Dialoog Klimaat en de Stad A17 : tussenrapportage fase 1 en PvA fase 2

De gemiddelde temperaturen in stedelijke gebieden liggen hoger dan in de omringende landelijke gebieden tengevolge van het warmte eiland effect. Het project is gericht op implementatie van maatregelen in die sterk verstedelijkte regio’s in Nederland die naar verwachting door zullen groeien in de nabije toekoms

An overview of Cdk1-controlled targets and processes

The cyclin dependent kinase Cdk1 controls the cell cycle, which is best understood in the model organism S. cerevisiae. Research performed during the past decade has significantly improved our understanding of the molecular machinery of the cell cycle. Approximately 75 targets of Cdk1 have been identified that control critical cell cycle events, such as DNA replication and segregation, transcriptional programs and cell morphogenesis. In this review we discuss currently known targets of Cdk1 in the budding yeast S. cerevisiae and highlight the role of Cdk1 in several crucial processes including maintenance of genome stability

Science Should Be in the Public Domain

Variants of avian influenza H5N1 virus that are transmitted by the airborne route among ferrets have been identified. The National Science Advisory Board for Biosecurity has advised against publication of the details of the methods used to obtain these viruses and the amino acid changes that lead to transmission in ferrets. This decision is not based on sound scientific principles and risks setting a precedent that will make it easier to put in place highly restrictive regulations on scientific research and publication

Sorghum agronomy in West Kenya : investigations from a farming systems perspective

An adaptive sorghum research and extension programme (1979-82) in West Kenya is reviewed. The focus is on factors operating at farm level. Research results are based on 70 on-farm trials and on some long-term experiments on NPK fertilizer and pest incidence. Extension results are based on two programmes using different approaches. 200 farmers participated in the demonstration approach; in the village approach 100 farmers participated the first year, and 400 the second year.The impact of the rainfall pattern on local cropping systems is highlighted with respect to 'first rains' (March-June) and 'second rains' (August-November). Until recently, the short unreliable season of second rains played a minor role. However, current constraints on ox-ploughing result in delays in land preparation. This reduces the growing period for cereal crops during the first rains and increases the risk of failure for local late-maturing varieties. Cropping areas are increasingly restricted to what can be cultivated manually; more farmers are tempted to grow cereal crops during the second rains. As an assured food supply dominates farmer decisions, it was hypothesized that introduction of early- maturing sorghum varieties with a potential for ratooning would increase farmers management flexibility.Initial knowledge of effects of sorghum pests, leaf blight and Striga hermonthica proved insufficient. Crop moisture availability analyses commonly used in Kenya do not permit sufficient quantification of variability to understand farmer response to uncertainty. Three types of sorghum cropping seasons must be distinguished based on the variable start of the first rains. These types differ not only in length of growing period but also in shoot fly and midge incidence. Success of late planted crops varies with type of season. Farmers must play each season by ear; conditional recommendations on variety use and time of planting were developed accordingly. Some early-maturing cultivars were selected. However, their ratooning potential proved limited. Hence, attention shifted to planting these cultivars at the start of the second rains. As such plantings are seriously affected by shoot fly, more research on control by seed treatments and cultural methods is required.Crop yields and weed composition in farmer fields are related to land use pattern and soil fertility depletion. P is the most limiting nutrient. As N applications often results in negative effects, P/N ratios may play a role. Current socio-economic conditions restrict P applications to first-rain crops to 20 kg/ha P 2 O 5 . Higher levels may only be recommended if residual effects of P on second-rain crops are optimized through land preparation. Row planting with 3 plants/hill is advised as it facilitates placement of P and rapid handhoe weedings.The on-farm demonstration approach proved ineffective in stimulating farmer participation in the sorghum technology development process; it puts too much emphasis on selling preconceived messages. Also, the small isolated plots are threatened by birds. In contrast, the village approach proved effective. Its large, clustered plots generated much discussions among farmers and minimized the bird damage threat. Farmer opinions and crop-cut sampling results were used to fine-tune the recommendations for husbandry practices.The former compartmentalized research structure in Kenya was not conducive to adaptive research. Insufficient critical mass was available within the small commodity sections at regional level. However, recent interdisciplinary adaptive Regional Research Programmes allow better priority setting. The Farming Systems Approach to Research, Extension and Training is used, which could lead to more demand-driven research

The small GTPase Rap1 in cAMP signalling

Cyclic AMP was the first identified second messenger. A large number of studies have elucidated the fundamental role of cAMP in the wide range of cellular responses to many hormones and neurotransmitters. Cyclic AMP activates three different signal transduction pathways: the protein kinase A (PKA) pathway, the cyclic nucleotide-gated ion channel pathway, and the Epac signalling pathway. Epac is an exchange factor for the small GTPases Rap1 and Rap2. Rap GTPases are closely related to the small GTPase Ras, and when it was found that Rap1 could trap Raf1 in an inactive complex, and that overexpression of an activated Rap1 mutant could interfere with ERK signalling in fibroblasts, it was hypothesized that Rap1 antagonizes Ras by trapping Ras effectors in an inactive complex through its highly homologous effector domain. In contrast, Rap1 has also been suggested to activate Ras effectors and induce cellular transformation of Swiss 3T3 fibroblasts. More recently, Rap1 has been implicated in integrin-dependent cell adhesion and migration. In this study we developed a novel cAMP analogue, which specifically activates Epac but not PKA. Using this analogue, we subsequently show that endogenous Rap1 is unlikely to play a role in ERK signalling. Rather, Rap1 is likely to have a signalling function independent of Ras. Indeed, we show a function of the cAMP-Epac-Rap1 signaling pathway in regulation of integrin-mediated cell adhesion, and possibly also in regulation of p70 S6 kinas

Mammalian-Transmissible H5N1 Influenza: the Dilemma of Dual-Use Research

The National Science Advisory Board for Biosecurity (NSABB)’s recommendation to restrict publication of the details of the generation of mammalian-transmissible H5N1 influenza virus is unprecedented. Dual-use considerations indicated that the potential biosecurity risks of a transmissible H5N1 virus with a possible mortality of 50% in humans outweigh the substantial benefits of open and complete scientific exchange in this case, although the benefits include potential early detection strategies for H5N1 viruses with specific genetic markers and control strategies, including development of antivirals and vaccines. It is argued that both the funding agency (the National Institute of Allergy and Infectious Diseases) and the scientists were responding to societal needs and acted entirely responsibly. These studies usher in a new era for life sciences, compelling the research community to confront important decisions: under what conditions should such research be done? How can the principle of full release of information be balanced with the moral imperative to protect the public health

The Ripple Effect of Women’s Name Changes in Indexing, Citation, and Authority Control

This study investigated name changes of women authors to determine how they were represented in indexes and cited references, and identify problem areas. A secondary purpose of the study was to investigate whether or not indexing services were using authority control and how this influenced the search results. The works of eight library science authors who had published under multiple names were examined. The researchers compared author names as they appeared on title pages of publications versus in four online databases and in bibliographies, by checking 380 publications and 1159 citations. Author names were correctly provided 81.22% of the time in indexing services and 90.94% in citation lists. The lowest accuracy (54.55%) occurred when limiting to publications found in Library Literature. The highest accuracy (94.18%) occurred with works published before a surname changed. Author names in indexes and citations correctly matched names on journal articles more often than for any other type of publication. Indexes and citation style manuals treated author names in multiple ways, often altering names substantially from how they appear on the title page. Recommendations were made for changes in editorial styles, by indexing services and by the authors themselves to help alleviate future confusion in author name searching