Critical Conversations: Basic Skills Students at the Table

“I am 44 years old and enrolled in the ABE class at Bellingham Technical College. The ABE class is very important to me right now in my life, while I am drawing unemployment. I dropped out when I was 16 and got married and had my first baby. So there is a lot of stuff I have forgotten. And with the help of the ABE class, I feel like I can do the stuff I thought I couldn\u27t. The ABE class made me have more confidence and self-esteem about myself, with the help of everyone in class.

On the Importance of Frictional Energy Dissipation in the Prevention of Undesirable Self-Excited Vibrations in Gas Foil Bearing Rotor Systems

In this contribution, a nonlinear and fully coupled fluid–structure–rotor interaction model of a gas foil bearing rotor system is presented. Aiming at the reduction of undesirable self-excited vibrations, many common bearing designs feature a compliant and slightly movable multi-part foil structure inside the lubrication gap. The present paper discusses the general impact of frictional energy dissipation within the foil structure by adding equivalent viscous damping to the widespread simple elastic foundation model. For the computational analysis, the PDEs describing the fluid pressure distribution and the foil structure deformation field are spatially discretized using finite difference schemes. After suitable nondimensionalization of the resulting system of nonlinear ODEs, a corresponding state-space representation is deduced. Using numerical simulation tools, the stability of equilibrium points and the occurrence of self-excited vibrations are addressed and possible bifurcation scenarios are discussed. Summing up all results, frictional energy dissipation proves to be of crucial importance with regard to the reduction or prevention of undesirable self-excited vibrations in gas foil bearing rotor systems

Photosystem II core phosphorylation and photosynthetic acclimation require two different protein kinases

Illumination changes elicit modifications of thylakoid proteins and reorganization of the photosynthetic machinery. This involves, in the short term, phosphorylation of photosystem II (PSII) and light-harvesting (LHCII) proteins. PSII phosphorylation is thought to be relevant for PSII turnover1,2, whereas LHCII phosphorylation is associated with the relocation of LHCII and the redistribution of excitation energy (state transitions) between photosystems3,4. In the long term, imbalances in energy distribution between photosystems are counteracted by adjusting photosystem stoichiometry5,6. In the green alga Chlamydomonas and the plant Arabidopsis, state transitions require the orthologous protein kinases STT7 and STN7, respectively7,8. Here we show that in Arabidopsis a second protein kinase, STN8, is required for the quantitative phosphorylation of PSII core proteins. However, PSII activity under high-intensity light is affected only slightly in stn8 mutants, and D1 turnover is indistinguishable from the wild type, implying that reversible protein phosphorylation is not essential for PSII repair. Acclimation to changes in light quality is defective in stn7 but not in stn8 mutants, indicating that short-term and long-term photosynthetic adaptations are coupled. Therefore the phosphorylation of LHCII, or of an unknown substrate of STN7, is also crucial for the control of photosynthetic gene expressio

Dynamics of reversible protein phosphorylation in thylakoids of flowering plants: the roles of STN7, STN8 and TAP38

Phosphorylation is the most common post-translational modification found in thylakoid membrane proteins of flowering plants, targeting more than two dozen subunits of all multiprotein complexes, including some light-harvesting proteins. Recent progress in mass spectrometry-based technologies has led to the detection of novel low-abundance thylakoid phosphoproteins and localised their phosphorylation sites. Three of the enzymes involved in phosphorylation/dephosphorylation cycles in thylakoids, the protein kinases STN7 and STN8 and the phosphatase TAP38/PPH1, have been characterised in the model species Arabidopsis thaliana. Differential protein phosphorylation is associated with changes in illumination and various other environmental parameters, and has been implicated in several acclimation responses, the molecular mechanisms of which are only partly understood. The phenomenon of State Transitions, which enables rapid adaptation to short-term changes in illumination, has recently been shown to depend on reversible phosphorylation of LHCII by STN7-TAP38/PPH1. STN7 is also necessary for long-term acclimation responses that counteract imbalances in energy distribution between PSII and PSI by changing the rates of accumulation of their reaction-centre and light-harvesting proteins. Another aspect of photosynthetic acclimation, the modulation of thylakoid ultrastructure, depends on phosphorylation of PSII core proteins, mainly executed by STN8. Here we review recent advances in the characterisation of STN7, STN8 and TAP38/ PPH1, and discuss their physiological significance within the overall network of thylakoid protein phosphorylation

Gun1 controls accumulation of the plastid ribosomal protein S1 at the protein level and interacts with proteins involved in plastid protein homeostasis

Developmental or metabolic changes in chloroplasts can have profound effects on the rest of the plant cell. Such intracellular responses are associated with signals that originate in chloroplasts and convey information on their physiological status to the nucleus, which leads to large-scale changes in gene expression (retrograde signaling). A screen designed to identify components of retrograde signaling resulted in the discovery of the so-called genomes uncoupled (gun) mutants. Genetic evidence suggests that the chloroplast protein GUN1 integrates signals derived from perturbations in plastid redox state, plastid gene expression, and tetrapyrrole biosynthesis (TPB) in Arabidopsis (Arabidopsis thaliana) seedlings, exerting biogenic control of chloroplast functions. However, the molecular mechanism by which GUN1 integrates retrograde signaling in the chloroplast is unclear. Here we show that GUN1 also operates in adult plants, contributing to operational control of chloroplasts. The gun1 mutation genetically interacts with mutations of genes for the chloroplast ribosomal proteins S1 (PRPS1) and L11. Analysis of gun1 prps1 lines indicates that GUN1 controls PRPS1 accumulation at the protein level. The GUN1 protein physically interacts with proteins involved in chloroplast protein homeostasis based on coimmunoprecipitation experiments. Furthermore, yeast two-hybrid and bimolecular fluorescence complementation experiments suggest that GUN1 might transiently interact with several TPB enzymes, including Mg-chelatase subunit D (CHLD) and two other TPB enzymes known to activate retrograde signaling. Moreover, the association of PRPS1 and CHLD with protein complexes is modulated by GUN1. These findings allow us to speculate that retrograde signaling might involve GUN1-dependent formation of protein complexes

Women’s pelvic floor muscle strength and urinary and anal incontinence after childbirth: a cross-sectional study

Abstract OBJECTIVE To analyse pelvic floor muscle strength (PFMS) and urinary and anal incontinence (UI and AI) in the postpartum period. METHOD Cross-sectional study carried out with women in their first seven months after child birth. Data were collected through interviews, perineometry (Peritron™), and the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF). RESULTS 128 women participated in the study. The PFMS mean was 33.1 (SD=16.0) cmH2O and the prevalence of UI and AI was 7.8% and 5.5%, respectively. In the multiple analyses, the variables associated with PFMS were type of birth and cohabitation with a partner. Newborn’s weight, previous pregnancy, UI during pregnancy, and sexual activity showed an association with UI after child birth. Only AI prior to pregnancy was associated with AI after childbirth. CONCLUSION Vaginal birth predisposes to the reduction of PFMS, and caesarean section had a protective effect to its reduction. The occurrence of UI during pregnancy is a predictor of UI after childbirth, and women with previous pregnancies and newborns with higher weights are more likely to have UI after childbirth.AI prior to pregnancy is the only risk factor for its occurrence after childbirth. Associations between PFMS and cohabitation with a partner, and between UI and sexual activity do not make possible to conclude that these variables are directly associated

Complementary and Integrative Health Practices in a Brazilian Freestanding Birth Center: A Cross-Sectional Study

The study aimed to analyze the use of complementary and integrative health practices (CIHPs) during labor and birth in a freestanding birth center. A total of 28 different CIHPs were applied with or used by laboring women. The most adopted CIHPs were mind-body practices (99.9%) and natural products (35.5%), mostly used by primiparous women (P <.05). Adopting CIHPs can increase care quality, increase positive experiences during childbirth, and promote evidence-based choices