The biological mechanisms of resistance in selected lines of Nicotiana tabacum L. to Myzus nicotianae Blackman (Homoptera : Aphididae)

Since 1993, several aphid-resistant breeding lines of tobacco, Nicotiana tabacum L. have been developed at the Tobacco Experiment Station, Greeneville, TN. Crosses were developed between TI 1068, a resistant to the tobacco aphid, Myzus nicotianae Blackman, and ‘TN 86’ or ‘KY 17,’ two tobacco cultivars susceptible to the tobacco aphid. A research project was conducted to: 1) reevaluate levels of resistance of selected tobacco lines to the tobacco aphid, 2) determine the population growth parameters of the tobacco aphis that are affected by resistant tobacco, and 3) simulate aphid population growth on resistant and non-resistant tobacco using a computer-generated model. In 1996 & 1997, several entries were evaluated for aphid population growth in open field plots, greenhouse, and growth room. Field plots were allowed to become infested naturally by aphids. In greenhouse and growth experiments, adult aphids were placed individually onto each plant and allowed to colonize. Results indicated high resistance to the tobacco aphid on TI 1068 for a variety of experiments, compared to other resistant tobacco lines. Initially 3 aphid-resistant tobacco entries (TI 1068, 301, 3001) were evaluated to determine their mechanisms of resistance. Four aphid growth parameters (life cycle, fecundity, reproductive longevity, survival) were investigated for their effects on aphid populations. Aphid development was significantly slower on leaf discs of TI 1068, 301, and 3001 than on TN leaf discs. Aphid development, fecundity, reproductive longevity, and survival did not differ significantly among all tobacco entries tested when reared on excised leaves from greenhouse-grown plants. Aphids reared on leaves excised from field-grown TI 1068 plants had a longer life cycle, lower reproductive rate, shorter reproductive longevity, and shorter survival time than aphids reared on the standard cultivar, TN 86. A computer simulation, based on data from laboratory experiments,was developed to predict seasonal population development of tobacco aphids on TN 86 and TI 1068 aphid populations under field conditions, but in the absence of limiting factors such as weather, predators, disease, and parasitoids. It was estimated using this model that progeny from one aphid on TN 86 could exceed to 10,000,000 individuals within 40 days; whereas, less than 700 aphids would develop on TI 1068. Future work on the effects of weather, predators, diseases, and parasitoids on an aphid populations could prove useful in more accurately predicting aphid population growth in a typical tobacco field

Is Honesty the Best Policy? Examining the Effect of Product Safety Communication on Blame Attributions in Causal Chains

This paper extends research on attribution theory through three studies examining how the accuracy and explicitness of product safety information communicated to various entities within a causal chain influences blame attributions after an accident. Unlike prior research, we find consistent evidence that entities in the causal chain were able to limit blame attributions by communicating safety information that’s quality met or exceeded the quality of information available to that entity. Entities did not, however, benefit from providing more accurate information than what had been communicated to them by previous members of the causal chain. This insight suggests that the controllability of information communicated played an important role in the relationship between accurate communication and blame attributions. Our findings provide meaningful insight into steps that organizations can take to limit their potential for receiving blame following an accident, helping to bridge the gap between basic and applied research

Changes in Risk Perceptions During the 2014 Ebola Virus Disease Epidemic: Results of Two Consecutive Surveys Among the General Population in Lower Saxony, Germany

Background: The Ebola virus disease (EVD) outbreak 2014 received extensive news media coverage, which faded out before the outbreak ended. News media coverage impacts risk perception; it is, however, unclear if the components of risk perception (affective and cognitive responses) change differently over time. Methods: In an online panel, we asked participants (n = 1376) about EVD risk perceptions at the epidemic\u27s peak (November 2014) and after news media coverage faded out (August 2015). We investigated worry (affective response), perceived likelihood of infection, perceived personal impact, and coping efficacy (dimensions of cognitive response), and knowledge about transmission. Differences between the surveys with respect to manifestations of affective and cognitive dimensions were tested using the Wilcoxon signed-rank test. The association between individual change in knowledge and worries about EVD in the first survey was investigated using linear regression. Results: In November 2014, the survey was filled in by 974 participants. Ten months later, 662 of them were still members of the online panel and were invited to the follow-up survey. Among the 620 respondents, affective response decreased between the surveys. Knowledge about EVD also decreased; however, participants worried about EVD in 2014 had increased knowledge in 2015. Perceived likelihood of infection decreased over time, while perceived personal impact and coping efficacy did not. Conclusions: Risk communication appealing to cognitive reactions by informing clearly on the risk of infection in unaffected countries may decrease inappropriate behaviors

Predicting post-translational lysine acetylation using support vector machines

Motivation: Lysine acetylation is a post-translational protein modification and a primary regulatory mechanism that controls many cell signaling processes. Lysine acetylation sites are recognized by acetyltransferases and deacetylases through sequence patterns (motifs). Recently, we used high-resolution mass spectrometry to identify 3600 lysine acetylation sites on 1750 human proteins covering most of the previously annotated sites and providing the most comprehensive acetylome so far. This dataset should provide an excellent source to train support vector machines (SVMs) allowing the high accuracy in silico prediction of acetylated lysine residues

PKA Phosphorylation of NCLX Reverses Mitochondrial Calcium Overload and Depolarization, Promoting Survival of PINK1-Deficient Dopaminergic Neurons

Mitochondrial Ca2+ overload is a critical, preceding event in neuronal damage encountered during neurodegenerative and ischemic insults. We found that loss of PTEN-induced putative kinase 1 (PINK1) function, implicated in Parkinson disease, inhibits the mitochondrial Na+/Ca2+ exchanger (NCLX), leading to impaired mitochondrial Ca2+ extrusion. NCLX activity was, however, fully rescued by activation of the protein kinase A (PKA) pathway. We further show that PKA rescues NCLX activity by phosphorylating serine 258, a putative regulatory NCLX site. Remarkably, a constitutively active phosphomimetic mutant of NCLX (NCLXS258D) prevents mitochondrial Ca2+ overload and mitochondrial depolarization in PINK1 knockout neurons, thereby enhancing neuronal survival. Our results identify an mitochondrial Ca2+ transport regulatory pathway that protects against mitochondrial Ca2+ overload. Because mitochondrial Ca2+ dyshomeostasis is a prominent feature of multiple disorders, the link between NCLX and PKA may offer a therapeutic target