Coherence betwwen 19th century sperm whale distributions and satellite-derived pigments in the tropical Pacific

It has often been suggested that, given their large food requirements, sperm whale Physeter macrocephalus distributions should reflect the distribution of productive ocean environments, and it seems therefore that chlorophyll concentration might be a good indicator of sperm whale distribution. To examine the existence of such a relationship, and to determine over which sclaes it occurs, sperm whale density was correlated with phytoplankton pigment concentration over a range of spatial and temporal scales. Sperm whale distribution was detrmined using records of kills from 19th century Yankee whaling, and the distribution of pigment concentration from satellite colour observations averaged over 8yr interval. These measures were compared over scales of 220km square to 1780km square. The distribution of sperm whales in the temperature and tropical Pacific Ocean was associated with distributions of phytoplankton pigment over every spatial scale considered, and the coefficient of correlation increased with increasing spatial scale. However, a few exceptions to this scheme were found, implying that other factors would be of importance in some regions. This study confirmed the existence of space lag and a time lag between a peak in chlorophyll concentration and a peak in sperm whale density. It also demonstrated that over large spatial scales, and when the data are averaged over large temporal scales, chlorophyll concentration is a good indicator of sperm whale distribution and that over these scales ocean colour recorded from space could help predict areas of high or low sperm whale density

Social Structure of Sperm Whales in the Northern Gulf of Mexico

Sperm whales exhibit highly structured social behavior that depends on sex, age, and possibly local ecological characteristics. We analyzed sighting data collected between 1994 and 2005 to determine the social structure of sperm whale groups in the northern Gulf of Mexico (714 good-quality photographs of 285 individual whales). Average typical group size was approximately eight when estimated with mark-recapture techniques and using data from 2003 to 2005. Lagged association rate analyses including data from 1994 to 2004 indicated average group sizes of 11.41. Therefore, groups in the Gulf are considerably smaller than groups in the Pacific Ocean, but similar to those from the Caribbean Sea. Similarly, groups in the Gulf of Mexico remained stable for longer periods (62.5 d, SE = 47.62) than Pacific groups, but were comparable to groups from the Gulf of California. Such differences and similarities between populations could be due to adaptations to local conditions, indicating that Gulf of Mexico sperm whales may live in ecological conditions more similar to those of the Caribbean and the Sea of Cortez than to the Pacific

Mechanics of hybrid polymer composites

Aoudi Mekki, Bessière Fabrice, Biagi Solange, Scheid John, Broise Henri, Monteix Nicolas, Rosso Emmanuelle, Ben Abed Aïcha, André Nathalie, Balmelle Catherine, Chbili Jarir, Durost Raphaël, Jaquet-Bessière Catharina, Curie Julien, Petit Christophe. Jebel Oust (Tunisie). In: Mélanges de l'École française de Rome. Antiquité, tome 120, n°1. 2008. Antiquité. pp. 260-270

Age-specific burden of cervical cancer associated with HIV: A global analysis with a focus on sub-Saharan Africa

HIV substantially worsens human papillomavirus (HPV) carcinogenicity and contributes to an important population excess of cervical cancer, particularly in sub-Saharan Africa (SSA). We estimated HIV- and age-stratified cervical cancer burden at a country, regional, and global level in 2020. Proportions of cervical cancer a) diagnosed in women living with HIV (WLHIV), and b) attributable to HIV, were calculated using age-specific estimates of HIV prevalence (UNAIDS) and relative risk. These proportions were validated against empirical data and applied to age-specific cervical cancer incidence (GLOBOCAN 2020). HIV was most important in SSA, where 24.9% of cervical cancers were diagnosed in WLHIV, and 20.4% were attributable to HIV (vs 1.3% and 1.1%, respectively, in the rest of the world). In all world regions, contribution of HIV to cervical cancer was far higher in younger women (as seen also in empirical series). For example, in Southern Africa, where more than half of cervical cancers were diagnosed in WLHIV, the HIV-attributable fraction decreased from 86% in women ≤34 years to only 12% in women ≥55 years. The absolute burden of HIV-attributable cervical cancer (approximately 28 000 cases globally) also shifted towards younger women: in Southern Africa, 63% of 5341 HIV-attributable cervical cancer occurred in women <45 years old, compared to only 17% of 6901 non-HIV-attributable cervical cancer. Improved quantification of cervical cancer burden by age and HIV status can inform cervical cancer prevention efforts in SSA, including prediction of the impact of WLHIV-targeted vs general population approaches to cervical screening, and impact of HIV prevention

A first update on mapping the human genetic architecture of COVID-19

peer reviewe

Social Structure of Sperm Whales in the Northern Gulf of Mexico

Sperm whales exhibit highly structured social behavior that depends on sex, age, and possibly local ecological characteristics. We analyzed sighting data collected between 1994 and 2005 to determine the social structure of sperm whale groups in the northern Gulf of Mexico (714 good-quality photographs of 285 individual whales). Average typical group size was approximately eight when estimated with mark-recapture techniques and using data from 2003 to 2005. Lagged association rate analyses including data from 1994 to 2004 indicated average group sizes of 11.41. Therefore, groups in the Gulf are considerably smaller than groups in the Pacific Ocean, but similar to those from the Caribbean Sea. Similarly, groups in the Gulf of Mexico remained stable for longer periods (62.5 d, SE = 47.62) than Pacific groups, but were comparable to groups from the Gulf of California. Such differences and similarities between populations could be due to adaptations to local conditions, indicating that Gulf of Mexico sperm whales may live in ecological conditions more similar to those of the Caribbean and the Sea of Cortez than to the Pacific