Studies of Paleozoic fungi. IV. Wall ultrastructure of fossil endogonaceous chlamydospores

Fossil endogonaceous chlamydospores are described from the aerial axes and roots of several Paleozoic plants preserved in calcilutite nodules and calcareous coal balls. Specimens come from six Paleozoic localities extending from the uppermost Lower Devonian through the Upper Pennsylvanian. Although fossil chlamydospores are markedly similar to the modern Endogonaceae in transmitted light, ultrastructural comparisons have not previously been made. The fine structure of the walls of these spores is consistent with past interpretations which relate them to the modern Endogonaceae, but thorough comparisons cannot be made due to the lack of comparable ultrastructural information from extant VA mycorrhizae. The evidence from mycorrhizal associations in the fossil record is evaluated

Sources of Nutrition Information in Recreational Ultra-marathon Runners: A Mixed Methods Analysis

Ultra-marathon events (i.e., .42.2-km) continue to grow in popularity; however, little is known regarding the sources of nutrition information which inform their beliefs and habits. The objective of this study was to characterize the acquisition of sport-specific nutrition information among ultra-endurance athletes using a mixed methods design. Qualitative data were collected through focus groups and analyzed using thematic analysis. Three primary higher order themes were identified: Optimal Diet for Ultra-Endurance Athletes, Common Sources of Information, and Barriers to Scientific Information. Then, a self-report inventory (Sources of Nutrition Information-SONI questionnaire) was developed to assess common sources of nutrition information and characterize their beliefs about those sources. Likert-type questions were used, and primary sources were scored out of 3, sub-questions out of 5. Differences between sources were assessed using RM-ANOVA. Participants (N = 224) accessed, responded to, and submitted the survey via a secure, study-specific web-based link. Peer reviewed literature was reported as the most frequently used (mean score = 1.64, p \u3c 0.001), credible (3.02, p \u3c 0.001), and interesting (2.62, p \u3c 0.002). Social media was the most accessible (2.81, p \u3c 0.001), but the least credible (1.87, p \u3c 0.001). While social media was perceived less credible than other sources, its accessibility could make it a promising tool to provide evidence-based nutrition information to this population

Kingella kingae expresses type IV pili that mediate adherence to respiratory epithelial and synovial cells

Kingella kingae is a gram-negative bacterium that colonizes the respiratory tract and is a common cause of septic arthritis and osteomyelitis. Despite the increasing frequency of K. kingae disease, little is known about the mechanism by which this organism adheres to respiratory epithelium and seeds joints and bones. Previous work showed that K. kingae expresses long surface fibers that vary in surface density. In the current study, we found that these fibers are type IV pili and are necessary for efficient adherence to respiratory epithelial and synovial cells and that the number of pili expressed by the bacterium correlates with the level of adherence to synovial cells but not with the level of adherence to respiratory cells. In addition, we established that the major pilin subunit is encoded by a pilA homolog in a conserved region of the chromosome that also contains a second pilin gene and a type IV pilus accessory gene, both of which are dispensable for pilus assembly and pilus-mediated adherence. Upon examination of the K. kingae genome, we identified two genes in physically separate locations on the chromosome that encode homologs of the Neisseria PilC proteins and that have only a low level homology to each other. Examination of mutant strains revealed that both of the K. kingae PilC homologs are essential for a wild-type level of adherence to both respiratory epithelial and synovial cells. Taken together, these results demonstrate that type IV pili and the two PilC homologs play important roles in mediating K. kingae adherence

Formation of a Unique Cluster of G-Quadruplex Structures in the HIV-1 nef Coding Region: Implications for Antiviral Activity

G-quadruplexes are tetraplex structures of nucleic acids that can form in G-rich sequences. Their presence and functional role have been established in telomeres, oncogene promoters and coding regions of the human chromosome. In particular, they have been proposed to be directly involved in gene regulation at the level of transcription. Because the HIV-1 Nef protein is a fundamental factor for efficient viral replication, infectivity and pathogenesis in vitro and in vivo, we investigated G-quadruplex formation in the HIV-1 nef gene to assess the potential for viral inhibition through G-quadruplex stabilization. A comprehensive computational analysis of the nef coding region of available strains showed the presence of three conserved sequences that were uniquely clustered. Biophysical testing proved that G-quadruplex conformations were efficiently stabilized or induced by G-quadruplex ligands in all three sequences. Upon incubation with a G-quadruplex ligand, Nef expression was reduced in a reporter gene assay and Nef-dependent enhancement of HIV-1 infectivity was significantly repressed in an antiviral assay. These data constitute the first evidence of the possibility to regulate HIV-1 gene expression and infectivity through G-quadruplex targeting and therefore open a new avenue for viral treatment. © 2013 Perrone et al

Formal verification of a microcoded VIPER microprocessor using HOL

The Royal Signals and Radar Establishment (RSRE) and members of the Hardware Verification Group at Cambridge University conducted a joint effort to prove the correspondence between the electronic block model and the top level specification of Viper. Unfortunately, the proof became too complex and unmanageable within the given time and funding constraints, and is thus incomplete as of the date of this report. This report describes an independent attempt to use the HOL (Cambridge Higher Order Logic) mechanical verifier to verify Viper. Deriving from recent results in hardware verification research at UC Davis, the approach has been to redesign the electronic block model to make it microcoded and to structure the proof in a series of decreasingly abstract interpreter levels, the lowest being the electronic block level. The highest level is the RSRE Viper instruction set. Owing to the new approach and some results on the proof of generic interpreters as applied to simple microprocessors, this attempt required an effort approximately an order of magnitude less than the previous one

Nutrition practices of nurseries in England. Comparison with national guidelines.

Recent national guidelines call for improved nutrition within early years settings. The aim of this cross-sectional study was to describe foods and beverages served in nurseries, assess provider behaviors related to feeding, and compare these practices to national guidelines. We administered a mailed survey to a random sample of nurseries across England, stratifying by tertile of deprivation. A total of 851 nurseries returned the survey (54.3% response rate). We fitted separate multivariate logistic regression models to estimate the association of deprivation with each of the 13 food and beverage guidelines and the seven provider behavior guidelines. We also conducted a joint F-test for any deprivation effect, to evaluate the effect of the guidelines combined. After adjusting for confounders, we observed differences in the frequency of nurseries that reported serving healthier foods across the tertiles of deprivation (p = 0.02 for joint F test). These adjusted results were driven mainly by nurseries in more deprived areas serving more whole grains (OR 1.57 (95% CI 1.00, 2.46)) and legumes, pulses, and lentils (1.40 (1.01, 2.14)). We also observed differences in the frequency of nurseries reporting more provider behaviors consistent with national guidelines across the tertiles of deprivation (p = 0.01 for joint F test). Nurseries in more deprived areas were more likely to dilute juice with water (2.35 (1.48, 3.73)), allow children to select their own portions (1.09 (1.06, 1.58)), and sit with children during meals (1.84 (1.07, 3.15)). While nurseries in the most deprived areas reported serving more healthy foods, a large percentage were still not meeting national guidelines. Policy and intervention efforts may increase compliance with national guidelines in nurseries in more deprived areas, and across England.This work was undertaken by the Centre for Diet and Activity Research (CEDAR), a UK Clinical Research Collaboration (UKCRC) Public Health Research Centre of Excellence. Funding from the British Heart Foundation, Economic and Social Research Council, Medical Research Council, the National Institute for Health Research and the Wellcome Trust under the auspices of the UK Clinical Research Collaboration, is gratefully acknowledged.This is the final published version. It first appeared at http://www.sciencedirect.com/science/article/pii/S0195666314005145#

When females compete and males care: Phenotypic differences in the spotted sandpiper

Ecology can shape variation in mating systems. Spotted sandpipers (Actitis macularius) are migratory shorebirds with a sequentially polyandrous mating system. Females compete for multiple mates, and males care for offspring, including through incubation and chick care. A study of a Midwestern population found that females have larger body mass and feather spots, but we do not know whether this pattern extends to other populations of this species. We studied a California population of spotted sandpipers surrounding Mono Lake. We used PCR to determine genetic sex from blood samples, and we used R to compare morphological traits between females and males. We find sexual dimorphism in several morphological traits, including tarsus, wing, and bill length, as well as body mass, suggesting the Midwestern and California populations have evolved similarly, and both have sexually dimorphic morphology

Feeling (Mis)Understood and Intergroup Friendships in Interracial Interactions

The present research investigated whether having out-group friends serves as a buffer for feeling misunderstood in interracial interactions. Across three experience sampling studies, we found that among ethnic minorities who have few White friends or are not interacting with White friends, daily interracial interactions are associated with feeling less understood. By contrast, we found that among ethnic minorities who have more White friends or are interacting with White friends, the relationship between daily interracial interactions and feeling understood is not significant. We did not find similar results for Whites; that is, having ethnic minority friends did not play a role in the relationship between daily interracial interactions and feeling understood. Together, these studies demonstrate the beneficial effects of intergroup friendships for ethnic minorities