Evaluation of Potential Low-stress Handling Methods in Crl:CDSD Rats (Rattus norvegicus).

Low-stress handling methods have been studied in detail in mice, but relatively little research exists concerning preferred handling methods in rats. Most recommendations for low-stress handling of rats have been extrapolated from the mouse literature, despite known differences in handler interaction between the 2 species. The goal of the current study was to evaluate common methods of handling in rats, including application of recognized, low-stress handling methods from other species to rats, in order to determine relative stress levels associated with the handling methods. Seventy male and 70 female, 8-wk-old, Crl:CDSD rats, were housed either individually or in pairs, and were handled weekly or daily using one of the following methods: encircling of the torso (standard thoracic hold), handled using a tunnel, handled using a protective bite glove, handled using a soft paper towel, or tickled prior to being handled by the torso ( n = 10 per sex per treatment group). Body weight and clinical observations were scored at each handling session, abbreviated functional observation batteries were performed every other week, and an interaction test and hematology were conducted prior to study and on the day of study termination. Rats that were socially housed and handled weekly using the standard thoracic hold showed the least evidence of stress, while those that were singly housed and handled weekly using a protective bite glove or tunnel showed the highest level of stress. These effects were predominantly seen in males. This study suggests that standard low-stress handling methods used for other species may not be optimal for rats, and that additional research is needed to identify alternative methods to the standard thoracic hold that would further reduce stress during handling in rats.

A Comparison of Historical Control Data From Cynomolgus Macaques (Macaca Fascicularis) of Chinese, Cambodian, and Vietnamese Origin.

Cynomolgus macaques, the most commonly utilized nonhuman primate in nonclinical toxicology studies, are acquired from purpose-bred colonies across various geographic locations, including China, Cambodia, and Vietnam. Importation challenges and limited availability have restricted animals suitable for inclusion in nonclinical studies. The coronavirus disease 2019 (COVID-19) outbreak further stressed supply chains, reducing the ability to source animals from a singular location to complete a drug development program. These challenges raised concerns of increased variability in study endpoints due to heterogeneity of animals and that this could subsequently impact historical control data and toxicology study interpretation. To investigate the impact of Chinese, Vietnamese, or Cambodian geographic origin on standard nonclinical toxicology study endpoints, historical control data from studies conducted at a single facility from 2005 to 2020 were compiled and evaluated for the following: clinical observations, body weight, ophthalmoscopic examinations, and clinical and anatomic pathology data. Study populations consisted of 2- to 5-year-old cynomolgus macaques sourced from China (n = 750 males/741 females), Cambodia (n = 282 males/271 females), and Vietnam (n = 122 males/120 females). Interpretation of the various data demonstrated no notable differences in standard toxicology study endpoints or background findings among cynomolgus macaques originating from China, Cambodia, or Vietnam.

Extirpated prairie species demonstrate more variable phenological responses to warming than extant congeners.

PREMISE: Shifting phenology in response to climate is one mechanism that can promote population persistence and geographic spread; therefore, species with limited ability to phenologically track changing environmental conditions may be more susceptible to population declines. Alternatively, apparently nonresponding species may demonstrate divergent responses to multiple environmental conditions experienced across seasons. METHODS: Capitalizing on herbarium records from across the midwestern United States and on detailed botanical surveys documenting local extinctions over the past century, we investigated whether extirpated and extant taxa differ in their phenological responses to temperature and precipitation during winter and spring (during flowering and the growing season before flowering) or in the magnitude of their flowering time shift over the past century. RESULTS: Although warmer temperatures across seasons advanced flowering, extirpated and extant species differed in the magnitude of their phenological responses to winter and spring warming. Extirpated species demonstrated inconsistent phenological responses to warmer spring temperatures, whereas extant species consistently advanced flowering in response to warmer spring temperatures. In contrast, extirpated species advanced flowering more than extant species in response to warmer winter temperatures. Greater spring precipitation tended to delay flowering for both extirpated and extant taxa. Finally, both extirpated and extant taxa delayed flowering over time. CONCLUSIONS: This study highlights the importance of understanding phenological responses to seasonal warming and indicates that extirpated species may demonstrate more variable phenological responses to temperature than extant congeners, a finding consistent with the hypothesis that appropriate phenological responses may reduce species' likelihood of extinction.

Racial bias in pain perception and response: experimental examination of automatic and deliberate processes.

UNLABELLED: Racial disparities in pain treatment pose a significant public health and scientific problem. Prior studies have demonstrated that clinicians and nonclinicians are less perceptive of, and suggest less treatment for, the pain of African Americans relative to European Americans. Here we investigate the effects of explicit/implicit patient race presentation, patient race, and perceiver race on pain perception and response. African American and European American participants rated pain perception, empathy, helping motivation, and treatment suggestion in response to vignettes about patients' pain. Vignettes were accompanied by a rapid (implicit) or static (explicit) presentation of an African or European American patient's face. Participants perceived and responded more to European American patients in the implicit prime condition, when the effect of patient race was below the level of conscious regulation. This effect was reversed when patient race was presented explicitly. Additionally, female participants perceived and responded more to the pain of all patients, relative to male participants, and in the implicit prime condition, African American participants were more perceptive and responsive than European Americans to the pain of all patients. Taken together, these results suggest that known disparities in pain treatment may be largely due to automatic (below the level of conscious regulation) rather than deliberate (subject to conscious regulation) biases. These biases were not associated with traditional implicit measures of racial attitudes, suggesting that biases in pain perception and response may be independent of general prejudice. PERSPECTIVE: Results suggest that racial biases in pain perception and treatment are at least partially due to automatic processes. When the relevance of patient race is made explicit, however, biases are attenuated and even reversed. We also find preliminary evidence that African Americans may be more sensitive to the pain of others than are European Americans.