Aanwezigheid van ascosporen van Sclerotinia sclerotiorum binnen en buiten besmette percelen

De aantasting van een gewas door Sclerotinia sclerotiorum hangt af van de aanwezigheid van ascosporen van deze schimmel in de lucht. In dit onderzoek dat gefinancierd wordt door PT en PA werd nagegaan in hoeverre de ascosporen van het eigen perceel afkomstig zijn of ook van een naburig perceel kunnen aanwaaien. In het eerste jaar van het onderzoek zijn aanwijzingen verkregen dat ascosporen in grote mate in de lucht aanwezig kunnen zijn zonder dat er duidelijk paddenstoelen in de omgeving aanwezig waren. Dat er niveauverschillen tussen percelen optreden wijst erop dat er per perceel toch meer of minder paddenstoelen aanwezig zijn. Afhankelijk van de situatie lijken er veel ascosporen van buiten het perceel te kunnen komen

Effects of Oestrogens and FSH on LH Stimulation of Steroid Production by Testis Leydig Cells from Immature Rats

Hypophysectomy of immature male rats results after 5 days in a decreased production of testosterone by isolated testis Leydig cells in response to LH. The LH responsiveness of the Leydig cells can be partly restored by treatment of the hypophysectomized rats with FSH. In continuation of previous reports on this subject (Steroids 28 (1976) 847; and 30 (1978) the following conclusions were derived from the results in the present paper: 1. After hypophysectomy of immature male rats the production of testosterone (T) as well as of 5‐pregnenolone (Δ5P) by isolated Leydig cells in response to LH is reduced. 2. Daily administration of FSH after hypophysectomy restores the Δ5P production in response to LH almost completely, but has a much smaller effect on the restoration of T production. 3. Administration of oestradiol benzoate (E2B) together with FSH has no effect on the restoration of LH‐stimulated Δ5P production, but causes a reduction of T production, when compared with Leydig cells from animals treated with FSH only. 4. Treatment of intact immature rats with E2B results in a decreased production of T and an increased production of Δ5P in isolated Leydig cells. 5. From experiments with labelled pregnenolone it appears that E2B and diethylstilboestrol (DES) inhibit the 17α‐hydroxylase activity of Leydig cells from intact as well as from hypophysectomized rats. This results in a reduced conversion of pregnenolone to C1:)‐steroids and in increased production of 3α‐hydroxy‐5α‐pregnan‐20‐one from δ5P. 6. The observed effects of FSH and E, were similar within a dose range of 100–10000 ng LH per 106 Leydig cells. Copyrigh

Onderzoek Sclerotinia in 2012 : Sclerotiën, sporen, BOS en spuittechniek

De problemen met Sclerotinia (rattenkeutelziekte), veroorzaakt door de schimmel Sclerotinia sclerotiorum, nemen de laatste jaren steeds meer toe. In diverse vollegrondsgroenten is Sclerotinia een van de belangrijkste ziekten. Om te komen tot een integrale aanpak van de problematiek is er door de Productschappen Tuinbouw en Akkerbouw voor 2012 gekozen voor een gezamenlijke financiering van een aantal onderzoeksthema's die ondergebracht zijn bij de onderzoeksinstellingen DLV Plant, PPO-AGV en Proeftuin Zwaagdijk. Deze thema’s waren: speuren naar sporen; aantal sclerotiën; beslissingsondersteunende systemen (BOS); spuittechniek

Collective effects of stellar winds and unidentified gamma-ray sources

We study collective wind configurations produced by a number of massive stars, and obtain densities and expansion velocities of the stellar wind gas that is to be target, in this model, of hadronic interactions. We study the expected $\gamma$-ray emission from these regions, considering in an approximate way the effect of cosmic ray modulation. We compute secondary particle production (electrons from knock-on interactions and electrons and positrons from charged pion decay), and solve the loss equation with ionization, synchrotron, bremsstrahlung, inverse Compton, and expansion losses. We provide examples where configurations can produce sources for GLAST satellite, and the MAGIC, HESS, or VERITAS telescopes in non-uniform ways, i.e., with or without the corresponding counterparts. We show that in all cases we studied no EGRET source is expected

The course of health-related quality of life in the first 2 years after a diagnosis of head and neck cancer:the role of personal, clinical, psychological, physical, social, lifestyle, disease-related, and biological factors

Purpose: The aim of this prospective cohort study was to estimate the relationship between the course of HRQOL in the first 2 years after diagnosis and treatment of head and neck cancer (HNC) and personal, clinical, psychological, physical, social, lifestyle, HNC-related, and biological factors. Methods: Data were used from 638 HNC patients of the NETherlands QUality of life and BIomedical Cohort study (NET-QUBIC). Linear mixed models were used to investigate factors associated with the course of HRQOL (EORTC QLQ-C30 global quality of life (QL) and summary score (SumSc)) from baseline to 3, 6, 12, and 24 months after treatment. Results: Baseline depressive symptoms, social contacts, and oral pain were significantly associated with the course of QL from baseline to 24 months. Tumor subsite and baseline social eating, stress (hyperarousal), coughing, feeling ill, and IL-10 were associated with the course of SumSc. Post-treatment social contacts and stress (avoidance) were significantly associated with the course of QL from 6 to 24 months, and social contacts and weight loss with the course of SumSc. The course of SumSc from 6 to 24 months was also significantly associated with a change in financial problems, speech problems, weight loss, and shoulder problems between baseline and 6 months. Conclusion: Baseline clinical, psychological, social, lifestyle, HNC-related, and biological factors are associated with the course of HRQOL from baseline to 24 months after treatment. Post-treatment social, lifestyle, and HNC-related factors are associated with the course of HRQOL from 6 to 24 months after treatment.</p

Physical Processes in Star Formation

© 2020 Springer-Verlag. The final publication is available at Springer via https://doi.org/10.1007/s11214-020-00693-8.Star formation is a complex multi-scale phenomenon that is of significant importance for astrophysics in general. Stars and star formation are key pillars in observational astronomy from local star forming regions in the Milky Way up to high-redshift galaxies. From a theoretical perspective, star formation and feedback processes (radiation, winds, and supernovae) play a pivotal role in advancing our understanding of the physical processes at work, both individually and of their interactions. In this review we will give an overview of the main processes that are important for the understanding of star formation. We start with an observationally motivated view on star formation from a global perspective and outline the general paradigm of the life-cycle of molecular clouds, in which star formation is the key process to close the cycle. After that we focus on the thermal and chemical aspects in star forming regions, discuss turbulence and magnetic fields as well as gravitational forces. Finally, we review the most important stellar feedback mechanisms.Peer reviewedFinal Accepted Versio

Speuren naar sporen van Sclerotinia sclerotiorum in de lucht

In 2011 hebben Productschap Akkerbouw en Productschap Tuinbouw onderzoek gefinancierd om te achterhalen of de sporendruk van Sclerotinia op een perceel afkomstig is van het eigen perceel of van naburige percelen. Dit is van belang om te achterhalen of teeltmaatregelen die gericht zijn op het tegengaan van sporenvorming op het eigen perceel perspectief kunnen hebben. In het eerste jaar van het onderzoek zijn er aanwijzingen verkregen dat ascosporen in grote mate in de lucht op gewashoogte aanwezig kunnen zijn zonder dat er duidelijk paddenstoelen in de omgeving aanwezig zijn. Afhankelijk van de situatie lijken er veel ascosporen van buiten het perceel te kunnen komen. Daarentegen zijn er ook situaties gevonden, waarbij de hoeveelheid ascosporen gekoppeld leek te zijn aan een bepaald perceel, ook al konden er geen paddenstoelen worden gevonden. Eerder hadden deze er wel gestaan

Umweltbildung und Umweltberatung fuer Betriebsraete in mittleren und kleinen Handelsunternehmen. Machbarkeitsstudie Abschlussbericht

SIGLEAvailable from TIB Hannover: F02B956 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDeutsche Bundesstiftung Umwelt, Osnabrueck (Germany)DEGerman