A heavyweight early whale pushes the boundaries of vertebrate morphology.

The fossil record of cetaceans documents how terrestrial animals acquired extreme adaptations and transitioned to a fully aquatic lifestyle1,2. In whales, this is associated with a substantial increase in maximum body size. Although an elongate body was acquired early in cetacean evolution3, the maximum body mass of baleen whales reflects a recent diversification that culminated in the blue whale4. More generally, hitherto known gigantism among aquatic tetrapods evolved within pelagic, active swimmers. Here we describe Perucetus colossus-a basilosaurid whale from the middle Eocene epoch of Peru. It displays, to our knowledge, the highest degree of bone mass increase known to date, an adaptation associated with shallow diving5. The estimated skeletal mass of P. colossus exceeds that of any known mammal or aquatic vertebrate. We show that the bone structure specializations of aquatic mammals are reflected in the scaling of skeletal fraction (skeletal mass versus whole-body mass) across the entire disparity of amniotes. We use the skeletal fraction to estimate the body mass of P. colossus, which proves to be a contender for the title of heaviest animal on record. Cetacean peak body mass had already been reached around 30 million years before previously assumed, in a coastal context in which primary productivity was particularly high.

Polyplacophoran Feeding Traces on Mediterranean Pliocene Sirenian Bones: Insights on the Role of Grazing Bioeroders in Shallow-Marine Vertebrate Falls.

Chitons (Polyplacophora) include some of the most conspicuous bioeroders of the present-day shallow seas. Abundant palaeontological evidence for the feeding activity of ancient chitons is preserved in the form of radular traces that are usually found on invertebrate shells and hardgrounds. We report on widespread grazing traces occurring on partial skeletons of the extinct sirenian Metaxytherium subapenninum from the Lower Pliocene (Zanclean) of Arcille (Grosseto Province, Tuscany, Italy). These distinctive ichnofossils are described under the ichnotaxonomic name Osteocallis leonardii isp. nov. and interpreted as reflecting substrate scraping by polyplacophorans. A scrutiny of palaeontological literature reveals that similar traces occur on fossil vertebrates as old as the Upper Cretaceous, suggesting that bone has served as a substrate for chiton feeding for more than 66 million years. Whether these bone modifications reflect algal grazing, carrion scavenging or bone consumption remains unsure, but the first hypothesis appears to be the most parsimonious, as well as the most likely in light of the available actualistic data. As the role of bioerosion in controlling fossilization can hardly be overestimated, further research investigating how grazing organisms contribute to the biostratinomic processes affecting bone promises to disclose new information on how some marine vertebrates manage to become fossils.

Supporting Return to Work after Breast Cancer: A Mixed Method Study.

Breast cancer (BC) is the most common invasive cancer in the world. Most BC survivors (BCSs) continue working while dealing with cancer-related disabilities. BCSs' return-to-work (RTW) after cancer treatment is an important stage of their recovery and is associated with a higher survival rate. In this study, we addressed the RTW of BCSs with the intention of facilitating this process through direct action in the workplace. Thirty-two women who requested assistance from January to December 2022 were enrolled in the study. Semi-structured interviews and medical examinations were conducted by a team of three physicians. Interviews were analyzed using Thematic Analysis. Moreover, a quantitative cross-sectional study was conducted to compare the health status of BCSs with that of a control group of 160 working women, using standardized questionnaires on work ability, fatigue, sleep problems, anxiety, depression, and happiness. BCSs were also asked to rate the level of organizational justice they perceived at work prior to their illness. From the qualitative analysis emerged three facilitating/hindering themes: (1) person-related factors, (2) company-related factors, and (3) society-related factors. In the quantitative analysis, BCSs had significantly higher scores for anxiety, depression, sleep problems and fatigue, and lower levels of happiness than controls. The RTW of BCSs entails adapting working conditions and providing adequate support. The work-related analysis of each case made it possible to highlight the measures that need to be taken in the workplace to promote RTW. The treatment of cancer should be paired with advice on the best way to regain the ability to work.

Post-COVID Symptoms in Occupational Cohorts: Effects on Health and Work Ability.

Post-acute COVID-19 syndrome is frequently observed in workers and has a substantial impact on work ability. We conducted a health promotion program to identify cases of post-COVID syndrome, analyze the distribution of symptoms and their association with work ability. Of the 1422 workers who underwent routine medical examination in 2021, 1378 agreed to participate. Among the latter, 164 had contracted SARS-CoV-2 and 115 (70% of those who were infected) had persistent symptoms. A cluster analysis showed that most of the post-COVID syndrome cases were characterized by sensory disturbances (anosmia and dysgeusia) and fatigue (weakness, fatigability, tiredness). In one-fifth of these cases, additional symptoms included dyspnea, tachycardia, headache, sleep disturbances, anxiety, and muscle aches. Workers with post-COVID were found to have poorer quality sleep, increased fatigue, anxiety, depression, and decreased work ability compared with workers whose symptoms had rapidly disappeared. It is important for the occupational physician to diagnose post-COVID syndrome in the workplace since this condition may require a temporary reduction in work tasks and supportive treatment.

The Impact of Workplace Violence on Headache and Sleep Problems in Nurses.

Workplace violence (WV) is a significant occupational hazard for nurses. Previous studies have shown that WV has a reciprocal relationship with occupational stress. Headaches and sleep problems are early neuropsychological signs of distress. This cross-sectional study aims to ascertain the frequency of physical or verbal assaults on nurses and to study the association of WV with headaches and sleep problems. During their regular medical examination in the workplace, 550 nurses and nursing assistants (105 males, 19.1%; mean age 48.02 ± 9.98 years) were asked to fill in a standardized questionnaire containing the Violent Incident Form (VIF) concerning the episodes of violence experienced, the Headache Impact Test (HIT-6) regarding headaches, and the Pittsburgh Sleep Quality Inventory (PSQI) on sleep quality. Occupational stress was measured using the Effort/Reward Imbalance questionnaire (ERI). Physical and non-physical violence experienced in the previous year was reported by 7.5% and 17.5% of workers, respectively. In the univariate logistic regression models, the workers who experienced violence had an increased risk of headaches and sleep problems. After adjusting for sex, age, job type, and ERI, the relationship between physical violence and headaches remained significant (adjusted odds ratio aOR = 2.25; confidence interval CI95% = 1.11; 4.57). All forms of WV were significantly associated with poor sleep in a multivariate logistic regression model adjusted for sex, age, job type, and ERI (aOR = 2.35 CI95% = 1.44; 3.85). WV was also associated with the impact of headaches and with sleep quality. WV prevention may reduce the frequency of lasting psychoneurological symptoms, such as headaches and poor sleep quality, that interfere with the ability to work.