Merger rates of dark matter haloes: a comparison between EPS and N-body results

We calculate merger rates of dark matter haloes using the Extended Press-Schechter approximation (EPS) for the Spherical Collapse (SC) and the Ellipsoidal Collapse (EC) models. Merger rates have been calculated for masses in the range $10^{10}M_{\odot}\mathrm{h}^{-1}$ to $10^{14}M_{\odot}\mathrm{h}^{-1}$ and for redshifts $z$ in the range 0 to 3 and they have been compared with merger rates that have been proposed by other authors as fits to the results of N-body simulations. The detailed comparison presented here shows that the agreement between the analytical models and N-body simulations depends crucially on the mass of the descendant halo. For some range of masses and redshifts either SC or EC models approximate satisfactory the results of N-body simulations but for other cases both models are less satisfactory or even bad approximations. We showed, by studying the parameters of the problem that a disagreement --if it appears-- does not depend on the values of the parameters but on the kind of the particular solution used for the distribution of progenitors or on the nature of EPS methods. Further studies could help to improve our understanding about the physical processes during the formation of dark matter haloes.Comment: 29 pages, 9 figure

Mannosylation in C andida albicans : role in cell wall function and immune recognition

The fungal cell wall is a dynamic organelle required for cell shape, protection against the environment and, in pathogenic species, recognition by the innate immune system. The outer layer of the cell wall is comprised of glycosylated mannoproteins with the majority of these post-translational modifications being the addition of O- and N-linked mannosides. These polysaccharides are exposed on the outer surface of the fungal cell wall and are, therefore, the first point of contact between the fungus and the host immune system. This review focuses on O- and N-linked mannan biosynthesis in the fungal pathogen Candida albicans and highlights new insights gained from the characterization of mannosylation mutants into the role of these cell wall components in host-fungus interactions. In addition, we discuss the use of fungal mannan as a diagnostic marker of fungal disease

Regulation of pentraxin-3 by antioxidants

Peer reviewedPublisher PD

Physical Characterization of an Unlensed, Dusty Star-forming Galaxy at z = 5.85

We present a physical characterization of MM J100026.36+021527.9 (a.k.a. "Mambo-9"), a dusty star-forming galaxy (DSFG) at z = 5.850 \ub1 0.001. This is the highest-redshift unlensed DSFG (and fourth most distant overall) found to date and is the first source identified in a new 2 mm blank-field map in the COSMOS field. Though identified in prior samples of DSFGs at 850 \u3bcm to 1.2 mm with unknown redshift, the detection at 2 mm prompted further follow-up as it indicated a much higher probability that the source was likely to sit at z > 4. Deep observations from the Atacama Large Millimeter and submillimeter Array (ALMA) presented here confirm the redshift through the secure detection of 12CO(J = 6\u21925) and p-H2O (21,1 \u2192 20,2). Mambo-9 is composed of a pair of galaxies separated by 6 kpc with corresponding star formation rates of 590 M o\u2d9 yr-1 and 220 M o\u2d9 yr-1, total molecular hydrogen gas mass of (1.7 \ub1 0.4) 7 1011 M o\u2d9, dust mass of (1.3 \ub1 0.3) 7 109 M o\u2d9, and stellar mass of (3.2-1.5+1.0) 7 109 M o\u2d9. The total halo mass, (3.3 \ub1 0.8) 7 1012 M o\u2d9, is predicted to exceed 1015 M o\u2d9 by z = 0. The system is undergoing a merger-driven starburst that will increase the stellar mass of the system tenfold in \u3c4 depl = 40-80 Myr, converting its large molecular gas reservoir (gas fraction of 96-2+1) into stars. Mambo-9 evaded firm spectroscopic identification for a decade, following a pattern that has emerged for some of the highest-redshift DSFGs found. And yet, the systematic identification of unlensed DSFGs like Mambo-9 is key to measuring the global contribution of obscured star formation to the star formation rate density at z \u2a86 4, the formation of the first massive galaxies, and the formation of interstellar dust at early times ( 721 Gyr)

Incident Non-AIDS Comorbidity Burden among Women with or at Risk for Human Immunodeficiency Virus in the United States

Background: Human immunodeficiency virus (HIV) infection may accelerate development of aging-related non-AIDS comorbidities (NACMs). The incidence of NACMs is poorly characterized among women living with HIV (WLWH). Methods: WLWH and HIV-seronegative participants followed in the Women's Interagency HIV Study (WIHS) through 2009 (when >80% of WLWH used antiretroviral therapy) or onward were included, with outcomes measured through 31 March 2018. Sociodemographics, clinical covariates, and prevalent NACM were determined at enrollment. We used Poisson regression models to determine incident NACM burden (number of NACMs accrued through most recent WIHS visit out of 10 total NACMs assessed) by HIV serostatus and age. Results: There were 3129 participants (2239 WLWH, 890 HIV seronegative) with 36 589 person-years of follow-up. At enrollment, median age was 37 years, 65% were black, and 47% currently smoked. In fully adjusted analyses, WLWH had a higher incident NACM rate compared with HIV-seronegative women (incidence rate ratio, 1.36 [95% confidence interval (CI), 1.02-1.81]). Incident NACM burden was higher among WLWH vs HIV-seronegative women in most age strata (HIV × age interaction: P = .0438), and women <25 years old had the greatest incidence rate ratio by HIV serostatus at 1.48 (95% CI, 1.19-1.84) compared with those in older age groups. Incident NACM burden was associated with traditional comorbidity risk factors but not HIV-specific indices. Conclusions: Incident NACM burden was higher among WLWH than HIV-seronegative women. This difference was most dramatic among women aged <25 years, a group for whom routine comorbidity screening is not prioritized. Established non-HIV comorbidity risk factors were significantly associated with incident NACM burden. More data are needed to inform best practices for NACM screening, prevention, and management among WLWH, particularly young women

The Prevalence and Burden of Non-AIDS Comorbidities Among Women Living With or at Risk for Human Immunodeficiency Virus Infection in the United States

Background: The prevalence and burden of age-related non-AIDS comorbidities (NACMs) are poorly characterized among women living with HIV (WLWH). Methods: Virologically suppressed WLWH and HIV-seronegative participants followed in the Women's Interagency HIV Study (WIHS) through at least 2009 (when >80% of WLWH used antiretroviral therapy) were included, with outcomes measured through 31 March 2018. Covariates, NACM number, and prevalence were summarized at most recent WIHS visit. We used linear regression models to determine NACM burden by HIV serostatus and age. Results: Among 3232 women (2309 WLWH, 923 HIV-seronegative) with median observation of 15.3 years, median age and body mass index (BMI) were 50 years and 30 kg/m2, respectively; 65% were black; 70% ever used cigarettes. WLWH had a higher mean NACM number than HIV-seronegative women (3.6 vs 3.0, P < .0001) and higher prevalence of psychiatric illness, dyslipidemia, non-AIDS cancer, kidney, liver, and bone disease (all P < .01). Prevalent hypertension, diabetes, and cardiovascular and lung disease did not differ by HIV serostatus. Estimated NACM burden was higher among WLWH versus HIV-seronegative women in those aged 40-49 (P < .0001) and ≥60 years (P = .0009) (HIV × age interaction, P = .0978). In adjusted analyses, NACM burden was associated with HIV, age, race, income, BMI, alcohol abstinence, cigarette, and crack/cocaine use; in WLWH, additional HIV-specific indices were not associated, aside from recent abacavir use. Conclusions: Overall, NACM burden was high in the cohort, but higher in WLWH and in certain age groups. Non-HIV traditional risk factors were significantly associated with NACM burden in WLWH and should be prioritized in clinical guidelines for screening and intervention to mitigate comorbidity burden in this high-risk population

Brief Report: PrEP Eligibility among At-Risk Women in the Southern United States: Associated Factors, Awareness, and Acceptability

Background:Among women in the United States, non-Latina black women in the South have disproportionately high rates of new HIV infections but low use of pre-exposure prophylaxis (PrEP). Effective strategies to identify factors associated with PrEP eligibility could facilitate improved screening, offering, and uptake of PrEP among US women at risk of HIV.Setting and methods:We applied 2014 CDC criteria for PrEP use to at-risk HIV-negative women enrolled in the Southern US sites (Atlanta, Chapel Hill, Birmingham/Jackson, Miami) of the Women's Interagency HIV Study from 2014 to 2015 to estimate PrEP eligibility and assess PrEP knowledge and acceptability. Factors associated with PrEP eligibility were assessed using multivariable models.Results:Among 225 women, 72 (32%) were PrEP-eligible; the most common PrEP indicator was condomless sex. The majority of PrEP-eligible women (88%) reported willingness to consider PrEP. Only 24 (11%) PrEP-eligible women had previously heard of PrEP, and only 1 reported previous use. Education level less than high school [adjusted odds ratio (aOR) 2.56; 95% confidence interval (CI): 1.22 to 5.37], history of sexual violence (aOR 4.52; 95% CI: 1.52 to 17.76), and medium to high self-perception of HIV risk (aOR 6.76; 95% CI: 3.26 to 14.05) were significantly associated with PrEP eligibility in adjusted models.Conclusions:Extremely low PrEP awareness and use despite a high proportion of eligibility and acceptability signify a critical need to enhance PrEP education and delivery for women in this region. Supplementing CDC eligibility criteria with questions about history of sexual violence and HIV risk self-assessment may enhance PrEP screening and uptake among US women

The Effect of Menopausal Status, Age, and Human Immunodeficiency Virus (HIV) on Non-AIDS Comorbidity Burden Among US Women

Menopause may impact the earlier onset of aging-related comorbidities among women with versus without human immunodeficiency virus (HIV). We found that menopausal status, age, and HIV were independently associated with higher comorbidity burden, and that HIV impacted burden most in the pre-/perimenopausal phases