Sodium butyrate induced cell cycle arrest in mammalian cells through an increase in p21 super(Waf1/Cip1), although another study showed that this arrest is related to pRB signaling. We isolated ...variants of HeLa cells adapted to growth in 5 mM butyrate. One of these variants, clone 5.1, constitutively expressed elevated levels of p21 super(Waf1/Cip1) when incubated in regular growth medium and in the presence of butyrate. Despite this elevated level of p21 super(Waf1/Cip1), the cells continue to proliferate, albeit at a slower rate than parental HeLa cells. Western blot analyses showed that other cell cycle regulatory proteins were not up-regulated to compensate for the elevated expression of p21 super(Waf1/Cip1). However, cyclin D1 was down-regulated by butyrate in HeLa cells but not in clone 5.1. We conclude that continued expression of cyclin D1 allowed clone 5.1 to grow in the presence of butyrate and elevated levels of p21 super(Waf1/Cip1).
House-sparrow populations have declined sharply in Western Europe in recent decades, but the reasons for this decline have yet to be identified, despite intense public interest in the matter. Here we ...use a combination of field experimentation, genetic analysis and demographic data to show that a reduction in winter food supply caused by agricultural intensification is probably the principal explanation for the widespread local extinctions of rural house-sparrow populations in southern England. We show that farmland populations exhibit fine-level genetic structuring and that some populations are unable to sustain themselves (sinks), whereas others act as sources.
The presence or absence of support from other people was one of the topics included in semi-structured interviews carried out with close relatives of people with alcohol or other drug problems in ...Mexico and England. Of the full set of interviews, matched sub-samples of twelve reports from each country were analysed qualitatively. Examples of the support received, or lacked, by two relatives are first presented in some detail. The main sub-categories of support, or its lack, described in the twenty-four reports are then presented. Finally a preliminary comparison of data from the two countries is also reported. As well as providing a detailed picture of types of support (e.g. emotional, material) that are familiar from studies with other populations, this paper also emphasizes the importance of the close relative's perception of the relationship between the alcohol or drug user and the supportive or unsupport-ive 'other', and describes a range of circumstances under which relatives are denied support. Preliminary support is obtained for the hypothesis that Mexican social networks would be more dominated by kin and neighbours, whilst English relatives would draw for support upon more diverse networks.
Dense graded hot mix asphalt (HMA) mixtures are designed to have low permeability to resist excessive penetration of water and avoid durability problems. With the introduction of Superpave mixes, ...there is a general concern that the coarse graded mixes are more permeable, at similar void levels, compared to fine graded mixes. However, at present there is a lack of a simple tool for measuring the in-place permeability of asphalt mixes. A simple permeability test was developed to determine the effect of voids and gradation on permeability. The field permeameter was used for testing projects with 9.5 mm, fine and coarse, 12.5 mm coarse, 19 mm coarse, and 25 mm coarse graded mixes. Testing of cores taken from location of field testing were also conducted in the laboratory. The results from the in-place permeability tests were found to be consistent with experience with fine and coarse graded mixes. The results indicated that mixes with different gradations and nominal maximum aggregate size have significant increase in permeability at different voids in total mix content. Field testing showed that 25 mm coarse, 19 mm coarse, 12.5 mm coarse and 9.5 mm coarse mixes show significant increase in permeability at 5, 6, 7 and 8 percent voids in total mix respectively, whereas a 9.5 mm fine mix showed a significant increase in permeability above eight percent voids in total mix. Field permeability of 19 mm and 25 mm coarse graded mixes are significantly higher than laboratory permeability, at similar voids in total mix content, most likely due to presence of horizontal flowpaths and high horizontal permeability. It is recommended that field permeability tests be conducted for all mixes, in order to get the best indication of permeability of these mixes.
Injecting and sharing injecting equipment are social activities for many injecting drug users (IDUs), yet many vary in the extent that they perform them autonomously. This study tested the hypothesis ...that greater autonomy within injecting episodes leads to reduced probability of sharing needles, syringes and other types of injecting equipment in these episodes. A community sample of 181 IDUs from two cities in Southern England participated in an interview which utilised both fully structured and semistructured components and the Severity of Dependence Scale. Lower autonomy within an injecting sequence was significantly associated with receiving (rather than passing on) needles and syringes, spoons, water, and filters late in the sequence. Sharing was associated with higher dependence but dependence and injecting autonomy were not significantly related. The finding that low autonomy over injection-related activities is a major risk factor for sharing has implications for preventive work with individuals, couples, and communities.
