A Southern Record of the Xenobiotic Ant Formicoxenus quebecensis from Eastern Wisconsin

The ant genus Formicoxenus is notable for the fact that all its species are xenobiotic and live inside or in close association with the nests of other ant species. Here, we report the occurrence of a colony of Formicoxenus quebecensis and its host, Myrmica alaskensis from the eastern side of the Door peninsula in Wisconsin. Both species are new records for the state, and F. quebecensis was previously known only from boreal habitats much farther north in Canada. We also provide some observations on this colony’s nest demography, morphology, and feeding behavior and discuss the ant community of this biogeographically interesting location.

RNA interference screening reveals host CaMK4 as a regulator of cryptococcal uptake and pathogenesis

ABSTRACT Cryptococcus neoformans , the causative agent of cryptococcosis, is an opportunistic fungal pathogen that kills over 200,000 individuals annually. This yeast may grow freely in body fluids, but it also flourishes within host cells. Despite extensive research on cryptococcal pathogenesis, host genes involved in the initial engulfment of fungi and subsequent stages of infection are woefully understudied. To address this issue, we combined short interfering RNA silencing and a high-throughput imaging assay to identify host regulators that specifically influence cryptococcal uptake. Of 868 phosphatase and kinase genes assayed, we discovered 79 whose silencing significantly affected cryptococcal engulfment. For 25 of these, the effects were fungus specific, as opposed to general alterations in phagocytosis. Four members of this group significantly and specifically altered cryptococcal uptake; one of them encoded CaMK4, a calcium/calmodulin-dependent protein kinase. Pharmacological inhibition of CaMK4 recapitulated the observed defects in phagocytosis. Furthermore, mice deficient in CaMK4 showed increased survival compared to wild-type mice upon infection with C. neoformans . This increase in survival correlated with decreased expression of pattern recognition receptors on host phagocytes known to recognize C. neoformans . Altogether, we have identified a kinase that is involved in C. neoformans internalization by host cells and in host resistance to this deadly infection. </jats:p

Riparian alder ecosystems as epiphytic lichen refugia in sub-boreal spruce forests of British Columbia. Botany 88

Abstract: Alder-dominated riparian forests represent only a small proportion of the landscape in central-interior British Columbia. However, they possess a suite of attributes that may allow them to function as refugia for canopy macrolichens. These include their deciduous habitat, their location in moist nutrient receiving sites, and their distribution as narrow corridors that cross broad regional landscapes. We have examined their potential role as lichen refugia by assessing canopy macrolichen communities in 75 riparian alder forests across a 200 km longitudinal gradient in central-interior British Columbia. Study sites were stratified equally between three climate subzones of the Sub-Boreal Spruce biogeoclimatic zone. Forty-nine macrolichen taxa were observed, including the old-growth indicator cyanolichen species Lobaria scrobiculata (Scop.) DC., L. retigera (Bory) Trevisan, Nephroma isidiosum (Nyl.) Gyelnik, and Sticta limbata (Sm.) Ach. Canonical correspondence analysis identified mean annual temperature, mean annual precipitation, age of adjacent conifer forest, and abundance of large stems (dbh &gt;10 cm) as significant explanatory variables. Regional precipitation gradients explained the exclusion of many lichen species from both the most westerly and most easterly riparian forests, with drier summer conditions and heavy winter snowpack, respectively, being major limiting factors. Lichens preferentially occupied large leaning stems, which may provide greater precipitation interception and continuity of substrate, when compared with smaller upright alder stems. We conclude that alder-dominated riparian forests represent a major refugium for old-growth dependent lichens in British Columbia&apos;s sub-boreal spruce landscapes and as such may provide valuable dispersal corridors between remnant old-growth coniferous forest patches. Key words: Alnus, riparian gallery, canopy macrolichens, sub-boreal spruce, old growth, lichen indicator species. Résumé : Les forêts riveraines dominées par les aulnes ne représentent qu&apos;une faible proportion du paysage dans la région du centre-intérieur de la Colombie Canadienne. Cependant, elles possèdent un ensemble d&apos;attributs qui pourraient leur permettre d&apos;agir comme refuge pour les macrolichens de la canopée. Ceux-ci incluent leur habitat décidu, leur localisation sur des sites recevant des embruns nutritifs, et leur distribution le long d&apos;étroits corridors traversant un ensemble de paysages régionaux. Les auteurs ont examiné leur potentiel comme refuge pour les lichens, en évaluant les communautés de macrolichens de la canopée dans 75 forêts riveraines le long d&apos;un gradient longitudinal de 200 km, dans le centre-intérieur de la Colombie Canadienne. Les sites d&apos;études furent également stratifiés entre trois sous-zones de la zone biogéoclimatique de la pessière sub-boréale. Les auteurs ont observé 49 taxons de macrolichens, incluant les Lobaria scrobiculata (Scop.) DC., L. retigera (Bory) Trevisan, Nephroma isidiosum (Nyl.) Gyelnik et Sticta limbata (Sm.) Ach., des espèces de cyanolichens indicatrices des forêts surannées. L&apos;analyse des correspondances canoniques identifie comme variables explicatives significatives, la température annuelle moyenne, la précipitation annuelle moyenne, l&apos;âge des forêts conifériennes adjacentes, et l&apos;abondance de tiges à fort diamètre (dhp &gt;10 cm). Les gradients de précipitation régionale expliquent l&apos;exclusion de plusieurs espèces de lichens le long des forêts riveraines à la fois les plus à l&apos;ouest et les plus à l&apos;est, subissant respectivement des conditions estivales plus sèches et d&apos;enneigement hivernal plus importantes qui agissent comme facteurs limites. Les lichens occupent de préférence les longues branches traînantes qui peuvent permettre une interception plus importante des précipitations et une continuité de substrat, lorsqu&apos;on les compare aux plus petites tiges dressées des aulnes. Les auteurs concluent que les forêts riveraines dominées par des aulnes constituent un refuge de premier ordre pour les lichens dépen-dant de forêts surannées dans les paysages de la pessière sub-boréale de la Colombie Canadienne, en fournissant des corridors utiles entre les aires de forêts conifériennes surannées. Mots-clés : Alnus, galerie riveraine, macrolichens de la canopée, pessière sub-boréale, espèces de lichens indicatrices d&apos;âge avancé. [Traduit par la Rédaction

Trust, Trust Repair, and Public Health: A Scoping Review Protocol

Trust can be defined as “a willingness to be vulnerable to another for a given set of tasks” and thus, trust and public health are inextricably linked. State actors are key participants in population health, organizing, among other things, mandates and guidelines that target health behaviors and encourage the uptake of medicines, screenings, diagnostics, and control of health conditions. Effective implementation of these crucial, government-sponsored health efforts is conditional on the public’s belief that the state is trustworthy and has one\u27s best interest in mind – positioning trust in government as a central determinant of public health. Trusting relationships between patients, health systems, and health care providers are also essential, as high-quality, safe care and adherence with healthcare professionals’ recommendations heavily depend upon trust. In many countries, trust in government and health care providers are inseparable, as governments are the primary providers of healthcare. Despite these critical relationships, existing studies that link trust and public health outcomes often focus on contemporaneous factors, many of which are endogenous to public health outcomes (e.g., support for the incumbent political party). For example, Sopory and colleagues reported a comprehensive examination of the phenomenon of trust during public health emergency events among 68 studies from 28 countries that included individuals who were directly affected by a public health emergency. Importantly, no studies from South America or Africa were included. The shortage of research on the sociostructural, historical, economic, and political sources of low trust limits our understanding of how trust deficits might be remedied so as to improve population health. Understanding why trust is low as well as how to repair trust are thus of critical importance

Toward an Integrated Model of Capsule Regulation in Cryptococcus neoformans

Cryptococcus neoformans is an opportunistic fungal pathogen that causes serious human disease in immunocompromised populations. Its polysaccharide capsule is a key virulence factor which is regulated in response to growth conditions, becoming enlarged in the context of infection. We used microarray analysis of cells stimulated to form capsule over a range of growth conditions to identify a transcriptional signature associated with capsule enlargement. The signature contains 880 genes, is enriched for genes encoding known capsule regulators, and includes many uncharacterized sequences. One uncharacterized sequence encodes a novel regulator of capsule and of fungal virulence. This factor is a homolog of the yeast protein Ada2, a member of the Spt-Ada-Gcn5 Acetyltransferase (SAGA) complex that regulates transcription of stress response genes via histone acetylation. Consistent with this homology, the C. neoformans null mutant exhibits reduced histone H3 lysine 9 acetylation. It is also defective in response to a variety of stress conditions, demonstrating phenotypes that overlap with, but are not identical to, those of other fungi with altered SAGA complexes. The mutant also exhibits significant defects in sexual development and virulence. To establish the role of Ada2 in the broader network of capsule regulation we performed RNA-Seq on strains lacking either Ada2 or one of two other capsule regulators: Cir1 and Nrg1. Analysis of the results suggested that Ada2 functions downstream of both Cir1 and Nrg1 via components of the high osmolarity glycerol (HOG) pathway. To identify direct targets of Ada2, we performed ChIP-Seq analysis of histone acetylation in the Ada2 null mutant. These studies supported the role of Ada2 in the direct regulation of capsule and mating responses and suggested that it may also play a direct role in regulating capsule-independent antiphagocytic virulence factors. These results validate our experimental approach to dissecting capsule regulation and provide multiple targets for future investigation

Cryptococcus neoformans Dual GDP-mannose transporters and their role in biology and virulence

Cryptococcus neoformans is an opportunistic yeast responsible for lethal meningoencephalitis in humans. This pathogen elaborates a polysaccharide capsule, which is its major virulence factor. Mannose constitutes over one-half of the capsule mass and is also extensively utilized in cell wall synthesis and in glycosylation of proteins and lipids. The activated mannose donor for most biosynthetic reactions, GDP-mannose, is made in the cytosol, although it is primarily consumed in secretory organelles. This compartmentalization necessitates specific transmembrane transporters to make the donor available for glycan synthesis. We previously identified two cryptococcal GDP-mannose transporters, Gmt1 and Gmt2. Biochemical studies of each protein expressed in Saccharomyces cerevisiae showed that both are functional, with similar kinetics and substrate specificities in vitro. We have now examined these proteins in vivo and demonstrate that cells lacking Gmt1 show significant phenotypic differences from those lacking Gmt2 in terms of growth, colony morphology, protein glycosylation, and capsule phenotypes. Some of these observations may be explained by differential expression of the two genes, but others suggest that the two proteins play overlapping but nonidentical roles in cryptococcal biology. Furthermore, gmt1 gmt2 double mutant cells, which are unexpectedly viable, exhibit severe defects in capsule synthesis and protein glycosylation and are avirulent in mouse models of cryptococcosis

A Sensitive High-Throughput Assay for Evaluating Host-Pathogen Interactions in Cryptococcus neoformans Infection

Background: Cryptococcus neoformans causes serious disease in immunocompromised individuals, leading to over 600,000 deaths per year worldwide. Part of this impact is due to the organism’s ability to thwart what should be the mammalian hosts ’ first line of defense against cryptococcal infection: internalization by macrophages. Even when C. neoformans is engulfed by host phagocytes, it can survive and replicate within them rather than being destroyed; this ability is central in cryptococcal virulence. It is therefore critical to elucidate the interactions of this facultative intracellular pathogen with phagocytic cells of its mammalian host. Methodology/Principal Findings: To accurately assess initial interactions between human phagocytic cells and fungi, we have developed a method using high-throughput microscopy to efficiently distinguish adherent and engulfed cryptococci and quantitate each population. This method offers significant advantages over currently available means of assaying hostfungal cell interactions, and remains statistically robust when implemented in an automated fashion appropriate for screening. It was used to demonstrate the sensitivity of human phagocytes to subtle changes in the cryptococcal capsule, a major virulence factor of this pathogen. Conclusions/Significance: Our high-throughput method for characterizing interactions between C. neoformans and mammalian phagocytic cells offers a powerful tool for elucidating the relationship between these cell types durin

Assessing the Impact of Holocaust Education on Adolescents’ Civic Values: Experimental Evidence from Arkansas

American adults overwhelmingly agree that the Holocaust should be taught in schools, yet few studies investigate the potential benefits of Holocaust education. We evaluate the impact of Holocaust education on several civic outcomes, including “upstander” efficacy (willingness to intervene on behalf of others), likelihood of exercising civil disobedience, empathy for the suffering of others, and tolerance of others with different values and lifestyles. We recruit students from two local high schools and randomize access to the Arkansas Holocaust Education Conference, where students have the chance to hear from a Holocaust survivor and to participate in breakout sessions with leading Holocaust experts. We find that students randomly assigned to attend the conference become more knowledgeable about the Holocaust and are more willing to act as an upstander on behalf of others. In our subgroup analysis, we find that minority students are significantly more willing to act as an upstander relative to their white peers