Orphaning Regimes: The Missing Link Between Flattened and Penetrating Slab Morphologies

Slab orphaning is a newly discovered phenomenological behavior, where the slab tip breaks off at the top of the lower mantle (~660 km depth) and is abandoned by its parent slab. Upon orphaning, subduction continues uninterrupted through the lateral motion of the parent slab above 660 km depth. In this work, we present a regime diagram for the range of conditions under which slabs can orphan at the top of the lower mantle. Our models show that a viscosity jump at 1,000 km depth not coincident with the endothermic phase change responsible for the 660 km seismic discontinuity, is necessary for orphaning as is the presence of a low viscosity channel between 660 and 1,000 km depth. We show that orphan slabs, similar to other deep slab morphologies, can be the end result for a wide range of physical parameters governing slab dynamics: slab orphaning persists across wide variations in slab dip, slab yield stress/strength, Clapeyron slope values, and overriding plate nature. The diversity in orphan slab sizes and orphaning periods is tied to the orphaning regime space, which describes a hitherto unexplored region between deflected and penetrating deep-subduction modes. Orphaning provides a simple dynamic link between the well-known deflection and penetration, and provides one possible way for slabs to switch from direct penetration to deflection, littering the mantle with abandoned fragments. Orphan slabs are therefore the intermediary between these two extensively studied slab morphologies

Abrupt upper-plate tilting during slab-transition-zone collision

The sinking remnant of a surface plate crosses and interacts with multiple boundaries in Earth's interior. Here, we specifically investigate the prominent dynamic interaction of the sinking plate portion with the upper-mantle transition zone and its corresponding surface elevation signal. We unravel, for the first time, that the collision of the sinking slab with the transition zone induces a sudden, dramatic downward tilt of the upper plate towards the subduction trench. Unraveling this crucial interaction was only possible thanks to state-of-the-art numerical modelling and post-processing. The new model that is introduced here to study the dynamically self-consistent temporal evolution of subduction features accurate subduction-zone topography, robust single-sided plate sinking, stronger plates close to laboratory values, an upper-mantle phase transition, and simple continents at a free surface. To distinguish the impact of the new physical model features, three different setups are used: the simplest model setup includes a basic high-viscosity lower mantle, the second adds a 660-km phase transition, and the third includes, additionally, a continental upper plate. Common to all models is the clear topographic signal upon slab-transition-zone interaction: the upper plate tilts abruptly towards the subduction trench by about 0.05° and over around 10. Ma. This dramatic increase in upper-plate tilt can be related to the slab-induced excitation of the high-viscosity lower mantle, which introduces a wider flow pattern. A large change in horizontal extent of inundation of up to 900. km is observed as a direct consequence of the upper-plate tilting. Such an abrupt variation in surface topography and inundation extent should be clearly visible in temporal records of large-scale surface elevation and might explain continental tilting as observed in Australia since the Eocene and North America during the Phanerozoic

Quantitative analysis of Nipah virus proteins released as virus-like particles reveals central role for the matrix protein

BACKGROUND: Nipah virus (NiV) is an emerging paramyxovirus distinguished by its ability to cause fatal disease in both animal and human hosts. Together with Hendra virus (HeV), they comprise the genus Henipavirus in the Paramyxoviridae family. NiV and HeV are also restricted to Biosafety Level-4 containment and this has hampered progress towards examining details of their replication and morphogenesis. Here, we have established recombinant expression systems to study NiV particle assembly and budding through the formation of virus-like particles (VLPs). RESULTS: When expressed by recombinant Modified Vaccinia virus Ankara (rMVA) or plasmid transfection, individual NiV matrix (M), fusion (F) and attachment (G) proteins were all released into culture supernatants in a membrane-associated state as determined by sucrose density gradient flotation and immunoprecipitation. However, co-expression of F and G along with M revealed a shift in their distribution across the gradient, indicating association with M in VLPs. Protein release was also altered depending on the context of viral proteins being expressed, with F, G and nucleocapsid (N) protein reducing M release, and N release dependent on the co-expression of M. Immunoelectron microscopy and density analysis revealed VLPs that were similar to authentic virus. Differences in the budding dynamics of NiV proteins were also noted between rMVA and plasmid based strategies, suggesting that over-expression by poxvirus may not be appropriate for studying the details of recombinant virus particle assembly and release. CONCLUSION: Taken together, the results indicate that NiV M, F, and G each possess some ability to bud from expressing cells, and that co-expression of these viral proteins results in a more organized budding process with M playing a central role. These findings will aid our understanding of paramyxovirus particle assembly in general and could help facilitate the development of a novel vaccine approach for henipaviruses

The Importance of Sex and the Meaning of Sex and Sexual Pleasure for Men Aged 60 and Older Who Engage in Heterosexual Relationships: Findings from a Qualitative Interview Study

That many older individuals continue to engage in various forms of sexual expression well into later life is now well established in the literature. To date, however, only a small body of qualitative research has examined older men’s experiences and understandings of sex in later life. Likewise, the ways in which older men’s discussions on sex may be used as an avenue for “doing” masculinity remain underexplored. Older men are particularly interesting in this regard, as they inhabit an increasingly subordinated position in relation to hegemonic masculine ideals because of their age. To what extent might this limit or, alternatively, open up the possibilities for sexual expression and subjectivity in later life? Drawing on a subset of findings from Sex, Age, and Me: A National Study with Australian Women and Men Aged 60 and Older, data from qualitative interviews with 27 Australian men were explored in this article. The first Australian study of its kind, we argue that older men who engage in heterosexual relationships draw on a diverse and complex array of discursive positions regarding sex, relationships, and masculinity in making sense of their experiences of sex in later life. Older men are a heterogeneous group, and their experiences and understandings of sex do not simplistically follow “decline” or “success” narratives of aging. The findings of this research build upon and extend emerging research illustrating the centrality of intimacy to older men’s sexual lives, while simultaneously highlighting the ways in which the body and discursive constructions of sex intersect to shape older men’s sexual subjectivities

Self-reported testing and treatment histories among older Australian men and women who may be at risk of a sexually transmissible infection

Background: Rates of sexually transmissible infections (STIs) are increasing among older adults in many countries. Little is known about the testing and treatment histories of these populations. Correlates of testing in the past 5 years among older adults who may be at risk of a STI were examined. Methods: A cross-sectional survey of 2137 Australians aged 60+ years that involved questions on STIs and STI testing was conducted in 2015. To help inform potential education campaigns, analyses focused on those who may have been at risk of a STI (n = 805, 38%). Results: Less than one in three reported a STI test in the past 5 years (n = 241, 30%) while 6% (n = 51) reported a STI diagnosis. Those diagnosed typically received treatment from a family doctor or general practitioner. Among men, lower testing rates were associated with older age, identifying as heterosexual, lower educational attainment, not using online dating and reporting one partner in the past 5 years. For women, lower rates of testing were found among those who did not use a condom at their most recent sexual encounter and those with one partner in the past 5 years. Conclusions: STI testing rates were low. This study indicates that consideration should be given to the way targeted education campaigns are formulated, such as emphasising the importance of STI testing to older people who are at risk, as well as encouraging healthcare professionals to discuss sexual health with their older patients

Safer sex in later life: Qualitative interviews with older Australians on their understandings and practices of safer sex

Rates of sexually transmitted infections (STIs) are increasing in older cohorts in Western countries such as Australia, the U.K. and the U.S., suggesting a need to examine the safer sex knowledge and practices of older people. This article presents findings from 53 qualitative interviews from the study “Sex, Age & Me: a National Study of Sex and Relationships Among Australians aged 60+.” Participants were recruited through an online national survey. We consider how participants understood “safer sex,” the importance of safer sex to them, the safer sex practices they used (and the contexts in which they used them), and the barriers to using safer sex. Older adults had diverse understandings, knowledge, and use of safer sex practices, although participants tended to focus most strongly on condom use. Having safer sex was strongly mediated by relationship context, trust, perceived risk of contracting an STI, concern for personal health, and stigma. Common barriers to safer sex included erectile difficulties, embarrassment, stigma, reduced pleasure, and the lack of a safer sex culture among older people. The data presented has important implications for sexual health policy, practice, and education and health promotion campaigns aimed at improving the sexual health and wellbeing of older cohorts

Sexually active older Australian's knowledge of sexually transmitted infections and safer sexual practices.

OBJECTIVE: Rates of sexually transmitted infections (STIs) are rising among older Australians. We conducted a large survey of older people's knowledge of STIs and safer sexual practices. METHODS: A total of 2,137 Australians aged 60 years and older completed the survey, which included 15 questions assessing knowledge of STIs and safer sexual practices. We examined both levels of knowledge and factors associated with an overall knowledge score. RESULTS: In total, 1,652 respondents reported having sex in the past five years and answered all knowledge questions. This group had good general knowledge but poorer knowledge in areas such as the protection offered by condoms and potential transmission modes for specific STIs. Women had better knowledge than men. Men in their 60s, men with higher education levels, and men who thought they were at risk of STIs reported better knowledge than other men. Knowledge was also better among men and women who had been tested for STIs or reported 'other' sources of knowledge on STIs. CONCLUSIONS: Many older Australians lack knowledge of STIs and safer sexual practices. Implications for public health: To reverse current trends toward increasing STI diagnoses in this population, policies and education campaigns aimed at improving knowledge levels may need to be considered

Through the labyrinth of yesteryears

Background Allergy to dog (Canis familiaris) is a worldwide common cause of asthma and allergic rhinitis. However, dander extract in routine diagnostics is not an optimal predictor of IgE-mediated dog allergy. Our objective was to evaluate saliva as an allergen source for improved diagnostics of allergy to dog. Methods IgE-binding proteins in dog saliva and dander extract were analysed by immunoblot and mass spectrometry (LC-MS/MS) using pooled or individual sera from dog-allergic patients (n=13). Sera from 59 patients IgE positive to dander and 55 patients IgE negative to dander but with symptoms to dog were analysed for IgE against saliva and dander by ELISA. Basophil stimulation with dog saliva and dander extract was measured by flow cytometry among three dog-allergic patients. Additionally, IgE-binding protein profiles of saliva from different breeds were investigated by immunoblot. Results Greater number and diversity of IgE-binding proteins was found in saliva compared to dander extract and varied among dog breeds. In saliva, Can f 1, 2, 3 and 6 were identified but also four new saliva allergen candidates. The majority of the 59 dog danderpositive sera (n=44) were IgE positive to dog saliva. Among patients IgE negative to dander, but with symptoms to dog, 20% were IgE positive to saliva. The biological activity of saliva was confirmed by basophil degranulation. Conclusions Dog saliva is an allergen source for improved diagnostics of dog allergy. The IgE-binding protein profile of saliva from different dogs varies.Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3488

GATA3-driven Th2 responses inhibit TGF-beta1-induced FOXP3 expression and the formation of regulatory T cells.

Transcription factors act in concert to induce lineage commitment towards Th1, Th2, or T regulatory (Treg) cells, and their counter-regulatory mechanisms were shown to be critical for polarization between Th1 and Th2 phenotypes. FOXP3 is an essential transcription factor for natural, thymus-derived (nTreg) and inducible Treg (iTreg) commitment; however, the mechanisms regulating its expression are as yet unknown. We describe a mechanism controlling iTreg polarization, which is overruled by the Th2 differentiation pathway. We demonstrated that interleukin 4 (IL-4) present at the time of T cell priming inhibits FOXP3. This inhibitory mechanism was also confirmed in Th2 cells and in T cells of transgenic mice overexpressing GATA-3 in T cells, which are shown to be deficient in transforming growth factor (TGF)-beta-mediated FOXP3 induction. This inhibition is mediated by direct binding of GATA3 to the FOXP3 promoter, which represses its transactivation process. Therefore, this study provides a new understanding of tolerance development, controlled by a type 2 immune response. IL-4 treatment in mice reduces iTreg cell frequency, highlighting that therapeutic approaches that target IL-4 or GATA3 might provide new preventive strategies facilitating tolerance induction particularly in Th2-mediated diseases, such as allergy

Social Connection, Relationships and Older Lesbian and Gay People

This paper presents data from a small study exploring the impacts of homophobia on the lives of older lesbian and gay Australians. Eleven in-depth interviews were conducted with older lesbians (6) and gay men (5) ranging in age from 65 to 79 years. The study found that participants’ sense of self was shaped by the dominant medical, legal and religious institutions of their youth that defined them as sick, immoral or criminal. Participants described enforced “cure” therapies, being imprisoned, having employment terminated and being disowned and disinherited by family. In this context, intimate relationships and social networks provided refuge where trust was rebuilt and sexuality affirmed. Many created safe spaces for themselves. This equilibrium was threatened with increasing age, disability and the reliance on health and social services. Participants feared a return to institutional control and a need to “straighten up” or hide their sexuality. In response, partners stepped into the role of caregiver, at times beyond their capacity and at a cost to their relationship. The study describes the importance of understanding social connections in the lives of older lesbians and gay men. It highlights the need for inclusive services to ensure that social networks are supported and that health and well-being are promoted