Establishing the Drosophila Larval Neuroblast as a System to Study Regulated Cell Death in vivo.

Programmed cell death is often thought of as a developmental process that is genetically hardwired to occur in the organism in a spatially and temporally specific manner. However, many forms of regulated cell death occur in response to pathological injury or environmental stress. Cell death in response to injury, in particular genotoxic stress, is well documented, but the pathways by which damage is translated to cell death have remained largely elusive. Furthermore, many cell death pathways function independently of the well-known process of apoptosis. These alternative regulated cell death pathways are likely controlled by novel molecular mechanisms. While examining mutations that cause loss of neural stem cells (neuroblasts) in Drosophila larval brains, we discovered a novel mechanism elicited by Cdc20/Fizzy (Fzy) that maintains neuroblasts by promoting their survival. We identified two fzy loss-of-function mutations that specifically led to neuroblast loss without perturbing the proliferation of other cell types. Consistently, mutant Fzy or Cdc20 carrying the analogous mutation can substitute for wild-type Cdc20 and restore cell cycle progression in fzy mutant brains. Furthermore, these fzy mutant neuroblasts do not display characteristics indicative of known cell death pathways, such as apoptosis, autophagic cell death, or mitotic catastrophe. Instead, morphological and functional analyses strongly suggest that Fzy maintains neuroblasts by suppressing necrotic cell death. Inactivating the function of apoptosis inducing factor (aif) or c-Jun N-terminal kinase (JNK) signaling prolonged the survival of fzy mutant neuroblasts, while ectopically activating JNK signaling triggers premature necrotic cell death in neuroblasts. These results suggest that JNK signaling and aif play a role in neuroblast necrosis. Loss of telomere capping proteins or chaperonin proteins required for spindle formation caused a similar necrosis phenotype as the fzy mutant neuroblasts. These mutations also caused DNA damage or cell cycle disruption. Furthermore, over-expression of the cell cycle checkpoint protein p53 also caused neuroblast necrosis. Importantly, Fzy expression was decreased in each of these mutations. We propose a novel necrotic cell death mechanism triggered by catastrophic damage of neuroblasts which leads to up-regulation of p53. Increased p53 activity results in loss of Fzy expression and Fzy-dependent necrotic cell death.PHDCellular and Molecular BiologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/111586/1/ckuang_1.pd

Social media dissemination of counter accounts and stakeholder support – evidence from greenpeace’s “Save the Arctic” campaign on Facebook

Prior studies have examined NGOs’ accounting practices and the implications of such practices within the social media realm. However, we know little about how NGOs use social media to disseminate counter accounts and the impacts of such dissemination beyond social media platforms. This paper examines whether NGOs’ dissemination of counter accounts can mobilize stakeholder support in a campaign against corporate actions. Drawing on Castells’ network-making perspective and the notion of dialogic accounting, I argue that social media dissemination of counter accounts strengthens NGOs’ network-making power so that a wide range of corporate stakeholders can be engaged, and a strong network can be potentially formed to increase the effectiveness of NGOs’ campaigns. Drawing on a unique dataset of Greenpeace “Save The Arctic” (STA) global petition signatories and stakeholder interactions from a sample of 8,336 Greenpeace Facebook messages related to the STA campaign, I find that stakeholder support is positively associated with stakeholder interactions with disseminated counter accounts and the number of Facebook accounts connected in disseminating such information. Additional analyses also reveal that Greenpeace disseminates counter accounts via social media to attract policymaker attention and the disseminated counter accounts are associated with public opinions towards climate change. Overall, this study sheds light on the implications of NGOs’ dissemination of counter accounts on social media in initiating social activism and accumulating power against irresponsible corporate practices

Overview of 2015 International Symposium on Animal Environment and Welfare held in Chongqing, China

On October 24-25, 2015 International Symposium on Animal Environment and Welfare (ISAEW2015), jointly sponsored by the International Research Center for Animal Environment and Welfare (IRCAEW) and the Chinese Society of Agricultural Engineering, was convened in Chongqing Academy of Animal Sciences (CAAS), Chongqing, China. Prof. Baoming Li from China Agricultural University (CAU) and Distinguished Prof. Hongwei Xin from Iowa State University were the Co-Chairs of ISAEW2015, and Prof. Zuohua Liu from CAAS chaired the Organizing Committee. Prof. Jun Bao, President of Northeast Agriculture University, China, presided over the opening ceremony. Prof. Xiwen Luo, an Academician of Chinese Academy of Engineering, presented the challenges and shared his thoughts on the sustainable development of animal production industry in China in the opening remarks

Managing stakeholder perceptions: Organized hypocrisy in CSR disclosures on Facebook

This study examines stakeholders’ perceptions of CSR disclosures by exploiting big data about the interactions between firms and stakeholders in social media. Given that social media represent public arenas where divergent – sometimes conflicting - stakeholder interests are present and debated, we draw on organized hypocrisy theory to explore how stakeholders react to hypocrisy talk, decisions, and actions strategies employed in CSR disclosures on Facebook. We retrieve and analyze S&P100 firms’ Facebook posts and the related stakeholders’ reactions for the period starting 24th February 2016 to 2nd March 2017. We find that stakeholders exhibit diverse reactions towards firms’ hypocrisy strategies. While stakeholders put more value on firms’ actions-related information, and such actions disclosures attract both positive and negative reactions, talk and decisions disclosures generate positive reactions and reduce negative perceptions. We also investigate how stakeholder reactions trigger firms’ post-disclosure replies and find that firms engage selectively with stakeholders, avoiding those who have concerns or criticism towards firms’ CSR practices. Overall, our findings show that the use of organized hypocrisy disclosure strategies in social media allows firms to manage stakeholder perceptions and maintain legitimacy

A governance approach to stakeholder engagement in sustainable enterprises – evidence from B Corps

Sustainable enterprises face a risk for which the pressure over financial sustainability “crowds out” their impact mission. Corporate governance mechanisms can play an important role in managing the tensions between the two objectives, by steering and driving stakeholder engagement processes. At the same time, the rise of social media has provided firms with a platform for undertaking stakeholder engagement on a large scale. Therefore, the aim of this study is to examine how the governance mechanisms of sustainable enterprises affect engagement with stakeholders on social media. Specifically, we identify three distinctive mechanisms for a governance approach to stakeholder engagement in sustainable enterprises: the legal purpose beyond profit maximisation, directors’ commitment to purpose, and the adoption of purpose-specific accountability mechanisms. We argue that each of them matters for the extent to which sustainable enterprises engage with stakeholders on social media, as well as the quality of this engagement. By scraping and classifying non-financial tweets posted by 1,074 U.S. B Corps between 2014 and 2018 and those posted by stakeholders towards the firm, we find that the legal and ethical mechanisms are positively related to the quality of engagement while the accountability mechanism is related to both the extent and quality of engagement. Our study sheds light on the implications of governance mechanisms in steering social media stakeholder engagement in sustainable enterprises

Study of (3He, t) charge exchange reactions to isobaric analog states in inverse kinematics

The transition between isobaric analog states (IAS) in the (3He, t) charge exchange reaction presents a unique opportunity to access the isospin structure of the nuclei. In this study not only the Fermi transition but also the Gamow-Teller (G-T) transition of the IAS reaction were investigated for the 13,14C(3He, t) and 17,18,19,20O(3He, t) reactions, in order to explore the neutron number dependence of the IAS reaction for the light neutron-rich nuclei. It was found that the G-T type IAS reaction also exhibited a significant dependence of the transition strength on the neutron number and the angular momentum configuration of the nuclei. Additionally, the inverse kinematics was also discussed for extracting the yields of the interested reaction channels in the proposed experiments on radioactive beams. The calculated triton yields demonstrated the capability of the proposed experiments to obtain meaningful results

Atomistic Quantum Transport Simulation of Multilayer Phosphorene Nanoribbon Field Effect Transistors

Few-layer black phosphorus is a semiconductor material, where its allotrope is called phosphorene; a new two-dimensional material which is discovered in 2014. In this paper, first we use the tight-binding method to implement a matrix representation for single-layer and multilayer structures of phosphorene nanoribbon (PNR) to define the Hamiltonian of the system. Second, we investigate the band structure and the band gap of multilayer PNRs. The band gap of armchair PNRs with 16 atoms across the width of PNR for single-layer, bilayer, and three-layer structures are obtained as 1.899, 1.224, and 0.937 eV, respectively. Third, we use the atomistic description of structure to simulate the performance characteristics of single and multilayer PNR field effect transistors (PNRFETs) by employing the non-equilibrium Green\u27s function (NEGF) formalism. Based on the properties of the material and device structures, Id-Vgs, Id-Vds characteristics, energy band diagram in the channel, and ION/IOFF are analyzed. The ON to OFF current ratio for single-layer, bilayer, and three-layer PNRFETs are increasing when the channel length increases from 5 nm to 15 nm. The current ratio for single-layer increases from 1277 for Lch=5 nm to 216.7×106 for Lch=15 nm. The ION/IOFF in single-layer PNRFET is higher in comparison with those values in bilayer and three-layer PNRFETs due to very small off-current in the single-layer PNRFET which in turn resulted from its larger band gap. The results show that the performance of PNRFET changes significantly depending on the number of phosphorene layers and the length of the channel of device