OBJECTIVE: The aim of this study was to examine the disease burden of lung cancer attributable to particulate matter (PM2.5) pollution in China from 1990 to 2019.
METHODS: Data from the Global Burden of Disease Study 2019 were used to estimate the disease burden of tracheal, bronchus and lung cancer attributed to PM2.5 over time in China.
METHODS: Joinpoint regression models were applied to disability-adjusted life years (DALYs) to assess the time trends and estimate the impact of PM2.5 on the overall disease burden of lung cancer. Furthermore, age-period-cohort models were conducted to assess the relationships between lung cancer DALYs attributed to PM2.5 exposure and age, calendar period and birth cohort trends in China from 1990 to 2019.
RESULTS: Lung cancer DALYs attributable to household air pollution from solid fuels decreased with an average annual percent change (AAPC) of 2.9 % per 100,000 population, while those attributable to ambient particular matter pollution (APE) increased (AAPC: -4.7 % per 100,000 population) over the past 30 years. The burden of lung cancer in terms of DALYs in males was higher than in females, and it demonstrated an age-dependent increase. The period and cohort effects also had significant impacts on the DALYs rates of lung cancer attributable to APE, indicating an overall increase in lung cancer DALYs for all age groups in each year.
CONCLUSIONS: This study highlights the need for effective strategies to reduce PM2.5 exposure in China, particularly from outdoor sources. Gender differences and age, period and cohort effects observed in the study provide valuable insights into long-term trends of lung cancer burden attributed to PM2.5.

Social learning is beneficial in almost every domain of a social animal\'s life, but it is particularly important in the context of predation and foraging. In both contexts, social animals tend to produce acoustically distinct vocalizations, alarms, and food calls, which have remained somewhat of an evolutionary conundrum as they appear to be costly for the signaller. Here, we investigated the hypothesis that food calls function to direct others toward novel food items, using a playback experiment on a group of chimpanzees. We showed chimpanzees novel (plausibly edible) items while simultaneously playing either conspecific food calls or acoustically similar greeting calls as a control. We found that individuals responded by staying longer near items previously associated with food calls even in the absence of these vocalizations, and peered more at these items compared with the control items, provided no conspecifics were nearby. We also found that once chimpanzees had access to both item types, they interacted more with the one previously associated with food calls than the control items. However, we found no evidence of social learning per se. Given these effects, we propose that food calls may gate and thus facilitate social learning by directing listeners\' attention to new feeding opportunities, which if integrated with additional cues could ultimately lead to new food preferences within social groups.

Flexor digitorum superficialis (FDS) shows diverse muscle-tendon arrangements among primates. The intramuscular nerve distribution pattern is a criterion for discussing the homology of FDS. In this study, the muscle-tendon arrangement and intramuscular nerve distribution of FDS were examined in the siamang, western lowland gorilla, western chimpanzee, and Japanese macaques. The FDS had muscle bellies to digits II-V. FDS had proximal belly and intermediate tendon except for siamang. Distal belly to digit II (in the western lowland gorilla and western chimpanzees) or distal bellies to digits II and V (in Japanese macaque) originated from the intermediate tendon. In all specimens, nerve branches within digit III belly extended into digit IV belly, and nerve branch(es) within digit IV belly extended into digit V belly. This consistent pattern suggested that each muscle belly to digits III-V is interspecifically homologous. The digit II belly in the siamang and the distal belly to digit II in the western lowland gorilla, western chimpanzees, and Japanese macaques could be homologous based on their similar innervating patterns. The proximal belly was innervated by branches from the communicating nerve between median and ulnar nerves in the western lowland gorilla or branches from median and ulnar nerves in western chimpanzees. In the siamang and Japanese macaque, the whole FDS was innervated by median nerve. The proximal belly in the western lowland gorilla, western chimpanzees, and Japanese macaques could be classified into different groups from the other part of the FDS.

A survey was sent to zoos, research facilities, and sanctuaries which housed chimpanzees. Data collected included information about 1122 chimpanzees’ age, sex, social group-size, rearing history, and enclosure. Respondents were also asked to indicate if certain behaviors had been observed in each chimpanzee over the prior two years. Species- typical behaviors (STBs) were queried, including copulation, tool-use, nest-building, and social grooming. Tool-use was reported present for 94.3% of the sample (n = 982), active social grooming for 85.7% (n = 1121), copulation for 68.3% (n = 863) and nest-building for 58.9% (n = 982). Of the subjects for whom we had data regarding all four STBs (n = 860), 45.6% were reported to engage in all four. Logistic regression analyses using forward Wald criteria were conducted to determine the best model for each STB based on the predictors of age, sex, rearing history, group-size, facility-type, and a sex-by-rearing interaction. The best model for copulation (χ2(6) = 124.62, p < 0.001) included rearing, group-size, facility-type, and the sex-by-rearing interaction. Chimpanzees were more likely to copulate if they were mother-reared, in larger groups, living in research facilities, and, if not mother-reared (NOTMR), more likely to copulate if they were female. The best model for tool-use retained the predictors of age category, facility-type, and sex-by-rearing (χ2(5) = 55.78, p < 0.001). Chimpanzees were more likely to use tools if they were adult, living in research facilities, and if NOTMR, were female. The best model for nest-building included facility-type and rearing (χ2(3) = 205.71, p < 0.001). Chimpanzees were more likely to build nests if they were MR and if they were living in zoos or in sanctuaries. The best model for active social grooming retained the predictors of age, sex, rearing, and type of facility (χ2(6) = 102.15, p < 0.001). Chimpanzees were more likely to engage in active social grooming if they were immature, female, mother-reared, and living in zoos. This research provides a basic behavioral profile for many chimpanzees living under human care in the United States and allows us to determine potential methods for improving the welfare of these and future chimpanzees in this population.

Many animals will seek information when they do not know the answer to a problem, suggesting that they monitor their knowledge state. In the classic \"tubes task,\" subjects are presented with a set of opaque tubes and either see (visible trials) or do not see (hidden trials) which tube holds a food reward on a given trial. Chimpanzees, bonobos, orangutans, and human children show information-seeking behavior on this task, looking into the tubes to find the reward more on hidden than on visible trials. However, evidence for information-seeking behavior in gorillas is limited. In Experiment 1, gorillas that were presented with a classic information-seeking tubes task showed performance patterns consistent with metacognitive behavior; they looked down tubes more on hidden than on visible trials, their accuracy on hidden trials on which they looked was higher than on hidden trials on which they did not look, and they primarily employed an appropriate search strategy when looking down the tubes. In Experiment 2, we decreased or increased the amount of effort required to look down the tubes by increasing or decreasing the height of the tubes, respectively. Gorillas were less likely to look in tubes on trials that required high effort, but continued to look more on hidden than on visible trials, indicating that their tendency to look was affected by both knowledge state and effort. Together these results provide strong evidence for logical, controlled information-seeking behavior by gorillas.

The present work proposes a method to characterize, calibrate, and compare, any 2D SLAM algorithm, providing strong statistical evidence, based on descriptive and inferential statistics to bring confidence levels about overall behavior of the algorithms and their comparisons. This work focuses on characterize, calibrate, and compare Cartographer, Gmapping, HECTOR-SLAM, KARTO-SLAM, and RTAB-Map SLAM algorithms. There were four metrics in place: pose error, map accuracy, CPU usage, and memory usage; from these four metrics, to characterize them, Plackett-Burman and factorial experiments were performed, and enhancement after characterization and calibration was granted using hypothesis tests, in addition to the central limit theorem.

Ape language acquisition studies have demonstrated that apes can learn arbitrary mappings between different auditory or visual patterns and concepts, satisfying the definition of symbol use. The extent to which apes understand aspects of grammar is less well accepted. On the production side, several studies have shown that apes sometimes combine two or more symbols together, in non-random patterns. However, this is quite limited compared to human language production. On the comprehension side, much greater abilities have been reported in apes. One of the most famous examples is Kanzi, a bonobo who reportedly responded correctly to a large number of novel commands. However, based on his performance on a small subset of reversible sentences-where the understanding of English syntax was critical-the extent to which he demonstrated grammatical knowledge has been questioned. Using a randomization study it is shown here that his performance actually vastly exceeds random chance, supporting the contention that he does in fact understand word order grammatical rules in English. This of course represents only one aspect of English grammar, and does not suggest he has completely human grammatical abilities. However, it does show that he understands one of the arbitrary grammatical devices used in many languages: The use of word order to code argument relations. It also removes from serious consideration the view that apes lack any kind of grammatical ability. From an evolutionary perspective, Kanzi\'s ability is most likely to result from homologous brain circuitry, although this is ultimately an empirical question.

Primatological research in zoos is increasing globally. Such research allows scientists to study primate biology, behavior, and cognition while helping to advance the welfare of captive primates. Moreover, zoos welcome millions of visitors annually, which creates unique opportunities for public engagement with this research. Reflecting the importance of zoos in the field of primatology, the articles in this special issue showcase the range of primatological research currently being conducted in zoos around the world. With this special issue, I have chosen to focus on research examining primate behavior and cognition, addressing both basic and applied questions. The articles included in this special issue also highlight the array of technologies and methods being used to study zoo-housed primates. While zoos house a variety of primate species, potentially enabling the testing of under-studied species or widescale comparative research, great apes are disproportionately represented in current zoo-based research. Thus, while an interest in conducting research with primates in zoos continues to grow, there are still opportunities to increase the breadth and diversity of this study.

Malaria is a deadly disease that affects the health of hundreds of millions of people annually. There are five Plasmodium parasite species that can naturally infect humans, including Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae, Plasmodium ovale and Plasmodium knowlesi. Some of the parasites can also infect various non-human primates. Parasites mainly infecting monkeys such as Plasmodium cynomolgi (in fact P. knowlesi was considered as a parasite of monkeys for years) can also be transmitted to human hosts. Recently, many new Plasmodium species were discovered in African apes, and it is possible that some of the parasites can be transmitted to humans in the future. Here, we searched PubMed and the internet via Google and selected articles concerning zoonotic transmission and evolution of selected malaria parasite species. We reviewed the current advances in the relevant topics emphasizing on transmissions of malaria parasites between humans and non-human primates. We also briefly discuss the transmissions of some avian malaria parasites between wild birds and domestic fowls. Zoonotic malaria transmissions are widespread, which poses a threat to public health. More studies on parasite species identification in non-human primates, transmission, and evolution are needed to reduce or prevent transmission of malaria parasites from non-human primates to humans.

Across a period of 54 months, several changes were made to the feeding protocols of 32 adult chimpanzees living at the Yerkes National Primate Research Center Field Station. Before implementing any changes in diet, baseline data were collected for 6 months. During Baseline (BS), the chimpanzees received unlimited amounts of primate biscuits twice a day and a limited amount of produce as enrichment. Treatment One (T1) dietary modifications included an increased amount of vegetables, primarily leafy greens, and biscuit feedings scheduled to occur an hour after vegetables were provided to the chimpanzees. T1 lasted for 1 year. At the end of T1, most of the chimpanzees had gained weight. Treatment Two (T2) occurred over the span of 3 years, during which all the chimpanzees were switched from unlimited, group-distributed primate biscuits to individually prescribed amounts of biscuits, fed in\\dividually, and increased daily feedings of leafy greens. By the end of T2, 10 of 15 chimpanzees who were overweight or obese at the start of the project were within range of ideal body condition, and 4 of the remaining 5 were improved. All the chimpanzees who started the project within ideal range were still within ideal range. Significantly more time was invested in eating, foraging, and processing food during T2 (p < .05), more appropriately replicating the natural time budget for a chimpanzee. There were not any increases in abnormal, stress-related, or agonistic behaviors as a function of dietary modifications. Inactivity, however, was significantly higher (p < .05) during the later protocol, and locomotion was concurrently lower (p < .05).