Inventarisatie lokstoffen : huidige en toekomstige trends in beheersing van plaaginsecten met signaalstoffen in combinatie met insecticiden t.b.v. de vollegrondsgroenteteelt

De effectiviteit van gewasbeschermingsmiddelen is sterk afhankelijk van de mate waarin het middel in contact komt met het insect (de raakkans). Insecten hebben de mogelijkheid om zich te verstoppen. Met lokstoffen zouden insecten uit hun verstopplek kunnen komen waarna ze beter geraakt kunnen worden. Internationaal zijn voorbeelden bekend waarbij lokmiddelen met bestrijdingsmiddel toegepast worden, o.a. tegen rupsen en als bait of als gel. Lokken/verstoren en daarna spuiten is een strategie die voor zover bekend nog weinig wordt toegepast. Wel zijn er veel lokstoffen van insecten op de markt. Onbekend is nu welke toepassingen er al zijn, in ontwikkeling zijn, of kansrijk ontwikkeld kunnen worden in de vollegrondsgroenteteelt. In dit verslag resultaten van onderzoek waarin een overzicht van de huidige stand van zaken en potentiële mogelijkheden van het gebruik van lokstoffen om insecten uit het gewas te lokken (om vervolgens gericht te bestrijden met een insecticide). Daarbij worden de volgende vragen beantwoord: o Welke lokstoffen zijn in gebruik (insecten – gewas)? o Welke lokstoffen zijn in ontwikkeling? o Hoe worden ze toegepast? o Wat is het effect / meerwaarde van de lokstof? o Wat zijn de voor% en nadelen van het gebruik van lokstoffen

Paringsverstoring: een innovatieve oplossing voor rupsenproblemen in de Nederlandse kassen : eindraportage

In de periode 2008-2012 is een paringsverstoringsmethode tegen Turkse mot Chrysodeixis chalcites getest. Er is gekozen voor Turkse mot omdat dit insect snel veel schade kan aanbrengen in de tomaten- en paprikateelt. Ook is in het verleden door PRI in samenwerking met TNO aangetoond dat paringsverstoring tegen Turkse mot voldoende werkt. De destijds gebruikte feromoonverdamper bleek echter onpraktisch en is in dit onderzoek vervangen door een alternatieve verdamper. De in dit onderzoek ontwikkelde verdamper is op 5 locaties getest in een dichtheid van 500 dispensers per hectare. In feromoonvallen in de behandelde percelen werd geen Turkse mot meer gevangen in tegenstelling tot de niet met feromoon behandelde percelen. Echter in het gewas werden nog steeds rupsjes en dus schade gevonden. De gevonden schade wisselde van bedrijf tot bedrijf. De uiteindelijke conclusie is dat deze methode nog onvoldoende robuust is voor commerciële implementati

Duurzame aanpak van plagen in de handel : duurzame bestrijding van plaaginsecten en plant parasitaire nematoden in de keten van internationale handel in plantmaterialen

Quarantaine organismen leveren cruciale problemen op in de internationale handel. Ondanks strikte maatregelen en controle worden insecten- en nematodenplagen regelmatig door toenemende internationale handel overgebracht naar niet besmette gebieden. Quarantaine plagen veroorzaken grote economische verliezen en leiden tot handelsbelemmeringen. Sommige kleine insecten zoals trips en witte vliegen of nematoden zijn moeilijk te bestrijden met pesticiden. Fumigatie met ontsmettingsmiddelen was een veel toegepaste methode om quarantaine plagen te bestrijden middels een pre-shipment behandeling. Een van de meest effectieve ontsmettingsmiddelen methylbromide (MeBr) is sinds 2010 niet meer toegelaten in Nederlands vanwege het chadelijke effect op de ozonlaag. Een effectief en milieuvriendelijk alternatief voor MeBr is zeer gewenst. Controlled atmosphere temperature treatment (CATT) is een fysieke behandelingsmethode en heeft een aantoonbaar dodelijk effect op diverse insecten- en nematodenplagen. De CATT methode is een combinatie van lucht en temperatuur over een bepaalde tijdsduur om plagen maximaal af te doden met een minimaal of acceptabel fytotoxisch effect op plantproducten. Dit is een milieuvriendelijke methode en heeft daardoor geen toelating nodig voor toepassing

Vascular architecture and hypoxic profiles in human head and neck squamous cell carcinomas

Tumour oxygenation and vasculature are determinants for radiation treatment outcome and prognosis in patients with squamous cell carcinomas of the head and neck. In this study we visualized and quantified these factors which may provide a predictive tool for new treatments. Twenty-one patients with stage III–IV squamous cell carcinomas of the head and neck were intravenously injected with pimonidazole, a bioreductive hypoxic marker. Tumour biopsies were taken 2 h later. Frozen tissue sections were stained for vessels and hypoxia by fluorescent immunohistochemistry. Twenty-two sections of biopsies of different head and neck sites were scanned and analysed with a computerized image analysis system. The hypoxic fractions varied from 0.02 to 0.29 and were independent from T- and N-classification, localization and differentiation grade. No significant correlation between hypoxic fraction and vascular density was observed. As a first attempt to categorize tumours based on their hypoxic profile, three different hypoxia patterns are described. The first category comprised tumours with large hypoxic, but viable, areas at distances even greater than 200 μm from the vessels. The second category showed a typical band-like distribution of hypoxia at an intermediate distance (50–200 μm) from the vessels with necrosis at greater distances. The third category demonstrated hypoxia already within 50 μm from the vessels, suggestive for acute hypoxia. This method of multiparameter analysis proved to be clinically feasible. The information on architectural patterns and the differences that exist between tumours can improve our understanding of the tumour micro-environment and may in the future be of assistance with the selection of (oxygenation modifying) treatment strategies. © 2000 Cancer Research Campaig

The late radiotherapy normal tissue injury phenotypes of telangiectasia, fibrosis and atrophy in breast cancer patients have distinct genotype-dependent causes

The relationship between late normal tissue radiation injury phenotypes in 167 breast cancer patients treated with radiotherapy and: (i) radiotherapy dose (boost); (ii) an early acute radiation reaction and (iii) genetic background was examined. Patients were genotyped at single nucleotide polymorphisms (SNPs) in eight candidate genes. An early acute reaction to radiation and/or the inheritance of the transforming growth factor-β1 (TGFβ1 −509T) SNP contributed to the risk of fibrosis. In contrast, an additional 15 Gy electron boost and/or the inheritance of X-ray repair cross-complementing 1 (XRCC1) (R399Q) SNP contributed to the risk of telangiectasia. Although fibrosis, telangiectasia and atrophy, all contribute to late radiation injury, the data suggest that they have distinct underlying genetic and radiobiological causes. Fibrosis risk is associated with an inflammatory response (an acute reaction and/or TGFβ1), whereas telangiectasia is associated with vascular endothelial cell damage (boost and/or XRCC1). Atrophy is associated with an acute response, but the genetic predisposing factors that determine the risk of an acute response or atrophy have yet to be identified. A combined analysis of two UK breast cancer patient studies shows that 8% of patients are homozygous (TT) for the TGFβ1 (C-509T) variant allele and have a 15-fold increased risk of fibrosis following radiotherapy (95% confidence interval: 3.76–60.3; P=0.000003) compared with (CC) homozygotes

Preventing crime in cooperation with the mental health care profession

Although major mental disorders do not have a central position in many criminological theories, there seems to be an evident relationship between these disorders and criminal behavior. In daily practice police officers and mental health care workers work jointly to prevent nuisance and crime and to keep the city livable. Examining the situations where the criminal justice system and mental health institutes are jointly involved to prevent crime, some pitfalls emerge that seem to threaten successful cooperation. There appear to be unrealistic expectations of the possibility to reduce the risk of reoffending by means of treatment and of the possibility to predict which offender poses a risk to society. Another complexity is the fact that both parties work from different backgrounds and pursue different goals. The way society and the criminal justice system deal with persons who are assumed to be a risk to the community because of a mental disorder demands a further investigation from a criminological perspective

The fitness of dispersing spotted hyaena sons is influenced by maternal social status

Life history theory predicts that mothers should provide their offspring with a privileged upbringing if this enhances their offspring's and their own fitness. In many mammals, high-ranking mothers provide their offspring with a privileged upbringing. Whether dispersing sons gain fitness benefits during adulthood from such privileges (a 'silver spoon' effect) has rarely been examined. In this paper, we show that in the complex, female-dominated society of spotted hyaenas, high-born sons grew at higher rates, were more likely to disperse to clans offering the best fitness prospects, started reproducing earlier and had a higher reproductive value than did lower-born sons. This illustrates the evolutionary importance of maternal effects even in societies in which male size or fighting ability does not influence fitness. By demonstrating for the first time in a non-human mammal that maternal status influences immigration patterns, the study also advances our understanding of two key ecological and evolutionary processes, dispersal and habitat selection

Getting a Head Start: Diet, Sub-Adult Growth, and Associative Learning in a Seed-Eating Passerine

Developmental stress, and individual variation in response to it, can have important fitness consequences. Here we investigated the consequences of variable dietary protein on the duration of growth and associative learning abilities of zebra finches, Taeniopygia guttata, which are obligate graminivores. The high-protein conditions that zebra finches would experience in nature when half-ripe seed is available were mimicked by the use of egg protein to supplement mature seed, which is low in protein content. Growth rates and relative body proportions of males reared either on a low-protein diet (mature seed only) or a high-protein diet (seed plus egg) were determined from body size traits (mass, head width, and tarsus) measured at three developmental stages. Birds reared on the high-protein diet were larger in all size traits at all ages, but growth rates of size traits showed no treatment effects. Relative head size of birds reared on the two diets differed from age day 95 onward, with high-diet birds having larger heads in proportion to both tarsus length and body mass. High-diet birds mastered an associative learning task in fewer bouts than those reared on the low-protein diet. In both diet treatments, amount of sub-adult head growth varied directly, and sub-adult mass change varied inversely, with performance on the learning task. Results indicate that small differences in head growth during the sub-adult period can be associated with substantial differences in adult cognitive performance. Contrary to a previous report, we found no evidence for growth compensation among birds on the low-protein diet. These results have implications for the study of vertebrate cognition, developmental stress, and growth compensation