Understanding Galaxy Formation and Evolution

The old dream of integrating into one the study of micro and macrocosmos is now a reality. Cosmology, astrophysics, and particle physics intersect in a scenario (but still not a theory) of cosmic structure formation and evolution called Lambda Cold Dark Matter (LCDM) model. This scenario emerged mainly to explain the origin of galaxies. In these lecture notes, I first present a review of the main galaxy properties, highlighting the questions that any theory of galaxy formation should explain. Then, the cosmological framework and the main aspects of primordial perturbation generation and evolution are pedagogically detached. Next, I focus on the ``dark side'' of galaxy formation, presenting a review on LCDM halo assembling and properties, and on the main candidates for non-baryonic dark matter. It is shown how the nature of elemental particles can influence on the features of galaxies and their systems. Finally, the complex processes of baryon dissipation inside the non-linearly evolving CDM halos, formation of disks and spheroids, and transformation of gas into stars are briefly described, remarking on the possibility of a few driving factors and parameters able to explain the main body of galaxy properties. A summary and a discussion of some of the issues and open problems of the LCDM paradigm are given in the final part of these notes.Comment: 50 pages, 10 low-resolution figures (for normal-resolution, DOWNLOAD THE PAPER (PDF, 1.9 Mb) FROM http://www.astroscu.unam.mx/~avila/avila.pdf). Lectures given at the IV Mexican School of Astrophysics, July 18-25, 2005 (submitted to the Editors on March 15, 2006

Five-Year Mortality for Adults Entering Human Immunodeficiency Virus Care Under Universal Early Treatment Compared With the General US Population

Background: Mortality among adults with human immunodeficiency virus (HIV) remains elevated over those in the US general population, even in the years after entry into HIV care. We explore whether the elevation in 5-year mortality would have persisted if all adults with HIV had initiated antiretroviral therapy within 3 months of entering care. Methods: Among 82 766 adults entering HIV care at North American AIDS Cohort Collaboration clinical sites in the United States, we computed mortality over 5 years since entry into HIV care under observed treatment patterns. We then used inverse probability weights to estimate mortality under universal early treatment. To compare mortality with those for similar individuals in the general population, we used National Center for Health Statistics data to construct a cohort representing the subset of the US population matched to study participants on key characteristics. Results: For the entire study period (1999-2017), the 5-year mortality among adults with HIV was 7.9% (95% confidence interval [CI]: 7.6%-8.2%) higher than expected based on the US general population. Under universal early treatment, the elevation in mortality for people with HIV would have been 7.2% (95% CI: 5.8%-8.6%). In the most recent calendar period examined (2011-2017), the elevation in mortality for people with HIV was 2.6% (95% CI: 2.0%-3.3%) under observed treatment patterns and 2.1% (.0%-4.2%) under universal early treatment. Conclusions: Expanding early treatment may modestly reduce, but not eliminate, the elevation in mortality for people with HIV

Virologic outcomes among adults with HIV using integrase inhibitor-based antiretroviral therapy

Background: Integrase strand transfer inhibitor (InSTI)-based regimens have been recommended as first-line antiretroviral therapy (ART) for adults with HIV. But data on long-term effects of InSTI-based regimens on virologic outcomes remain limited. Here we examined whether InSTI improved long-term virologic outcomes compared with efavirenz (EFV). Methods: We included adults from the North American AIDS Cohort Collaboration on Research and Design who initiated their first ART regimen containing either InSTI or EFV between 2009 and 2016. We estimated differences in the proportion virologically suppressed up to 7 years of follow-up in observational intention-to-treat and per-protocol analyses. Results: Of 15 318 participants, 5519 (36%) initiated an InSTI-based regimen and 9799 (64%) initiated the EFV-based regimen. In observational intention-to-treat analysis, 81.3% of patients in the InSTI group and 67.3% in the EFV group experienced virologic suppression at 3 months after ART initiation, corresponding to a difference of 14.0% (95% CI 12.4 – 15.6). At 1 year after ART initiation, the proportion virologically suppressed was 89.5% in the InSTI group and 90.2% in the EFV group, corresponding to a difference of -0.7% (95% CI -2.1 to 0.8). At 7 years, the proportion virologically suppressed was 94.5% in the InSTI group and 92.5% in the EFV group, corresponding to a difference of 2.0% (95% CI -7.3 to 11.3). The observational per-protocol results were similar to intention-to-treat analyses. Conclusions: Although InSTI-based initial ART regimens had more rapid virologic response than EFV-based regimens, the long-term virologic effect was similar. Our findings may inform guidelines regarding preferred initial regimens for HIV treatment

Clinical Effectiveness of Integrase Strand Transfer Inhibitor–Based Antiretroviral Regimens Among Adults With Human Immunodeficiency Virus: A Collaboration of Cohort Studies in the United States and Canada

Background. Integrase strand transfer inhibitor (InSTI)–based regimens are now recommended as first-line antiretroviral therapy (ART) for adults with human immunodeficiency virus, but evidence on long-term clinical effectiveness of InSTI-based regimens remains limited. We examined whether InSTI-based regimens improved longer-term clinical outcomes. Methods. We included participants from clinical cohorts in the North American AIDS Cohort Collaboration on Research and Design who initiated their first ART regimen, containing either InSTI (ie, raltegravir, dolutegravir, and elvitegravir-cobicistat) or efavirenz (EFV) as an active comparator, between 2009 and 2016. We estimated observational analogs of 6-year intention-to-treat and per-protocol risks, risk differences (RDs), and hazard ratios (HRs) for the composite outcome of AIDS, acute myocardial infarction, stroke, end-stage renal disease, end-stage liver disease, or death. Results. Of 15 993 participants, 5824 (36%) initiated an InSTI-based and 10 169 (64%) initiated an EFV-based regimen. During the 6-year follow-up, 440 in the InSTI group and 1097 in the EFV group incurred the composite outcome. The estimated 6-year intention-to-treat risks were 14.6% and 14.3% for the InSTI and EFV groups, respectively, corresponding to a RD of 0.3% (95% confidence interval, −2.7% to 3.3%) and a HR of 1.08 (.97–1.19); the estimated 6-year per-protocol risks were 12.2% for the InSTI group and 11.9% for the EFV group, corresponding to a RD of 0.3% (−3.0% to 3.7%) and a HR of 1.09 (.96–1.25). Conclusions. InSTI- and EFV-based initial ART regimens had similar 6-year composite clinical outcomes. The risk of adverse clinical outcomes remains substantial even when initiating modern ART

Association of Race and Ethnicity with Initial Prescription of Antiretroviral Therapy among People with HIV in the US

Importance: Integrase strand transfer inhibitor (INSTI)-containing antiretroviral therapy (ART) is currently the guideline-recommended first-line treatment for HIV. Delayed prescription of INSTI-containing ART may amplify differences and inequities in health outcomes. Objectives: To estimate racial and ethnic differences in the prescription of INSTI-containing ART among adults newly entering HIV care in the US and to examine variation in these differences over time in relation to changes in treatment guidelines. Design, Setting, and Participants: Retrospective observational study of 42841 adults entering HIV care from October 12, 2007, when the first INSTI was approved by the US Food and Drug Administration, to April 30, 2019, at more than 200 clinical sites contributing to the North American AIDS Cohort Collaboration on Research and Design. Exposures: Combined race and ethnicity as reported in patient medical records. Main Outcomes and Measures: Probability of initial prescription of ART within 1 month of care entry and probability of being prescribed INSTI-containing ART. Differences among non-Hispanic Black and Hispanic patients compared with non-Hispanic White patients were estimated by calendar year and time period in relation to changes in national guidelines on the timing of treatment initiation and recommended initial treatment regimens. Results: Of 41263 patients with information on race and ethnicity, 19378 (47%) as non-Hispanic Black, 6798 (16%) identified as Hispanic, and 13539 (33%) as non-Hispanic White; 36394 patients (85%) were male, and the median age was 42 years (IQR, 30 to 51). From 2007-2015, when guidelines recommended treatment initiation based on CD4+ cell count, the probability of ART initiation within 1 month of care entry was 45% among White patients, 45% among Black patients (difference, 0% [95% CI, -1% to 1%]), and 51% among Hispanic patients (difference, 5% [95% CI, 4% to 7%]). From 2016-2019, when guidelines strongly recommended treating all patients regardless of CD4+ cell count, this probability increased to 66% among White patients, 68% among Black patients (difference, 2% [95% CI, -1% to 5%]), and 71% among Hispanic patients (difference, 5% [95% CI, 1% to 9%]). INSTIs were prescribed to 22% of White patients and only 17% of Black patients (difference, -5% [95% CI, -7% to -4%]) and 17% of Hispanic patients (difference, -5% [95% CI, -7% to -3%]) from 2009-2014, when INSTIs were approved as initial therapy but were not yet guideline recommended. Significant differences persisted for Black patients (difference, -6% [95% CI, -8% to -4%]) but not for Hispanic patients (difference, -1% [95% CI, -4% to 2%]) compared with White patients from 2014-2017, when INSTI-containing ART was a guideline-recommended option for initial therapy; differences by race and ethnicity were not statistically significant from 2017-2019, when INSTI-containing ART was the single recommended initial therapy for most people with HIV. Conclusions and Relevance: Among adults entering HIV care within a large US research consortium from 2007-2019, the 1-month probability of ART prescription was not significantly different across most races and ethnicities, although Black and Hispanic patients were significantly less likely than White patients to receive INSTI-containing ART in earlier time periods but not after INSTIs became guideline-recommended initial therapy for most people with HIV. Additional research is needed to understand the underlying racial and ethnic differences and whether the differences in prescribing were associated with clinical outcomes.

The Large Scale Structure in the Universe: From Power-Laws to Acoustic Peaks

The most popular tools for analysing the large scale distribution of galaxies are second-order spatial statistics such as the two-point correlation function or its Fourier transform, the power spectrum. In this review, we explain how our knowledge of cosmic structures, encapsulated by these statistical descriptors, has evolved since their first use when applied on the early galaxy catalogues to the present generation of wide and deep redshift surveys, incorporating the most challenging discovery in the study of the galaxy distribution: the detection of Baryon Acoustic Oscillations.Comment: 20 pages, 12 figures, to appear in "Data Analysis in Cosmology", Lecture Notes in Physics, 2008, eds. V. J. Martinez, E. Saar, E. Martinez-Gonzalez, and M.J. Pons-Borderia, Springer-Verla

Mortality among persons entering hiv care compared with the general u.s. population: An observational study

Background: Understanding advances in the care and treatment of adults with HIV as well as remaining gaps requires comparing differences in mortality between persons entering care for HIV and the general population. Objective: To assess the extent to which mortality among persons entering HIV care in the United States is elevated over mortality among matched persons in the general U.S. population and trends in this difference over time. Design: Observational cohort study. Setting: Thirteen sites from the U.S. North American AIDS Cohort Collaboration on Research and Design. Participants: 82 766 adults entering HIV clinical care between 1999 and 2017 and a subset of the U.S. population matched on calendar time, age, sex, race/ethnicity, and county using U.S. mortality and population data compiled by the National Center for Health Statistics. Measurements: Five-year all-cause mortality, estimated using the Kaplan-Meier estimator of the survival function. Results: Overall 5-year mortality among persons entering HIV care was 10.6%, and mortality among the matched U.S. population was 2.9%, for a difference of 7.7 (95% CI, 7.4 to 7.9) percentage points. This difference decreased over time, from 11.1 percentage points among those entering care between 1999 and 2004 to 2.7 percentage points among those entering care between 2011 and 2017. Limitation: Matching on available covariates may have failed to account for differences in mortality that were due to sociodemographic factors rather than consequences of HIV infection and other modifiable factors. Conclusion: Mortality among persons entering HIV care decreased dramatically between 1999 and 2017, although those entering care remained at modestly higher risk for death in the years after starting care than comparable persons in the general U.S. population

The performance of the jet trigger for the ATLAS detector during 2011 data taking

The performance of the jet trigger for the ATLAS detector at the LHC during the 2011 data taking period is described. During 2011 the LHC provided proton–proton collisions with a centre-of-mass energy of 7 TeV and heavy ion collisions with a 2.76 TeV per nucleon–nucleon collision energy. The ATLAS trigger is a three level system designed to reduce the rate of events from the 40 MHz nominal maximum bunch crossing rate to the approximate 400 Hz which can be written to offline storage. The ATLAS jet trigger is the primary means for the online selection of events containing jets. Events are accepted by the trigger if they contain one or more jets above some transverse energy threshold. During 2011 data taking the jet trigger was fully efficient for jets with transverse energy above 25 GeV for triggers seeded randomly at Level 1. For triggers which require a jet to be identified at each of the three trigger levels, full efficiency is reached for offline jets with transverse energy above 60 GeV. Jets reconstructed in the final trigger level and corresponding to offline jets with transverse energy greater than 60 GeV, are reconstructed with a resolution in transverse energy with respect to offline jets, of better than 4 % in the central region and better than 2.5 % in the forward direction