The Pax6 genes eyeless and twin of eyeless are required for global patterning of the ocular segment in the Tribolium embryo

AbstractThe transcription factor gene Pax6 is widely considered a master regulator of eye development in bilaterian animals. However, the existence of visual organs that develop without Pax6 input and the considerable pleiotropy of Pax6 outside the visual system dictate further studies into defining ancestral functions of this important regulator. Previous work has shown that the combinatorial knockdown of the insect Pax6 orthologs eyeless (ey) and twin of eyeless (toy) perturbs the development of the visual system but also other areas of the larval head in the red flour beetle Tribolium castaneum. To elucidate the role of Pax6 during Tribolium head development in more detail, we studied head cuticle morphology, brain anatomy, embryonic head morphogenesis, and developmental marker gene expression in combinatorial ey and toy knockdown animals. Our experiments reveal that Pax6 is broadly required for patterning the anterior embryonic head. One of the earliest detectable roles is the formation of the embryonic head lobes, which originate from within the ocular segment and give rise to large parts of the supraesophageal brain including the mushroom body, a part of the posterior head capsule cuticle, and the visual system. We present further evidence that toy continues to be required for the development of the larval eyes after formation of the embryonic head lobes in cooperation with the eye developmental transcription factor dachshund (dac). The sum of our findings suggests that Pax6 functions as a competence factor throughout the development of the insect ocular segment. Comparative evidence identifies this function as an ancestral aspect of bilaterian head development

Pax6 is required for the development of the lateral procephalon in tribolium

In Tribolium, combinatorial knockdown of the Pax6 orthologs eyeless (ey) and twin of eyeless (toy) affects the peripheral visual system but also other areas of the dorsal larval head capsule. To elucidate the role of Pax6 genes during Tribolium embryonic head development in detail, we performed an extensive analysis of cuticle elements, brain anatomy, embryonic head morphogenesis and developmental marker gene expression. Our results reveal that Pax6 is required for the development of a large contiguous area of the lateral anterior head, morphologically addressed as the embryonic head lobes, which encompass the neuroectodermal precursor tissues of the visual system, parts of the mushroom bodies, and the dorsal head cuticle. In addition to consolidating our understanding of the developmental compartmentalization of the early Tribolium head, these data characterize Pax6 genes as regional regulators of development

UNDERSTANDING INDIVIDUAL LEVEL ERP ASSIMILATION FROM A SOCIAL NETWORK PERSPECTIVE: A MULTI-CASE STUDY

Prior research on ERP assimilation has primarily focused on influntial factors at the organizational level. In this study, we attempt to extend our understanding of individual level ERP assimilation from the perspective of social network theory. We designed a multi-case study to explore the relations between ERP users´ social networks and their levels of ERP assimilation based on the three dimensions of the social networks. We gathered data through interviews with 26 ERP users at different levels in five companies. Qualitative analysis was used to understand the effects of social networks and individual interactive learning. We found that user social networks play a significant role in individual level ERP assimilation through interactive learning behaviours among users. We also found five key factors that facilitate users´ assimilation of ERP knowledge: homogeneity (age, position and rank), tie content (instrumental and expressive ties), tie strength, external ties, and centrality. Our research has significant implications for managing assimilation of ERP systems and improving users´ ERP assimilation level in organizations

DEVELOPMENT AND VALIDATION OF AN INSTRUMENT TO MEASURE INDIVIDUAL LEVEL ERP ASSIMILATION

Case evidence has shown the important role of individual level assimilation of ERP technology in realizing the business value of implemented ERP systems. However, empirical research in this area has been constrained by the lack of a validated scale for measuring individual level ERP assimilation. This study address this limitation by first theoretically conceptualizing three key dimensions through a multi-case study and then following a rigorous development process to validate a formative measurement instrument for individual level ERP assimilation. The findings show that individual level ERP assimilation consists of width, depth, and innovation, and the proposed measurement instrument is reliable and meets the validity requirements

Synthesis, characterization, and antifungal evaluation of novel 1,2,3-triazolium-functionalized starch derivative

1,2,3-Triazolium-functionalized starch derivative was obtained by straightforward quaternization of the synthesized starch derivative bearing 1,2,3-triazole with benzyl bromide by combining the robust attributes of cuprous-catalyzed azide-alkyne cycloaddition. These novel starch derivatives were characterized by FTIR, UV-vis, H-1 NMR, C-13 NMR, and elemental analysis. Their antifungal activities against Colletotrichum lagenarium, Watermelon fusarium, and Phomopsis asparagi were investigated by hypha measurement in vitro. The fungicidal assessment revealed that compared with starch and starch derivative bearing 1,2,3-triazole with inhibitory indices of below 15% at 1.0 mg/mL, 1,2,3-triazolium-functionalized starch derivative had superior antifungal activity with inhibitory rates of over 60%. Especially, the best inhibitory index of 1,2,3-triazolium-functionalized starch derivative against Colletotrichum lagenarium attained 90% above at 1.0mg/mL. The results obviously showed that quaternization of 1,2,3-triazole with benzyl bromide could effectively enhance antifungal activity of the synthesized starch derivatives. The synthetic strategy described here could be utilized for the development of starch as novel antifungal biomaterial. (C) 2017 Elsevier B.V. All rights reserved

cis-Diammine(glycolato-κ2 O 1,O 2)platinum(II)

The reaction of cis-[Pt(NO3)2(NH3)2] and sodium glycolate yielded the title compound, [Pt(C2H2O3)(NH3)2]. The PtII atom, coordinated by two N atoms of ammine and two O atoms of the carboxyl­ate and oxido groups of the glycolate ligand, is in a square-planar environment. In the crystal structure, mol­ecules are connected by inter­molecular N—H⋯O hydrogen bonds, forming a three-dimensional network

Numerical computation of the flow noise for the centrifugal pump with considering the impeller outlet width

In order to study the effects of the impeller outlet width on the flow noise of the centrifugal pump, a centrifugal pump is applied in the paper as the research object. Geometric parameters of the pump and impeller are constant, and BEM (Boundary Element Method) and experimental method are adopted to analyze noises when the impeller outlet width is 8 mm, 10 mm, 12 mm and 14 mm, respectively. Firstly, Large-eddy simulation method is applied to compute the transient flow field of the centrifugal pump. Larger pressures and flow velocity of the centrifugal pump mainly are at the edge of the impeller. When the fluid flows from the centrifugal pump, there are two obvious separation vortexes at the outlet of the centrifugal pump. The flow velocity distribution of the centrifugal pump in the horizontal plane is basically symmetric. Based on modal analysis and the transient flow field of the pump, BEM is adopted to compute the noise in the centrifugal pump caused by the unsteady flow, and experiments are also conducted for verification. Based on the above analysis, the noise in the interior and exterior field of the centrifugal pump is computed, and the effects of the impeller outlet width on the noise of the centrifugal pump are then studied. As shown from the result, the radiation sound power at the characteristic frequency increases with the increase of the impeller outlet width. With a reasonable range, the impeller outlet width makes the sound pressure level (SPL) in the interior and external field of various flow conditions be smaller. Considering the energy performance and flow field noises of the centrifugal pump, the pump has the optimal comprehensive performance at the impeller outlet width of 10 mm. The research results can be applied to provide a reference for the optimization design of the centrifugal pump with low vibration and noise

Shooting method for free vibration of FGM Reissner-Mindlin circular plates resting on elastic foundation in thermal environments

This paper presents a free vibration analysis of functionally graded Reissner-Mindlin circular plates with various supported boundaries in thermal environments. A FGM consisting of metal and ceramic was considered in the study. Based on the geometric equation, physical equation and equilibrium equation of thick plate, taking into account the transverse shearing deformation, the free vibration equation of the axisymmetric FGM moderately thick circular plates was derived in terms of the middle surface angles of rotation and lateral displacement. The material properties of the plate were assumed to vary continuously in the thickness direction according a power law. By using shooting method to solve the coupled ordinary differential equations with different boundary conditions, the natural frequencies of FGM thick circular plates were obtained numerically. The effects of material gradient property, thickness ratio and boundary conditions on the natural frequencies were discussed in detail