Characterization of the Roco Protein Family in Dictyostelium discoideum

The Roco family consists of multidomain Ras-GTPases that include LRRK2, a protein mutated in familial Parkinson's disease. The genome of the cellular slime mold Dictyostelium discoideum encodes 11 Roco proteins. To study the functions of these proteins, we systematically knocked out the roco genes. Previously described functions for GbpC, Pats1, and QkgA (Roco1 to Roco3) were confirmed, while novel developmental defects were identified in roco4- and roco11-null cells. Cells lacking Roco11 form larger fruiting bodies than wild-type cells, while roco4-null cells show strong developmental defects during the transition from mound to fruiting body; prestalk cells produce reduced levels of cellulose, leading to unstable stalks that are unable to properly lift the spore head. Detailed phylogenetic analysis of four slime mold species reveals that QkgA and Roco11 evolved relatively late by duplication of an ancestor roco4 gene (later than ∼300 million years ago), contrary to the situation with other roco genes, which were already present before the split of the common ancestor of D. discoideum and Polysphondylium pallidum (before ∼600 million years ago). Together, our data show that the Dictyostelium Roco proteins serve a surprisingly diverse set of functions and highlight Roco4 as a key protein for proper stalk cell formation

What is or what ought to be? Hoe het idee van ‘vermogen tot lijden’ van Viktor Frankl toegepast kan worden in de behandeling voor mensen met een depressieve stoornis

Viktor Frankl onderscheidt zich door ‘lijden’ een bron van zin te noemen. Hij ontwikkelde de logotherapie waarin de wil-tot-betekenis centraal staat: het streven van de mens naar betekenis en zin in zijn of haar leven. Lijden kan volgens hem zingevend zijn door het vinden van betekenis in dit lijden. In dit onderzoek is gekeken naar de toepassing van dit ‘vermogen tot lijden’ in de behandeling van mensen met een depressie. Tien interviews zijn afgenomen, waarvan vijf met ervaringsdeskundigen en vijf met behandelaars in de GGZ. De zin in het lijden zelf blijkt beperkt aanwezig te zijn ten tijde van een klinische depressie. Wel kan er een sterk zingevende houding ten opzichte van het lijden worden aangenomen. Daarnaast kunnen werk, kennisvergaring en verbondenheid als zingevingsbron ervaren worden ten tijde van het lijden. Ook kan er achteraf, na enig herstel, zin aan het lijden zelf toegekend worden. Vermogen tot lijden lijkt nog steeds actueel te zijn in de huidige behandeling al heeft het een ander fundament. Zingeving wordt meer als een opportunistische aangelegenheid gezien. De wil-tot-betekenis heeft daarmee een eigentijdse invulling gekregen die minder omvat dan het oorspronkelijke idee. Concluderend wordt gesteld dat het vermogen tot lijden in de huidige behandeling van mensen met een depressieve stoornis hernieuwde aandacht zou moeten krijgen

ACTIVITIES AND SPACE USE FOR ENABLING LOCAL ECONOMY IN COASTAL LOW INCOME HOUSING

Many low income households are supported by Home Based Enterprises (HBE) for their income generation. However the settlements in coastal areas have physical problems related to the corrosive land and climate condition, as well as the possi-bilities of natural hazards such as flooding (ADB, 2003 : UNHABITAT 2003). The rapid growths of cities especially in developing countries (DCs) contribute to social problems, serious burdens for human health and the environment. In order to imp-rove the quality of human life in the coastal cities, some local government decided to remove some settlements to the inland area such as problems in some big coastal cities in Indonesia. In many cases, many resettlements of housing failed to meet community’s and user’s requirements. To reduce and avoid sustainability problems, it is necessary to have more insight and understanding of the used of space in coastal low income housing. This paper describes the use of communal spaces for daily activities which are indicating the lack of space available in coastal settlements in order to accomodate user’s needs

ACTIVITIES AND SPACE USE FOR ENABLING LOCAL ECONOMY IN COASTAL LOW INCOME HOUSING

Many low income households are supported by Home Based Enterprises (HBE) for their income generation. However the settlements in coastal areas have physical problems related to the corrosive land and climate condition, as well as the possi-bilities of natural hazards such as flooding (ADB, 2003 : UNHABITAT 2003). The rapid growths of cities especially in developing countries (DCs) contribute to social problems, serious burdens for human health and the environment. In order to imp-rove the quality of human life in the coastal cities, some local government decided to remove some settlements to the inland area such as problems in some big coastal cities in Indonesia. In many cases, many resettlements of housing failed to meet community’s and user’s requirements. To reduce and avoid sustainability problems, it is necessary to have more insight and understanding of the used of space in coastal low income housing. This paper describes the use of communal spaces for daily activities which are indicating the lack of space available in coastal settlements in order to accomodate user’s needs

Construction and Demolition Waste Characteristics in Tanzania

The construction industry generates a lot of construction and demolition (C&D) waste which puts some challenges to its management. For example, currently, in many towns in Tanzania, there are no landfill sites for solid waste disposal; and as a consequence open air dumping sites are used. Dumping C&D waste puts pressure for acquisition of large portions of land in order to accommodate the disposal of the growing waste generated from construction and demolition sites. Others include imposed economic burdens, social discomfort as well as sources of environmental pollution like air and water pollutants. Due to population growth and land limitation for waste disposal, the current practices will put extra pressure on C&D waste management in future as well. This paper aims to investigate the quantity and quality of C&D waste in Tanzania and the possibilities for reusing and recycling this waste in the production of building materials. The use of C&D waste for building material production can be a best option not only for waste management but also for providing alternative building material for present and future generations. Materials used in this study were cementitious rubble recovered from eight building construction and demolition sites in Dar es Salaam. Two samples from natural sources were used for comparison purposes. Secondary data from Dar es Salaam City Council was used to estimate the amount of C&D waste generated in Tanzania annually. Furthermore, the recovered C&D waste samples were crushed to get recycled aggregates that were used in laboratory analysis. The results showed that the C&D waste generation in Tanzania increased from 3.03 million tonnes to 7.9 million tonnes in the period ranging from 1994 to 2010 years. Furthermore, the results showed that the recycled aggregates were weaker than natural aggregates, however, mineralogically were not significantly different from natural aggregates. Thus, their chemical composition similarities suggest that recycled C&D waste is suitable for production of building materials in Tanzania. The recycling of C&D waste into building material will contribute to sustainable social, economic, and environmental improvements

Vertical variation of mixing within porous sediment beds below turbulent flows

River ecosystems are influenced by contaminants in the water column, in the pore water and adsorbed to sediment particles. When exchange across the sediment-water interface (hyporheic exchange) is included in modelling, the mixing coefficient is often assumed to be constant with depth below the interface. Novel fibre-optic fluorometers have been developed and combined with a modified EROSIMESS system to quantify the vertical variation in mixing coefficient with depth below the sediment-water interface. The study considered a range of particle diameters and bed shear velocities, with the permeability Péclet number, image between 1,000 and 77,000 and the shear Reynolds number, image between 5 and 600. Different parameterisation of both an interface exchange coefficient and a spatially variable in-sediment mixing coefficient are explored. The variation of in-sediment mixing is described by an exponential function applicable over the full range of parameter combinations tested. The empirical relationship enables estimates of the depth to which concentrations of pollutants will penetrate into the bed sediment, allowing the region where exchange will occur faster than molecular diffusion to be determined