On the Use of Objective Examinations

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67984/2/10.1177_001316445301300214.pd

Energy and low-income tropical housing in Tanzania

Low-income housing in Tanzania is traditionally made from mud and thatch. With thatch having a typical life span of 2-7 years and mangrove poles 5-15 years, low durability is identified as the key issue with the traditional low-income house design. This paper studies the financial and social implications, embodied energy (EE) and human energy (HE) of a variety of materials in a bid to identify both the positive and negative impacts of each material substitution on the overall design, the environment and the local community. Using primary data collected from houses in the Mbweni district of Dar es Salaam and The Inventory of Carbon and Energy to calculate EE, a qualitative and quantitative assessment of each material is made. 47% of residents questioned in Tanzania, identified low durability to be the key issue with their mud house, with design changes which address this issue therefore affecting the largest share of the population. Stabilised bricks are identified as the key material substitution that should be adopted by local people, they perform well in terms of improved durability, financial and environmental considerations, and have the potential to be socially beneficial as well. This research identifies the social considerations to be key to understanding how local people will respond to the suggested material substitutions and whether they are likely to be adopted in the future. Whilst the environmental considerations are important, this is not a concept local people can relate to and does not affect their day-to-day lives as much as financial and social implications. It is extremely difficult and ethically questionable, especially in communities with people living close to poverty, to expect someone to adopt a design which requires more effort/money on their part, just because it is better for the environment

Tracking autophagy during proliferation and differentiation of trypanosoma brucei

Autophagy is a lysosome-dependent degradation mechanism that sequesters target cargo into autophagosomal vesicles. The Trypanosoma brucei genome contains apparent orthologues of several autophagy-related proteins including an ATG8 family. These ubiquitin-like proteins are required for autophagosome membrane formation, but our studies show that ATG8.3 is atypical. To investigate the function of other ATG proteins, RNAi compatible T. brucei were modified to function as autophagy reporter lines by expressing only either YFP-ATG8.1 or YFP-ATG8.2. In the insect procyclic lifecycle stage, independent RNAi down-regulation of ATG3 or ATG7 generated autophagy-defective mutants and confirmed a pro-survival role for autophagy in the procyclic form nutrient starvation response. Similarly, RNAi depletion of ATG5 or ATG7 in the bloodstream form disrupted autophagy, but did not impede proliferation. Further characterisation showed bloodstream form autophagy mutants retain the capacity to undergo the complex cellular remodelling that occurs during differentiation to the procyclic form and are equally susceptible to dihydroxyacetone-induced cell death as wild type parasites, not supporting a role for autophagy in this cell death mechanism. The RNAi reporter system developed, which also identified TOR1 as a negative regulator controlling YFP-ATG8.2 but not YFP-ATG8.1 autophagosome formation, will enable further targeted analysis of the mechanisms and function of autophagy in the medically relevant bloodstream form of T. brucei

Bloodstream form trypanosoma brucei depend upon multiple metacaspases associated with RAB11-positive endosomes

Trypanosoma brucei possesses five metacaspase genes. Of these, MCA2 and MCA3 are expressed only in the mammalian bloodstream form of the parasite, whereas MCA5 is expressed also in the insect procyclic form. Triple RNAi analysis showed MCA2, MCA3 and MCA5 to be essential in the bloodstream form, with parasites accumulating pre-cytokinesis. Nevertheless, triple null mutants (Δmca2/3Δmca5) could be isolated after sequential gene deletion. Thereafter, Δmca2/3Δmca5 mutants were found to grow well both in vitro in culture and in vivo in mice. We hypothesise that metacaspases are essential for bloodstream form parasites, but they have overlapping functions and their progressive loss can be compensated for by activation of alternative biochemical pathways. Analysis of Δmca2/3Δmca5 revealed no greater or lesser susceptibility to stresses reported to initiate programmed cell death, such as treatment with prostaglandin D2. The metacaspases were found to colocalise with RAB11, a marker for recycling endosomes. However, variant surface glycoprotein (VSG) recycling processes and the degradation of internalised anti-VSG antibody were found to occur similarly in wild type, Δmca2/3Δmca5 and triple RNAi induced parasites. Thus, the data provide no support for the direct involvement of T. brucei metacaspases in programmed cell death and suggest that the proteins have a function associated with RAB11 vesicles that is independent of known recycling processes of RAB11-positive endosomes

SOME CHARACTERISTICS OF CHOICE BEHAVIOR IN RISKY SITUATIONS *

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73591/1/j.1749-6632.1961.tb20178.x.pd

The scale grid: Some interrelations of data models

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45699/1/11336_2005_Article_BF02296299.pd

The Concepts of Reliability and Homogeneity

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67956/2/10.1177_001316445001000103.pd