Iterative Mechanism of Macrodiolide Formation in the Anticancer Compound Conglobatin.

Conglobatin is an unusual C2-symmetrical macrodiolide from the bacterium Streptomyces conglobatus with promising antitumor activity. Insights into the genes and enzymes that govern both the assembly-line production of the conglobatin polyketide and its dimerization are essential to allow rational alterations to be made to the conglobatin structure. We have used a rapid, direct in vitro cloning method to obtain the entire cluster on a 41-kbp fragment, encoding a modular polyketide synthase assembly line. The cloned cluster directs conglobatin biosynthesis in a heterologous host strain. Using a model substrate to mimic the conglobatin monomer, we also show that the conglobatin cyclase/thioesterase acts iteratively, ligating two monomers head-to-tail then re-binding the dimer product and cyclizing it. Incubation of two different monomers with the cyclase produces hybrid dimers and trimers, providing the first evidence that conglobatin analogs may in future become accessible through engineering of the polyketide synthase.We gratefully acknowledge BBSRC (project grant BB/J007250/1 to P.F.L.), the European Commission (Marie Curie Fellowship to Y.Z.), and the University of Cambridge (Herchel Smith Research Fellowship to A.C.M.), and Ms. Asha Boodhun (Department of Chemistry, University of Cambridge) for help in HR-MS analysis. L.C.D. acknowledges the support of Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP, Proc. 2012/04616-3 and 2012/02230-0). P.F.L. is an International Research Awardee of the Alexander von Humboldt Foundation.This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.chembiol.2015.05.01

Monitoring of microalgal cultivations with on-line, flow-through microscopy

Microalgal cultivations present challenges for monitoring and process control posed by their large scale and the likelihood that they will be composed of multiple species. Cell concentration is a fundamental parameter in any cultivation but is typically measured using off-line methods that may be time-consuming, laborious, or subject to interferences. Here, an in-situ microscope has been adapted for monitoring microalgal cultivations by adding a flow-through cell and adjusting image-processing algorithms. After installation in the bypass of a photobioreactor, the microscope enabled the continuous, automated acquisition of cell count, cell size, and cell morphology data on-line during cultivation processes over a period of 20. days, without sampling. The flow-through microscope was tested in cultivations of Chlamydomonas reinhardtii and Chlorella vulgaris. Cell concentration measurements were in agreement with off-line optical density measurements for both species. In addition, cell size and morphology distributions were obtained that revealed population shifts during the cultivation of C. vulgaris. This monitoring system thus provides a means to obtain detailed, non-invasive insights of microalgal cultivation processes.Jud and Pat Harper Professorship in Chemical and Biological EngineeringSustainable Bioenergy Development Center of Colorado State Universit

Evaluating Behavioral Health Service Need for Sexual and Gender Minorities: A Community-Based Qualitative Study

The LGBTQ community experiences mental health challenges, such as anxiety, depression, and substance use disorders, at rates higher than heterosexual and cisgender counterparts. Given these disparities in mental health, it is crucial that the LGBTQ population has access to mental health services. However, LGBTQ individuals face barriers to accessing mental health care due to service affordability, availability, and/or lack of LGBT-inclusivity. A Place to Nourish your Health (APNH), formerly known as AIDS Project New Haven, has historically provided care to those in New Haven who live with HIV and AIDS. APNH is now seeking to re-define itself as an organization by expanding services to support those experiencing stigma related to gender identity, sexual orientation, addiction, and mental health. Thus, to aid APNH in their service expansion to stigmatized populations, we performed a qualitative community needs assessment in the greater New Haven area to inform where APNH’s priorities should lie in their expansion of services. Findings provided insight into the current mental health landscape of New Haven’s LGBTQ community and led to reccomendatios regarding APNH\u27s expanion of behavoral health services.https://elischolar.library.yale.edu/ysph_pbchrr/1024/thumbnail.jp

CDK5 Is Essential for Soluble Amyloid β-Induced Degradation of GKAP and Remodeling of the Synaptic Actin Cytoskeleton

The early stages of Alzheimer's disease are marked by synaptic dysfunction and loss. This process results from the disassembly and degradation of synaptic components, in particular of scaffolding proteins that compose the post-synaptic density (PSD), namely PSD95, Homer and Shank. Here we investigated in rat frontal cortex dissociated culture the mechanisms involved in the downregulation of GKAP (SAPAP1), which links the PSD95 complex to the Shank complex and cytoskeletal structures within the PSD. We show that Aβ causes the rapid loss of GKAP from synapses through a pathway that critically requires cdk5 activity, and is set in motion by NMDAR activity and Ca2+ influx. We show that GKAP is a direct substrate of cdk5 and that its phosphorylation results in polyubiquitination and proteasomal degradation of GKAP and remodeling (collapse) of the synaptic actin cytoskeleton; the latter effect is abolished in neurons expressing GKAP mutants that are resistant to phosphorylation by cdk5. Given that cdk5 also regulates degradation of PSD95, these results underscore the central position of cdk5 in mediating Aβ-induced PSD disassembly and synapse loss

RARE-Bestpractices: a platform for sharing best practices for the management of rare diseases

From 7th European Conference on Rare Diseases and Orphan Products (ECRD 2014).Rare diseases; clinical practice guidelines; recommendations. RARE-Bestpractices (http://www.rarebestpractices.eu) is a 4-year project (2013-2016) funded by the EC FP7. The project aims at improving clinical management of patients with rare diseases (RD) and at narrowing the existing gap in quality of healthcare among countries. Methods: RARE-Bestpractices (http://www.rarebestpractices.eu) involves 9 EU countries, including 15 partners from academic institutions, governmental bodies, patient organizations and networks, which will exploit the added value of integrating different contributions and viewpoints. The platform is developed involving both experts in RD research as well as experts in clinical practice guidelines (CPG) and systematic reviews. Results: Project expected outputs include: 1) identification of challenges to be considered in deriving high quality standards for CPG on RD; 2) transparent procedures and criteria for the evaluation of CPG and their collection in a publicly searchable database; 3) identification of notation criteria to improve user understandability and implementation of CPG; 4) production of mechanisms to assess RD clinical research needs; 5) development of training activities targeted to key stakeholders to disseminate process and tools for developing and evaluating CPG; 6) the publication of a new scientific journal (http://rarejournal.org). Discussion: RARE-Bestpractices addresses the demands from both patients and health care providers for updated and high quality CPG on RD. The project will meet the requirements laid down by to the Directive 2011/24/EU, which endorses EU MS to develop European Reference Networks (ERNs) for RD; in fact, one main criterion for ERNs should be the competence to produce CPG and actively disseminate them among Centers of Expertise.N

Sidestream cigarette smoke effects on cardiovascular responses in conscious rats: involvement of oxidative stress in the fourth cerebral ventricle

Background: Cigarette exposure increases brain oxidative stress. The literature showed that increased brain oxidative stress affects cardiovascular regulation. However, no previous study investigated the involvement of brain oxidative stress in animals exposed to cigarette and its relationship with cardiovascular regulation. We aimed to evaluate the effects of central catalase inhibition on baroreflex and cardiovascular responses in rats exposed to sidestream cigarette smoke (SSCS). Methods: We evaluated males Wistar rats (320-370 g), which were implanted with a stainless steel guide cannula into the fourth cerebral ventricle (4th V). Femoral artery and vein were cannulated for mean arterial pressure (MAP) and heart rate (HR) measurement and drug infusion, respectively. Rats were exposed to SSCS during three weeks, 180 minutes, 5 days/week (CO: 100-300 ppm). Baroreflex was tested with a pressor dose of phenylephrine (PHE, 8 mu g/kg, bolus) to induce bradycardic reflex and a depressor dose of sodium nitroprusside (SNP, 50 mu g/kg, bolus) to induce tachycardic reflex. Cardiovascular responses were evaluated before, 5, 15, 30 and 60 minutes after 3-amino-1,2,4-triazole (ATZ, catalase inhibitor, 0.001 g/100 mu L) injection into the 4th V. Results: Central catalase inhibition increased basal HR in the control group during the first 5 minutes. SSCS exposure increased basal HR and attenuated bradycardic peak during the first 15 minutes. Conclusion: We suggest that SSCS exposure affects cardiovascular regulation through its influence on catalase activity.Foundation of Support to Research of Sao Paulo State (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo-FAPESP [07/59127-9

The French Didactic Tradition in Mathematics

This chapter presents the French didactic tradition. It first describes theemergence and development of this tradition according to four key features (role ofmathematics and mathematicians, role of theories, role of design of teaching andlearning environments, and role of empirical research), and illustrates it through two case studies respectively devoted to research carried out within this traditionon algebra and on line symmetry-reflection. It then questions the influence of thistradition through the contributions of four researchers from Germany, Italy, Mexicoand Tunisia, before ending with a short epilogue