Genome-wide dFOXO targets and topology of the transcriptomic response to stress and insulin signalling

FoxO transcription factors, inhibited by insulin/insulin-like growth factor signalling (IIS), are crucial players in numerous organismal processes including lifespan. Using genomic tools, we uncover over 700 direct dFOXO targets in adult female Drosophila. dFOXO is directly required for transcription of several IIS components and interacting pathways, such as TOR, in the wild-type fly. The genomic locations occupied by dFOXO in adults are different from those observed in larvae or cultured cells. These locations remain unchanged upon activation by stresses or reduced IIS, but the binding is increased and additional targets activated upon genetic reduction in IIS. We identify the part of the IIS transcriptional response directly controlled by dFOXO and the indirect effects and show that parts of the transcriptional response to IIS reduction do not require dfoxo. Promoter analyses revealed GATA and other forkhead factors as candidate mediators of the indirect and dfoxoindependent effects. We demonstrate genome-wide evolutionary conservation of dFOXO targets between the fly and the worm Caenorhabditis elegans, enriched for a second tier of regulators including the dHR96/daf-12 nuclear hormone receptor. Molecular Systems Biology 7: 502; published online 21 June 2011; doi:10.1038/msb.2011.3

Operando XAFS investigation on the effect of ash deposition on three-way catalyst used in gasoline particulate filters and the effect of the manufacturing process on the catalytic activity

Platinum group metals such as palladium and rhodium based catalysts are currently being implemented in gasoline particulate filter (GPF) autoexhaust after treatment systems. However, little is known about how the trapped particulate matter, such as the incombustible ash, interacts with the catalyst and so may affect its performance. This operando study follows the evolution of the Pd found in two different model GPF systems: one containing ash components extracted from a GPF and another from a catalyst washcoat prior to adhesion onto the GPF. We show that the catalytic activity of the two systems vary when compared with a 0 g ash containing GPF. Compared to the 0 g ash sample the 20 g ash containing sample had a higher CO light off temperature, in addition, an oscillation profile for CO, CO2 and O2 was observed, which is speculated to be a combination of CO oxidation, C deposition via a Boudouard reaction and further partial oxidation of the deposited species to CO. During the ageing procedure the washcoat sample reduces NO at a lower temperature than the 0 g ash sample. However, post ageing the 0 g ash sample recovers and both samples reduce NO at 310 °C. In comparison, the 20 g ash GPF sample maintains a higher NO reduction temperature of 410 °C post ageing, implying that the combination of high temperature ageing and presence of ash has an irreversible negative effect on catalyst performance

Influence of synthesis conditions on the structure of nickel nanoparticles and their reactivity in selective asymmetric hydrogenation

Unsupported and SiO2-supported Ni nanoparticles (NPs), were synthesised via hot-injection colloidal route using oleylamine (OAm) and trioctylphosphine (TOP) as reducing and protective agents, respectively. By adopting a multi-length scale structural characterization, it was found that by changing equivalents of OAM and TOP not only the size of the nanoparticles is affected but also the Ni electronic structure. The synthetized NPs were modified with (R,R)-tartaric acid (TA) and investigated in the asymmetric hydrogenation of methyl acetoacetate to chiral methyl-3-hydroxy butyrate. The comparative analysis of structure and catalytic performance for the synthetized catalysts has enabled us to identify a Ni metallic active surface, whereby the activity increases with the size of the metallic domains. Conversely, at the high conversion obtained for the unsupported NPs no impact of particle size on the selectivity was observed. (R)-selectivity was very high only on catalysts containing positively charged Ni species such as over the SiO2-supported Ni oxide NPs. This work shows that the chiral modification of metallic Ni NPs with TA is insufficient to maintain high selectivity towards the (R)-enantiomer at long reaction time and provide guidance for the engineering of long-term stable enantioselective catalysts

Interfacial Chemistry in the Electrocatalytic Hydrogenation of CO_{2} over C-Supported Cu-Based Systems

Operando soft and hard X-ray spectroscopic techniques were used in combination with plane-wave density functional theory (DFT) simulations to rationalize the enhanced activities of Zn-containing Cu nanostructured electrocatalysts in the electrocatalytic CO2 hydrogenation reaction. We show that at a potential for CO2 hydrogenation, Zn is alloyed with Cu in the bulk of the nanoparticles with no metallic Zn segregated; at the interface, low reducible Cu(I)-O species are consumed. Additional spectroscopic features are observed, which are identified as various surface Cu(I) ligated species; these respond to the potential, revealing characteristic interfacial dynamics. Similar behavior was observed for the Fe-Cu system in its active state, confirming the general validity of this mechanism; however, the performance of this system deteriorates after successive applied cathodic potentials, as the hydrogen evolution reaction then becomes the main reaction pathway. In contrast to an active system, Cu(I)-O is now consumed at cathodic potentials and not reversibly reformed when the voltage is allowed to equilibrate at the open-circuit voltage; rather, only the oxidation to Cu(II) is observed. We show that the Cu-Zn system represents the optimal active ensembles with stabilized Cu(I)-O; DFT simulations rationalize this observation by indicating that Cu-Zn-O neighboring atoms are able to activate CO2, whereas Cu-Cu sites provide the supply of H atoms for the hydrogenation reaction. Our results demonstrate an electronic effect exerted by the heterometal, which depends on its intimate distribution within the Cu phase and confirms the general validity of these mechanistic insights for future electrocatalyst design strategies

Instrument development, data collection, and characteristics of practices, staff, and measures in the Improving Quality of Care in Diabetes (iQuaD) Study

Peer reviewedPublisher PD

Low-cost liquid medium for in vitro cultivation of Leishmania parasites in low-income countries

Background: Cutaneous Leishmaniasis (CL) induced by Leishmania aethiopica has two clinical manifestations: ulcerating, self-healing CL and non-ulcerating, non-healing CL. The grossly disfiguring multiple nodules on the face and exterior surface of limbs during non-ulcerative CL are sometimes misdiagnosed as other skin infections. Thus the need for definitive and prompt laboratory diagnosis will be required. Identifying Leishmania parasite by culture method is considered as a definitive method for initiation of treatment and as an effective component of leishmaniasis control methods. Recently the involvement of Fas (CD95) and Tumor Necrosis Factor (TNF) Related Apoptosis Inducing Ligand (TRAIL) induced apoptotic pathways were proposed to be involved in tissue destruction and ulceration during L. major induced CL. Aims: 1) to develop an alternative culture media that could minimize the cost for culturing Leishmania from patient lesions. 2) to investigate if the expression of FasL and TRAIL differs in ulcerating and non- ulcerative CL. Methods: GALF-1 media was formulated in our lab and compared to RPMI 1640 medium and conventional Locke s semi solid media (LSSM) which is one of the modifications of Novy-MacNeal-Nicolle (NNN) culture media. Amastigotes transformation, cryopreservation, recovery of parasites, cost and mass cultivation were analysed. Expression of Fas ligand (FasL), TRAIL and apoptosis were assessed by immunohistology in human skin biopsies from L. aethiopica induced ulcerative or non-ulcerative CL. FasL and TRAIL blocking experiments were performed in a murine model of CL. Results and discussion: GALF-1 is cheap and its ingredients available in a low income country such as Ethiopia. GALF-1 was able to transform amastigotes from Ethiopian patients samples and could be used to cultivate promastigotes in large quantities. Cost analysis showed 80% to 95 % decreased costs as compared to conventional media. Promastigotes cultured with GALF-1 could be cryopreserved in liquid nitrogen with comparable re-culture potential to conventional media. Affordability of diagnostic assays is a key issue for resource poor countries and the possibility to cut the cost of the efficient culture method for diagnosis through the use of inexpensive local formulated reagents could improve the diagnosis of leishmaniasis in low income endemic countries. More FasL expressing cells were detected in dermis of ulcerative CL as compared to non-ulcerative CL and controls. TRAIL expression was higher in ulcerative CL as compared to non-ulcerative CL and controls in both epidermis and dermis. Increased dermal expression of FasL and TRAIL was associated with ulcer formation during CL. This correlated with an inhibition of the ulcerative process in a murine CL model during FasL and TRAIL neutralisation.The mechanisms of the involvement of FasL and TRAIL in ulceration was not elucidated and putative reason(s) for the difference in dysregulation of apoptosis are discussed

Improving the delivery of care for patients with diabetes through understanding optimised team work and organisation in primary care

Peer reviewedPublisher PD

Treatment of distal humeral fractures using conventional implants. Biomechanical evaluation of a new implant configuration

<p>Abstract</p> <p>Background</p> <p>In the face of costly fixation hardware with varying performance for treatment of distal humeral fractures, a novel technique (U-Frame) is proposed using conventional implants in a 180° plate arrangement. In this in-vitro study the biomechanical stability of this method was compared with the established technique which utilizes angular stable locking compression plates (LCP) in a 90° configuration.</p> <p>Methods</p> <p>An unstable distal 3-part fracture (AO 13-C2.3) was created in eight pairs of human cadaveric humeri. All bone pairs were operated with either the "Frame" technique, where two parallel plates are distally interconnected, or with the LCP technique. The specimens were cyclically loaded in simulated flexion and extension of the arm until failure of the construct occurred. Motion of all fragments was tracked by means of optical motion capturing. Construct stiffness and cycles to failure were identified for all specimens.</p> <p>Results</p> <p>Compared to the LCP constructs, the "Frame" technique revealed significant higher construct stiffness in extension of the arm (P = 0.01). The stiffness in flexion was not significantly different (P = 0.16). Number of cycles to failure was found significantly larger for the "Frame" technique (P = 0.01).</p> <p>Conclusions</p> <p>In an in-vitro context the proposed method offers enhanced biomechanical stability and at the same time significantly reduces implant costs.</p

Long-distance endosome trafficking drives fungal effector production during plant infection

To cause plant disease, pathogenic fungi can secrete effector proteins into plant cells to suppress plant immunity and facilitate fungal infection. Most fungal pathogens infect plants using very long strand-like cells, called hyphae, that secrete effectors from their tips into host tissue. How fungi undergo long-distance cell signalling to regulate effector production during infection is not known. Here we show that long-distance retrograde motility of early endosomes (EEs) is necessary to trigger transcription of effector-encoding genes during plant infection by the pathogenic fungus Ustilago maydis. We demonstrate that motor-dependent retrograde EE motility is necessary for regulation of effector production and secretion during host cell invasion. We further show that retrograde signalling involves the mitogen-activated kinase Crk1 that travels on EEs and participates in control of effector production. Fungal pathogens therefore undergo long-range signalling to orchestrate host invasion