Cloning and characterisation of chlorophyll synthase from Avena sativa

The chlorophyll synthase gene from oat (Avena sativa) was cloned and expressed in Escherichia coli. The deduced amino acid sequence consists of 378 amino acids including a presequence, of 46 amino acids. Deletion mutants show that a core protein comprising amino acid residues 88 to 377 is enzymatically active. The sequence of the mature protein shows 85% identity with the chlorophyll synthase of Arabidopsis thaliana and 62% identity with the chlorophyll synthase of Synechocystis PCC 6803. The gene is constitutively expressed as the same transcript level is found in dark-grown and in light-grown seedlings. The enzyme requires magnesium ions for activity; manganese ions can reconstitute only part of the activity. Diacetyl and N-phenylmaleimide (NPM) inhibit the enzyme activity. Site-directed mutagenesis reveals that, out of the 4 Arg residues present in the active core protein, Arg-91 and Arg-161 are essential for the activity. Five cysteine residues are present in the core protein, of which only Cys-109 is essential for the enzyme activity. Since the wild-type and all other Cys-mutants with the exception of the mutant C304A are inhibited by N-phenylmaleimide, we conclude that the inhibitor binds to a non-essential Cys residue to abolish activity. The role of the various Arg and Cys residues is discussed

Wandel der Erwerbsformen: Berlin und die Bundesrepublik im Vergleich

Seit den 80er Jahren zeichnet sich die Erwerbstätigenstruktur in der Bundesrepublik Deutschland durch eine zunehmende Vielfalt aus. Das traditionelle Normalarbeitsverhältnis hat gegenüber anderen Erwerbsformen wie Teilzeitbeschäftigung, befristete Beschäftigung oder Leiharbeit an Bedeutung verloren, bleibt aber nach wie vor die mit Abstand häufigste Erwerbsform. In Berlin sind dagegen seit Anfang der 90er Jahre stärkere Veränderungen zu verzeichnen, insbesondere ein absoluter Rückgang der Normalarbeitsverhältnisse. Mittlerweile liegt hier der Anteil des Normalarbeitsverhältnisses an allen Erwerbsformen deutlich unter dem bundesdeutschen Durchschnitt. Gleichzeitig haben in Berlin aber auch atypische Beschäftigungsformen, wie geringfügige Beschäftigung und Leiharbeit, in kurzer Zeit kräftig zugenommen. Hier stellt sich die Frage, ob die Berliner Entwicklung zukunftsweisend ist, oder ob es sich um einen historisch bedingten Anpassungsprozeß handelt, der sich bald dem bundesweiten Trend angleichen wird. -- The structure of employment in the Federal Republic of Germany has been diversifying increasingly since the 1980s. The traditional regular employment relationship has lost ground to other employment forms such as part-time, fixed-term or agency work, though it is still by far the most common type of employment relationship. In Berlin, however, more substantial changes are evident since the early 1990s; in particular, there has been an absolute decline in the share of regular employment relationships. As a share of all forms of employment in Berlin, regular employment relationships are now well below the national average. However, at the same time atypical employment forms, such as marginal part-time work and agency work, have expanded significantly over a short period of time. Do the developments in Berlin represent the future structure of employment, or are we looking at an historically determined adjustment process that will soon conform to the national trend?

Biochemische Untersuchungen an der Chlorophyll Synthase aus Avena sativa

Die Chlorophyll Synthase ist ein äußerst hydrophobes Transmembranprotein und sitzt in der Thylakoidmembran im Chloroplasten. Sie verestert Chlorophyllid und Phytylpyrophosphat zu Chlorophyll. In dieser Arbeit sind Untersuchungen zur Lage der Transmembranbereiche, zum aktiven Zentrum bzw. zu essentiellen Aminosäuren und zum Reaktionsmechanismus dargestellt

Wandel der Erwerbsformen: Berlin und die Bundesrepublik im Vergleich

"Das traditionelle Normalarbeitsverhältnis hat seit den achtziger Jahren gegenüber anderen Erwerbsformen (Teilzeitbeschäftigung, befristete Beschäftigung, Leiharbeit) an Bedeutung verloren. In Berlin liegt mittlerweile der Anteil der Normalarbeitsverhältnisse an allen Erwerbsformen deutlich unter dem bundesdeutschen Durchschnitt. Einflußfaktoren wie wirtschaftlicher Strukturwandel, steigende Erwerbsbeteiligung der Frauen und institutionelle Rahmenbedingungen erklären den Wandel der Erwerbsformen nur zum Teil. Theoretische Basis der Analyse ist ein Modell, das - basierend auf den Arbeiten von Herbert A. Simon - zwischen Kauf- und Arbeitsverträgen unterscheidet. Welche Vertragsform gewählt wird, hängt einerseits vom Interesse an Einkommenssicherheit, Wettbewerbsbeschränkung und Qualifikationsentwicklung ab und andererseits vom Interesse an frei verfügbarer Arbeitskraft, zuverlässiger Leistung und (auf dem Markt nicht käuflichen) Erfahrungswissen. Infolge veränderter Kontextbedingungen kann - so die Annahme - auf beiden Seiten das Interesse an regulären Arbeitsverträgen zugunsten von Kaufverträgen oder von Mischformen nachlassen. Die Diskussion läßt erkennen, daß 'Arbeitnehmer' und 'Arbeitgeber' auch künftig ein starkes Interesse an dauerhaften Arbeitsverträgen habendiese werden jedoch zunehmend Elemente von Kaufverträgen (Zielvereinbarungen, Gewinn- und Kostenbeteiligung) aufweisen. Der Wandel der Erwerbsformen in der Bundesrepublik Deutschland und in Berlin wird auf Basis des Mikrozensus von 1985 bis 1998 verglichen. Im Unterschied zu bisherigen Studien wird auch die Entwicklung der Erwerbsbeteiligung in die Analyse miteinbezogen. Zudem erfolgt eine geschlechtsspezifische Differenzierung." (Autorenreferat)"The structure of employment in the Federal Republic of Germany has been diversifying increasingly since the 1980s. The traditional 'regular employment relationship' has lost ground to other employment forms such as part-time, fixed-term or agency work, though it is still by far the most common type of employment relationship. In Berlin, however, more substantial changes are evident since the early 1990sin particular, there has been an absolute decline in the share of regular employment relationships. As a share of all forms of employment in Berlin, regular employment relationships are now well below the national average. However, at the same time atypical employment forms, such as marginal part-time work and agency work, have expanded significantly over a short period of time. Do the developments in Berlin represent the future structure of employment, or are we looking at an historically determined adjustment process that will soon conform to the national trend? Possible determinants such as economic restructuring, the growth in female labour force participation or the institutional framework can only partly explain the change in employment forms. The development of employment forms in the foreseeable future is another interesting question: Will the regular employment relationship remain the dominant type, or can a further erosion in favour of other forms of employment be expected? A theoretical model based on the work of Herbert A. Simon and differentiating between sales contracts and employment contracts provides some answers. Each of these contractual forms has typical advantages and disadvantages. The choice between them depends, on the one hand, on the interest in income security, restraints on competition and development of professional skills and, on the other hand, on the interest in freely available work capacities, reliability of performance and experience knowledge which is usually not for sale on the market. Changing context conditions, it is assumed, can lead to a loss of interest on both sides in regular employment contracts in favour of sales contracts or in combinations that contain elements of both contractual forms. This would explain the increase in flexible employment relationships. However, the discussion of the model shows also that 'employees' and 'employers' will continue to have a considerable interest in permanent employment contracts in the future, but that these will increasingly incorporate elements of sales contracts (such as agreements on goal attainment and shares in profits and costs). The change in employment forms in Germany and Berlin is compared on the basis of microcensus data from 1985 to 1998. Unlike previous studies, the analysis includes not only the trends for types of employment as a share of all employment forms, but also labour force participation trends. In addition, the analysis specifies for gender throughout. Women work less often than men in a regular employment relationship. However, in Germany as a whole the activity rate of women in regular employment relationships rose, while it declined for men, and in Berlin women were less affected by the decline in regular employment relationships than men." (author's abstract

Erioflorin stabilizes the tumor suppressor Pdcd4 by inhibiting its interaction with the E3-ligase β-TrCP1

Loss of the tumor suppressor Pdcd4 was reported for various tumor entities and proposed as a prognostic marker in tumorigenesis. We previously characterized decreased Pdcd4 protein stability in response to mitogenic stimuli, which resulted from p70S6K1-dependent protein phosphorylation, β-TrCP1-mediated ubiquitination, and proteasomal destruction. Following high-throughput screening of natural product extract libraries using a luciferase-based reporter assay to monitor phosphorylation-dependent proteasomal degradation of the tumor suppressor Pdcd4, we succeeded in showing that a crude extract from Eriophyllum lanatum stabilized Pdcd4 from TPA-induced degradation. Erioflorin was identified as the active component and inhibited not only degradation of the Pdcd4-luciferase-based reporter but also of endogenous Pdcd4 at low micromolar concentrations. Mechanistically, erioflorin interfered with the interaction between the E3-ubiquitin ligase β-TrCP1 and Pdcd4 in cell culture and in in vitro binding assays, consequently decreasing ubiquitination and degradation of Pdcd4. Interestingly, while erioflorin stabilized additional β-TrCP-targets (such as IκBα and β-catenin), it did not prevent the degradation of targets of other E3-ubiquitin ligases such as p21 (a Skp2-target) and HIF-1α (a pVHL-target), implying selectivity for β-TrCP. Moreover, erioflorin inhibited the tumor-associated activity of known Pdcd4- and IκBα-regulated αtranscription factors, that is, AP-1 and NF-κB, altered cell cycle progression and suppressed proliferation of various cancer cell lines. Our studies succeeded in identifying erioflorin as a novel Pdcd4 stabilizer that inhibits the interaction of Pdcd4 with the E3-ubiquitin ligase β-TrCP1. Inhibition of E3-ligase/target-protein interactions may offer the possibility to target degradation of specific proteins only as compared to general proteasome inhibition

Validation of the newly developed Advanced Practice Nurse Task Questionnaire: A national survey

AIM: To describe psychometric validation of the newly developed Advanced Practice Nurse Task Questionnaire. DESIGN: Cross-sectional quantitative study. METHODS: The development of the questionnaire followed an adapted version of the seven steps described in the guide by the Association for Medical Education in Europe. A nationwide online survey tested the construct and structural validity and internal consistency using an exploratory factor analysis, Cronbach's alpha coefficient and a Kruskal-Wallis test to compare the hypotheses. RESULTS: We received 222 questionnaires between January and September 2020. The factor analysis produced a seven-factor solution as suggested in Hamric's model. However, not all item loadings aligned with the framework's competencies. Cronbach's alpha of factors ranged between .795 and .879. The analysis confirmed the construct validity of the Advanced Practice Nurse Task Questionnaire. The tool was able to discriminate the competencies of guidance and coaching, direct clinical practice and leadership across the three advanced practice nurse roles clinical nurse specialist, nurse practitioner or blended role. CONCLUSION: A precise assessment of advanced practice nurse tasks is crucial in clinical practice and in research as it may be a basis for further refinement, implementation and evaluation of roles. IMPACT: The Advanced Practice Nurse Task Questionnaire is the first valid tool to assess tasks according to Hamric's model of competencies independently of the role or the setting. Additionally, it distinguishes the most common advanced practice nurse roles according to the degree of tasks in direct clinical practice and leadership. The tool may be applied in various countries, independent of the degree of implementation and understanding of advanced nursing practice. REPORTING METHOD: The STARD 2015 guideline was used to report the study. PATIENT OR PUBLIC CONTRIBUTION: No patient or public contribution

Validation of the newly developed Advanced Practice Nurse Task Questionnaire: A national survey.

AIM To describe psychometric validation of the newly developed Advanced Practice Nurse Task Questionnaire. DESIGN Cross-sectional quantitative study. METHODS The development of the questionnaire followed an adapted version of the seven steps described in the guide by the Association for Medical Education in Europe. A nationwide online survey tested the construct and structural validity and internal consistency using an exploratory factor analysis, Cronbach's alpha coefficient and a Kruskal-Wallis test to compare the hypotheses. RESULTS We received 222 questionnaires between January and September 2020. The factor analysis produced a seven-factor solution as suggested in Hamric's model. However, not all item loadings aligned with the framework's competencies. Cronbach's alpha of factors ranged between .795 and .879. The analysis confirmed the construct validity of the Advanced Practice Nurse Task Questionnaire. The tool was able to discriminate the competencies of guidance and coaching, direct clinical practice and leadership across the three advanced practice nurse roles clinical nurse specialist, nurse practitioner or blended role. CONCLUSION A precise assessment of advanced practice nurse tasks is crucial in clinical practice and in research as it may be a basis for further refinement, implementation and evaluation of roles. IMPACT The Advanced Practice Nurse Task Questionnaire is the first valid tool to assess tasks according to Hamric's model of competencies independently of the role or the setting. Additionally, it distinguishes the most common advanced practice nurse roles according to the degree of tasks in direct clinical practice and leadership. The tool may be applied in various countries, independent of the degree of implementation and understanding of advanced nursing practice. REPORTING METHOD The STARD 2015 guideline was used to report the study. PATIENT OR PUBLIC CONTRIBUTION No patient or public contribution

The presence of air sac nematodes in passerines and near-passerines in southern Germany

Major climatic changes in conjunction with animal movement may be associated with the spread of parasites and their vectors into new populations, with potentially important consequences for population persistence. Parasites can evolve to adapt to unsuitable ecological conditions and take up refuge within new host species, with consequences for the population growth of the new host species. One parasite species that has likely been increasing its geographic range, and potentially infecting new hosts, is the recently described air sac nematode Serratospiculoides amaculata, in great tits (Parus major) in Slovakia. In this study, we screened wild birds for potential air sac nematode infection in a woodland area of southern Germany. We identified four additional host species: Eurasian nuthatch, great spotted woodpecker, greenfinch and robin. As infection by this group of nematodes can be highly pathogenic, we recommend further investigation into its potential risk to these populations

First Testing of Literature-Based Models for Predicting Increase in Body Weight and Adipose Tissue Mass After Kidney Transplantation

Introduction: Weight gain is a risk factor for poor clinical outcomes following kidney transplantation. Research Question: This study's aim was a first testing of 2 models to identify patients early after kidney transplantation who are at risk for weight gain and increase in adipose tissue mass in the first year after kidney transplantation. Design: The literature-based models were evaluated on longitudinal data of 88, respectively 79 kidney transplant recipients via ordinary and Firth regression, using gains ≥ 5% in weight and adipose tissue mass respectively as primary and secondary endpoints. Results: The models included physical activity, smoking cessation at time of kidney transplantation, self-reported health status, depressive symptomatology, gender, age, education, baseline body mass index and baseline trunk fat as predictors. Area under the curve was 0.797 (95%-CI 0.702 to 0.893) for the weight model and 0.767 (95%-CI 0.656 to 0.878) for the adipose tissue mass model-showing good, respectively fair discriminative ability. For weight gain ≥ 5%, main risk factors were smoking cessation at time of transplantation (OR 16.425, 95%-CI 1.737-155.288) and better self-reported baseline health state (OR 1.068 for each 1-unit increase, 95%-CI 1.012-1.128). For the adipose tissue mass gain ≥ 5%, main risk factor was overweight/obesity (BMI ≥ 25) at baseline (odds ratio 7.659, 95%-CI 1.789-32.789). Conclusions: The models have potential to assess patients' risk for weight or adipose tissue mass gain during the year after transplantation, but further testing is needed before implementation in clinical practice. Keywords: addictive; behavior; cardiovascular disease; clinical outcomes; depression; exercise outcomes; nutrition; performance improvement; quality; quality of life; quantitative methods; regression; research