Hard defences

Conventional earth-moving plant arc used in the construction of embankments, and are similar to those described above but with the addition of bulldozers and rollers. There may also be the need to use craneage for long-reach activities, such as the installation of sheet-pile cut off walls (see also hard defences below), or draglines for trimming slopes. 

As well as cailh-moving equipment, the construction of hard defences requires additional heavy plant in the form of cranes, which arc required to lift or suspend objects such as ... 

The possible involvement of polygalacturonic acid-containing molecules in the defence reactions of tomato root cells against Fusarium oxysporum was suggested about 20 years ago by their accumulation at penetration sites. Since papillae are held to serve as a resistance mechanism to fungal penetration, it was assumed that the interrelation between pectin and other polymers - such as lignin - may contribute to enhancing the hardness of these newly formed structures (Benhamou et al., 1990). 

Official statements at the time, and to an extent even now, refer to only the less-toxic defoliants. However, Assistant Secretary of Defence, Cyrus Vance, when asked in 1965 whether arsenic and cyanide compounds were being sprayed over South Vietnam, replied, We are making limited use of them in the southern part of Vietnam but not yet in the north. 52 It is hard to escape the conclusion then that aerial spraying of cacodylic acid continued unabated to at least 1971 and caused unknown casualties to human and animal life below. 

Two main hypotheses have been put forward to account for the occurrence of ecdysteroids in the plant world. The first is that PEs have a hormonal role within the plant, but there is very little hard evidence in support of this hypothesis (reviewed in [26]). Alternatively, PEs participate in the defence of plants against non-adapted phytophagous invertebrates. Deterrent effects of 20E on non-adapted insect species are... 

At the dawn of the human era man would seize upon any stones, branches, or other hard materials lying at hand for purposes of offence, defence, or the chase. Later on it would occur to him to improve upon the natural shapes by chipping, and he would soon discover that flint is particularly amenable to such treatment. Thus would originate the flint weapons and tools which have been discovered in large quantities in modern times, and which antiquaries have made use of to throw interesting light upon the manner in which primitive man lived during what has been aptly termed the Stone Age. 

In a few taxa that cluster within QA-accumulating genera, QAs are hardly detectable or levels are very low, such as in Ulex, Calicotome or Spartocytisus. These taxa have in common extensive spines that have apparently supplanted chemical defence. In such cases, the presence or absence of QAs is clearly a trait reflecting different ecological strategies rather than taxonomic relationships. 

Thanks, Leroy. I don t have your defences, you know The world s different for you. Hard and easy altogether."... 

Baker AA. Development of a hard-patch approach for scarf repair of composite structure 2006. Defence science and technology organisation report TR-1892, 19. 

Insects coimnunicate with one another concerning gender identification, sexual maturity, mate selection and reproduction, the tracking down of prey, marking of territory and routes, feeding and nesting places, as well defence and alarm behaviour, or the regulation of social and caste systems. [161] (In these terms their behaviour hardly differs from that what humans do.)... 

Harding, M., Treloar, B. and KaUir, A. (2006). Report of the Australian Defence Force Clothing Review. Canberra Department of Defence. Available from http //www. defence.gov.au/publications/Clothing Review Reportpdf [accessed 22 February 2011]. 

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