Building research capacity for evidence-informed tobacco control in Canada: a case description

Tobacco use remains the leading cause of death and disability in Canada. Insufficient research capacity can inhibit evidence-informed decision making for tobacco control. This paper outlines a Canadian project to build research capacity, defined as a community's ability to produce research that adequately informs practice, policy, and future research in a timely, practical manner. A key component is that individuals and teams within the community must mutually engage around common, collectively negotiated goals to address specific practices, policies or programs of research. An organizing framework, a set of activities to build strategic recruitment, productivity tools, and procedures for enhancing social capital are described. Actions are intended to facilitate better alignment between research and the priorities of policy developers and service providers, enhance the external validity of the work performed, and reduce the time required to inform policy and practice

The Method of Images in Cosmology

31 pages, 18 figures31 pages, 18 figuresWe apply the method of images to the exact initial data for cosmological models that contain a number of regularly arranged discrete masses. This allows us to join cosmological regions together by throats, and to construct wormholes in the initial data. These wormholes allow for the removal of the asymptotically flat "flange" regions that would otherwise exist on the far side of black holes. The method of images also provides us with a way to investigate the definition of mass is cosmology, and the cosmological consequences of the gravitational interaction energies between massive objects. We find evidence that the interaction energies within clusters of massive objects do indeed appear to contribute to the total energy budget in the cosmological regions of the space-time

Group 2 Innate Lymphoid Cells Exhibit Tissue-Specific Dynamic Behaviour During Type 2 Immune Responses.

Group 2 innate lymphoid cells (ILC2s) are early effectors of mucosal type 2 immunity, producing cytokines such as interleukin (IL)-13 to mediate responses to helminth infection and allergen-induced inflammation. ILC2s are also present in lymph nodes (LNs) and can express molecules required for antigen presentation, but to date there are limited data on their dynamic behaviour. We used a CD2/IL-13 dual fluorescent reporter mouse for in vivo imaging of ILC2s and Th2 T cells in real time following a type 2 priming helminth infection or egg injection. After helminth challenge, we found that ILC2s were the main source of IL-13 in lymphoid organs (Peyer's patches and peripheral LNs), and were located in T cell areas. Intravital imaging demonstrated an increase in IL-13+ ILC2 size and movement following helminth infection, but reduced duration of interactions with T cells compared with those in homeostasis. In contrast, in the intestinal mucosa, we observed an increase in ILC2-T cell interactions post-infection, including some of prolonged duration, as well as increased IL-13+ ILC2 movement. These data suggest that ILC2 activation enhances cell motility, with the potential to increase the area of distribution of cytokines to optimise the early generation of type 2 responses. The prolonged ILC2 interactions with T cells within the intestinal mucosa are consistent with the conclusion that contact-based T cell activation may occur within inflamed tissues rather than lymphoid organs. Our findings have important implications for our understanding of the in vivo biology of ILC2s and the way in which these cells facilitate adaptive immune responses

Striatal interneurons in dissociated cell culture

In addition to the well-characterized direct and indirect projection neurons there are four major interneuron types in the striatum. Three contain GABA and either parvalbumin, calretinin or NOS/NPY/somatostatin. The fourth is cholinergic. It might be assumed that dissociated cell cultures of striatum (typically from embryonic day E18.5 in rat and E14.5 for mouse) contain each of these neuronal types. However, in dissociated rat striatal (caudate/putamen, CPu) cultures arguably the most important interneuron, the giant aspiny cholinergic neuron, is not present. When dissociated striatal neurons from E14.5 Sprague–Dawley rats were mixed with those from E18.5 rats, combined cultures from these two gestational periods yielded surviving cholinergic interneurons and representative populations of the other interneuron types at 5 weeks in vitro. Neurons from E12.5 CD-1 mice were combined with CPu neurons from E14.5 mice and the characteristics of striatal interneurons after 5 weeks in vitro were determined. All four major classes of interneurons were identified in these cultures as well as rare tyrosine hydroxylase positive interneurons. However, E14.5 mouse CPu cultures contained relatively few cholinergic interneurons rather than the nearly total absence seen in the rat. A later dissection day (E16.5) was required to obtain mouse CPu cultures totally lacking the cholinergic interneuron. We show that these cultures generated from two gestational age cells have much more nearly normal proportions of interneurons than the more common organotypic cultures of striatum. Interneurons are generated from both ages of embryos except for the cholinergic interneurons that originate from the medial ganglionic eminence of younger embryos. Study of these cultures should more accurately reflect neuronal processing as it occurs in the striatum in vivo. Furthermore, these results reveal a procedure for parallel culture of striatum and cholinergic depleted striatum that can be used to examine the function of the cholinergic interneuron in striatal networks

The PHF21B gene is associated with major depression and modulates the stress response

Major depressive disorder (MDD) affects around 350 million people worldwide; however, the underlying genetic basis remains largely unknown. In this study, we took into account that MDD is a gene-environment disorder, in which stress is a critical component, and used whole-genome screening of functional variants to investigate the 'missing heritability' in MDD. Genome-wide association studies (GWAS) using single- and multi-locus linear mixed-effect models were performed in a Los Angeles Mexican-American cohort (196 controls, 203 MDD) and in a replication European-ancestry cohort (499 controls, 473 MDD). Our analyses took into consideration the stress levels in the control populations. The Mexican-American controls, comprised primarily of recent immigrants, had high levels of stress due to acculturation issues and the European-ancestry controls with high stress levels were given higher weights in our analysis. We identified 44 common and rare functional variants associated with mild to moderate MDD in the Mexican-American cohort (genome-wide false discovery rate, FDR, <0.05), and their pathway analysis revealed that the three top overrepresented Gene Ontology (GO) processes were innate immune response, glutamate receptor signaling and detection of chemical stimulus in smell sensory perception. Rare variant analysis replicated the association of the PHF21B gene in the ethnically unrelated European-ancestry cohort. The TRPM2 gene, previously implicated in mood disorders, may also be considered replicated by our analyses. Whole-genome sequencing analyses of a subset of the cohorts revealed that European-ancestry individuals have a significantly reduced (50%) number of single nucleotide variants compared with Mexican-American individuals, and for this reason the role of rare variants may vary across populations. PHF21b variants contribute significantly to differences in the levels of expression of this gene in several brain areas, including the hippocampus. Furthermore, using an animal model of stress, we found that Phf21b hippocampal gene expression is significantly decreased in animals resilient to chronic restraint stress when compared with non-chronically stressed animals. Together, our results reveal that including stress level data enables the identification of novel rare functional variants associated with MDD.M-L Wong, M Arcos-Burgos, S Liu, J I Vélez, C Yu, B T Baune, M C Jawahar, V Arolt, U Dannlowski, A Chuah, G A Huttley, R Fogarty, M D Lewis, S R Bornstein, and J Licini

Black-hole lattices as cosmological models

The search for solutions of Einstein's equations representing relativistic cosmological models with a discrete matter content has been remarkably fruitful in the last decade. In this review we discuss the progress made in the study of a specific subclass of discrete cosmologies, Black-Hole Lattice models. In particular, we illustrate the techniques used for the construction of these spacetimes, and examine their resulting physical properties. This includes their large-scale dynamics, the dressing of mass due to the interaction between individual black holes, along with features of direct observational interest such as the distance-to-redshift relation. This collection of results provides a novel perspective on the physical effects of averaging in General Relativity, as well as on the emergence of gravitational structures from solutions with isolated objects.Comment: 54 pages, 16 figures, review prepared for the CQG Special Focus Issue "Computational issues in mathematical cosmology

Effect of perinatal hypothyroidism on the developmental regulation of rat pituitary growth hormone and thyrotropin genes

We studied the effects of thyroid hormone (T3) on GH, TSH, and T3 receptor (TR) gene expression as well as deiodinase activities during rat pituitary development. By reverse transcriptase-polymerase chain reaction, GH and TSHβ transcripts were detectable on fetal day 15. Although with certain differences, the expression of both GH and TSHβ genes was under T3 control during fetal and neonatal life. Differences in plasma, but not pituitary, TSH concentrations were observed between control and hypothyroid animals throughout the period studied. Both TRα and TRβ genes were expressed in the fetal pituitary. TRα1, TRβ2, and c-erbAα2 transcripts displayed a developmental profile different from that of TRβ1. Thyroid hormone repressed TRα1, TRβ2, and c-erbAα2 and stimulated TRβ1. Type I and type II deiodinase activities (5'DI and 5'DII, respectively) had different ontogenic patterns; 5'D-II was the predominant activity in fetuses, with levels similar to those in adults, whereas the level of 5'D-I was low and increased with age. T3 stimulated 5'D-I and decreases 5'D-II. These results demonstrate that in somatotroph and thyrotroph cells, the mechanisms responsible for T3 action are mature and active very early in development and suggest an involvement of this hormone in the establishment and/or maintenance of the somatotroph and thyrotroph phenotype.Peer Reviewe

Insulin regulation of malic enzyme gene expression in rat liver: evidence for nuclear proteins that bind to two putative insulin response elements

Diabetes in rats is characterized by insulin deficiency accompanied by a decrease in lipogenic enzymes. The malic enzyme (ME) gene, which encodes an important lipogenic enzyme, was used to investigate insulin regulation of gene expression. ME mRNA levels were reduced by more than 90% in the liver of diabetic rats. The administration of insulin (3 U/15 days) to either control or diabetic rats increased ME mRNA by 2- to 10-fold, respectively. Since diabetes reduces circulating T3 and the levels of nuclear T3-receptors, the potential role of thyroid hormone on insulin regulation of ME gene expression was also evaluated in thyroidectomized-diabetic rats. In these animals the levels of ME mRNA were undetectable but were increased by insulin even in the absence of thyroid hormones. These in vivo effects of insulin and T3 were not additive. The transcription rate of the gene was also reduced in the diabetic liver and recovered after insulin therapy. By computer analyses we have identified two different putative insulin response elements (IREs) in the ME gene promoter, hereafter referred to as IRE-I (-683 to -692), which is similar to the phosphoenol pyruvate carboxy kinase promoter IRE and IRE-II (- 161 to -170), which is similar to the glyceraldehyde phosphate dehydrogenase gene promoter IRE-A. Results from gel retardation assays suggest that a single nuclear protein binds to IRE-I whereas two different nuclear proteins bind to IRE-II. The protein/IRE-I complex increased in liver nuclear extracts from diabetic rats and decreased after insulin administration. In contrast, the protein/IRE-II complex decreased in liver nuclear extracts from diabetic rats and increased after insulin administration. Analysis of the IRE-II sequence revealed a GC-rich motif similar to the Sp1 element. These results suggest that insulin increases ME gene transcription by modulating the levels of the above mentioned DNA nuclear protein complexes.Peer Reviewe