H-1-benzopyran]chromium(0)

The title compound, [Cr(C15H14O)(CO)3], displays a distorted envelope configuration of the dihydro­pyrane ring. The dihedral angle between the phenyl and phenyl­ene rings is 50.63 (4)°. The Cr0 atom is coordinated by three CO groups and the phenyl­ene ring of the flavan ligand in an η6 mode, with a common arene-to-metal distanc

Racemic tricarbon­yl(η6-7-meth­oxy­flavan)chromium(0)

In the title compound [systematic name: tricarbonyl(η6-7-methoxy-2-phenyl-3,4-dihydro-2H-1-benzopyran)chromium(0)], [Cr(C16H16O2)(CO)3], the Cr(CO)3 unit is coordinated by the phenyl­ene ring of the flavan ligand, exhibiting a three-legged piano-stool conformation, with a point to plane distance of 1.750 (1) Å. The phenyl ring is twisted away from the fused ring system by 36.49 (5)° (r.m.s. deviation = 0.027 Å; fitted atoms are the C6 ring and the attached fused-ring C and O atoms). The dihydro­pyran ring displays a distorted envelope configuration by displacement of the phenyl-bearing and the adjacent ring C atoms from the fused-ring system plane by 0.356 (2) and 0.402 (2) Å, respectively

Tricarbon­yl(η6-flavone)chromium(0)

In the title compound, [Cr(C15H10O2)(CO)3], the Cr(CO)3 unit exhibits a three-legged piano-stool conformation. The chromium metal centre is coordinated by the phenyl ring of the flavone ligand [Cr—(phenyl centroid) distance = 1.709 (1) Å]. The ligand is approximately planar, the dihedral angles between the γ-pyrone ring and the phenyl ring and between the γ-pyrone and the phenyl­ene ring being 2.91 (5) and 3.90 (5)°, respectively. The mol­ecular packing shows π–π stacking between the flavone ligands of neighbouring mol­ecules

2′,3,4,4′,5-Penta­meth­oxy­chalcone

In the title chalcone [systemetic name 1-(2,4-dimeth­oxy­phen­yl)-3-(3,4,5-trimeth­oxy­phen­yl)prop-2-en-1-one], C20H22O6, the dihedral angle between the plane of the two benzene rings is 7.03 (4)° with all but one of the meth­oxy groups essentially co-planar with these rings [C—C—O—C torsion angles = −76.1 (2), −0.7 (3), 1.8 (3), −6.2 (3), 2.0 (3)°]. An intra­molecular C—H⋯O inter­action occurs. The crystal packing is stabilized by weak inter­molecular C—H⋯O hydrogen bonds

Morphological Development in Sorghum Grain

Immature sorghum grain was harvested at various stages of maturity and its development followed by transmission and scanning electron microscopy . This was done to study the developmental morphology of the sorghum grain. The period immediately following fertilization is a time of rapid development in the sorghum caryopsis. The endosperm expands crush i ng the nucellus and in the nonbirdres i stant sorghums the inner integument is also crushed during this expansion. The cells of the ovary wal 1 expand and elongate to form the peri carp . By the soft dough stage the endosperm has gained most of its storage material and thereafter there is a considerable loss of moisture . During the early stages of development the endosperm cell walls were extensively pitted which could allow for translocation . However, once the period of translocation was over the cell walls became intact

4,5-Bis(2,4-di-tert-butyl­phen­oxy)phthalonitrile

In the title compound, C36H44N2O2, the dihedral angles between the phthalonitrile ring and the two di-tert-butyl­benzene rings are 68.134 (8) and 70.637 (11)°. The two nitrile groups are almost coplanar with the phthalonitrile ring except for one of the N atoms which deviates from the plane by 0.125 (4) Å. One of the tert-butyl groups is disordered over two orientations, with refined occupancies of 0.814 (6) and 0.186 (6). Intra­molecular C—H⋯O inter­actions stabilize the molecular structure. The crystal packing is stabilized by inter­molecular C—H⋯N inter­actions

2′,3,4,4′-Tetra­meth­oxy­chalcone

In the title compound [systematic name: 1-(2,4-dimethoxyphenyl)-3-(3,4-dimethoxyphenyl)prop-2-en-1-one], C19H20O5, the dihedral angle between the benzene rings is 26.88 (5)°. One of the meth­oxy groups is twisted slightly away from the plane [C—O—C—C torsion angle = −12.8 (3)°] while the others are almost co-planer [C—O—C—C torsion angles = −3.2 (3), 2.6 (3) and −3.6 (3)°]. The crystal packing is stabilized by inter­molecular C—H⋯O inter­actions. A weak intra­molecular C—H⋯O inter­action occurs

Antigenic diversity is generated by distinct evolutionary mechanisms in African trypanosome species

Antigenic variation enables pathogens to avoid the host immune response by continual switching of surface proteins. The protozoan blood parasite Trypanosoma brucei causes human African trypanosomiasis ("sleeping sickness") across sub-Saharan Africa and is a model system for antigenic variation, surviving by periodically replacing a monolayer of variant surface glycoproteins (VSG) that covers its cell surface. We compared the genome of Trypanosoma brucei with two closely related parasites Trypanosoma congolense and Trypanosoma vivax, to reveal how the variant antigen repertoire has evolved and how it might affect contemporary antigenic diversity. We reconstruct VSG diversification showing that Trypanosoma congolense uses variant antigens derived from multiple ancestral VSG lineages, whereas in Trypanosoma brucei VSG have recent origins, and ancestral gene lineages have been repeatedly co-opted to novel functions. These historical differences are reflected in fundamental differences between species in the scale and mechanism of recombination. Using phylogenetic incompatibility as a metric for genetic exchange, we show that the frequency of recombination is comparable between Trypanosoma congolense and Trypanosoma brucei but is much lower in Trypanosoma vivax. Furthermore, in showing that the C-terminal domain of Trypanosoma brucei VSG plays a crucial role in facilitating exchange, we reveal substantial species differences in the mechanism of VSG diversification. Our results demonstrate how past VSG evolution indirectly determines the ability of contemporary parasites to generate novel variant antigens through recombination and suggest that the current model for antigenic variation in Trypanosoma brucei is only one means by which these parasites maintain chronic infections

Development and usability evaluation of a nutrition and lifestyle guidance application for people living with and beyond cancer

There is a need to provide accessible information for health care professionals and for people living beyond treatment. Mobile and digital health technologies provide an ideal platform to access diet and nutrition guidance that is both trusted and evidence-based and so that people know how to alter and monitor eating patterns and behaviours to improve the quality of life. Participatory design and usability evaluation approaches have been utilised to develop a nutrition and lifestyle guidance smartphone application for both people living with and beyond cancer, and for health care professionals involved in advising such patients. The challenges centred on the design, development and evaluation of the first version of a new mobile application named ‘Life Beyond’ are presented. This proof of concept application aims to centralise evidence-based nutrition and lifestyle guidance for those living beyond cancer. It enables users to obtain guidance and information, create and track nutrition and activity related goals and track their progress in the completion of these goals. Consistent feedback from participatory design and usability evaluations drove this research and helped to create an initial solution that met the user expectations. The System Usability Scale (SUS) score of 67.69 denotes an ‘average’ usability and hence further development. More research of extensive end user engagement is needed before an optimal solution is disseminated

Measurements of q2 moments of inclusive B →xcℓ+νℓ decays with hadronic tagging

We present the measurement of the first to fourth order moments of the four-momentum transfer squared, q2, of inclusive B→Xcℓ+νℓ decays using the full Belle dataset of 711 fb-1 of integrated luminosity at the (4S) resonance where ℓ=e, μ. The determination of these moments and their systematic uncertainties open new pathways to determine the absolute value of the Cabibbo-Kobayashi-Maskawa matrix element Vcb using a reduced set of matrix elements of the heavy quark expansion. In order to identify and reconstruct the Xc system, we reconstruct one of the two B-mesons using machine learning techniques in fully hadronic decay modes. The moments are measured with progressively increasing threshold selections on q2 starting with a lower value of 3.0 GeV2 in steps of 0.5 GeV2 up to a value of 10.0 GeV2. The measured moments are further unfolded, correcting for reconstruction and selection effects as well as QED final state radiation. We report the moments separately for electron and muon final states and observe no lepton flavor universality violating effects