Mechanical adaptations of cleavers (Galium aparine)

• Background and Aims Cleavers (Galium aparine) is a fast-growing herbaceous annual with a semi-self-supporting, scrambling-ascending growth habit. Mature plants often use upright species for support. It is common in hedgerows and on waste ground. This study aims to characterize the mechanical behaviour of the stem and roots of cleavers and relate this to the arrangement of structural tissue, the net microfibrillar orientations in the cell walls, and plant growth habit. • Methods The morphology and mechanics of mature cleavers was investigated using plants grown in pots and ones collected from the grounds at the University of Lincoln, Lincoln, UK. Tensile tests were carried out on the stem and the basal section of the first-order lateral roots. The net orientation of cellulose microfibrils in the cell walls was investigated using polarized light microscopy. • Key Results Results show that the basal regions of the stem and first-order lateral roots were highly extensible. Breaking strains of 24 ± 7 % were recorded for the stem base and 28 ± 6 % for the roots. Anatomical observations showed that the lower stem (base + 100 mm) was circular in cross-section with a solid central core of vascular tissue, whereas further up the stem the transverse section showed a typical four-angled shape with a ring-like arrangement of vascular tissue and sclerenchyma bundles in the corners. The net orientation of wall microfibrils in the secondary xylem diverges from the longitudinal by between 8 and 9°. • Conclusions The basal region of the stem of cleavers is highly extensible, but the mechanism by which the stem is able to withstand such high breaking strains is unclear; reorientation of the cellulose fibrils in the stem along the axis of loading is not thought to be responsible. Key words: Anatomy, adaptation, cleavers, Galium aparine, growth habit, mechanics, cellulose microfibril orientation, extensibilit

Sharing in the nation’s prosperity? Pensioner poverty in Britain

This commentary reviews the government’s tax and benefit reforms affecting pensioners to date, and examines the evidence from the latest official low income figures on the government’s record on pensioner poverty so far

How has child poverty changed since 1998-99? An update

An additional 100,000 children were lifted out of poverty on the most commonly cited of the government's relative poverty measures between 2000-01 and 2001-02. The most recent figures show 3.8 million children (roughly 30 per cent of all children) in Britain in households with income below 60 per cent of the median income after housing costs. Although this means that almost one in three children in Britain live in poverty on this definition, this is the lowest level recorded since 1991. Since the Labour government came to power, the total drop in the numbers in child poverty has been around 500,000. In 1998-99, the government set a target for child poverty in 2004-05. If the rate of decline in child poverty observed since 1998-99 continues for three more years, then the government will miss this target. Indeed, it is now further behind schedule than it was based on figures from 2000-01. The rather slow decline in recorded child poverty is due, in large part, to the fact that the government is targeting relative, rather than absolute, poverty. Income growth has been particularly strong across society since 1998-99, and this means that the poverty line has risen significantly over this time. Although the government is continuing to increase the living standards of low-income households with children, the gap with the rest of society is not closing as fast as the government would like. Rectifying this may require additional resources to be directed to families with children in the forthcoming Budget, on top of measures already announced

A hard coat, a tough choice? The effects of host seed morphology and mechanics on the egg laying behaviour of the bruchid beetle, Callosobruchus maculatus.

This study investigated whether the egg laying behaviour of Callosobruchus maculatus, an important storage pest of leguminous seed crops, was related to the mechanical properties of the host seed. The hypothesis was that females avoid laying eggs on seeds with particularly tough seed coats and hard cotyledons to reduce the resistance their larvae are subjected to when they bore into the seed to complete their development. Females were presented with seeds from three leguminous species: Vigna unguiculata, V. angularis and V. radiata. The distribution of oviposition sites on the seed's surface was related to the morphology and mechanical properties of the seed. Vickers microhardness and fracture tests were used to investigate regional variation and compare the properties of seeds with and without eggs adhered to their surface. There were no significant regional differences in the hardness of the cotyledon material along the longitudinal axis of the seed (P > 0.05). However, there were significant differences between the mechanical properties of the seed coat and the cotyledons; in V. unguiculata the seed coat was tougher, 1249 ± 80.8 J m−2, than the cotyledons, 402 ± 30.0 J m−2 (P 0.05). Mechanical data are discussed in relation to the egg laying behaviour of C. maculatus

The government's child poverty target: how much progress has been made?

Before the 2001 election the Treasury said that `tax and benefit reforms announced in this Parliament will lift over 1.2 million children out of relative poverty'. But official figures released on 11 April show a smaller fall in child poverty, of only 0.5 million since 1996-97. This commentary attempts to explain the discrepancy. Using the data that lie behind the official Households Below Average Income publications, we analyse trend in child poverty, measured against various poverty lines, since 1979. We show how the government's choice of a relative poverty line is making its goal to abolish child poverty more difficult and more expensive. We also discuss how easy the government will find it to make further reductions in child poverty

Living standards, inequality and poverty

In this Election Briefing Note, we assess what has happened to living standards under Labour, setting out how average incomes, income inequality and poverty have changed since 1996- 97. We compare these changes with what happened under previous governments, and highlight where there have been differences between Labour's first and second terms

Poverty and inequality in Britain: 2005

This Commentary provides an update on trends in poverty and inequality in Great Britain, based on the latest official government statistics. It uses the same approach to measuring incomes and poverty in Great Britain as the government employs in its Households Below Average Income (HBAI) publication

Poverty and inequality in the UK: 2007

This Briefing Note provides an update on trends in living standards, income inequality and poverty. It uses the same approach to measuring income and poverty as the government employs in its Households Below Average Income (HBAI) publication. The analysis is based on the latest HBAI figures (published on 27 March 2007), providing information about incomes up to the year 2005-06. The measure of income used is net household weekly income, which has been adjusted to take account of family size ('equivalised'). The income amounts provided below are expressed as the equivalent for a couple with no children, and all changes given are in real terms (i.e. after adjusting for inflation). For the first time in recent years, data are available for the whole of the United Kingdom, not just Great Britain, but data for Northern Ireland are only available from 2002-03. Some comparisons over time are provided for Great Britain only, but others will compare statistics for GB before 2002-03 with those for the UK afterwards. PLEASE NOTE: On 23 April 2007, the Department for Work and Pensions announced that an error had occurred when producing the latest Households Below Average Income publication. This Briefing Note was based on the same dataset and therefore suffers from similar errors. In response to revisions announced by the DWP in May 2007, we have now updated our findings in a revised press release and have produced a revised summary