Plagiochila killarniensis Pears. in the British Isles

Abstract

Plagioehila killarniensis Pears. is reinstated as a species. It differs from P. spinulosa in many characters including its more patent leaves with a sharply defmed vitta, and the dentate antical margin of its female bracts. P. spinulosa var. inermis Carr. is shown to be a synonym of P. killarniensis, and P. punetata var. owenii (Steph.) Macv. of var. punctata. Both sexes of P. killarniensis occur in the British Isles, but male plants of P. spinulosa have not been detected, and those of P. punctata have been seen only once. P. killarniensis tolerates more exposure than P. spinulosa, but does not extend so far north.     

Cladonia azorica in the British Isles

Abstract:Cladonia azorica is widespread in western Great Britain, mainly as the grey colour-form lacking usnic acid. Cladonia azorica is distinguished from the related species C. portentosa and C. mediterranea by the presence of fumarprotocetraric acid, and from C. ciliata by a number of characters including the presence of perlatolic acid. The structure of the pycnidial wall may have some taxonomic significance in Cladonia subgenus Cladina.     

Shingle habitats in the British Isles

RANDALL, R. E., 1989. Shingle habitats in the British Isles . Shingle is the term applied to sediments larger in diameter than sand but smaller than boulders. Around Great Britain there are almost 900 km of pure shingle and vast stretches of rock/shingle, sand/shingle and mud/shingle mixtures. Outside Japan, New Zealand and north-west Europe, shingle is an uncommon coastal sediment. Shingle may form fringing beaches, spits, bars, cuspate forelands and offshore barrier islands, depending upon available supply of sedimentary material and coastal topography.
Species composition on shingle features is partly determined by climate which affects the geographic range of certain species. The other major factors are beach stability and beach composition. Climate results in distinctive patterns in the flora but within the each climate zone beach movement will affect the quantity of annuals, short-lived or long-lived perennials present. The presence or absence and nature of the fine material within the shingle will cause different combinations of species ecologically related to those of sand dunes, salt-marsh or cliff. Coastal shingle vegetation has a distinctive flora which contains several rare or declining species as well as some common coastal and ruderal plants.
At the largest shingle sites a successional sequence can be recorded which initiates with halophytic forbs near the foreshore and moves through neutral to acid grassland species with shrubs and prostrate scrub in the more inland areas.     

Hedwigia stellata and H. ciliata in the British Isles

Abstract

Hedwigia stellata Hedenäs, here reported for the first time from the British Isles, is common and widely distributed. H. ciliata var. ciliata is rare, var. leucophaea very rare.     

Vertical transmission rates for HIV in the British Isles: estimates based on surveillance data

ObjectiveTo estimate and interpret time trends in vertical transmission rates for HIV using data from national obstetric and paediatric surveillance registers.DesignProspective study of HIV infected women reported through obstetric surveillance. HIV infection status of the child and onset of AIDS were reported through paediatric surveillance. Rates of vertical transmission and progression to AIDS rate were estimated by methods that take account of incomplete follow up of children with indeterminate infection status and delay in AIDS reporting.SettingBritish Isles.SubjectsPregnant women infected with HIV whose infection was diagnosed before delivery, and their babies.ResultsBy January 1999, 800 children born to diagnosed HIV infected women who had not breast fed had been reported. Vertical transmission rates rose to 19.6% (95% confidence interval 8.0% to 32.5%) in 1993 before falling to 2.2% (0% to 7.8%) in 1998. Between 1995 and 1998 use of antiretroviral treatment increased significantly each year, reaching 97% of live births in 1998. The rate of elective caesarean section remained constant, at around 40%, up to 1997 but increased to 62% in 1998. Caesarean section and antiretroviral treatment together were estimated to reduce risk of transmission from 31.6% (13.6% to 52.2%) to 4.2% (0.8% to 8.5%). The proportion of infected children developing AIDS in the first 6 months fell from 17.7% (6.8% to 30.8%) before 1994 to 7.2% (0% to 15.7%) after, coinciding with increased use of prophylaxis against Pneumocystis carinii pneumonia.ConclusionsIn the British Isles both HIV related morbidity and vertical transmission are being reduced through increased use of interventions.

Key messages

• Reliable estimates of HIV vertical transmission rates can be derived from surveillance data
• Infected pregnant women are increasingly taking up elective caesarean section and antiretroviral treatment to reduce the risk of transmitting HIV to their babies
• Vertical transmission rates have fallen greatly over the past four years and progression to AIDS among infected children may also have slowed
• These benefits can occur only if infected women are diagnosed before or during pregnancy

     

The Criconematidae of the British Isles

A total of 2622 soil samples collected throughout the British Isles was examined for nematodes belonging to the family Criconematidae. Twenty-eight species were found representing nine genera, twenty-two of these species being reported for the first time. Only one species previously reported was not found. An analysis of the relationship between eleven of the most common species and biotic and abiotic factors showed vegetation to be of paramount importance.