due to a lower male: female ratio in these areas but this may ultimately be due to male infants having increased mortality from infectious diseases. Another example is that poor socioeconomic factors may ultimately in part be due to high pathogen load preventing economic development. Fossil record Evidence of infection in fossil remains is a subject of interest for paleopathologists, scientists who study occurrences of injuries and illness in extinct life forms. Signs of infection have been discovered in the bones of carnivorous dinosaurs. When present, however, these infections seem to tend to be confined to only small regions of the body. A skull attributed to the early carnivorous dinosaur Herrerasaurus ischigualastensis exhibits pit-like wounds surrounded by swollen and porous bone. The unusual texture of the bone around the wounds suggests they were affected by a short-lived, non-lethal infection. Scientists who studied the skull speculated that the bite marks were received in a fight with another Herrerasaurus. Other carnivorous dinosaurs with documented evidence of infection include Acrocanthosaurus, Allosaurus, Tyrannosaurus and a tyrannosaur from the Kirtland Formation. The infections from both tyrannosaurs were received by being bitten during a fight, like the Herrerasaurus specimen. Outer space A 2006 Space Shuttle experiment found that Salmonella typhimurium, a bacterium that can cause food poisoning, became more virulent when cultivated in space. On April 29, 2013, scientists in Rensselaer Polytechnic Institute, funded by NASA, reported that, during spaceflight on the International Space Station, microbes seem to adapt to the space environment in ways "not observed on Earth" and in ways that "can lead to increases in growth and virulence". More recently, in 2017, bacteria were found to be more resistant to antibiotics and to thrive in the near-weightlessness of space. Microorganisms have been observed to survive the vacuum of outer space. See also Bioinformatics Resource Centers for Infectious Diseases Biological hazard Blood-borne disease Coinfection Copenhagen Consensus Cordon sanitaire Disease diffusion mapping Epidemiological transition Foodborne illness Gene therapy History of medicine Hospital-acquired infection Eradication of infectious diseases Human Microbiome Project Infection control Isolation (health care) List of bacterial vaginosis microbiota List of causes of death by rate List of diseases caused by insects List of epidemics List of infectious diseases Mathematical modelling of infectious disease Multiplicity of infection Neglected tropical diseases Sentinel surveillance Social distancing Spatiotemporal Epidemiological Modeler (STEM) Spillover infection Threshold host density Transmission (medicine) Ubi pus, ibi evacua (Latin: "where there is pus,