A naturally occurring splicing site mutation in the Brassica rapa FLC1 gene is associated with variation in flowering time

FLOWERING LOCUS C (FLC), encoding a MADS-domain transcription factor in Arabidopsis, is a repressor of flowering involved in the vernalization pathway. This provides a good reference for Brassica species. Genomes of Brassica species contain several FLC homologues and several of these colocalize with flowering-time QTL. Here the analysis of sequence variation of BrFLC1 in Brassica rapa and its association with the flowering-time phenotype is reported. The analysis revealed that a G→A polymorphism at the 5’ splice site in intron 6 of BrFLC1 is associated with flowering phenotype. Three BrFLC1 alleles with alternative splicing patterns, including two with different parts of intron 6 retained and one with the entire exon 6 excluded from the transcript, were identified in addition to alleles with normal splicing. It was inferred that aberrant splicing of the pre-mRNA leads to loss-of-function of BrFLC1. A CAPS marker was developed for this locus to distinguish Pi6+1(G) and Pi6+1(A). The polymorphism detected with this marker was significantly associated with flowering time in a collection of 121 B. rapa accessions and in a segregating Chinese cabbage doubled-haploid population. These findings suggest that a naturally occurring splicing mutation in the BrFLC1 gene contributes greatly to flowering-time variation in B. rapa

Lattice Boltzmann simulations of soft matter systems

This article concerns numerical simulations of the dynamics of particles immersed in a continuum solvent. As prototypical systems, we consider colloidal dispersions of spherical particles and solutions of uncharged polymers. After a brief explanation of the concept of hydrodynamic interactions, we give a general overview over the various simulation methods that have been developed to cope with the resulting computational problems. We then focus on the approach we have developed, which couples a system of particles to a lattice Boltzmann model representing the solvent degrees of freedom. The standard D3Q19 lattice Boltzmann model is derived and explained in depth, followed by a detailed discussion of complementary methods for the coupling of solvent and solute. Colloidal dispersions are best described in terms of extended particles with appropriate boundary conditions at the surfaces, while particles with internal degrees of freedom are easier to simulate as an arrangement of mass points with frictional coupling to the solvent. In both cases, particular care has been taken to simulate thermal fluctuations in a consistent way. The usefulness of this methodology is illustrated by studies from our own research, where the dynamics of colloidal and polymeric systems has been investigated in both equilibrium and nonequilibrium situations.Comment: Review article, submitted to Advances in Polymer Science. 16 figures, 76 page

Evaluation of blood reservation and use for caesarean sections in a tertiary maternity unit in south western Nigeria

<p>Abstract</p> <p>Background</p> <p>Haemorrhage from obstetric causes is the most common cause of maternal mortality in the developing world. Prevention of mortality from haemorrhage will necessarily involve prompt blood transfusions among other life saving measures. There are however limited stocks of fresh or stored blood in many health care facilities in Sub Saharan Africa. Caesarean section has been identified as a common indication for blood transfusion in obstetrics practice and its performance is often delayed by non availability of blood in our centre. An evaluation of blood reservation and use at caesarean sections in a tertiary maternity unit in Lagos, south western Nigeria should therefore assist in formulating the most rational blood transfusion policies.</p> <p>Methods</p> <p>Case records of 327 patients who had elective and emergency caesarian sections at the Lagos State University Teaching Hospital between 1^stOctober and 31^stDecember 2007 were reviewed. Data pertaining to age, parity, booking status, type and indication for Caesarean section, pre- and post-operative packed cell volume, blood loss at surgery, units of blood reserved in the blood bank, unit(s) of blood transfused and duration of hospital stay was extracted and the data analysed.</p> <p>Results</p> <p>There were 1056 deliveries out of which 327 (31%) were by Caesarean section. During the study period, a total of 654 units of blood were reserved in the blood bank and subsequently made available in theatre. Out of this number, only 89 (13.6%) were transfused to 41 patients. Amongst those transfused, twenty-six (54%) were booked and 31 (75.6%) had primary caesarian section. About 81% of those transfused had emergency caesarean section. The most common indication for surgery among those transfused were placenta praevia (9 patients with 21 units of blood) and cephalo-pelvic disproportion (8 patients with 13 units).</p> <p>Conclusion</p> <p>Even though a large number of units of blood was reserved and made available in the theatre at the time of operation, majority of the patients operated did not need blood transfusion. Provision of a mini- blood bank within the obstetric unit and careful patient categorization will ensure timely availability of blood for surgery without necessarily tying down stock in the central blood bank.</p

Digital game elements, user experience and learning

The primary aim of this paper is to identify and theoretically validate the relationships between core game design elements and mechanics, user motivation and engagement and consequently learning. Additionally, it tries to highlight the moderating role of player personality traits on learning outcomes and acceptance and suggest ways to incorporate them in the game design process. To that end, it outlines the role of narrative, aesthetics and core game mechanics in facilitating higher learning outcomes through intrinsic motivation and engagement. At the same time, it discusses how player goal orientation, openness to experience, conscientiousness, sensation seeking and need for cognition influence the translation of the gameplay experience into valuable learning outcomes and user acceptance of the technology

CCDC98 is a BRCA1-BRCT domain-binding protein involved in the DNA damage response

The product of the breast cancer-1 gene, BRCA1, plays a crucial part in the DNA damage response through its interactions with many proteins, including BACH1, CtIP and RAP80. Here we identify a coiled-coil domain-containing protein, CCDC98, as a BRCA1-interacting protein. CCDC98 colocalizes with BRCA1 and is required for the formation of BRCA1 foci in response to ionizing radiation. Moreover, like BRCA1, CCDC98 has a role in radiation sensitivity and damage-induced G2/M checkpoint control. Together, these results suggest that CCDC98 is a mediator of BRCA1 function involved in the mammalian DNA damage response