Three new species of <Emphasis Type="Italic">Myrcia</Emphasis> section <Emphasis Type="Italic">Gomidesia</Emphasis> (Myrtaceae) — from Espírito Santo,Brazil

Three new species of Myrcia sect. Gomidesia: M. curtipendula Nic Lughadha, M. aurea Nic Lughadha and M. teresensis Nic Lughadha, from Espírito Santo are described. Their diagnostic characters and habitat are discussed; IUCN categories of threat are assigned.     

Subpopulations,locations and fragmentation: applying IUCN red list criteria to herbarium specimen data

Despite the ecological and economic importance of plants, the majority of plant species and their conservation status are still poorly known. Based on the limited knowledge we have of many plant species, especially those in the tropics, the use of GIS techniques can give us estimates of the degree of population subdivision to be used in conservation assessments of extinction risk. This paper evaluates how best to use the IUCN Red List Categories and Criteria to produce effective and consistent estimates of subpopulation structure based on specimen data available in the herbaria around the world. We assessed population structure through GIS-based analysis of the geographic distribution of collections, using herbarium specimen data for 11 species of Delonix sensu lato. We used four methods: grid adjacency, circular buffer, Rapoport’s mean propinquity and alpha hull, to quantify population structure according to the terms used in the IUCN Red List: numbers of subpopulations and locations, and degree of fragmentation. Based on our findings, we recommend using the circular buffer method, as it is not dependent on collection density and allows points to be added, subtracted and/or moved without altering the buffer placement. The ideal radius of the buffer is debatable; however when dispersal characteristics of the species are unknown then a sliding scale, such as the 1/10th maximum inter-point distance, is the preferred choice, as it is species-specific and not sensitive to collection density. Such quantitative measures of population structure provide a rigorous means of applying IUCN criteria to a wide range of plant species that hitherto were inaccessible to IUCN classification.     

Proteomic response of Schizosaccharomyces pombe to static and oscillating extremely low-frequency electromagnetic fields

There is considerable public concern regarding the health effects of exposure to low-frequency electromagnetic fields. In addition, the association between exposure and disease incidence or the possible biological effects of exposure are unclear. Using 2D-DIGE and MS in a blind study, we have investigated the effects of static and oscillating extremely low-frequency electromagnetic fields (ELF EMFs) on the proteomes of wild type Schizosaccharomyces pombe and a Sty1p deletion mutant which displays increased sensitivity to a variety of cellular stresses. Whilst this study identifies a number of protein isoforms that display significant differential expression across experimental conditions, there was no correlation between their patterns of expression and the ELF EMF exposure regimen. We conclude that there are no significant effects of either static or oscillating EMF on the yeast proteome at the sensitivity afforded by 2D-DIGE. We hypothesise that the proteins identified must be sensitive to subtle changes in culture and/or handling conditions, and that the identification of these proteins in other proteomic studies should be treated with some caution when the results of such studies are interpreted in a biological context.     

Osmotic stress,glucose transport capacity and consequences for glutamate overproduction in Corynebacterium glutamicum

Glucose uptake by Corynebacterium glutamicum is predominantly assured by a mannose phosphotransferase system (PTS) with a high affinity for glucose (Km=0.35 mM). Mutants selected for their resistance to 2-deoxyglucose (2DG) and lacking detectable PEP-dependent glucose-transporting activity, retained the capacity to grow on media in which glucose was the only carbon and energy source, albeit at significantly diminished rates, due to the presence of a low affinity (Ks=11 mM) non-PTS uptake system. During growth in media of different osmolarity, specific rates of glucose consumption and of growth of wild type cells were diminished. Cell samples from these cultures were shown to possess similar PTS activities when measured under standard conditions. However, when cells were resuspended in buffer solutions of different osmolarity measurable PTS activity was shown to be dependent upon osmolarity. This inhibition effect was sufficient to account for the decreased rates of both sugar uptake and growth observed in fermentation media of high osmolarity. The secondary glucose transporter was, however, not influenced by medium osmolarity. During industrial fermentation conditions with accumulation of glutamic acid and the corresponding increase in medium osmolarity, similar inhibition of the sugar transport capacity was observed. This phenomenon provokes a major process constraint since the decrease in specific rates leads to an increasing proportion of sugar catabolised for maintenance requirements with an associated decrease in product yields.     

Presence and location of endothelin and endothelin-binding sites in human nasal mucosa under normal and metaplastic conditions

The presence and site of production of endothelin-1 (ET-1) was investigated in biopsies obtained from the nasal mucosa of 10 healthy human subjects and 10 patients affected by chronic rhinitis. The presence and localization of receptors for ET-1 was also investigated. Bioptic fragments were examined by scanning electron microscopy. ET-1 was present in the vessels and in the respiratory epithelium of normal subjects, whereas in patients affected by epithelial metaplasia induced by chronic rhinitis, it was absent in the metaplastic epithelium and present in the endothelium and vascular wall. Receptors for ET (A- and B-receptor subtypes) were localized in the vessels of the nasal mucosa, both in normal and in pathological subjects. In particular, A-receptors were identified in the vascular wall, whereas B-receptors were mainly distributed in the endothelium. We suggest that ET-1 is involved in the homeostasis of nasal blood flow (shunting the blood toward the deep cavernous plexus and inducing mucosal swelling) by an autocrine and/or paracrine mechanism. Normal epithelium seems to be important in this mechanism, since it is able to produce ET. However, when pathologic conditions induce squamous or cuboidal metaplasia, the epithelium is no longer able to play this role.