A Relational Approach to Reducing Uncertainty during a Crisis through the use of Mobile Technology

It is estimated that six in ten American adults access the Internet using some form of a wireless device (Smith, 2010). In the years ahead, the United States is expected to reach 100 percent mobile phone penetration by 2013 (“Getting to Know the Mobile Population,” 2009). Recognizing that the ability to access the information network at any time and at any place will continue to expand in the near term, it is incumbent upon public relations practitioners to critically examine the opportunity to reduce uncertainty through a variety of digital applications. In this regard, this paper adopts a relational approach toward the examination of how mobile technologies cultivate personal relationships and reciprocal communication methods that are characteristic to those outlined within uncertainty reduction theory. Findings include facilitating intelligent crisis response, implementing two-way communication, and encouraging citizen participation

Forty years on: clathrin-coated pits continue to fascinate

Clathrin mediated endocytosis (CME) is a fundamental process in cell biology and has been extensively investigated throughout the last several decades. Every cell biologist learns about it at some point during their education and the beauty of this process has led many of us to go deeper and make it the topic of our own research. Great progress has been made towards elucidating the mechanisms of CME and the field is becoming increasingly complex with several hundred new publications every year. This makes it easy to get lost in the vast amount of literature and to forget about the fundamentals of the field, based on the careful interpretation of simple observations made over 40 years ago. A study performed by Anderson, Brown and Goldstein in 1977 (Anderson et al., 1977) is a prime example of this. We therefore want to take a step back and examine how this seminal study was pivotal to our understanding of CME and its progression into ever increasing complexity over the last four decades

Very Cold Gas and Dark Matter

We have recently proposed a new candidate for baryonic dark matter: very cold molecular gas, in near-isothermal equilibrium with the cosmic background radiation at 2.73 K. The cold gas, of quasi-primordial abundances, is condensed in a fractal structure, resembling the hierarchical structure of the detected interstellar medium. We present some perspectives of detecting this very cold gas, either directly or indirectly. The H$_2$ molecule has an "ultrafine" structure, due to the interaction between the rotation-induced magnetic moment and the nuclear spins. But the lines fall in the km domain, and are very weak. The best opportunity might be the UV absorption of H$_2$ in front of quasars. The unexpected cold dust component, revealed by the COBE/FIRAS submillimetric results, could also be due to this very cold H$_2$ gas, through collision-induced radiation, or solid H$_2$ grains or snowflakes. The $\gamma$-ray distribution, much more radially extended than the supernovae at the origin of cosmic rays acceleration, also points towards and extended gas distribution.Comment: 16 pages, Latex pages, crckapb macro, 3 postscript figures, uuencoded compressed tar file. To be published in the proceeedings of the "Dust-Morphology" conference, Johannesburg, 22-26 January, 1996, D. Block (ed.), (Kluwer Dordrecht

Population-Specific Responses to Interspecific Competition in the Gut Microbiota of Two Atlantic Salmon (Salmo salar) Populations

The gut microbial community in vertebrates plays a role in nutrient digestion and absorption, development of intestine and immune systems, resistance to infection, regulation of bone mass and even host behavior and can thus impact host fitness. Atlantic salmon (Salmo salar) reintroduction efforts into Lake Ontario, Canada, have been unsuccessful, likely due to competition with non-native salmonids. In this study, we explored interspecific competition effects on the gut microbiota of two Atlantic salmon populations (LaHave and Sebago) resulting from four non-native salmonids. After 10 months of rearing in semi-natural stream tanks under six interspecific competition treatments, we characterized the gut microbiota of 178 Atlantic salmon by parallel sequencing the 16S rRNA gene. We found 3978 bacterial OTUs across all samples. Microbiota alpha diversity and abundance of 27 OTUs significantly differed between the two populations. Interspecific competition reduced relative abundance of potential beneficial bacteria (six genera of lactic acid bacteria) as well as 13 OTUs, but only in the LaHave population, indicating population-specific competition effects. The pattern of gut microbiota response to interspecific competition may reflect local adaptation of the host-microbiota interactions and can be used to select candidate populations for improved species reintroduction success

Human SCARB2-Mediated Entry and Endocytosis of EV71

Enterovirus (EV) 71 infection is known to cause hand-foot-and-mouth disease (HFMD) and in severe cases, induces neurological disorders culminating in fatality. An outbreak of EV71 in South East Asia in 1997 affected over 120,000 people and caused neurological disorders in a few individuals. The control of EV71 infection through public health interventions remains minimal and treatments are only symptomatic. Recently, human scavenger receptor class B, member 2 (SCARB2) has been reported to be a cellular receptor of EV71. We expressed human SCARB2 gene in NIH3T3 cells (3T3-SCARB2) to study the mechanisms of EV71 entry and infection. We demonstrated that human SCARB2 serves as a cellular receptor for EV71 entry. Disruption of expression of SCARB2 using siRNAs can interfere EV71 infection and subsequent inhibit the expression of viral capsid proteins in RD and 3T3-SCARB2 but not Vero cells. SiRNAs specific to clathrin or dynamin or chemical inhibitor of clathrin-mediated endocytosis were all capable of interfering with the entry of EV71 into 3T3-SCARB2 cells. On the other hand, caveolin specific siRNA or inhibitors of caveolae-mediated endocytosis had no effect, confirming that only clathrin-mediated pathway was involved in EV71 infection. Endocytosis of EV71 was also found to be pH-dependent requiring endosomal acidification and also required intact membrane cholesterol. In summary, the mechanism of EV71 entry through SCARB2 as the receptor for attachment, and its cellular entry is through a clathrin-mediated and pH-dependent endocytic pathway. This study on the receptor and endocytic mechanisms of EV71 infection is useful for the development of effective medications and prophylactic treatment against the enterovirus

Entry of Human Papillomavirus Type 16 by Actin-Dependent, Clathrin- and Lipid Raft-Independent Endocytosis

Infectious endocytosis of incoming human papillomavirus type 16 (HPV-16), the main etiological agent of cervical cancer, is poorly characterized in terms of cellular requirements and pathways. Conflicting reports attribute HPV-16 entry to clathrin-dependent and -independent mechanisms. To comprehensively describe the cell biological features of HPV-16 entry into human epithelial cells, we compared HPV-16 pseudovirion (PsV) infection in the context of cell perturbations (drug inhibition, siRNA silencing, overexpression of dominant mutants) to five other viruses (influenza A virus, Semliki Forest virus, simian virus 40, vesicular stomatitis virus, and vaccinia virus) with defined endocytic requirements. Our analysis included infection data, i.e. GFP expression after plasmid delivery by HPV-16 PsV, and endocytosis assays in combination with electron, immunofluorescence, and video microscopy. The results indicated that HPV-16 entry into HeLa and HaCaT cells was clathrin-, caveolin-, cholesterol- and dynamin-independent. The virus made use of a potentially novel ligand-induced endocytic pathway related to macropinocytosis. This pathway was distinct from classical macropinocytosis in regards to vesicle size, cholesterol-sensitivity, and GTPase requirements, but similar in respect to the need for tyrosine kinase signaling, actin dynamics, Na+/H+ exchangers, PAK-1 and PKC. After internalization the virus was transported to late endosomes and/or endolysosomes, and activated through exposure to low pH

Recent progress in understanding and projecting regional and global mean sea-level change

Considerable progress has been made in understanding the present and future regional and global sea level in the 2 years since the publication of the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change. Here, we evaluate how the new results affect the AR5’s assessment of (i) historical sea level rise, including attribution of that rise and implications for the sea level budget, (ii) projections of the components and of total global mean sea level (GMSL), and (iii) projections of regional variability and emergence of the anthropogenic signal. In each of these cases, new work largely provides additional evidence in support of the AR5 assessment, providing greater confidence in those findings. Recent analyses confirm the twentieth century sea level rise, with some analyses showing a slightly smaller rate before 1990 and some a slightly larger value than reported in the AR5. There is now more evidence of an acceleration in the rate of rise. Ongoing ocean heat uptake and associated thermal expansion have continued since 2000, and are consistent with ocean thermal expansion reported in the AR5. A significant amount of heat is being stored deeper in the water column, with a larger rate of heat uptake since 2000 compared to the previous decades and with the largest storage in the Southern Ocean. The first formal detection studies for ocean thermal expansion and glacier mass loss since the AR5 have confirmed the AR5 finding of a significant anthropogenic contribution to sea level rise over the last 50 years. New projections of glacier loss from two regions suggest smaller contributions to GMSL rise from these regions than in studies assessed by the AR5; additional regional studies are required to further assess whether there are broader implications of these results. Mass loss from the Greenland Ice Sheet, primarily as a result of increased surface melting, and from the Antarctic Ice Sheet, primarily as a result of increased ice discharge, has accelerated. The largest estimates of acceleration in mass loss from the two ice sheets for 2003–2013 equal or exceed the acceleration of GMSL rise calculated from the satellite altimeter sea level record over the longer period of 1993–2014. However, when increased mass gain in land water storage and parts of East Antarctica, and decreased mass loss from glaciers in Alaska and some other regions are taken into account, the net acceleration in the ocean mass gain is consistent with the satellite altimeter record. New studies suggest that a marine ice sheet instability (MISI) may have been initiated in parts of the West Antarctic Ice Sheet (WAIS), but that it will affect only a limited number of ice streams in the twenty-first century. New projections of mass loss from the Greenland and Antarctic Ice Sheets by 2100, including a contribution from parts of WAIS undergoing unstable retreat, suggest a contribution that falls largely within the likely range (i.e., two thirds probability) of the AR5. These new results increase confidence in the AR5 likely range, indicating that there is a greater probability that sea level rise by 2100 will lie in this range with a corresponding decrease in the likelihood of an additional contribution of several tens of centimeters above the likely range. In view of the comparatively limited state of knowledge and understanding of rapid ice sheet dynamics, we continue to think that it is not yet possible to make reliable quantitative estimates of future GMSL rise outside the likely range. Projections of twenty-first century GMSL rise published since the AR5 depend on results from expert elicitation, but we have low confidence in conclusions based on these approaches. New work on regional projections and emergence of the anthropogenic signal suggests that the two commonly predicted features of future regional sea level change (the increasing tilt across the Antarctic Circumpolar Current and the dipole in the North Atlantic) are related to regional changes in wind stress and surface heat flux. Moreover, it is expected that sea level change in response to anthropogenic forcing, particularly in regions of relatively low unforced variability such as the low-latitude Atlantic, will be detectable over most of the ocean by 2040. The east-west contrast of sea level trends in the Pacific observed since the early 1990s cannot be satisfactorily accounted for by climate models, nor yet definitively attributed either to unforced variability or forced climate change