Dust Production and Mass Loss in the Galactic Globular Cluster NGC 362

We investigate dust production and stellar mass loss in the Galactic globular cluster NGC 362. Due to its close proximity to the Small Magellanic Cloud (SMC), NGC 362 was imaged with the IRAC and MIPS cameras onboard the Spitzer Space Telescope as part of the Surveying the Agents of Galaxy Evolution (SAGE-SMC) Spitzer Legacy program. We detect several cluster members near the tip of the Red Giant Branch that exhibit infrared excesses indicative of circumstellar dust and find that dust is not present in measurable quantities in stars below the tip of the Red Giant Branch. We modeled the spectral energy distribution (SED) of the stars with the strongest IR excess and find a total cluster dust mass-loss rate of 3.0(+2.0/-1.2) x 10^-9 solar masses per year, corresponding to a gas mass-loss rate of 8.6(+5.6/-3.4) x 10^-6 solar masses per year, assuming [Fe/H] = -1.16. This mass loss is in addition to any dust-less mass loss that is certainly occurring within the cluster. The two most extreme stars, variables V2 and V16, contribute up to 45% of the total cluster dust-traced mass loss. The SEDs of the more moderate stars indicate the presence of silicate dust, as expected for low-mass, low-metallicity stars. Surprisingly, the SED shapes of the stars with the strongest mass-loss rates appear to require the presence of amorphous carbon dust, possibly in combination with silicate dust, despite their oxygen-rich nature. These results corroborate our previous findings in omega Centauri.Comment: 13 pages, 11 figures. Accepted to Ap

Plant Immunity Directly or Indirectly Restricts the Injection of Type III Effectors by the \u3ci\u3ePseudomonas syringae\u3c/i\u3e Type III Secretion System

Plants perceive microorganisms by recognizing microbial molecules known as pathogen-associated molecular patterns (PAMPs) inducing PAMP-triggered immunity (PTI) or by recognizing pathogen effectors inducing effector-triggered immunity (ETI). The hypersensitive response (HR), a programmed cell death response associated with ETI, is known to be inhibited by PTI. Here, we show that PTI-induced HR inhibition is due to direct or indirect restriction of the type III protein secretion system’s (T3SS) ability to inject type III effectors (T3Es). We found that the Pseudomonas syringae T3SS was restricted in its ability to inject a T3E-adenylate cyclase (CyaA) injection reporter into PTI-induced tobacco (Nicotiana tabacum) cells. We confirmed this restriction with a direct injection assay that monitored the in planta processing of the AvrRpt2 T3E. Virulent P. syringae strains were able to overcome a PAMP pretreatment in tobacco or Arabidopsis (Arabidopsis thaliana) and continue to inject a T3E-CyaA reporter into host cells. In contrast, ETI-inducing P. syringae strains were unable to overcome PTI-induced injection restriction. A P. syringae pv tomato DC3000 mutant lacking about one-third of its T3E inventory was less capable of injecting into PTI-induced Arabidopsis plant cells, grew poorly in planta, and did not cause disease symptoms. PTI-induced transgenic Arabidopsis expressing the T3E HopAO1 or HopF2 allowed higher amounts of the T3E-CyaA reporter to be injected into plant cells compared to wild-type plants. Our results show that PTI-induced HR inhibition is due to direct or indirect restriction of T3E injection and that T3Es can relieve this restriction by suppressing PTI

Plant Immunity Directly or Indirectly Restricts the Injection of Type III Effectors by the \u3ci\u3ePseudomonas syringae\u3c/i\u3e Type III Secretion System

Plants perceive microorganisms by recognizing microbial molecules known as pathogen-associated molecular patterns (PAMPs) inducing PAMP-triggered immunity (PTI) or by recognizing pathogen effectors inducing effector-triggered immunity (ETI). The hypersensitive response (HR), a programmed cell death response associated with ETI, is known to be inhibited by PTI. Here, we show that PTI-induced HR inhibition is due to direct or indirect restriction of the type III protein secretion system’s (T3SS) ability to inject type III effectors (T3Es). We found that the Pseudomonas syringae T3SS was restricted in its ability to inject a T3E-adenylate cyclase (CyaA) injection reporter into PTI-induced tobacco (Nicotiana tabacum) cells. We confirmed this restriction with a direct injection assay that monitored the in planta processing of the AvrRpt2 T3E. Virulent P. syringae strains were able to overcome a PAMP pretreatment in tobacco or Arabidopsis (Arabidopsis thaliana) and continue to inject a T3E-CyaA reporter into host cells. In contrast, ETI-inducing P. syringae strains were unable to overcome PTI-induced injection restriction. A P. syringae pv tomato DC3000 mutant lacking about one-third of its T3E inventory was less capable of injecting into PTI-induced Arabidopsis plant cells, grew poorly in planta, and did not cause disease symptoms. PTI-induced transgenic Arabidopsis expressing the T3E HopAO1 or HopF2 allowed higher amounts of the T3E-CyaA reporter to be injected into plant cells compared to wild-type plants. Our results show that PTI-induced HR inhibition is due to direct or indirect restriction of T3E injection and that T3Es can relieve this restriction by suppressing PTI

Maize terpene synthase 1 impacts insect behavior via the production of monoterpene volatiles \u3ci\u3eβ\u3c/i\u3e-myrcene and linalool

Plant-derived volatiles are important mediators of plant-insect interactions as they can provide cues for host location and quality, or act as direct or indirect defense molecules. The volatiles produced by Zea mays (maize) include a range of terpenes, likely produced by several of the terpene synthases (TPS) present in maize. Determining the roles of specific terpene volatiles and individual TPSs in maize-insect interactions is challenging due to the promiscuous nature of TPSs in vitro and their potential for functional redundancy. In this study, we used metabolite GWAS of a sweetcorn diversity panel infested with Spodoptera frugiperda (fall armyworm) to identify genetic correlations between TPSs and individual volatiles. This analysis revealed a correlation between maize terpene synthase 1 (ZmTPS1) and emission of the monoterpene volatiles linalool and β-myrcene. Electroantennogram assays showed gravid S. frugiperda could detect both linalool and β-myrcene. Quantification of headspace volatiles in a maize tps1 loss-of-function mutant confirmed that ZmTPS1 is an important contributor to linalool and β-myrcene emission in maize. Furthermore, pairwise choice assays between tps1 mutant and wildtype plants showed that ZmTPS1, and by extension its volatile products, aid host location in the chewing insect S. frugiperda, yet repel the sap-sucking pest, Rhopalosiphum maidis (corn leaf aphid). On the other hand, ZmTPS1 had no impact on indirect defense via the recruitment of the parasitoid Cotesia marginiventris. ZmTPS1 is therefore an important mediator of the interactions between maize and its insect pests

Rapid antiretroviral therapy initiation in the Botswana Combination Prevention Project: a quasi-experimental before and after study.

BACKGROUND: Ensuring that individuals who are living with HIV rapidly initiate antiretroviral therapy (ART) is an essential step in meeting the 90-90-90 targets. We evaluated the feasibility and outcomes of rapid ART initiation in the Botswana Combination Prevention Project (BCPP). We aimed to establish whether simplified ART initiation with the offer of same-day treatment could increase uptake and reduce time from clinic linkage to treatment initiation, while maintaining rates of retention in care and viral suppression. METHODS: We did a quasi-experimental before and after study with use of data from the BCPP. The BCPP was a community-randomised HIV-prevention trial done in 30 communities across Botswana from Oct 1, 2013, to June 30, 2018. Participants in the 15 intervention clusters, who were HIV-positive and not already taking ART were offered universal HIV-treatment and same-day ART with a dolutegravir-based regimen at first clinic visit. This rapid ART intervention was implemented mid-way through the trial on June 1, 2016, enabling us to determine the effect of rapid ART guidelines on time to ART initiation and rates of retention in care and viral suppression at 1 year in the BCPP intervention group. FINDINGS: We assessed 1717 adults linked to study clinics before rapid ART introduction and 800 after rapid ART introduction. During the rapid ART period, 457 (57·1%, 95% CI 53·7-60·6) individuals initiated ART within 1 day of linkage, 589 (73·7%, 70·6-76·7) of 799 within 1 week, 678 (84·9%, 82·4-87·3) of 799 within 1 month, and 744 (93·5%, 91·6-95·1) of 796 within 1 year. Before the introduction of rapid ART, 163 (9·5%, 95% CI 8·2-11·0) individuals initiated ART within 1 day of linkage, 276 (16·1%, 14·4-17·9) within 1 week, 839 (48·9%, 46·5-51·3) within 1 month, and 1532 (89·2%, 87·7-90·6) within 1 year. 1 year after ART initiation, 1472 (90·5%, 87·4-92·8) of 1627 individuals who linked in the standard ART period were in care and had a viral load of less than 400 copies per mL, compared with 578 (91·6%, 88·1-94·1) of 631 in the rapid ART period (risk ratio 1·01, 95% CI 0·92-1·11). INTERPRETATION: Our findings provide support for the WHO recommendations for rapid ART initiation, and add to the accumulating evidence showing the feasibility, acceptability, and safety of rapid ART initiation in low-income and middle-income country settings. FUNDING: US President's Emergency Plan for AIDS Relief

Advanced HIV disease in the Botswana combination prevention project: prevalence, risk factors, and outcomes.

OBJECTIVE(S): To determine the proportion of individuals linking to HIV-care with advanced HIV-disease (CD4 cell counts ≤200 cells/μl) in the Botswana Combination Prevention Project, describe the characteristics of these individuals, and examine treatment outcomes. DESIGN: A subanalysis of a cluster-randomized HIV-prevention trial. HIV status was assessed in 16-64-year-olds through home and mobile testing. All HIV-positive persons not on antiretroviral therapy were referred to local Ministry of Health and Wellness clinics for treatment. METHODS: Analysis was restricted to the 15 intervention clusters. The proportion of individuals with advanced HIV disease was determined; associations between advanced HIV disease and sex and age explored; and rates of viral suppression determined at 1-year. Mortality and retention in care were compared between CD4 strata (CD4 cell counts ≤200 vs. >200 cells/μl). RESULTS: Overall, 17.2% [430/2499; 95% confidence interval (CI) 15.7-18.8%] of study participants had advanced HIV disease (CD4 cell counts ≤200 cells/μl) at time of clinic linkage. Men were significantly more likely to present with CD4 cell counts 200 cells/μl or less than women [23.7 vs. 13.4%, adjusted odds ratio 1.9, 95% CI 1.5-2.3]. The risk of advanced HIV disease increased with increasing age (adjusted odds ratio 2.2, 95% CI 1.4-3.2 >35 vs. <25 years). Patients with CD4 cell counts 200 cells/μl or less had significantly higher rates of attrition from care during follow-up (hazards ratio 1.47, 95% CI 1.1-2.1). CONCLUSION: Advanced HIV disease due to late presentation to or disengagement from antiretroviral therapy care remains common in the Treat All era in Botswana, calling for innovative testing, linkage, and treatment strategies to engage and retain harder-to-reach populations in care

Surveying the Agents of Galaxy Evolution in the Tidally-Stripped, Low Metallicity Small Magellanic Cloud (SAGE-SMC) II. Cool Evolved Stars

We investigate the infrared (IR) properties of cool, evolved stars in the Small Magellanic Cloud (SMC), including the red giant branch (RGB) stars and the dust-producing red supergiant (RSG) and asymptotic giant branch (AGB) stars using observations from the Spitzer Space Telescope Legacy program entitled: "Surveying the Agents of Galaxy Evolution in the Tidally-stripped, Low Metallicity SMC", or SAGE-SMC. The survey includes, for the first time, full spatial coverage of the SMC bar, wing, and tail regions at infrared (IR) wavelengths (3.6 - 160 microns). We identify evolved stars using a combination of near-IR and mid-IR photometry and point out a new feature in the mid-IR color-magnitude diagram that may be due to particularly dusty O-rich AGB stars. We find that the RSG and AGB stars each contribute ~20% of the global SMC flux (extended + point-source) at 3.6 microns, which emphasizes the importance of both stellar types to the integrated flux of distant metal-poor galaxies. The equivalent SAGE survey of the higher-metallicity Large Magellanic Cloud (SAGE-LMC) allows us to explore the influence of metallicity on dust production. We find that the SMC RSG stars are less likely to produce a large amount of dust (as indicated by the [3.6]-[8] color). There is a higher fraction of carbon-rich stars in the SMC, and these stars appear to able to reach colors as red as their LMC counterparts, indicating that C-rich dust forms efficiently in both galaxies. A preliminary estimate of the dust production in AGB and RSG stars reveals that the extreme C-rich AGB stars dominate the dust input in both galaxies, and that the O-rich stars may play a larger role in the LMC than in the SMC.Comment: Accepted for publication in AJ. 25 pages, 36 figures, Table 4 will be available electronically from A

Evidence-based Kernels: Fundamental Units of Behavioral Influence

This paper describes evidence-based kernels, fundamental units of behavioral influence that appear to underlie effective prevention and treatment for children, adults, and families. A kernel is a behavior–influence procedure shown through experimental analysis to affect a specific behavior and that is indivisible in the sense that removing any of its components would render it inert. Existing evidence shows that a variety of kernels can influence behavior in context, and some evidence suggests that frequent use or sufficient use of some kernels may produce longer lasting behavioral shifts. The analysis of kernels could contribute to an empirically based theory of behavioral influence, augment existing prevention or treatment efforts, facilitate the dissemination of effective prevention and treatment practices, clarify the active ingredients in existing interventions, and contribute to efficiently developing interventions that are more effective. Kernels involve one or more of the following mechanisms of behavior influence: reinforcement, altering antecedents, changing verbal relational responding, or changing physiological states directly. The paper describes 52 of these kernels, and details practical, theoretical, and research implications, including calling for a national database of kernels that influence human behavior