Attentional Avoidance of Historically Relevant, Task-Irrelevant Facial Affect: Past Depression, Interpersonal Characteristics, and Ethnicity.

Experiential background can influence how individuals respond to affective interpersonal information. For formerly depressed individuals, sad facial expressions are presumably salient. If so, when performing affectively neutral daily tasks, these individuals would find peripheral sad faces particularly distracting, and thus, they might shift their attention from them. The present study examined this hypothesis by comparing how euthymic formerly depressed and never depressed adults attended to sad and happy task-irrelevant emotional facial expression stimuli. The study also measured constructs linked to interpersonal functioning and depression and conducted exploratory analyses to examine whether Hispanic ethnicity status would moderate effects of study outcomes. Results of analyses indicated that formerly depressed individuals directed more attention away from sad faces than never depressed individuals. There were no significant between-group effects for happy faces and no moderation by ethnicity on attention to affective faces. However, irrespective of depression history, Hispanic individuals reported lower fear of negative evaluation compared to non-Hispanic Caucasian individuals. Findings are in line with hypothesized attentional avoidance among formerly depressed individuals and consistent with prior research suggesting that some Hispanic individuals experience protective mental health benefits through engagement with aspects of their culture. Directions for future research are discussed.

Fork pausing allows centromere DNA loop formation and kinetochore assembly.

De novo kinetochore assembly, but not template-directed assembly, is dependent on COMA, the kinetochore complex engaged in cohesin recruitment. The slowing of replication fork progression by treatment with phleomycin (PHL), hydroxyurea, or deletion of the replication fork protection protein Csm3 can activate de novo kinetochore assembly in COMA mutants. Centromere DNA looping at the site of de novo kinetochore assembly can be detected shortly after exposure to PHL. Using simulations to explore the thermodynamics of DNA loops, we propose that loop formation is disfavored during bidirectional replication fork migration. One function of replication fork stalling upon encounters with DNA damage or other blockades may be to allow time for thermal fluctuations of the DNA chain to explore numerous configurations. Biasing thermodynamics provides a mechanism to facilitate macromolecular assembly, DNA repair, and other nucleic acid transactions at the replication fork. These loop configurations are essential for sister centromere separation and kinetochore assembly in the absence of the COMA complex.

Stu2 uses a 15-nm parallel coiled coil for kinetochore localization and concomitant regulation of the mitotic spindle.

XMAP215/Dis1 family proteins are potent microtubule polymerases, critical for mitotic spindle structure and dynamics. While microtubule polymerase activity is driven by an N-terminal tumor overexpressed gene (TOG) domain array, proper cellular localization is a requisite for full activity and is mediated by a C-terminal domain. Structural insight into the C-terminal domain's architecture and localization mechanism remain outstanding. We present the crystal structure of the Saccharomyces cerevisiae Stu2 C-terminal domain, revealing a 15-nm parallel homodimeric coiled coil. The parallel architecture of the coiled coil has mechanistic implications for the arrangement of the homodimer's N-terminal TOG domains during microtubule polymerization. The coiled coil has two spatially distinct conserved regions: CRI and CRII. Mutations in CRI and CRII perturb the distribution and localization of Stu2 along the mitotic spindle and yield defects in spindle morphology including increased frequencies of mispositioned and fragmented spindles. Collectively, these data highlight roles for the Stu2 dimerization domain as a scaffold for factor binding that optimally positions Stu2 on the mitotic spindle to promote proper spindle structure and dynamics.

Microtubule dynamics drive enhanced chromatin motion and mobilize telomeres in response to DNA damage.

Chromatin exhibits increased mobility on DNA damage, but the biophysical basis for this behavior remains unknown. To explore the mechanisms that drive DNA damage-induced chromosome mobility, we use single-particle tracking of tagged chromosomal loci during interphase in live yeast cells together with polymer models of chromatin chains. Telomeres become mobilized from sites on the nuclear envelope and the pericentromere expands after exposure to DNA-damaging agents. The magnitude of chromatin mobility induced by a single double-strand break requires active microtubule function. These findings reveal how relaxation of external tethers to the nuclear envelope and internal chromatin-chromatin tethers, together with microtubule dynamics, can mobilize the genome in response to DNA damage.

A cohort study of the morbidity of combined anterior-posterior cervical spinal fusions: incidence and predictors of postoperative dysphagia.

PURPOSE: To identify risk factors that may lead to the development of dysphagia after combined anterior and posterior (360°) cervical fusion surgery. METHODS: A single center, retrospective analysis of patients who had same-day, 360° fusion at Henry Ford Hospital between 2008 and 2012 was performed. Variables analyzed included demographics, medical co-morbidities, levels fused, and degree of dysphagia. RESULTS: The overall dysphagia rate was 37.7 %. Patients with dysphagia had a longer mean length of stay (p < 0.001), longer mean operative time (p < 0.001), greater intraoperative blood loss (p = 0.002), and fusion above the fourth cervical vertebra, C4, (p = 0.007). There were no differences in the rates of dysphagia when comparing patients undergoing primary or revision surgery (p = 0.554). CONCLUSION: Prolonged surgery and fusion above C4 lead to higher rates of dysphagia after 360° fusions. Prior anterior cervical fusion does not increase the risk of dysphagia development.