PGC-1α Deficiency Causes Multi-System Energy Metabolic Derangements: Muscle Dysfunction, Abnormal Weight Control and Hepatic Steatosis

The gene encoding the transcriptional coactivator peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) was targeted in mice. PGC-1α null (PGC-1α(−/−)) mice were viable. However, extensive phenotyping revealed multi-system abnormalities indicative of an abnormal energy metabolic phenotype. The postnatal growth of heart and slow-twitch skeletal muscle, organs with high mitochondrial energy demands, is blunted in PGC-1α(−/−) mice. With age, the PGC-1α(−/−) mice develop abnormally increased body fat, a phenotype that is more severe in females. Mitochondrial number and respiratory capacity is diminished in slow-twitch skeletal muscle of PGC-1α(−/−) mice, leading to reduced muscle performance and exercise capacity. PGC-1α(−/−) mice exhibit a modest diminution in cardiac function related largely to abnormal control of heart rate. The PGC-1α(−/−) mice were unable to maintain core body temperature following exposure to cold, consistent with an altered thermogenic response. Following short-term starvation, PGC-1α(−/−) mice develop hepatic steatosis due to a combination of reduced mitochondrial respiratory capacity and an increased expression of lipogenic genes. Surprisingly, PGC-1α(−/−) mice were less susceptible to diet-induced insulin resistance than wild-type controls. Lastly, vacuolar lesions were detected in the central nervous system of PGC-1α(−/−) mice. These results demonstrate that PGC-1α is necessary for appropriate adaptation to the metabolic and physiologic stressors of postnatal life

Biocatalytic Synthesis of Polymers of Precisely Defined Structures

The fabrication of functional nanoscale devices requires the construction of complex architectures at length scales characteristic of atoms and molecules. Currently microlithography and micro-machining of macroscopic objects are the preferred methods for construction of small devices, but these methods are limited to the micron scale. An intriguing approach to nanoscale fabrication involves the association of individual molecular components into the desired architectures by supramolecular assembly. This process requires the precise specification of intermolecular interactions, which in turn requires precise control of molecular structure

Mindfulness at Work: Positive Affect, Hope, and Optimism Mediate the Relationship Between Dispositional Mindfulness, Work Engagement, and Well-Being

Mindfulness has been described as a state of awareness characterized by refined attentional skills and a non-evaluative attitude toward internal and external events. Recently it has been suggested that higher levels of mindfulness may be beneficial in the workplace and first programs aiming to increase mindful awareness in occupational settings have been introduced. The current study underpins these developments with empirical evidence regarding the involved psychological processes, by investigating the relationship between dispositional mindfulness, work engagement and well-being in 299 adults in fulltime employment. As hypothesized, the results confirm that self-reported mindfulness predicts work engagement and general well-being. Furthermore, these relationships are mediated by positive job-related affect and psychological capital (hope, optimism, resiliency, and self-efficacy). Investigating mindfulness and psychological capital as multi-faceted concepts by means of structural equation modeling yielded a more precise picture. The ability to step back from automatic, habitual reactions to distress turned out to be the mindfulness facet most central for predicting work engagement and well-being. Furthermore, mindfulness exerts its positive effect on work engagement by increasing positive affect, hope, and optimism, which on their own and in combination enhance work engagement (full mediation). Well-being, on the other hand, is directly influenced by mindfulness, which exerts additional indirect influence via positive affect, hope and optimism (partial mediation). Although exploratory in nature, the results identify non-reactivity and non-judging as important mindfulness skills in the workplace