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Organizational Disaster Communication Ecology: Examining Interagency Coordination on Social Media During the Onset of the COVID-19 Pandemic
Interagency coordination is crucial for effective multiagency disaster management. Viewing government and emergency management organizations as vital components of citizens’ disaster communication ecology, this study examines how a group of Texas-based public health departments and emergency management offices engaged in interagency coordination during different phases of the COVID-19 pandemic. By analyzing coronavirus-related agency tweets between early February and the end of August 2020, the study assesses two types of interagency coordination: (1) contentlevel coordination in the form of semantic similarity among the selected public agencies serving different jurisdictions and (2) relational-level coordination in terms of referencing common stakeholders through retweeting coronavirus-related information. Using a granular, four-stage construct of a crisis, results identify stage-based variation with regard to peer-to-peer and federal-to-local coordination. We conclude with theoretical and practical implications for communication ecology and disaster management
Increased ROS Production in Non-Polarized Mammary Epithelial Cells Induces Monocyte Infiltration in 3D Culture
Loss of epithelial cell polarity promotes cell invasion and cancer dissemination. Therefore, identification of factors that disrupt polarized acinar formation is crucial. Reactive oxygen species (ROS) drive cancer progression and promote inflammation. Here, we show that the non-polarized breast cancer cell line T4-2 generates significantly higher ROS levels than polarized S1 and T4R cells in three-dimensional (3D) culture, accompanied by induction of the nuclear factor κB (NF-κB) pathway and cytokine expression. Minimizing ROS in T4-2 cells with antioxidants reestablished basal polarity and inhibited cell proliferation. Introducing constitutively activated RAC1 disrupted cell polarity and increased ROS levels, indicating that RAC1 is a crucial regulator that links cell polarity and ROS generation. We also linked monocyte infiltration with disruption of polarized acinar structure using a 3D co-culture system. Gain- and loss-of-function experiments demonstrated that increased ROS in non-polarized cells is necessary and sufficient to enhance monocyte recruitment. ROS also induced cytokine expression and NF-κB activity. These results suggest that increased ROS production in mammary epithelial cell leads to disruption of cell polarity and promotes monocyte infiltration
418 cm-1 Raman scattering from gallium nitride nanowires: Is it a vibration mode of N-rich Ga-N bond configuration?
A Raman-active vibration mode at 418 cm-1 is observed in wurtzite gallium nitride (GaN) nanowires synthesized by different growth methods. In particular, Raman scattering measurements of a number of GaN nanowires systematically prepared by nitriding Β- Ga2 O3 nanowires at different temperatures show an interesting evolution of the mode, revealing that it is most likely the vibration mode of N-rich octahedral Ga- N6 bonds. This idea is further supported by the high-resolution transmission electron microscopic observation. © 2007 American Institute of Physics.published_or_final_versio
RelB Expression Determines the Differential Effects of Ascorbic Acid in Normal and Cancer Cells
Cancer cells typically experience higher oxidative stress than normal cells, such that elevating pro-oxidant levels can trigger cancer cell death. Although pre-exposure to mild oxidative agents will sensitize cancer cells to radiation, this pre-exposure may also activate the adaptive stress defense system in normal cells. Ascorbic acid is a prototype redox modulator that when infused intravenously appears to kill cancers without injury to normal tissues; however, the mechanisms involved remain elusive. In this study, we show how ascorbic acid kills cancer cells and sensitizes prostate cancer to radiation therapy while also conferring protection upon normal prostate epithelial cells against radiation-induced injury. We found that the NF-κB transcription factor RelB is a pivotal determinant in the differential radiosensitization effects of ascorbic acid in prostate cancer cells and normal prostate epithelial cells. Mechanistically, high reactive oxygen species concentrations suppress RelB in cancer cells. RelB suppression decreases expression of the sirtuin SIRT3 and the powerful antioxidant MnSOD, which in turn increases oxidative and metabolic stresses in prostate cancer cells. In contrast, ascorbic acid enhances RelB expression in normal cells, improving antioxidant and metabolic defenses against radiation injury. In addition to showing how RelB mediates the differential effects of ascorbic acid on cancer and normal tissue radiosensitivities, our work also provides a proof of concept for the existence of redox modulators that can improve the efficacy of radiotherapy while protecting against normal tissue injury in cancer settings
Ordered silicon nanocones arrays for label-free DNA quantitative analysis by surface-enhanced Raman spectroscopy
published_or_final_versio
International origins of walking school buses and child fatalities in Japan and Canada
The concept of a Walking School Bus (WSB) has existed in Japan for over half a century, but is a relatively new concept in Anglo-Saxon countries, tracing its origins to the early 1990s. In Anglo-Saxon countries the WSB is seen as a safe means of addressing the negative impacts of increased school trips by car. Recently in Japan, a discussion as to the value and appropriateness of the shuudantogeko (the Japanese WSB) has emerged as some suggest that it could reduce safety. This paper introduces and compares the two WSB systems, and then uses traffic fatality data from Canada and Japan to compare travel-to-school in an open choice system with a country where WSB is common practice
Effects of a Chinese Medicinal Plant Radix Astragali on the Ovariectomized Female Rats
Perimenopausal syndrome occurs during the transition to menopause. Complementary and alternative medicine, especially Chinese medicinal plants, has manifested significant effects in alleviating perimenopausal symptoms. However, little research has been focused on the effects of Chinese medicinal plant on the immune function of the perimenopausal women. The present study aimed to explore the effects of Radix Astragali (RA) on the sex hormone levels and the interleukins of the ovariectomized female rats. 24 female Sprague-Dawley (SD) rats were randomly divided into model control group (MOD group), sham-operation group (SHAM group), RA group and estrogen group (EST group). After all the treatment ended, the serum levels of estradiol (E2), follicle stimulating hormone (FSH), luteinizing hormone (LH), interleukin-2 (IL-2), and interleukin-8 (IL-8) were measured using enzyme-linked immune-sorbent assay (ELISA) and the uterus was removed and weighed after blood exsanguinations immediately. In the MOD group, the serum levels of E2 were significantly lower, and the serum levels of FSH and LH were markedly higher than those of the RA group, EST group and SHAM group (P<0.05). In the RA group, the serum levels of E2 were significantly lower, and the serum levels of FSH were markedly higher than those of the SHAM group and EST group, respectively. In the MOD group, the serum levels of IL-2 and IL-8 were significantly lower than those of the RA group, EST group and SHAM group (P<0.05), and no marked differences existed among RA group, EST group and SHAM group in the serum levels of IL-2 and IL-8 (P>0.05). The uterine weight of the rats in the RA group, EST group and SHAM group were significantly higher than those of the rats in MOD group (P<0.05). There were no marked differences among the rats from RA group, EST group and SHAM group on the uterine weight (P>0.05). It is concluded that RA can significantly improve the immune functions of the ovariectomized female rats, although it cannot change the sex hormones levels as significantly as estrogen
Irradiation-induced molecular dipole reorientation in inverted polymer solar cell using small molecular electron collection layer
Inverted polymer solar cell is developed using small molecular tris(8-hydroxyquinolinato) aluminum (Alq3) as an electron collection layer between the active layer and indium-tin-oxide bottom cathode. Upon post-processing light irradiation by simulated solar illumination, the open-circuit voltage of the inverted device increases from 0.52 V to 0.60 V, resulting in the enhancement of the power conversion efficiency from 2.54 to 3.33 with negligible change in the short-circuit current. The performance improvement is attributed to the removal of surface potential due to irradiation-induced molecular dipole reorientation in the Alq3 layer, which reduces the charge transport barrier and improves the charge collection efficiency. © 2011 American Institute of Physics
Efficient inverted polymer solar cells with thermal-evaporated and solution-processed small molecular electron extraction layer
Efficient inverted polymer solar cell is reported upon by integrating with a small molecular 1,3,5-tri(phenyl-2-benzimi-dazolyl)-benzene (TPBi) electron extraction layer (EEL) at low processing temperature with thermal-evaporation and solution-process, resulting in the power conversion efficiencies of 3.70 and 3.47, respectively. The potential of TPBi as an efficient EEL is associated with its suitable electronic energy level for electron extraction and hole blocking from the active layer to the indium tin oxide cathode. © 2013 American Institute of Physics
Enhanced performance in polymer photovoltaic cells with chloroform treated indium tin oxide anode modification
Enhanced performance of a poly(3-hexylthiophene):(6,6)-phenyl C61 butyric acid methyl ester bulk heterojunction polymer photovoltaic cell is reported by modifying the indium tin oxide (ITO) anode with chloroform solution. Instead of the traditional UV-ozone treatment, the optimized chloroform modification on ITO anode can result in an enhancement in the power conversion efficiency of an identical device, originating from an increase in the photocurrent with negligible change in the open-circuit voltage. The performance enhancement is attributed to the work function modification of the ITO substrate through the surface incorporation of the chlorine, and thus improved charge collection efficiency. © 2011 American Institute of Physics
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