Secular trends in sex ratios at birth in South America over the second half of the 20(th) century.

J Pediatr (Rio J)

PhD. Consultant Pediatrician, Department of Pediatrics, Mater Dei Hospital, Malta. Electronic address:

Published: September 2014

Objectives: Latitude gradients have been found in the male-female ratio at birth (M/F: male divided by total births), which is anticipated to be 0.515.

Methods: Annual national male and female live births by country were obtained for South America from the World Health Organization (WHO) and analysed with contingency tables. The continent was arbitrarily divided into two regions: a region 10° above the Equator to 20° below the Equator, and a second area 20° below the Equator.

Results: This study analyzed 147,773,689 live births. An overall increasing trend in M/F was found for the region >20° (p<0.0001) for the entire period. For the aggregate, a significant decrease was present for the period 1950-74 (p = 0.01) followed by a significant increase thereafter (p<0.001). A latitude gradient was also noted, with more males being born in cooler (more Southern > 20° S) latitudes (p<0.0001). There were 3,765,648 male births in excess of what was anticipated.

Conclusion: The M/F ratio is increasing in South America, unlike the decline present in Europe and North America. This study also showed that M/F latitude gradients are similar to those previously reported in North America, with more males being born in cooler latitudes, contrary to the trends reported in Europe. The interplay of several poorly understood factors is likely.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jped.2013.01.006DOI Listing

Publication Analysis

Top Keywords

south america
8
live births
8
secular trends
4
trends sex
4
sex ratios
4
ratios birth
4
birth south
4
america second
4
second half
4
half 20th
4

Similar Publications

Introduction: HIV self-testing (HIVST) is an innovative strategy that has been shown to increase uptake of HIV testing compared to conventional facility-based testing. HIVST implementation with digital-based supports may help facilitate testing accessibility and linkage to care after a reactive self-test. Economic evidence around community-based implementation of HIVST is growing; however, economic evidence around digital-based HIVST approaches remains limited.

View Article and Find Full Text PDF

sp. nov., the first representative of the New World micromoth genus Busck (Lepidoptera, Gelechiidae) associated with a member of Asteraceae.

Biodivers Data J

January 2025

Universidad de Tarapacá, Facultad de Ciencias Agronómicas, Departamento de Recursos Ambientales, Arica, Chile Universidad de Tarapacá, Facultad de Ciencias Agronómicas, Departamento de Recursos Ambientales Arica Chile.

Background: The New World micromoth genus Busck, 1939 (Lepidoptera, Gelechiidae, Gelechiinae, Gnorimoschemini) includes 21 described species, ten of which occur in South America. Like the tomato pinworm, (Walsingham, 1897), all the species of , whose host plants have been documented, are associated exclusively with members of the family Solanaceae.

New Information: sp.

View Article and Find Full Text PDF

Objectives: Advanced HIV disease (AHD) at HIV care enrollment is common in Latin America and may bias cross-sectional care continuum estimates. We therefore explored the impact of AHD on HIV care continuum outcomes using a longitudinal approach.

Methods: We analyzed trajectories of 26,174 adult people with HIV enrolled at Caribbean, Central and South America network for HIV epidemiology (CCASAnet) sites (2003-2019) using multi-state Cox regression across five stages: (i) enrolled without antiretroviral therapy (no-ART); (ii) on ART without viral suppression (viral load ≥200 copies/m; ART + non-VS); (iii) on ART with viral suppression (viral load <200 copies/ml; ART + VS); (iv) lost to follow-up; (v) death.

View Article and Find Full Text PDF

The methane seeps on the Pacific margin of Costa Rica support extensive animal diversity and offer insights into deep-sea biogeography. During five expeditions between 2009 and 2019, we conducted intensive faunal sampling via 63 submersible dives to 11 localities at depths of 300-3600 m. Based on these expeditions and published literature, we compiled voucher specimens, images, and 274 newly published DNA sequences to present a taxonomic inventory of macrofaunal and megafaunal diversity with a focus on invertebrates.

View Article and Find Full Text PDF

Building Localized NADP(H) Recycling Circuits to Advance Enzyme Cascadetronics.

Angew Chem Int Ed Engl

January 2025

University of Oxford, Chemistry, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND.

The catalytic action of enzymes of a cascade trapped within a mesoporous electrode material is simultaneously energized, controlled and observed through the efficient, reversible electrochemical NAD(P)(H) recycling catalyzed by one of the enzymes. In their nanoconfined state, nicotinamide cofactors are tightly channeled current carriers, mediating multi-step reactions in either direction (oxidation or reduction) with a rapid response time. By incorporating a hydrogen‑borrowing enzyme pair, the internal action of which opposes the external voltage bias driving oxidation or reduction, a reduction process can be performed under overall oxidizing conditions, and vice versa.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!