Stress, Subordination, and Anomalies of Feeding Across the Tree of Life: Implications for Interpreting Human Eating Disorders.

Eating behaviors of animals living in naturalistic environments offer unique insights into several dysregulated eating patterns observed in humans. Social subordination is a known precipitant of hyperphagia and hypophagia in human beings, and examples of similar responses have been identified in a phylogenetically widespread range of vertebral species. This points to potentially conserved, patterned responses to animals navigating lives within social hierarchies. Self-imposed food restriction in subordinate fish and hyperphagic responses in socially subordinated bird and primate individuals may represent evolved adaptations to the stress of social subordination. As such, hyperphagic and hypophagic responses to social subordination in these species may model the natural history, neurobiology, and behavioral ecology of human dieting and bingeing more accurately than some current animal models. Phylogenetically widespread similarities in eating patterns under the stress of social subordination point to potentially shared biological benefits of these behaviors across species and the role of evolutionary trade-offs, adaptations, and other processes in shaping them. The application of a broadly comparative lens to disordered eating behaviors in other species exposes important similarities and differences between neurophysiology of eating across species. In doing so, it highlights the value of phylogenetic analyses and macroevolution as tools for identifying novel, naturally occurring models for understanding disordered human eating. Moreover, this approach introduces the intriguing possibility that human cultural influences on disordered eating may have far more ancient origins than previously considered.

Remodeling of the Tumor Microenvironment by a Chemokine/Anti-PD-L1 Nanobody Fusion Protein.

An optimal response to immune checkpoint blockade requires the presence of effector cells in the tumor microenvironment. We designed a PD-L1-targeted delivery strategy for chemokines, key molecules that drive leukocyte trafficking, to the tumor microenvironment, as a means of attracting the relevant leukocyte populations. This strategy combines a PD-L1-blocking single-domain antibody fragment (nanobody or VHH), a charge-engineered chemokine CCL21, and its subsequent characterization in a microfluidic device that resembles the tumor microenvironment. We show that the PD-L1-blocking VHH is a reliable fusion partner for the preparation of a functional chemokine fusion. Engineering the surface charge of CCL21 reduced its nonspecific binding to glycosaminoglycans, a property of chemokines that complicates their targeted delivery. Using a microfluidic assay, we show that it is possible to deliver a chemokine-VHH fusion to a PD-L1-positive environment and recruit effector cells.

An orange calcium-modulated bioluminescent indicator for non-invasive activity imaging.

Fluorescent indicators are used widely to visualize calcium dynamics downstream of membrane depolarization or G-protein-coupled receptor activation, but are poorly suited for non-invasive imaging in mammals. Here, we report a bright calcium-modulated bioluminescent indicator named Orange CaMBI (Orange Calcium-modulated Bioluminescent Indicator). Orange CaMBI reports calcium dynamics in single cells and, in the context of a transgenic mouse, reveals calcium oscillations in whole organs in an entirely non-invasive manner.

Nanobody immunostaining for correlated light and electron microscopy with preservation of ultrastructure.

Morphological and molecular characteristics determine the function of biological tissues. Attempts to combine immunofluorescence and electron microscopy invariably compromise the quality of the ultrastructure of tissue sections. We developed NATIVE, a correlated light and electron microscopy approach that preserves ultrastructure while showing the locations of multiple molecular moieties, even deep within tissues. This technique allowed the large-scale 3D reconstruction of a volume of mouse hippocampal CA3 tissue at nanometer resolution.

Effects of Parental Status on Male Body Mass in the Monogamous, Biparental California Mouse.

Studies of biparental mammals demonstrate that males may undergo systematic changes in body mass as a consequence of changes in reproductive status; however, these studies typically have not teased apart effects of specific social and reproductive factors, such as cohabitation with a female per se, cohabitation with a breeding female specifically, and engagement in paternal care. We aimed to determine whether California mouse (Peromyscus californicus) fathers undergo systematic changes in body mass and if so, which specific social/reproductive factor(s) might contribute to these changes. We compared mean weekly body masses over a 5-week period in 1) males housed with another male vs. males housed with a non-reproductive (tubally ligated) female; 2) males housed with a tubally ligated female vs. males housed with a female that was undergoing her first pregnancy; and 3) experienced fathers housed with vs. without pups during their mate's subsequent pregnancy. Body mass did not differ between males housed with another male and those housed with a non-reproductive female; however, males housed with a non-reproductive female were significantly heavier than those housed with a primiparous female. Among experienced fathers, those housed with pups from their previous litter underwent significant increases in body mass across their mates' pregnancy, whereas fathers housed without pups did not. These results suggest that male body mass is reduced by cohabitation with a breeding (pregnant) female, but not by cohabitation with a non-reproductive female, and that increases in body mass across the mate's pregnancy are associated with concurrent care of offspring rather than cohabitation with a pregnant female. Additional work is needed to determine the mechanisms and functional significance, if any, of these changes in male body mass with reproductive condition.

Empowerment, engagement and perceived effectiveness in nursing work environments: does experience matter?

AIMS: We examined the impact of empowering work conditions on nurses' work engagement and effectiveness, and compared differences among these relationships in new graduates and experienced nurses. BACKGROUND: As many nurses near retirement, every effort is needed to retain nurses and to ensure that work environments are attractive to new nurses. Experience in the profession and generational differences may affect how important work factors interact to affect work behaviours. METHODS: We conducted a secondary analysis of survey data from two studies and compared the pattern of relationships among study variables in two groups: 185 nurses 2 years post-graduation and 294 nurses with more than 2 years of experience. RESULTS: A multi-group SEM analysis indicated a good fit of the hypothesized model. Work engagement significantly mediated the empowerment/effectiveness relationship in both groups, although the impact of engagement on work effectiveness was significantly stronger for experienced nurses. CONCLUSIONS: Engagement is an important mechanism by which empowerment affects nurses feelings of effectiveness but less important to new graduates' feelings of work effectiveness than empowerment. Implications for nursing management Managers must be aware of the role of empowerment in promoting work engagement and effectiveness and differential effects on new graduates and more seasoned nurses.

Workplace empowerment, work engagement and organizational commitment of new graduate nurses.

As a large cohort of experienced nurses approaches retirement, it is critical to examine factors that will promote the engagement and empowerment of the newer workforce, allowing them to provide high quality patient care. The authors used a predictive, non-experimental survey design to test a theoretical model in a sample of new graduate nurses. More specifically, the relationships among structural empowerment, six areas of work life (conceptualized as antecedents of work engagement), emotional exhaustion and organizational commitment were examined. As predicted, structural empowerment had a direct positive effect on the areas of work life, which in turn had a direct negative effect on emotional exhaustion. Subsequently, emotional exhaustion had a direct negative effect on commitment. Implications of these findings for nursing administrators are discussed.

Antecedents and consequences of nurse managers' perceptions of organizational support.

The antecedents and consequences of nurse managers' perceptions of organizational support were evaluated. Study results revealed that changeable work environment factors are important precursors of perceptions of organizational support, which, in turn, result in positive work attitudes and better health.