Recombinant yeast as a functional tool for understanding bitterness and cucurbitacin biosynthesis in watermelon (Citrullus spp.)

Cucurbitacins are a group of bitter‐tasting oxygenated tetracyclic triterpenes that are produced in the family Cucurbitaceae and other plant families. The natural roles of cucurbitacins in plants are probably related to defence against pathogens and pests. Cucurbitadienol, a triterpene synthesized from oxidosqualene, is the first committed precursor to cucurbitacins produced by a specialized oxidosqualene cyclase termed cucurbitadienol synthase. We explored cucurbitacin accumulation in watermelon in relation to bitterness. Our findings show that cucurbitacins are accumulated in bitter‐tasting watermelon, Citrullus lanatus var. citroides, as well as in their wild ancestor, C. colocynthis, but not in non‐bitter commercial cultivars of sweet watermelon (C. lanatus var. lanatus). Molecular analysis of genes expressed in the roots of several watermelon accessions led to the isolation of three sequences (CcCDS1, CcCDS2 and ClCDS1), all displaying high similarity to the pumpkin CpCPQ, encoding a protein previously shown to possess cucurbitadienol synthase activity. We utilized the Saccharomyces cerevisiae strain BY4743, heterozygous for lanosterol synthase, to probe for possible encoded cucurbitadienol synthase activity of the expressed watermelon sequences. Functional expression of the two sequences isolated from C. colocynthis (CcCDS1 and CcCDS2) in yeast revealed that only CcCDS2 possessed cucurbitadienol synthase activity, while CcCDS1 did not display cucurbitadienol synthase activity in recombinant yeast. ClCDS1 isolated from C. lanatus var. lanatus is almost identical to CcCDS1. Our results imply that CcCDS2 plays a role in imparting bitterness to watermelon. Yeast has been an excellent diagnostic tool to determine the first committed step of cucurbitacin biosynthesis in watermelon. Copyright © 2014 John Wiley & Sons, Ltd.     

Formation of microstructure and the superplasticity of Al–Mg-based alloys

The influence of a 3–10% content of magnesium in Al–Mg–Mn(Cr) alloys on the characteristics of the microstructure of sheet blanks and their superplasticity has been examined. It has been shown that the minimum size of grains and the best superplasticity are characteristic of the alloy that contains about 7% magnesium and is additionally alloyed simultaneously with manganese and chromium. An increase in the content of magnesium leads to the formation of conglomerates of particles of a chromium–manganese phase and, as a result, to a coarsening of the grain structure and a deterioration of superplasticity.     

Censored depth quantiles

Quantile regression is a wide spread regression technique which allows to model the entire conditional distribution of the response variable. A natural extension to the case of censored observations has been introduced using a reweighting scheme based on the Kaplan-Meier estimator. The same ideas can be applied to depth quantiles. This leads to regression quantiles for censored data which are robust to both outliers in the predictor and the response variable. For their computation, a fast algorithm over a grid of quantile values is proposed. The robustness of the method is shown in a simulation study and on two real data examples.     

Experimental manipulation of continuous speech in schizophrenic patients.

A method was developed for obtaining extended continuous speech samples from hospitalized schizophrenics. 1 group was reinforced for self-referred affect statements, 1 group for speech in general, and 1 group served as a no-reinforcement control. The effect of reinforcement proved specific to the response class reinforced, whether narrow (self-referred affect statements) or more general (total speech output). The conditioning process progresses from broad classes to the particular one on which reinforcement is contingent. The problem of respons-class identification and other implications of the findings are discussed. (36 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The competency movement within psychology: An historical perspective.

The authors provide a recitation of events in recent years that document an increased focus on competency-based models of education, training, and assessment in professional psychology, particularly clinical, counseling, and school psychology, based on the work of the American Psychological Association's (APA's) Task Force on Assessment of Competence in Professional Psychology. The article begins with the inclusion of competencies as part of the "Ethical Principles of Psychologists and Code of Conduct" (APA, 2002). Next, accreditation practices in the United States and Canada are summarized. Competency-based education, training, and credentialing efforts in professional psychology are reviewed, including graduate, practicum, internship, and postdoctoral levels; licensure; postlicensure certifications; and board certification. General and specialty credentialing efforts both in North America and internationally follow. The Competencies Conference: Education and Credentialing in Professional Psychology and work on developing competencies for the profession are discussed. Then initiatives focused specifically on the assessment of competence are delineated. Implications for continued progress toward a culture of the assessment of competence are discussed in light of the historical origins within the profession of the competency-based movement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Challenges to the assessment of competence and competencies.

Challenges to the assessment of competence and competencies in professional psychology are discussed in this article. These include difficulties in defining competencies in precise and measurable terms; reaching agreement within the profession about the key elements of each competence domain; establishing an armamentarium of tools for assessing all components of competence, including the knowledge base, skills, and attitudes (and their integration); determining appropriate agreed-upon minimal levels of competence for individuals at different levels of professional development and when "competence problems" exist for individuals; assuring the fidelity of competency assessments; and establishing mechanisms for providing effective evaluative feedback and remediation. But even if these challenges can be met, perhaps the single biggest obstacle would be convincing those who are skeptical of the value of the culture shift toward the implementation of comprehensive competence assessments across the professional life span. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

CA-125 and carcinoembryonic antigen assay vs. cytodiagnostic experience in the classification of benign ovarian cysts

OBJECTIVE: To compare the relative strengths of two factors involved in making an accurate differentiation between functional and epithelial ovarian cysts, along with their combination: (1) the cytologist's level of experience in interpreting ovarian cytology, (2) the use of the tumor markers carcinoembryonic antigen (CEA) and CA-125 in cyst fluid, and (3) a combination of (1) and (2). STUDY DESIGN: Papanicolaou-stained sediments from fluid aspirated from 31 resected ovarian cysts (6 functional and 25 epithelial) were blindly and independently evaluated by five pathologists with varying experience in ovarian cytology. Cyst fluid supernatant was used for CEA, enzyme-linked immunosorbent assay, and CA-125 radioimmunoassay; CEA levels > 5 ng/mL or CA-125 > 5,000 U/mL were considered elevated. Cysts were categorized cytologically and histologically as functional or epithelial and by tumor markers as "neither elevated" or "either or both elevated" (EBE). RESULTS: The agreement of histologic diagnosis with each pathologist's cytologic diagnosis ranged from 53% to 84% (53%, 71%, 83%, 82%, 84%), corresponding to increasing level of experience. The percentage of agreement with EBE was 77%, whereas combined experienced pathologist's diagnosis and EBE was 87%. Kappa equaled .45 for experienced cytopathologist's diagnosis or EBE alone. Kappa equaled .53 when the pathologist or EBE diagnosed an epithelial cyst, indicating results unlikely to occur by chance. CONCLUSION: The distinction of functional from epithelial ovarian cysts is best achieved by combining measurement of the tumor markers CEA and CA-125 with a high level of cytopathology experience.