Ordovician chitinous hydroids from Hudson Strait, District of Franklin, Northwest Territories

Chitinous hydroids are documented for the first time from the Upper Ordovician of Eastern Canada, and for the fourth time from North American rocks. One hydrosome branch segment is provisionally attributed to Rhabdohydra Kozlowski. The excellent three dimensional preservation shows the periderm is layered and vesiculate. Periderm thinning, present in Recent chitinous hydroids, is also noted for Ordovician hydroids. RÉSUMÉ Une premiére signalisation, d'hydro ides chitineuses dans l’Ordovicien sup iérieur de l'Est du Canada vient s'ajouter aux trois documents deja issus de roches nord-ameiicaines. Un segment de rameau hydrosomal est rapporte' avec r iéserve au genre Rhabdohydra Kozlowski. line excellente conservation dans ses trois dimensions d iémontre que le p iériderme est vésiculeux et constitu ié de plusieurs couches. L'amincissement du p iériderme, ph iénom iène connu des hydroides chitineuses actuelles, se manifeste aussi chez les hydroides ordoviciennes

Utilizing Gene Tree Variation to Identify Candidate Effector Genes in Zymoseptoria tritici

Zymoseptoria tritici is a host-specific, necrotrophic pathogen of wheat. Infection by Z. tritici is characterized by its extended latent period, which typically lasts two weeks, and is followed by extensive host cell death and rapid proliferation of fungal biomass. This work characterizes the level of genomic variation in 13 isolates for which we have measured virulence on 11 wheat cultivars with differential resistance genes. Between the reference isolate, IPO323, and the 13 Australian isolates we identified over 800,000 single nucleotide polymorphisms, of which ~10% had an effect on the coding regions of the genome. Furthermore we identified over 1700 probable presence/absence polymorphisms in genes across the Australian isolates using de novo assembly. Finally, we developed a gene tree sorting method that quickly identifies groups of isolates within a single gene alignment whose sequence haplotypes correspond with virulence scores on a single wheat cultivar. Using this method we have identified <100 candidate effector genes whose gene sequence correlates with virulence towards a wheat cultivar carrying a major resistance gene

Quorum-sensing and cheating in bacterial biofilms

The idea from human societies that self-interest can lead to a breakdown of cooperation at the group level is sometimes termed the public goods dilemma. We tested this idea in the opportunistic bacterial pathogen, Pseudomonas aeruginosa, by examining the influence of putative cheats that do not cooperate via cell-to-cell signalling (quorum-sensing, QS).We found that: (i) QS cheating occurs in biofilm populations owing to exploitation of QS-regulated public goods; (ii) the thickness and density of biofilms was reduced by the presence of non-cooperative cheats; (iii) population growth was reduced by the presence of cheats, and this reduction was greater in biofilms than in planktonic populations; (iv) the susceptibility of biofilms to antibiotics was increased by the presence of cheats; and (v) coercing cooperator cells to increase their level of cooperation decreases the extent to which the presence of cheats reduces population productivity. Our results provide clear support that conflict over public goods reduces population fitness in bacterial biofilms, and that this effect is greater than in planktonic populations. Finally, we discuss the clinical implications that arise from altering the susceptibility to antibiotics

Strange form factors of the nucleon in a two-component model

The strange form factors of the nucleon are studied in a two-component model consisting of a three-quark intrinsic structure surrounded by a meson cloud. A comparison with the available experimental world data from the SAMPLE, PVA4, HAPPEX and G0 collaborations shows a good overall agreement. The strange magnetic moment is found to be positive, 0.315 nm.Comment: 11 pages, 2 tables, 5 figures, accepted for publication in J. Phys. G. Revised version, new figures, extra table, new results, updated reference

External vs. Innate: Sources of Resiliency Among Emerging Adults, Black Gay and Bisexual Men

The purpose of this research was to examine the main sources and origins of resiliency that are present among Black gay and bisexual men. Resiliency refers to one’s response to adversity and ability to positively adapt to difficult situations. Twenty participants ranging in age between 18-25 years old (M = 22.8 years, SD = 1.7 years) participated in a semi-structured interview. Participants indicated varying sources of resiliency, which they utilize to encounter hardships. Innate sources (i.e., I was born this way) and external sources (i.e., music, my grandmother’s spirit) were conveyed by participants as mechanisms to overcome adversity. The current findings seek to increase social understanding of the means through which these emerging adults overcome adversity, in effort to decrease social marginalization, stigmatization, and discrimination

Searching for life with rovers: exploration methods and science results from the 2004 field campaign of the “Life in the Atacama” project and applications to future Mars Missions

LITA develops and field tests a long-range automated rover and a science payload to search for microbial life in the Atacama. The Atacama's evolution provides a unique training ground for designing and testing exploration strategies and life detection methods for the search for life on Mars

2-Amino-4,5,6,7-tetra­hydro­benzo[b]thio­phene-3-carbonitrile

The title compound, C9H10N2S, was synthesized according to Gewald procedures by the reaction of cyclo­hexa­none with malonitrile and sulfur in the presence morpholine. The cyclo­hexane ring adopts a half-chair conformation and the thio­phene ring is essentially planar (r.m.s. deviation = 0.05 Å). The crystal packing is stabilized by two inter­molecular N—H⋯N hydrogen bonds, which link the mol­ecules into centrosymmetric rings with graph-set motif R 2 2(12)

Crafting communities: promoting inclusion, empowerment, and learning between older women

While social policy and planning documents are replete with ominous warnings about the cost of an ageing population, this article tells a different story about the productive and self-sustaining networks that exist among older women in the community who do craftwork. From our research conducted in Victoria, Australia during 2007&ndash;2008 we discovered a resilient and committed group of older women quietly and steadily contributing to community fundraising, building social networks, and providing learning opportunities to each other in diverse ways. Through our conversations with nine craftswomen we have been able to articulate clear links between the theory and models commonly espoused in the community development literature and the life-enriching practices used in organising informal community craft group activities. From our interviews with the older women we provide evidence of sustained participation, the generation of social capital, and the fostering of life-long learning. While none of the women we spoke to were trained in community development and did not use language commonly associated with feminist ideology, the relationship between the informal group work with principles of empowerment and self-efficacy were unmistakeable. We conclude with a discussion of the implications of our findings for critical social work practice.<br /