Comparative morphology and physiology of the vocal production apparatus and the brain in the extant primates

Objective data mainly from the comparative anatomy of various organs related to human speech and language is considered to unearth clues about the mechanisms behind language development. The two organs of the larynx and hyoid bone are considered to have evolved towards suitable positions and forms in preparation for the occurrence of the large repertoire of vocalization necessary for human speech. However, some researchers have asserted that there is no significant difference of these organs between humans and non-human primates. Speech production is dependent on the voluntary control of the respiratory, laryngeal, and vocal tract musculature. Such control is fully present in humans but only partially so in non-human primates, which appear to be able to voluntarily control only supralaryngeal articulators. Both humans and non-human primates have direct cortical innervation of motor neurons controlling the supralaryngeal vocal tract but only human appear to have direct cortical innervation of motor neurons controlling the larynx. In this review, we investigate the comparative morphology and function of the wide range of components involved in vocal production, including the larynx, the hyoid bone, the tongue, and the vocal brain. We would like to emphasize the importance of the tongue in the primary development of human speech and language. It is now time to reconsider the possibility of the tongue playing a definitive role in the emergence of human speech. © 2022The authors are grateful to Ms. Aya Ishitani and Ms. Chisato Ueda, Department of Medical Technology and Clinical Engineering, Faculty of Health and Medical Sciences, for their helpful and devoted assistance in the manuscript preparation. The authors also thank Edanz (https://en-author-services.edanzgroup.com/ac) for editing the English text of a draft of this manuscript

Effectiveness of primary series, first, and second booster vaccination of monovalent mRNA COVID-19 vaccines against symptomatic SARS-CoV-2 infections and severe diseases during the SARS-CoV-2 omicron BA.5 epidemic in Japan: vaccine effectiveness real-time surveillance for SARS-CoV-2 (VERSUS)

This study aimed to evaluate VE of primary, first, and second booster ancestral-strain monovalent mRNA COVID-19 vaccination against symptomatic infections and severe diseases in Japan. We conducted a test-negative case-control study. We included medically attended episodes and hospitalizations involving individuals aged ≥16 with signs and symptoms from July to November 2022, when Omicron BA.5 was dominant nationwide. To evaluate VE, we calculated adjusted ORs of vaccination among test-positive versus test-negative individuals using a mixed-effects logistic regression. For VE against symptomatic infections among individuals aged 16 to 59, VE of primary vaccination at > 180 days was 26.1% (95% CI: 10.6–38.8%); VE of the first booster was 58.5% (48.4–66.7%) at ≤90 days, decreasing to 41.1% (29.5–50.8%) at 91 to 180 days. For individuals aged ≥60, VE of the first booster was 42.8% (1.7–66.7%) at ≤90 days, dropping to 15.4% (−25.9–43.2%) at 91 to 180 days, and then increasing to 44.0% (16.4–62.5%) after the second booster. For VE against severe diseases, VE of the first and second booster was 77.3% (61.2–86.7%) at ≤90 days and 55.9% (23.4–74.6%) afterward. mRNA booster vaccination provided moderate protection against symptomatic infections and high-level protection against severe diseases during the BA.5 epidemic in Japan.</p