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The aim of this study is to understand the role of pumilio (pure) in mouse embryonic development, focusing on posterior embryonic patterning and germ cell development. In Drosophila, pum mRNA is expressed throughout the embryo but is concentrated at the posterior pole where germ (pole) cells form. PUM protein is ubiquitously expressed, but found in high levels in germline stem cells in the ovary, pure is required for abdominal formation and maintenance of germline stem cells as well as pole cell migration and division. A mouse cDNA library was screened with a probe to pum and two homologues were cloned (Mpum-L and Mpum-S). Both mouse genes have the conserved RNA binding domain consisting of 8 repeats ('Puf' motif). Our initial studies have focused on examining the mRNA and protein expression pattern of both Mpum-L and Mpum-S in the mouse embryo and in adult testis and ovary. RT-PCR analysis of Mpum-L and Mpum-S revealed that these genes are expressed in all stages examined (E6.5-17.5). The MPUM protein is expressed ubiquitously at E8.5 but is expressed at high levels in the cells of the corpus luteum in the adult mouse ovary. Mpum-L and Mpum-S mRNAs are expressed in the spermatocytes and spermatogonia of the adult testis and in the follicle cells in the ovary. We have screened a mouse 129SvJ genomic library, identified genomic clones for both Mpum-L and Mpum-S, and are generating targeting vectors and mapping these genes. Our hypothesis is that Mpum-L and Mpum-S may play a role in germ cell development in the mouse embryo.

Copyright of Canadian Journal of Plant Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aim To compare bolus insulin delivery patterns during closed-loop home studies in adults with suboptimally [HbA1c 58–86 mmol/mol (7.5%–10%)] and well-controlled [58 mmol/mol (< 7.5%)] Type 1 diabetes. Methods Retrospective analysis of daytime and night-time insulin delivery during home use of closed-loop over 4 weeks. Daytime and night-time controller effort, defined as amount of insulin delivered by closed-loop relative to usual basal insulin delivery, and daytime bolus effort, defined as total bolus insulin delivery relative to total daytime insulin delivery were compared between both cohorts. Correlation analysis was performed between individual bolus behaviour (bolus effort and frequency) and daytime controller efforts, and proportion of time spent within and below sensor glucose target range. Results Individuals with suboptimally controlled Type 1 diabetes had significantly lower bolus effort (P = 0.038) and daily bolus frequency (P < 0.001) compared with those with well-controlled diabetes. Controller effort during both daytime (P = 0.007) and night-time (P = 0.005) were significantly higher for those with suboptimally controlled Type 1 diabetes. Time when glucose was within the target range (3.9–10.0 mmol/L) during daytime correlated positively with bolus effort (r = 0.37, P = 0.016) and bolus frequency (r = 0.33, P = 0.037). Time when glucose was below the target range during daytime was comparable in both groups (P = 0.36), and did not correlate significantly with bolus effort (r = 0.28, P = 0.066) or bolus frequency (r = –0.21, P = 0.19). Conclusion More frequent bolusing and higher proportion of insulin delivered as bolus during hybrid closed-loop use correlated positively with time glucose was in target range. This emphasises the need for user input and educational support to benefit from this novel therapeutic modality. [ABSTRACT FROM AUTHOR]

Liquid ternary FeCoCu alloy was undercooled by up to 357 K (0.21 T ) with glass fluxing method and its rapidly solidified microstructures were investigated by EDS and EBSD technologies. The ternary FeCoCu alloy rapidly solidifies with rapid dendritic growth of the primary γ-Fe phase within 37-243 K undercooling range. When the alloy melt is undercooled to 243 K, an obvious phase separation takes place and the uniform alloy melt separates into (Fe, Co)-rich and Cu-rich phases within 243-357 K undercooling range. The primary γ-Fe phase takes place in a solid-state phase transformation and becomes α-Fe phase in the final microstructure. The microstructure of α-Fe phase transforms from coarse dendrite at small undercoolings to equiaxed grain at large undercoolings. EBSD analysis reveals that the coarse α-Fe dendrites grows anisotropically with a $$\left\langle {110} \right\rangle$$ preferred orientation on condition that undercooling is less than 178 K, whereas no apparent preferred growth orientation is found in the equiaxed grains once undercooling exceeds this critical value. The growth velocity of primary γ-Fe dendrite increases up to 37 ms as undercooling increases to 243 K, but it decreases as undercooling further increases, ascribing to that the dendrite growth is impeded by phase separation. [ABSTRACT FROM AUTHOR]

Microgravity solidification provides a particular opportunity to produce an extraordinary microstructure and optimized mechanical properties. To shed further light on the influence of rapid solidification mechanism on mechanical properties, both the microgravity solidification mechanism and resultant micromechanical properties of ternary Al 57 Ag 12 Ge 31 alloy were analyzed by means of drop tube, nanoindentation and frictional sliding techniques, which was compared with equilibrium solidification condition. The solidification pathways changed with the decrease of droplet size, owing to a larger cooling rate and a higher undercooling. Consequently, the microstructure transformed from dendrites plus two-phase eutectic to two-phase eutectics, eventually to anomalous ternary eutectic, while the thickness of surface (Ge) layer decreased. The micromechanical properties of rapidly solidified alloy droplets were evidently improved with the decrease of droplet size, which is mainly ascribed to the microstructure refinement and the homogenous distribution especially of hardening (Ge) phase. The measured microhardness, yield strength, strain hardening exponent, pile-up resistance and friction coefficient were analyzed as a function of droplet size. [ABSTRACT FROM AUTHOR]

Recirculating biofloc technology (RBFT) has been gradually acknowledged for its positive effect on the control of biofloc concentration using a hydrodynamic vortex separator (HDVS). To operate an RBFT system at maximum performance, the removal efficiency of an HDVS at different hydraulic retention times (HRTs) must be fully predictable. Hence, a numerical study of the fluid flow and particle dynamics was performed to characterize the performance of an HDVS at varying HRTs. First, flow simulation was conducted to determine an economical mesh size at an HRT of 248 s. Then, with respect to the total suspended solids (TSS) in the RBFT system and the physical properties of the flocs, two-way coupling of the dense discrete phase model (DDPM) and discrete element model (DEM) methods was used to predict floc tracking in an HDVS. Additionally, the Reynolds averaged Navier-Stokes (RANS) equations with the Reynolds stress turbulence model (RSM) were solved using the finite volume method based on the semi-implicit method pressure-linked equations (SIMPLE) pressure correction algorithm in the computational domain. Finally, pilot-scale studies were conducted to verify the simulation models. Based on the simulation results, floc management in an RBFT system is briefly discussed. Due to limited research on the numerical simulation and operating conditions of an HDVS in an RBFT system, this article describes an original investigation of the modeling approach. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Plant Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Plant Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)