领导-部属交换对组织负面影响机制研究——印象管理的研究视角

在34个团队共688份问卷的基础上,从资源为导向的发展观出发,探讨领导-部属交换水平对员工职业成长的影响机制,并检验了领导-部属交换差异性在上述资源分配影响过程中的调节作用。通过跨层次的研究方法,研究发现领导-部属交换水平对员工职业成长有正向相关作用,并且对员工的迎合行为有正向影响,员工迎合行为在上述影响过程中起到中介作用。在探讨领导-部属交换差异性对上述影响机制的调节作用时,通过数据发现,领导-部属交换差异性在领导-部属交换水平对员工职业成长的影响中有调节作用。阐述了上述研究结论所产生的原因,探讨了领导-部属交换过程领导所面临的双重困境。     

Mitotic Diversity in Homeostatic Human Interfollicular Epidermis

Despite decades of skin research, regulation of proliferation and homeostasis in human epidermis is still insufficiently understood. To address the role of mitoses in tissue regulation, we utilized human long-term skin equivalents and systematically assessed mitoses during early epidermal development and long-term epidermal regeneration. We now demonstrate four different orientations: (1) horizontal, i.e., parallel to the basement membrane (BM) and suggestive of symmetric divisions; (2) oblique with an angle of 45°–70°; or (3) perpendicular, suggestive of asymmetric division. In addition, we demonstrate a fourth substantial fraction of suprabasal mitoses, many of which are committed to differentiation (Keratin K10-positive). As verified also for normal human skin, this spatial mitotic organization is part of the regulatory program of human epidermal tissue homeostasis. As a potential marker for asymmetric division, we investigated for Numb and found that it was evenly spread in almost all undifferentiated keratinocytes, but indeed asymmetrically distributed in some mitoses and particularly frequent under differentiation-repressing low-calcium conditions. Numb deletion (stable knockdown by CRISPR/Cas9), however, did not affect proliferation, neither in a three-day follow up study by life cell imaging nor during a 14-day culture period, suggesting that Numb is not essential for the general control of keratinocyte division.     

Advances and Perspectives in Dental Pulp Stem Cell Based Neuroregeneration Therapies

Human dental pulp stem cells (hDPSCs) are some of the most promising stem cell types for regenerative therapies given their ability to grow in the absence of serum and their realistic possibility to be used in autologous grafts. In this review, we describe the particular advantages of hDPSCs for neuroregenerative cell therapies. We thoroughly discuss the knowledge about their embryonic origin and characteristics of their postnatal niche, as well as the current status of cell culture protocols to maximize their multilineage differentiation potential, highlighting some common issues when assessing neuronal differentiation fates of hDPSCs. We also review the recent progress on neuroprotective and immunomodulatory capacity of hDPSCs and their secreted extracellular vesicles, as well as their combination with scaffold materials to improve their functional integration on the injured central nervous system (CNS) and peripheral nervous system (PNS). Finally, we offer some perspectives on the current and possible future applications of hDPSCs in neuroregenerative cell therapies.     

Mechanical and biological evaluation of 3D printed 10CeTZP-Al2O3 structures

Three-dimensional structures were robocasted from a 10 mol% ceria-stabilized zirconia and alumina composite (10CeTZP-Al₂O₃). A hydrogel-based printable ink was developed using a unique non-ionic copolymer surfactant. Self-supporting and free-standing structures, including round lattices with interconnected pores (200–600 μm pores; 30–50% porosity), rectangular bars (95% density on average) and cones were successfully printed. The round lattices of 200 μm pores and 30% porosity showed compression strengths similar to those of cortical bone, reaching almost 200 MPa. The maximum flexural strength value attained for the rectangular bars was 575 MPa. In vitro biological studies demonstrated that the samples allow for practically 100% cell viability, confirming their non-cytotoxic nature. Cell differentiation tests were performed using osteoblasts incubated for 7 days in supplemented cell culture medium. Quantification of specific osseous differentiation genes showed that the robocasted structures induced a higher degree of osseous differentiation than tissue culture polystyrene.     

Framework of emergence: from chain of value to value constellation

ABSTRACT

For academic design programmes and research councils, finding mechanisms to measure impact and valuate co-design research projects is very difficult. The metric parameters – number of attendees, volume, shape, length – have shown to be insufficient. The subject matter, the subjects and matters, do not easily fit within these parameters, which fail to translate the value of a ‘constellation of affections’ that emerge throughout co-design processes. Emphasis on quantifiable impact derives from particular ways of understanding production, reproduction, and dissemination of knowledge. This paper understands academic design programmes as a technology to discuss axiology in co-design practices. This paper re-configures a techno-logic of value; from chain of value to value constellation, intersecting a co-design case study with readings of Simondon’s philosophy of technology and Barad’s agential realism. Ageing Playfully was a knowledge exchange project from The Creative Exchange programme, that involved people living with dementia and their caregivers co-designing interventions to boost mobility and well-being. At the core, this paper, explores an axiological move that informs a framework of emergence, a way of thinking in methods to account for the value of co-design as site of emergence.     

Price and lead time differentiation,capacity strategy and market competition

We study a duopoly market in which customers are heterogeneous, and can be segmented as price or time sensitive. Each firm tailors (differentiates) its products/services for the two customer classes solely based on guaranteed lead time and the corresponding price. Our objective is to understand how competition affects price and lead time differentiation of the firms in the presence of different operations strategy (shared versus dedicated capacity), product substitution and asymmetry between the competing firms. Our results suggest that when firms use dedicated resources to serve the two market segments, pure price competition always tends to decrease individual prices as well as price differentiation, irrespective of the market behaviour. Further, the effect of competition is more pronounced when customers are allowed to self-select, thereby introducing substitutability between the two product options. On the other hand, when firms compete in time, in addition to price, the effect of competition on product differentiation depends crucially on the behaviour of the market. Our results further suggest that the firm with a larger market base should always maintain a larger price and lead time differentiation between the two market segments. Similarly, the firm with a capacity cost advantage should also maintain a larger lead time differentiation.     

Hypoxia Suppresses Spontaneous Mineralization and Osteogenic Differentiation of Mesenchymal Stem Cells via IGFBP3 Up-Regulation

Hypoxia has diverse stimulatory effects on human adipose-derived stem cells (ASCs). In the present study, we investigated whether hypoxic culture conditions (2% O₂) suppress spontaneous mineralization and osteogenic differentiation of ASCs. We also investigated signaling pathways and molecular mechanisms involved in this process. We found that hypoxia suppressed spontaneous mineralization and osteogenic differentiation of ASCs, and up-regulated mRNA and protein expression of Insulin-like growth factor binding proteins (IGFBPs) in ASCs. Although treatment with recombinant IGFBPs did not affect osteogenic differentiation of ASCs, siRNA-mediated inhibition of IGFBP3 attenuated hypoxia-suppressed osteogenic differentiation of ASCs. In contrast, overexpression of IGFBP3 via lentiviral vectors inhibited ASC osteogenic differentiation. These results indicate that hypoxia suppresses spontaneous mineralization and osteogenic differentiation of ASCs via intracellular IGFBP3 up-regulation. We determined that reactive oxygen species (ROS) generation followed by activation of the MAPK and PI3K/Akt pathways play pivotal roles in IGFBP3 expression under hypoxia. For example, ROS scavengers and inhibitors for MAPK and PI3K/Akt pathways attenuated the hypoxia-induced IGFBP3 expression. Inhibition of Elk1 and NF-κB through siRNA transfection also led to down-regulation of IGFBP3 mRNA expression. We next addressed the proliferative potential of ASCs with overexpressed IGFBP3, but IGFBP3 overexpression reduced the proliferation of ASCs. In addition, hypoxia reduced the osteogenic differentiation of bone marrow-derived clonal mesenchymal stem cells. Collectively, our results indicate that hypoxia suppresses the osteogenic differentiation of mesenchymal stem cells via IGFBP3 up-regulation.     

Throughput-based fair bandwidth allocation in OBS networks

Fair bandwidth allocation (FBA) has been studied in optical burst switching (OBS) networks, with the main idea being to map the max-min fairness in traditional IP networks to the fair-loss probability in OBS networks. This approach has proven to be fair in terms of the bandwidth allocation for differential connections, but the use of the ErlangB formula to calculate the theoretical loss probability has made this approach applicable only to Poisson flows. Furthermore, it is necessary to have a reasonable fairness measure to evaluate FBA models. This article proposes an approach involving throughput-based-FBA, called TFBA, and recommends a new fairness measure that is based on the ratio of the actual throughput to the allocated bandwidth. An analytical model for the performance of the output link with TFBA is also proposed.     

German consumer evaluations of milk in blind and nonblind tests

Greater differentiation is being made between types of milk according to product and process characteristics. This study investigated consumer preferences for 4 different types of milk in packaging-blind and nonblind experiments. The taste of long-life milk, conventional fresh whole milk, pasture-based milk, and organic milk was assessed by 138 randomly selected respondents. The average taste of packaging-blind versus nonblind milk types was statistically significantly different for each of the 4 milk types. Consumers appeared to be influenced by the milk's packaging and related credence-good attributes. It is noteworthy that the taste of organic milk during the blind tasting was given a lower rating, and the taste of long-life milk or UHT milk a higher rating, than when respondents were aware of the respective milk types. The study estimated multilevel mixed-effects logistic regression models with the response variable buying decision. Of all the factors studied in the blind and nonblind tasting of almost all milk types, buying decisions were influenced most by taste, overall assessment and income.