Structural elucidation of the multidomain response regulator PleD using X-ray crystallography

c-diGMP (bis-(3!5)-cyclic di-guanosine monophosphate) is used extensively in bacteria to control biofilm formation and is lately postulated as a novel secondary messenger. Little is known about the signalling process, nor the control, of this dinucleotide. It is clear, however, that its synthesis is catalysed by the DGC (diguanylate cyclase) domain that contains a conserved GG(D/E)EF sequence motif. Despite its high abundance in bacteria, the structure was until now unknown. The PleD protein from Caulobacter crescentus contains a C-terminal DGC domain, preceded by the input domain D1 and the adaptor domain D2. PleD is a response regulator from the two-component signalling system. The output DGC response relies phosphorylation at the N-terminal D1 input domain. Therefore, the control of c-diGMP signal can be revealed in this multi-domain protein. The objectives of my PhD work are to (1) reveal the structure of DGC domain, (2) understand the catalytic mechanism of DGC, and (3) understand the regulation of the DGC response through the structure of PleD. The crystal structure of PleD has been solved in complex with c-diGMP to 2.7 °A. The fold of the DGC domain is similar to adenylate cyclase, but the proposed nucleotide binding mode is substantially different. The crystal packing has suggested that two DGC domains align in a two-fold symmetric way to catalyse c-diGMP synthesis. Hence, PleD is active as a dimer using D1 and D2 domains for dimerisation. The dimer formation is probably caused by phosphorylation at the D1 domain. In addition, the structure shows that two intercalated products bind at the D2-DGC domain interface. Such binding is thought to serve an allosteric purpose by immobilising DGC domain movements and prevent them from forming the active site. This thesis reports the crystal structure of PleD in complex with cdiGMP, and discusses the implications of the structure on DGC catalysis and on activation and inhibition regulation of DGC activity in PleD. In addition, the thesis describes the preparative investigations and characteri sation that have led to structure determination of PleD. These include the design and screening of PleD constructs, the establishment and optimisation of expression and purification, protein characterisation, crystallisation optimisation, and diffraction data collection

Harnessing Change to Create Sustainable Growth; The Visitacion/ Guadalupe Valley

A Regional Perspective is a report authored by Visitacion Valley Community Development Corporation and Asian Neighborhood Design as the first steps in efforts to create a regional planning perspective, collecting and analyzing data to assist in planning efforts towards sustainable growth, building relationships between regional stakeholders and decision-makers, and providing community outreach to inform and encourage community participation

The Utilization of Amisulpride as a Rescue Drug for Postop Patients Compared to Promethazine for the Treatment of Postoperative Nausea and Vomiting: An Educational Module

Abstract Background: Postoperative nausea and vomiting (PONV) persist as one of the most common adverse effects experienced by patients undergoing general anesthesia, as it can prolong a patient’s stay in the hospital, increase hospital costs, and lead to further complications delaying the recovery process.1,3,7 Despite prophylactic treatment with a combination of drugs, some patients still experience PONV. Despite its adverse side effects, Promethazine is still utilized as a rescue drug for PONV after failed prophylaxis. Objective: This quality improvement project aims to increase anesthesia providers’ knowledge of the current literature on Amisulpride\u27s efficacy and safety profile for treating PONV after failed prophylaxis compared to Promethazine. Methods: An in-depth analysis was conducted by using CINAHL, PubMed, Google Scholar, and the Cochrane Library database to obtain research studies discussing the use of Amisulpride and Promethazine as rescue treatments for failed PONV prophylaxis. CRNAs were invited to participate by completing an online pre-test survey, followed by viewing an online educational module, and a post-survey questionnaire to assess their acquired knowledge. Results: There was an increase in knowledge among anesthesia providers on using Amisulpride as a rescue treatment for failed prevention of PONV compared to Promethazine. Amisulpride has a safer profile and is less likely to cause any side effects, unlike Promethazine, which has the potential for multiple adverse effects. Discussion: Data collected from the surveys showed that anesthesia providers had increased their knowledge of the use, mechanism of action, and minimal potential for side effects of Amisulpride when used to treat PONV. A small sample size of 7 people and the online distribution were limitations for this project. Conclusion: Evidence-based research shows Amisulpride has a safer profile for treating PONV when prophylaxis fails compared to Promethazine. Results from this quality improvement project showed an increase in anesthesia providers’ knowledge regarding the benefits and adverse effects of both antiemetics. Introduction of Amisulpride to clinical practice can lead to improvements in patient outcomes by decreasing the occurrence of PONV and further complications. Keywords: Postoperative nausea and vomiting, prophylaxis, rescue, antiemetic, Amisulpride, Barhemsys, Promethazine, Phenerga

Transcutaneous Electrical Acupoint Stimulation to Decrease Opiate Utilization in Surgical Patients: An Evidence Based Education Module

ABSTRACT Impact Statement: Improve provider knowledge on the use of transcutaneous electrical acupoint stimulation (TEAS) as an adjunct to anesthesia to decrease levels of pain and opiate usage in patients. Background: A non-pharmaceutical method of analgesia can decrease the amount of opioid analgesia required during the perioperative period. TEAS is noninvasive, affords no risk of infection, and is inexpensive. Disposable electrodes are placed on acupoints on the body and stimulated with an electrical current. TEAS has been shown to decrease perioperative opioid use and pain in surgical patients. The purpose of this evidence-based project was to answer the following clinical question: (P) For surgical patients in the perioperative period (I) does an educational module on transcutaneous electrical acupoint stimulation (C) compared to no educational module (O) increase the anesthesia provider’s knowledge in decreasing perioperative analgesia, nausea, vomiting, post-operative recovery time, pain, and increase patient satisfaction? Methods: After receiving IRB exemption, anesthesia providers at Mt. Sinai Medical Center, Miami Beach, FL were invited to participate in the study. An evidence based educational narrated video PowerPoint module and a pre- and post-test were created and distributed via email to potential participants. Responses and demographic data was collected via Qualtrics software. Results: A total of seven certified registered nurse anesthetists (CRNA) participated in the study. Results from the pre- and post-tests show that there was an average of 25.7% increase in test scores after viewing the evidence based educational module. There was also an improvement in providers’ attitudes towards TEAS. Conclusion: An evidence based educational module discussing TEAS increases anesthesia providers’ knowledge in decreasing perioperative analgesia, nausea, vomiting, post-operative recovery time, pain, and increasing patient satisfaction through the use of TEAS

The meaning of care for older Chinese caregivers : an exploratory model of positive caring

Caring is often a highly personalized and individual activity. Through in-depth and searching interviews with two older care-givers, this study explored the determinants that help to sustain cares in their long-term care role and proposes an explanatory model for sustaining care. Attempts were made to uncover those meanings held by Chinese care-givers in interpreting their roles in a positive way despite the enormous demands placed on them by care-giving or, if they interpreted their care giving negatively, the attitudes that sustained their giving of care. Narrative accounts were obtained through separate interviews (conducted by two experienced social workers) asking open-ended questions guided by prescribed themes (determinants). Content coverage included basic demographic variables: sex, income, education level, religion, age; family responsibility/reciprocity, doing what needs to be done, caring personality, satisfaction and gratification, friendship and company, improved relationship, personal growth and identifying specific rewards of care-giving for self (i.e. the care-giver). The respondents were asked to describe all the above in relation to providing the care as they themselves perceive these domains, then were encouraged to provide a detail explanation for how these domains were encouraging/ discouraging them to continue to care. Similar description and explanation given by the two care-givers were extracted as congruent to the prescribed themes- hence these consistent findings serve to inform the formation of a crude explanatory model for care givers’ commitment to long term care. The study also informs practice in identifying and sustaining good care-givers

Tuning Rules for a Class of Passivity-Based Controllers for Mechanical Systems

In this paper, we propose several rules to tune the gains for a class of passivity-based controllers for nonlinear mechanical systems. Such tuning rules prescribe a desired local transient response behavior to the closed-loop system. To establish the tuning rules, we implement a PID passivity-based controller. Then, we linearize the closed-loop system, and we transform the matrix of the resulting system into a class of saddle point matrices to analyze the influence of the control gains, in terms of the oscillations and the rise time, on the transient response of the closed-loop system. Hence, the resulting controllers stabilize the plant and simultaneously address the performance of the closed-loop system. Moreover, our analysis provides a clear insight into how the kinetic energy, the potential energy, and the damping of the mechanical system are related to its transient response, endowing in this way the tuning rules with a physical interpretation. Additionally, we corroborate the analytical results through the practical implementation of a controller that stabilizes a two degrees-of-freedom (DoF) planar manipulator, where the control gains are tuned following the proposed rules.Comment: Final submission for journal: IEEE Control Systems Letter

Effects of Dietary Fatty Acid Ethyl Esters on Polar and Nonpolar Tissue Lipids in Red Drum, Sciaenops Ocellatus.

Red drum juveniles of mean initial weight 9.23 $\pm$ 0.27 g were kept in indoor aquaria. The water was maintained at a salinity of 12 $\pm$ 0.5 ppt. The fish were fed six isonitrogenous (38% crude protein) and isocaloric (1.36 $\times$ 10\sp4 kJ/kg), purified diets differing in lipid content, for nine weeks, to investigate the effects of selected dietary essential fatty acids (EFA) on growth performance and tissue fatty acid composition. Each diet, except the low-fat (LF) diet, contained 8% total lipid from (1) menhaden fish oil (MFO), (2) oleate (18:1n-9) supplemented with linoleate (18:2n-6), (3) linolenate (18:3n-3), (4) a mixture of linoleate and linolenate, or (5) docosahexaenoate (22:6n-3). All fatty acids were provided as ethyl esters (FAEE). Fish fed MFO had highest weight gain and feed efficiency. Weight gain and feed efficiency of fish fed the LF diet was intermediate to that of fish fed MFO and FAEEs. Fish fed FAEE diets had the lowest weight gain and feed efficiency. There was no significant difference in weight gain and feed efficiency among fish fed the FAEE diets. Tissue fatty acid composition generally reflected the fatty acid composition of dietary lipid. Levels of saturated fatty acids (SFAs) in tissues were independent of levels of SFA in the diet. However, fish fed LF and FAEE diets had a decreased level of total SFAs in tissue, while fish fed MFO did not. Levels of monoenoic fatty acids were significantly lower in fish fed MFO than in those fed LF and FAEE diets. N-6 PUFAs were depleted in fish fed diets that did not contain 18:2n-6. N-3 PUFAs increased in muscle lipid of fish fed diets containing 18:3n-3. N-3 highly unsaturated fatty acids (HUFAs) were conserved in the polar lipid fraction of tissues. Results suggest that the poor growth of fish fed FAEE diets was probably due to the poor palatability and unusual fatty acid composition of those diets. The red drum has very limited ability to chain-elongate and desaturate fatty acids, and presumably has EFA requirements for long-chain unsaturated fatty acids, such as eicosapentaenoic acid (EPA, 20:5n-3), docosahexaenoic acid (DHA, 22:6n-3) and arachidonic acid (20:4n-6), as do other marine species studied to date