RELATIONSHIPS BETWEEN MONOMER CHEMICAL STRUCTURE, NETWORK ARCHITECTURE AND THERMAL STABILITY IN GLASSY POLYCYANURATES

We study monomer melt properties and polymer properties using two approaches. The first approach takes advantage of molecular dynamics to calculate monomer melt properties. The second approach involved an experimental investigation of polycyanurate networks with varying monomer functionality and rigidity. For our computational study we applied an existing voids method by Solca et al. to calculate melting temperature for four different cyanate esters: (a) 2’-(4-cyanatophenyl) propane (BADCy), (b) 4,4\u27-(ethane-1,1-diyl) bis(cyanatobenzene) (LECy), (c) tris(4-cyantophenyl) methylsilane (SiCy-3), and (d) bis(4-cyanatophenyl) dimethylsilane (SiMCy). For systems with 1 to 10% voids, the predicted melting temperature decreased due to a decrease in the free energy barrier to melting. We synthesized cyanate ester monomers from a plant source, resveratrol, and compared the properties to cyanate esters of bisphenol A and bisphenol E. Polymer properties were characterized via DSC, DMA, and TGA. The increase in functionality and backbone rigidity of the resveratrol polycyanurates produced networks with glass transition temperatures up to 296 °C and char yields up to 70 %. Additionally, thermal, thermo-oxidative, and ablative properties were measured by TGA, TGA-MS, cone calorimetry, SEM, and EDX. Cone calorimetry data revealed that networks from cisResCy produced a decrease in Total Heat Release. Monofunctional and trifunctional cyanate ester monomers, cardanol-cyanate ester (1-cyanato-3-pentadecylbenzene, CardCy) and cis-resveratrol-cyanate ester (cis-3,4’,5-tricyanatostilbene, cisResCy), respectively, were synthesized from biobased cardanol and resveratrol. The cisResCy monomer was blended with varying weights of CardCy and co-cured to produce five polycyanurate networks. The organic polymers displayed outstanding thermal stability and enhanced mechanical dampening

Political Skill Dimensionality And Impression Management Choice And Effective Use

Purpose The purpose of this study was to test a moderated mediation model of the dimensionality of political skill on influence tactic choice and performance ratings. Design/Mythology/Approach Dyadic data were analyzed using a mixed-method approach to account for any leaderlevel effects, as well as bootstrapping methods to account for the modest sample size (n = 116). Findings Social astuteness best predicted positive impression management (IM) over negative IM. Apparent sincerity interacted with positive impression management tactics to predict higher performance ratings, whereas interpersonal influence did not. Implications The findings support that socially astute individuals use more positive influence tactics in the workplace. This could impact the broader work environment, making it more pleasant than one with individuals using negative influence tactics. Thus, it might be the interest of organizations to train individuals to enhance their social astuteness. However, confirming prior research, performance evaluations made by managers are impacted by more than objective performance (e.g., political skill). Thus, organizations need to ensure the proper training of managers to lessen these types of biases. Originality/Value This research empirically validates components of the metatheoretical framework of political skill (Ferris et al. Journal of Management 33:290–320, 2007) by examining the impact that dimensions of political skill have on interpersonal processes and outcomes in the workplace

Political Skill Dimensionality And Impression Management Choice And Effective Use

Purpose The purpose of this study was to test a moderated mediation model of the dimensionality of political skill on influence tactic choice and performance ratings. Design/Mythology/Approach Dyadic data were analyzed using a mixed-method approach to account for any leaderlevel effects, as well as bootstrapping methods to account for the modest sample size (n = 116). Findings Social astuteness best predicted positive impression management (IM) over negative IM. Apparent sincerity interacted with positive impression management tactics to predict higher performance ratings, whereas interpersonal influence did not. Implications The findings support that socially astute individuals use more positive influence tactics in the workplace. This could impact the broader work environment, making it more pleasant than one with individuals using negative influence tactics. Thus, it might be the interest of organizations to train individuals to enhance their social astuteness. However, confirming prior research, performance evaluations made by managers are impacted by more than objective performance (e.g., political skill). Thus, organizations need to ensure the proper training of managers to lessen these types of biases. Originality/Value This research empirically validates components of the metatheoretical framework of political skill (Ferris et al. Journal of Management 33:290–320, 2007) by examining the impact that dimensions of political skill have on interpersonal processes and outcomes in the workplace

A Molecular Dynamics Study of Monomer Melt Properties of Cyanate Ester Monomer Melt Properties

The objective of this work was to computationally predict the melting temperature and melt properties of thermosetting monomers used in aerospace applications. In this study, we applied an existing voids method by Solca. to examine four cyanate ester monomers with a wide range of melting temperatures. Voids were introduced into some simulations by removal of molecules from lattice positions to lower the free-energy barrier to melting to directly simulate the transition from a stable crystal to amorphous solid and capture the melting temperature. We validated model predictions by comparing melting temperature against previously reported literature values. Additionally, the torsion and orientational order parameters were used to examine the monomers’ freedom of motion to investigate structure–property relationships. Ultimately, the voids method provided reasonable estimates of melting temperature while the torsion and order parameter analysis provided insight into sources of the differing melt properties between the thermosetting monomers. As a whole, the results shed light on how freedom of molecular motions in the monomer melt state may affect melting temperature and can be utilized to inspire the development of thermosetting monomers with optimal monomer melt properties for demanding applications

Reaching Hard-to-Reach Individuals: Nonselective Versus Targeted Outbreak Response Vaccination for Measles

Current mass vaccination campaigns in measles outbreak response are nonselective with respect to the immune status of individuals. However, the heterogeneity in immunity, due to previous vaccination coverage or infection, may lead to potential bias of such campaigns toward those with previous high access to vaccination and may result in a lower-than-expected effective impact. During the 2010 measles outbreak in Malawi, only 3 of the 8 districts where vaccination occurred achieved a measureable effective campaign impact (i.e., a reduction in measles cases in the targeted age groups greater than that observed in nonvaccinated districts). Simulation models suggest that selective campaigns targeting hard-to-reach individuals are of greater benefit, particularly in highly vaccinated populations, even for low target coverage and with late implementation. However, the choice between targeted and nonselective campaigns should be context specific, achieving a reasonable balance of feasibility, cost, and expected impact. In addition, it is critical to develop operational strategies to identify and target hard-to-reach individuals

Trait Rumination Influences Neural Correlates of the Anticipation but Not the Consumption Phase of Reward Processing

Cumulative evidence suggests that trait rumination can be defined as an abstract information processing mode, which leads people to constantly anticipate the likely impact of present events on future events and experiences. A previous study with remitted depressed patients suggested that enhanced rumination tendencies distort brain mechanisms of anticipatory processes associated with reward and loss cues. In the present study, we explored the impact of trait rumination on neural activity during reward and loss anticipation among never-depressed people. We analyzed the data of 37 healthy controls, who performed the monetary incentive delay (MID) task which was designed for the simultaneous measurement of the anticipation (motivational) and consumption (hedonic) phase of reward processing, during functional magnetic resonance imaging (fMRI). Our results show that rumination-after controlling for age, gender, and current mood-significantly influenced neural responses to reward (win) cues compared to loss cues. Blood-oxygenation-level-dependent (BOLD) activity in the left inferior frontal gyrus (IFG) triangularis, left anterior insula, and left rolandic operculum was positively related to Ruminative Response Scale (RRS) scores. We did not detect any significant rumination-related activations associated with win-neutral or loss-neutral cues and with reward or loss consumption. Our results highlight the influence of trait rumination on reward anticipation in a non-depressed sample. They also suggest that for never-depressed ruminators rewarding cues are more salient than loss cues. BOLD response during reward consumption did not relate to rumination, suggesting that rumination mainly relates to processing of the motivational (wanting) aspect of reward rather than the hedonic (liking) aspect, at least in the absence of pathological mood

Intra- and Inter-cellular Rewiring of the Human Colon during Ulcerative Colitis

Genome-wide association studies (GWAS) have revealed risk alleles for ulcerative colitis (UC). To understand their cell type specificities and pathways of action, we generate an atlas of 366,650 cells from the colon mucosa of 18 UC patients and 12 healthy individuals, revealing 51 epithelial, stromal, and immune cell subsets, including BEST4(+) enterocytes, microfold-like cells, and IL13RA2(+)IL11(+) inflammatory fibroblasts, which we associate with resistance to anti-TNF treatment. Inflammatory fibroblasts, inflammatory monocytes, microfold-like cells, and T cells that co-express CD8 and IL-17 expand with disease, forming intercellular interaction hubs. Many UC risk genes are cell type specific and coregulated within relatively few gene modules, suggesting convergence onto limited sets of cell types and pathways. Using this observation, we nominate and infer functions for specific risk genes across GWAS loci. Our work provides a framework for interrogating complex human diseases and mapping risk variants to cell types and pathways.Peer reviewe

Uganda Genome Resource Enables Insights into Population History and Genomic Discovery in Africa.

Genomic studies in African populations provide unique opportunities to understand disease etiology, human diversity, and population history. In the largest study of its kind, comprising genome-wide data from 6,400 individuals and whole-genome sequences from 1,978 individuals from rural Uganda, we find evidence of geographically correlated fine-scale population substructure. Historically, the ancestry of modern Ugandans was best represented by a mixture of ancient East African pastoralists. We demonstrate the value of the largest sequence panel from Africa to date as an imputation resource. Examining 34 cardiometabolic traits, we show systematic differences in trait heritability between European and African populations, probably reflecting the differential impact of genes and environment. In a multi-trait pan-African GWAS of up to 14,126 individuals, we identify novel loci associated with anthropometric, hematological, lipid, and glycemic traits. We find that several functionally important signals are driven by Africa-specific variants, highlighting the value of studying diverse populations across the region.Main funding: This work was funded by the Wellcome Trust, The Wellcome Sanger Institute (WT098051), the U.K. Medical Research Council (G0901213-92157, G0801566, and MR/K013491/1), and the Medical Research Council/Uganda Virus Research Institute Uganda Research Unit on AIDS core funding

Pan-cancer analysis of whole genomes identifies driver rearrangements promoted by LINE-1 retrotransposition

About half of all cancers have somatic integrations of retrotransposons. Here, to characterize their role in oncogenesis, we analyzed the patterns and mechanisms of somatic retrotransposition in 2,954 cancer genomes from 38 histological cancer subtypes within the framework of the Pan-Cancer Analysis of Whole Genomes (PCAWG) project. We identified 19,166 somatically acquired retrotransposition events, which affected 35% of samples and spanned a range of event types. Long interspersed nuclear element (LINE-1; L1 hereafter) insertions emerged as the first most frequent type of somatic structural variation in esophageal adenocarcinoma, and the second most frequent in head-and-neck and colorectal cancers. Aberrant L1 integrations can delete megabase-scale regions of a chromosome, which sometimes leads to the removal of tumor-suppressor genes, and can induce complex translocations and large-scale duplications. Somatic retrotranspositions can also initiate breakage–fusion–bridge cycles, leading to high-level amplification of oncogenes. These observations illuminate a relevant role of L1 retrotransposition in remodeling the cancer genome, with potential implications for the development of human tumors