Bibliographic record
Abstract
The early spread Here we will review how, from its central African crucible, HIV managed to disseminate throughout Africa, at the same time as it did so across the Atlantic. But first we need to review two epidemiological terms. As explained in Chapter 1, ‘incidence’ is a measure of new cases of HIV that occur among previously uninfected subjects over a period of time. The same individuals have to be tested repeatedly: this is time-consuming, expensive and rarely used. ‘Prevalence’ is the proportion of individuals who have HIV at some point in time, a snapshot that indicates the current distribution. As the median interval between HIV infection and death in Africa is about ten years, measures of HIV prevalence reflect an accumulation of individuals infected from as little as a few weeks ago to more than ten years earlier. Over time, prevalence in a population increases if the number of new infections since the previous survey was greater than the number of individuals who died from HIV or other causes. Prevalence decreases when the reverse occurs, i.e. the number of deaths is higher than the number of new infections.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.002 | 0.004 |
| Scholarly communication | 0.006 | 0.007 |
| Open science | 0.001 | 0.004 |
| Research integrity | 0.002 | 0.003 |
| Insufficient payload (model declined to judge) | 0.040 | 0.006 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".