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Summary1. This account reviews information on all aspects of the biology of Juniperus communis that are relevant to understanding its ecological characteristics and behaviour. The main topics are presented within the standard framework of the Biological Flora of the British Isles : distribution, habitat, communities, responses to biotic factors, responses to environment, structure and physiology, phenology, floral and seed characters, herbivores and disease, history and conservation. 2. Juniperus communis (juniper) is an evergreen dioecious gymnosperm shrub with two main population centres in Britain, one on chalk downlands of southern England and the other in northern England and Scotland. British populations are divided into two main subspecies although there is overlap in genetic and morphological features. Subspecies communis varies from a spreading shrub to an erect tree characteristic of calcareous soils in southern England, various soils in the Scottish highlands, while ssp. nana is a small procumbent shrub, restricted to well-drained bogs and, more usually, rocky outcrops, generally as a minor component of upland heaths and montane scrub. Both subspecies are drought and frost tolerant, although sensitive to fire. A third subspecies, hemisphaerica , primarily found in mountains of southern Europe has two small populations on maritime cliffs in the UK. 3. Although not very palatable, J. communis is grazed by small and large mammals when food is short, particularly in winter. Its low palatability is derived from oils found in the needles, cones and wood, dominated by monoterpenes. These have been extensively used in folklore medicine and to flavour alcoholic drinks, and are being investigated for new medicinal uses. 4. Juniperus communis ssp. communis is a characteristic light-demanding invader of pasture but has declined due to agricultural expansion, erosion, overgrazing, fire and poor regeneration, such that it is now rare and threatened across lowland/southern Europe. Although susceptible to overgrazing, some grazing can be beneficial to create the open sward necessary for seedling establishment. Other limits to regeneration are: progressively ageing stands in which male plants predominate; increasing fragmentation of stands that reduces pollination efficacy; and high seed dormancy with consequent variable germinability.Key-words : climatic limitation, communities, conservation, ecophysiology, geographical and altitudinal distribution, germination, herbivory, mycorrhiza, parasites and diseases, reproductive biology, soilsJournal of Ecology (2007) 95 , 1404-1440 doi: 10.1111/j.1365-2745.2007.01308.x *Abbreviated references are used for many standard works: see Journal of Ecology (1975), 63 , 335 -344. Nomenclature of vascular plants follows Flora Europaea and, where different, Stace (1997). †Author to whom correspondence should be addressed: P. A. Thomas. E-mail: p.a.thomas@biol.keele.ac.uk. Pinopsida (Coniferae), Cupressaceae. The junipers are a taxonomically difficult group, composed of about 68-80 s...

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Multiple sclerosis (MS) is a chronic, immune-mediated, demyelinating disease of the central nervous system of as yet unknown aetiology. A consensus of opinion has suggested that the disorder is the result of an interplay between environmental factors and susceptibility genes. We have used a battery of analytical techniques to determine if the urinary excretion of i) markers of oxidative damage; ii) iron and iii) the environmental toxin aluminium and its antagonist, silicon, are altered in relapsing-remitting (RRMS) and secondary progressive MS (SPMS). Urinary concentrations of oxidative biomarkers, MDA and TBARS, were not found to be useful indicators of inflammatory disease in MS. However, urinary concentrations of another potential marker for inflammation and oxidative stress, iron, were significantly increased in SPMS (P<0.01) and insignificantly increased in RRMS (P>0.05). Urinary concentrations of aluminium were also significantly increased in RRMS (P<0.001) and SPMS (P <0.05) such that the levels of aluminium excretion in the former were similar to those observed in individuals undergoing metal chelation therapy. The excretion of silicon was lower in MS and significantly so in SPMS (P<0.05). Increased excretion of iron in urine supported a role for iron dysmetabolism in MS. Levels of urinary aluminium excretion similar to those seen in aluminium intoxication suggested that aluminium may be a hitherto unrecognized environmental factor associated with the aetiology of MS. If aluminium is involved in MS then an increased dietary intake of its natural antagonist, silicon, might be a therapeutic option.

Tenebrio molitor is an intermediate host for the rat tapeworm, Hymenolepis diminuta. Parasite oncospheres hatch in the beetle midgut and burrow through into the haemocoel, where they rapidly grow and mature into metacestodes. Repair of damage incurred during invasion and the nutritional demands of the parasites are likely to impose costs on the host. Despite these costs, there is an overall very highly significant difference in survival time (p < 0.001) between infected and control populations of beetles, with a hazard ratio of 2.35 (control versus infected). Infected females showed a 40% increase in survival time to 50% mortality and males showed a 25% increase in survival time to 50% mortality. This parasite-induced increase in host longevity is discussed in the light of changes in resource allocation that may occur in infected beetles. Previous findings have demonstrated that reproductive success is significantly reduced in infected females. The outcome of changes in the reproductive effort made by male beetles is less clear. We suggest that the optimum trade-off between reproduction and longevity may be altered to favour longer host survivorship, which is likely to enhance parasite transmission.

We report that hamsters infected with Leishmania infantum are more attractive to female sandflies in bioassays. Entrained odours from infected animals were shown by gas chromatography to contain peaks absent from uninfected individuals. Implications of enhanced transmission, potential for developing novel diagnoses and the significance to epidemiological models are discussed.

The deposition in the brain of amyloid-β as beta sheet conformers associated with senile plaques and vasculature is frequently observed in Alzheimer’s disease. While metals, primarily aluminum, iron, zinc, and copper, have been implicated in amyloid-β deposition in vivo, there are few data specifically relating brain metal burden with extent of amyloid pathologies in human brains. Herein brain tissue content of aluminum, iron, and copper are compared with burdens of amyloid-β, as senile plaques and as congophilic amyloid angiopathy, in 60 aged human brains. Significant observations were strong negative correlations between brain copper burden and the degree of severity of both senile plaque and congophilic amyloid angiopathy pathologies with the relationship with the former reaching statistical significance. While we did not have access to the dementia status of the majority of the 60 brain donors, this knowledge for just 4 donors allowed us to speculate that diagnosis of dementia might be predicted by a combination of amyloid pathology and a ratio of the brain burden of copper to the brain burden of aluminum. Taking into account only those donor brains with either senile plaque scores ≥4 and/or congophilic amyloid angiopathy scores ≥12, a Cu:Al ratio of <20 would predict that at least 39 of the 60 donors would have been diagnosed as suffering from dementia. Future research should test the hypothesis that, in individuals with moderate to severe amyloid pathology, low brain copper is a predisposition to developing dementia.

There are unexplained links between human exposure to aluminium and the incidence, progression and aetiology of Alzheimer's disease. The null hypothesis which underlies any link is that there would be no Alzheimer's disease in the effective absence of a body burden of aluminium. To test this the latter would have to be reduced to and retained at a level that was commensurate with an Alzheimer's disease-free population. In the absence of recent human interference in the biogeochemical cycle of aluminium the reaction of silicic acid with aluminium has acted as a geochemical control of the biological availability of aluminium. This same mechanism might now be applied to both the removal of aluminium from the body and the reduced entry of aluminium into the body while ensuring that essential metals, such as iron, are unaffected. Based upon the premise that urinary aluminium is the best non-invasive estimate of body burden of aluminium patients with Alzheimer's disease were asked to drink 1.5 L of a silicic acid-rich mineral water each day for five days and, by comparison of their urinary excretion of aluminium pre-and post this simple procedure, the influence upon their body burden of aluminium was determined. Drinking the mineral water increased significantly (P < 0.001) their urinary excretion of silicic acid (34.3 ± 15.2 to 55.7 ± 14.2 µmol/mmol creatinine) and concomitantly reduced significantly (P = 0.037) their urinary excretion of aluminium (86.0 ± 24.3 to 62.2 ± 23.2 nmol/mmol creatinine). The latter was achieved without any significant (P > 0.05) influence upon the urinary excretion of iron (20.7 ± 9.5 to 21.7 ± 13.8 nmol/mmol creatinine). The reduction in urinary aluminium supported the future longer-term use of silicic acid as non-invasive therapy for reducing the body burden of aluminium in Alzheimer's disease.