A new role for thioredoxin in assimilatory sulphate reduction Activation of the adenylylsulphate kinase from the green alga Chlamydomonas reinhardii CW 15

AbstractThe activity of isolated APS-kinase (EC 2.7.1.25) from the green alga Chlamydomonas reinhardii CW15 was stimulated by catalytic amounts of spinach thioredoxin f. The stimulation amounted to a factor of 3 in the presence of excess reducing thiols. A regulatory function of thioredoxin f was deduced from two observations: (a) the enzyme supported a low basal rate of PAPS formation in the absence of its effector, and (b) the saturation of the enzyme activity by thioredoxin f was sigmoidal. No evidence has been obtained of thioredoxin f serving as in the reduction of PAPS to sulphite in this alga. The slight increase in sulphite formation as observed with enriched spinach thioredoxin m is assumed to be due to a residual APS-kinase contaminating the partially purified sulpho-nucleotide unspecific sulphotransferase

A maturity model for care pathways

Over the last recent decades, increasing the quality of healthcare services while reducing costs has been among the top concerns in the healthcare landscape. Several healthcare institutions have initiated improvement programs and invested considerably in process orientation and management. Care pathways are receiving increasing attention from clinicians, healthcare managers, and academics, as a way to standardize healthcare processes to improve the safety, quality, and efficiency of healthcare services. Despite considerable literature on the definition of care pathways, to date there is no agreement on their key process characteristics and the way they traverse from an immature to a mature state. Such a model would guide healthcare institutions to assess pathways’ level of maturity and generate a roadmap for improving towards higher levels. In this paper, we propose a maturity model for care pathways that is constructed taking a generic business process maturity model as a basis. The model was refined through a Delphi study with nine domain experts to address healthcare domain specific concerns. To evaluate its validity, we applied it in assessing the maturity of a particular care pathway taking place in 11 healthcare institutions. The results indicate the usefulness of the proposed model in assessing pathway’s maturity and its potential to provide guidance for its improvement

Concise gene signature for point‐of‐care classification of tuberculosis

There is an urgent need for new tools to combat the ongoing tuberculosis (TB) pandemic. Gene expression profiles based on blood signatures have proved useful in identifying genes that enable classification of TB patients, but have thus far been complex. Using real‐time PCR analysis, we evaluated the expression profiles from a large panel of genes in TB patients and healthy individuals in an Indian cohort. Classification models were built and validated for their capacity to discriminate samples from TB patients and controls within this cohort and on external independent gene expression datasets. A combination of only four genes distinguished TB patients from healthy individuals in both cross‐validations and on separate validation datasets with very high accuracy. An external validation on two distinct cohorts using a real‐time PCR setting confirmed the predictive power of this 4‐gene tool reaching sensitivity scores of 88% with a specificity of around 75%. Moreover, this gene signature demonstrated good classification power in HIV (+) populations and also between TB and several other pulmonary diseases. Here we present proof of concept that our 4‐gene signature and the top classifier genes from our models provide excellent candidates for the development of molecular point‐of‐care TB diagnosis in endemic areas

Open-answer questions vs. multiple-choice questions for undergraduate medical exams: a case study in topographical anatomy

Multiple choice questions (MCQ) have become the basis of state medical examinations in Germany since 1970. Single answer questions (SAQ) have become a convenient alternative for undergraduate testing in medicine. Our aim was to study the best use of both types of questions by comparison of examination results. In a retrospective study, examination results of 351 second year students of medicine were selected from written exams that contained both MCQ and SAQ, and evaluated by statistical analysis. Rank correlation coefficients according to Spearman and F-ratio were calculated from the paired data of rates of correct answers from MCQ and SAQ. The reliability of selected exam questions was estimated by comparing results from answers to comparable questions from consecutive years. The effect of learning was evaluated by comparing results from exams before the start of the class with results obtained during the course. Statistical evaluation revealed that the mean rate of correct answers was 0.84 (ratio right answers / total number) for SAQ, and significantly differed from the answer rate of 0.71 for MCQ. The difference was more pronounced in the subgroup of low performance students. The rate of correct answers of selected SAQ and MCQ were sufficiently reliable in consecutive examinations. There was a clear correlation between rate of successfully solved SAQ in entrance exams and in consecutive examination results. Parameters that were included in statistical calculation (Age, sex, language) as controls did not influence the difference between SAQ and MCQ. In conclusion, the results suggest that SAQ had the same level of discrimination when compared to MCQ, although their level of difficulty was lower than MCQ. They had a sufficient level of reliability, and were easier to modify for re-use in further examinations. Examinations that consist solely of MCQ are difficult to compose, and can hardly be re-used. The combination of SAQ and MCQ in exams helps to overcome this problem.Multiple-Choice (MC) Fragen sind seit 1970 die Grundlage der staatlichen Ärztlichen Prüfungen. In den vorklinischen Fächern werden neben MC-Fragen auch Aufgaben mit offenen Fragen (OF) zur Prüfung verwendet. Der statistische Vergleich beider Fragentypen in der praktischen Anwendung sollte ihre Eignung zur kursbegleitenden Prüfung, als Anreiz zur Steuerung des Lernverhaltens, prüfen. In einer retrospektiven Studie wurden die Prüfungsergebnisse von 351 Studierenden der Wintersemester 2003/04, 2004/05 und 2005/06 statistisch ausgewertet. Aus den gepaarten Daten der Prüfungsergebnisse von OF und MC-Fragen im gleichen Testatbogen wurden die Rang-Korrelationskoeffizienten nach Spearman und die F-Ratio berechnet. Zur Abschätzung der Reliabilität der beiden Fragenformate wurden die Raten korrekter Antworten auf einzelne, in zwei aufeinanderfolgenden Semestern eingesetzte, MC-Fragen und offene Fragen vergleichend untersucht. Als Maß für den Lernerfolg wurde die statistische Korrelation zwischen dem Ergebnis des Eingangstestats und späterer, im Verlaufe des Kurses abgelegter Testate ermittelt. Die statistische Untersuchung der gepaarten Daten ergab in allen untersuchten Semestern einen signifikanten Unterschied zwischen einem Anteil (Anzahl richtig beantworteter Fragen/Anzahl aller Testatfragen) von 0.84 richtig beantworteter OF und von 0.71 richtig beantworteter MC- Fragen. Studierende mit insgesamt schlechterem Abschneiden wiesen eine signifikant höhere Fehlerrate bei der Beantwortung von MC-Fragen im Vergleich zu OF auf. Studierende mit einem unterdurchschnittlichen Ergebnis im Eingangstestat schnitten auch in späteren Testaten signifikant schlechter ab. Andere Einflußgrößen, die als Kontrolle in die Berechnung einbezogen wurden (Alter, Geschlecht und Deutsch als Zweitsprache), beeinflußten das Ergebnis der Prüfung nicht. Offene Fragen mit einem niedrigen bis mittleren Schwierigkeitsgrad waren im Unterschied zu MC-Fragen geeignet, um Studierende mit befriedigendem Wissensniveau von Kursteilnehmern abzugrenzen, die die Kriterien zum Bestehen des Kurses nicht erfüllten. Im praktischen Einsatz erwiesen sich MC-Fragen wegen ihres größeren Aufwandes bei der Erstellung und ihrer eingeschränkten Wiederverwendbarkeit als problematischer als OF. Nach unseren Erfahrungen ist eine vom Kursabschnitt abhängige Kombination von OF und MC-Fragen empfehlenswert

Towards recommendations for metadata and data handling in plant phenotyping

Recent methodological developments in plant phenotyping, as well as the growing importance of its applications in plant science and breeding, are resulting in a fast accumulation of multidimensional data. There is great potential for expediting both discovery and application if these data are made publicly available for analysis. However, collection and storage of phenotypic observations is not yet sufficiently governed by standards that would ensure interoperability among data providers and precisely link specific phenotypes and associated genomic sequence information. This lack of standards is mainly a result of a large variability of phenotyping protocols, the multitude of phenotypic traits that are measured, and the dependence of these traits on the environment. This paper discusses the current situation of standardization in the area of phenomics, points out the problems and shortages, and presents the areas that would benefit from improvement in this field. In addition, the foundations of the work that could revise the situation are proposed, and practical solutions developed by the authors are introduced

Towards recommendations for metadata and data handling in plant phenotyping

Recent methodological developments in plant phenotyping, as well as the growing importance of its applications in plant science and breeding, are resulting in a fast accumulation of multidimensional data. There is great potential for expediting both discovery and application if these data are made publicly available for analysis. However, collection and storage of phenotypic observations is not yet sufficiently governed by standards that would ensure interoperability among data providers and precisely link specific phenotypes and associated genomic sequence information. This lack of standards is mainly a result of a large variability of phenotyping protocols, the multitude of phenotypic traits that are measured, and the dependence of these traits on the environment. This paper discusses the current situation of standardization in the area of phenomics, points out the problems and shortages, and presents the areas that would benefit from improvement in this field. In addition, the foundations of the work that could revise the situation are proposed, and practical solutions developed by the authors are introduced