440 research outputs found

    More than a second language: Leadership structure and pedagogic strategies in an Australian International Baccalaureate PYP additional language program.

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    Good second language classrooms in international schools are vehicles for fostering intercultural understandings as well as learning an additional language. This paper emanates from a study into the teaching of second languages undertaken across six countries in International Baccalaureate (IB) Primary Years Program schools. A range of languages, IB regions and language teaching approaches were investigated. This paper reports on the Australian case study. Three structural and pedagogic strategies that contribute to teaching a second language and fostering intercultural understandings are identified, including; school leadership, inquiry and concept based learning, and the inclusion of the school community. The findings highlight the compliance role of the IB Programme Standards and Practices for leadership, governance and management. It offers successful leadership and pedagogic strategies that may be useful for other schools engaged in teaching second languages as a means to nurturing intercultural understanding

    Genetic diversity of Chamaecrista fasciculata (Fabaceae) from the USDA germplasm collection

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    Objective: Chamaecrista fasciculata is a widespread annual legume across Eastern North America, with potential as a restoration planting, biofuel crop, and genetic model for non-papillinoid legumes. As a non-Papilinoid, C. fasciculata, belongs to the Caesalpiniod group in which nodulation likely arose independently of the nodulation in Papilinoid and Mimosoid legumes. Thus, C. fasciculata is an attractive model system for legume evolution. In this study, we describe population structure and genetic diversity among 32 USDA germplasm accessions of C. fasciculata using 317 AFLP markers developed from 12 primer pairs, to assess where geographically there is the most genetic variation. Results: We found that the C. fasciculata germplasm collection fall into four clusters with admixture among them. After correcting for outliers, our analysis shows two primary groups across Eastern and Central North America. To better understand the population biology of this species, further sampling of the full range of this widespread species is needed across North America, as well as the development of a larger set of markers providing denser coverage of the genome. Further sampling will help clarify geographical relationships in this widespread temperate species

    Immune Evasion by Herpes Simplex Viruses

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    Infection with herpes simplex viruses type 1 (HSV-1) and type 2 (HSV-2) is extremely frequent in the human population, as well as recurrent reactivations due to lifelong infection. Infection and persistence of HSVs within healthy individuals likely results as a consequence of numerous molecular determinants evolved by these pathogens to escape both immediate and long-term host antiviral mechanisms. Indeed, HSVs harbor an arsenal of proteins that confer them stealth by negatively modulating immune function. Consequently, these viruses perpetuate within the host, altogether silently shedding onto other individuals. In this chapter, we discuss HSV determinants that interfere with cellular antiviral factors, as well as viral determinants that hamper innate and adaptive immune components intended to control such microbes. The identification of HSV evasion molecules that modulate the immune system, as well as the understanding of their mechanisms of action, should facilitate the design of novel prophylactic and therapeutic strategies to overcome infection and disease elicited by these viruses. This chapter is intended to provide an overview of the evasion mechanisms evolved by herpes simplex viruses to escape numerous host antiviral mediators

    A Herpes Simplex Virus Type 2 Deleted for Glycoprotein D Enables Dendritic Cells to Activate CD4+ and CD8+ T Cells

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    Herpes simplex virus type 2 (HSV-2) is highly prevalent in the human population producing significant morbidity, mainly because of the generation of genital ulcers and neonatal encephalitis. Additionally, HSV-2 infection significantly increases the susceptibility of the host to acquire HIV and promotes the shedding of the latter in the coinfected. Despite numerous efforts to create a vaccine against HSV-2, no licensed vaccines are currently available. A long-standing strategy, based on few viral glycoproteins combined with adjuvants, recently displayed poor results in a Phase III clinical study fueling exploration on the development of mutant HSV viruses that are attenuated in vivo and elicit protective adaptive immune components, such as antiviral antibodies and T cells. Importantly, such specialized antiviral immune components are likely induced and modulated by dendritic cells, professional antigen presenting cells that process viral antigens and present them to T cells. However, HSV interferes with several functions of DCs and ultimately induces their death. Here, we propose that for an attenuated mutant virus to confer protective immunity against HSV in vivo based on adaptive immune components, such virus should also be attenuated in dendritic cells to promote a robust and effective antiviral response. We provide a background framework for this idea, considerations, as well as the means to assess this hypothesis. Addressing this hypothesis may provide valuable insights for the development of novel, safe, and effective vaccines against herpes simplex viruses

    Immune-Modulation by the Human Respiratory Syncytial Virus: Focus on Dendritic Cells

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    The human respiratory syncytial virus (hRSV) is the leading cause of pneumonia in infants and produces a significant burden in the elderly. It can also infect and produce disease in otherwise healthy adults and recurrently infect those previously exposed to the virus. Importantly, recurrent infections are not necessarily a consequence of antigenic variability, as described for other respiratory viruses, but most likely due to the capacity of this virus to interfere with the host's immune response and the establishment of a protective and long-lasting immunity. Although some genes encoded by hRSV are known to have a direct participation in immune evasion, it seems that repeated infection is mainly given by its capacity to modulate immune components in such a way to promote non-optimal antiviral responses in the host. Importantly, hRSV is known to interfere with dendritic cell (DC) function, which are key cells involved in establishing and regulating protective virus-specific immunity. Notably, hRSV infects DCs, alters their maturation, migration to lymph nodes and their capacity to activate virus-specific T cells, which likely impacts the host antiviral response against this virus. Here, we review and discuss the most important and recent findings related to DC modulation by hRSV, which might be at the basis of recurrent infections in previously infected individuals and hRSV-induced disease. A focus on the interaction between DCs and hRSV will likely contribute to the development of effective prophylactic and antiviral strategies against this virus

    Clinical and polysomnographic predictors of the Natural History of poor sleep in the general population

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    Study Objectives: Approximately 8-10% of the general population suffers from chronic insomnia, whereas another 20-30% of the population has insomnia symptoms at any given time (i.e., poor sleep). However, few longitudinal studies have examined risk factors of the natural history of poor sleep, and none have examined the role of polysomnographic (PSG) variables. Design: Representative longitudinal study. Setting: Sleep laboratory. Participants: From a random, general population sample of 1,741 individuals of the adult Penn State Cohort, 1,395 were followed up after 7.5 yr. Measurements: Full medical evaluation and 1-night PSG at baseline and telephone interview at follow-up. Results: The rate of incident poor sleep was 18.4%. Physical (e.g., obesity, sleep apnea, and ulcer) and mental (e.g., depression) health conditions and behavioral factors (e.g., smoking and alcohol consumption) increased the odds of incident poor sleep as compared to normal sleep. The rates of persistent, remitted, and poor sleepers who developed chronic insomnia were 39%, 44%, and 17%, respectively. Risk factors for persistent poor sleep were physical health conditions combined with psychologic distress. Shorter objective sleep duration and a family history of sleep problems were risk factors for poor sleep evolving into chronic insomnia. Conclusions: Poor sleep appears to be primarily a symptom of physical and mental health conditions, whereas the persistence of poor sleep is associated with psychologic distress. Importantly, sleep apnea appears to be associated with incident poor sleep but not with chronic insomnia. Finally, this study suggests that objective short sleep duration in poor sleepers is a biologic marker of genetic predisposition to chronic insomniaThis research was funded in part by the National Institutes of Health grants RO1 51931, RO1 40916 (to Dr. Bixler), and RO1 64415 (to Dr. Vgontzas)

    Naturally Derived Heme-Oxygenase 1 Inducers and Their Therapeutic Application to Immune-Mediated Diseases

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    Heme oxygenase (HO) is the primary antioxidant enzyme involved in heme group degradation. A variety of stimuli triggers the expression of the inducible HO-1 isoform, which is modulated by its substrate and cellular stressors. A major anti-inflammatory role has been assigned to the HO-1 activity. Therefore, in recent years HO-1 induction has been employed as an approach to treating several disorders displaying some immune alterations components, such as exacerbated inflammation or self-reactivity. Many natural compounds have shown to be effective inductors of HO-1 without cytotoxic effects; among them, most are chemicals present in plants used as food, flavoring, and medicine. Here we discuss some naturally derived compounds involved in HO-1 induction, their impact in the immune response modulation, and the beneficial effect in diverse autoimmune disorders. We conclude that the use of some compounds from natural sources able to induce HO-1 is an attractive lifestyle toward promoting human health. This review opens a new outlook on the investigation of naturally derived HO-1 inducers, mainly concerning autoimmunity.Fil: Funes, Samanta Celeste. Pontificia Universidad Católica de Chile; ChileFil: Rios, Mariana. Pontificia Universidad Católica de Chile; ChileFil: Fernández Fierro, Ayleen. Pontificia Universidad Católica de Chile; ChileFil: Covián, Camila. Pontificia Universidad Católica de Chile; ChileFil: Bueno, Susan M.. Pontificia Universidad Católica de Chile; ChileFil: Riedel, Claudia A.. Universidad Andrés Bello; ChileFil: Mackern Oberti, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Kalergis, Alexis M.. Pontificia Universidad Católica de Chile; Chil

    Identification of polyketide synthase genes required for aspinolide biosynthesis in Trichoderma arundinaceum

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    https://link.springer.com/article/10.1007/s00253-022-12182-9[EN] The fungus Trichoderma arundinaceum exhibits biological control activity against crop diseases caused by other fungi. Two mechanisms that likely contribute to this activity are upregulation of plant defenses and production of two types of antifungal secondary metabolites: the sesquiterpenoid harzianum A (HA) and the polyketide-derived aspinolides. The goal of the current study was to identify aspinolide biosynthetic genes as part of an effort to understand how these metabolites contribute to the biological control activity of T. arundinaceum. Comparative genomics identified two polyketide synthase genes (asp1 and asp2) that occur in T. arundinaceum and Aspergillus ochraceus, which also produces aspinolides. Gene deletion and biochemical analyses in T. arundinaceum indicated that both genes are required for aspinolide production: asp2 for formation of a 10-member lactone ring and asp1 for formation of a butenoyl subsituent at position 8 of the lactone ring. Gene expression and comparative genomics analyses indicated that asp1 and asp2 are located within a gene cluster that occurs in both T. arundinaceum and A. ochraceus. A survey of genome sequences representing 35 phylogenetically diverse Trichoderma species revealed that intact homologs of the cluster occurred in only two other species, which also produced aspinolides. An asp2 mutant inhibited fungal growth more than the wild type, but an asp1 mutant did not, and the greater inhibition by the asp2 mutant coincided with increased HA production. These findings indicate that asp1 and asp2 are aspinolide biosynthetic genes and that loss of either aspinolide or HA production in T. arundinaceum can be accompanied by increased production of the other metabolite(s).SIPublicación en abierto financiada por el Consorcio de Bibliotecas Universitarias de Castilla y León (BUCLE), con cargo al Programa Operativo 2014ES16RFOP009 FEDER 2014-2020 DE CASTILLA Y LEÓN, Actuación:20007-CL - Apoyo Consorcio BUCL

    Botrydial and botcinins produced by Botrytis cinerea regulate the expression of Trichoderma arundinaceum genes involved in trichothecene biosynthesis

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    Trichoderma arundinaceum IBT 40837 (Ta37) and Botrytis cinerea produce the sesquiterpenes harzianum A (HA) and botrydial (BOT), respectively, and also the polyketides aspinolides and botcinins (Botcs), respectively. We analysed the role of BOT and Botcs in the Ta37-B. cinerea interaction, including the transcriptomic changes in the genes involved in HA (tri) and ergosterol biosynthesis, as well as changes in the level of HA and squalene-ergosterol. We found that, when confronted with B. cinerea, the tri biosynthetic genes were up-regulated in all dual cultures analysed, but at higher levels when Ta37 was confronted with the BOT non-producer mutant bcbot2Δ. The production of HA was also higher in the interaction area with this mutant. In Ta37-bcbot2Δ confrontation experiments, the expression of the hmgR gene, encoding the 3-hydroxy-3-methylglutaryl coenzyme A reductase, which is the first enzyme of the terpene biosynthetic pathway, was also up-regulated, resulting in an increase in squalene production compared with the confrontation with B. cinerea B05.10. Botcs had an up-regulatory effect on the tri biosynthetic genes, with BotcA having a stronger effect than BotcB. The results indicate that the interaction between Ta37 and B. cinerea exerts a stimulatory effect on the expression of the tri biosynthetic genes, which, in the interaction zone, can be attenuated by BOT produced by B. cinerea B05.10. The present work provides evidence for a metabolic dialogue between T. arundinaceum and B. cinerea that is mediated by sesquiterpenes and polyketides, and that affects the outcome of the interaction of these fungi with each other and their environmentSIFunding was obtained from the Junta de Castilla y Leon (SA260A11-2,LE125A12-2 and LE228U14) and Spanish Government grants MICINN-AGL2009-13431-C02-02, MINECO-AGL2012-40041-C02-01, AGL2012-40041-C02-02 and AGL2012-39798-C02-01. MGM and II-B were granted fellowships from the Spanish Ministry of Science and Innovation(AP2007-02835, BES-2013-063411
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